Prime number gears

Prime number gears always have an odd number of teeth and are often used in practice to minimize wear of the individual teeth. If one gearwheel of a pair has a prime number as the number of teeth, the number of meshings of the same pair of teeth is minimized. This gear type is parameterized with IDN P-0-0279 “Modulo Value Remainder”.

Application example

Turntable with a gear reduction ratio of 63/17.
On the motor side, 360 ° (1 revolution) correspond to 2²⁰ increments.

The resulting modulo period at the gear output (turntable) is:

The modulo period of the AX5000 (S-0-0103) can only be parameterized with an integer value. Thus, if 3885899 inc is used as modulo period, the resulting error is 5/17 inc per modulo period on the turntable side and 5/17 x 63/17 = 1.08997 inc on the motor side. Because this error accumulates with each modulo revolution, the error becomes significant after n modulo revolutions in the same direction.

Extended parameterization

To avoid the accumulating error illustrated in the above application example, IDN P-0-0279 “Modulo Value Remainder” was implemented in the AX5000.

This IDN can be used to enter the residual (error) of the modulo period parameterized in S-0-0103, relative to the actual modulo period. The parameterized value may be positive or negative. It is best to always use the smallest absolute value. In the above example, this would be 5/17 with S-0-0103 = 3885899. The same result is obtained with the value
-12/17 with S-0-0103 = 3885900. However, this option results in a greater position jump at the correction point, since |-12/17| > |5/17|.

The drive corrects the modulo calculation as if the actual modulo period were to correspond to the value parameterized in
S-0-0103. Consequently, when calculating the NC scaling, the value in S-0-0103 must be used. The resulting scaling factor is
360°/ S-0-0103 = 360°/3885899 inc.