GB2350380A

GB2350380A - Bearing assembly in which the bearing surfaces are formed at least in part from a thermally stable product (TSP) material

Info

Publication number: GB2350380A
Application number: GB0010101A
Authority: GB
Inventors: Michael Frederick Thompson; Adrian Jupp
Original assignee: Habit Diamond Ltd
Current assignee: Habit Diamond Ltd
Priority date: 1999-04-26
Filing date: 2000-04-26
Publication date: 2000-11-29
Also published as: GB0010101D0; GB9909516D0

Abstract

In a bearing assembly, preferably for use with drilling apparatus in the oil industry, first 6 and second 14 bearing components are mounted or formed on first and second articles arranged for movement relative to each other and at least one of the bearing surfaces 8, 16 is partially formed of a thermally stable product (TSP) material. Preferably, the TSP material is provided in the form of studs (20, figure 2b) at spaced intervals on the bearing surfaces and the bearing assembly is used to linearly and rotatably guide a drilling pipe 2 with respect to an outer guide tube 4. The areas of the bearing surfaces not formed of TSP may be formed of tungsten carbide or steel.

Description

2350380 Bearing The invention to which this application relates is a

bearing particularly but not necessarily exclusively, for use with drilling apparatus used in the oil industry.

At the present time, in the oil drilling industries a drilling pipe passes down to the area of drilling through an outer tube which acts as a guide for the drilling pipe. At at least one location, or at spaced intervals, a series of bearings are provided which ensure that the drilling pipe is guided accurately by the bearing arrangement. Conventionally hard wearing 'materials have been used as standard for the bearing surfaces, but while these operate satisfactorily when the bearing surfaces are relatively clean, it is found that the ingress of mud, water and other debris from the drilling operation can cause rapid wear of the bearing surfaces and leads relatively quickly to failure of the bearing. Although many attempts have been made to solve this problem none, to date, have been found to be particularly successful.

The aim of the present invention is to provide a bearing which provides the required guiding of one component movement with respect to another and, in particular a bearing which can withstand effectively, the ingress of foreign matter and operate in inhospitable environments such as in the oil drilling industry.

In a first aspect of the invention there is provided a bearing assembly comprising a first bearing component with a bearing surface mounted or formed on a first article and a second bearing component with a bearing surface mounted or formed on a second article, said first and second articles arranged for movement with respect to each other and wherein at least part of at least one of the 2 first or second component bearing surfaces is at least partially formed of thermally stable product (TSP) material.

In one embodiment the first article is an outer tube and the second article is a drilling pipe mounted in the outer tube and linearly movable along the outer tube, and typically rotatably movable with respect to the outer tube.

In one embodiment both the first and second bearing component surfaces are formed at least partially from TSP material. In a preferred embodiment the TSP material is provided at spaced intervals along the first and/or second component bearing surfaces. Typically the TSP is provided in the form of studs arranged in a pre-designated position to provide the best benefit from use of the material.

In one preferred embodiment the remainder of the first and second bearing compact surfaces are formed of tungsten carbide and the backing material for the first and second bearing components may also be of tungsten carbide or alternatively may be of steel with the tungsten carbide and TSP material sintered onto the backing material.

Typically the first and second bearing component surfaces are attached to the first and second articles respectively by way of shrink fitting or braising.

An embodiment of the invention is now described with reference to the accompanying drawings, wherein:- Figure 1 illustrates an embodiment of the invention in use in section, 3 Figures 2A-2B illustrate the first bearing compact surface of one embodiment of the bearing; and Figures 3A-D illustrate the second bearing compact surface for use with the bearing surface of Figure 2.

Referring firstly to Figure 1, there is shown one use of the bearing of the invention in the oil/gas drilling industry where there is provided a drilling pipe 2 which is positioned within a guide tube 4 as shown. Provided on the inside surface of the guide tube 2 is a first bearing component 6 with a bearing surface 8. The drilling pipe 2 is arranged to move linearly and rotatably as indicated by arrows 10, 12 with respect to the guide tube 4 and there is provided a second bearing component 14 with a bearing surface 16 arranged to move past the first bearing component surface 8 as the drilling pipe 2 moves and provides guide means for the same, even when mud, and other foreign matter from the drilling operation ingresses on the bearing surfaces.

Figures 2A-2B illustrate the first bearing component 6 and bearing surface 8. It will be seen that the component 6 is provided as a ring with an inner bearing surface 8 which is formed from tungsten carbide material 18 and a matrix of studs 20 which are formed of TSP material.

Figures 3A-D illustrate the second bearing component 14 and illustrate that the component is in the form of a ring with an outer diameter slightly less than the inner diameter of the first bearing component 6 so as to allow the same to fit and pass through the first bearing component. Again the bearing surface 16 is provided of tungsten carbide material 18 and a series of studs 20 of TSP material in a matrix spacing arrangement.

4 It is found that the provision of TSP material and, in particular the spaced use of the same on the bearing surfaces has significantly improved the efficiency and life of bearings even when used in difficult and typically hard wearing, conditions.

Claims

1 A bearing assembly comprising a first bearing component with a bearing surface mounted or formed on a first article and a second bearing component with a bearing surface mounted or formed on a second article, said first and second articles arranged for movement with respect to each other and wherein at least part of at least one of the first or second component bearing surfaces is at least partially formed of thermally stable product (TSP) material.

2 A bearing assembly according to claim 1 wherein the first article is an outer tube and the second article is a drilling pipe mounted within the outer tube and linearly movable along the outer tube.

3 A bearing assembly according to claim 2 wherein the drilling pipe is rotatably movable with respect to the outer tube.

4 A bearing assembly according to claim 1 wherein both the first and second component bearing surfaces are formed at least partially from TSP material.

A bearing assembly according to claim 1 wherein the TSP material is provided at spaced intervals along the first and/or second component bearing surfaces.

6 A bearing assembly according to claim 5 wherein the TSP material is provided in the form of studs arranged in a pre-designated position to provide the best benefit from use of the material.

7 A bearing assembly according to claim 1 wherein any portion of the bearing surfaces not formed of TSP material is formed with a surface of tungsten carbide.

6

8 A bearing assembly according to claim 1 wherein the backing material for the first and/or second component bearing surfaces is formed of tungsten carbide.

9 A bearing assembly according to claim 1 wherein the backing material for the first and/or second component surfaces is steel with TSP material sintered onto the same to form at least part of the bearing surface.

A bearing assembly according to claim 1 wherein the first and second bearing components are attached to the first and second articles respectively by way of shrink fitting or braising.

11. A bearing assembly as hereinbefore described with reference to the accompanying drawings.