Part 1
What is a Mechanism?
the elements that transmit and transform force and motions from an input source to an output receptor, modifying it's characteristics
What is Torque?
Torque is the product of the force multiplied by the distance from the fulcrum
What does inversely mean?
Inversely: in the opposite way
What is reciprocating?
Reciprocating: moving forwards and backwards in a straight line
What does absorb mean?
Absorb: take in or reduce the effect of something
What is friction?
Friction is the force of an object moving past and against another object
What is a stem?
The stem is the part of the bicycle that joins the handlebars to the frame.
What does Simultaneously mean?
Simultaneously:at the exact same time
What does stationary mean?
stationary: not moving
What does aligned mean?
Aligned: together in a perfectly straight line
What are Simple Mechanisms? Give an example.
Simple mechanisms perform their function in a single step.
Examples: levers, wheels, and pulleys
What are Linear Transmission mechanisms? Provide examples.
Linear Transmission mechanisms have linear entry and exit movement or form an arc of a circle so small that it looks like a linear movement.
Examples: pulley, lever
What is an axis of rotation? Provide an example of something that changes the axis of rotation.
axis of rotation: straight line that an object rotates around
examples: pulleys, gears
Define brakes. Name 3 different types of brakes.
Brakes: mechanisms designed to reduce speed They use a device that presses against the moving wheel to create friction.
1. Disc Brake
2. Band Brake
3. Drum Brake
What does accumulate mean? What does dissipate mean?
Accumulate: Collect and store
Dissipate: Disperse or let go
What are the components of mechanisms?
1. Input sources that create force and motion
2. Transformation and transmission systems of energy, force, or motion
3. Output receptors that do the work the objects are made for
What is a compound pulley system? What are three types of compound pulley systems?
A compound pulley system combines fixed and movable pulleys. They force a rope to make a complex journey between the different pulleys.
1. Vertical System
2. Horizontal System
3. Exponential System
What is a rotary transmission mechanism? What is its purpose?
rotary transmission mechanisms: connect two rotating elements
Purpose:
1. to transfer the rotary force from an input location to another location
2. To change the rotary speed. The elements must be of different sizes.
What is a ratchet? What is a ratchet wrench?
Ratchet: a mechanism that controls the direction of motion. It allows motion in one direction but not the other.
Ratchet Wrench: a reversible ratchet that allows movement in both directions
What are coupling mechanisms? Name and explain the different types.
Coupling Mechanisms: transmit rotation from one axis to another
1. Rigid couplings: used to engage axes permanently
2. Clutches: Engaging the clutch allows power to transfer from the engine to the transmission. Disengaging the clutch stops the power transfer
What are Complex Mechanisms? Give an example.
Complex mechanisms complete the function in several stages.
Examples: bicycles, printers, and internal combustion engines.
What is the Law of the Lever? Define and dictate the mathematical expression.
Law of the Lever: When the forces acting on opposite ends of the lever are equal, then the lever is in equilibrium. This law is expressed with:
F (force applied)• D (F's distance from the fulcrum) = R (resistance/ the load we want to move)• r (R's distance from the fulcrum)
What is the ratio of transmission? What is the formula for calculating the ratio of transmission? Define the components of the formula.
Ratio of transmission: The relationship between the speeds of the two wheels is inversely proportional to their sizes.
Formula: N2/N1=D1/D2
N: speed of rotation
D: diameter of the wheel
What is a crankshift mechanism, and what are its uses?
crankshift mechanism: a crankshaft is composed of multiple rods that are connected to one rotational axis; the rods are connected to cranks, which are connected to the crankshaft.
Uses: combustion motors, sewing machines
What are springs? Name and explain the different ways they work when an external force is applied.
Springs: devices that are capable of absorbing energy when we apply force to them
1. Compression: We push on the spring to make it shorter
2. Traction: We pull on the spring to make it longer
3. Torsion: We bend the spring to make it curve, like a clothes peg