The A30VG Series 10 – and the Broader A20VG/A22VG/A24VG/A30VG Family

The A30VG series 10 is a swashplate‑design axial piston variable pump built by Bosch Rexroth for closed‑circuit hydrostatic travel drives. Unlike a conventional single‑circuit variable pump, the A30VG houses two synchronously variable circuits in one compact body, each delivering 28 cm³ per revolution, along with an integrated boost pump. This dual‑circuit architecture is shared across the entire A20VG/A22VG/A24VG/A30VG platform – with displacements ranging from 45 to 180 cc/rev – making it a proven solution for machines that demand two independent yet perfectly matched flows from a single prime mover.

That “2‑circuit” designation isn’t just a spec sheet detail — it’s the entire point of the design. By running two separate, precisely matched flows off a single common control, the pump can function as a hydraulic differential lock, splitting torque between two hydrostatic motors (typically wheel motors) without the efficiency losses that come from a mechanical flow divider.

Why the Dual‑Circuit Design Matters – the 50% Edge

Most axial piston pumps in mobile hydraulics move fluid through a single circuit, and if a machine needs two independent drive circuits, manufacturers historically bolted on a second pump or relied on a mechanical flow divider. Both approaches add weight, length, and — critically — parasitic losses. The A30VG sidesteps that by putting two variable circuits inside one housing, controlled together. The practical result is that both circuits stay synchronized without a flow divider stealing efficiency, and the pump still fits in a 300 mm installation envelope, which Rexroth positions as best‑in‑class for this displacement class.

Compared to twin‑pump setups, this integrated design delivers a 50% reduction in installation space and eliminates the need for external分流阀, cutting energy loss by up to 50% under partial‑load conditions. The common control also ensures near‑perfect synchronisation between circuits – a critical advantage for wheel drives where speed matching directly affects tyre wear and steering stability.

Typical Applications

Based on Rexroth’s own application guidance, the A30VG series 10 shows up most often in wheel drives paired with a mechanical differential lock or series motor control; roller drives, including compact and tandem road rollers; articulated machines with single‑wheel drives common in modern municipal and construction equipment; and synchronous working drives in closed circuits where efficiency requirements are high.

For smaller machines, the same dual‑circuit principle is embodied in the A22VG045HT1005M1/40B‑RNB2S73FB2S4A‑Y – a popular variant for skid‑steer loaders and compact utility vehicles. This specific model (material number R902211027) shares the compact, loss‑saving design of the A30VG and is field‑proven in demanding applications where space and fuel economy are at a premium.

If your machine falls into one of these categories and currently uses a flow divider or two separate pumps to manage dual circuits, the A30VG – or its smaller sibling the A22VG045 – is worth a second look during your next redesign cycle.

Selecting and Specifying an A30VG – or a Family Member

A few practical points worth confirming before ordering or swapping in an A30VG:

1. Confirm the control type you need. EP (proportional electric) suits machines already wired for electronic control; HW (proportional hydraulic, mechanical servo) suits simpler mechanical linkages. For the A22VG045 example above, the control is already fixed – always verify the full code against your system.

2. Check shaft and flange compatibility. The pump uses SAE J744 flange mounting and is available with either a 1 1/4 in or 1 3/8 in drive shaft — match this to your prime mover’s PTO or engine coupling.

3. Verify pressure margins for your duty cycle. With a 300 bar nominal rating and 350 bar maximum, make sure your peak working pressure — including transient spikes during hard direction changes — stays within that ceiling. The A22VG and A24VG variants offer even higher ratings (up to 500 bar) for more severe applications.

4. Don’t treat the two circuits as interchangeable with two separate pumps. Because both flows share a common control, sizing decisions (motor displacement, wheel diameter, etc.) need to keep both circuits balanced, or the differential‑lock behaviour won’t work as intended. This synchronisation advantage – unique to the integrated design – alone gives a 50% improvement in traction control consistency over split‑pump arrangements.