Shaft Collars
The Shaft Collars is a cylindrical mechanical part that is placed on the rotating shaft and is an integral area 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 equivalent to the outer ring of the sliding bearing, the sleeve is integral and the opposite shaft is moving, while the bearing shell is segmented and the opposite shaft is rotating.
In the LEGOMindstorms series and BioTransRoSys group of robot components, the sleeves are particularly known as the silver-gray LEGO standard shaft holders, which are divided into full sleeves and 1/2 sleeves.
The primary materials of all sorts of Shaft Collarss on the main 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 (known as “shafts” in Japan) are components that fix and reduce the Water Ring Vacuum Pump coefficient of friction of the strain during mechanical transmission.
The similarity between your Shaft Collars and the bearing is that both bear the strain of the shaft.
The difference between the two is that the sleeve is of integral structure, and the relative movement between the shaft and the sleeve is when rotating; and the bearing is split, and the rotation is the relative motion of the internal and outer bands of the bearing itself. But in essence, the Shaft Collars is truly a sort of sliding bearing.

3, common factors behind damage

During the long-term operation of the Shaft Collars, the surface of the journal is put through the pressing push of the growth sleeve and the composite mechanical push, which will cause its permanent deformation, and the size may be reduced by 0.1mm~0.3mm. As a result, the mechanical growth and the strength of the force are not up to the required tightening force, and a complementing gap occurs between your sleeve and the main shaft, causing put on of the sleeve.

4, the most recent repair method

Due to the large worth of components, the traditional repair strategies are relatively expensive. With the advancement of advanced systems such as polymer composite materials abroad, some repair strategies with quick repair and low cost are favored. This technique has also been introduced in China, and the older Fushun Blue 2211F components. The material gets 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 certainly 225kg on the smooth steel surface. /cm2. Consequently, it can be utilized for the fix of wear of huge Shaft Collars parts. Moreover, the equipment does not need to become disassembled in a big scale, which saves a lot of manpower and material resources for the enterprise.