Except efficiency, the other factors are almost similar.

eg service factor - typical are here, here,

The basic terminolgies with a bit of explanation

Here is the procedure (but does not talk about efficiency)

Thank you very much.

Can you please guide about efficiency of the wormgear?

How efficiency and the links given by you are different?

Pl guide.

T J Shah

Sir:

Efficiencies claimed by different manufacturers are different mentioned in range. If everybody is manufacturing as per the same code, why efficiencies are different? Which are the governing factors influencing the efficiency of the wormgear? Due to self-locking feature of the wormgear will there be any derating over a period of time ?

T J Shah

Also the self locking feature is a part of the worm technology and is the advantage provided by it (ie driven can not drive the driver)

Depending on your size and quantity requirement did you look at the options ?

single stage bevel+ planetary chain typically will have efficiency above 95% along with compactness.

The efficiency is a bit different from other factors.

As you know the worms do not (and can not) rotate in the pure rolling contact - like the involute gears do. The sliding contact reduces the efficiency of the system.

Different profiles are created by different manufactureres with claims of improved efficiency.

AGMA is silent on the profile aspect, rather liberal.

As per AGMA 6022-C93

"The thread profile or shape of the thread flanks ... no limitation is placed on the method used except that the hob or the tooling used to produce the worm gear should have substantially the same profile as the worm so that..."

AGMA 6034-B92 gives the worm efficiency calculations. However that may be out of your syllabus .

I will provide some links for this aspect

http://www.sdp-si.com/d220/HTML/D220T120.htm

http://machinedesign.com/article/worm-gear-reducers-reach-new-heights-0603

http://www.roymech.co.uk/Useful_Tables/Drive/Gear_Efficiency.html

These typically gives the efficiency about 50 to 95% or so. And you may have the suppliers claiming.

However in our gear boxes, a bit large, with ratios about 15:1 to 25:1 we have rarely achieved above 80-90%