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Hey guys, Today, we'll be analyzing the toggle mechanism.
Here's the simulation for this mechanism, if you're really interested. Like I said before,
visualizing is the heart of all kinds of analysis. You need to know how the individual links
move accordingly with the crank's rotation. Let's go for the velocity polygon. There's
an anticlockwise rotation of crank OC, and so here comes the tangential velocity from
fixed points O & A. As you can see, power from this crank is transferred to the next
crank through the rod BC, which in turn causes the piston to move to & fro. And, we're sure
about the surface over which the piston D is gonna slide.
Now, BC has a tangential velocity towards the right. We just draw a line, as we don't
know the magnitude yet. They're links having more than one relationship with the other
links. So, they won't be available for us explicitly.
As we move through the mechanism, we get into crank AB, which also has a tangential velocity
as it's spinning with some angular velocity. It looks like there's an intersection. That
should be B because that connects crank OC to the crank AB.
Now, let's move to the link BD. Its tangential velocity is perpendicular to the link. That
line extended from B in the velocity polygon, intersects the surface at D. Measuring the
lengths, and scaling them up gives you the relative velocities between those two points.
Okay, next we move on to the acceleration diagram. Always start with the given data.
We have the radial acceleration from OC, and we also have the surface. If you want, you
can also draw the tangential acceleration for OC.
Then, we have the radial acceleration from BC. We also have the tangential acceleration
from BC. There's another crank AB, which has its centripetal acceleration from B to A.
B to A. It's really hard to guess the lengths of those lines. They're somewhat exaggerated
here. Okay, this should be that crank's radial acceleration.
And, it has a tangential. We make use of the tangential components for all the other links
except the driver because those things are ran by the driver. And, as you can see in
the simulation, these links always have some kind of angular motion, and they accelerate
and decelerate often. So, there's a tangential acceleration.
And, there's an intersection. These intersecting lines are drawn from C & A. And, there's only
one joint connecting them. And, that's definitely B. Don't worry about those primes on the top.
I'm using that just to differentiate these from the other vectors.
Now, this link BD has a radial component which goes like that and a tangential component
that goes like that. And, there's an intersection. That should be D, because it's the only link
moving in the horizontal direction. On connecting the respective points in our
diagram, you'll get the relative acceleration between those two joints.
Thank you