Drive unit for inspecting nuclear fuel rods

This patent describes a drive unit for use in inspecting nuclear fuel rods. It comprises a housing; a drive motor mounted at the first end of the housing; a spindle directly coupled to the drive motor rotatably mounted on bearings in the housing and having a recess at its end adjacent the second end of the housing; a substantially donut shaped rubber bladder received in the recess and having its longitudinal axis coaxial with that of the spindle whereby the bladder rotates in conjunction with the spindle in response to driving rotation by the drive motor; and a flanged port extending radially from the bladder and in fluid communication with the interior thereof whereby the bladder may be pressurized, causing radial internal expansion thereof for gripping a fuel rod