For cylindrical gears, speed-increasing transmission stages are well known, and regarding profile shift, preferred pressure angles, and helix angles a set of rules applies, which is not much different from the rules for speed reducers. It is important to acknowledge that basically, a speed increaser has to be designed just like a speed reducer, but then the gear with the lower number of teeth is the output. Of course, the torque and the speed of the gear with the lower number of teeth (output) and the gear with the higher number of teeth (input) must be the same as if this transmission was used as a speed reducer. In the case of straight bevel gears, spiral bevel gears, and hypoid gears the same rules apply with some additions. Spiral bevel gears have many applications as speed increasers.
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“It appears that undercut can be eliminated in some cases but in most cases, the elimination of undercut, for example by increasing the root fillet radii of a pinion, results in performance problems in the operation with its mate. My question is, when can I eliminate undercut and why is it not possible in most cases?”
“ It is very hard to find out any paper regarding ‘tiger stripes’ failure, created by electrical discharge current over the gear teeth.” I wish to have some more information on this issue + how it affects the vibration / noise signatures; why does it creates the tiger stripes profile; how deep are the pittings; why does it create the noise and the possibility of running a gear with this failure?”
How does one select the correct size of hob/gashing cutter like hob OD,
length and number of flutes for teeth cutting process based on tip circle
diameter and face width of job?
We know that for cylindrical gears we have the standard DIN 3964 for defining deviations of shaft center distance and shaft position tolerances of casings. And for bevel gears? Is there some specific standard for defining deviations of center distance and shaft position tolerances of casings (orthogonal shafts), as DIN 3964 do?
A reader asks: We are currently revising our gear standards and tolerances and a few questions with the new standard AGMA 2002-C16 have risen. Firstly,
the way to calculate the tooth thickness tolerance seems to need a "manufacturing profile shift coefficient" that isn't specified in the standard; neither is another standard referred to for this coefficient. This tolerance on tooth thickness is needed later to calculate the span width as well as the pin diameter. Furthermore, there seems to be no tolerancing on the major and minor diameters of a gear.