Helical Inline Gear Motors Helical gears aren’t specifically much like worm or bevel gearbox systems. They are actually an alternative solution to spur gears where the teeth are parallel to the axis of the apparatus itself. For example, in an inline application, you could have either spur OR helical gears. An inline helical gearbox electric motor will usually be quieter and will carry higher loads than motors utilizing a spur gearbox. They could be more expensive in initial price, and manufacturers have to account for axial thrust. However, the fact that the helix angle may differ from 15 to 30 degrees permits flexibility in conditions of design. They are found in in-line applications as well as parallel shaft applications.
The advantage of helical gears is that it produces a rolling action, is quieter, and has less vibration in comparison to spur gears. It also produces less friction and allows for more tooth to be engaged concurrently as the teeth roll across each other.
There are myriad types 
of gearing. Some manufactures make use of spur gears rather than helical gearing, for instance. However, there is not as much surface get in touch with, as observed above and because of this there is more noise and less torque transfer possible.
Another program where noise is definitely helical spiral bevel gear motor common are planetary gear systems, where in fact the one gear is totally within the other. They also require grease lubrication plus they must be constructed with expensive materials in order to maintain a long-lifestyle and bearing integrity. An easier variant, internal gearing, is suffering from the same problems and can only be used with parallel shaft.
Finally, hypoid gearing could be best understood because similar to bevel gearing, but with the gear axes not really intersecting. The sliding actions can create huge amounts of temperature and the alignment requires great care.