Choosing a heavy-duty hydraulic motor is an engineering decision, not a catalogue lookup. The right starting point is the duty cycle: continuous or intermittent torque, operating pressure, shaft speed, and the environment. Once those four numbers are clear, the motor technology usually selects itself. The table below compares the three families we build and supply most often — radial piston, axial piston and gear motors.
| Feature | Radial Piston Motor | Axial Piston Motor | Gear Motor |
|---|---|---|---|
| Typical displacement | 0.2–10 L/rev | 10–250 cm³/rev | 1–100 cm³/rev |
| Max pressure | up to 45 MPa | up to 40 MPa | up to 25 MPa |
| Torque at low speed | Very high | High | Low–medium |
| Best speed range | 0–400 rpm | 500–3000 rpm | 500–3000 rpm |
| Typical cost (per kW) | Higher | Medium–high | Lowest |
| Typical use | Winches, conveyors, crushers | Travel drives, fans, mixers | Fans, conveyors, auxiliary drives |
Radial piston motors make the most sense when a load must be driven from a standstill with enormous torque and therefore no gearbox — think winch drums, mining conveyors, feeder breakers, screw conveyors and rotary drum cutters. Because torque is produced by pistons pushing radially against a cam ring, a large displacement delivers high torque at very low speed with excellent starting efficiency. Our Poclain MS/MK and Rexroth MCR replacements are specified for these high-torque, low-speed duties, with two-speed variants available where a fast return stroke is also required.
Axial piston motors are the natural choice for higher rotating speeds and compact envelopes — machine travel drives, mixer and fan drives, and closed-loop hydrostatic transmissions. They offer high power density and good efficiency at speed, but their torque at very low speed is lower than a radial design of the same size, and they are more sensitive to fine contamination. Bent-axis and swash-plate versions cover a wide displacement range and support variable-displacement control options for demanding mobile equipment.
Gear motors remain the economical option for light and medium duties where low cost and mechanical simplicity matter more than precision control — auxiliary fan drives, small conveyors and agricultural implements. They tolerate contamination relatively well and are easy to repair, but torque ripple, lower volumetric efficiency and a limited pressure ceiling rule them out for high-torque applications.
Radial piston motors win on low-speed torque, axial piston motors win on high-speed power density, and gear motors win on cost. If you send Helm Tower Noda your duty cycle — torque, speed, pressure, displacement and mounting details — our engineers will confirm the correct family, displacement and shaft configuration, and supply a Poclain or Rexroth-interchangeable motor tested and ready for your equipment.
Choosing a heavy-duty hydraulic motor is an engineering decision, not a catalogue lookup. The right starting point is the duty cycle: continuous or intermittent torque, operating pressure, shaft speed, and the environment. Once those four numbers are clear, the motor technology usually selects itself. The table below compares the three families we build and supply most often — radial piston, axial piston and gear motors.
| Feature | Radial Piston Motor | Axial Piston Motor | Gear Motor |
|---|---|---|---|
| Typical displacement | 0.2–10 L/rev | 10–250 cm³/rev | 1–100 cm³/rev |
| Max pressure | up to 45 MPa | up to 40 MPa | up to 25 MPa |
| Torque at low speed | Very high | High | Low–medium |
| Best speed range | 0–400 rpm | 500–3000 rpm | 500–3000 rpm |
| Typical cost (per kW) | Higher | Medium–high | Lowest |
| Typical use | Winches, conveyors, crushers | Travel drives, fans, mixers | Fans, conveyors, auxiliary drives |
Radial piston motors make the most sense when a load must be driven from a standstill with enormous torque and therefore no gearbox — think winch drums, mining conveyors, feeder breakers, screw conveyors and rotary drum cutters. Because torque is produced by pistons pushing radially against a cam ring, a large displacement delivers high torque at very low speed with excellent starting efficiency. Our Poclain MS/MK and Rexroth MCR replacements are specified for these high-torque, low-speed duties, with two-speed variants available where a fast return stroke is also required.
Axial piston motors are the natural choice for higher rotating speeds and compact envelopes — machine travel drives, mixer and fan drives, and closed-loop hydrostatic transmissions. They offer high power density and good efficiency at speed, but their torque at very low speed is lower than a radial design of the same size, and they are more sensitive to fine contamination. Bent-axis and swash-plate versions cover a wide displacement range and support variable-displacement control options for demanding mobile equipment.
Gear motors remain the economical option for light and medium duties where low cost and mechanical simplicity matter more than precision control — auxiliary fan drives, small conveyors and agricultural implements. They tolerate contamination relatively well and are easy to repair, but torque ripple, lower volumetric efficiency and a limited pressure ceiling rule them out for high-torque applications.
Radial piston motors win on low-speed torque, axial piston motors win on high-speed power density, and gear motors win on cost. If you send Helm Tower Noda your duty cycle — torque, speed, pressure, displacement and mounting details — our engineers will confirm the correct family, displacement and shaft configuration, and supply a Poclain or Rexroth-interchangeable motor tested and ready for your equipment.
