Analysis on the Arrangement of Two-support Spindle Rolling Bearings on Five-faced Gantry Milling Machine

Reasonable arrangement of the main shaft rolling bearing of the five-planer milling machine, the configuration of the two-support main shaft bearings The configuration of the two-support main shaft bearings, including the selection, combination, and arrangement of the main shaft bearings. Mainly based on the design of the spindle components in the speed, load capacity, stiffness and accuracy requirements. Gives a common two-support spindle bearing arrangement.

The following general principles should be observed when determining the bearing configuration of the two bearing spindles:

1) The requirements for adapting stiffness and load-carrying capacity of a five-plane gantry milling machine should first meet the required stiffness and load-carrying capacity. When the radial load is large, the bearing configuration can be used. When the radial load is small, the configuration can be used. In addition, double row bearings have higher stiffness than single row. Since increasing the stiffness of the front support can effectively increase the stiffness of the main shaft component, the bearings that increase the stiffness should be disposed on the front support.

2) The five-plane gantry milling machine adapts to the rotational speed requirements. The maximum permissible rotational speed for bearings of different models, specifications and accuracy classes is different. Under the same conditions, the point contact is higher than the line contact; the cylindrical roller is higher than the cone roller. Therefore, the bearing configuration should be selected in consideration of the requirements on the stiffness and rotation speed of the spindle component.

3) The requirements for the accuracy of the five-faced gantry milling machine The axial component of the spindle bearing the thrust of the axial bearing configuration directly affects the axial position accuracy of the spindle. Commonly used three types of configuration work performance and application range. When the front end is positioned, the main shaft is heated and deformed to extend backwards, the machining accuracy is not changed, but the front support structure is complicated, and it is inconvenient to adjust the bearing clearance, and the amount of heat generated at the front support is larger. The characteristics of the back-end positioning are opposite to the above. When the two ends are positioned, the axial clearance of the bearing changes greatly when the main shaft is heated.