What are the common faults when operating a gantry machining center?

1. Spindle assembly failure

The spindle is the core component of the machining center machine tool. The accuracy of most machining surfaces is related to the spindle, so the quality of the spindle is very important. Due to the use of speed regulating motors, the structure of the CNC machine tool spindle box is relatively simple, and the parts that are prone to failure are the automatic clamping mechanism and automatic speed regulating device inside the spindle. In order to ensure that the tool clamp does not loosen during work or when the power is turned off, the automatic clamping device uses spring clamping.

If the tool cannot be loosened after clamping, consider adjusting the pressure of the loosened hydraulic cylinder and the stroke switch device or adjusting the nut on the disc spring to reduce the spring compression. In addition, the problems of spindle heating and spindle box noise cannot be ignored. At this time, the main considerations are cleaning the spindle box, adjusting the amount of lubricating oil, ensuring the cleanliness of the spindle box, replacing the spindle bearings, repairing or replacing the spindle box gears, etc.

2. Feed transmission chain failure

In the feed drive system of the machining center, ball screw pairs, hydrostatic nut pairs, rolling guides, hydrostatic guides, and plastic guides are usually used. Therefore, the feed transmission chain fails, mainly manifested as a decrease in motion quality. For example: mechanical parts do not move to the specified position, operation is interrupted, positioning accuracy is reduced, clearance increases, creeping, bearing noise increases (after collision), etc.

(1) Improve transmission accuracy, adjust the preload of each movement pair, adjust the loose connecting rod, eliminate transmission clearance, shorten the transmission chain, and set a reduction gear on the transmission chain to improve transmission accuracy.

(2) Improve motion accuracy. Under the premise of meeting the strength and stiffness of the components, reduce the mass of the moving parts as much as possible, reduce the diameter and mass of the rotating parts, thereby reducing the inertia of the moving parts and improving motion accuracy.