Patent GB-817491-A (GB)
Title: Gear lapping machine
IPC: B23F19/02
Filed: 1956-05-28
Abstract: 817,491. Lapping gears. KLINGELNBERG, G., JAEGER, G., KLINGELNBERG, H. W., and BAUM, C. [trading as KLINGELNBERG SOHNE W. F.]. May 28, 1956 [May 27 1955], No. 16419/56. Class 60. [Also in Group XXXVII] A machine for correctly positioning the tooth bearings on a pair of gears which are lapped together in mesh, while given additional relative movements in the direction of, or at an angle to, the common tangent of the pitch cones of the gears, has the torque producing the lapping pressure derived from that gear whose tooth bearings produced by contact with the mating gear require a displacement in the direction from the dedendum to the addendum, and the lapping pressure between the gear flanks is produced by an electronically-controlled D.C. unit which effects acceleration or drag on the spindle carrying one of the gears relative to the speed at which such spindle is driven through the mating gears by a motor driving the other spindle. The gears to be lapped are mounted on spindles 3, 6 which are driven by motors 7, 8 and disposed on tables adjustable in directions at right angles to each other. The spindle 6 is carried by a secondary table 5, Fig. 3, which is mounted on the main table 4 so that it can be driven along guides 39 by means of a motor 10 operating through an eccentric 35 and dog 36 ; the guides 39 are adjustable so that the path of the table 5 and spindle 6 may be set to provide for the relative movement between the gears in a direction parallel, or at an angle, to the direction of the common pitch generator of the two gears. The machine is arranged so that either of the two gears may act as the driving member, the selected gear for this purpose being the one which is to have its bearing flanks displaced towards the addendum. The motors 7, 10 are reversible A.C. motors and the motor 8 is a D.C. motor operating in conjunction with a Ward-Leonard motor generator set 41, 42. The speed of the motor 8 is regulated by the field winding 69 of the. generator 42 which is controlled by current from a rectifier circuit 65 arranged to be regulated, in turn, by the differential current tn two rectifier circuits 66, 67. The current in the circuit 67 is controlled by the armature current of the motor 8 through a transductor 68 and that in the circuit 66 depends upon the setting of one of two potentiometers 17, 18 according to whether the gear on the spindle 3 or that on the spindle 6 is to drive ; the gear on the spindle 3 drives if it transmits a higher speed to the meshing gear on the spindle 6 than that gear would receive from the motor 8 with the gears not meshing, and is driven if its transmitted speed to the other gear is less than the speed by which that gear would be driven by the motor 8. The control circuit includes, in addition to the usual relays and start-and-stop push buttons, switches 55, 56, 25 for determining the intial direction of rotation of the motors, a switch 47 settable to determine which gear shall drive at the start, an intermittent timer 54 which can be inserted into the control circuit by a switch 16 and at selected intervals changes the drive from one gear to the other and reverses the motor 10, and an automatic timer 50 which can be set to stop the machine automatically after a preset time. The switch 16 can also be set to change the direction of rotation of the gears instead of the drive from one gear to the other ; the appropriate potentiometer 17, 18 is automatically switched into the rectifier control circuit according to which gear is set to drive by means of a switch 90 which is actuated according to the setting of the switch 47 or by the intermittent timer 54. In setting up the machine, the start push button is actuated with the gears out of mesh and either of the spindles 3, 6 set for drive by the switch 47. The motors 7, 8 then drive the spindles 3, 6 in opposite directions and the motor 10 is energised for movement of the table 5 in the direction set by the switch 25. The potentiometer 17 or 18 now in circuit is set by hand so as to regulate the motor 8 to equate the speed of the gear carried by the spindle 6 to what it would be when meshing with and driven by the other gear, compensation thus being made for friction in the spindle 6. The adjustment of the potentiometer produces a corresponding reading in an ammeter 19 which is then set back to zero by a potentiometer 20 and provides a reading of the actual lapping torque which is then set by the potentiometer 17 or 18 with the gears in mesh. With drive by the spindle 3, the armature current supplied to the motor 8 is controlled by the field winding of the generator 42 by means of the potentiometer 17 as long as the set lapping torque is less than the compensated friction in the spindle 6. Should, however, this lapping torque be greater than the friction, the motor is set for drive by the generator 41, 42 by operating a switch 21 to reverse the poles of the circuits 66, 67 and the contacts 87, 89 of the transductor 68 so as to maintain the same direction of current in the latter despite the reverasl of the armature current. The gears, which are spring-clamped on their spindles 3, 6, are released when the table 5 in its withdrawn position actuates a limit switch 57 to energise a motor 40<SP>1</SP> driving a pump to supply hydraulic fluid to the gears. Also included in the control circuit are a motor 43 driving a pump for delivering a lapping compound, and a number of lamps which are illuminated automatically to give an indication of how the machine is operating, e.g. the direction of rotation of the motors, which of the gears is driving and whether or not the timer 50 is functioning. The various steps in the machine cycle may also be carried out under manual control by actuating appropriate push buttons.