Abstract: An endless flexible belt extends around a set of end rollers supported by a frame with the axes of the rollers defining an angle of 90 degrees therebetween, and one of the end rollers is driven by a variable speed electric motor and gear reducer unit. A pair of vertically spaced and non-rotating parallel belt guide tubes have end portions rigidly supported by the frame and extend within the belt at a transverse angle of 45 degrees for changing the direction of the belt travel by 90 degrees. The belt wraps around the tubes and extends between the tubes to the driven roller. Pressurized air is supplied to the tubes, and the air flows outwardly through spaced holes within a high pressure zone on each tube to produce a film of air between the tube and the belt portion extending around the tube. The air films permit circumferential and axial movement of the belt on each tube with minimum friction so that the belt may be driven at a high speed with minimum belt wear.