Engineering

1
Engineering

• Creating objects that use verified technological
  principles to help humans meet their needs.
• Kinds?
• Mechanical, Chemical, Biomedical, Electrical,
  Computer, and Civil Engineering.

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What is Mechanical Engineering?

• It is a branch of engineering that deals with the
  design, construction, operation and improvement
  of systems or technical objects.

?
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What is a mechanical function?

• It is defined as the role played by a mechanism
  inside a more or less complex object.
• A mechanism is a part of substance having a
  specific function.
• YouTube - mechanical engineering

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The Five basic Mechanical Functions?
Typical Function Description
Link 2 or more parts are connected together.
Guiding Control One or more parts allows a part to rotate, translate or both together.
Lubrication A substance that reduces friction between two or more parts.
Seal A mechanism that prevents leaks of gases, liquids, or solids from an object
Support Part that is used to hold up another corresponding part.
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LINKS
How objects are connected together.
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Guiding Control
allows a part to rotate, translate or both
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Lubrication
reduces friction
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Seal
prevents leaks
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Support
hold up other corresponding parts
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A Mechanical Object
Link
Support
Guide Control
Lubrication
Seal
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How to Describe Links

• The link function is the connections between two
  parts or more.
• They exist when an object is composed of more
  than a single part.

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Kinds of Links
Direct Link Indirect Link
Connects parts with no other device being used. Lego Connects parts by using another device to hold them together. Nail Bolt Screw
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Removable Link Non-removable Link
Link can be removed without damaging anything on the object. Nut and Bolt separates the seat from the post. Connected parts can not be removed without damaging the object. Welded frame cant be separated.
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Rigid Link Elastic Link
Pieces of the object can not be interchanged when assembled. Table pieces. Allows for parts to change position. Shocks or Springs.
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Complete Link Partial Link
No parts move independently of each other. All move together. Hammer Parts can move independently to each other. C-Clamp
A link always has 4 of the 8 properties they
have one from each pair of properties Direct or
Indirect
Removable or Non-Removable
Rigid or Elastic
Complete or Partial
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Example A Door, its Hinge, and the Door Frame.
Link Property
Direct or Indirect? The door its frame are held by hinges which need screws. INDIRECT LINK
Removable or Non-removable? The door and hinges can be removed by unscrewing them. REMOVABLE LINK
Rigid or Elastic? Neither the doors wood or hinges metal can be stretched. RIGID LINK
Complete or Partial The door can move freely without causing the door frame to move. PARTIAL LINK
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Your Turn

• Describe the four characteristics of the links in
  each of the following examples
• Create a basic design plan using a ruler, BUT
  ONLY SYMBOL THE LINKS AND WHAT 4 PROPERTIES THEY
  HAVE.
• A table and its four legs connected with screws.
• A pair of scissors.
• c) A pen and its cap.

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Motion Transmission Systems

• Is defined as a systems ability to transmit the
  same motion from one part of an object to another.

When we pedal a bicycle, we transmit a force into
the peddles, which then transmits the motion into
the bikes wheels via the chain and
gears. Question? Does it always have to move in
the same way?
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Bidirectional Spiral Motion transmits into
Bidirectional Rectilinear Translation.
Egg Beater Hand Out
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Antique Egg Beater Motion Transmission System
__________________________________________________
__________________________________________________
___________________________________
Link
Indirect Non-removable Rigid Complete
Support
Guide Control
Seals? Lubrication?
Keep this sheet handy, you will need it later.
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Do Motion Systems need

• Lubrication?
• Guiding Control?
• Seals?
• Support?
• Not all of them, but where there is motion,
  usually lubrication is needed for limiting
  friction.which means there should be seals
  keeping the lubricant stored or inside the
  mechanism. Most movements require a guide
  control so the pieces dont fly as well as
  giving support frames where the mechanisms wont
  interfere with each other. Plus it depends on
  what the object is used for.

YouTube - ENGINE ANIMATION....
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From the Video, did you see evidence of each of
the following Mechanical Functions?

• Lubrication.
• Oil for the pistons, and gears.
• Guiding Control
• The Cylinders the pistons move through.
• The Gears proper rotation.
• Seals
• Keep the lubricants and gas from leaving the
  engine.
• Support
• All the nuts and bolts, molded frame.

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Types of Transmission Systems
Mechanisms Definition
Motor Mechanism Mechanism of a system on which force is applied. Bike Pedals transmit leg energy.
Intermediate Mechanism Mechanism of a system that transfers the action of a motor mechanism (driving force) to a receiving mechanism Chain on a Bike
Receiving Mechanism Mechanism of a system that receives the motion through an intermediate mechanism. Rear Wheel in a bike.
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Chain and Sprocket System
Back Wheel (Receiving Mechanism)
Chain (Intermediate Mechanism)
Pedal (Motor Mechanism)
If any of the pieces of the mechanism fail, what
would the possible result be?
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Antique Egg Beater Motion Transmission System
__________________________________________________
__________________________________________________
___________________________________
Link
Indirect Non-removable Rigid Complete
Motor Mechanism
Intermediate Mechanism
Support
Guide Control
Receiving Mechanism
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Different Types of Motion Transmission Systems

• Chain and Sprockets
• Belt and Pulley
• Gears
• Friction Gears
• Wheel and Worm Gear

Simple Machines
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Antique Egg Beater Motion Transmission System
Changed rotation direction 90o. Twice the
energy, with the same energy output.
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Transformation Systems

• The ability of one mechanism to CHANGE the
  nature of motion in another mechanism.

Options 1. Rotation into Translation 2.
Rotation into Rotation 3. Translation
into Rotation 4. Translation into
Translation.
B
A
Rotation
Translation
B
Examples Extraordinaire!
B
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Motion Transformation of a Bicycle
Rotation Motion
Translation Motion
Therefore, a bicycle transforms its motion
from Rotation Motion into Translation Motion.
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Different Types of Motion Transmission Systems
Name of System Diagram of System
Screw and Gear System Ex ________________
Wheel and Worm Gear Ex ________________
Cam and Follower Ex ________________
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Motion Transformation Systems

• Is the The ability of one mechanism to CHANGE the
  nature of motion in another mechanism.

Example C-Clamp
Rotation Motion Translation Motion
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Rack and Pinion Steering
Rack and Pinion Rotation Motion
Translation Motion
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Cam and Follower
Rotational Motion Alternating
Translation Motion
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Major Examples of Motion Transmission Systems

• Clock Towers have 4 types of motion transmission
  systems in use.
• Belt and Pulley
• Gears
• Friction Gears
• Wheel and Worm Gear

Any Mechanical Functions? Links?
Guiding Controls? Lubrication?
Seals? Supports?
Type of Motion Transformation?
Translation Motion Rotational
Motion
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Personal Questions

• Pg. 371 Synergy
• Questions 1-7, 10-12.