The present invention relates to a multispeed transmission.
As the development of smaller engines with relatively low fuel consumption has progressed, there has been an ongoing demand for transmissions with an ever larger range of transmission ratios and a large number of speeds as well as as uniform as possible a distribution of the transmission ratios.
U.S. Pat. No. 7,749,126, U.S. Pat. No. 7,731,625 and U.S. Pat. No. 7,736,263 have disclosed multispeed transmissions, each of which employs a Simpson planetary gearset in order to obtain an 8- or 9-speed transmission overall. As is known, a Simpson planetary gearset of this kind has a common sun wheel for two annuluses as well as two planet carrier arrangements.
FIG. 14 shows a multispeed transmission of the type in question in accordance with the preamble of claim 1, which is also referred to as a 5R55E transmission. A multispeed transmission of this kind comprises an input element, an output element, a Simpson planetary gearset, which has a common sun wheel, two annuluses and two planet carrier arrangements, and an overdrive planetary gear, which has a sun wheel, a planet carrier arrangement and an annulus and is connected in series with the Simpson planetary gearset.
It is the object of the present invention to provide a multispeed transmission which allows a high degree of flexibility as regards the speeds or transmission ratios that can be selected and as regards variation of the spread.
This object is achieved in accordance with the features of independent patent claim 1.
The multispeed transmission is distinguished by the fact that it furthermore has an underdrive planetary gear, which has a sun wheel, a planet carrier arrangement and an annulus and is connected in series with the Simpson planetary gearset and the overdrive planetary gear.
In particular, the invention is based on the concept of interconnecting a Simpson planetary gearset, an overdrive planetary gear and an underdrive planetary gear in series in such a way that the underdrive planetary gear adds a larger range of transmission ratios to the Simpson planetary gearset. At the same time, two advantages are achieved in the multispeed transmission according to the invention by virtue of the overdrive planetary gear: on the one hand, it is possible - depending on the gear selection ultimately made - to operate the multispeed transmission in the economy ratio.
On the other hand, it is also possible for the transmission ratio of the overdrive planetary gear to be shifted between the transmission ratios of the underdrive planetary gear and the transmission ratios of the Simpson planetary gearset, thereby avoiding large steps or jumps in overall transmission ratios. Overall, the combination according to the invention of an underdrive planetary transmission with an overdrive planetary transmission provides a multispeed transmission which achieves a high degree of flexibility as regards the speeds or transmission ratios which can be selected while simultaneously achieving a large or smaller transmission spread.
Conventional prior art automatic transmissions fitted with planetary gears generally allow geometric transmission jumps. This means that the gear ratio spread in first gear is very high and decreases geometrically in higher gears. This has the disadvantage that there are considerable gaps in acceleration, prejudicing the dynamic response and fuel consumption of the vehicle. In this case, the engine/transmission system does not fully exploit the power characteristic of the engine. Owing to the possibility of connecting and disconnecting the overdrive planetary gear, these gear ratio jumps can be reduced in order to obtain uniform gear ratio jumps or uniform accelerations.
According to one embodiment, either the sun wheel or the annulus can be fixed in the underdrive planetary gear. This has the advantage that large or medium transmission spreads can be accomplished.
In this way, a total of 12 different transmission ratios can be achieved. By means of the underdrive planetary gear with either a wide or a medium spread or transmission ratio (depending on whether the sun wheel or the annulus is fixed), it is possible to increase or reduce the overall transmission spread accordingly as a multiplier in order in this way to be able to provide different transmission ratios using the Simpson and the overdrive planetary gearset. In the multispeed transmission according to the invention, the combination of the underdrive planetary gear and the Simpson planetary gearset forms a 6-speed transmission arrangement, wherein the additional series connection with the overdrive planetary gear makes it possible to achieve a multispeed transmission with (in theory) 12 forward gears and 2 reverse gears.
Of these theoretically selectable 12 gears, the multispeed transmission according to the invention makes it possible to select up to 10 actual gears and to provide an overall transmission spread with a value of between 6.0 and 10.0.
It is even possible, by means of appropriate transmission control, to operate the multispeed transmission according to the invention as a 6-speed version or, alternatively, as an 8-, 9- or 10-speed version, without modifying the multispeed transmission physically or performing hardware changes. This has the advantage that the shifting frequency can be correspondingly reduced, something that can be accomplished with a particular engine version or with a special diesel version if necessary.
The multispeed transmission according to the invention can be operated optionally as a 6-speed transmission, 7-speed transmission, 8-speed transmission, 9-speed transmission or 10-speed transmission by means of the transmission control system in a single transmission. On the one hand, this makes it possible to achieve optimum starting characteristics and, at the same time, to minimize the shifting frequency, depending on the driving situation.
The invention furthermore comprises the implementation of the multispeed transmission described above, both within a ‘north-south’ arrangement and in an ‘east-west’ arrangement for vehicles with front wheel drive. The ‘north-south’ arrangement is distinguished by the fact that the underdrive, overdrive and Simpson planetary gearset are arranged on one transmission axis. The ‘east-west’ arrangement or embodiment contains at least two transmission axes, which are arranged in parallel and with which either the overdrive, the underdrive or the Simpson planetary gear are arranged either on the upper transmission axis in series with the starting system or on one of the lower transmission axes in combination with the differential. The individual axes can be connected by means of a transfer gear, either in the form of a gearwheel set or a chain link.
Further embodiments of the invention can be found in the description and in the dependent claims.
The invention is explained below by means of preferred embodiments with reference to the attached drawing. In the drawing,
In the drawing:
a-c show schematic illustrations of the construction of a multispeed transmission according to the invention in a first embodiment, wherein an overdrive planetary gear is connected in series with an underdrive planetary gear and in series with a Simpson planetary gearset, more specifically in embodiments in which the sun wheel is fixed (
a-c show a schematic illustration of the construction of a multispeed transmission according to the invention in a second embodiment, wherein a Simpson planetary gearset is connected in series with an underdrive planetary gear and in series with an overdrive planetary gear, more specifically in embodiments in which the sun wheel is fixed (
a-c show a schematic illustration of the construction of a multispeed transmission according to the invention in a third embodiment, wherein an underdrive planetary gear (with a fixed sun wheel and optionally with a fixed annulus) is connected in series with a Simpson planetary gearset and in series with an overdrive planetary gear, more specifically in embodiments in which the sun wheel is fixed (
a-c show a schematic illustration of the construction of a multispeed transmission according to the invention in a fourth embodiment, wherein an underdrive planetary gear is connected in series with an overdrive planetary gear and in series with a Simpson planetary gearset, more specifically in embodiments in which the sun wheel is fixed (
a-c show a schematic illustration of the construction of a multispeed transmission according to the invention in a fifth embodiment, wherein an overdrive planetary gear is connected in series with a Simpson planetary gearset and in series with an underdrive planetary gear, more specifically in embodiments in which the sun wheel is fixed (
a-c show a schematic illustration of the construction of a multispeed transmission according to the invention in a sixth embodiment, wherein a Simpson planetary gearset is connected in series with an overdrive planetary gear and in series with an underdrive planetary gear, more specifically in embodiments in which the sun wheel is fixed (
a-b show truth tables for the multispeed transmission with (
a-c show a multispeed transmission according to the invention. On the input side, the multispeed transmission has an input element 5 connected in the drive train to the engine and, on the output side, has an output element 35 connected in the drive train to the final drive.
The multispeed transmission shown in
The multispeed transmission furthermore comprises an overdrive planetary gear 10, which has a sun wheel S1, a planet carrier arrangement P1 and an annulus R1. The overdrive planetary gear 10 is connected in series with the Simpson planetary gearset 30 and is arranged ahead of the Simpson planetary gearset 30 on the transmission path from the input element 5 to the output element 35.
The multispeed transmission furthermore comprises an underdrive planetary gear 20, which has a sun wheel S2, a planet carrier arrangement P2 and an annulus R2 and is connected in series with the Simpson planetary gearset 30 and the overdrive planetary gear 10.
Moreover, the multispeed transmission shown in
More specifically, in
Sun wheel S2 or annulus R2 can optionally be fixed in the underdrive planetary gear 20.
b shows the configuration with annulus R2 fixed. This configuration allows transmission ratios of the underdrive planetary gear 20 of less than 2, and allows transmission ratios and an overall spread of the overall multispeed transmission of up to 8.5.
c shows the analogous configuration with sun wheel S2 fixed. This configuration allows transmission ratios of the underdrive planetary gear 20 of more than 2, and allows transmission ratios and an overall spread of the overall multispeed transmission of up to 10.0.
a-c to 6a-c show different configurations of the multispeed transmission according to the invention, which differ from one another as regards the sequence of Simpson planetary gearset 30, overdrive planetary gear 10 and underdrive planetary gear 20.
Common to the embodiments in
Common to the embodiments in
The configuration shown in
According to
In another embodiment (
The configuration shown in
In another embodiment (
The configuration shown in
In another embodiment (
The configuration shown in
According to
In another embodiment, sun wheel S2 can be coupled selectively to annulus R3 by means of a second clutch C2.
The configuration shown in
In another embodiment, annulus R1 can be coupled selectively to annulus R2 by means of a second clutch C2 and is rigidly connected to the sun wheel.
All the embodiments in
In another possible use, it is possible to dispense with a torque converter, even in applications involving a large transmission spread, and optionally, as shown in
a-b show truth tables for the multispeed transmission with (cf.
b corresponds to a configuration in which the three one-way clutches OWC1-OWC3 are eliminated and clutches C1 and C2 are ‘drive’ clutches. This configuration is shown in
These value tables show the Simpson planetary gearset 30 and the associated clutches in a block, enabling a total of three speeds to be selected (1S-3S with application of B3, C3, C4 and B4). In the Simpson planetary gearset 30, reverse gear is furthermore achieved by the application of brake band B4 and clutch C3. Another block shows the underdrive planetary gear 20 with a total of 2 gear ratio steps 1A and 2A. In another block, the overdrive planetary gear 10 with two gear ratio steps+OD or—OD with the application of B1 is shown. In total, 12 gear ratio steps including 2 reverse gears are achieved through variation of the individual gear ratio steps of the overdrive planetary gear 10, of the underdrive planetary gear 20 and of the Simpson planetary gearset 30.
a-b show schematically the construction of a multispeed transmission according to the invention in another embodiment. This has two transmission axes, wherein an overdrive planetary gear 10 is connected in series with an underdrive planetary gear 20 on one of said transmission axes, wherein this arrangement is connected in series with a Simpson planetary gearset 30 on a second transmission axis via a transfer gear 40 (
a-b show schematically the construction of a multispeed transmission according to the invention in another embodiment. This likewise has two transmission axes, wherein a Simpson planetary gearset 30 is arranged on one of said transmission axes and is connected in series, via a transfer gear 40, with an arrangement situated on a second transmission axis and comprising an overdrive planetary gear 10 and an underdrive planetary gear 20 (
a-b show schematically the construction of a multispeed transmission according to the invention in another embodiment. This likewise has two transmission axes, wherein an underdrive planetary gear 20 is arranged on one of said transmission axes and is connected in series, via a transfer gear 40, with an arrangement situated on a second transmission axis and comprising an overdrive planetary gear 10 and a Simpson planetary gearset 30 (
a-b show schematically the construction of a multispeed transmission according to the invention in another embodiment. This likewise has two transmission axes, wherein an overdrive planetary gear 10 is arranged on one of said transmission axes and is connected in series, via a transfer gear 40, with an arrangement situated on a second transmission axis and comprising an underdrive planetary gear 20 and a Simpson planetary gearset 30 (
Number | Date | Country | Kind |
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10 2010 043 670.4 | Nov 2010 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP2011/069379 | 11/4/2011 | WO | 00 | 3/14/2013 |