Patent GB-627778-A (GB)
Title: Engine starter
IPC: F02N15/02
Filed: 1947-04-21
Abstract: 627,778. Turning-gear. BENDIX AVIATION CORPORATION. April 21, 1947, No. 10560. Convention date, May 21, 1946. [Class 7 (v)] In an engine starter drive comprising a casing, an axially stationary rotatably driven nut, a screw shaft adapted to be moved by the nut axially relatively thereto and rotatable therewith and a clutch member extending through an opening in the casing and splined to the screw shaft for axial movement with the shaft, through the intermediary of buffer spring means, to engage the clutch member to an engine clutch-element and for rotation with the shaft to start the engine, the clutch member having axial movement relative to the screw shaft against the action of the spring means, there is provided a sealing device which has a resilient portion adapted to directly frictionally engage and hold the clutch member to effect an oil seal between the clutch member and the casing at 'all times, including periods of rotative movement of the clutch member and axial movement thereof in both directions. A rotatable barrel 24, which supports planet gear 30 operating between an orbital gear 32 fixed to the starter casing and a sun gear 34 driven from the starter motor through speed reducing means (not shown), is connected to the spline nut 38 by a multi-plate clutch 40. Upon operation of 'the starter motor, the screw shaft 46, which is threaded into the nut 38 and has a splined connection to the clutch member 50 that protrudes into an engine crank-case 12, moves the clutch member into engagement with the engine clutch-element 52. The clutch member 50 and screw shaft 46 are connected by a mesh rod 56 extending through an aperture in the clutch member 50, which aperture is closed by a seal 58 biased by the buffer spring 60. Right-hand axial movement of the screw shaft 46 is limited by the end wall of barrel 24 and its left-hand movement is limited by engagement of the shoulder 59 on the shaft 46 with a shoulder 61 on the nut 38. Around the periphery of the clutch member 50 is a combined oil-seal and friction-unit comprising a body 64 of moulded material, such as neoprene, the outside being vulcanized and the inner sleeve-part being soft and resilient with an annular groove 68 housing a ring spring 70 for maintaining the unit in contact with the clutch member 50. Internal, peripheral grooves 66 in the body 64 wipe the oil from the clutch member 50 upon its return stroke after disengaging the engine member 52. Attached to the starter casing is a ring member 72 abutting the body 64 and having a flange 74 that is a close fit with the periphery of the jaw member 50, thereby preventing any radial vibration of the latter from shortening the life of the combined oil-seal and friction-unit. In the event of the engine back-firing, the reaction is absorbed in the disc clutch. In a modification, a phosphorbronze ring positioned on the left-hand face of the body 64 replaces the ring member 72, and a number of springs replace the seal spring 60. The phosphor-bronze ring may be omitted and more than one ring spring may be used, whilst the mesh rod may be formed as an extension of the screw shaft, which rod has a shouldered collar axially slidable with the clutch member.