Basic Operation - BRADEN CH SERIES Installation Maintenance And Service Manual

DESCRIPTION OF HOIST
The hoist is made up of the following sub-assemblies:
1. Hydraulic motor and brake valve
2. Drum, drum closure, ball bearings and oil seals
3. Support end plate and bearing support
4. Motor end plate and motor adapter
5. Tie plates
6. Brake clutch assembly
7. Brake cylinder assembly and multiple-disc brake parts
8. Primary planetary reducer
9. Secondary planetary reducer
10. Ring gear and adapter
THEORY OF OPERATION
The primary sun gear, being coupled to the hydraulic motor
by the inner race of the brake clutch assembly, turns with
the motor. As the primary sun gear turns, the primary plan-
et gears, which are meshed with the primary sun gear and
ring gear, walk around the stationary ring gear, causing the
primary carrier to turn in the same direction as the motor
shaft, but at a reduced speed. The primary carrier is
meshed with the output sun gear which, therefore, turns in
the same direction and at the same speed as the primary
carrier. The output sun gear causes the output planet gears
to walk around the ring gear, turning the output carrier and
drum in the same direction as the primary carrier, but at a
further reduced speed.
D B S – D
UAL RAKE YSTEM
The dual brake system consists of a dynamic brake system
and a static brake system.
The dynamic brake system has two operating components:
1. Brake valve assembly
2. Hydraulic motor
The brake valve is basically a counterbalance valve. It con-
tains a check valve to allow free flow of oil to the motor in
the hoisting direction and a pilot operated, spring-loaded
spool valve that blocks the flow of oil out of the motor when
the control valve is placed in neutral. When the control
valve is placed in the lowering position, the spool valve
remains closed until sufficient pilot pressure is applied to
the end of the spool to shift it against spring pressure and
open a passage. After the spool valve cracks open, the pilot
pressure becomes flow-dependent and modulates the
spool valve opening which controls the lowering speed.
See figures 2, 3 and 4

BASIC OPERATION

ESCRIPTION
The static brake system has three operating components:
1. Spring Applied, Multiple Friction Disc Static Brake
2. Brake Clutch Assembly
3. Hydraulic Piston and Cylinder
Static
Brake
Brake
Valve
Pump
Low Pressure Medium Pressure
Static
Brake
Brake
Valve
Pump
Low Pressure Medium Pressure High Pressure
Static
Brake
Brake
Valve
Pump
Low Pressure Medium Pressure High Pressure
4
Motor
High Pressure
Motor
Motor
Figure 2
To
Tank
Control
Valve
Figure 3
To
Tank
Control
Valve
Figure 4
To
Tank
Control
Valve