Mark Pitchko, Vice President
Rotary shaft seals are a common component in machines and industrial equipment. Like all types of seals, they are designed to prevent substances, such as lubricants or other fluids from leaking out of the bearing/process equipment while also preventing dust/dirt from entering into the system. Traditionally, engineers had relied on lip seals and packing seals to address the issue of leakage. However, these mechanical seals fail to provide superior sealing capabilities due to their inherent working limitations. A common disadvantage of these seals is their inability to handle shaft runouts. During rotation, when the shaft moves up or down, the product places itself in the gap between the shaft and the stationary lip seal or the packing ropes, thus creating a leakage path for the product. Against this backdrop, CinchSeal, a global leader in manufacturing innovative rotary shaft seals, has come up with an alternative to eliminate such common limitations of mechanical seals. CinchSeal’s patented design provides hassle-free sealing without having to worry about the drawbacks of mechanical seals.
What makes CinchSeal different from traditional mechanical seals is its superior design. For example, unlike traditional mechanical seals that are stationery and damage rotating shafts, Cinchseal turns with the shaft which eliminates costly shaft wear. CinchSeal consists of five components: a metal endplate, a metal housing, a custom elastomer, and two PTFE rotor cups. The elastomersits on the shaft, seals it, and rotates along with it. The clover-shaped lugs on the elastomer fit inside the counterbores in the rotor cups, providing a positive drive. This rotor cup and elastomer assembly are compressed together with the help of a metal housing and an endplate and turn with the shaft.
Such a superior design helps engineers address many working limitations of traditional mechanical seals.
For example, mechanical seals constantly maintain a rubbing load on the shaft, which eventually leads to groove formations. This issue can be solved only by repairing damaged shafts, causing significant downtimes due to unplanned production stoppages. As CinchSeal’s internal seal components rotate with the shaft, there is no rubbing action at the shaft-boot interface, eliminating the problem of the shaft damage. In addition, the elastomer boot can mount on the shaft without needing a mirror finish. The elastomer I.D. is typically made a little smaller than the shaft O.D., enabling a good grip on the shaft. More importantly, the PTFE rotor cups and the elastomer, which are the wearable parts in the seal, are made up of FDA-compliant materials. As these parts are FDA certified, they are an apt choice for sealing in meat, poultry, and dairy applications. USDA Dairy and Meat and Poultry Seals are also available if needed.
As CinchSeals require the seal to be purged with air, a constant axial load is applied on the rotor cup rubbing faces, enabling efficient functioning even as the parts start to wear. This self-adjusting behavior of the seals facilitates the seal’s smooth performance, resulting in lesser unplanned downtimes and reduced maintenance requirements. Unlike traditional seals, the sealing in this case, takes place axially and also in the direction normal to the axis of the shaft. CinchSeal moves away from the rubbing action on the shaft and transfers it to the PTFE rotor cups, thuseliminating shaft wear. The endplate and housing can be made out of different metals to satisfy cost constraints. More importantly, replacing the wearable parts is easy and quick compared to mechanical seals.
Depending on the various products and chemicals required to be sealed, the elastomer material can range from silicone and VITON to AFLAS and EPDM for harsher chemicals. Similarly, depending on the shaft rotating speeds, the PTFE can be blended with certain minerals to reduce the coefficient of friction at the PTFE-metal interface.
The company also offers a variety of shaft seals based on application. Although split versions of the seals are preferred for easy disassembly and repairing purposes, CinchSeal also comes in solid versions matching CEMA standards. This is particularly beneficial for OEMs who can incorporate the seal in their equipment design stages.
In one instance, one of the largest commercial baking companies approached CinchSeal with a leakage problem. The client was experiencing significant yield loss due to a flour leakage through shaft penetrations on dough mixers. After knowing the client’s challenges, the company replaced their old seals with CinchSeal’s9700 series split stainless steel rotary shaft seals. Upon installation, the client not only eliminated the flour loss due to leakage but reduced downtime significantly. “CinchSeal is one of the most viable options for all types of sealing requirements. Our self-adjusting seals provide a fast ROI, protect bearings and gearboxes, eliminate shaft wear and product leakage, reduce unscheduled maintenance and downtime,” mentions Mark Pitchko, Vice President of the company.
Such success stories stem from the company’s 25 years of experience in manufacturing innovative rotary shaft seals for mixers, screw conveyors, and bulkhandling equipment. With its bespoke technology and innovation, the company continues to serve the world’s top organizations in every industry, ranging from food, beverages, and powders to chemical processing.