Hoist Operation - Manitowoc Grove CD3340B Service Manual

STRUCTURAL
the brake cylinder. The other end of the drum rotates on a
ball bearing on the support bolted to the base. The ring gear
for both planetary sets is machined into the drum's inside
surface.

Hoist Operation

The hydraulic motor drives the sun gear of the primary
planetary gear set through the spline inner race of the brake
A2205
Dual Brake System -Description
The dual brake system consists of dynamic brake system
and a static brake system.
The dynamic brake system has two operating components:
1. Brake valve assembly
2. Hydraulic motor
11-32
clutch. When driven by the sun gear, the primary planet
gears walk around the ring gear in the drum and drive the
planetary carrier.
The primary planet carrier drives the output planet sun gear,
which in turn drives the planet gears. The output planet
carrier is spline to the bearing support and cannot rotate.
Therefore, as the output planet gears are driven by the sun
gear, they will drive the ring gear/drum.
The brake valve is a counterbalance valve which contains 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 main control valve is placed in hoisting position,
oil, under pressure, from the pump is sent through the main
control valve to the counterbalance valve; opening the check
valve. Oil flows through the check valve to the motor, rotating
in the hoisting direction. See Figure 11-68.
Published 04/07/2015 Control # 569-00
CD3340B/YB4411
FIGURE 11-67