Product Overview
The A6VM series bent-axis axial piston variable motors are a flagship product line within the Bosch Rexroth hydraulic transmission platform, classified as all-purpose high-pressure motors. Featuring a bent-axis design with axial tapered piston rotary groups, these motors are specifically engineered for hydrostatic drives in both open and closed circuits. Designed to fully comply with Rexroth A6VM Series 63 mounting and interface standards, these motors offer 100% direct interchangeability with original Rexroth units—enabling plug-and-play replacement without any管路 modifications or adapter plates, significantly minimizing downtime and retrofit costs.
The A6VM series covers a wide displacement range from 28 to 1000 cm³/rev. Through various variable control methods—electrical proportional, hydraulic proportional, hydraulic two-point control, electric two-point control, and high-pressure related automatic control—the displacement can be continuously adjusted from Vg max down to Vg min ≈ 0. Every unit undergoes 100% factory testing under simulated real-world working conditions, validating pressure, flow, volumetric efficiency, and control characteristics before shipment—ensuring reliable operation from the very first start.
Model Code Interpretation (Series 63) :
A6VM107HD1/63W-VZB010B
A6VM – Series code: Bent-axis axial piston variable motor
107 – Displacement size: 107 cm³/rev
HD1 – Control type: Proportional control, hydraulic, with minimum pressure increase Δp ≈ 10 bar
63 – Series number: Series 63
W – Rotation direction and port configuration (standard)
VZB010B – Specific configuration code
A6VM80EZ4/63W-VAB010PB
A6VM – Series code: Bent-axis axial piston variable motor
80 – Displacement size: 80 cm³/rev
EZ4 – Control type: Two-point control, electric, 24V, with HIRSCHMANN connector (without suppressor diode)
63 – Series number: Series 63
W – Rotation direction and port configuration (standard)
VAB010PB – Specific configuration code (including flushing valve options)
Technical Specifications (Bulleted List)
A6VM107HD1/63W-VZB010B
Model: A6VM107HD1/63W-VZB010B
Type: Bent-axis axial piston variable motor (Series 63)
Displacement: 107 cm³/rev
Nominal Pressure: 400 bar
Maximum Pressure: 450 bar
Maximum Speed (at Vg max): 3550 r/min
Maximum Speed (at Vg < Vg max): 5600 r/min
Maximum Inlet Flow (at nmax): 380 L/min
Shaft Torque (Δp=400 bar): 681 Nm
Control Type: HD1 – Proportional control, hydraulic
Weight: Approx. 47 kg
Housing Material: Cast iron
Medium: Mineral oil, synthetic hydraulic oil (HFD, HFB, HFC acceptable; NOT suitable for HFA hydraulic fluids)
Operating Temperature Range: 30–90℃
A6VM80EZ4/63W-VAB010PB
Model: A6VM80EZ4/63W-VAB010PB
Type: Bent-axis axial piston variable motor (Series 63)
Displacement: 80 cm³/rev
Nominal Pressure: 400 bar
Maximum Pressure: 450 bar
Maximum Speed (at Vg max): 3900 r/min
Maximum Speed (at Vg < Vg max): 6150 r/min
Maximum Inlet Flow (at nmax): 312 L/min
Shaft Torque (Δp=400 bar): 509 Nm
Control Type: EZ4 – Two-point control, electric, 24V, HIRSCHMANN connector
Weight: Approx. 34 kg
Housing Material: Cast iron
Medium: Mineral oil, synthetic hydraulic oil (not suitable for HFA)
Operating Temperature Range: 30–90℃
Key Technical Advantages
1. 100% Direct Interchangeability – Zero Modification Required
The A6VM series is engineered to exact Rexroth A6VM Series 63 mounting and interface specifications, with identical dimensions, port locations, and shaft end configurations. End users can replace original units directly without any管路 modifications or adapter plates—transforming unplanned downtime into scheduled, rapid maintenance while significantly reducing spare parts procurement costs and equipment downtime losses.
2. Bent-Axis Design with High Power Density and Wide Control Range
The bent-axis design with axial tapered piston rotary groups delivers exceptional power density. Displacement can be steplessly adjusted from Vg max down to Vg min ≈ 0. By eliminating gear-shifting mechanisms, smaller pumps can be used to achieve a wide speed range, significantly reducing system cost and space requirements.
3. High-Speed Capability with Long-Life Bearing System
Approved for very high-speed operation. Equipped with a compact, robust long-life bearing system featuring an excellent power-to-weight ratio, superior starting characteristics, and low moment of inertia. The wide bent-axis swivel range provides strong adaptability.
4. Multiple Control Options for Flexible Adaptation
The A6VM series offers a wide range of control options—HD hydraulic proportional control (Δp ≈ 10 bar), EZ electric two-point control (24V), EP electric proportional control, HZ hydraulic two-point control, HA high-pressure related automatic control, and more. The EZ4 electric two-point control enables rapid displacement switching via 24V electrical signals, delivering fast response and precise control—ideal for applications requiring quick speed changes.
5. 100% Factory Testing Under Simulated Working Conditions
Every A6VM series unit undergoes rigorous factory testing under simulated real-world conditions, validating pressure, flow, volumetric efficiency, control response characteristics, and thermal performance across the full operating range. Test media match actual operating conditions, ensuring each unit is ready for immediate installation and reliable operation upon delivery—eliminating the risk of “dead on arrival” components.
6. Compact Design with Modular Architecture
The bent-axis compact design and high-strength bearing system deliver high power density and low moment of inertia, balancing long service life with fast dynamic response. Optimized hydraulic circuits and low-friction structures ensure high starting efficiency and smooth operation characteristics. Modular components support rapid maintenance and upgrades, with optional flushing and boost-pressure valves available.
Application Areas
The A6VM series variable motors are widely deployed across the following industries and equipment types:
Construction Machinery: Excavators, rotary drilling rigs, cranes, loaders
Road Construction Equipment: Rollers, asphalt pavers
Metallurgical Industry: Rolling mill hydraulic stations, forging equipment
Mining Equipment: Rock drilling rigs, mining shearers
Specialty Vehicles: Municipal vehicles, waste collection trucks
Port Machinery: Port handling and lifting equipment
Industrial Equipment: Injection molding machines, presses
Specific model applications include:
A6VM107HD1/63W-VZB010B: Medium excavator travel/swing drives, crane hoisting mechanisms
A6VM80EZ4/63W-VAB010PB: Compact excavators, compact loader travel drives
Expert Maintenance Tips
1. Hydraulic Fluid Cleanliness Management
The A6VM series utilizes bent-axis axial piston designs with minimal clearances between pistons and cylinder bores, making them highly sensitive to fluid contamination. It is recommended to install filters with ≤10μm filtration rating, maintaining fluid cleanliness to ISO 4406 19/17/14 or better. NEVER use HFA hydraulic fluids—the A6VM series is not suitable for operation with HFA fluids.
2. HD1 Hydraulic Proportional Control Tuning (A6VM107HD1)
The HD1 control is a proportional control, hydraulic type with minimum pressure increase Δp ≈ 10 bar. During commissioning, verify that the pilot oil supply pressure is stable and cleanliness is adequate. The control characteristic is proportional to the pilot pressure—fine-tune the pilot pressure setting according to actual operating conditions.
3. EZ4 Electric Two-Point Control Tuning (A6VM80EZ4)
The EZ4 control is an electric two-point control type, operating at 24V with a HIRSCHMANN connector (without suppressor diode). Before wiring, verify that the control system output voltage matches the coil specifications (24V DC) to avoid coil burnout from voltage mismatch or sluggish control response. The two-point control enables rapid switching between high and low displacement settings—ideal for speed variations in mobile machinery.
4. Air Bleeding and Pre-filling Before Start-up
Always bleed air from the motor housing via the highest vent port before initial start-up or after extended shutdown periods to prevent cavitation damage. Ensure the motor housing is completely filled with hydraulic fluid prior to starting.
5. Coupling Alignment Requirements
Maintain shaft alignment within 0.05 mm concentricity and 0.5° angular deviation between the drive shaft and the load shaft. Excessive misalignment will lead to premature bearing wear and shaft seal leakage. The use of flexible couplings is recommended to compensate for minor installation deviations.
6. Case Drain and Backpressure Control
Ensure the case drain line is unrestricted with no flow restrictions. Excessive case backpressure will cause shaft seal damage and premature bearing failure. The drain line should return directly to the reservoir, not in parallel with the return line. Note that the case drain temperature may be higher than the circuit or reservoir temperature.
7. Periodic Inspection and Maintenance
Inspect shaft seals for leakage and listen for abnormal operating noise every 1,000 operating hours or every 6 months (whichever comes first). If reduced volumetric efficiency or insufficient output torque is observed, timely overhaul of the piston assembly and valve plate is recommended.
