Hydraulic wheel motors convert oil flow into precise axle speed and oil pressure into very high axle torque. Most Wright mowers use pump and motor drive systems instead of transaxles so we can spec a heavier duty system and still position the operator and center of gravity for maximum stability. Many wheel motors are compact enough to fit entirely inside the rear wheels. The Stander ZK™ uses a higher speed piston type motor that efficiently provides high torque through a planetary* reduction system. This Hydro-Gear™ 15cu-in H-Series motor also contains an internal wet disk brake and serves as the oil reservoirs. All other motors are simple and compact gerotor** type motors. Stander X, Sport X, Large Frame Stander® and MMZ use 15cu-in motors. Walk behinds, Small Frame Stander®, Stander Intensity, and Sport Intensity™ use 12cu-in motors. Keeping oil pressure down is critical to cool running and long lasting hydro systems (the higher the wheel motor displacement, the lower the system pressure).
*Planetary gear reductions are the gear set that increases wheel torque on tractors and earth movers.
**Gerotor motors are the powered by a star shaped drive unit to turn the axle.