Shaft Collars
The Shaft Collars is a cylindrical mechanical part that's positioned on the rotating shaft and is an integral area of the sliding bearing.
Generally, the Shaft Collars and the bearing casing have an interference fit and a China Air Compressor clearance fit with the shaft.
1, concept
A sleeve made of a complete cylindrical protective shaft is called a Shaft Collar.
The bearing shell is equivalent to the external 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 group 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 main materials of all types of Shaft Collarss on the major 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 (known as "shafts" in Japan) are components that fix and reduce 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 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 certainly split, and the rotation may be the relative movement of the inner and outer bands of the bearing itself. But in essence, the Shaft Collars is actually a sort of sliding bearing.
3, common causes of damage
During the long-term procedure of the Shaft Collars, the top of journal is put through the pressing drive of the growth sleeve and the composite mechanical power, that will cause its long lasting deformation, and the diameter could be reduced by 0.1mm~0.3mm. Because of this, the mechanical expansion and the effectiveness of the force aren't up to the mandatory tightening pressure, and a complementing gap occurs between the sleeve and the main shaft, causing use of the sleeve.
4, the most recent repair method
Due to the large worth of components, the original repair methods are relatively expensive. With the development of advanced technology such as for example polymer composite materials overseas, 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 materials. The material gets the extensive mechanical properties, excellent adhesion and heat range and corrosion level of resistance which can't be compared with the traditional method. The maximum compressive 
strength can reach 1200kg/cm2, and the adhesion (overlap shear tensile test) is definitely 225kg on the smooth steel surface area. /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 large level, which saves a lot of manpower and materials resources for the enterprise.