GB896203A - Roll positioning system for toroidal variable ratio transmissions - Google Patents

Abstract

896,203. Variable-speed friction gear. AVCO CORPORATION. Dec. 24, 1959 [Jan. 29, 1959], No. 43841/59. Class 80 (2). Means are provided to ensure that during precessional ratio-shift movement of non- planetary rollers 50 in a toric-disc friction-gear they share the load equally. Each roller is rotatable about a sleeve 77 which pivots about a pin 78 mounted on a yoke 70. Each yoke 70 is pivotally mounted by means of hollow pivotpins 71, 72 on spring arms 63 secured to a threearmed element 60 fast with a stationary shaft 10. Each sleeve 77 has a cam groove 86 engaged by a button 85 on a common controlring 68 which is rotatably supported on the element 60 by rollers 66. Precession to change speed is initiated by rotating the control-ring 68 which initially tilts the rollers 50 about the pins 78 ; subsequently the tilting movement is about the pivots 71, 72, and during this latter movement the buttons 85 and cam grooves 86 restore the rollers to their initial positions relative to the pins 78. The spring arms 63 ensure that the rollers 50 share the load equally since the deflection they undergo is a function of the load. Three rollers 50 are provided and transmit torque from an input disc 5 to an output disc 7 ; Disc 7 is fast with a ring gear 35a meshing a stepped planet 36 in a stationary carrier 11, the other step of the planet meshing a sun 40 driving an output shaft 42. Gear 35a also drives a pump 44 supplying oil through passages 46 to the hollow pivots 71, 72 whence nozzles (Fig. 4, not shown) direct oil to the contact points of the rollers and discs. Disc 5 is mounted by means of a ball thrust bearing on a hub 12 and disc 7 is rotatably mounted on the stationary shaft 10; a bolt 15 is provided in the shaft 10 and a nut 18 thereon bears against the hub 12 and can be adjusted to vary the contact pressure between the rollers and discs.