Planetary gears can be spur or helical gears.
Advantages - Spur gears are simplest, easiest to design and manufacture and disadvanages i dunno :)
One of the most common types of gears is the Spur Gear. They are most round with teeth along the edging. Spur Gears are used in oscillating sprinklers or fans, windup clocks, washing machines and dyers.
spur gears are used because there are many things such as bicycles that cant exist without a spur gear' > gearboxes, mechanical watches, cam drives
In the differential.
You can see them in industries...
Spur gears have straight teeth while helical gears have curved teeth. Generally, helical gears are usually quieter and smoother in operation, while spur gears are easier to make and much less expensive.Helical gears are stronger than spur gears.
They don't. Most racing trans have straight cut gears. Spur cuts are a little easier to shift.
Spur gears give 180 degree drive, and worm gears give 90 degree drive.
Spur gears are cut with straight teeth. They can only transmit rotation between parallel shafts, and are relatively economical. Bevel gears have teeth cut on an angle. They transmit rotation between non-parallel shafts. Helical gears have curved teeth. They are generally quieter than spur gears, but are generally more difficult to make and more expensive.
Spur Gears.
Sliding Gears in a transmission are straight-tooth spur gears with a taper (also known as a lead) to make engaging easier. Helical gears are mostly used in a transmission because spur gears produce gear noise and have a great strain on the teeth of the gear since only one tooth can be in contact at any given time. But because helical gears cannot be taken out of mesh, spur gears are used for the reverse gear because reverse spins the opposite way and cannot be in constant mesh.