Bosch Rexroth A4VTG A10VG closed-circuit hydraulic pumps for the Sermac Road equipment 2401235 2401180 2401314

In an open-circuit hydraulic system, the pump draws fluid from a reservoir and returns it to the same reservoir after the motor or actuator has used it. It's simple and forgiving, but it wastes energy and requires larger tanks and coolers.

A closed-circuit system is different. The pump's outlet feeds directly into the motor's inlet, and the motor's return feeds directly back into the pump's inlet — fluid recirculates in a loop rather than cycling through a large tank. A smaller "charge pump" (usually built into the same housing) tops up the loop to replace internal leakage and provide cooling flow.

Why This Design Suits Sermac's Equipment

Precise, reversible control: Closed circuits allow smooth forward/reverse operation and infinitely variable speed, which is essential for drum rotation on mixers and travel drives on self-propelled units.

Compact packaging: Less plumbing and smaller reservoirs mean lighter, more compact machines — valuable on truck-mounted and trailer-based Sermac units.

Energy efficiency: Recirculating flow reduces throttling losses compared with open-circuit valve control.

Load responsiveness: The variable displacement design lets the machine automatically adjust flow and torque to match load conditions, from idle drum rotation to full-load pumping.

The Bosch Rexroth A4VTG Series: Built for Track and Travel Drives

The A4VTG is a variable-displacement axial piston pump using a bent-axis design, which Bosch Rexroth favors where high power density and durability under shock loading are priorities.

Key Characteristics

Bent-axis construction: Compared with swash-plate designs, bent-axis pumps generally tolerate higher pressure peaks and offer a favorable power-to-weight ratio, which matters on machines that see frequent load reversals.

Through-drive capability: Many A4VTG units support a through-drive shaft, allowing a second pump (often for auxiliary functions like hydraulic fans or steering) to be mounted directly on the back of the unit, saving space on compact machine platforms.

Electronic and hydraulic control options: Depending on configuration, displacement can be controlled electro-proportionally or via hydraulic pilot signals, giving machine builders like Sermac flexibility in how they integrate the pump with the machine's control system.

Integrated charge pump and control valves: Reduces external plumbing and failure points.

Typical Application on Sermac Machines

On self-propelled or track-driven equipment, the A4VTG is well suited to travel drive circuits where the machine needs strong tractive effort at low speed and smooth transitions as ground conditions change — for example, when a machine moves across uneven job-site terrain while maintaining stable output at the working end.

The Bosch Rexroth A10VG Series: The Workhorse for Rotary and Auxiliary Drives

The A10VG is a swash-plate-type variable displacement pump, also built for closed-circuit operation. It's one of Rexroth's most widely deployed pump families across construction, agricultural, and material-handling equipment.

Key Characteristics

Swash-plate design: Offers smooth, predictable displacement control and a well-understood service history, which matters for fleet operators standardizing on common components.

Compact axial layout: Favorable for confined mounting spaces on chassis-mounted equipment.

Wide displacement range: The A10VG family spans a broad range of displacement sizes, allowing machine builders to match pump output closely to the torque and flow needs of a specific drum, conveyor, or auger drive — avoiding the inefficiency of an oversized pump.

Robust charge circuit: Built-in charge pressure relief and flushing valves protect the loop from cavitation and help manage heat buildup during continuous-duty cycles.

Typical Application on Sermac Machines

On concrete mixers and mobile pumping units, the A10VG is commonly paired with a matching closed-circuit motor to drive the mixing drum or auxiliary rotary functions — applications where consistent torque at variable speed, rather than raw travel power, is the priority.

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Q1: What does "closed-circuit" mean in a hydraulic pump?

A1: It means the pump and motor form a recirculating loop rather than drawing from and returning to a large open reservoir, with a small charge pump replenishing fluid lost to internal leakage.

Q2: Can these pumps be repaired, or do they need full replacement?

A2: Both series are serviceable — seal kits, control valves, and rotating group components are available — but a decision to repair versus replace typically depends on wear extent, downtime cost, and parts availability.

Q3: What is the price and delivery time of the Rexroth A4VTG/A10VG pump for the Sermac Road equipment?

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

Q4: How to purchase a Rexroth A4VTG/A10VG pump for the Sermac Road equipment?

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