The following is usually a sample application used to illustrate the regular approach for picking out a Disc coupling. Any resemblance to any existing company?¡¥s application is neither intentional nor meant to resemble that company?¡¥s real application.
Sample Application:
An organization has a compressor application employing a 225 horsepower electrical motor running at one,150 RPM to drive a three cylinder multi stage reciprocating air compressor. The electrical motor includes a 3-3/8 inch shaft using a 7/8 inch keyway as well as compressor has a 92mm shaft with a 25mm keyway. The shaft separation is roughly 7 inches involving shaft ends with some capability to alter the motor area. The shafts have a parallel misalignment/offset of approximately 1/32 of an inch.
Phase 1: The primary stage is usually to determine what coupling style is usually to be chosen for this application. Since the SU Variety coupling only supports
just one flex plane, it may possibly only accommodate angular and axial misalignment, but not parallel misalignment. The following option will be to appear at an SX or DI Sort coupling. The six bolt SX Style will accommodate both parallel misalignment and also the defined shaft separation. The dimension will be determined from the choice torque as well as the shaft diameters.
Step two: Next, determine the application torque and apply the services aspect to calculate the variety torque.The formula utilized to calculate torque is as follows:
Application Torque ( in¡§Clb ) = ( HP x 63025 )/RPM
or Nm = ( KW x 9550)/RPM
Plugging while in the numbers from your application description:
Application Torque ( in-lbs ) =(HP x 63025)/RPM = (225 x 63025)/1150 = 12,331 in-lbs
Application Torque x Services Component = Assortment Torque
twelve,331 in-lbs x three.0 = 36,993 in-lbs
Phase 3: Utilize the SX coupling tables and note that the SX 202-6 is rated at forty,700 in-lbs, greater than ample to deal with the choice torque calculated in stage two. The SX202-6, nonetheless, is not going to assistance the 92mm shaft dimension. The subsequent more substantial dimension coupling, the SX228-6, will support the 92mm shaft dimension plus the shaft separation dimension (BSE) is six.88 inches, pretty close to the application?¡¥s preferred seven inch separation. The SX228-6 is rated at 62,000 in-lbs which may perhaps appear to be extreme, however, the coupling size is important to manage the bore size.
Stage 4: The SX228-6 coupling is rated to get a optimum unbalanced pace of three,400 RPM, in excess of sufficient to assistance the application velocity of 1,150 RPM.
Stage 5: To find out in the event the coupling will handle the parallel misalignment, utilize the trig perform of tan 1?? = offset allowed for one inch = 0.0174
Multiply the 0.0174 x the distance amongst disc packs or ??S?¡¥ dimension in the table on webpage D-13, or five.50 inches.
The allowable parallel offset is 0.0174 x five.50 = 0.096 inches. The utmost offset for your application is 1/32 inches (0.031), consequently this coupling can accommodate the parallel misalignment.
Note: It is actually always suggested to endeavor to install the coupling at approximately 20% from the allowable misalignment. For this coupling the installer need to endeavor to obtain greater than 0.020 parallel misalignment in the time of set up. This can allow for that additional misalignment that will occur as the end result of tools settle and general equipment wear.