JPS6337512Y2 - - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] (Field of industrial application) The present invention relates to a sealed electric blower, in which a motor is airtightly integrated at the bottom of the blower. This relates to something that prevents leakage from the motor side to the blower side.

(Prior art) Blower used in closed system equipment such as SF ₆ gas circulation in SF ₆ gas insulated transformers has the risk of reducing the performance of the equipment due to leakage of the handled gas or causing pollution problems. To avoid this problem, sealed electric blowers are generally used that do not have shaft seals such as oil seals or mechanical seals, and have a completely leak-free structure in which the blower and electric motor are airtightly integrated.

By the way, when restarting the sealed electric blower used in the closed system equipment after overhauling and inspection, the inside of the equipment must be evacuated and the atmosphere must be released before being filled with the gas to be handled, which costs a lot of money. Therefore, it is required to extend the period of periodic overhaul and inspection.

Since the period of periodic overhaul and inspection is mainly determined by the lifespan of the rotating parts, especially the lifespan of the bearing lubricant of the sealed electric blower, the applicant of this utility model registration is We proposed a sealed electric blower that lubricates the bearings by circulating lubricating oil.

To briefly explain this with reference to FIG. 6, the blower 2 is integrated with the upper side of the vertical electric motor 1 to form a sealed structure without a shaft seal, and the upper side is placed above the stator 3 and rotor 4 of the electric motor 1. A lower oil reservoir chamber 6 is provided below the oil reservoir chamber 5, and an upper bearing 7 and a lower bearing 8 of the electric motor 1 are disposed in both oil reservoir chambers 5 and 6, respectively, and bearing lubricating oil 9 is sealed therein. A closed-structure circulation pump 10 driven by the electric motor 1 is adjacent to the lower side of the lower oil reservoir chamber 6, and this circulation pump 10 supplies the bearing lubricating oil 9 in the lower oil reservoir chamber 6 to one of the circulation pipes 11. The bearing lubricating oil 9 in the upper oil reservoir chamber 5 is caused to fall by gravity from the other circulation pipe 12 to the lower oil reservoir chamber 6.
Both bearings 7 and 8 are lubricated while the bearing lubricating oil 9 is pumped up again to the upper oil reservoir chamber 5 by the pump 10 and circulated. According to this structure, the bearing lubricating oil 9 in the upper oil reservoir chamber 5 The temperature and degree of deterioration of the bearing lubricating oil 9 in the lower oil sump chamber 6 are averaged by the circulation, and when the bearing lubricating oil 9 passes through the circulation pipes 11 and 12 which also serve as radiators, Since it is cooled and the temperature is lowered, the lubrication and cooling effect of the upper bearing 7, which is particularly high temperature, is improved, and compared to a structure that uses grease lubrication, which may leak out at high temperatures, it also doubles as bearing lubricating oil. Since the insulating oil is in direct contact with the stator and rotor, which are the main heat generating parts of the electric motor, the insulating oil deteriorates quickly, and the rotor rotates in this insulating oil, causing losses in the electric motor. Compared to a structure employing an oil-immersed motor, which has the drawback of reduced efficiency, the bearing life is increased, the period for replacing the bearing lubricating oil 9 is significantly extended, and there is almost no reduction in the motor efficiency. An economical sealed electric blower is obtained.

(Problem to be solved by the invention) However, although there is no particular problem when the sealed electric blower shown in Fig. 6 is operated in atmospheric air, when it is operated with actual SF ₆ gas, SF ₆ gas Due to differences in blower specifications such as gas density, air volume, discharge pressure, and rotational speed, as well as structure and dimensions, problems have occurred in some models in which bearing lubricating oil 9 leaks from the motor 1 side to the blower 2 side.

Due to the lack of bearing lubricating oil 9 due to this leakage,
A closed system device in which the sealed electric blower is used after the bearings 7, 8 and the bearing lubricating oil 9 have increased in temperature and their lifespan has been shortened, and the bearing lubricating oil 9 has leaked to the blower 2 side either directly or after it has deteriorated. There is also the fear that it may have a negative impact on

The cause of this oil leakage is that the bearing lubricating oil 9 in the upper oil reservoir chamber 5 is scattered upward by the centrifugal force of the rotation in the upper bearing 7, causing the oil reservoir chamber cover 13 and the hollow rotating shaft 1
4 and the casing 1 of the blower 2 directly from the gap 15
It is conceivable that the oil may jump out to the 6 side, but since there is no oil leakage in atmospheric operation, this possibility is considered to be extremely slim.

The next possible cause is that the hollow rotating shaft 14
The lubricating oil 9 scattered by the upper bearing 7 collides with the swirling flow of the handled gas generated in the oil reservoir chamber 5 by the rotation of the handler, and is atomized into mist, thereby creating a swirling flow of the handled gas. The atomized bearing lubricating oil 9 mixed in the swirling flow of the handled gas comes into contact with the oil reservoir chamber lid 13 and adheres to the lower surface of this lid 13, or the upper bearing 7. The lubricating oil 9 splashed by the oil sump chamber lid 13 flies directly to the bottom surface of the lid 13, and the impeller 1 is caused by pressure pulsations in the swirl chamber of the casing 16 of the blower 2.
Due to pressure pulsations between the main plate 18 of No. 7 and the oil reservoir chamber lid 13, the pressure distribution on the circumference of the gap 15 between the lid 13 and the hollow rotating shaft 14 becomes unbalanced and changes periodically. Therefore, the handled gas flows in and out of the gap 15, and due to the handled gas flowing in and out of the gap 15, it adheres to the bearing lubricating oil 9 mixed in the swirling flow and the inner diameter part of the lid 13, and this lid Bearing lubricating oil 9 transferred to the inner diameter portion through the lower surface of the body 13
is carried to the casing 16 side. In this case, the reason why there is no oil leakage chamber in atmospheric operation is because the density of air as the handled gas is extremely low compared to the gas density in SF ₆ gas operation (the density of air is
This is approximately 1/5 of SF ₆ gas at the same temperature and pressure, but in actual gas operation, the SF ₆ gas is generally sealed at an absolute pressure of 2 kg/cm ² or more, so it is less than 1/10 of that of actual gas operation. ), the main plate 18 of the impeller 17 and the oil sump chamber lid chamber 1
3, the difference in pressure distribution imbalance on the circumference of the gap 15 is also extremely small. Casing 1
It seems that this does not lead to leakage to the 6th side.

Therefore, as shown in FIG. 7, the present applicant has taken measures to prevent the pressure distribution on the circumference of the gap 15 between the oil reservoir chamber cover 13 and the hollow rotating shaft 14 from becoming unbalanced, that is, to prevent the vortex chamber of the casing 16 from becoming unbalanced. The lower surface of the impeller 17, that is, the main plate 1, so as not to be affected by pressure pulsations.
Annular protrusions 18a and 13a are provided on the lower surface of 8 and the lower surface of the lid 13, respectively, and the annular projections 18a and 13a are opposed to each other with a narrow gap 19 interposed therebetween to form an orifice 20. A labyrinth 15a is provided in the gap 15 so as to increase the flow path resistance of the gap 15 between the hollow rotating shaft 13 and the hollow rotating shaft 14 and to suppress the handling gas from going in and out from the gap 15.
In order to prevent the bearing lubricating oil 9 adhering to the lower surface of the lid 13 from traveling along the lower surface to the inner diameter, the lower surface of the lid 13 is inclined so that the outer diameter side is lower, and The lubricating oil 9 attached to the inner diameter part of the lid body 13 is attached to the labyrinth 15a.
An annular protrusion 13b that protrudes downward on the inner diameter portion of the lid body 13 so that the liquid drips downward without moving to the side.
By providing a thin-walled annular protrusion 13c that protrudes further downward at the outer peripheral end of the annular protrusion 13b, the lower surface thereof is inclined so that the outer diameter side is lower _. During continuous gas operation, the amount of lubricating oil 9 leaked to the casing 16 side was only a few tens of c.c.
It was confirmed that the reduction was achieved to about 0.05 to 0.1cc, but within the scope of the improvement shown in Figure 7,
That is, the length of the gap 19 of the orifice 20,
Even if the width and diameter and the structure and dimensions of the labyrinth 15a were changed, the amount of leakage could not be further reduced from about 0.05 to 0.1 cc.

In addition, when the oil leakage amount was several cc or less, the value was calculated from the area of the portion to which the bearing lubricating oil was attached and the oil film thickness.

Even in the improved structure shown in FIG. 7, the bearing lubricating oil 9 leaks due to the swirling flow of the gas handled in the upper oil reservoir chamber 5, although it is extremely small compared to the structure shown in FIG. 6. The atomized bearing lubricating oil 9 mixed therein is mixed with the oil reservoir chamber lid 13 and the hollow rotating shaft 14 due to the concentration difference mixed in the handling gas.
The oil is dissipated from the upper oil reservoir chamber 5 to between the lid 13 and the main plate 18 of the impeller 17, that is, from the electric motor 1 side to the blower 2 side, through the labyrinth 15a formed in the gap 15. Seem.

Therefore, in order to completely eliminate the oil leakage chamber, it is sufficient to prevent the bearing lubricating oil 9 from scattering by the upper bearing 7, and for this purpose, in addition to the structure shown in FIG. By adopting the bearing structure of the vertical motor pump described in the publication, as shown in Fig. 8,
The hollow rotating shaft 14 is in contact with the upper end of the outer ring of the upper bearing 7.
It is also possible to arrange a liquid level stabilizing cylinder 7a surrounding the outer periphery of the liquid level stabilizing cylinder 7a, but the original purpose of this liquid level stabilizing cylinder 7a is
Due to the centrifugal force of the rotation of the upper bearing 7, the bearing lubricating fluid exhibits a mortar-shaped liquid level in the bearing 7 portion, and the liquid level fluctuates due to the revolution of each ball of the bearing 7,
Part or most of the bearing 7 is no longer immersed in the liquid, and especially when the lubricating liquid is LNG, the lubricating liquid boils and the liquid level fluctuates even further, making it impossible to obtain stable lubrication. If this liquid level stabilizing tube 7a is adopted, the lubricating oil 9 will be blown out from the gap 7b between the liquid level stabilizing tube 7a and the hollow rotating shaft 14 at the time of startup, which is contrary to the case with the sealed electric blower. Even if a plurality of communication holes 7c are provided in the radial direction in the portion of the liquid level stabilizing cylinder 7a corresponding to the hollow rotating shaft 14, the force with which the lubricating oil 9 blows upward from the gap 7b is reduced. In the gap 7b, the lubricating oil 9 is subjected to rotational centrifugal force by the hollow rotating shaft 14, and is blown out laterally from the plurality of communication holes 7c, collides with the swirling flow of the handled gas, and is atomized into mist. This also has the opposite effect.

In view of the above points, the present invention is based on the idea that the bearing lubricating oil, which attempts to scatter upward due to rotational centrifugal force in the upper bearing in the oil reservoir chamber, is blocked by the oil scattering prevention plate and is prevented from scattering upward. Therefore, the bearing lubricating oil may adhere to the lid of the oil reservoir on the upper bearing side, or collide with the swirling flow of the handled gas in the oil reservoir and become atomized into mist and mix in the swirling flow. To provide a sealed electric blower in which leakage of bearing lubricating oil from an electric motor side to a blower side is completely prevented.

[Structure of the idea]

(Means for solving the problem) The structure of the sealed electric blower of the present invention is that the electric motor is airtightly integrated on the lower side of the blower, an oil reservoir chamber containing the bearing of this electric motor is provided, and the upper bearing side In a sealed electric blower in which an oil sump chamber lid is attached to the upper end of the oil sump chamber with a narrow gap between the rotating shaft and the upper bearing, the upper bearing is placed near the oil level of bearing lubricating oil sealed in the oil sump chamber. An oil scattering prevention plate is disposed between the oil sump chamber cover body and the upper bearing, close to the upper bearing and covering the upper part of the upper bearing, and disposed on the rotating shaft with a narrow gap therebetween to prevent oil scattering. A communication path is provided that communicates the upper side of the upper bearing below the plate with the outer diameter side of the upper bearing.

In addition, an embodiment of the sealed electric blower of the present invention having the above-mentioned structure is provided with a communication passage that communicates the lower side of the upper bearing with the outer diameter side of the upper bearing, and the communication passage and the upper part below the oil scattering prevention plate. A circulation system in which bearing lubricating oil on the upper bearing side and bearing lubricating oil on the outer diameter side of the upper bearing are mutually circulated through a communication path that communicates between the upper side of the bearing and the outer diameter side of the upper bearing. The upper surface of the oil sump chamber on the upper bearing side on the outer diameter side of the bearing is covered with an oil scattering prevention plate, and the lower surface of the oil sump chamber lid is lowered on the outer diameter side. An annular protrusion protruding downward is provided on the inner diameter portion of the oil sump chamber lid body, and the lower surface thereof is inclined such that the outer diameter side is lower, and the outer circumferential end of the annular protrusion is provided with an annular protrusion protruding downward. A thin annular protrusion is provided on the lower surface of the impeller of the blower and an annular protrusion on the upper surface of the oil sump chamber lid body, and these annular protrusions are opposed to each other through a narrow gap. In addition, a labyrinth is formed in the gap between the oil reservoir chamber cover and the rotating shaft.

(Function) In the sealed electric blower of the present invention, the bearing lubricating oil that tries to scatter upward due to rotational centrifugal force in the upper bearing in the oil reservoir chamber is blocked by the oil scattering prevention plate and moves upward. After a small amount is slowly flowed out from the upper bearing side to the outer diameter side of this upper bearing through the communication path, the upper bearing side and the outer diameter side of this upper bearing due to the pulsating action of the upper bearing. It is slowly moved in and out of the upper bearing, or it is slowly circulated from the upper side of the upper bearing to the outer diameter side of the upper bearing through the communication path by the pump action of the upper bearing, and from this outer diameter side to the lower side of the upper bearing. .

(Embodiment) Next, the configuration of an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

Reference numeral 21 denotes a vertical electric motor. A blower 22 is integrally formed above the vertical electric motor 21 to have a sealed structure without a shaft seal, and an upper oil reservoir is provided above the stator 23 and rotor 24 of the electric motor 21. A lower oil reservoir chamber 26 is provided below the oil reservoir chamber 25, and both oil reservoir chambers 25, 26
An upper bearing 27 and a lower bearing 28 of the electric motor 21 are disposed therein, and bearing lubricating oil 2 is provided therein.
9 is enclosed, and a circulation pump 30 of a closed structure driven by the electric motor 21 is adjacent to the lower side of the lower oil reservoir chamber 26, and this circulation pump 30 circulates the lower oil reservoir chamber 2.
The bearing lubricating oil 29 of No. 6 is pumped up through one of the circulation pipes 31 to the upper oil reservoir chamber 25.
The bearing lubricating oil 29 of No. 5 is allowed to fall by gravity from the other circulation pipe 32 to the lower oil sump chamber 26, and is again pumped up to the upper oil sump chamber 25 by the pump 30, thereby circulating the bearing lubricating oil 29 between the two bearings 27. , 28.

As shown in FIG. 2, there is an oil reservoir chamber above the upper bearing 27 disposed near the oil surface of the bearing lubricating oil 29 sealed in the upper oil reservoir chamber 25, which covers the upper surface of the upper oil reservoir chamber 25. A lid 33 is provided between the oil sump chamber lid 33 and the upper bearing 27.
An oil scattering prevention plate 35 covering the upper part of the upper bearing 27 is disposed on the hollow rotating shaft 34 as a part of the rotating shaft with a narrow gap 36 in between. It is fixed by means such as bolts 38, and on the lower surface of the oil scattering prevention plate 35, there is a connection connecting the upper side of the upper bearing 27 below the oil scattering prevention plate 35 and the outer diameter side of the upper bearing 27. A plurality of radial grooves as passages 39 are provided.

An oil reservoir chamber lid 33 is attached to the upper end of the upper oil reservoir chamber 25 to the hollow rotating shaft 34 through a narrow gap 40. The blower is on the blower 22 side and the electric motor 21
It is divided into two sides.

Further, the rotating shaft 41 of the rotor 24 of the electric motor 21
An impeller 42 of the blower 22 is attached to the hollow rotating shaft 34 coupled to the hollow rotating shaft 34 .

According to the embodiment configured in this way, the bearing lubricating oil 29 that is urged by the rotational centrifugal force on the upper bearing 27 and tries to scatter upward is blocked by the oil scattering prevention plate 35, so that this oil is Although it tries to flow laterally along the lower surface of the scattering prevention plate 35, the communication passage 39 on the outer diameter side compared to the gap 36 on the inner diameter side
has an extremely large cross-sectional area, and the bearing lubricating oil 2
9 tries to flow outward due to the biased rotational centrifugal force, it does not flow out from the gap 36, but flows out from the communication path 39 to the outer diameter side of the bearing holder 37, and the flow rate is Since the cross-sectional area of the communication passage 39 is larger than that of the communication passage 39, the oil flows out slowly and its energy is absorbed, and a small amount of the oil flows out, and the bearing lubricating oil becomes cone-shaped at the upper bearing 27 due to the rotational centrifugal force. When the top level of the oil level of the upper bearing 27 reaches the bottom of the communication passage 39, the bearing lubricating oil 29 is slowly moved in and out of the communication passage 39 due to the pulsation caused by the revolution of each ball of the upper bearing 27, and its energy is absorbed. is absorbed and the upper bearing 2
The bearing lubricating oil 29 on the 7 side and the bearing lubricating oil 29 on the outer diameter side of the upper bearing 27 are replaced little by little.

In this way, the bearing lubricating oil 29, which is subjected to rotational centrifugal force on the upper bearing 27, is not scattered upward, but slowly flows out and comes in and out laterally from the communication passage 39, and its energy is absorbed. , collides with the swirling flow of the handled gas generated in the upper oil reservoir chamber 25 by the rotation of the hollow rotary shaft 34 and is atomized into mist and is not mixed in the swirling flow, thus preventing the bearing lubrication. Oil 29 flows from the electric motor 21 side to the blower 22
There is no problem of leakage to the side.

According to experiments conducted by the present applicant, leakage of the bearing lubricating oil 29 to the blower 22 side could not be detected as a result of 30 days of actual gas operation with SF ₆ gas in the sealed electric blower of this embodiment. .

In addition, this embodiment and the above-mentioned FIG. 7 and the above-mentioned FIG.
The casing 54 and impeller 42 of each sealed electric blower adopting the structure shown in the figure are removed.
By forming the oil reservoir chamber lid 33 from a transparent material and operating only the electric motor 21 in the atmosphere, the oil of the bearing lubricating oil 29 is scattered and attached to the lower surface of the transparent oil reservoir chamber lid 33. When the number of drops was measured, it was found that in the structure shown in FIG. 7, considerably larger oil droplets were produced in 10 seconds than in the structure of this example.
Approximately 100 drops were applied, and in about 5 minutes, the entire lower surface of the oil reservoir chamber cover 33 was covered with the bearing lubricating oil 29, which was the same level in the structure shown in FIG. With the structure of
Only drops were deposited.

As is clear from this experiment, according to the structure of the above embodiment, the scattering of the bearing lubricating oil 29 by the upper bearing 27 is almost completely prevented, so that the bearing lubricating oil 29 is disposed on the side of the blower 22 during actual gas operation. It can be seen that leakage is prevented.

In addition, in the above embodiment, the oil scattering prevention plate 3
Although the communication path 39 is formed by providing a plurality of radial grooves on the lower surface of the bearing holder 37, the communication path 39 may be formed by providing a plurality of radial grooves on the upper end surface of the bearing holder 37 as shown in FIG. As shown in FIG. 4, the oil scattering prevention plate 35 is suspended and fixed to the oil reservoir chamber lid 33 through a gap in the bearing holder 37, and this gap is formed by an appropriate means, such as using this gap as a communication path 39. Moreover, as shown in FIG. 4, the bearing lubricating oil 29 on the outer diameter side of the upper bearing 27 in the upper oil reservoir chamber 25 and the bearing lubricating oil 29 flowing in and out of the communication passage 39 directly flow into the swirling flow of the handled gas. Cover the oil surface with an enlarged oil scattering prevention plate 35 so as not to touch the oil surface, or apply pressure to the gap 40 between the oil sump chamber lid 33 and the hollow rotating shaft 34 as shown in FIG. The gap 40 is
The impeller 42
Annular protrusions 45 and 46 are provided on the lower surface of the main plate 43 and the upper surface of the lid body 33, respectively, and the annular protrusions 45 and 46 are opposed to each other with a narrow gap 47 interposed therebetween to form an orifice 48, or By forming a labyrinth 49 in the gap 40 to increase the flow resistance in the gap 40 between the lid 33 and the hollow rotating shaft 34, a more reliable effect of preventing oil leakage can be expected.

Further, as shown in FIGS. 3 and 5, the lower surface 33a of the oil sump chamber cover 33 is inclined so that the outer diameter side is lower, and the inner diameter of the oil sump chamber cover 33 has an annular shape projecting downward. A protrusion 51 is provided, the lower surface of the protrusion 51 is formed into an inclined surface 52 with the outer diameter side being lower, and a thin annular protrusion 53 is formed at the outer peripheral end of this inclined surface 52 to protrude downward. For example, the bearing lubricating oil 29 adhering to the lower surface 33a of the oil sump chamber cover 33 is not transferred to the lower surface 33a and moving to the inner diameter, and the bearing lubricating oil 29 adhering to the inner periphery of the oil sump chamber cover 33 is not moved to the inner diameter part. Since the lubricating oil 29 is dripped downward without being moved to the 49 side, even if the bearing lubricating oil 29 adheres to the lower surface 33a of the oil sump chamber cover 33, the blower 2
There is no leakage to the casing 54 of No. 2.

Furthermore, as shown in FIG. 5, if a communication passage 50 is provided that communicates the lower side of the upper bearing 27 with the outer diameter side of the upper bearing 27, the bearing lubricating oil 29 between the upper side and the lower side of the upper bearing 27 can be exchanged. Since the lifting heights reaching the oil surface on the outer diameter side of the upper bearing 27 are different, the bearing lubricating oil 29 on the upper and lower sides of the upper bearing 27 tends to flow out to the outer diameter side of the upper bearing 27 due to rotational centrifugal force. A difference occurs in the action, and the action of the upper bearing lubricating oil 29 prevails. In other words, due to the pumping action of the upper bearing 27, the bearing lubricating oil 29 is passed from above the upper bearing 27 through the communication passage 39, and has an outer diameter larger than that of the upper bearing 27. It flows from the outer diameter side through the communication path 50 to the lower side of the upper bearing 27 and is slowly circulated.

Therefore, the bearing lubricating oil 29 of the upper bearing 27 section
However, as in the conventional structure shown in FIGS. 6 and 7 and the structure shown in each of the embodiments described above, it is possible to replace the upper bearing 27 very little at a time by going in and out from the communication passage 39 on the upper side or only on one side of the upper bearing 27. Compared to the case where the upper bearing 27 is heated, the upper bearing 27 is sufficiently cooled and the bearing lubricating oil 29 does not locally become high temperature in the upper bearing 27 portion, but the temperature is averaged, so the upper bearing 27 has a longer life. The replacement period for the bearing lubricating oil 29 is also further extended.

In each of the above embodiments, the present invention is applied to a sealed electric blower using a radial gap type electric motor, but it can be similarly applied to a sealed electric blower using an axial gap type electric motor. Of course, it can also be applied to sealed electric blowers which have to use oil-immersed motors due to special specifications.

[Effect of idea]

According to the present invention, bearing lubricating oil that attempts to scatter upward due to rotational centrifugal force in the upper bearing in the oil reservoir chamber is prevented from scattering upward because its path is blocked by the oil scattering prevention plate. Since the bearing lubricating oil is slowly moved in and out or circulated between the upper bearing side and the outer diameter side of the upper bearing via the communication passage, the bearing lubricating oil may adhere to the lid of the oil reservoir chamber on the upper bearing side, or The bearing lubricating oil does not collide with the swirling flow of the handled gas in the oil sump chamber and become atomized into mist and become mixed in the swirling flow, and the leakage of the bearing lubricating oil from the motor side to the blower side is completely prevented. Ru.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of a sealed electric blower showing one embodiment of the present invention, Fig. 2 is an enlarged longitudinal sectional view of the main parts of the same, and Fig. 3 is a main part of a sealed electric blower showing another embodiment. FIG. 4 is a longitudinal sectional view of a main part of a sealed electric blower showing another embodiment; FIG. 5 is a longitudinal sectional view of a main part of a sealed electric blower showing another embodiment; FIG. is a vertical cross-sectional view of a conventional sealed electric blower,
FIGS. 7 and 8 are longitudinal sectional views of a part of the electric blower which is the premise of the present invention. 21...Electric motor, 22...Blower, 25...Upper oil sump chamber, 26...Lower oil sump chamber, 27...Upper bearing, 28...Lower bearing, 29...Lubricating oil, 33...
...Oil sump chamber lid body, 34...Hollow rotating shaft, 35...Oil scattering prevention plate, 39, 50...Communication path, 40...Gap between oil sump chamber lid body 33 and hollow rotating shaft 34, 4
5, 46, 51... Annular protrusion, 48... Orifice, 49... Labyrinth, 52... Annular protrusion.

Claims (1)

[Claims for Utility Model Registration] (1) An electric motor is airtightly integrated with the lower side of the blower, an oil sump chamber containing the bearings of the electric motor is provided, and an oil sump chamber is provided at the upper end of the oil sump chamber on the upper bearing side. In a sealed electric blower in which an oil sump chamber cover is attached to a rotating shaft through a narrow gap, the upper bearing is disposed near the oil level of bearing lubricating oil sealed in the oil sump chamber, and the oil sump chamber An oil scattering prevention plate that is close to and covers the upper bearing is disposed between the lid body and the upper bearing on the rotating shaft with a narrow gap therebetween, and an oil scattering prevention plate that is located above the upper bearing that is below the oil scattering prevention plate is disposed between the lid and the upper bearing. A sealed electric blower characterized by providing a communication path that communicates with the outer diameter side of the upper bearing. (2) Provide a communication passage that communicates between the lower side of the upper bearing and the outer diameter side of this upper bearing, and communicate this communication passage and the upper side of the upper bearing below the oil scattering prevention plate with the outer diameter side of this upper bearing. The utility model registration claim is characterized in that a circulation path is formed in which bearing lubricating oil on the upper bearing side and bearing lubricating oil on the outer diameter side of the upper bearing are mutually circulated by a communicating passage. A sealed electric blower as described in Scope 1. (3) Claims 1 or 2 of the utility model registration claim characterized in that the upper part of the oil surface on the outer diameter side of the bearing in the oil reservoir chamber on the upper bearing side is covered with an oil scattering prevention plate. Closed electric blower. (4) The lower surface of the oil sump chamber lid is sloped so that the outer diameter side is lower, and an annular protrusion that projects downward is provided on the inner diameter portion of the oil sump chamber lid so that the lower surface is lowered on the outer diameter side. According to any one of claims 1 to 3, registered as a utility model, the annular protrusion is inclined as shown in FIG. Closed electric blower. (5) A practical use characterized in that annular protrusions are provided on the lower surface of the impeller of the blower and on the upper surface of the oil reservoir lid body, respectively, and the annular protrusions are opposed to each other with a narrow gap to form an orifice. A sealed electric blower according to any one of claims 1 to 4 of the patent claims. (6) The sealed electric blower according to any one of claims 1 to 5, which is characterized in that a labyrinth is formed in the gap between the oil sump chamber cover and the rotating shaft.