Shaft Collars
The Shaft Collars is a cylindrical mechanical part that is placed on the rotating shaft and can be an integral part of the sliding bearing.
In general, the Shaft Collars and the bearing housing have an interference in shape and a clearance fit with the shaft.

1, concept

A sleeve made of a full cylindrical protective shaft is called a Shaft Collar.
The bearing shell is the same as the outer ring of the sliding bearing, the sleeve is integral and the contrary 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 standard shaft holders, which are split into full sleeves and 1/2 sleeves.
The main materials of all sorts 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 elements that fix and reduce the coefficient of friction of the strain during mechanical transmission.
The similarity Sprocket 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 rings of the bearing itself. However 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 put through the pressing pressure of the growth sleeve and the composite mechanical push, that may cause its long term deformation, and the diameter may be reduced by 0.1mm~0.3mm. Consequently, the mechanical growth and the strength of the force are not up to the required tightening push, and a coordinating gap occurs between the sleeve and the primary shaft, causing wear of the sleeve.

4, the latest repair method

Because of the large value of components, the traditional repair strategies are relatively expensive. With the development of advanced systems such as for example polymer composite materials overseas, some repair methods with quick restoration and low cost are favored. This method has also been released in China, and the more mature Fushun Blue 2211F materials. The material gets the comprehensive mechanical properties, superb adhesion and heat and corrosion resistance which can’t be compared with the traditional method. The utmost compressive strength can reach 1200kg/cm2, and the adhesion (overlap shear tensile check) is certainly 225kg on the smooth steel surface. /cm2. Consequently, 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 large level, which saves a lot of manpower and materials resources for the enterprise.