How to understand the drilling center of the spindle bearing is good?

 1. The spindle of the drilling and tapping center is undoubtedly one of the most important parts, because the efficiency is the most important for the drilling and tapping center, and for the relatively weak rigid machine tool structure, if you want to improve the processing efficiency, you have to "run fast" - that is, improve the spindle speed and displacement speed during processing, so the speed of the drilling and tapping center is usually higher than 12000rpm. 

 2. Usually the bearing of the spindle will choose different types of bearings according to different speed, and the most commonly used spindle speed for the drilling and tapping center is 12000rpm, 18000rpm, 24000rpm. 1) For the spindle below 12000rpm usually uses steel ball bearings, generally only the wind is required to ensure that the bearing will not be burned out due to heat caused by high speed (that is, the spindle is locked), usually only need to install an air-cooled oil cooler. 2) For the spindle above 12000rpm usually need to use ceramic ball bearings, but although ceramic ball bearings are used, but the spindle speed is higher than 18000rpm, there will still be a great difference, the use of grease is completely different, cooling means are also very different. 3) When the speed is higher than 12000rpm and lower than 18000rpm, it is necessary to use an oil cooler equipped with compressor refrigeration to force cooling; When the speed is higher than 18000rpm, it is no longer possible to use the oil cooling method, and it is not possible to use grease for lubrication, and it is necessary to use oil mist lubrication and cooling. Another point to be noted is that for the user, if you only occasionally use the highest speed marked by the machine tool, the general continuous operation shall not exceed 30 minutes, otherwise it will cause bearing damage, if you need to use 4) 12000rpm processing for a long time, please be sure to choose a higher speed, such as 15000rpm spindle is appropriate. Otherwise, it is easy to cause damage to the machine tool, causing losses to the manufacturer and the user