Hydraulic Pumps

Hydraulic systems are everywhere, in mobile and stationary applications, yet seem to be expected to run with little preventive maintenance. No piece of equipment in a plant is superfluous, and the hydraulic system is often mission critical.

Hydraulic systems are made up of the following main components: reservoir, pump, control valves, actuators, accumulators, and fluid. 

Common types of pumps used in hydraulic systems are:

• Gear pumps, which are less expensive and generally reliable.
• Vane Pumps, which are more efficient than gear pumps and are used for mid-range pressures.
• Axial Piston Pumps, which are widely used, variable displacement pumps that are particularly susceptible to fluid contamination.
• Radial Piston pumps, which are typically used for high-pressure, low-flow applications.

The hydraulic pump is generally the most expensive component on a hydraulic system and has the highest reliability risk, is most sensitive to contaminants, and will often cause chain-reaction failures. The great majority of pump failures are caused by contaminated hydraulic fluid. Pump failure can in turn allow debris to escape downstream with the possibility of reaching sensitive valves and actuators, potentially causing failure in those components as well.

While synthetic hydraulic fluids can be beneficial in the right application, it’s unwise to try to solve a contamination or filtration problem with a more expensive fluid. Instead, it is more important to maintain a clean, dry hydraulic fluid to keep pumps working properly.

The fluid is what actually does the work in a hydraulic system, so it is critical that the fluid be of good quality, proper viscosity, and well maintained.

Installing high-quality filters will help keep your hydraulic fluid free of contaminants. A desiccant breather fitted on the fill cap of the reservoir can also help to keep it dry and cool.

The cost of downtime due to pump failure in a plant can be staggering. Loss of production and labor to change the pump are often much more costly than the equipment itself, and certainly more than a high-quality filter and desiccant breather, which may prolong the life of the system. ​