Shaft seal with retractable polytetrafluoroethylene-lined sealing lip
US4258927A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 13, 1978 |
| Grant date | Mar 31, 1981 |
| Priority date | — |
| Expiry date | Dec 13, 1998 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16J15/3268
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A shaft seal with a polytetrafluoroethylene-lined lip having the following dimensional criteria thus providing sufficient retraction to effect positive sealing against a smaller diameter shaft section after installation and stretching over a larger diameter shaft section: PA1 (1) Lip Angle=15.degree.--25.degree.; PA1 (2) Included Angle--must be divergent axially from the flex secton; PA1 (3) Clearance Diameter--must be greater than the shaft oversized step diameter; PA1 (4) Lip Interference.gtoreq.125% of X (X is the difference between the diameters of the oversized shaft section and the diameter of the section to be sealed; and PA1 (5) Lip Height.gtoreq.175% of X. The above parameters are for seals to be used on shafts where there will be runout and/or angular shaft displacement. When there is no runout or angular shaft displacement, the seal parameters are identical to those listed above except that lip interference .gtoreq.100% of X, and lip height.gtoreq.150% of X. The present invention also includes the method of installation of such seal and the combination of such seal and the shaft on which it is installed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.