Page 245 - Gear Technology Solutions

The MicroPSF input screen is shown in Figure 1. Items MP1 to MP6 are the input
values which control MicroPulse. Items MP7 and MP8 control MicroShift and items
MF0 to MF-3 control MicroForm.

If a psychoacoustic optimization of a spiral bevel or hypoid gearset is planned, the
goal of this optimization is an important factor for the kind of the flank surface
structure change and for the flank form scattering.

· If a surface structure optimization is desired, for example to create a pinion

surface structure which is similar to lapped or honed surfaces, the right ef-
fect is MicroPulse

th

· If frequencies above the 4 harmonic mesh frequency have been detected
on a gearset, the MicroShift effect should be used

th
st

· If the harmonic frequency levels between the 1 and 6 mesh frequency
should be reduced, the MicroForm effect has the required potential

17.2 MicroForm

MicroPSF developments should begin with MicroForm. The MicroForm input items
are listed in Figure 2. MF1 gives the choice between a sine-function and a normal
distribution. The normal distribution is the recommended function for the first level
modification (see chapter 16).

The normal distribution is the function developed by Karl Friedrich Gauss based
on the Euler number to represent natural growth and natural degradation. This is
important for smooth amplitude buildup from one tooth to the next. The modifica-
tion amount begins at tooth one with the threshold value (calculated by the soft-
ware). At the center of the tooth count the modification amplitude reaches its max-
imum and reduces from there until it reaches the threshold value.

Standard input parameters for MF2 to MF5 are:

· MicroForm A max Correction = work axis rotation amplitude = 15µm
· MicroForm X max Correction = work axial movement = 5µm

· MicroForm Y max Correction = tool vertical movement = 5µm

· Pressure angle change amount = 0.005°

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