Cryogenic Shrink Fitting: What is it and What it Can Do for You?

Cryogenic liquids have plenty of practical uses. Aside from medical and laboratory functions, it is also useful for engineering purposes. For example, cryogenics is used to form an interference fit between two parts containing geometrical clearance. You can achieve an interference fit in cryogenics through Shrink fitting.

This process uses techniques where both thermal expansion and contraction effects are utilized to reach an interference fit. Most of the time, it involves heating the “outer” portion of the material to sustain thermal expansion. As a result, it will help the two pieces of the material to fit together easily and securely.

What Can This Process Do?

Shrink fitting offers more crucial advantages than the conventional fastening or press-fitting and assembly methods. One of these benefits includes reducing the need for component machining because you do not have to use turning to create keyways or threads. The assembly process is also simplified because you do not have to use keys or other materials for fitting. You also do not need any screws for turning or making any welds, which may eventually get loose over time.

Unlike traditional pressing, this method will not put too much pressure on the parts. Therefore, it can be very useful for shafts since it will reduce the risk of run-outs due to pressure-induced distortion.

Cryogenic vs. Induction: Which Is Better?

The traditional method using induction technology works by heating a cylindrical outer component with an open-end or a hole. It is necessary for the opening’s expansion in an adequate size to let the other part with a smaller diameter inside.

This technique depends on thermal expansion. It is fractional inflation in the size of the material due to the boost in the temperature. However, it will also affect other metal components, including electrical, structural, and magnetic properties.

Meanwhile, the cryogenic version of the process applies cooling methods instead of heating for lesser metallurgical alterations. Unlike the induction-based techniques, the cryogenic way depends greatly on thermal contraction. As a result, it reduces the size of the material as a result of the decrease in the temperature.

In addition, the dimensional changes can withhold extremely tight tolerances for parts with varied sizes.

Benefits of Cryogenic Shrink Fit Method

You can enjoy several practical benefits by using cryogenic techniques. It includes:

• Immediate results – The cryogenic cooling using liquid nitrogen only takes a few seconds to take effect. Because of this, you no longer need to wait for a while before you can complete the process.
• Economical – Since only the portion of the material that will form the join gets the cryogenic treatment, you will be assured that the other parts will not get damaged. It means you do not have to replace other parts affected by the process.
• Safe– Since it will not damage the components, it will not change all the material properties of the products. As a result, it will not compromise the integrity of the combined materials.

Using the freezing method is an important process to safely create strong interference between two materials that you need to link together. This technique is perfect for most components that require a precise and trustworthy interference fit, like shafts, sockets, and bearings. So, choose this option if you want a simpler, less complicated process to ensure that you will not experience any problems in the long run.