Download - EML 2023 – Modeling, Parts
CAM design
EML 2023 Modeling, PartsLecture 1.11 Equation Driven CurveEML 2023Department of Mechanical and Aerospace Engineering1Equation Driven Curve2
y= 2 x2 3 x + 2, x = 0.. 2EML 2023Department of Mechanical and Aerospace Engineering2Parametric Equations3
x = sin(t)y = 2 cos(t)t = 0 .. 1.25EML 2023Department of Mechanical and Aerospace Engineering
Parametric Equations4x = sin(t)y = 2 cos(t) + tt = 0 .. 4EML 2023Department of Mechanical and Aerospace EngineeringWhat is a cam?
5EML 2023Department of Mechanical and Aerospace Engineeringcam and follower
6EML 2023Department of Mechanical and Aerospace Engineeringdisc cam with flat follower
7EML 2023Department of Mechanical and Aerospace Engineeringrocker cam
8EML 2023Department of Mechanical and Aerospace Engineering4 cycle engine
9EML 2023Department of Mechanical and Aerospace EngineeringOur Problem
L1 = 2L2 = 3 = 12010EML 2023Department of Mechanical and Aerospace EngineeringOur problemDesign a disc cam (for use with a flat follower) such that:follower height is L1 when cam angle is 0follower height is L2 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.
11EML 2023Department of Mechanical and Aerospace EngineeringDetermine cam profile equation
Would like to have y = f(x).We want a linear relationshipbetween L and .L = A + BDetermine A and B.
When = 0, L = L1 ; when = , L = L2
L1 = A (0) + BL2 = A () + B
12EML 2023Department of Mechanical and Aerospace EngineeringCam profile equation
Now well get the x and y coordof point A (an arbitrary point) xA = L cosyA = L sinsubstitute for LA
13EML 2023Department of Mechanical and Aerospace EngineeringCam profile equation
We would like to have y as a functionof x.Instead we have y and x as a function of . This is called a parametric representation of x and y.A
14EML 2023Department of Mechanical and Aerospace EngineeringCam profile equation
Lets look at a numerical example:L1 = 2 (when = 0)L2 = 3 corresponding to = (120) A
15EML 2023Department of Mechanical and Aerospace EngineeringCam profile equation
Plot the x,y coordinates as variesfrom 0 to
A
16EML 2023Department of Mechanical and Aerospace EngineeringCam profileHow do we get this exact curve into SolidWorks?make a sketch with an equation driven curve (parametric)button is under the spline button
17L1 = 2L2 = 3 = 120EML 2023Department of Mechanical and Aerospace EngineeringCam Profile
equation driven curve (parametric)18L1 = 2L2 = 3 = 120EML 2023Department of Mechanical and Aerospace Engineeringcomplete the profile
19EML 2023Department of Mechanical and Aerospace Engineeringcomplete the profile
20EML 2023Department of Mechanical and Aerospace Engineeringcomplete the profile
21EML 2023Department of Mechanical and Aerospace Engineeringprofile
working region of cam22EML 2023Department of Mechanical and Aerospace Engineering
23EML 2023Department of Mechanical and Aerospace Engineering