| 摘要 |
1,211,650. Rotary motors. SKIL (NEDERLAND) N.V. May 6, 1968 [June 7, 1967], No.21272/68. Heading F1F. A rotary pneumatic motor particularly for use in hand held portable tools, e.g., an impact wrench, comprises a cylindrical member 15, Figs.1 2 having an eccentric cylindrical bore 18 rotatably mounting a rotor 25 so that the minimum and maximum spacing between the rotor and bore occurs at the 6 and 12 o'clock positions respectively and an inlet port opening into the bore adjacent the 6 o'clock position. The rotor includes at least three, four shown, radial axially-extending slots 43 each slidably receiving a vane 44 and housing a coilspring 45 between the vane and the base of the slot, with the coilspring of longitudinal extent such that when the motor is stationary its length is insufficient to urge a vane into engagement with the bore adjacent the 12 o'clock position, and when the motor is operating centrifugal force urges each vane into engagement with the bore and each spring away from the base of the slot when the associated vane is adjacent the 12 o'clock position. Thus during motor operation the springs are free from or relatively free from the base of the slots to reduce wear and lengthen the life of the vanes but at the same time have sufficient length and strength to urge that vane adjacent the 3 or 9 o'clock positions into sealing engagement with the bore to permit instantaneous starting of the motor. The rotor is supported by roller bearings 27, 32, drives the impact wrench through bevel gears 36, 38 and has a suitable thrust bearing 40. |
