Earth boring bit with convergent cutter bearing
US4899838A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 29, 1988 |
| Grant date | Feb 13, 1990 |
| Priority date | — |
| Expiry date | Nov 29, 2008 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16C2352/00
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
An earth boring bit having a body and a cantilevered bearing shaft extending inwardly and downwardly from the body. A rotatable cutter with an open end is assembled over the shaft, which has a journal surface formed around a longitudinal axis. The cutter has a bearing surface sized to permit assembly over the journal surface of the shaft. At the open end of the cutter bearing surface is a seal recess which includes an intersecting wall that defines an annular, generally curved corner to oppose the journal surface of the shaft. The cutter bearing surface has a curved outer region that converges from the annular corner of the seal recess into an inner region to reduce the stress the corner induces upon the journal bearing surface of the shaft, including the stress induced by cutter cocking during drilling.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.