Most motors will overheat and fail under these conditions. Hydraulic cylinders are very smooth and efficient for linear movement. There are no poles that cause cogging, and there's no need for backlash compensation. Although hydraulic and pneumatic power share many common characteristics, there are some key differences. For example, because hydraulic fluid is much less compressible than gas, hydraulics are preferable to pneumatics when precise position control is required.
Pneumatic systems are also typically less expensive to build.
Designing a Fluid Power System Designing the power circuit, as well as selecting and physically placing system components, is critical to maximizing the system's performance. Figure 1 shows a typical hydraulic system with an electronic motion controller. Following is a discussion of key system elements. Pumps Pumps supply the oil or air under pressure required to move the system's cylinder pistons, converting mechanical power to fluid power. Usually only one pump is required to power all the system's cylinders, and it needs to be only large enough to supply the average amount of oil required by the application per machine cycle.