GB1127549A - Air cooled friction coupling - Google Patents

Abstract

1,127,549. Cooling friction clutches and electromagnetic disc brakes. WARNER ELECTRIC BRAKE & CLUTCH CO. 11 April, 1967 [5 May, 1966], No. 16523/67. Headings F2C, F2E and F2L. A friction clutch and brake assembly has a cylindrical squirrel cage fan 83 fast with an input shaft 12 and surrounding the friction surfaces to produce a cooling air flow. The clutch and brake are both of the stationary magnet type, the clutch having a stationary magnet winding 30 co-operating with polepieces of a rotor 35 forming the driving element of the clutch and which is fast with the input shaft 12. A driven shaft 13 has an output clutch disc 51 splined thereto. The brake comprises a disc 93 splined to the shaft 13 and frictionally engageable with a stationary magnet 84-89. The fan 83 is riveted to the rotor 35 and extends axially over all the friction surfaces. The driven disc of the clutch, and the brake rotor, are of similar construction, and the clutch disc comprises friction segments 50 riveted to embossed portions of the disc so as to provide radial channels for cooling air between adjacent segments and a gap between the back of the segments and the face of the disc. The assembly has a stationary housing 10 by which it is secured to a casing 23 of a driving motor, holes 70 being provided in the periphery of the housing for the admission of cooling air to the clutch, and holes 100 in an end wall admitting air to the brake. The fan expels air through outlet apertures disposed in the lower half of the housing and having fins inclined forwardly and rearwardly in alternate apertures so that alternate apertures act as outlets for opposite directions of rotation. When the clutch and brake are disengaged a constant air gap is maintained between their friction elements despite wear. Again the clutch and brake arrangements are similar, and for the clutch the driven disc is disengaged by a wavy spring 63 acting through a disc 64 having an axial flange 65 bearing against the driven disc. A ring 66 is contracted around the teeth of the driven member 67, and is shifted axially when the clutch magnet is energized to permit clutch engagement. The spring 63 is not strong enough to move the ring 66, so that on deenergizing the clutch, the disc 64 is shifted by the spring 63 until it abuts the ring 66 so that a constant air gap is maintained as determined by the extent to which the axial length of the flange 65 exceeds the thickness of the ring 66. Reference has been directed by the Comptroller to Specification 1,040,864.