Vehicle drive train

• US 6,258,001 B1
• Filed: 12/16/1999
• Issued: 07/10/2001
• Est. Priority Date: 03/26/1999
• Status: Expired due to Term

• Current Assignee: Aisin AW Company Limited (Aisin Corp.), Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Aisin AW Company Limited (Aisin Corp.), Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Tabata, Atsushi, Tsuzuki, Shigeo, Taga, Yutaka, Nakamura, Seiji, Hasebe, Masahiro, Wakuta, Satoru, Amano, Masaya, Shinohara, Keiichi, Omote, Kenji
• Primary Examiner(s): Marmor, Charles A
• Assistant Examiner(s): HO, HA DINH
• Application Number:
  US09/461,802
• Time in Patent Office: 572 Days
• Field of Search: 475/5, 192/3.28, 192/3.32, 192/3.33, 192/3.31
• US Class Current: 475/5
• CPC Class Codes: B60K 6/26 characterised by the motors or the generators
• CPC Class Codes: B60K 6/36 characterised by the transmission gearings
• CPC Class Codes: B60K 6/387 Actuated clutches, i.e. clutches engaged or disengaged by electric, hydraulic or mechanical actuating means
• CPC Class Codes: B60K 6/40 characterised by the assembly or relative disposition of components
• CPC Class Codes: B60K 6/405 Housings
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60K 6/485 Motor-assist type
• CPC Class Codes: B60K 6/547 the transmission being a stepped gearing
• CPC Class Codes: F16H 2041/246 relating to one way clutch of the stator
• CPC Class Codes: F16H 2045/021 three chamber system, i.e. comprising a separated, closed chamber specially adapted for actuating a lock-up clutch
• CPC Class Codes: F16H 2045/0284 Multiple disk type lock-up clutch
• CPC Class Codes: F16H 41/24 Details
• CPC Class Codes: F16H 45/02 with mechanical clutches for bridging a fluid gearing of the hydrokinetic type control of torque converter lock-up clutches F16H61/14
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y10S 903/906 Motor or generator
• CPC Class Codes: Y10S 903/909 Gearing
• CPC Class Codes: Y10S 903/914 Actuated, e.g. engaged or disengaged by electrical, hydraulic or mechanical means
• CPC Class Codes: Y10S 903/919 Stepped shift
• CPC Class Codes: Y10S 903/951 Assembly or relative location of components
• CPC Class Codes: Y10S 903/952 Housing details

Abstract

The present invention improves mountability of a drive train in a hybrid vehicle by minimizing axial and radial dimensions while providing for adequate output torque of the motor/generator of the drive train. A center portion of a front cover of a torque converter extends axially and a multiple disc lock-up clutch is arranged at the inner circumferential surface of the center portion while the motor/generator is arranged at the outer circumferential surface of the center portion. A spring damper is provided at the radially inner side of a circumferential surface defined by friction plates of the lock-up clutch.

Claims

1. A vehicle drive train for powering a vehicle comprising:

an engine having a crankshaft;

a first transmission unit having an input shaft;

a second transmission unit interposed between the crankshaft and the input shaft of said first transmission unit;

a lock-up clutch; and

a motor having a stator and a rotor, said rotor being directly connected to an output element of said engine;

wherein;

said lock-up clutch is located axially intermediate said engine and said second transmission unit and has a diameter smaller than the largest diameter of said second transmission unit;

said motor axially overlaps an outer circumferential surface of said lock-up clutch; and

said stator has an inner diameter smaller than the largest diameter of said second transmission unit.

2. The vehicle drive train according to claim 1, wherein said lock-up clutch is a multiple disc clutch.

3. The vehicle drive train according to claim 2, wherein:

said lock-up clutch has a damper with circumferentially spaced coil springs; and

said damper is mounted axially overlapping the inner circumferential surface of friction plates of said lock-up clutch.

4. The vehicle drive train according to claim 1 wherein:

said second transmission unit is a hydraulic transmission having the shape of a torus and including a pump impeller, a turbine runner and a front cover which covers said turbine runner and said lock-up clutch, said front cover connecting said pump impeller, said crankshaft, and said rotor;

said front cover has an axially extending center portion;

said motor is arranged radially outward of said center portion; and

said lock-up clutch has a diameter smaller than the outside diameter of said torus and is arranged radially aligned with and radially inward of said center portion.

5. The vehicle drive train according to claim 1 further comprising:

a sensor for detecting a rotational position of said rotor, said sensor being arranged substantially axially aligned with said lock-up clutch and radially inward of said stator.

6. The vehicle drive train according to claim 1 further comprising:

a transmission housing covering said second transmission unit and said lock-up clutch; and

a motor housing, said stator being fixed to said motor housing, and said motor housing being arranged between said second transmission housing and said engine.

7. The vehicle drive train according to claim 4, wherein said rotor is directly connected to said front cover for rotation therewith in forward and reverse directions.

8. The vehicle drive train according to claim 1 wherein said second transmission unit is a torque converter in the shape of a torus and which includes a turbine runner, a pump impeller, and a stator and wherein said lock-up clutch has a diameter smaller than the outside diameter of the torus.

9. The vehicle drive train according to claim 1 wherein said motor is a motor/generator which has a motor operating mode and a generator operating mode.

10. The vehicle drive train according to claim 1 wherein said first transmission unit is an automatic transmission.

11. The vehicle drive train according to claim 1 wherein said motor is a motor/generator which has a generator operating mode and a motor operating mode in which said motor powers the vehicle, whereby the vehicle is a hybrid vehicle.

12. The vehicle drive train according to claim 1 wherein:

said second transmission unit comprises a front cover covering a turbine runner and said lock-up clutch and connecting a pump impeller to said motor and said output element of said engine;

said front cover comprises an outer diameter portion covering said turbine runner and a center portion having a smaller diameter than a largest diameter portion of said outer diameter portion;

said center portion of the front cover covering said lock-up clutch;

said outer diameter portion having a taper portion connecting the largest diameter portion of the outer diameter portion to said center portion;

said rotor is disposed so that the inner diameter of the rotor is larger than the diameter of said center portion of the front cover and the outer diameter of the rotor is smaller than the diameter of said largest diameter portion of the outer diameter portion of the front cover;

said stator comprises a stator core and a coil, said coil comprises a coil end portion axially extending from said stator core, said stator core is disposed so as to axially overlap with said rotor and so that the inner diameter of the stator core is larger than the diameter of said rotor and smaller than the diameter of said large diameter portion of said front cover, said coil end portion is disposed so that at least a portion of said coil end portion is positioned radially over said taper portion of said outer diameter portion of said front cover and is radially coextensive with said largest diameter portion of said outer diameter portion.

13. A vehicle drive train comprising:

an engine;

a hydraulic transmission including a pump impeller, a turbine runner and a front cover integrally connected to an outer shell of said pump impeller and covering said turbine runner;

a motor including a stator and a rotor and being disposed between said transmission unit and said engine, said rotor being connected to an output element of said engine;

a center shaft integrally connected to said front cover;

a support member rotatable supporting said rotor,

said support member having a hub fitted on said center shaft; and

a nut which screws onto threads formed on said center shaft so as to press the hub of the support member against said front cover for rotation therewith.

14. The vehicle drive train according to claim 13:

wherein said transmission unit is a hydraulic transmission including a pump impeller, a turbine runner, a lock-up clutch and a front cover which is integrally connected to an outer shell of said pump impeller, said front cover covering said turbine runner and said lock-up clutch, and

wherein said vehicle drive train further comprises support members for supporting the rotor independently of said front cover on an engine side thereof and bearings mounted in said motor housing, interposed between said support members.

15. The vehicle drive train according to claim 14, wherein:

said motor housing has a side wall which separates said engine from said motor; and

said bearings are installed in an inner circumference of said side wall.

16. The vehicle drive train according to claim 13:

wherein said center shaft is axially aligned with a crankshaft of said engine and has an end opposing an end of the crankshaft with a gap therebetween, said center shaft and the crankshaft being connected by impact cushioning members.

17. The vehicle drive train according to claim 16, further comprising:

a plate hub connected to said crankshaft through said impact cushioning members, said plate hub forming a spline-couple with said center shaft, said spline couple being a press-fit between a helical spline and straight splines.

18. The vehicle drive train according to claim 16, wherein said impact cushioning members comprise two flexible plates.

19. The vehicle drive train according to claim 17, wherein said impact cushioning members comprise two flexible plates.

20. The vehicle drive train according to claim 13 wherein:

said motor is a motor/generator which has both a motor operational mode and a generator operational mode.

21. The vehicle drive train according to claim 13 additionally comprising an automatic transmission.

22. The vehicle drive train according to claim 21 wherein said automatic transmission is axially aligned with said hydraulic transmission, said rotor and said engine and wherein said hydraulic transmission is axially intermediate said automatic transmission and said rotor.

23. The vehicle drive train according to claim 13 wherein said motor is a motor/generator which has a generator operating mode and a motor operating mode in which said motor powers a vehicle, whereby the vehicle is a hybrid vehicle.

24. A vehicle drive train comprising:

an engine;

a transmission connected to said engine;

a motor having a stator and a rotor, said rotor being directly connected to an output element of said engine;

wherein;

said transmission has a small diameter portion and a large diameter portion having a diameter larger than said small diameter portion, said small diameter portion and said engine;

said motor axially overlaps an outer circumferential surface of said small diameter portion; and

said stator has an inner diameter smaller than the largest diameter of said second transmission unit.

25. A vehicle drive train comprising:

an engine;

a hydraulic transmission including a pump impeller, turbine runner and a front cover integrally connected to an outer shell of said pump impeller and covering said turbine runner;

a motor including a stator and a rotor, said rotor being connected to an output element of said engine;

a transmission housing enclosing said hydraulic transmission;

a motor housing for said motor provided between said transmission housing and said engine, said stator being fixed to said motor housing and said rotor being rotatably supported by said motor housing;

a center shaft integrally connected to said front cover;

a support member rotatably supporting said rotor, said support member having a hub fitted on said center shaft; and

a nut which screws onto threads formed on said center shaft so as to press the hub of the support member against said front cover for rotation therewith.