Patent Description:
Centrifugal separators commonly comprise a centrifuge rotor mounted to a typically vertical spindle driven by a drive unit located beneath the centrifuge rotor. The centrifuge rotor typically has a relatively large weight in comparison to the drive unit. In addition, the centrifuge rotor is configured to receive a large amount of the product to be separated. The mass carried by the spindle during operation of the centrifugal separator is thus significant. Relatively small imbalances of the centrifuge rotor may create problems during operation, in particular when, during up-start, the centrifuge rotor has to pass the critical rotational speed in order to achieve the most appropriate supercritical rotational speed for the desired separation efficiency.

<CIT> discloses a centrifugal separator comprising a centrifugal drum and a drive spindle rotatably mounted in a drive housing by a neck bearing and a foot bearing. The drive housing encloses a drive chamber and an electric motor which has a stator and a motor rotor. The motor rotor is disposed on the drive spindle and the stator is fixedly connected to the drive housing. An air gap exists between the stator and the motor rotor. The stator and the motor rotor are arranged between the neck bearing and the foot bearing. The foot bearing is designed as a pivot bearing and axially supports the centrifugal drum. The neck bearing is radially supported, via at least one elastic element, in a bearing housing which in its turn is fastened on the drive housing. The elastic element consists of two metal sleeves which are interconnected by means of a ring consisting of elastomer material.

The elastic elements of <CIT> that support the neck bearing permit the spindle to make small radial movements during operation. However, the design may result in the spindle being slightly tilted when it is moved radially from a geometric center axis. The elastic elements supporting the neck bearing do not seem to be configured to compensate for such tilting. The tilting of the spindle may thus result in forces striving to rotate the inner and outer bearing rings of the neck bearing around a transversal axis in relation to each other, which may cause premature wear of the neck bearing.

<CIT> discloses a centrifugal separator which is suitable for heavy duty applications and comprises a frame, a spindle and centrifuge rotor on the spindle. The centrifuge rotor comprises a rotor casing forming an inner separation space, an inlet for supply of a fluid and an outlet for discharge of a separated component. A drive motor having a stator and a rotor drives the spindle and the centrifuge rotor. The motor rotor is supported by a first bearing and second bearing. A coupling member connects the motor rotor and the spindle for transmitting a rotary movement from the motor rotor to the spindle. A third bearing supports the spindle so that it is radially elastic in relation to the frame for transmitting a first part of radial forces between the spindle and the frame. The coupling member comprises a lamella coupling or a universal coupling, and transmits a second part of the radial forces, which exists between the spindle and the frame, to the frame via the motor rotor and the first and the second bearings.

Spherical bearings may be used for supporting a rotating shaft that must move both rotationally and at a small angle. However, spherical bearings may be complex and expensive. There is therefore a need in the art for further, less complex solutions for supporting a rotating shaft in different kinds of apparatuses.

The object of the present invention is to overcome the problems discussed above. In particular, it is aimed at a bearing member permitting tilting, or slight tilting, of a spindle during operation.

As an aspect of the present invention, there is provided the centrifugal separator initially defined, which is characterised in that that the upper bearing housing is mounted to the stationary frame via the elastic member and an upper tilting member permitting the spindle to tilt in relation to the central axis during operation of the centrifugal separator, wherein the elastic member and the upper tilting member are arranged one after the other in a radial direction.

According to an embodiment of the invention, the elastic member is located radially outside the tilting member. Alternatively, the elastic member may be located radially inside the tilting member.

By means of the upper tilting member, the forces, acting on the at least one bearing of the upper bearing housing and striving to rotate the bearing rings of the at least one bearing to each other and around a transversal axis, may be displaced from the bearing and radially outwards to the upper tilting member, which in turn permits the bearing housing to tilt in relation the central axis. Thus, torsional forces transverse to the spindle acting on the at least one bearing of the upper bearing housing when the spindle is tilted may be considerably reduced in comparison with the upper bearing housing being mounted directly, or only via the elastic member, in the stationary frame. Consequently, there may be no relative rotating movements between an inner bearing ring and an outer bearing ring of the one of more bearings of the upper bearing housing even if the spindle is tilted. The at least one bearing of the upper bearing housing may thus operate under low-force conditions even if the spindle is tilted. Moreover, the wear of the elastic member may be reduced in comparison with the upper bearing housing being mounted only via the elastic member in the stationary frame due to the reduced torsional forces. Consequently, there may be no relative rotating movements between an inner bearing ring and an outer bearing ring of the one of more bearings of the upper bearing housing even if the spindle is tilted.

According to an embodiment of the invention, the upper bearing housing is located between the rotating member of the drive unit and the centrifuge rotor.

According to an embodiment of the invention, the upper tilting member comprises a pack of annular disks extending around the upper bearing housing and being attached to the upper bearing housing and to the elastic member.

The pack of annular disks may be flexible. Each one of the annular disks may be flexible. The annular disks may adjoin each other in the pack of annular disks.

When subjected to bending stress, a tilting member comprising a pack of annular disks will bend easily in comparison with a tilting member made from one piece of homogenous material. Moreover, when a tilting member comprising a pack of annular disks is subjected to uniaxial stress, it is as strong as a tilting member made from one piece of homogenous material. Thus, the tilting member comprising a pack of annular disks provides the bendability to reduce the torsional load on the at least one bearing while being strong enough to support the spindle via the upper bearing housing.

According to an embodiment of the invention, the pack of annular disks of the upper tilting member is attached to the upper bearing housing by at least three primary attachment members equidistantly separated from each other around the annular disks, and attached to the elastic member by at least three secondary attachment members each being positioned between a respective pair of adjacent primary attachment members.

Such an alternating attachment of the pack of annular disks to the upper bearing housing and to the elastic member may ensure a rigid attachment to the upper bearing housing and to the elastic member, and a flexibility permitting the upper bearing housing and the spindle to tilt.

According to an embodiment of the invention, the pack of annular disks of the upper tilting member is attached to the stationary frame by at least three primary attachment members equidistantly separated from each other around the annular disks, and attached to the elastic member by at least three secondary attachment members each being positioned between a respective pair of adjacent primary attachment members.

Also such an alternating attachment of the pack of annular disks to the stationary frame and to the elastic member may ensure a rigid attachment to the stationary frame and to the elastic member, and a flexibility permitting the upper bearing housing and the spindle to tilt.

According to an embodiment of the invention, each of the primary and secondary attachment members comprises a screw bolt extending through a respective aperture through the pack of annular disks of the upper tilting member. Such screw bolts permit an easy and efficient mounting of the pack of annular disks to the upper bearing housing and the elastic member.

According to an embodiment of the invention, the at least one bearing comprises a first bearing comprising an outer bearing ring attached to the upper bearing housing and an inner bearing ring attached to the spindle, a second bearing comprising an outer bearing ring attached to the upper bearing housing and an inner bearing ring attached to the spindle, and possibly a third bearing comprising an outer bearing ring attached to the upper bearing housing and an inner bearing ring attached to the spindle. By arranging a number of bearings, i.e. at least the first bearing and the second bearing, in the upper bearing housing, a rigid support of the spindle is achieved.

According to an embodiment of the invention, the centrifugal separator comprises a lower bearing housing mounted to the stationary frame and supporting at least one bearing comprising an outer bearing ring attached to the lower bearing housing and an inner bearing ring attached to the spindle. The lower bearing housing may be provided outside the rotating member of the drive unit. The lower bearing housing and the at least one bearing may contribute to a more rigid support of the spindle and the centrifuge rotor.

According to an embodiment of the invention, the lower bearing housing is mounted to the stationary frame via a lower tilting member permitting the spindle to tilt in relation to the central axis_during operation of the centrifugal separator.

By means of the lower tilting member, the forces, acting on the at least one bearing of the lower bearing housing and striving to rotate the bearing rings of the at least one bearing in relation to each other and around a transversal axis, may be displaced from the bearing and radially outwards to the lower tilting member. The at least one bearing of the lower bearing housing may thus operate under low-force conditions even if the spindle is tilted. _Consequently, there may be no relative rotating movements between an inner bearing ring and an outer bearing ring of the one of more bearings of the lower bearing housing even if the spindle is tilted.

According to an embodiment of the invention, the lower tilting member comprises a pack of annular disks extending around the lower bearing housing and being attached to the lower bearing housing and to the stationary frame. In contrast to the upper tilting member, the lower tilting member may thus be attached directly to the stationary frame without any intermediate elastic member.

The pack of annular disks or the lower tilting member may be flexible. Each of the annular disks may be flexible. The annular disks may adjoin each other in the pack of annular disks of the lower tilting member.

When subjected to bending stress, a tilting member comprising a pack of annular disks will bend easily in comparison with a tilting member made from one piece of homogenous material. Moreover, when a tilting member comprising a pack of annular disks is subjected to uniaxial stress, it is as strong as a tilting member made from one piece of homogenous material. Thus, the tilting member comprising a pack of annular disks provides the bendability to reduce the torsional load on the at least one bearing while being strong enough to support the spindle via the lower bearing housing.

According to an embodiment of the invention, the pack of annular disks of the lower tilting member is attached to the lower bearing housing by at least three primary attachment members equidistantly separated from each other around the annular disks, and to the stationary frame by at least three secondary attachment members each being positioned between a respective pair of adjacent primary attachment members. This alternating attachment of the pack of annular disks to the lower bearing housing and the stationary frame ensures a rigid attachment to the lower bearing housing and to the stationary frame, and a flexibility permitting the lower bearing housing and the spindle to tilt.

According to an embodiment of the invention, each of the primary and secondary attachment members attaching the lower tilting member comprises a screw bolt extending through a respective aperture through the pack of annular disks of the lower tilting member, wherein the screw bolts of the primary attachment members extend through the pack of annular disks in a first axial direction and the screw bolts of the secondary attachment members extend through the pack of annular disks in an opposite second axial direction. The screw bolts permit an easy and efficient mounting of the pack of annular disks to the lower bearing housing and the stationary frame.

According to an embodiment of the invention, the at least one bearing of the lower bearing housing comprises a first bearing comprising an outer bearing ring attached to the lower bearing housing and an inner bearing ring attached to the spindle, a second bearing comprising an outer bearing ring attached to the lower bearing housing and an inner bearing ring attached to the spindle, and possibly a third bearing comprising an outer bearing ring attached to the lower bearing housing and an inner bearing ring attached to the spindle. By arranging a number of bearings, i.e. at least the first bearing and the second bearing, in the lower bearing housing, a rigid support of the spindle is achieved.

According to an embodiment of the invention, the lower bearing housing comprises a lower convex spherical surface supported by a concave spherical surface provided on the stationary frame. The spherical surfaces may provide a lower support for the spindle and may provide a tilting point around which the spindle may tilt.

According to an embodiment of the invention, the rotating member of the drive unit is mounted on the spindle between the upper bearing housing and the lower bearing housing. The rotating member may thus be fixed to the spindle, which may be supported at both an upper end and a lower end of the rotating member.

According to an embodiment of the invention, the drive unit comprises an electric motor having a stator attached to the stationary frame and a motor rotor.

According to an embodiment of the invention, the rotating member comprises the motor rotor. The motor rotor may thus be provided on and around the spindle.

According to an embodiment of the invention, the spindle is hollow and surrounds the inlet for the product and/or the first outlet for the relatively light component. However, in embodiments, the spindle is solid.

The tilting member as discussed above may also be used in other applications than centrifugal separators. Thus, as a further aspect of the invention, there is provided a bearing member for supporting a rotatable axle, comprising.

The tilting member is thus arranged for attaching a bearing housing to a stationary machine element to allow the bearing housing to tilt in relation to its central axis (X). The rotational axis of the at least one bearing may thus be parallel to the normal of the plane formed by the annular discs when the tilting member is mounted around the bearing housing.

This aspect is thus based on the inventor's insight that the tilting member with its disc pack may be used to hold a bearing in position. The disc pack is stiff in radial and polar direction but may be flexible in the axial direction. Due to this, the tilting torque is low. The disc pack contains multiple discs connected with sleeve elements. This is an advantage since multiple discs have a lower bending resistance than one disc with the same height. The tilting member of the present disclosure allows for a simpler ball bearing or roller bearing, such as a cylindrical roller bearing, an angular contact bearing or ball bearing to be used in applications where a sophisticated and expensive spherical bearing have been used for accommodating both static and dynamic misalignment.

As discussed above, forces acting on at least one bearing of a bearing housing striving to rotate the bearing rings of the bearing to each other and around a transversal axis, may be displaced from the bearing and radially outwards to the upper tilting member, which in turn permits a bearing housing to tilt in relation the central axis. Thus, torsional forces transverse to a rotating shaft acting on the bearing a bearing housing when the rotating shaft is tilted may be considerably reduced in comparison with a bearing housing being mounted directly in the stationary frame. Consequently, the tilting member of the present disclosure may provide for decreasing the relative rotating movements between an inner bearing ring and an outer bearing ring of even if the rotating shaft to which the bearing supports is tilted. The bearing may thus operate under low-force conditions even if the rotational shaft is tilted.

Further, a tilting member comprising a pack of annular disks will bend easily in comparison with a tilting member made from one piece of homogenous material. Moreover, when a tilting member comprising a pack of annular disks is subjected to uniaxial stress, it is as strong as a tilting member made from one piece of homogenous material. Thus, the tilting member comprising a pack of annular disks provides the bendability to reduce the torsional load on a bearing while being strong enough to support the rotatable shaft via the bearing housing.

The pack of annular discs are thus stacked. The discs of the pack may have been pressed together, such as with a pressure of at least <NUM> kN, so as to assure that there is no small play between the discs. Further, also the sleeve elements may have been pressed together with the pack so as to assure that there is a tight fit between sleeve member and the pack of annular discs. When mounted on the bearing housing, the pack of annular discs may be pretensioned with a certain spring force.

The sleeve elements used for holding the stack of annular discs together may have a through-going hole for receiving a fastening means, such as a screw member. The apertures of the tilting member may be equidistantly spaced around the annular discs. Thus, the sleeve elements may be equidistantly spaced around the annular discs.

Further, the body of the tilting member may be the pack of annular discs, meaning that the pack of annular discs may form the major portion of the tilting member. Consequently, the portion of the tilting member forming the through hole for the bearing housing may be the pack of discs only.

In embodiments, the pack of annular discs comprises at least two annular discs, such as at least four annular discs, such as at least eight annular discs.

In embodiments, he annular discs are metal lamellas, such as steel lamellas.

In embodiments, the annular discs are made from cold rolled sheet metal, such as cold rolled steel.

In embodiments, the at least one fastening element is attaching the tilting member to the bearing housing in every second aperture of the tilting member.

In embodiments, the bearing is a roller bearing other than a spherical roller bearing.

In embodiments, the thickness of the individual annular discs in the pack of annular discs is less than <NUM>, such as less than <NUM>, such as less than <NUM>. All annular discs of the pack may be of the same thickness.

The annular discs of the pack may have the form of a closed polygon with a plurality of corners, and the apertures may thus be arranged in the corners. As an example, the annular discs may comprise more than four, such as more than six, such as eight or more corners.

As an example, the annular discs may have the form of an octagon. The octagon shape may thus enclose the through-hole for receiving the bearing housing.

Thus, the pack of annular disks of the tilting member extends around the bearing housing, or bearing retainer, and is also attached to the bearing housing. The fastening element may for example be a screw element. As an example, the pack of annular disks of the tilting member may be attached to the bearing housing by at least three primary attachment members equidistantly separated from each other around the annular disks.

The annular discs of the tilting member may thus form a through hole that is larger than the diameter of the at least one bearing.

In embodiments, the bearing is a roller bearing, such as a cylindrical roller bearing. The roller bearing may be a roller bearing other than a spherical roller bearing. Thus, the bearing may be a roller bearing that does not permit angular rotation around a central point in two angled directions.

In embodiments, the at least one bearing comprises an outer bearing ring attached to the bearing housing and an inner bearing ring arranged for attachment to a rotatable shaft, such as a spindle. The at least one bearing may for example be one, two or three bearings.

The present disclosure also provides the tilting member discussed herein above as such, i.e. there is provided a tilting member arranged for attaching a bearing housing to a stationary machine element to allow the bearing housing to tilt in relation to its central axis, wherein the tilting member comprises a pack of annular discs forming a through hole for receiving a bearing housing; wherein each of the annular discs comprises a plurality of apertures extending through each of the discs and wherein the tilting member further comprises a sleeve element provided in each of the apertures for holding the annular discs together as a stack and for receiving a fastening means for attaching the tilting member to said bearing housing or said stationary machine element.

As a further aspect, there is provided an apparatus comprising.

The apparatus may be any kind of apparatus comprising a rotatable shaft, such e.g. a wind turbine.

In embodiments, the apparatus is further comprising at least one fastening element attaching the tilting member to the bearing housing in every second aperture of the tilting member and attaching the tilting member to the stationary machine element in every second aperture of the tilting member.

As an example, the pack of annular disks of the tilting member may be attached to the bearing housing by at least three primary attachment members equidistantly separated from each other around the annular disks, and attached to the stationary machine element by at least three secondary attachment members each being positioned between a respective pair of adjacent primary attachment members.

Such an alternating attachment of the pack of annular disks to the bearing housing and to the stationary machine element may ensure a rigid attachment to the bearing housing and to the stationary machine element, and a flexibility permitting the bearing housing and the rotatable shaft to tilt.

In embodiments, each of the primary and secondary attachment members comprises a screw bolt extending through a respective aperture through the pack of annular disks of the tilting member. Such screw bolts permit an easy and efficient mounting of the pack of annular disks to the upper bearing housing and the elastic member.

The present invention will now be explained more closely by means of a description of various embodiments and with reference to the drawings attached hereto.

<FIG> discloses a first embodiment of a centrifugal separator <NUM> for processing a product by separating a relatively heavy component and a relatively light component from the product. The centrifugal separator <NUM> comprises a stationary frame <NUM> and a spindle <NUM> extending in parallel with a central axis x.

The spindle <NUM> is supported by the stationary frame <NUM> and permitted to rotate in relation to the stationary frame <NUM>. The central axis x extends through a lower end and an upper end of the centrifugal separator <NUM>, as indicated in <FIG>. It shall be noted that the centrifugal separator <NUM> may be used in another position than with the central axis x extending vertically as shown in <FIG>.

The stationary frame <NUM> may also comprise a suitable base element (not disclosed) permitting the stationary frame <NUM> and the centrifugal separator <NUM> to be positioned on a ground, a floor or the like.

The centrifugal separator <NUM> comprises a drive unit <NUM>, see also <FIG>, comprising a rotating member <NUM> mounted on the spindle <NUM>. The drive unit <NUM> is configured to rotate the spindle <NUM> in relation to the stationary frame <NUM>, essentially around the central axis x. The drive unit <NUM> may comprise an electric motor having a stator <NUM> attached to the stationary frame <NUM> and a motor rotor <NUM>. In the embodiments disclosed, the rotating member <NUM> comprises or forms the motor rotor <NUM> of the electric motor.

Furthermore, the centrifugal separator <NUM> comprises a centrifuge rotor <NUM> that is mounted to an upper end of the spindle <NUM> to rotate together with the spindle <NUM>. The centrifuge rotor <NUM> encloses a separation space <NUM>. The centrifuge rotor <NUM> may comprise a stack of separation disks <NUM> provided in the separation space <NUM>. The separation disks <NUM> may be frusto-conical.

An inlet <NUM> for the product extends to the separation space <NUM>. A first outlet <NUM> for the relatively light component and a second outlet <NUM> for the relatively heavy component extends from the separation space <NUM>. The second outlet <NUM> may comprise a plurality of peripheral ports that extend through the centrifuge rotor <NUM>.

The peripheral ports may be openable for intermittent discharge of the relatively heavy component, such as sludge, from the separation space <NUM>.

In the embodiments disclosed, the inlet <NUM> is located in the proximity of the lower end of the centrifugal separator <NUM>. The first outlet <NUM> is located in the proximity of the upper end of the centrifugal separator <NUM>.

The spindle <NUM> may be hollow and form an inner channel to the separation space <NUM>. In the embodiments disclosed, the inlet <NUM> for the product extends through the inner channel of the hollow spindle <NUM> to the inner space <NUM> of the centrifuge rotor <NUM>. Alternatively, the first outlet <NUM> for the relatively light component may extend through the hollow spindle <NUM>. According to a further alternative both the inlet <NUM> and the outlet <NUM> may be arranged to extend through the hollow spindle <NUM>.

According to a still further alternative, the spindle <NUM> may lack any inlet or outlet, wherein both the inlet <NUM> and the first outlet <NUM> may be located in the proximity of the upper end of the centrifugal separator <NUM>.

The centrifugal separator <NUM> also comprises an outer casing <NUM> attached to the stationary frame <NUM> and enclosing the centrifuge rotor <NUM>.

In the embodiments disclosed, the centrifugal separator <NUM> comprises an upper bearing housing <NUM> and a lower bearing housing <NUM>. The upper bearing housing <NUM> may be located between the rotating member <NUM> of the drive unit <NUM> and the centrifuge rotor <NUM>. The lower bearing housing <NUM> may be provided outside the rotating member <NUM> of the drive unit <NUM>, i.e. between the rotating member <NUM> of the drive unit <NUM> and the lower end of the centrifugal separator <NUM>.

The upper bearing housing <NUM> is mounted to the stationary frame <NUM>, see also <FIG>. In the embodiments disclosed, the upper bearing housing <NUM> supports a first bearing <NUM> comprising an outer bearing ring <NUM> attached to the upper bearing housing <NUM> and an inner bearing ring <NUM> attached to the spindle <NUM>, and a second bearing <NUM> comprising an outer bearing ring <NUM> attached to the upper bearing housing <NUM> and an inner bearing ring <NUM> attached to the spindle <NUM>. Roller elements <NUM> may be provided between the outer bearing ring <NUM> and the inner bearing ring <NUM>.

The first and/or second bearings <NUM>, <NUM> of the upper bearing housing <NUM> may be configured to provide radial support to the spindle <NUM>, and possibly also axial support in order to carry the load of the centrifuge rotor <NUM>.

The lower bearing housing <NUM> is mounted to the stationary frame <NUM>, see also <FIG>. In the embodiments disclosed, the lower bearing housing <NUM> supports a first bearing <NUM> comprising an outer bearing ring <NUM> attached to the lower bearing housing <NUM> and an inner bearing ring <NUM> attached to the spindle <NUM>, and a second bearing <NUM> comprising an outer bearing ring <NUM> attached to the lower bearing housing <NUM> and an inner bearing ring <NUM> attached to the spindle <NUM>. Roller elements <NUM> may be provided between the outer bearing ring <NUM> and the inner bearing ring <NUM>.

The first and/or second bearings <NUM>, <NUM> of the lower bearing housing <NUM> may be configured to provide radial support to the spindle <NUM>, and possibly also axial support in order to carry the load of the centrifuge rotor <NUM>.

The upper bearing housing <NUM> is mounted to the stationary frame <NUM> via an elastic member <NUM> permitting the upper bearing housing <NUM> and thus the spindle <NUM> to move radially during the rotation of the spindle <NUM>.

In the first embodiment, the upper bearing housing <NUM> is mounted to the elastic member <NUM> via an upper tilting member <NUM> permitting the spindle <NUM> to tilt in relation to the central axis x.

In the embodiments disclosed, the elastic member <NUM> comprises an annular elastic element <NUM> and a ring element <NUM>. The elastic element <NUM> is attached to the frame <NUM> and the ring element <NUM> is attached to the tilting member <NUM>.

The elastic element <NUM> may be made of a rubber material, such as e.g. nitrile rubber.

In the first embodiment, the elastic member <NUM> is located radially outside the tilting member <NUM>, wherein the elastic element <NUM> may be located outside the ring element <NUM>.

In addition to the elastic member <NUM> and the tilting member <NUM>, the upper bearing housing <NUM> may be supported by a plurality of spring elements <NUM> circumferentially distributed around the spindle <NUM>. The spring elements <NUM> may rest against an upper intermediate wall <NUM> of the stationary frame <NUM> and may support the upper bearing housing <NUM> from beneath, as can be seen in <FIG>, <FIG> and <FIG>. The spring elements <NUM> permit the upper bearing housing <NUM> to move resiliently in an axial direction.

The upper tilting member <NUM> may comprise a pack of annular disks <NUM> extending around the upper bearing housing <NUM> and being attached to the upper bearing housing <NUM> and to the ring element <NUM> of the elastic member <NUM>, see <FIG> and <FIG>.

The pack of annular disks <NUM> may comprise a plurality of annular disks <NUM>, which may be identical with each other. Each of the annular disks <NUM> may be made from cold rolled sheet metal. Thus, a strong and flexible upper tilting member <NUM> may be provided, which has superior material properties in the context of the herein discussed tilting member as compared to hot rolled sheet metal. The annular disks <NUM> may be made from steel, such as stainless steel, spring steel, or similar, i.e. such as cold rolled steel sheet, cold rolled stainless steel sheet, cold rolled spring steel sheet, etc. A body of the upper tilting member <NUM> may be made up of annular disks <NUM> only.

In the embodiments disclosed, the pack of annular disks <NUM> comprises eight equidistant apertures extending through each of the annular disks <NUM>. A respective sleeve element <NUM> is provided in each of the apertures. The sleeve element <NUM> is configured to keep the annular disks <NUM> together, and thus to ensure the integrity of the pack upper tilting element <NUM>. Each of the sleeve elements <NUM> has a through-going hole as can be seen in Figs and <NUM>.

In the first embodiment, the pack of annular disks <NUM> of the upper tilting member <NUM> is attached to the upper bearing housing <NUM> by four primary attachment members <NUM> equidistantly separated from each other around the annular disks <NUM>, see <FIG>. In particular, the upper tilting member <NUM> may be attached to four radially extending projections <NUM>' of the upper bearing housing <NUM>, see <FIG>.

Furthermore, the pack of annular disks <NUM> of the upper tilting member <NUM> may be attached to ring element <NUM> of the elastic member <NUM> by four secondary attachment members <NUM> each being positioned between a respective pair of adjacent primary attachment members <NUM>, see <FIG>. In particular, the upper tilting member <NUM> may be attached to four radially extending projections <NUM>' of the ring element <NUM>, see <FIG> and <FIG>.

Each of the primary and secondary attachment members <NUM>, <NUM> may comprise a screw bolt extending through the hole of the sleeve element <NUM> of a respective one of the apertures through the pack of annular disks <NUM> of the upper tilting member <NUM>, wherein the screw bolts of the primary attachment members <NUM> may engage a respective threaded hole into a respective one of the projections <NUM>' of the upper bearing housing <NUM> and the screw bolts of the secondary attachment members <NUM> may engage a respective threaded hole into a respective one of the projections <NUM>' of the ring element <NUM> of the elastic member <NUM>.

The lower bearing housing <NUM> may be mounted to the stationary frame <NUM> via a lower tilting member <NUM> permitting the spindle <NUM> to tilt in relation to the central axis x. In the embodiments disclosed, the lower tilting member <NUM> comprises a pack of annular disks <NUM> extending around the lower bearing housing <NUM>. The pack of annular disks <NUM> are attached to the lower bearing housing <NUM> and to the stationary frame <NUM>, as can be seen in <FIG> and <FIG>.

Also the pack of annular disks <NUM> at the lower tilting member <NUM> may comprise a plurality of annular disks <NUM>, which may identical with each other. Thus, a strong and flexible lower tilting member <NUM> may be provided, which has superior material properties in the context of the herein discussed tilting member as compared to hot rolled sheet metal. The annular disks <NUM> may be made from steel, such as stainless steel, spring steel, or similar, i.e. such as cold rolled steel sheet, cold rolled stainless steel sheet, cold rolled spring steel sheet, etc. A body of the lower tilting member <NUM> may be made up of annular disks <NUM> only.

In the embodiments disclosed, the pack of annular disks <NUM> comprises eight equidistant apertures extending through each of the annular disks <NUM>. A respective sleeve element <NUM> is provided in each of the apertures. The sleeve element <NUM> is configured to keep the annular disks <NUM> together, and thus to ensure the integrity of the pack lower tilting element <NUM>. Each of the sleeve elements <NUM> has a through-going hole as can be seen in <FIG>.

In the embodiments disclosed, the pack of annular disks <NUM> of the lower tilting member <NUM> is attached to the lower bearing housing <NUM> by four primary attachment members <NUM> equidistantly separated from each other around the annular disks <NUM>, see <FIG>. In particular, the lower tilting member <NUM> may be attached to radially extending projections <NUM>' of the lower bearing housing <NUM>, see <FIG>.

Furthermore, the pack of annular disks <NUM> may be attached to the stationary frame <NUM> by four secondary attachment members <NUM> each being positioned between a respective pair of adjacent primary attachment members <NUM>, see <FIG>.

Each of the primary attachment members <NUM> and the secondary attachment members <NUM> attaching the lower tilting member <NUM> comprises a screw bolt extending through the hole of the sleeve element <NUM> of a respective one of the apertures through the pack of annular disks <NUM> of the lower tilting member <NUM>.

The screw bolts of the primary attachment members <NUM> may extend through the pack of annular disks <NUM> in a first axial direction upwards as can be seen in <FIG>. The screw bolts of the secondary attachment members <NUM> may extend through the pack of annular disks <NUM> in an opposite second axial direction downwards as can be seen in <FIG>.

The lower bearing housing <NUM> may comprise a lower convex spherical surface <NUM> that is supported by and may rest against a concave spherical surface <NUM> provided on the stationary frame <NUM>, see <FIG> and <FIG>. The spherical surfaces <NUM>, <NUM> may provide a lower support for the spindle <NUM> and may provide a tilting point around which the spindle <NUM> may tilt.

<FIG> refers to a second embodiment which differs from the first embodiment only with respect to the attachment of the upper bearing housing <NUM>, and in particular through the positioning of the elastic member <NUM> and the tilting member <NUM> in relation to each other. In the second embodiment, the elastic member <NUM> is located radially inside the tilting member <NUM>. In the second embodiment, the configuration and arrangement of the lower bearing housing <NUM> are the same as in the first embodiment.

Also in the second embodiment, the elastic member <NUM> comprises an annular elastic element <NUM> and a ring element <NUM>, as can be seen in <FIG> and <FIG>, but the elastic element <NUM> is located radially inside the ring element <NUM>. The elastic element <NUM> is attached to the upper bearing housing <NUM> and the ring element <NUM> is attached to the tilting member <NUM>.

In the second embodiment, the pack of annular disks <NUM> of the upper tilting member <NUM> is attached to the stationary frame <NUM> by four primary attachment members <NUM> equidistantly separated from each other around the annular disks <NUM>, see <FIG>. In particular, the upper tilting member <NUM> may be attached to four radially extending projections <NUM>' of the stationary frame <NUM>, see <FIG>.

Furthermore, the pack of annular disks <NUM> of the upper tilting member <NUM> may be attached to ring element <NUM> of the elastic member <NUM> by four secondary attachment members <NUM> each being positioned between a respective pair of adjacent primary attachment members <NUM>, see <FIG>. In particular, the upper tilting member <NUM> may be attached to four radially extending projections <NUM>' of the ring element <NUM>, see <FIG>.

<FIG> further shows a tilting member <NUM> that may be used in a bearing member according to the present invention. It is to be understood that the tilting member <NUM> discussed herein is not only useful for supporting the bearing housing of a centrifugal separator but may be used in other apparatuses as well. <FIG> show a tilting member <NUM> in the form of a pack of annular discs <NUM>. The tilting member <NUM> is arranged for attaching a bearing housing <NUM> to a stationary machine element <NUM>. Thereby it may allow the bearing housing <NUM> to tilt in relation to its central axis (X), i.e. the axis of rotation of the actual bearing arranged within the bearing housing. The tilting member <NUM> comprises a pack of annular discs <NUM> forming a through hole <NUM>. This through hole <NUM> is thus for receiving a bearing housing <NUM> or a portion of a bearing housing <NUM>.

<FIG> shows a close-up view of a portion of the tilting member <NUM> and the pack of annular discs <NUM>. An annular disc 44a comprises a plurality of straight portions <NUM> connected by corners <NUM> to form a closed polygon. In the embodiment shown in <FIG>, the pack of annular discs <NUM> forms an octagon. Moreover, each of the annular discs <NUM> comprises a plurality of apertures extending through each of the discs 44a. The apertures may be located in the corners <NUM> of the annular discs <NUM>. The tilting element <NUM> further comprises sleeve elements <NUM> provided in each of the apertures for holding the annular discs <NUM> together as a stack. Further, the sleeve elements <NUM> have a through opening 47a for receiving a fastening means <NUM>, such as a screw member. The fastening means <NUM> is used for attaching the tilting member <NUM> to a bearing housing <NUM> or a stationary machine element <NUM>. Some of the sleeve elements may be used for attaching the tilting member to a bearing housing <NUM>, whereas other of the sleeve elements may be used for attaching the tilting member to a stationary machine element <NUM>. The sleeve elements <NUM> may have a flange extending out on the upper surface of the pack of annular discs <NUM> and a washer <NUM> on the opposite side of the pack of annular discs <NUM>.

As an example, the straight portions may have a width that is smaller than the through hole <NUM> formed by the annular discs. As an example, the diameter of the through hole <NUM> may be at least five times, such as at least ten times, larger than the width of the straight portion <NUM> of the discs <NUM>.

The pack of annular discs <NUM> comprises in this embodiment more than eight annular discs. The annular discs are in the form of a steel lamella, with a thickness of about <NUM>.

<FIG> schematically illustrates a bearing member <NUM> comprising a bearing housing <NUM>. The bearing housing <NUM> is thus a retainer for the bearing <NUM>. In this embodiment, the bearing housing comprises a single bearing <NUM>, but the bearing housing may also retain more than one bearing <NUM>, such as at least two bearings <NUM>. The bearing <NUM> is thus inserted into the bearing housing <NUM> and may have its central through hole such it may receive and support a rotatable shaft extending through the bearing <NUM>. A tilting member <NUM>, such as the tilting member discussed in relation to <FIG> above, is arranged around an upper portion of the bearing housing <NUM>. Further, there are fastening elements <NUM>, such as screws, extending through some, but not all, of the sleeve elements <NUM>. These fastening elements <NUM> are used to attach the tilting member <NUM> to the bearing housing <NUM>. The sleeve elements <NUM> in which there is no fastening element <NUM> attaching the tilting member to the bearing housing <NUM> may be used for attaching the whole bearing member <NUM> to a stationary machine element <NUM>. As discussed herein above, the design of the tilting member <NUM> makes it possible to use other bearings than spherical roller bearings for supporting a rotatable shaft <NUM>. Thus, the tilting member <NUM> of the present disclosure still allows some change in the alignment of the rotational axis during use, e.g. during the rotational motion of the rotatable shaft. This is advantageous, since plain roller bearings, such as a cylindrical roller bearing or a plain roller bearing, may be used instead of a spherical bearing.

<FIG> discloses schematically an apparatus <NUM> of the present invention that comprises the bearing member <NUM> and the tilting member <NUM>. The apparatus <NUM> comprises a stationary machine element <NUM> and a rotatable shaft <NUM> that is rotatable around axis of rotation (X). the rotatable shaft <NUM> is supported by the stationary machine element <NUM> by at least one bearing member <NUM>. In <FIG>, the rotatable shaft <NUM> is supported by two bearing members <NUM>, such as two bearing members <NUM> as discussed in relation to <FIG> above. The bearing members <NUM> could also be mounted with a spring element (not shown) under one or both of the bearing housings <NUM>. In this way, the bearing members <NUM> of the apparatus could better withstand any axial forces. The tilting member <NUM> of the bearing member <NUM> is attached to both the bearing housing <NUM> and to the stationary machine element <NUM>. As an example, the tilting member <NUM> may be attached to the bearing housing <NUM> via fastening members <NUM> arranged in every second sleeve element and to the stationary machine element <NUM> via fastening members <NUM> arranged in the remaining sleeve elements <NUM>. In <FIG>, the axis of rotation is vertical. However, the axis of rotation may as well be a horizontal axis. The apparatus <NUM> may be any kind of apparatus having a rotatable shaft. As an example, the apparatus <NUM> may be any kind of apparatus in which rotational motion must be allowed to change the alignment of the rotation axis of the rotatable shaft.

Claim 1:
A bearing member (<NUM>) for supporting a rotatable axle, comprising
- a bearing housing (<NUM>);
- at least one bearing (<NUM>) inserted into the bearing housing (<NUM>); wherein the bearing (<NUM>) is configured to receive a rotatable shaft (<NUM>) extending through the bearing; and
- a tilting member (<NUM>) arranged around the bearing housing (<NUM>); characterised in that the tilting member (<NUM>) comprises a pack of annular discs (<NUM>) forming a through hole (<NUM>) for receiving said bearing housing (<NUM>); wherein each of the annular discs (<NUM>) comprises a plurality of apertures extending through each of the discs and wherein the tilting member (<NUM>) further comprises a sleeve element (<NUM>) provided in each of the apertures for holding the annular discs (<NUM>) together as a stack and arranged for receiving a fastening means for attaching the tilting member (<NUM>) to said bearing housing (<NUM>) or a stationary machine element (<NUM>);
and wherein the bearing member (<NUM>) further comprises
- at least one fastening element (<NUM>) extending through a sleeve (<NUM>) of the tilting member (<NUM>) and attaching the tilting member (<NUM>) to the bearing housing (<NUM>).