GB259844A - A bevel gear shaping machine operating by rolling movements - Google Patents

Abstract

259,844. Harbeck, M. April 10, 1926. Gear-cutting. -In a machine for shap ing bevel gears on the rolling generating principle of the kind in which the blank and the toolhead carrying the reciprocating tools representing a crown wheel tooth are both rotated in unison, the generating mechanism may be disengaged and the blank roughed out by a gashing operation wherein the tools are fed radially into the blank to the required depth, without disconnecting the dividing gear. In one application of the invention, the generating machine comprises a tool head 2 carrying the usual reciprocating rams, and rotated by worm gearing 4, and a work head 3 carrying a spindle which is rotated by worm-gearing 5. The gearing is shown diagrammatically in Fig. 6. A shaft 8 carries loose gears 9, 10 driven in opposite directions from the main shaft and selectively clutched to the shaft 8 by means of a sliding clutch member 11. The shaft 8 drives the work head through spur gears 12 - - 15, change gears 7, and bevel gearing 17, and a gear 20 on the shaft 8 rotates the tool head in unison through a gear 22, shaft 21, change gears 6, and bevel gearing 24. During the forward generating movement the shaft 8 is driven by the wheel 9 and at the end of this movement the member 11 is actuated by a projection 25 on a nut 26 moving axially on the spindle 21. This engages the high speed drive for the return movement and towards the end of this movement the dividing of the blank is effected by interrupting the tool-head drive while the blank rotates backwards through one or more pitches. In order to interrupt the tool-head drive a splined clutch 19 is disengaged by the nut 26 from the loose wheel 20 thus arresting both the shaft 21 and the wheel 28 of a planetary gear. This causes the casing 29, which carries gears 33 - - '- 35 to drive the locking-disc 36 which has a recess engaged by a projection on the clutch-operating lever. By appropriate selection of one of the gear pairs 33 - - 35, the disc 36 may be driven at such a speed that it completes a revolution and allows the clutch 19 to be re-engaged after an indexing movement of either one, two or four pitches. For roughing out the gear teeth in accordance with the invention, the tool head is slidable on its frame and the tools are first fed radially to depth and then withdrawn while the blank is indexed. Two spaces may be gashed simultaneously, the blank being indexed through two pitches at each cycle. The clutch 44, Fig. 7, which is normally engaged to rotate the tool-head is disengaged and the radial feed and the withdrawal of the tools are effected by means of a screwed spindle 43 working in a nut 42 driven by bevel gearing 38 from the spindle 21. The wheel 15 of the dividing train is loose on its spindle and a splined clutch 46 is engaged, for gashing, with a wheel 45 driven from the wheel 33 to impart the dividing movement when the clutch 19 is disengaged. When the generating movement is required the clutch 46 is engaged with the wheel 15. Specifications 12689/07 and 14207/08 are referred to.