OIL MIST SUCTION DEVICE

Abstract

Oil mist suction device The present invention relates to a suction device (1) arranged to be implemented on a bearing (2) receiving a shaft (3) of a rotating machine, the latter passing through said bearing (2) between a first side wall (7) and a second side wall (8), remarkable in that it comprises at least: - a first and a second oil mist collector (10, 11) each comprising a casing arranged around the shaft (3) so as to leave an annular space between it and said shaft (3) and against respectively said first side wall (7) and said second side wall (8), and connected respectively to a first and a second pipe (12, 13) for evacuating the oil mist sucked by and towards treatment means making it possible to capture the oil particles from the mist and to reject the purified air. Fig 1

Description

Title of the invention: OIL MIST SUCTION DEVICE Technical field of the invention

[0001] The present invention relates to the general field of bearings intended in particular for turbines or alternators of power plants. It relates more specifically to a device for extracting oil mists generated by said bearings. State of the art

[0002] In the field of turbines or alternators of power plants, it is known to use bearings to allow the rotation of these different pieces of equipment. Said bearings are advantageously lubricated and comprise, in a conventional manner, a reservoir containing oil.

[0003] The implementation of these lubricated bearings is certainly effective, but has the disadvantage of a risk of pollution of the alternators by the oil they contain.

[0004] Thus, in the event of an oil leak or overflow from the tank, the turbines or alternators may then be polluted by liquid oil. However, this type of pollution is quite rare, because the personnel who operate and / or maintain the turbines or alternators are qualified and errors or failures are rare.

[0005] On the other hand, it is not uncommon to see turbines or alternators polluted by oil mists. These oil mists form on the free surface of the oil and more particularly when the latter is hot and / or agitated during the operation of the turbines or alternators. In this case, the oil mists tend to escape through the breathers of the bearing or at the junction between the latter and the rotating part, in particular the shaft line of the turbines and / or alternators. In addition, the ventilation system allowing the evacuation of calories from the energy losses of operation of the turbine or the alternator, contributes greatly to the diffusion of these mists and very many parts of the turbine or the alternator then become dirty. The deposit of oil on the machine tends to fix the dust which can obstruct ventilation ducts or create a layer reducing the heat exchange.When the oil binds conductive dust (commutator brushes for example), insulation problems can appear on the alternators.

[0006] Furthermore, these oil mists can also represent risks to the health of personnel ensuring the operation and / or maintenance of turbines or alternators, the oil mists being able in fact to cause falls by making slippery surfaces.

[0007] To overcome this drawback, it is known to implement oil mist suction devices directly connected to the inside of the reservoir of each of the bearings associated with the turbines or alternators. These known suction devices draw directly into the reservoir to capture the oil mist at the source. This type of suction device is quite effective, but it has the disadvantage of generating variations in the oil level in the reservoir, due to the pressure differences it generates. In addition, this type of suction device also presents a risk with regard to the air potentially polluted by dust which enters the reservoir to replace the extracted air and which can thus cause lubrication problems. Summary of the invention

[0008] The aim of the present invention is therefore to propose a device for extracting oil mists generated by bearings of rotating machines such as, for example, turbines or alternators, which is efficient, easy to implement and makes it possible not to modify the oil level in the reservoir associated with each of the bearings, nor to circulate air in said reservoir.

[0009] In accordance with the invention, there is therefore proposed a suction device arranged to be implemented on a bearing receiving a shaft of a rotating machine, the latter passing through said bearing between a first transverse wall and a second transverse wall, remarkable in that it comprises at least: - a first oil mist collector comprising a casing arranged to be placed around the shaft, so as to leave an annular space between it and said shaft, and close to said first side wall, said casing being connected to a first pipe for evacuating the oil mist sucked in by and towards treatment means making it possible to capture the oil particles from the mist and to discharge the purified air, - an axial orifice provided between the casing and the shaft on the side opposite the bearing, to connect the exterior of said casing and said annular space, and - a radial orifice arranged between the casing and said first side wall, to connect the exterior of said casing and said annular space.

[0010] According to an advantageous embodiment, the suction device comprises: - a second oil mist collector comprising a casing arranged to be disposed around the shaft, so as to leave an annular space between it and said shaft, and in the vicinity of said second side wall, and connected to a second pipe for discharging the oil mist sucked in by and towards treatment means for capturing the oil particles from the mist and discharging the air refined, - an axial orifice provided between the casing and the shaft on the side opposite the bearing, to connect the exterior of said casing and said annular space, and - a radial orifice arranged between the casing and said second side wall, to connect the exterior of said casing and said annular space.

[0011] Advantageously, each of the casings of the first and second oil mist collectors comprises at least: - a suction chamber of generally annular shape arranged around the shaft and having a radial opening located on the side of said shaft and connecting the corresponding annular space and the interior of said suction chamber, - a homogenization chamber arranged around said suction and connected respectively to the first and second corresponding pipes, and - a transfer orifice connecting the interior of said suction chamber and the interior of said homogenization chamber.

[0012] Each axial orifice advantageously has an annular shape surrounding the shaft.

[0013] Advantageously, each radial orifice has the overall shape of a perimeter groove.

[0014] Each casing preferably comprises a plurality of transfer orifices arranged to create restrictions which function to distribute the air flow uniformly around the circumference of the rotating shaft.

[0015] According to an alternative embodiment, the first oil mist collector comprises a seeping oil deflection ring arranged to be placed around said shaft in line with the radial opening of the suction chamber of said first collector. Brief description of the figures

[0016] Other advantages and characteristics will emerge more clearly from the following description of an embodiment of the invention with reference to the appended figures in which:

[0017] [Fig-1] is a vertical sectional view of a mist suction device oil, according to the invention, arranged to be implemented on a bearing of a shaft of a vertical rotating machine,

[0018] [Fig.2] is an enlarged view of detail A of [Fig.l],

[0019] [Fig.3] is an enlarged view of detail B of [Fig.l],

[0020] [Fig.4] is an enlarged view of detail A of [Fig.l] according to a variant of realization lization. Description of the embodiments

[0021] In [Fig.l], there is shown, in accordance with the invention, a device suction 1 arranged to be implemented on a bearing 2 receiving a shaft 3 of a rotating machine, not shown, intended for a power station and such as, for example, a turbine or an alternator.

[0022] Furthermore, in the embodiment shown in [Fig.l], the suction device 1 is placed on a bearing 2 receiving a shaft 3 extending vertically, but it goes without saying that the shaft 3 could also be horizontal, without departing from the scope of the present invention, terms such as, for example, lower, upper, horizontal or even vertical will then have to be adapted.

[0023] Said bearing 2 comprises, in a conventional manner, a casing 4 determining a lower reservoir 5 containing oil and an upper space 6 in which oil mists are formed. The shaft 3 is arranged so as to pass through the bearing 2 between a first side wall 7 located on the side of said reservoir 5 and a second side wall 8 located on the side of said space 6.

[0024] According to the embodiment shown, the suction device 1 comprises at least a first oil mist collector 10 arranged around the shaft 3 near the first side wall 7 of the bearing 2 and a second oil mist collector 11 arranged around the shaft 3 near the second side wall 8. Said first and second collectors 10, 11 are each connected respectively to a first and a second pipe 12, 13 for evacuating the oil mist sucked in by and towards treatment means, not shown, making it possible to capture the oil particles from the mist and to discharge the purified air. Such treatment means are known to those skilled in the art.

[0025] Here, the term "nearby" refers to the fact that the respective space between the first and second collectors 10, 11 and the first and second side walls 7, 8 of the bearing 2 is of the order of a few centimeters.

[0026] Furthermore, depending on the configuration of the bearing 2, the suction device 1 may only comprise a first oil mist collector 10 or 11, without departing from the scope of the present invention.

[0027] Furthermore, with reference to [Fig.2], the first oil mist collector 10 comprises at least: - a casing 14 connected to the first pipe 12, and arranged around the shaft 3 so as to leave an annular space 15 between it and said shaft 3, - an axial orifice 16 arranged between the casing 14 and the shaft 3 on the side opposite the bearing 2, to connect said annular space 15 and the exterior of said casing 14, and - a radial orifice 17 arranged between the casing 14 and the first side wall 7 of the bearing 2, to connect said annular space 15 and the exterior of said casing 14.

[0028] Furthermore, according to an advantageous embodiment, the casing 14 comprises at least: - a suction chamber 18 of generally annular shape arranged around the shaft 3 and having a radial opening 19 located on the side of said shaft 3 and connecting the annular space 15 and the interior of said suction chamber 18, - a homogenization chamber 20 arranged around said suction chamber 18 and connected to the first pipe 12, and - a transfer orifice 21 connecting the interior of said suction chamber 18 and the interior of said homogenization chamber 20.

[0029] According to an advantageous embodiment, the first collector 10 comprises an axial orifice 16 having an annular shape surrounding the shaft 3 and a radial orifice 17 in the overall shape of a perimeter groove.

[0030] Furthermore, to the extent that the shaft 3 is rotating when the corresponding rotating machine is operating and in fact creates airflow disturbances, the casing 14 preferably comprises a plurality of transfer orifices 21 arranged so as to create restrictions which have the function of uniformly distributing the air flow all around the circumference of the rotating shaft 3.

[0031] With reference to [Fig. 3], the second oil mist collector 11 is identical to the first oil mist collector 10 described previously, and comprises at least: - a casing 22 connected to the second pipe 13, and arranged around the shaft 3 so as to leave an annular space 23 between it and said shaft 3, - an axial orifice 24 arranged between the casing 22 and the shaft 3 on the side opposite the bearing 2, to connect said annular space 23 and the exterior of said casing 22, and - a radial orifice 25 arranged between the casing 22 and the second side wall 8 of the bearing 2, to connect said annular space 23 and the exterior of said casing 22.

[0032] Furthermore, according to an advantageous embodiment, the casing 22 comprises at least: - a suction chamber 26 of generally annular shape arranged around the shaft 3 and having a radial opening 27 located on the side of said shaft 3 and connecting the annular space 23 and the interior of said suction chamber 26, - a homogenization chamber 28 arranged around said suction chamber 26 and connected to the second pipe 13, and - a transfer orifice 29 connecting the interior of said suction chamber 26 and the interior of said homogenization chamber 28.

[0033] According to an even more advantageous embodiment, the second collector 11 comprises an axial orifice 24 having an annular shape surrounding the shaft 3 and a radial orifice 25 in the overall shape of a perimeter groove.

[0034] Furthermore, to the extent that the shaft 3 is rotating when the corresponding rotating machine is operating and in fact creates airflow disturbances, the casing 22 preferably comprises a plurality of transfer orifices 29 arranged so as to create restrictions which have the function of uniformly distributing the air flow while around the circumference of the rotating shaft 3.

[0035] Thus configured, the suction device 1 according to the invention operates in the manner described below to efficiently collect the oil mists escaping from the bearing 2.

[0036] During operation of the suction device 1, the treatment means suck up, thanks to the first and second collectors 10, 11 and the associated first and second pipes 12, 13 via successively the radial opening 19, 27, the suction chamber 18, 26, the transfer orifice 21, 29 and the homogenization chamber 20, 28, not only oil mists escaping from the bearing 2, but also outside air coming from the respective axial orifices 16, 24 and radial orifices 17, 25.

[0037] First of all, it is recalled that it is known that oil mists escape from a bearing mainly at the junction between the bearing and the rotating part, that is to say in the embodiment shown, between the shaft 3 and the first and second side walls 7, 8 of the bearing 2. It is then clearly understood that the fact of positioning the first and second collectors 10, 11 arranged around the shaft 3 and respectively against the first side wall 7 and the second side wall 8 makes it possible to collect, in a particularly localized and very effective manner, the oil mists escaping from the bearing 2.

[0038] Furthermore, as described above, thanks to the suction of the treatment means, an external air flow is created from the respective axial orifices 16, 24 and radial orifices 17, 25 of the first and second collectors 10, 11 to the first and second pipes 12, 13. It is understood that this external air flow prevents any escape of oil mists by forcing the latter to move towards the annular spaces 15, 23 in order to be sucked in by the radial openings 19, 27 of the respective suction chambers 18, 26 of the first and second collectors 10, 11.

[0039] This particular configuration therefore further reinforces the effectiveness of the suction device 1 according to the invention. Finally, it is understood that with this configuration, the suction device 1 creates an air flow around the bearing 2 without putting the interior of the bearing 2 under depression or overpressure and therefore has little or no influence on the variation of the oil level contained in the reservoir 4 of said bearing 2. This particular configuration also makes it possible to avoid the entry of external air into the bearing 2, potentially polluted with the associated lubrication risks.

[0040] Furthermore, according to an alternative embodiment shown in [Fig. 4] and in a configuration with a shaft 3 extending vertically, the first collector 10 of the oil mist suction device 1 arranged under the bearing 2 advantageously comprises a ring 30 for deflecting seeping oil arranged to be arranged around said shaft 3 in line with the radial opening 19 of the suction chamber 18 of said first collector 10.

[0041] Furthermore, it is understood that the suction device 1 according to the invention is particularly interesting because it is completely independent of the bearing 2 and can be implemented on existing machines after the fact as well as on new machines from their design.

[0042] The suction device 1 according to the invention finds a particular application for the collection of oil mists generated by bearings of turbines or alternators of hydroelectric power stations, but it goes without saying that it could be adapted to collect oil mists generated by bearings of turbines or alternators of electric power stations or by bearings of rotating machines of a completely different type.

[0043] Finally, it goes without saying that the examples of suction devices 1 in accordance with the invention which have just been described are only particular illustrations, in no way limiting the invention.

Claims

1.

2.

3. Claims Suction device (1) arranged to be implemented on a bearing (2) receiving a shaft (3) of a rotating machine, the latter passing through said bearing (2) between a first side wall (7) and a second side wall (8), characterized in that it comprises at least: - a first oil mist collector (10) comprising a casing (14) arranged to be arranged around the shaft (3), so as to leave an annular space (15) between it and said shaft (3), and close to said first side wall (7), and connected to a first pipe (12) for evacuating the oil mist sucked in by and towards treatment means making it possible to capture the oil particles from the mist and to discharge the purified air, - an axial orifice (16) arranged between the casing (14) and the shaft (3) on the side opposite the bearing (2), to connect the outside of said casing (14) and said annular space (15),and - a radial orifice (17) arranged between the casing (14) and said first side wall (7), to connect the exterior of said casing (14) and said annular space (15)., Suction device (1) according to claim 1, characterized in that it comprises: - a second oil mist collector (11) comprising a casing (22) arranged to be placed around the shaft (3), so as to leave an annular space (23) between it and said shaft (3), and close to said second side wall (8), and connected to a second pipe (13) for evacuating the oil mist sucked in by and towards treatment means making it possible to capture the oil particles from the mist and to discharge the purified air, - an axial orifice (24) arranged between the casing (22) and the shaft (3) on the side opposite the bearing (2), to connect the exterior of said casing (22) and said annular space (23), and - a radial orifice (25) arranged between the casing (22) and said second side wall (8), to connect the exterior of said casing (22) and said annular space (23). Suction device (1) according to claim 2 characterized in that each casing (14, 22) comprises at least: - a suction chamber (18, 26) of generally annular shape arranged around the shaft (3) and having a radial opening (19, 27) located on the side of said shaft (3) and connecting the corresponding annular space (15, 23) and the interior of said suction chamber (18, 26), - a homogenization chamber (20, 28) arranged around said suction (18, 26) and connected respectively to the first and second corresponding pipes (12, 13), and - a transfer orifice (21, 29) connecting the interior of said suction chamber (18, 26) and the interior of said homogenization chamber (20, 28).

4. Suction device (1) according to any one of claims 2 to 3 characterized in that each axial orifice (16, 24) has an annular shape surrounding the shaft (3).

5. Suction device (1) according to any one of claims 2 to 4, characterized in that each radial orifice (17, 25) is in the overall shape of a perimeter groove.

6. Suction device (1) according to any one of claims 2 to 5, characterized in that each casing (14, 22) comprises a plurality of transfer orifices (21, 29) arranged so as to create restrictions which have the function of uniformly distributing the air flow all around the circumference of the rotating shaft (3).

7. Suction device (1) according to any one of claims 3 to 6, characterized in that the first oil mist collector (10) comprises a ring (30) for deflecting seeping oil arranged to be placed around said shaft (3) in line with the radial opening (19) of the suction chamber (18) of said first collector (10).

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