Bearing PV Value

The maximum operating PV value of EPX plastic bearing is 1.4 N/mm²·m/s. It means the load capacity of the bearing is inversely proportional to speed. Refer to Diagram EPX-1 for details.

Bearing Load, Speed and Temperature

The maximum static load of EPX plastic bearing is 110 MPa. Refer to Diagram EPX-2 for the maximum compressive deformation of the bearing under this load. The actual working load of the bearing shall be slightly less than 110 MPa. The load capacity is also affected by operating speed and temperature. Higher speed (Vmax: 1.5 m/s) will raise frictional temperature, and temperature rise (Tmax: 250°C) will gradually reduce the bearing load capacity. Refer to Diagram EPX-3 for load variation with bearing operating temperature.

Friction Coefficient of Bearing

Diagram EPX-4 shows that the friction coefficient of EPX plastic bearings gradually increases with rising operating speed under constant load. Diagram EPX-5 shows that at constant speed and loads below 20 MPa, the friction coefficient decreases rapidly as load increases. When the load exceeds 20 MPa, the change in friction coefficient becomes moderate. Diagram EPX-6 indicates that the recommended shaft surface roughness for EPX plastic bearings is Ra 0.6~0.8 μm.

Wear and Shaft Material

Diagram EPX-7 and Diagram EPX-8 compare the operational wear of EPX plastic bearings running on different shaft materials. For rotary motion under loads below 2 MPa, stainless steel shafts and carbon steel shafts are suitable. When the load exceeds 2 MPa, better performance is achieved with hardened steel shafts and carbon steel shafts. Diagram EPX-7 shows EPX plastic bearings are well suited for rotary motion. It is particularly noteworthy from Diagram EPX-9 that the friction and wear performance of EPX plastic bearings at room temperature of 23°C is inferior to that at a high temperature of 150°C.

Chemical Resistance

EPX plastic bearings feature excellent chemical resistance and can withstand strong acids with a concentration up to 65%.

Water Absorption

EPX plastic bearings have a moisture absorption rate of 0.1% under standard atmospheric pressure, with a maximum water absorption of 0.5% when immersed in water. Its ultra-low water absorption will not cause changes in bearing performance or dimensions, making it highly suitable for humid environments.

UV Resistance

When EPX plastic bearings are exposed to ultraviolet radiation for a long time, the material properties remain unchanged.

Installation Tolerance

Tolerance of EPX plastic bearing after press fitting