Electric motor actuator for motor vehicles

摘要

An electric drive mechanism for motor vehicle central locking systems has a split housing (1,2) in which an electric motor (3) drives an externally threaded (9) shaft (6) via a motor pinion (not shown) and toothed wheel (5) having a torsion-absorbing spider moulded from plastic, integral with the shaft (6) and working in conjunction with a torsion spring (not shown) mounted on the splines (7). A hollow pushrod (12) having an internal thread (10) which meshes with the shaft thread (9) moves axially within a labyrinth seal (15) over a maximum distance (L) at least equal to the housing length (H) whilst the shaft thread length (I) is limited to approx. 1/3 L. The endstop moulding (20) has a shock-absorbent structure which together with the torque control feature prevents system overload.