The production of spiral bevel gears plays an important role in the modern machinery manufacturing industry. Because of its large coincidence coefficient, stable transmission, strong bearing capacity and high strength, it is widely used in ships, aerospace equipment, national defense technical equipment, machine tools, automobiles, construction machinery and other mechanical products. In order to further understand the spiral bevel gears, the classification, meshing characteristics and key names and codes of spiral bevel gears are analyzed.
1、 According to the angle of axis intersection of spiral bevel gears in meshing transmission, they are mainly divided into the following two categories:
(1) vertical intersection of two axes
The axes of the spiral bevel gears are intersected and the angle is 90 °, as shown in Fig. (a). This kind of bevel gear has no relative slip in the direction of tooth length, and it is the most widely used one in the transmission of spiral bevel gear.
(2) axes intersect but not vertical
This kind of spiral bevel gears mesh transmission when the axis intersects, and the angle of axis intersection can be any angle beyond 90 °. One is that the axial angle is less than 90 °, the other is that the axial angle is greater than 90 °, as shown in Fig. (b) and Fig. (c). The spiral bevel gear with different shaft intersection angle can only be used under special circumstances, and it is seldom used in mechanical production and manufacturing.
2、 According to whether the tooth height is consistent, it is mainly divided into the following two categories:
(1) equal height spiral bevel gear
The root cone angle δ F of this kind of spiral bevel gear, the root cone angle δ F of this kind of spiral bevel gear, the root cone angle δ F, the face cone angle δ A and, the face cone angle δ A and the pitch cone angle δ of this kind of spiral bevel gear are all equal, so that the tooth height from the big end to the small end of the spiral bevel gear is the same, so it is called the constant height spiral bevel gear, as shown in Fig. (a). It is not necessary to correct the pressure angle of the cutting tool for the machining of the spiral bevel gear with equal height teeth, and the adjustment of the machine tool is also relatively simple.
(2) tapered spiral bevel gear
The so-called involute spiral bevel gear is that the tooth height of the bevel gear gradually decreases from the big end to the small end. According to whether the backlash C is the same, the tapered spiral bevel gear can also be divided into the following two types: one is that the tooth top of one of the bevel gear pairs in the mutual meshing transmission is parallel to the tooth root of the matching bevel gear, and the vertex of the face cone is not coincident with the vertex of the pitch cone, as shown in figure (b); the other is that the vertex of the root cone, the pitch cone and the face cone of the bevel gear are coincident with each other, as shown in figure (c). The spiral bevel gear is the second kind of spiral bevel gear.