Standard or special design?

Design engineers seek the most efficient and reliable solutions to their applications. While often times, standard products are ideal, there are instances when an application challenge requires something other than a standard solution.

For these situations, DieQua offers custom designs that range from slight modifications to existing products, all the way to complete special designs, including couplings.

DieQua’s special design solutions are not limited to any industry, but are in fact necessary for certain specific industries like food, medical, or clean room environments. Special designs are available for all types of couplings we offer, including bellow couplings, elastomer insert couplings, torque limiters or line shafts.

Figure 1: The full range of food-processing relevant coupling models are available in stainless steel.

Food grade applications

Most coupling selections are made using the basic available data, including the amount of torque to be transmitted, the type and amount of misalignment to compensate for, and the maximum overload torque that cannot be exceeded, and so on. Food grade applications have additional requirements, like anti-corrosion and wash-down surfaces.

They must withstand wash-down with caustic solutions and high-pressure water spray and extreme temperature fluctuations. Often in these applications where a torque limiter is required, our standard design is simply not enough.

For this scenario in particular, the exterior components need to be protected from corrosion using materials like stainless steel or nickel plate. The body of the coupling needs to be sealed. This is to ensure that any high-pressure spray or cleaning agent does not enter the internal workings of the coupling, or that anything internal to the coupling can get into the environment where food is processed.

Figure 2: One specific example of food industry that utilizes couplings is filling machines that are for handling juice or milk.

Extreme environments

Often we are confronted with very extreme conditions and environmental requirements. For an aviation application, our customer wanted a coupling that needed to operate within a part of the aircraft that is subject to all the environmental and operational conditions which the aircraft is exposed to during flight.

The coupling needed to function in any weather condition, and would be subject to a very wide temperature range - from hot desert conditions to the extreme cold from flying at high altitude. This application presented a series of challenges. The coupling needed to be 100% reliable for the life of the aircraft.

Not only was the temperature range quite wide, the rate of change was also very rapid. Being an aircraft application, traceability of all components is a must, requiring a form of marking that was permanent and with many digits. Finally, the coupling needed to be mounted onto very small spline shafts. The resulting design, shown in Figure 3 below, was a coupling made entirely of stainless steel. The bellow had an extended length and was laser-welded to the coupling hubs.

Figure 3: Special design miniature coupling used for extreme temperatures due to high altitudes.

The required information identifying the coupling and all the traceability data was la­ser marked onto each hub, and a custom spline was broached into the coupling hubs. The screws used to fasten the coupling also had a special coating on the threads to ensure that, after they were tightened to the specified torque, they would never loosen from the normal use, or the rapid change in temperature during flight.

Enhancing standard products

Often times the solution is a modified or enhanced standard product. When a concept works reliably for an application, it can often times be slightly modified to meet specific needs that may not be common use for most customers. An example of this is a standard Elastomer Insert coupling used in an electronic assembly application.

Figure 4: Clockwise from top left: Metal bellows couplings, elastomer couplings, torque limiters and line shafts.

Often in these types of machines, everything needs to be grounded to avoid an electrostatic charge from building and possibly damaging the product being assembled. The elastomer insert typically used in our couplings is non-conductive. In other words, they will insulate or block the path of the built up electrostatic energy from reaching ground. The solution here was to make a conductive elastomer insert.

Challenging requirements

These few examples show how the ever-growing needs of customers are the catalyst for an endless innovative approach to creating solutions with customized couplings. DieQua is able to work with design engineers to provide specific solutions to any type of application across many industries.

If you have a challenging or specific need where a standard off-the-shelf design is not enough, contact DieQua Corporation today and let’s work together to create the design that will work for your specific application.