Manual electric spindle maintenance for machining center

ForManual electric spindle maintenance for machining centerThe steps I learned from researching include: replacing bearings, grinding taper holes, and dynamic balancing. The common mechanical spindles for machining centers are BT30, BT40, and BT50. Among them, BT40 and BT30 are commonly compared in the market. Below is a brief introduction to how to disassemble and assemble the BT40 spindle.

1、 Pre disassembly inspection:

Check the traces left by the fault and investigate the cause of bearing failure. Check for any impact marks on the taper hole and front end cover. Check for looseness in the rear end couplings and connecting components. If these hidden dangers are not eliminated, even if the spindle of the machining center is repaired well, it will still be easily damaged in the later stage. Create a spindle repair form to record all hidden dangers and spindle model information.

2、 Spindle disassembly:

Mark with a marker pen before disassembly, especially for some covers and pulleys that are prone to misalignment during installation. If the parts are not marked, subsequent misalignment during installation will have a significant impact on the dynamic balance in the later stage. Misalignment during the installation of the puller mechanism will cause the spindle to be unable to be replaced properly after being installed on the machine tool. Before disassembly, be sure to take photos of all parts.

　　Manual electric spindle maintenance for machining center：

1. A device to prevent the pull rod from protruding from the back, which serves to pre press the pull rod and has a dynamic balance screw hole on the outer circle.

2. The pulley tensioning sleeve device is preloaded and tightened through the taper inside. Generally, this structure has good concentricity. When disassembling, use a pin puller to pull the end face outward.

3. The device for preloading the inner ring of the spindle bearing also serves the purpose of dust prevention. It also has dynamic balance screw holes on it, which are used to transmit force preloading and fastening through the end face of the pulley.

3、 Dismantling bearings:

After removing the bearing and core shaft from the main shaft housing, if the interference fit between the inner ring of the bearing and the outer ring of the core shaft is not very large, you can gently vibrate the rear end face of the main shaft on a wooden board or aluminum copper plate to gently shake the bearing out; If the bearing is difficult to disassemble due to burning, it can be pulled, but attention should be paid to pulling the inner ring of the bearing as much as possible; If it is really impossible to pull the inner ring of the bearing, you can gently pull the outer ring until there is a certain gap in the bearing, and then use the bearing puller to pull the inner ring of the bearing (be sure to pull the inner ring again), otherwise the bearing is prone to scattering.

4、 Spindle installation:

First, clean all the parts thoroughly, usually using alcohol and a 3m scouring pad for cleaning. After cleaning, wipe them clean with dust-free paper and wrap them up.

Then measure the bearing spacer, bearing height, and bearing cover with a high-precision height gauge. The main purpose is to calculate the preload of the outer ring of the bearing and check the flatness of the bearing spacer and cover. If there is a slight error, a piece of fine sandpaper can be placed on a marble platform and manually ground lightly. Usually, the flatness of the parts is controlled within 3um. The preloading amount of the outer ring of the bearing can refer to the bearing information.

　　Manual electric spindle maintenance for machining centerThe project includes: replacement of spindle bearings, spindle claws, spindle pull rods, replacement of spindle spring discs, grinding of spindle taper holes, spindle dynamic balancing, and rewinding of electric spindle coils.