How do I configure a gearbox and motor together?

[Ronnin]

I feel like a fool having to ask this question here but I'm trying to learn this without calling engineering everytime I have a PT question. Is anyone here familiar with gearbox/motor configuration? I was going to use Emerson's boxes since I'm a distributor for them. Anyone here familar with them or anyone elses for that matter?

 

[Q_Goest]

Hi Ronnin. I'm not very familiar with the Emerson line, though I've used similar equipment in the past. What's your question?

 

[Ronnin]

Here is what I'm trying to do. Customer is requesting a 1HP 3phase 220 Motor. Connecting to a GB with a C56 flange (Is that normal?). 40:1 Ratio, Right Hand output. I don't know how many input RPM (Is there a standard for that HP?) Service factor (I don't know what would be normal for that). Do I have enough info from the customer? I know this is a new design for him but unfortunately I'm not of much help. I really want to try to understand the right questions to ask because I want to be able to configure solutions without having to call the customer back after I had to call engineering.

 

[Q_Goest]

A 1 hp, 3 phase, 220 volt motor is typically 1750 RPM, and he's saying it has a NEMA C-face connection and the frame size of the motor is 56. A C-face connection is where the motor bolts up to something on the face that has the shaft protruding as shown here:
http://www.bearingsdirect.com/emotor/images/rigid_cface.htm

The 40:1 ratio I'm assuming reduces the RPM from 1750 on the input to 1750/40 on the output.

Service factor is essentially a type of safety factor, but the gear box is rated in torque, not power, so you may need to determine the input torque, x (from the electric motor), and then explain that the torque capacity of the model you're offering is X which gives a X/x 'service factor' over the point at which he's operating.

Take a look at the Emerson page here:
http://www.emerson-ept.com/eptroot/public/prod/brghelc/TorqTaperPlusCFace.asp
and see if one of these models would work. It looks like they only go to 35:1 so this customer may want a custom unit.

I think he's given you enough info for you to offer some potential solutions. There may be more than one gear box that can meet those criteria, cost and other factors being the differentiators.

 

[Ronnin]

Thanks for the info. I will pull some potentials from the book and try to pin the customer down. Thanks again for your input.

 

[FredGarvin]

If I may...in situations like these, a good sales rep for a distributor can really be a godsend. You sound like you have the major required details. If you were to present that to a sales rep, they should be able to give you options and possibly give you things to think about that neither you or your customer thought about.

If it's worth your while to think about other options, I use Baldor motors and drives quite a bit. I havenever had problems with them. Just another place you can look. Good luck.

 

[Chronos]

I've had some bad experiences with high horsepower Baldor motors. They had some shaft sparking issues under shock loads.