ELECTRIC POWER STEERING DEVICE

• Main Authors: SUGIMORI YOICHIRO, MIYAJIMA HIROTOSHI, NAKA MICHIHARU
• Format: Patent
• Language: English
• Published: 02.12.2005
• Edition: 7
• Subjects: BLASTING; CHEMISTRY; ENGINEERING ELEMENTS AND UNITS; FUELS; GEARING; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATINGCOMPOSITIONS; LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS; LIGHTING; LUBRICANTS; LUBRICATING COMPOSITIONS; MECHANICAL ENGINEERING; METALLURGY; MOTOR VEHICLES; PEAT; PERFORMING OPERATIONS; PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; THERMAL INSULATION IN GENERAL; TRAILERS; TRANSPORTING; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATINGINGREDIENTS IN A LUBRICATING COMPOSITION; WEAPONS

PROBLEM TO BE SOLVED: To transmit power of a reduction gear of an electric power steering device with high efficiency. SOLUTION: The electric power steering device transmits an auxiliary output by an electric motor to a steering mechanism of a vehicle via a reduction gear mechanism comprising a worm 8 and a worm wheel 7. The worm wheel comprises a metallic core pipe and a resin section integrated with this. Gear teeth 202 are formed on the outer periphery of the resin section. An engaging section of the worm with the worm wheel is lubricated with grease composition. The relation of shearing rate X(s-1) to apparent viscosity Y(Pas) at 25°C of the grease composition is within a region sandwiched by two curves expressed by Y=492.01×X-0.9713and Y=421.19×X-0.5063. COPYRIGHT: (C)2006,JPO&NCIPI