Main shaft of high speed report is filled with the design of coupling device too

7 document label piles up: B article number: Zhang BolinAbstract of 　 of 1001-2265(1999)10-0037-05Design Of Positioning And Transmitting Device With Stepped Fitting Facesfor High Speed Electro-spindleXiao Shuhong: This Paper Introduces A Transmitting And Axial Positioning Device With Stepped Fitting Faces For High-speed High Accuracy Machine Tool Spindles.

It Is A Kind Of Interference Fit Device That Can Be Reassembled.

The Structure Characteristics And Design Method Of The Device Are Carefully Described.

Factors That Influence The Device Loading Capacity Are Analyzed.

The Reasonability Of The Design Method Is Testified By An Actual High Speed Spindle ' S Design.

Key Words:hUnit of main shaft of high speed of 　 of Igh-speed Machine Tool;spindle Unit;electro-spindle;stepped Sleeves is the key of cutting of high speed of machine tool implementation. Use structure of electric main shaft, cancelled link of all the transmission intermediate, can realize very high limited speed [1] . When undertaking to electric main shaft the structure is designed, need considers the following issues: Above all, it is a kind of accurate component, main shaft bearing needs to adjust or change, ask facilitating outfit of the spare parts on the axis is torn open. Next, main shaft bearing is tightening the job below strength effect beforehand, the fixed position component of bearing needs the axial power with bear certain below high speed; The rotor installation of electric machinery is on main shaft, the combinative scale of it and main shaft should deliver the torsion of electric machinery. The 3rd, main shaft is in below high speed when movement, dynamic balancing demand is very high, should not be between electric machinery rotor and machine tool main shaft use key coupling to deliver torque. To solve afore-mentioned problems, we were used in the structural design of electric main shaft new-style be filled with coupling structure too, design the form that covers into a flight of stairs. A flight of stairs is filled with too set tighten solid component as fixed position, with whorl coupling and key coupling photograph compare have the following advantage: ① won't bend in the generation on the axis and turn round stress, consequently the whirl of countershaft precision does not have an influence. ② is easy the verticality that assures end of spare parts fixed position and axes line, when be being tightened beforehand to bearing, won't cause bearing to get power not all, do not affect the life of bearing. ③ is filled with a quality too even, main shaft dynamic balancing is easy get assuring. ④ commonly used heat covers a law to undertake installing, the method of infuse pressure oil undertakes disassembling, kill to main shaft nondestructive. ⑤ fixed position is reliable, can raise the stiffness of main shaft. Carry out a proof, be filled with coupling characteristic to agree with too to rotating the fixed position of the spare parts of precision of high speed main shaft with precision very high demand and torque are delivered. The characteristic a flight of stairs that 1 a flight of stairs is filled with a structure too is filled with too covering is by adjacent of two paragraphs of photographs be filled with coupling surface composition too, set inside the coupling device that submits form of a flight of stairs, if pursue,1 is shown. The characteristic that a flight of stairs is filled with a structure too basically has [2] : Graph 1 a flight of stairs is filled with covered main configuration 　 too (1) disassembles to facilitate, a flight of stairs is filled with too those who cover inside the surface has an a flight of stairs. When oil groove of pressure oily infuse undertakes disassembling, this a flight of stairs can produce an axial thrust to covering, if two had cooperated to was filled with a face to already formed pressure oily film right now, this axial thrust can be filled with a flight of stairs too automatically set push from the axis, be filled with a two a flight of stairs that are filled with a face too too difference is very little, it is normally under 1mm. (The interference that 2) is filled with a two union scale too in affirmatory a flight of stairs when, should note the machining error effect to final interference, especially the influence that coaxial of circularity sum of errors spends an error. Be filled with a two paragraphs interference too normally abhorrent. But the difference that is filled with a size to carry interference too is worth cannot too big, its differ a value to should compensate treatment circularity and coaxial to spend error opposite to be filled with the influence of the quantity. Otherwise, will increase disassembled difficulty greatly. (3) disassembles to go to the lavatory, size carries the width B １ that coordinates a side, b2 to should agree. A flight of stairs that uses on the machine tool of certain high speed that 2 a flight of stairs are filled with an interference too is filled with too covering is a kind detachable be filled with coupling too, when the job, cooperate a face not to allow to produce plasticity to be out of shape. Accordingly, interference should control what do not produce plasticity to be out of shape place allows in material in limits of the biggest interference; The smallest interference that on the other hand it must be more than this to be filled with coupling to deliver bear place to need too again. Set D to be covered to be filled with too (include) external diameter, d0 gives priority to the diameter of the aperture inside the axis, d is in to cooperate (combinative scale) the external diameter of main shaft; L is the effective length that coordinates a side (l2 of ＋ of １ of L ＝ L) , if pursue,2 are shown. Graph 2 a flight of stairs are filled with too set deliver force and torsion to should be filled with coupling to deliver torsion to be Nm for M(unit too) when, the place on combinative scale needs Pmin of pressure of the youngest couple, can press type calculates: (1) 　 should be filled with coupling to bear too axial force is F ｘ (when the unit is N) , the pressure of the youngest couple that needs on combinative scale can press type calculates: (2) the μ in type -- the basis of coefficient of friction that coordinates a side is stretch and mechanical principle, the smallest effective interference that is filled with coupling to deliver bear place to need too δ Emin can press type calculates [3] : (3) ｉ of ａ of the E in type, E -- the stretch model quantity that is filled with a material and main shaft material too, ｉ of PaC ａ , C -- and include (be filled with too set) with be included (main shaft) the coefficient that diametical comparing concerns (ｉ of ａ of the V in 4) (5) type, V -- the Poisson that is filled with a material and main shaft material too is compared must point out, press type (what 3) place begs is not final place needed the smallest interference, return the impact that should consider the following factor: (1) cooperates exterior surface roughness. Consider the correction δ ｓ that exterior surface roughness affects, double of the sum of ｉ of planish deepness S that has been equal to the ａ of planish deepness S that is filled with a combinative scale and scale of main shaft union, namely: (6) the RaH in type, RaS -- be filled with an exterior outline arithmetic that is in with main shaft union too average deviation, μ MRzH, RzS -- be filled with an appearance that handles with main shaft union too microcosmic and rough degree at 10 o'clock height, 　 of μ M 　 (2) binds working temperature and the difference that assemble temperature, and main shaft and be filled with a material line to bilge too the difference of coefficient. This correction is: D of δ ｔ ＝ (ｉ of T of α ｉ Δ - ａ of T of α ａ Δ ) 　 　 (M) ａ of ｉ of the α in type, α -- main shaft and the line that are filled with a material too bilge coefficient, ａ of T of ｉ of T of 1/ ℃ Δ , Δ -- main shaft, be filled with a working temperature and the difference that assemble temperature too, ℃ 　 　 (the centrifugal force that a place is filled with to get too when high speed of 3) main shaft rotates. Should leave mental efforts to be able to have been caused be filled with set inside the dilate of aperture, bring about interference to decrease. Had mixed when main shaft material be filled with covered material quantity of Poisson comparing, stretch model and density differ not quite when, the decrement δ ω that causes interference from mental efforts can get by next type [4] : (7) the ω in type -- the rotate speed of main shaft, ρ of 　 of 　 of 　 of Rad ／ S -- main shaft material and the density that are filled with a material too, v of 　 of 　 of 　 of Kg ／ m3 -- main shaft material and the Poisson that are filled with a material too compare 　 　 E -- main shaft material and the stretch model quantity that are filled with a material too, pa 　 　 (4) repeats assemble and unassemble cause interference reduce δ ｐ . Compensation is worth δ ｐ but what basis outfit tears open a method is different, press experience method to decide. (5) combines face form the tolerancepublic errand influence to interference. The form that combines an aspect tolerancepublic errand, especially circularity and coaxial spend tolerancepublic errand opposite to be filled with coupling intensity the effect is very mixed, still do not have mensurable compensation measure at present. Classics is finite yuan the analysis makes clear, spend an error when cylinder very hour, although axis and covered combinative pressure are in,go up to change as the size of the appearance that is filled with too, displacement, condition somehow, but its be filled with on average too changeless, average band pressure is roughly constant also, not big to coupling strength effect. Be filled with covered design too in a flight of stairs of high speed main shaft in, because the production precision of main shaft is very tall () of IT6 class above, when be being designed accordingly, if had risen to be filled with a production precision that coordinates a side appropriately, criterion this influence is negligible not plan. After considering above factor, can get deliver pitching moment to perhaps bear the smallest interference that axial force place needs δ Min: ｐ of δ of ＋ of ω of δ of ＋ of ｔ of δ of ＋ of ｓ of δ of ＋ of Emin of δ of δ Min ＝ (8) 　 is in when be filled with covered basic interference too certainly, the influence with the stress concentration that still needs to consider to be filled with a structure to cause too by a flight of stairs, fluctuant load and dependability, safe element [4] . Take a flight of stairs to be filled with covered basic interference too: Min of δ of K of δ ｂ ＝ (9) the K in type -- safety factor, k is taken 1.

5 ～ 2.

0 　 are inside stretch limits, δ Emax can press the biggest effective interference with the concessional place when be filled with coupling to combine a face not to produce plasticity to be out of shape too undermentioned measure computation: According to theory of the 4th intensity, be filled with too set do not produce plasticity to be out of shape a pressure of concessional the biggest union [3] for: (10) Sa of the σ in type -- be filled with those who cover material to succumb too intensity, pa 　 manages together, main shaft combines a face not to produce plasticity to be out of shape the pressure of the biggest union with concessional place: (11) Si of the σ in type -- of main shaft material succumb intensity, pa 　 compares afore-mentioned two type numerical value, desirable and lesser person the Pmax of pressure of the biggest union that as computation countenance of union of the biggest effective interference makes, the biggest effective interference presses type gets [3] : (12) the 3 implementation method 　 that are filled with an interference too (1) uses tolerancepublic errand to cooperate to come true. According to basic interference the computation of δ ｂ is worth and cooperate the nominal dimension D of the face, check concerned manual chart [3] , can reach cooperate accordingly. Single out cooperate to should satisfy: The biggest interference [δ Max] ＜ δ Emax, the smallest interference [δ Min] ＞ δ Min. (2) uses the poor value of the nominal measure that coordinates a side to come true, choose the transition fit of H4 ／ H4. This kind of method is controlled easily and assure assorted actual interference, the spare parts that applies to high accuracy cooperates and undertake standardization, seriation is produced. In the main shaft of report of high speed CNC Milling that 4 designs example develops in us, to assure the whirl of main shaft precision is mixed dynamic balancing precision, locate to the axial of bearing and inside the coupling that installs electric machinery rotor and main shaft all uses a flight of stairs to be filled with too set. To show the design method of device of this one new-style coupling, below be filled with too with a flight of stairs of rotor of coupling electric machinery and main shaft set (like the graph 3 are shown) for exemple, introduce its design stage and applied case. Foregone parameter has: Electric machinery is highest rotate speed 18 000r/min, 1500r/min of rated rotate speed, rated power 13.

5kW, rated torsion 85Nm, the width 260mm of electric machinery rotor, union is in the 66mm of main aspects diameter of main shaft, small end the diameter is 65.

8mm, union is in what size carries to cooperate length to all be 52mm, as a result of rotor silicon steel dish press in directly be filled with too set on, when be filled with coupling parameter too certainly, rotor and be filled with too set can regard as look upon of a whole, rotor external diameter is 134.

2mm, main shaft and covered Poisson all are than ｉ of V ａ , V 0.

3, ｉ of ａ of E of stretch model quantity, E is 2.

1 × 10 5 MPa, diameter of the aperture inside main shaft is 25mm, 2 μ M covers main shaft and the RzS ＝ that cover combinative part inside the RzH ＝ of aperture 3. 2 μ M, the ＝ of μ of coefficient of friction that combines an aspect 0. 08. Be filled with covered material to be 65Mn too, its succumb the limit is 800MPa; The material of main shaft is 38CrMnAl, its succumb the limit is 850MPa, density is 7.

8 × m3 of ／ of 10 3 Kg. Graph rotor of electric machinery of main shaft of report of 3 high speed and the knot composition of a picture that main shaft binds 1.

Disassemble with oil filler point 2.

Electric machinery rotor 3.

Aperture of dynamic balancing screw 4.

Electric machinery rotor is filled with too set 5.

O sealing ring 4.

The smallest interference that 1 computation delivers torsion place to need 　 of δ Min 　 (the smallest effective interference that 1) delivers torsion place to need certainly δ Emin. afore-mentioned place row parameter generation enters type (3) , can beg piece: δ Emin ＝ 1. 395 μ M, the combinative place that gets among them needs ＝ of Pmin of pressure of the youngest couple 1. 49MPa. (2) considers to cooperate the influence of exterior surface roughness, according to type (6) , computation its correction δ ｓ ＝ 4. 16 μ M. (When 3) computation high speed rotates, centrifugal force causes interference to reduce the ω that be worth δ , concerned data era enters type (7) , get δ ω ＝ 31. 199 μ M. (4) considers to repeat outfit tear open interference to reduce, take compensation to be worth δ ｐ ＝ 8 μ M. (When 5) main shaft works, be filled with too set differ with main shaft temperature rise not quite, and both material line bilges coefficient is almost equal, consequently δ ｔ ＝ 0. Inspect above element integratedly, by type (8) can reach the smallest interference that delivers torsion place to need δ Min: δ Min ＝ 1. 395 ＋ 4. 16 ＋ 31. 8 ＝ of 199 ＋ 44. M4 of 754 　 μ .

The biggest effective interference presses type inside limits of 2 computation flexibility (10) begs an a flight of stairs to cover do not produce plasticity to be out of shape the pressure of the biggest union with concessional place: Pamax ＝ 346. 　 of 704 　 MPa presses type (11) begs the point of main shaft union that give not to produce plasticity to be out of shape the pressure of the biggest union with concessional place: Pimax ＝ 363. 　 of 95 　 MPa is taken lesser person the ＝ of Pmax of pressure of the biggest union that as computation combinative scale a flight of stairs is covered and the axis all does not produce plasticity to be out of shape place allows 346. 704MPa, era enters type (12) gets do not producing plasticity metabolic the biggest effective interference: δ Emax ＝ 0. The choice that 324 μ M5 cooperates 324mm ＝ considers safe factor, take ＝ of safety factor K 1. 5, basic interference presses type (9) can get: δ ｂ ＝ 1. 5 × 44. 754 ＝ 67. 　 of 324 μ M is filled with ＝ of Emax of δ of ＜ of 131 μ M too cover and main shaft won't produce plasticity to be out of shape, can check concerned manual chart by δ ｂ and D [3] , the basic error code name that must cooperate is S. Can choose a flight of stairs to be filled with a main aspects to cooperate to be 66(H6)/(s6(too further actual the biggest interference is 78 μ M, the smallest interference is 40 μ M) . The place before be like is narrated, the consideration makes shaping the influence of the error, it is due and certain that a flight of stairs is filled with a two interferences that coordinate a side too poor value, with compensation form the influence of the error, accordingly, the interference that takes small end is largish, for 65. 8H6)/(t6(is actual the biggest interference is 94 μ M, the smallest interference is 56 μ M) . Because the length of electric machinery is bigger, be in specific when undertaking the structure is designed, two be filled with too cooperate stay between Duan Zhi a length is not a contact for 130mm paragraph, in order to form oil pocket and the pressure that had bilged to be filled with a place to need, for disassembling of rotor with; Because main aspects interference is lesser, cause to prevent oily leak of the high pressure when disassembling it is difficult to disassemble, paragraph of design is contacted to have O seal unit in main aspects blame, if pursue,3 are shown. 6 conclusion a flight of stairs is filled with too covering is a kind of new-style and detachable formula that is used at transferring torque and axial fixed position be filled with coupling device too, have a structure simple, dynamic balancing is characteristic the advantage such as good, on the safe side, special agree with to the axial of the spare parts on main shaft of unit of main shaft of high speed, high accuracy locates and deliver torsion. The design method that article place introduces goes easily simply, already got applied in the design of real report main shaft and development. Carry out a proof, a flight of stairs is filled with too set had favorable effect to improve the dynamic performance of electric main shaft. CNC Milling