Motion Devices Flashcards
Movement and motion
Motion is the action of something being moved
• Motionless is something at rest
• There are different types of
•motion which can be added together and even changed from one to another
Linear motion
Movement in one direction along a straight line
Reciprocating motion
A repetitive back-and-forth or up-and-down linear action
Oscillating motion
A repetitive back-and-forth motion along a curved path
Rotary motion
Objects moving in a circular motion usually around a fixed axis
Levers
Levers help provide mechanical advantage (MA)
• They have two parts – a bar and a pivot also known as
the fulcrum
• Identify the three elements at
work: the effort, the load and
the position of the fulcrum
• To calculate the MA, use
the formula:
• Also written as 3:1 or MA of 3
First order lever (Class 1)
Class 1 levers act in a seesaw or scissor action
Second order lever (Class 2)
Class 2 levers act in a wheelbarrow action or that similar to a nutcracker.
Third order lever (Class 3)
Class 3 levers have a pincer-like action seen with tweezers and tongs
Equilibrium
When the effort and the load are equal, equilibriumcan be created in a mechanism
Linkages
Linkages are mechanisms that use rigid parts to:
• Change the magnitude of a force
• Change the direction of a force, or
• Transform it into a different motion
Reverse motion linkage
This changes the direction of the input motion
• If the input is pulled, the output will push
• The linkage uses a fixed central pivot
Parallel motion linkage
Also known as push / pull linkage as it keeps the direction of the output the same as the input
Bell crank linkage
Input direction is converted through 90 degrees It changes horizontal motion to vertical and vice versa • Often found in steering and throttle mechanisms on vehicles
