COUPLING 1W5345 - Caterpillar

2-3 Operation
(1) Pump main body When drive shaft (11) is driven by the pump drive gear box, cylinder (43) is rotated at the same time through the spline coupling. When swash plate (37) is inclined piston (39), which is inside the cylinder, rotates together with the cylinder and also performs reciprocating motion relative to the cylinder. Consequently, focusing for the moment on only one cylinder, as the cylinder goes through one complete revolution, for 180° the piston moves away from the valve plate (49), so that oil is sucked in, and for the other 180° the piston approaches the valve plate so that oil is delivered. When the swash plate inclination angle (a) is zero the piston does not stroke and oil is not delivered. As the inclination angle (a) becomes larger the piston stroke increases, and the amount of oil delivered increases. Swash plate (37) is supported by swash plate supporter (38) through thrust metal (36) and can rotate through an inclination angle (a) range of 0° to 16°. On top of the swash plate a pin is formed, and slide ring (69) is attached to it. When this slide ring causes lever (72) to reciprocate by regulator control, the inclination angle of the swash plate changes. (2) Regulator This regulator has the following control functions.a. Compensation control As the pump delivery pressure (Pd) of the same pump rises, the pump delivery rate (inclination angle) is automatically decreased to hold the torque constant (if the r.p.m. is also constant, this means that the horsepower is constant.)b. Flow control (positive control) The pump delivery rate (inclination angle) is controlled by pilot pressure.c. Cut-off control When the circuit pressure rises above the set cut-off pressure, the pump delivery rate is rapidly decreased (flowrate cut-off control).1. Compensation control 1) Overload prevention When the delivery pressure exceeds a certain set pressure, the delivery rate is decreased so that the horsepower does not become excessive.When a pump on the compensation control line is operating at Pd1, Q1, as shown in the graph above, and then goes beyond the Pd-Q line to Pd2, then pilot spool (91) is moved by the pump pressure acting on the compensation pressure chamber through the path connecting to the pump delivery line until compensation piston (55) causes the force of compensation springs (78) and (79) to balance the hydraulic pressure.The movement of the pilot spool causes the tank port of sleeve (92) to open (