BRADEN C2H150A, Installation Maintenance And Service Manual

4

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

UAL

B

RAKE

S

YSTEM

– D

ESCRIPTION

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

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

BASIC OPERATION

Pump

Brake
Valve

Static
Brake

Motor

Control
Valve

Low Pressure Medium Pressure

High Pressure

Pump

Brake
Valve

Static
Brake

Motor

Control
Valve

Low Pressure Medium Pressure High Pressure

To
Tank

To
Tank

Pump

Brake
Valve

Static
Brake

Motor

Control
Valve

Low Pressure Medium Pressure High Pressure

To
Tank

Figure 2

Figure 4

Figure 3