A8VO80LA1KH2/63R1-NSG05F000-S Rexroth Variable Double Pump 350/400bar

Product Overview

The A8VO80LA1KH2/63R1-NSG05F000-S is a Bosch Rexroth A8VO Series 63 variable double axial piston pump for open-circuit hydraulic systems. It uses two axial tapered-piston rotary groups in bent-axis design, sharing a common suction port while supplying two separate hydraulic circuits. Bosch Rexroth positions the A8VO family for multi-circuit machinery such as excavators, cranes and drilling equipment.

The complete order code can be technically interpreted from Bosch Rexroth RE 93010/03.09:

• A8VO80: nominal size 80, with 2 × 80 cm³/rev maximum displacement.
• LA1KH2: individual power control with pilot-pressure power override, hydraulic power coupling, hydraulic stroke limiter, positive control and external pilot-pressure supply.
• /63: Series 63.
• R: clockwise rotation viewed from the shaft end.
• 1: gear ratio 1.0 between input and rotary groups.
• N: NBR seals with FKM shaft seal.
• Z: DIN 5480 splined shaft.
• G: flywheel-housing mounting configuration according to SAE J617.
• 05: SAE service-port arrangement with A1/A2 at the sides and S at the rear.
• F00: integrated auxiliary pump without PTO.
• -S: special version.

This is therefore not simply an “A8VO80 double pump.” The LA1KH2 control package combines individual power control, hydraulic summation-power coupling and positive hydraulic stroke limitation. This configuration is particularly relevant where two hydraulic circuits experience changing loads and available diesel-engine input power must be shared dynamically.

For replacement applications, engineering verification should be performed against the complete order code, including shaft, flange, rotation, service ports, auxiliary-pump configuration, control-pressure connections and control characteristics. Our replacement program can additionally use 100% simulated working-condition testing to verify flow, pressure, power control and dynamic response.

Technical Specifications

A8VO80LA1KH2/63R1-NSG05F000-S

• Manufacturer: Bosch Rexroth
• Series: A8VO
• Complete Type Code: A8VO80LA1KH2/63R1-NSG05F000-S
• Pump Type: Axial piston variable double pump
• Design: Bent-axis axial piston
• Circuit: Open circuit
• Number of Rotary Groups: 2
• Maximum Displacement per Rotary Group: 80 cm³/rev
• Total Maximum Geometric Displacement: 2 × 80 cm³/rev
• Minimum Displacement: 0 cm³/rev
• Nominal Pressure: 350 bar
• Peak Pressure: 400 bar
• Peak Pressure Duration: Short-term, t < 1 s
• Input Speed at Vg max: 2,240 rpm
• Maximum Speed: 2,750 rpm under the specified reduced-displacement/speed-limit conditions
• Theoretical Maximum Flow: 2 × 179 L/min
• Input Power at 350 bar, Vg max: 209 kW
• Input Torque at 350 bar, Vg max: 891 Nm
• Catalog Mass: approximately 90 kg for the A8VO80 size; exact complete F00/-S assembly mass should be confirmed from the order confirmation or installation drawing
• Rotation: Clockwise, viewed from the shaft end
• Gear Ratio: 1.0
• Shaft: DIN 5480 splined shaft
• Sealing: NBR with FKM shaft seal
• Mounting: SAE J617 flywheel-housing configuration
• Service Ports: A1/A2 side SAE flange ports; S rear SAE flange port
• Auxiliary Pump: Integrated, F00 configuration
• Auxiliary Pump Displacement: 8.6 cm³/rev for the A8VO80 F00/F.. configuration
• Auxiliary Pump Maximum Permissible Pressure: 40 bar
• Optimum Operating Viscosity: 16–36 mm²/s
• Extreme Short-Time Viscosity Limits: 5–1600 mm²/s under specified start/temperature conditions
• Hydraulic Fluid Temperature Range: −40 to +115 °C
• Required Hydraulic Fluid Cleanliness: ISO 4406 20/18/15 minimum
• High-Temperature Cleanliness Requirement: ISO 4406 19/17/14 minimum at 90–115 °C
• Minimum Absolute Inlet Pressure: 0.8 bar, with the permissible inlet pressure increasing with speed and depending on displacement.

The listed flow, power and torque figures are theoretical catalog values without efficiency or tolerance corrections. They should therefore be used for engineering sizing rather than interpreted as guaranteed field measurements.

LA1KH2 Control System

1. Individual Power Control

LA1 provides an individual power controller for each rotary group. The two rotary groups are not mechanically coupled, and each controller regulates displacement as a function of operating pressure to prevent the defined input-power setting from being exceeded.

2. Pilot-Pressure Power Override

An external pilot pressure can be applied through port X3 to reduce the configured power level. Rexroth describes this as negative power override. This allows an external load-limiting strategy to dynamically reduce available pump power.

3. Hydraulic Stroke Limiter with Positive Control

The KH2 configuration adds hydraulic stroke limitation with positive control. Increasing pilot pressure moves the pump toward a larger displacement, with the control range from Vg min to Vg max. The stroke limiter can vary or restrict displacement across the complete control range.

4. External Pilot-Pressure Supply

For H2 configurations, port Y3 is used for external control pressure. Rexroth specifies that when Y3 is present it must be connected to an external control-pressure supply; without such a supply it must be depressurized. The H2 control arrangement requires approximately 30 bar or more control pressure for the relevant control function.

5. Hydraulic Summation Power Coupling

The hydraulic coupling in LA1KH2 provides a summation power-control function. The two individual controllers are hydraulically rather than mechanically coupled. When one pump operates below 50% of the total input-power capability, the remaining available power can be transferred to the other pump, up to 100% of the total input-power capability.

A8VO Family Reference Sizes

The supplied title also contains A8VO55, A8VO80, A8VO107, A8VO140 and A8VO200. Bosch Rexroth RE 93010/03.09 specifies the following standard size data:

A8VO55

• Displacement per rotary group: 54.8 cm³/rev
• Input speed at Vg max: 2,500 rpm
• Maximum speed: 3,000 rpm
• Theoretical flow: 2 × 137 L/min
• Approximate catalog mass: 82 kg.

A8VO80

• Displacement per rotary group: 80 cm³/rev
• Input speed at Vg max: 2,240 rpm
• Maximum speed: 2,750 rpm
• Theoretical flow: 2 × 179 L/min
• Approximate catalog mass: 90 kg.

A8VO107

• Displacement per rotary group: 107 cm³/rev
• Input speed at Vg max: 2,150 rpm
• Maximum speed: 2,450 rpm
• Theoretical flow: 2 × 230 L/min
• Approximate catalog mass: 116 kg.

A8VO140

• Displacement per rotary group: 140 cm³/rev
• Input speed at Vg max: 2,100 rpm
• Maximum speed: 2,450 rpm
• Theoretical flow: 2 × 294 L/min
• Approximate catalog mass: 146 kg.

A8VO200

• Displacement per rotary group: 200 cm³/rev
• Input speed at Vg max: 1,950 rpm
• Maximum speed: 2,250 rpm
• Theoretical flow: 2 × 390 L/min
• Approximate catalog mass: 180 kg.

These are standard family-level data. Actual order-code assemblies can vary because of auxiliary pumps, PTOs, special configurations and control hardware.

Key Technical Advantages

1. Dual Rotary Groups for Independent Hydraulic Circuits

The A8VO contains two independent axial piston rotary groups with a common suction port, allowing two separate hydraulic circuits to be supplied simultaneously. Each rotary group can be varied independently.

2. Hydraulic Power Sharing

The LA1KH2 hydraulic coupling allows available input power to be distributed between the two hydraulic circuits according to actual operating demand. This is particularly useful on mobile machinery where the load on each circuit changes continuously.

3. Individual Power Control

Each rotary group has its own power controller, allowing the pump to regulate displacement according to operating pressure and the configured power characteristic. This supports closer matching between hydraulic demand and the available diesel-engine input power.

4. Positive Hydraulic Stroke Limitation

The KH2 control provides positive hydraulic stroke limitation and external pilot-pressure control from Vg min toward Vg max, offering an additional interface for machine-level flow-management strategies.

5. Bent-Axis Axial Piston Architecture

The A8VO uses two tapered-piston rotary groups in bent-axis configuration. Flow is proportional to drive speed and displacement, which provides the variable-output capability required by high-demand open-circuit mobile hydraulic systems.

6. Integrated Auxiliary Pump

The F00 configuration incorporates an auxiliary pump. For A8VO80, the catalog specifies approximately 8.6 cm³/rev maximum displacement for the integrated auxiliary-pump configuration.

7. Direct Flywheel-Housing Installation

The A8VO is designed for direct installation on the flywheel housing of diesel engines, while the G mounting code corresponds to the SAE J617 flywheel-housing interface.

Materials and Manufacturing Engineering

The public Bosch Rexroth RE 93010 datasheet does not disclose the complete internal material BOM, exact steel grades, heat-treatment hardness values or every proprietary surface treatment used in the A8VO80LA1KH2/63R1-NSG05F000-S.

Therefore, verified engineering descriptions should focus on manufacturing controls rather than unsupported material claims.

Recommended replacement-manufacturing controls include:

• Precision machining of the bent-axis rotary groups
• Piston/cylinder mating accuracy
• Port-plate and sealing-surface control
• Drive-shaft and bearing alignment
• Mounting-flange positional accuracy
• Matching of the two rotary-group control characteristics
• LA1KH2 regulator assembly consistency
• Verification of X1, X3 and Y3 control circuits
• Auxiliary-pump flow and pressure testing
• Internal cleanliness and contamination control
• Pressure, flow and dynamic-response testing
• 100% simulated working-condition testing

For an interchangeable replacement, the engineering objective is therefore not merely dimensional copying. It is to reproduce the mechanical interface + hydraulic performance + control response + duty-cycle behavior of the specified order code.

Application Areas

Bosch Rexroth documentation identifies A8VO as a variable double-pump solution for multi-circuit machinery, including excavators; additional A8VO application material identifies cranes and drilling equipment.

Typical applications include:

• Hydraulic excavators
• Large crawler construction machines
• Multi-circuit mobile hydraulic equipment
• Crawler and rough-terrain cranes
• Rotary drilling and drilling equipment
• Dual-circuit main hydraulic systems
• Diesel-engine flywheel-mounted hydraulic power systems

The independent rotary groups make the A8VO particularly suitable for machines where two hydraulic circuits operate simultaneously with changing and unbalanced loads.

Expert Maintenance Tips

1. Handle Y3 Correctly on LA1KH2 Systems

For H2 configurations, Y3 is the external control-pressure port. When external pilot pressure is used, it must be supplied according to the control design. When no external supply is present, the port must not be left with unintended trapped pressure.

2. Keep the Dual-Pump Circuit Absolutely Clean

Bosch Rexroth emphasizes absolute cleanliness during assembly to prevent welding beads, metal chips and other contaminants from entering hydraulic lines. On a two-circuit A8VO, contamination can affect both rotary groups and their control components.

3. Maintain the Correct Hydraulic-Fluid Viscosity

The documented optimum operating viscosity is 16–36 mm²/s. Extreme low- or high-viscosity values are only permitted for specified short-duration conditions. Local hydraulic-fluid temperature must not exceed 115 °C.

4. Maintain Fluid Cleanliness

Bosch Rexroth specifies ISO 4406 20/18/15 minimum cleanliness for normal operation and 19/17/14 minimum at very high fluid temperatures of 90–115 °C.

5. Check Suction Pressure Against Speed

The documented minimum absolute pressure at suction port S is 0.8 bar, but the actual minimum permissible inlet pressure changes with speed and displacement. Higher speed requires appropriate suction conditions to prevent cavitation.

6. Do Not Treat 400 Bar as Continuous Operating Pressure

For Series 63, the official datasheet distinguishes 350 bar nominal pressure from 400 bar peak pressure, with the peak rating limited to short-term operation of less than one second. System relief settings and duty-cycle calculations must therefore be based on the actual operating cycle rather than the peak figure alone.

7. Test Both Hydraulic Circuits During Commissioning

Because LA1KH2 includes hydraulic power coupling, commissioning should verify both A1 and A2 circuits independently and then evaluate system behavior when demand shifts from one circuit to the other. Pressure, flow, displacement response and power-sharing behavior should all be checked.