Lapping The Bevel Spiral (Crown ) Gear Set in Lath Machine |Technical Legend

Technical Legend

Lapping The Bevel Spiral (Crown ) Gear Set in Lath Machine

Point of contact
Any point at which two tooth profiles touch each other.

Line of contact
A line or curve along which two tooth surfaces are tangent to each other.

Path of action
The locus of successive contact points between a pair of gear teeth, during the phase of engagement. For conjugate gear teeth, the path of action passes through the pitch point. It is the trace of the surface of action in the plane of rotation.

Line of action
The path of action for involute gears. It is the straight line passing through the pitch point and tangent to both base circles.

Surface of action
The imaginary surface in which contact occurs between two engaging tooth surfaces. It is the summation of the paths of action in all sections of the engaging teeth.

Plane of action
The surface of action for involute, parallel axis gears with either spur or helical teeth. It is tangent to the base cylinders.

Zone of action (contact zone)
For involute, parallel-axis gears with either spur or helical teeth are the rectangular area in the plane of action bounded by the length of action and the effective face width.

Path of contact
The curve on either the tooth surface along which theoretical single-point contact occurs during the engagement of gears with crowned tooth surfaces or gears that normally engage with only single-point contact.

Length of action
The distance on the line of action through which the point of contact moves during the action of the tooth profile.

Arc of action, Qt
The arc of the pitch circle through which a tooth profile moves from the beginning to the end of contact with a mating profile.

Arc of approach, Qa
The arc of the pitch circle through which a tooth profile moves from its beginning of contact until the point of contact arrives at the pitch point.

Arc of recess, Qr
The arc of the pitch circle through which a tooth profile moves from contact at the pitch point until contact ends.

Contact ratio, mc, ε
The number of angular pitches through which a tooth surface rotates from the beginning to the end of contact. Simply, it can be defined as a measure of the average number of teeth in contact during the period during which a tooth comes and goes out of contact with the mating gear.