Precision of circumgyrate of main shaft trends checks the introduction

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One, the precision of component of main shaft of introductive tool machine includes the following two respects: 1.

Geometrical precision - the geometrical precision of main shaft component, it is to point to after assembling, turning without laden low speed (the roll that use a hand or rotate speed of low speed machinery) below the condition, main shaft axes and the radial that main shaft front installs workpiece or cutting tool place and axial are jumpy, and main shaft is referenced to some system (the direction of vertical, horizontal shift that is like tool carrier or workbench) positional precision, wait like parallelism and verticality; 2.

Circumgyrate precision - those who point to is main shaft when doing circumgyrate to move with regular job rotate speed, the change of axes position. 2, when the definition main shaft of precision of main shaft circumgyrate is making rotational motion, in same instant, what the linear velocity on main shaft is the dot of 0 is online, call main shaft to be in the line of centre of turning circle of this instant, below ideal situation, main shaft is in the dimensional position of line of every instant centre of turning circle, the referenced system that secures relative to Yu Mou (for example: The working mesa of casing of tool carrier, main shaft or tool machine) for, should be changeless. But actually, because the journal bearing of main shaft is on bearing, bearing is installed again inside aperture of main shaft casing, there still are gear or other drive on main shaft, of line of center of neck of countershaft of end panel of the blemish of the out of round as a result of journal, bearing, bearing not perpendicular, the reason such as the resonance of the bending of main shaft and tool machine construction, the dimensional position of line of main shaft centre of turning circle, be fluctuant when every an instant. The line of ideal centre of turning circle that the definition of average space position of lines of these instantaneous centre of turning circle circumgyrate main shaft gives priority to an axis, and contact together with fixed referenced coordinate system. Such, the dimensional position of line of centre of turning circle of main shaft instant is relative the deviate of the dimensional position at ideal center line is circumgyrate main shaft move in the error of this instant. The contrail that these instantaneous errors move, it is the contrail that error of circumgyrate main shaft moves. The limits that main shaft error moves, it is so called " precision of main shaft circumgyrate " . This shows, the circumgyrate precision of main shaft, show the stability characteristic of position of space of line of center of circumgyrate main shaft. 3, precision of main shaft circumgyrate is measured 3.

The measurement that the measurement that error of circumgyrate of 1 main shaft moves and research end move to error of main shaft circumgyrate and research have the objective of two respects: (1) .

Set out from design, production point of view, the hope finds out the relation of design, production element and motion of main shaft error through measuring research, reach the characteristic that how moves according to the error, design and produce quality of system of assess main shaft, find out the main reason that produces error motion at the same time, so that make further improvement. (2) .

Set out from use angle, the hope finds out main shaft motion and the relation that machine precision and exterior surface roughness, reach the characteristic that how moves according to the error, dope tool machine can machine the workpiece geometry that go out and exterior surface roughness below ideal condition, to choose tool machine and design tool machine to put forward a basis. 3.

The checks precision of circumgyrate of methodological main shaft measurement technique of precision of circumgyrate of 2 main shaft, have measure law and indirect method of measurement directly (test specimen law) two kinds big, measure a law to again static state and trends measure two kinds of way directly among them. (1) .

The static state tests a standard - the test that inserts nicety in main shaft taper hole is good, dosage expresses a contact to try good appearance and end panel, rotate gently main shaft measures what go up in different point of view to read a value. Advantage: Measurement technique is simple, maneuverable, can examine a line of center of main shaft taper hole and line of centre of turning circle are homocentric; Defect: The error that cannot reflect main shaft to fall in real work rotate speed moves, and the treatment appearance error that cannot reflect this error to move to be caused possibly and the influence to exterior surface roughness. (2) .

Dynamic test law - try fine prejudicial installation with the standard, two mutual and perpendicular displacement sensor are secured in radial, again axial is additional the displacement sensor that installs one perpendicular direction, amplifier of its signal classics inputs oscillograph, measure rotate the main shaft error of sensitive direction moves. 3.

Noun of graph of 3 motion error explains (1) .

Total error moves (Total Error Motion) - with enough what the much record that encircle number falls is all graph of error pole coordinate, the error campaign state that it leaves in certain rotate speed on behalf of main shaft. (2) .

Average error moves (Average Error Motion) - it is total error the mean contour line that athletic pole coordinate pursues, the best circularity that gives a part can be machined below ideal cutting condition on behalf of this machine stage. (3) .

Random error moves (Asynchronous Error Motion) - it is the deviate that total error motion moves to average error, it expresses the treatment surface surface roughness that can obtain below ideal cutting condition. (4) .

Intrinsic error (Fundamental Error) - the most intimate circle that average error moves, the axial error that on behalf of line of main shaft axes every turn. (5) .

Leftover error (Residual Error) - average error movement is right the deviate of intrinsic error image, represent the flatness that end panel machines. Nextpage3.

Precision of circumgyrate of trends of 4 main shaft analyses A.

Cause radial motion error (the reason: of Radial Error Motion) ? Fei of flood dragon of  of head of  of Tao of laborious reef crucian carp basks in ぞ Fu  to show  of  of cut down of Yi of  children's hair to hold the post of Peng? : 1.

Bearing (Bearings) , include bearing incorrect heart (Bearing Alignment) . 2.

Machine platform construction is out of shape cause main shaft and measure the dynamic displacement between the dot (Structural Motion Between Wher The Probe Is Mounted And The Spindle.

) . B.

Cause radial and average error (the reason of Average Error) : 1.

Inside bearing (outside) annulus orbit out of round (Out Of Round Stationary Bearing Races) . 2.

Bearing out of round (Out Of Round Bearing Seats) . 3.

Bearing incorrect heart (Misaligned Bearing Seats) . 4.

Tigidity of structure of coincidence of main shaft dynamic unbalance is inhomogenous (Out Of Balance Condition Coupled With Non-uniform) , (I.

E.

A Structure That Is Weak In One Direction) . 5.

Machine platform construction and resonance of main shaft rotate speed (Resonant Conditions Of The Machine Structure That Are Synchronized With The Rotational Speed) . C.

Cause radial asynchronous error (the reason of Asynchronous Error) : 1.

Bearing is pressed beforehand undeserved (Improper Preload) . 2.

Bearing blemish (Bearing Defects) for example: ? Ling of Ni of coerce of Xie of Ji of  of crucian carp of Xian of crucian carp hazel harding iron finishs?Size Variation Or Defects In Rolling Elements.

) . The attrition of ball or roller and orbit face (Defects Such As Galling Of Rotating Race) . Maintain implement deterioration of ropes or assemble undesirable. (Worn Or Installed Improperly)3 of – of Bearing Cages.

Machine platform construction is out of shape cause opposite vibration (Structural Motion / Relative Vibration) . 4.

The structural vibration that by machine stage exterior and oscillatory source causes is out of shape (Conducted Vibration From The Floor That Caused Motion Between The Probe And Master Target.

) . 5.

Source of vibration of machine stage interior (the: that Self Excited Motion) causes? Cooling system of low?Hydraulic System) of racoon dog melon (Coolant System) gear, leather belt reachs leather belt annulus (Gears, belts, pulleys) lubricant system (Lubrication Systems)6.

The resonance of rigid structure or main shaft (Resonant Frequencies Of The Machine Elements Including The Spindle That Are Not Synchronized To The Rotational Speed.

) . 4, precision of main shaft circumgyrate checks precision of circumgyrate of main shaft of example ØVICTOR lathe actually to check erect example NextpageØVCENTER to machine precision of circumgyrate of machine main shaft integratedly to check laboratory of precision of circumgyrate of main shaft of erect example Ø to measure result example to explain 5, conclusion uses this one nicety to measure a technology to have following advantage: 1.

Precision of circumgyrate of main shaft trends measures the locomotive character that can evaluate main shaft, this measures by means of can be informed main shaft to assemble case, decide to whether need to be assembled afresh again. 2.

This measures by means of, can be informed main shaft relatively beautiful movement rotate speed and get better work, and need not push ideal movement rate instead by actual cutting result. 3.

When rotate speed is close to resonance frequency, can urgent hurriedly increases the circumgyrate error of main shaft, measure Yi Ke to be measured from this its resonance frequency. 4.

In exercise of the weak opening that nod evade, average error motion and the true circularity that machine finished aperture have direct and relevant; Random error motion machines the exterior surface roughness of finished aperture to also have direct conjunction, if main shaft has lesser random error campaign, can machine piece relatively the exterior surface roughness of beautiful. CNC Milling