Why does the pressure of the shaft head oil pump fluctuate with the motor speed?
Thread Content
The oil pressure of the 50 Hz high-speed cooling motor is 2.3 kg, and the oil temperature slowly drops to 1.2 kg as the oil temperature rises. The oil temperature of the 28 Hz low-speed motor drops from 1.2 to 0.7 kg, and the alarm stops. After inspection, no oil leakage was found in the air intake tunnel.
The oil temperature is high and the oil pressure is low. The process conditions of each part must be strictly controlled according to the equipment usage conditions. The cooling temperature at maximum load should be set to adjust the cooler temperature to control the upper temperature limit. It is possible that the cooling efficiency is reduced due to a clogged cooler. For reference.
1. Adjust the voltage first. 2 If it doesn't go up again, it should be repaired.
The oil temperature is low, the viscosity is high, and the oil pressure is high. The motor speed drops, the pump speed also drops, and of course the oil pressure is low. The design idea seems wrong.
Most shaft head oil pumps are gear pumps. The oil has high viscosity and small internal leakage at normal temperature, so the pressure is naturally high. After the oil temperature rises, the viscosity becomes smaller and the pressure will naturally decrease.
Oil pressure and oil temperature are related. If the oil temperature is low and the oil viscosity is high, the oil pressure will be high. If the oil temperature is high and the oil viscosity is low, the oil pressure will be low. The speed of the oil pump on the shaft head is directly proportional to the speed of the motor. When the motor speed decreases and the oil pump speed decreases, the oil pressure will inevitably decrease. When the motor is 30Hz, you can increase the oil pressure and then lower it to 28Hz, and the pressure will not drop to 0.7.
It depends on the oil brand and the different viscosity-temperature properties of different oil products. It is not simply that low oil temperature and high oil viscosity mean high oil pressure; high oil temperature and low oil viscosity mean low oil pressure. Find out whether the reason is that the selected oil does not match the equipment, and whether the oil is contaminated by wear and tear. This is just based on the industry I am in.
The 50HZ heat engine is only 1.2, and the difference between 30 and 28 is not much, less than one kilogram. When the gear was disassembled, it was worn, and the leader thought it was fine. . . , now the oil in the crankcase is changed to splash and pressure lubrication and it will start.
Try adjusting the gear end clearance smaller, or there is a pressure regulating valve next to the oil pump. You can adjust the oil pressure to increase the oil pressure. It is the return valve that returns to the oil tank and is also a pressure relief valve. Turn it down to reduce the return flow and the oil pressure can be raised. If the oil pressure is low for a long time, the large bearing bush and the small head bush will be seriously worn, and the machine will vibrate and make abnormal noises. In serious cases, accidents such as shaft locking, scrapped crankshaft, connecting rod and crosshead locking may occur.
Thank you very much. The pressure regulating valve has been screwed all the way. When the engine is cold, the pressure is 4.5 kg. After the oil temperature comes up, it drops to 1.2. How to adjust the gear end clearance? Grind off the end cap? There is no adjustment mechanism or gasket on the end face of this pump gear.