Shift transmission and drive unit having such shift transmission

Abstract

The invention relates to a shift transmission and a drive unit having such a shift transmission, comprising a drive shaft, an output shaft, three shift elements and three planetary gear sets, in which a first sun shaft, a second sun shaft and the drive shaft are connected in a rotationally fixed manner, a first ring gear shaft is connected in a rotationally fixed manner to a stationary component, and a second ring gear shaft is connected in a rotationally fixed manner to a second component. The first planet carrier shaft and the second gear ring shaft are connected in a rotationally fixed manner, the second planet carrier shaft and the third sun shaft are connected in a rotationally fixed manner, the third planet carrier shaft and the output shaft are connected in a rotationally fixed manner, and the third gear ring shaft and a stationary component are connected in a rotationally fixed manner in the closed state of the first shifting element, in the closed state of the second shift element, the first planet carrier shaft, the second ring gear shaft, the third planet carrier shaft and the output shaft are connected in a rotationally fixed manner, and in the closed state of the third shift element, two of the three shafts of the third planetary gear set are connected to each other.

Description

Technical Field

[0001] The present invention relates to a gearshift transmission for a vehicle. Furthermore, the present invention relates to a drive unit equipped with a single electric machine and a gearshift transmission having three planetary gear sets. The present invention also relates to a vehicle having such a drive unit. Background Art

[0002] For example, US Pat. No. 4,702,125 A discloses a drive unit having an electric motor, a two-gear transmission, and a differential. The transmission has two shifting elements designed as brakes and three planetary gear sets coupled to one another, wherein, when one of the two shifting elements is engaged, the ring gear shaft of the first planetary gear set is connected to the housing in a rotationally fixed manner, and when the other of the two shifting elements is engaged, the ring gear shaft of the second planetary gear set is connected to the housing in a rotationally fixed manner. Summary of the Invention

[0003] The object of the present invention is to provide an alternative manual transmission for a vehicle having three planetary gear sets. In particular, the manual transmission should have three gears, good efficiency, and low planetary gear 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 drawings.

[0004] The gear shifting transmission for a vehicle according to the present invention comprises: a driving shaft for connecting an electric motor; a driven shaft; a first shifting element; a second shifting element; a third shifting element; a first planetary gear set having a first sun shaft, a first ring gear shaft and a first planetary carrier shaft; a second planetary gear set having a second sun shaft, a second ring gear shaft and a second planetary carrier shaft; and a third planetary gear set having a third sun shaft, a third ring gear shaft and a third planetary carrier shaft; wherein the first sun shaft, the second sun shaft and the driving shaft are connected in a manner that is non-rotatable relative to each other, wherein the first ring gear shaft is connected in a manner that is non-rotatable relative to a fixed component, wherein the first planetary carrier shaft and the second ring gear shaft are connected in a manner that is non-rotatable relative to each other, wherein the second planetary carrier shaft and the third sun shaft are connected in a manner that is non-rotatable relative to each other The male shaft is connected in a rotationally fixed manner, wherein the third planetary carrier shaft and the driven shaft are connected in a rotationally fixed manner, wherein in the closed state of the first shifting element, a first gear with a first transmission ratio is shifted, wherein in the first gear, the third ring gear shaft and the fixed component are connected in a rotationally fixed manner, wherein in the closed state of the second shifting element, a second gear with a second transmission ratio is shifted, wherein in the second gear, the first planetary carrier shaft, the second ring gear shaft, the third planetary carrier shaft and the driven shaft are connected in a rotationally fixed manner, wherein in the closed state of the third shifting element, a third gear with a third transmission ratio is shifted, wherein in the third gear, two of the three shafts of the third planetary gear set are connected to each other.

[0005] The third planetary gear set is interlocked by coupling two of the three shafts of the third planetary gear set when the third shifting element is in the closed state. Due to the interlocking of the third planetary gear set, the transmission ratio is always 1, independent of the number of teeth on the elements of the third planetary gear set that are in meshing engagement with one another. In other words, the third planetary gear set rotates as a whole. According to one embodiment, when the third shifting element is in the closed state, the third planetary carrier shaft and the third ring gear shaft are connected to each other in a rotationally fixed manner. According to an alternative embodiment, when the third shifting element is in the closed state, the third planetary carrier shaft and the third sun gear shaft are connected to each other in a rotationally fixed manner. The transmission ratio of the third gear is defined solely by the third planetary gear set.

[0006] The manual transmission allows the introduction of drive power via the electric motor connected to the drive shaft. The manual transmission is drivingly connected to either the differential or the wheels via the driven shaft. Each of the three planetary gear sets includes three shafts: a respective sun shaft, a respective ring gear shaft, and a respective planet carrier shaft. Each planet carrier shaft carries a plurality of planetary gears that mesh with, or are in toothed engagement with, the respective sun shaft and the respective ring gear shaft.

[0007] In the sense of the present invention, a "shaft" is understood to be a rotatable component of a transmission, by means of which the respective components of the transmission are connected to one another in a rotationally fixed manner, or by means of which such a connection can be established when one of the shifting elements is actuated. In this case, the respective shaft can connect the components to one another axially or radially or both axially and radially. Therefore, the respective shaft can also serve as an intermediate piece, by means of which, for example, the respective components are connected radially. The term "shaft" does not exclude that the components to be connected can be implemented as a single piece. In particular, two or more shafts that are connected to one another in a rotationally fixed manner can be constructed as a single piece. A "stationary component" is understood to be a component that is mounted in a stationary manner, in particular connected to the housing or a part of the housing in a rotationally fixed manner or connected as a single piece.

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

[0009] According to one embodiment, the first and third shifting elements are configured to form a combined double shifting element. According to an alternative embodiment, the second and third shifting elements are configured to form a combined double shifting element. The double shifting element requires only a single actuator for shifting. By using a double shifting element, only two actuators are required to shift into three gears, rather than three, thereby improving compactness. For example, either the first and third shifting elements or the second and third shifting elements are configured as a shifting unit having a single sleeve that can be moved into the respective shifting positions by means of a single actuator, wherein the shifting unit has two gears and a neutral position. In a gear, the shifting element connects two shafts or a shaft to the housing. In the neutral position, the two shafts or a shaft and the housing are decoupled from each other by the shifting unit. In particular, the sliding sleeve is designed to be form-locking and has form-locking claws that, in the respective gear position, interact in a form-locking manner with the respective corresponding claws to establish a rotationally fixed connection between the two shafts or between a shaft and the housing. The respective claws with which the sliding sleeve interacts in a form-locking manner are thus considered shifting elements. Preferably, the shifting unit includes a non-synchronized dog clutch. Using the sliding sleeve for shifting gears further increases compactness.

[0010] According to one embodiment, all three shift elements are designed as positive-locking shift elements, in particular dog-type shift elements. Positive-locking shift elements can increase the efficiency of the manual transmission due to reduced drag losses. In particular, positive-locking shift elements are more compact and have optimized efficiency, and offer cost advantages over friction-locking shift elements. Positive-locking shift elements can be synchronized by an electric motor.

[0011] A vehicle drive unit according to the present invention includes an electric motor and a manual transmission according to the present invention, wherein the electric motor and the manual transmission are arranged coaxially or with their axes parallel to each other. Preferably, the drive unit further includes a differential having a differential input shaft for connecting to a driven shaft and two differential output shafts for connecting to respective wheels.

[0012] According to a preferred embodiment, the differential is configured as a bevel gear differential. A differential configured as a bevel gear differential has two wheel-side driven elements, in particular a first driven gear and a second driven gear. The two driven gears each mesh with a compensating element. The compensating element is supported in the differential case so as to be rotatable about its own axis. The respective driven gears are connected to the respective differential output shaft in a rotationally fixed manner. The drive to the differential is achieved via the differential case, which is configured as a differential input shaft. In addition, alternative configurations of the differential are also conceivable, such as as a spherical differential, a cylindrical gear differential, or a planetary differential. The drive power fed into the differential via the differential input shaft is distributed in a known manner to the two differential output shafts and transmitted to the drive wheels of the vehicle axles. The differential output shaft is configured to be drivingly connected to the drive wheels of the vehicle. The respective differential output shaft can be connected to the associated wheel directly or indirectly or indirectly or indirectly via a downstream fixed gear, a joint, a cardan shaft and / or a wheel hub.

[0013] The shift transmission according to the present invention is particularly suitable for electric central drives with a downstream differential, in particular a bevel gear. The preferred installation position for the drive unit is in the vehicle's direction of travel. Alternatively, the drive unit can be installed transversely to the vehicle's direction of travel, eliminating the downstream bevel gear on the differential and connecting the electric motor in a parallel axis via at least one spur gear. For example, one or more spur gear stages can be provided for this purpose, depending on the desired transmission ratio and the available space.

[0014] The vehicle according to the invention comprises a drive unit according to the invention. The above definitions and the embodiments concerning the technical effects, advantages and advantageous embodiments of the gearshift transmission according to the invention apply equally to the drive unit according to the invention and the vehicle according to the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Advantageous embodiments of the present invention described below are shown in the accompanying drawings, wherein identical or similar elements are identified by the same reference numerals.

[0016] Figure 1 A highly abstract schematic diagram of a vehicle with a drive axle having a drive unit according to the invention is shown;

[0017] Figure 2 A highly abstract schematic diagram of a drive unit according to the invention is shown, which has a shift transmission according to a first embodiment;

[0018] Figure 3 A highly abstract schematic diagram of a drive unit according to the invention is shown, which has a shift transmission according to a second embodiment;

[0019] Figure 4 A highly abstract schematic diagram of a drive unit according to the invention is shown, which has a shift transmission according to a third embodiment; and

[0020] Figure 5 A highly abstract schematic diagram of a drive unit according to the invention is shown, which has a manual transmission according to a fourth embodiment. DETAILED DESCRIPTION

[0021] Figure 1 A vehicle 100 is shown, which is equipped with a first axle 101 having two wheels R1 and R2 and a second axle 102 having two wheels R3 and R4. Here, 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 present invention. The drive unit comprises an electric motor EM configured to generate drive power, a gearshift transmission SG having multiple gears, and a differential DG. Thus, the vehicle 100 is configured as an electric vehicle, i.e., a vehicle that can be driven electrically. The drive unit is arranged transversely to the longitudinal direction of the vehicle and is drivingly connected to the wheels R1 and R2 of the first axle 101. Alternatively, the drive unit can be arranged in the longitudinal direction of the vehicle. Figures 2 to 4 shows the respective drive units that can be installed in the vehicle in the longitudinal direction of the vehicle, and Figure 5 A drive unit is shown which can be installed in a vehicle transversely to the longitudinal direction of the vehicle.

[0022] Here, 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 the rear axle. To implement an all-wheel drive system, another drive unit can be arranged on the second axle 102 and connected in a driving manner to the wheels R3 and R4 of this axle 102.

[0023] Figure 2The figure shows a vehicle drive unit having a manual transmission SG according to a first embodiment. This embodiment is designed for installation in the vehicle in the direction of travel. The manual transmission SG is connected via a drive shaft An to an electric motor EM, which has a stator EMS fixed relative to the housing and a rotatable rotor EMR. The electric motor EM is arranged coaxially with the manual transmission SG. Thus, the manual transmission SG and the electric motor EM form an electric drive unit.

[0024] The manual transmission SG has exactly three shifting elements: the first shifting element A, the second shifting element B, and the third shifting element C, as well as exactly three planetary gear sets: the first planetary gear set PS1, the second planetary gear set PS2, and the third planetary gear set PS3. The first planetary gear set PS1 comprises three shafts: the first sun shaft SO1, the first ring gear shaft HR1, and the first planetary carrier shaft ST1. The first planetary carrier shaft ST1 carries a plurality of planetary gears that mesh with the first sun shaft SO1 and the first ring gear shaft HR1, i.e., are in tooth engagement. The second planetary gear set PS2 also comprises three shafts: the second sun shaft SO2, the second ring gear shaft HR2, and the second planetary carrier shaft ST2. The second planetary carrier shaft ST2 carries a plurality of planetary gears that mesh with the second sun shaft SO2 and the second ring gear shaft HR2. The third planetary gear set PS3 also comprises three shafts: the third sun shaft SO3, the third ring gear shaft HR3, and the third planetary carrier shaft ST3. The third planet carrier shaft ST3 carries multiple planet gears that mesh with the third sun 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 enhance compactness. Shifting elements A, B, and C are arranged around the periphery of the planetary gear sets, particularly around the third planetary gear set PS3. The second planetary gear set PS2 is positioned axially between the first and third planetary gear sets PS1 and PS3.

[0025] The first sun shaft SO1, the second sun shaft SO2, and the drive 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 in a rotationally fixed manner. The first planet carrier shaft ST1 and the second ring gear shaft HR2 are connected to one another in a rotationally fixed manner. The second planet carrier shaft ST2 and the third sun shaft SO3 are connected to one another in a rotationally fixed manner. Furthermore, the third planet carrier shaft ST3 is connected to the output shaft Ab in a rotationally fixed manner. The output shaft Ab can be drivingly connected to at least one drive wheel of the vehicle indirectly, for example via a differential, or directly, as indicated by an arrow on the output shaft Ab. The manual transmission SG has an axis of rotational symmetry R that coincides with the drive 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 drive shaft An and the output shaft Ab. Figures 2 to 4The illustrated embodiment shows only the “upper” half of the respective drive unit, wherein the “lower” half (not shown) is constructed symmetrically to the “upper” half.

[0026] All shifting elements A, B, and C are designed as form-locking shifting elements. The first shifting element A and the third shifting element C are designed as a double shifting element and can be shifted by the first actuator AK1. The second shifting element B can be shifted by the second actuator AK2. When the first shifting element A is in the closed position, a first gear with a first transmission ratio is engaged. In this first gear, the third ring gear shaft HR3 is connected in a rotationally fixed manner to a fixed component designed as the housing G. When the second shifting element B is in the closed position, a second gear with a second transmission ratio is engaged. In this second gear, the first planetary carrier shaft ST1, the second ring gear shaft HR2, the third planetary carrier shaft ST3, and the output shaft Ab are connected in a rotationally fixed manner. When the third shifting element C is in the closed position, a third gear with a third transmission ratio is engaged. In this third gear, two of the three shafts of the third planetary gear set are connected in a rotationally fixed manner to one another, resulting in the third planetary gear set PS3 being interlocked and having a transmission ratio of 1. The third planet carrier shaft ST3 and the third ring gear shaft HR3 are connected to each other in a rotationally fixed manner in the engaged state of the third shifting element C. Currently, none of the three shifting elements A, B, and C are shifted.

[0027] Figure 3 A second embodiment of the manual transmission SG according to the invention is shown, which is connected to the electric machine EM via a drive shaft An. Figure 3 The electric drive unit thus formed corresponds approximately to Figure 2 The electric drive unit of the present invention differs from the electric drive unit of the present invention in that the two embodiments differ in the design of the shifting elements A, B, and C. In this case, the second shifting element B and the third shifting element C are designed in such a way as to form a double shifting element and can be shifted by the first actuator AK1. The first shifting element A can be shifted by the second actuator AK2. In other respects, according to Figure 3 The embodiment corresponds to Figure 2 and reference is made thereto.

[0028] Figure 4 A third embodiment of the manual transmission SG according to the invention is shown, which is connected to the electric machine EM via a drive shaft An. Figure 4 The electric drive unit thus formed corresponds approximately to Figure 3The electric drive unit of the present invention is different from the electric drive unit of the present invention in that the difference between the two embodiments lies in the arrangement and connection of the second and third shifting elements B, C. Here, the second shifting element B and the third shifting element C are also constructed in a manner that is combined into a double shifting element, but are arranged axially between the second and third planetary gear sets PS2, PS3 with a smaller spacing relative to the axis of rotation R. In the closed state of the third shifting element C, the third planetary carrier shaft ST3 and the third sun shaft SO3 are connected to each other in a rotationally fixed manner. This represents an interlocking variant of the third planetary gear set PS3. In other respects, according to Figure 4 The embodiment corresponds to Figure 3 and reference is made thereto.

[0029] Figure 5 A fourth embodiment of the manual transmission SG according to the invention is shown, which is connected to the electric machine EM via a drive shaft An. Figure 5 The electric drive unit thus formed corresponds approximately to Figure 2 An electric drive unit, wherein the two embodiments differ in the arrangement and connection of the electric motor EM. The electric motor EM is connected to the drive shaft An via first and second spur gear stages SR1 and SR2. The first spur gear stage SR1 comprises first and second spur gears Z1 and Z2, which are in meshing engagement with one another. The first spur gear Z1 is connected in a rotationally fixed manner to the rotor shaft of the electric motor EM. The second spur gear stage SR2 comprises third and fourth spur gears Z3 and Z4, which are in meshing engagement with one another. 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 motor can be connected to the manual transmission SG via a single spur gear stage.

[0030] The drive unit also includes a differential DG having a differential input shaft D1 for connection to the driven shaft Ab and two differential output shafts D2 and D3 for connection to the respective wheels. The differential DG is configured as a bevel gear differential. The differential input shaft D1 is rotationally fixedly connected to the driven shaft Ab and to the third planetary carrier shaft ST3, which is rotationally fixedly connected thereto. The bevel gear differential has two wheel-side driven elements, specifically a first driven gear and a second driven gear. Each of the two driven gears meshes with a compensating element. These compensating elements are rotatably mounted about their own axes in a differential case, which is configured as the differential input shaft D1. The respective driven gears are rotationally fixedly connected to the respective differential output shafts D2 and D3. The drive to the differential DG is provided via the differential case. The arrows on the differential output shafts D2 and D3 indicate the connection to the respective wheels of the axle. This embodiment is designed to be installed in a vehicle transversely to the direction of travel of the vehicle. Figure 5The embodiment corresponds to Figure 2 and reference is made thereto.

[0031] Reference numerals

[0032] 100 vehicles

[0033] 101 First Axle

[0034] 102 Second Axle

[0035] R1 wheels

[0036] R2 Wheels

[0037] R3 Wheels

[0038] R4 wheels

[0039] An drive shaft

[0040] Ab driven shaft

[0041] SG gear shift transmission

[0042] EM motor

[0043] Stator of an EMS motor

[0044] EMR motor rotor

[0045] SR1 first spur gear stage

[0046] SR2 second spur gear stage

[0047] Z1 First cylindrical gear

[0048] Z2 Second cylindrical gear

[0049] Z3 third cylindrical gear

[0050] Z4 fourth cylindrical gear

[0051] PS1 first planetary gear set

[0052] SO1 First Sun Axis

[0053] HO1 first ring gear shaft

[0054] ST1 First planet carrier shaft

[0055] PS2 Second Planetary Gear Set

[0056] SO2 Second Sun Axis

[0057] HO2 second ring gear shaft

[0058] ST2 Second planet carrier shaft

[0059] PS3 third planetary gear set

[0060] SO3 Third Sun Axis

[0061] HO3 third ring gear shaft

[0062] ST3 third planet carrier shaft

[0063] AK1 first actuator

[0064] AK2 Second Actuator

[0065] G housing

[0066] R Axis of symmetry

[0067] DG differential

[0068] D1 differential input shaft

[0069] D2 First differential output shaft

[0070] D3 Second differential output shaft

[0071] A First shift element

[0072] B Second shift element

[0073] C Third shift element

Claims

1. A power transmission (SG) for a vehicle (100), the power transmission comprising: • Drive shaft (An) for connecting to the electric motor (EM), • Driven shaft (Ab), • 1st shift element (A), 2nd shift element (B), 3rd shift element (C), • A first planetary gear set (PS1) with a first sun gear shaft (SO1), a first ring gear shaft (HR1) and a first planet carrier shaft (ST1), • A second planetary gear set (PS2) having a second sun gear shaft (SO2), a second ring gear shaft (HR2), and a second planet carrier shaft (ST2), and • The third planetary gear set (PS3) with the third sun gear shaft (SO3), the third ring gear shaft (HR3) and the third planet carrier shaft (ST3), • in, 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 planet carrier shaft (ST1) and the second ring gear shaft (HR2) are connected in a rotationally fixed manner, • wherein the second planet carrier shaft (ST2) and the third sun shaft (SO3) are connected in a rotationally fixed manner, • wherein the third planet carrier shaft (ST3) and the driven shaft (Ab) are connected in a rotationally fixed manner, • wherein, in the closed state of the first shifting element (A), a first gear with a first transmission ratio is engaged, wherein in the first gear, the third ring gear shaft (HR3) is connected to a stationary component in a rotationally fixed manner, • wherein, in the closed state of the second shifting element (B), a second gear with a second transmission ratio is engaged, wherein in the second gear, the first planetary carrier shaft (ST1), the second ring gear shaft (HR2), the third planetary carrier shaft (ST3) and the output shaft (Ab) are connected in a rotationally fixed manner, • In the closed state of the third shifting element (C), a third gear with a third transmission 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. The power shift transmission (SG) according to claim 1, wherein: The first shifting element (A) and the third shifting element (C) are designed to be combined into a double shifting element.

3. The power shift transmission (SG) according to claim 1, wherein: The second shifting element (B) and the third shifting element (C) are designed to be combined into a double shifting element.

4. The power shift transmission (SG) according to claim 1, wherein: All shifting elements (A, B, C) are designed as form-locking shifting elements.

5. The powershift transmission (SG) according to any one of the preceding claims, wherein: In the engaged state of the third shifting element (C), the third planet carrier shaft (ST3) and the third ring gear shaft (HR3) are connected to one another in a rotationally fixed manner.

6. The power shift transmission (SG) according to any one of claims 1 to 4, wherein: In the engaged state of the third shifting element (C), the third planet carrier shaft (ST3) and the third sun shaft (SO3) are connected to one another in a rotationally fixed manner.

7. A drive unit for a vehicle (100), comprising an electric machine (EM) and a manual transmission (SG) according to any one of the preceding claims, wherein: The electric machine (EM) is arranged coaxially with the gearshift transmission (SG).

8. A drive unit for a vehicle (100), comprising an electric machine (EM) and a power transmission (SG) according to any one of claims 1 to 6, wherein: The electric machine (EM) is arranged parallel to the axis of the manual transmission (SG).

9. The drive unit according to claim 7 or 8, further comprising a differential (DG), the differential comprising a differential input shaft (D1) for connecting to the driven shaft (Ab) and two differential output shafts (D2, D3) for connecting to respective wheels.

10. Vehicle (100) comprising at least one drive unit according to any one of claims 7 to 9.

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