Mobile equipment used in construction and agriculture is better served by hydraulic orbital motors than electrical motors. This blog delves into why that is, and identifies a number of applications. First though, it’s important to understand what these motors are and how they work.

A Pump for Liquids, Reversed

Pumps, of which there are many types, use mechanical motion to push liquid through pipes. Hydraulic motors do the reverse. In these, liquid flow and pressure creates motion, usually rotation.

Hydraulic motors take many forms, but the type best suited for mobile power applications in construction and agriculture is the orbital motor or gerotor design.

Gerotor Basics

A gerotor is an assembly of two spur gears, with the unique feature that the smaller of the two, the rotor, rolls around the inner surface of the stationary larger gear or stator.

Hydraulic orbital motors use this gerotor design to turn liquid flow and pressure into rotary motion. The way this works is the rotor has one tooth less than the stator, and is sized so the tips of two, approximately opposite, teeth are always touching the surface of the stator.

This arrangement divides the space in the center of the stator into two halves. Fluid is allowed into one half, where it pushes on the rotor teeth and makes it move towards the other half. As the rotor is constrained to roll, this generates a circular motion that can be taken to an output shaft.

What Makes Hydraulic Orbital Motors Useful?

The gerotor design acts as a reduction gear, slowing the output rotation. At the same time, fluid acting on the rotor generates high torque, making this a smooth-acting, low speed, high torque motor. This kind of functionality is needed in applications where a large mass must be moved slowly.

Hydraulic orbital motors are also compact for their output, which simplifies integration. They are, for example, used as wheel motors in many mobile applications.

Other important characteristics of the design are durability – they perform reliably in challenging environments – and controllability. Speed and direction of rotation can be regulated through control of fluid flow and pressure, and they can be held in a fixed position without needing an external brake.

In comparison with electric motors of equivalent power and torque, hydraulic orbital motors are smaller, easier to integrate, and don’t need high voltages, generators, or reduction drives.

Construction Applications

These motors are used for both motive power and driving accessory equipment. They are found in:

• Skid steers
• Sweepers
• Compact loaders
• Trenchers
• Drilling equipment
• Excavators
• Concrete mixing and conveying

Agricultural Applications

As with the construction applications above, hydraulic orbital motors are used for powering mobile machinery and for operating equipment mounted to that machinery. Applications include:

• Plowing
• Augers
• Harvesting
• Seed planters
• Sprayers
• Combines

The Durability and Adaptability for Challenging Environments

Machinery used in construction and agriculture needs low speed, high torque rotary power to apply high forces and move heavy loads. These motors need to be compact and controllable, rugged enough to handle wet, dirty, and dusty conditions and temperature extremes, and reliable.

Hydraulic orbital motors deliver in all these regards. That’s why they are the technology preferred by many leading equipment manufacturers. If you’re looking for a dependable way of providing low speed, high torque motion in mobile applications, we have a range of solutions to explore. Contact us for more information.