Mechanical Engineering Flashcards
What are Links?
Two parts that come together.
What is a Complete Link?
When both parts move together.
What is a partial link?
Parts that move separately.
Is the relationship between a tire and a wheel complete or partial?
Complete.
Is the relationship between the two handles of a can opener partial or complete?
Partial
What is a direct link?
2 parts together without a linking component.
What is a indirect link?
2 parts together with a linking component.
In a pair of scissors, is the relationship between the two handles direct or indirect?
Indirect (due to the rivet)
Is the link between a blade and shoe on a skate direct or indirect?
Indirect (due to the screw)
What is a removable link?
Parts that can be removed without breaking the parts or linking component.
What is a non-removable link?
Parts that can’t be removed without breaking parts or linking component.
What is a flexible link?
One of the parts must come back to it’s original position when deformed (usually needs a spring).
What is a rigid link?
A part that can only go back to it’s original position through human force.
In a bookshelf, is the relationship between the shelf and side panel rigid or flexible?
Rigid.
In a clothespin, is the relationship between the two prongs rigid or flexible?
Flexible.
When looking at an object, and we must identify whether the characteristic of a link is direct or indirect.
What question should we ask ourselves?
Do the parts require something else to hold them together?
When looking at an object, and we must identify whether the characteristic of a link is rigid or flexible.
What question should we ask ourselves?
Can the linking component be deformed when used and will it return to it’s original position?
When looking at an object, and we must identify whether the characteristic of a link is Removable or Non-Removable.
What question should we ask ourselves?
Can the object be taken apart without causing damage to the object?
When looking at an object, and we must identify whether the characteristic of a link is Partial or Complete.
What question should we ask ourselves?
Is movement possible between the two parts?
What are the characteristics of using a screw as a linking component?
It’s removable, indirect and rigid.
What are the characteristics of using a rivet as a linking component?
It’s indirect, rigid and non-removable.
What are the two main differences between a screw and a rivet.
A screw is removable and exerts a helical guide.
A rivet is non removable and exerts a rotational guide.
What are the three guiding controls?
Translational
Rotational
Helical
What component in a system typically acts as the guide for translational motion.
A track.
What is an axle?
A rod or shaft that connects a pair of wheels to propel them and retain the position of the wheels to one another.
What is Motion Transmission?
Motion that moves from one place to another.
What is Motion Transformation?
When there is a change in the type the motion.
Is Gear Train a motion Transmission or motion Transformation system?
Motion Transmission.
Is Belt and Pulley motion Transmission or motion Transformation system?
Motion Transmission.
Is Chain and Sprocket motion Transmission or motion Transformation system?
Motion Transmission.
Is Friction Gears motion Transmission or motion Transformation system?
Motion Transmission.
Is Worm and Worm Gear motion Transmission or motion Transformation system?
Motion Transmission.
Is Rack and Pinion motion Motion Transformation or Motion Transmission system?
Motion Transformation.
Is Cam and Follower Motion Transformation or Motion Transmission system?
Motion Transformation.
Is Crank and Connecting Rod Motion Transformation or Motion Transmission system?
Motion Transformation.
Is Screw Gear System Motion Transformation or Motion Transmission system?
Motion Transformation.
Is Rotating Slider Crank Motion Transformation or Motion Transmission system?
Motion Transformation.
What will the speed change be from small gear to big?
A decrease in speed.
What will the speed change be from big to small?
Increase in Speed.
What are the two speed ratios?
Speed Ration #1: #of teeth Driver/#of teeth of Driven.
Speed Ratio #2: Diameter of Driver/Diameter of Driven.
What is reversible gear system?
The Driver become the Driven.
Are Friction Gears Reversible?
Yes.
Is Belt and Pulley Reversible?
Yes.
Is Gear Train Reversible?
Yes.
Is Chain and Sprocket Reversible?
Yes.
Is Worm and Worm Gear Reversible?
No.
Is Screw Gear System Reversible?
No.
Is Cam and Follower Reversible?
No.
Is Connecting Rod and Crank Reversible?
Yes.
Is Rack and Pinion Reversible?
Yes.
What are the Advantages and Disadvantages of Friction Gears?
Advantages: Easy to assemble, cheap and allows slippage.
Disadvantages: Wheels must always be together, wheels can slip.
What are the Advantages and Disadvantages of Belt and Pulley?
Advantages: Easy to assemble, allows slippage, allows for transmission of motion over long distances.
Disadvantages: Slippage will occur as the belt’s condition gets worse over time and must be kept clean.
What are the advantages and disadvantages of a Gear Train?
Advantages: Will not allow slippage, Allows for large forces to be transmitted.
Disadvantages: Needs lubrication, Subject to severe damage if one of the parts malfunctions.
What are the advantages and disadvantages of Chain and Sprocket system?
Advantages: Will not allow slippage and Allows for large forces to be transmitted.
Disadvantages: Needs Lubrication.
What are the advantages and disadvantages of Wheel and Worm Gear?
Advantages: Will not allow slippage and Allows for fine adjustment.
Disadvantages: Needs lubrication.
What are the advantages and disadvantages of a screw gear system?
Advantages: Allows for precise adjustment in its use.
Disadvantages: Parts need to be lubricated.
What are the advantages and disadvantages of Cam and Follower?
Advantages: Allows for very precise and custom translational motion.
Disadvantages: Parts need to be lubricated A return mechanism (ex: spring has to be built into design).
What are the advantages and disadvantages of Connecting Rod and Crank?
Advantages: Allows force to be applied without slippage and change motion from translational to rotational or vice versa.
Disadvantages: Parts need to be lubricated
What are the advantages and disadvantages of Rotating Slider Crank Mechanism?
Advantages: Change motion from translational to rotational or vice versa
Disadvantages: Parts need to be lubricated and Reversibility is only partial.
What are the advantages and disadvantages of Rack and Pinion?
Advantages: Allows force to be applied without slippage.
Disadvantages: Parts need to be lubricated and Very precise fit needed between teeth of rack and pinion.
What are Degrees of Freedom?
The ways parts move independently.
How many degrees of freedom are there?
6.
What is Adhesion?
Two surfaces that remain in contact with each other without slipping.
What is Friction?
A force that resists motion when the surface of one object comes in contact with the surface of another.
What is the Advantage of adhesion and friction.
Controlling Motion.
What is the Disadvantage of adhesion and friction?
Wearing down of parts of an object and production of unwanted heat.
What are the 5 factors Adhesion depends on?
The Nature of the Surface
Weight of the object
(Perpendicular Force)
Temperature
Condition of the surface
Presence of a Lubricant
