Because the former three machining methods are based on the simulation of meshing between the small wheel (or the profile wheel) and the face gear, as long as the parameters of the small wheel are changed, the tool must be replaced and re trimmed, resulting in the lack of universality of the tool, and limiting the flexibility of the design parameters of the face gear transmission.
In recent years, Gleason has taken another shortcut to develop the processing technology of rough cutting and grinding face gear on Phoenix bevel gear machine with coniflex cutter. The profile line of the cutter is actually a straight line, and the face gear obtained by this processing method is called coniface face gear. There is a certain deviation between the tooth surface developed by this method and the theoretical tooth surface developed by the traditional method, but the deviation is within the controllable range, so the company later directly called it face gear. In fact, whether it is rough cutting or fine grinding tool, the profile of the tool is a line, so the author tends to call this tool “straight edge tool”, which is only affected by the tooth width parameters of face gear, so it has the potential of generalization and standardization. In addition, because Phoenix bevel gear machine tool has been successfully developed and applied for many years, the problem of developing high-precision special machine tool is also avoided.
The principle of machining face gear with straight edge cutter is shown in Fig. 5. Its ingenious point is to make the profile plane of cutter approach the involute of profile wheel through the movement of machine tool, so that the rotation angle of face gear and tangential feed movement of cutter are required to be expressed as high-order function of tool rotation angle. Although the cutter and face gear are point contact, in order to improve the machining efficiency, the cutter does not do the tooth feed movement, using line contact instead of point contact. Therefore, if this method is used to process face gear, if the tooth surface accuracy is not required to be very high, the line contact method can be used. If the high accuracy is required and the machining efficiency can be sacrificed, the point contact method can be used for machining. Its advantages are three: universal cutter, high precision of existing machine tools and machining, which is an optional method in China.
However, Dr. Stadtfeld of Grimson has applied for the invention patent of this processing technology in the United States and Europe, and promoted this technology in AGMA. Professor Mao Shimin of our country first put forward his own opinion on this technology, that is to optimize the tool motion path to optimize the meshing performance [32]. The author has also carried out research on this technology, which shows that the meshing of the machined face gear and the small wheel has “quasi conjugate” characteristics, and will continue to be further studied in the future.