Application of the Month

Gearbox Heated Over Antarctic Assignment
April, 2006

I am sure just about everyone would be a little heated after being assigned to a stint in Antarctica. Working conditions are miserable at best. But that's exactly where a Tandler Spiral Bevel Gearbox was slated to go.

It's well known that a variety of research and monitoring stations are based in Antarctica. It's a unique environment not found in many places on earth. The conditions are extreme. Many machines and instruments require special characteristics to be able to perform their expected duties.

DieQua was presented with a challenge to provide a spiral bevel gearbox to be used as a drive mechanism in a radar dish application. Its task was to drive the main gear reducer that adjusted the position of the radar dish. Proper selection to handle the torque requirements was not difficult. Providing proper lubrication for the gears and bearings in the extremely cold environment was.

While cold temperature oils and greases are available, the low temperatures experienced in this environment presented a test of even the best compounds. The thicker viscosity would increase the input torque required to make the required dish movements. With only intermittent operation, the oil wasn't able to heat up. This required the gearbox to work harder, while reducing the protective properties of the selected lubrication.

To combat this, DieQua created a special design that included installing heaters in the internal oil reservoir of the gearbox. This not only allowed the oil to maintain an acceptable operating temperature, but also helped reduce material tolerance changes, due to temperature variation, which optimized bearing pre-loads to assure long life operation.

The heaters installed were cartridge style, set to activate at ­29 degrees C by thermo switches. Two heaters were included. Although one was deemed sufficient, the second was provided as a back up.