Disc Couplings
disc-couplings
SU Type (Single Disc Pack)
- The SU Type coupling has a single flex plane, and is comprised of a single disc pack kit with two hubs. It is suitable for angular and axial misalignment only. Two SU couplings are often combined with a shaft to make a floating shaft coupling. The shaft can be hollow for long light weight floating shaft couplings.
- Note: SU and SX coupling hubs are identical parts, and are generally individually called out as SX hubs.
SX Type (Two Disc Pack)
- This is the standard coupling type that includes two hubs, a stock length spacer designed to meet industry standard lengths, and two unitized disc packs. The coupling has two flex planes, one at each disc pack, allowing this coupling to accommodate parallel, angular, and axial misalignment with specified limits. The coupling is available in 4, 6, and 8 bolt designs and bore sizes up to 13 inches (330mm) on the largest size. Custom spacer lengths can be manufactured to meet special shaft separations required for specific applications. The SX coupling can be fitted with overload bushings to protect the disc packs in over torque conditions and can act as an anti-flail device. SX couplings are assembled at the time of installation on the equipment where the coupling will be in service.
SXC Type (Close Coupled)
- The SXC Type is the close coupled variation of the SX Type coupling. The SXC is similar to the SX coupling in that the disc packs are attached when the coupling is installed. In the close coupled units, the hubs are turned inward and are mounted inside the spacer. Note that with the hubs inside the spacer, the maximum bore allowed in the hub will be decreased. The SXC couplings can be used with one or both hubs turned outward to allow the coupling to accommodate different shaft separations.
- Note: The SXC Type uses the same disc pack kits and spacers as the SX Type.
DI Type (Drop-In Spacer)
- The DI Type coupling has a “Drop-In” spacer assembly that is assembled at the factory. The coupling consists of two hubs and a spacer assembly comprising of the spacer, two unitized disc packs, and two guard rings. The disc packs are bolted to the spacer and guard rings at the factory using the torque values recommended by Lovejoy for the disc pack bolts. With the hubs mounted on the shafts, the entire disc pack assembly can be “Dropped In” place between the two hubs. The hubs are piloted to ensure proper centering of the spacer assembly. This piloting serves as an anti-flail feature and aids in the coupling’s ability to meet the balance standards mandated by API. This style coupling is designed to meet the balance and anti-flail requirements specified in API-610.
- Oversized, or Jumbo, hubs are available for use with the DI Type coupling to allow for larger bore sizes on most DI coupling sizes. This allows for the use of smaller DI couplings in applications where a smaller size coupling can still accommodate the application torque.
