SUCTION FILTER DEVICE WITH AIR SEPARATION

Abstract

A suction filter device for filtering oil includes a filter housing having an oil inlet opening and an oil outlet opening, via which a filter housing interior can be fluidically connected to a suction line. An oil filter medium is arranged in the filter housing interior between the oil inlet opening and the oil outlet opening, so that, by means of negative pressure generated via the suction line within the filter housing interior in relation to an environment of the filter housing, an oil flow can be generated from the oil inlet opening through the oil filter medium and through the oil outlet opening. Further, an oil-permeable and air-impermeable air separation medium is included. The air separation medium is arranged upstream of the oil outlet opening when a vacuum is generated via the suction line within the filter housing interior in relation to an environment of the filter housing.

Claims

1. A suction filter device for filtering oil, comprising a filter casing having an oil inlet opening and an oil outlet opening, by means of which a filter casing interior can be brought into fluid communication with a suction line; and at least one oil filter medium for filtering oil, said oil filter medium being arranged in the filter casing interior between the oil inlet opening and the oil outlet opening such that an oil flow from the oil inlet opening through the oil filter medium and through the oil outlet opening can be generated by negative pressure within the filter casing interior relative to a surrounding region of the filter casing, said negative pressure being generated by means of the suction line, wherein: the suction filter device comprises an oil-permeable air separator medium; the air separator medium is arranged upstream of the oil outlet opening when the negative pressure within the filter casing interior relative to a surrounding region of the filter casing is applied, said negative pressure being generated by means of the suction line.

2. The suction filter device according to claim 1, wherein the suction filter device further comprises a retaining frame connected to the filter casing and arranged outside the filter casing interior; and wherein the retaining frame comprises at least one through-opening, which is closed by the air separator medium in such a way that the at least one through-opening is oil-permeable.

3. The suction filter device according to claim 2, wherein the air separator medium is formed in one piece with the retaining frame.

4. The suction filter device according to claim 2, wherein the retaining frame is formed around the periphery of the filter casing.

5. The suction filter device according to claim 2, wherein the retaining frame is arranged on the filter casing in a collar-like manner.

6. The suction filter device according to claim 2, wherein: the suction filter device comprises an oil pan and/or a motor or transmission casing part; and the retaining frame is connected to the filter casing and to the oil pan and/or to the motor or transmission casing part in a fluid-tight manner.

7. The suction filter device according to claim 6, wherein the retaining frame is an integral component of the oil pan and/or of the motor or transmission casing part.

8. The suction filter device according to claim 6, wherein the retaining frame is interlockingly connected to the oil pan and/or to the motor or transmission casing part.

9. The suction filter device according to claim 2, wherein the retaining frame is interlockingly connected to the filter casing.

10. The suction filter device according to claim 1, wherein: the suction filter device further comprises a second oil outlet opening on the suction filter, by means of which the filter casing interior can be brought into fluid communication with a second suction line; the air separator medium is arranged upstream of the second oil outlet opening when the negative pressure within the filter casing interior 0 relative to a surrounding region of the filter casing is applied, said negative pressure being generated by means of the second suction line.

11. The suction filter device according to claim 10, wherein the second oil outlet opening is arranged upstream of the oil filter medium.

12. The suction filter device according to claim 10, wherein the second oil outlet opening is arranged downstream of the oil filter medium.

13. The suction filter device according to claim 1, wherein, when the suction filter device is in the installed position, the air separator medium forms an angle of more than 10 with a horizontal plane at least in some portions.

Description

[0041] Further advantages, details and features of the invention will become apparent below from the described embodiment examples. In the drawings:

[0042] FIG. 1 is a schematic cross-sectional view of a suction filter device according to the invention in accordance with a first embodiment of the present invention;

[0043] FIG. 2 is a schematic cross-sectional view of a suction filter device according to the invention in accordance with a second embodiment of the present invention;

[0044] FIG. 2A is a schematic cross-sectional view of a connection region of a retaining frame to a filter casing and to an oil pan of the suction filter device shown in FIGS. 1 and 2;

[0045] FIG. 2B is a schematic cross-sectional view of a section along the plane A-A shown in FIG. 2A;

[0046] FIG. 3 is a schematic cross-sectional view of a suction filter device according to the invention in accordance with a third embodiment of the present invention;

[0047] FIG. 4 is a schematic cross-sectional view of a suction filter device according to the invention in accordance with a fourth embodiment of the present invention;

[0048] FIG. 5 is a schematic cross-sectional view of a suction filter device according to the invention in accordance with a fifth embodiment of the present invention; and

[0049] FIG. 6 is a schematic cross-sectional view of a suction filter device according to the invention in accordance with a sixth embodiment of the present invention.

[0050] In the following description, like reference numerals denote like components or like features, so any description of a component given in relation to one figure also applies to the other figures, thereby avoiding a repetitive description. In addition, individual features described in connection with an embodiment can also be used separately in other embodiments.

[0051] FIG. 1 is a schematic cross-sectional view of a suction filter device 1 according to the invention in accordance with a first embodiment of the present invention. The suction filter device comprises a filter casing 10, which, in the embodiment example shown, comprises a filter casing top shell half 12 and a filter casing bottom shell half 13 connected thereto. The filter casing top shell half 12 and the filter casing bottom shell half 13 enclose a filter casing interior 11 of the filter casing 10. The filter casing 10 has an oil inlet opening 14 and an oil outlet opening 15, the oil inlet opening 14 being arranged in the filter casing bottom shell half 13 and the oil outlet opening 15 being arranged in the filter casing top shell half 12. The filter casing interior 11 can be brought into fluid communication with a suction pump (not shown in the drawings) by means of a suction line 21.

[0052] The suction filter device 1 further comprises an oil filter medium 17 for filtering oil, the oil filter medium 17 being arranged in the filter casing interior 10 between the oil inlet opening 14 and the oil outlet opening 15. Thus, an oil flow from the oil inlet opening 14 through the oil filter medium 17 and through the oil outlet opening 15 is generated by negative pressure within the filter casing interior 11 relative to a surrounding region of the filter casing 10, said negative pressure being generated by means of the suction line 21.

[0053] The suction filter device 1 according to the invention further comprises an oil-permeable air separator medium 18. The air separator medium 18 preferably comprises a grating structure and is further preferably made of a plastics material. It is also possible for the air separator medium 18 to be formed from a metal grating. The air separator medium 18 is arranged upstream of the oil outlet opening 15 when the negative pressure within the filter casing interior 11 relative to a surrounding region of the filter casing 10 is applied, said negative pressure being generated by means of the suction line 21. Since the air separator medium 18 is arranged upstream of the oil outlet opening 15, the air separator medium 18 is arranged fluidically before the oil outlet opening 15. Therefore, as a result of the suction of oil by the suction line 21, the oil is suctioned or conveyed through the air separator medium 18 before passing through the oil outlet opening 15. In the embodiment example shown in FIG. 1, the air separator medium 18 is also arranged upstream of the oil inlet opening 14.

[0054] The suction filter device 1 shown in FIG. 1 further comprises a retaining frame 30 connected to the filter casing 10 and arranged outside the filter casing interior 11. The retaining frame 30 comprises at least one through-opening 31. In the embodiment example shown, the retaining frame 30 comprises a plurality of through-openings 31. The through-openings 31 are each closed by an air separator medium 18 in such a way that the through-openings 31 are oil-permeable

[0055] It can be seen from FIG. 1 that, when the suction filter device 1 is in the installation position, the air separator medium 18 forms an angle W with a horizontal plane, which, in the embodiment example shown, coincides with a plane of extension of an oil pan 40. In the embodiment example shown, the angle W is approximately 45. Due to a corresponding sloped position of the air separator medium 18, relatively small air bubbles L combine, due to their buoyancy force, to form larger air bubbles L, and so the air bubbles L exposed to a higher buoyancy force then detach from the air separator medium 18 and rise to an oil surface outside the filter casing 10.

[0056] The air separator medium 18 is preferably formed in one piece with the retaining frame 30. For example, the air separator medium 18 may be an integral component of the retaining frame 30. For example, the air separator medium 18 may be injection-molded in the retaining frame 30.

[0057] In the embodiment example shown, the retaining frame 30 is an integral component of the filter casing 10. In the embodiment example shown, the retaining frame 30 is formed in one piece with the filter casing bottom shell half 13.

[0058] As can be seen from FIG. 1, the retaining frame 30 is formed around the periphery of the filter casing 10. Furthermore, the retaining frame 30 is arranged on the filter casing 10 in a collar-like manner, such that the retaining frame 30 is formed so as to protrude from the filter casing 10.

[0059] The suction filter device 1 shown in FIG. 1 further comprises an oil pan 40, the retaining frame 30 being connected to both the filter casing 10 and the oil pan 40 in a fluid-tight manner. As regards the connection of the retaining frame 30 to the oil pan 40 and to the filter casing 10, reference is made to FIG. 2A and 2B, which are described further below.

[0060] Instead of an oil pan, reference sign 40 can also denote a part of a motor or transmission casing.

[0061] FIG. 2 is a schematic cross-sectional view of a suction filter device 1 according to the invention in accordance with a second embodiment of the present invention. In the suction filter device 1 according to the second embodiment, the filter casing bottom shell half 13 is connected to the oil pan 40 in one piece. The oil inlet opening 14 is formed by a side opening in the filter casing bottom shell half 13. The retaining frame 30 is provided upstream of the oil inlet opening 14, an air separator medium 18 being inserted into the through-opening 31 in said retaining frame. The air separator medium 18 shown in FIG. 2 also forms an angle W of approximately 45 together with a horizontal plane.

[0062] FIG. 2A is a schematic cross section of a connection region of the retaining frame 30 to the oil pan 40 and to the filter casing 10. It can be seen that the oil pan 40 comprises a fastening projection 41 with which the retaining frame 30 engages. It can also be seen that the filter casing top shell half 12 also comprises a corresponding fastening projection with which the retaining frame 30 also engages.

[0063] FIG. 2B shows a connection region of the suction filter device 1, the cross-sectional view according to FIG. 2B showing the suction filter device 1 along the plane A-A shown in FIG. 2A. It can be seen that the oil pan 40 comprises a retaining groove 42 with which the retaining frame 30 engages.

[0064] It can be seen from FIG. 2A and 2B that the retaining frame 30 is interlockingly connected to the oil pan 40 and also to the filter casing 10 in such a way that the labyrinthine shape of the contact surfaces of the retaining frame 30 with both the oil pan 40 and the filter casing 10 causes air bubbles to unavoidably pass through the air separator medium 18.

[0065] FIG. 3 is a schematic cross-sectional view of a suction filter device 1 according to a third embodiment of the present invention. In the suction filter device 1 according to the third embodiment, the through-opening 31 of the retaining frame 30 is arranged on the underside of the retaining frame 30 and is also closed by an air separator medium 18. The angle W that the air separator medium 18 forms with the horizontal plane is smaller in the embodiment example shown in FIG. 3 than in the embodiment examples shown in FIGS. 1 and 2.

[0066] FIG. 4 is a schematic cross-sectional view of a suction filter device 1 according to a fourth embodiment of the present invention. In addition to a first oil outlet opening 15, the filter casing 1 comprises a second oil outlet opening 16. The first oil outlet opening 15 can also be referred to as the primary oil outlet opening 15 and the second oil outlet opening 16 can also be referred to as the secondary oil outlet opening 16. The filter casing interior 11 is in fluid communication with a second suction line 22, which can also be referred to as the secondary suction line 22, by means of the second oil outlet opening 16. The air separator medium 18 is arranged upstream of the second oil outlet opening 16 when the negative pressure within the filter casing interior 11 relative to a surrounding region of the filter casing 10 is applied, said negative pressure being generated by means of the second suction line 22. In the embodiment example shown, the air separator medium 18 is arranged upstream of the oil filter medium 17. In the suction filter device 1 according to the fourth embodiment, the air separator medium 18 also forms an angle W with the horizontal plane, said angle being approximately 20 in the embodiment example shown.

[0067] FIG. 5 shows a suction filter device 1 according to a fifth embodiment of the present invention. The suction filter device 1 according to the fifth embodiment is identical to the suction filter device 1 according to the fourth embodiment, although the second suction line 22 protrudes through the oil filter medium 12 such that the second oil outlet opening 16 is arranged downstream of the oil filter medium 17.

[0068] The suction filter device 1 according to the fourth embodiment and according to the fifth embodiment share the feature whereby the respective second oil outlet openings 16 are each arranged in the filter casing bottom shell half 13.

[0069] FIG. 6 is a schematic cross-sectional view of a suction filter device 1 according to a sixth embodiment of the present invention. The suction filter device 1 shown in FIG. 6 is identical to the suction filter device 1 shown in FIG. 5, although the second suction line 22 is attached to the filter casing top shell half 12. The second oil outlet opening 16 is thus also provided on the filter casing top shell half 12. The rest of the structure of the suction filter device 1 according to the sixth embodiment is identical to the configuration of the suction filter device 1 according to the fifth embodiment.

LIST OF REFERENCE SIGNS

[0070] 1 Suction filter device [0071] 10 Filter casing [0072] 11 Filter casing interior [0073] 12 Filter casing top shell half/filter top shell half [0074] 13 Filter casing bottom shell half/filter bottom shell half [0075] 14 Oil inlet opening [0076] 15 (First) oil outlet opening/primary oil outlet opening [0077] 16 Second oil outlet opening/secondary oil outlet opening [0078] 17 Oil filter medium [0079] 18 Air separator medium [0080] 21 (First) suction line/primary suction line [0081] 22 Second suction line/secondary suction line [0082] 30 Retaining frame [0083] 31 Through-opening (in the retaining frame) [0084] 40 Oil pan/part of a motor or transmission casing [0085] 41 Fastening projection (of the oil pan) [0086] 42 Retaining groove (in the oil pan) [0087] L Air bubbles [0088] W Angle (between the air separator medium and a horizontal plane)