Danfoss 42 4T 41/51 User guide

Technical Information

Series 42 4T Axial Piston Tandem Pumps

Size 41/51

www.danfoss.com

Technical Information

Series 42 4T Axial Piston Tandem Pumps Size 41/51

Revision history Table of revisions

Date Changed Rev

November 2020 Minor update in Hydraulic Fluid Parameters 0302

July 2020 Changed document number from 'BC00000036' to 'BC152886482857' 0301

December 2018 Corrected technical data in System Parameters 0201

June 2016 converted to new layout 0101

May 2015 Converted to DITA CMS BA

February 2008 Corrections-Drawings AB

January 2008 First edition AA

2 | © Danfoss | November 2020 BC152886482857en-000302

Technical Information

Series 42 4T Axial Piston Tandem Pumps Size 41/51

Series 42 warehouse

General Description

Basic Design........................................................................................................................................................................................6

System Diagram................................................................................................................................................................................7

System Schematic............................................................................................................................................................................ 8

Technical Specifications

System Specifications...................................................................................................................................................................10

System Parameters........................................................................................................................................................................10

Hydraulic Fluid Parameters........................................................................................................................................................ 11

Operating Parameters

System Requirements...................................................................................................................................................................12

System Parameters........................................................................................................................................................................12

Hydraulic Fluid Parameters........................................................................................................................................................ 13

Sizing Equations............................................................................................................................................................................. 14

System Design Parameters

Fluid and Filtration........................................................................................................................................................................ 15

Filtration Configuration...............................................................................................................................................................15

Mounting Flange Loads...............................................................................................................................................................16

Estimating Overhung Load Moment.................................................................................................................................16

Case Drain.........................................................................................................................................................................................17

External Shaft Load and Bearing Life......................................................................................................................................17

Hydraulic Unit Life......................................................................................................................................................................... 18

Efficiency Graphs............................................................................................................................................................................19

Features and Options

Charge Pump...................................................................................................................................................................................20

Charge Pump Sizing Example:.............................................................................................................................................20

Charge Relief Valve........................................................................................................................................................................20

Overpressure Protection............................................................................................................................................................. 21

Bypass Valve.....................................................................................................................................................................................22

Displacement Limiters................................................................................................................................................................. 22

Shaft Options...................................................................................................................................................................................22

Auxiliary Mounting Pads............................................................................................................................................................. 23

Center Coupling............................................................................................................................................................................. 24

Control Selection............................................................................................................................................................................24

Manual Displacement Control (MDC).....................................................................................................................................26

Features and Benefit of MDC................................................................................................................................................26

Control Input Signal.................................................................................................................................................................27

Response Time...........................................................................................................................................................................27

Control Handles.........................................................................................................................................................................28

Electric Solenoid Override to Neutral................................................................................................................................28

Emergency Override to Neutral with Port for Brake Pressure Release..................................................................29

Neutral Start Switch (NSS)..................................................................................................................................................... 30

NSS with Back-up Alarm (BUA) Switch..............................................................................................................................30

Connectors..................................................................................................................................................................................30

Non-Feedback, Proportional Hydraulic (NFPH) Control.................................................................................................. 32

Features and Benefits of the NFPH control..................................................................................................................... 33

Connectors and Port locations............................................................................................................................................ 33

Installation Drawings

Manual Displacement Control (MDC).....................................................................................................................................34

Port Description........................................................................................................................................................................ 34

Dimensions................................................................................................................................................................................. 36

Non-Feedback, Proportional Hydraulic (NFPH).................................................................................................................. 39

Port Description........................................................................................................................................................................ 39

Dimensions................................................................................................................................................................................. 41

Shaft Options...................................................................................................................................................................................44

Displacement Limiter................................................................................................................................................................... 45

Danfoss | November 2020 BC152886482857en-000302 | 3

Technical Information

Series 42 4T Axial Piston Tandem Pumps Size 41/51

Contents

By-pass Valve...................................................................................................................................................................................46

Control Modules.............................................................................................................................................................................46

Auxiliary Mounting Pads............................................................................................................................................................. 48

Model Code

Model Code: A, Y, Z........................................................................................................................................................................50

Model Code: FD, FX, RD, RX........................................................................................................................................................51

Model Code: FE, RE........................................................................................................................................................................ 52

Model Code: FT, RT, FH, RH, FJ, RJ, FK, RK..............................................................................................................................53

Model Code: FL, RL, FM. RM........................................................................................................................................................54

Model Code: C, F, S........................................................................................................................................................................ 56

Model Code: U, G, V.......................................................................................................................................................................57

Model Code: N, P............................................................................................................................................................................58

4 | © Danfoss | November 2020 BC152886482857en-000302

Piston centering spring

Servo piston

P100412E

P400169

X2 X1

100%

15 18

1518

P001628E

Signal Dp (bar)

Dp system=345bar

Dp system=35bar

Technical Information

Series 42 4T Axial Piston Tandem Pumps Size 41/51

Series 42 warehouse

Pump displacement versus signal pressure

NFPH pump displacement to Input signal

Non-feedback proportional hydraulic control schematic

Danfoss | November 2020 BC152886482857en-000302 | 5

Piston Swashplate

Roller bearing

Valve plate

Ball bearing

P400160

Technical Information

Series 42 4T Axial Piston Tandem Pumps Size 41/51

General Description

Basic Design

S42 Integrated Tandem Pumps (4T) are advanced hydrostatic units for medium power applications with maximum loads of 415 Bar [6020 psi] (41 cm3) and 350 Bar [5075 psi] (51 cm3). You can combine these pumps with a suitable Danfoss motor or other products in a system to transfer and control hydraulic power.

The 4T axial piston pump is a compact, high power density unit, using the parallel axial piston/slipper concept in conjunction with tiltable swashplates to vary the pumps’ displacements.

Reversing the angle of the swashplate reverses the flow of fluid from the pump, and reversing the direction of rotation of the motor output. 4T axial piston pumps provide an infinitely variable speed range between zero and maximum in both forward and reverse.

4T axial piston pumps use a cradle swashplate design with a hydraulic servo control cylinder. Control is provided through a compact servo control system. Two types of servo controls are available. These include mechanical hydraulic actuated feedback controls, and hydraulic proportional control. These controls feature low hysteresis and responsive performance.

Cross-sectional view

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Reservoir

Suction Screen

Charge Pressure Relief Valve

Servo Control Cylinder

Swash Plate

Bypass Check

Heat Exchanger

Control Handle

Displacement Control Spool

Cylinder Block Assembly

Valiable Displacement Pump

Charge Pump

System Pressure

Control Pressure

Low Loop Pressure

Suction/Case Drain/ System Return

Charge Pressure

P106 147E

Loop Flushing Valve

Motor Gear boxMotorGear box

Loop Flushing Valve

Input Shaft

Charge check/ HPRV valve

Brake release control valve

Motor displacement control valve

Filter

Technical Information

Series 42 4T Axial Piston Tandem Pumps Size 41/51

General Description

System Diagram

Danfoss | November 2020 BC152886482857en-000302 | 7

P400161

M1M1 M2

B C DA

Front Rear

GearboxGearbox MotorMotor

Technical Information

Series 42 4T Axial Piston Tandem Pumps Size 41/51

General Description

System Schematic

4T Axial Piston Pump

The illustration above shows a schematic of a 4T axial piston pump. System ports A, C and B, D connect to the high pressure work lines. Return fluid is received from its inlet port and discharged through the outlet port. Flow direction is determined by swashplate position. You can read system port pressure through ports M1 and M2. The pump has two case drains (L1 and L2) to ensure there is lubricating fluid in the

8 | © Danfoss | November 2020 BC152886482857en-000302

Technical Information

Series 42 4T Axial Piston Tandem Pumps Size 41/51

General Description

system. This schematic includes a manual displacement control. For other control schematics see the related control section: Manual Displacement Control (MDC) on page 26, Non-Feedback, Proportional

Hydraulic (NFPH) Control on page 32

Danfoss | November 2020 BC152886482857en-000302 | 9

Technical Information

Series 42 4T Axial Piston Tandem Pumps Size 41/51

Technical Specifications

System Specifications

General Specifications

Feature Series 42 4T

Pump type

Direction of input rotation Clockwise or counterclockwise

Recommended installation position

Other system requirements Independent braking system, suitable reservoir and heat exchanger.

Hardware Features

Pump configuration Single variable pump

Displacement

Weight

Mass moment of inertia

Type of front mounting flange

(SAE flange size per SAE J744)

Port connections SAE-twin ports, radial, opposite side ports

System pressure regulation

Displacement limiters Option Input shaft options Splined Auxiliary mounting pad

(SAE pad per SAE J744)

Control options MDC, NFPH Loop flushing None

cm [in3]

kgf [lbf]

kg•m [lbf•ft2]

bar [psi]

In-line, axial piston, positive displacement pumps including cradle swashplate and servo control

Pump installation recommended with control position on the top or side. Consult Danfoss for non conformance guidelines. The housing must always be filled with hydraulic fluid.

40.9 [2.50] x 2 51 [3.11] x 2

MDC: 76 [168] NFPH: 72 [158]

0.0072 [0.0054] 0.0076 [0.0056]

2 Bolt SAE C (4 additional bolt holes available)

210-415 [3045-6020] 210-325 [3045-4715]

SAE A (9 tooth, 11 tooth and 13 tooth) SAE B (13 tooth)

System Parameters

Case pressure

Continuous pressure

Maximum pressure (cold start)

bar [psi]

3 [44]

10.3 [150]

Pressure Limits

bar [psi]

41 51

350 [5075] 325 [4713]

450 [6265] 400 [5800]

Displacement cm

Rated pressure

Maximum pressure

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Technical Information

Series 42 4T Axial Piston Tandem Pumps Size 41/51

Technical Specifications

Speed Limits

Frame size cm

Minimum speed

Rated speed at maximum displacement

Maximum speed at maximum displacement

Charge Pump Displacement and Setting Pressure

Frame size cm

Internal -

Charge relief valve settings

Theoretical Flow

Frame size cm

Theoretical flow at rated speed

Standard Optional 14-24 [203-340]

-1

min (rpm)

-1

min (rpm)

-1

min (rpm)

cm3/rev [in3/rev]

bar [psi]

l/min [US gal/ min]

41 51

500

3200 2900

3450 3400

41 51

none none

20 [290]

41 51

131 [34.6] 148 [39.1]

Hydraulic Fluid Parameters

Check/high Pressure Relief Valve

Options

Setting —

bar [psi]

No relief valve /check only Relief valve / check

210-415 [3045-6020] or by setting available 210, 250, 280, 300, 325, 345, 360, 385, 415

Fluid temperature range

Minimum -40 °C [-40 °F] Intermittent, cold start Maximum continuous 104 °C [220 °F] - Maximum 115 °C [240 °F] Intermittent

Fluid cleanliness level

Required fluid cleanliness level ISO 4406 Class 22/18/13

Fluid viscosity

Minimum 7.0 mm2/s (cSt) Intermittent Recommended operating range 12-60 mm2/s (cSt) Maximum 1600 mm2/s (cSt) Intermittent, cold start

Danfoss | November 2020 BC152886482857en-000302 | 11

Technical Information

Series 42 4T Axial Piston Tandem Pumps Size 41/51

Operating Parameters

System Requirements

Independent braking system

Warning

Unintended vehicle or machine movement hazard. The loss of hydrostatic drive line power, in any

mode of operation (forward, neutral, or reverse) may cause the system to lose hydrostatic braking capacity. You must provide a braking system, redundant to the hydrostatic transmission, sufficient to stop and hold the vehicle or machine in the event of hydrostatic drive power loss.

Reservoir

Design the system to accommodate maximum volume changes during all system operating modes and to promote de-aeration of the fluid as it passes through the tank. Minimum reservoir volume is 5/8 of the maximum charge pump flow per minute with a minimum fluid volume equal to 1/2 of the maximum charge pump flow per minute. At the maximum return flow, this allows 30 seconds fluid dwell for removing entrained air. This is adequate for a closed reservoir (no breather) in most applications. Position the reservoir outlet (pump inlet) above the bottom of the reservoir to take advantage of gravity separation and prevent large foreign particles from entering the charge inlet line. Use a 100 - 125 μm screen over the outlet port. Position the reservoir inlet (fluid return) so that flow to the reservoir is discharged below the normal fluid level, and directed into the interior of the reservoir for maximum dwell and efficient de-aeration. Use a baffle (or baffles) between the inlet and outlet ports to promote deaeration and reduce surging of the fluid.

System Parameters

Speed limits

Rated speed is the speed limit we recommend at full power condition and is the highest value at which you can expect normal life. Maximum speed is the highest operating speed we permit. You cannot operate above this speed without risk of immediate failure and loss of drive line power and hydrostatic braking capacity (which may create a hazard). In mobile applications, you must apply this pump with a speed speed below the stated maximum. Consult Pressure and Speed Limits, BC152886484313, when determining speed limits for a particular application.

Inlet pressure

Control charge pump inlet conditions to achieve expected life and performance. Ensure a continuous inlet pressure of not less than 0.8 bar absolute (not more than 6 in Hg vacuum). Normal pressures less than 0.7 bar absolute (greater than 9 in Hg vacuum) indicate inadequate inlet design or a restricted filter. Pressures less than 0.7 bar absolute (greater than 9 in Hg vac) during cold start are possible, but should improve quickly as the fluid warms. Never exceed the maximum inlet vacuum.

Theoretical output

The theoretical maximum flow at rated speed is a simple function of pump displacement and speed. This is a good gauge for sizing a companion motor. This does not take into account losses due to leakage or variations in displacement.

Case pressure

Under normal operating conditions, the rated case pressure must not be exceeded. During cold start case pressure must be kept below maximum intermittent case pressure. Size drain plumbing accordingly.

12 | © Danfoss | November 2020 BC152886482857en-000302

Technical Information

Series 42 4T Axial Piston Tandem Pumps Size 41/51

Operating Parameters

System pressure System pressure is the differential pressure between high pressure system ports. It is the dominant

operating variable affecting hydraulic unit life. High system pressure, which results from high load, reduces expected life. Hydraulic unit life depends on the speed and normal operating, or weighted average, pressure that can only be determined from a duty cycle analysis.

Application pressure - is the high pressure relief or pressure limiter setting normally defined within the order code of the pump. This is the applied system pressure at which the driveline generates the maximum calculated pull or torque in the application. Maximum Working Pressure - is the highest recommended Application pressure.

Maximum working pressure is not intended to be a continuous pressure. Propel systems with Application pressures at, or below, this pressure should yield satisfactory unit life given proper component sizing.

Maximum pressure is the highest allowable Application pressure under any circumstance. Application pressures above Maximum Working Pressure will only be considered with duty cycle analysis and factory approval.

Minimum pressure must be maintained under all operating conditions to avoid cavitation.

Warning

Hydraulic Fluid Parameters

All pressure limits are differential pressures referenced to low loop (charge) pressure. Subtract low loop pressure from gauge readings to compute the differential.

Hydraulic fluid

Ratings and data are based on operating with hydraulic fluids containing inhibitors to prevent oxidation, rust, and foam. These fluids must possess good thermal and hydrolytic stability to prevent wear, erosion, and corrosion of the internal components.

Caution

Never mix hydraulic fluids of different types.

Temperature and viscosity

Ensure the application satisfies temperature and viscosity requirements concurrently. The data shown in the tables on Hydraulic Fluid Parameters on page 11, assume petroleum-based fluids.

High temperature limits apply at the hottest point in the transmission, which is normally the case drain. Always run the pump at or below the continuous temperature. Never exceed maximum temperature.

Durability of transmission components is not affected by cold oil, but it may affect the ability of oil to flow and transmit power. Keep temperatures 16 °C [30 °F] above the pour point of the hydraulic fluid. The minimum temperature relates to physical properties of component materials.

For maximum unit efficiency and bearing life, keep fluid viscosity in the continuous viscosity range. During brief occasions of maximum ambient temperature and severe duty cycle operation, minimum viscosity may occur. The system should encounter maximum viscosity only at cold start.

Size heat exchangers to keep the fluid temperature and viscosity within these limits. Test the system to verify that these temperature limits are not exceeded.

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Based on SI units

= (l/min)

Input torque M = (N•m)

Input power P = = (kW)

Based on US units

= (US gal/min)

Input torque M = (lbf•in)

Input power P = = (hp)

Vg • n • η

1000

Vg • ∆p

20 • π • η

Q • ∆p

600 • η

M • n • π

30 000

Vg • n • η

231

Vg • ∆p

2 • π • η

Q • ∆p

1714 • η

M • n • π 198 000

Flow

Torque

Power

Technical Information

Series 42 4T Axial Piston Tandem Pumps Size 41/51

Operating Parameters

Sizing Equations

Use these equations to help choose the right pump size and displacement for your application.

Variables

SI units [US units]

Vg= Displacement per revolution cm3/rev [in3/rev] PO= Outlet pressure bar [psi] Pi= Inlet pressure bar [psi] ∆p = pO - pi (system pressure) bar [psi] n = Speed min-1 (rpm) ηv= Volumetric efficiency ηm= Mechanical efficiency ηt= Overall efficiency (ηv • ηm)

Reservoir

Filter

Charge

pum p

Charge relief valve

To pump case

Internal

To low pressur e

side of loop and

servo contro l

Strainer

P400162

P400163

Charge

Filter

pump

Charge relief valve

To pump case

Internal

To low pressure

side of loop and

servo control

Reservoir

Strainer

Technical Information

Series 42 4T Axial Piston Tandem Pumps Size 41/51

System Design Parameters

Fluid and Filtration

To prevent premature wear, use only new clean fluid. Use a filter capable of controlling fluid cleanliness to ISO 4406 Class 22/18/13 (SAE J1165).

Locate the filter on the inlet (suction filtration) or discharge (charge pressure filtration) side of the charge pump: 4T axial piston pumps are available with provisions for either configuration.

The selection of a filter depends on a number of factors including the contaminant ingression rate, the generation of contaminants in the system, the required fluid cleanliness, and the desired maintenance interval. Use filters that meet the above requirements of efficiency and capacity.

Filter efficiency can be measured with a Beta ratio (βX). For simple suction-filtered closed circuit transmissions and open circuit transmissions with return line filtration, a filter with a β-ratio within the range of β and closed circuits with cylinders being supplied from the same reservoir, a higher filter efficiency is recommended. This also applies to systems with gears or clutches using a common reservoir. For these systems, a charge pressure or return filtration system with a filter β-ratio in the range of β

10) or better is typically required. Because each system is unique, only a thorough testing and evaluation program can fully validate the

filtration system. Please see Design Guidelines for Hydraulic Fluid Cleanliness, BC152886482150, Technical Information for more information.

= 75 (β10 ≥ 2) or better has been found to be satisfactory. For some open circuit systems,

35-45

= 75 (β10 ≥

15-20

Filtration Configuration

Locate the filter on the inlet (Suction filtration) or discharge (Charge pressure filtration) side of the external charge pump.

Suction filtration

Charge pressure filtration, full flow

Danfoss | November 2020 BC152886482857en-000302 | 15

Technical Information

Series 42 4T Axial Piston Tandem Pumps Size 41/51

System Design Parameters

Mounting Flange Loads

Adding tandem mounted auxiliary pumps and/or subjecting pumps to high shock loads may result in excessive loading of the mounting flange. Design pump applications to stay within the allowable shock load and continuous load moments.

Shock load moment MS is the result of an instantaneous jolt to the system. Rated (continuous) load moments MR are generated by the typical vibratory movement of the application.

Estimated maximum and continuous acceleration factors for some typical applications are shown in the table.

Applications which experience extreme resonant vibrations may require additional pump support. Exceeding the allowable overhung values listed below will require additional pump support.

G-factors for sample applications

Application Continuous (vibratory)

Skid steer loader 4 10 Trencher (rubber tires) 3 8 Asphalt paver 2 6 Windrower 2 5 Turf care vehicle 1.5 4 Vibratory roller 6 10

acceleration (GR)

Maximum (shock) acceleration (GS)

Allowable overhung load moments

Rated load moment (MR) Shock load moment (MS)

1441 N•m [12750 in•lbf] 3413 N•m [30200 in•lbf]

Estimating Overhung Load Moment

MR = GR (W1L1 + W2L2 + ... +WnLn) MS = GS (W1L1 + W2L2 + ... +WnLn)

Where:

MRRated load moment N•m [lbf•in]

MSShock load moment N•m [lbf•in]

GRRated (vibratory) acceleration (G-factors: unitless)

GSMaximum shock acceleration (G-factors: unitless)

W Weight of the pump N [lbf]

L Distance from mounting flange to the center of gravity mm [in]

Mounting flange

Pump 1 Center of gravity

Pump 2 Center of gravity

P400164

Technical Information

Series 42 4T Axial Piston Tandem Pumps Size 41/51

System Design Parameters

Overhung load moments

Case Drain

The front and rear pumps are connected by cast passages in the housing. The charge relief valve discharges oil into the front housing. In order to provide positive housing flow thru both pumps, use of rear case drain is required. The front case drain should only be used if the pumps are used as a common drain manifold for the vehicle whereas external drain flow is brought into the rear case port and discharged out the front.

External Shaft Load and Bearing Life

Bearing life is a function of speed, pressure, and swashplate angle, plus any external loads. Other factors that affect life include fluid type, viscosity, and cleanliness.

In vehicle propulsion drives with no external loads—where the speed, pressure, and swashplate angle are often changing—normal bearing B10 (90% survival) life exceeds the hydraulic unit life.

In non-propel drives, such as conveyors or fan drives, the operating speed and pressure may be nearly constant leading to a distinctive duty cycle compared to that of a propulsion drive. In these types of applications, we recommend a bearing life review. 4T axial piston pumps use bearings that can accept some incidental external radial and thrust loads. However, any amount of external load reduces the expected bearing life.

The allowable radial shaft loads are a function of the load position, orientation, and operating pressures of the hydraulic unit. In applications where you cannot avoid external shaft loads, minimize the impact on bearing life by orienting the load to the 0° or 180° position.

The maximum allowable radial load is calculated as: Re = Me / L Where:

L Distance from mounting flange to point of load

out

Maximum external moment

Maximum radial side load

Thrust load

Load to cylinder block kit

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P400165

0 Re

180 Re

90 Re

270 Re

out

Technical Information

Series 42 4T Axial Piston Tandem Pumps Size 41/51

System Design Parameters

Allowable shaft loads

Displacement (cm3) 41 51

N•m [in•lbf] T

OUT

N [lbf]

Avoid thrust loads in Tin direction. If continuously applied external radial loads are 25% of the maximum allowable or more, or thrust loads

are known to occur, contact your Danfoss representative for an evaluation of unit bearing life. Use clamp-type couplings where radial shaft side loads are present.

External shaft load orientation

111 [982]

1110 [250]

90 [800]

1110 [250]

Hydraulic Unit Life

Use the table and drawing to determine maximum allowable radial loads (Re), based on the maximum external moment (Me) and the distance (L) from the mounting flange to the load.

Hydraulic unit life is the life expectancy of the hydraulic components. Hydraulic unit life is a function of speed and system pressure. However, system pressure is the dominant operating variable. High pressure, which results from high load, reduces expected life.

Design the hydraulic system to a projected machine duty cycle. Know the expected percentages of time at various loads and speeds. Ask your Danfoss representative to calculate an appropriate pressure based your hydraulic system design. If duty cycle data is not available, input power and pump displacement are used to calculate system pressure.

All pressure limits are differential pressures (referenced to charge pressure) and assume normal charge pressure.

4T axial piston pumps will meet satisfactory life expectancy if applied within the parameters specified in this bulletin. For more detailed information on hydraulic unit life see BC152886484313, Pressure and Speed Limits.

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