Rexroth A10VO A10VSO axial piston tandem hydraulic pump

The A10VO and A10VSO are swashplate-type axial piston pumps manufactured by Bosch Rexroth, designed specifically for open-circuit hydraulic systems. In an open circuit, the pump draws fluid from the reservoir and delivers it to the system, while the return fluid flows back to the reservoir.

Inside, a rotating group of pistons runs against an adjustable swashplate. Tilt the plate more and the pistons stroke further, so flow rises. Tilt it toward zero and flow drops, along with the power draw. That's why these pumps are favored over fixed-displacement designs: they deliver only the flow the system needs, which cuts heat and energy waste.

How a Tandem A10VO/A10VSO Setup Works

"Tandem" here means two pumps in line on a shared drive. The first pump has a through-drive, a flange and shaft coupling on its rear that lets a second pump bolt directly on and turn off the same input shaft.

Why Use a Tandem Arrangement?

Dual independent circuits from a single motor or engine

Smaller footprint than two separate motor-pump sets

Lower cost than a second drive motor and coupling

Mixed pump types, such as an A10VSO for the main circuit and a gear pump for pilot, cooling, or filtration

The Through-Drive Rule Everyone Forgets

The input shaft of the first pump carries the torque for both pumps. That total must stay within the permissible through-drive torque in the data sheet. Exceeding it is one of the classic ways to shear a shaft or damage the coupling splines. Check three things:

1. Combined input torque at maximum pressure and displacement

2. Maximum permissible torque at the drive shaft

3. Maximum permissible torque at the through-drive

Also account for the mass of the second pump. A heavy rear pump can overload the front flange in vibrating machinery, so large combinations may need a support bracket.

Common Control Options

The control is what turns a simple variable pump into a smart one:

DR (pressure control): holds a set maximum pressure by reducing flow. The workhorse for constant-pressure systems.

DFR / DFR1 (pressure and flow control): adds load-sensing behavior, so the pump delivers only the flow the valves are asking for.

LA-type (power control): limits torque so the pump never overloads the prime mover. Useful for engine-driven systems.

ED (electro-hydraulic control): lets a PLC or controller adjust pressure proportionally.

In a tandem setup, each pump has its own control, which allows, for example, one pump on load sensing and the other on constant pressure.

Installation and Commissioning Best Practices

Most premature failures trace back to a few avoidable mistakes.

Fill the Case Before Starting

Always fill the pump housing with clean hydraulic fluid through the highest case drain port before first start. Running the pump dry, even briefly, can damage the bearings and slippers.

Mind the Suction Line

Keep the inlet line short, with a generous diameter and minimal bends. Low suction pressure causes cavitation, which shows up as noise, erosion on the port plate, and fast wear.

Control the Case Drain

Keep case pressure low, usually under about 2 bar absolute, and route the drain line to the tank below the fluid level. Excessive case pressure damages the shaft seal.

Fluid and Filtration

Use quality mineral oil to DIN 51524 (HLP grade), typically viscosity class 46 in moderate climates. Target cleanliness around ISO 4406 20/18/15 or better. Contamination is the leading killer of axial piston pumps, so don't skimp on return and pressure filtration.

Temperature

Watch fluid temperature. Sustained operation well above 80 °C degrades the oil and shortens seal and bearing life.

For more information on the A10VO A10VSO tandem hydraulic pump, please visit https://www.baolilaihydraulic.com/product/.

Specifications

Series 31

Series 32

Series 52 and 53

Q1: Can I run an A10VSO in a closed circuit?

A1: No. The A10VSO is designed for open circuits. Closed-circuit hydrostatic drives use different pump families, such as the A4VG.

Q2: How long does an A10VSO last?

A2: With clean oil, correct fluid temperature, and proper suction conditions, many run well past 10,000 hours. Contamination and cavitation are the main life-shorteners.

Q3: How to purchase an A10VO/A10VSO tandem hydraulic pump?

A3: You can visit https://www.baolilaihydraulic.com/contact/ to contact us and purchase our products through various methods.

Q4: What is the price and delivery time of the A10VO/A10VSO tandem hydraulic pump?

A4: The specific price and delivery time will be provided based on the specific model you provide.