Linear screw drive mechanism - has rotatable, threaded nut movable along fixed spindle and mounted in axially movable supports allowing free movement on one direction and to internal projections in other direction

摘要

The screw jack drive consists of a threaded shaft (15) mounted within a housing (36). The shaft is fitted with a drive nut (20) which moves the head (22). Two or more rings (26,33) of composite material support the shaft. These are movable in an axial direction only. The rings are coupled to the nut housing (21) via permanent magnets (41). The supports travel with the housing until disengaged by stops (34), ensuring that the unsupported length of shaft is not too great. ADVANTAGE - Reduced number of movable parts.