Spiral bevel gear is the general name of bevel gear whose tooth surface pitch line (the intersection line of tooth surface and pitch cone along the tooth length direction) is curve. It is also called curved bevel gear, which is called spiral bevel gear for short. Spiral bevel gears can be classified into many kinds according to their tooth surface pitch, tooth height, tooth shape, helix angle, mutual position of axis and purpose: according to the curve form of tooth surface pitch, spiral bevel gears can be divided into circular arc bevel gears, extended epicycloid bevel gears and quasi involute bevel gears. Circular arc bevel gears are most widely used; According to the tooth height, that is, according to whether the tooth height at the big end and the small end along the tooth rectangle is consistent, it can be divided into equal height bevel gear, tapered bevel gear and double shrinkage bevel gear; According to the mutual position of axes, it can be divided into bevel gears with two axes intersecting vertically, bevel gears with two axes intersecting but not perpendicular, and bevel gears with axis offset.
Compared with straight bevel gear, spiral bevel gear has many advantages, mainly including the following two aspects:
- 1) The tooth shape of spiral bevel gear is spiral curved teeth and the tooth groove is deep, so its overlap coefficient is large. At least two teeth contact at the same time in the transmission process. Compared with straight bevel gear, it has stable transmission, uniform tooth surface wear, large bearing capacity and small impact vibration in the transmission process.
- 2) It can realize gear transmission with large transmission ratio, with high transmission efficiency and less energy consumption in the transmission process. It is especially suitable for high-power transmission.