WO2008069708A1

WO2008069708A1 - Bearing component and bearing arrangement comprising the bearing component

Info

Publication number: WO2008069708A1
Application number: PCT/SE2006/001396
Authority: WO
Inventors: Johan Larsson; Fredrik LÜSCH
Original assignee: Aktiebolaget Skf
Priority date: 2006-12-07
Filing date: 2006-12-07
Publication date: 2008-06-12

Abstract

A bearing component (1) is disclosed. It comprises a rotary and circular ring (3) that has means (5) allowing fixing to a mechanical element (7), wherein the means (5) is intended to receive a fixing means (9) for fixing in a direction essentially perpendicular (F) in relation to a plane of the ring (3), and an outer radial surface of the ring (3) which is a raceway to be radially supported by at least one non metal-to-metal contact bearing (13). Also, a bearing arrangement (21) is disclosed that comprises the bearing component (1), at least one non metal-to-metal contact bearing (13) for supporting the bearing component (1) and an oil film supplying means (23).

Description

TITLE

Bearing component and bearing arrangement comprising the bearing component

FIELD OF INVENTION

According to a first aspect of the invention, a bearing component is disclosed.

According to a second aspect of the invention, a bearing arrangement comprising the first aspect is disclosed.

SUMMARY OF INVENTION According to the first aspect of the invention, a bearing component is disclosed. It comprises a rotary and circular ring that has means allowing fixing to a mechanical element, wherein the means is intended to receive a fixing means for fixing in a direction essentially perpendicular in relation to a plane of the ring, and an outer radial surface of the ring which is a raceway to be radially supported by at least one non metal-to-metal contact bearing. Herein, non metal-to- metal contact bearing is a segment, shoe or a pad of a hydrostatic or a hydrodynamic bearing with essentially the same shape as the shape of the supported surface of the ring. Thus the bearing component is a component intended to be supported by the non metal-to-metal contact bearing. The bearing component offers an advantage of being easy to manufacture as compared to a construction comprising both the ring and the mechanical element. From a manufacturing viewpoint, it may be preferred to manufacture the bearing component, or the bearing arrangement, separately for later fixing to the mechanical element. Also, separate manufacturing is cheaper and does not take as long time . Factors influencing the difficulty related to manufacturing and transporting includes size of the mechanical element and the size of the bearing component. Another advantage is that by separately manufacturing the ring is that it is possible to optimize a seal contact surface when designing and mounting a seal for sealing a housing and the ring. Another advantage with separate manufacturing is that it is possible to manufacture a ring with higher tolerance leading to increased reliability.

In an embodiment, a part of the radial outer surface, a part that extends fully around the ring, is intended to be -supported by a non metal-to-metal contact bearing .

In an embodiment, the outer radial surface presents a R_A value, i.e. a measure of surface roughness, that is one of lower than 3.5, lower than 3.2, lower than 1.5, lower than 1.0, lower than 0.7, lower than 0.5, and lower than 0.4. A lower R_A value leads to the advantage of being able to reduce the thickness of the oil film between the radial outer surface and the non metal-to- metal contact bearing, leading to lower energy consumption and a stiffer bearing.

In an embodiment, the means allowing fixing to a mechanical element is at least 12 holes extending through the ring in axial direction. The at least 12 holes extend through the metal material of the ring. In an embodiment, the means allowing fixing is not a through hole but an indentation, or a bottom hole, indicating where the hole is to be placed and the through hole may be forged e.g. when mounting to the mechanical element .

In an embodiment, the at least 12 holes are placed symmetrically in angular position of the ring in order to allow a secure and tight fixing of the ring to the mechanical element, meaning that, in a case of having 36 holes there would be 360/36 = 10 degrees between each hole. In an embodiment, the at least 12 holes are placed asymmetrically in angular position. In an embodiment, the bearing component further comprises the fixing means, which is constituted by: -bolts,

-arresting pins , -or a combination of bolts and arresting pins, for fixing the ring to the mechanical element via the at least 12 holes.

In an embodiment, the number of nuts is the same as the number of bolts. In another embodiment, bolts may used to fix using a matching thread in the mechanical element. In an embodiment, nuts are used to fix the ring to the mechanical element .

In an embodiment, the fixing means are constituted by bolts designed specifically for high torque applications such as propeller shafts, rudder assemblies, turbine generators, rolling mills and similar applications. The bolts are designed to be inserted and removed with an initial clearance fit. The bolts are threaded at both ends and have a tapered shank. An expansion sleeve of each bolt with a corresponding tapered bore fits over the shank. Two nuts are used for accomplishing the actual fixing from a corresponding side. The outside of the sleeve is cylindrical and dimensioned for an initial clearance fit in the bolt hole corresponding to 0.05% to 0.15% of the bolt hole diameter.

In an embodiment, the ring has an inner diameter larger than 1.600 meters. In an embodiment, the ring has an inner diameter in the interval 1.600 to 14 meters.

In an embodiment, the thickness in axial direction of the ring is in the interval 0.085 to 0.600 meters.

In an embodiment, the thickness in radial direction of the ring is in the interval 0.10 to 0.45 meters. In an embodiment, the thickness in radial direction is in the interval 0.15 to 0.40 meters. The thickness in radial direction of the ring is the same as half of the difference of the inner diameter and outer diameter.

In an embodiment, the cross section of the ring has a rectangular shape.

In an embodiment, the cross section, at the outer radial surface, presents a shape having at least one radial recess or radial protrusion, the shape matching a shape of a load receiving portion of the at least one non metal-to-metal contact bearing. This leads to a means allowing axial locking of the ring (and also a mechanical element fixed. to the ring) in relation to. the at least one non metal-to-metal contact bearing. This is advantageous if the ring is subjected to an axial force since such a means limits the axial movement of the ring. In an embodiment, the recess, or the protrusion extends fully around the periphery of the ring.

In an embodiment, the at least one non metal-to- metal contact bearing is one of a hydrostatic bearing, and a hydrodynamic bearing. The term hydrostatic bearing includes a segmented hydrostatic bearing, a bearing having hydrostatic pads, and a shoe bearing.

In an embodiment, the ring is hardened. According to the second aspect, a bearing arrangement is disclosed. It comprises the first aspect, at least one non metal-to-metal contact bearing for supporting the bearing component, and an oil film supplying means. Having at least one non metal-to-metal contact bearing leads to easier and faster replacement of bearing components in case of failure. This also leads to shorter down time. The oil film supplying means is responsive for providing a sliding oil contact between the outer radial surface and the non metal-to- metal contact bearing.

I an embodiment, the number of non metal-to-metal contact bearings is two, three or more. They are located to support the ring. In an embodiment, the bearing arrangement comprises the mechanical element. In an embodiment, the mechanical element is a drum of a mill. In this embodiment, the other end of the mechanical element, in this case the drum, may be supported by a bearing arrangement similar to the second aspect, or a ring similar to the first aspect .

In an embodiment, the bearing arrangement further comprises a housing housing the bearing arrangement.

In an embodiment, the bearing arrangement further comprises a seal sealing the housing and the ring.

It should be pointed out that features related to the first aspect may be applicable to the second aspect and features of the second aspect may be applicable to the first aspect.

BRIEF DESCRIPTION OF THE DRAWINGS In Figure 1, a schematic illustration of the ring is given.

In Figure 2, a cross section view of the ring is given . In Figure 3A, a schematic illustration of the radial and peripheral surface of the ring is given.

In Figures 3B to 31, several alternative designs for accomplishing an axial locking for the radial and peripheral surface of the ring in relation to the at least one non metal-to-metal contact bearing is given.

In Figure 4, a schematic illustration of a bearing arrangement is given.

In Figure 5 , a schematic illustration of two bearing arrangements and a mechanical element is given.

DESCRIPTION OF PREFERRED EMBODIMENTS

In Figures 1 and 2 , an embodiment of a bearing component 1 is given. It comprises a rotary and circular ring 3 that has means 5 allowing fixing to a mechanical element 7 (indicated in Figure 2 with dotted lines) , wherein the means 5 is intended to receive a fixing means 9 for fixing in a direction essentially perpendicular in relation to a plane of the ring. In Figure 2, this direction is indicated with two arrows marked 'F'. The bearing component 1 further comprises an outer radial surface 11 of the ring 3 which is a raceway to be radially supported by at least one non metal-to- metal contact bearing 13. The outer radial surface 11 presents a R_A value that is lower than 3.5. The means 5 allowing fixing to a mechanical element 7 is at least 12 holes extending through the ring 3 in axial direction. The at least 12 holes are placed symmetrically in. angular position of the ring 3. The fixing means 9 is constituted by at least 12 bolts fixing the ring to the mechanical element via the at least 12 holes. The ring 3 has an inner diameter in the interval 1.600 to 14 meters. The thickness in axial direction of the ring 3 is in the interval 0.085 to 0.600 meters. The thickness in radial direction of the ring 3 is in the interval 0.10 to 0.35 meters. The cross section of the ring 3 has a rectangular shape, as shown in Figure 3A. Also in Figure 3A₇ the load receiving portion 15 of the at least one non metal-to-metal contact bearing 13 is indicated by a dotted line.

In embodiments, cross sections of the ring 3, at the outer radial surface, present a shape having at least one radial recess or radial protrusion, the shape matching a load receiving portion 15 of the at least one non metal-to-metal contact bearing 13 and thereby allowing axial locking of the ring 3. Non-limiting alternatives of designs accomplishing this are given in Figures 3B to 31, wherein the outer radial surface presents a recess 17 or radial protrusion 19 which is matched by a matching shape of the at least one on metal-to-metal contact bearing 13. The matching shape of the at least one non metal-to-metal contact bearing 13 is shown in dotted lines in Figures 3B to 31. A recess 17 or protrusion 19 extends fully around the periphery of the ring 3.

In Figure 4, a bearing arrangement 21 comprising the bearing component 1 is given. In this embodiment, there are two segmented non metal-to-metal contact bearings 13 for supporting the bearing component 1, and an oil film supplying means 23 connected to the non metal-to-metal contact bearings 13. The two non metal- to-metal contact bearings 13 support the ring 3 symmetricalIy.

In Figure 5, an embodiment of two bearing arrangements 21 and also comprising the mechanical element 7 is given. A ring 3 of a first bearing arrangement A is fixed to the mechanical element 7 at one side thereof and a ring 3 of a second bearing arrangement B is fixed to another side of the mechanical element 7. In an embodiment, the two bearing arrangements 21 are identical. In an embodiment, the two bearing arrangements 21 differ in that one of them presents a recess or a protrusion, e.g. as shown in anyone of Figures 3B to 31 in order to provide a locking effect of the ring 3. The mechanical element 7 is fixed to the rings using bolts 9, e.g. 'super grip bolts'. The mechanical element 7 may be an application associated with high torque, such as a drum.

Claims

1. A bearing component (1) comprising:

-a rotary and circular ring (3) that has means (5) allowing fixing to a mechanical element (7), wherein the means (5) is intended to receive a fixing means (9) for fixing in a direction essentially perpendicular (F) in relation to a plane of the ring (3), and -an outer radial surface of the ring (3) which is a raceway to be radially supported by at least one non metal-to-metal contact bearing (13).

2. A bearing component according to claim 1, wherein the outer radial surface presents a R_A value that is one of: -lower than 3.5, -lower than 3.2,

-lower than 1.5, and -lower than 0.7.

3. A bearing component according to claim 1, wherein the means (5) allowing fixing to a mechanical element (7) is at least 12 holes extending through the ring (3) in axial direction (F) ..

4. A bearing component according to claim 3 , further comprising the fixing means (9) , which is constituted by:

-bolts,

-arresting pins,

-or a combination of bolts and arresting pins, for fixing the ring to the mechanical element (7) via the at least 12 holes (5) .

5. A bearing component according to claim 1, wherein the ring (3) has an inner diameter in the interval 1.600 to 14 meters .

6. A bearing component according to claim 1, wherein the thickness in axial direction (F) of the ring (3) is in the interval 0.085 to 0.600 meters.

7. A bearing component according to claim 1, wherein the thickness in radial direction of the ring (3) is in the interval 0.10 to 0.45 meters.

8. A bearing component according to claim 1, wherein the cross section of the ring (3) has a rectangular shape.

9. A bearing component according to claim 8, wherein the cross section, at the outer radial surface, presents a shape having at least one radial recess (17) or radial protrusion (19), the shape matching a shape of a load receiving portion (15) of the at least one non metal-to- metal contact bearing (13) and thereby allowing axial locking of the ring (3) .

10. A bearing component according to claim 9, wherein the recess (17) or protrusion (19) extends fully around the periphery of the ring (3) .

11. A bearing component according to claim 1, wherein the at least one non metal-to-metal contact bearing (13) is one of:

-a hydrostatic bearing, and -a hydro dynamic bearing.

12. A bearing arrangement comprising

-a bearing component (1) according to any one of claims 1 to 11. -at least one non metal-to-metal contact bearing (13) for supporting the bearing component (1) , and -an oil film supplying means (23) .

13. A bearing arrangement according to claim 12, further comprising the mechanical element (7).