Non-Lubricated Gear and Roller Bearings

Non-lubricated gears and rollers operate without the need for a lubricant and have been shown to be less prone to wear than conventional metal gears. They also perform quieter and more quietly than steel gears.

 

They require no lubrication unless the flank load is excessive, and they operate more quietly than metal gears due to their better vibration absorption.

 

Several issues can be associated with non-lubricated gears and rollers including scoring, galling, abrasive wear, pitting and breakdown of the oil film, all of which result in gear damage. Typically, these issues are the result of contaminants or too light of a viscosity in the gear lubricant being used.

 

If these lubricant issues are not remedied, the damage will progress until the gear teeth degrade and fail. This can cause a range of problems such as misalignment, stalling, and gear lock.

 

These issues can be prevented by utilizing a proper lubricant in the right viscosity, and by maintaining the correct lubrication schedule. The lubricant selection should be based on the application, and the viscosity grade of industrial lubricants is regulated here in JIS K 2001 (Table 20-4).

 

The correct viscosity is essential for a lubricant to work properly and prevent rust and corrosion. This is especially true for gears and roller bearings. A correct viscosity will help remove wear particles from the rolling contact areas, reduce metal-to-metal friction, increase bearing seal bonds, and disperse heat and moisture to help prevent rusting and corrosion.

 

In addition, a correct lubricant will keep the roller bearings separated and help them run at peak efficiency. This will also help to avoid slipping and sliding, which can lead to catastrophic failure of the rolling bearing.

 

This condition is often referred to as roller-contact fatigue (RCF). It is a common problem with gears and other machinery.

 

RCF occurs when there is metal-to-metal friction between the teeth and the roller. This can be caused by the dynamic loads and pitch line speed of gears or by other factors such as the presence of foreign particles in the lubricant.

 

Using a lubricant particle counter can help to detect these early signs of wear in a gear or a roller bearing. This tool is available from Pruftechnik's website. This website teaches you to quickly catch early damage to the gear teeth or roller bearings.

 

A lubricant particle counter can be helpful in determining the appropriate lubricant for a specific application. It can be used to take oil samples from as close to the gearset as possible and then analyzed for a variety of different wear particles that could indicate early damage.

 

One of the most important parts of any rotating machine is a roller bearing. The job of the roller bearing is to reduce rotational friction to support radial and axial loads. When the bearing becomes damaged, the machinery will stop operating and can result in severe downtime.

 

When the rollers are lubricated they create a hydrodynamic film that separates them from each other, as simple hydrodynamic theory would suggest. This film varies in thickness, inversely with the load, and proportionally with the speed as the rollers rotate.
For more details on gear and roller systems lubrication, click here: https://en.wikipedia.org/wiki/Gear