LOAD KING 35-127 M, Руководство оператора

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35-127 M
Troubleshooting
Winch System Maintenance and Troubleshooting
Winch Maintenance and Repair
The Load King Boom Truck is equipped with a power drum type winch� It is equipped with a spring-
applied, pressure-released brake� Operation of this system requires a counterbalance valve to insure
that the brake is totally released when winching down, with or without a load� When winching in the up
direction, the input shaft turns through a sprag clutch in the freewheel direction, which does not require
the brake to be released�
Winching up the load is quite simple� To winch in, we simply supply the winch motor with enough
pressure to lift the load� When pressure is removed, the sprag clutch engages the brake automatically
to prevent the load from dropping�
Winching down is a little more complicated� There are two systems that prevent the winch from back
driving and allowing a load to drop�
1� Winch brake is a spring applied, pressure released brake that requires internal pressure to release�
The sprag clutch connects the brake to the winch drum� Being a special one way clutch, it allows
the winch to free-wheel in the up direction, and lock in the winch down direction�
2� Counterbalance valve is a special valve blocking the flow of oil at the motor� To winch down, the
motor is pressurized and through a pilot signal passage it releases the brake and opens the
counterbalance which allows oil to flow through the motor� It takes more pressure to open the
counterbalance than to release the brake, so the brake is totally released before the winch rotates�
NOTE:
Incorporated into the counterbalance is an in-line check which allows the motor case to
drain while preventing winch pressure from entering the motor case.
To test the counterbalance valve, tee a gauge to the brake release line at the winch� The winch should
begin to move down at no lower pressure than 300- 400 PSI�
If the counterbalance system is working properly, the winch will make no attempt to turn until this 300-
400 PSI is reached� Contact Load King Service Department to receive overhaul information for the winch
on the unit� Have the serial number available at time of call and the information will be sent to you�