CYLINDER GP-HOIST 2414065 - Caterpillar

Illustration 1 g02920440
Parking brake (parking brake engaged)
(1) Brake Spring
(2) Brake Piston
(3) Separation plate
(4) Friction plate
(5) Barrel
(6) Passage
(7) Spring
(8) Spindle
(9) Housing
(10) Piston chamber
(11) Orifice
(12) Shaft
(13) Valve
(14) Passage When the travel lever/pedal is returned to the NEUTRAL position, oil delivery from the main pump is blocked at the travel control valve in the main control valve. Valve (13) moves to the left by the force of spring (7). The oil delivery from the pump does not flow through passage (14). The force of the oil pressure on the left side of brake piston (2) now becomes lower than the force of brake spring (1). Brake piston (2) is pushed slowly to the right by the force of brake spring (1). The oil in piston chamber (10) now flows through passage (14) and orifice (11). The oil flows into the valve of the motor case drain line. Friction plates (4) and separator plates (3) are forced together by the force of brake spring (1). Friction plates (4) are splined to barrel (5). Separator plates (3) are splined to housing (9). When separator plates (3) and friction plates (4) are forced together, the rotation of drive shaft (12) in the travel motor gradually slows to a stop as the parking brake engages. Orifice (11) restricts return oil flow from piston chamber (10). The restriction of the return oil flow delays the application of the parking brake. The parking brake is delayed in order to give the machine time to stop. Earlier wear and/or damage to the machine could result if the machine stayed in motion.The parking brake for the travel motor is activated by spring pressure and the parking brake is released by hydraulic pressure. When pump oil is supplied to the travel motor, the parking brake releases. The motor starts rotating. When no pump oil is supplied to the motor, the motor stops and the parking brake engages.
Illustration 2 g02921136
Parking brake (parking brake disengaged)
(1) Spring
(2) Piston
(3) Separation plate
(4) Friction plate
(5) Barrel
(6) Passage
(7) Spring
(8) Spindle
(9) Housing
(10) Piston chamber
(11) Orifice
(12) Shaft
(13) Valve
(14) Passage When travel lever/pedal is moved from the NEUTRAL position, oil delivery from the main pump flows to the inlet port of the travel motor from the travel control valve in the main control valve. A portion of the oil delivery from the pump flows through passage (6). Valve (13) moves to the right against the force of spring (7). The oil then flows through passages (14) and orifice (11) to piston chamber (10). Brake piston (2) moves to the left against the force of brake spring (1). The spring force that is holding friction plates (4) and separator plates (3) together is released. Barrel (5) and shaft (12) start to rotate.