GB623003A - Clutches actuated by centrifugal pressure of a liquid - Google Patents

Abstract

623,003. Friction clutches. MERCURY CLUTCH CORPORATION. Oct. 26, 1945, No. 28371. Convention date, Nov. 11, 1944. [Class 80 (ii)] [Also in Group XXVI] In a clutch actuated by the centrifugal pressure of a rotating body of mercury or other heavy liquid, clutch operation is effected by initiating or suppressing liquid circulation between integral pump and pressure chambers, rotating with the driving member, so as to cause an operative piston between the chambers and rotating therewith to move axially relative thereto. The liquid circulation is initiated and suppressed by the selective operation of pump means comprising a hollow disc member, in the pump chamber and communicating with the pressure chamber, which normally rotates but is brakable to relieve the centrifugal pressure within it so that the liquid circulation is set up by differential centrifugal action. As shown applied to a plate clutch having single clutching members 29, 30, a housing 18 integral with the member 29 defines a pump chamber 46 and a pressure chamber 45 of smaller diameter, separated by a piston 5 keyed to a driving shaft 2. The member 30 is secured on a driven shaft 31 having an enlarged portion forming a bearing for the member 29, which has a sliding pin connection 36 with the piston 5. The hollow pump disc 12 is mounted on a sleeve 7 and dips at its periphery into the working liquid which, when the driving shaft is rotating, normally collects as an annulus in the larger diameter pump chamber and carries the disc 12 round with it. On applying a brake 11 to the sleeve 7 the disc 12, which may have polished or chromium plated surfaces to reduce friction, is arrested and the liquid is forced through it into the pressure chamber 45 via passages 13, 15, 50 and 44, moving the member 29 to the right for clutch engagement as shown. A continuous circulation is established through small orifices in, or clearances such as helicoidal grooves 40 around, the piston head which grooves or orifices, though by themselves insufficient normally to return all the liquid, allow it to drain completely back into the pump chamber for clutch disengagement on releasing the brake 11. During engagement, surplus liquid is returned through overflow passages 43 in the piston wall, which by their position determine the clutching force exerted. In Fig. 5 (not shown), the clutch is of the multi-disc type spring loaded to engage, and is disengaged by braking the pump disc, the piston in this case being the movable member. The application of this clutch to a dual turbine marine drive is described. Specification 594,790 is referred to.