Mounting gears / pinions to motor shafts... 1

[Syncro5]

Hi all,

I'm currently working on a design which uses a geared motor which is linked directly to a rack and pinion system. The motor I'm looking at has a Ø6mm shaft with a flat spot 5.5mm from one side (making it a D shape). I need a pinion to fit to the motor shaft with little chance of slipping (a complementary fit would be ideal). The pinion has a 12mm PCD and MOD of 1 / 1.5 if that helps.

I can't seem to find any pinions with a similar (D) fit to the motor shaft - does anyone know if they are available in standard sizes?

What other options do I have?

I thought this might be a common question but, after a quick search, I can't find any previous threads covering the matter! Maybe I'm missing something?

Cheers in advance!

Joe.

 

[Syncro5]

I should have also mentioned:

The geared motor im using is capable of torques up to 1N.m but the application shouldn't see torques exceed 0.5N.m

 

[dvd]

One item to consider is whether the motor shaft is capable of withstanding the bending load caused by the gear tooth load. This motor may be more suited to transmit torque only. Before you end up with problems, you should make sure that the motor shaft and bearings are designed to accept the resultant forces.

 

[drawoh]

syncross,

Rarely have I been successful at finding pinion gears with the correct shaft diameters. Your choices are to buy an off the shelf gear and bore it out to your required size, or to have someone fabricate a gear to your drawings.

Don't reject the second choice for being more expensive. On a custom gear, they make the bore first, then they cut the teeth. Your centreing is more reliable.

It will be tempting to engage your shaft flat with a set screw. Don't. Search the W.M.Berg, Nordex. PIC and Stock Drive catalogues. They all have all sorts of clamp type hubs that are way more reliable. They may even have the 6mm bores you are looking fore!

--
JHG