Bearing device

Abstract

1. A bearing device comprising: a shaft (1); a housing (2); an oil bath (3) disposed within the housing; a support structure (4) coupled to the housing; and at least one seal (6) supported by the support structure and extending between the support structure and the shaft; the bearing device comprises at least one electrode (5) coupled to the support structure and disposed between the support structure and the shaft such that oil vapor must pass from the oil bath through the seal and into a gap between the electrode and the shaft to be able to escape; the bearing device is configured such that a voltage can be applied between the electrode and the shaft to direct oil particles contained in the oil vapor to the electrode; and the bearing device comprises at least one outflow passage (8) configured such that oil separated at the electrode can flow through the outflow passage into the oil bath.

Description

[Technical field]

[0001] The present invention relates to a bearing arrangement in which the lubrication of the bearings is effected via an oil bath. Such a bearing arrangement is used in particular in hydroelectric power plants.

[0002] Such a bearing arrangement is shown, for example, in Russian Patent No. 2161730. To avoid the leakage of oil vapor from the bearing housing, oil vapor suction means are used, which are a cost factor and furthermore lead to continuous operating costs and continuous energy consumption.

[0003] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a bearing device which sufficiently prevents leakage of oil vapor without requiring an oil vapor suction means.

[0004] This object is achieved according to the invention by a bearing arrangement according to the independent claims. Further advantageous features of the configuration according to the invention are given in the dependent claims.

[0005] Hereinafter, a bearing device according to the present invention will be described with reference to the drawings. [Brief description of the drawings]

[0006] [Figure 1] 1 is a diagram showing a first embodiment of a bearing device according to the present invention. [Diagram 2] FIG. 4 is a diagram showing a second embodiment of a bearing device according to the present invention.

[0007] In FIG. 1, a first embodiment of a bearing arrangement according to the invention is shown in a schematic diagram. The bearing arrangement comprises a shaft, designated 1, a housing, designated 2, and a bath, designated 3, containing oil. The embodiment shown in FIG. 1 is an embodiment with a vertically arranged shaft 1. The bath 3 is arranged inside the housing 2. This oil bath 3 serves to lubricate and cool the bearing surfaces and bearing segments, which are not shown in FIG. 1 for the sake of clarity. The oil is then heated, which leads to the formation of oil vapors or oil mist. In order to prevent this oil vapor from contaminating sensitive areas outside the housing 2, the bearing arrangement comprises a first seal, designated 6 in FIG. 1, and a second seal, designated 7. The seals 6, 7 are supported by a support structure, designated 4. The support structure 4 is connected to the housing 2 and is arranged around the shaft 1. For this purpose, it is advantageous if the support structure 4 is made up of several segments. The seals 6, 7 extend between the support structure 4 and the shaft 1. The seals 6, 7 shown in FIG. 1 are formed as knife-edge seals. However, the seals 6, 7 may be formed in any other known suitable manner. Since the actual seals do not provide an ideal seal, further means must be provided which can additionally prevent the escape of oil vapours.

[0008] For this purpose, the prior art bearing arrangement is provided with the oil vapour suction means already mentioned at the outset, in which the suction pipe opens into a chamber between the seals 6, 7, the support structure 4 and the shaft 1. In this known arrangement, the seals 6, 7 are also used to limit the suction volume flow.

[0009] In contrast, the bearing arrangement according to the invention comprises at least one electrode, which is indicated by the reference number 5 in Fig. 1. The electrode or electrodes 5 are connected to the support structure 4 and are arranged between the support structure 4 and the shaft 1 in such a way that oil vapor must pass from the oil bath 3 through the first seal 6 into the gap between the electrode 5 and the shaft 1 in order to be able to escape. This means that the electrode or electrodes 5 are arranged around the shaft 1 and the first seal 6 is arranged between the oil bath 3 and the electrode or electrodes 5.

[0010] It is known that oil particles can be deflected by an electric field. The bearing arrangement according to the invention is therefore designed in such a way that a voltage can be applied between the electrode 5 and the shaft 1 in order to direct the oil particles contained in the oil vapor towards the electrode 5, whereby the oil particles can be separated there. This results in the removal of oil from the gas flow passing through the gap between the electrode 5 and the shaft 1. The described desired effect can be optimised by the gap width and the axial length of the electrode 5, the latter being the extension of the electrode 5 in the direction of the axis of the shaft. The smaller the gap width and the larger the axial length of the electrode 5 chosen to be, the more efficient the removal of oil from the aforementioned gas flow. This means that according to the invention, the second seal 7 can possibly be dispensed with. The second seal 7 can therefore be considered optional. The optional second seal 7 is arranged axially beyond the electrode 5 from the first seal 6. Optionally, the bearing arrangement may also comprise more seals. These further seals may for example be arranged between the first seal 6 and the electrode 5 or between the second seal 7 and the electrode 5 .

[0011] The oil separated at the electrode 5 flows down as an oil film under the force of gravity. To discharge the separated oil, the bearing arrangement is provided with at least one outflow passage which is arranged in such a way that the separated oil can flow through it into the oil bath 3. In FIG. 1 the outflow passage is marked with the reference number 8.

[0012] In the embodiment with a vertically arranged shaft 1 shown in FIG. 1, it is advantageous if means are also provided for collecting the separated oil. In FIG. 1, these comprise an overhang of the support structure 4, which is arranged in such a way that the oil separated at the electrode 5 can drip onto the overhang. The outflow channel 8 opens directly onto the upper surface of the overhang, so that the oil collected by the overhang can flow down without problems. To better guide the oil away, the overhang can also be inclined, so that the oil collected by the overhang flows in the direction of the opening of the outflow channel.

[0013] In the embodiment with a horizontally arranged shaft 1, the separated oil is collected at the lowest point of the surface of the electrode 5 facing the shaft 1. This requires that the electrodes 5 are possibly adjacent to one another in the circumferential direction, so that the oil can flow from one electrode 5 to the adjacent electrode 5. However, the oil can also possibly fall from one electrode 5 to the adjacent electrode 5, i.e. as droplets, overcoming any intermediate chambers present. In the embodiment with a vertically arranged shaft 1, a gap may also be present in the circumferential direction between the electrodes 5. However, the width of this gap is advantageously in any case not as large as the width of the gap between the shaft 1 and the electrodes 5.

[0014] In an embodiment with a horizontally arranged shaft 1, at least one outlet passage 5 opens at the point where the separated oil collects, i.e., for example at the lowest point of the above-mentioned electrode surface. Another suitable opening point is arranged axially alongside an electrode 5 at the lowest point of the support structure 4. In this case, openings are advantageously arranged on both axial sides of the electrode 5 in question.

[0015] Another embodiment according to the invention is shown in figure 2. The bearing arrangement shown comprises a siphon, designated by the reference number 9, arranged in the outflow passage 8. This siphon 9 is arranged so that it can be filled with separated oil and thereby seal the outflow passage 8 in such a way that oil vapours cannot pass from the oil bath 3 through the siphon.

[0016] The bearing arrangement according to the invention is able to sufficiently prevent oil vapor leakage without the need for oil suction, where the energy required to create and maintain an electrostatic field between the shaft and the electrodes is significantly less than the energy consumption of oil suction.

[0017] Finally, it should be mentioned that, conventionally, the bearing arrangement described at the beginning is designed in such a way that the shaft 1 is grounded, i.e. the bearing arrangement according to the invention comprises a voltage source which is designed and arranged in such a way that in this case an electric potential can be established between the electrode 5 and the ground. If the shaft 1 is not grounded, then the voltage source must be connectable or connected both to the electrode 5 and to the shaft 1. [Explanation of symbols]

[0018] 1-axis 2. Housing 3 Oil bath 4 Support structure 5 electrodes 6 Seal 7 Seal 8 Outflow passage 9. Siphon

Claims

1. A bearing device comprising a shaft (1), a housing (2), an oil bath (3) arranged within the housing (2), a support structure (4) coupled to the housing (2) and arranged surrounding the shaft (1), and at least one first seal (6) supported by the support structure (4) and extending between the support structure (4) and the shaft (1), The bearing arrangement comprises at least one electrode (5) coupled to the support structure (4) and arranged between the support structure (4) and the shaft (1) in such a way that oil vapor must pass through the gap between the electrode (5) and the shaft (1) from the oil bath (3) through the first seal (6) to be able to escape, The bearing device is configured such that a voltage can be applied between the electrode (5) and the shaft (1) in order to guide oil particles contained in the oil vapor to the electrode (5), thereby separating the oil particles at the electrode (5); The bearing device comprises at least one outflow passage (8), which is configured to allow oil separated at the electrode (5) to flow through the outflow passage (8) into the oil bath (3). A bearing device comprising:

2. 2. The bearing arrangement according to claim 1, further comprising a second seal (7) supported by the support structure (4) and extending between the support structure (4) and the shaft (1), the second seal (7) being arranged beyond the electrode (5) as viewed from the first seal (6).

3. 3. The bearing arrangement according to claim 1, further comprising a siphon (9) arranged in the outflow passage (8), the siphon (9) being filled with the oil separated at the electrode (5) and arranged so as to seal the outflow passage (8) in such a way that the oil vapor cannot pass from the oil bath (3) through the siphon (9).

4. 3. The bearing arrangement according to claim 1, wherein the shaft (1) is arranged horizontally.

5. 3. The bearing arrangement according to claim 1, wherein the shaft (1) is arranged vertically.

6. 6. A bearing arrangement according to claim 5, characterized in that it comprises means for collecting the oil separated at the electrode (5).

7. 7. The bearing device according to claim 6, wherein the means for collecting the oil separated at the electrode (5) comprises an overhang of the support structure (4), the overhang being arranged so that the oil separated at the electrode (5) can drip onto the overhang.

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