Seeking worm-drive gearmotor with encoder

Community General Discussions
1

I origially started a thread at RobotShop, but they don't have anything that meets my needs in terms of torque. I am designing a mechanism that needs a Right-Angle gearbox with worm drive. 

I need the following;

1)  Right-Angle gearmotor with worm drive.
2)  12v DC. (I can change to 24v if necessary)
3)  Output torque in the 200 to 400 in-lbs range. (edit. I can go as low as 150 in-lbs if necessary)
4)  Max RPM I need at output is only10 RPM under load.
5)  Encoder.

I had hoped to find a planetary gear motor that a standard NEMA mounting, and couple that with a worm drive that can accept NEMA  mounting. But, that does not seem to be typical in the world of gearboxes.

I did eventually find a company that has a product that will meet my needs.  It is from an Italian company, CBF Motors. Their 752 26 1/10 [from 86 to 106 Euros-depending on options] with the EB 04 magnetic encoder [25 EUR] is a total of 111 EUR, which is $120 USD. The pricing is certainly extremely good. But, it is also possible that I am misunderstanding something, because of language issues.

Understanding their literature is a challenge. While they provide English translations on the PDFs, the charts are only labeled in Italian. One column is labeled Coppia S 2, with units as Nm. Another give Coppia Max. This translates to couple, pair, or match.

Any ideas what the word Coppia might be referring to?

There may be other manufacturers with similar offerings, but generally, if a web page does not provide English units, I tended to pass it by. CBF Motors, at least provided the English units, even if they don't really provide for standard English sizes for the output shafts.  Note that in my 30+ year career, all the companies I have worked for used English units almost exclusively.  That even includes a medcial device firm.  But, I suppose since most things sold in the US are made elsewhere, it is natural that those companies only offer metric.  Still, the ciitizens of the US normally use Englis units, unless they are foreign born.

Does anyone have any recommendations for a USA based source that at least provides conversions to English units, and preferable offering things like output shafts in normal English units.

-Joe

2

Possible motors

I don’t have the specs but did you look at automobile power window motors?

3

Power window motors would

Power window motors would not have nearly as much power as I would need.  

4

The Italian company

The Italian company confirmed that “Coppia”, is torque. I vaguely recall the term “couple” being used in an engineering class I took many years ago, in reference to a pair of forces.  So, it makes sense now.

So far, this company CBF Motors, www.cbfmotors.it ,  is the only dealer I have come across with worm-drive gearmotors that have an encoder option.  They have a wide range of gear ratios,and were responsive to my questions.  The gearmotor I was looking at is actually manufactured by Bernio, another Itallian company. http://www.bernio.it/en/home-riduttori-nema-ita-6.html

I am surprised that the robotics parts web pages didn’t have anything like this.

-Joe

5

Motors

Looking at the physical size makes me think power window motors are more than enough. Specs are hard to comeby but I did find:

84 rpm free, 10.6 N*m stall torque

from:

http://www.chiefdelphi.com/forums/showthread.php?t=97537

6

I am going to assume that

I am going to assume that you saw this and discounted for some reason.  You seem to have done your homework with US distributors.  

These two together might do the trick depending on if you have room for the worm drive.

https://www.servocity.com/html/12_rpm_hd_planetary_gear_motor.html#.Vk9lw3arRQI

shows a stall torque of 8,110.2 oz in or 507 in lb for 12 rpm.

https://www.servocity.com/html/vertical_shaft_worm_drive_gear.html#.Vk9kUHarRQK

Since the worm gear is a 30:1 ratio, you could go with the 313 rpm and get similar torque to the 12 rpm. 

Regards,

Bill 

7

Yes, I did come across the

Yes, I did come across the Servocity product.  However, I did not come across any torque spec saying what the worm drive can handle, so I went on. The plastic main frame and Images of it being used for a camera indicated that it was a fairly light duty unit.

It is possible that I overlooked something.  My specs were changing as I realized that these slow gear ratios were hard to come by, and I both reduced expectations, and reduced the size of my V-belt drive pulley, to increase the gear ratio.

Thank you all for your comments.

-Joe