GB752611A - Magnetic powder clutch and rotor therefor - Google Patents

Abstract

752,611. Magnetic clutches. INTERNATIONAL BUSINESS MACHINES CORPORATION. Aug. 13, 1954 [Aug. 18, 1953], No. 23566/54. Class 35. In a magnetic powder clutch high rate of acceleration and deceleration is obtained by reducing the drag of the clutch members on the iron powder and this is achieved by providing one of the clutch members with a disc rotor having a number of blades separate from one another by slots opening through their peripheral edges, the blade edges being so shaped that the density of the powder is less dense near the blade trailing edges than at the leading edges. The clutch has a disc rotor 48 with radial thin blades 50 (best seen in Fig. 2) extending into a space 29 formed in the field core of the driving outer member A. The blades 50 are separated from one another by inclined slots 60. The Specification describes various shapes and dimensions of these rotor blades the main object of which is to prevent a uniform density of the iron powder in the working gap. Whereas in Fig. 2 the outer ends 61 of the blades 50 are concentric to the rotor axis and thereby forming a constant clearance 63 in another form the blades have the ends eccentric to the rotor axis, but in both cases the thickness of the leading edges 58 of each blade is greater than that of the trailing edges 59 as illustrated in Fig. 4. The field core of the clutch driving member A comprises a number of U-shaped laminations 30 separated into segments by anchors 32 (Fig. 2), and these laminations are so assembled so as to provide a groove to accommodate the field coils 37 part of the radial slot 29 in which the rotor blades rotate. The brake B (Fig. 1) is similarly constructed. Specification 649,553, [Group XXIV], is referred to.