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 device in which the lubrication of a bearing is performed via an oil bath. Such a bearing device is particularly used in a hydroelectric power plant.

[0002] Such a bearing device is shown, for example, in the specification of Russian Patent No. 2161730. In order to avoid leakage of oil vapor from the bearing housing, oil vapor suction means are used. The oil vapor suction means is a cost factor and furthermore causes continuous operating costs and continuous energy consumption.

[0003] An object of the present invention is to provide a bearing device that sufficiently prevents leakage of oil vapor without requiring oil vapor suction means.

[0004] According to the present invention, this problem is solved by a bearing device corresponding to the independent claims. Further advantageous features of the configuration according to the present invention are recognized in the dependent claims.

[0005] Hereinafter, the bearing device according to the present invention will be described based on the drawings.

Brief Description of the Drawings

[0006] [Figure 1] It is a figure which shows 1st Embodiment of the bearing device which concerns on this invention. [Figure 2] It is a figure which shows 2nd Embodiment of the bearing device which concerns on this invention.

[0007] Figure 1 shows a schematic diagram of a first embodiment of a bearing device according to the present invention. The bearing device comprises a shaft denoted by reference numeral 1, a housing denoted by reference numeral 2, and an oil-containing bath denoted by reference numeral 3. The embodiment shown in Figure 1 is an embodiment in which the shaft 1 is arranged vertically. The bath 3 is located inside the housing 2. This oil bath 3 is used to lubricate and cool the bearing surface and bearing segments, which are not shown in Figure 1 for clarity of the drawing. At this time, the oil is heated, thereby forming oil vapor or oil mist. To prevent this oil vapor from contaminating sensitive areas outside the housing 2, the bearing device is provided with a first seal denoted by reference numeral 6 and a second seal denoted by reference numeral 7 in Figure 1. These seals 6 and 7 are supported by a support structure denoted by reference numeral 4. This support structure 4 is coupled to the housing 2 and is arranged surrounding the shaft 1. For this reason, it is advantageous that the support structure 4 is composed of multiple segments. The seals 6 and 7 extend between the support structure 4 and the shaft 1. The seals 6 and 7 shown in Figure 1 are formed as knife-edge seals. However, seals 6 and 7 may be formed in any other known suitable form. Since an ideal seal cannot be achieved by the actual seal, further means must be provided to additionally prevent leakage of oil vapor.

[0008] For this reason, bearing devices according to prior art are provided with the oil vapor suction means already mentioned at the beginning. In this oil vapor suction means, the suction pipe opens into a chamber between the seals 6 and 7, the support structure 4, and the shaft 1. In this known device, the seals 6 and 7 are also used to limit the suction volume flow.

[0009] In contrast, the bearing device according to the present invention comprises at least one electrode denoted by reference numeral 5 in Figure 1. One or more electrodes 5 are coupled to a support structure 4 and are positioned between the support structure 4 and the shaft 1 such that oil vapor must pass through the gap between the one electrode 5 and the shaft 1 from the oil bath 3 through the first seal 6 in order to be able to leak out. This means that one or more electrodes 5 are arranged to surround the shaft 1, and the first seal 6 is positioned between the oil bath 3 and one or more electrodes 5.

[0010] It is known that oil particles can be deflected by an electric field. Therefore, the bearing device according to the present invention is configured to apply a voltage between the electrode 5 and the shaft 1 in order to guide the oil particles contained in the oil vapor to the electrode 5, thereby separating the oil particles at the electrode 5. This removes oil from the gas flow passing through the gap between the electrode 5 and the shaft 1. The desired effect described can be optimized by the gap width and the axial length of the electrode 5. The axial length is the extending length 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, the better the efficiency of oil removal from the gas flow described above. This means that, according to the present invention, the second seal 7 may be unnecessary in some cases. Therefore, the second seal 7 can be considered optional. The optional second seal 7 is located on the side beyond the electrode 5 in the axial direction when viewed from the first seal 6. Optionally, the bearing device may have even more seals. These additional seals may be placed, for example, between the first seal 6 and the electrode 5, or between the second seal 7 and the electrode 5.

[0011] The oil separated at electrode 5 flows down as an oil film due to gravity. To discharge the separated oil, the bearing device is provided with at least one outlet passage. This outlet passage is arranged so that the separated oil can flow into the oil bath 3 through the outlet passage. In Figure 1, the outlet passage is labeled 8.

[0012] In the embodiment shown in Figure 1, which has a vertically positioned shaft 1, it is also advantageous to provide means for collecting the separated oil. In Figure 1, this means is provided by an overhang of the support structure 4. This overhang is positioned so that the oil separated by the electrode 5 can drip onto the overhang. The outflow passage 8 opens directly to the upper surface of the overhang, so that the oil collected by the overhang can flow down without any problems. To better guide the oil out, the overhang may be inclined, and this inclination causes the oil collected by the overhang to flow in the direction of the opening of the outflow passage.

[0013] In embodiments with a horizontally positioned shaft 1, the separated oil is collected at the lowest point of the surface of the electrode 5 facing the shaft 1. For this to occur, it may be necessary that multiple electrodes 5 are adjacent to each other in the circumferential direction, thereby allowing the oil to flow from one electrode 5 to an adjacent electrode 5. However, the oil may also fall from one electrode 5 to an adjacent electrode 5, i.e., as droplets, and may pass through any intermediate chambers that exist. In embodiments with a vertically positioned shaft 1, there may also be circumferential gaps between the electrodes 5. However, it is advantageous that the width of these gaps is not as large as the width of the gap between the shaft 1 and the electrodes 5.

[0014] In embodiments with horizontally positioned shafts 1, at least one outflow passage 5 opens where the separated oil is collected, i.e., at the lowest point of the electrode surface as described above. Another suitable opening is located at the lowest point of the support structure 4, adjacent to one electrode 5 in the axial direction. In this case, it is advantageous that the openings are located on both sides of the electrode 5 in the axial direction.

[0015] Figure 2 shows another embodiment of the present invention. The illustrated bearing device includes a siphon, denoted by reference numeral 9, located in an outlet passage 8. The siphon 9 is filled with separated oil and is positioned to seal the outlet passage 8 so that oil vapor cannot pass from the oil bath 3 through the siphon.

[0016] The bearing device according to the present invention can effectively prevent oil vapor leakage without requiring oil suction. In this case, the energy required to form and maintain an electrostatic field between the shaft and the electrode is significantly less than the energy consumption of oil suction.

[0017] Finally, it should be noted that conventional bearing devices described at the beginning are configured such that shaft 1 is grounded. In other words, in this example, the bearing device according to the present invention includes a voltage source configured and positioned to form a potential between electrode 5 and earth. If shaft 1 is not grounded, the voltage source must be connectable to or connected to both electrode 5 and shaft 1. [Explanation of symbols]

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

Claims

1. A bearing device comprising a shaft (1), a housing (2), an oil bath (3) disposed 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 device comprises at least one electrode (5), which is coupled to the support structure (4) and positioned between the support structure (4) and the shaft (1) such 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) so that oil vapor can leak out. The bearing device is configured such that a voltage can be applied between the electrode (5) and the shaft (1) in order to guide the oil particles contained in the oil vapor to the electrode (5), thereby separating the oil particles at the electrode (5). The bearing device is provided with at least one outflow passage (8), and the outflow passage (8) is configured to allow the oil separated by the electrode (5) to flow into the oil bath (3) through the outflow passage (8). A bearing device characterized by the following features.

2. The bearing device according to claim 1, wherein the bearing device is supported by the support structure (4) and comprises a second seal (7) extending between the support structure (4) and the shaft (1), the second seal (7) being positioned on the side beyond the electrode (5) when viewed from the first seal (6).

3. The bearing device according to claim 1 or 2, further comprising a siphon (9) disposed within the outflow passage (8), wherein the siphon (9) is filled with the oil separated by the electrode (5), thereby sealing the outflow passage (8) so that the oil vapor cannot pass from the oil bath (3) through the siphon (9).

4. The bearing device according to claim 1 or 2, wherein the shaft (1) is arranged horizontally.

5. The bearing device according to claim 1 or 2, wherein the shaft (1) is arranged vertically.

6. The bearing device according to claim 5, further comprising means for collecting the oil separated by the electrode (5).

7. The bearing device according to claim 6, wherein the means for collecting the oil separated by the electrode (5) comprises an overhang of the support structure (4), and the overhang is positioned such that the oil separated by the electrode (5) can drip onto the overhang.

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