What are the components are castor

Universal wheel, adjust the foot manufacturers 1, shaft sleeve, sleeve is set to the outside of the wheel and axle steel manufacture of rotating parts. Set on the outside of the shaft, steel manufacturing of rotational parts, fixed wheels in stent for wheel bearing rotation. On the shaft sleeve with the axis of rotation. 2, rotating bearing: steering bearings have a number of different models, such as: single bearing: big tracks only a layer of steel ball, commonly known as single row ball bearing. Double bearing: also called double row ball bearing, in two different orbit, double ball. Economical bearing: the stamping forming of bead disc retainer on the ball. Precise bearing: the standard of industrial bearings. 3, the assembly: live a assembly is composed of the legs, shaft and nut. Do not include the wheel, wheel bearings and bushings. , 4 rivets, rivet is floor of local, bolts or rivets for fixed rotating device. Can adjust screw down the bolt type rivet caused by rotation wear loose. 5, single theory