GB547534A - Improvements in torque amplifiers - Google Patents

Abstract

547,534. Hydraulic couplings. WINDER, A. S. April 16, 1941, No. 4956. [Class 69 (ii)] To boost the power transmitted by a gear train such as that employed between the steering- wheel of a car and the road wheels, or by a long train of gears in a calculating machine, a gear wheel 2 driven by a power shaft 1 transmits power to the gear train through a hydraulic transmission device comprising a pump casing 8, Fig. 2, filled with oil ducts secured to a sleeve 9 on the gear 2. A series of gear wheels 6, 61, 62 are mounted in the casing and form gear pumps with a central gear 4 mounted on the power shaft 1. The power transmitted by the gear 2 is controlled by a rotary valve 12 concentric to the shaft 1 and operated by a control gear 3 which is driven by the gear train. The valve plate has apertures 17, 171 which may register with the gear pump outlets and inlets 15, 16, when no power is to be transmitted by the gear 2; the maximum power is transmitted when the passages 15, 16 are completely closed. Normally the gear 3 automatically adjusts the valve to supply the power required by a follow-up action. The casing 8 is enclosed in a rotary cover 18 which may be filled completely with oil, and oil seals 22, 23, 24 are provided to keep the gear mountings leak proof. The level of the oil need only be sufficient to cover the valve plate 12. Leakage into the pockets 10, 11 of the pump plates may be prevented by cover plates 26. In a modification the valve 12 is replaced by a ported disc, or sleeve mounted concentrically at the side of the pump casing and pressed towards the casing by a thrust ball bearing. A number of such control devices may be arranged side by side on a common power shaft.