Patent GB-817658-A (GB)
Title: Method and machine for displacing the tooth bearing on gears by lapping
Inventor: SCHICHT HEINRICH
IPC: B23F19/00
Filed: 1956-01-10
Abstract: 817,658. Lapping gears. KLINGELNBERG, G., JAEGER, G., KLINGELNBERG, H. W., and BAUM, C., [trading as KLINGELNBERG SOHN W. F.]. Jan. 10, 1956, No. 829/56. Class 60. A method for correcting the tooth bearings on gears consists in running two gears together in mesh for a lapping operation, with provision for relative movement between them in the direction of the common pitch cone tangent of the meshing gears, and causing more material to be removed from specific flank zones and thereby displacing the tooth bearings as desired by exerting the pressure producing the flank thrust by driving that gear whose resultant tooth bearing when exerting pressure on the mating gear requires a displacement in the direction from the dedendum to the addendum. As described for the lapping together of two bevel gears 13, 14, Fig. 3, the gear 14 is journaled on a head 18 on a table 19 which is mounted for straight-line movement on a base 20. The table is secured on the base at four points 22<SP>1</SP> by ball-joint devices, Fig. 5 (not shown), providing sufficient play to permit straight-line movement between the table and base as determined by two straight guides 30. Each guide has a pivot 31, Fig. 6, fixed in a hollow cylinder 32 journalled for adjustment in the table 19 and is engaged by a pin 37 journalled in the base 20, and the two guides are connected by an endless band 33, Fig. 3, or linkage so that they can be adjusted in unison. The movement of the table on the guides 30 is effected against the action of springs 50, 51 by a cam 44 which is driven by a motor 41 and acts through a disc 48 upon a push rod 45 pivoted at 46 to the table ; pins 47 can be set to determine the extent of swinging movement of the push rod to either side of its mean position when the direction of rotation of the cam is reversed at each change of tooth profile abutment, i.e. at a change in the rotational direction of the gears 13, 14 or of the driving gear. The gear 13 is rotated by an electric motor through a pulley drive 15, and the gear 14 by another electric motor 60, Fig. 7, driving through an infinitelyvariable drive unit 59, pulley 17 and spring- pressed friction member 16, Fig. 8 ; the friction member 16, which like the pulley 17 is journalled on the spindle 52 of the gear 14, is urged against a face plate 58 keyed on the spindle. The friction member also drives through worm gearing a dial 67, Fig. 7 and the face plate similarly drives a pointer 71 moving over the dial. In operation, the guides 30 are set so as to be parallel with the common pitch cone tangent 72, Fig. 3, of the meshing gears, and the pressure producing the flank thrust is provided by that gear whose resultant tooth bearing is to be displaced towards the addendum, this effect being achieved by driving that gear at the higher speed by appropriate setting of the drive unit 59, the relative positions of the dial and pointer showing which gear is the source of pressure. The direction of rotation of the cam 44 is reversed at each change of rotational direction of the gears to be lapped or when there is a change in the drive. With the gears rotating always in the same direction, the opposite flanks of the teeth are operated upon by causing the two gears alternately to act as drivers. Modifications consist in providing hydraulic or electric control means to replace the mechanical drive unit 59, and mounting both gears on tables which are moved, as described for the table 19 along straight guides 30. Specification 817,491 is referred to.