Drive mechanism with a rotary drive motor

摘要

The invention relates to a drive mechanism which comprises a single-phase synchronous motor (5) for converting the rotation of the motor shaft (3) into a pulsating axial movement by means of an eccentric cam (25). The motor shaft (3) carries a coaxial cylindrical body (13) whose eccentric cam (25) co-operates with a piston rod. The drive-shaft system comprising the motor shaft and body is supported in a multiple bearing comprising a broad-area bearing (23) for the circumferential surface (21) of the cylindrical body (13) and a shaft bearing (19) for the shaft end (15) which projects from the body (13) at the end which is remote from the motor (5). The end portion (29) of the piston rod is guided so as to be axially slidable.