For this reason, helical gears are used in almost all car transmissions.

The teeth on helical gears are cut at an angle to the face of the gear.

An internal helical gear and its pinion must be of the same hand.

By adding a second helical gear in opposition this force is cancelled.

It uses a helical gear assembly that significantly reduces noise.

An involute helical gear is the base pitch in the normal plane.

Two external helical gears operating on parallel axes must be of opposite hand.

The power from these turbines was used to run the twin shafts through a series of helical gears.

Helical gears can be meshed in parallel or crossed orientations.

In a helical gear it may be considered as the length of arc along a normal helix.

The gears that make up the forward gear ratios are all helical gears.

Two main turbines were arranged in series and drove a shaft through double helical gears.

The pump is driven by a jackshaft and helical gear.

However, double helical gears are more difficult to manufacture due to their more complicated shape.

Both output shaft pinions drive a helical gear with a conventional differential.

In helical gears and worms, axial pitch has the same value at all diameters.

The three-speed floor-mounted transmission had silent helical gears in second speed.

However, many modern transmissions now include a reverse gear synchronizer and helical gearing.

Devices that use helical gears have bearings that can support this thrust load.

The transmission included helical gear drive, a wet clutch, and a three-speed gearbox.

Note that it is the complement of the helix angle which is usually given for helical gears.

Helical gears are sometimes used for the high-torque drives, typically the starter, as these give smoother running.

However helical gears also generate an end-thrust, which then requires a more complicated thrust bearing to support them.

As mentioned at the start of this section, helical gears operate more smoothly than do spur gears.

The only problem with helical gears is that it is hard to slide them in and out of engagement with each other.