The investigative object of the article is the stepless speed regulating system.

The analysis on the simulation results in stepless speed regulating system of automotive air-conditioning fan shows that the fuzzy PI control is better than the conventional PI control.

The production practice of frequency converting reform of 6/500 strander shows that the average loading current of motor is from 50?A before reform to 20?A after reform,consumed electricity energy is cut down greatly,stepless speed regulating and soft starting are realized,noise and fault rate are decreased,and output is increased.

The finisher's oilstone-pressing system adopted air-pressing technology by combining shuttle valve with proportion valve,which made oilstone pressure realize classless pressure adjustment .

It is verified that the new hydraulic breaking hammer features simple structure,stepless adjustment of impacting power and frequency,power saving,easy maintenance,etc.

A new stepless speed regulation booster pump drove by hydraulic power was developed according to this oil driving technology.

A scheme for DF_(4A) diesel locomotive combined governor to convert to stepless speed regulation from step one in depot work shop was proposed.

Stator double fed sine phase moving stepless speed regulation asynchronous machine is a new type of speed regulation motor, it integrates motor and speeder system.

Development of dedicated all-fresh air dehumidifiers with stepless load regulation for underground spaces;