Patent GB-1328522-A (GB)
Title: Continuously variable speed variator
IPC: F16H15/52
Filed: 1970-09-16
Abstract: 1328522 Variable-speed friction planetary gear; one-way clutches; slip couplings B A GUSTAFSSON 16 Sept 19704 4164/70 Headings F2C, F2D and F2U In an underdrive-through direct-to overdrive steplessly-variable planetary ball friction gear comprising planetary ball idlers 10 carried by a disc 6 fast on a driving shaft 1 and engaging internal conical spring-loaded friction tracks, one 16 on a stationary reaction-casing 2, the other 17 on a disc-like member 18 rotationally connected to the output shaft 4, at points of contact which can be varied by tilting the axes of bearing studs 9 of the balls 10 by axial adjusting movement of a slide block 13 connected by rigid wires 12 to U-shaped yokes 7 which carry the bearing studs 9 and are pivoted by trunnions 8, in fork-like notches in the disc 6, each on an axis which passes through its ball centre, said axial adjustment of the block 13 to vary the ratio being effected by turning a thumb-screw 15 mounted within the driving shaft 2, the torque transfer from the driving shaft 1 to the driven shaft 4, which is dependent on the spring- loading of the friction tracks 16 and 17 against the balls 10 by cup springs 20, is relatively small and is increased for heavy duty work by a torque transfer strengthening device in the form of a multi-disc friction slip one-way clutch 23, 25 directly connecting the driving shaft 1 to the driven shaft 4 whereby the clutch slips according to the steplessly variable ratio of the friction balls whilst directly transmitting a substantial part of the input torque direct to the driven shaft 4. The inner and outer multi-discs 23, 25 of the one-way slip clutch are respectively slidably keyed to a collar 24 on the driving shaft 1 and pegs 27 on a clutch pressure plate 26 which is slidably keyed via a claw coupling to the driven shaft 4, the pressure plate 26 being directly connected to the ball track plate 18 by links 28 pivotally mounted on radial studs 29 and retained in position by wire springs 30, the lengths of the links 28 being such that in their axial position illustrated in Fig. 4 the multi-disc clutch plates are disengaged and no torque transfer therethrough is possible. During drive, the ball track plate 18 under the influence of the balls 10 is rotated relative to the pressure plate 26 causing the links 28 to incline to engage the multi-disc clutch plates 23, 25 for the direct transfer of torque between the driving and driven shafts 1, 4, the torque transfer increasing the more the inclination of the links 28 increases until the plates 26 and 28 rotate at the same speed at which a stable condition occurs under which the speed of the output shaft follows the speed of the input shaft in constant proportion according to the set ratio position of the balls 10 with slip occurring between the discs and plates of the one-way slip clutch. Fig. 5, graphically illustrates the steplessly-variable underdrivedirect-overdrive ratios according to the tilt angle of the planetary balls 10. Longitudinal and circumferential micrometer scale markings are provided on the peripheral surface of the ratio adjustment screw 15 to show the speed ratio variation. (For Figures see next page.)