GB1363504A - Torque responsive pressure devices - Google Patents

Abstract

1363504 Expanding-pulley gear H VOGEL 1 Sept 1971 40679/71 Heading F2D A torque (and also in some embodiments, speed) responsive device for applying adjustable axial pressure to a member such as a flange 5 of an expanding pulley, splined to a companion flange 3, freely rotatable on a shaft 1 and axially adjustable by a manual fork 7, comprises a diametral pin 10 (fixed to the shaft 1 in Fig. 1), carrying rollers 11 which, under torque load, apply axial pressure to the flange 5 through wedge shoes 15 carried in an annular channel between the rollers 11 and a roller race 17 in the hub 25a of the flange 5, means being provided to adjust the shoes 15 in the channel to vary the angle a of contact between the shoes 15 and rollers 11 to vary the torque responsive axial pressure. As shown, such ajdustment is produced by the axial adjustment of the pulley flange 3 whereby the torque-responsive axial pressure is reduced by increase of contact angle α as the pulley flanges are closed. For this purpose the shoes 15 are carried on pivot pins 16 engaging slots in plates 12, forked around the shaft pin 10 and shifted axially through levers 19 by the axial movement of the pulley flange 3, the closing movement, to dotted position of which, turns the shoes 15 to the dotted position, producing an increased contact angle α<SP>1</SP>, thereby reducing the axial pressure component of the torque. In Figs. 5 to 7, not shown, the two pulley flanges are simultaneously adjusted through thrust bearings by interconnected levers, and the plates (equivalent to 12 of Fig. 1) which adjust the wedge shoes are replaced by flats and inclined grooves (56) in the shaft, the diametral pin (42) being axially slidably in a shaft slot. In Figs. 8 to 10, not shown, one pulley flange (72) is fixed to its shaft, and the diametral pin (80), together with its wedge shoe assembly, is carried by an internal plunger (79) which can be adjusted axially in a shaft bore through a thrust bearing (90) which adjusts the axial spacing of the pulley flanges and hence the speed ratio. The shoe pins (85) slide in asymmetric slots (87, 91) in the hub of the axially fixed flange to produce a different pressure response in accordance with the direction of rotation. Springs (77) preload the pulley flange (73) axially. In Figs. 11 and 12, not shown, such a plunger (97) is axially adjusted by centrifugal masses (103) pivoted to the shaft, whilst in Fig. 13, not shown, such axial adjustment is produced by hydraulic or pneumatic pressure, proportional to shaft speed, acting on the plunger (113) through a rolling diaphragm. In these cases the axial spacing of the pulley flanges for ratio control, and also for varying the torque-responsive pressure on the wedge-shoes, is speed-responsive.