GB1344105A - Gear making and testing machine - Google Patents

Abstract

1344105 Gear cutting W HOFLER 19 April 1971 [2 March 1970] 22863/71 Heading B3K [Also in Division F2] In a machine for tooth-forming and/or testing straight and helical involate spur gears in use of which machine a gear workpiece 1 is caused to execute both rectilinear and rotary movements combining to roll the workpiece, on its base circle, relative to a tooth-forming tool (rackshaped cutter, two disc-shaped grinding wheels or, as shown, one grinding wheel 10) or testing tracer, a workpiece support 2 is rotatably mounted on a rectilinearly movable table 3 and is connected, directly or indirectly, to a carriage 18 which is slidably mounted on the table for movement normal thereto and is guided by a stationary cam 20, the inclination of the cam being adjustable and determining the relationship between said rectilinear and rotary workpiece movements. When used for tooth forming, the tool may be reciprocated or, with the tool stationary, the workpiece may execute both the rolling and reciprocation. The cam 20 may be set optically. The carriage 18 may be connected to the workpiece support 2 by a friction bar/disc or rack-and-pinion connection, or, as shown, straps 5 fixed to diametrically opposite parts of a cylinder portion 4 of the support 2 and to the carriage. Drive may be transmitted to the table from a motor 8 acting via a feed gear mechanism 9 and a spindle 7, to the carriage 18 from a motor 23 acting via a spindle 22, or to the workpiece support 2. For base circles having the diameter of the cylinder portion 4, the cam 20 is set to γ = 45 degrees. For larger base circles, γ < 45 degrees and drive is from the motor 8. For smaller base circles, γ < 45 degrees and drive is from the motor 23 or to the workpiece support. In Fig. 4 (not shown), the carriage is connected to the workpiece support via a further cam mechanism and a further carriage which is slidable in the table direction. The specification also describes prior art machines where (Fig. 1, not shown) the workpiece support rolls on fixed anchor straps; and (Fig. 2, not shown) rectilinear and rotary workpiece movement relationship is determined by change-speed gearing, and said rotary movement is transmitted through an index plate and a differential gear to provide also for indexing.