| abstract |
In a rotary bearing grease seal for an industrial robot or the like that repeats forward / reverse rotation / stop, nitrile rubber is used as a rubber seal lip material, and molybdenum sulfide dialkyldithiocarbamate (MoDTC) is blended as grease. When used, grease that uses MoDTC-containing grease and nitrile rubber as the rubber seal lip material based on the knowledge that yellow sticking matter precipitates on the lip surface and causes grease leakage. In the seal, a grease seal that does not deposit yellow sticking matter on the lip surface is provided. SOLUTION: The material hardness (durometer A) is 60 to 80, the sliding surface has a centerline average roughness Ra of 0.5 to 0.65 μm, and a 10-point average roughness Rz of 1.5 to 2.5 μm. Grease seal used for grease bearings with grease containing a nitrile rubber seal lip and containing 0.5% by weight or more of molybdenum dialkyldithiocarbamate. [Selection] Figure 3 |