Archive: Nov 2021

Installation Guide for Rigid Shaft Couplings

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Stafford Manufacturing Corporation is a leading manufacturer and distributor of a variety of shaft collars, specialty mechanical components, and rigid shaft couplings for use in many types of applications. At Stafford Manufacturing Corp., we offer a wide range of rigid couplings to allow two shafts to function as one.

When deciding on the right coupling for your application, one key factor will be whether you need a one-piece,  two-piece or three-piece coupling. One-piece clamp couplings offer zero backlash and feature high torsional holding power with no damage to the shafts. Two-piece couplings feature the same advantages, with the added benefit of allowing in-place service. Three-piece couplings allow you to keep one shaft in place while the other is changed.

In this guide, we’ll detail the steps for proper shaft coupling installation for the main types of rigid couplings, along with some factors that determine which couplings to use.

Materials

Based on an application’s specific requirements, rigid shaft couplings can consist of a vast array of materials, including 303, 316, and 304 stainless steel, 2024 aluminum, carbon steel or black oxide-finished carbon steel, or brass. The installation steps for rigid couplings will differ depending on the coupling type (one, two or three-piece).

Installation of a One-Piece Rigid CouplingInstallation of a One-Piece Rigid Coupling

The steps for installing a one-piece rigid coupling are as follows.

Alignment

Rigid couplings are used when an application requires coupling of two aligned shafts (they can be shafts of the same sizes or different sizes). High stress could result if axial or radial misalignment takes place, potentially causing failure so they are only to be used with unsupported or fully aligned shafts. Once connected to two shafts, rigid couplings will prevent any relative motion from occurring. One-piece rigid couplings ensure alignment.

Installation Process

When installing a one-piece rigid coupling, take these steps:

  1. Wipe any excess dirt or oil off the shaft as well as the  bore of the coupling.
  2. Slide one end of the coupling over its mating shaft until that shaft is 1/32” short of the cross slot
  3. Adjust the center screw to half of the recommended seating torque.
  4. Adjust the outer screw to half of the recommended seating torque.
  5. Slide the other shaft into the remaining end of the coupling until it is 1/32” short of the cross slot.
  6. Adjust the center screw to half of the recommended seating torque
  7. Adjust the outer screw to half of the recommended seating torque
  8. Use a torque wrench to fully adjust all screws to the recommended seating torque, going from the center screws to the outer screws.
  9. If possible, slowly rotate shafts to ensure proper alignment.

 

Installation of a Two-Piece Rigid CouplingInstallation of a Two-Piece Rigid Coupling

The steps for installing a two-piece rigid coupling are:

Alignment

Like one-piece rigid couplings, two-piece couplings are used to join two aligned shafts. The use of a two-piece coupling allows installation while both shafts remain in place.

Installation Process

The steps for installing a two-piece rigid coupling are:

  1. Wipe any dirt or excess oil off shafts and coupling bore.
  2. Assemble the top and bottom halves of the coupling over the two shafts, making sure that the ends with the face groove are together.
  3. Assemble the two-piece coupling to the point where there is mild resistance in the screws.
  4. Use a torque wrench to adjust the center screws to half of the recommended seating torque.
  5. Use the same wrench to adjust the outer screws to half of the recommended seating torque.
  6. Use the torque wrench to adjust all screws until they’re at the full recommended seating torque, starting with the center screws and completing the process with the outer screws.
  7. Ensure the clamping is even by checking that the slot  gap is the same on both sides
  8. If possible, slowly rotate shafts to ensure proper alignment.

 

Installation of a Three-Piece Rigid CouplingInstallation of a Three-Piece Rigid Coupling

The steps for installing a three-piece rigid coupling are:

Alignment

Designed for aligned shafts, the three-piece clamp coupling makes two shafts function as one. It can remain fixed to one shaft while the other is moved or changed, or come completely apart to allow the most convenient assembly and adjustment.

Installation Process

The following are the steps for installing a three-piece rigid coupling:

  1. Wipe any dirt or excess oil off shafts and coupling bore.
  2. Assemble the ends of the coupling with the matching face groove onto its mating shaft
  3. 3. Use a torque wrench to adjust the center screws to half of the recommended seating torque.
  4. Use the same wrench to adjust the outer screws to half of the recommended seating torque.
  5. Mate the other shaft with the open end of the coupling and loosely assemble the coupling top, making sure that the machined end is towards the outside..
  6. Use the torque wrench to adjust the center screws to half the recommended seating torque
  7. Use the same wrench to adjust the outer screws to half the recommended seating torque.
  8. Use the torque wrench to adjust all screws until they’re at the full recommended seating torque, starting with the center screws and completing the process with the outer screws.
  9. Ensure the clamping is even by checking the saw slot gap.
  10. If possible, slowly rotate shafts to ensure proper alignment.

 

High-Quality Rigid Shaft Couplings from Stafford Manufacturing Corporation

If your application requires rigid couplings, please check out our wide variety of couplings, precision couplings, and shaft adaptors at www.staffordmfg.com. Applications include motion control, power transmission, automation, and other types of MRO and OEM applications for consumer or industrial products.

To find out more about our products and custom capabilities, contact us today with any questions or request a quote for our products.