Extending Bearing Life and Performance - An Engineered Solution

Yehia El-Ibiary, Rockwell Automation
Tags: bearing lubrication

You’ll often find bearings operating in harsh and dirty environments where the product is exposed to airborne contaminants and high temperatures. In many cases, these applications are in hard-to-access areas, making routine maintenance difficult and costly.

In an effort to increase bearing life, improve product performance and extend maintenance periods, Rockwell Automation engineers developed the new Dodge Oil Level and Filtration System (OLF); a patented, low-cost, easy-to-connect system that continuously circulates the oil and filters harmful particles from the bearings’ oil sump.

The OLF system not only provides clean oil to the bearing, it also controls and maintains the proper oil level while the equipment is running. In addition, test results have also shown that the OLF system provides cooler oil. The packaged system is compact and consists of a 1/2 HP single-phase TEFC motor, a 1/2 GPM fixed displacement pump, a one-gallon tank with oil level gauge and a large return fitting, a 10-micron spin-on filter, and a pressure gauge.

In designing the system, engineers sized the motor to be lightly loaded so its cooling fan can be used to cool the oil tank. An integrated pump relief valve protects the system, while a pump inlet strainer decreases contaminants that can affect the pump or the bearings. The tank features a large return-line fitting to accommodate the return of oil by gravity. The oil level gauge, which is mounted on the reservoir, gives the user a quick indication of the oil level in the tank, while a pressure gauge indicates the condition of the filter. There’s also a magnetic plug mounted inside the tank to attract ferrous contaminants.

Figure 1. Dodge OLF System

1. Oil Gauge
2. One-gallon Tank
3. Return Fitting
4. Supply Line Fitting
5. Pressure Gauge

6. Spin-on Filter
7. 1/2 HP Single-Phase TEFC Motor
8. Motor Fan
9. Filler Breather
10. Mounting Bracket

The OLF system has been extensively tested to ensure reliability and performance. In side-by-side comparison tests, engineers tracked the bearing temperature of two bearing applications; one with the OLF system and one without (Figure 1). Test results show that at higher speeds, the bearing application with the OLF system ran nearly 16°F cooler than the other application. Reducing operating temperature is a significant benefit, especially for bearings that are currently running at marginally high temperatures (145ºF to 175ºF).

A second test detailed the effect of the OLF system on oil film thickness in SleeveOil (plain) bearings (Figure 2). The results of this test indicate the OLF system increased the oil film thickness by as much as 12 percent based on actual measurement. Increased oil film thickness protects the bearing from potential damage.

Figure 2

The Dodge OLF system can be easily connected to operating bearings by simply mounting the compact package and connecting two lines. The OLF system is a low-cost alternative that will increase the life of the bearing, minimize maintenance and improve performance.