Power transmission apparatus for a vehicle

Patent metadata

Field	Value
Publication number	US-10272765-B1
Application number	US-201715821487-A
Country	US
Kind code	B1
Filing date	Nov 22, 2017
Priority date	Nov 1, 2017
Publication date	Apr 30, 2019
Grant date	Apr 30, 2019

Abstract

A power transmission apparatus for a vehicle may include: a first, second, third, and fourth input shaft; an output shaft; an idle shaft; a fixed transmission performing shifts to fixed shift stages depending on gear ratios of four change gear trains; and a torque assist driving and electronic continuously variable automatic transmission performing a torque assist for a torque input from the fixed transmission and performing electric vehicle driving and electronic continuously variable automatic transmission functions to output the torque through the output shaft. The disclosed power transmission apparatus implements fixed shift stages of four forward speeds and one reverse speed in a dual clutch transmission (DCT) structure that uses three synchronizers. The disclosed power transmission apparatus improves fuel consumption and acceleration performance by adding one planetary gear set and a motor/generator to enable driving in an electric vehicle (EV) mode and an electronic continuously variable automatic transmission (e-CVT) mode.

First claim

What is claimed is:

1. A power transmission apparatus for a vehicle, the power transmission apparatus comprising:
a first input shaft selectively connected to an engine output shaft through a first clutch;
a second input shaft formed of a hollow shaft and disposed on an outer circumference of the first input shaft without rotation interference to overlap the first input shaft, the second input shaft being selectively connected to the engine output shaft through a second clutch;
a third input shaft disposed in parallel with the first and second input shafts, wherein the third input shaft is spaced apart from the first and second input shafts by predetermined intervals;
an output shaft disposed in parallel with the first and second input shafts, wherein the output shaft is spaced apart from the first and second input shafts by predetermined intervals;
a fourth input shaft formed of a hollow shaft and disposed on an outer circumference of the output shaft without rotation interference to overlap the output shaft;
an idle shaft spaced apart from the first and second input shafts by predetermined intervals;
a fixed transmission configured to shift fixed shift stages depending on gear ratios of four change gear trains, wherein the four change gear trains are selectively disposed on the first, second, third, and fourth input shafts and the idle shaft and externally connected to each other; and
a torque assist driving and electronic continuously variable automatic transmission disposed on the output shaft and one side end of the fourth input shaft, wherein the torque assist driving and electronic continuously variable automatic transmission is configured to perform a torque assist for a torque input from the fixed transmission as well as electric vehicle driving and electronic continuously variable automatic transmission functions to output the torque through the output shaft,
wherein the four change gear trains include:
a first change gear train including a first drive gear disposed on the outer circumference of the first input shaft without rotation interference, a second drive gear disposed on an outer circumference of the third input shaft without rotation interference, and a first driven gear formed integrally with the fourth input shaft and externally connected to both of the first drive gear and the second drive gear;
a second change gear train including a reverse drive gear disposed on an outer circumference of the idle shaft without rotation interference and a second driven gear formed integrally with the fourth input shaft and externally connected to the reverse drive gear;
a third change gear train including a third drive gear disposed on the outer circumference of the first input shaft without rotation interference, a fourth drive gear disposed on the outer circumference of the third input shaft without rotation interference, and a third driven gear formed integrally with the fourth input shaft and externally connected to both of the third drive gear and the fourth drive gear; and
a fourth change gear train including a first power transferring gear formed integrally with the second input shaft, a second power transferring gear formed integrally with the third input shaft, and an idle gear formed integrally with the idle shaft and externally connected to both of the first power transferring gear and the second power transferring gear.

2. The power transmission apparatus of claim 1 , wherein:
the first drive gear and the third drive gear are selectively synchronously connected to the first input shaft by a first synchronizer,
the second drive gear and the fourth drive gear are selectively synchronously connected to the third input shaft by a second synchronizer, and
the reverse drive gear is synchronously connected to the idle shaft by a third synchronizer.

3. The power transmission apparatus of claim 1 , wherein:
the first change gear train has a gear ratio for forward 1-speed and 2-speed,
the second change gear train has a gear ratio for reverse,
the third change gear train has a gear ratio for forward 3-speed and 4-speed, and
the fourth change gear train has a gear ratio for forward 2-speed and 4-speed and reverse.

4. The power transmission apparatus of claim 1 , wherein:
the torque assist driving and electronic continuously variable automatic transmission includes:
a motor/generator;
a planetary gear set configured to transfer torque input from the third input shaft and the motor/generator to the output shaft or control a rotation speed of the third input shaft depending on a rotation speed of a motor shaft of the motor/generator; and
a third clutch selectively connecting two of three rotation elements to each other so that the planetary gear set integrally rotates.

5. The power transmission apparatus of claim 4 , wherein:
the planetary gear set is a pinion planetary gear set, and includes:
a sun gear fixedly connected to the motor shaft of the motor/generator;
a planetary carrier fixedly connected to the output shaft; and
a ring gear fixedly connected to the third input shaft and selectively connected to the planetary carrier by the third clutch.

Assignees

• Hyundai Motor Co Ltd
• Kia Motors Corp

Inventors

• Cho Wonmin
• Hwang Seong Wook
• Park Kijong
• Ji Seongwook
• Kim Ki Dong
• KWON Hyun Sik
• Jang Cheol Ho
• Kook Jae Chang
• Kim Ki Tae

Classifications

• B60K6/547

  the transmission being a stepped gearing · CPC title

• B60K6/543 Primary

  the transmission being a continuously variable transmission · CPC title

• B60Y2200/92

  Hybrid vehicles · CPC title

• Y10S903/919

  Stepped shift · CPC title

• F16H2200/2005

  with one sets of orbital gears · CPC title