Transmission unit, power transmission system and vehicle comprising the same

• US 9,568,065 B2
• Filed: 03/11/2015
• Issued: 02/14/2017
• Est. Priority Date: 09/10/2014
• Status: Active Grant

• Current Assignee: BYD Company Limited
• Original Assignee: BYD Company Limited
• Inventors: Yang, Dongsheng, Lian, Yubo, Zhang, Jintao, Luo, Hongbin
• Primary Examiner(s): Ho, Ha D
• Application Number:
  US14/644,818
• Publication Number:
  US 20160069425A1
• Time in Patent Office: 706 Days
• Field of Search: 743/30, 743/31, 743/33, 743/40, 746/61
• US Class Current: 1/1
• CPC Class Codes: B60K 17/165 provided between independent half axles B60K17/18, B60K17/20 take precedence
• CPC Class Codes: B60K 17/356 having fluid or electric motor, for driving one or more wheels disposition of motor in, or adjacent to, traction wheel B60K7/00
• CPC Class Codes: B60K 2007/0046 the motor moving together with the vehicle body, i.e. moving independently from the wheel axle
• CPC Class Codes: B60K 2007/0061 the motor axle being parallel to the wheel axle
• CPC Class Codes: B60K 6/442 Series-parallel switching type
• CPC Class Codes: B60K 6/52 Driving a plurality of drive axles, e.g. four-wheel drive
• CPC Class Codes: B60K 6/547 the transmission being a stepped gearing
• CPC Class Codes: B60K 7/0007 the motor being electric
• CPC Class Codes: F16H 2003/0807 with gear ratios in which the power is transferred by axially coupling idle gears
• CPC Class Codes: F16H 2003/0822 characterised by the arrangement of at least one reverse gear
• CPC Class Codes: F16H 2003/0931 each countershaft having an output gear meshing with a single common gear on the output shaft
• CPC Class Codes: F16H 2200/0056 the gear ratios comprising seven forward speeds
• CPC Class Codes: F16H 3/006 power being selectively transmitted by either one of the parallel flow paths
• CPC Class Codes: F16H 3/093 with two or more countershafts
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y10S 903/917 with transmission for changing gear ratio

Abstract

A transmission unit for a vehicle is provided. The transmission unit includes: a plurality of input shafts, each of the input shafts being provided with a shift driving gear thereon; a plurality of output shafts, each of the output shafts being provided with a shift driven gear configured to mesh with a corresponding shift driving gear; a motor power shaft; first and second motor gears fitted over the motor power shaft; a motor synchronizer disposed on the motor power shaft and between the first and second motor gears; in which the first motor gear is configured to rotate together with one of the input shafts; the second motor gear is configured to rotate together with one of the output shafts. A power transmission system including the transmission unit and a vehicle including the power transmission system are also provided.

Claims

1. A transmission unit for a vehicle, comprising:

a plurality of input shafts, each of the input shafts being provided with a shift driving gear thereon;

a plurality of output shafts, each of the output shafts being provided with a shift driven gear configured to mesh with a corresponding shift driving gear;

a motor power shaft;

a first motor gear freely fitted over the motor power shaft and configured to rotate together with one of the input shafts;

a second motor gear freely fitted over the motor power shaft and configured to rotate together with one of the output shafts; and

a motor synchronizer disposed on the motor power shaft and between the first and second motor gears.

2. The transmission unit according to claim 1, further comprising:

a reverse gear freely fitted over the motor power shaft;

a middle idler configured to mesh with the shift driving gear provided on the one of the input shafts; and

a reverse idler gear configured to mesh with the reverse gear and to selectively rotate together with the middle idler.

3. The transmission unit according to claim 2, further comprising:

a reverse synchronizer configured to synchronize the middle idler and the reverse idler gear.

4. The transmission unit according to claim 3, wherein the reverse idler gear comprises a gear sleeve and the middle idler is freely fitted over the gear sleeve;

wherein the reverse synchronizer is disposed on the gear sleeve and configured to engage with the middle idler.

5. The transmission unit according to claim 3, wherein the plurality of input shafts comprise a first input shaft and a second input shaft coaxially fitted over the first input shaft;

wherein the plurality of output shafts comprise first and second output shafts disposed parallel to the first and second input shafts.

6. The transmission unit according to claim 5, wherein the plurality of shift driving gears comprise:

a first-gear driving gear disposed on the first input shaft, a second-gear driving gear disposed on the second input shaft, a third-gear driving gear disposed on the first input shaft, a fourth-gear driving gear disposed on the second input shaft, and a fifth-gear driving gear disposed on the first input shaft;

wherein the plurality of shift driven gears comprise first-gear to fourth-gear driven gears disposed on the first output shaft, and a fifth-gear driven gear disposed on the second output shaft; and

wherein the power transmission system further comprise a first-third gear synchronizer disposed between the first-gear driven gear and the third-gear driven gear, a second-fourth gear synchronizer disposed between the second-gear driven gear and the fourth-gear driven gear, and a fifth gear synchronizer disposed on a side of the fifth-gear driven gear.

7. The transmission unit according to claim 6, wherein the reverse idler gear is freely fitted over the second output shaft, the middle idler is configured to mesh with the second-gear driving gear, and a transmission gear fixed on the second output shaft is meshed with the second motor gear.

8. The transmission unit according to claim 6, wherein the reverse synchronizer and the fifth gear synchronizer share a shift fork mechanism.

9. The transmission unit according to claim 6, wherein the reverse gear is configured as a duplex gear, the duplex gear comprises a first part to mesh with the reverse idler gear and a second part to mesh with a driven gear of a main reducer of the vehicle.

10. The transmission unit according to claim 5, further comprising a first output gear fixed on the first output shaft and a second output gear fixed on the second output shaft, wherein the first and second output gears are both configured to mesh with the driven gear of the main reducer.

11. A power transmission system for a vehicle, comprising:

a transmission unit according to claim 1; and

a first motor generator configured to rotate together with the motor power shaft of the transmission unit.

12. The power transmission system according to claim 11, wherein the power transmission system further comprises a dual clutch and an engine, wherein the dual clutch comprises:

an input terminal connected with the engine, a first output terminal connected with the first input shaft of the transmission unit, and a second output terminal connected with the second input shaft of the transmission unit.

13. The power transmission system according to claim 12, wherein

the engine is configured to transmit a first part of power to wheels of the vehicle via one of the output shafts by engaging the input terminal of the dual clutch with the first output terminal and the second output terminal of the dual clutch simultaneously to drive the vehicle, and to transmit a second part of power to the first motor generator via the motor power shaft to drive the first motor generator to generate electric power.

14. The power transmission system according to claim 12, wherein the engine is configured to transmit power to one of the input shafts of the transmission unit, and to transmit the power to the first motor generator by synchronizing the first motor gear via a motor synchronizer to drive the first motor generator to generate electric power, when the vehicle is in a parking state.

15. The power transmission system according to claim 12, wherein the vehicle is operable in a mechanical reverse mode, an electric reverse mode and a hybrid reverse mode,

wherein when the vehicle is operated in the mechanical reverse mode, the engine is configured to generate a first power, to transmit the first power to one of the input shafts of the transmission unit, and to transmit the first power to the reverse gear via a synchronization of the reverse synchronizer of the transmission unit;

wherein when the vehicle is operated in the electric reverse mode, the first motor generator is configured to generate a second power and transmit the second power to the reverse gear via the synchronization of the reverse synchronizer and a synchronization of the motor synchronizer to the first motor gear; and

wherein when the vehicle is operated in the hybrid reverse mode, the engine is configured to generate a first power, to transmit the first power to one of the input shafts of the transmission unit, and to transmit the first power to the reverse gear via synchronization of the reverse synchronizer; and

the first motor generator is configured to generate a second power and to transmit the second power to the reverse gear via the synchronization of the reverse synchronizer and the synchronization of the motor synchronizer to the first motor gear.

16. The power transmission system according to claim 11, further comprising an engine and a dual clutch;

wherein the dual clutch includes an input terminal connected with the engine, a first output terminal connected with the first input shaft of the transmission unit, and a second output terminal connected with the second input shaft of the transmission unit;

wherein the vehicle is operable in a mechanical reverse mode, an electric reverse mode and a hybrid reverse mode;

wherein when the vehicle is operated in the mechanical reverse mode, the engine is configured to generate a first power, to transmit the first power to one of the input shafts of the transmission unit, and to transmit the first power to the reverse gear via a synchronization of the reverse synchronizer of the transmission unit;

wherein when the vehicle is operated in an electric reverse mode, the first motor generator is configured to generate a second power and output the second power from the second output shaft via a synchronization of motor synchronizer to the second motor gear; and

wherein when the vehicle is operated in a hybrid reverse mode, the engine is configured to generate a first power, to transmit the first power to one of the input shafts of the transmission unit, and to transmit the first power to the reverse gear via the synchronization of the reverse synchronizer of the transmission unit; and

the first motor generator is configured to generate a second power and output the second power from the second output shaft via the synchronization of motor synchronizer to the second motor gear.

17. The power transmission system according to claim 11, wherein the first motor generator is configured to rotate along a predetermined direction all the time when being operated as a motor or a generator.

18. The power transmission system according to claim 11, wherein during the motor synchronizer switching from engaging with one of the first and second motor gears to engaging with the other of the first and second motor gears, the first motor generator is configured to adjust a rotating speed of the motor power shaft based on a rotating speed of the other of the first and second motor gears.

19. The power transmission system according to claim 11, further comprising a second motor generator, wherein the second motor generator is configured to perform power transmission with a driven gear of a main reducer of the vehicle;

or

wherein the second motor generator is connected with the first output shaft;

or

wherein the second motor generator is connected with the first input shaft;

or

wherein the driven gear of the main reducer is disposed on a differential of the vehicle, and two second motor generators are provided and disposed on two sides of the differential respectively.

20. The power transmission system according to claim 12, wherein the engine and/or the first motor generator is configured to drive a first pair of wheels of the vehicle, and the power transmission system further comprises:

i. a third motor generator configured to rotate together with one of a second pair of wheels of the vehicle;

ii. a fourth motor generator configured to rotate together with the other of the second pair of wheels of the vehicle,

iii. an antiskid synchronizer configured to selectively synchronize the second pair of wheels,

wherein the first pair of wheels are one of front wheels and rear wheels of the vehicle, and the second pair of wheels are the other of the front wheels and the rear wheels.

21. The power transmission system according to claim 20, further comprising a first gear disposed on a first power output shaft corresponding to the third motor generator;

a second gear disposed on a first drive shaft connected with the one of the second pair of wheels corresponding to the third motor generator;

a third gear configured to mesh with the first gear;

a fourth gear coaxially arranged with the third gear and configured to mesh with the second gear and rotate synchronously with the third gear;

a fifth gear disposed on a second power output shaft corresponding to the fourth motor generator;

a sixth gear disposed on a second drive shaft connected with a wheel corresponding to the fifth motor generator;

a seventh gear configured to mesh with the fifth gear;

an eighth gear coaxially arranged with the seventh gear and configured to mesh with the sixth gear and rotate synchronously with the seventh gear,

wherein the antiskid synchronizer is disposed on the first drive shaft and configured to selectively engage with the sixth gear;

or

wherein the antiskid synchronizer is disposed on the first power output shaft corresponding to the third motor generator and is configured to selectively engage with the fifth gear;

or

wherein the third gear and the fourth gear are fixed on a first gear shaft, the seventh gear and the eighth gear are fixed on a second gear shaft, and the antiskid synchronizer is disposed on the first gear shaft and configured to selectively engage with the seventh gear.

22. The power transmission system according to claim 20, wherein the first power output shaft is coaxially connected with a wheel corresponding to the first output shaft, the second power output shaft is coaxially connected with a wheel corresponding to the second output shaft, the antiskid synchronizer is disposed on the first power output shaft and configured to engage with the second power output shaft.

23. A vehicle comprising a power transmission system for a vehicle according to claim 11.