Gearbox, Mixer Drive… What’s the Difference?
Posted by: David Geesaman
While a mixer drive is also a gearbox, a gearbox is not necessarily a mixer drive – and the difference can be costly if you get the wrong one.
The basic difference is that a mixer drive is designed for one specific purpose – mixing. Knowing what to look for in the design will help you know what you’re getting. A few things to consider:
- Size matters. On average a mixer drive should be heavier than its commercial gearbox counterpart. A mixer drive with a heavy duty output shaft is better suited to handle unbalanced hydraulic loads inherent in mixing applications.
- How dry is the drywell? Another element is a drywell, which ensures no oil leakage. A drywell should have no moving parts so there is no need for maintenance and no risk of failure. Commercial gearboxes are usually equipped with lip seals which fail in one to two years, causing severe oil leaks.
- Lubrication. The manner of lubrication is an area of critical difference. Commercial gearboxes typically use an oil pump. Over time oil pumps are likely to fail, resulting in damage to gears and bearings. A mixer drive is designed with an oil bath or oil splash lubrication, providing more reliable lubrication and reducing maintenance requirements to monitor a forced lubrication package.
- Bearings. Tapered roller bearings or spherical roller bearings are best for handling thrust loads typical for mixing applications. Some commercial gearboxes use ball bearings, which do not handle the thrust loads nearly as well.
About the author: Mr. Geesaman has been engineering rotating equipment for 8 years and with Philadelphia Mixing Solutions for 4 years. He holds a Bachelors degree in Mechanical Engineering.
Tags: bearings, gearbox, lubrication