Gears can be traditionally described as rotating machines parts which so as to transmit torque have cut structures called teeth which mesh with one more similar toothed structure. This explains why two gears working in tandem are referred to as transmission and produce mechanical advantage. Gears can again be broadly classified into two categories, that is helical spur gears. Every car lover or motor enthusiast will agree that spur gears are replaceable by helical gears.
Conventionally the gears that one notices in cars are spur gears. If you are a novice with no knowledge about gears the only way you can identify a spur gear is through its teeth. They have teeth which are projected radially and these teeth are parallel to the gear axis. Spur gears are considered to be the simplest off gears and the teeth are also at right angles. The design and manufacturing process of spur gears is very easy firstly and for two gears of the same size, one spur and the other helical it can be easily deduced that the spur gear is far more efficient despite the same size. This is, actually caused by the fact that the helical gear teeth have sliding contacts located between them and this causes the production of heat and hence a decrease in the efficiency. Spur gears are also somewhat far easier to assemble in comparison to helical gears and can be assembled by simply using ball bearings.(More Info: Pump Gears)
On the other hand if we consider helical gears then the main difference from a spur gear lies in its teeth. In case of helical gears the teeth are cut at an angle to the face of the gear. The teeth take the shape of a helix .Helical gears when compared to spur gears are however far less noisy since the teeth don’t engage all at once. This considered, the power can also be transferred between non parallel shafts and load handling capability of helical gears is also far more.(Mor Info: Pinion Gears)
A modified version of helical gear that is often used is the double helical gear. They are as smooth and beneficial as the single helical gears but provide much greater strength in the case of teeth contact and do not exert any sideways force on the mounting shaft which is definitely a desirable but at the same time these gears are more expensive than spur gears.(https://www.pinterest.com/sumitsahagal358/industrial-gears-manufacturers/)
All three gears in the end find application in specific domains based on their benefits provided. While the spur gears find their application specifically where easier domain and efficiency are required and that applies to robotics. On the other hand when one looks for high speed and noise helical gears are preferred. Double helical gears again are used in cranes and pumps and also in certain military ships for specialized applications. In the end the usage is finally based on the requirements where simplicity and efficiency is the mainstay of spur gears and smooth high power application the forte of helical gears.
Source By: Industrial Gears Manufacturers
Crane Duty Helical Gearbox 