Manual transmission and drive unit with such a manual transmission

Abstract

manual transmission (SG) for one vehicle (100) • a drive shaft (An) for connecting an electric machine (EM), • an output shaft (Ab), • a first switching element (A), a second switching element (B), a third switching element (C), • a first planetary set (PS1) with a first sun shaft (SO1), a first ring gear shaft (HR1) and a first bridge shaft (ST1), • a second planetary gear set (PS2) with a second sun gear shaft (SO2), a second ring gear shaft (HR2) and a second bridge shaft (ST2) and • a third planetary gear set (PS3) with a third sun gear shaft (SO3), a third ring gear shaft (HR3) and a third bridge shaft (ST3), • wherein the first solar shaft (SO1), the second solar shaft (SO2) and the drive shaft (An) are connected in a rotationally fixed manner, • wherein the first ring gear shaft (HR1) is connected to a stationary component (G) in a rotationally fixed manner, • wherein the first web shaft (ST1) and the second ring gear shaft (HR2) are connected in a rotationally fixed manner, • wherein the second bridge shaft (ST2) and the third sun shaft (SO3) are connected in a rotationally fixed manner, • wherein the third web shaft (ST3) and the output shaft (Ab) are connected in a rotationally fixed manner, • wherein in the closed state of the first switching element (A) a first gear with a first gear ratio is engaged, wherein in the first gear the third ring gear shaft (HR3) and a stationary component (G) are connected in a rotationally fixed manner, • wherein in the closed state of the second switching element (B) a second gear with a second gear ratio is engaged, wherein in the second gear the first web shaft (ST1), the second ring gear shaft (HR2), the third web shaft (ST3) and the output shaft (Ab) are connected in a rotationally fixed manner, • wherein in the closed state of the third switching element (C) a third gear with a third gear ratio is engaged, wherein in the third gear two of the three shafts (SO3, ST3, HR3) of the third planetary set (PS3) are connected to each other.

Description

[0001] The invention relates to a manual transmission for a vehicle. Furthermore, the invention relates to a drive unit with a single electric motor and a manual transmission with three planetary gear sets. The invention also relates to a vehicle with such a drive unit.

[0002] For example, US patent 4,702,125 A discloses a drive unit comprising an electric machine, a two-speed transmission, and a differential. The transmission has two shift elements designed as brakes and three interconnected planetary gear sets, wherein one of the two shift elements, in the closed state, non-rotatably connects the ring gear shaft of the first planetary gear set to the housing, and wherein the other of the two shift elements, in the closed state, non-rotatably connects the ring gear shaft of the second planetary gear set to the housing.

[0003] The object of the present invention is to provide an alternative transmission with three planetary gear sets for a vehicle. In particular, the transmission should have three gears, good efficiency, and low planetary gear speeds. This object is achieved by a transmission with the features of independent claim 1. Advantageous embodiments are the subject of the dependent claims, the following description, and the figures.

[0004] A transmission according to the invention for a vehicle comprises a drive shaft for connecting an electric machine, an output shaft, a first switching element, a second switching element, a third switching element, a first planetary gear set with a first sun shaft, a first ring gear shaft and a first carrier shaft, a second planetary gear set with a second sun shaft, a second ring gear shaft and a second carrier shaft and a third planetary gear set with a third sun shaft, a third ring gear shaft and a third carrier shaft, wherein the first sun shaft, the second sun shaft and the drive shaft are non-rotatably connected, wherein the first ring gear shaft is non-rotatably connected to a stationary component, wherein the first carrier shaft and the second ring gear shaft are non-rotatably connected, wherein the second carrier shaft and the third sun shaft are non-rotatably connected, wherein the third carrier shaft and the output shaft are non-rotatably connected.wherein in the closed state of the first switching element a first gear with a first ratio is engaged, wherein in the first gear the third ring gear shaft and a stationary component are rotationally fixed, wherein in the closed state of the second switching element a second gear with a second ratio is engaged, wherein in the second gear the first connecting shaft, the second ring gear shaft, the third connecting shaft and the output shaft are rotationally fixed, wherein in the closed state of the third switching element a third gear with a third ratio is engaged, wherein in the third gear two of the three shafts of the third planetary gear set are connected to each other.

[0005] By coupling two of the three shafts of the third planetary gear set when the third switching element is closed, the third planetary gear set is locked. This locking action ensures that the gear ratio is always 1, regardless of the number of teeth on the meshing elements of the third planetary gear set. In other words, the third planetary gear set rotates as a single unit. According to one embodiment, when the third switching element is closed, the third web shaft and the third ring gear shaft are rotationally fixed to each other. According to an alternative embodiment, when the third switching element is closed, the third web shaft and the third sun shaft are rotationally fixed to each other. The gear ratio of the third gear is then defined solely by the third planetary gear set.

[0006] The gearbox allows the electric motor to be connected to transmit drive power via the drive shaft. The gearbox is effectively connected to either a differential or a vehicle wheel via the output shaft. Each of the three planetary gear sets comprises three shafts: the respective sun gear shaft, the respective ring gear shaft, and the respective carrier shaft. Each carrier shaft carries several planet gears that mesh with the respective sun gear shaft and the respective ring gear shaft, i.e., they are in tooth mesh.

[0007] For the purposes of this invention, a "shaft" is understood to be a rotatable component of the transmission by which the respective components of the transmission are connected to one another in a rotationally fixed manner, or by which such a connection can be established when one of the switching elements is actuated. The shaft can connect the components axially or radially, or both axially and radially. The shaft can also serve as an intermediate piece by which a component is connected, for example, radially. The term "shaft" does not preclude the possibility that the components to be connected may be manufactured as a single piece. In particular, two or more shafts connected in a rotationally fixed manner can be manufactured as a single piece. A "stationary component" is understood to be a component that is fixed in a stationary position, in particular that is rotationally fixed or integrally connected to a housing or a part of a housing.

[0008] A "switching element" is understood to be a switchable device that, in a closed state, connects two shafts or a shaft and a housing in a rotationally fixed manner, and, in an open state, decouples the two shafts or the shaft and the housing from each other. The two shafts can then rotate relative to each other. The switching elements are designed as gear-shifting elements and are thus configured for shifting gears. To shift into first gear, the first switching element can be actuated or closed, whereby in first gear only the first switching element is closed and the other two switching elements are open. To shift into second gear, the second switching element can be actuated or closed, whereby in second gear only the second switching element is closed and the other two switching elements are open. To shift into third gear, the third switching element can be actuated or closed.lockable, whereby in the third gear only the third switching element is closed and the other two switching elements are open.

[0009] According to one embodiment, the first and third switching elements are combined to form a double switching element. According to an alternative embodiment, the second and third switching elements are combined to form a double switching element. A double switching element requires only a single actuator for switching. By using a double switching element, only two actuators, instead of three, are needed to switch three gears, thus increasing compactness. For example, either the first and third switching elements or the second and third switching elements are combined to form a switching unit with a single sliding sleeve that can be moved into the respective switching position by means of a single actuator, the switching unit having two gear positions and a neutral position.The shifting elements connect two shafts or a shaft and a housing in a gear position. In the neutral position, the shifting unit decouples the two shafts or the shaft and the housing. In particular, the sliding sleeve is designed to be positively engaged and features positively engaging claws that, in the respective gear position, interact positively with corresponding claw teeth to establish a rotationally fixed connection between two shafts or a shaft and the housing. Thus, the respective claw teeth with which the sliding sleeve positively engages can be understood as the shifting element. Preferably, the shifting unit comprises an unsynchronized claw clutch. Using the sliding sleeve to shift gears further increases the compactness of the design.

[0010] According to one embodiment, all three switching elements are designed as positive-locking switching elements, in particular as claw switching elements. Positive-locking switching elements increase the efficiency of the transmission due to reduced drag losses. In particular, positive-locking switching elements are more compact, efficiency-optimized, and offer a cost advantage over friction-locking switching elements. The positive-locking switching elements can be synchronized by the electric motor.

[0011] A drive unit according to the invention for a vehicle comprises an electric machine and a transmission according to the invention, wherein the electric machine is arranged either coaxially or parallel to the transmission. Preferably, the drive unit further comprises a differential with a differential input shaft for connecting the output shaft and two differential output shafts for connecting a respective vehicle wheel.

[0012] According to a preferred embodiment, the differential is designed as a bevel gear differential. A differential designed as a bevel gear differential has two wheel-side output elements, in particular a first output gear and a second output gear. The two output gears each mesh with a compensating element. The compensating elements are rotatably mounted in a differential housing about their own axis. The respective output gear is non-rotatably connected to the respective differential output shaft. The differential is driven via the differential housing, which is configured as the differential input shaft. Furthermore, alternative differential designs are also conceivable, for example, as a ball differential, a spur gear differential, or a planetary differential.The drive power fed into the differential via the differential input shaft is distributed to the two differential output shafts and transmitted to the drive wheels of the axle in a known manner. The differential output shafts are designed to be effectively connected to the vehicle's drive wheels. Each differential output shaft can be connected directly or indirectly via a downstream fixed gear ratio, a joint, a driveshaft, and / or a wheel hub to its corresponding vehicle wheel.

[0013] The transmission according to the invention is particularly suitable for an electric central drive that has a downstream differential reduction, in particular a bevel gear reduction. The preferred installation position of the drive unit is longitudinal to the direction of travel of the vehicle. Alternatively, the drive unit can be installed transversely to the direction of travel of the vehicle, in which case a downstream bevel gear reduction at the differential is omitted and the electric motor can be connected parallel to the axle via at least one spur gear reduction. For example, depending on the required gear ratio and the available installation space, one or more spur gear stages can be provided for this purpose.

[0014] A vehicle according to the invention comprises a drive unit according to the invention. The above definitions and descriptions of technical effects, advantages and advantageous embodiments of the transmission according to the invention also apply mutatis mutandis to the drive unit and the vehicle according to the invention.

[0015] Advantageous embodiments of the invention, which are explained below, are illustrated in the drawings, wherein identical or similar elements are designated with the same reference numeral. They show: Fig. 1 a highly abstracted schematic view of a vehicle with a drive axle which has a drive unit according to the invention; Fig. 2 a highly abstracted schematic view of a drive unit according to the invention with a gearbox according to a first embodiment; Fig. 3 a highly abstracted schematic view of a drive unit according to the invention with a gearbox according to a second embodiment; Fig. 4 a highly abstracted schematic view of a drive unit according to the invention with a gearbox according to a third embodiment and Fig. 5 a highly abstracted schematic view of a drive unit according to the invention with a gearbox according to a fourth embodiment.

[0016] Fig. Figure 1 shows a vehicle 100 with a first axle 101 having two wheels R1, R2 and a second axle 102 having two wheels R3, R4. In this case, the first axle 101 is configured as the rear drive axle of the vehicle 100 and is equipped with a drive unit according to the invention. The drive unit comprises an electric machine EM, which is configured to generate drive power, a multi-gear transmission SG, and a differential DG. Thus, the vehicle 100 is designed as an electric vehicle, i.e., an electrically driven vehicle. The drive unit is arranged transversely to the longitudinal direction of the vehicle and is effectively connected to the wheels R1, R2 of the first axle 101. Alternatively, the drive unit can be arranged longitudinally. Fig. 2 to Fig. Figure 5 shows a respective drive unit that can be installed in the vehicle in the longitudinal direction and Fig. Figure 5 shows a drive unit that can be installed transversely to the vehicle's longitudinal direction.

[0017] In this case, no additional drive unit is arranged on the second axle 102, i.e., the front axle of the vehicle 100, thus saving costs, weight, and installation space. Alternatively, the drive unit can be arranged on the front axle of the vehicle 100 instead of the rear axle. To implement an all-wheel drive system, another drive unit can be arranged on the second axle 102 and effectively connected to the vehicle wheels R3 and R4 of this axle 102.

[0018] Fig. Figure 2 shows a drive unit for a vehicle with a manual transmission SG according to a first embodiment. This embodiment is designed for installation in the vehicle longitudinally to the vehicle's direction of travel. The manual transmission SG is connected via a drive shaft An to an electric machine EM, which has a housing-mounted stator EMS and a rotatable rotor EMR. The electric machine EM is arranged coaxially with the manual transmission SG. Thus, the manual transmission SG and the electric machine EM form the electric drive unit.

[0019] The SG transmission has exactly three shift elements: a first shift element A, a second shift element B, and a third shift element C, and exactly three planetary gear sets: a first planetary gear set PS1, a second planetary gear set PS2, and a third planetary gear set PS3. The first planetary gear set PS1 comprises three shafts: a first sun gear shaft SO1, a first ring gear shaft HR1, and a first carrier shaft ST1. The first carrier shaft ST1 carries several planet gears that mesh with the first sun gear shaft SO1 and the first ring gear shaft HR1. The second planetary gear set PS2 also comprises three shafts: a second sun gear shaft SO2, a second ring gear shaft HR2, and a second carrier shaft ST2. The second carrier shaft ST2 carries several planet gears that mesh with the second sun gear shaft SO2 and the second ring gear shaft HR2.The third planetary gear set PS3 also comprises three shafts: a third sun gear shaft SO3, a third ring gear shaft HR3, and a third carrier shaft ST3. The third carrier shaft ST3 carries several planet gears that mesh with the third sun gear shaft SO3 and the third ring gear shaft HR3. Furthermore, the three planetary gear sets PS1, PS2, and PS3 are arranged axially adjacent to one another to increase compactness. The switching elements A, B, and C are located on one circumference of the planetary gear sets, specifically on one circumference of the third planetary gear set PS3. The second planetary gear set PS2 is arranged axially between the first and third planetary gear sets PS1 and PS3.

[0020] The first sun gear shaft SO1, the second sun gear shaft SO2, and the drive shaft An are non-rotatably connected to each other. The first ring gear shaft HR1 is non-rotatably connected to a stationary component designed as a housing G. The first web shaft ST1 and the second ring gear shaft HR2 are non-rotatably connected to each other. The second web shaft ST2 and the third sun gear shaft SO3 are non-rotatably connected to each other. Furthermore, the third web shaft ST3 and an output shaft Ab are non-rotatably connected to each other. The output shaft Ab can be indirectly, for example via a differential, or directly connected to at least one drive wheel of the vehicle, as indicated here by an arrow on the output shaft Ab. The transmission SG has a rotational axis of symmetry R, ​​which coincides with the drive shaft An and the output shaft Ab.The electric machine EM, as well as the three planetary gear sets PS1, PS2, and PS3, are arranged coaxially to the drive shaft An and the output shaft Ab. The embodiments described in . Fig. 2 to Fig. Figures 4 show only the “upper” half of the respective drive unit, with the “lower”, not shown half being symmetrical to the “upper” half.

[0021] All switching elements A, B, and C are designed as positive-locking switching elements. The first switching element A and the third switching element C are combined to form a double switching element and can be switched by a first actuator AK1. The second switching element B can be switched by a second actuator AK2. In the closed state of the first switching element A, a first gear with a first transmission ratio is engaged, whereby in the first gear the third ring gear shaft HR3 and a stationary component designed as a housing G are rotationally fixed.

[0022] When the second shift element B is closed, a second gear with a second gear ratio is engaged, in which the first connecting shaft ST1, the second ring gear shaft HR2, the third connecting shaft ST3, and the output shaft Ab are non-rotatably connected. When the third shift element C is closed, a third gear with a third gear ratio is engaged, in which two of the three shafts of the third planetary gear set are non-rotatably connected to each other, thus locking the third planetary gear set PS3 and giving it a gear ratio of 1. When the third shift element C is closed, the third connecting shaft ST3 and the third ring gear shaft HR3 are non-rotatably connected to each other. In this case, none of the three shift elements A, B, or C are engaged.

[0023] Fig. Figure 3 shows a second embodiment of the SG transmission according to the invention, which is connected to an electric machine EM via the drive shaft An. The resulting electric drive unit according to Fig. 3 essentially corresponds to the electric drive unit according to Fig. 2, the difference between these two embodiments being the design of the switching elements A, B, and C. In the present embodiment, the second switching element B and the third switching element C are combined to form a double switching element and can be switched by a first actuator AK1. The first switching element A can be switched by a second actuator AK2. Otherwise, the embodiment corresponds to the embodiment shown in the above. Fig. 3 according to the exemplary embodiment Fig. 2, which is referenced.

[0024] Fig. Figure 4 shows a third embodiment of the SG transmission according to the invention, which is connected to an electric machine EM via the drive shaft An. The resulting electric drive unit according to Fig. 4 essentially corresponds to the electric drive unit according to Fig. 3, the difference between these two embodiments being the arrangement and connection of the second and third switching elements B, C. In the present embodiment, the second switching element B and the third switching element C are also combined to form a double switching element, but are arranged axially between the second and third planetary sets PS2, PS3 at a smaller distance from the axis of rotation R. In the closed state of the third switching element C, the third web shaft ST3 and the third sun shaft SO3 are rotationally fixed to each other. This represents a locking variant of the third planetary set PS3. Otherwise, the embodiment corresponds to the above. Fig. 4 according to the exemplary embodiment Fig. 3, which is referenced.

[0025] Fig. Figure 5 shows a fourth embodiment of the SG transmission according to the invention, which is connected to an electric machine EM via the drive shaft An. The resulting electric drive unit according to Fig. 5 essentially corresponds to the electric drive unit according to Fig. 2, a difference between these two embodiments lies in the arrangement and connection of the electric machine EM. In the present embodiment, the electric machine EM is connected to the drive shaft An via a first and a second spur gear stage SR1, SR2. The first spur gear stage SR1 has a first and a second spur gear Z1, Z2, which mesh with each other, the first spur gear Z1 being non-rotatably connected to a rotor shaft of the electric machine EM. The second spur gear stage SR2 has a third and a fourth spur gear Z3, Z4, which mesh with each other, the third spur gear Z3 being non-rotatably connected to the second spur gear Z2 and the fourth spur gear Z4 being non-rotatably connected to the drive shaft An. Alternatively, the electric machine can be connected to the transmission SG via a single spur gear stage.

[0026] Furthermore, the drive unit comprises a differential DG with a differential input shaft D1 for connection to the output shaft Ab and two differential output shafts D2 and D3 for connection to a respective vehicle wheel. The differential DG is designed as a bevel gear differential. The differential input shaft D1 is non-rotatably connected to the output shaft Ab and the third web shaft ST3, which is non-rotatably connected to it. The bevel gear differential has two wheel-side output elements, specifically a first output gear and a second output gear. Each of the two output gears meshes with a compensating element. The compensating elements are rotatably mounted about their own axis in a differential housing designed as the differential input shaft D1. The respective output gear is non-rotatably connected to the respective differential output shaft D2 or D3. The differential DG is driven via the differential housing.Arrows on the differential output shafts D2 and D3 indicate a connection to a respective vehicle wheel on this axle.

[0027] This embodiment is designed for installation in the vehicle transversely to the vehicle's direction of travel. Otherwise, the embodiment corresponds to the following. Fig. 5 according to the exemplary embodiment Fig. 2, which is referenced. Reference sign 100 vehicles 101 first axis 102 second axis R1 vehicle wheel R2 vehicle wheel R3 vehicle wheel R4 vehicle wheel On drive shaft From the output shaft SG manual transmission EM electric machine EMS stator of the electric machine EMR Rotor of the electric machine SR1 first spur gear stage SR2 second spur gear stage Z1 first spur gear Z2 second spur gear Z3 third spur gear Z4 fourth spur gear PS1 first planetary set SO1 first solar wave HO1 first hollow gear shaft ST1 first bridge wave PS2 second planetary set SO2 second solar wave HO2 second hollow gear shaft ST2 second bridge shaft PS3 third planetary set SO3 third solar wave HO3 third hollow gear shaft ST3 third bridge wave AK1 first actuator AK2 second actuator G Housing R axis of symmetry DG Differential D1 Differential input shaft D2 first differential output shaft D3 second differential output shaft A first switching element B second switching element C third switching element

Claims

[1] Manual transmission (SG) for a vehicle (100) comprising • a drive shaft (An) for connecting an electric machine (EM), • an output shaft (Ab), • a first switching element (A), a second switching element (B), a third switching element (C), • a first planetary set (PS1) with a first sun shaft (SO1), a first ring gear shaft (HR1) and a first bridge shaft (ST1), • a second planetary gear set (PS2) with a second sun gear shaft (SO2), a second ring gear shaft (HR2) and a second bridge shaft (ST2) and • a third planetary gear set (PS3) with a third sun gear shaft (SO3), a third ring gear shaft (HR3) and a third bridge shaft (ST3), • wherein the first solar shaft (SO1), the second solar shaft (SO2) and the drive shaft (An) are connected in a rotationally fixed manner, • wherein the first ring gear shaft (HR1) is connected to a stationary component (G) in a rotationally fixed manner, • wherein the first web shaft (ST1) and the second ring gear shaft (HR2) are connected in a rotationally fixed manner, • wherein the second bridge shaft (ST2) and the third sun shaft (SO3) are connected in a rotationally fixed manner, • wherein the third web shaft (ST3) and the output shaft (Ab) are connected in a rotationally fixed manner, • wherein in the closed state of the first switching element (A) a first gear with a first gear ratio is engaged, wherein in the first gear the third ring gear shaft (HR3) and a stationary component (G) are connected in a rotationally fixed manner, • wherein in the closed state of the second switching element (B) a second gear with a second gear ratio is engaged, wherein in the second gear the first web shaft (ST1), the second ring gear shaft (HR2), the third web shaft (ST3) and the output shaft (Ab) are connected in a rotationally fixed manner, • wherein in the closed state of the third switching element (C) a third gear with a third gear ratio is engaged, wherein in the third gear two of the three shafts (SO3, ST3, HR3) of the third planetary set (PS3) are connected to each other. [2] Gearbox (SG) according to claim 1, wherein the first shifting element (A) and the third shifting element (C) are combined to form a double shifting element. [3] Gearbox (SG) according to claim 1, wherein the second shifting element (B) and the third shifting element (C) are combined to form a double shifting element. [4] Gearbox (SG) according to one of the preceding claims, wherein all switching elements (A, B, C) are designed as positive-locking switching elements. [5] Gearbox (SG) according to one of the preceding claims, wherein in the closed state of the third switching element (C) the third web shaft (ST3) and the third ring gear shaft (HR3) are connected to each other in a rotationally fixed manner. [6] Gearbox (SG) according to one of claims 1 to 4, wherein in the closed state of the third switching element (C) the third web shaft (ST3) and the third sun shaft (SO3) are connected to each other in a rotationally fixed manner. [7] Drive unit for a vehicle (100) comprising an electric machine (EM) and a manual transmission (SG) according to one of the preceding claims, wherein the electric machine (EM) is arranged coaxially to the manual transmission (SG). [8] Drive unit for a vehicle (100) comprising an electric machine (EM) and a manual transmission (SG) according to one of claims 1 to 6, wherein the electric machine (EM) is arranged parallel to the axis of the manual transmission (SG). [9] Drive unit according to claim 7 or 8, further comprising a differential (DG) with a differential input shaft (D1) for connecting the output shaft (Ab) and two differential output shafts (D2, D3) for connecting a respective vehicle wheel. [10] Vehicle (100) comprising at least one drive unit according to any one of claims 7 to 9.

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