Helical gears are cut into helical teeth on pitch cylinders. Spiral shaped teeth have many advantages, such as gradually absorbing load, vibration, noise, wear, etc. on the teeth.

The tooth shape of bevel gears can be divided into straight and spiral shapes; Two types are suitable for intersecting shafts. In straight bevel gears, the tooth shape and spur gear shape are straight and cut along the gear axis while maintaining an inclination. Due to sudden contact between the teeth of two mating gears, the teeth are subjected to impact loads, which can cause vibration and noise.

Flat bevel gears and helical bevel gears also have straight teeth. Helical helical gears and straight bevel gears have similar advantages compared to spur gears. The teeth here have a spiral profile, so they gradually come into contact during the fit. Therefore, it provides smooth, vibration free, and quiet operation. However, it will apply a thrust load on the bearing. Hypoid gears also have helical teeth.

straight bevel gear

A straight bevel gear is a gear where the axes of two component axes intersect and the tooth shape is conical. However, straight bevel gear sets are usually installed at a 90 ° angle; It also affects other factors. The pitch of the bevel gear is conical. The two most important characteristics of gears are their teeth and pitch.

Spiral bevel gear

The pitch of a spur gear is zero, while the pitch of a bevel gear is usually between 0 ° and 90 °. The more common types of bevel gears have a conical shape and a pitch angle of 90 ° or more. This type of bevel gear is called an outer bevel gear because the teeth are facing outward. The meshing outer bevel gear pitch is coaxial with the gear shaft. The vertices of two curves are always at the intersection of the axes. A bevel gear with a pitch greater than 90 ° is called an internal bevel gear; The tooth tip of the gear faces inward. The teeth of a bevel gear with a pitch of exactly 90 ° are parallel to the shaft.

Spiral bevel gears are bevel gears that form helical teeth along the helical line on the gear surface. The main advantage of helical gears over spur gears is smooth operation, as the teeth gradually mesh. When each pair of gears contacts, the transmission of ? is smoother. The spiral bevel gears should be replaced in pairs, and it is necessary to refer to the main spiral gear for transportation. Spiral bevel gears are more commonly used in vehicle differentials, automotive and aerospace, and in comparison to straight bevel gears, and spiral designs produce higher vibrations and noise.

The difference between spiral bevel gears and straight bevel gears

1. A straight bevel gear is a type of gear where the teeth are straight and cut along the axis on the cone. A helical bevel gear is a type of gear where the teeth are helical and cut into a helical curve on the pitch cone.

2. Sudden contact of straight bevel gears can also produce noise, while the noise during operation of spiral bevel gears is relatively low.

3. A straight bevel gear has two paired gears with teeth that suddenly come into contact. Contact is a line with a length equal to the width of the tooth, where the teeth of two mating gears of a spiral bevel gear gradually come into contact.

4. In straight bevel gears, impact load can cause vibration, making their operation unstable. However, spiral bevel gears gradually increase the load, resulting in lower vibration and therefore smoother operation.

5. In straight bevel gears, due to sudden contact, the teeth will also be subjected to impact or impact loads, while in spiral bevel gears, the teeth will be gradually loaded.

6. The straight bevel gear applies a relatively high thrust force to the bearing of the supporting shaft, while the spiral bevel gear applies a relatively high thrust force to the bearing.

7. Straight bevel gears are easier to design and manufacture, resulting in lower costs, while spiral bevel gears are more complex to design and manufacture, resulting in higher costs for such gears.

8. The service life of straight bevel gears is shorter because they withstand impact loads and vibrations, and the service life of spiral bevel gears is longer.