Cross section view
Piston
Slipper
Valve plate
Ball bearing
Shaft
Journal Bearing
Swashplate bearing pin
Servo piston
Swashplate
Cylinder block
Sleeve Bearing
Needle bearing
Manual displacement Control
Gerotor
Shaft Seal
The system circuit
The basic closed circuit
Hydraulic lines connect the main ports of the pump to the main ports of the motor. Fluid flows in either
direction from the pump to the motor and back in this closed circuit. Either of the hydraulic lines can be
under high pressure. In pumping mode the angle of the pump swashplate determines which line is high
pressure as well as the direction of fluid flow.
Case drain and heat exchanger
The pump and motor require case drain lines to remove hot fluid from the system. The pump and motor
should be drained from their top most drain port to ensure the case remains full of fluid. Flow from the
motor case drain may route to the lower drain port on the pump housing and out the top most port, or
feed directly to the heat exchanger. The system requires a heat exchanger with a bypass valve to cool the
case drain fluid before it returns to the reservoir.
Service Manual
Series 40 M46 Variable Pumps
Introduction
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©
Danfoss | September 2017
11026743 | AX00000027en-US0202