Mechanisms Flashcards
Mechanisms are used in everyday life, list an example
A door handle
There are various types of mechanisms, such as…
Levers and linkages
Wheels
Pulleys
Gears
Mechanical control:
There are three basic build blocks of mechanical control, what are they
Input
Process
Output
What is the input
The input is usually a force and initiates the process
What is the process
The process will change the magnitude or direction of the force
What is the output
The output is what performs the desired task
Give an example of and input, process and output
Input: foot on a pedal
Process: mechanisms allow petrol into engine
Output: car moves
List some properties of a mechanism
Has an input, process and output
Can change the direction in which a force acts
Can change the size of a force
Can change the place where a force acts
What is a lever?
A lever is a type of mechanism, perhaps the earliest form of mechanism.
In a lever there are three basic parts, what are they?
Fulcrum
Load
Effort
What is the arrangement of the fulcrum load and effort in a class 1 lever
Class 1 lever= scissors/crowbar
Arrangement left to right=
Load, fulcrum or pivot point, Effort
What is the arrangement of the fulcrum load and effort in a class 2 lever
Class 2 lever = wheelbarrow
Arrangement left to right =
Fulcrum or pivot point, load, effort
What is the arrangement of the fulcrum load and effort in a class 3 lever
Class 3 lever = tweezers
Arrangement left to right =
Fulcrum or pivot point, effort, load
What are gears?
Gears are wheels with teeth which mesh to transmit rotary motion. When two or more gears mesh it is called a gear train. There are two types: Simple and Compound.
Other gear systems:
What does a rack and pinion do
Converts rotary motion into linear
Other gear systems:
What does a worm and wheel do?
The worm gear is usually found on an electric motor.
For one rotation of the worm the wheel rotates by one tooth.
Other gear systems:
What do bevel gears do
Gears are cone-shaped. The angle is known as a bevel. They transfer rotary motion through 90 degrees.
What are the four types of motion
Linear
Reciprocating
Rotary
Oscillating
What type of motion is linear
Straight line motion
What type of motion is reciprocating
Straight line - backwards and forwards
What type of motion is rotary
Round and round
What type of motion is oscillating
Swing backwards and forwards. (Rotary)
What is a mechanism
A mechanism is a system of moving parts that performs some function, they are used to reduce the effort in relation to work
List some examples of rotary motion
Wheel
Roundabout
Gears
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