Piston Pump

Bharat Hydraulic is a distinguished Retailer, Service Provider and Trader offering an enormous consignment Of Hydraulic Pump Repairing Service, Mild Steel Hyraulic Pump etc.

Bharat Hydraulic is a distinguished Retailer, Service Provider and Trader offering an enormous consignment Of Hydraulic Pump Repairing Service, Mild Steel Hyraulic Pump etc.

Basic Pump

• Figure 1 shows the basic construction of the PVH series piston pump. Major parts include the drive shaft, housing, yoke, rotating group, valve plate, control piston, bias piston, valve block and compensator control.

The PVH series replaces the pintle bearing assembly with saddle bearings, which reduces weight and eliminates the roller bearings that added to maintenance time and overhaul costs.

B. Pump Controls

• Two common pump control types are available. One type is the standard “C” compensator control that limits pump outlet pressure to a desired level. The other type is the “CV” pressure limiter/load sensing control. Now available is the
• “IC” (Industrial Control) which can be used as a load sensing compensator, remote compensator control and electrohydraulic control. These limit pump outlet pressure and also regulate pump displacement to match load requirements. Section 3 – Principles of Operation

A. Pump Operation
Rotation of the pump drive shaft causes the cylinder block, shoe plate and pistons to rotate (See Figure 2). The piston
shoes are held against the yoke face by the shoe plate. The angle of the yoke face creates a reciprocating motion to each piston within the cylinder block. Inlet and outlet ports connect to a kidney slotted wafer plate. As the pistons move out of the cylinder block, a vacuum is created and fluid is forced into the void by atmospheric pressure. The fluid moves with the cylinder block past the intake kidney slot.

The motion of the piston reverses and fluid is pushed out of the cylinder block into the outlet port.

Warning
Before breaking a circuit connection, make certain that power is off and system pressure has been released. Lower all vertical cylinders, discharge accumulators, and block any load whose movement
could generate pressure. Plug all removed units and cap all lines to prevent the entry of dirt into the system.B. Pump Controls
Pressure Compensator Controls “C” & “CM”
(Figure 3) The standard “C” and low pressure “CM” compensator controls are internally pilot operated, spring offset, 2-way
valves. Their purpose is to limit system pressure to a desired level by varying pump displacement. These controls only provide the flow required to satisfy the load demand, while maintaining a constant preset pressure.

During operation, load or system pressure is continually fed to the bias piston. The function of the bias piston is to maintain the yoke at a full pump displacement position. Load or system pressure is also fed to the compensator spool chamber within the control. Pressure within the compensator
spool chamber acts upon the spring force of the compensator spring. When load or system pressure is below the pressure setting of the compensator spring, the compensator spool remains offset and the pump continues to operate at full displacement. When load or system pressure approaches the compensator pressure setting, the compensator spool will start to move and overcome the compensator spring.