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Mechanisms :male-mechanic::skin-tone-2: - Coggle Diagram
Mechanisms :male-mechanic::skin-tone-2:
Classification of mechanisms
Transmitting motion
Rotary
Linear
Storing energy
Transforming motion
Rotary to linear
Rotary to reciprocrating
Joining elements
Controlling and regulating motion
Motion uses
Telling the time
entertaining children in the park
Transporting people from A to B
lifting and carrying objects
Linear motion mechanisms
Levers
Types of levers
Class 1
The fulcrum is between the effort applied and the resistance
The effect of the effort applied can be multiplied or reduced
Class 2
The resistance is between the fulcrum and the efford applied
The effect of the efford applied is always multiplied
Class 3
The efford applied is between the fulcrum and the resistance
The effect of the efford iapplied s always reduced
Pulley
Compoud pulley
F=R/2xN
F=R/2n
Fixed pulley
A fixed pulley is balanced when the effort F is equal to the resistance of the
load, R:
F=R
Mobable pulley
A mobable pulley is balanced when it satisfies this equation:
F=R/2
Rotary motion mechanisms
Friction drives
Friction drives are made up of two or more wheels that are in contact
The ratio between the rotation velocity of the wheels or pulleys depends on the relative size of the wheels.
It is expressed by the followmg equation:
N1 x D1=N2 x D2 --> D1/D2 - N2/N1
Pulleys with belt
They consist of two pulleys or wheels that are a certain distance apart.
Gear mechanisms and cogwheels
Cogwheels are sets of wheels that have teeth called cogs
The ratio between the rotation velocities of the wheels depends on the
number of teeth on each wheel. It's expressed by this equation:
N1 x Z1 = N2 x Z2 --> Z1/Z2 = N2/N1
Worm gear
This is a screw that moves a helical cogwheel that is set perpendicular
to the screw
A worm screw fulfils this equation: Nwheel = Nscrew/Zwheel x Zgrooves/Zwheel
Gear mechanisms with a chain
These are two cogwheels with parallel axles that are a certain distance apart
The relation between the rotation velocities of the wheels depends on the
number of teeth on each gear:
N1 x Z1 = N2 x Z2 --> Z1/Z2 = N2/N1
Gear chain
This is a system of more than two gears, connected together
The gear ratio between the drive wheel and the driven wheel depends
on the number of geared teeth in the system:
N4/N1 = Z1 x Z3/Z2 x Z4
Pulley trains with belts
It's a system of pulleys, or wheels, with a belt
formed by more than two wheels.
The gear ratio between the drive pulley abd the driven pulley depends on the relative size of the pulleys in the system. It's expressed as a function of their diameters:
N4/N1 = D1 x D3/ D2 x D4
Other mechanisms
Mechanisms for controlling and directing motion
The mechanisms used to reduce velocity are called brakes. There are three
several types:
Disc brakes
Band brakes
Drum brakes
Mechanisms that store energy
Springs are devices that absorb energy
Mechanisms that transform motion
From rotary into linear
Rack and pinion system
lhe ratio between the number of rotations of the pinion and the velocity of
the movement of the rack is expressed by this equation:
L = P x Z x N
Nut and bolt system
Winch and crank handle
A winch is balanced when it satisfies this equation F x d = R x r --> F = R x R x r/ d
From rotary into reciprocating motion
Crank-link-slider
Crankshaft
Cam
Eccentric cam
Connecting mechanisms
Fixed connections are used to make permanent connections
between axles and shafts
Clutches are mechanisms that allow axles or shafts to be connected
or separated
Movable connections are used to connect shafts that can move
along the axle or at an angle to each other. There are two main types:Oldham iomts and Cardan joints.
Supports: bushings and bearings
Bearings are made up of two concentric rings with balls or rollers
between them.
In bushings the axle or the shaft is inserted in a plain circular piece
that is placed inside a housing to provide a bearing surface.
