Rexroth A8VO Axial piston variable double pump for the Casagrande drilling rig 92201038 92201041 92201042 92201043 92201044 92201045 92201050

The A8VO is a variable displacement axial piston double pump built by Bosch Rexroth for open-circuit, multi-circuit mobile machinery — the same category that includes excavators, cranes, and, notably, drilling rigs. It's rated for sizes 55 through 225, with nominal pressure up to 380 bar and maximum pressure up to 420 bar.

Why Casagrande Chose the A8VO for Its Piling Rigs

Casagrande builds multifunctional rigs — machines that drill large-diameter rotary piles, run continuous flight auger (CFA) work, handle casing oscillators, and convert into diaphragm wall equipment, sometimes all on the same base carrier. That versatility only works if the hydraulic power source can be split, redirected, and modulated on demand.

Direct Engine Coupling and Power-to-Weight

The A8VO is built for direct mounting on the flywheel case of a diesel engine, giving it an excellent power-to-weight ratio — a real consideration on a rig where every kilogram on the upper structure affects stability and lift capacity. Bolting the pump straight to the engine flywheel also eliminates a driveline coupling that would otherwise be one more point of vibration, misalignment, and maintenance.

Smart Power Management Integration

Modern Casagrande rigs run what the company calls Smart Power Management (SPM) — an engine power management system that monitors the power flows drawn from the engine and allocates the maximum available power to whichever function needs it. This only works because the A8VO's variable displacement can be commanded electronically in real time. When the crowd system suddenly needs more force to push a kelly bar through a hard layer, SPM can reduce flow elsewhere and let the A8VO redirect swept volume to where it's needed — without stalling the engine or wasting diesel.

Load-Sensing Efficiency on XP-2 Rig

Casagrande's XP-2 series uses a flow-sharing system where the pump only pressurizes the amount of oil actually requested by the active functions, thanks to feedback between the pumps and distributors — a design that can save up to roughly 25% in fuel over a theoretical working cycle. The A8VO's load-sensing control variant is what makes that feedback loop physically possible: the pump's swash plate angle adjusts continuously to match demand rather than running at fixed maximum displacement and dumping excess flow over a relief valve.

How the A8VO Fits Into the Rig's Hydraulic Architecture

Auxiliary Pump and Auxiliary Functions

Beyond the two main rotary groups, the A8VO typically integrates a through-drive and an auxiliary gear pump take-off, letting the manufacturer stack a smaller pump onto the back of the unit for auxiliary circuits — cooling fans, pilot pressure supply, or steering functions — without adding another driveline connection to the engine.

Control Devices: Matching the Pump to the Job

Rexroth offers a genuine menu of control options on the A8VO, and the choice affects how the rig behaves under load:

Individual power control — each rotary group manages its own power limit independently, useful when circuits need to operate without influencing each other.

Load sensing (LS) — the pump only makes the pressure and flow that the downstream valve actually calls for, minimizing throttling losses.

Hydraulic power coupling/summation power control — the two rotary groups share total available power, so if one circuit backs off, the other can draw more, which suits a drilling cycle where crowd and rotary loads shift constantly.

Casagrande's rig designers pick among these depending on the model and generation of machine, and it's one of the first things a technician should confirm before ordering a replacement pump — the ordering code on the nameplate isn't just a part number, it's a functional specification.

The Suction Side Nobody Thinks About Until It Fails

The A8VO uses one common suction port for the auxiliary pump and both main circuits. On a piling rig working in hot climates or at altitude, that shared suction path means a single blocked strainer or an undersized suction hose can starve both rotary groups simultaneously — a classic case where a "pump problem" is actually a suction-side problem. Any troubleshooting sequence should rule out suction restriction before condemning the pump internals.

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Q1: What sizes of A8VO are used on Casagrande rigs?

A1: Depending on the rig model and torque/flow requirements, Casagrande specifies units across the A8VO55 to A8VO200 range, with size selected to match the rig's rotary head torque rating and winch line pull.

Q2: How often should the A8VO be serviced on a drilling rig in heavy use?

A2: There's no universal interval, since it depends on duty cycle and environment, but most operators tie A8VO inspection to the rig's broader hydraulic service schedule — typically every 500–1,000 hours for fluid analysis and filter changes, with a more detailed internal inspection at major overhaul intervals recommended by Casagrande and Rexroth documentation.

Q3: What is the price and delivery time of the A8vo hydraulic pump for the Casagrande drilling rig？

A3: The specific price and delivery time will depend on the equipment model or specific product model you provide.

Q4: How to purchase an A8VO hydraulic pump for a Casagrande drilling rig?

A4: You can visit https://www.baolilaihydraulic.com/contact/ to contact us and purchase our products through various methods.