Focused on high-precision gear manufacturing, dedicated to advancing the transmission industry.
The differences between helical gears, bevel gears, spur gears, and worm gears
2025-08-22
1. Helical Gear
The teeth on a helical gear are cut at an angle to the gear's surface. When two teeth begin to engage, the contact gradually starts at one end of the tooth and continues as the gear rotates until full engagement is achieved.
Due to the nature of tooth interaction, helical gears operate more smoothly and quietly compared to spur gears.
The typical helix angle ranges from about 15 to 30 degrees. The thrust load varies directly with the magnitude of the helix angle's tangent.
Helical gears are the most commonly used gears in transmissions.
They also generate significant thrust and use bearings to help support the thrust load. Bevel gears can be used to adjust the rotation angle by 90 degrees when mounted on a vertical shaft. Their typical gear ratio range is from 3:2 to 10:1.
2. Spur Gears
The most common type of gear is the spur cylindrical gear, which is used for applications like reducing speed in large gears. The teeth on a spur gear are straight and are mounted parallel to each other on different shafts.
Due to gear meshing and collisions, each impact generates significant noise and causes vibrations—this is precisely why straight-toothed cylindrical gears are not used in machinery like automobiles.
A typical gear ratio ranges from 1:1 to 6:1.
Spur cylindrical gears are commonly used in washing machines, screwdrivers, spring-powered alarm clocks, and other devices.
3. Worm Gear
Worm gears are used in large gear reducers. Typical gear ratios range from 5:1 to 300:1. The design ensures that the worm can turn the gear, but the gear cannot rotate the worm. The worm has a shallow angle, which allows the gear to remain securely in place due to the friction between the two components.
This transmission device is suitable for conveyor systems, where the locking function can be used as a brake or emergency stop mechanism.
4. Bevel Gears
Bevel gears are used to change the direction of shaft rotation. They come in straight-tooth, helical, or hypoid tooth designs.
Straight teeth share similar characteristics with spur gears and significantly influence their meshing behavior.
Similar to spur gears, straight-tooth bevel gears have a typical speed ratio range of 3:2 to 5:1.
Spiral bevel gears operate in the same way as helical gears. Compared to straight teeth, they generate less vibration and noise.
To the right of the helical ramp is the outer half of the tooth, angled as it progresses clockwise from the axial plane.
The left-hand spiral helical gear moves counterclockwise. The standard gear ratio range is from 3:2 to 4:1.
A quasi-hypoid gear is a type of helical gear whose shape resembles a rotating hyperboloid rather than a cone.
The hypoid gear places the pinion on either the ring gear or the crown wheel. This allows for a larger pinion diameter and provides a greater contact area.
The pinion and gear are typically always opposite in direction, with the pinion usually having a helix angle greater than that of the gear.
Beveloid gears are used in power transmission systems due to their high gear ratios, which typically range from 10:1 to 200:1.
TAG:
Next
Next:
More Blog
Unlocking Precision: The World of Custom Non-Standard Gear Manufacturing
High-precision Gear Manufacturing
KeXin Gear welcomes industry professionals and manufacturers to visit, offer guidance, exchange technical expertise, and explore business opportunities—let’s collaborate sincerely to create a brilliant future together!
CONTACT
Internal Trade: +86-13582027480 (Manager Zhang)
Sales: +86-13785171103 (Director Duan)
Foreign Trade: +86-17531190369 (Mr. Gu)
Email: lxc@lxc.cn
Foreign Trade Email: kexin@lxc.cn
Address: Renmin Village, Fanzhuang Town, Zhao County, Shijiazhuang City, Hebei Province