TELESCOPING LINEAR ACTUATOR WITH SCREW DRIVES

摘要

A linear actuator (20) including three nested telescoping sections (22, 24, 26) actuated by two internal screw drives (28, 30). First and second screw drive nuts (32, 34) are rotatably mounted in the intermediate telescoping section (24) to linearly translate respective first and second screw shafts (36, 38), which are fixed to respective distal ends (21, 27) of the outer (22) and inner (26) telescoping sections. The drive nuts may be mounted at opposite ends of the intermediate section in a housing (23, 25, 29), and may be driven by a motor (40) therein via an idler shaft (42) that spans between the two drive nuts. The motor may be designed to serve alternately as a regenerative resistance brake (R1). A mechanical brake (43) may alternately or additionally be provided. Either or both brakes may be set to engage by default on power outage.

主权项

1. A telescoping linear actuator, comprising:
an outer telescoping section; an intermediate telescoping section slidably nested in the outer telescoping section; an inner telescoping section slidably nested in the intermediate telescoping section; an actuator housing comprising a housing base attached to a bottom end of the intermediate section and an upper support plate supported proximate an upper end of the intermediate section by a support extending from the housing base; a motor mounted in the actuator housing; a first screw drive comprising a first screw drive nut rotatably mounted on the housing base and a first screw shaft having a bottom end mounted non-rotatably to a bottom plate of the outer telescoping section, the first screw shaft threaded through the first screw drive nut; a second screw drive comprising a second screw drive nut rotatably mounted on the upper support plate of the actuator housing and a second screw shaft having a top end mounted non-rotatably to a top plate of the inner telescoping section, the second screw shaft threaded through the second screw drive nut; and an idler shaft mounted rotatably in the actuator housing and extending between the first and second screw drive nuts, wherein the idler shaft is driven to rotate by the motor, and the idler shaft drives both the first and second screw drive nuts to rotate; wherein rotating the idler shaft in a first direction translates the first and second screw shafts in opposite directions relative to the intermediate telescoping section, translating the outer telescoping section and the inner telescoping section in opposite directions relative to the intermediate telescoping section.