Computing excitation frequency for a three lobe screw compressor

[mechanicaljw]

Hi All,

I am new to srew compressors and was wondering how to compute the excitation frequency for such a compressor at a speed of 1350 rpm with 3 male lobes and 5 female flutes?

Thanks in advace for your help.
Jimmy

 

[JJPellin]

Which screw is the drive and which is the driven? If the male is the drive, then the run speed of the male is 1350 cpm and the run speed of the female is 810 cpm . The lobe mesh frequency is 4,050 cpm (1350 X 3 or 810 X 5). If it is a dry screw machine, you will also have gear mesh frequency for the timing gears. If it is a wet screw machine, then there are no timing gears.

Johnny Pellin

 

[mechanicaljw]

Hi Johnny,
And thanks for responding to my question. For our screw compressor, the driver is the female and the driven is the male lobe. Does that change the calculation of the excitation frequecy at 1350 rpm?

Warmest regards,
James