- ① Rotation accuracy: The radial and axial runout (see shape and position tolerance) under no-load and low-speed conditions mainly depends on the manufacturing and assembly quality of the main shaft and bearings.
- ② Dynamic and static stiffness: mainly determined by the bending stiffness of the main shaft, the stiffness and damping of the bearing. Insufficient static rigidity of the spindle will have a direct impact on machining accuracy and machine performance.
- ③ Speed adaptability: The maximum allowable speed and speed range are mainly determined by the structure and lubrication of the bearing, as well as the heat dissipation conditions.