| 摘要 |
A linear actuator with a reversible electric motor (3,11,26,27,34), which over a transmission (4,12,24,25,35) drives a non-self locking spindle (5,14,22,23,36), by which a tube-shaped positioning element can be moved axially, in that it with one end is connected to a spindle nut (6,15) on a spindle (5,14,22,23,36). The actuator comprises a quick release (9,13) for releasing the tube-shaped positioning element (7,16,28,29,37) from the electric motor (3,11,26,27,34) and the part of the transmission (4,12,24,25,35) that lies from the motor (3,11,26,27,34) to the quick release (9,13) such that the spindle (5,14,22,23,36) is set to rotate by the load on the tube-shaped positioning element (7,16,28,29,37). The actuator further comprises braking means for controlling the speed of the tube-shaped positioning element (7,16,28,29,37) during the outer load, when the quick release (9,13) is activated. The braking means consists of a centrifugal brake (38,60), by which it is possible to provide a construction where the lowering speed is self-controlled when the quick release (9,13) is activated. |
