R&M Materials Handling, Inc
STAGEMAKER® COMPACT Concert Hoist
Springfield, Ohio USA
SM5 Manual
: 800 955-9967
Revision 1
web:
www.rmhoist.com
08/14/02
RM-SM5-MAN-2001-1-ENG
4-2
Motors
The hoist motors are designed to provide dependable hoisting service. The standard motors are
enclosed for protection against normal hazards of dust and moisture. The bearings are sealed and
lifetime lubricated and they do not require regreasing.
Brake/Torque Limiting Device
The hoist brake is a D.C. disc type. The function of the hoist brake is to minimize hook drift by
bringing the motor to a quick and smooth stop, and to hold loads suspended from the hook with
the power off.
In addition to the hoist brake, the hoist is furnished with a torque-limiting device, integral with
the hoist brake. The torque-limiting device helps prevent the lifting of excessive loads, which
may damage the hoist.
1
3
4
6
7
Air gap
2
5
8
X
9
10
Figure 4-2 – Hoist Brake/Torque-limiter
Operation of Brake/Torque-limiter
Even if the torque-limiter slips, once power is removed the brake will engage and hold.
The parts of the limiter and the brake disc are mounted on the gear input shaft (1). Other brake
parts are mounted to the brake housing.
The spring (2) keeps the limiter (3) and the brake discs (4) plated together and defines the
maximum torque that can be transferred through the limiter.
The nut (5) maintains the assembly on the gear-input shaft.
When the coil (6) is energized, during lifting or lowering, it moves against the anchor disc (7),
which is fixed to the brake housing by an attachment screw (10)
(there is an air gap for this
purpose).
The discs (3 and 4), that are connected together by the friction of the limiter, turn
freely, transmitting the movement to the pinion (8).
Braking occurs when the coil is no longer energized and the spring (9) drives back coil (6).
