The next is really a sample application employed to illustrate the regular system for picking a Disc coupling. Any resemblance to any present company?¡¥s application is neither intentional nor meant to resemble that company?¡¥s real application.
Sample Application:
A company has a compressor application making use of a 225 horsepower electric motor running at one,150 RPM to drive a three cylinder multi stage reciprocating air compressor. The electric motor has a 3-3/8 inch shaft by using a 7/8 inch keyway along with the compressor has a 92mm shaft using a 25mm keyway. The shaft separation is approximately seven inches involving shaft ends with some means to adjust the motor area. The shafts possess a parallel misalignment/offset of approximately 1/32 of an inch.
Phase 1: The very first phase should be to decide what coupling style should be to be selected for this application. Because the SU Variety coupling only supports
just one flex plane, it could possibly only accommodate angular and axial misalignment, but not parallel misalignment. The subsequent alternative could be to appear at an SX or DI Sort coupling. The 6 bolt SX Kind will accommodate both parallel misalignment along with the defined shaft separation. The dimension might be established by the choice torque and also the shaft diameters.
Phase two: Up coming, determine the application torque and apply the services issue to determine the assortment torque.The formula employed to determine torque is as follows:
Application Torque ( in¡§Clb ) = ( HP x 63025 )/RPM
or Nm = ( KW x 9550)/RPM
Plugging within the numbers from the application description:
Application Torque ( in-lbs ) =(HP x 63025)/RPM = (225 x 63025)/1150 = twelve,331 in-lbs
Application Torque x Support Factor = Variety Torque
12,331 in-lbs x three.0 = 36,993 in-lbs
Step three: Use the SX coupling tables and note the SX 202-6 is rated at forty,700 in-lbs, a lot more than ample to manage the selection torque calculated in phase two. The SX202-6, however, will not support the 92mm shaft dimension. The subsequent more substantial size coupling, the SX228-6, will support the 92mm shaft dimension along with the shaft separation dimension (BSE) is 6.88 inches, very near to the application?¡¥s sought after 7 inch separation. The SX228-6 is rated at 62,000 in-lbs which could seem to be extreme, on the other hand, the coupling dimension is important to take care of the bore dimension.
Stage four: The SX228-6 coupling is rated for a highest unbalanced pace of three,400 RPM, a lot more than ample to assistance the application speed of one,150 RPM.
Step 5: To find out in case the coupling will handle the parallel misalignment, utilize the trig perform of tan 1?? = offset permitted for 1 inch = 0.0174
Multiply the 0.0174 x the distance involving disc packs or ??S?¡¥ dimension through the table on web page D-13, or five.50 inches.
The allowable parallel offset is 0.0174 x 5.50 = 0.096 inches. The maximum offset for your application is 1/32 inches (0.031), therefore this coupling can accommodate the parallel misalignment.
Note: It really is always advised to endeavor to install the coupling at approximately 20% with the allowable misalignment. For this coupling the installer need to try to reach far better than 0.020 parallel misalignment at the time of installation. This may permit to the supplemental misalignment that should happen because the end result of products settle and basic equipment put on.