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223
Table 7.2: Eigen frequencies of the elements of gear-box
Elements
Cover
Input shaft
Middle shaft
Output shaft
0 kg
500 kg
First frequency
15.8 Hz
165 Hz
3.5 Hz
89 Hz
61.2 Hz
Second frequency
23.6 Hz
303.6 Hz 25.1 Hz
139 Hz
110.8 Hz
The calculation was done for three cases:
1.
without the influence of the couple,
2.
a part of a coupling mass on the shaft of electromotor is 80 kg, and a part on a
input-shaft of gear-box is 400 kg,
3.
a part of a coupling mass on the shaft of electromotor is 100 kg, and a part on an
input-shaft of gear-box is 500 kg.
Table 7.3: Eigen frequencies of the drive unit
1. [Hz]
2. [Hz]
3. [Hz]
4. [Hz]
5. [Hz]
First case
23.7
27.4
33.3
35.5
36.8
Second case
14.2
20.3
22
23.3
27.3
Third case
13.2
18.9
20.4
23.3
27.3
First mode
Second mode
Third mode
Fourth mode
Figure 7.13: Amplitudes in first four modes of oscillations
CONCLUSION
Presented calculation is shown that the eigen frequencies of all shafts of a gear-box are
high enough. Dynamic behaviour of electromotor is satisfied, as well behaviour of the
momentum bar. The problem is immanent only in the input-shaft of the gear-box because
of the influence of coupling. This influence is dominant in the first three modes.