Input Shafts; Control Options; General; Pc Control - Danfoss 45 E Frame Series Service Manual

Service Manual
Series 45 E Frame Open Circuit Pumps
Features

Input shafts

Control options

© Danfoss | September 2016
All manuals and user guides at all-guides.com
Auxiliary pad options
Series 45 E frame pumps are available with a variety of splined and straight keyed shafts. For information
on shafts refer to Series 45 Axial Piston Open Circuit Pumps Technical Information 520L0519.
The Series 45 Frames E have three possible control options, a Load Sensing (LS) control with Pressure
Compensator (PC), a PC only control, or an electric control.

General

The bias piston and spring (1) acts at all times to push the swashplate (2) to maximum angle causing the
pump to stroke. The servo piston (3) acts against the bias piston and spring to reduce the swashplate
angle causing the pump to destroke. Swashplate angle determines pump outlet flow. The pump control,
depending on conditions in the system circuit, sets swashplate angle by metering system pressure to the
servo piston.
Cross-section pump
3
1 2
Bias spring and servo piston set swashplate position

PC control

The PC control design maintains a constant pressure in the hydraulic circuit as flow varies. The PC control
modulates pump flow accordingly to maintain system pressure at the PC setting as the PC adjusting plug
(4) and spring (5) defines.
When system pressure, acting on the non-spring end of the PC spool (6), overcomes the force of the PC
spring, the spool shifts porting system pressure to the servo piston and the swashplate angle decreases.
When system pressure drops below the PC setting, the PC spring shifts the spool in the opposite
P104 047
P104 048
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