GB618774A - Steplessly variable transmission gears with substantially spherical rollers - Google Patents

Abstract

618,774. Variable-speed friction gearing. KOPP, J. Jan. 29, 1946, No. 2905. Convention date, Feb. 1, 1945. [Class 80 (ii)] [Also in Group XXXIII] In an infinitely variable friction gearing having spaced coaxial driving and driven edge-friction discs connected by a number of circumferentially disposed and substantially spherical rollers held in driving contact with the discs by an encircling ring, tilting of the roller axles to vary the speed ratio is effected by rotary adjustment of a control disc coacting with the axles. As shown, the rollers 3, Fig. 1, bear on rimmed wheels 2, 6 secured to driving and driven shafts 1, 8 respectively, the wheel 6 being hollow and receiving the end of the shaft 1 in bearings. Contact pressure is maintained by a spring 11 acting through a thrust bearing on the wheel 6 and through a tension adjusting nut on the shaft 1. The rollers are tiltable about their axles 50 in radial grooves 52a in the gear casing 22 under the action of a control disc 53 having spiral slots 52, Fig. 3, engaged by crowned collars 51 on the axles and which is rotatable relative to the casing by means of a lever 16. Contact pressure proportional to the torque transmitted may be attained by making the rollers grooved, ellipsoidal or otherwise deviated slightly from a true spherical shape, and by providing a diametrical seating groove for the retaining ring 5 so that it moves axially as the rollers tilt. In Fig. 6 (not shown), the gearing is applied to control the pitch of an aircraft propeller, the wheel 2 being mounted on the propeller shaft and the wheel 6 being connected to pitch-varying spur and worm gearing, whilst the disc 53 is rotated by means of a speed regulator and manually from the pilot's seat.