Patent GB-1264757-A (GB)
IPC: F16D59/02
Filed: 1970-03-18
Abstract: 1,264,757. Electric - motor multiple - disc brakes; electromagnetic release. ADAM BAUMULLER G.m.b.H. FABRIK FUR ELECTROTECHNIK. 18 March, 1970 [21 March, 1969], No. 13165/70. Heading F2E. In a spring-applied, electromagneticallyreleased, disc brake for a motor, particularly an electric motor, including a brake disc axially displaceable on the motor shaft, and an axiallydisplaceable armature disc movable by the spring means, the element in which the electromagnet is mounted is also axially displaceable, and movements of the armature disc and of the magnet element away from the brake disc are limited by respective locking devices. As shown in Figs. 1 and 3, in operation, springs 15 urge an armature disc 14 slidably mounted on fixed bolts 6 into contact with a brake disc 9 mounted by an adjusting spring 8 on a motor shaft 7 so as to rotate therewith. The brake disc 9 is in turn urged into contact with a mounting plate 5 screwed on to the motor housing 1. Recesses 22 in the armature disc 14 accommodate insert pieces 24 each of which retains a dished spring 28. The spring has radial slots in its inner periphery leaving resilient tongues which engage the bolt 6. The arrangement is such that the armature disc may move freely to the left but only very slight movement to the right is permitted to permit release of the brake when winding 18 is energized. The magnet element 17 is similarly furnished with insertpieces 25 but each piece locates two dished springs 28; element 17 is permitted to move to the left only. When wear of brake linings 12 takes place, armature disc 14 follows brake disc 9 to the left on brake application. Correspondingly, on brake release, element 17 moves to the left in addition to the movement of disc 14 to the right. Packings 35 and 36 and plugs 37 are provided. A fan 38 is mounted on shaft 7, and an apertured hood 39 is fitted. In Fig. 2 (not shown), recesses 16 for springs 15 are open at the right-hand end, and a threaded bolt (19) is screwed into each recess to enable the spring force to be pre-adjusted. In Fig. 4 (not shown), the opening for the spring in each insert piece is frusto-conical, widening to the right, and a ring of hardened steel balls is located in the opening to the left of the spring. The spring in this instance is inclined in the opposite direction, and does not touch the bolt 6 even when pressed flat by the balls. Only one spring is located in each insertpiece in the element 19 in this instance. In Fig. 5 (not shown), the ring 11 of Fig. 1, which is of sintered metal and saturated with oil or grease, is omitted. Instead, a ring packing (45) surrounds shaft 7 at each end of brake disc 9, and a conical tongue (44) on each packing bears against a recess in the adjacent face of the disc. The tongue (44) on the right is initially more tightly engaged than that on the left because during lining wear, disc 9 moves more to the left, while the packings (45) remain stationary. In this embodiment the mounting of armature disc 14 and element 17 are as shown in Fig. 6. In the disc 14 balls 31 are arranged in a cage 46 located on bolt 6 within a conical depression 29 having a half-angle of, e.g., 8 degrees. Movement to the right of 0À2 to 0À3 mm. is permitted. In element 17 the same arrangement is supplemented by a shim 49 and two dished springs 48. Movement to the right is thus prevented.