Involute Harmonic Gear Flexible Gear Profile Parameters

1. Basic profile parameters and definitions

Taking the involute profile as an example, the figure is an illustration of the involute profile.

In Figure, the curve AH is involute, intersecting point A and point H with the top circle and the root circle of flexible gear with radii RA and RF respectively. The center of circle is O1, the radius is R4 root chamfer and the root circle of tooth profile AH and tooth root circle are tangential to point B and point C respectively; theta 1 is the center angle corresponding to half pitch. The tooth thicknesses and the width e of standard spur gear on the indexing circle R are equal, and the ring wall thickness h is the root circle to the inner wall of the flexible wheel.Distance.

2. Positive displacement profile

To avoid tooth profile interference, a positive modified involute profile (Fig.) is used. The positive modified profile can increase the strength of the root [3]. Any circular upper tooth thickness Si with RI upper half diameter of the flexible gear teeth

Si=srir_2ri (inv_i_inv_0)

Where the involute function inv alpha i=tan alpha i-alpha i, alpha I is the pressure angle, and alpha 0 is the reference tooth angle;

Referring to the fact that the thickness of indexing circular teeth of standard spur gear equals the width of the slot, there is a circle (figure) with radius rk along the height of the tooth for the positively deformed involute profile, which is derived from the thickness sk=width EK of the slot:

Sk=srkr_2rk (inv_k_inv_0)=pirkz1

3. Wide Groove Profile

Wide-groove profile can greatly reduce ring stress. For this reason, a wide-groove flexible profile is constructed and a slot width ratio is defined.


V=1 is narrow-slotted teeth. Wide-slotted flexible wheel is formed by reducing tooth height and removing adjacent teeth, and experimental curves are given; however, the height, number and pitch of wide-slotted flexible wheel remain unchanged in practical application, and the width of slot is increased by reducing tooth thickness. Therefore, the wide-slotted flexible wheel model in this paper represents the wide-slotted profile of v>1 as shown in the dashed line.