Rotating machinery and the main motor-pump assembly on which the rotating machinery is installed

Abstract

The present invention relates to a rotating machine (10) comprising an oil-sealed device (35) having an external air suction groove (52). The invention is characterized in that the device (35) includes a groove (252) in the lower portion (321) of the wall (320) and / or the lower portion (361) of the rotating component (360) for drawing air from a suction region (253) located between an upper opening (322) of the housing (32) and the air suction groove (252), the groove (252) extending from the region (253) to an air collection region (254), and is configured to draw air from the compartment (31) through the region (253) and through the opening (322) of the housing toward the region (254) when the shaft (33) rotates in a predetermined rotational direction (S).

Description

Technical Field

[0001] The present invention relates to a rotating machine and a motor-driven pump unit equipped with such a rotating machine. Background Technology

[0002] The scope of this invention generally relates to rotating machinery that requires oil lubrication. This is, for example, the motors of circulating water pumps installed in the main circuit of a nuclear power plant; hereinafter, these circulating pumps and their respective motors will be referred to as main motor driven pump units. The scope of application can be extended to turbines, pumps, motors, alternators, and any other machinery or equipment involving rotating shafts.

[0003] According to a first prior art known in document WO2022 / 248220 A1, a rotating machine is known, which includes a housing, a rotating shaft rotatably mounted in the housing, an oil compartment for lubricating bearings defined by the housing, and an oil sealing device including an external air suction groove located between a rotating component fixed to the shaft and an upper portion of the housing, so as to draw air through the groove toward the compartment when the shaft rotates in a predetermined rotational direction.

[0004] Therefore, in this known rotating machinery, the oil compartment is pressurized relative to the outside air, and this pressurization is associated with the air inlet in the oil tank via grooves and with the pressure loss of the exhaust filter connected to the compartment.

[0005] Therefore, the first problem posed by this first prior art is that, in the event of failure of the static seal of the compartment (e.g., failure at a static joint located elsewhere on the housing and which should seal the housing to contain oil), oil-laden air can easily contaminate the exterior of the machine. In particular, for large rotating machinery, especially older (not new) machinery, properly sealing the bearings can sometimes be complex.

[0006] Furthermore, in a second prior art of other known rotating machinery (which has a sealing device with baffles and bevels, rather than grooves, located between the rotating parts and the upper components of the housing), operational experience feedback highlights the problem of oil leakage via splashing at the upper bearing of the motor in the motor-driven pump unit. Calculations and experiments have confirmed that the rotation of the inertial flywheel causes pressure loss and accelerates the air in the section below the flywheel.

[0007] Therefore, the second problem posed by this second prior art is that the dynamic tortuous seal cannot effectively block such pressure loss or turbulence. Consequently, oil flows back from the oil compartment to the open air via this dynamic tortuous seal in the form of splashed oil. Summary of the Invention

[0008] The object of the present invention is to provide a rotating machine and a main motor-driven pump unit equipped with such a rotating machine, which solves the first and second problems mentioned above, and enables more robust limitation or even more extensive elimination of oil leakage originating from the oil compartment.

[0009] For this purpose, the first subject of the present invention is a rotating machine comprising a housing, at least one rotating shaft along a predetermined direction of rotation, and at least one guide bearing mounted in the housing and the rotating shaft rotatably mounted in the guide bearing.

[0010] The housing defines a compartment for containing a certain volume of air and a certain volume of lubricating oil to lubricate the bearing.

[0011] The rotating machinery includes a rotating component in the upper opening of the housing, the rotating component being rotatably attached to a rotating shaft, and the rotating component being surrounded by a wall at a distance from the bearing in a direction transverse to the rotating shaft.

[0012] The rotating machinery includes an oil seal device located between the rotating components and the wall, and a device for filtering the air in the compartment and discharging the air to the outside of the compartment.

[0013] The oil sealing device includes at least one first groove for drawing in external air in the direction of shaft rotation.

[0014] Its features are,

[0015] The oil sealing device includes at least one second groove in the lower portion of the wall and / or the lower portion of the rotating component for drawing air from a suction region in the direction of shaft rotation. This suction region is located between the upper opening of the housing and the second air suction groove, and is first in communication with the upper opening of the housing and secondly in communication with the first air inlet.

[0016] The second air suction groove extends from the suction area to the air collection area and is configured to draw air from the compartment through the suction area and through the upper opening of the housing toward the air collection area when the shaft rotates in a predetermined rotational direction.

[0017] The air collection area is located between the first external air suction groove and the second air suction groove, and is connected to the first air outlet.

[0018] The first external air suction groove is located in the upper part of the wall and / or the upper part of the rotating component, and is configured to draw air from the opening in the upper part of the wall toward the air collection area when the shaft rotates in a predetermined rotational direction.

[0019] With the aid of this invention, rotation of the shaft in a predetermined direction generates a pressure loss relative to the outside air in the oil compartment via a second groove. This pressure loss is due to air being drawn in by the second groove as the shaft rotates in the predetermined direction, as well as pressure loss due to the first air inlet. The pressure loss level in the oil compartment is very low (equal to the pressure loss at the first air inlet).

[0020] Therefore, the present invention, through the pressure loss caused by the second groove, can prevent oil-laden air from escaping from the inside of the compartment to the outside via the channel point in the case where the housing of the oil compartment fails and includes an undesirable channel point (such as at the static joint of the housing) in addition to the upper opening of the housing. This solves the first problem mentioned above, and by forcing the outside air back into the compartment via the leakage point due to this pressure loss, the sealing of the entire bearing can be guaranteed.

[0021] The present invention can also form an effective barrier against turbulence present in the oil compartment and prevent oil from flowing back into the open air in the form of splashing from the oil compartment through the sealing device located at the upper opening of the housing, which solves the second problem mentioned above.

[0022] According to an embodiment of the present invention, the device for filtering air from a compartment and discharging air to the outside of the compartment includes a second air inlet connected to a first air outlet, and further includes a first filter for separating air and oil received at the second air inlet.

[0023] The first filter is capable of delivering filtered oil to the filtered oil outlet connected to the oil inlet of the compartment.

[0024] According to an embodiment of the present invention, the apparatus for filtering air in a compartment and for discharging air to the outside of the compartment includes a second air inlet connected to a first air outlet, and a first filter for separating air and oil received at the second air inlet.

[0025] The first filter is capable of delivering filtered oil to a filtered oil outlet connected to the oil inlet of the compartment, and delivering filtered air to a filtered air pipe disposed between the first filter and a passage for discharging filtered air to the outside of the compartment.

[0026] According to another embodiment of the invention, the device for filtering the air in the compartment includes a second air inlet connected to a first air outlet, and a first filter for separating the air and oil received at the second air inlet.

[0027] The first filter is capable of delivering filtered oil to a filtered oil outlet connected to the oil inlet of the compartment, and delivering filtered air to a filtered air pipe disposed between the first filter and an air suction passage for a motor-driven fan for drawing air to the outside of the compartment.

[0028] According to an embodiment of the present invention, a first air inlet is connected to a filter for drawing air from the outside, and the first air inlet is located between the suction filter and the suction area.

[0029] According to another embodiment of the invention, a first air inlet is connected to a filtered air duct and extends between the first filter and the passage to the filtered air duct.

[0030] According to an embodiment of the present invention, the suction region includes a first bend for air passage and / or a first baffle for air passage.

[0031] According to an embodiment of the present invention, the air collection area includes a second bend for air passage and / or a second baffle for air passage.

[0032] According to an embodiment of the present invention, the air collection area includes at least one air guiding wall located at a distance between and from the first external air suction groove and the second air suction groove.

[0033] The at least one air guide wall extends toward the first air outlet along the common guiding direction of air from the first external suction groove abutting against the first surface of the air guide wall and air from the second air suction groove abutting against the second surface of the air guide wall.

[0034] The second surface of the air guiding wall is opposite to the first surface of the guiding wall.

[0035] The air collection area also includes an air mixing area located at one end of the air guide wall, which is downstream along the guide direction.

[0036] The air mixing zone is located between the air guide wall and the first air outlet.

[0037] According to an embodiment of the present invention, the first external air suction groove is inclined at a non-zero first predetermined angle relative to a plane transverse to the axis, and extends about the extension direction of the axis, the axis being rotatable about the extension direction in a predetermined rotational direction.

[0038] The second air suction groove is inclined at a non-zero second set angle relative to the plane and extends around the extension direction of the axis.

[0039] The first angle is oriented in a direction opposite to the second angle relative to the plane.

[0040] According to an embodiment of the present invention, the first external air suction groove is spiral-shaped in its extension direction around the shaft.

[0041] The second air suction groove extends in a spiral shape around the shaft.

[0042] According to an embodiment of the present invention, the wall, the first air inlet, the suction area, the first external air suction groove, the second air suction groove, the opening of the upper portion of the wall, the air collection area, and the first air outlet are components of a removable module, including at least one first removable connecting fitting to removably connect the suction area to the upper opening of the housing.

[0043] The second subject of the invention is a main motor driven pump unit intended to be installed in at least one pressurized main water circuit in a nuclear power plant. The main motor driven pump unit includes a main pump having a pump impeller and a rotating mechanism as described above, the rotating shaft of which is attached to the pump impeller of the main pump for rotational drive.

[0044] According to an embodiment of the present invention, the main motor drives the pump unit, which includes an inertial flywheel attached to a rotating shaft, and the rotating component is an annular wall fixed to the inertial flywheel and extending about the rotating shaft. Attached Figure Description

[0045] The invention will be better understood by reading the following description, which is given only by way of non-limiting example with reference to the accompanying drawings.

[0046] [ Figure 1 A schematic vertical cross-sectional view of a known rotating machine is shown.

[0047] [ Figure 2 It shows Figure 1 A schematic enlarged vertical cross-sectional view of a known rotating machine.

[0048] [ Figure 3 The diagram shows a schematic perspective view of the main circuit of a nuclear power plant, in which rotating machinery according to an embodiment of the invention can be installed.

[0049] [ Figure 4 It shows Figure 3 A schematic open perspective view of the main motor drive pump unit of the main circuit, which may include rotating machinery according to embodiments of the present invention.

[0050] [ Figure 5 It shows Figure 4 A schematic vertical cross-sectional view of a portion of the main motor drive pump unit of the main circuit, which may include rotating machinery according to embodiments of the present invention.

[0051] [ Figure 6 This image shows a schematic vertical cross-sectional view of a portion of a rotating machine according to an embodiment of the present invention in normal mode.

[0052] [ Figure 7 The diagram shows a schematic vertical cross-sectional view of a portion of a rotating machine according to an embodiment of the present invention in a degradation mode.

[0053] [ Figure 8 The diagram shows a schematic vertical cross-sectional view of a portion of a rotating machine according to a variant of the invention in normal mode. Detailed Implementation

[0054] Overall reference Figure 1 and 2 The rotating machinery 10 known in the second prior art includes a housing 32 and a rotating shaft 33 on guide bearings 22, 23, and 24. The housing 32 contains a certain volume of lubricating oil 310 to lubricate the bearings 22, 23, and 24. The rotating machinery 10 includes a rotating component 360 rotatably attached to the rotating shaft 33. The rotating machinery 10 includes an oil seal device 35 located between the rotating component 360 fixed to the shaft 33 and the upper component 320 of the housing 32.

[0055] In the field of rotating machinery 10, which is a pump unit driven by a main motor and formed by a motor installed in the main circuit of a nuclear power plant, such a sealing device 35 is known. It is formed by a baffle and a curved sealing system 35 located between the rotating component 360 and the upper component 320 of the housing 32, such as... Figure 1 and Figure 2 As shown.

[0056] The device 35 is often referred to as a “sealing device” because it enables the lubricant to be prevented from leaking from the housing 32 to the outside of the housing.

[0057] This limitation of leakage will not result in a complete seal. However, it depends on several parameters, including, but not limited to:

[0058] - Baffle length: The longer the baffle, the more the leakage is limited.

[0059] - The number of teeth between the baffle and the rotating component: The more teeth, the better the leakage limitation.

[0060] - The distance between the rotating component 360° and the end of the tooth of the curved diameter: the smaller this distance, the greater the improvement in leakage limitation.

[0061] - Pressure and velocity fluctuations originating from rotating components, including the rotating shaft 33 itself (in the case of a pump unit driven by a main motor, combined with an inertial flywheel 36): the smaller these fluctuations are, the more the limitation on leakage is improved.

[0062] Therefore, the second problem arising from the aforementioned second prior art of the rotating machinery 10 with a baffle and a curved seal 35 is that the rotation of the shaft 33 and the presence of oil 310 in the housing cause oil to leak to the outside at the seal 35 between the shaft 33 and the housing 32. Pressure changes and turbulence associated with motor operation (especially the rotation of the shaft 33) cause the oil to migrate by diffusion and pass through the installed seal 35. Specifically, the rotation of the shaft 33 in contact with the oil generates oil splashing, and the oil spray escapes through the seal 35 between the shaft 33 and the housing 32, forming a leakage path, such as... Figure 2 As indicated by arrow F in the diagram. Therefore, the oil-laden air flows along... Figure 1 Arrow M shown is released into the environment of the rotating machinery 10 and will cause oil contamination on different surfaces and equipment located near the rotating machinery 10.

[0063] Reference Figure 1 and Figure 2 In some of the known rotating machinery 10 having the aforementioned second prior art baffle and curved sealing device 35, in order to limit oil leakage at the device 35, a device 100 for filtering oil-laden air is provided, which is connected to a motor-driven fan 101. The filtering device 100 is designed to ensure the separation of oil contained in the air, which is then reinjected into the housing 32. The motor-driven fan 101 provides pressure relief to the housing 32 relative to the external pressure of the machinery, thereby generating an airflow from outside the machinery and through the sealing device 35, which has the effect of limiting the backflow of oil mist 39 from the housing 32 through the sealing device 35.

[0064] This known rotating machinery 10 has the disadvantage of requiring a motor-driven fan / exhaust fan 101, which must be powered to operate (or even mechanically driven). This type of motor-driven fan / exhaust fan 101 has high installation costs, especially in nuclear power plants, due to the large number of components to be installed, such as lead wires, cables, and control / command components. Furthermore, this installation adds extra maintenance costs, including routine maintenance of the motor-driven fan / exhaust fan 101 (bearing replacement, mechanical repairs). Finally, this installation results in high operating costs due to the high power consumption of the motor-driven fan.

[0065] Furthermore, dynamic sealing of the main pump motor bearings has become the subject of various modifications (including the shape of the bend 35, an increase in the number of teeth forming the bend, and the addition of fins under the cover 38 of the inertial flywheel 36). However, these modifications do not guarantee a low level of oil leakage.

[0066] Usually, in Figures 3 to 8The rotating machinery 10 according to the invention includes a housing 32, at least one rotating shaft 33 along a predetermined rotation direction S, and at least one guide bearing 22, 23, 24 mounted in the housing 32, the rotating shaft 33 being rotatably mounted in the guide bearings 22, 23, 24. In an embodiment of the invention, the rotating machinery 10 can operate as a motor. In another embodiment, the rotating machinery 10 can operate as a generator. The rotating shaft 33 is rotatable about its extension direction D in the predetermined rotation direction S. The housing 32 defines a compartment 31 designed to contain a volume of air 34 and a volume of liquid lubricating oil 310 to lubricate the bearings 22, 23, 24.

[0067] The rotating machinery 10 includes a rotating component 360 rotatably attached to a rotating shaft 33. The rotating shaft 360 passes through an upper opening 322 of a housing 32. The rotating component 360 is surrounded by a wall 320 in a direction transverse to the rotating shaft 33 and at a distance from bearings 22, 23, and 24. The rotating component 360 surrounds the rotating shaft 33 and may be annular about the extending direction D of the shaft 33, or, for example, cylindrical about that direction D. The rotating machinery 10 includes a through-hole 50 of the shaft 33 in the upper opening 322 of the housing 32. In this through-hole 50, the rotating component 360 faces and is surrounded by the wall 320, which is transverse to the rotating shaft 33 and spaced a distance from bearings 22, 23, and 24. The wall 320 may be annular about the extending direction D of the shaft 33 and may be cylindrical about that direction D.

[0068] The rotating machinery 10 includes an oil seal 35 located between a rotating component 360 and a wall 320, and a device 100 for filtering air from the compartment 31, which separates air from the oil. The oil seal 35 is located at a distance from bearings 22, 23, and 24. A shaft 33 passes through the housing 32 and the oil seal 35. According to an embodiment of the invention, the air filter 100 is configured to re-inject oil that has been captured by the filter 100 into a volume of oil 310.

[0069] exist Figure 3 , Figure 4 and Figure 5 An example of the use of the rotating machinery 10 according to the invention is a main motor driven pump unit 2 installed in the main circuit 20 of a nuclear power plant. This main motor driven pump unit 2 includes a main pump 28 having a pump impeller 280 and the rotating machinery 10 according to the invention, which operates as a motor. A rotating shaft 33 is attached to the pump impeller 280 of the main pump 28, such that rotation of the shaft 33 drives rotation of the pump impeller 280. Of course, the rotating machinery 10 according to the invention can be used in other places besides the main motor driven pump unit 2. Other application examples include bearing seals for turbines, alternators, pumps, and motors.

[0070] exist Figure 3 In a nuclear power plant, for example, a main water circulation loop 20 with a pressurized water reactor includes one or more main water circulation loops 11a, 11b, 11c connected to a water tank 1. In each main water circulation loop 11a, 11b, 11c, there is a main motor-driven pump unit 2 and a steam generator 3 for continuously pumping water from the water tank 1 to the steam generator (in the water circulation direction S1), then from the steam generator 3 to the upstream inlet channel 29 of the main motor-driven pump unit 2 (in the water circulation direction S2), and finally from the downstream outlet channel 30 of the main motor-driven pump unit 2 back to the water tank 1 (in the water circulation direction S3). One of the main loops 11a, 11b, 11c, such as main loop 11a, includes a water pressurizer designed to control the pressure of the entire main loop 20.

[0071] exist Figure 4 The image shows an example of a main motor-driven pump unit 2, including a rotating machine 10 that operates as a motor, and from top to bottom includes:

[0072] - An inertial flywheel 36 attached to the upper part of the rotating shaft 33.

[0073] - Upper guide bearings 22, 23, and 24, which include an upper radial guide bearing 22 and double stops, namely a lower axial stop bearing 24 and an upper axial stop bearing 23.

[0074] - Rotor-stator assembly 25, wherein the rotor is attached to the middle portion of the rotating shaft 33 and the stator is attached to the housing 32, the stator being rotatably capable of driving the rotor and the rotating shaft 33.

[0075] - Lower radial guide bearing 26.

[0076] -Motor bracket 27, which is attached to the lower part of the motor frame 32.

[0077] - Main pump 28, which includes a volute casing of the main pump, a pump impeller 280 of the main pump, a diffuser of the main pump, a sealing device of the main pump, and a pivoting component of the main pump.

[0078] The lower bearing 26 has its own oil housing (different from the upper bearings 22, 23, 24) and its own oil, and therefore is not involved in the leakage problem according to the invention (separate from the leakage problem of the upper bearing).

[0079] according to Figure 1 In order to ensure the operation of the rotating machinery 10 (and the main motor drive pump unit 2, if the rotating machinery 10 is used therein) and to limit friction, the pivoting components 22, 23, 24 of the rotating machinery 10, such as radial guide bearing 22 and axial stop bearings 23, 24, are lubricated with oil 310 located in the compartment 31 of the housing 32.

[0080] refer to Figure 1 During operation, due to the rotation of shaft 33 and the operation of bearings 22, 23, and 24, especially the operation of upper guide bearing 22, oil mist 39 is generated, until the air 34 above the liquid surface 313 of oil 310 in compartment 31 is filled with oil vapor and fine oil mist 39. More than 95% of the oil droplets in this mist 39 have a size between 0.15 and 1.0 μm.

[0081] In the above Figure 1 and Figure 2 In the second prior art case, fog 39 along such Figure 5 The path B shown is a loop in which the mist 39 diffuses into two separate paths, the first along the internal leakage path FI and the second along the external leakage path F, which passes through the seal 35 and creates an external overall leakage path M carrying oil. Due to the dynamic control of the leakage F, the present invention attempts to limit or eliminate this external overall leakage path.

[0082] exist Figure 1 and Figure 2 In the second prior art, the dynamic seal between the oil housing 32 and the rotating component 360 of the rotating machinery 10 is provided by a baffle / torque sealing system 35. The purpose of this dynamic sealing device 35 is to prevent mist / oil vapor 39 from transferring from the interior of the housing 32 to the exterior 60 of the housing 32.

[0083] Nevertheless, the above Figure 1 and Figure 2 The second prior art raises the following second problem: pressure fluctuations and air circulation associated with the operation of the rotating machinery 10, particularly the rotation of the shaft 33, allow air 34 carrying oil 39 to migrate by diffusion and pass through the dynamically positioned seal 35, such as... Figure 1 As indicated by arrow M, air 34 carrying oil 39 is released along arrow M into the environment 60 of the rotating machinery 10, undesirably causing oil contamination on various surfaces and equipment near the rotating machinery 10 outside the compartment 31 of the housing 32. Figures 3 to 5 When the main motor drives the pump unit 2, the presence of the inertial flywheel 36 exacerbates this phenomenon. Then, the air 34 carrying oil 39 is discharged to the outside 60 of the rotating machinery 10 through the vent 37 of the housing 38 of the inertial flywheel 36 that protects the rotating machinery 10.

[0084] In order to resolve the above Figure 1 and Figure 2Regarding the second problem mentioned above related to the second type of prior art, the object of the present invention is to limit or even eliminate all these disadvantages by providing a device for providing dynamic sealing on rotating machinery 10 in operation, through a device incorporated in the manufacture and implementation of such rotating machinery 10. The object of the present invention is to significantly reduce the need for lubrication... Figure 6 , Figure 7 and Figure 8 Rotating machinery 10 (e.g., according to Figures 3 to 5 Oil leaks (M) are caused by splashing oil / oil mist emitted into the atmosphere from the motor of a water circulation pump operating in a nuclear power plant.

[0085] According to the present invention, such as Figure 6 , Figure 7 and Figure 8 As shown, the oil sealing device 35 includes one (or more) first grooves 52 for drawing in external air in the rotational direction S of the shaft 33.

[0086] The oil sealing device 35 includes one (or more) second air suction grooves 252 in the lower portion 321 of the wall 320 and / or the lower portion 361 of the rotating component 360, starting from the suction region 253 in the rotational direction S of the shaft 33. The suction region 253 is located between the upper opening 322 of the housing 32 and the second air suction grooves 252. The suction region 253 communicates with the upper opening 322 of the housing 32 on one hand and with the first air inlet 255 on the other. The first air inlet 255 allows airflow into the suction region 253 and can generate a pressure drop, which creates a pressure loss relative to the external air inside the oil compartment 31.

[0087] The second air suction groove 252 extends from the suction region 253 to the air collection region 254. This second air suction groove 252 is configured to draw air from the compartment 31 through the suction region 253 and through the upper opening 322 of the housing 32 toward the air collection region 254 when the shaft 33 rotates in the predetermined rotational direction S. Therefore, the second air suction groove 252 is configured to draw air from the suction region 253 to the air collection region 254 when the shaft 33 rotates in the predetermined rotational direction S, and thus draw air from the upper opening 322 of the housing 32 to the air collection region 254 and the first air outlet 115. The oil-laden air in the compartment 31 is therefore discharged to the outside via the first air outlet 115.

[0088] The air collection area 254 is located between the first external air suction groove 52 and the second air suction groove 252. The air collection area 254 is connected to the first air outlet 115.

[0089] A first external air suction groove 52 is located in the upper portion 323 of the wall 320 and / or the upper portion 363 of the rotating component 360. The first external air suction groove 52 extends from the opening 324 of the upper portion 323 of the wall 320 to the air collection area 254. The first external air suction groove 52 is configured to draw air from the opening 324 of the upper portion 323 of the wall 320 toward the air collection area 254 when the shaft 33 rotates in a predetermined rotational direction S.

[0090] Air collection area 254 is located between the upper portion 323 and the lower portion 321 of wall 320.

[0091] Therefore, when the shaft 33 rotates in the predetermined rotation direction S, the second air suction groove 252 of the present invention allows a pressure loss relative to the external air to be generated in the air volume 24 of the oil compartment. Airflow drawn from the opening 324 of the upper portion 323 of the wall 320 to the air collection area 254 by the first external air suction groove 52... Figure 6 , Figure 7 and Figure 8 Arrow AA) acts as the air carrying oil ( Figure 6 , Figure 7 and Figure 8 The arrows DD and EE) obstruct the return flow, and the oil-laden air is transported from the suction area 253 to the air collection area 254 via the second air suction groove 252.

[0092] like Figure 6 and Figure 8 As shown, in the first case of normal operation, there is no leakage from the housing 32 defining the oil compartment 31 away from the upper opening 322, and a static seal between the bearing and the oil compartment 31 is ensured, for example, by the static joint of the bearing (in addition to the dynamic seal). In this case, most of the air drawn in by the second groove 252 comes from the first air inlet 255 ( Figure 6 and Figure 8 Arrows BB and CC in the image), a relatively small portion comes from inside oil compartment 31 ( Figure 6 and Figure 8 (The arrow DD in the image).

[0093] In the second case of degradation operation, such as Figure 7 As shown, there is a passage point PF (or fault area PF) in the housing 32 away from the upper opening 32, caused, for example, by a failure of the static joint of the bearing (other than the dynamic seal). Without the present invention, this passage point PF causes oil or oil-laden air to leak from the compartment 31 outward through this passage point PF, and it is considered that the static seal of the bearing and the oil compartment 31 is no longer fully guaranteed.

[0094] In the second case of degradation operation, such as Figure 7 As shown, the present invention ensures that during the rotation of shaft 23 in a predetermined rotational direction S, the air drawn in by the second groove 252 causes a pressure loss in the oil compartment 31 relative to the outside air. Therefore, unoil-laden outside air is drawn from the outside of housing 32 into compartment 31 via passage point PF, preventing oil-laden air from escaping through this passage point PF. This solves both the first and second problems mentioned above. A portion of the drawn air originates from the first air inlet 255 ( Figure 7 (Arrows BB and CC in the image), another part comes from inside oil compartment 31 ( Figure 7 Arrow DD in the diagram and arrow EE passing through the external air at point PF.

[0095] One or more grooves may be provided in the first air suction groove 52.

[0096] According to embodiments of the present invention, such as Figure 6 , Figure 7 and Figure 8 As shown, the rotating component 360 (or rotor) fixed to the shaft 33 does not contact the wall 320 (or stator) of the housing 32, and the first air suction groove 52 is located between the rotating component 360 fixed to the shaft 33 and the wall 320. Therefore, the sealing device 35 does not contact the through portion 50 of the shaft 33 in the housing 32.

[0097] According to embodiments of the present invention, such as Figure 6 , Figure 7 and Figure 8 As shown, the first air suction groove 52 extends from the opening 324 at the upper air suction end 521 of the upper portion 323 of the rotating component 360 and / or wall 320 to an upper intermediate portion 522, which is used to discharge air from the upper portion 323 of the rotating component 360 and / or wall 320. The upper air suction end 521 is located on one side of the opening 37 of the rotating machinery 10 that communicates with the outside air 60. The upper intermediate air discharge portion 522 leads to the air collection area 254.

[0098] According to one embodiment of the present invention, the first air suction groove 52 is configured (oriented) to draw air from the upper end 521 toward the upper middle portion 522, i.e., from the air-connecting openings 37, 324 toward the air collection area 254 when the shaft 33 rotates in a predetermined rotational direction S. Figure 6 and Figure 7 (Arrow AA in the image).

[0099] According to embodiments of the present invention, such as Figure 6 , Figure 7 and Figure 8As shown, the second air suction groove 252 extends from the opening 325 of the lower air suction end 524 of the lower portion 321 of the rotating component 360 and / or wall 320 to the lower intermediate air discharge portion 523 of the lower portion 321 of the rotating component 360 and / or wall 320. The lower air suction end 524 leads to the suction area 253. The lower intermediate portion 523 for injecting air is located below the upper intermediate air discharge portion 522. The lower intermediate air discharge portion 524 leads to the air collection area 254.

[0100] According to an embodiment of the present invention, the second air suction groove 252 is configured (oriented) to draw air from the lower air suction end 524, i.e., from the suction region 253, toward the lower middle air discharge portion 523, i.e., toward the air collection region 254, when the shaft 33 rotates in a predetermined rotation direction S. Figure 6 , Figure 7 and Figure 8 (The arrow BB in the middle).

[0101] According to embodiments of the present invention, such as Figures 1 to 8 As shown, the rotation axis 33 is vertical and can rotate about the extension direction D of the axis 33 in a specified rotation direction S, which is the vertical direction Z.

[0102] According to another embodiment of the invention (not shown), the rotation axis 33 is not vertical and is capable of rotating about its extension direction D in a predetermined rotation direction S, which is not parallel to the vertical direction Z. The spatial orientation of the extension direction D can be greater than 0 degrees relative to the horizontal plane.

[0103] In the remainder of this document, reference will be made to a rotating machine 10 with rotation axis 33 shown along vertical axis D, Z (i.e. at a 90-degree angle relative to the horizontal plane); however, the scope of the invention relates to any type of rotating machine, regardless of the spatial orientation of rotation axis D, which may be between 0 and 90 degrees relative to the horizontal plane.

[0104] According to embodiments of the present invention, such as Figure 6 , Figure 7 and Figure 8 As shown, the first air suction groove 52 is continuous from the opening 324 of the upper part 323 of the wall 320 to the air collection area 254.

[0105] According to embodiments of the present invention, such as Figure 6 , Figure 7 and Figure 8 As shown, the second air suction groove 252 is continuous from the suction area 253 to the air collection area 254.

[0106] According to embodiments of the present invention, such as Figure 6 , Figure 7 and Figure 8 As shown, the first external air suction groove 52 is inclined at a non-zero first determined tilt angle ANG1 relative to the transverse (orthogonal) plane PT of the shaft 33, and extends about the extension direction D of the shaft 33, which is capable of rotating about the extension direction in a predetermined rotation direction S. For example, when the direction D of the shaft 33 is vertical, the plane PT is horizontal.

[0107] According to embodiments of the present invention, such as Figure 6 , Figure 7 and Figure 8 As shown, the set angle ANG1 relative to the transverse plane PT is between 0° and 60°, particularly between 1° and 45°, for example, between 1° and 25°. The number of grooves 52 connected to each other along direction D, the depth of the grooves in the transverse plane PT, the shape of the grooves, the angle ANG1 of the grooves with respect to the normal of the extending direction D, the length of the sealing device 35 along the extending direction D, and the radial clearance between the outer diameter of the rotating component 360 and the inner diameter of the wall 320 (in the direction of the transverse plane PT, starting from direction D) depend on the geometry of the area 50 to be sealed and the functional parameters of the machinery (vibration level, clearance at bearings, etc.). According to an embodiment of the present invention, on the main pump motor 28, the number of grooves is greater than or equal to 1 and less than or equal to 150, the depth of the groove 52 is between 0 and 30 mm, the angle ANG1 between the groove and the normal of the extension direction D is between 0 and 60°, the length of the sealing device 35 along the extension direction D is between 0 and 200 mm, and the radial clearance between the outer diameter of the rotating member 360 and the inner diameter of the upper portion 320 is greater than 0 mm and less than or equal to 6 mm.

[0108] The second air suction groove 252 is tilted at a non-zero second determined angle ANG2 relative to the extension direction D of the shaft 33.

[0109] With respect to the plane PT, the first angle ANG1 is oriented in the opposite direction to the second angle ANG2. The first angle ANG1 may have the same absolute value as the second angle ANG2 with respect to the plane PT, but has the opposite sign with respect to the plane PT.

[0110] According to embodiments of the present invention, such as Figure 6 , Figure 7 and Figure 8As shown, the set angle ANG2 relative to the transverse plane PT is between 0° and 60°, particularly between 1° and 45°, for example, between 1° and 25°. The number of grooves 252 connected sequentially along direction D, the depth of the grooves in the transverse plane PT, the shape of the grooves, the angle ANG2 of the grooves with respect to the normal of the extending direction D, the length of the sealing device 35 along the extending direction D, and the radial clearance between the outer diameter of the rotating component 360 and the inner diameter of the wall 320 (in the direction of the transverse plane PT, starting from direction D) depend on the geometry of the area 50 to be sealed and the functional parameters of the machinery (vibration level, clearance at bearings, etc.). According to an embodiment of the present invention, on the main pump motor 28, the number of grooves is greater than or equal to 1 and less than or equal to 150, the depth of the groove 52 is between 0 and 30 mm, the angle ANG2 between the groove and the normal of the extension direction D is between 0 and 60°, the length of the sealing device 35 along the extension direction D is between 0 and 200 mm, and the radial gap between the outer diameter of the rotating part 360 and the inner diameter of the upper part 320 is greater than 0 mm and less than or equal to 6 mm.

[0111] For the first external air suction groove 52 and the second air suction groove 252, the number of grooves connected sequentially along the direction D, the depth of the groove in the transverse plane PT, the shape of the groove, the angle between the groove and the normal in the extension direction D, the length of the sealing device 35 along the extension direction D, and the radial clearance can be different or the same.

[0112] According to embodiments of the present invention, such as Figure 6 , Figure 7 and Figure 8 As shown, the first external air suction groove 52 is in the form of a screw extending from the opening 324 of the upper portion 323 of the wall 320 to the air collection area 254 in a predetermined rotational direction S. This can be a specific implementation of setting angle ANG1, the number of grooves (in this case, each groove is a thread that turns once around the direction D, and the grooves are connected to each other along the direction D), depth, length, and gap.

[0113] According to embodiments of the present invention, such as Figure 6 , Figure 7 and Figure 8 As shown, the first external air suction groove 52 is spiral about the extension direction D of the shaft 33. This can be a specific implementation of setting the angle ANG1, the number of grooves (in this case, each groove is a thread that goes around the direction D once, and the grooves are connected to each other along the direction D), depth, length and gap.

[0114] Therefore, when the shaft 33 rotates in the specified rotation direction S, the first external air suction groove 52 forms a first external pumping screw for air to flow from the opening 324 of the upper portion 323 of the wall 320 to the air collection area 254, and thereby from the opening 324 of the upper portion 323 of the wall 320 to the first air outlet 115.

[0115] According to embodiments of the present invention, such as Figure 6 , Figure 7 and Figure 8 As shown, the second air suction groove 252 is in the form of a screw extending from the suction region 253 to the air collection region 254 along a predetermined rotational direction S. This can be a specific implementation of the setting angle ANG2, the number of grooves (in this case, each groove is a thread that rotates once around the direction D, and the grooves are connected to each other along the direction D), depth, length, and gap.

[0116] According to embodiments of the present invention, such as Figure 6 , Figure 7 and 8 As shown, the second external air suction groove 252 is spiral about the extension direction D of the shaft 33. This can be a specific implementation of setting the angle ANG2, the number of grooves (in this case, each groove is a thread that goes around the direction D once, and the grooves are connected to each other along the direction D), depth, length and gap.

[0117] Therefore, when the shaft 33 rotates in the specified rotation direction S, the second air suction groove 252 forms a second pumping screw for air to flow from the suction area 253 to the air collection area 254, and from the upper opening 322 of the housing 32 to the air collection area 254 and to the first air outlet 115.

[0118] When the first angle ANG1 has the same absolute value as the second angle ANG2 relative to the plane PT and has the opposite sign to the second angle ANG2 relative to the plane PT, the first external pumping screw has a pitch opposite to that of the second pumping screw.

[0119] According to embodiments of the present invention, such as Figure 6 and Figure 7 As shown, a first air inlet 255 is connected externally to an air suction filter 256. The first air inlet 255 is located between the suction filter 256 and the suction zone 253. The suction filter 256 allows incoming airflow to enter the suction zone 253 via the first air inlet 255 to create a pressure drop. This pressure drop generates a pressure loss relative to the outside air inside the oil compartment 31 (this pressure loss is the direct basis for the pressure drop of the filter 256), and allows the air entering the suction zone 253 to be purified, thereby ensuring that there is no contamination in the bearing and ventilation system.

[0120] exist Figure 8 In the variant shown, at the air suction filter 256 of the last embodiment described above, the first air inlet 255 is connected to the filtered air duct 105 and leads to the filtered air duct 105 between the first filter 104 and a passage (a passage 102 for discharging filtered air, or an air suction passage for drawing air to the outside of a motor-driven fan). Therefore, a filtered air recirculation channel 258 is provided to connect the filtered air duct 105 to the first air inlet 255, which leads to the filtered air duct 105 between the first filter 104 and a passage (a vent 102 for discharging filtered air, or an air suction passage for drawing air to the outside of a motor-driven fan). Therefore, in this variant, the air suction filter 256 can be omitted.

[0121] Therefore, in this variant, the air drawn by the second air suction groove 252 is taken directly from the outlet of the ventilation system 100, i.e., from the filtered air duct 105. This arrangement improves the efficiency of the device and eliminates the need for the air suction filter 256, thus reducing its installation cost, as a portion of the purified air from the filtered air duct 105 is recirculated in the channel 258. Specifically, in the filtered air duct 105 at the outlet of the ventilation system 100, the air exiting the filter 104 is clean (free of particles or dust) and free of any oil (99% oil-free). The increased recirculation firstly reduces the outflow of purified air 120 via the inlet passage (filtered air outlet passage 102, ventilation ducts for drawing air to the outside, or air suction passages for motor-driven fans), and secondly, the recirculated air 121 in the inlet 255 (drawn from the filtered air duct 105) passes through the filter 104 again, resulting in better air purification due to this second passage through the filter 104.

[0122] Two points should be noted when operating this variant.

[0123] The first key point is that the suction pressure of the second air suction channel 252 must be kept lower than the ambient pressure (in order to ensure the establishment of pressure loss in the oil compartment 31). To achieve this, if the primary and secondary pressure drops of the supply lines (255, 258) of the second air suction channel 252 are insufficient, a secondary pressure drop can be added at the first air inlet 255, for example, by installing a diaphragm 257 in the first air inlet 255 or in the filtered air recirculation channel 258.

[0124] The second key point is that, in order to avoid heating of the recirculated air 121, the flow rate 121 through the filtered air recirculation channel 258 must be adjusted or cooled relative to the suction flow rate of the first external air suction channel 52 and the power of the first external air suction channel 52 and the second air suction channel 252.

[0125] According to embodiments of the present invention, such as Figure 6 , Figure 7 and Figure 8 As shown, the suction region 253 includes a first bend 2530 for air passage and / or a first baffle 2530 for air passage. The pressure drop of the bend 2530 of the suction region 253 allows for minimizing airflow from inside the compartment 31.

[0126] According to an embodiment of the invention, as shown, the air collection region 254 includes a second bend 2540 for air passage and / or a second baffle 2540 for air passage, for example at the air guide wall 2541 described below. The second bend 2540 and / or the second baffle 2540 can minimize the airflow drawn from the opening 324 of the upper portion 323 of the wall 320 into the air collection region 254 by the first external air suction groove 52. Figure 6 , Figure 7 and Figure 8 The mixing of the airflow (arrow AA) with the airflow delivered from the suction area 253 to the air collection area 254 by the second air suction groove 252 prevents oil from flowing back from the compartment 31 to the first external air suction groove 52.

[0127] According to embodiments of the present invention, such as Figure 6 , Figure 7 and Figure 8As shown, the air collection area 254 may include one or more air guide walls 2541. The one or more air guide walls 2541 are located at a certain distance between and from the first external air suction groove 52 and the second air suction groove 252. Therefore, the one or more air guide walls 2541 are located between the upper portion 323 and the lower portion 321 of the wall 320, and / or between the upper intermediate air discharge portion 522 and the lower intermediate air discharge portion 523. The one or more air guide walls 2541 are used to guide air from the first surface 2542 of the first external air suction groove 52 and air from the second air suction groove 252 towards the second surface 2543 of the air guide wall 2541 along a common guiding direction 2544 oriented towards the first air outlet 115. The second surface 2543 of the air guide wall 2541 is opposite to the first surface 2542 of the air guide wall 2541. The air collection area 254 also includes an air mixing area 2545 located at one end 2546 of the air guide wall 2541, downstream of the first air outlet 115 along the guide direction 2544. The air mixing area 2545 is located between the air guide wall 2541 and the first air outlet 115. The air mixing area 2545 can mix air from the first external air suction groove 52 and air from the second air suction groove 252. The air guide wall 2541 can further minimize the airflow drawn from the opening 324 of the upper portion 323 of the wall 320 into the air collection area 254 by the first external air suction groove 52. Figure 6 , Figure 7 and Figure 8 The mixing of the airflow (arrow AA) and the airflow delivered from the suction region 253 to the air collection region 254 by the second air suction channel 252 further prevents oil from flowing back from the compartment 31 toward the first external air suction channel 52. The air guide wall 2541 allows these airflows to be directed along a common guide direction 2544 oriented toward the first air outlet 115, so that the two airflows abutting the air guide wall 2541 have the most tangential orientation possible, thereby largely preventing their mixing. Then, in the air mixing region 2545, the two airflows will meet and proceed toward the first air outlet 115.

[0128] The first external air suction groove 52 draws air from the opening 324 of the upper part 323 of the wall 320 into the air collection area 254. Figure 6 , Figure 7 and Figure 8 The arrow AA) accelerates and injects it into the air mixing zone 2545.

[0129] According to embodiments of the present invention, such as Figure 6 , Figure 7 and Figure 8 As shown, the device 100 for filtering air in compartment 31 and discharging air to the outside 60 of compartment 31 includes a second air inlet 112 that connects a first air outlet 115 to a filter 104, such as a condensate filter. The filter 104 filters oil-laden air 34 arriving at air inlet 112 to separate oil and air, and delivers the recovered oil to its filtered oil outlet 110, and then to compartment 31 via an oil passage 114 connecting the oil inlet 311 of compartment 31 to the filtered oil outlet 110. The filter 104 delivers filtered air 120 to a filtered air duct 105. The filtered air duct 105 extends from the first filter 104 to a filtered air exhaust passage 102 that vents to the outside 60 of compartment 31. Therefore, the air filtration device 100 can ventilate the oil 310 compartment 31, filter the air 34 contained in the oil 310 compartment 31, separate the air 34 from the oil droplets / vapor 39 in the air, deliver the air 120 without oil 39 to the outside 60 of the housing 32, and return the oil condensate 39 extracted from the air 34 to a certain volume of liquid oil 310 in the compartment 31 via the outlet 110 and the inlet 311. The air 34 carrying oil 39 and particles from the oil compartment 31 passes through the filter medium 150 of the filter 104. The oil droplets and vapor 39 are separated from the air by the filter medium 150. Once separated, the oil droplets 39 aggregate into larger oil droplets and fall through the filter 104 under gravity. The oil condensate 39 is returned to the oil compartment 31 via the oil return system 110, 311, characterized by the fact that this return flow prevents the particulate-laden air 34 located in the housing 32 to be sealed from bypassing one or more filters 104 of the filtration system 100. For example, oil inlet 311 is located above the oil level 313 of a certain volume of liquid oil 310 in compartment 31; therefore, oil condensate 39 returns via inlet 311 above the oil level 313, thereby reducing potential leakage points. Air 120 leaving one or more filter elements 150, in which oil 39 is purified, is discharged into the environment 60 of the rotating machinery 10. The number of filters 104 in the ventilator 100 depends on several parameters, including: the performance of the sealing device 35, the degree of particulate and oil 39 contamination in the air 34 in compartment 31, the required maintenance schedule, and the characteristics of the filters 104 (pressure drop, oil separation efficiency, etc.). Of course, this embodiment can be combined with different embodiments of trenches 52 and 252.

[0130] According to another embodiment of the invention (not shown), the device 100 for filtering the air in compartment 31 and discharging the air to the outside 60 of compartment 31 further includes a filtered air pipe 105 disposed between the first filter 104 and the air suction channel of a motor-driven fan for drawing air to the outside 60 of compartment 31. The air outlet of the motor-driven fan for drawing air is vented to the outside 60 of compartment 31. Of course, this embodiment can be combined with different embodiments of grooves 52 and 252.

[0131] like Figure 6 and Figure 8 As shown, in the first case of normal operation described above, a relatively small portion of the air filtered by the ventilation device 100 comes from inside the compartment 31, so the air discharged through its filtered air exhaust passage 102 after being processed by the filtration system 104 is very clean.

[0132] like Figure 7 As shown, in the second case of the aforementioned deterioration operation, a portion of the air filtered by the venting device 100 comes from compartment 31. Empirical feedback indicates that although the air in compartment 31 carries more oil than in the first case of normal operation, the total volume of oil discharged into oil passage 114 by the filtration system 104 over a year is not zero and may be less than 1 liter.

[0133] The design according to the invention allows for the restriction of clean air from entering the top of the oil compartment 31 (the top containing oil vapor). Therefore, in the first case of normal operation described above, such as... Figure 6 and Figure 8 As shown, almost all the air drawn by the second air suction groove 252 comes from the air suction filter 256 (arrow CC). Therefore, the air filtered by the ventilation device 100 is virtually free of oil vapor (arrow DD), and thus the filter 104 has a longer lifespan and oil emissions to the outside are very limited (an improvement compared to the design according to WO2022 / 248220 A1).

[0134] According to embodiments of the present invention, such as Figure 6 and Figure 8As shown, wall 320, first air inlet 255, suction area 253, first external air suction groove 52, second air suction groove 252, opening 324 of upper portion 323 of wall 320, air collection area 254, and first air outlet 115 are components of removable module 1000. Removable module 1000 includes a first connecting connector for removably connecting suction area 253 to upper opening 322 of housing 32. Removable module 1000 may include a second removable connecting connector for removably connecting first air outlet 115 to second air inlet 112. Wall 320, first air inlet 255, suction area 253, first external air suction groove 52, second air suction groove 252, opening 324 of upper portion 323 of wall 320, air collection area 254, and first air outlet 115 can be made into a single component 1000.

[0135] By forming an "integrated" module 1000, the removable module 1000 or component 1000 can improve the integration of the device and increase its efficiency. Therefore, the removable module 1000 or component 1000 can be directly installed at the outlet of the shaft 33 of rotating machinery (e.g., replacing and as an alternative to a rotary seal), making it suitable for as many machines as possible, and minimizing the adjustments required for installing the removable module 1000 or component 1000 (significantly reducing installation costs).

[0136] According to embodiments of the present invention, such as Figure 5 As shown, the rotating component 360 is an annular wall fixed to the inertia flywheel 36 and extending around the rotation axis 33. The inertia flywheel 36 extends transversely to the extending direction D of the axis 33. The rotating component 360 can be formed of an annular portion, which can take the form of a ring attached to the underside of the inertia flywheel 36. The wall 320 is located at a certain distance below the inertia flywheel 36. The sealing device 35 according to the invention is located at a certain distance below the inertia flywheel 36.

[0137] like Figures 3 to 8 As shown, the present invention also relates to a main motor driven pump unit 2, which is intended to be installed in at least one main pressurized water circuit in a nuclear power plant. The main motor driven pump unit 2 includes a main pump 28 having a pump impeller 280 and a rotating mechanism 10 as described above, the rotating mechanism having a rotating shaft 33 attached to the pump impeller 280 of the main pump 28 for its rotation drive.

[0138] According to embodiments of the present invention, such as Figures 3 to 8 As shown, the main motor drives the pump unit 2, which includes an inertial flywheel 36 connected to and attached to a rotating shaft 33. The rotating component 360 is an annular wall fixed to the inertial flywheel 36 and extending around the rotating shaft 33.

[0139] Of course, the above embodiments, possible variations and examples can be combined with different embodiments of trenches 52 and 252.

[0140] Of course, the above embodiments, features, possible variations and examples can be combined with each other or selected independently of each other.

Claims

1. A rotating machine (10) comprising: The housing (32), at least one rotating shaft (33) along a predetermined rotation direction (S), and at least one guide bearing (22, 23, 24), the guide bearing being mounted in the housing (32) and the rotating shaft (33) being rotatably mounted in the guide bearing. The housing (32) defines a compartment (31) designed to contain a volume of air (34) and a volume of lubricating oil (310) to lubricate the bearings (22, 23, 24). The rotating mechanism (10) includes a rotating component (360) in the upper opening (322) of the housing (32), the rotating component being rotatably attached to the rotating shaft (33), and the rotating component being surrounded by a wall (320) at a distance from the bearings (22, 23, 24) and transverse to the rotating shaft (33). The rotating machinery (10) includes an oil sealing device (35) located between the rotating component (360) and the wall (320), and a device (100) for filtering the air in the compartment (31) and discharging the air to the outside (60) of the compartment (31). The oil sealing device (35) includes at least one first groove (52) for drawing in external air in the rotational direction (S) of the shaft (33). Its features are, The oil sealing device (35) includes at least one second groove (252) in the lower portion (321) of the wall (320) and / or the lower portion (361) of the rotating component (360) for drawing air from a suction region (253) in the rotational direction (S) of the shaft (33), the suction region being located between the upper opening (322) of the housing (32) and the second air suction groove (252), and communicating firstly with the upper opening (322) of the housing (32) and secondly with the first air inlet (255). The second air suction groove (252) extends from the suction region (253) to the air collection region (254) and is configured to draw air from the compartment (31) through the suction region (253) and through the upper opening (322) of the housing (32) toward the air collection region (254) when the shaft (33) rotates in a predetermined rotation direction (S). The air collection area (254) is located between the first external air suction groove (52) and the second air suction groove (252), and is connected to the first air outlet (115). The first external air suction groove (52) is located in the upper portion (323) of the wall (320) and / or the upper portion (363) of the rotating component (360), and is configured to draw air from the opening (324) of the upper portion (323) of the wall (320) toward the air collection area (254) when the shaft (33) rotates in a predetermined rotation direction (S). The device (100) for filtering the air in the compartment (31) and discharging the air to the outside (60) of the compartment (31) includes a second air inlet (112) connected to the first air outlet (115), and further includes a first filter (104) for separating the air and oil received at the second air inlet (112). The first filter (104) is capable of delivering filtered oil to a filtered oil outlet (110) connected to an oil inlet (311) of the compartment (31).

2. The rotating machinery according to claim 1, characterized in that, The first filter (104) is capable of delivering filtered air to a filtered air duct (105), which is disposed between the first filter (104) and a passage (102) for discharging filtered air to the outside (60) of the compartment (31).

3. The rotating machinery according to claim 1, characterized in that, The first filter (104) is capable of delivering filtered air to a filtered air duct (105), which is disposed between the first filter (104) and an air intake passage of a motor-driven fan for drawing air to the outside (60) of the compartment (31).

4. The rotating machinery according to any one of claims 1 to 3, characterized in that, The first air inlet (255) is connected to a filter (256) for drawing air from the outside, and the first air inlet (255) is located between the suction filter (256) and the suction area (253).

5. The rotating machinery according to claim 2 or 3, characterized in that, The first air inlet (255) is connected to the filtered air duct (105) and leads to the filtered air duct (105) between the first filter (104) and the passage (102).

6. The rotating machinery according to any one of the preceding claims, characterized in that, The suction area (253) includes a first bend (2530) for air passage and / or a first baffle (2530) for air passage.

7. The rotating machinery according to any one of the preceding claims, characterized in that, The air collection area (254) includes a second bend (2540) for air passage and / or a second baffle (2540) for air passage.

8. The rotating machinery according to any one of the preceding claims, characterized in that, The air collection area (254) includes at least one air guide wall (2541) located at a certain distance between and away from the first external air suction groove (52) and the second air suction groove (252). The at least one air guide wall (2541) extends toward the first air outlet (115) along the common guiding direction (2544) of the air from the first external air suction groove (52) abutting the first surface (2542) of the air guide wall (2541) and the air from the second air suction groove (2542) abutting the second surface (2543) of the air guide wall (2541). The second surface (2543) of the air guide wall (2541) is opposite to the first surface (2542) of the air guide wall (2541). The air collection area (254) further includes an air mixing area (2545) located at one end (2546) of the air guide wall (2541), the air mixing area being located downstream along the guide direction (2544). The air mixing zone (2545) is located between the air guide wall (2541) and the first air outlet (115).

9. The rotating machinery according to any one of the preceding claims, characterized in that, The first external air suction groove (52) is inclined at a non-zero first set angle (ANG1) relative to a plane (PT) transverse to the shaft (33), and extends about the extension direction (D) of the shaft (33), which is capable of rotating about the extension direction in a predetermined rotation direction (S). The second air suction groove (252) is inclined at a non-zero second set angle (ANG2) relative to the plane (PT) and extends about the extension direction (D) of the axis (33). The first angle (ANG1) is oriented in a direction opposite to the second angle (ANG2) relative to the plane (PT).

10. The rotating machinery according to claim 9, characterized in that, The first external air suction groove (52) is spiral-shaped around the extension direction (D) of the shaft (33). The second air suction groove (252) is spiral in the direction (D) of the extension of the shaft (33).

11. The rotating machinery according to any one of the preceding claims, characterized in that, The wall (320), the first air inlet (255), the suction area (253), the first external air suction groove (52), the second air suction groove (252), the opening (324) of the upper portion (323) of the wall (320), the air collection area (254) and the first air outlet (115) are components of the removable module (1000), including at least one first removable connecting fitting to removably connect the suction area (253) to the upper opening (322) of the housing (32).

12. A main motor driven pump unit (2) intended for installation in at least one pressurized main water circuit of a nuclear power plant, the main motor driven pump unit (2) comprising a main pump (28) having a pump impeller (280) and a rotating mechanism (10) according to any one of the preceding claims, the rotating shaft (33) of the rotating mechanism being attached to the pump impeller (280) of the main pump (28) for rotational drive.

13. The main motor driven pump unit (2) according to claim 12, characterized in that, The main motor drive pump unit (2) includes an inertial flywheel (36) attached to the rotating shaft (33), and the rotating component (360) is an annular wall fixed to the inertial flywheel (36) and extending around the rotating shaft (33).

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