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 housing have an interference fit and a clearance fit with 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 contrary 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 specifically referred to as the silver-gray LEGO standard shaft holders, which are divided into full sleeves and 1/2 sleeves.
The main materials of all sorts of Shaft Collarss on the main hydropower producing 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 strain during mechanical transmission.
The similarity between the Shaft Collars and the bearing is that both bear the load of the shaft.
The difference between the two is that the sleeve is of integral structure, and the relative movement between your shaft and the sleeve is when rotating; and the bearing is certainly split, and the rotation may be the relative movement of the inner and outer rings of the bearing itself. But in essence, the Shaft Collars is Oil less Air Compressors actually a kind of sliding bearing.

3, common causes of damage

During the long-term operation of the Shaft Collars, the top of journal is subjected to the pressing power of the growth sleeve and the composite mechanical pressure, that may cause its long term deformation, and the diameter could be reduced by 0.1mm~0.3mm. As a result, the mechanical growth and the effectiveness of the force are not up to the mandatory tightening pressure, and a matching gap occurs between the sleeve and the main shaft, causing put on of the sleeve.

4, the latest repair method

Due to the large worth of components, the traditional repair strategies are relatively expensive. With the development of advanced technologies such as polymer composite materials abroad, some repair strategies with quick repair and low cost are favored. This technique has also been released in China, and the more mature Fushun Blue 2211F materials. The material gets the extensive mechanical properties, exceptional adhesion and heat and corrosion resistance which cannot be compared with the traditional method. The maximum compressive strength can reach 1200kg/cm2, and the adhesion (overlap shear tensile test) is usually 225kg on the smooth steel surface area. /cm2. Therefore, it can be used for the restoration of wear of large Shaft Collars parts. Moreover, the equipment does not need to become disassembled in a large level, which saves a whole lot of manpower and material resources for the enterprise.