Abstract: An actuator (10) and adapter (16,116), in particular with an electric motor (60), and a highly reduced gearing (48), is used for transmitting a torque to a continuous drive shaft (24) of at least one flap or at least one valve to control a gas or liquid volume flow. The adapter (16,116) which is used in particular in the sector of heating/ventilation/air-conditioning (HVAC), fire and space protection can be fitted in a manner which is locked against rotation in the radial direction to a frame or support of the actuated member. With the drive shaft (24,124) it forms a releasable frictional and/or positive connection. The actuator is preferably actuated by an electric actuator motor but also pneumatically, hydraulically or manually. The actuator (10) and adapter (16,116) can optionally be used as a bridging drive.

Abstract: The invention relates to an actuator (10) for actuating a device in a linear manner by means of a tangential rod which can be displaced in a longitudinal manner by converting the torque of a motor-driven pinion (32), in particular for a flap or for a valve in the field of heating-ventilation-climatisation (HLK), or fire and smoke protection. According to the invention, a normal threaded rod (24) which can be displaced in the axial direction thereof (L) and which can be cut to an individual length, has a radius (r) which is rotationally secured in the actuator (10). The pinion (32) in connected in a positive fit to at least one drive wheel (36) which is mounted in a freely rotational manner, and an elastic and/or adjustable pressure element (38, 54, 64, 66) which carry out a play-free engagement of drive wheels (36) and the normal threaded rod (24).