GB816465A - Improvements in or relating to powder couplings - Google Patents

Abstract

816,465. Friction clutches. SOC. MEDITERRANEENNE MINIERE METALLURGIQUE ET COMMERCIALE. Sept. 2, 1957 [Sept. 3, 1956], No. 27613/57. Class 80 (2). In a powder clutch, to permit free relative movement of a disc 7 under pressure of the powder 4 in a surrounding casing 3, the disc 7 is universally mounted on its shaft 5 by two groups 8 of radially inclined tangential coilsprings. This permits both the casing shaft 1 and disc shaft 5 to be mounted in external bearings 2, 13 which need not be accurately aligned. A flexible seal 11 bearing on a powderproof inner ball-bearing 12 is provided between the casing 3 and shaft 5. The powder 4 is in the form of a metallic shot, the diameter of which is more than 0.2 mm., permitting a slight slip between the disc 7 and casing 3 (slip between 0.1 and 0.01 per cent) and more slip on overload. To increase the torque transmitted the surfaces of the disc and/or the casing 3 may be locally roughened by metallisation or hammering to form rounded deformations. The contact pressure between the disc 7 and powder 4 may be increased by providing the ring with slight undulations, the size of which is generally not more than 15 per cent of their pitch, and the disc may be externally and internally round or polygonal.