| 摘要 |
There is disclosed for use in powering a hoist or the like a pressured fluid powered machine of the rotary vane motor or pump type, improved means for "lifting" and maintaining the vanes in pressure-sealing contact with the wall of the machine casing, and for substantially preventing pressure losses around the ends of the vanes particularly when the machine is starting up and/or operating at low speeds. A pair of resilient "lifting rings" are provided to ride under the vanes at opposite ends thereof and "air cushion" float about specially shaped seals fixed upon opposite ends of the casing, so as to function at all times to maintain the vanes in contact with the machine casing inner wall. The seals operate to prevent fluid leakages via the vane accommodating slots in the machine rotor around the ends of the vanes; thereby providing the machine with a smooth torque output capability at start-up and low operating speeds, such as is of particular importance in hoisting machine systems. Also, the inboard and outboard edges of the vanes are of improved configurations in order to provide improved vane operating and pressure-sealing effects. |
