Evolving circle
The circle evolving is the curve that describes the point A of a semiretta that rolls without crawling on a circumference. As a practical application it is used to shape the contours of the toothed teeth of the toothed wheels as it has the property of ensuring the constantness of the transmission ratio.
Its coordinates given in a parametric form are:
x = a ( cos t + t without t ) {\displaystyle x=a(\cos {t}+t\sin {t})}
Y = a ( without t & # x2212; t cos t ) {\displaystyle y=a(\sin {t}-t\cos {t})}
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