LOVEJOY Jaw Coupling Spiders

Lovejoy jaw coupling spiders are engineered to transfer torque and rotation from one shaft to another. These Lovejoy couplings can accommodate misaligned shafts, and secure them from damage due to damping & vibrations. Lovejoy spider couplings are available in L, AL and LC types, as well as bronze, Hytrel, polyurethane, SOX (NBR), rubber and stainless steel construction variants.

What is a spider in a coupling?

Lovejoy jaw couplings are composed of three parts, i.e. an elastomer insert known as a spider and two metallic hubs on both the sides. These three separate parts are pressed together with the help of a jaw from each hub, both of which are fitted alternately with the lobes of the spider to form a Lovejoy spider coupling.

How do you install a spider coupling?

• Before installing the hubs on the shaft, slide the retaining collar onto either shaft.
• Insert the key into the keyway. Make sure that the key fits snugly in the keyway, with minimal side to side movement.
• Slide a hub on each of the shafts over the keys and align the face of the hub with the end of the shaft.
• Using a calibrated torque wrench, tighten the set screws.
• Check alignment using either straight edge method or a dial indicator taking measurements at four locations 90 degrees apart.
• Wrap the spider (in case of jaw in-shear units) around the hubs and insert a leg of the spider into each space between the coupling jaws.
• Align the pins on the side of the collar with the grooves in the spider.
• Recheck set screws for tightness and recheck the axial & angular alignment for accuracy.
• Remove any material and tooling away from the coupling and shafts. Install the appropriate coupling guard as per OSHA requirements.

Why is a spider used in a coupling?

The spider determines the torque rating of a coupling. It also affects the coupling's response to temperature, vibration, misalignment, chemicals and high speed. Lovejoy coupling spiders provide ease of installation of the coupling.

What is the significance of the colours of Lovejoy spiders?

• Black - Lovejoy spiders with 80 Shore A hardness ensuring excellent damping properties.
• Yellow - Spiders with 92 Shore A hardness used in hydraulic applications.
• Red - Lovejoy coupling spiders with 95 / 98 Shore A hardness suitable in high torque applications.
• Green - Lovejoy spiders with 64 Shore D hardness for humid environments.
• Blue - Lovejoy spiders with 92 & 95 Shore A hardness for chemical resistance and high torque capabilities.
• Tan / Bronze - Lovejoy coupling spiders with 55 Shore D hardness to ensure excellent chemical resistance.

What is the difference between open center & solid center Lovejoy spider designs?

The open center design of Lovejoy coupling spiders is suitable in close BE situations (distance between ends of driven and driving shafts), where units must be positioned as closely together as possible. However, this design has no full-diameter support, as the spider's legs are joined only by a thin segment of material. It has speed limitations up to 1750 rpm for NBR and 3600 rpm for Urethane / Hytrel.
The solid center design of Lovejoy spiders is suitable for general power transmission applications where the BE dimension will remain fairly constant and will be capable of affording a suitable gap.