Small drilling and milling machines are widely used in daily production and processing. Small drilling and milling machines are machine tools that integrate drilling, milling, boring and grinding. The small drilling and milling machine produced by our Shandong Highland Machine Tool Co., Ltd. has the advantages of low noise and wide speed range. It adopts belt drive, the spindle box can be raised and lowered, and it can also rotate around the column to expand the processing range. There is a very important component in the small drilling and milling machine-rolling bearing, which is an important component that causes and reduces friction on the small drilling and milling machine equipment.
In processing and production, in order to meet the smooth processing of small drilling and milling machines, certain conditions must be met when rolling bearings are selected.
Selection of rolling bearings for small drilling and milling machines. The load of the screw bearing is mainly the axial load. The radial load generally has no external load except the weight of the screw and the table. The requirements for the screw bearing are mainly the axial accuracy and rigidity. High, the friction torque should be small. Therefore, when selecting, meet the following requirements:
(1) The contact angle is large, the number of steel balls is large, the bearing capacity is high, and the rigidity is high.
(2) It can bear both axial load and radial load, and the supporting structure can be simplified.
(3) The starting friction torque of the bearing is small, which reduces the driving power of the screw pair and improves the sensitivity of the feed system.
In addition, in order to ensure the selection of suitable rolling bearings for small drilling and milling machines, there are also certain requirements for the basic dimensions of the rolling bearings. The angular contact ball bearings of model 7000C are selected. The basic dimensions are: inner diameter d=10mm, outer diameter D=26mm, width B= 8mm, the basic dynamic load rating Cr=4.29kN, the basic static load rating C0r=2.25kN, the limit speed (oil lubrication) is 28000r/min.
Finally, when users choose rolling bearings, in order to ensure that the axial force of the vertical feed movement is greater than the other two directions, it is recommended to select thrust bearings that can withstand greater axial force.