| 摘要 |
1,231,676. Positive clutches. GARRETT CORP. 16 Sept., 1969 [10 Oct., 1968], No. 45678/69. Heading F2C. A positive clutch in a safety decoupler shaft, e.g. between a gas turbine engine and a starting motor, comprises teeth (16), Fig. 2 (not shown), shaped on one side 16A to transmit drive from one splined shaft part 14 to another part 15 on relative rotation in one direction, and shaped on their other side (18), (19) to move the parts axially apart against the resistance of a torsionally prestressed torsion bar 20 to permanently disengage the clutch on relative rotation in the opposite direction. The bar 20 has a slot 22 at one end through which passes two pins 23, 23A attached to part 14. The other end of the bar has an hexagonal head 21 engaging in a corresponding bore in part 15. The rod is axially split to provide torsion portions and engages freely within a sleeve 24 brazed to part 14 with a free groove 25 underlying a groove 27 in part 14 at which the part shears if the engine binds. If overload occurs in the reverse direction, the faces (18), (19) or the teeth urge the parts 14, 15 apart against the resistance of the torsion bar until the head 21 leaves its corresponding bore in part 15, when the parts separate freely and are retained disengaged by a split ring 30 abutting the end of sleeve 24 until the clutch is manually re-engaged. To re-engage the clutch, the pin 23A is withdrawn and bar 20 moved so that head 21 enters its bore in part 15. The parts 14, 15 are then relatively turned and moved together to allow teeth (16) to intermesh and prestress the bar 20 to urge surfaces 16A together for drive. Pin 23A is then replaced. The teeth 16A are slightly inclined relative to the axis to urge the parts 14, 15 axially together. |
