Performance of the numerical control lathe spindle and bearing detection method
Performance of the numerical control lathe spindle and bearing the detection method of release time: 2018 - 09 - 06 clicks: 3092 times of CNC lathe spindle is referring to the machine drives the workpiece or tool axis of rotation. Usually consists of main shaft, bearing and transmission parts ( Gear or pulley) Of the main shaft parts. In the machine is mainly used to support transmission parts such as gears, pulleys, transfer movement and torque, such as the machine tool spindle; Some to the clamping workpiece, such as the spindle. In addition to planing machine, broaching machine, such as the main motion to linear motion of the machine tool, most of the machine tool spindle assembly. Motion precision of the spindle assembly and structural stiffness is one of the important factors determine the processing quality and cutting efficiency. Main spindle assembly performance index are measured is the speed rotation precision and rigidity and adaptability. (1) rotation accuracy: the spindle rotates in influencing the direction of the machining accuracy in radial and axial runout ( See the form tolerance) Main shaft and bearing, mainly depends on the manufacturing and assembly quality. (2) the dynamic and static stiffness: mainly depends on the bending stiffness of the spindle, the stiffness and damping of the bearing. (3) the speed adaptive: allows the highest speed and speed range, mainly depends on the structure and lubrication of the bearing, and the cooling conditions. Numerical control lathe long-term use can lead to the main shaft bearing damaged, affect the geometry precision machine tool, to restore precision, needs & other Directional method of assembling & throughout; Implementation of main shaft bearing replacement and assembly. Detection of CNC lathe spindle bearing CNC lathe spindle bearings generally adopts the angular contact ball bearings, micrometer is used to inspect bearing inner diameter and thickness, compared with national standard is in accordance with the requirements. Measuring angular contact ball bearing inner and outer ring thickness difference, adopting lever micrometer ( Dial indicator) , magnetic table, 100 mm long standard block 3 pieces, 1 block marble tablets, 100 mm & times; 100mm× 20 mm parallel block 1. Tablet, three standard block 6 face, parallel to the magnetic table base, block below clean, the standard 120 & deg; Distribution on the tablet, angular contact ball bearing up on top of standard block (top of the Measured angular contact ball bearings to clean, uniform rotation, may be slightly within the raceway sundry) , magnetic table on the parallel block absorption, will leverage on dial gauge head towards the mouth under the angular contact ball bearing outer ring end surface, make the lever micrometer head down 0 chang 4 mm or so, read the dial indicator reading and record. With handle gently push the parallel block together with the magnetic table c2: in a move to the mouth inner ring face under angular contact ball bearing, read the dial indicator reading and record, calculate the difference between two sets of readings X, namely reading large end face low X smaller than reading. Such as the dial gauge head for - in outer end face reading 0 chang 014 mm, inside face reading is 0, this shows that the inner ring end face is lower than outer end face 0 chang 014 mm ( The inner ring end face than outer end face close to the flat surface 0 chang 014 mm) 。 Bearing, in turn, placed the same, will leverage dial gauge upside down in angular contact ball bearing outer ring end face and the upper side header pressure 0 chang 4 mm or so, read the dial indicator reading and record. Then moved to the inner ring end face read the dial indicator reading and record, calculating difference between two sets of readings Y, namely reading large end face Y higher than reading the small face. Such as micrometer head in the reading of the outer end face of 0 chang 014 mm, inside face reading is 0, this suggests that the angular contact ball bearing a flowing within the end 0 chang 014 mm lower than the outer end face. Using the above process in symmetrical four measuring points on the circumference of a circle, measured value is the same as the best, if measured on four points vary by 0 chang 01 ~ 0 chang 02 mm can also be used, if the difference is too big, the bearing is unqualified. And so on for all bearing numerical measure the two groups. Measured after every dish bearing condition, consistent to be equipped with two sets of bearing ( Height difference within 0 chang 02 mm can) Same direction assembly so that we can ensure that the two plate of bearing inner and outer end face all contact no clearance ( This is very critical, see figure 2) 。 To measure the third set of bearing fluently and lower height difference, at this point you can consider the third set bearing and bearing of two before the assembly time interval set size in back to back. Inside the casing and the outer casing and the other is the same thickness depends on the third set of bearing a plate bearing the height difference of back to back. When two sets of back-to-back bearing to 0, both internal and external ring height difference inside and outside the ring thickness are the same. When two plates bearing, back to back with a plate of bearing outer ring inner circle minus tolerance, the thickness of the inner ring thinner than the thickness of the outer ring a tolerance value. When two sets of bearing outer ring back to back is minus tolerance than inner ring, inner ring thickness is thinner than the thickness of the outer ring of two tolerance values. When the bearing outer ring than the inner ring plus tolerance, algorithm and vice. Bearing between inside and outside the circle have combined with pressure, must ensure that the outer ring of inner ring and outer ring, with no clearance between inner ring, and a pre-tightening force, clearance of 0 pretightening chang 03 ~ 0 chang 4 mm ( 240, Yue Yue 340). 150 bearing pre-tightening force, less than Yue clearance of 0 02 mm.