Patent ID: 6805017
Filing Date: 2004-10-19
Classification: B62D,F16D,F16H,Y10T

Abstract:
An electrical power assisted steering apparatus provided with a torque limiter having a ring member formed with a plurality of radially outwardly curved projections for applying elastic force mounted between a worm wheel and an output shaft, wherein said output shaft is made of iron material, a gear portion of said worm wheel is made of synthetic resin material, and a core metal portion of said worm wheel is made of aluminum material which has a specific gravity smaller than that of said iron material of the output shaft and which has a coefficient of linear thermal expansion larger than that of said iron material of the output shaft, and wherein the gear portion and the core metal portion are fixedly joined, whereby a change in spacing between said worm wheel and said output shaft as a result of differential thermal expansion therebetween operates to change a limit torque of said torque limiter from a lower value under high temperature to a higher value under low temperature.