Drive unit for hybrid vehicle

• US 6,041,877 A
• Filed: 09/27/1996
• Issued: 03/28/2000
• Est. Priority Date: 09/29/1995
• Status: Expired due to Term

• Current Assignee: Fuji Heavy Industries Limited (Subaru Corp.)
• Original Assignee: Fuji Heavy Industries Limited (Subaru Corp.)
• Inventors: Matsui, Fujio, Hiroishi, Shihomi, Yamada, Takemasa, Komatsu, Kenzo
• Primary Examiner(s): Swann, J J
• Assistant Examiner(s): VANAMAN, FRANK BENNETT
• Application Number:
  US08/721,657
• Time in Patent Office: 1,278 Days
• Field of Search: 180/65.2, 180/65.3, 180/65.6, 180/68.5, 180/242, 180/243, 180/233
• US Class Current: 180/65.25
• CPC Class Codes: B60K 17/344 having a transfer gear
• CPC Class Codes: B60K 17/346 the transfer gear being a differential gear
• 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 23/08 for changing number of driven wheels , for switching from driving one axle to driving two or more axles B60K17/3515 takes precedence
• CPC Class Codes: B60K 6/40 characterised by the assembly or relative disposition of components
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60K 6/52 Driving a plurality of drive axles, e.g. four-wheel drive
• CPC Class Codes: B60K 6/543 the transmission being a continuously variable transmission
• CPC Class Codes: B60L 2260/28 Four wheel or all wheel drive
• CPC Class Codes: B60L 2270/40 related to technical updates when adding new parts or software
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 50/40 using propulsion power supplied by capacitors
• CPC Class Codes: B60L 50/66 Arrangements of batteries
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/10 including control of change-speed gearings
• CPC Class Codes: F16H 2003/123 using a brake
• CPC Class Codes: F16H 2061/0422 by an electric machine, e.g. by accelerating or braking the input shaft
• CPC Class Codes: F16H 3/126 using an electric drive
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y10S 903/903 : having energy storing means, e.g. battery, capacitor
• CPC Class Codes: Y10S 903/906 : Motor or generator
• CPC Class Codes: Y10S 903/907 : Electricity storage, e.g. battery, capacitor
• 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 903/916 : with plurality of drive axles
• CPC Class Codes: Y10S 903/918 : Continuously variable
• CPC Class Codes: Y10S 903/945 : Characterized by control of gearing, e.g. control of transmission ratio
• CPC Class Codes: Y10S 903/946 : Characterized by control of driveline clutch
• CPC Class Codes: Y10S 903/951 : Assembly or relative location of components

Abstract

A drive unit for a hybrid vehicle includes: an internal combustion engine 1; a transmission 3 connected to the internal combustion engine 1 via a clutch 2; a primary differential gear 11 for distributing a driving force transmitted from the transmission 3, to primary driving wheels 17 and 18; a transfer 20 connected to the primary differential gear for taking out a part of the driving force transmitted from the transmission 3 to the primary differential gear 11; a pair of propeller shafts 26 and 27 formed by dividing two parts in axial directions for transmitting part of the driving force from the transfer to a secondary differential gear 33; an electric motor 31 provided between these propeller shafts 26 and 27; and a pair of clutches 29 and 30, each connecting the electric motor 31 to one of the pair of propeller shafts 26 and 27. Therefore, the drive unit can be used for 2WD or 4WD hybrid vehicles without changing the main components.

Claims

1. In a driving force transmitting system that modifies a conventional four-wheel drive vehicle to a two-wheel drive hybrid vehicle, wherein the conventional four-wheel drive vehicle includes (a) an internal combustion engine for generating a driving force, (b) a transmission connected to the engine via a clutch, (c) a first differential mechanically connected to the transmission and provided to absorb a speed difference between a first pair of left and right wheels, and (d) a transfer unit mounting portion provided outside the transmission, wherein the improvement comprises:

an electric motor mounted on the transfer unit mounting portion in place of a transfer unit, wherein the electric motor is operatively connected, via the first differential, to drive the first pair of left and right wheels, and

wherein the hybrid vehicle operates in a two-wheel drive operating mode, wherein the first pair of left and right wheels are driven by the internal combustion engine, the electric motor, or both.

2. The driving force transmitting system according to claim 1, wherein the electric motor includes a reduction gear for reducing the motor speed, an output shaft operatively engaged with the first differential, and a motor clutch for engaging the reduction gear with the output shaft.

3. The driving force transmitting system according to claim 1, wherein the clutch that connects the internal combustion engine with the transmission is an electromagnetic clutch.

4. The driving force transmitting system according to claim 1, wherein the transmission is a continuously variable transmission.

5. The driving force transmitting system according to claim 1, further including a capacitor and a battery, located in a central portion of the hybrid vehicle and operatively connected to supply electric power to the electric motor.

6. A driving force transmitting system for a hybrid vehicle having (a) an internal combustion engine for generating a driving force, (b) a transmission connected to the engine via a clutch, and (c) a first differential operatively connected to the transmission and provided to absorb a speed difference between a first pair of left and right wheels, the driving force transmitting system comprising:

a transfer unit operatively connected to the first differential and provided with an output shaft to transmit driving force to a second pair of left and right wheels, to drive the vehicle in a four-wheel drive mode, wherein, in the four-wheel drive mode, the internal combustion engine exclusively provides driving force to drive both the first pair of left and right wheels and the second pair of left and right wheels;

an electric motor located outside the transmission and directly connected to the output shaft of the transfer unit when the vehicle is operated in a two-wheel drive mode, wherein the electric motor is operatively connected to drive the first pair of right and left wheels by driving the output shaft of the transfer unit, and wherein the electric motor drives the vehicle only in the two-wheel drive mode.

7. The driving force transmitting system according to claim 6, wherein the electric motor includes a reduction gear for reducing the motor speed, a motor output shaft operatively engaged with the output shaft of the transfer unit, and a motor clutch for engaging the reduction gear with the motor output shaft.

8. The driving force transmitting system according to claim 6, wherein the clutch that connects the internal combustion engine with the transmission is an electromagnetic clutch.

9. The driving force transmitting system according to claim 6, wherein the transmission is a continuously variable transmission.

10. The driving force transmitting system according to claim 6, further including a capacitor and a battery, located in a central portion of the hybrid vehicle and operatively connected to supply electric power to the electric motor.

11. The driving force transmitting system according to claim 6, wherein the transfer unit includes an input shaft coupled to the output shaft of the transfer unit via a viscous coupling.

12. The driving force transmitting system according to claim 6, wherein the transfer unit includes a transfer clutch for connecting the transfer unit to the first differential.

13. The driving force transmitting system according to claim 12, wherein the transfer clutch is a hydraulic multiple-disc clutch.