Snap Wrap, Flexible Spiders
Lovejoy snap wrap spider couplings provide shaft-to-shaft connection for power transmission and accommodating parallel & angular misalignment in industrial machinery, electric motors & compressors. These jaw couplings feature radially removable elastomeric cushions for ease-of-maintenance and no metal to metal contact for wear minimisation. SOX (NBR) rubber / urethane construction provides resistance against oil, sand, dirt, grease & moisture while ensuring fail-safe operation, even upon elastomeric cushion failure. These snap wrap spiders are capable of delivering torque up to 3510 inch-lb and the collar configuration of these snap wrap spiders can achieve the same speed as standard couplings since the collar is attached to one hub. Raptor Supplies, a trusted distributor of Lovejoy snap wrap spiders, also offers coupling spacers, jaw couplings, sleeve gear couplings, gaskets, hydraulic tanks and related accessories.
Lovejoy snap wrap spider couplings offer a wide combination of features, making them useful for low to medium power applications in the power generation, wastewater, aggregate, food & beverage, pulp & paper, steel and marine industries.
Lovejoy CJ Series coupling hubs are connected with these Lovejoy snap wrap spiders to form couplings. In jaw couplings, the elastomeric elements are compressed between the jaws of the mating hubs. These connected jaws operate in the same plane as the driving hub jaws that are pushed towards the driven hub jaws. The legs of the elastomeric Lovejoy spiders ensure transmission and are capable of cushioning the force between the driven and the driving jaws by being compressed between them.
The curved jaw hubs are press-fit into the spider to allow the coupling to operate with zero backlash. The curved jaw profile of these wrap spiders helps eliminate deformation and limits the effects of centrifugal force during high speed operations. To ensure full angular misalignment capabilities, raised contact points are added to the spider limbs to maintain proper spacing between the coupling hubs and the spiders.
Standards and Approvals
Lovejoy jaw coupling spiders are designed to comply with ISO 9001:2008 international standards for efficient performance.
The flat-strip, open-end design of snap wrap spiders connects the spider legs around the perimeter of the coupling rather than at the centre, allowing easy removal or installation without disturbing the alignment of either coupling hub. Without centre connections, this design does not overlap into the bore, therefore shaft ends are allowed to extend at the maximum bore diameter to a minimal distance between the ends of the driving and driven shafts. Radially wrapped around the jaws, these snap wrap spiders must be held in place by either a ring or a collar. When retained by a ring, they have a maximum speed limit of 1750 rpm and when retained by a collar, the normal speed of the coupling applies.
Frequently Asked Questions
What are Lovejoy couplings used for?
Lovejoy couplings require no lubrication and are ideal for medium, light & heavy duty internal combustion power transmission and electrical motor applications. They are used for industrial equipment like blowers, compressors, gear boxes, pumps, mixers and conveyors.
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.
Which company owns Lovejoy Inc.?
The Timken Company, the global leader of bearings and power transmission products, owns Lovejoy.
What is the difference between open centre & solid centre Lovejoy spider designs?
The open centre 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 centre 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.
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.
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.
For a clear Lovejoy spider coupling installation manual, check out the following link: https://www.youtube.com/watch?v=I0D0nrwzzm0