mechanical components and devices

• What are the four types of motion?

  Rotary, linear, oscillating, reciprocating
• What is rotary motion?

  Movement in a circular path
• What is linear motion?

  Movement in a straight line
• What is oscillating motion?

  Movement back and forth in a circular path
• What is reciprocating motion?

  Movement back and forth in a straight line
• What is the formula for rotational speed?

  Rotational speed = number of revolutions / time taken
• What is the formula for speed in linear motion?

  Speed = distance travelled / time taken
• What is motion defined as?

  When an object moves its position over time
• How is frequency defined in oscillating motion?

  Frequency = number of oscillations / time taken
• What is the unit for rotational speed?

  Revolutions per minute (rpm)
• How do you convert revolutions per second into rpm?

  Multiply by 60
• What are typical units for speed?

  m/s, km/h, mm/s
• How do you convert mm/s into m/s?

  Divide by 1000
• What are the functions of mechanical systems?

  • Produce different types of movement
  • Change magnitude and direction of forces
  • Process input force to produce output force
• What is a force?

  A push, a pull, or a twist
• What is a simple mechanism's trade-off?

  • If one increases, the other must decrease
  • Relates to forces and distances moved
• What is a lever?

  A rigid bar that pivots on a fulcrum
• What is the input force on a lever called?

  Effort
• What is the output force from a lever called?

  Load
• What is the lever arm length?

  Distance between the force and the fulcrum
• What happens if the input arm length is larger than the output arm length?

  The lever increases the force applied
• How does the lever arm length relate to force?

  In inverse proportion to the force
• What is the formula relating load, input arm length, effort, and output arm length?

  Load = input arm length / Effort = output arm length
• What are the key components of a lever system?

  • Fulcrum: pivot point
  • Effort: input force
  • Load: output force
• What is a linkage?

  • Directs forces and movement
  • Changes direction of motion
• What does a simple pulley do?

  Changes the direction of motion of a cord
• What does a reverse motion linkage do?

  Reverses the direction of input motion
• What does a bell crank do?

  Transfers motion around a corner
• What does a peg and slot mechanism do?

  Converts rotary motion into oscillating motion
• What does a crank and slider mechanism do?

  Converts rotary motion into reciprocating motion
• What is the function of a cam?

  • Converts rotary motion into reciprocating motion
  • Used with a follower
• What does a snail cam do?

  Causes the follower to steadily rise, then drop
• What does a pear-shaped cam do?

  Creates a sudden rise and fall, then no movement
• What does an eccentric cam do?

  Creates an even rise and fall motion
• Where are cams used?

  • Toys
  • Machinery
  • Engines
• What is the function of gear systems?

  • Transfer rotary motion
  • Consist of interlocking spur gears
• What is the input gear in a gear system called?

  Driver gear
• What is the output gear in a gear system called?

  Driven gear
• What happens when the driver gear is smaller?

  It is sometimes called a pinion
• How do two gears rotate in a gear system?

  They rotate in opposite directions