Gerotor orbital motors are the value end of the low-speed high-torque range - and for most jobs on a farm, a tipper or a sweeper, they are all the motor you need. Inside, a gear set slides against the stator. It is a simpler, cheaper build than a geroler, it runs happily on modest pressure, and it is the right answer wherever the motor works in bursts rather than all day.

What these suit

Fans and radiator drives, grain and seed augers, slasher and sweeper brushes, conveyors, small winches, bin lifters, salt and fertiliser spreaders - anything that starts, does its work and stops. If your motor runs continuously under full load, or the shaft carries a heavy side pull from a chain or belt, step up to a geroler instead.

Choosing one

Work through it in this order: displacement sets your speed and torque for a given flow, mount has to match your bracket (SAE A 2-bolt, SAE A 4-bolt, magneto 4-bolt or square 4-bolt), shaft has to match your coupling or sprocket, then the seal and port options. Every one of those choices is a real factory part number on our listings, priced and ready - not an enquiry form.

Needle bearings under 100cc

On the small displacements the standard bearing arrangement is the weak point as soon as the shaft carries any side load. Every gerotor we supply under 100cc is built with needle roller bearings as standard. We do not sell the plain-bearing version in those sizes, because it comes back.

What these replace

Our gerotor range interchanges with Danfoss OMP and OMM, Eaton and Char-Lynn H Series, Parker TE, White WP and Bosch MGP and GMP. Each listing spells out its own cross-reference, and the part number breakdown is on the page so you can check a code you already have against what you are ordering.