1. Face gear tooth surface contact detection machine

According to the parameters of the face gear, the corresponding face gear and cylindrical gear are processed. The experiment is carried out on the yd9550 rolling inspection machine produced by Sichuan Neijiang machine tool works. Yd9550 low-noise semi-automatic gear rolling inspection machine is used to simulate and check the contact accuracy, installation distance, backlash and working stability of gear pairs with an intersection angle of 90 °.

2. Gear installation

The matching cylindrical gear and the face gear coated with red lead powder are respectively installed on the two main shafts of the machine tool with clamps, the driving shaft is installed with the cylindrical gear, and the driven wheel is installed with the face gear. Adjust the machine tool, check its offset error, radial error and axial angle error to make it mesh normally. Start the machine tool, make the driven spindle under the low brake, and the driving spindle respectively (high speed and low speed) forward and reverse. After short-term operation, the contact accuracy, noise and stability of the tooth surface are obtained.

3. Tooth contact detection and analysis

3.1 influence of tooth number difference of spur gear on contact area of tooth surface

In order to check the influence of the number of teeth of the cylindrical gear on the meshing contact area of the gear, three cylindrical gears with the tooth number difference of 1 ~ 3 (the number of teeth of the cylindrical gear is 17, 18 and 19) are used to mesh with the face gear, and the contact spots of the three cylindrical gears are shown in Fig. 6. From the contact spots of three cylindrical gears, the number of teeth has little effect on the position and size of the contact spots. Figure 1 shows the contact spots of the face gear after meshing, and the results are consistent with the simulation results of the front face gear contact area.

3.2 influence of manufacturing accuracy of single gear on contact area of tooth surface

Two face gears are processed by milling and grinding methods respectively. The accuracy grade of face gears after milling is grade 7, and the accuracy grade of face gears after grinding is grade 6. Two kinds of precision face gears are installed on the yd9550 rolling inspection machine, meshing with the cylindrical gear with 18 teeth, and the tooth surface contact detection is carried out. After meshing for 30 minutes, check the contact condition of two gears. Fig. 2 and Fig. 3 show the contact spots on the gear surface milled and grinded respectively. From the experimental results, the size and shape of the contact spots (areas a, B and C) on the three consecutive tooth surfaces in Figure 2 are different, while the size and shape of the contact spots (areas a, B and C) on the three consecutive tooth surfaces in Figure 3 are very similar. It can be seen that the size and shape of the contact area on the tooth surface of the face gear are closely related to the manufacturing accuracy of the gear, and the higher the accuracy is, The more stable the contact area is, the higher the transmission quality is.

(1) In the face gear transmission with point contact, the contact area of the tooth surface is an ellipse, the area of the contact area reaches the maximum in the middle and middle part of the tooth, and the area of the contact area at the top of the tooth is the minimum.

(2) The size and position of the contact area of the point contact face gear are not related to the difference of the number of teeth of the cylindrical gear.

(3) The size and shape of the tooth contact area of face gear are related to the manufacturing accuracy of gear. The higher the accuracy is, the more stable the tooth contact area is, and the higher the transmission quality is.

(4) The transmission ratio of face gear transmission has great influence on the position of tooth contact area. The larger the transmission ratio is, the closer the tooth contact area is to the middle of face gear tooth, which is beneficial to improve the quality of face gear transmission. Therefore, in the case of face gear transmission, large transmission ratio should be considered to avoid edge contact.