Patent US3981984A successfully refreshed from Google Patents.
US4061376A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rock bit bearing structure
Assignee: Smith International Inc
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Filing: 1977-02-15
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Granted: 1977-12-06
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Expires: 1997-02-15
Abstract
Abstract A rock bit has a rotary cutter cone journaled on a fixed journal bearing shaft with the radial load being taken by a cylindrical journal bearing. The friction bearing portion of the fixed shaft has a groove extending around the periphery of the shaft. The groove is filled with a bearing metal over an arc on the lower load bearing fraction of the shaft. The remaining unfilled portion of the groove is connected through a lubricant supply passage in the bit body with a pressure-compensated grease reservoir in the bit body, to supply lubrication to the journal bearing.
Inventors
- 👤 Arthur A. Villaloboz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 07:34
CPC Classifications
F; F16; F16C; F16C33/00; F16C33/30; F16C33/58; F16C33/64; E; E21; E21B; E21B10/00; E21B10/08; E21B10/22; E21B10/24; F16C2352/00
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
109 words
A rock bit comprising a drill bit body having a journal bearing spindle shaft, a rotary cutter cone rotatably supported on the shaft, the shaft having a cylindrical bearing portion, the cutter cone having a cylindrical bore extending around the bearing portion for forming a friction bearing, the bearing portion of the shaft having a shallow groove extending around the periphery thereof, bearing metal applied in the groove over less than about half the circumference of the groove, the bearing metal forming a surface flush with said cylindrical bearing portion, a pressure compensating grease reservoir in the bit body, and a passage connecting the grease reservoir to the groove.
Claim 2
Dependent Claim
109 words
A rock bit comprising a drill bit body having a journal bearing spindle shaft, a rotary cutter cone rotatably supported on the shaft, the shaft having a cylindrical bearing portion, the cutter cone having a cylindrical bore extending around the bearing portion for forming a friction bearing, the bearing portion of the shaft having a shallow groove extending around the periphery thereof, bearing metal applied in the groove over less than about half the circumference of the groove, the bearing metal forming a surface flush with said cylindrical bearing portion, a pressure compensating grease reservoir in the bit body, and a passage connecting the grease reservoir to the groove.
Claim 3
Dependent Claim
17 words
A rock bit as recited in claim 1 wherein the bearing metal is chamfered at both ends.
Claim 4
Dependent Claim
28 words
A rock bit as recited in claim 1 wherein the axial width of the groove is less than the axial length of the bearing portion of the shaft.
Claim 5
Dependent Claim
28 words
A rock bit as recited in claim 1 wherein the bearing metal is a hard facing material having a higher hardness than the bearing portion of the shaft.
Claim 6
Dependent Claim
143 words
A rock bit comprising: a bit body; a journal bearing shaft on the bit body; a rotary cutter cone rotatably supported on the journal bearing shaft and including a cylindrical bore extending around a portion of the journal bearing shaft for forming a friction bearing surface; a cyclindrical bearing portion on the journal bearing shaft opposite the cylindrical bore, said cylindrical bearing portion including a pair of axially spaced apart cyclindrical bearing surfaces of hardened steel, a circumferential groove between the cylindrical bearing surfaces, and a bearing metal applied in the groove in only the lower load bearing fraction of the journal bearing shaft and flush with the cylindrical bearing surfaces; a lubricant reservoir in the bit body; means in the lubricant reservoir for compensating for pressure changes; and a lubricant passage between the reservoir and the unfilled portion of the circumferential groove.
Claim 7
Dependent Claim
143 words
A rock bit comprising: a bit body; a journal bearing shaft on the bit body; a rotary cutter cone rotatably supported on the journal bearing shaft and including a cylindrical bore extending around a portion of the journal bearing shaft for forming a friction bearing surface; a cyclindrical bearing portion on the journal bearing shaft opposite the cylindrical bore, said cylindrical bearing portion including a pair of axially spaced apart cyclindrical bearing surfaces of hardened steel, a circumferential groove between the cylindrical bearing surfaces, and a bearing metal applied in the groove in only the lower load bearing fraction of the journal bearing shaft and flush with the cylindrical bearing surfaces; a lubricant reservoir in the bit body; means in the lubricant reservoir for compensating for pressure changes; and a lubricant passage between the reservoir and the unfilled portion of the circumferential groove.
Claim 8
Dependent Claim
29 words
A rock bit as recited in claim 5 wherein the bearing metal comprises a hard facing alloy having a higher hardness than the adjacent hardened steel cylindrical bearing surfaces.
Claim 9
Independent Claim
61 words
A method of making a friction type bearing for a rotary rock bit comprising the steps of: turning a journal bearing shaft, forming a cylindrical bearing surface on the shaft, forming a groove around the circumference of the bearing surface, filling only a portion of the groove with a bearing metal, and machining the bearing metal flush with the cylindrical surface.
Claim 10
Independent Claim
61 words
A method of making a friction type bearing for a rotary rock bit comprising the steps of: turning a journal bearing shaft, forming a cylindrical bearing surface on the shaft, forming a groove around the circumference of the bearing surface, filling only a portion of the groove with a bearing metal, and machining the bearing metal flush with the cylindrical surface.
Claim 11
Dependent Claim
22 words
The method of claim 7 wherein the bearing metal is filled in over less than about half the circumference of the groove.
Claim 12
Dependent Claim
30 words
The method of claim 7 wherein the bearing metal comprises a hard facing alloy having a higher hardness than the cylindrical bearing surface on the shaft welded into the groove.
Claim 13
Dependent Claim
37 words
The method of claim 7 wherein the groove is formed with a width less than the axial extent of said cylindrical bearing surface on the shaft, the cylindrical bearing surface extending on both sides of the groove.
Claim 14
Dependent Claim
36 words
The method of claim 7 further including the step of: forming a hole through the journal bearing shaft and opening into the unfilled portion of the groove to provide a passage for lubricant to the groove.
Claim 15
Independent Claim
70 words
A method of making a rotary rock bit having a friction type bearing for a cutter cone comprising the steps of: turning a journal bearing shaft including a pair of axially spaced apart cylindrical bearing surfaces and a circumferential groove therebetween; filling a fraction of the circumference of the groove with bearing metal; and removing excess bearing metal to form the outer surface thereof flush with the cylindrical bearing surfaces.
Claim 16
Independent Claim
70 words
A method of making a rotary rock bit having a friction type bearing for a cutter cone comprising the steps of: turning a journal bearing shaft including a pair of axially spaced apart cylindrical bearing surfaces and a circumferential groove therebetween; filling a fraction of the circumference of the groove with bearing metal; and removing excess bearing metal to form the outer surface thereof flush with the cylindrical bearing surfaces.
Claim 17
Dependent Claim
31 words
A method as recited in claim 12 wherein the filling step comprises welding a hard facing alloy having a higher hardness than the adjacent cylindrical bearing surfaces into the circumferential groove.
Claim 18
Dependent Claim
104 words
A rock bit comprising a drill bit body having a journal bearing spindle shaft, a rotary cutter cone rotatably supported on the shaft, the shaft having a cylindrical bearing portion, the cutter cone having a cylindrical bore extending around the bearing portion for forming a friction bearing, the bearing portion of the shaft having a shallow groove extending around the periphery thereof, bearing metal applied in the groove over less than about half the circumference of the groove and having a load bearing outer surface, a pressure compensating grease reservoir in the bit body, and a passage connecting the grease reservoir to the groove.
Claim 19
Dependent Claim
104 words
A rock bit comprising a drill bit body having a journal bearing spindle shaft, a rotary cutter cone rotatably supported on the shaft, the shaft having a cylindrical bearing portion, the cutter cone having a cylindrical bore extending around the bearing portion for forming a friction bearing, the bearing portion of the shaft having a shallow groove extending around the periphery thereof, bearing metal applied in the groove over less than about half the circumference of the groove and having a load bearing outer surface, a pressure compensating grease reservoir in the bit body, and a passage connecting the grease reservoir to the groove.
Claim 20
Dependent Claim
17 words
A rock bit as recited in claim 14 wherein the bearing metal is chamfered at both ends.
Claim 21
Dependent Claim
28 words
A rock bit as recited in claim 14 wherein the axial width of the groove is less than the axial length of the bearing portion of the shaft.
Claim 22
Dependent Claim
28 words
A rock bit as recited in claim 14 wherein the bearing metal is a hard facing material having a higher hardness than the bearing portion of the shaft.
Claim 23
Dependent Claim
141 words
A rock bit comprising: a bit body; a journal bearing shaft on the bit body; a rotary cutter cone rotatably supported on the journal bearing shaft and including a cylindrical bore extending around a portion of the journal bearing shaft for forming a friction bearing surface; a bearing portion on the journal bearing shaft opposite the cylindrical bore, said bearing portion including a pair of axially spaced apart cylindrical bearing surfaces of hardened steel, a circumferential groove between the cylindrical bearing surfaces, and a bearing metal applied in the groove in only the lower load bearing fraction of the journal bearing shaft and having a load bearing outer surface; a lubricant reservoir in the bit body; means in the lubricant reservoir for compensating for pressure changes; and a lubricant passage between the reservoir and the unfilled portion of the circumferential groove.
Claim 24
Dependent Claim
141 words
A rock bit comprising: a bit body; a journal bearing shaft on the bit body; a rotary cutter cone rotatably supported on the journal bearing shaft and including a cylindrical bore extending around a portion of the journal bearing shaft for forming a friction bearing surface; a bearing portion on the journal bearing shaft opposite the cylindrical bore, said bearing portion including a pair of axially spaced apart cylindrical bearing surfaces of hardened steel, a circumferential groove between the cylindrical bearing surfaces, and a bearing metal applied in the groove in only the lower load bearing fraction of the journal bearing shaft and having a load bearing outer surface; a lubricant reservoir in the bit body; means in the lubricant reservoir for compensating for pressure changes; and a lubricant passage between the reservoir and the unfilled portion of the circumferential groove.
Claim 25
Dependent Claim
29 words
A rock bit as recited in claim 18 wherein the bearing metal comprises a hard facing alloy having a higher hardness than the adjacent hardened steel cylindrical bearing surfaces.
Claim 26
Independent Claim
62 words
A method of making a friction type bearing for a rotary rock bit comprising the steps of: turning a journal bearing shaft, forming a cylindrical bearing surface on the shaft, forming a groove around the circumference of the bearing surface, filling only a portion of the groove with a bearing metal, and machining an outer load bearing surface on the bearing metal.
Claim 27
Independent Claim
62 words
A method of making a friction type bearing for a rotary rock bit comprising the steps of: turning a journal bearing shaft, forming a cylindrical bearing surface on the shaft, forming a groove around the circumference of the bearing surface, filling only a portion of the groove with a bearing metal, and machining an outer load bearing surface on the bearing metal.
Claim 28
Dependent Claim
22 words
The method of claim 20 wherein the bearing metal is filled in over less than about half the circumference of the groove.
Claim 29
Dependent Claim
30 words
The method of claim 20 wherein the bearing metal comprises a hard facing alloy having a higher hardness than the cylindrical bearing surface on the shaft welded into the groove.
Claim 30
Dependent Claim
37 words
The method of claim 20 wherein the groove is formed with a width less than the axial extent of said cylindrical bearing surface on the shaft, the cylindrical bearing surface extending on both sides of the groove.
Claim 31
Dependent Claim
36 words
The method of claim 20 further including the step of: forming a hole through the journal bearing shaft and opening into the unfilled portion of the groove to provide a passage for lubricant to the groove.
Claim 32
Independent Claim
69 words
A method of making a rotary rock bit having a friction type bearing for a cutter cone comprising the steps of: turning a journal bearing shaft including a pair of axially spaced apart cylindrical bearing surfaces and a circumferential groove therebetween; filling a fraction of the circumference of the groove with bearing metal; and removing excess bearing metal to form a load bearing surface on the outer surface thereof.
Claim 33
Independent Claim
69 words
A method of making a rotary rock bit having a friction type bearing for a cutter cone comprising the steps of: turning a journal bearing shaft including a pair of axially spaced apart cylindrical bearing surfaces and a circumferential groove therebetween; filling a fraction of the circumference of the groove with bearing metal; and removing excess bearing metal to form a load bearing surface on the outer surface thereof.
Claim 34
Dependent Claim
31 words
A method as recited in claim 25 wherein the filling step comprises welding a hard facing alloy having a higher hardness than the adjacent cylindrical bearing surfaces into the circumferential groove.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-12-05 | 1981-06-06 | 1981-12-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-12-05 | 1985-06-06 | 1985-12-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-12-05 | 1989-06-06 | 1989-12-06 | $7700.00 | Window Closed / Lapsed |