1. Friction compatibility
    the shaft and the bearing direct contact with preventing the occurrence of adhesion and the formation of the boundary lubrication performance. Compatibility of materials of the impact of Friction factors are:
    (1) as vice Materials and Metallurgy, constitute the degree of difficulty of the alloy.
    (2) The affinity and capacity of the materials and lubricants.
    (3) Into a pair materials state without lubrication, the friction factor.
    (4) The microstructure of the material.
    (5) The thermal conductivity.
    (6) The size of the surface oxide film characteristics.
     2. Clamp 
     Materials, external hard particles clamp allows the lubricant into to prevent scratches or (and) the ability of the abrasive wear. Metal materials, the low hardness and elastic modulus of the lower clamp into like, non-metallic materials are not to be, such as carbon graphite, lower modulus of elasticity, but the clamp into the bad. Cylindrical roller bearings are usually relatively soft material and hard material composition friction pieces, generally with soft materials bearing.
    3. Run
    In the shaft and the bearing run-in process, reducing the shaft diameter and bearing machining error, concentricity error, the surface roughness parameter values ??to make uniform contact, thereby reducing the ability of the friction and wear rate.