SEALING

Field of the Invention

The present invention relates to a large sealed self-aligning rolling bearing, and to a method for manufacturing a large sealed self-aligning rolling bearing, which bearing comprises an inner ring, an outer ring, rolling elements, and a built-in sealing member which is build-in into the inner or outer ring.

Background Art

Bearings are often used in applications which require the use of a sealing. For example, the mounting of the bearing may take place in an environment which is dirty, or bearings may be subjected to dirt, metal chips, and other impurities, during operation in demanding applications, for example in applications such as continuous casting machines, rolling mills, etc.

By providing the bearing with a seal, impurities and dirty may be prevented from penetrating into the bearing thereby causing a reduction of the service life of the bearing and an increase of maintenance needs. Hence, the performance of the seal is an important aspect for providing increased service life and more cost-effective operation and maintenance of bearings.

According to a known technique the seal is assembled on the bearing, as shown in e.g. SE-B-451 081. In this solution the seal is formed by two cooperating sheet metal rings wherein at least one of the sheet metal rings is notch joined into the outer race ring, whereas the other is fitted to the inner race ring. This solution however means that the seal will project outside the side planes, which in some cases necessitates modifications of the bearing housing and also of the mounting and dismantling tools, etcetera.

According to an alternative technique, the seal is built-in into the bearing such that the seal does not project from the side surface of the bearing. In order to accommodate the seal, however, the rolling elements and raceway are typically reduced in width. Alternatively, the width of the bearing may be increased in order to maintain the carrying capacity in comparsion with a corresponding unsealed bearing.

In smaller size bearings, typically less than 200 mm in outer diameter, it is common to provide the sealing member with an attachment portion at first peripheral portion of an annular plate with a spring portion arranged for introduction into a groove. The spring, which typically is a bent part of the annular plate ring will keep the sealing member in place. This solution which has been promising for smaller size bearings has not been used for larger size bearings. One reason for this is that the sealing lips of larger size bearing are positioned at a greater distance from the mounting groove and that higher tolerance requirements regarding the position of the built-in sealing member is required. Another reason is that due to the increased requirement of rigidity of the annular plate member need to be thicker, which increases difficulties with forming a spring portion without formation of cracks that may lead to breaking of the annular plate ring.

Large size bearings which are self-aligning are difficult to seal since these bearings are made for handling large angular misalignments. For using seals in those types of bearings it is necessary to compromise. A typical maximum misalignment for a sealed off spherical roller bearing using conventional technology is 0.5 [deg.]. With large size self aligning bearings is intended self aligning bearings having an outer diameter above 500 mm.

A built in seal for a large size self-aligning bearings is proposed in WO2006/019347. This type of bearing requires additional space in an axial direction. Further the seal is somewhat sensitive due to the pliable nature of the bellow forming the seal for the bearing. Summary of the Invention

In view of the above-mentioned and other drawbacks of the prior art, a general object of the present invention is to provide an improved large size sealed self-aligning rolling bearing, and a method for manufacturing a large size sealed self-aligning rolling bearing, which obviates the need for a bellow as a built-in sealing member.

Another object is to provide a large size sealed self-aligning bearing, which allows for additional space for cages/retainers extending outside of the rolling bodies and/or which gives more space for the rolling bodies before the ring cage or rolling body interferes with the built-in sealing member. Still another object is to provide a sealed self-aligning bearing with an improved seal design for a large size bearing, allowing for improved alignment and positioning of the built-in sealing member in relation to the bearing rings.

These and other objects are met by the subject matters provided in the independent claims. Preferred embodiments of the invention are presented in the dependent claims.

According to a first aspect thereof, the present invention relates to a large sealed self-aligning rolling bearing comprising a first ring, a second ring, rolling elements, such as symmetrical or non-symmetrical rollers having spherical contacting surfaces, which are arranged in one or more rows between the first and second rings, and a built-in sealing member comprising an annular plate with a first periphery portion. Furthermore, the first ring comprises a mounting groove, wherein the first periphery portion is received in the mounting groove. In addition, the mounting groove comprises an axially inner side wall, and the first periphery portion of the annular plate comprises a first contacting surface arranged on an axially inner side of the annular plate, wherein the first contacting surface of the first periphery portion is arranged in abutment with the axially inner side wall, and a first resilient member is arranged in the mounting groove for sealing the mounting groove.

The invention is based on the realization by the inventors that a large size self-aligning bearing with improved sealing design and sealing

characteristics is provided by providing a built-in sealing member formed of an annular ring, and by arranging the first contacting surface of the first periphery portion of the annular ring to coincide with the axially inner side wall of the mounting groove. Thereby, fixation and positioning of the sealing member body formed of the annular ring in relation to the bearing rings is improved such that the sealing capability and cooperation between the bearing rings and the sealing member is enhanced.

By providing direct contact between the first contacting surface of the first periphery portion of the annular plate and the inner side wall of the mounting groove, the position and location of the built-in sealing member is defined and controlled with improved accuracy. During operating involving angular displacement between the first and second rings, the invention allows for improved and more accurate sealing pressure and cooperation between the sealing member, such as a radially inner lip portion of the sealing member, and a sealing surface having a relative rotational movement in relation to the sealing member. Also, for large size self-aligning rolling bearings, the configuration of the built-in sealing member, wherein the first contacting surface of the first periphery portion coincide with the axially inner side wall, allows for that the position of the rigid annular plate forming the body of the sealing member is locked and secured to the groove with increased accuracy and strength, such that undesired movements and bending motions of the sealing member in relation to the first ring is reduced.

The invention is further advantageous in that the built-in sealing member may be mounted and fitted into the mounting groove in an efficient and reliable manner. Moreover, the first resilient member advantageously allows for efficient mounting in the mounting groove, wherein the first contacting surface of the first periphery portion of the annular plate is secured and maintained in a durable manner in abutment with the axially inner side wall.

For large size self-aligning bearing, the cooperation enabling sealing functionality between the sealing member and a sealing surface, which sealing surface has a rotational movement in relation to the sealing member, takes place a relatively large distance from the mounting groove. The invention is advantageous in that such cooperation is improved by more accurately controlling the position of the portions of the sealing member which are located a relatively large distance from the mounting groove, for example at a location of a sealing surface arranged on the second ring.

A large sealed self-aligning rolling bearing is a bearing having an external diameter of 500 mm or more.

A built-in sealing member is a sealing member which is attached directly to one of the bearings rings, i.e. the first or second ring, which rings are monolithic annular bodies at which the raceways for the rolling elements are formed.

According to an exemplifying embodiment, the first periphery portion is formed of the radially outer portion of the annular plate and the first ring is the outer ring. However, the first periphery portion may also be formed of the radially inner portion of the annular plate and the first ring may be the inner ring of the bearing.

According to an exemplifying embodiment, the first periphery portion of the annular plate comprises a second contacting surface arranged on an axially outer side of the annular plate, wherein the first resilient member is attached on the second surface of the first periphery portion. By attaching the first resilient member on the axially outer side of the annular plate, correct position and mounting of the resilient member and annular plate is

advantageously provided. Also the sealing member and the first resilient member may advantageously be mounted simultaneously as a single unit forming the sealing member. Furthermore, the first resilient member may advantageously be attached to the annular plate in the correct position only on the second contacting surface during an attachment step, which

attachment step precedes the mounting of the built-in sealing member in the mounting groove of the first ring.

According to an exemplifying embodiment, the first periphery portion of the annular plate further comprises a top surface, wherein the first resilient member is further attached on the top surface. Hence, in a similar manner, the first resilient member may advantageously be attached to the annular plate in the correct position only on the second contacting surface and the top surface. According to yet an exemplifying embodiment, the first resilient member is formed from a band-shaped element folded to form a ring and attached to the annular plate member.

According to an exemplifying embodiment, the first contacting surface is free from resilient material, such that that the first contacting surface of the annular plate is in direct abutment with the inner side wall of the mounting groove.

According to an exemplifying embodiment, the large sealed self- aligning rolling bearing further comprises a locking ring which is inserted into the mounting groove axially outside the first periphery portion of the annular plate for securing the sealing member in the mounting groove. The locking ring advantageously forms a retaining element securing the built-in sealing member in the mounting groove in a reliable manner, such that the contacting interface between the first contacting surface and the inner side wall of the mounting groove is maintained during operation involving angular

displacement of the bearing. Also, the locking ring facilitates and enables cost-efficient mounting/demounting and maintenance.

According to an exemplifying embodiment, the first resilient member is arranged between the first periphery portion and the locking ring. Hence, the first resilient member is arranged in an advantageous compressed state between the annular plate and the locking ring, wherein the first resilient member, due to its compressed state, exerts a pressing force on the annular plate such that it is forced and retained in the correct position in relation to the inner side wall of the mounting groove. Also, the frictional force between the inner side wall of the mounting groove and the fist contacting surface of the annular plate advantageously allows for improved fixation of the sealing member.

According to an exemplifying embodiment, the mounting groove comprises an axially outer side wall extending circumferentially around the first ring, wherein the locking ring is arranged in abutment with the axially outer side wall. By arranging the locking ring in direct contact with the outer side wall of the mounting groove, the correct position of the locking ring in relation to the first resilient member and the annular plate may be ensured in an advantageous manner.

According to an exemplifying embodiment, the first resilient member includes protrusions on an axially outer side facing from the annular plate, which protrusions engages with the locking ring to allow a for a reliable mounting of said sealing member. Advantageoulsy the protrusions cooperate with the locking ring and allows for improved accuracy of resilient

characteristics of the first resilint member such that suitable retainmenment with suitable compression of the first resilient member may be provided, which in turn provides suitable axial clamping forces fixating the sealing member.

According to an exemplifying embodiment, the mounting groove is situated inside a side plane of the first race ring and is arranged to taper at an angle relative to the side plane. This allows for a compact bearing solution and a durable attachment of the built-in sealing member to the first ring.

By providing a tapered mounting groove, the axially inner side wall extending circumferentially around the first ring forms a conical surface against which the first contacting surface of the first periphery portion of the annular plate is arranged.

According to an exemplifying embodiment, the first periphery portion and a mid section of the annular plate are joined at a first knee at which first knee the first periphery portion and mid section forms a tapering angle with respect to each other.

According to an exemplifying embodiment, the mounting groove has an opening on the inner periphery of the first race ring which opening is situated outside a race track of the first race ring and a closed inner end which lies at a radial distance R and axially inside said opening. In more detail, the inner end is situated fully, or at least partially, axially inside an outer axial limit of said race track in the first race ring. This allows for a particularly compact design of the bearing.

According to an exemplifying embodiment, the annular plate of the sealing member further comprising a second periphery portion, and the second ring comprises a sealing surface, wherein a second resilient member is attached to the second periphery portion for sealing abutment with the sealing surface on the second ring, which first and second separate resilient members are spaced apart to leave an annular land in a midsection of the annular plate in between the separate first and second resilient members.

According to an exemplifying embodiment, the annular land is free from resilient material on both sides of the annular plate.

At this mid section, the built-in sealing member will have the thickness of only the annular plate itself, which increases the space available for the rolling elements and/or of a cage restricting the movement of the rolling elements. Misalignment can therefore be accepted to a larger degree before e.g. a roller or a cage will interfere with the sealing member. Hence, a more compact bearing can be designed, which may house a wider rolling element body in relation to the total axial extension of the roller bearing.

Hence, by providing a built in sealing member where separate resilient members are arranged at respective periphery portions of the annular plate, a self aligning roller bearing is provided, which gives additional space for ring cages extending outside of the rolling bodies or which gives more space for the rolling bodies before the ring cage or rolling body interferes with the built- in sealing member.

The resilient members may be produced by turning a ring shaped element. The ring may then be cut and subsequently adhered to the annular plate ring. The resilient members could also be extruded to either a band- shaped element or a ring shape. The band-shaped elements may then be cut in appropriate lengths to be adhered onto the annular plate ring. The resilient members may be adhered in many different ways, such as gluing or spot vulcanization around the annular plate, i.e. there is no need of large vulcanization tools.

For spherical roller bearings, the sealing surface may, according to exemplifying embodiment, be cone-shaped with its decreasing radius being directed from the centre of the roller bearing. The sealing surface may also, according to an embodiment, have a spherical surface shape.

For example, the first and second periphery portions are respectively constituted by a radially outer part of the annular plate positioned away from the centre axis of the annular plate and a radially inner part of the annular plate positioned toward the centre axis of the annular plate. The annular plate may have a flat or a curved cross section. The shape of the annular plate will generally be designed to reduce the amount that the sealing member protrudes from a side plane defined by the sides of the first and seocnd rings or to allow a portion of the built in sealing member to be flush with or lie at a small axial distance inside the side plane defined by the sides of the rings.

According to yet an exemplifying embodiment, the second periphery portion and mid section are joined at a second knee, at which second knee the second periphery portion and mid section forms an angle with respect to each other. The plate ring may have a curved or flat cross-section between the knees.

According to an exemplifying embodiment the mid section is parallel with a side plane of said first race ring and/or a side plane of said second race ring. For example, the mid section is flush with or lies at a small axial distance inside the side plane of the first race ring and/or a the plane of the second race ring.

For example, according to an embodiment, at least the second periphery portion will be inclined toward a centre of the roller bearing. When the built-in sealing member is mounted in the mounting groove, the mid portion will be the part of the built in sealing member, which is located at the largest distance in an axial direction from the centre of the roller bearing. This means that by providing a mid section that is free from resilient material, the plate ring of built-in member can be located further away from the centre of the rolling bearing.

According to an exemplifying embodiment, the second resilient member includes a lip portion extending outwardly from the annular plate to be in abutment with the sealing surface, and an attachment portion for attachment of the second resilient member to the second periphery portion, wherein a length extension of the lip portion and the attachment portion are essentially the same. According to an exemplifying embodiment the first and second resilient members are each formed from a band-shaped element folded to form a ring and attached to respective periphery portions of the annular plate.

According to an exemplifying embodiment each of the first and second resilient members includes a joint, which joints are circumpherentially displaced in relation to each other. By circumpherentially displacing the joints, any imbalance due to the joints may be reduced.

According to an exemplifying embodiment, the large sealed self- aligning rolling bearing is a spherical roller bearing. According to an

alternative exemplifying embodiment, the large sealed self-aligning rolling bearing is a toroidal roller bearing. The large sealed self-aligning rolling bearing may also, according to an embodiment, be a spherical roller thrust bearing.

For large self aligning roller bearings, the annular plate is preferably roll formed, or press formed, from a sheet metal workpiece. It has shown to be difficult to form the annular plate with other technologies while maintaining high tolerances and preventing crack initiation for large self aligning roller bearings.

According to a second aspect thereof, the present invention relates to a method for manufacturing a large sealed self-aligning rolling bearing comprising a first ring and a second ring, and rolling elements arranged in one or more rows between the first and second rings, which method

comprises providing a built-in sealing member comprising an annular plate, which annular plate comprising a first periphery portion provided with a first resilient member, attaching the built-in sealing member to the first ring by receiving the first periphery portion and the first resilient member in a mounting groove provided in the first ring, and arranging a first contacting surface of the first periphery portion which is arranged on an axially inner side of the annular plate in abutment with an axially inner side wall of the mounting groove.

The method provides an improved and more compact bearing and sealing member arrangement which is advantageous in similar manners as described in relation to the first aspect of the present invention. The step of attaching the resilient members to the annular plate may preferably be made by an adhesive.

According to an exemplifying embodiment, the method further comprises attaching the first resilient member on a second contacting surface of the first periphery portion of the annular plate, which second contacting surface is arranged on an axially outer side of the annular plate.

According to an exemplifying embodiment, the method further comprises securing the built-in sealing member to the first ring by inserting a locking ring into the mounting groove axially outside the first periphery portion of the annular plate.

Generally, other objectives, features, and advantages of the present invention will appear from the following detailed disclosure, from the attached dependent claims as well as from the drawings are equally possible within the scope of the invention.

Brief Description of Drawings

Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, wherein:

Fig. 1 is a partial schematic cross-sectional view of an embodiment of the bearing with sealing member according to the present invention.

Fig. 2 is a schematic enlarged cross-sectional view of the embodiment of the bearing and sealing member in Fig. 1.

Fig. 3 is a partial schematic cross-sectional view of the sealing member according to an embodiment of the present invention.

Fig. 4 is a partial schematic cross-sectional view of the locking ring for securing the sealing member in the mounting groove, according to an embodiment of the present invention.

It should be understood that the drawings are not true to scale and, as is readily appreciated by a person skilled in the art, dimensions other than those illustrated in the drawings are equally possible within the scope of the invention.

Detailed Description of Embodiments of the Invention

In the drawings, similar, or equal elements are referred to by equal reference numerals.

In Fig. 1 , a partial cross-sectional view of a large size sealed self- aligning rolling bearing 100 is illustrated. An enlarged view is shown in Fig. 2. The bearing 100 comprises a first ring 1 forming the outer ring, a second ring

2 forming the inner ring, and rolling elements 3 in the form of having rollers spherical raceway-contacting surface. The rings 1 , 2 and the rolling elements

3 are typically formed by steel.

The bearing 100 also has a built-in sealing member 4 formed by an annular plate 10 having a first periphery portion 1 formed of a portion of the annular plate 10 being located at an radially outer end of the annular plate 10. In addition, the first ring 1 comprises a mounting groove 5, wherein the first periphery portion 11 is received in the mounting groove 5. The mounting groove 5 comprises an axially inner side wall 6, and the first periphery portion 11 comprises a first contacting surface 11a on an axially inner side of the annular plate 10, as defined in the main axial direction of the bearing 100.

As illustrated in Figs. 1 and 2, the first contacting surface 1a of the first periphery portion 11 is arranged in abutment with the axially inner side wall 6. In more detail, the axially inner side wall 6 forms a conical ring-shaped surface extending circumferentially around the first ring 1 and is in direct contact with the corresponding coinciding first contacting surface 11a of the first periphery portion 11. As shown, a contacting interface is formed between the inner side wall 6 and the first contacting surface 11a, which contacting interface extends at a tapered angle A from the outer radial end of the axially inner side of the annular plate 11 to the radially inner end of the axially outer side wall 6. For example, the tilted angle A is between 7 and 27 degrees, or between 12 and 22 degrees, or about 17 degrees +/- up to 2 degrees. The radial extension of the contacting interface between the inner side wall 6 and the first contacting surface 1 a may for example be in the range between 1/20 and 1/3 of the radial extension of the cross-section of the annular plate 10 between the edges of the first and second periphery portions 11 and 12, or in the range between 1/10 and 1/4 of the radial extension of the cross-section of the annular plate 10 between the edges of the first and second periphery portions 11 and 12.

As further shown, the first periphery portion 11 of the annular plate 10 comprises a second contacting surface 11b arranged on an axially outer side of the annular plate 10, such that the second contacting surface 11b is arranged on an external side of the annular plate 10 facing away from the interior of the bearing 100.

A first resilient member 20, e.g. formed of a suitable elastomer or rubber material, is provided in direct contact with the first periphery portion 11 of the annular plate 10 and arranged in the mounting groove 5. In more detail the first resilient member 20 is attached to and covers the second contacting surface 11 b and a top surface 11c (shown in Fig. 3) of the first periphery portion 11. Furthermore, the first contacting surface 11a of the first periphery portion is not in contact with or covered by the resilient member 20, or any resilient material. This allows for a direct contact and a coinciding contact interface between the first contacting surface 11a and the axial inner side wall 6 in the mounting groove 5.

The large sealed self-aligning rolling bearing 100 further comprises a locking ring 8 which is inserted into the mounting groove 5 externally of, i.e. axially outside, the first periphery portion 11 of the annular plate 10 for securing the sealing member 4 in the mounting groove 5. As illustrated, the first resilient member 20 is arranged between the first periphery portion 11 and the locking ring 8, such that, due to the limiting axial space in the mounting groove 5, the locking ring exerts a compressing force on the resilient member which is at least partially elastically deformed. In turn, the elastically deformed resilient member exerts a suitable axial clamping force on the first periphery portion 11a of the annular plate 10 such that it is retained in the correct position in abutment with the axially inner side wall 6 of the mounting groove 5.

As further illustrated with reference to Fig. 1 and Fig. 2, the mounting groove 5 is situated axially inside a side plane 101 of the first ring 1.

Moreover, the mounting groove 5 has an opening 5a on the inner periphery 30 of the first ring 1 , which opening 5a is situated outside a race track 31 of the first ring 1 and a closed inner end 5b. Moreover, the closed inner end 5b lies at a radial distance R in relation to an outer end of the race track 31 and is axially shifted a distance L in an axial direction toward a centre of the bearing 00 to preferably be located inside said opening 5b. This allows for a particularly compact design of the bearing. In close proximity to the opening 5a, the first ring comprises an insertion surface 40. The insertion surface 40 is provided circumferentially around and radially outside the annular opening 5b and is arranged to faciliate the insertion of the sealing member 4 and/or locking ring 8 into the mounting groove 5. In more detail, the insertion surface 40 guides the sealing member and/or locking ring into the correct position and alignment in the mounting groove during mounting. As illustrated, the insersion surface forms a conical surface and has a tapering angle B in relation to a plane 102 being parallell with the bearing axis. The insertion surface also facilitates insertion of the sealing member 4 without breaking the first resilient member 20. In more detail, the first resilient member 20 may be guide into the correct position while being gently elastically deformed by the insertion surface 40.

In a similar manner as described with reference to first ring 1 forming the outer ring, the second ring 2 forming the inner ring comprises an inner periphery 32. As illustrated, the inner periphery 32 of the inner ring comprises a race track 33 for the rolling element 3, and a flange which is located axially outside the race track 33. Also, a guide ring 35 is provided axially outside the race track 33 on the other axial side. The inner periphery 32 further comprises a sealing surface 13 arrange to cooperate with the sealing member 4. The sealing surface 13 is arranged axially outside race track 33, but axially inside the side plane 101 of the first ring 1. In more detail, as shown with reference to Fig. 1 and Fig. 3, the annular plate 10 of the sealing member 4 comprises a second periphery portion 12 arranged in close proximity with the sealing surface. A second resilient member 21 is attached to the second periphery portion 12 for sealing abutment with the sealing surface 13 on the second ring 2. By arranging the first and second separate resilient members 20 and 21 in a spaced apart configuration on the annular plate, an annular land 22a is formed on an axially inner side of the annular plate 10, and an annular land 22b is formed on an axially outer side of the annular plate 10, which annular lands 22a and 22b are free from resilient material. In particular, the annular land 22a extends to the edge of the annular plate 10 on its axially inner side, thereby covering the first contacting surface 11a at the first periphery portion 11 of the annular plate 10.

The second resilient member 12 includes a lip portion 21a extending outwardly from the annular plate 10 towards the sealing surface 13, and an attachment portion 21b for attachment of the second resilient member 21 to the second periphery portion 12. The length extension forming the lip portion 21a and the attachment portion 21b are essentially the same.

As shown, the lip portion 21a is in contact with and arranged in sealing abutment with the sealing surface 13. During operation, wherein the second ring 2 and the sealing surface 13 have a relative rotational movement in relation to the sealing member 4 with is fixed to the first ring 1 , the increased accuracy of the position of the annular plate 10 provides improved sealing cooperation and contact pressure between the lip portion 21a and the sealing surface 13. Thereby, the contact pressure between the lip portion 21a and the sealing surface 13 may be controlled with higher accuracy during annular misalignment between the first and second rings 1 , 2. With increased accuracy of the sealing pressure, service life and maintenance forecasts may be improved.

As further illustrated in Fig. 1 and Fig. 3, the first periphery portion 11 and a mid section 22 of the annular plate 10 are joined at a first knee 23 at which first knee 23 the first periphery portion 11 and mid section 22 forms a tapering angle with respect to each other. In a similar manner, the second periphery portion 12 and the mid section 22 are joined at a second knee 24, at which second knee 24 the second periphery portion 12 and mid section 22 forms an angle with respect to each other. As shown, the mid section 22 is essentially parallell with the side plane 101 of the first ring 1 , and the second periphery portion 12 is inclined toward a centre of the roller bearing 100.

In Fig. 3, the sealing member 4 depicted and described in relation to Fig, 1 and Fig, 2, is shown in a separated view. As shown, the annular plate 10 which forms the body of the sealing member 4 comprises a top surface 11c which is covered by the first resilient member 20. The top surface 11c is the edge of the annular ring 10.

According to an exemplifying embodiment, the portion of the first resilient member covering the top surface 11c and being attached to the annular plate, may further extend axially towards the axially inner side wall of the mounting groove and frictionally engage the side wall so as to further improve the fixation of the annular plate in its correct position in relation to the first ring.

The portion of the first resilient member covering the top surface 11c and being attached to the annular plate, may further be arranged such that it fully occupy the space in the mounting groove. Thereby improved fixation may be provided by increased contacting surface between the first resilient member and the side walls of the mounting groove. Also, no space or void is formed in the mounting groove radially outside the annular plate.

The elastic deformation of the first resilient member 20 providing the retaining clamping force of the sealing member 4 in the mounting groove may be an inherent capability of the resilient material of which the first resilient member 20 is formed. However, as shown, the first resilient member 20 may also include protrusions 20a, 20b, 20c on a side of the first resilient member 20 facing from the annular plate ring 7, which protrusions are arranged to engage with a side wall of the locking ring 8 (see Fig. 2) to allow for a secure mounting of said sealing member. In more detail, the protrusions 20a and 20b are arranged axailly outside the second contacting surface 11 b of the annular plate 0, while protrusion 20c is arranged radially beyond the second contacting surface 11b and the top surface 11c of the annular plate 10. The first and/or second resilient members 20 and 21 may for example be based on a nitrile butadiene rubber (NBR) which is a family of synthetic rubber copolymers of acrylonitrile and butadiene, or a hydrogenated nitrile butadiene rubbers (HNBR) which are saturated copolymers of acrylonitrile and butadiene, or an elastomer based on fluoro rubbers which have good resistance to heat, weathering and many other chemicals, or a carboxylated nitrile rubber, or a EPDM rubber (ethylene propylene diene monomer (M- class) rubber). The first and/or second resilient members 20 and 21 may also be formed from a polyurethane-based material.

In Fig. 4, a schematic partial cross-sectional view of the locking ring 8 depicted and described in relation to Fig. 1 and Fig. 2, is shown in a separated view. The drawing is not true to scale.

As shown, the locking ring 8 has an annular shape extending circumferentially around a center axis indicated by center line 103.

Furthermore, the locking ring 8 has a tapering shape having a tapering angle C. For example, the tapering angle C may be little smaller than the tapering angle A of the mounting groove 5 (see Fig. 1). This allows for a preload between the locking ring 8 and the first resilient member 20 which clamps the sealing member 4. For example, the locking ring is forced, or wedged, into its locking position in the mounting groove such that the first resilient member is deformed, which deformation give rise to a clamping force securing the first periphery portion of the annular member against the axially inner side wall of the mounting groove.

It is also possible to use a locking ring having a tapering angle C = 0 DEG, i.e. such that the locking ring is not tapering.

As further shown, the locking ring comprises an axially outer side 8a arranged to engage and to be in abutment with the axially outer side wall 7 of the mounting groove 5, and an axially inner side 8b arranged to engage and to be in abutment with the protrusions 20a, 20b, and 20c of the first resilient member 20.

It should be noted that the invention has mainly been described above with reference to a few embodiments. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the invention, as defined by the appended patent claims.

In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single apparatus or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain features or method steps are recited in mutually different dependent claims does not indicate that a combination of these features or steps cannot be used to advantage.