Bearing PV Value

The maximum operating PV value of EPS plastic bearing is 0.3 N/mm²·m/s. It means the load capacity of the bearing is inversely proportional to speed. Refer to Diagram EPS-1 for details.

Bearing Load, Speed and Temperature

The maximum static load of EPS plastic bearing is 8 MPa. Refer to Diagram EPS-2 for the maximum compressive deformation of the bearing under this load. The actual working load of the bearing shall be slightly less than 8 MPa. The load capacity is also affected by operating speed and temperature. Higher speed (Vmax: 2.0 m/s) will raise frictional temperature, and temperature rise (Tmax: 260°C) will gradually reduce the bearing load capacity. Refer to Diagram EPS-3 for load variation with bearing operating temperature.

Friction Coefficient of Bearing

Normally, the wear resistance and friction coefficient of plastic bearings degrade as speed increases. However, EPS bearings are relatively less affected by changes induced by high speed (see Diagram EPS-4 and Diagram EPS-5). As shown in Diagram EPS-6, the friction coefficient of EPS bearings varies depending on the surface roughness of the mating shaft. We recommend using shafts with a surface roughness of Ra 0.2–0.5 μm for this bearing.

Wear and Shaft Material

Shaft material has a significant impact on bearing wear, yet EPS bearings are compatible with nearly all shaft materials. It can be seen from Diagram EPS-7 that EPS bearings exhibit excellent wear characteristics when paired with hard chrome steel shafts or hardened steel shafts. Diagram EPS-7 also shows that EPS bearings are more suitable for rotary motion applications.

Chemical Resistance

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

Water Absorption

Under standard atmospheric pressure, EPS plastic bearings have an extremely low water absorption rate of less than 0.1%. The maximum equilibrium water absorption when immersed in water is also below 0.1%. Therefore, the material will not undergo performance or dimensional changes due to water absorption, making it suitable for humid and underwater environments.

UV Resistance

The material properties of EPS remain unchanged under long-term exposure to ultraviolet radiation.

Installation Tolerance

Tolerance of EPS plastic bearing after press fitting