Helical Inline Gear Motors Helical gears are not specifically comparable to worm or bevel gearbox systems. They are in fact an alternative solution to spur gears where the tooth 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 motor will most likely be quieter and can bring higher loads than motors using a spur gearbox. They could be more expensive in initial cost, and manufacturers need to take into account axial thrust. However, the actual fact that the helix position may differ from 15 to 30 degrees permits flexibility with regards to design. They are used in in-line applications along with parallel shaft applications.

The benefit of helical gears is that it produces a helical spiral bevel gear motor rolling action, is quieter, and has less vibration compared to spur gears. In addition, it produces much less friction and allows for more the teeth to be engaged at the same time as the teeth roll across each other.
There are myriad types of gearing. Some manufactures make use of spur gears instead of helical gearing, for instance. However, there isn’t as much surface contact, as mentioned above and consequently there is more noise and much less torque transfer possible.

Another system where noise can be common are planetary equipment systems, where in fact the one gear is totally within the other. In addition they require grease lubrication and they must be built with expensive materials in order to maintain a long-life and bearing integrity. An easier variant, internal gearing, suffers from the same problems and can only be utilized with parallel shaft.

Finally, hypoid gearing could be best understood as similar to bevel gearing, but with the apparatus axes not intersecting. The sliding actions can create large amounts of heat and the alignment requires great care.