TEST 2 Machine dyn and vibr

Average velocity

Displacement divided by the time interval

Instantaneous velocity (velocity)

Rate of change of position at a specific instant

Velocity

Rate of change of position with respect to time

Angular velocity

The rate of change of angular position of a rotating body

Scotch yoke linkage (drawing)

Simple harmonic motion

Repetitive back and forth motion which acceleration is proportional to displacement

Acceleration

Rate of change of velocity with respect to time

Instantaneous acceleration

Rate of change of velocity at a specific instant

Average acceleration

Change in velocity divided by the time interval

Angular acceleration

The rate of change of angular velocity of a rigid body

Jerk

Time rate of change of acceleration

Cam

A machine element used to drive another element, called a follower

Follower

A component that follows the cam’s surface

Plate/disk cam

Wedge cam

Cylindric/barrel cam

End/face cam

Knife edge follower

Flat face follower

Roller follower

Spherical face follower

Iteration

Process in which a trial cam is designed and characteristics are calculated

Undercutting

A defect in a cam where the profile intersects itself causing material to be removed in manufacturing

Pressure angle

Angle between the follower’s axis of motion and the line of force exerted by the cam

Spur gears

Gears with straight teeth parallel to the shaft axes

Pinion

The smaller of the two meshing gears

Gearset

A pair of gears that work together

Diametral pitch

Ratio of number of gear teeth to pitch diameter

Addendum

Radial distance from pitch circle to the top of each tooth

Dedendum

Radial distance from pitch circle to the bottom of each tooth

Whole depth

Sum of addendum and dedendum

Clearance

How much of the dedendum exceeds addendum of mating gear

Helical gear

Gears with angled teeth

Bevel gear

Cone shaped gears to transmit rotational motion

Worm gear

Screw like worm meshes with worm gear

Compound gear train

Two or more gears on one or more axes

Reverted gear train

First and last gears have collinear axes of rotation

Kinematic coefficients

Derivatives of the follower displacement y with respect to the cam input angle