Help for design a rack and pinion please.

[JohnBC]

Hi to all,

I need some help, I have to design a rack and pinion, the only two parameters that I have are: linear velocity of rack and load to be drag by rack. What criteria should I have in mind to determine the most efficient: module, pitch diameter and teeth number (in rack and pinion)?

Parameters:
Speed: 4 m/min
Load: 2.5 kN
Material: I guess stainless steel is the best because it will be used in a humid environment.

Any help would be really appreciated!


Best regards,

John.

 

[IRstuff]

IS this for school? Student posting is not allowed.

TTFN
I can do absolutely anything. I'm an expert!
homework forum: //

http://www.engineering.com/AskForum/aff/32.aspx

faq731-376 forum1529

 

[drawoh]

JohnBC,

You did gear design in college, right? You have the force and speed, so you can figure out torque and ratios. This is a rather basic question.

--
JHG

 

[JohnBC]

IRstuff: No, this is not for school.

drawoh: I did, but all books (at least the books that I have checked so far says assume pitch diameter and teeth number).

I'm sorry if my question is too basic or too silly for this forum.

 

[drawoh]

JohnBC,

Pick a module or diametric pitch. Pick some number of teeth. Do the analysis. Use a spreadsheet. No one gets this stuff right on the first pass.

--
JHG

 

[3DDave]

So far, you've gotten about 1% of the information to make any reasonable determination. There's too many unknowns to guess what else you might need to know. It would probably be best to contact rack and pinion manufacturers.

 

[TheTick]

Speed x Force = Power
Power = Torque x angular velocity (in radians)

If you know speed and force and pick a gear diameter, you can determine how thick the gear needs to be to bear the torque.

 

[BUGGAR]

Your goal is an efficient design. How are you measuring efficiency, force-in (torque on the pinion) divided by force-out (linear on the rack)?
Do you have any info on the available input torque?

 

[Jboggs]

You mentioned "dragging" the load. Does that mean that friction will be a factor? Do you know what the actual load is at the rack? Once you know what that load is, select a pinion diameter to give you an acceptable torque. That diameter will also determine the required rotational speed of the pinion. The force involved will also help you select the DP or module. You might want to get in touch directly with a manufacturer. Their application engineers are paid to help you find the bets solution.