A pressure stepless transmission based on nw type planetary gear train

Abstract

The invention discloses an NW-type planetary gear train-based pressure stepless speed change device. In a planetary gear train structure, a rotating body is arranged in a rack shell, and the rotating body is fixedly provided with three planetary shafts vertically distributed evenly along circumference; a duplex planetary gear which consists of a small planetary gear and a large planetary gear is arranged on each planetary shaft through a bearing; an eccentric gear is located between the small planetary gear and the large planetary gear; a sun gear is located among the three large planetary gears; in a pressure stepless speed change structure, a hollow drive shaft is arranged at a central position of the sun, and the hollow drive shaft is provided with hydraulic clutches, hydraulic motors and sensors in sequence; the hollow drive shaft is driven by the hydraulic motors; hydraulic oil is delivered into the hydraulic clutches through a hollow channel of the hollow drive shaft to transmit power to realize pressure stepless speed change. The NW-type planetary gear train-based pressure stepless speed change device disclosed by the invention is simple and compact in structure, low in manufacturing cost and stable in speed change, and drive efficiency reaches up to 99 percent.

Description

technical field [0001] The invention relates to a continuously variable transmission, especially on the basis of the NW type two-degree-of-freedom planetary gear train, a continuously variable transmission structure that uses hydraulic speed regulation to perform stepless transmission. The continuously variable transmission structure can be used according to the input power of the motor, The input power and load of the hydraulic pump are actively and continuously variable, and are suitable for variable speed transmission mechanisms of various types of machinery such as vehicles and machine tools. Background technique [0002] CVT devices are mainly divided into two categories: mechanical and electrical. The electric type is currently used more in the market, that is, the stepless speed regulation is realized through frequency conversion. However, there are many shortcomings that are difficult to overcome in the electric stepless speed regulation: complex technology, high co...

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Problems solved by technology

However, there are many shortcomings that are difficult to overcome in the electric stepless speed regulation: complex technology, high cost, and difficult maintenance; generation of harmonics pollutes the power grid; output PWM waves cause additional heat generation of motors and cables; generation of common-mode voltage is possible It will reduce the life of the motor shaft; it will bring extra noise to the motor; the energy consumption of the motor will increase by 3-5% compared with direct starting after the motor is controlled by a frequency converter; The occasions are limited, and it is only suitable for places that require high speed regulation accuracy, good speed regulation performance, and small starting torque

Therefore, the continuously variable transmission device is only suitable for small electric vehicles, and its application range is limited

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