Patent ID: 8567364

Claim:
A starter for an engine comprising: a motor working to rotate to output torque; an output shaft on which a pinion gear disposed; a planetary gear speed reducer which is equipped with an internal gear, said planetary gear speed reducing working to reduce a rotational speed of said motor and transmit it to said output shaft for starting an engine; a shock absorber including a rotary disc, a stationary disc, a case in which the rotary disc and the stationary disc are disposed, a load applying mechanism, and a load adjuster, the rotary disc being formed integrally with the internal gear of said planetary gear speed reducer, the stationary disc being arrayed adjacent the rotary disc in a thickness-wise direction of the rotary disc and being held from rotating, the case having an open end and an internal thread formed on an inner periphery of the open end, the load applying mechanism being disposed inwardly of the internal thread of the case in a radius direction of the internal thread to apply a load to the stationary and rotary discs to develop a given degree of friction therebetween, the load adjuster being placed in threadable engagement with the internal thread of the case to achieve adjustment of the load, as applied by the load applying mechanism to the stationary and rotary discs, when a degree of torque greater than a given value acts on the rotary disc through the internal gear, said shock absorber working to induce the rotary disc to rotate against the given degree of friction to absorb the torque to eliminate a physical impact to be exerted on said planetary gear speed reducer; and a restraining mechanism serving to restrain the load applying mechanism from moving in the radius direction of the internal thread to keep a portion of the load applying mechanism, which is located most outwardly in the radius direction of the internal thread, disposed away from a portion of the internal thread which is located most inwardly in the radius direction of the internal thread.