Transmission, vehicle, hybrid vehicle, and control unit therefor

• US 6,258,006 B1
• Filed: 02/04/2000
• Issued: 07/10/2001
• Est. Priority Date: 02/05/1999
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Sakamoto, Hiroshi, Minowa, Toshimichi, Masaki, Ryoso, Hanyu, Tomoyuki, Miyazaki, Taizo
• Primary Examiner(s): Wright, Dirk
• Application Number:
  US09/498,065
• Time in Patent Office: 522 Days
• Field of Search: 475/5, 477/5
• US Class Current: 477/5
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• 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 6/445 Differential gearing distribution type
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: F16H 2037/0873 with switching, e.g. to change ranges
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y10S 903/903 having energy storing means, e.g. battery, capacitor
• CPC Class Codes: Y10S 903/905 Combustion engine
• CPC Class Codes: Y10S 903/906 Motor or generator
• CPC Class Codes: Y10S 903/91 Orbital, e.g. planetary gears
• 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 903/945 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

Disclosed is a transmission comprising a first power transfer path for transferring an output of an engine to a vehicle driving shaft through a planetary gear connected to a motor, a second power transfer path for transferring the output of the engine to the vehicle driving shaft through gears and, and a power transfer switch which switches over the first and second power transfer paths from one to the other. In a hybrid vehicle wherein an engine, a motor and a generator are connected to a planetary gear, a follow-up loss caused by the generator is avoided in the case where the engine stops and the vehicle travels with the motor alone. In high-speed running, it is avoided that an electric energy for stopping the rotation of the generator is consumed. Further, torque assist by the generator is not restricted by constraints of the planetary gear.

Claims

1. A transmission comprising:

a first power transfer path for transferring an output of an internal combustion engine to a vehicle driving shaft through a differential mechanism in which power of an electric rotary machine is transferred to one of rotary elements;

a second power transfer path for transferring the output of said internal combustion engine to said vehicle driving shaft through gears; and

a power transfer switching means for switching over said first and second power transfer paths from one to the other.

2. A transmission according to claim 1, wherein said power transfer switching means has a neutral mode in which the output of said internal combustion engine is separated from both said first and second power transfer paths.

3. A transmission according to claim 1, further including a lock mechanism for restricting the rotation of a rotary element in said differential mechanism which rotary element is located on the internal combustion engine side.

4. A transmission according to claim 1, wherein said power transfer switching means is a dog clutch.

12. A transmission according to claim 2, wherein said power transfer switching means is a dog clutch.

13. A transmission according to claim 3, wherein said power transfer switching means is a dog clutch.

5. A vehicle having an internal combustion engine and an electric rotary machine, said vehicle comprising:

a vehicle driving shaft to which are fixed at least a high speed gear and a low speed gear;

a planetary gear having at least three rotary elements, of which a first rotary element is connected to said low speed gear and a second rotary element is connected to a rotating shaft of said electric rotary machine; and

a dog clutch having at least three rotary elements, of which a first rotary element is connected to a rotating shaft of said internal combustion engine, a second rotary element is connected to said high speed gear, and a third rotary element is connected to a third rotary element of said planetary gear;

said dog clutch having a mechanism for selectively connecting the first rotary element thereof to the second or the third rotary element thereof and for neutralizing the first rotary element relative to the second and third rotary elements.

6. A vehicle according to claim 5, further including a lock mechanism for restricting the rotation of the third rotary element in said dog clutch.

7. A vehicle having an internal combustion engine and a motor generator, said vehicle comprising:

a first power transfer path for transferring an output of said internal combustion engine to a vehicle driving shaft through a differential mechanism in which power of said motor generator is transferred to one of rotary elements;

a second power transfer path for transferring the output of said internal combustion engine to said vehicle driving shaft through gears; and

a dog clutch for switching over from one to another among a first mode which selects said first power transfer path, a second mode which selects said second power transfer path, and a neutral mode which separates said internal combustion engine from the first and second power transfer paths.

8. A vehicle having an internal combustion engine and a motor generator, said vehicle comprising:

a vehicle driving shaft to which are fixed at least a high speed gear and a low speed gear;

a planetary gear having at least three rotary elements, of which a first rotary element is connected to said low speed gear and a second rotary element is connected to a rotating shaft of said motor generator; and

a dog clutch having at least three rotary elements, of which a first rotary element is connected to a rotating shaft of said internal combustion engine, a second rotary element is connected to said high speed gear, and a third rotary element is connected to a third rotary element in said planetary gear;

said dog clutch having a mechanism for selectively connecting the first rotary element thereof to the second or the third rotary element thereof and for neutralizing the first rotary element relative to the second and third rotary elements.

9. A hybrid vehicle comprising:

an internal combustion engine;

a plurality of electric rotary machines;

a first drive path through which an output obtained by the addition of an output of said internal combustion engine and an output of the first electric rotary machine is transferred to a vehicle driving shaft;

a second drive path through which an output obtained by subtracting one of an output of said internal combustion engine and an output of the second electric rotary machine from the other is transferred to said vehicle driving shaft; and

means for selecting either said first or said second drive path.

10. A control unit provided in a hybrid vehicle, said hybrid vehicle comprising:

an internal combustion engine;

an electric rotary machine;

a vehicle driving shaft to which are fixed at least a high speed gear and a low speed gear;

a planetary gear having at least three rotary elements, of which a first rotary element is connected to said low speed gear and a second rotary element is connected to a rotating shaft of a motor generator; and

a dog clutch having at least three rotary elements, of which a first rotary element is connected to a rotating shaft of said internal combustion engine, a second rotary element is connected to said high speed gear, and a third rotary element is connected to a third rotary element of said planetary gear;

said dog clutch having a mechanism for selectively connecting the first rotary element thereof to the second or the third rotary element thereof and for neutralizing the first rotary element relative to the second and third rotary elements,

wherein the number of rotation of the third rotary element in said dog clutch is controlled in accordance with a detected number of rotation of said vehicle driving shaft and by controlling the number of rotation of said electric rotary machine, and the first and third rotary elements in said dog clutch are connected together upon substantial coincidence in the number of rotation of the two.

11. A control unit provided in a hybrid vehicle, said hybrid vehicle comprising;

an internal combustion engine;

an electric rotary machine;

a vehicle driving shaft to which are fixed at least a high speed gear and a low speed gear;

a planetary gear having at least three rotary elements, of which a first rotary element is connected to said low speed gear and a second rotary element is connected to a rotating shaft of a motor generator; and

a dog clutch having at least three rotary elements, of which a first rotary element is connected to a rotating shaft of said internal combustion engine, a second rotary element is connected to said high speed gear, and a third rotary element is connected to a third rotary element in said planetary gear;

said dog clutch having a mechanism for connecting the first rotary element thereof to the second or the third rotary element thereof selectively and for neutralizing the first rotary element relative to the second and third rotary elements and a locking mechanism which restricts the number of rotation of the third rotary element in the dog clutch,

wherein the number of rotation of the third rotary element in the dog clutch is controlled in accordance with a detected number of rotation of said vehicle driving shaft and by controlling the number of rotation of said electric rotary machine, and said locking mechanism is operated upon substantial stop of rotation of the third rotary element in said dog clutch.