The structural design of the shaft in the cylindrical roller bearing must be carried out after preliminary strength calculations, the small diameter of the shaft and the size of the parts on the shaft are known. The main steps are: determine the assembly plan of the parts on the shaft in the cylindrical roller bearing: The structure of the shaft is related to the position of the parts on the shaft and which end of the shaft is assembled from. Determine the positioning method of the parts on the shaft: According to the specific working conditions, select the axial and circumferential positioning methods of the parts on the shaft. Axial positioning in cylindrical roller bearings is usually a combination of shoulders or collars with sleeves, nuts, retaining rings, etc., and circumferential positioning mostly uses flat keys, splines or interference fit connections.

Determine the diameter of each shaft section: The structural design of the shaft is carried out on the basis of preliminary estimation of the shaft diameter. In order to locate the parts on the shaft, the shaft in the cylindrical roller bearing is usually designed as a stepped shaft. According to different functions, shaft shoulders can be divided into positioning shoulders and process shoulders (designed for ease of assembly). The height of the positioning shoulders has certain requirements; the height of the process shoulders is smaller, and there is nothing special. Require. Therefore, the determination of the diameter is based on the strength calculation, and the final diameter of each shaft section is determined according to the requirements of axial positioning.

Determine the length of each shaft section: mainly based on factors such as the length of the hub hole on the shaft of the cylindrical roller bearing, the position, the width of the bearing, and the thickness of the bearing end cover. The so-called manufacturability of the shaft structure of the cylindrical roller bearing means that the structure of the shaft of the cylindrical roller bearing should be as simple as possible, with good processing and assembly manufacturability, in order to reduce labor, increase labor productivity and reduce stress concentration. Improve the fatigue strength of the shaft.

(1) In order to reduce the time for tool change and workpiece clamping during processing, all fillet radii, chamfer dimensions, and undercut widths on the same shaft should be as uniform as possible; when there are more than two keyways on the shaft, they should be placed The shaft is on the same generatrix, so that it can be machined after one clamping.

(2) When a certain shaft section of the cylindrical roller bearing shaft needs to be ground, there should be an overtravel groove of the grinding wheel; when the thread needs to be cut, an undercut groove should be left.

(3) To remove burrs and facilitate assembly, the shaft end should be chamfered.

(4) When the interference fit connection is adopted, the fitting end of the fitting shaft section is often processed into a guide cone surface. If there is an additional key connection, the length of the keyway should be extended to the tapered surface to facilitate the centering of the keyway and the key on the hub.

(5) If it is necessary to install two interference fit parts from one end of the shaft, the diameters of the two mating shaft sections on the shaft of the cylindrical roller bearing should not be equal, otherwise after one part is pressed in, the second part will be The mating surface is roughened, which affects the mating.