Power train for hybrid electric vehicles and method of controlling the same

• US 20070287564A1
• Filed: 12/04/2006
• Published: 12/13/2007
• Est. Priority Date: 06/09/2006
• Status: Active Grant

• Current Assignee: Hyundai Motor Company (Hyundai Motor Group)
• Original Assignee: Hyundai Motor Company (Hyundai Motor Group)
• Inventors: Cho, Sung-Tae, Lee, Jang-Moo, Yang, Ho-Rim
• Granted Patent: US 7,691,021 B2
• Time in Patent Office: Days
• US Class Current: 475/5
• 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 6/40 characterised by the assembly or relative disposition of components
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60K 6/547 the transmission being a stepped gearing
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/115 with planetary gears
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/40 Controlling the engagement or disengagement of prime movers, e.g. for transition between prime movers power-up or power-down of the driveline B60W30/192
• CPC Class Codes: F16H 2037/102 the input or output shaft of the transmission is connected or connectable to two or more differentials
• CPC Class Codes: F16H 2037/104 Power split variators with one end of the CVT connected or connectable to two or more differentials
• CPC Class Codes: F16H 2037/106 with switching means to provide two variator modes or ranges
• CPC Class Codes: F16H 2200/2007 with two sets of orbital gears
• CPC Class Codes: F16H 2200/2035 with two engaging means
• CPC Class Codes: F16H 3/728 with means to change ratio in the mechanical gearing
• CPC Class Codes: Y02T 10/62 Hybrid vehicles

Abstract

A power train for hybrid vehicles increases the range of the transmission gear ratio within which the efficiency of the power train is superior. The method of operating the power train varies depending on the transmission gear ratio, and thus the power train can be operated with superior efficiency.

Claims

1. A power train having dual modes for hybrid electric vehicles, comprising:

an engine;

a first planetary gear set, comprising a first ring gear coupled to the engine;

a first motor generator coupled to a sun gear of the first planetary gear set;

a second planetary gear set;

a first clutch to couple or decouple the first sun gear of the first planetary gear set to or from a second sun gear of the second planetary gear set;

a second clutch to convert the second sun gear of the second planetary gear set between a stationary state and a rotatable state; and

a second motor generator, wherein

a first carrier of the first planetary gear set is coupled to a drive wheel through one operational element of the second planetary gear set, and the second motor generator is coupled to another operational element of the second planetary gear set.

2. The power train as defined in claim 1, wherein the first carrier of the first planetary gear set is coupled to the drive wheel through a second carrier of the second planetary gear set, and the second motor generator is coupled to a second ring gear of the second planetary gear set.

3. The power train as defined in claim 1, wherein the second clutch is provided between a power train case and the second sun gear of the second planetary gear set.

4. The power train as defined in claim 1, wherein each of the first and second planetary gear sets comprises a single pinion planetary gear.

5. The power train as defined in claim 1, wherein the first carrier of the first planetary gear set is coupled to the drive wheel through a second ring gear of the second planetary gear set, and the second motor generator is coupled to a second carrier of the second planetary gear set.

6. A method for controlling the power train of claim 2, wherein, relative to a mechanical point at which a speed of a first motor generator is zero, in a high transmission gear ratio region, a first clutch is disengaged and a second clutch is engaged, and, in a low transmission gear ratio region, the first clutch is engaged and the second clutch is disengaged.

7. A method for controlling the power train of claim 5, wherein, relative to a mechanical point at which a speed of a first motor generator is zero, in a high transmission gear ratio region, a first clutch is engaged and a second clutch is disengaged, and, in a low transmission gear ratio region, the first clutch is disengaged and the second clutch is engaged.

8. A method for controlling the power train in a hybrid electric vehicle having a transmission with at least two clutches and at least one electric motor generator, said method comprising:

disengaging one clutch and engaging the other clutch, wherein said clutches control cooperation of planetary gear sets with said electric motor generator, when motor generator speed is zero in a high transmission gear ratio; and

engaging said one clutch and disengaging said other clutch when said speed is zero in a low transmission gear ratio.