Transmission for hybrid drive systems in motor vehicles

Abstract

This invention relates to a transmission device for a hybrid drive system in motor vehicles, particularly commercial vehicles, comprising: a transmission (G) having an output shaft (AW); a reducer (RE) having a reduction shaft (RW); an electric motor (EM) having a rotor shaft (RO); and a first transmission stage between the output shaft (AW) and the reducer shaft (RW), wherein the reducer (RE) can be driven via the first transmission stage. The invention proposes that the electric motor (EM) and the reducer (RE) are arranged axially parallel and can be connected to the reducer shaft (RW) via a second transmission stage.

Description

Technical Field

[0001] The present invention relates to a transmission device for a hybrid drive system for motor vehicles, particularly commercial vehicles, the transmission device comprising: a transmission having an output shaft; a reducer having a reducer shaft; an electric motor having a rotor shaft; and a first transmission stage between the output shaft and the reducer shaft, wherein the reducer can be driven by the first transmission stage. Background Technology

[0002] A powertrain for a motor vehicle is known through DE 10 2009 001 146 A1. This powertrain includes a combustion engine, a multi-stage transmission, and a hydraulic reducer serving as a continuous brake. The reducer, having a rotor, stator, and a reducer shaft, is connected to the output shaft of the multi-stage transmission via a transmission stage, a so-called hochtrieb, and is therefore capable of being driven by the transmission output shaft. An electric motor, having a rotor shaft, is arranged coaxially with the reducer shaft, and this rotor shaft is connected to the rotor of the reducer. The electric motor is primarily configured as a second continuous brake (besides the reducer), whereby the electric motor operates as a generator. Furthermore, the electric motor also assists in driving the combustion engine (hybrid operation) to reduce fuel consumption. Summary of the Invention

[0003] Based on this prior art, the objective of this invention is to realize further potential in the type of transmission device mentioned at the beginning, primarily through smaller electric motors.

[0004] This invention includes the features of the specification. Advantageous design solutions are derived from the specification.

[0005] According to the present invention, the electric motor is arranged axially parallel to the reducer and can be connected to the reducer shaft via a second transmission stage. Preferably, the first and second transmission stages, i.e., a known speed-up transmission on the one hand and a second transmission stage located between the rotor shaft of the electric motor and the reducer shaft on the other hand, are in the same plane. An axially parallel or lateral arrangement is advantageous because it eliminates the need for additional structural space in the axial direction, i.e., along the output shaft of the transmission, for the integration of the electric motor.

[0006] According to a preferred embodiment, a first shift element, preferably a claw clutch, is arranged on the reducer shaft, and the rotor of the reducer can be connected to the first transmission stage and the second transmission stage via the claw clutch. That is, when the first shift element is engaged, the reducer is driven by the transmission output shaft via a speed-up transmission and thereby driven on the vehicle side. Optionally, the reducer or the reducer rotor can be accelerated by an electric motor via the second transmission stage. In other cases, the electric motor is integrated into the powertrain as part of a P3 hybrid system.

[0007] According to another preferred embodiment, the first transmission stage and the second transmission stage have a common driven gear, which is arranged on the reducer shaft and configured as a free-spinning gear. This results in significant savings in weight and structural space, particularly in the axial direction.

[0008] According to another preferred embodiment, an additional transmission stage that can be engaged when needed is arranged between the rotor shaft of the electric machine and the reducer shaft. Therefore, the additional transmission stage is arranged in parallel with the second transmission stage and can be engaged via a second shifting element arranged on the rotor shaft. Through this additional transmission stage, the rotor of the reducer can be accelerated and driven, i.e., synchronized to the speed of the speed-up transmission, after the reducer has been previously shut off and stopped. At the same speed, an anti-rotation connection is established between the driven gear of the speed-up transmission and the reducer shaft via a first shifting element on the reducer shaft.

[0009] According to another preferred embodiment, a switchable first planetary gear set is arranged between the second transmission stage and the electric motor, the electric motor driving the second transmission stage via the switchable first planetary gear set. Advantageously, in this case, the driver and driven of the planetary gear set are arranged coaxially, and an additional transmission ratio for the electric motor's speed can be achieved.

[0010] According to another preferred embodiment, the first planetary gear set has a sun shaft configured as a drive shaft, a planet carrier shaft configured as a driven shaft, and a switchable ring gear shaft. This allows the planetary gear set to operate at two different gear ratios.

[0011] According to another preferred embodiment, the ring gear shaft is supported, i.e., fixed to the housing, in the first switching position, thereby achieving a reduced-speed transmission between the driving sun shaft and the driven planetary carrier shaft, whereby the speed of the electric motor can be matched with the speed of the reducer. In the second switching position, the ring gear shaft is locked to the sun shaft, i.e., the planetary gear set rotates as a whole, resulting in a 1:1 transmission ratio (so-called direct drive). Gear shifting is performed via a shifting element. Synchronization is achieved by the electric motor.

[0012] According to another preferred embodiment, the planet carrier shaft of the planetary gear set is anti-rotatably connected to the drive gear of the second transmission stage. This allows the electric motor to drive the transmission output shaft via both transmission stages when the reducer shaft is disengaged, thus assisting the combustion engine (hybrid operation).

[0013] According to another preferred embodiment, an additional transmission stage for synchronizing the reducer shaft is arranged parallel to the second transmission stage. When the reducer is switched off, its rotor must be accelerated (driven) to the driven side speed of the speed-up transmission during resuming braking operation. This is achieved via the additional transmission stage when the reducer shaft is disengaged from the speed-up transmission. At the same speed, the first shifting element can be closed.

[0014] According to another preferred embodiment, the transmission has a countershaft capable of being coupled to a hybrid power module. A hybrid power module detailed in a concurrent application filed with the applicant under internal file number ZF 205196 includes a second electric motor, an additional transmission, and a switchable second planetary gear set. Thus, the transmission has two electric motors, a first electric motor driving the transmission output shaft and a second electric motor driving the transmission countershaft. This increases the additional electrical power for the drive system in a motor vehicle.

[0015] According to another preferred embodiment, the switchable first planetary gear set and the switchable second planetary gear set are constructed identically, thereby reducing the manufacturing cost of the entire transmission device.

[0016] According to another preferred embodiment, the first electric motor and the second electric motor are constructed identically, thereby further reducing the manufacturing cost of the entire transmission device.

[0017] According to another preferred embodiment, an air conditioning system compressor is compacted at the auxiliary transmission of the hybrid power module, the compressor being driven by the second electric motor. Other auxiliary equipment can also be arranged at the auxiliary transmission and driven by the second electric motor. Attached Figure Description

[0018] Embodiments of the invention are shown in the accompanying drawings and described in more detail below, wherein other features and / or advantages may be derived from the description and / or the drawings. In the drawings:

[0019] Figure 1 A first embodiment of the present invention is shown for a first transmission device having a transmission, a reduction gear assembly and an electric motor.

[0020] Figure 2A second embodiment of the present invention is shown for a second transmission device having a switchable first planetary gear set;

[0021] Figure 3 A third embodiment of the present invention is shown for a third transmission device having an additional hybrid power module and a second electric motor; and

[0022] Figure 4 It shows according to Figure 3 3D diagram of the third transmission device. Detailed Implementation

[0023] As a first embodiment of the present invention Figure 1 A first transmission 1 with a gearbox G is shown, which has a transmission input shaft EW, a main shaft HW, a countershaft VW, and a transmission output shaft AW (also simply referred to as the output shaft AW) that can be driven by a combustion engine (not shown). The transmission output shaft has an output flange AF. The gearbox G has five gear planes R1, R2, R3, R4, and R5, which have idler gears on the input shaft EW and the main shaft HW, and fixed gears on the countershaft VW that mesh with these idler gears. The first two gear planes R1 and R2 form a gear group, the other gear planes R3, R4, and R5 form a main gear group, and a switchable planetary gear PG connected to the main gear group via the main shaft HW forms a range gear group. The planetary gear PG has two gear stages, namely a downshifting gear and a direct drive gear (Durchtrieb) (gear ratio 1:1). Therefore, a total of twelve gears can be switched using the gearbox G, which is specified for use in commercial vehicles. A reducer assembly BG with an electric motor EM is arranged on the driven side of the transmission G. The reducer assembly BG includes a hydraulic reducer RE, which consists of a rotor RR, a stator RS, and a reducer shaft RW. The rotor RR is arranged anti-rotationally on the reducer shaft. The reducer shaft RW is connected via a first transmission stage. Driven by the first transmission stage, this first transmission stage consists of a first gear Z1, configured as a fixed gear, arranged on the output shaft AW, and a second gear Z2, configured as a free-spinning gear, arranged on the reducer shaft RW. The free-spinning gear Z2 can be connected to the reducer shaft RW via a first shifting element SE1, preferably a claw clutch. The electric motor EM is arranged axially parallel to the reducer RE, meaning that there is a axial distance between the reducer shaft RW and the rotor shaft RO of the electric motor EM, which is determined by the second transmission stage. The second transmission stage, bridging the gap, includes a third gear Z3 and a second gear Z2. The third gear is configured as a freewheeling gear Z3 on the rotor shaft RO. The freewheeling gear Z3 can be connected to the rotor shaft RO via a second shifting element SE2. Between the rotor shaft RO and the reducer shaft RW, there is a connection with the second transmission stage. Additional drive stages are arranged in parallel. This additional transmission stage consists of a fourth gear Z4 configured as a freewheeling gear and a fifth gear Z5 configured as a stationary gear. The freewheeling gear Z4 can be connected to the rotor shaft RO via a second shifting element SE2. The electric machine EM can operate as both a motor and a generator and is preferably designed for low voltage (i.e., within the so-called low voltage limit of 48 volts).

[0024] During operation, with the reducer RE off (first shift element SE1 disengaged), the electric motor EM assists in combustion of the engine by means of the rotor shaft RO being engaged via the second transmission stage when the second shift element SE2 is closed. (that is, the third gear Z3 and the second gear Z2) and the first transmission stage (That is, the second gear Z2 and the first gear Z1) drive the output shaft AW. Therefore, at the output flange AF, the power of the electric motor EM and the power of the combustion engine can control the drive of the vehicle. Furthermore, the electric motor EM functions during braking, that is, when the reducer RE is engaged (the first shift element SE1 and the second shift element SE2 are closed), by means of two transmission stages. Driven by the output shaft AW and operating as a generator, the electric motor EM can finally be used to synchronize or accelerate the reducer shaft RW while the reducer RE is off. In this case, the second shift element SE2 connects the rotor shaft RO to the idler gear Z4, while the first shift element SE1 remains off. If the reducer shaft RW has reached the speed-up drive... The rotational speed of the second gear Z2 can close the first shifting element SE1, that is, make the second gear Z2 connected to the reducer shaft RW.

[0025] As a second embodiment of the present invention Figure 2 A second transmission device 2 is shown, which includes a gearbox Ga, a reducer assembly BGa, and a switchable first planetary gear set PS1 arranged in the power flow between the electric motor EM and the reducer assembly BGa. The same components are used... Figure 1 The same reference numerals are used in the accompanying drawings. The transmission Ga has one input shaft EW, two countershafts VW1 and VW2, one main shaft HW, and one transmission output shaft AW (also simply referred to as the output shaft AW), which has an output flange AF. As per... Figure 1 As in the embodiment, the transmission Ga is also a group transmission with a gear group, a main gear group, and a range gear group, the range gear group being constructed as planetary gears PG. Therefore, relative to according to Figure 1The fundamental difference in this embodiment lies in the switchable first planetary gear set PS1, which has a sun shaft SO driven by an electric machine EM, a planet carrier shaft ST configured as a driven shaft, and a ring gear shaft HR, which allows for two switching positions. In the first switching position, the ring gear shaft HR is supported, i.e., fixed, relative to the housing. In the second switching position, the ring gear shaft HR is locked to the sun shaft SO, causing the first planetary gear set PS1 to rotate as a whole. With the ring gear shaft HR fixed, a speed reduction transmission is achieved for the electric machine EM.

[0026] As in the previous embodiments, the reducer assembly BGa has a first transmission between the output shaft AW and the reducer shaft RW. (The so-called speed-up transmission) and a first shifting element SE1 arranged on the reducer shaft RW, which is preferably constructed as a claw clutch. The idler gear Z2 arranged on the reducer shaft RW meshes with the third gear Z3a and forms the second transmission stage. The third gear is fixedly connected to the planetary carrier shaft ST. It is connected to the second transmission stage. Additional transmission stages are provided in parallel. The additional transmission stage consists of gear Z4a, which can be driven by the planetary carrier shaft ST, and gear Z5a, which is arranged anti-rotationally on the reducer shaft RW.

[0027] The second transmission 2 can perform the following three functions: in hybrid mode, the electric motor EM assists in combustion of the engine, and when the first shift element SE1 is disengaged, it utilizes the two transmissions. This drives the output shaft AW. During typical commercial vehicle operation (e.g., between 60 km / h and 80 km / h), the gear ratio is limited to allow the electric motor EM to operate within its optimal efficiency range. In hybrid mode, the first planetary gear set PS1 is locked and therefore operates with virtually no losses. During braking operation, i.e., with the first shift element SE1 engaged, the transmission is activated not only via the speed booster... To drive the rotor RR of the reducer RE, and also through a second transmission The first planetary gear set PS1, rotating as a whole, drives the electric motor EM, which functions as a generator during braking operation. A third function is that after the reducer RE is switched off, that is, during resuming braking operation, the rotor RR of the reducer RE is driven by the electric motor EM, the first planetary gear set PS1, and an additional transmission stage. Speed ​​synchronization, that is, reaching the speed-up drive The rotational speed of the second gear Z2. Here, the first planetary gear set PS1 operates as a transmission gear via the fixed ring gear shaft HR. Subsequently, at the same rotational speed, the first shifting element SE1, that is, the claw clutch, can be engaged.

[0028] As a third embodiment of the present invention Figure 3 A third transmission device 3 is shown, which is relative to the transmission device according to Figure 2 The second transmission device 2 differs in that it includes an additional hybrid power module HM, as detailed in the applicant's concurrent application with internal file number ZF 205196; the concurrent application with internal file number ZF205196 is fully incorporated into the disclosure of this application. Figure 3 The hybrid module HM shown includes an auxiliary transmission AG with a first gear ZR1, a second gear ZR2, and a third gear ZR3, arranged in a plane and meshing with each other. A second electric motor EM2 is mounted on one side of the auxiliary transmission AG, and a second planetary gear set PS2 is mounted coaxially with the second electric motor EM2 on the other side. Like the first planetary gear set PS1, the second planetary gear set PS2 is switchable and has a sun shaft SO2 driven by the second electric motor EM2, a planet carrier shaft ST2 acting as the driven shaft, and a ring gear shaft HR2. This ring gear shaft can be engaged in two different positions via a shifting element (not shown): for a downshift drive, the ring gear shaft HR2 is fixed; while for a direct drive or a 1:1 gear ratio, the ring gear shaft HR2 is engaged (locked) with the sun shaft SO2. The auxiliary transmission AG is connected to the first countershaft VW1 of the transmission Gb via a connecting shaft or intermediate shaft ZW, wherein the first gear ZR1 is rotatably arranged on the intermediate shaft ZW, and the third shift element SE3, preferably a claw clutch, is arranged on this intermediate shaft. Therefore, the second electric motor EM2 can be engaged for hybrid mode or disengaged by disconnecting the third shift element SE3. The two planetary gear sets PS1, PS2 and the two electric motors EM1, EM2 can be constructed identically.

[0029] In the third transmission device 3, in hybrid mode, two electric motors EM1 and EM2 are available to assist the combustion engine. The first electric motor EM1 drives the output shaft AW, and the second electric motor EM2 drives the first countershaft VW1 via the intermediate shaft ZW through the second planetary gear set PS2 and the transmission stage ZR2 / ZR1 when the shift element SE3 is closed.

[0030] Figure 4 The diagram is shown in 3D according to Figure 3The third transmission unit 3, wherein the same reference numerals are used for the same parts. The transmission Gb has an input shaft EW on its drive side and an output flange AF on its driven side. On the driven side of the transmission Gb, a reduction gear assembly BGa and an auxiliary transmission AG are arranged, the reduction gear assembly having a first planetary gear set (not shown), and the auxiliary transmission having a second electric motor EM2 and a second planetary gear set PS2. As can be seen from the figure, all components are arranged on the side of the output flange AF, and the output area with the output flange AF and the universal joint (not shown) connected thereto remains empty. An additional heat exchanger for cooling the reduction gear oil and / or transmission oil is tightly fitted at the reduction gear assembly BGa.

[0031] List of reference numerals

[0032] 1. First transmission device

[0033] 2 Second transmission device

[0034] 3. Third transmission device

[0035] AF output flange

[0036] AG Additional Transmission

[0037] AW output shaft

[0038] BG reducer assembly ( Figure 1 )

[0039] BGa reducer assembly ( Figure 2 )

[0040] EM electric motor

[0041] EM1 First Electric Machine

[0042] EM2 Second Electric Machine

[0043] EW Input Axis

[0044] G transmission ( Figure 1 )

[0045] Ga transmission ( Figure 2 )

[0046] Gb transmission ( Figure 3 )

[0047] HM Hybrid Power Module

[0048] HR Ring Gear Shaft (PS1)

[0049] HR2 Ring Gear Shaft (PS2)

[0050] HW spindle

[0051] PG Planetary Gear

[0052] PS1 First Planetary Gear Set

[0053] PS2 Second Planetary Gear Set

[0054] R1 First gear plane

[0055] R2 Second Gear Plane

[0056] R3 Third Gear Plane

[0057] R4 Fourth Gear Plane

[0058] R5 Fifth Gear Plane

[0059] RE reducer

[0060] RO rotor shaft (EM)

[0061] RR reducer rotor

[0062] RS reducer stator

[0063] RW reducer shaft

[0064] SE1 First Shift Element

[0065] SE2 Second Shift Element

[0066] SE3 Third Shift Element

[0067] SO Sun Axis (PS1)

[0068] SO2 Sun Axis (PS2)

[0069] ST Planetary Carrier Spindle (PS1)

[0070] ST2 Planetary Carrier (PS2)

[0071] First transmission stage

[0072] Second transmission stage

[0073] Second transmission stage

[0074] Third transmission stage

[0075] Additional transmission stage

[0076] Additional transmission stage

[0077] VW sub-shaft

[0078] VW1 First Subshaft

[0079] heat exchanger

[0080] Z1 First Gear

[0081] Z2 Second Gear

[0082] Z3 Third Gear

[0083] Z3a Third Gear

[0084] Z4 Fourth Gear

[0085] Z4a Fourth Gear

[0086] Z5 Fifth Gear

[0087] Z5a Fifth Gear

[0088] ZR1 First Gear

[0089] ZR2 Second Gear

[0090] ZR3 Third Gear

[0091] ZW intermediate shaft

Claims

1. A transmission device for a hybrid drive system in a motor vehicle, comprising: Transmissions (G, Ga, Gb) with an output shaft (AW); A reducer (RE) with a reducer shaft (RW); An electric motor (EM) having a rotor shaft (RO) and a first transmission stage between the output shaft (AW) and the reducer shaft (RW). ), wherein the reducer (RE) is capable of being driven by the first transmission stage ( The device is driven by a second transmission stage, characterized in that the electric motor (EM) is arranged axially parallel to the reducer (RE) and is capable of being driven by the reducer. ) is connected to the reducer shaft (RW), wherein the first transmission stage ( ) and the second transmission stage ( It has a common driven gear (Z2), which is arranged on the reducer shaft (RW) and is configured as an idler gear.

2. The transmission device according to claim 1, characterized in that, A first shifting element (SE1) is arranged on the reducer shaft (RW), and the reducer (RE) can be connected to the first transmission stage (RE) via the first shifting element. ) and the second transmission stage ( ) connection.

3. The transmission device according to claim 1, characterized in that, Between the rotor shaft (RO) of the electric motor (EM) and the reducer shaft (RW) and the second transmission stage ( Additional drive stages are arranged in parallel and can be activated when needed. ).

4. The transmission device according to claim 1, characterized in that, The electric motor (EM) and the second transmission stage ( A first planetary gear set (PS1) capable of switching is arranged in the power flow between the two.

5. The transmission device according to claim 4, characterized in that, The first planetary gear set (PS1) has a sun shaft (SO) as a drive shaft, a planet carrier shaft (ST) as a driven shaft, and a ring gear shaft (HR) that can be switched.

6. The transmission device according to claim 5, characterized in that, The ring gear shaft (HR) is fixed to the housing side in the first switching position and can be connected to the sun shaft (SO) in the second switching position.

7. The transmission device according to claim 5, characterized in that, The planetary carrier shaft (ST) and the second transmission stage ( The gear (Z3) is anti-rotationally connected.

8. The transmission device according to claim 5, characterized in that, With the second transmission stage ( Additional transmission stages for synchronizing the reducer shaft (RW) are arranged in parallel. ).

9. The transmission device according to any one of claims 4 to 8, characterized in that, The transmission (G, Ga, Gb) has a countershaft (VW, VW1) that can be connected to a second electric motor (EM2) via an additional transmission (AG) and a switchable second planetary gear set (PS2).

10. The transmission device according to claim 9, characterized in that, The second planetary gear set (PS2) corresponds to the first planetary gear set (PS1).

11. The transmission device according to claim 9, characterized in that, The second electric machine (EM2) corresponds to the first electric machine (EM1).

12. The transmission device according to claim 9, characterized in that, The additional transmission (AG) refers to a compressor (KO) equipped with an air conditioning system.

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