What is the significance of pitch circle?

Pitch Circle Diameter (PCD) – Gear Terminology The pitch circle diameters are important numbers in locating the shafts of two mating gears. The center distance of two meshing gears is expressed as the sum of the pitch circle radii of the two gears. The pitch circle of a gear does not physically exist as a form.

What is circular pitch in gear?

A circular pitch is the distance between the corresponding points of the adjacent teeth measured on the pitch circle. In other words, it is the space between the teeth. In order for the gears to mesh properly, the meshing gear teeth must be of an equal size. That is to say, the circular pitches must be equal.

Why is pitch important in gears?

Pitch line velocity is measured at the pitch line of the gear, which is midway along the length of the gear teeth. Pitch line velocity determines the contact time between gear teeth, which has a significant impact on the required oil viscosity.

Do gears have to be circular?

A regular gear pair can be represented as two circles rolling together without slip. For this reason NCGs in most cases are not round, but round NCGs looking like regular gears are also possible (small ratio variations result from meshing area modifications).

How do you find a circular pitch?

“Pitch” sometimes instead refers to the circular pitch, which is the distance between corresponding points on successive teeth. To find this value, divide pi by the diametral pitch. With this example: 3.142 / 5 = 0.628 inches.

What is pitch point?

Definition of pitch point : the point of contact of the pitch lines of two gears or of a rack and pinion when in mesh.

What is addendum and Dedendum?

Addendum: It is the radial distance of a tooth from the pitch circle to the top of the tooth (or addendum circle). Dedendum. It is the radial distance of a tooth from the pitch circle to the bottom of the tooth (or dedendum circle).

What is stub tooth?

Definition of stub tooth : a short gear tooth of great strength with a large angle of obliquity.

What is gear terminology?

Basic Gear Terminology Face Width is the length of the teeth in the axial direction. Outside Diameter (O.D.) is the diameter of a circle around the outer surface, or tops of the gear teeth. Root Diameter (R.D.) is the diameter of a circle around the bottom (root) of the gear tooth spaces.

What is pitch surface?

Definition of pitch surface : the surface of either of two tangent imaginary friction wheels having the same axes and the same angular velocities as those of a pair of real gears in mesh.