How to solve CNC Engraving Machine bearing failure
The engraving machine disassembles the front and rear end covers and the front and rear nuts.
Push out the main shaft, rear bearing seat, linear bearing and other accessories from the front end of the shaft.
Front and rear bearing washers.
The front and rear bearings of the motorized spindle are in series.
According to the axial force direction of the bearing, you can support the inner sleeve and press down the outer sleeve with hand force. The force is roughly the same as the preload of the spring on the bearing.And adjust the clearance of the washer. There are two methods: one is to replace the bearing and the upper and lower position of the bearing. The other is to grind the height of the washer. Grind the washer with the 8-shaped grinding method, and rotate the position of the washer at the same time.Ensure that the parallel difference of the washer is within 2um. And adjust the clearance of the washer to make the inner and outer washer bear uniform force. And then the preload of the two sets of bearings is uniform.
If the matched bearing is selected, the size difference between the inner and outer washers shall be within 2mm.
The parallel difference between the washers shall be within 2mm. And the bearings shall be installed in pairs according to the V-shaped mark on the outer diameter.
Long term use of preload spring will lead to fatigue and reduce elasticity. The preload of the bearing is reduced, which affects the accuracy and life of the motorized spindle. At this time, a new spring of the same specification should be replaced.
If the washer is not equipped properly, the load of one set of two sets of bearings is small, and the load of the other set is too large, the bearing force is not uniform, which will heat up and seriously affect the service life. When the inner and outer washers bear the same force, the preload load of two sets of bearings is uniform.
Clean the bearing, the outer sleeve slope downward (or the inner sleeve slope upward) rotating cleaning (in the clean gasoline), the bearing should be cleaned more than twice, pay attention to the cleaning of the bearing, bearing up and down position can not be wrong.
Before installing the bearing, the bearing, the inner hole of the shaft shell and the main shaft should be lubricated with engine oil (special lubricating oil for motorized spindle). One is to facilitate the installation, and the other is to ensure the lubrication of the bearing at the initial stage of motorized spindle startup.
Install the rear end bearing first, tighten the nut, fix the spring on the bearing seat with grease, and keep the spring gland in the wrong position.
Assemble the front-end bearing, fix the front-end cover and pre press the bearing sleeve. (the special sleeve shall be used for assembling the bearing, and the sleeve shall be machined with nylon rod, and the shape is as follows: D is less than the outer diameter of the bearing, D is greater than the inner diameter of the bearing).
Tighten the front nut, install the front and rear end covers, and pay attention to the position of the air inlet when installing the rear end cover. The sealing rings of the air inlet, water inlet and water outlet shall be intact and placed correctly.
After the front and rear bearings are installed, push the spindle forward from the rear end of the motorized spindle and the linear bearing at the same time.
How to maintain the bearing of engraving machine?
The first reason is the quality of the engraving machine spindle. The quality of the spindle itself is not up to standard, resulting in the damage of the bearing. The bearing used is of poor quality. When the main shaft of the engraving machine runs at high speed, its service life becomes shorter and it is easy to damage.
The second reason is that the cooling system of the carving spindle has no consequences. Engraving machine spindle water cooling has water circulation system, if the temporary water circulation is not good, perhaps forget the boiling water circulation, a long time, there will be thermal effect, resulting in increased friction, the formation of the bearing damage.
The third reason has something to do with the detailed operation of the engraving machine. Some customers start engraving before the rotational speed of the main shaft has reached. It easily leads to the damage of the bearing. Some customers do