How to Install Lovejoy Coupling

David Gaines

Lovejoy, Inc., offers many designs within its gear coupling family, including standard, off-the-shelf stock and upgraded, high-speed, specialized models. Some of these couplings consists of a wide range of configurations, including C and F standard hub and sleeves, mill motor hubs, floating shafts, vertical and spacer designs, brake drums, sliding hubs, shear pins and custom lengths for nonstandard shafts. Standard applications for the Lovejoy coupling range from services involving distances between shaft ends and limited end float situations.

  1. Inspect all parts for damages that may have occurred during shipment. Check all hubs, shafts and key-ways for burrs. Verify the measurements of the parts to see if they meet application requirements, including the hub and shaft fits and shaft separation. Clean all parts that came with the Lovejoy coupling assembly with an inflammable solvent before installing the unit.

  2. Match the coupling keys with the corresponding shafts. Insert each coupling key until it fits snugly into the key seat shaft. Apply anti-galling lubricant to the shafts. Verify that the seals and pipe plugs sit in the gear sleeve. Seal around the gear sleeve teeth and surface, then position it over the corresponding shaft before mounting hubs.

  3. Preheat hubs in an oil bath with a flash point of 350 degrees Fahrenheit or higher until the bores become larger than the shaft's diameter. Mount each hub flush with the end of the shaft. Allow time for the hubs to cool before proceeding.

  4. Align the equipment according to the appropriate "G" dimension for your coupling type. Use an inside micrometer to assess readings at four points 90 degrees apart for an angular alignment. Adjust the shafts until all four readings match perfectly. Verify whether the difference between maximum and minimum measurements exceeds the recommended angular limits listed in the installation manual.

  5. Secure a dial indicator to one hub and position the dial indicator's needle in direct contact with the outside diameter of the opposite hub. Spin the hub with the mounted dial indicator 360 degrees and record the indicator readings at four points 90 degrees apart. Reposition the shafts until all four readings match perfectly. Verify whether the difference between the maximum and minimum measurements exceeds the installation and offset limits listed in the installation manual. Mount the indicator dial base on the opposite hub and repeat the process. Tighten all foundation bolts, then repeat steps 4 and 5.

  6. Apply coupling grease to the hub teeth, body and inside the sleeve. Slide the sleeve gradually onto its corresponding hub, making sure that the gear teeth seat properly. Coat light oil dots on one side of the gasket. Insert the gasket between the sleeve flanges, then align the bolt guideposts. Press the side with the oil lubricated against the flange.

  7. Position the plate into the counter bore of the hub sleeve. Sandwich the sleeves together with the lube plugs set 90 degrees apart. Insert the locking bolts and nuts, then tighten accordingly. Dislodge and remove the two lube plugs in each sleeve and add coupling grease to the coupling unit. Reinstall the lube plugs and tighten accordingly.