Automatic transmission for electric vehicle

Abstract

An automatic transmission for an electric vehicle is provided with a belt type continuously variable transmission mechanism (3) in which an input unit (30P) is arranged so as to be capable of rotation relative to an input shaft (2A) and that adjusts a pulley winding radius and a clamping force by an electric actuator (80A) and a mechanical reaction force mechanism (80B, 9), a constant mesh parallel shaft geared transmission mechanism (4) that is coupled to an output unit (30S) of the belt type continuously variable transmission mechanism (3) and has a plurality of speed stages, an input gear (21) that is arranged on the input shaft (2A) so as to be capable of relative rotation and is drivably coupled to one of a plurality of transmission gears fixedly installed on an output-side shaft of the constant mesh parallel shaft geared transmission mechanism (4), and a meshing clutch mechanism (5A) that is arranged on the input shaft (2A) and selectively couples either one of the input unit (30P) of the belt type continuously variable transmission mechanism (3) or the input gear (21) to a main electric motor (1).

Description

Technical field [0001] The present invention relates to an automatic transmission for an electric vehicle having a belt-type continuously variable transmission mechanism for an electric vehicle running only with an electric motor as a driving source. Background technique [0002] In the case of an electric vehicle (also referred to as EV) that only uses an electric motor as a driving source, the electric motor has a gentle torque characteristic, so the power train is usually composed of a combination of the electric motor of the driving source and a reducer with a constant speed ratio. And output the structure. [0003] In such electric vehicles, ensuring the cruising distance has become a major issue. As a way to extend the cruising distance, first consider increasing the battery capacity and reducing the weight of the vehicle. However, if the battery capacity is increased, the weight of the vehicle will increase, which will shorten the cruising distance. [0004] In addition, in...

AI Technical Summary

Problems solved by technology

In addition, oil pumps and pump-driving motors not only increase the cost, but also increase the weight of the vehicle. From this point of view, the cruising distance of electric vehicles is also shortened.

[0009] In addition, in the case of a CVT, compared with an automatic transmission using a gear mechanism such as a planetary gear, the transmission efficiency at high speed and high load is generally inferior, and there is a problem of poor power consumption at high speed driving.

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