Patent GB-680484-A (GB)
Title: Improvements in combined engine starters and dynamos
IPC: F02N15/04
Filed: 1950-05-16
Abstract: 680,484. Turning gear. BENDIX AVIATION CORPORATION. May 16, 1950 [May 25, 1949], No. 12237/50. Class 7 (v). In a starter-generator device comprising a dynamo-electric machine 14, an engine-engaging member 78, a reduction gearing having an output member, such as planet cage 34, connected to the engaging member 78 through an overruning clutch 68, there is provided clutching means, for example, friction clutches 24, 49 and 72, 76, which means are interrelated and adapted to connect the machine 14 and engaging-member 78 through the reduction gearing during the cranking operation in response to the relative rotational speed of the machine 14 and output member 34 and to connect the machine directly to the engaging member 78 when the engine fires. When the dynamo-electric machine 14 is energised the armature shaft 12 rotates and since the splined engaging-member 78 is drivingly connected with the engine and the members 72, 76 of one friction clutch are in engagement, a shaft 26 is moved rightwardly due to its threaded connection 22 with the armature shaft 12, which movement of shaft 26 causes the clutch members 72, 76 to disengage because member 76 is formed on the outer end of this shaft, and the other friction clutch 24, 49 to be engaged; the clutch member 24 is secured to the inner end of the shaft 26. Rotation of clutch member 49, and hence of a sun gear 48 integral therewith, is transmitted through one planet gear train including a planet cage 52 to a second train, the sun gear 56 of which is integral with cage 52, the motion being taken from the planet cage 34 of the latter train through a stub shaft 38, overrunning clutch 68, a cylindrical member 70 to the splined member 78 to crank the engine. The stub shaft 38 is integral with both the planet cage 34 of the second gear train and a sleeve 32 through which passes the shaft 26, the sleeve having journalled thereon the two sun gears 48 and 56. The first gear train includes a stationary orbital gear 58 comprising a friction disc clutch which is arranged to slip in the event of a back fire during the cranking operation and thus protect the gearing from overloading; the disc clutch pressure plate 62, orbital gear 54, one set of clutch discs and a ring member 64 are axially splined to the gear housing 40 and so transmit the pressure of a spring 66 to the disc clutch. The outer end of shaft 26 is held in the centred position by a ball 82 which is also partly located in a recess in a pressure member. 86 slidably mounted in the splined member 78, the pressure member being loaded by a spring 84. The clutch, member 72 is formed on a radial flange integral with cylindrical member 70, which latter is connected to the stub shaft 38 through the overrunning clutch 68. When the engine fires the cylindrical member 70 is driven faster than stub shaft 38 and hence clutch 68 overruns and as soon as the dynamoelectric machine is de-energised the spring 84 will force the shaft 26 and therefore clutch member 24 to the position shown and at the same time clutch 72, 76 will be closed so enabling the engine to drive the dynamo-electric machine directly through the shaft 26 and therefore bye-pass the planet reduction gearing. Depending upon the type of engine with which this apparatus is used a third planet gear train may be used or one of the existing ones removed.