Rover relies on bearings for support and analysis

    Curiosity, NASA’s latest Martian rover, successfully landed on Mars, thanks partially to four sets of Real-Slim thin-section bearings from Kaydon Bearings, Muskegon, Mich. The bearings, which have a seven-inch outer diameter and a six-inch bore, support steering actuators at the Curiosity’s four corners. (One set is located on the left front wheel and is circled in the photo). They relieve some of the load on the actuators, which was critical during landing. The angular-contact bearings have built-in preload. The races and balls are made of 440C stainless steel. The bearings were sent to NASA dry so they could add a space-rated lubricant, one that would not become viscous in extreme cold or evaporate in the thin atmosphere.
    A smaller pair of Real-slim bearings are in the device used to collect rocks samples. (The device is in the upper right circle on the photo.) The device, called a thwack mechanism, keeps 150-micron pores in a sieve clean by giving the sieve an impact shock periodically. The sieve ensures only powdered rocks and soil get sent to analysis. NASA engineers decided that thin-section bearing would be the best way to handle the shock loads in the small space available and designed the assembly around them.

Resources
Kaydon Bearings, www.kaydonbearings.com