{"id":8959,"date":"2021-07-15T09:41:35","date_gmt":"2021-07-15T17:41:35","guid":{"rendered":"https:\/\/www.linquip.com\/blog\/?p=8959"},"modified":"2023-01-10T01:19:59","modified_gmt":"2023-01-10T09:19:59","slug":"types-of-flexible-coupling","status":"publish","type":"post","link":"https:\/\/www.linquip.com\/blog\/types-of-flexible-coupling\/","title":{"rendered":"The Complete Library of Types of Flexible Coupling"},"content":{"rendered":"

Flexible couplings are one of the major types of couplings. They find use to connect two shafts, end-to-end in the same line to transmit power that is torque from one shaft to another, thereby causing both to rotate in unison, at the same rpm. The other purpose is to compensate for small amounts of misalignment and random movement between the two shafts. Several factors should always be taken into consideration when looking to specify flexible couplings.<\/span><\/p>\n

These are torsional stiffness, backlash, torque, life, and attachment system. All of these have bearing on coupling selection. Specific details vary depending on the different types and their functions. In this article, we review the different <\/span>types of flexible coupling<\/span> in all aspects. Follow this new blog in Linquip to find out more about these types of couplings.<\/span><\/p>\n

What Are The Different Types Of Flexible Coupling?<\/h2>\n

Most Flexible couplings are characterized as belonging to one of four main categories:\u00a0<\/span><\/p>\n

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  1. Mechanical Flexible Couplings<\/span><\/li>\n
  2. Elastomeric Couplings<\/span><\/li>\n
  3. Metallic Membrane Couplings<\/span><\/li>\n
  4. Miscellaneous Couplings<\/span><\/li>\n<\/ol>\n
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    • \n

      Mechanical Flexible Couplings<\/h3>\n<\/li>\n<\/ul>\n

      The mechanical flexible coupling generally obtains its flexibility from loose-fitting parts by rolling, sliding, or from both with some flexure of material. Flexible mechanical couplings provide a flexible or movable connection that accommodates misalignment between the shafts. This flexible feature reduces the forces or loads caused by the reaction to the misalignment. The mechanical nature of these <\/span>types of flexible coupling<\/span> allows for nearly unlimited horsepower and torque capabilities.<\/span><\/p>\n

      \"types<\/p>\n

      They maintain high torsional rigidity and allow a considerable degree of angular misalignment; however, they are not maintenance-free and require occasional lubrication unless one moving part is made of a material that supplies its own lubrication needs. Several different types of mechanical flexible couplings are as follow:<\/span><\/p>\n

      Gear Couplings<\/h4>\n

      A common type of mechanical flexible coupling is gear coupling. Each coupling consists of two hubs with crowned external gear teeth. The hubs mesh with two internally splined flanged sleeves that are bolted together. They are called gears as a result of the generally huge size of the teeth. These couplings are commonly constrained to precise misalignments of 4\u00b0 to 5\u00b0.<\/span><\/p>\n

      The gear coupling provides good torque characteristics. Gear couplings transmit the highest amount of torque and the highest amount of torque in the smallest diameter of any flexible coupling. Gear couplings require periodic lubrication depending on the application. These couplings have a service life of 3 to 5 years and in some cases, they can last for decades.<\/span><\/p>\n

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      • High torque density<\/span><\/li>\n
      • All types of misalignment (angular, parallel, axial)\u00a0<\/span><\/li>\n
      • High torque at high speeds<\/span><\/li>\n
      • Sensitive to lubrication failures<\/span><\/li>\n<\/ul>\n

        Application: Metal industry such as steel or wire mills, large industrial machines such as pumps, blowers, compressors, mixers, etc.<\/span><\/p>\n

        Grid Couplings<\/h4>\n

        Grid couplings are multi-piece mechanical couplings used to transmit torque and rotation between shafts in mechanical power transmission assemblies. Grid couplings are comprised of two radially slotted hubs, a grid spring element, and a split cover kit. These <\/span>types of flexible coupling<\/span> are a popular option where both high torque levels and dampening requirements exist.<\/span><\/p>\n

        Grid couplings have a unique ability to reduces vibration by as much as 30%, and cushions shock loads to safeguard driving and driven power transmission equipment. They are available with either a horizontal or vertical split cover design. Grid couplings transmit torque and accommodate angular, parallel, and axial misalignment from one hub to the other through the rocking and sliding of a tapered grid in the mating hub slots.\u00a0<\/span><\/p>\n

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        • Interchangeable components<\/span><\/li>\n
        • High power density\u00a0<\/span><\/li>\n
        • Relatively straightforward\u00a0<\/span><\/li>\n
        • Simple installing<\/span><\/li>\n
        • Good resistance to environmental conditions<\/span><\/li>\n
        • Available for both inch and metric bores<\/span><\/li>\n
        • Not maintenance-free<\/span><\/li>\n
        • Require periodic lubrication\u00a0<\/span><\/li>\n<\/ul>\n

          Application: Motors, pumps, reducers, conveyors, etc<\/span><\/p>\n

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           <\/p>\n

          Roller Chain Couplings<\/h4>\n

          Roller Chain type couplings consist of two radially sprocketed hubs that engage a strand of double pitch roller chain. These couplings find a use for low to moderate torque and speed applications. The meshing of the sprocket teeth and chain transmits torque and the associated clearances accommodate angular parallel, and axial misalignment. These couplings are also able to accommodate up to 2 degrees of misalignment. They have flanges that are linked with duplex roller chains, giving them a high level of strength. Roller chain couplings are considered an economical way to transmit power between shafts.<\/span><\/p>\n

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          • High levels of torque<\/span><\/li>\n
          • Requires frequent lubrication<\/span><\/li>\n
          • Not suitable where slip and precise motion is required<\/span><\/li>\n
          • Not affected by temperature and environmental conditions<\/span><\/li>\n
          • Easy to install<\/span><\/li>\n<\/ul>\n

            Application:\u00a0 Transportation industry, woodworking machinery, agricultural machinery, oil well drilling rigs, building construction, material handling equipment, lifting load<\/span><\/p>\n

            Slider Block Couplings (Oldham’s)<\/h4>\n

            Oldham\u2019s couplings consist of three discs, one coupled to the input, one coupled to the output, and a middle disc that is trapped by 90\u00b0 displaced grooves between the tongue and groove. These couplings can accommodate lateral shaft misalignments up to 10% of nominal shaft diameters and up to 3 angular misalignments. Some manufacturers claim an ability to tolerate up to 5-degree angular misalignment through the use of cylindrical, rather than rectangular, sliders. Lubrication is a problem but can be overcome by choosing a wear-resistant plastic or an elastomer in place of steel or bronze floating members.<\/span><\/p>\n

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            • No velocity variation as with universal joints<\/span><\/li>\n
            • High lateral misalignments possible<\/span><\/li>\n
            • High torque capacity<\/span><\/li>\n
            • Oil resistance and electrical insulation<\/span><\/li>\n
            • Suitable for small transmission torque occasions and connecting two coaxial transmission shafts<\/span><\/li>\n
            • Sliders Can be chosen with different materials<\/span><\/li>\n
            • Requires periodic lubrication due to relative sliding motion unless nylon or rubber construction is employed.<\/span><\/li>\n
            • Possible loss of loose members during disassembly<\/span><\/li>\n<\/ul>\n

              Application: Robotics, printers, copy machines<\/span><\/p>\n

              \"types<\/p>\n

              Metallic Beam Couplings<\/h4>\n

              Beam couplings are one-piece metal beam cylinders with spiral slots that are cut to form a spring-like flexing portion. Beams are shaped to allow torque transmission in either direction. They are considered miniature and used in small-sized equipment applications where and easy installation is important. The beam couplings are classified into two series: helical beam coupling and parallel slit coupling.<\/span><\/p>\n

              These couplings can accommodate parallel misalignments up to 0.025 inches and angular misalignments up to 7 degrees. They are used primarily for motion control applications where torques are typically below 100 inch-lbs. Zero backlash designs available ensure positioning accuracy between driving and driven shafts. These <\/span>types of flexible coupling<\/span> generally feature excellent flexibility and a lower price, as well as zero need for maintenance.<\/span><\/p>\n

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              • Good misalignment capabilities<\/span><\/li>\n
              • No need for lubrication<\/span><\/li>\n
              • Torsional stiffness for accuracy<\/span><\/li>\n
              • Strong for carrying torque loads<\/span><\/li>\n
              • Not suited for extreme operating environments with extreme temperatures and harsh chemicals<\/span><\/li>\n
              • Identical clockwise and counterclockwise rotation characteristic<\/span><\/li>\n<\/ul>\n

                Application: CT scan, laser marking device, confectionery equipment, automatic rotation stage, matching box for RF power, 3D printer, food processing equipment, index table, encoders, tachometers, and other instrumentations<\/span><\/p>\n

                Bellows Couplings<\/h4>\n

                Bellows couplings are single-piece flexible shaft connectors that are used to couple driving and driven shafts in mechanical power transmission assemblies. They consist of two hubs connected by a flexible bellows section. Typical bellows couplings tolerate angular misalignment of 1\u00b0 to 2\u00b0 and parallel misalignment from 0.01 to 0.02 in. Bellows couplings are known for their exceptional torsional rigidity to accurately transmit velocity, angular position, and torque.<\/span><\/p>\n

                They are used where precise rotation, high speeds, and dynamic motion must be transmitted. They exhibit zero-backlash and a high level of torsional stiffness, offering distinct performance advantages. Unlike other mechanical flexible shaft couplings, these generally need no lubrication.\u00a0<\/span><\/p>\n

                Bellows couplings are often selected in place of low-cost jaw couplings and disc couplings by engineers looking to benefit from their well-documented performance advantages. It is also used in some heavy industry applications, where its ability to accommodate axial thermal growth makes it useful for installations with large temperature swings.<\/span><\/p>\n