Double differential type planetary stepless automatic variable speed gear for vehicle

Abstract

A double differential planetary stepless automatic speed change device for vehicle in which the main speed reducer is composed of a differential planetary gear train, and the differential speed feedback system is composed of another differential planetary gear train, both of the two parts connect to the one-way deceleration system. According to the invention, when the rotating speed difference between the input shaft and output shaft of the main speed reducer varies continuously, the rotating speed of the planet carrier of the differential speed feedback system varies continuously to control the rotating speed of the ring gear of the main speed reducer to vary continuously, so as to realize the full stepless variation of the transmission ratio of the main speed reducers. Then invention employs gear transmission which can greatly improve the reliability and the transmission efficiency of the stepless automatic speed change device.

Description

1. Technical field [0001] The invention is a double-differential planetary stepless automatic transmission device for vehicles, which belongs to the field of vehicle transmission technology. It can cooperate with the engine to realize automatic stepless speed change and torque conversion according to the road surface conditions. vehicle. 2. Background technology [0002] The transmission devices widely used in vehicles include manual transmission (MT), hydraulic automatic transmission (AT), electronically controlled mechanical automatic transmission (AMT) and mechanical continuously variable automatic transmission (CVT). [0003] MT-simple in structure, reliable in operation, low in cost and complex in operation. [0004] AT-consists of hydraulic torque converter, planetary gear and hydraulic control system, and achieves variable speed and torque through hydraulic transmission and gear combination. It already has an average loading rate of 70 percent in city cars produced ...

AI Technical Summary

Problems solved by technology

The combination of hydraulic torque converter and planetary gear has obvious disadvantages: the transmission ratio is discontinuous, and it can only realize stepless speed change within the subsection range; the efficiency of hydraulic transmission is low, which affects the power performance and fuel consumption of the whole vehicle. Economical; to increase the number of gears of the transmission to expand the coverage of continuously variable transmission, more actuators must be used to control the power transmission route of the planetary gear, resulting in too many parts of the automatic transmission, complex structure, and difficult repair; When the battery cannot be started due to lack of power, it cannot be started by pushing a cart or trailer

However, the hydraulic device in the CVT system is indispensable, so its manufacturing precision and structure complexity will make the production cost higher

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