Patent Application
20220260153
The present invention relates to a transmission (gearbox), in particular a twin transmission (gearbox) of a duo electric machine powertrain, having a sump and a multi-chamber system via which individual gears of the transmission can be lubricated.
The present invention also relates to a spectacles-type bearing bracket having a hole structure for receiving in each case one end of two drive shafts, by which advantageous lubrication in the region of these shaft ends of the transmission is possible.
Furthermore, the present invention relates to a method for lubricating a transmission, in particular a twin transmission of a duo electric machine powertrain, in which running surfaces of gears and preferably transmission bearings of the transmission are lubricated by means of a passive lubricating film distribution.
In other words, the present invention relates to a transmission according to the preamble of claim 1.
The present invention also relates to a transmission according to the preamble of claim 5, and to a spectacles-type bearing bracket according to the preamble of claim 14.
In addition, the present invention relates to a lubrication method according to the preamble of claim 15.
Electrically powered vehicles can be designed in such a way that at least two wheels, for example the two wheels of a rear axle, are driven by a dedicated electric motor. The electric motor often rotates at high speed compared to the desired wheel speed (for example at up to 15,000 rpm, in higher-speed designs at up to 18,000 rpm or even at up to 20,000 rpm). For this reason, the speed of the electric motor must be reduced (for example by a ratio i between 6 to 9, possibly even by a ratio i in a ratio range of 4 to 12). The first electric motor acts on an input gear of a first step-down gearing. The second electric motor acts on a different, second input gear of a second, different step-down gearing. The transformation to driven shafts, which at the same time may be the wheel half-axles of the motor vehicle, takes place via one or more stages. If the two transmissions are installed in one complete transmission case (overall transmission housing), the electric motors may be flanged onto the side of the transmission case, i.e. the first electric motor onto a first side and the second electric motor onto another side.
Powertrains designed in such a way are presented both in the drawings of JP 2016 205 444 A (publication date: 8 Dec. 2016; applicant: NTN TOYO BEARING CO LTD) and in the drawings of JP 2017 019 319 A (publication date: 26 Jan. 2017; applicant: NTN TOYO BEARING CO LTD).
Such transmissions can be referred to as dual transmissions or also as twin transmissions because ultimately two completely independent transmissions are joined to form a larger transmission unit. Owing to the two electric machines that are present, which are usually of identical type, the expression “duo electric machine” can also be used.
Any actuations, particularly with regard to speed and torque, of the connected wheels can be carried out with the aid of motor controls. Such a powertrain is commonly referred to as electric “torque-vectoring”. This enables a continuously variable control of the respective wheel torque on the driven wheels of the motor vehicle, particularly when cornering, as a result of which the driving stability of the motor vehicle can be improved and steering effort can be reduced. This category of transmission can also be referred to as an active differential. This type of transmission also increases the efficiency of a powertrain of a motor vehicle. In the case of motor vehicles that have just one driving traction motor at a time, transmissions of the superimposing type are required for this. Based on the mode of operation, therefore, the transmissions can also be referred to as multiple single-wheel transmissions.
Dual transmissions are often ultimately designed as two completely separate single transmissions connected by a common partition wall, as can be seen, for example, from the drawings of JP 2016 205 444 A (applicant: NTN TOYO BEARING CO LTD; laid-open date: 8 Dec. 2016) and CN 201 800 514 U (applicant: Anhui Oulin Electrical and Mechanical Co. Ltd.; laid-open date: 20 Apr. 2011). Although the single transmissions are structurally joined together, they can nevertheless be regarded in many respects as separate, independent units.
A somewhat different case structure in comparison to the aforementioned disclosures is presented in FIGS. 1 and 4 of WO 2010/021 413 A2 (applicants: Aisin AW Co. Ltd., Toyoto Jidosha Kabushiki Kaisha; laid-open date: 25 Feb. 2010). On one side the case has a central partition structure, whereas toward the driven shafts the case encloses the two sub-transmissions, but rises again in the middle. Because the torques may be relatively large, with the magnitude thereof depending on the actual dimensions of the electric machines, a relatively large connecting structure should be expected for a case structure according to WO 2010/021 413 A2, which significantly contributes to the weight of the transmission.
WO 2018/121 420 A1 (applicant: BYD Co. Ltd.; publication date: 5 Jul. 2018) describes a dual transmission in which the two transmissions arranged next to each other can be coupled to each other via a clutch. The case of the transmission is said to be composed of three components, of which a middle component is described in greater detail in various exemplary embodiments. This middle component of the case serves as a central bearing for all the transmission shafts. FIG. 5 and FIG. 6 are said to show an exemplary embodiment without a clutch. The other exemplary embodiments deal with the case structure for the arrangement of the clutch. It is said to be possible to synchronize a first shaft of a first sub-transmission with a second shaft of a second sub-transmission.
US 2016/226 289 A1 (applicant: Acrimoto, Inc.; publication date: 11 Aug. 2016) describes a dual drive system for a vehicle, the two sub-transmissions of which are mechanically decoupled from each other. The case thereof comprises a central frame, to which covers are attached on both sides. The central frame is said to have a first set of bearings on a first side for the first motor shaft, for the first drive connection shaft and for intermediate shafts, and a corresponding second set on a second side. A fluid exchange between the two transmission regions is said to be permitted.
US 2014/353 052 A1 (applicant: Honda Motor Co. Ltd.; publication date: 4 Dec. 2014) relates to a vehicle which is said to be constructed in the manner of an inverted pendulum. The vehicle has a dual transmission, which has a centrally arranged case component in which shafts are mounted. This component is also referred to as the intermediate case, which is embedded between a left case half-body and a right case half-body held together by bolts.
Further interesting aspects, concerning in particular the arrangement of shafts and gears in the transmission, can be found in US 2018/015 815 A1 (applicant: NTN Corporation; publication date: 18 Jan. 2018) and in WO 2016/152 454 A1 (applicant: NTN Corporation; publication date: 29 Sep. 2016).
Usually, the transmissions have to be lubricated. Depending on the design of the electric machines, however, it may happen that the transmissions must be able to handle two directions of rotation (forward running/reverse running). Depending on the application, electric machines are designed in such a way that they can be operated as drive machines in motor mode or sometimes also in generator mode.
In such transmissions, therefore, special attention must be paid to the reliable lubrication of the transmission. Transmissions that do not require their own pump circuit are advantageous both from an energy point of view and from a financial perspective.
Immersion sump lubrication is common at various points in a powertrain. Immersion lubrication is said to keep energy losses caused by splashing to a minimum.
DE 10 2014 216 753 A1 (publication date: 19 Mar. 2015; applicant: BorgWarner, Inc.) and DE 10 2015 202 711 A1 (publication date: 27 Aug. 2015; applicant: BorgWarner, Inc.) describe a type of transfer case in which a lubricant collecting receptacle, also referred to as a fluid receptacle, is part of a reservoir system arranged at a distance from the sump of the transmission. DE 10 2014 216 753 A1 further states that the lubricant is collected with the aid of a collecting plate and therefore the fluid receptacle must have an air outlet so that air distributed in the oil can be separated from the oil in the collecting receptacle. DE 10 2015 202 711 A1 states that the oil system is designed for normal operation and for operation with a higher torque demand. Via a valve that is operated by way of an electronic control unit, a relatively large amount of lubricant can be released through the valve. All the transfer cases shown are based on oil being conveyed by a pump, the oil being intended to hit against a collecting element, such as a collecting plate. As can be seen from DE 10 2015 202 711 A1, the distribution of the oil must also be adjusted by an electronic control system. In other words, although DE 10 2014 216 753 A1 addresses parasitic energy consumption, both publications still consider it necessary to install numerous parasitic consumers in order to maintain the oil flows and oil distribution in a transmission.
A much more primitive variant of oil storage in a three-axle reduction transmission can be seen in the figures of WO 2017/063 595 A1 (applicant: BEIJING ELECTRIC VEHICLE CO., LTD.; publication date: 20 Apr. 2017), also published as CN 205 101 518 U and as CN 105 179 650 A, wherein the shafts lie next to each other in one plane. A horizontal installation orientation of the transmission, a transmission orientation when traveling downhill and a changed oil level when traveling uphill are shown schematically. Perpendicularly arranged bars in a sump are shown, as a result of which oil can be held back behind the bars. In addition, the bars may have holes for a throughflow into the sump. During horizontal operation of the vehicle, the liquid level is said to be always above this so-called separation arrangement, so that some of the lubricating oil always flows back into the static storage area. The entire system is referred to as a dynamic oil reservoir with a cyclic oil inlet and a cyclic oil outlet.
Documents JP 2009 030 743 A (applicant: Nissan Motor Co. Ltd.; publication date: 12 Feb. 2009), JP 2009 180 281 A (applicant: Aisin Al Co. Ltd.; publication date: 13 Aug. 2009), JP 60 215 159 A (applicants: Fuji Tekkosho K.K., Nissan Motor Co. Ltd.; publication date: 28 Oct. 1985), JP 2007 032 797 A (applicant: Toyota Motor Corp.; publication date: 8 Feb. 2007) and DE 38 19 519 A1 (applicant: Siemens AG; laid-open date: 21 Dec. 1989) present transmissions, such as rear-axle transmissions or differential transmissions, which may have an upper (in the context of an installation direction) oil pan in which oil can be collected, which oil can then be discharged again according to various criteria, such as temperature or such as point distribution.
DE 10 2009 057 458 A1 (applicant: American Axle & Mfg., Inc.; laid-open date: 1 Jul. 2010), also published as US 2010/144 480 A1, shows in one of its rear exemplary embodiments an axle transmission that has a plurality of collecting containers along a shaft, between which partition walls define the height of the respective oil chamber. Lubricating oil that has been conveyed via a ring gear to the edge of the collecting container can be collected in the collecting containers, and only once the collecting container in question is completely full is the excess oil routed onward to the next collecting container. Such a device can fill lubricating oil, which initially comes from a sump, into the collecting containers at the start of an operating phase. The lubricant, which is conveyed counter to the force of gravity, then returns to the sump via channels, the recirculation path also being routed via parts of the transmission that are to be lubricated.
The description of JP 2017-129 205 A (applicant: NTN Toyo Bearing Co. Ltd.; publication date: 27 Jul. 2017) relates to a drive unit comprising an electric motor and a speed reducer, i.e. a transmission having a ratio>1. Each transmission has three shafts, with an output gear and a central gear splashing into a sump. An oil supply plate is mentioned, which is said to be insertable into the transmission case; two different embodiments of said plate are shown on the basis of FIGS. 8 and 11. Said plate is said to enable lubricating oil to drip onto a desired location, namely onto the region where the smaller gear of the central gear, which is designed as a double gear, meshes with the output gear, because the smaller gear does not rotate in the oil bath. As shown in FIG. 7 of JP 2017-129 205 A, the plate can be formed with a triangular wall part, which has a drip opening at its tip. No onward routing into an adjacent region for oil recirculation can be seen.
In DE 10 2006 043 723 A1 (applicant: Daimler AG; laid-open date: 27 Mar. 2008) an all-wheel drive unit is described, in which the oil level of a main transmission is said to be kept as constant as possible so that the transmission oil pump does not intake any air. As indicated by droplets shown in FIG. 3 of DE 10 2006 043 723 A1, oil is conveyed via an outlet opening from an output bevel gear to a storage chamber. The storage chamber has a bore provided at the bottom thereof, via which the oil flows into a power take-off chamber. In the storage chamber, it is possible to distinguish between a left and a right storage chamber area, but there are no partition walls. The gears of a transfer case are passively lubricated gears, but the transmission as a whole is described as a main transmission with a pressurized supply of transmission oil.
Patent application JP 2017-129 178 A (applicant: NTN Toyo Bearing Co. Ltd.; publication date: 27 Jul. 2017) also relates to a transmission for two electric motors. A bottom region of the transmission case is said to serve as a lubricating oil tank. Splash gears of the transmission are said to convey the oil out of the lubricating oil tank. Said case also contains a lubricating oil store, which is located in the case above the lubricating oil tank, on the outflow side of which a valve is provided that can be opened and closed in order to connect the reservoir of the lubricating oil store. Oil from this additional reservoir is thus said to be actively connected only in phases of particularly high speeds. After start-up and during operation, the valve is otherwise kept in the closed state. This storage region is said to be arranged in an axial direction, i.e. laterally, in relation to the input gear and the bottom region thereof is said to lie below a center of the middle shafts. It is intended for oil that is splashed onto the case by the output gear to flow along an upper surface of the case to the input gear shafts. The oil is then intended to collect in the lubricating oil store in that region.
Further interesting transmission configurations are described in the following documents:
DD 143 174 A (inventors: W. Beyer et al.; publication date: 6 Aug. 1980),
WO 2017/138 312 A1 (applicant: NTN Toyo Bearing Co. Ltd.; publication date: 17 Aug. 2017),
JP 2005-083 491 A (applicant: Toyota Motor Corp.; publication date: 31 Mar. 2005),
JP 2014-015 976 A (applicant: Honda Motor Co. Ltd, Yanagawa Seiki Co. Ltd.; publication date: 30 Jan. 2014),
JP 2014-015 977 A (applicant: Honda Motor Co. Ltd, Yanagawa Seiki Co. Ltd; publication date: 30 Jan. 2014),
JP 2007-032 797 A (applicant: Toyota Motor Corp.; publication date: 8 Feb. 2007),
JP S60-215 159 A (applicants: Fuji Tekkosho: KK, Nissan Co. Ltd.; publication date: 28 Oct. 1985), and
JP 2017-019 319 A (applicant: NTN Toyo Bearing Co. Ltd.; publication date: 26 Jan. 2017).
The documents mentioned above are deemed to be fully incorporated in the description of the present invention by way of reference. This is intended to avoid repeatedly explaining generally known relationships between transmissions, the gears thereof and the associated lubrication by using the force of gravity; instead, this should be regarded as likewise defined for the present invention by way of reference to said documents.
There is a need for suitable lubrication concepts by which twin transmissions in particular can be used with sufficient lubrication as early as possible, i.e. as close to the start of operation as possible or right from the start of operation. On the other hand, excessive amounts of lubricating oil are undesirable, not least for energy reasons. Once there is sufficient initial lubrication, i.e. the lubricating film has been built up, the question arises as to what amount of lubricant is actually required by the transmission.
Much consideration and thought must be given as to how a suitable transmission, which is preferably of compact construction and designed for long operating times under changing loads, can be designed, particularly with regard to its lubrication concept using preferably transmission oil, in particular as part of an electrically driven powertrain.
The problem addressed by the invention is solved by a transmission according to claim 1.
The problem addressed by the invention is also solved by a transmission according to claim 5 and by a spectacles-type bearing bracket according to claim 14.
In addition, the problem addressed by the invention is solved by a lubrication method according to claim 15.
Advantageous further developments can be found in the dependent claims.
A transmission typically includes gears, in particular spur gears, and bearings, in particular rolling bearings, needle bearings or ball bearings, which are to be lubricated by means of a lubricating film, such as an oil film for example. The gears are located in the interior of one of the sub-cases of the transmission. The lubrication, preferably using oil, preferably takes place in a passive manner, i.e. the lubricating film, namely the oil film in the case of oil, is distributed by being conveyed in rotation and moved onward by means of gears (splashing). It can also be said that the gears entrain the oil film. After being at a standstill (for a relatively long period of time), but as soon as the gears rotate again, the oil film is gradually distributed over all the gears, in particular by building up the oil film again. The gears are designed to lubricate themselves. The oil lubrication takes place in the interior of the transmission case (transmission housing).
Splashing enables a lubrication of the transmission when the transmission is running forward and also when the transmission is running in reverse, i.e. when the direction of rotation is reversed. Lubrication is particularly advantageous during a load reversal, when the tooth flanks to be lubricated on the gears change. Four operating modes can be mentioned: forward traction, reverse propulsion, reverse traction, and forward propulsion, for which lubrication is ensured both in the motor mode and in the generator mode of the electric machines.
However, the transmission is not completely filled with the lubricant, which in particular is a liquid lubricant, but rather the total available volume (in each sub-transmission) is greater than the volume taken up by the lubricant in the interior of the transmission. Therefore, at least one of the gears is at least partially in an air environment, but as a result of its lubrication and its rotations may be separated from the air by an oil lubrication film.
A certain amount of lubricant is located in the sump, the fill level of which should be highest after relatively long standstill phases of the transmission.
Once the intended fill level of the transmission is reached, i.e. the amount of lubricant in the transmission is at its intended level (target fill level), at least one first gear dips with at least one gear segment into this sump to such an extent that the lubricant can adhere to the dipping part of the gear. Of particular interest is the state immediately after a relatively long standstill phase, specifically when the transmission starts to run again. When at a standstill, therefore, part of a first gear, such as a first spur gear, dips into the sump.
In addition to the first gear, there is a second gear as part of the twin transmission. The first gear and the second gear are intended to mesh with each other; together they form a gear stage. In particular, the transmission comprises more than the two gears mentioned in the introduction.
In addition to the gears of the transmission, the transmission has a multi-chamber system. The multi-chamber system is located in the vicinity of individual gears of the transmission. In particular, it is advantageous if the multi-chamber system is located next to a gear stage, preferably in the immediate vicinity of the gear stage, in order to store lubricant or transmission oil in the vicinity of the gear stage. The reservoir formed by the multi-chamber system is located physically close to at least one gear stage.
Ideally, there is at least one gear in the transmission that can be referred to as the highest gear (for example in relation to a bottom position). There is a (preferred) installation position for the transmission. One of the possible positions of the transmission is an ideally suited orientation of the transmission, in which the transmission can be attached to a vehicle by attachment means. When the transmission is in this particular position, the transmission is said to be in the installation position. Due to the design of the transmission (for example due to the locations of the attachment points), one installation position is assigned thereto. If the transmission is viewed in an (imaginary) positioning in its installation position (for example by being viewed in section), there are gears that are positioned closer to the ground, and there is at least one gear that can be referred to as the closest to the side of the transmission remote from the ground. The at least one gear remote from the ground serves not only to transmit power and torque, but also for conveying the lubricant onward, in particular in the form of a lubricating film that wets the gear.
The gear referred to as the second gear is part of a gear transmission chain (transmission path) having multiple gear stages. As part of a powertrain, the torque(s) of which is/are provided by electric motors, the transmission is designed to reduce the speed on the output side of the transmission, as will be explained below. Via the individual gear stages, the speed is reduced from stage to stage. During operation of the transmission comprising this chain of individual gear stages composed of multiple gears, the second gear rotates at a medium speed. At least one gear, but possibly also multiple gears, is an upstream gear in the flow of torque through the transmission. In the motor drive mode of the transmission (traction mode), the at least one upstream gear rotates faster than the subsequent, in particular second gear. Further gears may be arranged after the second gear in the flow of torque in order to achieve even lower rotational speeds or lower speeds.
The second gear can thus be described from different viewing angles or from different perspectives.
One way of designating the second gear is based on the installation position of the gear when the transmission is in the installation position. The second gear is the gear in the transmission that is located furthest away from the ground or from a road. However, the gears can also be named or defined on the basis of the (relative) speed compared to each other in a similar way. The second gear is the gear that is intended to rotate not at the highest speed and also not at the lowest speed, but rather for rotation, which takes place in a medium speed range (when considering all the speeds of all the gears and comparing these with each other).
In addition, the second gear serves to remove some of the lubricating film that is formed on the gear, for example by knocking it off, separating it or stripping it. Ideally, even after some of the lubricating film has been removed, lubricating film still adheres to the gear, in particular for as long as the transmission is in operation (rotating). Any excess of lubricant or lubricating oil can be discharged via the second gear to the multi-chamber system. The centrifugal force that is available when the transmission is working properly is advantageously used for this. Such a separation by means of centrifugal force can be brought about or facilitated by means of a rake, a separator plate or a spatula-like lubricating film or oil separator. In other words, in addition to its task of distributing the lubricant, the second gear also performs the function of a centrifugal lubricating film separator gear. By using the centrifugal force, the gear is used to separate some of the lubricant and to introduce it into a processing and recirculating device provided by the multi-chamber system.
The multi-chamber system is designed to route the lubricant back into the sump. The intention here is not to interrupt the returning flow of the lubricant, during operation of the transmission, once it has started to flow. However, one of the aims of the multi-chamber system is to remove a proportion of lubricant or a quantum of lubricant from the direct supply of lubricant to the gears. This can be done by controlling the recirculation. One approach is to influence the supply of lubricant by using at least one delay means. The lubricant, i.e. the oil when oil is used as the lubricant for the transmission, more precisely the oil introduced into the multi-chamber system by the centrifugal lubricating film separator gear, runs continuously back into the sump in order to be available again from there for gear lubrication. The multi-chamber system thus provides a flow path for the lubricant. The lubricant can return to the sump along the flow path. Ideally, however, although this is referred to as a continuous recirculation, at least one delay means is provided in the flow path so that (in relation to the total amount of lubricant) a delayed recirculation (i.e. in relation to the total flow quantity) can occur. The multi-chamber system makes it possible to initially hold back or store a quantum of lubricant.
The acceleration force exerted on the lubricant by acceleration due to gravity is used to achieve a return flow through the multi-chamber system toward the sump.
The transmission, which is advantageously designed as a twin transmission for individual drive in two powertrains, i.e. for a separate, dual drive via the same transmission, comprises multiple assemblies and components, including a multi-chamber system which advantageously comprises at least three chambers. The three chambers of the multi-chamber system include different chambers (by way of example, the distinction between the chambers can be made on the basis of their function). It can also be said that the chambers perform different tasks in the transmission. To achieve its variable tasks, the chamber system has several chambers. Based on the different tasks and functions of the various chambers of the multi-chamber system, the chambers may be of different size. In one embodiment, which is as space-saving as possible, the chambers are intended to be filled with lubricant as fully as possible after an initial phase of operation. It can also be said that the multi-chamber system has at least two chambers which have different volumes to each other. The chambers can be characterized on the basis of their respective function, or also on the basis of their dimensions and their lubricant-holding volumes.
Once the transmission or the powertrain has been started, the gears and thus the components of the gear stages begin to rotate. From an energy point of view, it is advantageous if the distribution of the lubricating film over the gears takes place not by using a circulating pump, but rather as a result of the lubricant being entrained from one gear to the next gear. This should take place until all the gears are covered with lubricant, at least with regard to their teeth in revolutions. For the initial phase, it is possible to postpone the wetting of the end faces of the gears with a lubricant, in particular with an oil.
By rotating different gears of the transmission, the lubricant is distributed along the running surfaces of the transmission and its gears. This can be referred to as a passive lubricating film distribution because no active components, in particular components that provide pumping power, are installed in the transmission, but rather the gears themselves ensure the teeth-covering lubricating film and the distribution thereof.
The gears are designed to rotate, with each gear being designed for its own speed range. One of the gears, in particular the gear located in second place in the output flow or torque flow, can be used as a lubricant-dispensing gear. For the dispensing, use can advantageously be made of a centrifugal force that acts on the lubricant as a result of the rotation of the gear.
The situation regarding the reserve of lubricant can also be explained as follows:
The multi-chamber system stores a certain quantity of lubricant during operation of the transmission and returns this quantity to the (re-)circulation only after some time. The rotation, in particular of the second gear, can advantageously be used to separate the lubricant by using a centrifugal force. The separated lubricant (at least partially) enters the multi-chamber system, more precisely a first receiving chamber which is, for example, a reservoir chamber.
A recirculation path leads from chamber to chamber. On the other hand, after an initial operation start phase, a certain amount of lubricant is to be applied from the lubricant circuit. It can also be said that the lubricant is returned to the lubricant circuit in a delayed manner. These delays can be brought about by one or more delay means in the recirculation path. Once the lubricant returns to the sump, it is available to be distributed over the gears again. A first gear is permanently operated from the sump of the transmission and distributes the lubricant from gear to gear, more precisely from running surface to running surface of the individual gears, in order to lubricate the surface of the gears, in particular the teeth of the gears.
According to the invention, a method for lubricating a transmission is described, the transmission preferably being a twin transmission, in particular a spur gear transmission, of a duo electric machine powertrain. The lubricating film is distributed in a passive manner. As they rotate, rotating gears of the transmission entrain lubricant and distribute it over all the running surfaces of the transmission. Centrifugal force brought about by the rotation splashes the lubricant. Provided in the transmission is a multi-chamber system, in which the lubricant, in particular lubricating oil, is stored. The lubricant splashed by the gears is received by one chamber of a multi-chamber system. It is then supplied to a further chamber, where it is stored. Only via a delay means is the lubricant recirculated back into a sump of the transmission, in a delayed manner, in order to cover a first gear of the transmission again for surface lubrication.
A continuous lubricant circuit may also be formed, in particular in addition to the previously described circulation path, via a spectacles-type bearing bracket in a transmission case. The spectacles-type bearing bracket preferably has a plurality of chambers which delay a return flow of the lubricant back into the sump. A spectacles-type bearing bracket according to the invention has a single hole structure. The hole structure receives in each case one end of two driven shafts. The hole structure is a single, preferably centrally arranged through-opening in the spectacles-type bearing bracket. The spectacles-type bearing bracket has oil supply surfaces. These are sheet-type, plate-type or blade-type elements which route oil that hits them in the direction of the hole structure, so that the oil enters the interior of the hole structure in order to lubricate the bearing located therein. The oil supply surfaces may extend along a plate body of the spectacles-type bearing bracket, for example from an edge of the spectacles-type bearing bracket toward a center of the spectacles-type bearing bracket. Preferably, the oil supply surfaces are formed as part of a supporting structure or web structure. The spectacles-type bearing bracket can also be referred to as a single-hole support structure. In particular, the oil supply surfaces extend at an angle. In other words, the oil supply surfaces may have a slope that leads to the driven shaft receiving opening. The oil collects at the end region thereof located at the driven shaft receiving opening, and therefore this can also be referred to as a collection chamber or oil collection region. This is followed by a lubrication reservoir, which merges into a reservoir chamber. In other words, the collection chamber is adjoined by a preferably funnel-shaped reservoir chamber, in particular in a barrier-free manner. Where the term “connected” is used here, this also expresses the possibility that the chambers are provided in a one-piece spectacles-type bearing bracket, for example as a multi-chamber system formed in particular by metal casting of the spectacles-type bearing bracket. The reservoir chamber opens via a lubrication opening or via a lubrication nozzle into a bearing lubrication chamber of the hole structure. The bearing lubrication chamber is bounded laterally by two rolling-element bearings or rolling-body bearings, such as two barrel bearings. A gap between these rolling-element bearings defines a size of the bearing lubrication chamber in one spatial direction. The bearing lubrication chamber preferably has a cylindrical volume. Lubricating oil that collects in the bearing lubrication chamber can flow off laterally toward the rolling-element bearings. From the rolling-element bearings, the lubricating oil, driven by the force of gravity, passes back into the sump in a delayed manner. Preferably, a flow-off direction toward a bearing is defined by an angle position of the lubrication nozzle, which deviates from a case longitudinal direction. The collection chamber and the reservoir chamber are preferably provided as a pair on the spectacles-type bearing bracket, for example on both sides of the plate body of the spectacles-type bearing bracket. This ensures that sufficient oil constantly reaches the two rolling-element bearings, i.e. continuously without any break in the flow. Furthermore, an oil level in the sump is kept low during operation of the transmission.
As is apparent from the description of the process of distributing the surface lubricating film, this is a continuous lubrication process. The initially dry gears are supplied with lubricant to their surfaces within the first few revolutions, ideally already by the first complete revolution. Any excess, i.e. a superfluous proportion of the lubricant, is routed back to the sump via the multi-chamber system. Owing to a delayed or reduced or slowed return, lubricant volumes accumulate in the multi-chamber system. The lubricant is discharged into the sump in smaller volumes in a delayed manner. Some of the lubricant remains in the chambers of the multi-chamber system. Only when the gears are dry due to the effects of gravity should the lubricant in the multi-chamber system be returned to the sump.
The delay in the return flow of the lubricant into the sump, which is brought about by the one or more delay means, should take as long as the gears take to dry (in particular due to the return flow).
Advantageous embodiments and further developments will be presented below which, considered per se, both individually and in combination, may likewise disclose inventive aspects.
The transmissions, which in particular as so-called reduction transmissions, i.e. as transmissions with a step-down ratio, are parts of electric powertrains, should as far as possible be designed in such a way that, particularly with regard to the limited electrical storage capacity in motor vehicle construction, as far as possible all of the electrical energy is available for the drive, i.e. as little electrical energy as possible should be “consumed” for auxiliary units, other tasks or as a result of power losses. The input shafts of the transmission according to the invention, in particular a dual transmission, and the output shafts of the transmission are arranged in a middle region in relation to an extension transverse to a direction of travel, i.e. in particular a relatively short distance from one case wall to an opposite case wall of the transmission case, in particular at the same height. The input shafts and the output shafts define a reference plane within the transmission case. The position of a middle axle of one of the gear centers, which is in angular alignment with the reference plane, is provided as a position at a distance from the transmission case bottom. This elevation of the position of the middle axle in relation to the reference plane gives rise to an axle arrangement of all the gear centers in the manner of a triangle. In this (imaginary) triangle, a first side, preferably a long side, such as a hypotenuse, is preferably brought into coincidence with the reference plane. In this (imaginary) triangle, a second side and a third side preferably form two short sides, which each intersect the first side, in particular at a respective end of the first side, in each case a straight line, such as two legs or such as an opposite leg and an adjacent leg. Straight lines that follow the short sides opposite the first side intersect the reference plane or the first side at an inclination having a value that can be taken from the angle range between approximately 5° and 70°. In other words, the second side and the third side can each form an (imaginary) corner enclosing an angle with the first side. It is advantageous if an angle is selected from an angle range between 10° and 50°. Various mathematical simulations and calculations have led to the situation where angles in an angle range between 15° and 48° appear to be particularly advantageous.
The transmission case is preferably installed in the motor vehicle with its case longitudinal direction or case longitudinal axis along a vehicle longitudinal axis, in particular parallel thereto, preferably even arranged on the central longitudinal axis of the vehicle. The input shafts and the output shafts extend transversely to the case longitudinal direction, i.e. preferably form an angle of approximately 90° with the case longitudinal direction.
In order to further specify the transmission category presented in the introduction, it can also be said that the transmission, the transmission case of which can be based on two half-shells, in the interior of each of which a preferably stand-alone transmission is realized, is constructed as a paired transmission, i.e. in an almost twin-like manner; another term for this is a twin transmission. The twin transmission is part of a motor vehicle powertrain. The motor vehicle powertrain includes two electric machines. Using the transmission, each electric machine is designed to drive a road wheel assigned to the respective electric machine. From one electric machine, the flow of torque to one of the road wheels is provided using half of the transmission.
The transmission case offers multiple positions for gear centers. Two positions for gear centers are occupied by the drive shaft(s) and by the driven shaft(s). A first position is occupied by two input shafts of the dual transmission. A second position for gear centers is occupied by the two output shafts. Located between the first position and the second position is a middle or third position, which is not in line with the two other positions. This position of a middle axle of one of the gear centers, which is in alignment with the reference plane, is provided as a position at a distance from the transmission case bottom. This can also be referred to as a roof-ridge-like arrangement of the middle axle relative to a loft-like plane. Overall, this elevation of the position of the middle axle in relation to the reference plane gives rise to an axle arrangement of all the gear centers in the manner of a triangle.
Owing to the arrangement of the middle axle above the reference plane, it is possible for the two other shafts and thus the reference plane to be located low in the vehicle, i.e. closer to the ground. The center of gravity of the motor vehicle can thus be placed in a low position, for example less than 50 cm or even less than 30 cm from the ground. In other words, the electric machines (operated as electric motors in the mode of operation considered here) that act on the input shafts and drive the input shafts, with their individual weights (due to their copper components), can be mounted in the motor vehicle at a height (as viewed from a road) that corresponds to the position or height (as viewed from the road) of the output shafts. This results in particular in a more stable cornering behavior for a compact case design in the longitudinal direction of the transmission case. If cornering is realized or aided by “torque-vectoring”, this increases the permissible cornering speeds.
As already mentioned above, the transmission is advantageously a passively lubricated transmission, in particular in the form of a twin transmission. The transmission, which is driven by an electromotive drive source, consumes as little energy as possible for auxiliary supplies, such as, for example, for conveying the lubricant through a lubricant pump. Instead, the transmission is lubricated passively, more precisely by the gears themselves and by the level of lubricant, in particular oil, present in the transmission during regular operation. In other words, the transmission can be referred to as a pump-free transmission when discussing the lubricant circuit, more precisely the lubricating oil circuit. With regard to the lubricant circuit, such as the oil circuit for example, the transmission is a pump-free transmission.
A return flow of the lubricant advantageously takes place by using or under the effect of gravity. Counter to this effect of gravity, the lubricant is distributed over the gear surfaces of the gears by virtue of the fact that the gears rotate and take over the lubricant from the previous gear stage or from the previous gear.
For reasons of clarity, it should be noted that, in the traction mode of the transmission, the lubricant path for distributing the lubricant over the gears may differ from the torque path through the transmission. In one positive embodiment of the transmission, a gear located in last place in the torque path can be used as a lubricant input gear. Considered somewhat more abstractly, gears arranged in a middle region in the torque path or even a last gear in the torque path can be used as gears lubricated first. As a result, the lubricant can be distributed by rotation and by mutual tooth meshing between gear and gear, starting from these middle gears or from the gear arranged on the output side and moving in the direction of the gears arranged more toward the edges of the torque path.
The lubricant is distributed over the running surfaces of two gears of the transmission by utilizing the gear rotations.
As delay means, consideration is given to hydraulic components which cause the hydraulic medium, the lubricant or the transmission oil, to move more slowly or in a reduced volume. Such (hydraulic) delay means are, for example, nozzles, shutters, chokes and flow valves. A lubricant flow-off can be delayed, for example, by constrictions in cross-section. The lubricant is routed back to the recirculation in a delayed manner. Another possibility for delaying is provided by particular delay paths. For example, a passively operated delay means can be realized via flow lengths and backpressure systems. As already mentioned in the introduction, delay means which are realized without active functional groups, in particular electrically operated functional groups, are particularly advantageous for energy-saving reasons.
The flow path may be designed for a continuous return flow of the lubricant after a first start-up phase. A flow path is a route in the transmission case along which the transmission oil passes, in a manner driven by the force of gravity, preferably without being assisted by a powered conveying device, from a higher point to a predefined lower point. Preferably, the multi-chamber system remains in the open state after the end of operation of the transmission. This can also be referred to as a passive multi-chamber system if no active, i.e. switchable, element is provided between the chambers. The transmission preferably has at least one open return flow or return flow path and/or at least one open forward flow path. After a few rotations of transmission gears, a constant return flow of oil spun out from the sump can be formed, with reservoir-forming devices being provided on the path or paths specified for the return flow. The reservoir-forming devices delay the return flow in comparison to running off on a direct route from a collection region or from a drip-on region into the sump.
For the individual torque paths, separate gearing/transmission assemblies may be provided in the transmission, said transmission being composed of sub-transmissions which in particular are designed to transmit torque independently of the respective other sub-transmission. In other words, the transmission can also be regarded as a block of multiple single transmissions, the (so-called) sub-transmissions. Ideally, each sub-transmission is (substantially) identical to another sub-transmission of the transmission. Each sub-transmission comprises multiple stages. To reduce the speed at which the output shaft of the respective sub-transmission rotates, at least two stages may be provided, but also three or more stages may be provided in order to reduce the speed further. Spur gears are advantageous, from which the individual stages are constructed. To enhance integration and/or to aid the compactness of the transmission and of its sub-transmissions, stepped gears may be provided. In this design, two stepped gears, or even more, may be provided in the transmission. One possible embodiment of the transmission consists in having at least one stepped gear installed in each sub-transmission.
A stage is regarded as two gears which mesh with each other or which engage with each other in the transmission as a complete group to form the stage. If the sub-transmission is considered from such a perspective, a stepped gear does not form a stage, even though two gears of different diameter are coupled.
If aspects such as weight, manufacturing effort and installation space are taken into consideration when developing and designing the multi-chamber system, a favorable number of individual chambers, which together form the multi-chamber system, is the number 3. Three individual chambers are combined to form the multi-chamber system. Of course, it is also possible to construct the multi-chamber system from more than three chambers. However, each chamber requires its partition walls, so that a multi-chamber system larger than a three-chamber system requires a larger number of chamber partition walls. The partition walls may be provided in an integrated manner in a mold for producing case halves.
If the various delays and the delivery quantities during the different operating phases and operating states as well as the expected speeds of the transmission and of its gears are taken into consideration, it is advantageous to tailor the volumes and sizes of the chambers of the multi-chamber system to the average flow and/or reservoir quantity that is to be expected. The chambers are therefore not all the same size as each other; a last chamber, in particular leading directly into the sump, may for example be larger than a chamber upstream of this last chamber.
As already mentioned above, the transmission has a preferred direction, which corresponds to the installation orientation or an installation position. The transmission is designed for a very specific installation direction or position. When the transmission is in the installation position, the chambers of the multi-chamber system are located at different heights or levels. A single chamber of the multi-chamber system is advantageously the highest chamber. The chamber from which the run-off distance under the effect of gravity is longest (compared to other lubricant run-off distances), i.e. the lubricant run-off distance under the effect of gravity that may also lead via other chambers, can be referred to as the highest or uppermost chamber. The highest chamber can thus be defined on the basis of the run-off distances under the effect of gravity. A run-off distance under the effect of gravity exists in particular when oil, driven by the force of gravity, can take up a lower potential energy, for example by running off, driven by the force of gravity, from a point of impact on a surface or from a collecting reservoir, preferably until it is received again by a reservoir. The (re-)circulating lubricant, such as the lubricating oil for example, follows gravity. From the gravity point of view, there is a highest or uppermost chamber, namely the one that has the longest run-off distance, measured from the run-off side of a chamber. In other words, the uppermost chamber is furthest from the ground when the transmission is installed. This highest chamber may be designed as a drip and collection chamber. The highest chamber may be intended to receive the lubricant that is to be separated from the, in particular second, gear. Because centrifugal effects are also used when separating the lubricant, it may be advantageous to locate the drip and collection chamber as a collecting basin and thus in a cuff-like manner around at least one side of the gear provided for the separation. To concentrate the lubricant in the highest chamber, to collect the lubricant more quickly and also to clean the lubricant, the drip and collection chamber may additionally be equipped with a separating magnet. The separating magnet may be arranged, for example, at the bottom of the drip and collection chamber. The lubricant initially collects at the bottom of the drip and collection chamber. A first reservoir of lubricant can form in the collection chamber. Metal chips, contaminants and magnetically conductive parts can be taken out of the recirculating fluid that helps to cool the transmission, i.e. the lubricant, by means of the separating magnet.
One of the chambers of the multi-chamber system that follows (from the perspective of the flow path) the highest chamber, also referred to as the uppermost chamber, can be referred to as a reservoir chamber, in particular as a first or second reservoir chamber. From the reservoir chamber, the lubricant flows off, in particular exclusively, more slowly than it can flow off from the drip and collection chamber, inter alia due to a constriction in the flow path. Within a few revolutions or rotations of the gears of the transmission, lubricant accumulates in the reservoir chamber. In an initial phase of operation of the transmission, this lubricant located in the reservoir chamber takes longer to flow off than it does to accumulate, in particular due to separation from the second gear. The delayed discharge, in particular return flow, can also be brought about by using the force of gravity. Here, too, no further energy is used for control purposes.
The delay means, via which the delay with which the lubricant is routed back out of the first or possibly second reservoir chamber can be set, may be located on a discharge side of the reservoir chamber and may represent a sole possibility for discharging from the reservoir chamber. The delay means is advantageously arranged on the discharge side of the reservoir chamber. This ensures that the lubricant can enter the reservoir chamber from the drip and collection chamber in a non-delayed manner. Only the departure from the reservoir chamber is delayed. The entire chamber formed of the reservoir chamber and the drip and collection chamber as storage volumes is therefore provided as a collection and receiving space.
The sub-transmissions themselves are independent of each other. This means that the transmissions or the sub-transmissions of the (complete) transmission can each independently carry out a speed/torque conversion. In physical terms, it is advantageous to arrange the two sub-transmissions next to each other, in particular parallel to each other. Common axles and common shafts can thus be used. For example, the gears can be borne on common sleeves. In addition, such an arrangement makes it possible for a single multi-chamber system to be sufficient for the two sub-transmissions. Each of the sub-transmissions is a multi-stage transmission, i.e. each sub-transmission has a two-stage or three-stage transmission path. The transmission can also be referred to as a two-stage or three-stage spur gear transmission. The transmission paths are intended to convert higher speeds on the input side into comparatively lower speeds on the output side, i.e. to reduce the speeds. Each of the transmission paths is part of a separate powertrain. As already mentioned above, each powertrain includes a separate electric machine. Two electric machines are therefore provided in the case of a twin transmission.
Preferably, the transmission is a transmission having two three-stage transmission paths arranged in parallel, which in particular have a step-down ratio. Each transmission path is designed for a separate powertrain and has two connections, to which in each case one of the two duo electric machines can be connected for drive purposes.
Preferably, at least one gear of the transmission or of the sub-transmission is a stepped gear. Two stepped gears may be arranged in the transmission case. Each of the sub-transmissions has an internal volume. Two spatially connected, but rotationally isolated, sub-transmissions can be arranged in a single transmission case. The transmission case preferably encloses a contiguous internal volume. The sump occupies a variable part of the internal volume, it being possible for this part to decrease proportionally in relation to an increasing drive speed of the transmission. A simultaneous, sufficient lubrication of the sub-transmissions is ensured.
Immediately upstream of the sump of the transmission, the multi-chamber system may have a further chamber, in particular a lowermost chamber with regard to the installation position. This lowermost chamber is a pre-chamber to the sump. The pre-chamber to the sump can merge into the sump, for example with a further delay element interposed therebetween. By providing a pre-chamber in front of the sump, it is possible to operate with different fill levels between the pre-chamber and the sump during an operating phase of the transmission.
In one advantageous design, the multi-chamber system may be formed in such a way that it has several chambers in its interior, which are part of the run-off path intended for recirculating the oil. At the same time, the multi-chamber system may be formed in such a way that it also provides at least one depression or chamber outside its multi-chamber system, in order for example to keep in a (second or separate) sump a gear that lies or rotates in this depression, in particular a highly loaded gear. When increased lubrication or a supply of more lubricant to a gear or a gear stage of the transmission is necessary, a lubricant-collecting depression or chamber arranged in particular in the exterior of the multi-chamber system can ensure this increased supply of lubricant. The level of the lubricant in the sump and the level of lubricant in the further depression, which can also be referred to as the gear lubrication pan, may consequently differ from each other. The gear running in the gear lubrication pan thus performs the task of a further splash gear.
In other words, a transmission according to the invention may also be equipped with multiple sources of lubrication by providing, in addition to a sump, at least one further storage region for distributing a lubricating film.
The combinations and embodiments presented above can also be considered in numerous further connections and combinations.
From another perspective, it can also be said that the transmission has a lubricant supply path which extends in a manner differing from the torque flow path, said lubricant supply path being arranged in particular in a central region. A gear arranged downstream in the torque flow path, i.e. a second, third or fourth gear in the flow of torque, is a gear provided first for the lubricant and therefore is a centrally distributing gear. A first gear provided for introducing the flow of torque into the transmission, i.e. via which the flow of torque is introduced into the transmission, can draw the increased amount of lubricant that is requires from a gear lubrication pan. This gear lubrication pan may need to be filled the first time, i.e. in an initial phase. The lubricant is then available as an additional source.
In order to lubricate all the running surfaces of all the gears of the transmission as quickly and as comprehensively as possible, a gear supply for passively lubricating the gears is formed in a middle region. Starting from the middle, the lubricant is drawn over the other gears. Additional gear lubrication pans may be provided at the gears that require an increased supply of lubricant. Besides the actual sump of the transmission, therefore, there are one, two or more than two so-called auxiliary sumps. If such an auxiliary sump is designed without any run-off, then after an initial filling phase the gear that has an increased lubricant requirement is also a splash gear.
Material is saved in particular if walls of the chambers are formed by the transmission case, walls that provide at least partial separation between the chambers. A partition wall between two chambers may be formed by at least one partition plate, which is inserted into the case. Advantageously, partition walls between the chambers are integrally molded onto the transmission case, for example by casting. On account of low mechanical stress, partition walls that serve to guide the oil may be formed in the manner of sheet metal, i.e. may have a thickness of less than 1 centimeter.
In other words, the transmission can also be described as a dual transmission as follows. In addition, further very interesting and also advantageous design features emerge therefrom.
The dual transmission comprises two single transmissions arranged in parallel next to each other. The single transmissions are preferably each designed to transmit, in multiple stages, a rotational movement of a shaft, provided in each single transmission and driven by an electric motor, to a wheel half-axle, such as a universal (joint) shaft for example, as the respective output shaft, i.e. to two output shafts. The gears of a respective single transmission may be rotatable independently of the gears of the other single transmission. Preferably, all the gears are arranged in a contiguous space within the transmission case.
The transmission could thus in fact be split into a first (sub-)transmission and a second (sub-)transmission. In a manner of speaking, the transmission consists of two single transmissions in a common (overall) transmission case. The single transmissions are arranged parallel to each other. In terms of rotation, the two single transmissions or the first and second (sub-)transmissions are independent torque transmission units, particularly if an effective coupling via a wheel that can be driven by the (sub-)transmission across a pathway is ignored. The single transmissions are combined to form a dual transmission.
Via each single transmission, a rotational movement of a shaft to be driven can be transmitted via at least two stages to an output shaft. Each single transmission is intended to transmit a rotational movement of a shaft to be driven to a (separate) output shaft.
The dual transmission has a first output shaft and a second output shaft. The dual transmission has a first shaft to be driven and a second shaft to be driven. The two shafts to be driven can be operated independently of each other.
Each shaft to be driven is designed to be driven by an electric motor. The output shafts are intended to act on wheel half-axles, which are usually formed by wheel drive shafts having two joints, namely one joint in each end region of the wheel drive shaft. Each output shaft (indirectly) drives a wheel half-axle or a drive shaft leading to a wheel.
The rotational movement, which is introduced into the transmission by a shaft to be driven, can be applied to at least one of the (road) wheels via the output shaft. The transmission, which is a dual transmission, thus has a first shaft to be driven and a second shaft to be driven. Each shaft to be driven rotates at its own speed, depending on the drive by an electric motor. Each output shaft thus also has its own speed. For example, when the motor vehicle is traveling straight ahead, the speeds of the two output shafts should be as synchronous and as equal as possible if the (road) wheels have the same rolling radius. When cornering, however, it is helpful if the speed of one output shaft differs from the speed of the other output shaft. A speed control system is able to adapt or adjust a speed of at least one of the two electric motors so that, particularly in the case of different rolling radii, for example owing to different tire pressures, no torque is generated about a vehicle vertical axis and traveling in a straight line is ensured.
The two single transmissions that form the dual transmission are arranged parallel to each other, i.e. next to each other. Each single transmission extends in a contiguous space that is separated from the next space, this being the space for the single transmission. The space is located inside a transmission case. The gears of one transmission can rotate at a different speed than the gears of the other transmission. The gears of one transmission can be operated or rotated independently of the gears of the other transmission.
The dual transmission has a common spectacles-type bearing bracket as a component that is common to both output shafts, namely a first output shaft and a second output shaft. The spectacles-type bearing bracket, via its cuff around its ring-shaped internal opening, supports the respective output shaft extending into it at one end. In other words, the two output shafts, which in particular are arranged with a respective end face parallel to and opposite each other in the spectacles-type bearing bracket or the opening thereof, with the two end faces preferably being spaced apart from each other, lead out of the spectacles-type bearing bracket into a region outside the case of the dual transmission. The output shafts can in particular be supported together with the associated third gears. The bearings of the input shafts can also be supported. In other words, the spectacles-type bearing bracket may be a support structure for two output shafts, two bearings, such as rolling-element bearings or rolling-body bearings, in particular two barrel bearings, as well as two rotatable third gears, wherein at least one of the aforementioned components may be at least partially enclosed in a ring-like manner.
It is particularly advantageous if the spectacles-type bearing bracket is arranged centrally. The spectacles-type bearing bracket is located in the middle, so to speak, between two transmission case half-shells. From a different perspective, the spectacles-type bearing bracket is the central, middle component that separates the single transmissions of the dual transmission from each other. The spectacles-type bearing bracket divides the transmission chamber of the dual transmission into a left half and a right half (in the direction of travel). Across a boundary surface, which can be considered as a design aid, between the two halves of the dual transmission on which the spectacles-type bearing bracket extends, a flow or exchange of transmission oil takes place, but not a transmission of torque.
One component that can be assigned to the case is the spectacles-type bearing bracket, which from one perspective can be regarded as a partition element of the (sub-)transmission.
A spectacles-type bearing bracket, which may be provided in the dual transmission as a component thereof, may exist around a hole structure. The hole structure is in the center of the spectacles-type bearing bracket. The central hole, the hole structure, is designed to receive two ends of driven shafts, i.e. a first end of a first driven shaft and a second end of a second driven shaft.
Such a spectacles-type bearing bracket may be installed in a dual transmission of the type presented above.
For attachment purposes, the spectacles-type bearing bracket may have pin receptacles at its edges, i.e. in its edge regions. A suitable number of pin receptacles is, for example, four pin receptacles. Via these, torques that have been introduced, for example introduced via the driven shafts, can be dissipated to a case that carries the spectacles-type bearing bracket, such as the transmission case for example. Torques that would actually load the spectacles-type bearing bracket are thus dissipated via the case, for example via the sub-case thereof. Preferably at right angles to the pin receptacle, the spectacles-type bearing bracket has in particular flat contact surfaces. It is advantageous if the contact surfaces are in each case located opposite support surfaces in an inner region of the sub-case. In particular, three or four flat, ring-like contact surfaces may be provided on the spectacles-type bearing bracket, which together form parts of a smooth, geometric surface. All the pairs consisting of support surface and contact surface can be brought closer to each other until they touch. Two contact surfaces of the spectacles-type bearing bracket are located at a fixed distance opposite each other in the manner of a mirror image.
The spectacles-type bearing bracket centers around an elongate, cylindrical opening, into which two shafts can be inserted, each from one side of the spectacles-type bearing bracket. To this end, the spectacles-type bearing bracket has roller bearings, such as barrel bearings. The spectacles-type bearing bracket provides the lateral attachment for the respective driven shaft.
The receptacles for the driven shafts are located in the center of the spectacles-type bearing bracket. The spectacles-type bearing bracket is in turn attached to other case components. To this end, the spectacles-type bearing bracket has pin receptacles in its edge region, so that a connection between the spectacles-type bearing bracket and the case parts carrying the spectacles-type bearing bracket can be established via pins. In other words, pins serve to fix the spectacles-type bearing bracket on the transmission case. The pins may be subjected to shear stress by the spectacles-type bearing bracket during operation of the transmission. The spectacles-type bearing bracket may be a removable part of the transmission case. Removal of the spectacles-type bearing bracket is possible if both shells of the transmission case are separated from each other.
Owing in particular to the spectacles-type bearing bracket in the dual transmission, the dual transmission described above provides a good way of supporting and carrying the shafts that open out into the spectacles-type bearing bracket, in particular the output shafts. The dual transmission comprises two independent input shafts, one input shaft for each side of the dual transmission. The dual transmission comprises two output shafts, one output shaft for each side of the dual transmission. The input shafts and the output shafts protrude from the case. The first output shaft protrudes from the case in the opposite direction to the second output shaft. Similarly, the first input shaft protrudes into the case on a side and which from the other side is penetrated by the second output shaft. The respective input shaft and the associated output shaft are arranged at an equal height, i.e. at the same height.
The two output shafts are supported at the mutually facing ends by one and the same spectacles-type bearing bracket. In other words, the end faces of each output shaft face toward each other. One output shaft is located with its end face opposite the end face of the second output shaft. Torques introduced laterally into the axles can be dissipated to the case via the spectacles-type bearing bracket.
Further advantageous embodiments and further developments will be presented below which, considered per se, both individually and in combination, may likewise disclose inventive aspects.
A (virtual) mirror surface can be “drawn” through the entire case. This mirror surface separates the region of the first single transmission from the region of the second single transmission. The mirror surface runs through the spectacles-type bearing bracket. The mirror surface is referred to as a mirror surface because a reflection of the gears of the individual stages could be performed at this surface. A gear of the first sub-transmission or single transmission is located identically in the region of the second single transmission at the point equidistant from the mirror surface.
Advantageously, spur gears are used as gears of the transmission for a single transmission. The transmission is a transmission extending longitudinally in the direction of travel.
The individual gears of the gear stages mesh with each other; a transmission chain of gears starts at the input shaft and passes in stages, i.e. from gear to gear, until it reaches the region of the spectacles-type bearing bracket. When running through the gear stages in the output direction, there is a last gear stage that is provided directly in the region of the spectacles-type bearing bracket. The last gear stage opens out in the region of the spectacles-type bearing bracket.
However, the spectacles-type bearing bracket not only carries a respective output shaft at each end, i.e. more precisely two output shafts via its ends, but rather in one advantageous embodiment the spectacles-type bearing bracket is at the same time a mounting frame for two barrel bearings. The barrel bearings may be axially delimited by retaining clips. The two barrel bearings arranged in the spectacles-type bearing bracket can be held in position in a laterally delimited manner by the retaining clips holding the barrel bearings.
In one advantageous embodiment, the output shafts are supported by a single spectacles-type bearing bracket in an end region of the output shafts. The spectacles-type bearing bracket, which is referred to as “spectacles-type” because two output shafts are supported, could also be referred to as a monocle-type bearing bracket because the output shafts jointly extend longitudinally along a line such that the radii thereof overlap when viewed perpendicular to the case longitudinal direction. The spectacles-type bearing bracket preferably has a single, in particular central, hole structure. The hole structure preferably receives two respective driven shafts at one of their ends. The hole structure includes in particular two floating bearings. Each floating bearing can support one wheel half-axle, particularly when a shaft of the wheel half-axle extends into the transmission case. The spectacles-type bearing bracket is preferably attached to a support structure in the case interior. There is no need to provide sealing surfaces between the spectacles-type bearing bracket and the case. Such sealing surfaces could leak due to mechanical loads in continuous operation. The transmission may be equipped with a single sub-case connection surface.
In one advantageous embodiment, two barrel bearings are provided in the spectacles-type bearing bracket. Each barrel bearing is intended to receive one end of one of the output shafts. The respective barrel bearing receives one output shaft. With regard to an axial extension, such a barrel bearing can be referred to as an outermost (or innermost, depending on the viewing direction) bearing for a wheel half-axle or wheel drive shaft. In addition, a further bearing on the transmission case takes place via a ball bearing, such as a deep groove ball bearing.
It is advantageous if the spectacles-type bearing bracket is fixed to at least one sub-case of the transmission case via pins, which are preferably to be inserted into the spectacles-type bearing bracket in the edge region of the spectacles-type bearing bracket. The spectacles-type bearing bracket is mounted in a fixed position via the pins. Such a mounting is possible in a force-fitting or form-fitting manner.
In one advantageous further development, the spectacles-type bearing bracket is a removable structure, in particular because it is held only by pins, said structure having a single central hole. The spectacles-type bearing bracket can also be referred to as a single-hole support structure. The spectacles-type bearing bracket is fixed to the transmission case via pins. The hole in the spectacles-type bearing bracket is preferably arranged centrally in the spectacles-type bearing bracket.
In addition, it is advantageous if the spectacles-type bearing bracket, via at least one lubrication nozzle integrated therein, can discharge oil to the shafts carried therein. Such one or more lubrication nozzles may be arranged in such a way that they can introduce oil radially into the space in one hole of the spectacles-type bearing bracket. Depending on the flow rate, this can also be referred to as an injection, i.e. if an applied hydrostatic pressure is high enough to prevent the flow breaking down into a series of droplets. The lubrication nozzle or the lubrication opening is preferably supplied with transmission oil from a lubrication reservoir. In the lubrication reservoir, oil accumulates through an inflow of collected droplets or splashes. This is followed by a reservoir chamber. Splash oil is thrown from gears onto oil supply surfaces, inter alia. Gears that dip into a sump convey oil upward when splashing and release it as splashes. Splashes may also be droplets or may consolidate to form droplets under the effect of the surface tension.
The spectacles-type bearing bracket can also be compared to a web plate. A web plate of this type may be a shaped structure which laterally delimits the central opening and which, by way of its projected shape, retains the character of a single-hole support structure.
It is advantageously provided that just one single spectacles-type bearing bracket is formed as a support for two ends of the output shaft.
The spectacles-type bearing bracket carries the output shafts. The spectacles-type bearing bracket itself, in particular owing to its roller bearings, is designed as a floating bearing for each output shaft.
Viewed from one side, the spectacles-type bearing bracket looks like a rectangular plate that tapers toward its edges. In one advantageous embodiment, the plate that represents the spectacles-type bearing bracket tapers at least toward its edges. Webs protrude in some regions of the plate, which webs have a stabilizing effect on the bearing plate or spectacles-type bearing bracket. Further toward the outside, a drive gear can be arranged on each side of the spectacles-type bearing bracket.
The combinations and embodiments presented above can also be considered in numerous further connections and combinations.
In one embodiment, the spectacles-type bearing bracket may have a width such that it encloses and thus supports the respective ends of two individual shafts with equal width. The spectacles-type bearing bracket has a width that is more than twice as wide as one of the bearings for one of the shafts.
In an alternative embodiment, the spectacles-type bearing bracket may also be designed as a dual bearing for two shafts, the two shafts engaging one inside the other, for example concentric to each other, in order to be supported in the region of the spectacles-type bearing bracket in one case as an outer shaft relative to the spectacles-type bearing bracket and in one case as an inner shaft in the region of the spectacles-type bearing bracket opposite the outer shaft.
In addition, it is possible to design the input shaft(s) and/or the output shaft(s) as shafts which are likewise borne on sleeve-like hollow bodies, for example.
By way of example, consideration can also be given to using more than four bearings, in particular more than two bearing combinations, to attach the input shaft to the case, more precisely the case pans.
The present invention can be understood even better if reference is made to the accompanying figures which show particularly advantageous design possibilities by way of example, without limiting the present invention thereto, wherein
A particularly advantageous motor vehicle body exists if the electric machines 5, 7, which in
According to
The transmission 1 or 1I is arranged on the vehicle longitudinal axis 524. One electric machine 5 or 5II and one half-axle 520 are located on one side of the vehicle longitudinal axis 524, while the other electric machine 7 and the other half-axle 522 are arranged on the other side of the longitudinal axis 524. The electric machine 5 or 7, which according to
The vehicle 500 or 500I shown in
Interesting aspects of the dual transmission 1 will be explained below primarily on the basis of
The transmission 1 is shown in a sectional view in
As already discussed above, the dual transmission 1 shown in greater detail in
As shown in
The two input shafts 33, 35 are combined to form a dual input shaft 32. They are mechanically connected to form the dual input shaft 32. The two input shafts 33, 35 extend along the axis 44 and in this way form the dual input shaft 32. The two coaxially arranged input shafts 33, 35 are connected to each other in such a way as to be rotatable relative to each other.
The middle axle 45 can be intersected by a straight line G (see
As can likewise be seen from
The respective gear 75, 75I on the input shaft side of each single transmission 15, 17 drives a respective gear 49, 49I on the middle axle 45. In the exemplary embodiment shown, the directions of rotation of the electric machines 5, 7 (see
If, in a manner differing from the advantageous motor vehicle body shown in
According to
As illustrated in particular in
In contrast, the input shafts 33, 35 and the output shafts 37, 39 are mounted by way of rolling bearings 65, 67, 69 and 71 in outer walls of the transmission case 31. Furthermore, the input shafts 33, 35 are mounted by means of ball bearings in the vicinity of a case partition wall 73 that has apertures, such as the aperture 212, for the joint lubrication of the single transmissions 15 and 17. A wall support 210, designed as part of the case partition wall 73, establishes a connection to the transmission case 31. The output shafts 37 and 39 are mounted in a second case partition wall 73I, more precisely a spectacles-type bearing bracket, by means of needle bearings (without reference signs) or one needle bearing per single transmission 15, 17.
As can be seen particularly well from looking at the sub-transmission 17 shown
The stepped gears, such as the stepped gear 79 on the axle 45 (see
In the dual transmission 1 according to the invention, as shown in
As shown in particular by
For the gears 49I, 50I and the teeth 57I, 59I of the other single transmission 15, the same applies on account of an identical design of transmission parts, i.e. the sub-transmission 15, which is constructed in a manner identical to the sub-transmission 17, has adjacent gears 49I, 50I which are designed with a corresponding inclination of the teeth 57I, 59I. In other words, what has been described above correspondingly applies to the gears 49I, 50I and the teeth 57I, 59I of the other single transmission 15 due to an identical design of transmission parts.
The gears 49, 50 or 49I, 50I are free of axial forces, at least in the traction mode of the vehicle.
It may be advantageous to provide thrust washers to support the gears 49, 50 or 49I, 50I on the transmission case 31.
Furthermore, in order to vent the transmission case 31, instead of a solid middle axle it may be advantageous to provide the middle axle 45 as a sleeve or to additionally provide a sleeve on the middle axle 45, which sleeve makes it possible to equalize the pressure in the transmission case 31.
The gears 49, 49I, 50, 50I, 75, 75I, 77 and 77I are formed as disk wheels on account of the high torques to be transmitted. As shown in
All the gears 49, 49I, 50, 50I, 75, 75I, 77, 77I, axles and shafts 33, 35, 37, 39 installed in the transmission case 31 are lubricated via a common sump (see
In a regular filling state, the transmission case 31 is filled with a transmission oil, but not completely filled with oil; instead, part of the interior, i.e. part of the internal volume 108 of the transmission case 31 is filled with air.
By way of its internal cavity, the transmission 1 shown in
The internal volume 108 is partly split into chambers. The oil-guiding wall 226 separates regions of the internal volume 108 from each other. The oil-guiding wall 226 is connected to the transmission case 31. Provided in the region of a center 110 of the transmission 1 is the wall support 210 of the oil-guiding wall 226, which at the same time is designed as a bearing support for two shafts 33, 35. The wall support 210 separates a collection chamber 204I of one single transmission 15 from a collection chamber 204 of the other single transmission 17. In the wall support 210, at least one equalizing flow opening 212 ensures an equalization of the level of transmission oil in the collection chambers 204, 204I between the single transmissions 15, 17.
In other words, the single transmissions 15, 17 are decoupled from each other in terms of torque transmission, but are coupled to each other in terms of lubrication. A needs-based lubrication of the transmissions takes place through separate, but oil-permeable, regions of the internal volume 108 with the aid of delay means for a flow of transmission oil, such as the delay means 180II, as will be explained in greater detail below.
For air that is to pass outward via a bore 118 in the sleeve 116 to a breather cap 130 in order to be discharged, a vent structure is incorporated in the transmission 1.
The sleeve 116, which is hollow due to a bore 118, is located in the region of the gear axle 114 among the gear pairs 49, 50 or 49I, 50I designed as stepped gears 79. The cavity created by the bore 118 in the interior of the sleeve 116 has connections to the rest of the internal volume 108 of the transmission 1I or of the transmission case 31 via further bores 118I, 118II.
The sleeve 116 extends from one inner side 102 to the opposite inner side 104 of the transmission case 31. The sleeve 116 is a transverse strut that stiffens the case 31. The (internal) width 106 of the transmission case 31 is completely spanned by the sleeve 116. The sleeve 116 therefore extends from a first case wall 41 to a second case wall 43.
Advantageously, the sleeve 116 is located in a middle region M of the transmission 1. The middle region M of the transmission 1 is used by the second, middle position 21 to center gears 49, 49I, 50, 50I.
Via the (feed) bores 118I, 118II, air from the internal volume 108, namely from anywhere therein so long as it is somehow distributed over the width 106, can enter the centrally arranged bore 118 of the sleeve 116, which in particular spans the width 106 of the case 31. The air then passes to the breather cap 130. The case wall 41, 43 may contain further bores (not shown), which extend partially along the case wall 41, 43 and via which air enters the bore 118 that spans the width 106 of the case 31. Such bores in the case wall also serve to supply oil to the needle bearings of the gears 49, 49I, 50, 50I.
As can be seen from looking at the details of
A corresponding section through the first sub-transmission 15, which is likewise shown in
Hereinbelow, the description will focus on individual aspects of the lubrication, in particular the oil lubrication.
The transmission sump 160 is located in a bottom region of the dual transmission 1. The bottom region is also referred to as the sump 160 because it accommodates the lubricant 162 in the case 31 when the dual transmission 1 is in a rest state. A first lubricant level 164 of the sump 160 is set. The lubricant level 164 can also be referred to as the fill level. A first gear segment 240 of the first gear 77 dips into the lubricant 162. When the dual transmission 1 is set in rotation by a motor drive, for example to move the motor vehicle 500 or 500I shown in
Meanwhile, the fourth gear 75 draws lubricant 162 upward from a gear lubrication pan 208 by means of second splash teeth, such as the second splash tooth 232, with a direction of rotation identical to the first gear 77 with its direction of rotation 260. The direction of rotation 260 refers to one of two possible directions of rotation of the gear 77. The lubricant 162 from the gear lubrication pan 208 is at least partially transferred to the third gear 49. In a rest state of the dual transmission 1, the gear lubrication pan 208 has a second lubricant level 166, the height of which is limited by a flow-off barrier 224 of the gear lubrication pan 208. The second lubricant level 166 can be lowered to another, lower lubricant level 166II by the delay means 180II, preferably in the form of an electromechanically closable shutter opening in a gear lubrication wall 208. The gear lubrication pan 208 and the oil collection pan 234 that adjoins it in a vertical direction are formed as regions of the oil-guiding wall 226. The oil collection pan 234 is located in an angular range around the input shaft 35 and around the gear 75 arranged on the input shaft 35 (see
By means of centrifugal forces, excess lubricant 162 that is drawn upward to the stepped gear 79 is supplied at least partially in droplet form to a gravity run-off path 190. The gravity run-off path 190 extends along an inner side 104I of the transmission case 31. Located between the inner side 104I and the oil-guiding wall 226, which partially surrounds the gears 49, 75 and 77, is a system consisting of a plurality of chambers arranged one after the other in the direction of gravity, i.e. a chamber system 200 which has a plurality of delay means, such as the delay means 180, which is a wall constriction, or the delay means 180I, which is a flow valve 188, for a lubricant run-off. The oil-guiding wall 226 has the shape of a scraper at its upper end, so that lubricant 162 can be stripped by the scraper from the gear 49 moving past. A first chamber is the drip chamber 202, in which lubricant droplets are collected. The drip chamber forms an uppermost chamber in a vertical sequence of chambers. Collected lubricant is separated from abraded metal material by a separating magnet 228 at the bottom of the drip chamber. Lubricant that has thus been cleaned is supplied in droplet form, via a nozzle 182 in conjunction with a shutter 184, to the collection chamber 204. The expression “in droplet form” also encompasses the situation where the oil may be supplied as a narrow flow; no particular droplet shape of the lubricant is required. The separating magnet 228 prevents clogging of the nozzle 182. The shutter 184 prevents oil droplets from passing directly downward from the inner side 104I. Droplets from the nozzle 182 enter the collection chamber 204. A reservoir of lubricant can accumulate in the collection chamber 204. The collection chamber as a middle chamber can thus also be referred to as a first reservoir chamber. The collection chamber 204 has a wall portion which can be referred to as a discharge-side part 222 and forms a flow-off choke 186. From the collection chamber 204, the lubricant 162 enters the reservoir chamber 206. The reservoir chamber 206, which can also be referred to as the second reservoir chamber 206, is a lowermost chamber of the multi-chamber system 200. The reservoir chamber 206 is equipped with the flow valve 188 in its discharge-side part 222I. A return flow of lubricant 162 into the sump 160 can be at least intermittently blocked by the flow valve 188, which forms a delay means 180I. The delay means 180, 180I thus described ensure that the third lubricant level 168 has a height sufficient for lubricating the dual transmission 1, while ensuring that energy losses caused by a stirring of the first gear 77 in the sump 160 are kept as low as possible. By way of the delay means 180I, i.e. by way of the flow valve 188, the second lubricant level 166I in the reservoir chamber 206 may decrease toward the lubricant level 168, provided that the lubricant level 168 is below the second lubricant level 166I. Thanks to the delay means 180I, an equalization of the lubricant level takes place between the lubricant level 168 present in the sump 160 and the second lubricant level 166I present in the reservoir chamber 206. The first lubricant level 164 encourages a rapid, pump-free distribution of oil when starting up the dual transmission 1. It is thus possible to equip the teeth 77, 50, 49, 75 with a surface lubrication 220 by a lubricant 162.
With reference to
The spectacles-type bearing bracket 330 has a circular hole structure 344 approximately in the center between the pin receptacles 424, 426, 428, 430. The hole structure 344 is provided as a continuous opening with a stepped wall through the web plate 352. The hole structure 344 defines an orientation of shafts to be attached, such as the output shafts 37, 39 shown in
As a further measure to mechanically stabilize the spectacles-type bearing bracket 330, the web plate 352 is strutted by a plurality of webs, such as the first web 400. The webs 400 can also be referred to as web plate thickenings.
Located in the hole structure 344, in particular lined up next to each other in a ring-shaped arrangement, is a plurality of identical barrel rolling elements, for example the barrel rolling element 372.
The section line A-A in
Inter alia, it can be seen in
As the bearing lubrication chamber 450, the lubrication space 462 is at the same time part of a multi-chamber system 200I which serves to return transmission oil to the sump (see sump 160 in
The barrel bearings 362, 364 are of identical construction, i.e. they each have barrel rolling elements, such as the barrel rolling element 372, which are guided in an outer barrel bearing ring, such as the barrel bearing ring 370. The outer barrel bearing ring 370 is held in the spectacles-type bearing bracket 330 by a retaining clip 366. The barrel bearings 362, 364 can thus be separated from the spectacles-type bearing bracket 330 for maintenance after long-term operation, for example if bearing wear has occurred. This facilitates maintenance work, such as replacement or exchange of the bearings 362, 364.
A respective contact surface 436 of the pin receptacles, such as the first pin receptacle 424 or the second pin receptacle 426, is located in an intermediate region between an internal diameter 434 and an external diameter 432. For both pin receptacles 424, 426, mention can also be made of a contact surface, more precisely the contact surface 436, at which the pin receptacles 424, 426 end. A pin receptacle can also be referred to as a receptacle for a pin. A pin receptacle extension 438 is assigned to the contact surfaces, such as the contact surface 436, as a gap. A pin receptacle extension 438 is larger than the barrel bearing gap 368, which is defined by the outer barrel bearing rings, such as by the barrel bearing ring 370. The pin receptacle extension 438 spaces apart a pair of contact surfaces and is preferably larger than the external diameter 432. Pin receptacles, such as the pin receptacles 424, 426, are suitable for receiving a pin having a pin diameter that is only slightly smaller than the internal diameter 434, so that the pin can be received with as little play as possible in the opening having the internal diameter 434. A size of the external diameter 432 secures the pin receptacles 424, 226 against breaking free. The external diameter is preferably at least twice the internal diameter 434. All the pin receptacles 424, 426 may be of equal size.
Webs, such as the web 400I, form a splined connection between the contact surfaces, such as the contact surface 436, and the hole structure 344. The web 400I is tapered toward the first pin receptacle 424. The webs, such as the web 400I, stiffen the spectacles-type bearing bracket 330 in a manner that is efficient in terms of material and weight, in particular against torsion.
To continue the description of the multi-chamber system 200I according to
As can also be seen from
As a further interesting aspect, it can be mentioned with regard to a structural reinforcement of the web plate 352 that the plate-like oil guides 412, 414 projecting perpendicularly from the web plate 352 are a stabilizing structural element of the single-hole support structure 342 and thus of the spectacles-type bearing bracket. Other elements that form stabilizing structures are hole structure supports, such as the hole structure support 346I, webs, such as the first web 400, the second web 402, the third web 404, the fourth web 406, as well as a first web intersection 408 and a second web intersection 410. Web intersections, such as the first web intersection 408 and the second web intersection 410, are formed in each case of two or three intersecting webs. Stabilizing structural elements serve to dissipate forces, such as deformation forces or lever forces, which act on the hole structure 344 in an operating state of a transmission, to the pin receptacles, such as the first pin receptacle 424, the second pin receptacle 426, the third pin receptacle 428 or the fourth pin receptacle 430, in a manner that is spatially distributed as evenly as possible. The aforementioned forces or structural loads that occur during operation are transmitted to the case (see sub-case 331 in
The view shown in
It can also be said that the single-hole support structure 342 forms part of the floating bearing 380.
The pin receptacles, such as the first pin receptacle 424, of the spectacles-type bearing bracket 330 form a mounting frame 340 for the floating bearing 380. The mounting frame 340 can be attached to the pin holders, such as the pin holder 460, a first pin holder, by the pin receptacles, such as the pin receptacle 424. The third pin receptacle 428 is located diagonally opposite the first pin receptacle 424 on the spectacles-type bearing bracket 330 and is associated with a pin holder 460I which, depending on the manner of counting, can also be referred to as the third pin holder. The pin holders 460, 460I each have support surfaces 458, 458I. The contact surface 436 (see
The design possibilities shown in the individual figures can also be combined with each other in any form.
For instance, it is possible to make the partition walls 73, 73I longer or shorter and yet still leave one complete, contiguous oil space in the transmission case 31.
Of course, it is also possible for the transmission 1, which according to
The central axle 45, which is shown as hollow in
A person skilled in the art understands that the rear-axle drive variant of a motor vehicle 500 of a vehicle with front-axle drive, which is shown by way of example in
The invention can also be presented as follows. A transmission 1, for example for a duo electric machine powertrain, has a sump 160, into which at least a first gear 77 dips. Adjacent to a multi-chamber system 200, a gear stage 55 is formed by a first gear 77 and a second gear 49, 3550, 79. The second gear 49, 50, 79 performs the function of a centrifugal lubricating film separator gear for separating oil from the surface of the gear 49, 50, 79, by using a centrifugal force, and delivering said oil to the multi-chamber system 200. The multi-chamber system 200 acts as a flow path which continuously delivers a lubricant 162 and by way of which lubricant can enter the sump 160 through a delay means 180, 180I, 180II. Such a system can also be part of a spectacles-type bearing bracket. In the case of such a multi-chamber system 200, lubricant 162 that is splashed by the second gear 49, 50, 79 is received in one chamber 202, 204 of the multi-chamber system 200, is stored in a further chamber 204, 206, and is recirculated to the sump 160 only via a delay means 180, 180I, 180II.
| Number | Date | Country | Kind |
|---|---|---|---|
| 20 2019 103 770.9 | Jul 2019 | DE | national |
| 20 2019 103 771.7 | Jul 2019 | DE | national |
| 20 2019 103 778.4 | Jul 2019 | DE | national |
| 20 2019 103 779.2 | Jul 2019 | DE | national |
| 20 2019 103 781.4 | Jul 2019 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2020/069463 | 7/9/2020 | WO |
