Have striaght cut teeth and can be manufactured by either shaping or hobbing, they come in a variety of pitches module or D.P. and normally with a 20 degree pressure angle.
Teeth are at an angle called a helix, up to a maximum of 45 degrees. Normally a right hand will run a left hand helical, This can help with noise reduction compared with a spur gear.
Allows power tranmission for shafts at 90 degree angles, cut to the Gleason system from 8mm to 400mm diameter. The smaller of the pair is called the pinion. Bevel gears with an equal number of teeth than run together are called Miter gears.
Worm & Wormwheels
Worm gears which are normally hardened steel, resemble a screw thread and can be single or multistart, these are thread milled.
Wormwheels are like helical gears but have a throat so they fit around the worm gear, normally made from Phosphorous Bronze for good wear properties.
Allow a chain to drive, come in a variety of sizes depending on the chain roller and the pitch.
Are driven by a toothed belt and come in many different tooth forms.