The following is actually a sample application utilised to illustrate the regular process for choosing a Disc coupling. Any resemblance to any present company?¡¥s application is neither intentional nor meant to resemble that company?¡¥s actual application.
Sample Application:
A company features a compressor application making use of a 225 horsepower electrical motor operating at one,150 RPM to drive a three cylinder multi stage reciprocating air compressor. The electrical motor includes a 3-3/8 inch shaft by using a 7/8 inch keyway as well as the compressor includes a 92mm shaft by using a 25mm keyway. The shaft separation is roughly seven inches concerning shaft ends with some potential to alter the motor place. The shafts have a parallel misalignment/offset of approximately 1/32 of an inch.
Phase 1: The initial step is always to figure out what coupling kind will be to be chosen for this application. Because the SU Sort coupling only supports
just one flex plane, it could possibly only accommodate angular and axial misalignment, but not parallel misalignment. The next decision would be to look at an SX or DI Type coupling. The 6 bolt SX Sort will accommodate each parallel misalignment and the defined shaft separation. The size will probably be determined from the assortment torque and also the shaft diameters.
Stage two: Subsequent, calculate the application torque and apply the service issue to determine the assortment torque.The formula applied to determine torque is as follows:
Application Torque ( in¡§Clb ) = ( HP x 63025 )/RPM
or Nm = ( KW x 9550)/RPM
Plugging while in the numbers in the application description:
Application Torque ( in-lbs ) =(HP x 63025)/RPM = (225 x 63025)/1150 = twelve,331 in-lbs
Application Torque x Service Element = Choice Torque
twelve,331 in-lbs x three.0 = 36,993 in-lbs
Phase three: Use the SX coupling tables and note that the SX 202-6 is rated at 40,700 in-lbs, more than adequate to manage the selection torque calculated in stage two. The SX202-6, however, will not assistance the 92mm shaft dimension. The following bigger dimension coupling, the SX228-6, will support the 92mm shaft size plus the shaft separation dimension (BSE) is 6.88 inches, incredibly near to the application?¡¥s wanted 7 inch separation. The SX228-6 is rated at 62,000 in-lbs which may possibly appear to be extreme, however, the coupling size is critical to take care of the bore size.
Step 4: The SX228-6 coupling is rated to get a highest unbalanced velocity of 3,400 RPM, more than sufficient to help the application pace of 1,150 RPM.
Step five: To determine in the event the coupling will manage the parallel misalignment, make use of the trig perform of tan 1?? = offset allowed for 1 inch = 0.0174
Multiply the 0.0174 x the distance between disc packs or ??S?¡¥ dimension from the table on web page D-13, or five.50 inches.
The allowable parallel offset is 0.0174 x five.50 = 0.096 inches. The maximum offset to the application is 1/32 inches (0.031), thus this coupling can accommodate the parallel misalignment.
Note: It is always recommended to seek to install the coupling at approximately 20% on the allowable misalignment. For this coupling the installer ought to seek to achieve far better than 0.020 parallel misalignment with the time of installation. This may permit for that extra misalignment that could arise as the outcome of tools settle and general tools wear.