Flexible Couplings - Main Engine and Propulsion

Flexible couplings transmit torque between a marine main engine, gearbox, generator, or propeller shaft while accommodating limited misalignment. Torsionally flexible designs also reduce vibration, shock loads, and drivetrain resonance.

ProShipWorks provides end-to-end support to source and supply Flexible Couplings for marine vessels, ship operators, industrial facilities, maintenance teams and procurement departments.

Last updated: October 11, 2026

Product Information

Product Name	Flexible Couplings
Product Category	Main Engine and Propulsion
Product Reference	323
Brands / Manufacturers	VULKAN, Geislinger, CENTA
Unit of Measure	Piece

Key Features

Key Feature
1. Transmits propulsion torque between connected machinery
2. Compensates for limited axial, radial, and angular misalignment
3. Reduces torsional vibration and shock loading
4. Protects gears, shafts, bearings, and driven equipment
5. Available with elastomeric or all-steel flexible elements

Applications of Flexible Couplings

Application
1. Main engine to reduction gearbox connection
2. Diesel-electric propulsion and generator drive systems
3. Propeller shaft and auxiliary machinery drivetrains

Models & Manufacturers

Model	Manufacturer
RATO S	VULKAN
RATO R	VULKAN
Geislinger Coupling	Geislinger
CENTAX-V	CENTA

Technical Specifications

Model	Specification	Value	Unit
RATO S	Coupling type	Highly flexible elastomer coupling	—
RATO R	Coupling type	Torsionally flexible elastomer coupling	—
Geislinger Coupling	Flexible element	All-steel spring-pack system	—
CENTAX-V	Coupling type	Highly flexible elastomer coupling	—

Standards, Certifications & Class Approval

Review the available standards and approval information relevant to the product. Actual certification, material traceability, inspection and classification requirements depend on the product type, intended application and purchasing specification.

Applicable Standards & Certification	Selection and design may reference DIN 740 for flexible shaft couplings and applicable IACS and classification-society rules for propulsion shafting and torsional vibration. Compliance depends on the specific coupling size, arrangement, and manufacturer documentation.
Class Approval	Type approval or case-specific acceptance may be available from DNV, ABS, Lloyd's Register, Bureau Veritas, ClassNK, RINA, and other societies. Approval must be verified for the exact model, size, vessel, torque rating, and propulsion arrangement.

Installation, Maintenance & Safety Information

Installation Notes	Perform drivetrain torsional-vibration and coupling selection calculations before installation. Align shafts within manufacturer limits, use specified fasteners and tightening torques, maintain required axial position, and verify clearances before commissioning.
Maintenance Tips	Inspect elastomer elements, spring packs, bolts, and flanges at prescribed intervals. Check for cracks, deformation, corrosion, oil contamination, overheating, looseness, and abnormal vibration. Replace elements only with approved parts and recheck alignment.
Safety Notes	Isolate and lock out the engine before inspection. Fit coupling guards before operation. Never exceed rated torque, speed, temperature, or misalignment limits, and do not run with damaged elements or loose fasteners.