Patent GB-712476-A (GB)
Title: Improvements in and relating to hydraulic power transmission devices
IPC: F16D35/00
Filed: 1949-12-08
Abstract: 712,476. Hydraulic power transmission devices. TENOT, A. L., and PICAND, R. A. Dec. 8, 1949 [Nov. 29, 1949], No. 31526/49. [A Specification was laid open to inspection under Sect. 91 of the Acts, June 9, 1950]. Class 69 (2) The invention relates to a hydraulic power transmission device comprising a plurality of discs some of which are fixed to a driven shaft while others on a rotary casing are fixed to a driving shaft and interspaced between the discs on the driven shaft or vice versa and having a viscous liquid such as oil interposed between the discs and flowing in a closed circuit. As shown a pump P withdraws liquid from a casing K and supplies it by way of spaces cl, C into the interior of a rotating casing Q mounted on a driving shaft 1a. The liquid flows back into the casing through orifices g. When valves h are opened the apparatus is drained rapidly through the orifices G. The valves may be operated as shown by a sleeve ml and there may be an interconnection between the valves and a cock R. In a modification the valves may be operated by an annular piston member subjected to pressure the arrangement being such that when the flow of liquid is stopped the consequent loss of pressure produces movement of the annular member and opening of the valves. By varying the output of the pump P the inner radius n can be altered and thus the torque transmitted can be varied. The chamber C may have radial partitions for rotating the liquid therein. The discs may be very thin and relatively pliable. The liquid used may comprise oils or liquid silicon compounds. The Specification as open to inspection under Sect. 91, which does not admit of satisfactory abridgment, comprises also numerous modifications. In one modification the valves h are dispensed with. The liquid may enter through the driven shaft. The discs on one shaft may be moved longitudinally relatively to those on the other shaft. This movement may be effected by springs and by the liquid pressure. The discs may be brought into contact. Various arrangements of radial partitions are shown. These may be radial grooves in the discs. The rotating casings are shown carried by the secondary shaft. A cooler may be provided between the outlet from the casing K and the liquid inlet. In the form shown in Fig. 3, (Cancelled), a driving shaft 1 carries a rotor 3 into which fit cylindrical portions 5 of a rotor carried by a driven shaft 2. In the regions 7 the surfaces of the members are preferably corrugated but are smooth in the region of the ends 6 of the cylindrical portions 5. Fig. 5 (Cancelled) shows a modification in which a member P1 on the driving shaft and a member P2 on the driven shaft carry annular projections C1, C2 with conical surfaces the projections fitting between one another. Liquid is supplied by a pump not shown. One of the members P1, P2 may be moved axially in relation to the other. Adjustment of the torque may be effected by varying the delivery of the pump. In a modification of Fig. 5 (Cancelled) the member PI is enclosed within the member P2. Orifices extend through the member P1 at the region of the inner end of the recesses between the three outermost projections on this member and orifices are provided in the radial wall of the member P2 at the driving shaft end and in the outer cylindrical wall of this member. In a further modification the member P1 has projections C1 extending axially in both directions from a central wall and these fit between corresponding projections on the member P2 in which the member P1 is enclosed. Fig. 8 (Cancelled) shows another modification in which hollow discs C1 are employed. Longitudinal adjustment may be provided for. Engagement may be effected through gripping of both systems of paired tapered surfaces. In Fig. 9 (Cancelled) corrugated discs are employed the discs d2 carried on the driven member being adjustable axially. The discs d1 also move in an axial direction, adjustment being effected by a control rod E. Discs with projections on one or both sides are described. The control of the orifices G may be effected by a hydraulic or electromagnetic control. The valves h may be ball valves. The degree of cooling may be varied and a thermostat may be used for automatic adjustment. Adjustment might be effected by causing variation of the cross-sectional area of the holes that discharge liquid on its outlet from the discs. In another modification the discs on each shaft are carried by means of longitudinal grooves. The pressure acts on a piston which decreases the thickness of the liquid films between the discs. The transmission disengages automatically at a certain speed under the effect of the liquid pressure. Use of compressed air for effecting disengagement is referred to. This subject-matter does not appear in the Specification as accepted.