Silicon carbide bushings are accessories used outside mechanical parts to achieve sealing, wear protection, etc. They refer to rings that function as gaskets. Let’s introduce to you the key technologies of silicon carbide bushings.
1. The adapter sleeve taper angle difference must be good. The national standard is represented by △D1mp-△d3mp. The tolerance of different size segments is from +0.018-0.09. The upper deviation requires that the adapter sleeve taper angle difference can only be large but not small, that is, the big end. When in contact, there may be a slight gap at the small end of the taper. If the taper hole does not match well, the matching spherical roller bearing will cause a single row of rollers to be stressed, resulting in unstable operation, large vibration, loud noise, and easy loosening. The service life of the bearing will be affected. The cone angle difference of short, high-precision adapter sleeves should also be ≤0.005, ensuring that the mating contact area is not less than 90%.
2. The radial runout of the outer cone surface of the tightening bushing in the inner hole (commonly known as the wall thickness difference) must be highly accurate. Otherwise, the rotating shaft will generate a centripetal force due to a fair amount and cannot run bumpyly. The vibration will be large, the noise will be loud, and the wall will be damaged. A thickness difference of "0" is the ideal form. The size section of large bearings with an inner diameter of 65 or less specified by the national standard is about 1/2 of the maximum clearance of the bearing standard group, which is very similar to the maximum clearance value of C-level precision. Therefore, the adapter sleeve products qualified by the national standard are used in precision-level heavy loads. It is not possible to match the bearings.
3. The straightness of the outer cone surface and the inner hole surface of the adapter sleeve should be good, that is, the shape tolerance should be good, and the cylindricity accuracy should be good. There is no rule in the national standard that any single cross-sectional dimension is qualified within the tolerance range. This is the formation of The linearity of the outer cone surface is not strictly controlled, especially when grinding the outer cone surface for plunge grinding. The linearity of the blank itself is not good, and the grinding wheel is not well corrected, so the linearity of the surface is very poor. Ordinary companies do not have a profiler for inspection, so this The project has serious problems with the products of my country's adapter sleeve industry, which seriously affects the matching accuracy and stability, and also causes poor bearing performance.
4. The thread locking function of the adapter sleeve matched with the bearing is to rotate the locking nut and move axially to squeeze the end face of the inner sleeve of the bearing, so that the taper of the adapter sleeve and the inner hole of the bearing is tightened, thereby achieving the purpose of fixing the bearing on the rotating shaft. Therefore, the thread fit between the bearing nut and the tightening bushing must be good and meet the national standard requirements for ordinary threads.
