SENSOR AS-PRESSURE 4455108 - Caterpillar

Basic Winch Operation
The full output of the tractor implement pump flows through the tractor implement valve, which controls both the blade and ripper. The ripper valve section has been replaced with a special winch section to enhance the winch performance capabilities. The valve is a four way, three position valve.The winch control valve is connected to the operator's joystick control lever by a series of hydraulic hoses.Movement of the control lever directs the oil flow to the winch motor through hydraulic lines. The hydraulic motor converts the flow and pressure of the tractor hydraulic system into the mechanical energy needed to drive the winch gear train.The tractor can walk away from a winch load to reposition the tractor for another pull by releasing the drum clutch. The spring applied, hydraulically released multi-discclutch locks the secondary planetary ring gear to the winch housing. When released, the ring gear will turn as the secondary planetary assembly walks around the secondary sun gear, which allows the output planetary assembly and cable drum to turn free of the remaining reduction gears, static brake and hydraulic motor. The cable drum drag observed during brake-off (drum clutch release) is caused by the rotating output and secondary planetary gear sets and viscous drag of the friction discs. The brake-off drag force increases as the tractor ground speed increases.Dual Brake System - Description
The dual brake system consists of a dynamic brake system and a static brake system. The dynamic brake system has two operating components: 1. Hydraulic Brake valve assembly2. Hydraulic motorThe brake valve is similar to a counter-balance valve. It contains a check valve to allow free flow of oil to the motor in the Reel-In direction and a pilot-operated, spring-loaded spool valve which blocks the flow of oil out of the motor when the control valve is placed in neutral. When the control valve is moved into the Reel-Out position, the spool in the brake valve remains closed until sufficient pilot pressure is applied to the end of the spool to shift it against the 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 Reel-Out speed. See figures 2, 3 & 4. The static brake system has three operating components: Spring applied, multiple friction disc static brake Sprag-type overrunning brake clutch assembly Hydraulic piston and cylinder The static brake is released by the brake valve pilot pressure at a pressure lower than that required to open the pilot operated spool valve in the brake valve assembly. This sequence assures that dynamic braking takes place in the brake valve and that little, if any, heat is absorbed by the friction discs.The friction brake is a load holding brake only and has nothing to do with dynamic braking or the rate of release of a heavy or suspended load.The overrunning brake clutch is splined to the primary sun gear shaft between the motor and the primary sun gear.