Danfoss 20 Series - Table of Contents

Service Manual and
Axial Piston Pumps Series 20
Repair Instructions
L1003506 • Rev BA • Jun 2014 3
Contents
Model Code
Recommended Tools and
Installation
Start-up procedure
System Maintenance
Trouble Shooting
Disassembly and Assembly
Model Code ................................................................................................................................................................................. 4
Tools for Minor Repairs and Unit Maintenance ............................................................................................................. 5
Additional Tools for Complete Stripping of Units ......................................................................................................... 5
Measurement Instruments .................................................................................................................................................... 5
Trouble Shooting, Gauge Installation and Information .............................................................................................. 6
Preconditions for Trouble-free Operation ....................................................................................................................... 7
First-time Operation................................................................................................................................................................. 8
Plumbing Installa tion (Variable Displacement Pump - Fixed Displacement Motor) ..................................... 10
System circuit Description ................................................................................................................................................... 10
Inlet Filter .................................................................................................................................................................................. 11
Changing the oil ...................................................................................................................................................................... 11
Leak Test ..................................................................................................................................................................................... 11
Cleanliness ................................................................................................................................................................................. 11
Checking the oil level ............................................................................................................................................................ 11
Recommended oils................................................................................................................................................................. 11
Transmission Operates in one Direction Only .............................................................................................................. 12
System response is sluggish ............................................................................................................................................... 12
Neutral Difficult or Impossible to Find ............................................................................................................................ 13
System will not Operate in either Direction .................................................................................................................. 13
Inspection Instructions ........................................................................................................................................................ 14
Checking the servo valve (control valve) ................................................................................................................. 15
Sectional View .......................................................................................................................................................................... 16
Axial piston variable displacement pump ............................................................................................................... 16
Exploded View ......................................................................................................................................................................... 17
Minor repairs ............................................................................................................................................................................. 18
Mounting block ................................................................................................................................................................. 18
Changing the shaft seal (disassembly)...................................................................................................................... 19
Changing the shaft seal (assembly) ...........................................................................................................................20
Changing the charge pump and the charge check valves ................................................................................ 21
Changing the servo valve (control valve) .................................................................................................................23
Major repairs ............................................................................................................................................................................. 24
Changing the valve- and bearing plate (disassembly) .......................................................................................24
Changing the valve- and bearing plate (assembly) .............................................................................................25
Changing the cylinder block kit (disassembly) ...................................................................................................... 27
Changing the cylinder block kit (assembly) ............................................................................................................28
Changing the swash plate and servo piston (disassembly) .............................................................................. 29
Changing the swash plate and servo piston (assembly) .................................................................................... 31
Changing the pump shaft ............................................................................................................................................. 33
Installation Torque Values .................................................................................................................................................... 35