Shaft Collars
The Shaft Collars is a cylindrical mechanical part that’s placed on the rotating shaft and can be an integral area of the sliding bearing.
In general, the Shaft Collars and the bearing casing have an interference fit and a clearance match the shaft.
1, concept
A sleeve made of a full cylindrical protective shaft is called 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 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 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 elements that fix and reduce the coefficient of friction of the strain during mechanical transmission.
The similarity between the 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 motion between your shaft and the sleeve is when rotating; and the bearing is 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 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 drive of the expansion sleeve and the composite mechanical pressure, that may cause its permanent deformation, and the size may be reduced by 0.1mm~0.3mm. Because of this, the mechanical growth and the strength of the force are not up to the mandatory tightening push, and a matching gap occurs between your sleeve and the primary 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 systems such as polymer composite materials abroad, some repair methods with quick repair and low priced are favored. This Pulley method has also been launched in China, and the more mature Fushun Blue 2211F components. The material gets the comprehensive mechanical properties, superb adhesion and heat range and corrosion resistance which can’t be compared with the traditional method. The maximum compressive power can reach 1200kg/cm2, and the adhesion (overlap shear tensile check) is normally 225kg on the smooth steel surface. /cm2. Therefore, it can be used for the fix of wear of large Shaft Collars parts. Moreover, the equipment doesn’t need to be disassembled in a large level, which saves a whole lot of manpower and materials resources for the business.
