The rehabilitate of precision of main shaft of SCHAUBLIN150 accurate lathe

0006mm left and right sides, of main shaft precision be in high home is infrequent, although my courtyard already owned a large number of advanced machining center and turning center now, xiao Bailin lathe still produced main effect in daily production, finish for what my courtyard produces the job made important contribution. Through the use of 20 the coming year, this model the geometrical precision of equipment and mechanical function had apparent fall, especially main shaft precision drops badly, main shaft radial beats precision already was achieved 0.

02 ～ 0.

03mm left and right sides, cannot get used to the treatment of high accuracy spare parts. To rehabilitate each precision of the machine tool and property, be opposite a few this model the machine tool undertook heavying repair. The key of overhaul depends on repair precision of its main shaft. Before the structure of 2 main shaft and transmission principle 　 begin to maintain, want to know the detailed structure that maintains position through data and examination above all, how be so that decide,maintained and maintain a key. (1) the whirl of the structure of main shaft and transmission 　 main shaft precision is to rely on around bearing of 4 main shaft will assure, journal of main shaft front has 3 accuracy class to be P4 (be equivalent to homebred C class) FAG7014 horn contacts ball bearing (8) will prop up, basically be to make sure main shaft radial beats and axial change moves precision, the whirl of main shaft precision and tigidity rely on these 3 bearing to assure namely. Main shaft rear is ball bearing of contact of horn of FAG7212 of class of a P4, basically be the axes consistency that assures main shaft, main shaft is far carrying 300mm place to beat basically is the precision that relies on it. The drive of main shaft is by 3 photographs double the leather belt that fast communication electric machinery drives main shaft to go up through V of 2 stage speed change leather belt annulus (4) , leather belt annulus drives main shaft directly through gear knot zygote (leather belt annulus and gear union child be an organic whole) ; Or pass slip gear 1 (6) the slip gear that goes up with main shaft 2 (7) clench the teeth, drive main shaft to rotate. Among them leather belt annulus is by FAG7015 of 2 groups of bearing (5) prop up independently, do not have direct contact with main shaft, because its roll is right the each precision impact of main shaft is not big. (2) the characteristic 　 of main shaft box structure of box of this main shaft is simple and compact, the design is reasonable. Inside the lubricating oil that the drive of each spare parts makes by lubricant pump lubricates directly. Run through 20 the coming year, outside dividing main shaft bearing, other part wears away few. Whole casing has wonderful tigidity, make sure main shaft runs from time to tome good precision peace stability. 3 maintenance prepare 　 to want to undertake detecting to the precision of main shaft above all, detect the radial of main shaft beats and axial change is moved, accurate the important basis that detecting is right repair main shaft. Check precision of the surface roughness of spare parts surface that has been machined and treatment. Detect the circularity that machines a spare parts, beat the circularity of the spare parts and main shaft radial again trade off study- - for example main shaft radial is jumpy 0.

005mm, and the circularity of the spare parts is 0.

01mm, the tigidity that shows main shaft is insufficient. Listen to main shaft carefully whether do all sorts of rotate speed have unusual noise and vibration in on any account, if do not have, because wear away,proving main shaft bearing is only and bring about bearing windage to increase and did not damage. Because price of bearing of class of on main shaft 4 P4 is high (of the entrance control in 10 thousand yuan) , main shaft short of is so unusual noise and vibration, can judge main shaft bearing to wear away commonly make windage increases, need readjust to restore its to tighten force to be able to restore precision beforehand only; If main shaft has unusual noise and vibration, proof to bearing of individual main shaft damages, need changes to be damaged bearing, heavy new clothes deserves to adjust precision, and do not need to change entirely. If bearing changes entirely, not only increase repair charge, and precision assures not easily also. The repair 　 of precision of 4 main shaft because the cost of main shaft bearing is very high, according to the discretion of main shaft precision and relevant circumstance, maintenance can continue to use former bearing. If bearing damages, need to change. (1) do not change after bearing rehabilitate main shaft loses a reason to make correct judgement to main shaft precision, if main shaft bearing does not have attaint, just wear away normally, main shaft bearing does not need to change, should choose correctly only match bearing between it is OK to tighten force gasket beforehand, undertake to bearing force is adjusted be tighteninged beforehand. Bearing had tighten force beforehand, can make ball and raceway are increasing negative charge beforehand, eliminated total space and formed certain flexibility to be out of shape, when adscititious load bearing has certain tigidity. Below outside force action, bearing won't make because of adscititious load gap produces between ball and raceway, the whirl that raised main shaft thereby precision, enhanced the tigidity of main shaft, improved service life. Ministry of main shaft diameter is combined by ball bearing of contact of actor of 3 7014P4 stage (part from Zun Duan mark is) of Ⅰ Ⅱ Ⅲ , basically be to make sure radial beats and axial change moves precision. If want readjust of these 3 groups of bearing tighten force beforehand, should choose only it is OK to match the gasket between bearing. Tighten force to adjust computation to be as follows beforehand: Tighten force to be Fao beforehand, rated axial load is Fa. Fa should increase to make A0 of δ A= δ , δ A shows the bearing that Fa causes is out of shape, δ A0 shows bearing Ⅲ is tightening what force Fao falls to be out of shape beforehand. At this moment, criterion bearing Ⅲ complete discharge carries on his shoulder or back, δ A0=0. Have at this moment: Ao of δ of Ao+ of δ of δ A = ... ... ... ... ... ... ... (1) in 　 type: δ A- - bearing Ⅰ , be out of shape below Ⅱ outer load, mm; δ Ao- - bearing Ⅰ , Ⅱ is tightening force beforehand next is out of shape, mm. Bearing Ⅰ and Ⅱ are loaded each outside load and the half that tighten force beforehand, concern according to load and metabolic correspondence, ＝ of reason K() K()+kFao... ... ... ... ... ... (2) in 　 type: Fao- - tighten force beforehand, n; Fa- - rated axial load, n; K- - fixed coefficient. By formula (2) calculate: Fao=0.

24Fa... ... ... ... ... ... ... (3) 　 reckons this main shaft is rated load is 4000N, tighten force to make an appointment with 1000N left and right sides beforehand, check a watch to be able to get: Core gasket should subtract below original measure 0.

02 ～ 0.

03mm (this wants to be decided according to beating to main shaft precision is judged) the parallelism that assures two end panel is in 0.

In 001mm, this should lean on flat handiwork is abrade will achieve dimension precision to ask. (2) change bearing rehabilitate main shaft has unusual noise and vibration like main shaft, be had by surface of treatment spare parts apparent Zhen Wen, can judge main shaft bearing to wear away badly likely reach attaint, need changes bearing. Bearing is impossible to damage at the same time, want certain bearing to damage only, can create afore-mentioned situations, look for the certain bearing of attaint to change so can. For example: It is cervical suppose an attaint among 3 bearing, need to change only intermediate bearing. Changing before bearing, answer new bearing precision to undertake detecting, detect the parallelism of bearing end panel, end panel and radial oneself are jumpy, end panel of bearing of abrade on flat examination has the place that does not have knock against, be in accurate the poor δ that finds out annulus of bearing inside and outside, with 0.

02-0.

The brass skin of 1 does washerbed down the livestock to eliminate the difference of annulus of inside and outside, will assure to be the same as to bearing cooperate to eliminate gap. Again the difference according to annulus of bearing inside and outside will choose deserve to tighten force gasket beforehand the dimension of annulus of 1 inside and outside. No matter main shaft bearing is which attaint, the element of the respect differs in wanting to analyse the position that is in by attaint bearing and each afresh, will think to repair a method newly afresh, do not lift one by one here exemple. After main shaft is assembled, should beat to radial of main shaft front with axial the radial of jumpy, rear beats undertake detecting. Detect commonly the precision that pays attention to radial of main shaft front and axial only, to this machine tool, it is likewise important that caudal radial beats, it matters to 300mm of main shaft axes to be in jumpy precision. Basically detect the project is as follows: Radial of A) main shaft beats and axial change is moved do not allow to exceed 0.

001mm; B) rear radial is jumpy do not allow to exceed 0.

005mm; C) uses hand roll main shaft not be patient of loosens to tighten a phenomenon, cannot tighten too. Of 5 main shaft tear open install the link that tearing open outfit main shaft also is a key, main shaft oneself beats precision is in 0.

In 001mm. So tall main shaft precision, via having any loss, do not allow knock absolutely. Disassemble when main shaft, we were used abstain main shaft to pull a hook, main shaft from main shaft box inside slow pull. Main shaft repairs tone to get ready after matching, go in main shaft installation with same method, the exert oneself dot that just installs a tool at this moment is in rear of main shaft box. When assembling main shaft, want special attention whether do main shaft and installing hole have burr, clean relevant spare parts clean. When assembling main shaft bearing, also must operate correctly, and cannot optional knock bearing, can injure bearing otherwise, affect bearing precision. Can use hand hammer and sleeve installation, knock wants action to be on sleeve. Outer lane is hit when allowing to holding bearing inner ring absolutely or inner ring is made when installing outer lane, beat the meeting that knock power to deliver another ferrule through scroll body and raceway otherwise, cause the loss of raceway and scroll body. We had been opposite 6 summary 　 accurate lathe undertook 4 Xiao Bailin heavy repair, each precision after main shaft rehabilitate was achieved expect the result, the radial of main shaft beats and axial change is moved be in 0.

001mm less than, can be amounted to by the circularity of treatment spare parts 0.

0005mm left and right sides. The course heavies repair, make accurate lathe restored a batch of Xiao Bailin to leave factory treatment precision, begin for what my courtyard overhaul works managing capital, accumulated experience, exercised a procession. CNC Milling