GB605479A - Friction wheel variable speed gear - Google Patents

Abstract

605,479. Friction wheel gearing. LESUEUR, J. M. Nov. 19, 1945, No. 31046. Convention date, Jan. 17, 1942. [Class 80 (ii)] A friction wheel gear comprises two frustoconical discs having tiltable frusto-conical rollers between the discs, either the peripheries of the discs or the rollers being convex, resilient means keeping the driving members in engagement and the rollers being so supported at each end that they are tilted about points in their axes lying substantially at the point of intersection of the mean radius of the generatrix. In an embodiment, an inner friction disc 1 is secured to a driven shaft 2 with a spring 3 interposed between the disc and a shoulder on the shaft. An outer friction disc 6 is rotationally secured inside a pulley 7, but is free to move axially against the action of a spring 8. The discs 1, 6 are concentric and have frustoconical friction surfaces as have the intermediate rollers 10 whose surfaces are also slightly convex. The two springs 3, 8 moving the discs into contact with the rollers are balanced by a spring 20 moving a dished plate 18 bearing against the ends of the roller spindles. These rollers are supported in bearings 11, 12 mounted in cheeks 13, 14, the latter being connected together and rotatable in the housing 15, 16 by movement of an arm 13 carrying a jockey pulley 29 spring loaded by a spring 32 attached to the casing. A second jockey pulley 23 is mounted on an arm 22 rotatable about the casing 16 and loaded with spring 34 which is attached to the arm and the casing. The spherical bearings 11, 12 of the rollers 10 are located in grooves b of cheeks 13, 14 and in radial grooves a of casings 15, 16 so that relative movement of the jockey pulleys due to increasing or decreasing tension in the driving belt 37 causes the rollers to be tilted about their transverse axes to change the transmission ratio and thus maintain constant torque. In other embodiments shown, the roller axes are radial and provision is made for manual or automatic regulation of the transmission ratio.