Torque and Materials
To take advantage of the Ikona Gear tooth form, it is preferable to use a gear pair in which the contact ratio is as large as possible. For Ikona Gear pairs, the rating methods for spur gears by the A.G.M.A. and the I.S.O. are no longer appropriate. By making assumptions about the proportion of the total tooth force carried by each contacting tooth pair, it will be possible to develop rating procedures using the same principles as the current procedures. It is clear that the Ikona Gear multiple tooth contact will allow output torque values that are considerably higher than those produced by involute teeth.
As in any gears, the allowable bending and contact stresses will be increased if we increase the hardness of the material. The advantage of the Ikona tooth form is that, with the high contact ratio, the stresses are generally considerably lower than they would be in involute gears. It may therefore be sufficient to harden the gears to 300-350 BHN, and then to cut the teeth with no further hardening. The advantage is that there will be no distortion due to heat treatment in the final tooth profiles. This cost saving is another advantage of the Ikona Gear.
Because the contact ratio is so high with Ikona Gear sets, materials such as plastics, magnesium, aluminum, and brass can perform better as gears compared with conventional involute gearing.
The potential to use soft materials for Ikona gears is inherent in the technology. Ikona's plastic gears are presently used in the medical industry for Aircast's © joint-hinged Mayo Clinic Elbow Brace.
One of the main advantages of conventional involute gearing is that many different gear designs can be cut using the same Hob or Shaper cutter. This is an inherent property of the involute tooth form. With the Ikona Tooth Form, this is not possible. However, with the many, highly sophisticated, modern manufacturing processes presently available to companies, these old restrictions no longer apply. Many methods can be used to manufacture Ikona Gears:
Many methods can be used to manufacture Ikona Gears: