Features of gear and rack:

Features of gear and rack:

When the number of teeth of the gear increases to infinity, the diameter of the gear indexing circle and the base circle becomes infinite, and then the radius of curvature becomes infinite, so the gradually opened gear becomes an inclined straight line. $=0.5p, e=0.5p The involute gear is no longer the original shape, but becomes a gear rack with a straight tooth profile, as shown in Figure 1-18. In the rule of tooth center, the straight line equivalent to the gear indexing circle is called the center line. On the centerline, the tooth thickness s is equal to the groove width e, and the sum of the two is called the pitch guard, which is equivalent to the gear indexing circumferential pitch s-e=_ Add (1-31) the tooth height of the gear rack is divided by the center line. Compared with the involute cylindrical gear, the reference teeth of the 1-18 gear have the following characteristics: ① the different heights of the gear rack and the same pitch, while the pitch of the involute cylindrical gear is different in different circles.

② The pressure angle at any point on the gear rack tooth profile is equal, which is equivalent to the gear rack tooth profile angle α， The pressure angles on different circumferential tooth profiles are different.

Features of gear and rack:

When the number of teeth of the gear increases to infinity, the diameter of the gear indexing circle and the base circle becomes infinite, and then the radius of curvature becomes infinite, so the gradually opened gear becomes an inclined straight line. $=0.5p, e=0.5p The involute gear is no longer the original shape, but becomes a gear rack with a straight tooth profile, as shown in Figure 1-18. In the rule of tooth center, the straight line equivalent to the gear indexing circle is called the center line. On the centerline, the tooth thickness s is equal to the groove width e, and the sum of the two is called the pitch guard, which is equivalent to the gear indexing circumferential pitch s-e=_ Add (1-31) the tooth height of the gear rack is divided by the center line. Compared with the involute cylindrical gear, the reference teeth of the 1-18 gear have the following characteristics: ① the different heights of the gear rack and the same pitch, while the pitch of the involute cylindrical gear is different in different circles.

② The pressure angle at any point on the gear rack tooth profile is equal, which is equivalent to the gear rack tooth profile angle α， The pressure angles on different circumferential tooth profiles are different.