Grease filter and method of use

Abstract

A grease filter for filtering grease and the use of the grease filter for a bearing in a wind turbine is provided. A grease filter is disclosed for filtering grease used for lubrication. The grease filter includes and inlet to allow the grease to enter the filter and an outlet to allow the grease to leave the filter, whereby the grease flows from the inlet towards the outlet along a flow path. The filter includes at least one magnetic element present in the flow path of the grease to attract magnetic particles present in the grease and deviate the particles out of the grease flow path.

Claims

1. A grease filter for filtering grease used for lubrication, comprising: an inlet to allow the grease to enter the grease filter; an outlet to allow the grease to leave the grease filter, whereby the grease flows from the inlet towards the outlet along a central flow path; and a plurality of pairs of co-axial magnetic elements each having a central opening forming the central flow path of the grease, the pairs of co-axial magnetic elements being configured to attract magnetic particles present in the grease and deviate the magnetic particles out of the grease from the central flow path and into a bay formed between the pairs of co-axial magnetic elements.

2. The grease filter according to claim 1, further a spacer disposed between each of the pairs of co-axial magnetic elements.

3. The grease filter according to claim 1, wherein the plurality of pairs of co-axial magnetic elements includes at least three magnetic elements arranged mainly along the flow path of the grease, and spaced apart by a spacer present between two neighboring magnetic elements, whereby the two spacers comprise a different length, so that a distance between a first magnetic element and a neighboring second magnetic element differs from a distance between the neighboring second magnetic element and a neighboring third magnetic element.

4. The grease filter according to claim 1, wherein the magnetic elements are ring shaped and the grease flow is oriented mainly in a direction of a middle axis of the ring shaped magnetic element.

5. The grease filter according to claim 2, wherein the magnetic elements comprise a north pole and a south pole, such that that the pairs of co-axial magnetic elements are arranged in a way that the equal poles of the magnetic elements face the flow direction of the grease flow.

6. The grease filter according to claim 2, whereby the magnetic elements comprise a north pole and a south pole, wherein the magnetic elements are arranged in a way that unequal poles of consecutive magnetic elements face the flow direction of the grease flow.

7. The grease filter according to claim 1, further comprising a mesh filter stage, whereby the grease flow is directed through a mesh of the filter, and whereby the mesh comprises a certain predetermined mesh width to filter particles of a certain particle size from the grease flow.

8. The grease filter according to claim 7, wherein at least two mesh filter stages are spaced apart by a spacer.

9. The grease filter according to claim 8, wherein the at least two mesh filter stages each have a different mesh width, whereby the mesh width of the filter stages decreases in the direction of the flow of the grease in the filter.

10. The grease filter according to claim 1 further comprising an end filter mesh close to the outlet of the grease filter, as safety filter to hold back particles and parts of the grease filter in case of a failure of the grease filter.

11. The grease filter according to claim 7, wherein the flow of grease through the grease filter first passes by the pairs of co-axial magnetic elements, and thereafter passes through the at least one mesh filter stage.

12. The grease filter according to claim 1, wherein the pairs of co-axial magnetic elements and at least one mesh filter stage are arranged in a common housing, that is covered at least at one of the inlet end or the outlet end by a lid to allow service and maintenance of the grease filter.

13. The grease filter according to claim 12, wherein the inlet side of the housing of the grease filter comprises a lid to allow service and maintenance of the magnetic elements, and the outlet side of the housing of the grease filter comprises a lid to allow service and maintenance of the at least one mesh filter stage.

14. A method comprising: utilizing a grease filter according to claim 1, to filter grease used for the lubrication of a bearing in a wind turbine.

Description

BRIEF DESCRIPTION

(1) Some of the embodiments will be described in detail, with reference to the following figures, wherein like designations denote like members, wherein:

(2) FIG. 1 shows a grease filter, in accordance with embodiments of the present invention;

(3) FIG. 2 shows a grease filter in more detail, in accordance with embodiments of the present invention;

(4) FIG. 3 shows a grease filter with one stage, in accordance with embodiments of the present invention;

(5) FIG. 4 shows an explosive view of the grease filter, in accordance with embodiments of the present invention; and

(6) FIG. 5 shows an arrangement with the filter, in accordance with embodiments of the present invention.

DETAILED DESCRIPTION

(7) FIG. 1 shows a grease filter.

(8) FIG. 1 shows a grease filter 1. The grease filter 1 comprises an inlet 14, where the oil can flow into the grease filter 1, and an outlet 15, where the grease leaves the grease filter. The direction of the grease flowing through the grease filter 1, from the inlet 14 to the outlet 15, defines a flow direction 8 of the grease.

(9) In the flow direction 8 of the grease the grease filter 1 comprises a metal filter 2 and a non-metal filter 3. The metal filter 2 magnetic particles present in the grease are filtered out of the grease flowing through the filter.

(10) To filter the magnetic particles out of the grease the grease filter 2 comprises magnetic elements 4. The magnetic elements 4, or magnets, are arranged close to, or in, the flow path of the grease. Metal particles present in the grease flowing through the filter are attracted by the magnetic elements 4, and are thus sorted out of the grease flow by the magnets.

(11) At least one magnet or magnetic element 4 is necessary to filter magnetic parts out of the grease. In FIG. 1 four magnets 4 are shown. The magnets 4 are separated by spacers that allow the magnets 4 to be arranged in a certain distance to each other.

(12) In the embodiment of FIG. 1 a first spacer 5 comprises a different length than a second spacer 6. Thus, the first and second magnetic elements 4 are arranged at a different distance in respect to each other than a second and a third magnetic element.

(13) Thus, the magnets 4 arranged in the metal filter 2 of the grease filter 1 are not evenly distributed within the filter. The magnets 4 are not evenly spaced throughout the filter 2 along the flow path of the grease.

(14) In the embodiment of FIG. 1 the first spacer 5 is dimensioned in a way to lead to a longer distance between the first and the second magnet than the spacer 6, so that the magnets 4 are arranged with decreasing distances between each other.

(15) A spacer 7 between the third and the fourth magnet might even lead to a smaller distance between the third and the fourth magnet than between the second and the third magnet.

(16) While the magnets 4 reach into the grease flow and are surrounded by grease at three sides, the spacers between the magnets are set back from the main grease flow to achieve a little bay between the magnets. Particles of magnetic material that are attracted by the magnets 4, deviate from the main grease flow 8 towards the magnets and get to rest in the bays between the magnets.

(17) Along the main grease flow direction 8 the grease leaving the metal filter 2 flows into the non-metal filter 3.

(18) In the embodiment of FIG. 1 the non-metal filter 3 comprises several stages of mesh. In the non-metal filter 3 non-magnetic particles are filtered out of the grease flow. In addition, also magnetic particles that were not held back by the magnetic elements in the metal filter stage will be held back by the mesh.

(19) The different stages of mesh can show a different width of the mesh to sort out particles of different size from the grease flow. Thus, the first mesh stage 9 can, for example, show a width of the mesh of 500 micrometers. The first stage of the mesh 9 is separated from the second stage of the mesh 10 by a spacer 12.

(20) The second stage of the mesh 10 can have a mesh width of 250 micrometers, for example. The second stage of the mesh 10 is separated from the third stage of the mesh 11 by a spacer 12 again.

(21) The third stage of the mesh 11 can have a width of the mesh of 125 micrometers, for example. The non-metal filter 3 can be equipped with more or less than three stages of mesh.

(22) At the outlet 15 of the filter 1, there is a rough end filter mesh 17 as a safety filter in the case of a failure of one of the mesh stages before. The rough end filter mesh 17 can be designed stronger to hold back mesh stages or parts of mesh stages of the meshes in the filter.

(23) FIG. 2 shows a grease filter in more detail.

(24) FIG. 2 shows a grease filter 1 with a metal filter 2 from magnetic particles and a non-metal filter 3 for non-magnetic particles.

(25) The two filter stages are arranged in a filter cover unit 18. The filter cover unit 18 is equipped with an inlet lid 20 at the inlet 14. The inlet lid 20 is sealed towards the filter cover unit 18 with an O-ring 19.

(26) In addition, the grease filter 1 is equipped with an outlet lid 21 at the outlet 15 of the filter. Also the outlet lid 21 can be sealed towards the filter cover unit 18 with an O-ring 19.

(27) Both the inlet lid 20 and outlet lid 21 are equipped with a thread to connect conduits for the grease to be supplied to and from the filter.

(28) The lids 20, 21 can be detached from the filter cover unit 18 to allow the grease filter 1 to be disassembled and cleaned. Thus, the different filter stages within the metal filter 2 and the non-metal filter 3 can be disassembled from the filter 1 and can be cleaned.

(29) Magnetic and non-magnetic particles held back in the filter can be removed from the filter stages.

(30) The metal filter 2 shows several stages of magnetic elements or magnets 4 spaced apart from each other by spacers 5, 6.

(31) The magnets 4 might be arranged equally distanced in respect to each other or in another embodiment the spacers 5, 6 might be of different length leading to an unequal distribution of the magnets in the filter.

(32) The non-metal filter shows mesh stages 9, 10 whereby the mesh stages might be equipped with a mesh of different mesh width, especially with a decreasing mesh width from one mesh stage to the next.

(33) The mesh stages 9, 10 of the non-metal filter 3 are spaced apart by spacers 12.

(34) FIG. 3 shows a grease filter 1 with one stage.

(35) FIG. 3 shows a grease filter 1 with a stage for magnetic particles only. The grease filter 1 comprises a metal filter 2 comprising magnets 4.

(36) The metal filter 2 in FIG. 3 comprises a filter cover unit 18 that comprises an inlet lid 20 with an inlet opening 14. At the outlet side the filter cover unit 18 comprises an outlet lid 21 with an outlet 15.

(37) At the outlet side of the metal filter 2, the filter can be connected to a non-metal filter if necessary. The lids 20, 21, are sealed towards the filter cover unit by O-rings 19.

(38) The metal filter 2 comprises several stages of magnets 4 that are spaced apart by spacers 7. The magnets 4 attract magnetic particles present in the grease flowing through the filter. The magnetic particles interact with the magnetic field of the magnetic elements and deviate out of the grease flow. The magnetic particles attach to the magnets 4, or come to rest at the spacers 7.

(39) The inlet lid 20, the outlet lid 21 and the filter cover unit 18 are connected by screws or bowls. The connection can be released and the filter can be opened to be cleaned.

(40) The stages of magnets 4 and spacers 7 can be removed from the filter cover unit 18 and can be cleaned from the magnetic particles resting on the magnets 4 or the spacers 7.

(41) FIG. 4 shows an explosive view of the grease filter.

(42) FIG. 4 shows an explosive view of the grease filter 1 with a metal filter 2 and a non-metal filter 3. The metal filter 2 comprises several stages of magnets 4, spaced apart from each other by spacers 7.

(43) The non-metal filter 3 comprises stages of mesh 9, 10, 11 that are spaced apart from each other by spacers 12.

(44) The metal filter 2 and the non-metal filter 3 are arranged in a filter cover unit 18. The filter cover unit is closed by an inlet lid 20 and an outlet lid 21.

(45) The grease flows from an inlet opening in the inlet lid 20 through the metal filter 2. Thereafter, through the non-metal filter 3 and leaves the grease filter 1 at an outlet opening 15 in an outlet lid 21.

(46) The inlet lid 20 and the outlet lid 21 are sealed by an O-ring 19 to avoid the loss of grease.

(47) The inlet lid 20 can be removed from the filter cover unit 18 to allow access to the magnets 4 and the spacers 7 of the metal filter 2 for service and maintenance.

(48) Also the outlet lid 21 can be removed for service and maintenance of the mesh stages 9, 10, 11 and the spacers 12 of the non-metal filter 3.

(49) As shown in FIG. 4, the magnets 4 have a ring-shaped form allowing the grease to flow through the middle hole in the magnets.

(50) The outlet lid 21 comprises a threat at the outlet 15 to allow a conduit for the grease to be connected to the outlet lid.

(51) FIG. 5 shows an arrangement with the filter.

(52) FIG. 5 shows a block diagram with the grease filter 23. The grease is used to lubricate a bearing 25.

(53) The grease is supplied by a grease reservoir and the grease pump 22. The grease is then pumped through the grease filter 23 to remove magnetic and non-magnetic particles from the grease.

(54) Thereafter, the grease flows through a distribution block 24, where the grease is distributed to different lubrication inlets at the bearing 25.

(55) The illustration in the drawings is in schematic form. It is noted that in different figures, similar or identical elements are provided with the same reference signs.

(56) Although the present invention has been described in detail with reference to the preferred embodiment, it is to be understood that the present invention is not limited by the disclosed examples, and that numerous additional modifications and variations could be made thereto by a person skilled in the art without departing from the scope of the invention.

(57) It should be noted that the use of a or an throughout this application does not exclude a plurality, and comprising does not exclude other steps or elements. Also elements described in association with different embodiments may be combined. It should also be noted that reference signs in the claims should not be construed as limiting the scope of the claims.