Timing Pulleys
Timing Pulleys
(OP)
Was wondering how to obtain tooth geometry information to create pulleys for standard timing belts.
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS Come Join Us!Are you an
Engineering professional? Join Eng-Tips Forums!
*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail. Posting GuidelinesJobs |
|
RE: Timing Pulleys
The wisest course is to buy a length of pulley stock >for the specific belt profile you intend to use<, and machine it into a pulley.
Or just buy the exact pulley you need from someone who makes them all the time.
Mike Halloran
Pembroke Pines, FL, USA
RE: Timing Pulleys
RE: Timing Pulleys
RE: Timing Pulleys
Is the tooth geometry the same on a HTD belt that has a different pitch? Or different belt length? I'm wondering if one hob cutter can cut multiple different pulleys for different pitches and belt lengths.
Please advise...Thanks
RE: Timing Pulleys
The pulley profile usually but not always matches the profile of the belt when the belt is held to the curvature of the pulley.
This is further complicated because the real pitch radius of the belt lies in the plane of the cable reinforcement, which lies entirely outside of the pulley OD, and that some belts are designed to ride on the pulley OD, some are designed to ride on the teeth flanks, and I've found 'scrum' belts whose teeth are covered with something that looks like hair, and I don't know where the hell they ride.
Just buy the damn pulley stock, or the finished pulley; making your own is insane.
Mike Halloran
Pembroke Pines, FL, USA
RE: Timing Pulleys
Gates and Goodyear will make you a custom pulley for reasonable cost and lead time, plus you get the genuine article.
HTD designs are the closest thing I know if to being a "standard" and available from multiple manufacturers. I infer then that they are not strictly proprietary, but if you want a full warranty probably not an option.
David
RE: Timing Pulleys
Mfgenggear
RE: Timing Pulleys
The prototype parts are then made using wire EDM and a little CNC.
Production parts are powder metal.
I'd give you an example tooth profile but they are all proprietary.
RE: Timing Pulleys
RE: Timing Pulleys
http://g04.s.alicdn.com/kf/HT1KIoMFHRcXXagOFbXI/79...
RE: Timing Pulleys
RE: Timing Pulleys
Sometimes they will not reveal the geometry they use unless there is a contract for doing business.
There are usually 2 types of companies. The ones that only give you profile points (eg. excel sheet or stp file) so that it is very difficult to figure out the actual geometry, but you can still use the points to make prototypes for experiments.
Then there are the companies that give a profile drawing, sometimes the dimensions are 'estimates'.
However, if you are a Tier1 supplier it is usually not a problem.
RE: Timing Pulleys
RE: Timing Pulleys
Ex: gates htd 3mm pitch belt versus gates 5mm pitch belt
Is the tooth profile same but the belts just have them spaced differently?
Also, on the flip side, 2 belts of the same pitch that have different lengths, are the tooth profiles the same? I'm leaning towards yes on this one but I want to learn all I can about timing belts/pulleys.
Thanks in advance.
RE: Timing Pulleys
Indeed this is correct.
RE: Timing Pulleys
As for two belts of the same tooth pitch having different lengths, that would depend on what location on the belt section you measured the length at. Most belts and sprockets are measured based on a defined pitch location, and the offset from this pitch location to the outside of the belt can vary among different manufacturers.
RE: Timing Pulleys
RE: Timing Pulleys
http://partview.gates.com/catalog3/d/gates.pt/?c=f...
again, this only seems to be available for belt geometry, not pulley geometry. I'm thinking if I have belt geometry I can somehow generate pulleys.
RE: Timing Pulleys
And remember to design mid-tolerance. Many drawings are low-side tolerance.