Smooth Operators: Hydraulic Orbital Motors in Material Handling Equipment
It takes lots of motor torque to move heavy loads, which is one reason hydraulic orbital motors are widely used in material handling equipment. Fork trucks, cranes and heavy-duty or long-distance conveyor systems all benefit from the smooth, high-torque, low-speed motion this motor technology provides. If you’re designing material handling equipment or systems, and you’re exploring motor technology, this blog is for you.
Hydraulic Vs. Electric Motors
A hydraulic motor is like a pump working in reverse: fluid flow and pressure are used to create rotary motion. There are various designs but all require a hydraulic power pack of some form. This makes them useful in mobile equipment applications where the power pack can be driven by an engine. Compared to electric motors, they avoid the cost, weight and long charging times of batteries.
Two other factors to consider when evaluating motor technology are the current drawn by a large motor, and its rated speed. For multi-horsepower motors, current is significant, especially at startup, and rated speed can be in the region of 1,700rpm. Both aspects can pose design challenges that hydraulic motors avoid: supplying sufficient power and the need for a reduction drive or gearbox.
Understanding Orbital Motors
Of the various types of hydraulic motor, the approach often preferred for mobile and material handling equipment is the orbital design. This gets its name from the internal gerotor mechanism where the output shaft is connected to an inner gear that rolls around – or orbits – teeth on the inner surface of a fixed gear.
The inner gear, or rotor, has one less teeth than the stator, and is sized so as to divide the volume at the center of the stator into two chambers. Hydraulic pressure is applied to one side, creating torque that turns the rotor.
Achieving steady rotation requires a form of commutation for the hydraulic fluid where the input and output valving rotates with the rotor gear. There are various valving systems for achieving this.
Beneficial Characteristics of Hydraulic Orbital Motors
The gerotor-based hydraulic orbital motor produces high torque at low speed. For example, Impro Fluidtek’s CE750 motor from the medium-duty CE line produces 798 ft-lbs (1,082 Nm) at just 100 rpm in continuous motion. (Intermittent usage torque and speed limits are 912 ft-lbs (1,237 Nm) and 130 rpm.)
A second notable characteristic of this motor is its small size. In common with all hydraulic orbital motors, the CE line of motors is extremely compact for their output. This simplifies integration within mobile and static equipment like that used for material handling.
In addition, the motion generated by this motor technology is fully reversible and its speed is controllable. Together, these attributes help simplify drivetrain requirements. Furthermore, the precision machining that goes into motors produced by Impro results in particularly smooth rotation.
Hydraulic Orbital Motors for Material Handling Equipment
Besides having enough torque, other requirements for the motors used in material handling machinery are smooth operation and controllability. Together, these give operators the confidence in the equipment that lets them focus on the task in hand.
Impro Fluidtek low speed, high torque hydraulic orbital motors help make material handling equipment safe and controllable. Their compact packaging simplifies integration, especially where space is limited as in wheel motor designs. Models are available for high pressure, low-flow applications and heavy duty bearings and seals ensure long life.
For help selecting the best hydraulic orbital motors for your material handling equipment, contact us.