Patent Application
20160001624
The invention relates to a compressor arrangement in accordance with the preamble of claim 1. The invention furthermore relates to a compressed air supply facility and a compressed air supply system and to a vehicle with such a compressed air supply facility.
Air supply facilities for air spring facilities or other applications in a vehicle are known. Such air supply facilities produce compressed air in order to feed it to an air spring facility, which is mentioned by way of example. The compressed air is produced by means of a compressor element, which is driven by an electric motor. A DC motor with brushes is generally used as an electric motor for this purpose. In the onboard electrical system of the vehicle, especially a motor car, this motor is supplied with electrical energy from a battery. Such batteries have an electrical voltage across the terminals in the range of from 9 to 15 V, for example. The voltage amplitude depends especially on the current loading of the battery and on its state of charge.
To operate the electric motor of a compressor, it can be connected electrically to the battery by means of a relay. The voltage of 9 V to 15 V, to remain with the example, is then applied to the motor and the motor is driven thereby. As the motor starts up, a very high starting current can occur, and this also leads to at least temporary voltage drop in the battery. The operation of other loads in the onboard electrical system, especially the starting up of other loads in the onboard electrical system, can likewise lower the battery voltage, and the switching off of such a load can raise the battery voltage again. Such fluctuating voltages in the battery lead to different currents, which, in turn, can lead to suboptimal operating conditions and, for example, increased brush wear in the electric motor. Moreover the result is different speeds of the electric motor and hence of the compressor element, which can lead to differences in the noise generated. In particular, it is difficult to match soundproofing to a predetermined noise frequency.
A brushless electric motor is known from CN201794753U, for example. In principle, an electrically commutated brushless motor is constructed as a DC motor having a power electronics unit (“BLDC motor”). The winding is generally mounted on the stator, not in the rotor (as in the DC motor with brushes); in the case of the BLDC motor, the mechanical commutator or brush system is replaced by an electronic commutator, namely a “BLDC control circuit” for controlling a drive of the motor. In general, permanent magnets are seated in the rotor for permanent excitation. A control circuit with the power electronics unit can switch the DC supply voltage to the motor windings. Most BLDC motors have three windings, which are arranged in a star shape. By means of pulse width modulation (PWM), the control circuit can change the average voltage to the motor, for example, in order to control the rotational speed. Hall-effect sensors, for example, which are embedded in the stator, can measure the angular position of the rotor. When the rotor magnet poles then pass the Hall-effect sensors, they emit a high or low signal, thereby indicating whether this is a north or a south pole. BLDC motors can also be commutated by monitoring the back EMF signals instead of using Hall-effect sensors. The motor is then started in an open circuit, and the control then switches to the sensing of the back EMF. However, there is generally a limitation to applications with a relatively constant torque and without dynamic requirements.
DE 10 2007 042 318 A1 describes a compressor arrangement mentioned at the outset having a compact dry piston compressor having at least one cylinder for compressing air of an associated piston, which can be moved using an electric motor by a crank mechanism consisting of a crankshaft and a connecting rod. For this purpose, the crank mechanism is accommodated in a first housing half of a housing, and the electric motor is accommodated within a second housing half of the housing. A rolling bearing common to the crank mechanism and to the electric motor is inserted in a dividing wall dividing the housing halves. The electric motor is embodied in the manner of a brushless DC motor, the stator of which consists of coil windings with an iron core and the rotor of which is equipped with permanent magnets. An electronic commutator of the electric motor is arranged on a circuit board accommodated in the second housing half. The electric motor, which is designed as an internal rotor motor, can have a rotor formed integrally with the crankshaft, which is rotatable within the stator. A compressor arrangement of this kind mentioned at the outset is capable of further improvements as regards control and structural design.
A pneumatic facility of the type stated at the outset is constructed, in particular, in the form of a pneumatic spring system of a vehicle, which is operated using a compressed air supply facility.
A compressed air supply facility is used in vehicles of all kinds, especially to supply an air spring facility of a vehicle with compressed air. Air spring facilities can also include leveling devices, by means of which the distance between the vehicle axle and the vehicle body can be adjusted. An air spring facility of a pneumatic system mentioned at the outset comprises a number of pneumatic bellows pneumatically connected to a common line (gallery), which can raise the vehicle body as the compressed air charge increases—also referred to as air admission—and can correspondingly lower the vehicle body as the compressed air charge decreases—also referred to as venting. In this case, there is generally a need for compressed air flows at pressures of up to 20 bar or above. With increasing distance between the vehicle axle and the vehicle body or ground clearance, the spring travels become longer and it is also possible to compensate for larger irregularities in the ground without contact with the vehicle body. Such systems are increasingly being used for preference in all-terrain vehicles and sport utility vehicles (SUV). In the case of very powerful engines, especially in SUVs, it is desirable to provide the vehicle with a relatively small ground clearance for high speeds on the road, on the one hand, and to provide it with a relatively large ground clearance for off-road use, on the other. It is furthermore desirable to implement a change in the ground clearance as quickly as possible, something that increases the demands as regards rapidity, flexibility and reliability of a compressed air supply facility, especially also that of a compressor arrangement. Nevertheless, this should involve as little wear as possible and be as robust and compact as possible and, in particular, should meet the installation space requirements in a vehicle.
In order to ensure long-term operation of the compressed air supply facility, a pneumatic main line of the compressed air supply facility has an air dryer, by means of which the compressed air can be dried. Accumulation of moisture in the pneumatic system is thereby avoided. At relatively low temperatures, moisture can lead to crystal formation, which damages valves, and can furthermore lead to unwanted effects in the compressed air supply facility and in the pneumatic facility. An air dryer has a desiccant, usually granules, through which the compressed air can flow, allowing the granules to remove moisture contained in the compressed air by adsorption. If appropriate, an air dryer can be designed as a regenerative air dryer. In this case, the dried compressed air from the pneumatic facility, in particular an air spring facility, is made to flow through the granules during each venting cycle, usually as a countercurrent but, depending on the design, possibly also as a co-current relative to the air admission direction. Regeneration of the air dryer is made possible essentially by a pressure change at the air dryer, wherein a pressure present during regeneration, as compared with that for adsorption, is as a rule lower in order to allow release of moisture from the granules. For this purpose, the vent valve arrangement can be opened, wherein the regenerability of the air dryer is generally dependent on the pressure conditions and the pressure change amplitude in the compressed air supply facility. For “pressure change adsorption” of this kind too, it has proven desirable to make a compressed air supply facility flexible and, at the same time, reliable. In particular, the aim is, on the one hand, to allow relatively quick venting, while a sufficiently high pressure change amplitude at a low air pressure—i.e. during regeneration—should nevertheless be available for regeneration of the air dryer.
It is desirable to adapt a compressed air supply facility to the requirements of a vehicle in a manner which is as advantageous as possible; this applies to a pneumatic, structural and/or electrical and/or electronic configuration thereof—in particular, it applies to a compressor arrangement for operating the compressed air supply facility.
This is the starting point for the invention, the object of which is to indicate an apparatus and a method by means of which compressed air can be made available in a better way; in particular, a structural and/or electrical and/or electronic configuration thereof should be improved. In particular, the intention is to indicate a compressor arrangement, a compressed air supply facility, preferably furthermore a compressed air supply system and a vehicle.
In particular, it is an object of the invention to indicate a compressor arrangement which is designed to be relatively compact, in particular both robust and relatively flexible, for operation of a compressed air supply facility. In particular, it is a further object to embody the apparatus in a simplified way and to design it for relatively reduced servicing and/or assembly outlay; the intention is likewise to sustainably improve a service life of the apparatus. In particular, it is yet another object of the invention to indicate an apparatus which can be operated in an improved manner, in particular in a relatively advantageously specified operating context, in terms of electrical, pneumatic and structural aspects. It is particularly advantageous that wow and flutter and noise pollution are advantageously reduced in an apparatus and, in particular, it should be possible to make synergistic use of electronic and electrical parameters of existing peripheral systems for open-loop and/or closed-loop control of an apparatus for producing compressed air.
Regarding the apparatus, the object is achieved by the invention by means of a compressor arrangement of the type stated at the outset in which, according to the invention, the features of the characterizing part of claim 1 are provided.
The compressor arrangement is designed for operating a compressed air supply facility of a vehicle and has a compressor having:
Regarding the method, the object is achieved by the invention by means of a method in claim 24. According to the invention, it is envisaged that the compressed air supply facility of a vehicle is operated using a compressor arrangement in which the electric motor is constructed in the form of an external rotor motor.
In the context of a particularly preferred development of the method, provision can be made for storing a measure of the energy storage capacity for a rotational energy of the rotor.
The concept of the invention leads to a compressed air supply facility according to claim 21, to a compressed air supply system according to claim 18, to a vehicle according to claim 22 and to a vehicle according to claim 23.
The compressed air supply facility having the compressor arrangement is preferably designed for operating a pneumatic facility, in particular an air spring facility of a vehicle, and has:
The pneumatic facility is preferably constructed in the form of an air spring facility, which has a gallery and at least one branch line connected pneumatically to the gallery and having a bellows and/or an accumulator and a directional control valve arranged ahead of the bellows and/or the accumulator.
The compressed air supply system having a pneumatic facility and having a compressed air supply facility is preferably designed for operating the pneumatic facility with a compressed air flow, in particular an air spring facility of a vehicle, preferably of a motor car, wherein the pneumatic main line pneumatically connects a compressed air feed from a compressor and a compressed air port leading to the pneumatic facility.
The vehicle, in particular motor car, is provided with a pneumatic facility, in particular an air spring facility, and a compressed air supply facility for operating the pneumatic facility with a compressed air flow.
In principle, the concept of the invention with the compressor arrangement configured in accordance with the invention can also be implemented for other applications in the vehicle sector, in particular in the motorcar and/or commercial vehicle sector; in particular, it is not restricted to a pneumatic facility in the form of an air spring facility. Thus, the compressor arrangement—with or without a compressed air supply facility for producing a compressed air flow and/or for preparing compressed air—can also preferably be used for other automotive pneumatic facilities. In principle, these include any type of compressor application in the vehicle sector, whether with a dynamic or static operating requirement profile, especially, for example, furthermore the use of the compressor arrangement according to the concept of the invention for an air-conditioning compressor application, in particular as part of an air-conditioning system in vehicles, for electrohydraulic compressor applications, in particular as part of a servo steering system or as part of a pump, in particular for an ABS/EBS hydraulic pump or a vacuum pump or the like.
The invention starts from the consideration that a compressor arrangement for operating a compressed air supply facility should provide a compressor in the form of a pneumatic compressor element which can be driven via a drive having an electric motor.
The invention furthermore starts from the consideration that an electronically commutated brushless motor—to this extent referred to as a brushless DC motor (BL-DC motor)—is advantageously suitable for constructing the compressor arrangement in a compact way and can nevertheless be configured in such a way that it can be operated sustainably and flexibly by means of the use in accordance with the invention of the electric motor in the form of an external rotor motor; this being the case, even given concepts with brush-fitted electric motors which are initially less expensive overall by way of comparison. The invention has recognized that such an electronically commutated, brushless electric motor can be embodied in a further improved way if the electric motor is constructed in the form of an external rotor motor. This provides the basis for enabling even dynamic requirements in the automotive sector to be met through the exploitation of an increase in the moment of inertia of the external rotor motor by means of the BLDC motor.
It is furthermore advantageously possible, by means of the structural design of the electric motor in the form of an external rotor motor, to achieve a considerable reduction in the installation space for the electric motor and hence for the compressor arrangement and also for the compressed air supply facility. In a first aspect, the invention has recognized that, in the context of the concept of the invention, an external rotor motor brings with it considerable advantages for the design, in particular the structural design, of the compressor arrangement.
Advantageous developments of the invention can be found in the dependent claims and, more specifically, indicate advantageous possibilities for implementing the concept explained above in the context of the object stated and in respect of further advantages.
The compressor element can be constructed as a single-cylinder compressor element. However, the compressor preferably has more than one cylinder; in particular, being constructed as a two-cylinder or multi-cylinder compressor element to form a two- or multi-stage compressor. In particular, it is possible for a stepped piston having two or more steps to be arranged in a two-cylinder or multi-cylinder arrangement of the compressor element to form the two- or multistage compressor. A stepped piston in a two-cylinder or multi-cylinder arrangement of the compressor element, in particular, proves capable of being configured in a space-saving, efficient and flexible way.
In particular, a whole series of advantages in terms of outlay when producing and servicing the compressor arrangement are obtained in respect of the first aspect, these advantages being based inter alia on one or more of the advantages, such as a reduction in the number of components, simplified assembly or the possibility of an integrated design or the elimination of separate parts. Thus, for example, it is found that, with the concept of the invention as a basis and with appropriate development of the concept, a balance weight, a housing cover, a separate crankshaft, a pressed composite part can be achieved or are possible in a technically reliable way and that this is not otherwise possible or not possible in the same advantageous way as with a development of the invention. In particular, it is possible, for example, for the electric motor to be accommodated in an advantageous way in a combined crankcase and/or motor housing in the form of an integrated drive housing.
Likewise, it is found that the magnetic properties of an external rotor motor can be used in an improved way to improve the performance of the electric motor. Moreover, mechanical loads on the electric motor can be achieved with an improved support bearing while eliminating the brushes. Overall, this leads to an increased service life of the motor.
An improved mode of operation of the motor is achievable simply by the fact that wow and flutter are fundamentally reduced in the case of an external rotor motor owing to an increased rotational moment of inertia; this has already taken into account a reduced susceptibility to wobbling operation with high current amplitudes. Irrespective of this, a rotor as an external rotor in an external rotor motor can be serviced, balanced and supported in an improved way.
In the context of a particularly preferred development, it is envisaged that the electric motor is connected for control to an electronic control circuit, which is designed to commutate the brushless motor electronically. The electric motor is preferably connected to an electronic commutator and at least one electronic relay and/or a DC-DC converter is provided in the power electronics unit, such that the power electronics unit has a DC voltage source as an input and an AC voltage source as an output.
A closed-loop control system, which can be implemented especially in the context of the control circuit, is based in the context of a particularly preferred development on the energy storage capacity of the rotor—according to the concept of the invention an external rotor, in particular a rotor bell or the like—and/or uses this to produce an improved “smooth” current profile. The storage capacity of the external-rotor-type rotor is obtained principally on the basis of its larger radius in comparison with its internal-rotor-type rotor and also given the possibility of increasing the mass at the outer radius of the external-rotor-type rotor. It is thereby advantageously possible to avoid reactive effects on the onboard electrical system when the electric motor is subject to high loads. It is possible, in particular, by means of closed-loop control, using the increased momentum of the external-rotor-type rotor in comparison with an internal-rotor-type rotor, to attenuate and/or reduce and/or delay load peaks in the onboard electrical system of the vehicle in an improved manner; in particular, it is thereby possible to avoid superposition of peak amplitudes in the case of a plurality of loads being used simultaneously. As a result, it is thereby possible to achieve a relief of the load on the onboard electrical system of the vehicle.
In a particularly advantageous way, it is envisaged that, in a particularly preferred first development, the electronic control circuit furthermore has: a first control module, which is designed to store a measure of an energy storage capacity for a rotational energy of the rotor, being designed, in particular, to monitor and or perform open-loop or closed-loop control of an angular speed of the rotor. Thus, it is advantageously possible, for example, to assist the storage of rotational energy in the external-rotor-type rotor during a startup in a first circumferential part of an angular motion (e.g. ¾ of a circumference during a starting angular motion (especially the acceleration phase)) and/or to assist the discharge of rotational energy by the external-rotor-type rotor during a rundown process in a second circumferential part of an angular motion (e.g. ¼ of a circumference during a rundown angular motion (especially the compression phase)). In the context of this particularly preferred development, it has been recognized, in particular, that monitoring of the angular speed is advantageous in order, first of all, to detect a wobbling mode of the electric motor and, to this extent, the prerequisites for avoiding a wobbling mode or for shutting it down as quickly as possible are created.
As a particularly preferred option, it is possible in the context of the abovementioned first development to implement a suitable speed significantly above the wobbling limit by means of the first control module. At the same time, a preferred prerequisite for the first development consists in an operating point of a BLDC motor, the definition of which is improved to the greatest possible extent. This can be achieved, in particular, by means of speed control. Provision is preferably made for the electronic control circuit to furthermore have: a second control module, which is designed to monitor a speed of the rotor, in particular to perform open-loop or closed-loop control of a speed of the rotor. In particular, the electric motor is connected to a speed controller, which is designed to set the operating voltage at the motor in an adjustable manner, preferably holding it constant or increasing it.
A particularly preferred second development has recognized that speed monitoring is at any event beneficial for securing the operating point. This advantageously results in the possibility of fault diagnosis (e.g. detection of a motor fault by way of matching or plausibility control of different parameters, e.g. from a motor current and speed measurement).
By means of a bandwidth, defined by control, of an angular speed and/or speed of the external-rotor-type rotor, it is advantageously possible to implement optimized matching of acoustics of the compressor arrangement to the vehicle. Thus, a “whisper mode” of the compressor arrangement can be implemented in the context of the electronic control circuit, for example; e.g. a “whisper mode” of the compressor arrangement with a reduced speed above the wobbling mode of the electric motor. For example, it has proven advantageous to keep the angular speed constant for a “whisper mode”. It is then possible, in addition or as an alternative, to permit a higher current ripple but lower wow and flutter. Use can also be made of these to make up for non-compensatable vibration transmission to the vehicle. “Anti-noise” control of the compressor arrangement can be introduced particularly in the context of this development by means of the electric motor in the context of the electronic control circuit but also, in addition or as an alternative, in conjunction with or via a central vehicle controller. These and other developments prove advantageous, in particular, in the case of an electric or hybrid vehicle, for example, in town traffic or when stationary for instance. These and other developments can also be supported by advantageous primary and secondary support for the electric motor and/or compressor, on the one hand, and of the compressor arrangement on the vehicle, on the other hand.
In particular, it has furthermore proven advantageous in the context of speed monitoring largely to eliminate but at least to reduce a dependence of the speed of the compressor, in particular first of all of the electric motor, on the voltage situation in the onboard electrical system. It can be advantageous to provide matching of the motor speed to an optimum functioning range of the overall assembly, e.g. in respect of the internal valves, piston speeds, bearings, allowance for motor-specific characteristic curves and parameters (speed; torque profile etc.). In particular, it has proven advantageous to achieve a minimization of the wear on the compressor by implementing a limitation of the speed by means of speed control if the piston speeds are too high, for example.
For this purpose, electric motor control and/or monitoring in real time can be provided for a BLDC motor.
For example, it has proven advantageous to read out the motor speed via an unenergized coil and to use this as a monitoring value and/or to use it as an ACTUAL value for speed control. A mechanical fault, e.g. the locking of the electric motor, can advantageously be detected.
By way of example, it has furthermore proven advantageous to provide evaluation of the current pulsation (e.g. peak-peak evaluation for speed analysis and/or averaging to determine power consumption).
In particular, it has proven advantageous to provide a control module which can determine the current crankshaft position. It is thereby advantageously possible to influence the starting and rundown behavior, especially, for instance, by means of determining the crankshaft position from a current peak at the top dead center position thereof. For example, the control module can maintain a high but defined torque (current) until a top dead center position of the electric motor has been reached or passed or until said motor is running normally; a shunt can advantageously be used for this purpose.
As regards the second aspect, it is found that control of the electric motor in the form of an external rotor motor is possible in a synergistic way and with synergistic use of existing peripheral systems in a pressure control mode. A third development has recognized that control can be used for electronic commutation of the brushless motor in a synergistic way in order to make available a pressure control mode. The particularly preferred development has recognized that an external rotor motor which is designed to be operated in a pressure control mode brings with it considerable advantages, in particular, for the electrical and/or electronic design of the compressor arrangement. A pressure control mode should be taken to mean, in particular, that the compressor is approved for appropriate pressure loads and/or a development of pressure in the compressor element is specifically monitored and controlled. In particular, it has proven advantageous, in the case of processes where time is not critical for example, to lower a pressure load by means of the electronic control circuit. For this purpose, slower accumulator or bellows filling by means of a reduced load speed can be provided where there is a lack of energy and a demand for air, for example. On the other hand, it is possible when required, especially in the case of processes where time is critical, to increase a pressure load in a controlled manner; for this purpose, it is possible, for example, to use possibilities for rapid lifting from compressor element by means of overspeed, e.g. a boost mode.
In a preferred fourth development, a fourth control module can be provided, which is designed to implement a gentle startup and/or rundown control operation, to limit a startup current and/or a rundown current of the electric motor (CSS), in particular to set the operating voltage at the motor in an adjustable manner, preferably holding it constant or reducing it. A complete armature winding can have three windings of three coils, which are connected, for example. At least one winding of the complete armature winding is preferably connected to an electric and/or electronic control circuit, with the result that a pressure control mode and/or gentle startup and/or adaptation to an onboard electrical voltage for the electric motor can be accomplished by means of voltage regulation. For example, it is possible to implement current limitation during starting and operation and/or minimization of the current peaks in the case of a “gentle startup” function, such as a slower speed increase for the electric motor. It is thereby possible, in particular, to prevent a load reversal shock on a shaft of the electric motor and/or compressor about the rotating axis due to a spontaneous increase in the back torque.
In particular, it is also possible to make provision for running down with the minimum possible power consumption (e.g. close to a bottom dead center position of the electric motor) to be used to relieve the load on an onboard electrical system by bringing about a reduction in a current flank associated with the minimum power consumption. For this purpose, a hard shutdown at minimum current can be used; the fourth control module can obtain a reference for each revolution.
In addition or as an alternative, it is advantageously possible to provide controlled, in particular electronic, braking of the motor at the shutdown torque. In particular, this can also be used to reduce a wobbling motion about the motor axis. This can be implemented effectively, especially owing to the higher mass of the external-rotor-type rotor.
In one embodiment, the armature winding is connected to the external control circuit and/or an onboard electrical system by means of an electronic relay and/or a DC-DC converter.
The electric motor is preferably connected to an electronic control circuit in terms of load and/or control. For this purpose, control current and/or load current can pass through the controller. The control circuit is preferably arranged on the outside of a housing of the compressor arrangement, preferably comprising at least one electronic relay and/or a DC-DC converter, and which has a first and/or second and/or third control module.
In the context of a particularly preferred development, it is envisaged that the electric motor is connected for control to an electronic control circuit, which is designed to electronically commutate the brushless motor. In this case, the electronic control circuit is furthermore designed to operate the electric motor in a pressure control mode.
It has proven particularly advantageous that the control circuit is accommodated as an internal control circuit in a housing of the compressor of the compressor arrangement. On the one hand, it is found that installation space for a power electronics unit and/or the control circuit can be created in the housing of the compressor; i.e., in particular, without significantly increasing the installation space requirement of the compressor. On the other hand, it is found that, in the case of a BLDC motor of the type in question, short cable lengths without twisting can be very much advantageous, e.g. in order to keep electromagnetic emissions as low as possible. Nevertheless, it is also possible to provide an external control circuit, i.e. outside the compressor, in particular outside the electric motor, i.e. outside a housing of the compressor and/or electric motor, in particular outside a combined compressor and motor housing, even in cases in which there is installation space available externally. For example, it is also advantageously possible for a control circuit to be provided as part of or in the vicinity of the ECU or some other central vehicle controller; synergistic effects can thereby be exploited.
In a particularly preferred development, the control circuit is connected to an electronic commutator. The control circuit furthermore preferably has a pressure control input and/or a connection to a speed controller. On this basis, the control circuit is, in particular, designed to set the operating voltage at the motor in an adjustable manner.
In particular, the control circuit is designed to hold the operating voltage at the motor constant or to increase it. At the same time, it has proven advantageous to further develop the control circuit, in particular the external control circuit, in the context of soft startup control. The control circuit preferably has a control module which is designed to implement soft startup control, limiting a starting current of the electric motor. In the context of the operating voltage that can be set in an adjustable manner, it can furthermore prove advantageous to hold this voltage constant or to lower it.
To set an operating voltage, the electric control circuit is advantageously designed to adapt an operating voltage, preferably in the form of an AC voltage source, to an onboard electrical system voltage—preferably alternately or optionally alternately or with the possibility of combination or simultaneously—in one or more of the voltage ranges, preferably a DC voltage, selected from the group of ranges comprising:
The electric and/or electronic control circuit can preferably have a control module, in particular at least one electronic relay and/or a DC-DC converter. In the context of a particularly preferred development, it has proven advantageous that an electric and/or electronic control circuit comprises:
The electric and/or electronic control circuit of the compressor arrangement preferably furthermore has:
As regards the structural design of the compressor arrangement, the construction of the electric motor in the form of an external rotor motor offers a particularly advantageous foundation for implementing advantages in terms of installation space and stability of running.
In particular, it is found that the compressor element can be driven by means of a drive formed by the electric motor and a crank mechanism, wherein the drive is accommodated in an integrated drive housing surrounding the crank mechanism and the electric motor. In particular, the integrated drive housing combines a motor housing and a crankcase and adjoins a piston housing.
It is advantageous if the electric motor has a stator, a rotor and a drive shaft coupled to the rotor, wherein the stator is held in the rotor in a manner separated by an air gap and is surrounded rotatably by the rotor, wherein the rotor is constructed with a rotor bell. In particular, it is envisaged that
The compressor element preferably has at least one connecting rod and/or at least one piston, which can be driven via a crankshaft, wherein the crankshaft is coupled to the drive shaft.
In principle, the permanent magnets can be formed in a comparatively simple and low-cost way on the basis of a ferrous material in the form of ferrite. Other materials, which can furthermore have weight advantages, are also suitable for advantageous magnetic design of the stator.
In particular, it has proven advantageous that the permanent magnets are formed on the basis of a ferrous material containing a cobalt compound, such as an aluminum-nickel-cobalt or samarium-cobalt-iron compound. In particular, the permanent magnets can also be formed on the basis of a ferrous material containing a bismuth compound, in particular a bismuth-manganese-iron compound (bismanol). It has proven advantageous in the context of a particularly preferred development that the permanent magnets are formed on the basis of a ferrous material containing a rare-earth compound, such as a neodymium compound, preferably a neodymium-iron-boron compound.
In the context of a particularly preferred development, a crankpin formed eccentrically with respect to the motor axis, which forms the crankshaft, adjoins the drive shaft on the motor output side. This can be implemented in a particularly compact way and offers the basis for further preferred design developments.
In particular, the crankpin can be attached to the drive shaft integrally or by means of an interference fit or similar frictional and/or positive connection. In addition or as an alternative, it is advantageously possible, at least in a connection part, for the rotor bell to be attached integrally or by means of an interference fit or a similar frictional and/or positive connection. In a first variant of this development, the rotor bell can be attached to the drive shaft. In a second variant, which is an alternative or can be used in combination, the rotor bell is attached to the crankpin. In this way, it is possible, in particular, to use the drive shaft, the crankpin and at least the connection part to form a crank mechanism component which is integral or formed by means of an interference fit or a similar frictional and/or positive connection.
It is found that a crank mechanism component of this kind can be supported in a particularly advantageous way, in particular in a stable manner and with advantages in terms of wow and flutter and/or noise generation. Nevertheless, the installation space for a bearing arrangement can be made relatively flexible, preferably according to requirements, and compact.
In a first particularly preferred variant of this development, the crank mechanism component can be supported by a bearing arrangement comprising a big end bearing and at least one axle bearing, in particular a big end bearing, preferably in the form of a rolling bearing, and a first and a second axle bearing. The bearing arrangement preferably has a big end bearing, a first axle bearing (A bearing) and a second axle bearing (B bearing). In particular a first axle bearing (A bearing) and/or a second axle bearing (B bearing) is formed by means of at least one rolling bearing or one needle bearing, in particular having at least one bearing sleeve.
In a second particularly preferred variant of this development, the crank mechanism component in combination with a counter bearing piece can be supported by a bearing arrangement comprising a big end bearing, an axle bearing and a counter axle bearing, in particular a big end bearing and precisely one first or one second axle bearing and the counter axle bearing. Thus, the bearing arrangement preferably has a big end bearing, preferably in the form of a rolling bearing, and a first axle bearing (A bearing) or a second axle bearing (B bearing) and a counter axle bearing.
In other words, it is possible in a preferred first modification for this for the bearing arrangement to comprise a big end bearing, precisely one axle bearing, namely the first axle bearing, and a counter axle bearing. In a preferred second modification, the bearing arrangement can comprise a big end bearing, precisely one axle bearing, namely the second axle bearing, and a counter axle bearing.
In particular, it is possible to obtain a balance weight by means of the rotor bell; by means of a compensating hole or similar removal of material, for instance, or by means of additional material applied on one side, for instance.
In addition or as an alternative, it is possible, in particular, to form the crank mechanism component or the counter bearing piece with a balance weight on the motor output side and eccentrically with respect to the motor axis.
In particular, it is possible in a first variant of this development for the balance weight to be formed between the big end bearing and the first axle bearing (A bearing) on the crank mechanism component, in particular integrally as part of a crankpin.
In particular, it is possible in a second variant of this development for the balance weight to be formed between the big end bearing and the counter axle bearing on the counter bearing piece, in particular integrally as part of a counter bearing piece.
In particular, the drive shaft can be supported in a first axle bearing, which is arranged directly adjacent to a big end bearing, in particular being supported only in the first axle bearing.
In particular, the rotor (
In particular to achieve relatively stable support, the first and/or second axle bearing can be arranged outside the rotor bell. In particular to achieve relatively space-saving support, the first and/or second axle bearing can be arranged inside the rotor bell.
The compressor element preferably has a connecting rod which can be driven by means of a crankshaft, wherein the crankshaft is coupled to the drive shaft and wherein the drive shaft has an extension formed eccentrically with respect to the axle shaft on the output side, said extension forming the crankshaft. The extension is preferably attached integrally.
In particular, it has proven advantageous that the drive shaft has a diameter of less than 20 mm, preferably less than 15 mm—and, in a particularly preferred embodiment, it has proven feasible to design the drive shaft with a diameter in a region of 12 mm or less. This is conducive overall to a compact design of the compressor arrangement and of the parts of the compressed air supply facility which are attached thereto.
This structural design of the compressor arrangement serves as a preferred basis for the support of the drive shaft and/or of the rotor in combination with the support of a connecting rod on the crankshaft.
In a first variant, which can be formed independently of other variants, it has proven advantageous that the drive shaft is supported in a first bearing (A bearing), which is accommodated in the electric motor, in particular in a housing of the electric motor. The drive shaft is preferably supported only in the first axle bearing. The latter option avoids static overdetermination and can be implemented in the context of a suitably designed rolling bearing and/or needle bearing. For this purpose, provision can be made, in particular, to provide a counterweight bearing and/or a counterweight on a rotating part, such as the drive shaft and/or the crankshaft.
In a particularly preferred second variant of a development, which can be implemented independently of other variants, it has proven advantageous that the rotor and/or the drive shaft is/are supported in a second axle bearing (B bearing); in particular, it can prove advantageous to support the rotor and/or the drive shaft only in the second axle bearing. The latter option once again avoids static overdetermination and, in particular, can be implemented advantageously using a counter bearing and/or counterweight on a rotating part, e.g. by means of a rolling bearing and/or needle bearing.
Both in the first and in the second variant, it has proven advantageous that a connecting rod is additionally supported on a big end bearing between the crankshaft and the connecting rod.
The possibility of supporting the rotor additionally or alternatively to the drive shaft proves advantageous, especially in the context of the design of the electric motor as an external rotor motor. With particular advantage, the rotor in one embodiment can be supported on the rotor bell additionally or alternatively to the drive shaft, e.g. in a rolling bearing. This increases the reliability of positioning of the rotating parts of the compressor arrangement.
Both the first axle bearing and the abovementioned second axle bearing can advantageously be provided in the electric motor, that is to say, in particular, in a housing of the electric motor, e.g. a housing closure of the electric motor or, alternatively, in the compressor element, in particular in a compressor housing, preferably in a compressor housing closure of the compressor element. It is found to be particularly advantageous to arrange the first and/or second bearing in a housing cap, for example in a housing cap on a housing closure of the electric motor or in a housing cap on a housing closure of the crankcase of the compressor element.
In the context of a preferred development, the first axle bearing (A bearing) can be arranged as an axle bearing on the motor output side, directly adjacent to a big end bearing; a big end bearing is intended to mean an axle bearing between the crankshaft and the connecting rod. In addition or as an alternative, the second axle bearing (B bearing) can be arranged directly adjacent to a housing closure. In particular, it is possible for this purpose for the second axle bearing to be designed as an axle bearing situated opposite the axle bearing on the motor output side.
At the same time, it has also proven advantageous, in a modification, for the first axle bearing (A bearing) to be arranged as an axle bearing on the motor output side, directly adjacent to a big end bearing, and for it to be arranged directly adjacent to a housing closure; the last-mentioned modification is described in a preferred embodiment in
Thus it is advantageous in general terms for the second axle bearing to be arranged adjacent to a motor housing closure, in particular as an axle bearing situated opposite the axle bearing on the motor output side, opposite an output side of the motor—this advantageously being implemented in the context of the embodiment in
The embodiment which is shown, in particular, in
Thus—in a manner similar to the embodiment in FIG. 7—the big end bearing can be arranged in general terms directly between the first and the second axle bearing. In addition or as an alternative, it is also possible, as illustrated in
A rolling bearing has proven to be a particularly preferred form of a bearing for the embodiment of the first and/or second bearing. Particularly in the case where the first and/or second axle bearing is/are supposed to be the only axle bearing for the drive shaft and/or the rotor, it has proven advantageous to embody the axle bearing as a bearing sleeve.
In a particularly preferred development, it is envisaged that the drive shaft is supported in a bearing sleeve, in particular in the form of a needle bearing in the electric motor. As a preferred possibility, only the bearing sleeve is provided, while a connecting rod is additionally supported on a big end bearing between the crankshaft and the connecting rod.
In the context of a particularly preferred development, to spend advantageous that the big end bearing and/or the first axle bearing and/or the second axle bearing have a balance weight. A balance weight is advantageously formed on the drive shaft on the motor output side and eccentrically with respect to the axle shaft, between the big end bearing and the first axle bearing. In addition or as an alternative, a balance weight can be formed on the drive shaft and/or the crankshaft on the motor output side and eccentrically with respect to the axle shaft, between the big end bearing and the second axle bearing.
The first axle bearing (A bearing) is preferably fixed on an intermediate wall of the drive housing as an axle bearing on the motor output side.
In addition or as an alternative, the second axle bearing (B bearing) can be fixed, as an axle bearing situated opposite an axle bearing on the motor output side, on a housing outer wall, associated with the electric motor, of the drive housing, in particular on a protrusion thereof, preferably a housing cap, in particular adjacent to an electric motor housing closure.
In addition or as an alternative, the counter axle bearing can be fixed, as an axle bearing situated on the motor output side, on another housing outer wall, associated with the crank mechanism, of the drive housing, in particular on a protrusion thereof, preferably a housing cover plate, in particular adjacent to a compressor-element housing closure.
In the context of another particularly preferred development, it has proven advantageous that the stator and/or the rotor are held by means of a cantilever, which has a curved cantilever arm section having an approximately V-shaped cross section. Fundamentally, the cantilever arm section extends transversely to the drive shaft. To hold the stator, the cantilever on the one hand preferably adjoins a motor housing closure and, on the other hand, adjoins the stator by means of a cantilever arm extending transversely to the axle shaft of the drive shaft.
In a first modification, a first cantilever arm section for the stator can start at the drive housing.
In addition or as an alternative, it is possible, in a second modification, for a second cantilever arm section for the rotor to start at the drive shaft and/or the crankpin.
In both cases, for example, the first and/or second cantilever arm section, in particular, can be held integrally or by means of an interference fit or a similar frictional and/or positive connection.
To form the cantilever on the rotor, it is advantageous if, at one end, said cantilever adjoins the rotor and, at the other end, adjoins the drive shaft in the form of a cantilever arm extending transversely to the axle shaft of the drive shaft. The cantilever arms adjoining the rotor and the stator are preferably arranged opposite one another on the housing closure side and the output side, in particular being spaced apart by the stator.
Illustrative embodiments of the invention are now described below with reference to the drawing. These are not necessarily intended to show the illustrative embodiments to scale; on the contrary, the drawing is embodied in a schematic and/or slightly distorted form, where helpful for explanatory purposes. In respect of additions to the teachings that can be identified directly from the drawing, attention is drawn to the relevant prior art. It should be taken into account here that many different modifications and changes as regards the form and detail of an embodiment can be made without departing from the general concept of the invention. The features of the invention which are disclosed in the description, in the drawing and in the claims may be essential either individually or in any combination for the development of the invention. Moreover, all combinations comprising at least two of the features disclosed in the description, the drawing and/or the claims may fall within the scope of the invention. The general concept of the invention is not restricted to the exact form or detail of the preferred embodiment shown and described below or restricted to subject matter which would be restricted in comparison with the subject matter claimed in the claims. Where dimensional ranges are given, the intention is also to disclose values lying within the limits mentioned as limiting values and that it should be possible to apply them in any desired manner and to claim them. For the sake of simplicity, the same reference signs are used below for identical or similar parts or parts with an identical or similar function.
Further advantages, features and details of the invention will emerge from the following description of the preferred illustrative embodiments and from the drawing, in which:
The control state of the 2/2-way valves 301 to 305 can be set by means of control current lines 300, which are connected to an onboard electrical system 100 of the compressed air supply system 1002 and which are actuated by means of a vehicle controller or signal lines 301 emanating from the vehicle controller 410. Similarly, said sensors 401 to 406 are actuated by means of the vehicle controller 410 (ECU) via signal lines 401 and are supplied with current via sensor lines 400.
Signals on the signal lines 301, 401 are also made available to a vehicle bus 420, here in the form of a CAN bus.
The operation of the compressed air supply facility 1000 is as follows. Via a relay control line 510 between the vehicle controller 410 (ECU) and a relay 520 for controlling the compressor 330, the compressor is actuated in order to produce compressed air; for this purpose, the relay 520 is supplied with power via the power lines 500 and in accordance with the onboard electrical system 100. The compressed air available to the compressed air feed 1 is fed to the compressed air port 2 in the pneumatic main line 210 via an air dryer 211 and a restrictor 212 and is then made available as well to the gallery 250 of the pneumatic facility 1001 via the further pneumatic line 240.
To vent the pneumatic facility 1001 and/or the compressed air supply facility 1000 or pneumatic components thereof, compressed air can be passed in the opposite direction from the compressed air port 2, via the restrictor 212, regenerating the air dryer 211 in the pneumatic main line 210; here, further venting is accomplished by diverting the compressed air to be vented into a vent line 220 at the compressed air feed 1.
For this purpose, a pilot controlled vent valve 322 is actuated by a control pressure in the pneumatic control line 240 when the control valve 321 opens the pneumatic control line 240 to the actuating plunger of the vent valve 322. For this purpose, the control valve 321 can be controlled via a vent valve control power line 310, i.e. the solenoid thereof can be energized and transfers the control valve 321 from the first control position to the second control position counter to the spring force of a symbolically indicated spring of the control valve 321.
It is self-evident that the compressed air supply system 1002 shown and described in
Independently of the abovementioned aspect, it is possible in accordance with the concept of the invention to operate different electric and/or electronic components, especially on the onboard electrical system 100, instead of or in addition to the relay 520, especially in the context of the modifications and changes; preferred embodiments of the invention are explained in relation to this aspect. In particular, there is the possibility of various variants of an onboard electrical system which are advantageous for operating the compressor 330, that is to say, in this case, an electric motor 332 for operating the compressor element 331.
In the context of a first variant of a particularly preferred embodiment,
In the design drawing of the compressed air supply facility 1000 in
For this purpose, the housing arrangement 1100 comprises a compressor-element housing 1101 for the compressor element 331 having a piston housing 1101A and a crankcase 1101B. Adjoining the crankcase 1101B of the compressor-element housing 1101 is a motor housing 1102 to form the electric motor 332. Adjoining the piston housing 1101A is a dryer and valve housing 1103 comprising the dryer housing 1103A—to form the air dryer 211—and the control housing 1103B comprising electrical and/or electronic and pneumatic interfaces together with a mechatronic system and an arrangement of valves—essentially to form the valve arrangement 320. Without explaining the design details specifically, it is readily apparent from
In the piston housing 1101A, a reciprocating piston 1301 is held on a connecting rod 1302 of a crank mechanism 1300. The connecting rod 1302 itself, which is designed as a piston rod, is supported on a crankshaft (designated below) via a big end bearing, which is here designated as an eccentric shaft 1304 or eccentric bearing 1303 of the crank mechanism 1300.
The drive 1400, formed with the electric motor 332, for the crank mechanism 1300 and the crank mechanism 1300 are substantially accommodated in the motor housing 1102 and the crankcase 1101B. To form the electric motor 332, the drive 1400 itself has a stator 1410 having a stator winding 1411 on an armature 1412 or similar yoke—in this case a laminated core. Moreover, the drive 1400 has a rotor 1420 having a rotor bell 1422 and an arrangement of permanent magnets 1421 mounted thereon. Here, the rotor bell 1422 comprises at least one rotor flange 41, a cantilever arm section 41.1 to form a cantilever dome and a rotor shell 42, in this case cylindrical, attached integrally thereto or in engagement therewith.
To form the motor 332 in the form of an external rotor motor for the drive 1400, the stator 1410 is held in the rotor 1420 while being separated by an air gap 1430 and is surrounded rotatably by the rotor 1420. Here, the rotor 1420 is held on an axle shaft 1305 and held so as to be rotatable therewith, while the stator 1410 is held by a supporting structure 1440. The rotatable axle shaft 1305 and crankshaft 1304 as well as the connecting rod 1302 form the essential power-transmitting elements of the crank mechanism 1300 driven by the drive 1400, wherein these elements are held in a bearing assembly 1500. The bearing assembly 1500 comprises an A bearing 1501, a B bearing 1502 and an eccentric bearing 1303 for the performance of a rotary motion by the axle shaft 1305 or crankshaft 1304 and a reciprocating motion of the connecting rod 1302. In this connection, the parts of the crank mechanism 1300, of the bearing assembly 1500 and of the holder 1440 or the rotor 1420 and of the drive housing 30—i.e. the motor housing 1102 and the crankcase 1101B—are explained below in detail using the reference signs, which also apply to the following
The axle shaft 1305, which is embodied as a drive shaft 10, is arranged in a manner centered with respect to a motor axis MA and held rotatably in the stator 1410, namely by means of the rolling bearings 1502, 1501 designated above, which are here referred to as axle bearings 51, 52 of the bearing arrangement 50. More specifically, the drive shaft 10 is held directly in a rotating manner in the second axle bearing 52 (B bearing) on a tapered journal 11 on the housing closure side and, at its untapered and, if appropriate, thickened second end 12 carries a crankpin 20 for the formation of the crankshaft 1304. In the present case, this crankpin 20 is fixed frictionally and/or positively by means of an interference fit on the drive shaft 10 and is rotatable with the drive shaft 10. The crankpin 20, in turn, is held directly in a rotatable manner in the first axle bearing 51 (A bearing), with the result that the drive shaft 10 is supported indirectly in the first axle bearing 51 via the crankpin 20. The first axle bearing 51 and the second axle bearing 52 are furthermore in practice arranged within the motor housing 1102, wherein the first axle bearing 51 is held in a centered manner in a first housing wall 31, which adjoins the crankcase 1101B or is formed as part thereof, and the second axle bearing 52 is held in a centered manner in a housing outer wall 32 of the motor housing 1102, said wall being situated opposite the output side. In the present case, the housing outer wall 32 is in the form of a closure cap for the motor housing toward the outside of the motor housing. In the present case, the first housing wall 131 is formed as part of the crankcase 1101B, wherein a housing part 33 in the form of an annular cylinder is connected to the first housing wall 31, onto which or into which part the abovementioned housing cap is placed. Via the crankcase 1101B there is in turn access to the crank mechanism 1300, namely via the housing cover plate 34 mounted on the output side in the crankcase 1101B, approximately as an extension of the motor axis MA. Inserted between the closure cap 32 and the cylindrical motor housing part 33 and between the latter and the first housing wall 31 and between the housing cover plate 34 and the remaining part of the crankcase 1101B there is in each case a seal, in particular in the form of a ring seal or lip-type ring seal 61, 62, 63, with the result that the motor housing 1102 and the crankcase 1101B—here referred to as drive housing 30—are closed off in an airtight and liquid-tight manner by the seal arrangement 60 comprising the abovementioned seals 61, 62, 63.
In the present case, the first and the second axle bearing 51, 52 are fixed centrally with respect to the motor axis MA in cylindrical protrusions 31.1 and 32.1 on the first and second housing walls 31, 32, into which the axle bearings 51, 52 are inserted. Taking into account also the seals 61, 62 as damping elements, the first and the second housing wall 31, 32 thus advantageously serve to hold the drive shaft 10 in a manner centered by means of the first and second axle bearings 51, 52 and with a certain vibration damping.
Moreover, adjacent to the crankpin 20 mounted on the first end 11, the drive shaft 10 carries a rotor flange 41 of approximately V-shaped cross section, on which a cantilever arm section 41.1 in the form of a cantilever dome is formed to form an approximately V-shaped cantilever, said section being cylindrical and extending approximately transversely to a motor axis MA of the drive shaft in cross section. A cylindrical body, a rotor shell 42, which is cylindrical and can be seen as a first and a second limb parallel to the motor axis MA in cross section, is, in turn, connected to the cantilever arm section 41.1 to form the rotor bell 1422 designated above, on which, in turn, the arrangement of permanent magnets 1421 is mounted. In the present case, the rotor flange 41 is mounted by means of an interference fit on the first end 11 of the drive shaft 10, like the crankpin flange 21 of the crankpin 20. In a modification, the connections designated here as flanges 21, 41 with an interference fit can also be embodied as an integral connection to the drive shaft 10—in other words, the drive shaft 10 can be formed integrally with the flanges 21, 41 and, if appropriate, the adjoining cantilever arm section 41.1 and, if appropriate, the rotor shell 42 and/or crankpin 20.
The crankpin 20 furthermore has a crankpin base 22, which is centered eccentrically on an eccentric axis EA, and a balance weight 23, which is situated opposite said base in relation to the motor axis MA, with the result that the unbalance of the crankpin base 22 and of the balance weight 23 balance each other out approximately during rotary actuation of the crankpin 20—this also approximately takes into account the weight of a screw 29 in crankpin stub 22, said screw holding a big end bearing 53 of the bearing arrangement 50 on the crankpin stub 22 when tightened, exerting pressure on a washer 28. The above-designated connecting rod 1302 is supported on the big end bearing 53 on a bearing opening of a lug or the like, said bearing opening being designated there by 1303. The bearing arrangement 50 of the first and the second axle bearing 51, 52 and of the big end bearing 53 first of all provides for the alignment of the first axle bearing 51 and of the big end bearing 53 on the crankpin 20—the first axle bearing 51 on the crankpin flange 21 and the big end bearing 53 on the crankpin stud 22—in such a way that they are arranged directly adjacent to one another; these being associated with the first end 11 of the drive shaft 10 on the output side of the motor 40. The bearings being the second axle bearing 52 (B bearing) is associated with the second end 12 of the drive shaft 10, the end situated opposite the output side. In the present case, both the first and the second axle bearing 51, 52 are arranged outside the stator 1410 and also outside the rotor 1420 of the drive 1400 and therefore are situated, in particular, outside the extent of the rotor shell 42—as seen relative to an extent of the motor axis MA. This has advantages, in particular, as regards the stability of support for the drive shaft 10 since said drive shaft is in practice supported at its end points, namely at the outermost end of the first end 11 of the drive shaft 10 and at the outermost end of the second end 12 of the drive shaft 10. Moreover, wow and flutter during the rotary actuation of the drive shaft 10 and the crankpin 20 are kept relatively small owing to a close proximity of the first axle bearing 51 and big end bearing 53 and of the mutually opposite moments of weight of the balance weight 23 and of the crankpin stud 22.
It is a relatively simple matter to install the first axle bearing 51 and the big end bearing 53 with the components adjoining them by means of access via a housing cover plate 34 in the crankcase 1101B. It is a relatively simple matter to install the second axle bearing 52 by removing the housing cap 32 on the motor-side cylindrical part 33 of the drive housing 30. In the present case, the cantilever arm support holder 32.2, designated above as supporting structure 1440 also adjoins the abovementioned housing cap 32. The cantilever arm support holder 32.2 for supporting the stator 1410 is formed concentrically around the cylindrical protrusion 32.1 on the housing cap 32 and fits over said protrusion in the direction of the motor axis MA while leaving an air gap 1450 between the drive shaft 10 and the cantilever arm structure 1440.
The housing cover toward the outside of the motor housing 1102 is thus constructed in the form of a bearing shield in order, on the one hand, to serve as a bearing receptacle for the second axle bearing 52 and, on the other hand, for the mounting of the cantilever arm structure 1440.
In a modification of the first variant, the second axle bearing 52 can be brought closer to the stator 1410, in particular can be accommodated in the yoke 1412 or laminated core and the winding 1411, i.e. in the installation space for these (e.g. as shown schematically in
In all the abovementioned cases, the preferred variant shown in
Overall, significantly improved efficiency of the compressor 330, especially of the electric motor 332, is obtained. The overall efficiency of the compressed air supply facility 1000 is thereby improved to a considerable degree. Also contributing to this is a significantly improved power to weight ratio with a considerably reduced installation space volume. Increases in power of up to five times that of previous brush-fitted motors at the rated voltage are possible. Eliminating the wear of the carbon as compared with the brush-fitted motor results in a significantly extended life for the brushless motor, and this is achieved without the risk of contamination of the compressor 330 and of the dryer 211 due to brush abrasion.
By means of a control circuit, to be found in the developed versions, in the mechatronic part of the compressed air supply facility 1000 or, alternatively, externally with respect thereto—in particular an electronic control circuit for electronic commutation of the brushless motor and/or speed adjustment in the pressure control mode and/or for implementing a soft startup control regime and/or for adapting an onboard electrical voltage—it is possible to perform the control of the motor synergistically; i.e. at neutral cost with multiple functions. In this way, for example, it is possible, by means of the electric motor 332, to intensify specified speed changes of up to 100 rpm over the charging process. In this case, such a speed can be set independently of a supply voltage of the onboard electrical system. Overall, very good smoothness of running is obtained, even at relatively low speeds. In all cases, the starting behavior can be influenced in an effective manner by means of suitable controllers.
Moreover, the embodiment shown in
In this connection,
This time, however, the holder for the stator 1410 is associated with the output-side part of the motor 40, while the mounting of the rotor flange 41 is initially adjacent to the outward-facing housing closure 32. Thus, the axial arrangement of the stator 1410 and of the rotor 1420 is mirror-symmetrical about a perpendicular to the motor axis MA. The rotor flange 41 and the crankpin flange 21 are now spaced apart by the stator 1410. The rotor flange 41 is mounted directly adjacent to the second axle bearing 52 on a thickened part 13 of the drive shaft 10, which directly adjoins the tapered end part 12 of the drive shaft. The open side of the rotor shell 42 faces in the direction of the output side of the motor 40, while the cantilever arm dome 41.1 of the rotor 1420 approximately follows the curvature of the housing closure 32. Improved shielding of the motor parts from the outside environment is thereby achieved in addition to the housing cap 32. In contrast to the first variant in
In the modification of the embodiment in
Moreover, the modification in
In order to pursue this principle consistently further, the modification in
In summary, the embodiments in
With reference to
Owing to the elimination of the requirement for a first, second axle bearing 51, 52 or further axle bearings, such as an abovementioned counter axle bearing 54, said requirement taking up installation space, the modification in
Overall, the following advantages are obtained from the embodiments described above:
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2013 003 513.9 | Mar 2013 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2014/000441 | 2/18/2014 | WO | 00 |
