EML 2023 Modeling, Parts Lecture 1.11 Equation Driven
Curve
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EML 2023 Department of Mechanical and Aerospace Engineering
Equation Driven Curve 2 y= 2 x 2 3 x + 2, x = 0.. 2
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EML 2023 Department of Mechanical and Aerospace Engineering
Parametric Equations 3 x = sin(t) y = 2 cos(t) t = 0.. 1.25
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EML 2023 Department of Mechanical and Aerospace Engineering
Parametric Equations 4 x = sin(t) y = 2 cos(t) + t t = 0.. 4
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EML 2023 Department of Mechanical and Aerospace Engineering
What is a cam? 5
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EML 2023 Department of Mechanical and Aerospace Engineering cam
and follower 6
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EML 2023 Department of Mechanical and Aerospace Engineering
disc cam with flat follower 7
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EML 2023 Department of Mechanical and Aerospace Engineering
rocker cam 8
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EML 2023 Department of Mechanical and Aerospace Engineering 4
cycle engine 9
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EML 2023 Department of Mechanical and Aerospace Engineering Our
Problem L 1 = 2 L 2 = 3 = 120 10
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EML 2023 Department of Mechanical and Aerospace Engineering Our
problem Design a disc cam (for use with a flat follower) such that:
follower height is L 1 when cam angle is 0 follower height is L 2
when cam angle is the relationship between the height, L, and the
cam angle, , is linear We need to get the function of the cam
profile and then draw a curve in SolidWorks that exactly models
this profile. 11
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EML 2023 Department of Mechanical and Aerospace Engineering
Determine cam profile equation Would like to have y = f(x). We want
a linear relationship between L and . L = A + B Determine A and B.
When = 0, L = L 1 ; when = , L = L 2 L 1 = A (0) + B L 2 = A ( ) +
B 12
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EML 2023 Department of Mechanical and Aerospace Engineering Cam
profile equation Now well get the x and y coord of point A (an
arbitrary point) x A = L cos y A = L sin substitute for L A 13
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EML 2023 Department of Mechanical and Aerospace Engineering Cam
profile equation We would like to have y as a function of x.
Instead we have y and x as a function of . This is called a
parametric representation of x and y. A 14
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EML 2023 Department of Mechanical and Aerospace Engineering Cam
profile equation Lets look at a numerical example: L 1 = 2 (when =
0) L 2 = 3 corresponding to = (120 ) A 15
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EML 2023 Department of Mechanical and Aerospace Engineering Cam
profile equation Plot the x,y coordinates as varies from 0 to A
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EML 2023 Department of Mechanical and Aerospace Engineering Cam
profile How do we get this exact curve into SolidWorks? make a
sketch with an equation driven curve (parametric) button is under
the spline button 17 L 1 = 2 L 2 = 3 = 120
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EML 2023 Department of Mechanical and Aerospace Engineering Cam
Profile equation driven curve (parametric) 18 L 1 = 2 L 2 = 3 =
120
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EML 2023 Department of Mechanical and Aerospace Engineering
complete the profile 19
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EML 2023 Department of Mechanical and Aerospace Engineering
complete the profile 20
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EML 2023 Department of Mechanical and Aerospace Engineering
complete the profile 21
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EML 2023 Department of Mechanical and Aerospace Engineering
profile working region of cam 22
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EML 2023 Department of Mechanical and Aerospace Engineering
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