Danfoss OSQA - Introduction

Introduction
Safety precautions............................................................................................................................................................................4
Symbols used in this literature.................................................................................................................................................... 4
OSQ versions......................................................................................................................................................................................5
Technical specifications
Exploded view................................................................................................................................................................................... 6
Parts list................................................................................................................................................................................................6
OSQA and OSQB parts list........................................................................................................................................................6
OSQ spare parts list.................................................................................................................................................................... 8
Tools......................................................................................................................................................................................................8
Disassembly
Dismantling counter pressure valve..........................................................................................................................................9
Removing pressure relief valve ................................................................................................................................................11
Removing end cover at PP-connection................................................................................................................................. 12
Removing end cover at LS-connection..................................................................................................................................13
Unscrew orifices, throttle check valve....................................................................................................................................16
Housing and end cover with accessories..............................................................................................................................16
Spools with accessories............................................................................................................................................................... 17
Dismantling directional spool...................................................................................................................................................17
Priority valve spool number of orifices...................................................................................................................................17
Dismantling priority valve spool.............................................................................................................................................. 18
Dismantling amplifier spool.......................................................................................................................................................19
Shock and suction valves............................................................................................................................................................23
Cleaning............................................................................................................................................................................................ 24
Inspection and replacement......................................................................................................................................................24
Lubrication....................................................................................................................................................................................... 24
Assembly
Assembling shock, suction, and check valve.......................................................................................................................25
Assembling amplifier spool........................................................................................................................................................26
Assembling priority valve spool............................................................................................................................................... 28
Assembling directional spool....................................................................................................................................................29
Installing orifice and throttle check valve.............................................................................................................................29
Installing shock valves..................................................................................................................................................................30
Assembling pressure relief valve..............................................................................................................................................31
Installing OSQB back pressure valve.......................................................................................................................................32
Installing spools..............................................................................................................................................................................33
Installing PP end cover.................................................................................................................................................................34
Installing LS end cover.................................................................................................................................................................37
Plastic plugs..................................................................................................................................................................................... 39
Testing
Set-up for testing........................................................................................................................................................................... 40
Steering test using steering unit type OSPBX LS................................................................................................................40
Pilot relief valve...............................................................................................................................................................................41
Neutral positioning....................................................................................................................................................................... 41
Manual steering test..................................................................................................................................................................... 41
Service Manual
OSQA/OSQB
Contents
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Danfoss | July 2016 HN25D293 | AX00000127en-US0101 | 3