Even if your hydraulic system is made of only the highest quality parts and you follow an aggressive preventative maintenance plan, the hydraulic components will inevitably begin to suffer the effects of wear and tear. Depending on the type and severity of the wear, the result will be a loss in performance. The goal of this article is to discuss the six most common types of hydraulic component wear and what can be done to minimize their effects.
Abrasive Hydraulic Component Wear
Abrasive wear is one of the most common types of wear on hydraulic components. There are two types of abrasive wear: two-body wear and three-body wear:
- Two-body wear occurs when two surfaces come into direct contact without a sufficient layer of lubrication between them.
- Three-body wear occurs when the clearance between two surfaces has filled with hard particulate matter.
With both types of abrasion you will see scoring and scuffing of the surfaces involved.
There are two key steps to minimizing abrasive hydraulic component wear – making sure lubricants and hydraulic fluids are kept at an appropriate level, and avoid contamination of the fluid. The basic means of preventing fluid contamination involves filtering the fluids before they enter the hydraulic system, replacing filters on a regular basis, and performing service tasks in a clean work area.
Another common type of wear is adhesive wear. Adhesive hydraulic component wear occurs when two surfaces begin to lose the lubricating film that protects them, creating two-body abrasion. As the lubricating film disappears, the surfaces come into contact with each other, causing scuffing. The scuffing results in the generation of heat due to friction. When the heat builds up sufficiently, a friction weld results; in other words, the parts begin to adhere to each other and metal is transferred between them.
The result is a repeated process of friction welding and tearing between the high points on the two surfaces. To help prevent adhesive wear, keep the hydraulic fluid clean and ensure that all parts are appropriately lubricated.
Fatigue Wear in Your Hydraulic Components
Fatigue wear is typically manifested as cracking and subsequent material breaking away. It usually occurs in heavily lubricated parts like bearings and gears. Point loading can potentially lead to high stresses and elastic deformation of the part surface. As the loading continues, the surface fractures and breaks down the exterior parts.
While fatigue wear cannot be completely eliminated, it can be somewhat minimized by avoiding unnecessary shock loading on the system.
Cavitation results from the collapse of air bubbles or oil vapor bubbles, which typically form at pump inlets and collapse at the pump outlet. When these bubbles collapse, they form a micro-jet that has sufficient power to erode even case-hardened steel. Any time bubbles like this collapse near metal, they will do damage that includes not only erosion but metal loss as well. Metal loss can result in particulate contaminants being introduced into the hydraulic system.
Erosive Hydraulic Component Wear
Erosive wear is likely to occur when hard particles that are less than 2 microns contaminate hydraulic fluid. When the contaminated hydraulic fluid passes over lubricated areas at a high velocity, they turn into a very effective slurry that erodes surfaces they encounter. This wears away the interior of the system.
Erosive wear can be minimized by avoiding particulate contamination of the hydraulic fluid and checking the filters on a regular basis.
Another damaging type of wear is corrosive wear, which is the result of chemical reactions. Most people immediately think of corrosive wear as rusting, but there are other types that can occur in hydraulic systems. One example is when hydraulic fluid is contaminated by water or degraded by heat and produces metal-attacking acids as a chemical byproduct.
Corrosive wear is best avoided by changing out the hydraulic fluid on a regular basis (following manufacturer’s recommendations), changing it out after the system has been exposed to excessive heat, and performing regular analysis on the fluids to detect degradation before it can do extensive damage.
Hydraulic Component Wear and Tear
These types of hydraulic component wear – abrasive, adhesive, fatigue, cavitation, erosive, and corrosive – can occur in any hydraulic system and affect just about any components in your system, including motors, pumps, valves, gears, and bearings. There are certain preventative maintenance activities that can minimize the effects of the wear, including:
- Avoiding contamination of the hydraulic fluid (including particulate, air, and water contamination);
- Changing the filters in the hydraulic system as recommended by the manufacturer;
- Replacing the hydraulic fluid when contamination or degradation of the fluid is suspected; and
- Replacing the hydraulic fluid when the system has been exposed to excessive heat.
In short, the key to minimizing wear is preventative maintenance for your system. While it will not completely eliminate wear, it will significantly reduce it and help to keep your hydraulic components performing at optimum levels.
Preventative Maintenance Company for Your Hydraulic Systems
Keeping your hydraulic components and systems running at peak performance is necessary for customer satisfaction and your bottom line. You don’t have time to worry about maintenance issues like contamination and wear. To keep your operations running optimally, contact MAC Hydraulics. We will perform the preventative maintenance that your system requires, either on-site or in our facility.
Let us worry about the condition of your hydraulic fluid, when to change the filters on your system, and maintaining a contamination-free environment during repairs and maintenance. Our trucks have everything needed to maintain your operations, minimize downtime, and maximize performance. Contact us today!