We encounter fans in many areas of our everyday lives, not just in the warmer months of the year. Their air flow sometimes conceals complex technology in which the right coupling often plays a central role. For example, elastomer couplings ensure high efficiency in various fan designs, such as axial and centrifugal fans, which move air in different ways and generate cool air flows.
Whether in simple axial fans or complex ventilation systems – reliable cooling by fans is not possible without the support of coupling technology. In an axial fan, the rotor blades, which are arranged around the axis, generate an air flow that runs parallel to the axis of the fan. This air flow is driven by the motor that moves the rotor blades – the design is similar to the propeller of an airplane. Thanks to this design, an axial fan is inexpensive to manufacture and also requires little space. In the industrial sector, straight airflow with direct intake and direct discharge is used for wall or window fans, for example.
A centrifugal fan, on the other hand, works by generating an airflow that flows radially outwards from the center of the fan. This is achieved by rotating a paddle wheel that is driven by a motor. The shape is reminiscent of a snail shell with the air being sucked in at the center and then blown out again at the outlet. Due to the rotationally symmetrical arrangement of the blades, the air is discharged at a 90° angle to the intake direction. Due to their high pressure build-up, centrifugal fans are able to transport air over long distances and generate a strong air flow. Centrifugal fans are therefore typically used in industrial processes to convey air or gas, remove exhaust gases or ensure cooling.
Elastomer couplings ensure efficient operation
The use of a precise elastomer couplings in fans is particularly important in complex ventilation systems, as it helps to optimize operating conditions. As the connecting link between the motor and the fan wheel, the component transmits the torque. Its flexibility and elasticity help to efficiently dissipate the heat generated by the motor, as the elastomer ring of the coupling reduces vibrations and loads. The elastomer ring used has a vibration-damping effect and also reduces shock loads that can be caused by imbalances or misalignment. This results in quieter and more stable operation of the fan – especially over long distances in industrial applications for conveying air or gases.
R+W offers elastomer couplings with clamping hubs, clamping ring hubs and pure keyway connections as well as a compact version for particularly tight installation situations. High-quality hubs and plug-in intermediate elements guarantee high concentricity for all models. This reduces noise and vibrations, resulting in quieter and more stable fan operation.
The balancing element
In addition to cost-effectiveness, the requirements placed on precision couplings are based on three criteria in particular: running behavior, transmission properties and service life. Parameters for the running behavior of a clutch are concentricity, balancing quality and low noise. “Out-of-round” hubs not only result in poorer concentricity properties, but also lead to pulsating lateral forces on the rotary axes during operation. The greater the misalignment of both axles, the more the disadvantages of inaccurately manufactured couplings become apparent. An extension of the service life of the input and output units can then hardly be expected. An optimum result in this respect can only be achieved by high-precision manufacturing of the hub and elastomer ring.
In the R+W coupling technology installed between the motor shaft and the impeller shaft, the elastomer ring acts as a compensating element. It transmits the torque backlash-free and vibration-damping. The elastomer ring has a decisive influence on the properties of the entire coupling or the entire drivetrain: The backlash-free coupling is ensured by the compressive preload of the elastomer ring, while different Shore hardnesses ensure torsional vibration optimization.
Efficient heat dissipation
When fans are operated at high temperatures for long periods of time, various challenges arise. One of these is the generation of heat produced by the motor and fan components of a fan during operation. If this heat cannot be dissipated effectively, there is a risk of the components overheating, which leads to a reduction in performance and ultimately to damage.
Once again, this is where R+W’s elastomer couplings come into play: thanks to their flexibility and elasticity, they help to efficiently dissipate the heat generated by the motor by reducing vibrations and loads on the elastomer ring of the coupling. This helps to extend the service life of the fan and ensure a more difficult performance even under extreme heat conditions