Robot system and method for driving robot

A robot system comprising a robot, the robot comprising:

• a movable moving part;
• an upper body part disposed above the moving part;
• and
• a driving mechanism for tilting the upper body part and moving a lower end of the upper body part in a direction in which the upper body part is tilted, the driving mechanism being a spherical link mechanism for moving a support surface supporting the upper body part from below along a spherical surface, wherein:
• the spherical link mechanism includes a pair of links,
• a first link of the pair of links has (i) a first base end mounted for rotation about a first rotational center of the first base end and (ii) a tip end,
• a second link of the pair of links has (i) a second base end mounted for rotation about a second rotational center of the second base end, the second base end being rotatably connected to the tip end of the first link,
• the spherical link mechanism includes a support base including the support surface, the support base being rotatably connected to a connecting part connected to the second link, wherein
• the connecting part is a speed reducer configured to lower a rotational speed of the support base relative to the second link of the pair of links to a half of a rotation speed of a third link of another pair of links relative to the second link.