A coupling connects two spinning shafts and transfers rotational motion and torque. To function efficiently, a gear coupling must meet all of the needed requirements, which include performance, environmental, usage, and service considerations. If all of these factors are considered while selecting a coupling, the coupling should not fail over its lifespan.
However, if any one of these conditions is not satisfied, a coupling may fail prematurely, resulting in anything from a minor annoyance to severe financial loss and even physical damage.
In this blog, we will discuss the most common reasons why couplings fail, as well as provide important information and recommendations to help you reduce the failure risk.
Selection of wrong gear coupling for the application
You need to consider many factors while buying a coupling, including the kind of application, torque, misalignment, stiffness, inertia, RPM, shaft mounting, environmental concerns, space constraints, service requirements, and cost. Each criterion must be evaluated separately to ensure that the connection is acceptable for the application and does not fail prematurely. This assessment step must be performed for any changes in circumstances that occur during the application’s lifespan.
Failure to address severe misalignment
Even flexible couplings designed for use on misaligned shafts have restrictions. A typical cause of failure is an underestimation of the degree of misalignment, resulting in loads that exceed the gear coupling parameters. This accelerates the wear of the coupling and may cause other components, such as bearings, to fail prematurely. If there is misalignment that exceeds the manufacturer’s standards for the connection, it should be corrected with shaft realignment before installation.
Torque Overload
The torque of an application is often underestimated. In addition to steady state torque, consider the maximal instantaneous torque for the application. Flexible couplings feature static torque ratings that vary based on the design type. For example, a double disc coupling would usually have a 15-20% greater static torque rating than an equally sized Oldham coupling with an acetal disk.
Incorrect amount of dampening
Dampening is the process of minimizing shock and vibration, which is especially significant in motion control and power transmission applications to avoid energy loss and undue stress on system components. Shock dampening reduces the impact of impulsive loads on the motor and other sensitive equipment. When the gear coupling type is not chosen with the necessary dampening levels in mind, the risk of early coupling failure increases.
Failure to consider inertia
Inertia refers to the coupling’s resistance to angular velocity change and affects the coupling’s tendency to maintain a steady speed in response to applied external forces (e.g., torque). Too much coupling inertia in an application can significantly reduce overall system performance by producing resonance and increasing the system’s natural frequency. A low inertia coupling allows the system to be set to a higher performance level and is ideal for high precision applications.
Application shaft speed
Failure to consider the coupling’s maximum safe working speed at the design stage can swiftly lead to failure, with disastrous results. A balanced coupling is critical in high-speed applications. Any amount of misalignment can alter the coupling’s safe working speed.
Electrical isolation
Electrical isolation is the separation of two mechanical components that prevents electrical current flow while permitting mechanical energy transfer. When non-metallic or polymer inserts are used in Oldham and jaw couplings, they can be electrically isolating, and other types of couplings can also be made from electrically isolating materials.
At Harjot International, we are leading gear coupling manufacturers. Our firm has consistently followed the “quality first, user first” business concept. We assure that you receive top-class qualified products from us at competitive price ranges.
Harjot International
With over 25 years of experience, Harjot International, based in Punjab, India, has built a strong reputation as a trusted provider of heavy industrial machinery.