Centritec Seals has developed a unique, patented non-contact seal that utilizes centrifugal forces to pressurize the lubricating fluid entering a seal. This lubricant forms a pressurized barrier, which keeps additional lubricating fluid from entering the seal. The pressure also pumps lubricant back into the housing which contains the seal, the lubricating fluid and the operating components.
As shown in the video to the right, the inner race of a Centritec Seal and the shaft are rotating, while the shaft and the seal's outer race is stationary. The fluid entering the seal from the housing or sump (represented in blue) migrates into the passageway between the seal's outer race and inner race. The fluid moves through the passageway and eventually reaches the outer surface of the rotating inner race, where it is centrifugally forced outward to the inside of the rotating inner race fluid cavity, passing through the pumping disc. The fluid cavity is an integral part of the inner race, and therefore rotates.
The fluid cannot splash or migrate axially in the fluid cavity, and is forced to flow through the pumping disc thereby keeping the lubricating fluid in laminar flow. As the fluid cavity fills with lubricant, the lubricating fluid is pressurized by the rotating chamber's centrifugal forces, and ultimately returns to the inlet path between the rotating chamber and the stationary outer ring by way of communication holes in the rotating chamber. This motion forces the fluid out of the seal and forms a pressurized barrier to entry. Additional fluid cannot enter the seal until the lubrication fluid is pumped from the cavity. This is a continual process, and the process will vary depending upon the lubrication oil sump height, the operating speed and the fluid viscosity.
The pressurized lubricating fluid can be channeled throughout the lubricant housing, which will keep bearings constantly lubricated and will ensure proper bearing lubrication, without relying on the splashing of rotating components.
This offers the designer a unique opportunity to utilize the pumping action of the centrifugal seal to positively lubricate the bearings, and eliminates the need to rely on a splash lubrication system – which can only operate horizontally. With less lubricating fluid required in the housing sump, the seal can pump the lubricant directly to the bearings, which results in less heat generated through oil shear (caused by the splashing of housing components through the sump's lubricating oil).
Centritec Seals' operations result is significantly lower operating temperatures of the lubricating fluid, the bearings, and the components within the contained mechanical shaft seal housing.
Contact Centritec Seals for more information on our centrifugal seal manufacturer services, or to request a quote for your application.