EngineeringEngineering

Creating objects that use verified technological Creating objects that use verified technological principles to help humans meet their needs.principles to help humans meet their needs.

Kinds?Kinds?

Mechanical, Chemical, Biomedical, Electrical, Mechanical, Chemical, Biomedical, Electrical, Computer, and Civil Engineering.Computer, and Civil Engineering.

What is Mechanical Engineering?What is Mechanical Engineering?

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

→

What is a mechanical function?What is a mechanical function?

It is defined as the role played by a It is defined as the role played by a mechanismmechanism** inside a more or less inside a more or less complex object. complex object.

** A mechanism is a part of substance A mechanism is a part of substance having a specific function.having a specific function.

YouTube - mechanical engineeringYouTube - mechanical engineering

The Five basic Mechanical The Five basic Mechanical Functions?Functions?

Typical FunctionTypical Function DescriptionDescription

LinkLink 2 or more parts are connected 2 or more parts are connected together.together.

Guiding ControlGuiding Control One or more parts allows a One or more parts allows a part to rotate, translate or part to rotate, translate or both together.both together.

LubricationLubrication A substance that reduces A substance that reduces friction between two or more friction between two or more parts.parts.

SealSeal A mechanism that prevents A mechanism that prevents leaks of gases, liquids, or leaks of gases, liquids, or solids from an objectsolids from an object

SupportSupport Part that is used to hold up Part that is used to hold up another corresponding part.another corresponding part.

LINKSLINKSHow objects are “connected together”.

Guiding ControlGuiding Control““allows a part to rotate, translate or both”allows a part to rotate, translate or both”

LubricationLubrication““reduces friction”reduces friction”

SealSeal““prevents leaks”prevents leaks”

SupportSupport““hold up other corresponding parts”hold up other corresponding parts”

A Mechanical ObjectA Mechanical Object

LinkSupport

SealLubrication

Guide Control

How to Describe LinksHow to Describe Links

The link function is the connections The link function is the connections between two parts or more.between two parts or more.

They exist when an object is composed of They exist when an object is composed of more than a single part.more than a single part.

Kinds of LinksKinds of Links

Direct LinkDirect Link Indirect LinkIndirect LinkConnects parts with no other Connects parts with no other device being used.device being used.

LegoLego

Connects parts by using another Connects parts by using another device to hold them together.device to hold them together.

NailNail

Bolt Bolt

ScrewScrew

Removable LinkRemovable Link Non-removable LinkNon-removable Link

Link can be removed without Link can be removed without damaging anything on the object.damaging anything on the object.

Nut and BoltNut and Bolt

separates the separates the

seat from the post.seat from the post.

Connected parts can not be Connected parts can not be removed without damaging the removed without damaging the object.object.

Welded frameWelded frame

can’t be can’t be

separated.separated.

Rigid LinkRigid Link Elastic LinkElastic Link

Pieces of the object can not be Pieces of the object can not be interchanged when assembled.interchanged when assembled.

Table pieces.Table pieces.

Allows for parts to change Allows for parts to change position.position.

Shocks or Springs.Shocks or Springs.

Complete LinkComplete Link Partial LinkPartial LinkNo parts move independently of No parts move independently of each other. All move together.each other. All move together.

HammerHammer

Parts can move independently to Parts can move independently to each other. each other.

C-ClampC-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

Example: A Door, its Hinge, and the Door Frame.

LinkLink PropertyPropertyDirect or Indirect?Direct or Indirect? The door & its frame are The door & its frame are

held by hinges which need held by hinges which need screws.screws.

INDIRECT LINKINDIRECT LINK

Removable or Removable or

Non-removable?Non-removable?

The door and hinges can be The door and hinges can be removed by unscrewing removed by unscrewing

them. them.

REMOVABLE LINKREMOVABLE LINK

Rigid or Elastic?Rigid or Elastic? Neither the door’s wood or Neither the door’s wood or hinges metal can be hinges metal can be

stretched. stretched.

RIGID LINKRIGID LINK

Complete or PartialComplete or Partial The door can move freely The door can move freely without causing the door without causing the door frame to move. frame to move. PARTIAL PARTIAL

LINKLINK

Your TurnYour 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) A table and its four legs connected with screws.

b) A pair of scissors.

c) A pen and its cap.

Motion Transmission SystemsMotion Transmission SystemsIs defined as a system’s ability to transmit the Is defined as a system’s ability to transmit the same motion from one part of an object to another.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 bike’s wheels via the chain and gears.

Question?

Does it always have to move in the same way?

Bidirectional Spiral Motion transmits into Bidirectional Rectilinear Translation.

Egg Beater Hand Out

Antique Egg Beater Motion Transmission System_______________________________________________________________________________________________________________________________________

Support

Link Indirect

Non-removable

Rigid

Complete

Guide Control

Seals?

Lubrication?

Keep this sheet handy, you will need it later.

Do Motion Systems need…Do Motion Systems need…LubricationLubrication**? ? Guiding ControlGuiding Control**??SealsSeals**??SupportSupport**??

Not all of them, but Not all of them, but where there is motionwhere there is motion, usually , usually lubricationlubrication** is needed is needed for limiting friction….which for limiting friction….which means there should be means there should be sealsseals** keeping the lubricant keeping the lubricant stored or inside the mechanism. stored or inside the mechanism. Most movementsMost movements require a require a guide controlguide control** so the “pieces don’t fly” as well so the “pieces don’t fly” as well as giving as giving supportsupport** frames where the mechanisms won’t frames where the mechanisms won’t interfere with each other. Plus it depends on what the interfere with each other. Plus it depends on what the object is used for.object is used for.

YouTube - ENGINE ANIMATION....

Lubrication. Lubrication. Oil for the pistons, and gears.Oil for the pistons, and gears.

Guiding Control:Guiding Control:The Cylinders the pistons move through. The Cylinders the pistons move through. The Gears proper rotation.The Gears proper rotation.

Seals:Seals:Keep the lubricants and gas from leaving the engine.Keep the lubricants and gas from leaving the engine.

Support:Support:All the nuts and bolts, molded frame.All the nuts and bolts, molded frame.

From the Video, did you see evidence of each of the following Mechanical Functions?

MechanismsMechanisms DefinitionDefinition

Motor MechanismMotor Mechanism Mechanism of a system on which Mechanism of a system on which force is applied.force is applied.

Bike: Pedals transmit leg energy.Bike: Pedals transmit leg energy.

Intermediate MechanismIntermediate Mechanism Mechanism of a system that Mechanism of a system that transfers the action of a motor transfers the action of a motor mechanism (driving force) to a mechanism (driving force) to a receiving mechanismreceiving mechanism

Chain on a BikeChain on a Bike

Receiving MechanismReceiving Mechanism Mechanism of a system that Mechanism of a system that receives the motion through an receives the motion through an intermediate mechanism.intermediate mechanism.

Rear Wheel in a bike.Rear Wheel in a bike.

Types of Transmission Systems:

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?

Chain and Sprocket System

Antique Egg Beater Motion Transmission System_______________________________________________________________________________________________________________________________________

Support

Link Indirect

Non-removable

Rigid

Complete

Guide Control

Motor Mechanism

Intermediate

Mechanism

Receiving Mechanism

Different Types of Motion Different Types of Motion Transmission SystemsTransmission Systems

Chain and SprocketsChain and Sprockets

Belt and PulleyBelt and Pulley

GearsGears

Friction GearsFriction Gears

Wheel and Worm GearWheel and Worm Gear

Simple Machines

Antique Egg Beater Motion Transmission SystemChanged rotation direction 90o.

Twice the energy, with the same energy output.

Transformation SystemsTransformation Systems The ability of one mechanism to CHANGE The ability of one mechanism to CHANGE

the nature of motion in another mechanismthe nature of motion in another mechanism..

Options: 1. Rotation into Translation;

2. Rotation into Rotation;

3. Translation into Rotation;

4. Translation into Translation.

Rotation: Translation: A B

B

BExamples Extraordinaire!

Motion Transformation of a Bicycle

Rotation Motion

Translation Motion

Therefore, a bicycle transforms its motion from:

Rotation Motion into Translation Motion.

Different Types of Motion Different Types of Motion Transmission SystemsTransmission Systems

Name of SystemName of System Diagram of SystemDiagram of SystemScrew and Gear SystemScrew and Gear System

Ex: ________________Ex: ________________

Wheel and Worm GearWheel and Worm Gear

Ex: ________________Ex: ________________

Cam and FollowerCam and Follower

Ex: ________________Ex: ________________

Motion Transformation SystemsMotion Transformation SystemsIs theIs the The ability of one mechanism to The ability of one mechanism to CHANGE the nature of motion in another CHANGE the nature of motion in another mechanism.mechanism.

Example: C-Clamp

Rotation Motion

Translation Motion

Rack and Pinion SteeringRack and Pinion Steering

Rack and Pinion: Rotation Motion Translation Motion

Cam and FollowerCam and Follower

Rotational Motion Alternating Translation Motion

Clock Towers have 4 types of motion transmission systems in use.Clock Towers have 4 types of motion transmission systems in use.

Belt and PulleyBelt and PulleyGearsGearsFriction GearsFriction GearsWheel and Worm GearWheel and Worm Gear

Major Examples of Motion Transmission Systems

Any Mechanical Functions?

Links?

Guiding Controls?

Lubrication?

Seals?

Supports?

Type of Motion Transformation?

Translation Motion Rotational Motion

Personal QuestionsPersonal Questions

Pg. 371 Pg. 371 Synergy;Synergy;

Questions: 1-7, 10-12.Questions: 1-7, 10-12.