Abstract: High speed bearing has high demand in speed of revolution and flexibility, and its usage performance is usually influenced by improper assembly methods.In order to solve the problem, this new assembly die was designed. Usage methods and design points were also expounded. It has good effectiveness after putting into production.
Key words: high speed bearing; assembly die; flexibility of revolution; ball-placing sleeve; locating seat
1 Introduction The 7000CETA series of angular contact ball bearings are widely used on high precision machine tool spindles with a contact angle of 15°. Because it can withstand both radial and one-way axial combined loads, it can also withstand pure axial loads. Under the action of axial preload, the radial clearance can be eliminated, which relatively improves the rotation precision of the bearing, minimizes the radial and axial runout of the main shaft, and the product is in short supply. Due to the higher limit speed, the outer guide cage is used and the inner ring has a lock. In view of this structural feature and the small size of the bearing product, it is difficult to assemble, the ball of the steel ball is easily scratched, and the rotation flexibility and various precisions of the product are damaged. Therefore, the improved assembly method must have a reliable set. Craft equipment.
2 Previous assembly methods First, the bearing needs to be heated to about 130 °C when the bearing is assembled. At the same time, the steel ball is glued to the pocket of the cage with yellow dry oil and placed on the table with the inner sleeve. The ring is pressed in quickly, then the bearing is placed in the gasoline and washed repeatedly until the yellow dry oil is completely washed away. This method is very difficult to clean, and if the technique is slow during the assembly process, the ferrule will quickly cool down, and then it will not fit in. The steel ball and the channel will be slightly damaged, which will affect the flexibility of rotation and other. Rotation accuracy and service life are also shortened. For the above situation, a set of assembly molds has been designed, the structure of which is shown in Figure 1. The left part of the center line of the figure is the front section of the bearing sleeve, and the right part is the rear section of the bearing sleeve.
3 How to use the assembly mold First, put the inner ring and the cage on the positioning seat, and then put a set of steel balls. At this time, the steel ball quickly slides from the inclined surface of the ball sleeve into the pocket of the cage, and finally After heating to the outer ring of a certain temperature, a little force is applied, and the steel ball enters the outer ring channel. After the hand is released, the whole set of bearings is lifted by the spring force, and then the next step is taken. Group assembly. Several assembly dies can be made to improve assembly efficiency.