Bearing PV Value

The maximum operating PV value of EPQ 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 EPQ-1 for details.

Bearing Load, Speed and Temperature

The maximum static load of EPQ plastic bearing is 75 MPa. Refer to Diagram EPQ-2 for the maximum compressive deformation of the bearing under this load. The actual working load of the bearing shall be slightly less than 75 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: 130°C) will gradually reduce the bearing load capacity. Refer to Diagram EPQ-3 for load variation with bearing operating temperature.

Friction Coefficient of Bearing

Diagram EPQ-4 shows that, like most plain bearings, the friction coefficient of EPQ plastic bearings rises slightly with increasing rotational speed under constant load. Diagram EPQ-5 shows that the friction coefficient of EPQ plastic bearings decreases gradually as load increases under constant speed. Diagram EPQ-6 indicates that the optimum shaft surface roughness for EPQ plastic bearings is Ra 0.1~0.2 μm. Both overly smooth and excessively rough shaft surfaces will lead to an increase in friction coefficient.

Wear and Shaft Material

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

Chemical Resistance

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

Water Absorption

EPQ plastic bearings have a moisture absorption rate of 0.2% under standard atmospheric conditions, with a maximum water absorption of 0.4% when immersed in water. The ultra-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, EPQ plastic bearings will experience color fading and partial degradation of material properties.

Installation Tolerance

Tolerance of EPQ plastic bearing after press fitting