Lovejoy Cast Iron 3JN Sleeve 1.88″ OD Flexible Coupling Gear

Description

Product Overview

The Lovejoy 3JN Cast Iron Sleeve is engineered as a high‑performance flexible coupling for demanding power transmission applications. Featuring a 1.88 inch outer diameter, the sleeve is forged from premium cast iron that delivers exceptional strength and rigidity while maintaining a compact footprint. The inner surface is molded as a single‑piece sleeve of EPDM and Neoprene rubber, providing a resilient interface that absorbs shock, compensates for misalignment, and reduces vibration across a wide range of operating speeds. Designed to meet the rigorous standards of industrial machinery, the product is rated for 60 inch‑pounds of torque, making it suitable for medium‑size shafts in pumps, compressors, conveyors, and gearboxes. Its dimensions—2 × 1.88 × 1.25 inches and a weight of 1.44 ounces—allow easy installation in confined spaces, while the one‑piece construction eliminates the need for additional fasteners or seals, simplifying maintenance and reducing downtime.

Usage

Designed for versatility, this flexible coupling thrives in environments where exposure to chemicals, dirt, and moisture is common. Whether installed in a chemical processing plant, a food‑grade production line, or a heavy‑duty mining operation, the EPDM/Neoprene sleeve resists degradation from oils, solvents, and abrasive particles, ensuring long‑term reliability. The coupling is ideal for applications that require occasional shaft misalignment—up to 2 degrees of angular offset—allowing equipment to operate smoothly without premature wear. It is frequently used in motor‑driven pumps, fan assemblies, and rotary equipment where torque transmission must be consistent and where the ability to absorb shock loads extends the life of both the coupling and the connected machinery. Technicians appreciate the straightforward installation: the sleeve slides onto the shaft ends, and the cast‑iron hubs are secured with set screws, providing a secure, repeatable fit that can be quickly disassembled for inspection or replacement.

Why Choose Us

Choosing the Lovejoy 3JN Sleeve means selecting a product backed by decades of expertise in power transmission technology. Lovejoy’s reputation for precision engineering ensures that each coupling is manufactured to tight tolerances, delivering predictable performance across the entire product line. The cast‑iron hub is heat‑treated to achieve a hardness that resists wear, while the EPDM/Neoprene sleeve is formulated to maintain elasticity over a temperature range of –40 °F to 250 °F, protecting equipment from thermal expansion and contraction. Quality assurance processes include rigorous dimensional inspection, torque testing, and chemical resistance validation, guaranteeing that every unit meets or exceeds industry specifications. In addition, Lovejoy provides comprehensive technical support, offering guidance on proper installation, alignment procedures, and maintenance best practices. Customers benefit from a responsive service team that can address inquiries promptly, as well as a robust warranty that covers material defects, reinforcing confidence in the durability and performance of the coupling.

Key Features

• Durable cast‑iron hub delivers high torque capacity and long service life
• One‑piece EPDM/Neoprene sleeve resists chemicals, dirt, and moisture
• Accommodates up to 2° of angular misalignment, reducing vibration and wear
• Compact size and lightweight design simplify installation in tight spaces
• Comes with dedicated technical support and a warranty for peace of mind

FAQ

What size shaft does the 3JN sleeve fit?

The 3JN sleeve is designed for a 1.88 inch outer diameter shaft, which corresponds to a standard 1.88 inch (48 mm) bore size. It is compatible with most medium‑size industrial shafts used in pumps, fans, and gearboxes.

Can the coupling handle axial loads?

Yes, the Lovejoy 3JN sleeve can transmit axial loads in addition to torque. The robust cast‑iron hubs and the resilient rubber sleeve work together to distribute axial forces evenly, preventing premature wear while maintaining accurate shaft alignment.

Is the EPDM/Neoprene sleeve replaceable?

The sleeve is molded as a single piece with the hub, which simplifies the design and eliminates the need for separate replacement parts. If the sleeve becomes damaged, the entire coupling can be replaced quickly, minimizing downtime.

What temperature range is the coupling rated for?

The EPDM/Neoprene material remains flexible and maintains its sealing properties from –40 °F (‑40 °C) up to 250 °F (121 °C), making it suitable for most industrial temperature environments.

How do I ensure proper alignment during installation?

Begin by cleaning the shaft ends and the hub surfaces. Use a dial indicator or laser alignment tool to verify that the shafts are parallel within the allowable tolerance. Install the sleeve, secure the set screws evenly, and re‑check alignment after tightening to confirm that the coupling is correctly positioned.