Functions

1. Torque Transmission: The pin is the primary force-transmitting component; the rubber ring transmits torque under compression.

Displacement Compensation: The rubber ring elastically deforms to compensate for radial axial and angular misalignment between shafts (radial 2–0.6mm.

Angular less-than-or-equal-to 5 degrees). Shock Absorption and Vibration Damping: The rubber ring absorbs impact and torsional vibration.

Reduces noise and shield bearings and equipment. Electrical Insulation and Vibration Isolation: Rubber/polyurethane can isolate stray currents and reduce vibration transmission.

Forms

1. Pin (Metal Core) Typical structure: Cylindrical rod with a conical head + nut locking at one end and a cylindrical surface fitting the rubber ring at the other.

4–12 pins evenly distributed on the flange end face. Auxiliary structures:Stepped shaft: Positions the rubber ring to stop axial movement.

Hard chrome plating/zinc plating: Rust and wear resistance.

Split type: Individual replacement for easy maintenance. Damping Rubber Ring (Elastic Sleeve) Integral type (mainstream): Made of rubber/polyurethane.

With trapezoidal grooves on the outer wall and smooth inner wall; fits over the pin with clearance in the half-coupling bore.

Split type (older style): Composed of multiple elastic rings stacked together, now obsolete.

Special shapes: Plum blossom, star, and multi-angular forms, for different couplings (e.g., HL, LM types).

Materials

1. Pin Material (Metal)45# steel (most common): Quenched and tempered hardness HB220–250 high strength.

Good cost-performance.40Cr/42Cr Mo (heavy-duty/high-speed): Alloy structural steel quenched and tempered + surface hardening.

Wear-resistant and anti-fatigue used in high-torque high-speed applications. Damping Rubber Ring Material (Elastomer) Natural rubber (NR): Shore A70 plus-or-minus 5, good elasticity, high damping, low cost.

Temperature -30 to 80 degrees C, used for general water pumps, fans, and reducers. Nitrile rubber (NBR): Oil-resistant, wear-resistant, anti-aging.

Temperature -35 to 100 degrees C, used for oil pumps, compressors, and gearboxes. Polyurethane (PU/TPU): Shore A85–95, highly wear-resistant, high tear strength, high load-bearing.

Temperature -20 to 80 degrees C used for equipment with high impact frequent start-stop and high-speed operation (e.g.

Crushers vibrating screens).