NO762541L

NO762541L -

Info

Publication number: NO762541L
Application number: NO762541A
Authority: NO
Inventors: H W Murdoch
Original assignee: Reed Tool Co
Priority date: 1975-08-13
Filing date: 1976-07-21
Publication date: 1977-02-15
Also published as: BR7605280A; AT352052B; AU502035B2; DE2636179A1; AU1680476A; IT1073442B; CH610982A5; ATA601176A; JPS5222501A; MX143147A; FR2321034B1; FR2321034A1; SE7609015L; ES450637A1; NL7608964A; GB1521833A; DK363976A; CA1039266A

Abstract

BORKRONEBORKRONE

Description

Bore industrien søker stadig å forbedre lagrene for .rullekutter-borkroner. For oppnåelse av en kommersielt aksepta-bel levetid må lagrene oppvise minimal friksjon og slitasje. Man-ge harde, seige lagermetaller har en meget ugunstig gnagende eller rivende (galling) tendens. The drilling industry is constantly seeking to improve bearings for .roll cutter drill bits. To achieve a commercially acceptable service life, the bearings must exhibit minimal friction and wear. Many hard, tough bearing metals have a very unfavorable galling or galling tendency.

Foreliggende oppfinnelse tilveiebringer et forbedret lager for en rullekutter-borkrone, hvilket lager omfatter et hardt, seigt metall med tilstrekkelig smøreevne til å motvirke gnage- eller rivetendensen. The present invention provides an improved bearing for a roller cutter drill bit, which bearing comprises a hard, tough metal with sufficient lubricity to counteract the tendency to chafe or tear.

Et formål med foreliggende oppfinnelse er så å tilveiebringe en forbedret rullekutter-borkrone med et lagerorgan med lang levetid. An object of the present invention is then to provide an improved roller cutter drill bit with a long-life bearing member.

Et ytterligere formål er å tilveiebringe en forbedret rullekutter-borkrone med et lager av hardt, seigt metall som ikke utsettes for oppriving eller avgnaging. A further object is to provide an improved roll cutter drill bit having a stock of hard, tough metal which is not subject to tearing or galling.

Tegningen viser i snitt et parti av en borkrone hvor den forbedrede konstruksjon ifølge foreliggende oppfinnelse er be-nyttet . The drawing shows in section a part of a drill bit where the improved construction according to the present invention is used.

Borkronen 10 vist på tegningen innbefatter hoveddelen eller kroppen 12 fra hvilken i det minste ett ben 14 strekker seg. Benet 14 ender i akseltappen 16 på hvilken rullekutteren 18 er dreibart montert ved hjelp av.hensiktsmessige lagerorganer. Lagerorganene omfatter kulelagrene 20, hylselager 22 og lagerflatene 24 og 26. Tetningen 28 er plasert i sporet 30 i rullekutteren 18. Tetningen 28 virker som den ytre tetning for smøresystemet (ikke vist) som tilfører smøremiddel til lagrene. The drill bit 10 shown in the drawing includes the main part or body 12 from which at least one leg 14 extends. The leg 14 ends in the axle pin 16 on which the roller cutter 18 is rotatably mounted by means of suitable bearing means. The bearing members comprise the ball bearings 20, sleeve bearing 22 and the bearing surfaces 24 and 26. The seal 28 is placed in the groove 30 in the roller cutter 18. The seal 28 acts as the outer seal for the lubrication system (not shown) which supplies lubricant to the bearings.

Hylselageret 22 er et lager eller en foring av en flytende eller svevende hylsetype.Hylselageret 22 er fremstilt av et hardt, seigt metall som har en Rockwell C hardhet på minst 35 og er behandlet for å oppvise en smurt overflate som delvis eller tilnærmet fullstendig eliminerer rive- eller gnagetendensen. Metallet i lageret bør være hardt og seigt for å motstå den høye slitasjepåkjenning i en borkrone. Lageret kan være av en beryllium-kopperlegering såsom en legering av kopper inneholdende 0,25 til 3,0 % beryllium, fortrinnsvis mellom 1,80 - 2,05 %. Legerin-gen kan inneholde mindre mengder kobolt, nikkel og jern, f.eks. 0,20 -0,30 % kobolt eller en blanding av kobolt og nikkel på i The sleeve bearing 22 is a floating or floating sleeve type bearing or liner. The sleeve bearing 22 is made of a hard, tough metal having a Rockwell C hardness of at least 35 and is treated to present a lubricated surface that partially or substantially eliminates tearing. - or the tendency to gnaw. The metal in the bearing should be hard and tough to withstand the high wear stress in a drill bit. The bearing may be of a beryllium-copper alloy such as an alloy of copper containing 0.25 to 3.0% beryllium, preferably between 1.80 - 2.05%. The alloy may contain smaller amounts of cobalt, nickel and iron, e.g. 0.20 -0.30% cobalt or a mixture of cobalt and nickel on i

det minste 0,2 % eller en blanding av kobolt, nikkel og jern som ikke overstiger 0,6 %. En legering av denne type kan ha en elas-tisitetsmodul på 1 300 000 og kan være en oppløsning som er glø-det.og herdet ved eldning til en strekkfasthet på 11 600 til 13 300 kg/cm 2 og med en Rockwell C hardhet på 36 til 41. at least 0.2% or a mixture of cobalt, nickel and iron not exceeding 0.6%. An alloy of this type may have a modulus of elasticity of 1,300,000 and may be a solution annealed and hardened by ageing to a tensile strength of 11,600 to 13,300 kg/cm 2 and with a Rockwell C hardness of 36 to 41.

Alternativt kan lageret 22 være av en mareldningsstållegering som er blitt varmebehandlet til maksimal hardhet som fortrinnsvis er omkring Rockwell C 50 til 55. Andre harde, seige le-geringer kan anvendes og de nødvendige egenskaper er en kombina-sjon av fasthet, hardhet og seighet. Metallet bør ha en høy strekkfasthet kombinert med betydelig seighet og en Rockwell C hardhet i overkant av 35. Alternatively, the bearing 22 may be of a mar-alloy steel alloy which has been heat-treated to a maximum hardness which is preferably around Rockwell C 50 to 55. Other hard, tough alloys may be used and the required properties are a combination of firmness, hardness and toughness. The metal should have a high tensile strength combined with considerable toughness and a Rockwell C hardness in excess of 35.

For å hindre avskalling eller oppriving er hylselageret 22 belagt, f.eks. ved plettering eller forskjellige andre metalliseringsteknikker, med et bløtt lagermetall såsom bly, indium, tinn, kopper eller sølv. En sølvplettering eller annet sølv-belegg foretrekkes for lageret 22 og legges på utvendig og innven-dig i rimelig tykkelse, f.eks. 25 ^um. Også flerlags belegg kan anvendes, f.eks. bly over sølv, indium over bly over sølv, tinn over sølv etc. To prevent peeling or tearing, the sleeve bearing 22 is coated, e.g. by plating or various other metallization techniques, with a soft base metal such as lead, indium, tin, copper or silver. A silver plating or other silver coating is preferred for the bearing 22 and applied externally and internally in a reasonable thickness, e.g. 25 µm. Multi-layer coatings can also be used, e.g. lead over silver, indium over lead over silver, tin over silver etc.

Borkronen kan også være forsynt med et supplerende smøremiddel bestående av fine partikler av et lagermetall såsom kopper eller sølv suspendert i fettet som fylles i smøresystemet. På dette vis er lagerhylsen 22 helt fra begynnelsen omgitt av partiklene og under drift virker partiklene som ytterligere smøre-middel som bidrar til å unngå de gnage- eller riveproblemer som oppstår ved de fleste harde, seige metallagre. The drill bit can also be provided with a supplementary lubricant consisting of fine particles of a bearing metal such as copper or silver suspended in the grease that is filled in the lubrication system. In this way, the bearing sleeve 22 is surrounded by the particles from the very beginning and during operation the particles act as an additional lubricant which helps to avoid the chafing or tearing problems that occur with most hard, tough metal bearings.

I en borkrone som er konstruert som ovenfor beskre-vet kan lagerhylsen motstå utpressing under tunge belastninger og hylsen virker bedre som et lager fordi den har større hardhet og seighet.Belegget eller pletteringen av sølv eller kopper eller annet bløtt lagermetall på lagerhylsen gir større motstand mot avgnaging, avskalling eller oppriving ettersom metallbelegget kan overføres frem og tilbake mellom lageret og de flater som lageret ligger an mot under drift. Metallbelegget på lageret vandrer fritt mellom anleggs flåtene og hindrer avgnaging eller oppriving. In a drill bit constructed as described above, the bearing sleeve can resist extrusion under heavy loads and the sleeve acts better as a bearing because it has greater hardness and toughness. The coating or plating of silver or copper or other soft bearing metal on the bearing sleeve provides greater resistance to chafing, peeling or tearing as the metal coating can be transferred back and forth between the bearing and the surfaces against which the bearing abuts during operation. The metal coating on the bearing moves freely between the construction rafts and prevents chafing or tearing.

Det vil fremgå av ovenstående at fore liggende oppfinnelse tilveiebringer en forbedret borkrone med et hylselager som har større seighet, hardhet og temperaturfasthet enn tidligere hylse-lagere, og som på grunn av smørebelegget ikke utsettes for nevne-verdig avgnaging, avskalling eller oppriving. It will be apparent from the above that the present invention provides an improved drill bit with a sleeve bearing which has greater toughness, hardness and temperature resistance than previous sleeve bearings, and which, due to the lubricating coating, is not exposed to significant chafing, peeling or tearing.

Claims

1. Drill bit comprising a body with a protruding shaft pin, a roller cutter, bearing means for rotatable storage of the roller cutter on the bearing pin, characterized in that at least part of the bearing means includes a hard, tough me- . number sleeve (22) with a Rockwell C hardness of at least 35 arranged around the axle pin (16) in the roller cutter (18), and a metal coating on the sleeve with lubricating properties placed between the sleeve and the bearing pin and between the sleeve and the roller cutter, which metal coating imparts sufficient lubrication properties to the sleeve to to prevent chafing, peeling or tearing of the roll cutter and bearing pin.

2. Drill bit as stated in claim 1, characterized in that the metal coating is plated on the sleeve.

3. Drill bit as specified in claim 1, characterized in that the metal coating is applied to the sleeve by metallization.

4. Drill bit as stated in claim 1, characterized in that the metal coating comprises a number of layers of bearing metal.

5.B ork crown as stated in claim 1, characterized in that the metal coating includes at least one layer of silver, copper, tin, lead or indium.

6. Drill bit as stated in claim 1, characterized in that the metal coating is a number of layers of copper, silver, tin, lead or indium.

7. Drill bit as stated in claim 1, characterized in that the sleeve is of beryllium - copper alloy or a mareldnings steel alloy which has been heat-treated to considerable hardness.

8. Boring crown as specified in claim 1, characterized in that additional lubricating material comprising a grease containing particles of indium, tin, lead, silver is provided. or cups.

9. Drill bit as specified in claim 1 including a lubrication system in the body (10) and in communication with the bearing members, characterized by a lubricating grease in which particles of silver or copper are distributed, and by said lubricating grease being supplied to the lubrication system whereby grease and particles are delivered to the areas of the sleeve with contact surfaces against the bearing pin and the roller cutter.

10. Drill bit as specified in claim 9, characterized in that the metal coating is silver plating or metallization on the sleeve.