REXROTH hydraulic motor product series

REXROTH Hydraulic Motor Comprehensive Guide

1. Product overview
   REXROTH (Rexroth) hydraulic motor is the core hydraulic component of the German Bosch Rexroth company, which is widely used in construction machinery, industrial automation, ships, mines and other fields.Its products are known for their high efficiency, reliability and durability, supporting a wide range of operating conditions from low pressure to high pressure (up to 450bar), and have the ability to rotate in both directions.
2. Mainstream product series and technical parameters
3. Axial piston motor
   Representative model: A4FM series (such as A4FM28/32W, A4FM71/10W)
   Technical features：
   Pressure level: nominal pressure 400bar, peak pressure 450bar.
   Displacement range: 22～500 cm3/rev, support variable control.
   Efficiency: The total efficiency is about 90%, and the volumetric efficiency is 95%.
   Application scenario: Medium and high pressure closed/open circuit, suitable for excavators, cranes, injection molding machines and other equipment that require precise control.
   Advantages: Compact design, low noise, long life, support swash plate structure, adapt to high dynamic loads.
4. Radial plunger motor
   Representative model: Hägglunds CA series (such as CA5020, CA5025)
   Technical features：
   Torque density: High power density, compact structure (such as CA gold Pai motor).
   Speed range: low speed and high torque (the minimum speed can reach 0.1rpm), directly drive the load.
   Impact resistance: Suitable for heavy-duty environments such as mining machinery and ship propulsion.
   Application scenarios: shearers, port cranes, shield machines, etc. require high reliability and impact resistance.
5. Gear motor and blade motor
   Gear motor：
   Features: High speed and low torque (speed ≥500rpm), low cost, suitable for auxiliary drives such as fans and pumps.
   Limitations: Poor sealing, not suitable for high-pressure working conditions.
   Vane motor：
   Features: Sensitive movement, suitable for frequent commutation (such as mold opening and closing of injection molding machines).
   Limitation: The stability at low speed is poor, and a check valve is required to maintain the blade pressure.
6. Working principle and classification
7. Basic principle
   The hydraulic motor converts hydraulic energy into mechanical energy through the following steps：
   Pressure oil input: The hydraulic oil enters the motor cavity through the oil distribution mechanism.
   Torque generation: The hydraulic pressure of the oil is used on the plunger, blade or gear to generate torque.
   Output rotation: Torque drives the output shaft to rotate to complete the energy conversion.
8. Classification method
   By structure：
   Plunger type (axial/radial): high efficiency, high torque, suitable for high pressure scenarios.
   Gear type: simple and economical, suitable for low pressure and high speed.
   Blade type: high sensitivity, but limited performance at low speed.
   Press the speed：
   High-speed motor (≥500rpm): gear, blade, axial plunger type.
   Low-speed motor (<500rpm): mainly radial plunger type.

Fourth, the application field
Recommended models for typical applications in the field
Construction machinery excavator walking drive, crane hoist A4FM series, Hägglunds CA
Industrial automation injection molding machine mold closing, steel rolling mill rolling blade motor, A4FM series
Ship rudder control, deck machinery radial plunger motor
Mine shearer cutting, transport aircraft drive Hägglunds CA, radial plunger type
High-torque radial plunger motors for port container cranes and shore bridge hoisting

V. Maintenance and troubleshooting

1. Common faults and causes
   Insufficient speed：
   Reasons: Low oil supply pressure, clogged oil filter, internal leakage.
   Solution: Check the pump pressure, clean the filter element, and replace the seals.
   Noise/vibration：
   Reasons: The coaxiality of the coupling is too poor, the stator is worn, and the air is mixed.
   Solution: correct the coaxiality, repair the stator, and exhaust treatment.
   leak：
   Cause: Aging of the oil seal, damage to the sealing ring, and loosening of the pipe joint.
   Solution: Replace the seals and tighten the joints.
2. Maintenance recommendations
   Regular inspection: replace the hydraulic oil every 500 hours and clean the filter element.
   Seal maintenance: Check the oil seal and O-ring every 2000 hours, and replace it when the wear exceeds the standard.
   Temperature control: Ensure that the oil temperature is ≤80℃ to avoid leakage caused by viscosity drop.

VI. Summary
With its diverse product range, excellent performance and reliability, REXROTH hydraulic motors have become the benchmark in the field of hydraulic drives around the world.Users should choose the appropriate model according to the specific working conditions (pressure, speed, space), and rely on the official maintenance system to ensure the long-term stable operation of the equipment.