Search Results

Nowadays, the design of radiator of hydraulic system is based on the equilibrium temperature, i.e. under that temperature the heat energy generated by system is equal to the heat energy dissipated. When the working time is not long, the oil temperature can't reach the equilibrium temperature. If the design is still based on the equilibrium temperature, the designed radiator will be larger than needed. This paper studies the temperature rising transient of hydraulic system and suggests a new method of radiator design, which can rationally determine the dissipating area of radiator. This method have been used in the radiator design of a hydraulic crane and get a satisfied result.

When the speed of actuator is quickly changed in hydraulic system, the great pressure surge and noise are generally caused. In this paper, the optimal control for the minimum pressure surge in shortest speed conversion time is approached. The optimal control is obtained by applying the Pontryagin's Maximum Principle. Experimental results and simulation calculation show that using the optimal control can reduce the pressure surge to about 5 times in comparison with that of step input.

Base on the experience of practical operation and the results of model test, paper points out the features of tensioner hydraulic system and two main troubles that often cause the damage of hydraulic components. The mathematical model of the system is analyzed and the pressure response is calculated with respect to the step input of torque on hydraulic actuator. This calculated result agrees with our experimental result. For overcoming the shortage of pressure impulse, the measure of “prebuilding up pressure” is suggested, which was tested in our laboratory. The test proofs that this measure can effectively prevent pressure impulse caused by starting under full load.