Summary: The ball screw application on machine tool of numerical control of high speed high spirit was elaborated in article, be in to ball screw mainly the installation in applying actually, debug and detect and the analysis of breakdown eliminated to make the introduction, at be being discussed together with work in the same placing, the user that also hopes to be able to give us brings a help in application. One, the introductory ball screw of ball screw is circumgyrate athletic translate into moves point-blank, or the good product that moves circumgyrate of sharp movement translate into. Ball screw deputy have a variety of structure type. By ball circular means cent is mixed for outer circulation inside circularly two kinds big. Outer circulation is answered bead implement those who use intubate formula is more, answer circularly inside bead implement those who use formula of quadrat of lumbar form chamfer is more. By whorl orbital sectional appearance cent is odd circular arc and double circular arc form of two kinds of cut. Be more than form of cut of odd circular arc as a result of stiffness of axial of form of cut of double circular arc, because this uses guide screw of truncate of double circular arc generally at present. By add laden form cent beforehand, can divide the nut that it is sheet to not have beforehand close, Chan Luo's mother runs a lead beforehand close, Chan Luo's mother increases steel ball radial to be tightened beforehand, double nut spacer is tightened beforehand, double nut differs tine to be tightened beforehand, double nut whorl is tightened beforehand. On numerical control machine tool type of spacer of commonly used double nut is tightened beforehand, its tighten force to be the 1/3 of axial load commonly beforehand. Ball screw and slip lever nut deputy have a lot of advantages quite: Transmission efficiency tall, sensitivity tall, drive is smooth: Wear away small, life is long; Can eliminate axial gap, raise axial stiffness to wait. 2, ball screw is machined in the applied high speed on machine tool of high speed numerical control is a when face 21 centuries new and high technology, it is main feature with efficient, high accuracy and fast face quality, make in spaceflight aviation, auto industry, mould, wider and wider application was won in the industry such as appearance of photoelectricity project and instrument, already obtained major technical economic benefits, it is contemporary and advanced the main component of production technology. To realize high speed treatment, want to have machine tool of high speed numerical control above all. Machine tool of high speed numerical control must have system of high speed main shaft and system of high speed feed at the same time, ability realizes the high speed of material cutting process to change. To realize high speed feed, take step domestic and internationally ceaselessly about mill business, improve the high speed performance of ball screw. Main measure has: (1) increases the rotate speed of screw, lead and whorl head number appropriately. Of diameter of name of screw of ball of current and commonly used big lead and lead match for: 40mm × 20mm, 50mm × 25mm, 50mm × 30mm, its feed speed all can achieve 60m/min above. To increase the stiffness of ball silk lever and carrying capacity, screw of big lead ball uses double head whorl commonly, with raising ball bear the weight of effectively a number. (2) improves a composition, raise the fluent sex that ball moves. Improve ball to circulate retrorse device, optimize the curvilinear parameter that answers bead chamfer, use three-dimensional formative to guide bead canal is mixed time bead implement, accomplish truly along inside the lead part way of whorl introduces ball nut system in, the direction that makes ball moves and raceway are tangent and not be to intersect. Can reduce concussion loss and noise to so the smallest. (3) is used " hollow strong cold " technology. Screw of high speed ball produces high temperature as a result of attrition when move, the heat that causes screw is out of shape, affect the treatment precision of high speed machine tool directly. Use " hollow strong cold " technology, connect fluid of constant temperature cutting the Kong Zhong of hollow silk lever namely, undertake enforcing cooling to ball screw, those who maintain ball deputy temperature is constant. This measure is to raise the efficient way of precision of function of high speed of screw of medium, large ball and job. (4) the system of high speed feed to great distance, can use screw the transmission way that fixed, nut rotates. Right now, nut turns at the same time, make axial move along fixed screw at the same time, because filar lever is not moved, can avoid to accept the restriction of critical rotate speed, a variety of problems that when avoiding high speed of screw of long and thin ball to run, appear. Nut is inertial small, campaign is slick, realizable rotate speed is high. (5) improves the production quality of ball screw further. Through using afore-mentioned after a variety of measure, a few problems that traditional ball screw exists can be overcome on certain level. Its are the biggest fast and floating rate can amount to 60m/min, individual situation falls to be able to amount to 90m/min even, acceleration can amount to 15m/s2. As a result of ball screw history maturity of long, craft, application extensive, cost is inferior, because this is in,speed of medium load, feed asks not range of very tall, journey is not quite big (often still be used on machine tool of numerical control of the machining center of general high speed that is less than 4 ～ 5m) and other economy high speed. 3, the installs numerical control machine tool feed system of ball screw should obtain taller transmission stiffness, besides the stiffness that strengthens itself of ball screw nut, the structural stiffness of the installation with ball correct screw and its bearing also is the factor that cannot ignore. Nut reach bearing should have enough stiffness and precision. Increase the interface that combines a part with the machine tool to accumulate appropriately normally, in order to raise nut local stiffness and osculatory intensity, the machine tool of new design allows in craft condition constant constant nut or bearing will increase stiffness with whole of make it of machine tool noumenon. To raise the axial stiffness of bearing, choosing proper scroll bearing also is very important. Home basically uses two kinds of combination at present. One kind is a radial bearing and conic bearing combination are used, although its structure is simple, but axial stiffness is insufficient. Another kind is a thrust bearing or afferent thrust bearing and radial bearing combination use, its axial stiffness had rise, but the attrition resistance that increased bearing and calorific and the structural size that increased bearing support. In recent years domestic and international bearing production manufacturer already produced a screw of a kind of ball special bearing (like Japanese NSK, german FAG) , this is one kind can bear the ball bearing of special and afferent thrust of force of very big axial, compare with general afferent thrust ball bearing, osculatory horn increases 60º , the number that increased ball reduces the diameter of ball accordingly. The bearing of this kind of new structure raised double above than the axial stiffness of general bearing, and use very convenient, the product sells in couples, and had chosen the ply that matchs annulus of good inside and outside when leave factory, nut and end should be used only when assembling lid general core and outer shroud impaction, can obtain what when leaving factory, had adjusted to tighten force beforehand. The installation means of ball screw has the following kinds normally: (1) double push one aspect of the matter of lever of silk of one free means to secure, freedom of one aspect of the matter. Secure upright bearing to bear at the same time axial force and radial load. Means of this kind of bearing uses at the short guide screw with small journey -- advantage: Assemble more easily, geometrical precision influence is minor, apply to short screw and perpendicular screw; Defect: The distance between action point is lesser, tigidity is poorer. (2) double push one aspect of the matter of lever of silk of one bearing means to secure, bearing of other one aspect of the matter. Secure upright bearing to bear at the same time axial force and radial load; Bearing carries bearing to bear only radial load, and the axial that can make drop drifts, because of,reduce screw self-prossessed and appear bend. At the same time guide screw heat is out of shape OK and free land to one aspect of the matter stretchy. Nextpage(3) double push a pair to push means silk lever two end all are secured. Secure upright bearing to be able to bear at the same time axial force and radial load, means of this kind of bearing, can bring to bear on to screw proper beforehand tensile, raise screw bearing stiffness, the heat that can compensate screw partly is out of shape. Its advantage is: The space between action point is larger, rigid relatively beautiful; Defect: Suffer effect of precision of assembly parts geometry more easily. (4) uses screw the transmission way that fixed, nut rotates right now, nut turns at the same time, make axial move along fixed screw at the same time: Because screw is not moved, can avoid to accept the restriction of critical rotate speed, a variety of problems that when avoiding high speed of screw of long and thin ball to run, appear. Nut is inertial small, campaign is slick, realizable rotate speed is high. This kind of means can bring to bear on to screw bigger beforehand tensile, raise screw bearing stiffness, the heat that compensates screw is out of shape. 4, of ball screw nut defend and lubricate (1) ball screw defends deputily ball screw deputy the transmission parts of an apparatus with other rolling friction is same, should avoid horniness dirt or cut bits contamination to enter, must contain accordingly guard. If ball screw deputy appear on the machine tool, should introduce the shield that close, if use bushing of helix bedspring metal strip, adjustable bushing and fold type bushing,wait. the one aspect of the matter of shield join is in when installation the flank of ball nut, another end secures the bearing in ball silk lever on. If ball screw deputy be in covert position, can use sealing ring to defend, sealing ring holds the two end in nut. The stretch sealing ring of contact uses oil resistant balata or nylon is made, the appearance with make it of the aperture inside its and screw whorl suitable raceway; The dustproof effect of contact sealing ring is good, but contact pressure as a result of existence, make attrition moment of force increases somewhat. Blame contact sealing ring calls labyrinth sealing ring again, it uses rigid plastics to be made, the appearance of the aperture inside its and screw whorl raceway is contrary, have space a bit, can prevent attrition moment of force so, but dustproof effect is poor. Should avoid to touch in the job attack guard, guard has attaint to should change in time. (Deputy lubricant lubricant can raise 2) ball screw wearability and transmission efficiency. Lubricant can be divided for lube and grease two kinds big. Lube uses oil for system of total loss bad news commonly: Grease can use lithium radical grease, when high speed, the viscosity index limits when suggesting use lubricating oil is 40 ℃ 68)(DIN 51519) of ～ of 32 ～ 68 CSt (ISO VG 32. When low speed, the viscosity index limits when suggesting use lubricating oil is 40 ℃ is in above of 90 CSt (ISO VG 90) . Grease is added inside whorl raceway and the housing space that install nut commonly, and inside the space of the nut of oily aperture infuse that lube passes housing to go up. Every half an year changes to the grease on ball screw, clean the old grease on screw, tu Shangxin's grease. The ball screw that lubricates with lube deputy, can be in before the machine tool works, be cheered every time or time according to working requirement cheer. 5, the note ball screw when ball screw is being used is assembled for nice mechanical spare parts, need to notice following item when use so: (The 1) attrition because of ball screw is very small, if will not bring to bear on to be pressed beforehand (small press beforehand same also) screw is perpendicular when placing, because of,nut is met self-prossessed and fall off from screw axis come down, so perpendicular when using, ask ten million caution. If nut falls off screw, ball can fall off. Additional, the ball circulation department such as circular conduit also has the risk of attaint. If nut falls off from screw, please with contact of personnel of the technology after carry out. (2) because the circular department of nut of ball silk lever (the loop is tracheal, upright lid) outstanding in nut exterior, notice please cannot knock and collision. (3) does not want a radial load please, pitching moment bear is added to ball screw directly. If action has radial load, pitching moment bear, can make the service life of screw exceeding reduce or bring about screw movement is not smooth. (When 4) is the same as screw stack mounting of other machinery spare parts, do not take out nut from screw please. If in case when must parting, the bushing that uses small 1mm of smaller than screw groove way please serves as auxiliary make, get off nut and ball together, at the same time the attention does not let ball fall off. (The whorl groove of 5) ball screw is the course quenchs with abrade treatment, if will exterior component infiltrates forcibly when screw axis or nut edge, the meeting on scroll groove produces impress, when installing component so, notice not to want to had brought to bear on to assign outside force to screw or nut please. (6) if the axes of the center that prop up of two end mixes ball screw the center of nut is different when the heart, can produce exorbitant attrition obstruction to ball screw, produce torque to increase thereby, calorific wait for a phenomenon. Make ball screw appears to wear away inchoately, shorten greatly its service life. Accordingly, when installation must of corrective screw " 3.1 line " . Additional, after installation is over, must turn please screw, make nut mobile on the effective journey of screw, affirm whether to have the unusual appearance such as interference. (7) is best in screw two end are added outfit prevent bump implement, movement exceeds journey limit and injure ball screw in order to avoid. 6, the end that ball screw plays beforehand and pull a quantity to screw is pulled beforehand even if use screw when assemble beforehand the locknut of two end presses the pulling force with ask the length direction to screw brings to bear on certain in order to adjust nut of screw positive and negative spend closely reversely, the reason is screw is when the temperature rise in moving, thermal stress effect can make screw stretchy, make the length of screw becomes not stable. The purpose is to eliminate the stretch variable of this component effectively with period obtain smooth athletic precision. Become when minim feed otherwise the workbench when the damp force of saddle or workbench is more than the stretch moment of force of screw and nut does not produce displacement, as the accumulation of ceaseless feed screw and nut stretch moment of force exceeds workbench damp moment of force right now workbench produces actuation displacement. Although total feed is likely insusceptible, but the output of the feed of actual pace number, every pace and controller produces an error, it is precision of serious effect treatment if really ever since. Too big pull the can burned-out bearing that prop up beforehand, here the proposal uses those who be less than 5 ℃ to drag a value beforehand, but if the diameter of ball screw does not suit to do when 50mm more than,pull beforehand, screw diameter needs greatly big beforehand tensile, can bring about bearing to give out heat right now and burn out. What because this suggests,be worth T as compensation with the temperature rise of 3 ℃ is fiducial (screw every 1000mm, - 0. 02~ -0.
03mm) . Different application needs different T to be worth, about the extraction that T is worth the value consults please product technology manual. 7, of the backlash after ball screw is installed detect the artery that use a hand moves to generator relevant axis (X, y, z) , (it is fold of hand arteries and veins 1 × surely of 100 block, namely every change one pace, electric machinery feed 0.
1mm) , cooperate dial gauge to observe the athletic condition of relevant axis. Serve as initial drop after one-way motion precision keeps normal to motion, hand arteries and veins every change one pace, machine tool the actual distance D=d1=d2=d3 that this axis moves... =0.
1mm, explain electric accident travel is good, fixed position precision is good. And return a machine tool on the change of virtual campaign displacement, can divide for 4 phase: Motion of ① machine tool is apart from D1 ＞ D=0.
1mm(slope is more than 1); ② to show for D=0.
Slope of D3(of ＞ of 1mm ＞ D2 is less than 1) ; Orgnaization of ③ machine tool did not move actually, show most standard backlash; Distance of motion of ④ machine tool and set-point of hand arteries and veins are equal (slope is equal to 1) , renew the normal campaign of the machine tool. The breakdown analysis of screw of nextpage8, ball in application and because athletic quality drops,removing trouble of ball snail bar is for the most part, backlash is too big, mechanical crawl, lubricant undesirable wait for a reason to cause. Next watches are ball screw common breakdown and diagnostic method. Normal MARGIN of Center" Align=center> serial number: 0cm 0cm 0pt; TEXT-ALIGN: Normal Align=left> breakdown: 0cm 0cm 0pt; TEXT-ALIGN: Normal Align=center> breakdown: 0cm 0cm 0pt; TEXT-ALIGN: Center" Align=center> eliminates methodological Normal Align=center>1normal Align=left> is added Normal Align=left> slideway is not enough, cause smooth board creeping Normal Align=left> adds lubricating oil, eliminate lubricant breakdown Normal Align=left> ball has local pull or wear away Normal Align=left> changes or maintain screw Normal Align=left> screw sustains bearing damage, move not smooth and have shake Normal Align=left> changes attaint bearing Normal Align=left> servo was not adjusted good, gain crosses big Normal Align=left> adjusts servo electromotor to control systematic Normal Align=center>2normal Align=left> backlash, treatment precision does not stabilize Normal Align=left> silk carries awl of shaft coupling locking to cover shake Normal Align=left> tightens solid Normal Align=left> each slideway and the contact of the face that stick model catch bit of inhomogenous Normal Align=left> new nicety matchs a shovel, make interface catchs a dot to amount to 80 ％ above, 0.
02mm contest feet does not enter for eligible Normal Align=left> slideway had cooperated to tighten or cross loose Normal Align=left> readjust or match a shovel, make interface catchs a dot to amount to 80 ％ above, 0.
02mm surpasses feet not to enter Normal Align=left> ball tightens force to cross close or too loose Normal Align=left> is adjusted tighten force beforehand, examination axial change changes a value, make its error is more than 0.
005mmnormal Align=left> ball and combinative scale are not perpendicular, had combined loose Normal Align=left> repairs, adjust and make repairs and supply replacements handles Normal Align=left> silk props up a bearing to close force tightens too or cross loose Normal Align=left> repairs adjust Normal Align=left> ball makes an error big or axial change moves Normal Align=left> is compensated automatically with control system can eliminate gap, measure with the instrument and adjust screw change to move Normal Align=left> lube is not worth or do not have Normal Align=left> adjustment all has lube Normal Align=center>3normal Align=left> ball crosses big Normal Align=left> each slideway had cooperated to tighten Normal Align=left> readjust or match a shovel, make 0.
A place of strategic importance of 02mm contest feet does not enter for eligible Normal Align=left> ball damages, nut gets stuck dead or the axis carries nut to tighten force to cross big Normal Align=left> rehabilitate or change screw adjusts Normal Align=left> silk has wear away Normal Align=left> changes Normal Align=left> servo and ball screw connection are not coaxial Normal Align=left> adjusts coaxial to spend and close solid joins a Normal Align=left> does not have lube Normal Align=left> adjusts lube road Normal Align=left> exceeds Cheng switch malfunction to cause mechanical failure Normal Align=left> checks breakdown and eliminate Normal Align=left> servo calls the police Normal Align=left> checks breakdown and eliminate Normal Align=center>4normal Align=left> screw is lubricant and undesirable Normal Align=left> cent is oily implement whether to divide oily Normal Align=left> examination distributes oil implement Normal Align=left> vitta jam Normal Align=left> cleared contamination makes vitta expedite Normal Align=center>5normal MARGIN of noise of screw of Left" Align=left> ball: 0cm 0cm 0pt; TEXT-ALIGN: The installation gland of the bearing of screw of Left" Align=left> ball that prop up has shake Normal Align=left> adjusts gland, make Normal Align=left> ball is lubricant and undesirable Normal Align=left> examination distributes oil implement with oil path, make lubricating oil enough Normal Align=left> ball produces damaged Normal Align=left> changes ball Normal Align=left> screw becomes loose or electric machinery installing plate and screw axis carry different heart Normal Align=left> screws bolt of shaft coupling locking, corrective coaxial spends 9, last word: The technology after making work as uses an engineer, we should have solid integrated knowledge already, want to have rich practice experience again. In ball screw installation, debug, detect and integrated consideration should have to the problem when breakdown analysis eliminates. Additional, want mutual communication with technical personnel, cooperate and support each other. CNC Milling