Rexroth A4FM500 Fixed-Displacement Axial Piston Motor
Overview and key specifications
The A4FM500 is a swashplate‑type, fixed‑displacement axial‑piston motor rated for 350 bar nominal and 400 bar maximum pressure. With a geometric displacement of 500 cm³/rev, it delivers high torque for industrial, marine, and engineering drives where compact, high-power packages are required. The motor is suitable for both open and closed circuits and is offered in Series 1 and Series 3. Typical rated speed at n nom is about 1800 rpm, with a corresponding theoretical flow of roughly 900 L/min; at maximum speed (approx. 2000 rpm), flow is about 1000 L/min. Approximate weight is 260 kg. These ratings position the A4FM500 as a robust large‑displacement choice for heavy‑duty applications.
Parameter | Value |
|---|---|
Displacement (Vg) | 500 cm³/rev |
Nominal pressure (p nom) | 350 bar |
Maximum pressure (p max) | 400 bar |
Rated speed (n nom) | ≈ 1800 rpm |
Max. speed (n max) | ≈ 2000 rpm |
Flow at n nom (qV nom) | ≈ 900 L/min |
Flow at n max (qV max) | ≈ 1000 L/min |
Torque at p nom (M) | ≈ 2783 N·m |
Approx. weight | ≈ 260 kg |
Circuit | Open and closed |
Series | 1 / 3 |
Notes: Values per A4FM series data for size 500; exact limits depend on options and system conditions.
Design features and benefits
Swashplate axial‑pistondesign with high power density and very high total efficiency for energy-efficient drive trains.
Low noise operation and long service lifeunder high pressure; suitable for torsional vibration environments.
Compact envelope with through‑drive capabilityfor compact multi‑motor arrangements.
Supports open and closed circuits; widely used where A2FM‑size packages are constrained.
Typical applications
Industrial drives: conveyors, winches, test rigs, and heavy machinery requiring high continuous torque.
Marine equipment: deck machinery, thrusters, and winches where reliability and corrosion-resistant designs are specified.
Engineering machinery: drilling rigs, mining trucks, and other high-torque, low-speed applications in harsh environments.
Model code and ordering guidance
Example breakdown: A4FM500 / 61W – VAB020
A4FM500: Series and size (500 cm³/rev).
/61: Series suffix (Series 1); use /63 for Series 3.
W: Mounting/through-drive orientation code.
VAB020: Port/flange/design and variant suffix (must match your mechanical interface and oil port layout).
Always order the complete type code (including Series, flange/shaft/through-drive, ports, and suffix) and verify against the nameplateand machine parts list.
Commissioning and operation essentials
During start-up and operation, the motor housing must remain full of oil and be properly vented; after long idle periods, re-prime before running.
Minimum suction pressure at port S ≥ 0.8 bar; avoid cavitation.
Observe installation rules: shaft horizontal with bottom, do not use “shaft horizontal with suction port down” when mounted above tank; ensure suction and drain lines are submerged to at least 200 mm below minimum oil level; maximum suction line length h max ≈ 800 mm.
Case drain (T1/T2) must return below the minimum oil level; avoid case pressure build‑up.
Oil cleanliness: maintain at least ISO/DIS 4406 18/15; if oil temperatures exceed component limits, use case flushingvia port U.
Temperature limits: no point in the system above 115°C for sizes 22–56; for sizes 71–500, do not exceed 90°C.
