Power loss analysis of hydraulic pump of hydraulic press

The hydraulic pump of the hydraulic press has two losses during operation. One is quantity loss, the other is machine loss.

First, the main cause of volume loss

1. Displacement hydraulic pump The suction chamber and the discharge chamber of the displacement pump are separated in the pump, but there is always a certain gap in the relative movement. Therefore, the oil in the high-pressure area of the pump must leak through the gap. To the low pressure area. The lower the viscosity of hydraulic oil, the higher the pressure, the greater the leakage.

2. The hydraulic pump of the hydraulic press is in the process of suction. Because the suction resistance is too large, the oil is too viscous or the pump shaft speed is too fast, the suction force of the pump will be formed, resulting in the working volume of the seal can not be filled with oil. The working chamber of the hydraulic pump is not fully utilized.

Due to the above reasons, the hydraulic pump of the hydraulic press is lost. However, as long as the pump is designed and used properly, the loss caused by the second reason can be overcome, that is, the volume loss of the pump can be reduced. However, the volume loss due to leakage during the operation of the hydraulic pump of the hydraulic press is inevitable. That is to say, the loss of pump volume can be approximated as a complete leak, and the actual flow of the hydraulic pump of the hydraulic press is always less than the theoretical flow. . The practice process and management flow ratio is called volume power and indicates the degree of volume loss of the hydraulic pump of the hydraulic press. The volume power of the hydraulic pump of the hydraulic press indicates the degree of volume loss of the hydraulic pump of the hydraulic press.

Second, the main reasons for the formation of mechanical losses

1. When the hydraulic pump of the hydraulic press works, there is a mechanical conflict between the relative moving parts between the bearing and the shaft, between the shaft and the seal, and between the blade and the inner wall of the pump, and then the collision resistance will be lost. This loss is related to the output pressure of the hydraulic pump of the hydraulic press. The higher the output pressure, the greater the loss of conflict resistance.

2. When the oil moves in the pump, viscous resistance occurs due to the viscosity of the liquid, and mechanical losses are also formed. This loss is related to the viscosity of the oil and the speed of the pump. The thicker the oil, the higher the pump speed, the greater the mechanical loss.

Due to the above reasons, the input power of the pump is greater than the theoretically required power. The ratio of the theoretical input power to the actual input power of the hydraulic pump of the hydraulic press is called the mechanical power, indicating the degree of power loss. The ratio of the output power and input power of the hydraulic pump of the hydraulic press is called the total power of the hydraulic pump of the hydraulic press

Four-column trimming hydraulic press