Patent GB-600670-A (GB)
Title: Improvements in or relating to apparatus for testing gear drives
IPC: G01B5/20
Filed: 1945-05-17
Abstract: 600,670. Testing gears. ERNST, D. May 17, 1945, No. 12465. [Class 106 (ii)] In an apparatus for testing gears, measuring cylinders, having the same gear ratio as the test specimens, are connected with the axles of the test specimens and with each other and the axle of one test specimen is connected with the axle of the corresponding measuring cylinder by means of a universal joint. The gears to be tested 4 and 12, Figs. 1 and 2, are mounted on axles carried by an'adjustable slide 2 and a slide 11 mounted on ball-bearings for transverse movement, respectively. The corresponding measuring cylinders 5 and 7 have diameters equal to the pitch diameters of their gears and are mounted in frictional contact on the axle of the gear 4 and on an axle carried in the bed of the device respectively. The axles of the gear 12 and measuring cylinder 7 are connected by means of a double cross-pivot universal joint 16 which permits any transverse movement of the gear 12, due to erroneous tooth configurations, when the gears are rotated. Such transverse movements are recorded on a recording drum 25 by means of a scriber 24 operated through multiplying levers by a bolt 20 secured, to the slide 7, which may be urged in either direction by adjusting a fork 48 to bring a spring to bear on a projection 49 of the slide. The slide may be clamped in its central position when clamping the gear 12 into position by means of a screw 46. The axle to which the measuring cylinder 7 is secured and the recording drum may be hand-driven or driven by a motor 26, as shown, by means of worm and bevel gears. The speed of the drive may be varied by a change-over coupling 34 and the drive to the recording drum is by means of an adjustable friction drive 43, 44. The gears and measuring cylinders may be interchanged and the measuring cylinders may be of smaller size, but of the same ratio, the drive then being effected by a thin steel band or by means of intermediate spring- loaded rollers. In a similar apparatus for testing bevel wheel, Fig. 7, a bevel wheel 112 is connected with the measuring cylinder 7 by means of a universal joint. The measuring cylinder 5, which is driven by an intermediate roller from the measuring cylinder 7, is connected with one roller 157 of a friction-cone drive, the other roller 158 of which is mounted in a spring-loaded fork 161 and connected, by means of a second universal joint, to a measuring cylinder 163. An intermediate roller connects the latter with a measuring cylinder 164 secured on the axle of the second bevel wheel 104. The friction-cone drive may be replaced by an accurate bevel gear and the measuring cylinders may contact directly without the use of the intermediate rollers. In an embodiment for testing worm gears, Fig. 10, the worm 204 is mounted between centering points and is driven. by the motor 26. The worm wheel 212 is mounted on the slide 11 and is connected with the worm by means of two pairs of measuring cylinders and a friction-cone drive in a similar manner to that of the drive between the bevel wheels shown in Fig. 7. An adjustable friction-cone drive for use in the apparatus for testing bevel and worm gears is described.