Bosch Rexroth A6VE A6VM variable hydraulic motor for Kamag Engineering equipment 356003 61120629 80337327

The A6VM and A6VE motors are bent-axis, axial piston, variable displacement hydraulic motors built for closed-circuit hydrostatic drives. Both belong to Rexroth's well-established mobile hydraulics range and share the same fundamental piston-and-swashplate architecture; the difference is packaging.

A6VM: The Standalone Variable Motor

The A6VM is a free-standing motor with its own housing, shaft, and mounting flange. It's the version most commonly bolted directly into a gearbox or driveline, and it's available in a nominal pressure rating of 450 bar with a maximum pressure of 500 bar, depending on the series. Displacement sizes commonly run from 60 to 280 cc/rev in the Series 71 line, giving engineers a wide range of torque and speed options for a given application.

A6VE: The Plug-In (Wheel Hub) Variant

The A6VE is the "plug-in" version of the same motor concept — designed without its own separate housing so it can be integrated directly into a planetary wheel drive or gearbox assembly. This is the configuration you'll most often find inside a Kamag SPMT axle line or drive module, since it saves space and weight right at the wheel, where every millimeter of ground clearance and every kilogram of unsprung mass matters.

How the A6VE/A6VM Fits Into a Kamag Drivetrain

Kamag transporters are built around independently steerable, independently driven axle lines. Each drive axle typically carries its own hydrostatic drive: a variable pump (often the matching A4VG family) feeding one or more variable motors at the wheel end, in a closed hydraulic circuit.

A Practical Example: SPMT Axle Line Drive

Picture a 6-axle-line Kamag SPMT module used to transport a pressure vessel across a fabrication yard:

1. A central diesel-driven power pack supplies a variable displacement pump to each drive circuit.

2. That pump pushes oil through a closed loop to an A6VE plug-in motor integrated into each drive axle's planetary hub.

3. As the operator commands "start," the motor is stroked toward Vg max, generating maximum torque to overcome static friction and begin rolling the load.

4. Once moving, the DA or HP control gradually reduces displacement, trading torque for speed as the transporter reaches its creep travel speed (often under 1 mph / 1.6 km/h fully loaded).

5. Because every axle line has its own motor and control loop, the system can compensate for uneven ground, tire wear, or load distribution across dozens of wheels without a single mechanical differential.

This same basic pattern — power pack, closed-circuit pump, wheel-end variable motor — underlies Kamag's industrial transporters and lift-and-carry vehicles as well, just scaled to different capacities and axle counts.

Counterbalance and Flushing Functions

Because these transporters frequently operate on slopes, ramps, and loading docks, the motor also needs to manage overrunning loads safely. The A6VM is designed with both an optional attached flushing and boost-pressure valve and an integrated or attached counterbalance valve, which prevents the load from running away with the motor (and the vehicle) if a downhill grade tries to accelerate the wheels faster than the pump is supplying flow. The flushing valve also continuously exchanges a portion of the closed-loop oil, helping control temperature and remove contamination — important on equipment that can run for hours at a stretch during a single heavy lift move.

Key Technical Considerations When Specifying or Servicing These Motors

Control Type Identification

Before ordering a replacement or troubleshooting sluggish response, confirm which control the motor uses:

HP (proportional hydraulic): positive (HP1/HP2) or negative (HP5/HP6) acting, controlled by pilot pressure at port X, with a maximum permissible pilot pressure of 100 bar.

DA (speed-dependent): paired with an A4VG pump signal for automatic travel-drive behavior.

HD/EP variants: used on some series for pressure-cutoff or electric proportional control.

Mixing up control types during a rebuild is one of the most common causes of a "new" motor behaving unpredictably after installation.

Bearing and Fluid Compatibility

Long-life bearing options and compatibility with HFA/HFB/HFC/HFD environmentally acceptable fluids are available on most series, which matters for transporters that operate in shipyards or offshore environments where mineral oil use may be restricted. Fluid choice directly affects seal material selection (FKM vs. NBR) and cold-weather operating range.

Maintenance Signals Worth Watching

Rising case-drain temperature or flow — often an early sign of internal wear or a failing counterbalance valve.

Loss of full displacement swing — check pilot pressure supply and control valve condition before condemning the motor itself.

Uneven creep speed across axle lines points to a control calibration or pump-signal mismatch rather than the motor itself in many cases.

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Q1: What's the actual difference between an A6VE and an A6VM motor?

A1: They share the same internal piston/swashplate design principle. The A6VM is a self-contained unit with its own housing and shaft; the A6VE is a "plug-in" version without a separate housing, designed to be built directly into a gearbox or wheel hub — the more common choice inside Kamag axle drives.

Q2: How do I know which control type (HP, DA, HD, EP) my motor uses?

A2: Check the motor's type code/nameplate against the relevant Rexroth data sheet (RE 91607 for Series 65, RE 91610 for Series 71, etc.), or trace the pilot line connections. DA control is specifically paired with an A4VG variable pump signal and is common on hydrostatic travel drives like those in Kamag SPMTs.

Q3:What is the price and delivery time of the Rexroth A6VM/A6VE motor for the Kamag Engineering 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 A6VM/A6VE motor for the Kamag Engineering equipment?

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