Shaft Collars
The Shaft Chain Collars is a cylindrical mechanical part that’s positioned on the rotating shaft and can be an integral part of the sliding bearing.
In general, the Shaft Collars and the bearing casing have an interference in shape and a clearance match the shaft.

1, concept

A sleeve made of a complete cylindrical protective shaft is named a Shaft Collar.
The bearing shell is the same as the outer ring of the sliding bearing, the sleeve is integral and the opposite shaft is moving, as the bearing shell is segmented and the opposite shaft is rotating.
In the LEGOMindstorms series and BioTransRoSys series of robot components, the sleeves are specifically known as the silver-gray LEGO regular shaft holders, which are split into full sleeves and 1/2 sleeves.
The primary materials of all sorts of Shaft Collarss on the major hydropower generating units are ZQAl9-4, ZQSn10-1 and ZQSn6-6-3.

2, the difference

A Shaft Collars is a sleeve on a propeller shaft or a yoke shaft. Bearings (referred to as “shafts” in Japan) are parts that fix and decrease the coefficient of friction of the load during mechanical transmission.
The similarity between your Shaft Collars and the bearing is that both bear the strain of the shaft.
The difference between your two is that the sleeve is of integral structure, and the relative motion between your shaft and the sleeve is when rotating; and the bearing is certainly split, and the rotation is the relative movement of the internal and outer rings of the bearing itself. But in essence, the Shaft Collars is truly a kind of sliding bearing.

3, common factors behind damage

During the long-term operation of the Shaft Collars, the top of journal is subjected to the pressing push of the growth sleeve and the composite mechanical power, which will cause its long lasting deformation, and the diameter could be reduced by 0.1mm~0.3mm. As a result, the mechanical expansion and the strength of the force are not up to the mandatory tightening drive, and a matching gap occurs between the sleeve and the main shaft, causing use of the sleeve.

4, the most recent repair method

Due to the large value of components, the original repair strategies are relatively expensive. With the development of advanced systems such as polymer composite materials overseas, some repair strategies with quick fix and low priced are favored. This technique has also been released in China, and the older Fushun Blue 2211F components. The material has the extensive mechanical properties, exceptional adhesion and temperature and corrosion level of resistance which can’t be compared with the original method. The maximum compressive power can reach 1200kg/cm2, and the adhesion (overlap shear tensile test) is usually 225kg on the smooth steel surface area. /cm2. As a result, it can be used for the fix of wear of huge Shaft Collars parts. Moreover, the equipment does not need to end up being disassembled in a sizable level, which saves a whole lot of manpower and material resources for the enterprise.