Two ways to lubricate the shaft bearing of submersible water pump

Oil drop from oil cup (submersible water pump):

This way of lubricating is to let oil drop onto the shaft bearing from the outlet of oil cup. Its advantages are simple structure, convenience and oil-saving. Besides, the supply amount can be adjusted through the outlet. Generally, the speed had better be 3~8 drops per second. Too much lubricating oil will make the shaft bearing rise in temperature. Its disadvantages are that the viscosity of the lubricating oil has to meet certain requirement. If it has too high viscosity, it will lose the function of dissipation. The oil drop way of lubricating is suitable for occasions where the submersible water pump rotates at low speed, with fewer load and the working temperature is low.

Oil bath or oil immersed lubricating:
This way is to immerse the shaft bearing into the lubricating oil. When the shaft bearing moves, it will bring the oil to other parts of the submersible water pump. Oil bath lubricating is one of the most common and easiest ways.

Considering about oil loss in mixing and temperature rise, for horizontal shafts, there should be a limit to the depth of shaft bearing in lubricating oil. Usually, we should keep the oil level near the center of the rolling body at bottom of the shaft bearing. With oil bath, we can thoroughly lubricate the shaft bearing. But it is not convenient to adjust the supply amount of oil. If there is no filter device, it will be easy for impurities to enter the shaft bearing and damage it. This method is usually suitable for submersible water pumps rotating at low speed or medium speed, more common for low speed shaft bearings.

According to our experience, separable reinforcing rib can be installed at the bottom of the shaft base to reduce blending or to improve dissipation. Static oil level should a little lower than the center of the rolling body of the horizontal shaft. As for vertical shaft, static oil level should cover 50%~80% of the rolling body. If the temperature of the shaft bearing is high when you use oil bath system, you can change to the oil drop method.