Manual transmission and drive unit with such a manual transmission

Abstract

The invention relates to a manual transmission (SG) for a vehicle (100) comprising an input shaft (An), an output shaft (Ab), three shifting elements (A, B, C) and three planetary gear sets (PS1, PS2, PS3) with a respective sun gear shaft, a respective ring gear shaft and a respective planetary gear shaft, wherein the first sun gear shaft (SO1), the second sun gear shaft (SO2) and the input shaft (An) are connected in a rotationally fixed manner, wherein the first ring gear shaft (HR1) is connected in a rotationally fixed manner to a stationary component, wherein the first planetary gear shaft (ST1) and the second ring gear shaft (HR2) are connected in a rotationally fixed manner, wherein the second planetary gear shaft (ST2) and the third sun gear shaft (SO3) are connected in a rotationally fixed manner, wherein the third planetary gear shaft (ST3) and the output shaft (Ab) are connected in a rotationally fixed manner, wherein in the closed state of the first shifting element (A), the third ring gear shaft (HR3) and a stationary component are connected in a rotationally fixed manner, wherein in the closed state of the second shifting element (B) the first web wave (ST1),The second ring gear shaft (HR2), the third carrier shaft (ST3), and the output shaft (Ab) are connected in a rotationally fixed manner, wherein, when the third shift element (C) is engaged, two of the three shafts of the third planetary gear set are connected to one another. Furthermore, the invention relates to a drive unit for a vehicle, comprising an electric machine (EM) and such a manual transmission (SG), wherein the electric machine is arranged coaxially or axially parallel to the manual transmission.

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 4,702,125 A discloses a drive unit with an electric motor, a manual transmission with two gears and a differential. The manual transmission has two shifting elements designed as brakes and three interconnected planetary gear sets. One of the two shifting elements, when closed, connects the ring gear shaft of the first planetary gear set to the housing in a rotationally fixed manner, while the other of the two shifting elements, when closed, connects the ring gear shaft of the second planetary gear set to the housing in a rotationally fixed manner.

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

[0004] A manual transmission according to the invention for a vehicle comprises an input shaft for connecting an electric machine, an output shaft, a first shifting element, a second shifting element, a third shifting element, a first planetary gear set with a first sun gear shaft, a first ring gear shaft, and a first carrier shaft, a second planetary gear set with a second sun gear shaft, a second ring gear shaft, and a second carrier shaft, and a third planetary gear set with a third sun gear shaft, a third ring gear shaft, and a third carrier shaft, wherein the first sun gear shaft, the second sun gear shaft, and the input shaft are connected in a rotationally fixed manner, wherein the first ring gear shaft is connected in a rotationally fixed manner to a stationary component, wherein the first carrier shaft and the second ring gear shaft are connected in a rotationally fixed manner, wherein the second carrier shaft and the third sun gear shaft are connected in a rotationally fixed manner, wherein the third carrier shaft and the output shaft are connected in a rotationally fixed manner,wherein, in the closed state of the first shifting element, a first gear is engaged with a first gear ratio, wherein, in the first gear, the third ring gear shaft and a stationary component are connected in a rotationally fixed manner, wherein, in the closed state of the second shifting element, a second gear is engaged with a second gear ratio, wherein, in the second gear, the first carrier shaft, the second ring gear shaft, the third carrier shaft and the output shaft are connected in a rotationally fixed manner, wherein, in the closed state of the third shifting element, a third gear is engaged with a third gear ratio, wherein, in the third gear, two of the three shafts of the third planetary gear set are connected to one another.

[0005] By coupling two of the three shafts of the third planetary gear set when the third shifting element is engaged, the third planetary gear set is locked. By locking the third planetary gear set, the gear ratio is always 1, regardless of the number of teeth of the meshing elements of the third planetary gear set. In other words, the third planetary gear set rotates as a block. According to one embodiment, when the third shifting element is engaged, the third carrier shaft and the third ring gear shaft are connected to one another in a rotationally fixed manner. According to an alternative embodiment, when the third shifting element is engaged, the third carrier shaft and the third sun gear shaft are connected to one another in a rotationally fixed manner. The gear ratio of the third gear is defined solely by the third planetary gear set.

[0006] The manual transmission connects the electric motor to the input shaft to generate drive power. The manual transmission is 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 planetary gear shaft. Each planetary gear shaft carries several planetary gears that mesh with the respective sun gear shaft and the respective ring gear shaft.

[0007] For the purposes of the invention, a “shaft” is understood to be a rotatable component of the transmission via which associated components of the transmission are connected to one another in a rotationally fixed manner or via which such a connection can be established upon actuation of one of the shift elements. The respective shaft can connect the components axially or radially, or even both axially and radially. For example, the respective shaft can also be in the form of an intermediate piece via which a respective component is connected radially, for example. The term “shaft” does not exclude the possibility that the components to be connected can be designed as a single piece. In particular, two or more shafts connected to one another in a rotationally fixed manner can be designed as a single piece. A “stationary component” is understood to be a component that is fixed in a stationary manner, in particular is connected to a housing or part of a housing in a rotationally fixed manner or as a single piece.

[0008] A “shifting element” is a switchable device which, when closed, connects two shafts or a shaft and a housing in a rotationally fixed manner and, when open, decouples the two shafts or the shaft and the housing from one another. Two shafts can then rotate relative to one another. The shifting elements are designed as gear shifting elements and are therefore set up to shift gears. To shift first gear, the first shifting element can be actuated or closed, whereby in first gear only the first shifting element is closed and the other two shifting elements are open. To shift second gear, the second shifting element can be actuated or closed, whereby in second gear only the second shifting element is closed and the other two shifting elements are open. To shift third gear, the third shifting element can be actuated or closed.lockable, whereby in third gear only the third switching element is closed and the other two switching elements are open.

[0009] According to one embodiment, the first shifting element and the third shifting element are combined to form a double shifting element. According to an alternative embodiment, the second shifting element and the third shifting element are combined to form a double shifting element. A double shifting element requires only a single actuator for shifting. By using a double shifting element, only two, instead of three, actuators are required to shift three gears, thereby increasing compactness. For example, either the first shifting element and the third shifting element or the second shifting element and the third shifting element are designed to form a shifting unit with a single sliding sleeve that can be moved into the respective shift position by means of a single actuator, wherein the shifting unit has two gear positions and a neutral position.In a gear position, the shift elements connect two shafts or a shaft and a housing. In the neutral position, two shafts or the shaft and the housing are decoupled from one another via the shift unit. In particular, the sliding sleeve is designed to be form-fitting and has form-fitting claws that interact positively with a corresponding claw toothing in the respective gear position to establish a rotationally fixed connection between two shafts or a shaft and the housing. Therefore, the respective claw toothing with which the sliding sleeve interacts positively is to be understood as a shift element. The shift unit preferably comprises an unsynchronized claw clutch. The use of the sliding sleeve for shifting gears further increases compactness.

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

[0011] A drive unit for a vehicle according to the invention comprises an electric motor and a manual transmission according to the invention, wherein the electric motor is arranged either coaxially or axially parallel to the manual 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 gear-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 mounted in a differential carrier so they can rotate about their own axis. The respective output gear is connected in a rotationally fixed manner to the respective differential output shaft. The differential is driven via the differential carrier, which is configured as the differential input shaft. Furthermore, alternative designs of the differential are also conceivable, for example, as a ball differential, spur gear differential, or planetary differential.The drive power fed into the differential via the differential input shaft is distributed in a conventional manner between the two differential output shafts and transmitted to the drive wheels of the axle. The differential output shafts are designed to be connected to the vehicle's drive wheels in a drivingly effective manner. The respective differential output shaft can be connected to the corresponding vehicle wheel directly or indirectly via a downstream fixed gear, a joint, a propeller shaft, and / or a wheel hub.

[0013] The manual transmission according to the invention is particularly suitable for an electric central drive that has a downstream differential gear, in particular a bevel gear. 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 on the differential is eliminated and the electric motor can be connected axially parallel via at least one spur gear. For example, one or more spur gear stages can be provided for this purpose, depending on the required gear ratio and the installation space available.

[0014] A vehicle according to the invention comprises a drive unit according to the invention. The above definitions as well as explanations regarding technical effects, advantages, and advantageous embodiments of the manual transmission according to the invention also apply mutatis mutandis to the drive unit according to the invention 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 provided with the same reference numerals. They show: Fig. 1 is a highly abstracted schematic view of a vehicle with a drive axle having a drive unit according to the invention; Fig. 2 a highly abstracted schematic view of a drive unit according to the invention with a manual transmission according to a first embodiment; Fig. 3 a highly abstracted schematic view of a drive unit according to the invention with a manual transmission according to a second embodiment; Fig. 4 a highly abstracted schematic view of a drive unit according to the invention with a manual transmission according to a third embodiment and Fig. 5 a highly abstracted schematic view of a drive unit according to the invention with a manual transmission according to a fourth embodiment.

[0016] Fig. 1 shows a vehicle 100 with a first axle 101 with two vehicle wheels R1, R2 and a second axle 102 with two vehicle wheels R3, R4. In the present case, the first axle 101 is designed 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 manual transmission SG with several gears, and a differential DG. Thus, the vehicle 100 is designed as an electric vehicle, i.e., as an electrically driven vehicle. The drive unit is arranged transversely to the vehicle's longitudinal direction and is drivingly connected to the vehicle wheels R1, R2 of the first axle 101. Alternatively, the drive unit can be arranged in the vehicle's longitudinal direction. Fig. 2 to Fig. 5 show a respective drive unit which can be installed in the vehicle longitudinal direction and Fig. 5 shows a drive unit that can be installed transversely to the vehicle's longitudinal direction.

[0017] In the present case, no additional drive unit is arranged on the second axle 102, i.e., the front axle of the vehicle 100, thereby saving costs, weight, and installation space. Alternatively, the drive unit can be arranged on the front axle of the vehicle 100 instead of on the rear axle. To implement an all-wheel drive system, an additional drive unit can be arranged on the second axle 102 and be drivingly connected to the vehicle wheels R3, 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 intended for installation in the vehicle longitudinally relative to the direction of travel of the vehicle. The manual transmission SG is connected via a drive shaft An to an electric machine EM, which has a housing-fixed 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 manual transmission SG has exactly three shifting elements, namely a first shifting element A, a second shifting element B and a third shifting element C, and exactly three planetary sets, namely a first planetary set PS1, a second planetary set PS2 and a third planetary set PS3. The first planetary set PS1 comprises three shafts, namely a first sun shaft SO1, a first ring gear shaft HR1 and a first planetary shaft ST1. The first ring shaft ST1 carries several planet gears that mesh with the first sun shaft SO1 and with the first ring gear shaft HR1, i.e. are in tooth engagement. The second planetary set PS2 also comprises three shafts, namely a second sun shaft SO2, a second ring gear shaft HR2 and a second ring shaft ST2. The second ring shaft ST2 carries several planet gears that mesh with the second sun shaft SO2 and with the second ring gear shaft HR2.The third planetary gear set PS3 also comprises three shafts, namely a third sun gear shaft SO3, a third ring gear shaft HR3, and a third planetary gear shaft ST3. The third ring gear shaft ST3 carries a plurality of planetary 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, PS3 are arranged axially adjacent to one another to increase compactness. The shifting elements A, B, C are arranged on a circumference of the planetary gear sets, in particular on a 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, PS3.

[0020] The first sun shaft SO1, the second sun shaft SO2 and the input shaft An are connected to one another in a rotationally fixed manner. The first ring gear shaft HR1 is connected to a stationary component designed as a housing G. The first carrier shaft ST1 and the second ring gear shaft HR2 are connected to one another in a rotationally fixed manner. The second carrier shaft ST2 and the third sun shaft SO3 are connected to one another in a rotationally fixed manner. Furthermore, the third carrier shaft ST3 and an output shaft Ab are connected to one another in a rotationally fixed manner. The output shaft Ab can be drivingly connected indirectly, for example via a differential, or directly to at least one drive wheel of the vehicle, this being indicated in the present case by an arrow on the output shaft Ab. The manual transmission SG has a rotational axis of symmetry R which coincides with the input shaft An and the output shaft Ab.The electric motor EM, like the three planetary gear sets PS1, PS2, and PS3, is arranged coaxially with the input shaft An and the output shaft Ab. The embodiments shown in . Fig. 2 to Fig. 4 show only the “upper” half of the respective drive unit, whereby the “lower”, not shown half is designed symmetrically to the “upper” half.

[0021] All shift elements A, B, and C are designed as positive-locking shift elements. The first shift element A and the third shift element C are combined to form a double shift element and can be shifted by a first actuator AK1. The second shift element B can be shifted by a second actuator AK2. When the first shift element A is closed, a first gear with a first ratio is engaged, with the third ring gear shaft HR3 and a stationary component designed as a housing G being non-rotatably connected in first gear.

[0022] When the second shifting element B is closed, a second gear with a second ratio is engaged, whereby in second gear the first carrier shaft ST1, the second ring gear shaft HR2, the third carrier shaft ST3 and the output shaft Ab are connected in a rotationally fixed manner. When the third shifting element C is closed, a third gear with a third ratio is engaged, whereby in third gear two of the three shafts of the third planetary gear set are connected in a rotationally fixed manner, whereby the third planetary gear set PS3 is blocked and has a ratio of 1. When the third shifting element C is closed, the third carrier shaft ST3 and the third ring gear shaft HR3 are connected in a rotationally fixed manner. In this case, none of the three shifting elements A, B, C are engaged.

[0023] Fig. Figure 3 shows a second embodiment of the manual transmission SG according to the invention, which is connected to an electric machine EM via the drive shaft An. The electric drive unit formed thereby 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, C. In the present case, 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 according to Fig. 3 the embodiment according to Fig. 2, to which reference is made.

[0024] Fig. Figure 4 shows a third embodiment of the gearbox SG according to the invention, which is connected to an electric machine EM via the drive shaft An. The electric drive unit formed thereby according to Fig. 4 essentially corresponds to the electric drive unit according to Fig. 3, whereby the difference between these two embodiments lies in the arrangement and connection of the second and third switching elements B, C. In the present case, 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 the third planetary gear set PS2, PS3 with a smaller distance to the rotation axis R. In the closed state of the third switching element C, the third carrier shaft ST3 and the third sun shaft SO3 are connected to one another in a rotationally fixed manner. This represents a blocking variant of the third planetary gear set PS3. Otherwise, the embodiment according to Fig. 4 the embodiment according to Fig. 3, to which reference is made.

[0025] Fig. Figure 5 shows a fourth embodiment of the gearbox SG according to the invention, which is connected to an electric machine EM via the drive shaft An. The electric drive unit formed thereby according to Fig. 5 essentially corresponds to the electric drive unit according to Fig. 2, wherein a difference between these two embodiments lies in the arrangement and connection of the electric machine EM. In the present case, 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 that mesh with one another, wherein the first spur gear Z1 is connected in a rotationally fixed manner 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 that mesh with one another, wherein the third spur gear Z3 is connected in a rotationally fixed manner to the second spur gear Z2 and the fourth spur gear Z4 is connected in a rotationally fixed manner to the drive shaft An. Alternatively, the electric machine can be connected to the manual transmission SG via a single spur gear stage.

[0026] The drive unit also has a differential DG with a differential input shaft D1 for connection to the output shaft Ab and two differential output shafts D2, D3 for connecting a respective vehicle wheel. The differential DG is designed as a bevel gear differential. The differential input shaft D1 is rotationally fixedly connected to the output shaft Ab and the third carrier shaft ST3 connected thereto in a rotationally fixed manner. The 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 mounted rotatably about their own axis in a differential carrier designed as a differential input shaft D1. The respective output gear is rotationally fixedly connected to the respective differential output shaft D2, D3. The differential DG is driven via the differential carrier.Arrows on the differential output shafts D2, D3 indicate a connection to a respective vehicle wheel of this vehicle axle.

[0027] This embodiment is intended for installation in the vehicle transverse to the direction of travel. Otherwise, the embodiment according to Fig. 5 the embodiment according to Fig. 2, to which reference is made. Reference symbol 100 vehicles 101 first axis 102 second axis R1 vehicle wheel R2 vehicle wheel R3 vehicle wheel R4 vehicle wheel On drive shaft From output shaft SG manual transmission EM electric machine EMS stator of the electrical 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 gear set SO1 first solar wave HO1 first ring gear shaft ST1 first bridge wave PS2 second planetary gear set SO2 second solar wave HO2 second ring gear shaft ST2 second web wave PS3 third planetary set SO3 third solar wave HO3 third ring gear shaft ST3 third web 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 QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 4 702 125 A

[0002]

Claims

[1] Manual transmission (SG) for a vehicle (100) comprising • a drive shaft (An) for connecting an electrical machine (EM), • an output shaft (Ab), • a first switching element (A), a second switching element (B), a third switching element (C), • a first planetary gear set (PS1) with a first sun shaft (SO1), a first ring gear shaft (HR1) and a first carrier shaft (ST1), • a second planetary gear set (PS2) with a second sun shaft (SO2), a second ring gear shaft (HR2) and a second carrier shaft (ST2) and • a third planetary gear set (PS3) with a third sun shaft (SO3), a third ring gear shaft (HR3) and a third carrier shaft (ST3), • wherein the first sun shaft (SO1), the second sun 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 in a rotationally fixed manner, • wherein the first carrier shaft (ST1) and the second ring gear shaft (HR2) are connected in a rotationally fixed manner, • the second web shaft (ST2) and the third sun shaft (SO3) are connected in a rotationally fixed manner, • the third carrier 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 is engaged with a first gear ratio, wherein in the first gear the third ring gear shaft (HR3) and a stationary component are connected in a rotationally fixed manner, • wherein in the closed state of the second switching element (B) a second gear with a second transmission ratio is engaged, wherein in the second gear the first carrier shaft (ST1), the second ring gear shaft (HR2), the third carrier 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 ratio is engaged, wherein in the third gear two of the three shafts of the third planetary gear set are connected to one another. [2] Manual transmission (SG) according to claim 1, wherein the first switching element (A) and the third switching element (C) are combined to form a double switching element. [3] Manual transmission (SG) according to claim 1, wherein the second switching element (B) and the third switching element (C) are combined to form a double switching element. [4] Manual transmission (SG) according to one of the preceding claims, wherein all shifting elements (A, B, C) are designed as positive shifting elements. [5] Manual transmission (SG) according to one of the preceding claims, wherein in the closed state of the third shift element (C) the third carrier shaft (ST3) and the third ring gear shaft (HR3) are connected to one another in a rotationally fixed manner. [6] Manual transmission (SG) according to one of claims 1 to 4, wherein in the closed state of the third switching element (C) the third carrier shaft (ST3) and the third sun shaft (SO3) are connected to one another 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 with 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 axially parallel to 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 one of claims 7 to 9.

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