Planet gear type automatic speed change system for electric automobile

Abstract

The invention relates to a planet gear type automatic speed change system for an electric automobile, which comprises a front planet row, a rear planet row and an input shaft, wherein a sun gear at the front end of the input shaft is meshed and connected with a first planet gear and a second planet gear; the first planet gear and the second planet gear are respectively meshed and connected with a first gear ring; a first clutch is arranged between a first planet carrier and the first gear ring; a first brake is arranged on the first gear ring; the first planet carrier is meshed and connected with a third planet gear and a fourth planet gear; the third planet gear and the fourth planet gear are respectively meshed and connected with a second gear ring; a second clutch is arranged between a second planet carrier and the second gear ring; a second brake is arranged on the second gear ring; and the second planet carrier is connected with an output shaft. The planet gear type automatic speed change system provided by the invention has the beneficial effects of simple and compact structure, smaller volume and weight and higher transmission efficiency, omits the link of adjusting the speed by a motor, shortens the gear shift time, improves the gear shift quality, and meets the light weight principle of an automobile.

Description

technical field [0001] The invention relates to a planetary gear type automatic transmission system for an electric vehicle. Background technique [0002] At present, electric vehicles, especially electric buses, have entered the stage of industrialization in China. Since the drive motor cannot meet the requirements of high speed and high climbing performance of electric vehicles at the same time, the gearbox cannot be replaced. Due to its high transmission efficiency, simple structure and low cost, mechanical automatic transmissions are widely used in electric buses. At present, the most advanced pure electric buses in China (operated in the Olympic Games, World Expo and Asian Games) adopt A mechanical automatic transmission is adopted. The car integrates the control of the motor and the mechanical automatic transmission (AMT), utilizes the characteristics of motor speed regulation, cancels the clutch, and realizes automatic gear shifting. However, in actual operation, the...

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Problems solved by technology

However, in actual operation, there are also disadvantages such as long shifting time and obvious shifting impact. The root cause is that the current mechanical automatic transmission uses a traditional fixed-shaft gearbox. When the gear is removed and engaged, the speed of the motor must be adjusted, resulting in an increase in the shifting time. At the same time, during the shifting process, the driving force of the drive motor disappears first and then recovers, which will also cause a more obvious shifting impact.

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