The difference between gear index circle and pitch circle

XNUMX. The difference in definition:

1. Pitch circle: a purely rolling circle during the transmission process, and the movement track of the node relative to the gear.

2. Index circle: a reference circle taken for the convenience of calculation, a specific circle whose modulus and pressure angle are standard values.

XNUMX. The difference in pressure angle:

1. The pressure angle of the pitch circle changes with the diameter of the pitch circle.

2. The standard value of the pressure angle of the graduated circle is α=20°.

XNUMX. The difference in nature:

1. There is a pitch circle when a pair of gears mesh.

2. A gear has an index circle.

Fourth, the difference in location:

1. The two circle circles are always tangent.

2. The indexing circles intersect or separate during non-standard installation.

Five, the difference in size:

1. The pitch circle changes with the center distance.

2. The index circle is d=mz, which is fixed.

In addition, when non-standard installation (installation center distance is not equal to the standard center distance), the index circle radius is unchanged, but the pitch circle radius will change, the index circle and the pitch circle are separated.The position of the meshing line changes, and the meshing angle is no longer equal to the pressure angle on the index circle.

The above is the description of the difference between the gear index circle and the pitch circle, including but not limited to, if there are unclear places or relatedGear processingIf you need, you can seek help from EP technology.