Problem S
For the Scotch yoke mechanism shown in the figure below, link 2 (O2B) rotates at a constant
speed w2 of 25 rad/sec CCW. Determine
(a) The expression of the linear acceleration for link 4 as a function of and 2 .
(b) The expression of relative ac

Ch 9 of the textbook
Mechanics of
Figure 9.1 Machines
a four-bar mechanism.
Cleghorn
1
Angle of total shaking force
(-30)
(-60)
Figure 9.3/9.4/9.6 Driving torque and shaking force/moment.
Mechanics of Machines
Cleghorn
2
Figure 9.7 a slider crank mechanis

R1 Use loop closure analysis to determine RC and (angle of link BC from the horizontal axis)
for (The figure is not drawn to scale)
R2
For the V-shaped, two-cylinder engine shown in the figure, the two connecting rods, BC and BD,
share the same crank AB.

Problem Q In the mechanism shown below, link AE rotates with a constant angular velocity
200 rpm (CW). Find acceleration of point D at the moment.
E
Figure 2.5 Relative acceleration components between two points.
Mechanics of Machines
Cleghorn
Copyright 2

Balance
1)
Im
After the four-bar
mechanism is
balanced
Figure 9.14 Location of center of mass of a four-bar mechanism in balance.
fecnamcs 0 ' V‘s-1*." 55
J egho'n
I)
(dig): a 177.6" "“‘\
Figure 9.17 Force balanced mechanism. ISO
“23
l 80 .
Pnor t

Mec E 362 Mechanics of Machines
Assignment #6
Due: Oct 16 (F), 4 pm
NOTE: Midterm will be held in CCIS L2 200 on Oct 21 (W), 6-8 pm
Problem 1: P2.26 in the textbook
1
Problem 2: P3.2 in the textbook
2
Problem 3: P3.6 in the textbook (Distance between two

Mechanics of Machines
1 Introduction
1.1 Basic concepts
Machines: any mechanical or electrical devices that transmit or modify energy to perform
or assist in the performance of human tasks.
Mechanisms: subsystems of a machine, which perform specific motio

Chapter 2 Gears
Introduction
Gears: Machine elements that transfer rotary motion between two shafts.
The key issue in gear design is how to ensure a smooth transfer of the rotary motion, i.e.
how to ensure that the ratio between angular velocities of the

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Chapter 1 Kinematics of Mechanisms
A mechanism usually consists of several links connected by joints. When the deformation
of the links is negligible these links can be considered as rigid bodies. As a model of a
real link, a rigid body model should captu

1 Introduction
Machines: any mechanical or electrical devices that transmit or
modify energy to perform or assist in the performance of human
tasks.
Mechanisms: subsystems of a machine, which perform specific
motions or tasks
Links: individual parts of a

MECE 362 Mechanics of Machines: Balancing
Chapter 5 Balancing
The motion of any mechanism can be sustained only if proper forces and moments are
applied to the mechanism. For high speed machinery, the acceleration could be very
significant during the moti

MECE 362 Mechanics of Machines: Force Analysis
Chapter 4 Force Analysis of Mechanisms
In previous chapters, attention has been paid only to the kinematics of mechanisms, i.e.
the position, velocity and acceleration analyses of mechanisms. In this chapter

MECE 362 Mechanics of Machines: Gear Trains
Chapter 3 Gear Trains
3.1. Introduction
Machines are mostly driven by electric motors, internal-combustion engines, and turbines, which
operate at much higher speed than that of the machines. Gear trains are com

MECE 362 Mechanics of Machines: Kinematics
Chapter 1 Kinematics of Mechanisms
1.2 Velocity Analysis Using Instant Centers
An important method for the velocity analysis of mechanisms is the use of instant centers.
This method, which is usually done graphic

Example 1.3.2.
For the mechanism shown, determine the angular velocity of link 2 and the sliding
velocity of link 3 with respect to link 2 if VA= 2 [in/s].
Use loop closure equation.
Example 1.3.3.
For a slider crank mechnism, determine the displacement,

Example 1.2.5
For an inverted slider crank mechanism, determine (i) ICs, and (ii) velocity of point B
as a function of the angular velocity of link 2.
Example 1.2.4
Determine (i) the angualr velocity of link 4 and (b) the velocity of D

Matlab script to plot a four-bar linkage with a coupler point
% Analyze and plot a four-bar linkage with a coupler point %
clc, clear, close all
r1=8;
r2=3.5;
r3=10;
r4=9;
r6=3; % test other values
r7=4; % test other values
for t2=1:1*360 % theta 2
t3=aco

Step 1: Find ICs using kinematic pairs: we can determine IC12, IC14, IC23, IC34.
Step 2: Determine IC24 and IC13.
To determine IC24, we use Kennedy's theorem.
A) Consider first a triangle 124 from the polygon, corresponding to three links 1,2,4. The
corre

1.3 Kinematic analysis of mechanisms using Loop Closure Equations
- In a mechanism, the postion of individual links are not independent, since the motion is
restricted by the kinematic pairs.
- The relation between different links can be represented by a

Chapter 1: Kinematics of Mechanisms
Assumption:
For a mechanism, each link will be treated as a rigid body unless specified otherwise.
Rigid body model is represented by:
i) Location of connecting points on each link
ii) Mass of each link
iii) Location of

Feb 26, 2014
Midterm exam
University of Alberta
Faculty of Engineering
Mec E 362
Mechanics of Machines
Time: 120 min
Instructor: Dr. Ben Jar
Opebook exam: Exam is open book, but only Faculty-approved non-programmable or programmable calculators
are allowe

MecE 362 Mechanics of Machines Review
CD
Note that this is not an exhaustive review but aims to highlight some of the essentials
7%?
Chapter 5 & 6: Gears 3
Speed ratio: ‘
P . 5.7;. _ .N a‘. - T: . _
= w ‘ " ‘ T:— "' " '
z f:3 :5 t 5 2 '
External geari

Q2 (10 marks)
For the mechanism shown in the figure below, use loop closure analysis to determine the
sliding velocity of B4 with respect to 83 at this instant.
It is known that 62 = 135° and 64 = 84.78° at this instant, and 0', = 30 rad/sec CW (constant)

MecE 362 Mechanics of Machines Rate of Work
NN) Rate of Work Principle (Dynamic case)
At this instant shown the crank AB of the four-bar linkage has a constant angular
velocity of 10 rad / s (CW). What torque is required on AB to achieve this motion at