When the thickness of straight bevel gear blank is 90mm, the y-direction displacement nephogram of straight bevel gear blank with two different processing methods is shown in Figure 1. It can be seen from the figure that in the process of adding straight bevel gear to divide the wheel blank in two ways, the straight bevel gear wheel blank has a negative displacement along the y-axis (the direction of the big end of the wheel blank), the y-direction displacement of the lower surface of the straight bevel gear wheel blank is almost 0, and the negative displacement gradually increases from the lower surface to the upper surface. And in the processing process, the processed tooth top part shows a large negative displacement at the dark blue position, and the maximum negative displacement in the unprocessed area is concentrated at the large end of the straight bevel gear blank. With the continuation of processing, the negative displacement of the straight bevel gear blank along the Y direction gradually increases, and the negative displacement in the Y direction at the tooth top of the left and right ends of the straight bevel gear blank is the largest after processing.

It can be seen from the cloud diagram in Figure 1 that different processing methods will make the deformation of spur bevel gear blank in the processing process different, but the deformation mode and amount corresponding to the two processing methods are the same after processing. After processing, the maximum negative displacement of the upper surface of spur bevel gear blank reaches 0.029mm.

When the thickness of straight bevel gear blank is 85mm, the y-direction displacement nephogram of straight bevel gear blank with two different processing methods is shown in Figure 2. It can be seen from the figure that after changing the thickness of spur bevel gear blank, the two processing methods make the deformation form of split wheel blank in Y direction consistent with the previous 90mm thick spur bevel gear blank. The maximum negative displacement of spur bevel gear blank reaches 0.033mm after processing in two ways.

Through the machining simulation results of the finite element analysis of the straight bevel gear blank with the thickness of 90mm and 85mm, it can be inferred that when only the thickness of the straight bevel gear blank is changed, the deformation form in the Y direction of the straight bevel gear blank will not change, but the displacement value in the Y direction of the straight bevel gear blank will change.

When the thickness of spur bevel gear blank is 80mm, the displacement nephogram in Y direction of spur bevel gear blank with two different processing methods is shown in Figure 3. It can be seen from the figure that the overall deformation of the straight bevel gear split wheel blank with two processing methods is the same after processing. The maximum negative displacement displayed in the dark blue area after processing the straight bevel gear blank is 0.036mm. Therefore, it can be judged that the displacement in Y direction of spur bevel gear blank caused by the two processing methods is the same.

When the thickness of straight bevel gear blank is 75mm or 70mm, the displacement nephogram of straight bevel gear blank in Y direction is shown in Figure 4. It can be seen from the figure that the maximum negative displacement of 75mm thick spur bevel gear blank along the Y direction is 0.041mm; The maximum negative displacement of 70mm thick spur bevel gear blank along the Y direction is 0.048mm.

Take the absolute value of the maximum displacement in the Y direction of the spur bevel gear blank with different thickness and draw it into a broken line diagram, as shown in Fig. 5. It can be seen from the figure that when the thickness of straight bevel gear split wheel blank gradually decreases, the displacement in the Y direction of its upper surface gradually increases. Compared with the deformation in the X and Z directions, the deformation in the Y direction is relatively small. After machining, the deformation in the Z direction is the largest, followed by the deformation in the X direction. This is because the deformation form of the straight bevel gear blank in the machining process is mainly the bending deformation in the Z direction, and the bending deformation causes the upper surface of the straight bevel gear blank to be compressed and the lower surface to be stretched, resulting in the displacement in the X direction. Therefore, the deformation of the straight bevel gear blank in the Y direction is the smallest.

To sum up, the smaller the thickness of the straight bevel gear blank, the greater the deformation in the machining process, and the maximum deformation occurs in the thickness direction in the gear cutting process. Therefore, in the subsequent deformation analysis, only the z-direction deformation of spur bevel gear is analyzed. In order to control the deformation of the split gear and reduce the cost as much as possible, how to reasonably select the thickness of the split gear blank in the design stage of the straight bevel gear blank is the focus of the follow-up research.