Variable-displacement plunger pump and constant-power control device thereof

Abstract

The invention discloses a constant-power control device. The constant-power control device comprises a rotary element, wherein a rotary central element is arranged on the rotary element; the rotary central element is connected with a power element; the rotary element is capable of rotating around the rotary central element; the rotary element is connected with a variable-displacement pump outputting a hydraulic liquid to the outside; and the position of the rotary central element can be adjusted and fixed, so that adjustment for the force arm of the thrust force of the power element on the rotary element relative to a rotary center is facilitated. When the position of the rotary central element is changed, the force arm is also changed; because the force arm is a parameter for judging theoutput power of the variable-displacement pump, in a rotation process, output power curves corresponding to the whole change range of the force arm are also changed; and a user can determine the output power curve with the minimum deviation, and the corresponding position of the rotary central element in a plurality of different output power curves corresponding to the different position adjustment amounts of the rotary central element. The invention further discloses a variable-displacement plunger pump comprising the constant-power control device.

Description

technical field [0001] The present invention relates to the field of mechanical control, and more specifically, relates to a constant power control device of a piston variable displacement pump. In addition, the present invention also relates to a plunger variable displacement pump including the above constant power control device. Background technique [0002] In the hydraulic control system of construction machinery, constant power control is one of the most widely used variable modes for axial piston variable pumps. Using constant power control can make full use of the power of the engine, so that the output of the main pump when the main engine performs multiple actions The flow rate corresponds to the load pressure. In constant power control, the main pump can automatically adjust the output flow according to the load pressure, so as to control the movement speed of the main engine's hoisting, telescopic and slewing actions. [0003] For a certain plunger variable disp...

AI Technical Summary

Problems solved by technology

[0003] For a certain plunger variable displacement pump, the spring preload can be adjusted through the power valve to adjust the pressure starting point of its constant power control during the factory test, but it cannot adjust the changing trend of the constant power curve in the entire variable range

Due to the inherent characteristics of the constant power control mechanism of the plunger variable pump, the output power of the variable pump will deviate to varying degrees under different starting pressures, and the constant power output cannot be maintained, and the obtained constant power curve has a large deviation. As a result, the pressure and flow output by the plunger variable pump do not match the parameters required by the host, and the higher the system pressure, the greater the deviation of the output power of the plunger variable pump, which will easily lead to malfunction of the host, and even a safety accident in severe cases

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