GB1224140A - Pressure-forming of gear wheels - Google Patents

Abstract

1,224,140. Rolling gears. CARL HURTH MASCHINEN-UND ZAHNRADFABRIK. 16 May, 1969 [9 July, 1968], No. 24993/69. Head-- ing B3M. In a machine for chipless pressure-working of gears with a gear-like tool the tool and workpiece are fed into meshing engagement with their axes parallel or very slightly crossed the minimum distance between the axes being such that substantial radial pressure is generated between the gear and workpiece. The direction of feed lies in a plane parallel to the tangent plane to the pitch circles of the tool and work when fully meshed and may be perpendicular to their axes or at an angle thereto to produce relative sliding movement between the teeth. The machining operation may comprise one or more feed and return strokes or even one feed stroke only, the workpiece in this case being loaded at one side of the tool and released at the other. Depth feed may take place at the end points of the strokes or may be initiated then and continue during the strokes. A machine for carrying out the process comprises a frame 10 carrying an angularly adjustable tool head 100 with pressure-working tool 12 driven from a motor 14. A vertically adjustable support 18 mounted on slideways 17 carries an angularly adjustable table 28a on which there is mounted a slide 29, feed movement of which provides feed of the workpiece 38 and is derived from a motor 32 through suitable gearing. A further angularly adjustable member comprising base 104 is mounted on the slide 29 and supports a workpiece table 116 which is pivoted to the base 104 and 115, stocks 36, 37 operable, e.g. by pneumatic, hydraulic or electrical means being provided for gripping the work. Dogs 34 on the slide 29 co-operate with switches 35 to control the reversal of the feed and the increments of depth feed. Depth feed is effected by a motor 24 through a nut 21 mounted in the support 18 and threaded on a stationary screw 19 projecting upwardly from a base 20 of the machine frame. The pivotal mounting of the workpiece table 116 allows for the tool or workpiece to be of conical form while the angular adjustments of table 28a and base 104 allow for angular feed while ensuring that the teeth are in proper alignment. The tool may be convexly or concavely crowned (Figs. 5, 6, not shown). The tool may be provided with grooves 63 in the flanks 61 of the teeth the grooves of successive teeth being aligned or staggered so as to lie on helical lines about the tool periphery. The edges formed between the flanks and groove walls are rounded or blunt so that chips or shavings are not removed, the machining action depending largely upon the pressure generated at the tooth flanks to compact the surface of the teeth of the workpiece.