Combining the research of machine tool adjustment parameters with finite element analysis is of great significance to the research of spiral bevel gear. As shown above, firstly, finite element analysis can predict and evaluate the performance of virtual machined spiral bevel gears. Furthermore, the contact area and transmission error curve are obtained through finite element analysis. On this basis, the adjustment law of machine tool adjustment parameters that has guiding significance for spiral bevel gear processing is found, and the machine tool adjustment parameters of spiral bevel gear are inversely adjusted.
Secondly, the adjustment parameters of the machine tool can be modified according to the specific situation to simulate the machining error, which is convenient for people to study the performance of the spiral bevel gear with the installation error of the machine tool. According to the Hertz stress principle, a pair of spiral bevel gears will produce a narrow contact line when the tooth surfaces of spiral bevel gears squeeze each other. The contact area of spiral bevel gears is composed of continuous instantaneous contact lines. Adjust the machine tool adjustment parameters of the initial small wheel to obtain the machining parameters of the tool inclination method as shown in the table.
After processing the spiral bevel gear with the adjusted processing parameters, analyze it, and then take the small wheel as the observation object. As shown in Figure 1, the spiral bevel gear has slight tooth top contact. Assuming that the theoretical installation position of the spiral bevel gear pair on the rolling inspection machine is zero, move the change amount of the small wheel along the axis of the small wheel Δ H. The position and shape of the contact area in the tooth height direction will change, and the change distance is set Δ H = 2mm, using a simple first-order correction, increase the pressure angle by changing the horizontal wheel position, then the horizontal wheel position change should be Δ XP = － Δ H. In order to ensure the depth of the tooth slot, it can be made up by changing the bed, Δ Xb = － Δ Xp sin δ 1 = 0.59 mm, where δ 1 is the root cone angle of the small wheel. The eccentric angle needs to be adjusted to ensure that the midpoint spiral angle is not affected by the horizontal wheel position. The formula is Δε = 3438sinqcos δ one Δ Xp /( Kcos( ε / 2) ), K is the machine tool constant, ε Is the eccentricity angle. After modifying the adjustment parameters of the machine tool, a new spiral bevel gear model is obtained. After finite element analysis, the modified contact area is obtained, as shown in Figure 2. It is found that the poor tooth top contact of spiral bevel gear has been eliminated. Fig. 4 is the transmission error curve of spiral bevel gear. Compared with the initial model analyzed above (normal processing and good performance), the transmission error deviation from the zero line of spiral bevel gear with tooth top contact increases and the vibration amplitude increases. After the tooth top modification of spiral bevel gear, the transmission error curve deviation from the zero line decreases and the amplitude decreases, This not only shows that optimizing the machine tool adjustment parameters in CATIA can improve the performance of spiral bevel gear, but also the research on the dynamic characteristics of spiral bevel gear can help people adjust the machine tool adjustment parameters. In order to obtain better contact area and transmission characteristics, more complex methods of machine tool adjustment and parameter adjustment are needed. This is just to prove the significance of CATIA virtual machining spiral bevel gear.
In CATIA, the radial tool position error of spiral bevel gear is 3 mm, and the inner diagonal contact area is shown in Figure 3, which is mainly caused by the unqualified short-range torsion in the tooth length direction. Figure 4 shows that the transmission error curve of spiral bevel gear with installation error deviates the farthest from the zero line than the initial spiral bevel gear, the vibration amplitude is the largest, and the performance of spiral bevel gear is the worst. Therefore, the simulation machining of spiral bevel gear in CATIA can facilitate the research on the machining error of spiral bevel gear.
The above contact area and transmission error curve of spiral bevel gear are in line with the transmission characteristics of spiral bevel gear. CATIA simulation gear cutting can provide a reliable model for theoretical research, improve production efficiency and shorten the R & D cycle.
Through virtual simulation technology and finite element analysis, the following conclusions can be obtained:
1) CATIA virtual machining of spiral bevel gear has high efficiency, simple machining method, high precision of spiral bevel gear model and good visualization effect of machining process.
2) The finite element analysis of spiral bevel gear obtained by virtual machining can study the law of spiral bevel gear transmission error and the characteristics of contact area, predict and evaluate the performance of virtual machining gear, and obtain the relationship between spiral bevel gear transmission characteristics and machine tool adjustment parameters, so as to provide guidance for spiral bevel gear manufacturing and processing.
3) Adjust the machine tool adjustment parameters to simulate the machining error according to the actual situation, compare the spiral bevel gear with error and the simulated spiral bevel gear with good performance through the finite element method, study the relationship between the machining error factors and the spiral bevel gear performance (including machining accuracy), and change the blindness of adjusting the machine tool adjustment parameters according to the operation experience in the past.