The difference between helical gears, bevel gears, spur gears and worm gears

release time:

2022-02-15

Worm gears are used for large gear reductions. Gear ratios ranging from 5:1 to 300:1 are typical. The purpose of the setup is so that the worm can turn the gear, but the gear cannot turn the worm. The worm has a shallower angle so the gears stay in place due to friction between the two.

The difference between helical gears, bevel gears, spur gears and worm gears

1. Helical gear

The teeth on a helical gear are cut at an angle to the gear face. When two teeth come into engagement, contact is gradual from one end of the tooth and remains in contact as the gears rotate to full engagement.

Due to the interaction of the teeth, helical gears work more smoothly and quietly than spur gears.

Typical helix angles range from about 15-30 degrees. Thrust loads vary directly with the magnitude of the tangent to the helix angle.

Helical gears are the most commonly used gears in transmissions.

They also generate a lot of thrust and use bearings to help support the thrust load. Helical gears can be used to adjust the rotation angle by 90 degrees. when mounted on a vertical axis. Its normal gear ratio range is 3:2 to 10:1.

2. Spur gear

The most common gears are spur gears, which are used for large gear reductions, etc. The teeth on spur gears are straight and mounted parallel on different shafts.

Each bump creates a loud noise and causes vibrations as the gears mesh and bump, which is why spur gears are not used in machinery such as cars.

A normal gear ratio ranges from 1:1 to 6:1.

Spur gears are commonly used in washing machines, screwdrivers, wind-up alarm clocks, and other appliances.

3. Worm gear

The drive is suitable for use in conveyor belt systems where the locking function can be used as a brake or as an emergency stop.

4. Bevel gear

Bevel gears are used to change the direction of rotation of a shaft. Bevel gears have straight teeth, helical or hypoid shaped teeth.

Spur teeth have similar characteristics to spur gears and also have a large influence when meshing.

Similar to spur gears, normal gear ratios for spur bevel gears range from 3:2 to 5:1.

Helical teeth operate the same as helical gears. They generate less vibration and noise than straight teeth.

To the right of the helical ramp is the outer half of the tooth, inclined to travel clockwise from the plane of the axis.

The left hand of the spiral bevel travels in a counterclockwise direction. Normal gear ratios range from 3:2 to 4:1.

A hypoid gear is a helical gear whose shape is a hypoid of revolution rather than a cone.

A hypoid gear places the pinion on the ring gear or crown wheel. This allows the pinion to be larger in diameter and provides more contact area.

Pinions and gears are usually always opposite, and the helix angle of the pinion is usually greater than the angle of the gear.

Hypoid gears are used in drivetrains due to their large ratios. Normal gear ratios range from 10:1 to 200:1.