A roller of a support arrangement includes a first unit and a second unit releasably connected to each other via a connection mechanism, the first unit including a first side flange as well as an entire peripheral contact surface of the roller, and the second unit including a second side flange of the roller. In a mounted state, the peripheral contact surface is in contact with a contact portion of a first rail member connected to a rotary platform, and a contact portion of a stationary second rail member, with the two side flanges arranged on opposite sides of the contact surface. A plurality of the rollers is arranged in a vertical space between the first and second rail members.
