A2FE180/61W-VVAL010 Rexroth Bent Axis Piston Motor 400 Bar

Product Overview

The A2FE180/61W-VVAL010 is a fixed-displacement plug-in axial piston motor from Bosch Rexroth’s A2FE series, featuring a bent-axis design with an axial tapered piston rotary group. Engineered for hydrostatic drives in both open and closed circuits, this motor delivers a geometric displacement of 180 cm³/rev, a nominal pressure of 400 bar, and a peak pressure of 450 bar. At a nominal speed of 3600 rpm and a pressure differential of 400 bar, it generates an output torque of 1146 N·m — making it an ideal drive solution for medium-to-large tonnage construction machinery track and slew drives.

Manufactured to strict Rexroth OEM specifications, this motor offers full drop-in interchangeability: the mounting flange, splined shaft, port locations, and envelope dimensions match the original unit exactly, enabling direct replacement without any machine modification. Every unit undergoes 100% simulated working-condition testing before shipment — including high-pressure load cycling, speed sweep, volumetric efficiency verification, and leakage measurement — guaranteeing field-proven reliability and consistent performance.

Model Code Breakdown:

• A2F: Axial piston unit, bent-axis design, fixed displacement
• E: Plug-in motor version (for gearbox integration)
• 180: Size 180 — geometric displacement 180 cm³/rev
• 61: Series 61
• W: Alternating direction of rotation (clockwise & counterclockwise, viewed from shaft end)
• V: FKM (fluorocarbon/Viton) seals
• V: Plug-in mounting flange configuration
• A: Splined shaft end
• L: 2-hole mounting flange (ISO 3019-2 compatible)
• 010: SAE flange ports A and B (rear), without integrated valves

Technical Specifications

• Model: A2FE180/61W-VVAL010
• Type: Fixed-displacement plug-in axial piston motor (bent-axis design)
• Geometric Displacement (Vg): 180 cm³/rev
• Nominal Pressure (pN): 400 bar (shaft end A, pulsating load)
• Peak Pressure (pmax): 450 bar (intermittent duty)
• Max Sum of Pressures at Ports A + B: ≤ 700 bar
• Nominal Speed (nnom): 3600 rpm
• Maximum Speed (nmax, intermittent): 4000 rpm
• Minimum Speed: No lower limit; ≥ 50 rpm recommended for uniform rotation
• Input Flow at nnom: 648 L/min
• Output Torque (Δp = 350 bar): 1003 N·m
• Output Torque (Δp = 400 bar): 1146 N·m
• Rotary Stiffness (c): 18.2 kNm/rad
• Moment of Inertia (JGR): 0.0220 kg·m²
• Max Angular Acceleration (α): 3500 rad/s²
• Case Volume: 1.1 L
• Max Case Pressure (absolute): 10 bar
• Direction of Rotation: Reversible (W)
• Shaft End: Splined shaft
• Mounting Flange: 2-hole flange, ISO 3019-2 compatible
• Port Configuration: SAE flange ports A/B rear (010), no integrated valves
• Seal Material: FKM (Viton)
• Approved Fluids: Mineral oil (HLP), HFB, HFC fire-resistant fluids
• Optimum Operating Viscosity: 16–36 mm²/s
• Permissible Viscosity Range: 5–1000 mm²/s
• Operating Temperature Range: -25°C to +115°C (sizes 28–180)
• Filtration Requirement: ISO 4406 class 17/14
• Approximate Weight: ~48 kg (configuration-dependent)

Key Technical Advantages

1. Bent-Axis Tapered Piston Design — Superior Volumetric and Starting Efficiency The A2FE employs a 40° bent-axis arrangement where tapered pistons bear directly on the drive shaft’s spherical surface, eliminating the slipper friction pair found in swash-plate designs. This architecture delivers volumetric efficiency of ≥94% across the full pressure range and minimizes low-speed starting torque loss — critical for track drive applications requiring precise inching and frequent start-stop cycles.

2. Nodular Cast Iron Housing — Exceptional Shock and Vibration Resistance The housing is precision-cast from nodular (ductile) cast iron, offering significantly higher mechanical strength and damping capacity than aluminum alternatives. It effectively absorbs impact loads transmitted from track drive gearboxes. The recessed central mounting flange allows near-complete integration into the gearbox, producing an extremely compact drive unit with minimal axial envelope — a decisive advantage in space-constrained track drive compartments.

3. Plug-In Integration — Zero Installation Tolerance, True Drop-In Replacement As a plug-in motor, the A2FE arrives fully assembled and tested. Installation requires only insertion into the gearbox bore and flange bolt tightening — no gear backlash adjustment, no alignment procedures, and no special tooling. This design reduces OEM assembly time dramatically and lowers the technical barrier for field replacement, minimizing machinery downtime.

4. FKM Fluorocarbon Seals — Wide Temperature Range and Extended Service Life Standard-equipped FKM (Viton) shaft seals and gaskets provide a continuous operating temperature range up to 115°C with excellent resistance to thermal shock. FKM demonstrates superior chemical compatibility with mineral oils and HFC fire-resistant fluids, and exhibits far lower compression set than NBR at elevated temperatures — directly extending seal replacement intervals. The housing permits up to 10 bar absolute pressure, accommodating the high case-pressure conditions typical of closed-loop track drive systems.

5. Splined Shaft and High-Capacity Bearings — Heavy-Duty Transmission Reliability The involute splined shaft, paired with tapered roller bearings, accommodates substantial external radial and axial loads. With a rotary stiffness of 18.2 kNm/rad and a low moment of inertia of 0.0220 kg·m², the motor delivers rapid response and excellent dynamic stability during frequent direction changes. A maximum angular acceleration of 3500 rad/s² ensures it withstands the severe torque shocks associated with machinery start-up and braking.

Application Areas

• Crawler Excavators: Track drive (left/right final drives) for 20–30 ton class machines
• Crawler Dozers / Loaders: Hydrostatic track propulsion
• Rotary Drilling Rigs: Main winch drive and track propulsion
• Crawler Cranes: Travel mechanism and slew drive
• Asphalt Pavers: Track drive systems
• Mining Equipment: Underground roadheaders, LHD (Load-Haul-Dump) vehicle track drives
• Agricultural Machinery: Large combine harvesters, self-propelled sprayer track drives
• Forestry Equipment: Skidders, feller buncher track propulsion
• Port Machinery: Rail-mounted gantry crane travel mechanisms
• Industrial Winches: Fixed-displacement hydraulic winch drives

Expert Maintenance Tips

Installation Guidelines:

• Before installation, thoroughly clean the gearbox bore to remove all metal debris and residual sealant. Use a guide tool when inserting the motor — never hammer the housing directly.
• Tighten flange bolts diagonally in 2–3 incremental steps using a calibrated torque wrench to the manufacturer’s specified torque. Never fully tighten a single bolt before all others are seated.
• Prior to first start-up, fill the motor housing completely with clean hydraulic oil through the case drain port. This ensures immediate lubrication of bearings and friction surfaces, preventing dry-start damage.
• Verify that ports A and B are connected to the correct hydraulic lines. Although the W-code motor supports both directions of rotation, perform a brief jog test to confirm rotation direction before continuous operation.

Routine Maintenance:

• Fluid Management: Maintain oil cleanliness at ISO 4406 class 17/14 or better. Sample oil every 500 hours for particle count and viscosity analysis; replace hydraulic oil and return-line filters every 2000 hours or 12 months, whichever comes first.
• Case Pressure Monitoring: Regularly inspect the case drain line for obstructions. Case absolute pressure must never exceed 10 bar. A blocked drain line is the most common cause of shaft seal blowout and oil leakage in the field.
• Temperature Monitoring: Continuous operating oil temperature should not exceed 90°C, with a transient maximum of 115°C. Prolonged high-temperature operation accelerates FKM seal aging and oil oxidation — ensure adequate cooler capacity in closed-loop systems.
• Leakage Observation: Normal case leakage increases with speed and pressure. A sudden increase in leakage (exceeding 2× the normal baseline) typically indicates piston pair or valve plate wear. Arrange for inspection promptly to prevent catastrophic secondary damage.
• Long-Term Storage: If the motor is stored for more than 3 months, fill the housing with rust-inhibitive hydraulic oil, seal all ports, and store in a dry, well-ventilated area. Apply a light corrosion inhibitor to the splined shaft to prevent rust.