The following can be a sample application made use of to illustrate the standard system for picking a Disc coupling. Any resemblance to any current company?¡¥s application is neither intentional nor meant to resemble that company?¡¥s actual application.
Sample Application:
A company features a compressor application utilizing a 225 horsepower electric motor operating at one,150 RPM to drive a three cylinder multi stage reciprocating air compressor. The electric motor features a 3-3/8 inch shaft using a 7/8 inch keyway as well as the compressor has a 92mm shaft that has a 25mm keyway. The shaft separation is roughly seven inches concerning shaft ends with some potential to modify the motor area. The shafts possess a parallel misalignment/offset of roughly 1/32 of an inch.
Stage one: The initial stage would be to figure out what coupling form should be to be selected for this application. Because the SU Type coupling only supports
just one flex plane, it can only accommodate angular and axial misalignment, but not parallel misalignment. The following alternative will be to appear at an SX or DI Sort coupling. The six bolt SX Variety will accommodate both parallel misalignment plus the defined shaft separation. The dimension will be determined by the variety torque along with the shaft diameters.
Phase 2: Next, determine the application torque and apply the service component to calculate the assortment torque.The formula made use of to calculate torque is as follows:
Application Torque ( in¡§Clb ) = ( HP x 63025 )/RPM
or Nm = ( KW x 9550)/RPM
Plugging inside 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 Issue = Variety Torque
twelve,331 in-lbs x three.0 = 36,993 in-lbs
Stage three: Use the SX coupling tables and note the SX 202-6 is rated at 40,700 in-lbs, a lot more than adequate to take care of the variety torque calculated in step two. The SX202-6, nevertheless, is not going to help the 92mm shaft dimension. The next more substantial dimension coupling, the SX228-6, will help the 92mm shaft size plus the shaft separation dimension (BSE) is six.88 inches, quite close to the application?¡¥s sought after 7 inch separation. The SX228-6 is rated at 62,000 in-lbs which could appear to be excessive, on the other hand, the coupling size is critical to handle the bore dimension.
Phase four: The SX228-6 coupling is rated for a greatest unbalanced pace of three,400 RPM, greater than sufficient to support the application pace of one,150 RPM.
Phase 5: To determine in case the coupling will manage the parallel misalignment, make use of the trig function of tan 1?? = offset allowed for one inch = 0.0174
Multiply the 0.0174 x the distance in between disc packs or ??S?¡¥ dimension from your table on web page D-13, or 5.50 inches.
The allowable parallel offset is 0.0174 x five.50 = 0.096 inches. The maximum offset for the application is 1/32 inches (0.031), therefore this coupling can accommodate the parallel misalignment.
Note: It is normally encouraged to seek to install the coupling at approximately 20% with the allowable misalignment. For this coupling the installer should really try to achieve improved than 0.020 parallel misalignment in the time of set up. This can permit for that supplemental misalignment that can come about since the outcome of gear settle and standard equipment dress in.