AC & DC Gear Motor Lubrication Best Practices

Sinotech    May 20, 2014

AC & DC Gear MotorsThere is truth behind the notion of a well-oiled machine. The life of a lubricant in AC or DC gear motors is directly related to its temperature. As lubrication minimizes friction within a gear motor, it lowers the generation of heat. For every 25-degree decrease in a gear motor’s temperature, the lubricant’s life doubles. Consider the following tips to keep your machinery running at an optimal level.


Oil is the best type of lubrication to use when a gear motor is 1/10 horsepower or larger, like those used in industrial applications. It’s optimal because it’s free-flowing and constantly present on the surfaces of the teeth as the motor runs. The best lubrication for large gear motors comes in the form of a circulating fluid lubrication system, which can increase its service life by up to 10,000 hours or more. The oil should form a continuous and consistent film at the load zone.

Parallel shaft gear motors with helical or spur gearing generally use mineral-based oils with extreme-pressure (EP) additives.

To decrease journal or gear shaft wear on fractional HP gear motors, use hydraulic-type oils.

Look for oil with a high viscosity level and additives that prevents oxidation for right-angle gear motors that have sliding-contact gearing.


Grease is the best type of lubricant to use for smaller AC or DC gear motors that are ¼ horsepower or less. While grease doesn’t offer as much consistent lubrication as oil, it doesn’t leak as much, is simple to apply and doesn’t require visual lubrication level inspections.

The type of lubrication to use on a DC or AC gear motor depends on factors such as horsepower, application and ambient temperature. Looking for high-performing AC and DC gear motors? View Sinotech’s AC and DC gear motor catalog, request a quote and more.

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