What is a hydrostatic bearing?

The bearings we usually hear about are deep groove ball bearings or roller bearings. Basically, we rarely hear hydrostatic bearings. Do you know hydrostatic bearings? The following YWS bearings take you through the characteristics of hydrostatic bearings.

A plain bearing that uses static lubrication is called a hydrostatic bearing. Hydrostatic lubrication differs from the principle of dynamic lubrication in that the hydrostatic bearing is supplied with pressurized oil by an external lubricating oil pump to form a pressurized oil film to withstand the load. Although many dynamic pressure bearings also use a lubricating oil pump to supply pressure oil, their properties are different. The most obvious is that the oil supply pressure is different. The hydraulic pressure of the hydrostatic bearing is much higher than that of the dynamic pressure bearing.

One of the main features of the hydrostatic bearing is that it can also establish a bearing oil film in a completely static state, which ensures that there is no direct contact between the two surfaces of the friction pair during the starting phase, which is absolutely impossible in dynamic pressure bearings.

Therefore, when starting a rotor with a hydrostatic bearing, the hydrostatic lubrication system must be activated first.

When the hydrostatic bearing is in operation, the dynamic pressure effect may occur due to the relative movement of the friction pair. When the dynamic pressure effect reaches a certain share, the bearing becomes a dynamic and static pressure hybrid bearing.

The advantages of hydrostatic bearings are:

1. The friction pairs are separated by the pressure oil film during start-up and operation. The sliding resistance is only from the viscosity of the fluid, the friction factor is small, and the working life is long.

2. Static pressure bearing has the function of “homogenization” error, which can reduce the influence of inaccuracy in manufacturing, so the requirement for manufacturing precision is lower than that of dynamic pressure bearing.

3. The pressure on the surface of the friction pair is relatively uniform, and the reliability and life of the bearing are high.

4. Accurately achieve the desired bearing performance.

5. The temperature distribution of the bearing is relatively uniform, and the thermal expansion problem is not as serious as the dynamic pressure bearing.

Hydrostatic bearings are suitable for a wide range of operating conditions, from precision instruments in grams to heavy-duty equipment with loads up to several thousand tons.