Danfoss Series 42 Service Manual
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Danfoss Series 42 Service Manual

Danfoss Series 42 Service Manual

Axial piston closed circuit pumps
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MAKING MODERN LIVING POSSIBLE
Service Manual
Axial Piston Closed Circuit Pumps
Series 42
powersolutions.danfoss.com

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  • Page 1 MAKING MODERN LIVING POSSIBLE Service Manual Axial Piston Closed Circuit Pumps Series 42 powersolutions.danfoss.com...
  • Page 2 Service Manual Series 42 Axial Piston Closed Circuit Pumps Revision history Table of revisions Date Changed July 2015 Danfoss layout 0300 Nov 2010 new back page Dec 2009 Major update Jul 2007 Major update 520L0638 • Rev 0300 • July 2015...

  • Page 3: Table Of Contents

    Service Manual Series 42 Axial Piston Closed Circuit Pumps Contents Introduction Overview......................................5 Warranty......................................5 General instructions..................................5 Safety precautions....................................6 Symbols used in Danfoss literature............................7 1998 Model Release Overview......................................8 Description of change..................................8 Functional Description Overview......................................9 General description and cross-sectional view........................9 The system circuit..................................
  • Page 4 Service Manual Series 42 Axial Piston Closed Circuit Pumps Contents MDC Module....................................40 HC-EDC and EDC Module................................43 MDC/EDC Spool, linkage, and neutral adjustment screw....................44 MDC Neutral start / backup alarm switch..........................46 MDC Solenoid override valve..............................49 FNR, NFPE, and NFPH Controls (bolt-on valves)......................... 51 FNR, NFPE, and NFPH Controls (integral valves).........................52...

  • Page 5: Overview

    Series 42 Axial Piston Closed Circuit Pumps Introduction Overview This manual includes information for the installation, maintenance, and minor repair of Series 42 axial piston closed circuit pumps. It includes a description of the unit and its individual components, troubleshooting information, and minor repair procedures.

  • Page 6: Safety Precautions

    Service Manual Series 42 Axial Piston Closed Circuit Pumps Introduction Secure the unit For repair, place the unit in a stable position with the shaft pointing downward. It is necessary to secure the pump while removing and torquing end covers, controls, and valves.

  • Page 7: Symbols Used In Danfoss Literature

    Service Manual Series 42 Axial Piston Closed Circuit Pumps Introduction Symbols used in Danfoss literature WARNING may result in injury Tip, helpful suggestion CAUTION may result in damage to product or Lubricate with hydraulic fluid property Reusable part Apply grease / petroleum jelly...

  • Page 8: 1998 Model Release

    Service Manual Series 42 Axial Piston Closed Circuit Pumps 1998 Model Release Overview Parts may or may not be interchangeable between pre-1998 and post-1998 model year pumps. Many parts, including the housing assembly, are unique to the model year change.

  • Page 9: Functional Description

    General description and cross-sectional view The Series 42 pumps are servo controlled, axial piston pumps designed for closed circuit applications. The input shaft turns the pump cylinder block containing nine reciprocating pistons that are held to the swashplate with a block spring.

  • Page 10: The System Circuit

    Service Manual Series 42 Axial Piston Closed Circuit Pumps Functional Description The system circuit System circuit diagram Servo control cylinder Displacement control valve Heat exchanger Reservoir bypass Filter Fixed Heat displacement Control exchanger motor handle Cylinder Cylinder block block Charge relief...
  • Page 11 Service Manual Series 42 Axial Piston Closed Circuit Pumps Functional Description Charge pump O-ring Gerotor cover Seal Coupling Square key Gerotor set Retainer Orientation ring P108 065E The charge pump is a fixed-displacement, gerotor type pump. The main pump drives the charge pump off the main shaft.

  • Page 12: Filtration Options

    P108 095E Filtration options Series 42 pumps may be equipped with provisions for either suction or charge pressure filtration to filter the fluid entering the circuit. Suction filtration The suction filter is in the circuit between the reservoir and the inlet to the charge pump.
  • Page 13 Charge pressure filtration The pressure filter is remotely mounted in the circuit after the charge pump. You may use partial or full flow pressure filtration circuits with Series 42 pumps. Without a filter adapter, suction filtration is the only option.

  • Page 14: Displacement Limiters

    Charge check / high pressure relief valves All series 42 pumps have a combination charge check/high pressure relief valve. The charge check function allows pressurized flow from the charge pump to enter the low pressure side of the loop. This flow is necessary to replenish fluid discharged to the pump/motor case for lubrication and cooling requirements.

  • Page 15: Bypass Valves

    P100394E Auxiliary mounting pads SAE A and SAE B auxiliary mounting flanges are available on all Series 42 pumps and are integral to the charge pump cover. This flange allows mounting of auxiliary hydraulic pumps and mounting of additional Series 42 pumps to make tandem pumps. The pads allow full through-torque capability.
  • Page 16 Service Manual Series 42 Axial Piston Closed Circuit Pumps Functional Description Auxiliary mounting pads Charge pump cover O-ring U085 U035 (x8) Cover plate Pad seal P108 096E 520L0638 • Rev 0300 • July 2015...

  • Page 17: Control Options

    Service Manual Series 42 Axial Piston Closed Circuit Pumps Control Options Manual displacement control (MDC) The Manual Displacement Control (MDC) uses a mechanical input to operate the control spool in the pump. A cam connects the input handle to the control spool allowing manipulation of the operating curve using different cam profiles.

  • Page 18: High Current Electrical Displacement Control (Hc-Edc)

    Service Manual Series 42 Axial Piston Closed Circuit Pumps Control Options the pump to hold very accurately at the commanded displacement. Centering springs and internal moments return the swashplate to neutral position in the absence of control input. EDC on series 42 pump...

  • Page 19: Non-Feedback Proportional Electric (Nfpe) Control

    Service Manual Series 42 Axial Piston Closed Circuit Pumps Control Options pressure. This characteristic provides a power limiting function by reducing displacement as system pressure increases. NFPH control on series 42 pump Non-feedback proportional electric (NFPE) control The Non-Feedback Proportional Electric (NFPE) control is an electric control. A PWM input signal to one of two solenoids on the control valve ports charge pressure to one side of the servo piston.

  • Page 20: Forward-Neutral-Reverse (Fnr) Three-Position Electric Control

    Service Manual Series 42 Axial Piston Closed Circuit Pumps Control Options NFPE control on series 42 pump (41/51cc) P100 415 Forward-Neutral-Reverse (FNR) three-position electric control The Forward-Neutral-Reverse (FNR) is a three-position control. It uses a 12 or 24 Vdc electrically operated spool valve to port pressure to either side of the servo piston.
  • Page 21 Service Manual Series 42 Axial Piston Closed Circuit Pumps Control Options FNR control on series 42 pump (41/51cc) 520L0638 • Rev 0300 • July 2015...

  • Page 22: Technical Specifications

    Direction of input rotation Clockwise or counterclockwise available Installation position Pump installation recommended with the control at the top or side. Consult Danfoss for non-conformance guidelines. Housing must always be filled with hydraulic fluid. Filtration configuration Suction or charge pressure filtration Other system requirements Independent braking system, suitable reservoir and heat exchanger.

  • Page 23: Pressure Measurement

    Proper service and diagnosis may require pressure measurement at various points in the hydraulic circuit. The Series 42 pump has several locations at which to take these measurements. The following illustration shows the locations of the various gauge ports. The table shows the recommended gauge size and the fitting size for each port.
  • Page 24 Service Manual Series 42 Axial Piston Closed Circuit Pumps Pressure Measurement 41/51 cm base unit with MDC and no filtration adapter Servo pressure System pressure gauge port M5 Charge pressure gauge port M2 gauge port M3 System Servo pressure pressure...

  • Page 25: Initial Start-Up Procedure

    Series 42 Axial Piston Closed Circuit Pumps Initial Start-Up Procedure General Follow this procedure when starting-up a new Series 42 installation or when restarting an installation in which the pump has been removed. Warning Unintended movement of the machine or mechanism may cause injury to the technician or bystanders.

  • Page 26: Fluid And Filter Maintenance

    Series 42 Axial Piston Closed Circuit Pumps Fluid and Filter Maintenance Recommendations To ensure optimum life of Series 42 products, perform regular maintenance of the fluid and filter. Contaminated fluid is the main cause of unit failure. Take care to maintain fluid cleanliness when servicing.

  • Page 27: Troubleshooting

    This section provides general steps to follow if you observe certain undesirable system conditions. Some of the items are system specific. Always observe the safety precautions listed in the introduction of this manual. If standard troubleshooting procedures do not remedy the problem, contact a Danfoss Global Service Partner.

  • Page 28: System Will Not Operate In Either Direction

    Service Manual Series 42 Axial Piston Closed Circuit Pumps Troubleshooting Item Description Action Charge pressure (in neutral) The is low charge pressure resulting Inspect the charge pump for damage from a damaged charge pump or low and verify the charge pressure relief charge pressure relief valve setting.

  • Page 29: System Will Not Operate In One Direction

    Service Manual Series 42 Axial Piston Closed Circuit Pumps Troubleshooting Item Description Action SCR (system check / relief) valves The SCR valves are malfunctioning or Verify that the SCR valves are operating improperly set. and properly set. Repair or replace them as necessary.

  • Page 30: Adjustments

    Series 42 Axial Piston Closed Circuit Pumps Adjustments Overview This section offers instruction on how to perform adjustments to the Series 42 pump. Read through the entire procedure before beginning any service activity. Displacement limiter adjustment Mount the pump on a test stand capable of measuring system flow from the A and B ports.
  • Page 31 Service Manual Series 42 Axial Piston Closed Circuit Pumps Adjustments Displacement limiters L025 Displacement limiter seal lock nut L020 13 mm Displacement 3 N•m limiter [17 lbf•ft] 4 mm L001 Servo piston cover RIGHT SIDE VIEW (M4) M020 Displacement M025...

  • Page 32: Pump Neutral Adjustment

    Service Manual Series 42 Axial Piston Closed Circuit Pumps Adjustments Pump neutral adjustment Zero output flow from the pump defines the neutral condition. To attain zero output flow, the pump must achieve both mechanical neutral and control neutral conditions. Mechanical neutral is the condition when the swashplate is at zero angle without any signal input from the control.

  • Page 33: Control Neutral Adjustment For Mdc And Edc/Hc-Edc

    Service Manual Series 42 Axial Piston Closed Circuit Pumps Adjustments Frame size cm 28/32 41/51 Control MDC/EDC/HC-EDC MDC/EDC/HC-EDC Lock nut mm Servo adjust screw mm [in] Lock nut torque N•m [lbf•ft ] 23 [17] 40 [30] 40 [30] 40 [30]...
  • Page 34 Service Manual Series 42 Axial Piston Closed Circuit Pumps Adjustments Control neutral adjustment screw D014 neutral adjustment screw 5 mm D015 neutral adjustment lock nut 17 mm 40 N•m [30 lbf•ft] P108 080E Equalization of pressure gauges using pump neutral adjustment screw...

  • Page 35: Minor Repair

    Standard procedures Remove the pump Prior to performing certain minor repairs on the Series 42 pump, it may be necessary to remove the pump from the machine. Chock the vehicle to prohibit movement. Be aware that hydraulic fluid may be under high pressure and may be hot.
  • Page 36 Service Manual Series 42 Axial Piston Closed Circuit Pumps Minor Repair Case drain plug F091 28/32 cm 41/51 cm Internal hex 9/16 in 5/8 in Torque 120 N•m 200 N•m [89 lbf•ft] [150 lbf•ft] Size and torque for plugs and fittings...

  • Page 37: Charge Relief Valve

    Service Manual Series 42 Axial Piston Closed Circuit Pumps Minor Repair Charge relief valve You may remove the charge relief valve for cleaning and installation of new O-rings. You may change the pressure setting, however, note that the setting will vary for different charge flows depending on charge pump size and pump speed.
  • Page 38 Service Manual Series 42 Axial Piston Closed Circuit Pumps Minor Repair Externally adjustable style The 1998 block point change discontinued the use of the shim adjustable charge relief valve and made the externally adjustable charge relief valve standard. The charge pressure changes by approximately 1.4 bar (20 psi) per quarter turn of the adjustable charge relief valve plug (this applies to both external and internal hex style plugs).

  • Page 39: Optional Speed Sensor

    Service Manual Series 42 Axial Piston Closed Circuit Pumps Minor Repair Optional speed sensor When installing or adjusting the speed sensor on a pump, you must set it to a specific distance from the speed ring on the cylinder block.

  • Page 40: Mdc Module

    Service Manual Series 42 Axial Piston Closed Circuit Pumps Minor Repair 4. Then turn the sensor clockwise (CW) until the wrench flats on sensor body are positioned at a 22° angle to the pump shaft center line. Most adjustable wrenches have a 22° handle offset.
  • Page 41 Service Manual Series 42 Axial Piston Closed Circuit Pumps Minor Repair For exact positioning, place the MDC alignment tool (see dimensioned diagram , next page) over the exposed summing link pin. If MDC alignment tool is not available, skip to MDC alignment without tool (steps 3a-5a).
  • Page 42 Service Manual Series 42 Axial Piston Closed Circuit Pumps Minor Repair 4. Remove the alignment tool and install plug (D003); torque to 17 N•m [13 lbf•ft]. 5. Replace the spring (D91) and spool plugs (D032 and D035). 6. Adjust control neutral (see Control neutral adjustment for MDC and EDC/HC-EDC on page 33).

  • Page 43: Hc-Edc And Edc Module

    Service Manual Series 42 Axial Piston Closed Circuit Pumps Minor Repair 4a. Adjust the control position so that the summing link pin is aligned as described above, and torque bolts (D002) to 17 N•m [13 lbf•ft]. 5a. Replace the cover plug (D003) and torque to 13 N•m [9.5 lbf•ft].

  • Page 44: Mdc/Edc Spool, Linkage, And Neutral Adjustment Screw

    Service Manual Series 42 Axial Piston Closed Circuit Pumps Minor Repair Replacement 1. Clean the sealing surfaces of the control and the pump housing. Place a new gasket (E001) in position on the housing. The control orifices are part of the control gasket. Refer to the appropriate Service Parts List to determine the correct gasket.
  • Page 45 Remove spring and spool. Prior to the 1998 block point change, the full-featured 28 cm housing for the Series 42 pump used a control spool cover (F035), gasket (F034), and two screws (F036) instead of a bore plug on the control spool’s non-spring side.

  • Page 46: Mdc Neutral Start / Backup Alarm Switch

    Service Manual Series 42 Axial Piston Closed Circuit Pumps Minor Repair (D010) and torque to 11 N•m [8 lbf•ft]. Install the summing link (D011). It may be necessary to rotate the control spool so that the summing link fork engages the flats on the control spool.
  • Page 47 Service Manual Series 42 Axial Piston Closed Circuit Pumps Minor Repair Top view of NSS showing NSS cam positions Control Control Control Yoke Yoke Yoke NSS cam NSS cam I. NSS ONLY II. NSS WITH BAS III. NSS WITH BAS...
  • Page 48 Service Manual Series 42 Axial Piston Closed Circuit Pumps Minor Repair 1. Remove the MDC module from the pump housing. Side view of NSS and NSS cavity D039 23.3 mm [0.916 in] D038 8 mm 6 N•m D037 1 mm [4.4 lbf•f t]...

  • Page 49: Mdc Solenoid Override Valve

    Service Manual Series 42 Axial Piston Closed Circuit Pumps Minor Repair 7. Set the NSS cam (D037) in the proper orientation (I, II, or III). See the illustration on previous page. NSS assembly on MDC D040 (with weatherpack connector) D040...
  • Page 50 Service Manual Series 42 Axial Piston Closed Circuit Pumps Minor Repair Solenoid override assembly D056B / in 6 N•m D056 [4.4 lbf•ft] D056C D054 D056D D056 D056A D056F D056G D053 P108 099E Port X7 Removal 1. Using a 3/4 inch wrench, remove the coil nut (D056B) from the valve stem.

  • Page 51: Fnr, Nfpe, And Nfph Controls (Bolt-On Valves)

    Service Manual Series 42 Axial Piston Closed Circuit Pumps Minor Repair FNR, NFPE, and NFPH Controls (bolt-on valves) The FNR, NFPE, and NFPH are non-feedback type controls. The FNR and NFPE controls consist of external, solenoid-actuated spool valves mounted on the pump housing. The pump receives hydraulic input for NFPH through ports on the pump’s control surface (9/16–18 SAE O-ring boss port).

  • Page 52: Fnr, Nfpe, And Nfph Controls (Integral Valves)

    Service Manual Series 42 Axial Piston Closed Circuit Pumps Minor Repair Installation of FNR and NFPE modules (bolt-on valves) 1. Clean the sealing surfaces. Install new gasket (E074). 2. Using petroleum jelly to retain them, install new O-rings (D004A) in the bottom of the control.

  • Page 53: System Check Relief (Scr) Valves (High Pressure Relief, Charge Check, And Bypass Valves)

    Service Manual Series 42 Axial Piston Closed Circuit Pumps Minor Repair Installation of FNR and NFPE modules (integral valve style) 1. Clean the valves and ports. 2. Install new O-rings on valve actuator stems (D060). 3. Install actuator stems (D060) and torque to 30.5 N•m [22.5 lbf•ft].
  • Page 54 Filtration adapters Filter-related pump hardware Filtration systems for Series 42 pump include full flow suction filtration, pressure filtration, and partial flow pressure filtration. Danfoss provides a filtration adapter for each configuration. If filtration is provided elsewhere in the hydraulic circuit, the pump may not have a filtration adapter.

  • Page 55: Auxiliary Pad/Charge Pump Cover

    Service Manual Series 42 Axial Piston Closed Circuit Pumps Minor Repair Removal 1. Clean the exterior of the pump. 2. Remove any hoses or piping from the filter adapter. 3. Using a T30 Torx driver or 5 mm internal hex, remove the six screws (R042) securing the filter adapter to the housing.
  • Page 56 Service Manual Series 42 Axial Piston Closed Circuit Pumps Minor Repair Auxiliary pad options U040 No pad charge U035 (x8) pump cover 6 mm 45 N•m [33 lbf•ft] (x8) U090 U035 G023 / in 42 N•m [31 lbf•ft] U080 U085...

  • Page 57: Charge Pump

    Service Manual Series 42 Axial Piston Closed Circuit Pumps Minor Repair Bolt torque patterns TORQUE BOLTS IN ORDER INDICATED Torque this bolt first and last. Torque this bolt first and last P108 083E Charge pump You may disassemble the charge pump to inspect, clean, or to change the auxiliary shaft drive coupling (U015).
  • Page 58 Service Manual Series 42 Axial Piston Closed Circuit Pumps Minor Repair Charge pump components G023 G020 G015 U015 Use feeler gauge G005 Keyway G010 G006 U025 U025 G065 P108 092E Disassembly 1. Remove alignment pins (U025) 2. Remove the gerotor cover assembly (G020). Remove and discard gerotor cover O-ring (G023) (early production SAE A pad models may contain two or three seals: only the inner G023 seal is required).
  • Page 59 Service Manual Series 42 Axial Piston Closed Circuit Pumps Minor Repair coupling should fit the journal bearing with a relatively close fit. If the coupling has worn through the bearing and into the aluminum gerotor cover, replace the gerotor cover and drive coupling. If the fit...

  • Page 60: Servo Piston Covers And Nfph Control Orifice

    Service Manual Series 42 Axial Piston Closed Circuit Pumps Minor Repair No charge pump option components G023 G020 R020 U015 R020A G010 Charge inlet G006 G004 Charge inlet To filter G004 R086 P108 093E Housing with filtration adapter (left) Housing without filtration adapter (right)
  • Page 61 Service Manual Series 42 Axial Piston Closed Circuit Pumps Minor Repair Servo piston cover components L005 M005 5 mm 5 mm T060 Locknut 17 N•m 17 N•m see table [13 lbf•ft] [13 lbf•ft] L001 L005 (non-feedback T060 M001 5 mm...

  • Page 62: Loop Flushing And Loop Flushing Relief Valve

    Danfoss specifically instructs you to do so. You may also defeat the loop flushing function by installing a defeat spool. Series 42 pumps built prior to 1998 use unique loop flushing spools. Post 1998 release pumps use a common loop flushing spool. They are not interchangeable.
  • Page 63 Service Manual Series 42 Axial Piston Closed Circuit Pumps Minor Repair Loop flushing valve and loop flushing defeat components Q050 / i n 37 N•m [27 lbf•ft] Q060 / in 27 N•m [20 lbf•ft] Q050A Q050A Q060A Q051 Q051 Q061...

  • Page 64: Shaft Seal, Roller Bearing, And Shaft Replacement

    6. Install the loop flushing relief plug (Q060) with a new O-ring (Q060A) into the housing and torque to 27 N•m [20 lbf•ft]. Shaft seal, roller bearing, and shaft replacement Series 42 pumps use a lip type shaft seal. You can replace the seal and/or shaft without major disassembly. Shaft seal components...
  • Page 65 Service Manual Series 42 Axial Piston Closed Circuit Pumps Minor Repair Case Drain Plug Frame Size 28/32 cm3 41/51 cm3 Internal Hex 9/16 in 5/8 in Torque 120 N•m 200 N•m [89 lbf•ft] [150 lbf•ft] Seal removal 1. Position the pump with the shaft facing up.
  • Page 66 Service Manual Series 42 Axial Piston Closed Circuit Pumps Minor Repair Shaft seal, roller bearing, and shaft replacement C002 C003 C001 P108 107E 3. Inspect the shaft bearing (C003) for damage and rotate to ensure smoothness. If you suspect contamination or damage, clean with solvent and lubricate with hydraulic fluid. Replace if necessary.
  • Page 67 Service Manual Series 42 Axial Piston Closed Circuit Pumps Minor Repair Reassembly 1. Ensure that the cylinder kit and rear bearing are aligned. Insert the shaft assembly into the pump. It may be necessary to grip the splined end of the shaft and twist to align it with the block splines and properly seat it into the rear bearing.

  • Page 68: Appendix A - Torques

    Service Manual Series 42 Axial Piston Closed Circuit Pumps Appendix A - Torques Torque table Sequence Part Description Tool Type Tool Size Torque Number N•m [lbf•ft] D002 MDC bolts Torx wrench/ Internal hex T-30/5 mm 17 [13] D003 Cover plug...
  • Page 69 Service Manual Series 42 Axial Piston Closed Circuit Pumps Appendix A - Torques Sequence Part Description Tool Type Tool Size Torque Number N•m [lbf•ft] U035 Charge pump cover bolts Torx wrench/ Internal hex T-45/6 mm 45 [33] U090 Auxiliary pump screws...

  • Page 70: Appendix B - Specification Tags

    Service Manual Series 42 Axial Piston Closed Circuit Pumps Appendix B - Specification Tags Pre-block point change Ames, Iowa, U.S.A. Neumünster, Germany Model Code 42L28 - C - ANN1 - 01 - Model code ANA - 2CNB - NN - NN - N - N - N - NNN - NNN Model No.

  • Page 71: Post-Block Point Change

    Service Manual Series 42 Axial Piston Closed Circuit Pumps Appendix B - Specification Tags Post-block point change Name plate (USA) Model number Model-No./Ident-No. Model Model Code code Serial number Serial-No. A=Ames, IA Made in USA P100438E Place of manufacture Specifications...

  • Page 72: Appendix C - Nomenclature

    Service Manual Series 42 Axial Piston Closed Circuit Pumps Appendix C - Nomenclature Pre-block point change nomenclature • Series • Rotation • Frame Size • Input Shaft • Control • Control Response • Housing • Charge Pump • System Relief - Port A •...

  • Page 73: Post-Block Point Change Nomenclature

    Service Manual Series 42 Axial Piston Closed Circuit Pumps Appendix C - Nomenclature Post-block point change nomenclature • Series • Rotation • Frame Size • Input Shaft • Control • Control Response • Housing • Loop Flushing • Filtration • Charge Pump •...
  • Page 74 Service Manual Series 42 Axial Piston Closed Circuit Pumps Appendix C - Nomenclature • Special Features 520L0638 • Rev 0300 • July 2015...
  • Page 75 Service Manual Series 42 Axial Piston Closed Circuit Pumps 520L0638 • Rev 0300 • July 2015...
  • Page 76 Phone: +86 21 3418 5200 Danfoss can accept no responsibility for possible errors in catalogues, brochures and other printed material. Danfoss reserves the right to alter its products without notice. This also applies to products already on order provided that such alterations can be made without changes being necessary in specifications already agreed.

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