Mechanisms

• Four types of motions:

  Linear: Moving forward in a straight line

  Reciprocating: An up and down movement

  Rotary motion: Moving about in a circle

  Oscillating motion: Moving back and forth in an arc
• What does every lever have?

  A load , effort and fulcrum
• What is Load (levers)

  Load is what your are moving
• What is effort (levers)

  Effort is the force applied also known as the input force
• What is a fulcrum (lever)

  Also known as a pivot is the point it is moved on
• Class 1 lever

  A class 1 lever has the load and the effort on opposite sides of the fulcrum. Like a seesaw
• Class 2 lever


  the load and the effort on the same side of the fulcrum like a wheelbarrow
• Class 3 lever

  has the effort and the load on the same side of the fulcrum but the effort is closer to the fulcrum. like tweezers
• Formula for mechanical advantage

  Load/Effort
• Cam

  a component used with a follower converts rotary to reciprocating
• Eccentric cam

  Causes an even rise and full motion throughout it's rotation
• Pearshaped CAM

  Creates a sudden rise and fall followed by a long period where the follower does not move
• Snail Cam

  causes the follower to steadily rise, followed by a sudden drop
• Velocity ratio

  Driver gear/ Driven gear
• Output speed

  Input speed/ velocity ratio
• Rack and pinion

  Changes rotation into linear motion e.g. stair lifts and sliding doors
• Linkage

  A component which directs forces and movement to where they are needed
• Simple pulley (linkage)

  changes the direction of motion of a cord
• Reverse motion linkage

  reverses the direction of the input motion
• Bell crank

  transfer motion around a corner
• Peg and slot

  Converts rotary motion into oscillating motion
• Crank and slider

  converts rotary motion into reciprocating motion
• Pulley and belt (Gear)

  transfers rotary motion