| 摘要 |
A pneumatic balancing hoist comprising a frame rotatably supporting a hollow drum upon which is wound a cable or similar flexible element. The hollow drum includes a pressure chamber containing a piston movable in response to pressurization of the chamber. The piston includes a plurality of cam rollers which are each engaged with a rotatable cam member. The cam members are also formed as planet gears of a planetary gear drive in which a planet gear carrier is formed as an end wall of the hollow drum. The planet gears are engaged with a stationary sun gear fixed to the frame. In response to valving compressed air to the pressure chamber the piston and cam rollers force the cam members to rotate whereby the drum is operated to wind the cable thereon to raise and balance a load. |
