Dual-diaphragm lubricant compensator for earth-boring bits
US5363930A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 15, 1993 |
| Grant date | Nov 15, 1994 |
| Priority date | — |
| Expiry date | Oct 15, 2013 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16N9/02
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
An earth-boring bit has a bit body and at least one saddle member secured to the bit body to receive and support each of a pair of ends of a journal member. A cutter is mounted for rotation on the journal member and a bearing is defined between the cutter and journal member. A lubricant reservoir is formed in the journal member to receive a quantity of lubricant and is in fluid communication with the bearing. A seal means is provided between the cutter and journal member to retain lubricant in the bearing. A hydrostatic-pressure compensator is disposed in the lubricant reservoir in communication with hydrostatic-pressure in the borehole in which the bit operates. The hydrostatic-pressure compensator responses to hydrostatic-pressure to equalize a pressure differential across the seal means. An internal-pressure compensator is disposed in the lubricant reservoir and is responsive to the internal pressure of the lubricant to prevent the lubricant from being extruded past the seal means.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.