Bearing PV Value

The maximum operating PV value of EPD plastic bearing is 0.4 N/mm²·m/s. It means the load capacity of the bearing is inversely proportional to speed. Refer to Diagram EPD-1 for details.

Bearing Load, Speed and Temperature

The maximum static load of EPD plastic bearing is 50 MPa. Refer to Diagram EPD-2 for the maximum compressive deformation of the bearing under this load. The actual working load of the bearing shall be slightly less than 50 MPa. The load capacity is also affected by operating speed and temperature. Higher speed (Vmax: 1.0 m/s) will raise frictional temperature, and temperature rise (Tmax: 100°C) will gradually reduce the bearing load capacity. Refer to Diagram EPD-3 for load variation with bearing operating temperature.

Friction Coefficient of Bearing

Diagram EPD-4 shows that, like most plain bearings, the friction coefficient of EPD plastic bearings rises slightly with increasing rotational speed under constant load. Diagram EPD-5 shows that the friction coefficient of EPD plastic bearings decreases gradually as the load increases at a constant speed. Diagram EPD-6 indicates that the optimum shaft surface roughness for EPD plastic bearings is Ra 0.2~0.6 μm. Both overly smooth and excessively rough shaft surfaces will cause an increase in friction coefficient.

Wear and Shaft Material

Diagram EPD-7 and Diagram EPD-8 show that the wear of EPD plastic bearings is greatly affected by shaft material. Hardened steel shafts and hard chrome steel shafts are suitable for this bearing. Diagram EPD-7 indicates that hardened steel shafts and hard chrome steel shafts are preferred for EPD plastic bearings under both rotary and oscillating motion.

Chemical Resistance

EPD plastic bearings are resistant to weak alkalis and corrosion from various lubricating oils.

Water Absorption

EPD plastic bearings have a moisture absorption rate of 0.3% under standard atmospheric pressure, with a maximum water absorption of 0.5% when immersed in water. Its very low water absorption will not cause changes in bearing performance or dimensions, making it well suited for humid environments.

UV Resistance

Upon long-term exposure to ultraviolet radiation, EPD plastic bearings will suffer color fading and partial degradation of material properties.

Installation Tolerance

Tolerance of EPD plastic bearing after press fitting