Before proposing a lubricant, checking and evaluating the equipment on-site is an excellent practice. Many manufacturers give lubricant choosing instructions but overlook certain critical factors. The optimum operational dependability of a gearbox is reliant not only on operating materials but also on selecting the appropriate lubricants as essential structural elements during all design phases.
Factors that influence selection include:
- Dimensions, the metal used for teeth, sliding qualities, gear ratio, and open or closed housing.
- Operating conditions: load, vibration, and shock levels, anti-wear, and severe pressure qualities.
- Temperatures of service oil: extremely low, moderate (+20°C and +80°C), hot (+80°C), and extreme (+120°C).
- Machine environment and maintenance requirements
Once these aspects are considered, the following gear oil choosing criteria to become relevant:
- One of the most significant qualities of lubricating lubricants is viscosity.
- Additives – This establishes the category and influences certain operational qualities.
- Base oil – Determines overall operating conditions, gear type, and other variables.
VISCOSITY:
This element is critical since it determines the creation of the lubricating film. It calculates the thickness of the film between interacting surfaces at a given speed and weight. Most viscosity selection techniques make determining the ‘load’ problematic. Because of this, ‘load’ is assumed, and ‘speed’ becomes the deciding factor.
The degree to which the base oil, such as mineral oil, polyalphaolefin, ester, or polyglycol, determines viscosity changes with temperature. In addition, this lubricant uses VI improver additives.
The AGMA (American Gear Manufacturers Association) standard ANSI/AGMA 9005-E02 and ANSI (American National Standards Institute) is one of the most widely used techniques for assessing viscosity. This approach considers the lubricant’s load, viscosity index, and pressure-viscosity coefficient.
ADDITIVES:
While there are numerous variants, gear lubricants are classified into three types: R&O, anti-scuff, and compounded. Operating conditions determine the additives used in gear oils.
R&O is an abbreviation for Rust and Oxidation. Gear oil anti-corrosion capabilities are evaluated independently for corrosion prevention on steel and copper.
Water present owing to leakage or condensation can combine with atmospheric oxygen, resulting in rust on poorly protected steel surfaces. Polar rust inhibitor additives provide a compact and protective, water-repellent coating. Chemical stability, corrosion avoidance, and foam suppression are all areas where R&O gear oils excel.
Anti-scuff, sometimes known as extreme pressure (EP) lubricants, have some performance attributes that outperform R&O oils. Anti-scuff lubricants have specific additives that improve their film strength or load-carrying capabilities in addition to the features described for R&O lubricants.
A compounded lubricant has been combined with synthetic fatty acids to boost its lubricity and film strength. Worm gear applications are the most prevalent use for these gear lubricants.
BASE OIL:
The quality of the base oil is an essential aspect of deciding how well your gear oil performs. Most applications benefit from high-quality mineral base oils. Mineral oils have higher pressure-viscosity coefficients than synthetics, allowing for larger film thickness at operating viscosities. However, there are times when synthetic base oils are desirable. These synthetic oils are the most effective in gear lubricants: polyalphaolefin (PAO), polyglycol (PG), and ester (E).
Conclusion-
Beyond merely picking a product from the maintenance manual’s QPL, other elements must be considered when selecting lubricants for industrial gears. These include product availability, operating conditions, the chosen lubricant brand, and product consolidation initiatives. Proper lubricant selection is the foundation of every successful lubrication program.
With a firm grasp of this, the lubrication engineer may enhance machinery dependability under normal conditions while using lubricant specification as a problem solution in atypical situations.
In most cases, selecting lubricants for industrial gears is straightforward. A proper specification does not need any specific characteristics or values. To choose the optimum option for a specific application, the suitable viscosity, base oil, and lubricant type must be selected, and the necessary performance qualities must be analyzed. Please consult our lubrication experts at GRENVOLubetech for further details on this topic.
