What are the management points for hydraulic gear pumps?

1. Pay attention to the steering and connection of the pump

Reversal will reverse the direction of suction and discharge

Keep pump and motor well aligned, preferably with flexibility

2. Although the gear pump has self-priming ability

There must be oil in the pump before starting (otherwise it will be severely worn)

The oil suction height is generally not greater than 0.5m.

3. Mechanical shaft seals are relatively precise components

Be careful not to damage the sealing components during disassembly and assembly

During installation, lubricating oil should be applied to the shaft and installed in the correct order. The ring should be floating when pushed by hand.

The shaft seal cover must be tightened evenly, and the mechanical shaft seal must prevent dry friction.

4. Do not work beyond the rated P

It will overload the prime mover, increase the load on the bearings, deform the working parts, increase wear and leakage, and cause jamming in severe cases.

5. Prevent the vacuum degree at the suction port from being greater than the allowable vacuum degree.

Otherwise, it cannot be inhaled normally

When the inhaled P is too low, "cavitation" will occur

The oil precipitates many bubbles in the low pressure area, and Q decreases

When the bubbles reach the high-pressure area, the air redissolves into the oil, forming a partial vacuum, and the surrounding high-pressure oil will flow at high speed to fill it.

Produces hydraulic shock, accompanied by violent noise

6. Maintain appropriate oil temperature and viscosity

The kinematic viscosity is preferably 25~33 mm2/s

If the viscosity is too small, leakage will increase and cavitation will easily occur.

Excessive viscosity will also reduce etav and cause abnormal inhalation.

7. Prevent inhalation of air

The flow rate will be reduced and noise will be generated.

8. The end clearance has a great influence on the self-priming capacity and ηv of the gear pump

It can be measured by pressing soft lead wire.

9. High-pressure gear pump is highly sensitive

The oil suction port can be used with a 150-mesh mesh filter.

Hydraulic system pumps require oil filter accuracy ≤30-40μm

The best accuracy of the oil return line filter is ≤20μm