Schaeffler North America

Chain drive systems

Systems development


Chain drive systems in modern internal combustion engines comprise a large number of individual components such as the tensioning element, rails, sprockets and a chain, which interact with each other. In order to achieve the maximum smooth running and life, it is necessary to consider the system as an entity instead of each component individually. INA therefore offers complete chain drive systems and develops these in co-operation with the specific engine manufacturer.


INA Calculation Software (1)
At the start of any chain drive development, the layout must be defined, in other words the position, size and design of the rails and sprockets must be determined, thus defining the chain path. This is carried out using a modern CAD system and calculation software specially developed by INA. This program checks the CAD layout taking account of parameters such as tolerances, thermal expansion, wear and elastic deformation. The geometrical changes arising from these influences are displayed to the designer in diagrammatic form, a further function of the CAD software.

In addition to this kinematic design, the dynamic behaviour of the multi-body system "Chain drive" can also be simulated. As a result, statements can be made at an early stage in the project about loads and oscillations, saving valuable time.


Once the design work is complete, samples close to mass production status are produced for various tests. The function of the components is tested on the fired engine on the engine test rig under operating conditions close to volume use. This is used to check whether the selected configuration of the tensioning element actually represents the ideal case in relation to correct phasing of the shafts, component loads and chain oscillation. Furthermore, these tests are used to check a large number of other parameters as to their suitability for volume application. Engine endurance tests are also used to ensure the service life of the components. These investigations can be carried out either on INA's own test rigs or integrated in endurance tests for the complete engine or complete vehicle at the engine manufacturer. The condition of the components that have passed such a test show the expert precisely how the chain drive behaved during the test. The service life of the components can also be verified using component tests on appropriate testing machines.

Once the tests are completed successfully and approval has been granted, the components can be put into mass production. While tensioning elements, sprockets and tensioning and guide rails are manufactured in specialised plants of the Schaeffler Group, the chains are supplied by an experienced partner.