The main shaft of CNC Milling of nicety of machining center, high speed is designed

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High speed is machined not only can twice land improves manufacturing efficiency, return the treatment precision that can improve a spare parts further and exterior quality, the efficient treatment problem of the certain and special material that in solving a few convention to machine, solves hard, accordingly, high speed treatment caused height to take seriously on the world. Graph treatment of 1 high speed is opposite construction of type of unit of 1 main shaft the treatment of requirement high speed of machine tool main shaft is right system of machine tool main shaft asks rotate speed is high not only, the torque of output and power want big, still ask to have taller main shaft turn precision and maintain in high speed movement have good stiffness, aseismatic sex and thermal stability. Current, the main shaft of high speed machining center that developed country of the industry on international produces is highest rotate speed is as high as 20, 000 ~ 100, 000r/min, home is medium or small top rotate speed also amounts to the main shaft of machining center, CNC Milling 4000 ~ 6000r/min. There basically is main shaft of two kinds of high speeds in applying actually: One kind is the main shaft of high speed report that has 0 drive, because this kind of main shaft uses the structure of electric machinery and unifinication of machine tool main shaft, pass meticulous dynamic balancing corrective, because this has good circumgyrate precision and stability, but restrict somewhat to the torque of output and power; Another kind is the main shaft that is united in wedlock with electric machinery of frequency conversion main shaft and photograph of mechanical gearshift orgnaization, the torque that this kind of main shaft outputs and power should be gotten greatly much, but opposite for stability of circumgyrate precision peace wants all but, accordingly to this kind of main shaft, the influence that how designs machine tool main shaft and its component correctly to machine precision to the machine tool is crucial. The structure of component of 2 main shaft is designed 2.

Machining center of high speed of construction of type of unit of 1 main shaft and CNC Milling use structure of unit type main shaft mostly, undertake bearing of main shaft around deserving to grind below constant temperature environment, a round sleeve is loaded after deserving to had been ground inside, load box of machine tool main shaft with a complete unit when general assembly next inside, the assembly that assured component of machine tool main shaft not only so precision, and be installed easily again and maintenance is adjusted, if pursue,1 is shown. Graph bearing of 2 horn contact becomes group matched stack 2.

The choice of bearing of main shaft of 1) of bearing of 2 main shaft: The requirement of the big negative charge in view of machining center and high speed CNC Milling, high rotate speed and tall nicety, structure of double couplet bearing already cannot satisfy common main shaft to ask to be mixed to high speed machining center now CNC Milling, use horn to contact bearing to combine a design mostly. Because horn contacts bearing to be able to bear at the same time radial and an axial load of direction, permission limited speed is higher. If the graph is shown 2 times, use two horn to contact ball bearing back to carry matched stack on the back, make bearing dot A, B expanded outwards at 2 o'clock, shortened of main shaft head dangerous extend, reduced main shaft greatly to carry the bending of the ministry to be out of shape, raised main shaft stiffness. Of bearing of 2) main shaft tighten beforehand: Make spacing of axial of main shaft bearing with common nut, make sure nut end panel and axes line have taller verticality hard normally (the 3a) that be like a graph, locking hind makes bearing easily deflective, make the axis bends likely even (the 3b) that be like a graph, this rotates those who affect an axis precision. A) B) pursues the whorl when locking of 3 common nut is deflective the influence to bearing 1, 4, 11.

Flange dish 2, 7.

Bearing 3, 9.

Locknut 5, 6.

Ring washer 8.

Adjust nut 10.

Block oil dish 12.

Main shaft graph is locking of bearing of 4 main shaft, sealed structural sketch map 1.

Compress air to be in charge of 2.

Piston 3.

Double channel locknut 4.

Dish form bedspring 5.

Pull rod 6.

Main shaft 7.

Main shaft sleeve 8.

Annulus of the refrigeration inside main shaft 9.

Cutting tool pulls a hammer 10.

Structure of main shaft of 5KX714 of graph of the flange that block oil shows locknut like graph 4a place 3, in the verticality of unwarrantable end panel and aperture when locking, the adjustment to raise bearing precision should if instead uses back-up ring in graph 4b 5, 6 long grind adjust, so that rise,repair grind precision. With two depart nut 8, 9 adjust, or use double groove locknut (5) seeing a picture adds a cross spacer and had used be filled with set wait for locking means. Of bearing of 3) main shaft sealed and lubricant: Because rotate speed of main shaft of high speed machine tool is higher, the fat when above of turn up 5000r/min is lubricant very inaccessible already requirement, and rare oil-lubricated the smooth sex that the how much apparently influence in the lube in high speed motion runs to main shaft. Because this is in current design,majority uses concentration mist of mensurable and time oil or drop-feed lubrication means. To raise main shaft in high speed treatment the life of bearing is mixed ensure the whirl of bearing precision, must take rigid sealed step, however the contact with sealed better effect is sealed certainly will affects main shaft rotate speed rise, because this has main shaft generally to blow at present labyrinthian and gas, sealed wait for blame contact sealed means, can use space not high to the requirement sealed, but the bulk that must control clearance well and truly, it is commonly in 0.

02 ~ 0.

Between 04mm. 2.

Pull rod of 3 main shaft installs knife system automatically to install certainly will to use orgnaization of automatic outfit knife in the cutting tool in machining center and high speed CNC Milling. By tighten bedspring to command axial pulling force beforehand, the pull rod orgnaization that realizes loose knife and clip knife movement by the actuator such as baric, hydraulic pressure or mechanical screw again (the 5) that be like a graph. Actuator has what rotate together with main shaft to follow use unit, also have the depart that does not rotate along with main shaft structure, former structure is more compact, complex rate is high, latter structure is simple, cost is low, but take up the space is larger. Additional, install precision to raise cutting tool to repeat, reduce handle of cutting tool awl and main shaft taper hole to be not normal joint, the blows gas or gush fluid orgnaization that must install main shaft to stop cone of handle of awl of cutting tool of orgnaization and cleanness of in order to, main shaft definitely in installing knife system automatically. 2.

Cooling system is in water of 4 main shaft temperature rise of the bearing in high speed whirligig is to cause main shaft to be out of shape, one of main factors that treatment precision drops. Much heat energy can cause the heat with severe main shaft to be out of shape, affect precision of main shaft circumgyrate not only, and still meet those who control main shaft rotate speed rise, speed heals this kind tall the phenomenon heals apparent. Accordingly, how to improve system of machine tool main shaft to heat up character, reduce heat source intensity of the system, reduce temperature rise and the hot displacement that reduce a system, appear in design of high speed main shaft particularly important. Main shaft component chooses besides correct ground in main shaft design, outside reducing intensity of systematic heat source, want to undertake water cools to main shaft, microtherm rises and reduce a system in order to fall to heat up displacement. Chamfer of successive water refrigeration annulus is designed outside main shaft sleeve, let machine tool cooling fluid shed the cooling annulus chamfer on sleeve of classics main shaft first, next again ejective to cutting tool point of a knife, take away the majority quantity of heat that bearing produces with this kind of means, reduce systematic heat energy to be conducted to machine tool main shaft. Taller to some requirements machine tool can cool main shaft water and cutting fluid cent is two different systems, of course this kind of structure can apply to unit type main shaft only. 3 designs give typical examples pursues the designs of 5 main shaft structure that are milling machine of lathe bed of XK714 numerical control, (Main shaft rotate speed is 50 ~ 4200r/min) . Because this main shaft is longer, use two so advocate the texture that bearing adds an auxiliary bearing. Before, in the part of high speed nicety that bearing uses two groups of back to carry matched stack on the back contacts ball bearing, in order to increase carrying capacity, of bearing it is good to tighten force to already deserved to grind in couples in bearing plant beforehand, belong to general matched stack model. Bearing uses ball bearing of deep trench of two light series after, bearing outer lane drifts, withhold windage, prevent axial interference. Ministry of main shaft end uses space sealed as sealed as what swing union of oil groove photograph with dustproof technology. Pull rod of machine tool main shaft commands the axial pulling force that cutting tool installs by dish form bedspring, carry out movement of loose knife, clip knife by pneumatic orgnaization, pull rod and piston have the via of diametical F4 inside lever, when in order to changes a knife, mix to main shaft taper hole handle of cutting tool awl blows gas cleanness. Whole main shaft designs unit type structure, water refrigeration hoop is set outside main shaft sleeve, in order to reduces main shaft temperature rise. CNC Milling CNC Machining