Steps in designing Rack and Pinion system

[blckwtr]

Hello everyone...

I have tried to find some information on this subject, but it seems to be different approaches when designing a rack and pinion system. If I have a given pinion diameter, can I design the number of teeth etc from this? ...or do I need some more parameters? This is not a highly stressed part of the design...

Does anyone have a mathcad or excel sheet calculating the different parameters?

Also, the rack needs to be positioned correct relative to the pinion, does this also come from these parameters?

Best regards

Tommy

 

[Timelord]

Tommy,

Are you given the outside diameter or the pitch diameter of the pinion? The circumference of the pitch diameter is the distance the rack will move for one revolution, so it would be the logical given parameter. I would simply chose a pinion from a catalog with the given pitch diameter and find a rack with matching teeth from the same catalog. The diametral pitch and face width should be chosen so the teeth are big enough to carry the load. If this system needs to carry large loads, you may want to double check the tooth loading to verify that the system can carry the load. When mounting, the critical dimension is to locate the pinions pitch circle tangent to the pitch line of the rack. The catalog should list these dimensions.

Timelord

 

[hydtools]

Check out Boston Gear:

http://bostongear.com/products/open/spur.html

Ted

 

[blckwtr]

Thank you very much, I should maybe try to find a reseller here in Norway. The rack and pinion is a one-go application. A sort of a "release" mechanism, and the stress level is relatively low. I have looked into some other solutions as well but for my application I would think the rack and pinion is the best...

 

[dinjin]

The smaller the Diametral Pitch, the more teeth you
will have in contact for a given pitch diameter. Without load data or pitch diameter it is hard to give you advice. If you have any gear program, you can get some parameters from simply entering 10000 teeth for the gear and get some approximation for the strength of the gear. The pinion will be the weaker member if both are of the same material and hardness. Are you considering plastic
or are you using metal parts?