Bevel Gear Drive

- Dec 17, 2019-

Bevel gear drive

Its movement is the same as that of a pair of conical friction wheels with coincident vertices, which are used for pure rolling friction wheel transmission. The friction cone is equivalent to the pitch cone of a bevel gear transmission. The angle δ between the pitch cone generatrix and the axis is called the pitch angle. The included angle between the bevel gear transmission axes = δ1 + δ2, which can be determined according to needs, usually 90 °. The transmission ratio is where n, Z, and d are the speed, the number of teeth, and the diameter of the large end pitch circle of the gear. The subscript 1 refers to the small wheel and 2 refers to the large wheel. When = 90 ° Classification 锥 Bevel gear transmission according to the shape of the tooth line can be divided into straight, helical and curved bevel gear transmissions, of which straight and curved teeth are widely used. The bevel gear teeth can be divided into the following 4 types according to the change of tooth height at both ends of the gear teeth: ①The teeth height of the same height teeth is unchanged from the large end to the small end. It is often used for cycloidal bevel gears. The adjustment of the tool and the machine is relatively simple; ② For normal shrinking teeth, the apex of the top cone, the apex of the pitch cone, and the apex of the root cone coincide. This type of tooth is also used in straight bevel gears, but the root radius of the tooth is small, which is not conducive to The strength of the root and the life of the cutting tool; ③ For the top gap shrinking teeth, the top cone generatrix is parallel to the root cone generating line of the meshing gear teeth, and the gap from the large end to the small end is equal; The apex of the cone, the apex of the node cone, and the apex of the root cone do not coincide, and the top cone generatrix is parallel to the root cone generatrix of the meshing gear teeth. The roots of the latter two teeth have larger fillets and are commonly used in bevel gears. Straight-bevel gear transmission This kind of transmission has poor running stability, and is usually suitable for average pitch circle speed vm <5m / s.