Bearing PV Value

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

Bearing Load, Speed and Temperature

The maximum static load of EPA plastic bearing is 35 MPa. Refer to Diagram EPA-2 for the maximum compressive deformation of the bearing under this load. The actual working load of the bearing shall be slightly less than 35 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: 80°C) will gradually reduce the bearing load capacity. Refer to Diagram EPA-3 for load variation with bearing operating temperature.

Friction Coefficient of Bearing

Diagram EPA-4 shows that for EPA plastic bearings under constant load, the friction coefficient rises slightly with increasing operating speed. Diagram EPA-5 indicates that for EPA plastic bearings at a constant speed, the friction coefficient decreases gradually as the load increases. Diagram EPA-6 shows that the friction coefficient of EPA plastic bearings varies with shaft surface roughness. The recommended shaft surface roughness is Ra 0.3~0.6 μm.

Wear and Shaft Material

Diagram EPA-7 and Diagram EPA-8 show that hardened steel shafts or hard chrome shafts are suitable for EPA plastic bearings. The wear performance of EPA plastic bearings is basically the same under rotary motion and oscillating motion, which makes this bearing applicable for a wide range of scenarios.

Chemical Resistance

EPA plastic bearings can resist corrosion from weak alkalis, weak acids and various lubricating oils.

Water Absorption

EPA plastic bearings have a moisture absorption rate of 0.3% under standard atmospheric pressure, and the maximum water absorption reaches 1.2% when immersed in water. Thanks to its low water absorption, modification to bearing design is only required under extreme application conditions.

UV Resistance

Upon long-term exposure to ultraviolet radiation, the color of EPA plastic bearings remains basically unchanged. The hardness, compressive strength and wear resistance of the material stay unchanged.

Installation Tolerance

Tolerance of EPA plastic bearing after press fitting