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Coupling for Reciprocating Compressor

Coupling for Reciprocating Compressor

Coupling for Reciprocating Compressor

(OP)
Hi,

I am designing a direct drive system including an electric motor and a 6 -cylinder reciprocating compressor.

How much is the service factor I should use when I size the key and coupling hub/spider (because of the vibration)?

Thanks,


RE: Coupling for Reciprocating Compressor

wzal
This seems to be an odd question to me because all the open compressor/motor interfaces I have done (50 to 100hp). The motor/compressor shafts are already machined for a key.
You need to match each (if each is diffrent)with the correct coupling with the correct keyway.
In addition, I would recommend that you choose a flexible plate coupling instead of a spider type. Alignment of the motor/compressor is very, very critical. A spider type is not up to that task.
Contact the compressor manufacture for motor/compressor coupling guidlines, Iam sure they will be glad to help you.

Best Regards

pennpoint

RE: Coupling for Reciprocating Compressor

Absolutely right - With an open type compressor, one of the biggest problems faced is a shaft seal leak due to mis-alignment.  Get this done correctly and the compressor (generally) is a workhorse and doesn't pose too many problems.

HVAC68

RE: Coupling for Reciprocating Compressor

If Pennpoint means bush and pin type coupling by flexible plate coupling, then I also suggest tyre coupling as an alternative.

RE: Coupling for Reciprocating Compressor

A Thomas coupling has always been the perfect choice for me
Look here: http://www.couplingcorp.com/

RE: Coupling for Reciprocating Compressor

quark

The type of coupling I meant is shown in the attached.

http://www.rinomechanical.com/couplings/high-torque-flex.pdf

This type does not tolorate much missalignment therefore the motor/compressor alignment is critical. A tire (tyre) or elastomeric type you suggest dismisses the the critical alignment because they have a large compensation factor. Misleading the installer into a false sence of "thats GOOD ENOUGH".  The seals on an open style refrigeration compressor cannot tolorate "ANY" side load.
I have to admit that its been awhile since I have done one of these, but I would still use dial indicators, alignment V-blocks and get it done right.
I strongly recommend that the compressor manufacture be consulted. If this were a Carlyle Compressor I know they have accepted procedures and approved couplings.
BTW stating that the compressor has six cylinders means nothing, it could be a 25hp or up to a 120hp compressor. These compressors are brutes and worth the big $$$ they get for them. Do a good job of installing them and you'll get long time service from them without expensive refrigerant loss and warranty service calls.

All this is only my opinion.

Best Regards
pennpoint

  
    


RE: Coupling for Reciprocating Compressor

(OP)
Thank you all for your valuable input.
I have a Lovejoy Jaw type and a Rex Omega coupling. Both of them have torque capacity 4 times of continuous torque of the application. But both of the 2 coupling manufacturers didn't say how much is the service factor I should use on the spec. (it seems to me recip compressor system is special application for these guys cause I can find service factor for all sorts of other applications).
Does anyone use any of the 2 types of coupling on recip compressor?

Regards,
 

RE: Coupling for Reciprocating Compressor

Has anyone ever used a Falk coupling in this same service?

krb

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