The Mars Science Laboratory rover Curiosity will have to endure an extremely harsh environment, including temperatures ranging from -90 to 0°C in the Gale Crater, and hurricanes with top speeds of 140km per hour whirling around huge amounts of sand. The bearings used on the vehicle therefore needed to be robust enough to not fail or present any problems for the NASA control centre back on Earth.
To cope with the demands, Barden bearings are used. Several are positioned in the turret at the end of the robotic arm, on the drill bit assembly and in the vibration motor, an integral part of the CHIMRA tool (Collection and Handling for In-situ Martian Rock Analysis).
The turret on the robotic arm holds two scientific instruments and three other devices. The arm places and holds turret-mounted tools on rock and soil targets and manipulates the sample-processing mechanisms on the turret. It is strong enough to hold the 33kg turret at full extension of the arm and, with the arm extended straight forward, the centre of the turret is 1.9m from the front of the rover body. The diameter of the turret, including the tools mounted on it, is almost 60cm.
The bearings on the drill bit assembly are angular contact (15° contact angle) versions manufactured to ABEC 7 standards, with SAE 52100 steel rings and balls and Phenolic ball retainers. In addition, the bearings on the vibration motor were also manufactured to ABEC 7 standards, with 440C rings, Phenolic ball retainer and were lightly pre-loaded.
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