FINAL Flashcards
(31 cards)
height of tooth above pitch circle or the distance
between the pitch circle and the top of the tooth,
Addendum
the circle that bounds
the outer ends of the teeth.
Addendum Circle ( or Outside Circle)
arc of the pitch circle through which a tooth travels from the first point of contact with the rating tooth to the point where the contact ceases.
Arc of Action
arc of the circle through which a tooth travels
from the point of contact with the mating tooth to the pitch point.
Arc of Approach
arc of the pitch circle through which a tooth travels from its contact with the mating tooth at the pitch point to the point where the contact ceases.
Arc of Recess
in a pair of gears it is the plane that contains the two axes. in a single gear, it may be any plane containing the axis and the given point.
Axial Plane
the amount by which the width of a tooth space
exceeds the thickness of the engaging tooth on the pitch circles.
Backlash
the circle from which an involute tooth is
generated or developed.
Base Circle
the angle, at the base cylinder if an involute
gear, that the tooth maxes with the gear axis.
Base Helix Angle
In an involute gear it is the pitch on the base circle
or along the line of action.
Base Pitch
is the base pitch in the normal plane.
Normal Base Pitch
the distance between the parallel axes of spur gears and parallel helical gears, or between the crossed axes of helical gears and worm gears. Also it is the distance between the centers of the pitch circles.
Center Distance
in a worm gear this is the plane perpendicular to the gear axis and contains the common perpendicular of the gear and the worm axes.
Central Plane
the height from the top of the tooth to
the chord subtending the circular-thickness arc.
Chordal Addendum
length of the chord subtended by the circular thickness arc (the dimension obtained when a gear tooth caliper is used to measure the thickness at the pitch circle.
Chordal Thickness
length of the arc of the pitch circle between the
centers or other corresponding points of adjacent teeth.
Circular Pitch
is the circular pitch in the normal
plane.
Normal Circular Pitch
the length of the arc between the two
sides of a gear tooth, on the pitch circles unless otherwise specified.
Circular Thickness
is the base pitch in the axial plane.
Axial Base Pitch
is the circular thickness in the
normal plane.
Normal Circular Thickness
the amount by which the dedendum exceeds the addendum of the mating tooth. It is also the radial distance between the top of’a tooth and the bottoms of the mating tooth space.
-the dedendum minus the mating addendum.
Clearance
the smallest diameter on a gear tooth with
which the mating gear makes contact.
Central Diameter
the ratio of the arc of action to the circular pitch. It is sometimes thought-of as the average number of teeth in contact. For involute gears, the contact ratio is obtain most directly as the ratio of the length of action to the base pitch.
Contact Ratio
the curve formed by the path of a point on a circle as it rolls along a straight line. When this circle rolls along the outer side of another circle, the curve is called an Epicycloid: When it rolls along the inner side of another circle it is called a Hypocycloid
Cycloid
