Cost is clearly a huge factor in any component selection, but initial cost and expected life are just one part of the. You must also know the motor’s efficiency rating, as this will factor in whether it runs cost-effectively or not. In addition, a component that is easy to restoration and maintain or is easily transformed out with various other brands will reduce overall system costs ultimately. Finally, consider the motor’s size and weight, as this will effect the size and weight of the system or 
machine with which it is being used.
Hydraulic motors can use different types of fluids, which means you must know the system’s requirements-does it require a bio-based, environmentally-friendly liquid or fire resistant one, for example. In addition, contamination could be a problem, so knowing its resistance amounts is important.
You must know the maximum operating pressure, speed, and torque the motor will need to accommodate. Knowing its displacement and circulation requirements within something is equally important.
At the medium-pressure and cost range, vane motors feature a housing with an eccentric bore. Vanes rotor slide in and out, operate by the eccentric bore. The motion of the pressurized fluid causes an unbalanced power, which in turn forces the rotor to turn in one direction.
Piston-type motors are available in a variety of different styles, including radial-, axial-, and other less common styles. Radial-piston motors feature pistons arranged perpendicularly to the crankshaft’s axis. As the crankshaft rotates, the pistons are moved linearly by the fluid pressure. Axial-piston designs include a quantity of pistons organized in a circular pattern in the housing (cylinder block, rotor, or barrel). This housing rotates about its axis by a shaft that is aligned with the pumping pistons. Two designs of axial piston motors exist-swashplate and bent axis types. Swashplate styles feature the pistons and drive shaft in a parallel set up. In the bent axis edition, the pistons are organized at an position to the primary drive shaft.
Of the lesser used two designs, roller celebrity motors offer lower friction, higher mechanical effectiveness and higher start-up torque than gerotor designs. In addition, they provide smooth, low-speed operation and provide longer life with much less use on the rollers. Gerotors offer continuous fluid-tight sealing throughout their soft operation.
Specifying hydraulic motors
There are several important things to consider when selecting a hydraulic motor.