Bearing device for rotary machine

Abstract

To suppress oil leakage of a bearing device having a cooling fan that cools a rotary machine by using a simple structure.SOLUTION: A bearing device 20 includes: a bearing body 22 pivotally supporting a rotating shaft 10; a support cover 30 mounted to a casing 2 of a rotary machine 1; a cooling fan 33 fixed to an outer part 11 of the rotating shaft 10; and a pressure boost member 38 for boosting pressure around an insertion hole 30c through air blowing by the cooling fan 33. The pressure boost member 38 has a cylindrical shape, is located on a radial outer side of a tip part 34c located nearest to the support cover 30 side of a boss 34 of the cooling fan 33, and is located on a radial inner side of an end 35c located on the radial outermost side of a blade part 35 of the cooling fan 33.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a bearing device for a rotary machine. [Background technology]

[0002] The rotating electric machine disclosed in Patent Document 1 is equipped with a cooling fan attached to the rotating shaft in order to cool an object to be cooled (a motor mechanism in a housing). In the bearing structure of this rotating electric machine, the portion of the housing through which the rotating shaft passes becomes low pressure due to the air blown by the cooling fan, which can cause oil leakage. In Patent Document 1, to prevent this oil leakage, an oil thrower and a labyrinth seal are arranged on the rotating shaft, and these are covered by a cover. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-145500 Summary of the Invention [Problem to be solved by the invention]

[0004] In the bearing structure of Patent Document 1, the oil thrower, labyrinth seal, and cover prevent the portion through which the rotating shaft passes from becoming low pressure due to the air blown by the cooling fan, thereby suppressing oil leakage. However, the oil leakage countermeasures in the bearing structure of Patent Document 1 are complicated, and there is room for improvement in simplification.

[0005] An object of the present invention is to suppress oil leakage from a bearing device equipped with a cooling fan that cools a rotating machine, using a simple structure. [Means for solving the problem]

[0006] One aspect of the present invention provides a bearing device for a rotating machine, comprising: a bearing body attached to a mounting hole at an end of a casing of a rotating machine and supporting a rotating shaft; a support cover having an insertion hole through which the rotating shaft passes, attached to the end of the casing and supporting the bearing body; a cooling fan fixed to an outer portion of the rotating shaft protruding outward from the support cover and blowing air into the casing by rotation of the rotating shaft; and a pressure booster member protruding from the support cover or the casing toward the cooling fan and for increasing the pressure around the insertion hole by blowing air by the cooling fan, wherein the cooling fan has a plurality of wing portions protruding radially outward from a boss, and the pressure booster member is cylindrical and is located radially outward of a tip portion of the boss that is located closest to the support cover, and is located radially inward of an end portion of the wing portion that is located outermost in the radial direction.

[0007] The structure of the bearing device of this aspect is simple, since it is simply a configuration in which a booster member protruding toward the cooling fan is provided on the support cover or casing. Meanwhile, the booster member is cylindrical and located radially outward from the tip of the boss and radially inward from the end of the blade. Therefore, most of the air blown by the rotation of the cooling fan flows along the casing to cool the rotating machine, but a part of the air is taken into the booster member. This makes it possible to increase the pressure value in the booster member to the same level as in the pump casing, thereby suppressing leakage of lubricating oil from the inside of the support cover to the outside through the insertion hole and the rotating shaft. Effect of the Invention

[0008] According to the present invention, oil leakage from a bearing device equipped with a cooling fan for cooling a rotating machine can be suppressed with a simple structure. [Brief description of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view showing a single suction pump, which is a rotary machine using a bearing device according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is an enlarged cross-sectional view of part II in FIG. [Diagram 3] 5 is a schematic diagram showing the relationship between the air blown by the cooling fan and the ambient pressure of the bearing device and the pump casing. FIG. [Figure 4] FIG. 13 is a schematic diagram showing the relationship between the air blown and the ambient pressure of the bearing device and the pump casing in a comparative example having no pressure-increasing member. [Diagram 5] 5 is a cross-sectional view similar to FIG. 2, showing a single suction pump using a bearing device according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0011] (First embodiment) 1, a bearing device 20 according to a first embodiment of the present invention is attached to a single suction pump 1, which is an example of a rotary machine. However, the rotary machine may be a pump other than the single suction pump 1, a drive source such as a waterproof motor, or a machine other than a pump that includes a rotating shaft 10 rotated by a drive source (electric motor or internal combustion engine) not shown.

[0012] First, the configuration of a single suction pump 1, which is a rotary machine of this embodiment, will be described with reference to FIG.

[0013] Single suction pump 1 includes a pump casing 2, a rotating shaft 10, an impeller 15, and a drive source (not shown), and discharges liquid (water) sucked in through suction port 3b to the downstream side through discharge port 3e. In the following description, the left side in Fig. 1 may be referred to as the suction side, and the right side in Fig. 1 may be referred to as the drive side.

[0014] The pump casing 2 includes a casing body 3, a cover 4, and a bearing case 6. A bearing device 20 of this embodiment is attached to the driving side end of the bearing case 6.

[0015] The casing body 3 is formed with a liquid flow path 3a for sucking in and discharging liquid. The liquid flow path 3a includes an inlet 3b, an arrangement space 3c, a volute passage 3d, and a discharge port 3e. The inlet 3b is a circular opening located at the left end in FIG. 1, is connected to an upstream pipe, and constitutes an inlet of the liquid flow path 3a. The arrangement space 3c is a space for arranging the impeller 15, and is provided adjacent to the drive side of the inlet 3b. The volute passage 3d is formed in a spiral shape (spiral shape) centered on the axis A of the rotating shaft 10 so as to be located on the outer periphery of the arrangement space 3c. The discharge port 3e is a circular opening located at the upper end in FIG. 1, and is located at the downstream end of the volute passage 3d to constitute an outlet of the liquid flow path 3a. The portion of the casing body 3 located on the drive side of the arrangement space 3c is opened to accommodate the impeller 15, and is closed by a cover 4.

[0016] The cover 4 is attached liquid-tightly to the drive side of the casing body 3, and closes the opening communicating with the arrangement space 3c. The cover 4 is provided with a through hole 4a through which the rotating shaft 10 passes. The gap between the through hole 4a and the rotating shaft 10 is sealed by a mechanical seal (shaft seal device) 5. However, the shaft seal device may be something other than the mechanical seal 5 as long as it is configured to suppress liquid leakage.

[0017] The bearing case 6 is cylindrical and is attached to the drive side of the cover 4. A rolling bearing 7 that supports a rotating shaft 10 is attached to the suction side of the bearing case 6. A mounting hole 6a for mounting a bearing device 20 is formed at the end of the driving side of the bearing case 6. A storage section 6b for storing lubricating oil (not shown) is formed between the rolling bearing 7 and the bearing device 20.

[0018] In order to increase the surface area and improve the cooling performance, a plurality of cooling fins 6c are provided on the outer periphery of the bearing case 6. These cooling fins 6c are radially protruding outward in the radial direction, which is a direction perpendicular to the axis A of the rotating shaft 10, and are plate-shaped extending along the axis A of the rotating shaft 10.

[0019] The rotating shaft 10 is rotatably attached to the pump casing 2. The rotating shaft 10 includes an outer portion 11 which is a first end side protruding to the outside of the pump casing 2, and an inner portion 12 which is a second end side which penetrates through the bearing case 6 including the bearing device 20 and the cover 4 and is disposed within the casing body 3. However, in the case of a rotary machine such as a double suction pump, for example, the second end side of the rotating shaft 10 is disposed in a state protruding to the outside of the pump casing.

[0020] The outer part 11 has a connection part 11a and an attachment part 11b. The connection part 11a is configured by the drive side end (outer end side) of the outer part 11, and is mechanically connected to a drive source via a coupling 13 (see FIG. 3). The attachment part 11b is configured by a portion of the outer part 11 adjacent to the suction side of the connection part 11a. This attachment part 11b is provided with a key hole for attaching the cooling fan 33 provided in the bearing device 20 so that it cannot rotate relative to the drive source.

[0021] The inner portion 12 includes an attachment portion 12a, a shaft-sealed portion 12b, a middle portion 12c, a pair of supported portions 12d, 12e, and a through portion 12f.

[0022] The mounting portion 12a is disposed within the arrangement space 3c of the casing body 3. The sealed portion 12b is formed by a portion located within the through hole 4a of the cover 4 adjacent to the drive side of the mounting portion 12a, and is sealed by a mechanical seal 5. The intermediate portion 12c is formed by a portion located within the accommodation portion 6b of the bearing case 6, and is a large-diameter cylindrical portion positioned between the rolling bearing 7 and the rolling bearing 23 of the bearing device 20.

[0023] The supported parts 12d, 12e are provided adjacent to both sides of the intermediate part 12c. The supported part 12d located on the suction side of the intermediate part 12c is journaled by a rolling bearing 7 and sealed by a labyrinth seal 8a formed in the cover member 8. The supported part 12e located on the drive side of the intermediate part 12c is journaled by a rolling bearing 23 of the bearing device 20. The through part 12f is located within the support cover 30 provided in the bearing device 20, is constituted by a part adjacent to the drive side of the supported part 12e, and is sealed by a labyrinth seal 30d formed in the support cover 30.

[0024] The impeller 15 is disposed in the arrangement space 3c of the casing body 3, and is attached to the mounting portion 12a of the rotating shaft 10 so as not to rotate relative to the rotating shaft 10. The impeller 15 is circular when viewed from the direction in which the axis A of the rotating shaft 10 extends, and is a closed type including a plurality of blade plates 15a extending radially from the rotating shaft 10, a substantially annular front shroud 15b, and a substantially disk-shaped rear shroud 15c. The impeller 15 rotates integrally with the rotating shaft 10 by a drive source. As a result, the impeller 15 sucks in liquid from the opening of the front shroud 15b, and discharges the liquid radially outward from a flow path defined by the blade plates 15a, the front shroud 15b, and the rear shroud 15c to the volute passage 3d.

[0025] Next, the bearing device 20 of this embodiment will be specifically described with reference to FIG.

[0026] The bearing device 20 includes a bearing body 22 , a support cover 30 , a cooling fan 33 , a pressure boosting member 38 , and a guide cover 45 .

[0027] The bearing body 22 is constituted by a pair of rolling bearings 23 and supports the rotating shaft 10. Each rolling bearing 23 includes an inner ring 24, an outer ring 25, and a plurality of rolling elements 26. The inner ring 24 is annular with an inner diameter equal to the outer diameter of the supported portion 12e of the rotating shaft 10, and is disposed in close contact with the supported portion 12e. The outer ring 25 is annular with an inner diameter larger than the outer diameter of the inner ring 24 and an outer diameter equal to the diameter of the mounting hole 6a of the pump casing 2, and is disposed in close contact with the hole wall of the mounting hole 6a. The rolling elements 26 are spherical and disposed between the inner ring 24 and the outer ring 25 so as to be able to roll. However, the rolling elements 26 may be cylindrical extending along the axis A of the rotating shaft 10. An outer ring 25 of the rolling bearing 23 located on the suction side is positioned by an annular positioning member 27 arranged on the hole wall of the mounting hole 6a of the pump casing 2, and movement towards the suction side is restricted.

[0028] The support cover 30 includes a cover body 30a that covers the drive side end of the pump casing 2, and a fitting portion 30b that is fitted into the mounting hole 6a of the pump casing 2. The cover body 30a is circular when viewed from the direction in which the axis A of the rotating shaft 10 extends, and is attached liquid-tight to the pump casing 2. The fitting portion 30b protrudes cylindrically from the cover body 30a toward the suction side, and positions the outer ring 25 of the rolling bearing 23 located on the drive side. In other words, the support cover 30 supports the pair of rolling bearings 23 between itself and the positioning member 27.

[0029] The cover body 30a is provided with an insertion hole 30c through which the rotating shaft 10 is inserted. A labyrinth seal 30d is provided on the hole wall of the insertion hole 30c to suppress oil leakage from between the insertion hole 30c and the rotating shaft 10. A deflector 31 is attached to the rotating shaft 10 so as to be located outside the labyrinth seal 30d.

[0030] The cover body 30a is provided with two types of bolt holes 30e, 30f spaced apart in the circumferential direction. The first bolt hole 30e is provided at a position corresponding to the existing bolt hole 6d in the drive side end face of the pump casing 2. The second bolt hole 30f has a smaller diameter than the first bolt hole 30e and is provided at a circumferential distance from the first bolt hole 30e. There is no bolt hole in the pump casing 2 corresponding to the second bolt hole 30f. The fastening of the support cover 30 to the pump casing 2 using the bolt holes 30e, 30f will be described in detail later.

[0031] The cooling fan 33 is fixed to the outer portion 11 of the rotating shaft 10 that protrudes outward from the support cover 30, and sends air to the pump casing 2 by the rotation of the rotating shaft 10. The cooling fan 33 includes a boss 34 for fixing to the rotating shaft 10, and a plurality of blades 35 for sending air.

[0032] The boss 34 includes a cylindrical boss body 34a attached to the mounting portion 11b of the rotating shaft 10, and a cone-shaped base 34b protruding radially outward from the boss body 34a. The boss body 34a has an inner diameter equal to the outer diameter of the mounting portion 11b, and is attached to the mounting portion 11b by inserting a key 36 so as to be non-rotatable relative to the mounting portion 11b and non-movable in the axial direction. The cone-shaped base 34b is a conical cylindrical shape that is inclined radially outward as it approaches the support cover 30. The maximum diameter portion of the cone-shaped base 34b that is located closest to the support cover 30 is the tip 34c of the cone-shaped base 34b (boss 34). However, a cylindrical base having a diameter larger than the outer diameter of the boss body 34a may be used instead of the cone-shaped base 34b.

[0033] The blades 35 protrude radially outward from the boss 34, and send air on the drive side toward the pump casing 2, which is the suction side, by the rotation of the rotary shaft 10. The base end of each blade 35 is connected to the boss body 34a and the cone-shaped base 34b. The outer edge 35a of each blade 35, which is the furthest from the cone-shaped base 34b, is inclined radially outward from the upstream end 35b toward the downstream end 35c, that is, toward the support cover 30. The outer edge 35a is also inclined in a direction approaching the cone-shaped base 34b as it approaches the support cover 30. Most of the outer edge 35a protrudes radially outward from the tip 34c of the cone-shaped base 34b.

[0034] The air blown by the cooling fan 33 configured in this manner is blown along the cone-shaped base 34b. The range Rb1 in which the air can be blown by the blades 35, which is a direction perpendicular to the air blowing direction Db (hereinafter referred to as the "air blowing range"), is the region from the cone-shaped base 34b of the boss 34 to the upstream end 35b of the blades 35.

[0035] The pressure-increasing member 38 is provided to increase the pressure around the rotating shaft 10 and the insertion hole 30c of the support cover 30 by air blown by the cooling fan 33. The pressure-increasing member 38 is separate from the support cover 30 and the pump casing 2, and includes a base portion 39 fixed to the support cover 30, and an enclosure portion 40 protruding from the base portion 39 toward the cooling fan 33.

[0036] The base portion 39 is an annular plate body and is disposed on the outer surface of the support cover 30. The base portion 39 is provided with a first through hole 39a and a second through hole 39b corresponding to the first bolt hole 30e and the second bolt hole 30f of the support cover 30, respectively. A first bolt 42 is inserted through the first through hole 39a and fastened to the first bolt hole 30e of the support cover 30 and the bolt hole 6d of the pump casing 2. A second bolt 43 is inserted through the second through hole 39b and fastened to the second bolt hole 30f of the support cover 30. As a result, the pressure boosting member 38 including the base portion 39 and the surrounding portion 40 is fastened to the pump casing 2 via the support cover 30.

[0037] The enclosure 40 is provided to take in a part of the air blown by the cooling fan 33 and increase the pressure around the insertion hole 30c around the rotation shaft 10 to prevent oil leakage. The enclosure 40 is a cylindrical plate body and protrudes from the support cover 30 toward the cooling fan 33. However, the enclosure 40 may be provided with slits or holes as long as it is capable of taking in the air blown by the cooling fan 33 and can obtain a pressure increase capable of suppressing oil leakage. The enclosure 40 may also be in the form of a conical cylinder, and the shape of the enclosure 40 may be changed as necessary as long as it is capable of taking in the air blown by the cooling fan 33.

[0038] The surrounding portion 40 is located radially outward of the tip portion 34c of the boss 34 and radially inward of the downstream end 35c, which is the radially outermost end of the blade portion 35. The tip of the surrounding portion 40 is located closer to the drive side than the tip portion 34c of the boss 34, that is, on the outer end side of the outer portion 11 of the rotating shaft 10, in the direction in which the axis A of the rotating shaft 10 extends. The surrounding portion 40 configured in this manner overlaps a part of the air blowing range Rb1 by the cooling fan 33 (overlapping range Ro). More specifically, this is as follows.

[0039] If the overlapping range Ro of the enclosure 40 with respect to the airflow range Rb1 is excessively large, the cooling efficiency of the pump casing 2 and the mechanism inside the pump casing 2 may decrease. On the other hand, if the overlapping range Ro of the enclosure 40 with respect to the airflow range Rb1 is excessively small, the amount of air taken in by the cooling fan 33 may be insufficient, the pressure rise around the insertion hole 30c of the rotating shaft 10 and the support cover 30 may be insufficient, and oil leakage may not be suppressed. Therefore, the airflow range Rb1 of this embodiment is narrowed toward the downstream side by the guide cover 45 described in detail later. In addition, the ratio of the overlapping range Ro of the enclosure 40 to the airflow range Rb2 from the cone-shaped base 34b of the boss 34 to the downstream end 35c of the blade portion 35 is preferably set to a range of 5% to 25%, and is set to 18% in this embodiment.

[0040] The guide cover 45 is generally cylindrical, and is provided to guide the air blown by the cooling fan 33 to the outer circumferential surface of the pump casing 2. The guide cover 45 is attached to the support cover 30 via mounting pins 46 so as to be positioned outside the cooling fan 33 and the pressure boosting member 38 with a gap therebetween.

[0041] More specifically, the guide cover 45 includes a cylindrical first portion 45a and a conical second portion 45b. The first portion 45a extends along the axis A of the rotating shaft 10 and surrounds the boosting member 38. The second portion 45b extends along the outer edge 35a of the blade portion 35 and surrounds the cooling fan 33. A plurality of mounting pins 46 (e.g., eight pins) are arranged at intervals in the circumferential direction of the support cover 30.

[0042] In the bearing device 20 configured in this manner, when the cooling fan 33 rotates integrally with the rotating shaft 10 due to its rotation, air is sucked in from the drive side (downstream side) of the cooling fan 33 and sent to the suction side (upstream side) toward the pump casing 2. Most of the air passes between the pressurizing member 38 and the guide cover 45, flows around the outer periphery of the pump casing 2, and passes between adjacent cooling fins 6c before being released into the atmosphere. Meanwhile, the remaining part of the air is taken in by the pressurizing member 38 into a space 48 defined by the rotating shaft 10, the support cover 30, the cone-shaped base 34b of the boss 34, and the enclosure 40 of the pressurizing member 38.

[0043] As a result, the pressure distribution around the single suction pump 1 including the bearing device 20 is as shown in Figure 3. Referring to Figure 3, the pressure on the upstream side of the cooling fan 33 decreases as one approaches the cooling fan 33, with the portion where the blades 35 are located being the lowest pressure (-400 PaG). The pressure on the downstream side of the cooling fan 33 increases as one moves away from the cooling fan 33, with the highest pressure (-20 PaG) being around the pump casing 2. Meanwhile, in space 48 including the rotating shaft 10 and the periphery of the insertion hole 30c of the support cover 30, a portion of the air blown by the cooling fan 33 continues to be taken in, resulting in high pressure (-20 PaG).

[0044] Incidentally, the pressure distribution around the single suction pump 1 including the bearing device 20 without using the pressurizing member 38 is as shown in Fig. 4. Referring to Fig. 4, in the absence of the pressurizing member 38, in a space 48 including the rotating shaft 10 and the periphery of the insertion hole 30c of the support cover 30, the air inside is attracted by the blowing air from the cooling fan 33, so that the pressure becomes lower (-320 PaG) as it gets closer to the rotating shaft 10.

[0045] As is clear from FIG. 3 and FIG. 4, the pressure value in the space 48 around the insertion hole 30c of the support cover 30 is higher in the shaft seal device 20 of this embodiment using the booster member 38 than in the conventional shaft seal device 20 not using the booster member 38. Here, the pressure value in the pump casing 2 is usually about the same as atmospheric pressure. Since the pressure value (-320 PaG) in the space 48 in the conventional shaft seal device 20 is much lower than the pressure value in the pump casing 2, the lubricating oil in the pump casing 2 is likely to leak out from between the rotating shaft 10 and the hole wall of the insertion hole 30c. On the other hand, the pressure value (-20 PaG) in the space 48 in the shaft seal device 20 of this embodiment is significantly higher than the pressure value (-320 PaG) of the conventional shaft seal device 20, and is equivalent to the pressure value in the pump casing 2. More specifically, in this embodiment, the difference between the pressure value (-20 PaG) in the space 48 and the pressure value in the pump casing 2 can be increased to a value that can be sealed by the labyrinth seal 30c. Therefore, it is possible to effectively prevent the lubricating oil in the pump casing 2 from leaking to the outside from between the rotating shaft 10 and the wall of the insertion hole 30c.

[0046] The bearing device 20 configured in this manner has the following features.

[0047] The structure of the bearing device 20 is simple because it is configured by simply providing the boost member 38 protruding from the support cover 30 toward the cooling fan 33. Meanwhile, the surrounding portion 40 of the boost member 38 is cylindrical and located radially outward from the tip portion 34c of the boss 34 and radially inward from the downstream end 35c of the blade portion 35. Therefore, most of the air blown by the rotation of the cooling fan 33 flows along the pump casing 2 to cool the single suction pump 1, but a part of the air blown is taken into the boost member 38. This makes it possible to increase the pressure value in the boost member 38 to the same level as in the pump casing 2, thereby making it possible to suppress leakage of lubricating oil from the inside of the support cover 30 to the outside through the insertion hole 30c and the rotating shaft 10. In other words, oil leakage from the bearing device 20 equipped with the cooling fan 33 that cools the single suction pump 1 can be suppressed with a simple structure.

[0048] Boss 34 of cooling fan 33 has a cone-shaped base 34b that is inclined radially outwardly in a direction intersecting with axis A of rotating shaft 10 as it approaches support cover 30. Therefore, air blown by cooling fan 33 can be reliably guided to pump casing 2, which is the object to be cooled.

[0049] The tip of the pressurizing member 38 is located closer to the outer end of the outer part 11 of the rotating shaft 10 than the tip part 34c of the boss 34. This ensures that part of the air blown by the rotation of the cooling fan 33 is taken into the pressurizing member 38, and the inside of the pressurizing member 38 is kept in a high-pressure state. This effectively prevents the lubricating oil from leaking from the inside of the support cover 30 to the outside.

[0050] The pressurizing member 38 is separate from the support cover 30 and the pump casing 2, and is fastened to the support cover 30 by bolts 42, 43. In other words, the pressurizing member 38 can be retrofitted by simply providing the bolt hole 6d in the pump casing 2 and the bolt holes 30e, 30f in the support cover 30, so that measures against oil leakage can be easily implemented even in an existing single suction pump 1.

[0051] A cylindrical guide cover 45 that surrounds the cooling fan 33 and the pressure increasing member 38 is attached to the support cover 30. This allows most of the air blown by the rotation of the cooling fan 33 to be guided to the pump casing 2, thereby ensuring cooling of the single suction pump 1.

[0052] Other embodiments and various modifications of the present invention will be described below, but in these descriptions, points that are not particularly mentioned are the same as those in the first embodiment. In the drawings referred to below, the same elements as those in the first embodiment are given the same reference numerals.

[0053] Second embodiment Referring to FIG. 5, the bearing device 20 of the second embodiment differs from the bearing device 20 of the first embodiment in that the enclosing portion 40 of the pressurizing member 38 is provided with a plurality of fixed vanes 50 for suppressing the flow (swirling) of air within the space 48.

[0054] The fixed blades 50 are plate-shaped protruding from the enclosure 40 of the pressurizing member 38 toward the rotating shaft 10 and extending along the axis of the rotating shaft 10, and are provided radially at intervals in the circumferential direction. These fixed blades 50 provide resistance to the airflow in the space 48 and suppress the swirling flow around the rotating shaft 10. In other words, the fixed blades 50 convert the dynamic pressure in the space 48 caused by the intake of the air from the cooling fan 33 into static pressure. However, the fixed blades 50 may be provided on the base portion 39 of the pressurizing member 38 or on the cover body 30a of the support cover 30, as long as they can convert the dynamic pressure in the space 48 into static pressure.

[0055] As in the first embodiment, the bearing device 20 of the second embodiment can suppress oil leakage with a simple structure, even though the bearing device 20 includes the cooling fan 33 for cooling the single suction pump 1. Moreover, the space 48 can be brought into a static pressure state, so that oil leakage can be suppressed more effectively.

[0056] The present invention is not limited to the configurations of the above-described embodiments, and various modifications are possible.

[0057] For example, only the support cover 30 may be fastened to the pump casing 2 by the first bolt 42, and the pressurizing member 38 may be fastened to only the support cover 30 by the second bolt 43. The pressurizing member 38 may also be fastened directly to the pump casing 2. The pressurizing member 38 may also be constituted by only the surrounding portion 40, and may be provided integrally with the support cover 30 or the pump casing 2.

[0058] The guide cover 45 may be attached to the pump casing 2 via a mounting pin 46 . [Explanation of symbols]

[0059] 1 Single suction pump (rotary machine) 2 Pump casing (casing) 3 Casing body 3a Liquid flow path 3b Intake port 3c Placement space 3d volute passage 3e outlet 4 Cover 4a through hole 5 Mechanical seal 6 Bearing case 6a Mounting hole 6b Storage section 6c Cooling fins 6d Bolt holes (fastening holes) 7. Rolling bearings 8 Cover member 8a Labyrinth Seal 10 Rotation axis 11 Outer part 11a Connection 11b Mounting part 12 Inner part 12a Mounting part 12b Shafted seal part 12c middle part 12d Supported part 12e Supported part 12f Penetration 15 Impeller 15a Slats 15b Front shroud 15c Rear Shroud 20 Bearing device 22 Bearing body 23 Rolling bearings 24 Inner Circle 25 Outer ring 26 Rolling elements 27 Positioning member 30 Support cover 30a Cover body 30b Mating part 30c Insertion hole 30d labyrinth seal 30e First bolt hole 30f 2nd bolt hole 31 Deflector 33 Cooling fan 34 Boss 34a Boss body 34b conical base 34c Tip 35 Wings 35a Outer edge 35b Upstream end 35c Downstream end (end) 36 Keys 38 Pressure boosting member 39 Base 39a 1st through hole (fastening hole) 39b 2nd through hole (fastening hole) 40 Enclosure 42 First bolt (fastening member) 43 Second bolt (fastening member) 45 Guide cover 45a Part 1 45b Part 2 46 Mounting pin 48 Space around the insertion hole 50 Fixed blade A axis

Claims

1. a bearing body attached to a mounting hole at an end of a casing of a rotary machine and supporting a rotary shaft; a support cover having an insertion hole through which the rotating shaft passes and attached to an end of the casing to support the bearing body; a cooling fan fixed to an outer portion of the rotating shaft protruding from the support cover to the outside, the cooling fan blowing air into the casing by rotation of the rotating shaft; a pressure increasing member that protrudes from the support cover or the casing toward the cooling fan and increases the pressure around the insertion hole by blowing air from the cooling fan; Equipped with The cooling fan has a plurality of blades protruding radially outward from a boss, the pressure boosting member is cylindrical and is located radially outwardly of a tip end of the boss that is located closest to the support cover, and is located radially inwardly of an end of the wing that is located radially outwardly of the blade.

2. 2. The bearing device for a rotary machine according to claim 1, wherein the boss is fixed to the rotary shaft and has a cone shape inclined radially outwardly in a direction intersecting with an axis of the rotary shaft as the boss approaches the support cover.

3. 3. The bearing device for a rotary machine according to claim 1, wherein a tip end of the pressure boosting member is located closer to an outer end of the outer portion than the tip end of the boss.

4. 3. The bearing device for a rotary machine according to claim 1, wherein the pressure increasing member is separate from the support cover or the casing, and is fastened to the support cover or the casing by a fastening member.

5. 3. The bearing device for a rotary machine according to claim 1, further comprising a cylindrical guide cover attached to the support cover or the casing and surrounding the cooling fan and the pressure increasing member.

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