TRAITS OF A GOOD GEAR OIL*
LOW VISCOSITY. As the lubricant travels through the filter system, contaminants, (which may originate outside the system or result from inside wear) should be removed. Slow-moving, highly viscous lubricants can be difficult to filter. They can cause pressure at the filter to increase. If sufficiently high, it will trigger a system bypass and allow contaminant-laden lubricant to circumvent the filters. Less viscous lubricants flow more easily through the filtration system where contaminants are effectively removed. This reduces the likelihood of machinery damage and increases equipment life.
Another benefit of using a lower viscosity gear oil is that it may not need to be changed as often, resulting in less costly downtime. Industrial gears operating under heavy loads require extreme-pressure protection for gear components, but mainstream industrial gear oils do not always provide high extreme-pressure performance at low viscosity grades. This means that not just any low viscosity fluid will perform well.
DURABILITY. Industrial gear oils formulated for extended durability keep gears operating correctly and protect equipment by prolonging life, minimizing downtime, maximizing productivity and reducing maintenance costs.
DEMULSIBILITY. Water can get into the system (especially the reservoir) in many ways, leading to corrosion and compromised performance. Because of this, gear oil must be formulated to quickly separate water through the range of temperatures found in industrial gearboxes. This will extend the life of the oil and the machinery.
DEDICATED FOR INDUSTRIAL USE. There are two types of industrial gear lubricants. The first, so-called universal gear oils, are formulated so they can also be used in automotive gear applications. Universal fluids (formulated for automotive and industrial use) may contain components that are unnecessary for and/or harmful to industrial gears. On the other hand, they may omit components that are critical to industrial use (demulsibility additives). Gear oils for industrial applications are formulated with additives necessary for protection and optimal functioning.
SMART ADDITIVES. Conventional additives that improve extreme-pressure properties in gear oil are often susceptible to thermal instability, which encourages sludge. But additives are available that improve thermal stability, discourage sludge formation and provide extreme-pressure protection. This allows high extreme-pressure performance and cleanliness throughout the full range of viscosities.
*Based on five factors cited by Lubrizol product manager Tim Cooper