Contactless Shaft Sealing via Centrifugal Disk Oil Recirculation

The patent replaces the mechanical contact-based radial shaft sealing ring with a contactless sealing system using a centrifugal disk. The centrifugal disk utilizes centrifugal force generated by rotation to throw oil radially outward through radial bores, creating a pressure gradient that prevents oil from entering the bearing chamber without requiring direct mechanical contact between sealing surfaces, thereby eliminating friction losses while maintaining sealing effectiveness.

The patent employs hydraulic principles by utilizing the centrifugal force generated during rotation to create a pressure gradient within the lubricating oil. The rotating centrifugal disk generates centrifugal pressure that forces oil through radial bores into the bearing chamber, using the fluid dynamics of the lubricating oil itself as the sealing mechanism rather than mechanical contact.

The patent merges multiple functions into the centrifugal disk structure: sealing (preventing oil entry), recirculation (returning oil to the sump), and pressure compensation (maintaining pressure balance). The centrifugal disk with its radial bores and axial gap integrates these functions into a single rotating component, eliminating the need for separate mechanical seals, recirculation pumps, and pressure compensation devices, thereby reducing overall system complexity despite the contactless sealing mechanism.

The centrifugal disk serves multiple functions simultaneously: it acts as a sealing barrier, an oil recirculation device, and a pressure compensation mechanism. The same rotating structure that prevents oil from entering the bearing chamber also facilitates oil return to the sump and maintains pressure equilibrium, making the system more efficient and less complex than dedicated separate components for each function.

The patent divides the oil evacuation function into multiple radial bores distributed around the centrifugal disk rather than using a single large opening. This segmentation allows oil to be evacuated at multiple locations simultaneously, improving overall evacuation efficiency. The segmented bore structure also tolerates minor manufacturing variations in individual bores better than a single precision-bored channel would require.

The patent utilizes the dynamic centrifugal force generated during rotation to enhance oil evacuation through the radial bores. The centrifugal force, which increases with rotational speed, actively drives oil through the bores and into the bearing chamber, compensating for any minor blockages or misalignments that might occur during manufacturing. This dynamic mechanism makes the system more robust to manufacturing tolerances compared to static sealing structures.

The patent introduces a labyrinth seal as an intermediary structure between the rotating centrifugal disk and the stationary housing. The labyrinth seal consists of alternating radial and axial passages that create a tortuous path for oil flow. This intermediary structure allows oil to recirculate through the axial gap while preventing external contaminants from entering the bearing chamber, as contaminants would need to navigate the complex labyrinthine path to penetrate the seal.

The patent transitions from a simple radial gap to a three-dimensional labyrinthine structure with both radial and axial passages. This dimensional complexity creates a multi-stage sealing path that oil can traverse for recirculation while contaminants find difficult to penetrate. The labyrinth seal adds an axial dimension to the sealing path, creating a more effective barrier against contamination while maintaining oil recirculation capability.