Page 19 - June
P. 19

METALWORKING EQUIPMENT AND TOOLS

            Figure  2 shows graphs  of  the  dependence  of  the                                   Binomial of Newton
    amplitude of oscillations arising in a drive tuned to various                                  Double proportions
    polynomials when exposed to harmonic load of variable                                          Gauss
    frequency with an amplitude of 1 Nm. It follows from the
    graphs that the maximum deviations under the influence
    of the external load will be observed when its frequency
    approaches the upper limit of the drive bandwidth. At the                    error (μm)
    same time, for almost all polynomials studied, the wider
    the drive bandwidth, the less influence the external load
    has.  An  exception  is  the  Butterworth  filter,  although  its
    passband is wider than the IWMO passband, the resulting                              Frequency Hz)
    error turns out to be larger. In the Matlab environment                                      a
    was  developed  a  special  program  evaluating  the
    possibility of implementation on the basis of the existing                                          IVMO
    component  polynomials  listed above  [8].  With  its help,                                         Butterworth
    each combination of weight parameters (in the range from
    50 to 4000 kg, in 50 kg increments) and the travel of the
    unit being moved (in the range from 50 to 4000 mm, in
    50 mm increments) was checked for compliance with the                       error (μm)
    required:
    ●  the  relationship  between  the  moments  of  inertia  of
    the unit being moved and the rotating parts of the drive
    mechanism, dependence (1);                                                        Frequency Hz)
    ● axial stiffness of the traction device, dependence (2).                                   b
    Analysis of the data obtained showed that the polynomials
    corresponding  to  the  settings  "double  proportions"  and                                       Gauss
    "binomial expansion"  have  the  widest range  of  possible                                        Gauss
                                                                                                       Linear
    combinations  of  mass and  displacement  of  the  node.  It                                       phase
                                                                                                       Linear
                                                                                                       phase
    is  rational  to  use  the  filter  "double  proportions"  for  the
    mass of the unit from 500 to 4000 kg and the value of
    displacement up to 2000 mm, for Newton's binomial - the
    mass is 250 ... 3500 kg, the stroke is up to 1500 mm.                       error (μm)
    Machine tools whose drive components are very different
    (the mass or the stroke of the moved unit differs several
    times), it is easiest to tune to these polynomials. At the                        Frequency Hz)
    same time, they have the narrowest bandwidths - 23 and                                      c
    31 Hz, respectively. Gauss, Bessel, Butterworth and IWMO
    filters have an average range of possible applications (the              Fig. 2. Amplitude of oscillations arising under
    names are arranged in descending order).                                 the action of a harmonic disturbing load of
                                                                             variable frequency when the drive is tuned to
                                                                             different polynomials.


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