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‑piston design with high power density and very high total efficiency for energy‑efficient drive trains.
Low noise operation and long service life under high pressure; suitable for torsional vibration environments.
Compact envelope with through‑drive capability for 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 nameplate and 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 flushing via 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.
