Heat resistant lithium grease composition and a small motor reduced noise bearing

摘要

A heat-resistant noise-reduction grease and a bearing containing the grease for a small motor such as a motor for imaging equipment such as a blower fan and motor bearing for a household electrical appliance such as an air conditioner, which is eco-friendly and excellent in noise-reduction properties is provided.;The heat-resistant lithium grease composition is composed of 5 to 20% by weight of a thickener and 95 to 80% by weight of a base oil, wherein long-chain fatty acid lithium soap with 26 to 32 carbon atoms and lithium soap comprising a higher fatty acid with 10 to 20 carbon atoms and/or a higher hydroxyfatty acid with one or more hydroxyl groups and 10 or more carbon atoms are used as the thickener, and the base oil contains, as a main component, polymer ester oil (A) in which 8 or more ester groups are arranged in comb tooth form on one side of chain molecules of oil constituted with 8 or more carbon atoms, which is expressed by the following general formula:; ;(where each of R₁, R₂, R₃ and R₄ represents an alkyl group, x represents an integer satisfying x≧2, and y represents an integer satisfying y≧2).and the base oil has a viscosity (40° C.) of 30 to 100 mm²/s.