Mechanism to Draw Three-Petalled Rose

Input: pink crank.
Output: green slider. Its center D draws three-petalled rose (in red). Its equation in polar coordinate system OX:
OD = a*sin(3φ)
φ: angle DOX
a: vertical distance between O and the center of the lower revolution joint of the blue part.
Center distance of two revolution joints of the blue bar = 4a. The joints are symmetric over the horizontal bar of the blue part.
The violet slider has revolution joint with the yellow part.

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