The role of steel tube bushings
1. In moving parts, the wear of parts is caused by long-term friction. When the clearance between important officials and holes is worn to a certain extent, parts must be replaced. Therefore, the designer selects the material with low hardness and good wear resistance as the shaft sleeve or bushing in the design, which can reduce the wear of the shaft and seat. When the shaft sleeve or bushing is worn to a certain extent, it can be replaced, which can save the cost of replacing the shaft or seat. Generally speaking, the bushing and valve seat adopt interference fit.
However, the clearance fit with the shaft can only prolong the service life, because wear can not be avoided in any case, and the shaft parts are relatively easy to process. Some new designers don’t like this design and think it increases the manufacturing cost. However, after a period of use, the maintenance still needs such transformation, but the transformation is easy to reduce the accuracy of the equipment, and the reason is very simple. Secondary processing cannot guarantee the position of the seat hole center.
2. In some places with low speed, large radial load and high clearance requirements (such as camshaft), rice is used to replace the rolling bearing (in fact, the shaft sleeve can be regarded as sliding bearing). This material requires low hardness and wear resistance. After grinding and scraping the inner hole of the shaft sleeve, the matching accuracy can be very high. There must be an oil coffin with lubricating oil on the inner wall. Lubrication of shaft sleeve is very important. If it is dry grinding, the shaft and shaft sleeve will quickly. In order to save materials, the wall thickness of the shaft sleeve is designed according to the axial load required by the bearing.
3. Cast copper and bearing alloy materials are generally selected. Shaft sleeves can be divided into open and non open, depending on the needs of the structure. Generally, the shaft sleeve can not bear axial load, or can only bear small axial load. Or thrust bearing. The shaft is usually circular.
4. Bushing sleeve is usually used as lining. The shaft can be in various shapes, as can the bushing. The sleeve can be protected against corrosion with rice to eliminate assembly clearance, etc. And the materials used are the same.
5. The shaft sleeve generally plays the role of axial positioning, and the compressive stress at the end is in contact with parts such as gear bearings, and sometimes the shaft is in contact with sealing rings.
6. It is not suitable for occasions with high speed and large length.
7. The shaft sleeve can be used for different purposes in different occasions. It can be positioned axially to reduce wear and vibration. It can also be used to isolate the shaft from harmful media, so as to prolong the service life and durability of the shaft.