Rexnord Gmbh

Pt Components, Inc.

Harold Lorenz

Bernard J Lindner

Walter G Stelzer

Jerry L Hamberger

A brake assembly (10) for selectively starting and stopping rotation of a shaft (12) journaled in a frame (14) of a motor comprises an end plate (16) mounted to the motor frame, the end plate (16) being formed with mounting slots (40) formed axially therein. Friction discs (26, 26a) are secured to the shaft (12) for rotation therewith about the longitudinal axis of the shaft (12) and pressure plates (36, 36a, 36b) are non-rotatably mounted in the mounting slots (40) of the end plates (16) and axially movable toward and away from the friction discs (26, 26a). Separator springs (124) are slidably mounted around a peripheral portion of the pressure plates (36, 36a) mounted in the mounting slots (40) for urging the pressure plates (36, 36a) away from the friction discs (26, 26a) to minimize brake drag caused by contact of the pressure plates (36, 36a, 36b) and the friction discs (26, 26a) during rotation of the shaft (12), and for suppressing noise and wear caused by contact of the pressure plates (36, 36a) relative to the end plate (16) during brake operation.

Orientation-free brake mechanism

A motor brake mechanism (10) includes retaining structure (46) permitting removal and replacement of friction discs (16, 18) without disassembling the brake mechanism. When the brake mechanism is detached from the motor, removal of a single bolt (46) permits radial removal and replacement of the friction discs. Minimizing of brake drag is enabled by adding low force compression springs (162, 164, 166, 168, 170, 172) without otherwise modifying the structure which prevents rotation of the pressure plates (38, 40) relative to the end plate (28) of the brake mechanism (10), wherein a first set of studs (42, 44, 46) provide both functions of non-rotatably mounting the pressure plates (38, 40) to the end plate (28) and mounting the low force compression springs, all separate from another set of studs (70, 72) mounting the brake lever (68) to the end plate (28). The brake solenoid (104) is mounted on another set of studs (122, 124) by resilient shock absorbers (126, 128, 130, 132) which perform dual functions of absorbing mechanical shock from the solenoid plunger (106) at the end of its travel stroke and minimizing solenoid buzz. The latter function is provided in conjunction with simplified single nut(148, 150) adjustment of the solenoid abutment surface (120). Separate cover mounting studs are eliminated, and the cover (98) is mounted on the same set of studs (70 and 72) which mount the brake lever (68). Improved and simplified pivot bearings are provided by hardened drive pins (64 and 66) providing substantially point contact and facilitating smooth pivotal bearing movement of the brake lever (68). A simplified manual release (182) includes a spacer (206) accommodating two friction discs (16, 18).

Simplified motor brake

A brake mechanism is disclosed wherein a support lever is pivoted at a pivot end to a stationary bearing plate and is urged by a plurality of springs, which engage the support lever radially inwardly from its pivot end, toward the end plate to effect clamping of a rotatable friction disc between the end plate and a brake shoe disposed near the pivot end of the support lever. A solenoid has a plunger pivotally connected directly to a bracket end of the support lever adapted to overcome the forces applied by the springs and release the brake when the solenoid is energized. The springs apply pressure in close proximity to the pivot point and with the solenoid being disposed at the remote free end of the support lever, there are achieved greater mechanical advantages without the need for complicated linkage assemblies. The arrangement of parts is such that the solenoid mechanical advantage is substantially 7 to 1, while the spring-set mechanical advantage is approximately 7 1/2 to 1. The greater spring-set mechanical advantage ensures that the support lever always maintains contact with the stationary bearing plate.

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Greenfield, WI, United States of America

Harold Lorenz