R902447875 Bosch Rexroth 74cc Variable Piston Pump

Product Overview

The Bosch Rexroth R902447875 / A10VO74DFLR/31R-VSC46N00-S2116 belongs to the A10VO Series 31 variable displacement axial piston pump family for open-circuit hydraulic systems.

Bosch Rexroth defines the A10VO Series 31 as an all-purpose medium-pressure swashplate pump for open-circuit hydrostatic drives. The official Series 31 documentation specifies 280 bar nominal pressure and 350 bar maximum pressure, with a variable axial-piston displacement system controlled by swashplate angle. The DFLR option is defined as a pressure, flow and power controller.

The supplied identifier uses the form LA10VO74DFLR/31R-VSC46N00-S21. Public material-number indexes associate R902447875 with the more complete configuration A10VO74DFLR/31R-VSC46N00-S2116. For procurement and replacement work, R902447875 should therefore be used as the primary material-number anchor and the complete nameplate code should be verified before shipment.

For an aftermarket equivalent replacement, interchangeability must cover the complete mechanical and hydraulic configuration, including rotation, shaft, mounting, ports, seals, control and special-version suffixes.

Our replacement units can undergo 100% simulated working-condition testing to verify displacement response, DFLR control behavior, leakage, rotation and load stability before delivery.

Technical Specifications

R902447875 / A10VO74DFLR/31R-VSC46N00-S2116

• Brand: Bosch Rexroth
• Material Number: R902447875
• Product Family: A10VO Series 31
• Operation: Open circuit
• Pump Type: Variable displacement axial piston pump
• Design: Swashplate axial piston
• Displacement: 74 cm³/rev
• Control: DFLR — Pressure, Flow and Power Control
• Series: 31
• Rotation: R — Clockwise
• Sealing: V — FKM / Fluoroelastomer
• Drive Shaft: S — Standard splined shaft
• Through Drive: N00 — No through drive
• Nominal Pressure: 280 bar / 4,060 psi class
• Maximum Pressure: 350 bar / 5,075 psi class
• Published A10VO74 maximum-speed reference: approximately 2200 rpm in public 74 cm³ product listings; this value should be confirmed against the original nameplate or project drawing because current standard Rexroth Series 31 tables do not list 74 cm³ as a separate standard nominal-size column.
• Theoretical Flow at 1800 rpm: approximately 133.2 L/min, calculated from 74 cm³/rev × 1800 rpm
• Theoretical Flow at 2200 rpm: approximately 162.8 L/min, calculated from 74 cm³/rev × 2200 rpm
• Reference Weight: not independently confirmed as an exact R902447875 OEM value; public A10VO74 listings generally fall around the mid-30 kg range.
• Exact publicly indexed Type Code: A10VO74DFLR/31R-VSC46N00-S2116

The 280/350 bar pressure class, open-circuit architecture, DFLR control definition and standard code logic are confirmed by Bosch Rexroth Series 31 documentation. The 74 cm³ exact configuration and R902447875 association are corroborated by A10VO74 material-number indexes.

Important Pressure Definition

For engineering documentation, the product should be described as:

• Nominal Pressure: 280 bar
• Maximum Pressure: 350 bar

Rexroth defines the maximum-pressure value as a limited operating condition, not an unlimited continuous-duty pressure. The current Series 31 documentation specifies operating-period restrictions for maximum pressure.

Therefore, the product page should not state “350 bar continuous working pressure.”

Key Technical Advantages

1. DFLR Pressure, Flow and Power Control

The DFLR controller combines pressure control, flow control and power control.

Rexroth explains that the control adjusts swashplate angle so that, under changing working pressure, the product of flow × pressure remains within the corresponding power-control characteristic. Flow control is available below the power-control curve.

2. Variable Swashplate Axial-Piston Design

The A10VO architecture uses an axial-piston rotating group in swashplate design. Pump flow is proportional to drive speed and displacement, while displacement can be continuously varied through swashplate adjustment.

3. 280 Bar Medium-Pressure Platform

The Series 31 A10VO is designed around a 280 bar nominal / 350 bar maximum pressure class for general-purpose open-circuit hydraulic applications.

4. Standard Splined Drive Interface

The S drive-shaft code identifies a standard splined-shaft configuration within the Series 31 coding system. Rexroth specifies ANSI B92.1a / ISO 3019-1 related spline interfaces.

5. Dual Case-Drain Ports

The A10VO Series 31 uses two case-drain ports. Rexroth installation instructions require the appropriate highest drain port to be connected according to installation position.

6. Strong Suction Characteristics

Excellent suction performance is listed as a Series 31 feature, while Rexroth specifies minimum inlet-pressure requirements to prevent cavitation damage.

7. Short Control Response and Broad Controller Selection

Rexroth lists short control times, low noise, long service life, favorable power-to-weight ratio and a versatile controller range among the A10VO Series 31 characteristics.

8. Controlled Engineering Material Claims

The public Rexroth documentation does not publish exact alloy grades, heat-treatment depths or component hardness values for this specific R902447875 configuration.

Therefore, the technical description should focus on verified architecture, controller type, pressure class, shaft/seal configuration and service requirements rather than inventing unsupported material specifications.

Application Areas

A10VO Series 31 is positioned by Bosch Rexroth as a general-purpose medium-pressure open-circuit variable pump. Typical engineering applications include:

• Excavators
• Wheel Loaders
• Construction Machinery
• Agricultural Machinery
• Forestry Equipment
• Material Handling Machinery
• Industrial Hydraulic Power Units
• Machine Tools
• Pressing and Forming Systems
• Mobile Working Hydraulics
• Auxiliary Hydraulic Circuits

Final compatibility should be confirmed against the machine model, hydraulic schematic and complete pump ordering code.

Expert Maintenance Tips

1. Fill and Bleed the Pump Before Commissioning

Rexroth requires the axial piston unit to be filled with hydraulic fluid and air-bleeded during commissioning and operation. The same requirement applies after a long standstill because hydraulic lines can allow the pump to drain.

2. Route Case Drain Through the Appropriate Highest Port

The leakage from the housing must be routed to the reservoir through the highest available drain port, L or L1, according to installation position.

3. Maintain Correct Inlet Pressure

Rexroth specifies:

• Minimum inlet pressure at suction port S: 0.8 bar absolute under the standard reference condition
• Maximum inlet pressure: 10 bar absolute

The actual minimum inlet-pressure requirement also depends on pump speed and displacement.

4. Control Case Pressure

The maximum case pressure specified for Series 31 is 2 bar absolute, and the case-drain circuit must be connected correctly to the reservoir.

5. Maintain Hydraulic-Fluid Cleanliness

Rexroth specifies at least:

ISO 4406 Class 20/18/15

When hydraulic-fluid viscosity at the drain port drops below 10 mm²/s, the required cleanliness level becomes at least:

ISO 4406 Class 19/17/14.

6. Maintain Correct Viscosity and Temperature

For the published FKM configuration, Rexroth lists:

• Continuous viscosity range: 10–400 mm²/s
• Optimum viscosity range: 16–36 mm²/s
• Short-term minimum viscosity: 7 mm²/s
• Maximum cold-start viscosity: 1600 mm²/s

Actual limits must be evaluated together with fluid temperature, pressure, speed and operating duration.

7. Diagnose the DFLR Controller as a Three-Function System

For abnormal pressure or flow behavior, inspect:

• Pressure-control setting
• Flow-control setting
• Power-control characteristic
• Load pressure
• Pump speed
• Swashplate response

DFLR is not merely a pressure compensator; it is a combined pressure/flow/power controller.

8. Do Not Use 350 Bar as Continuous-Duty Pressure

Design normal continuous operation around the 280 bar nominal-pressure rating. The 350 bar value is a limited maximum-pressure condition with specified operating-period constraints.

9. Verify the Complete R902447875 Configuration

For replacement procurement, request:

• Material Number: R902447875
• Full nameplate Type Code
• Shaft-end dimensions
• Mounting-flange dimensions
• Port orientation
• Machine model
• Hydraulic schematic

The public material-number index associates R902447875 with A10VO74DFLR/31R-VSC46N00-S2116. The final S2116 special-version information should therefore be retained rather than shortened to S21 during purchasing.

10. 100% Simulated Working-Condition Testing

For an equivalent replacement unit, our QC program can include:

• Displacement-response testing
• DFLR pressure-response testing
• Flow-control verification
• Power-control verification
• Rotation verification
• Case-leakage testing
• Suction-condition verification
• Load-stability testing

This provides a more meaningful replacement-validation process than dimensional inspection alone.