Orbital and Radial Piston Motors
Low-speed, high-torque motors for winches, drum drives, augers, slew and conveyor circuits, where a gearbox would otherwise be needed to get torque at low shaft speed.
Features
- Torque is set by displacement and pressure drop across the motor, so a motor is selected on required torque first and speed second.
- Shaft options are the usual reason a motor cannot be swapped: tapered, splined, keyed and wheel-flange variants share one body.
- Integral parking brakes and flushing valves are build options and have to be specified, since they are not visible from the outside.
- Case pressure limits are low on many orbital motors; a shared drain line from several motors can exceed them and push out the seal.
- Back pressure on the return line lifts case pressure as well, so long return runs need checking when a motor keeps losing seals.
Specifications
| Figure | Typical range | Unit | Why it matters |
|---|---|---|---|
| Displacement | 80 - 800 | cm3/rev | with pressure drop it sets output torque |
| Continuous torque | 150 - 2 500 | Nm | the figure the driven load is matched against |
| Speed range | 10 - 750 | rpm | low-speed smoothness varies by motor type |
| Shaft type | tapered with nut / 4-bolt wheel flange | single most common reason a replacement will not fit | |
| Maximum case pressure | 3 - 14 | bar | exceeding it pushes out the shaft seal with no other warning |
| Integral brake | spring applied, 20 bar release | must match the machine's brake release circuit |