To provide a grease composition for a resin lubrication capable of reducing a noise by a contact of a resin member and a metal member or the resin members, a gear device reducing a noise by an engagement of gear teeth, and an electric power steering device.
The grease composition for the resin lubrication is applied to a portion where the resin and the metal or the resin and the resin are contacted with each other, and contains a base oil containing at least one kind of a poly-α-olefin oil, a mineral oil and a highly purified mineral oil at a ratio of 70 mass% or more based on the whole amount of the base oil, a thickener containing at least one kind of a metal soap, a metal composite soap and a urea compound at a ratio of 50 mass% or more based on the whole amount of the thickener, and a vulcanized rubber fine particle having an average particle diameter of 300 nm or less. In the gear device or the electric power steering device, the clearance between the gear teeth is lubricated by the grease composition for the resin lubrication.
COPYRIGHT: (C)2008,JPO&INPIT
Hironori Honda
Toshimitsu Ichikawa
Takeshi Takamatsu