Tooth Profile Modeling And Machining Error Analysis Of The Face Gear

Face gear drives,declared in last century 40s but developing in the recent ten years,is a new type of gear drives compared with other traditional gear drives in many areas. Overseas scholars including Litvin had contributed to the deve1opment of face gear drives,and found out that face gear drives have many advantages applied in helicopter transmissions. In mainland face gear drives were studied little,and almost were not used actually. So it is important to research face gear drives for the development of the gear drives.This paper researches on the face gear drives composed of a face gear and a spur involute pinion. Based on the surface equation of the pinion, the equation of the face gear is obtained according to the differential geometry theory. With the analysis of the model ,the conditions of undercutting and pointing were studied,and the radius of un-undercutting and un-pointing are obtained. Three-dimensional model of face gear drives are built in Pro/e.According to theory of Litvin, the contact points on the surface of the face gear drives are analyzed, also the patch of the points on the surface of the face gear and pinion are emulated with Matlab program. Considering of the machining principles, the perpendicular face gear generation assistant equipment based on YM5150A gear shaper is designed and its three-dimensional model is built in Pro/e.Based on the equation of the face gear , the machining errors including the crossing eagle error between the face gear and pinion axes,the pressure eagle error of the gear shaper cutter,the transmission error and the geometry eccentricity error are studied. The results show that the crossing eagle error results in the shift of along the tooth depth, while the geometry eccentricity error results in the shift of along the tooth thickness. The two both have no effect on the tooth form. The other two the pressure eagle error of the gear shaper cutter and the transmission error have effect on the pressure eagle of tooth surface. Also, the tooth thickness is changed by these two errors.