What Are The Functions of Hydraulic Oils?

Hydraulic oils today need to provide longer oil drain intervals, better stick/slip characteristics, increased efficiency, improved conductivity and wear performance and an added level of sustainability.

Hydraulic oils are used in many areas of our life, from the telescopic booms of cranes to the control valves in a tractor. These oils are special as they perform a particular function which is unique to them. In addition to the regular functions of an oil, hydraulic oils can transmit power which truly sets them apart. In this article, we will take a deeper dive into the world of hydraulic oils, how they can be used, ways that they should be stored and handled and of course some advancements that we’ve seen over the years.

What Are The Functions of Hydraulic Oils?

Before going any further, we must understand how hydraulic oils function and the impact that they create for our equipment. As per (Pirro, Webster, & Daschner, 2016), the concept of hydraulics revolves around the transmission of force from one point to another where the fluid is the transmitter of this force. Ideally, this is based off Pascal’s Law where, “The pressure applied to a confined fluid is transmitted undiminished in all directions and acts with equal force and at right angles to them.”

As applied to hydraulic oils, once a force is exerted on an oil, the oil can transmit this force to either help an actuator turn or stop an excavator from moving (through braking). This is the transmission of pressure, but hydraulic oils can also provide the functions of reduced wear, prevention of rust and corrosion, reduction in wear and friction and an overall improvement in system efficiency.

For anyone who has worked with hydraulic oils, they will be familiar with the fact that these oils have very tight clearances which requires them to be clean. As they are transmitting power through the fluid, having clean hydraulic oil is essential, so this flow is not disrupted. Since the force will be the same throughout the lubricant, having these tighter clearances allows for more force to be output per square area at the intended target without the contaminants.

Overall, hydraulics will perform the regular functions of an oil but with the added benefit of the transmission of force for these applications. But not all hydraulic oils are created equally and some need to be specifically designed for particular applications within our industry.