US 7,588,120 B2
Electric power steering apparatus using coated pulley
Dong Hun Ha, Gyeonggi-do (Korea, Republic of); Seong Soo Kim, Seoul (Korea, Republic of); and Gung Joo Nam, Gangwon-do (Korea, Republic of)
Assigned to Mando Corporation, Seoul (Korea, Republic of)
Filed on Feb. 15, 2007, as Appl. No. 11/707,474.
Claims priority of application No. 10-2006-0018332 (KR), filed on Feb. 24, 2006.
Prior Publication US 2007/0221439 A1, Sep. 27, 2007
Int. Cl. B62D 5/04 (2006.01)
U.S. Cl. 180—444  [427/384; 427/385.5] 2 Claims
OG exemplary drawing
 
1. An electric power steering apparatus using a coated pulley, comprising:
a pinion shaft coupled to a shaft of a steering wheel and having teeth formed on the pinion shaft;
a rack shaft having teeth formed in one end thereof and a ball screw formed in the other end thereof, the teeth of the rack shaft being meshed with the teeth of the pinion shaft;
a ball nut provided on the ball screw through a plurality of balls interposed between the ball nut and the ball screw;
a first pulley coupled to the ball nut to cooperate therewith;
a torque sensor for sensing a torque generated from the steering wheel;
an electric motor for generating a steering assisting force according to a signal from the torque sensor;
a second pulley installed to one end of the electric motor;
a belt connecting the first pulley and the second pulley to each other to transmit the steering assisting force generated from the electric motor to the ball nut; and
a coating layer formed on an outer surface of the first or second pulley, the coating layer having a composition ratio of molybdenum sulfide of 10 to 90 wt %, antimony trioxide of 5 to 10 wt %, antirust agent of 1 to 5 wt %, auxiliary lubricant of 1 to 5 wt % and organic adhesive of 1 to 3 wt % dispersed in a solvent of 1 to 10 wt %.