| Summary: | 碩士 === 國立成功大學 === 機械工程研究所 === 82 === The purpose of this work is to study the effects of
manufacturing errors on the geometry design and dynamic
characteristics of planar conjugate cams. Positive-drive cams
and conjugate cams are defined and classified first in order to
clarify their differences. The traditional approach for
deriving planar cams are applied to the geometry design of
planar conjugate cams by modifying some parameters. Then,
Taguchi method is used to the parameter design of conjugate
cams, and signal- noise (SN) ratios are calculated from
geometrical errors. The major factors which dominate
geometrical errors are concluded,and moderate tolerances are
given to the design parameters. The precision of the distance
between the axes of the cam and the follower is found to be the
most important factor to the assembly of conjugate cams. A
simple but adequate measurement procedure is illustrated for
checking the accuracy of conjugate cams with swing followers.
In the range with large pressure angles, obvious fluctuation of
the distance between the axes is induced by manufacturing
errors. Both kineto-static and dynamic analysis methods are
carried out to obtain the stress between the rollers and the
cam and the required input torque. Furthermore, a generalized
mass-spring-damping model is established for the dynamic
analysis, and the influences of manufacturing errors on system
dynamics are observed. The waviness of manufacturing errors is
found to be the major factor for inducing vibrations, noises,
and fatigue failures. Kineto-static analysis can not predict
the occurrences of jump phenomena; on the other hand, dynamic
analysis can achieve that by taking account of flexibility of
cams and followers. Finally, the conjugate cam of a shuttleless
weaving loom mechanism is used as an example for considering
the effects of manufacturing errors on the stress and input
torque. As a result, we conclude some important rules for
designing planar conjugate cams with swing followers.
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