JP6682374B2 - Electric supercharged compressor - Google Patents

Description

  The present disclosure relates to, for example, an electric supercharged compressor mounted on a vehicle and driven by an electric motor.

  Improvements in fuel efficiency and exhaust emissions of engines are being strengthened year by year, and as a countermeasure against this, town sizing of engines using supercharging using a supercharger is being promoted. Against this background, electric supercharged compressors (electric compressors) that use electric motors to drive compressors generally reach a target boost pressure as compared with exhaust turbine superchargers (turbochargers). The arrival time is short and the transient response is excellent. In recent years, an electric two-stage turbo system in which a turbocharger and an electric supercharged compressor are combined has been proposed. With the electric two-stage turbo system, a wide range and transient response in a compressor operation map such as an increase in torque at low speed are proposed. Can be improved.

  On the other hand, in an electric supercharged compressor, the electric motor generates heat by rotating the compressor, but the heat generated by the electric motor transfers heat to a bearing that supports the rotary shaft of the compressor wheel. There is a risk that the bearing will be damaged beyond the allowable temperature. Therefore, in order to prevent the bearing from exceeding the allowable temperature due to the heat generated by the electric motor, for example, the number of rotations of the electric motor and the driving time are limited. It is one of the factors that determine the reliability and performance of the turbocharger.

  Further, unlike the exhaust turbine supercharger, the electric supercharged compressor has an impeller (compressor wheel) only on one side of the rotary shaft. Therefore, a thrust load always acts on the rotating body (rotor) including the rotating shaft and the compressor wheel in the direction from the back surface to the front surface of the compressor wheel (for example, Patent Document 1). The thrust load acting on the rotating body serves as a load on the bearing that supports the rotating body and causes mechanical loss when driving the rotating body. Therefore, in order to protect the bearing and improve the performance, it is also important to reduce the thrust load acting on the rotating body in order to improve the reliability and performance of the electric supercharger. In the exhaust turbine supercharger, impellers are provided at both ends of the rotating shaft, and thrust loads in opposite directions generated by the impellers on both sides cancel each thrust load. .

  In this respect, in Patent Document 1, a canceller chamber for canceling the thrust load is formed on the end portion side of the rotating shaft where the impeller is not provided, and the gap on the back surface of the impeller and the above canceller chamber are formed. The thrust load is reduced by connecting the stationary members, which are stationary without moving like a rotating body, by the passage portions formed by sewing. More specifically, compressed air compressed by the compressor leaks from the gap between the outer peripheral end of the impeller and the scroll, and the above-mentioned passage portion introduces the leaked compressed air into the canceller chamber. By doing so, this compressed air is used as pressurized air that generates a canceller pressure for canceling the thrust load generated in the rotating body. It is also described that the compressed air leaking from the gap is used as cooling air for cooling the pair of bearing shafts and the rotor.

JP, 2011-202589, A

  However, Patent Document 1 presupposes a canceller chamber for canceling the thrust load, and the rotating shaft of the electric supercharged compressor is supported by an air bearing (thrust air bearing). Therefore, the above passage portion of Patent Document 1 cannot be directly applied to an electric supercharged compressor that does not have a canceller chamber or an electric supercharged compressor that uses a rolling bearing. Further, the passage portion of Patent Document 1 is formed between the stationary members and guides the compressed air leaking from the gap between the outer peripheral end of the impeller and the scroll so as to be separated from the rotating shaft along the radial direction. After that, it is guided along the axial direction, and again guided toward the rotation axis along the radial direction, so that it has a complicated structure. Therefore, for example, even if the above passage portion is applied to an electric supercharged compressor that does not have a canceller chamber, the flow rate of compressed air passing through the passage portion due to pressure loss when passing through the passage portion. There is also a concern that the effect of reducing the thrust load and the effect of cooling the bearing may not be fully exerted.

  In view of the above-mentioned circumstances, at least one embodiment of the present invention aims to provide an electric supercharged compressor in which a load on a lubricant-filled bearing that supports a rotating body is reduced during operation.

(1) The electric supercharged compressor according to at least one embodiment of the present invention is
A rotation axis,
A compressor wheel provided on one end side of the rotating shaft,
A compressor housing that rotatably accommodates the compressor wheel,
An electric motor provided on the other end side of the rotary shaft with respect to the compressor wheel, for applying a rotational force to the rotary shaft,
A motor housing that houses the electric motor;
A bearing for rotatably supporting the rotating shaft, provided between the compressor wheel and the electric motor, wherein the lubricant-enclosed bearing has a lubricant enclosed therein,
A bearing support member that is fixed to at least one of the compressor housing and the motor housing and that supports the lubricant-filled bearing, and that opposes the rear surface of the compressor wheel with a gap between them. A bearing support member having a surface,
The bearing support member has a through hole extending from the opening formed in the wheel-side facing surface toward the electric motor along the axial direction of the rotating shaft.

  According to the above configuration (1), the compressed air (air) leaking into the gap formed by the back side of the compressor wheel and the bearing support portion passes through the through hole of the bearing support member toward the electric motor. Be guided. Further, the through hole of the bearing support member extends along the axial direction of the rotating shaft, so that the passage length of the air formed by the through hole is shortened. That is, in the electric supercharged compressor, the through hole formed in the bearing support member allows compressed air leaking from the intake passage side formed inside the compressor housing to the above gap to the electric motor side in a shorter distance. It is configured to escape. Here, a thrust load in the direction from the back surface to the front surface of the compressor wheel is constantly applied to the rotating body including the compressor wheel and the rotating shaft of the electric supercharged compressor during operation. According to the above configuration, the pressure difference between the front surface side and the back surface side of the compressor wheel can be further reduced, and the thrust load acting on the rotating body can be further reduced. Therefore, the load due to the thrust load of the lubricant-containing bearing that supports the rotating body can be reduced.

  It is also possible to cool the electric motor and the lubricant-filled bearing on the relatively high temperature side by the compressed air on the relatively low temperature side supplied from the through hole of the bearing support member. In particular, the lubricant-filled bearing does not supply lubricant oil from the outside, and by cooling the lubricant-filled bearing with the compressed air described above, the situation in which the lubricant-filled bearing exceeds the allowable temperature due to heat generation of the electric motor Can be suppressed. Further, by improving the cooling capacity of the lubricant-filled bearing in this way, there is a situation in which the rotation speed and drive time of the electric motor are limited in order to protect the lubricant-filled bearing from the heat of the electric motor that generates heat. Can be suppressed. Therefore, the performance of the electric supercharged compressor can be improved while improving the reliability of the lubricant-filled bearing.

(2) In some embodiments, in the configuration of (1) above,
The electric motor is
A rotor fixed to the rotating shaft,
A stator that is supported by the motor housing around the rotor and that applies a rotational force to the rotor by an electromagnetic force,
A heat dissipation space is formed between the stator and the bearing support member,
The through hole connects the gap and the heat dissipation space.
According to the above configuration (2), the through hole of the bearing support member communicates the heat dissipation space with the gap formed by the back surface side of the compressor wheel and the bearing support portion. By guiding the compressed air through the through holes to such a heat radiation space, the stator, which is the main heat generating point of the electric motor, is cooled, and thus the electric motor can be cooled more effectively. Further, by cooling the electric motor, the lubricant-containing bearing can be indirectly cooled.

(3) In some embodiments, in the configurations of (1) and (2) above,
The opening of the through hole is formed in an outer peripheral region of the wheel-side facing surface.
According to the configuration of (3), the thrust load generated in the rotating body of the electric supercharged compressor can be reduced as compared with the case where the opening of the through hole is formed in the region other than the outer peripheral region of the wheel-side facing surface. You can

(4) In some embodiments, in the configurations of (1) and (2) above,
The opening of the through hole, while being formed on the inner peripheral side of the outer peripheral side region in the wheel-side facing surface,
The through hole extends on the outer peripheral side of the outer peripheral surface of the lubricant-containing bearing.
According to the configuration of (4) above, the lubricant-containing bearing on one end side (compressor wheel side) of the rotating body can be made more direct than in the case where the opening of the through hole is formed in the outer peripheral side region of the wheel side facing surface. Can be cooled.

(5) In some embodiments, in the configuration of (3) above,
The bearing support member,
A diffuser forming portion having a diffuser passage surface that defines a diffuser passage between the compressor housing and the compressor housing;
A fixed part having an outer peripheral side connecting part connected to an outer peripheral part of the diffuser forming part and extending toward the motor housing, and a sandwiching part sandwiched between the compressor housing and the motor housing,
An inner peripheral side connecting part that is connected to an inner peripheral part of the diffuser forming part and extends toward the stator of the electric motor;
A radial support portion extending from the inner peripheral side connection portion toward the lubricant-filled bearing and supporting the lubricant-filled bearing in a radial direction;
An axial support portion that extends from the inner peripheral side connection portion toward the rotation shaft and that axially supports the lubricant-filled bearing,
The wheel-side facing surface is formed over the inner peripheral side connection portion and the axial support portion,
The opening of the through hole is formed in the wheel-side facing surface of the inner peripheral side connecting portion.

  According to the above configuration (5), the bearing support member includes the diffuser forming portion having the diffuser passage surface forming the diffuser passage, and the fixing portion having the portion extending from the outer peripheral portion of the diffuser forming portion toward the motor housing. And an inner peripheral side connecting portion extending from the inner peripheral portion of the diffuser forming portion toward the stator, a space is formed, and the space is connected to the heat radiating space to expand the heat radiating space. . Further, the through hole is configured to guide the compressed air to the above space formed by the bearing support member. As a result, the passage length of the compressed air due to the through hole can be further shortened, and the compressed air can be guided from the rear clearance to the heat dissipation space with less pressure loss as compared with the case where the above-mentioned space is not formed in the bearing support member. be able to.

(6) In some embodiments, in the configuration of (4) above,
The bearing support member,
A diffuser forming portion having a diffuser passage surface that defines a diffuser passage between the compressor housing and the compressor housing;
A fixed part having an outer peripheral side connecting part connected to an outer peripheral part of the diffuser forming part and extending toward the motor housing, and a sandwiching part sandwiched between the compressor housing and the motor housing,
An inner peripheral side connecting part that is connected to an inner peripheral part of the diffuser forming part and extends toward the stator of the electric motor;
A radial support portion extending from the inner peripheral side connection portion toward the lubricant-filled bearing and supporting the lubricant-filled bearing in a radial direction;
An axial support portion that extends from the inner peripheral side connection portion toward the rotation shaft and that axially supports the lubricant-filled bearing,
The wheel-side facing surface is formed over the inner peripheral side connection portion and the axial support portion,
The opening of the through hole is formed on the wheel-side facing surface of the axial support portion.

  According to the configuration of the above (6), the bearing support member has the diffuser forming portion having the diffuser passage surface forming the diffuser passage, and the fixing portion having the portion extending from the outer peripheral portion of the diffuser forming portion toward the motor housing. And an inner peripheral side connecting portion extending from the inner peripheral portion of the diffuser forming portion toward the stator, a space is formed, and the space is connected to the heat radiating space to expand the heat radiating space. . Further, since the through hole is formed on the wheel-side facing surface of the axial support portion, the lubricant-filled bearing on one end side (compressor wheel side) of the rotating body can be cooled more directly.

(7) In some embodiments, in the configurations of (1) to (6) above,
The through hole has a cross-sectional shape having a longitudinal direction in the circumferential direction and a lateral direction in the radial direction.
With configuration (7) above, the time and man-hours required to form the through hole of the bearing support member can be reduced, and the manufacturing cost of the through hole can be reduced.

  According to at least one embodiment of the present invention, there is provided an electric supercharged compressor in which a load during operation of a lubricant-filled bearing that supports a rotating body is reduced.

It is a sectional view showing roughly composition of an electric supercharging compressor concerning one embodiment of the present invention. It is a partially expanded view of FIG. It is a figure which shows the AA cross section of FIG. 2, and shows the cross-sectional shape of the through hole of a bearing support member. It is sectional drawing which shows schematically the structure of the electric supercharged compressor which concerns on other embodiment of this invention. FIG. 5 is a partially enlarged view of FIG. 4. FIG. 3 is a cross-sectional view showing a cross-sectional shape of a through hole of the bearing support member according to the embodiment of the present invention, the view corresponding to the cross-sectional view taken along the line AA in FIG.

Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative positions, and the like of the components described as the embodiments or shown in the drawings are not intended to limit the scope of the present invention thereto, but are merely illustrative examples. Absent.
For example, expressions that represent relative or absolute arrangements such as “in a certain direction”, “along a certain direction”, “parallel”, “orthogonal”, “center”, “concentric”, or “coaxial” are strict. In addition to representing such an arrangement, it also represents a state in which the components are relatively displaced by a tolerance or an angle or a distance at which the same function can be obtained.
For example, expressions such as "identical", "equal", and "homogeneous" that indicate that they are in the same state are not limited to strict equality, but also include tolerances or differences in the degree to which the same function is obtained. It also represents the existing state.
For example, the representation of a shape such as a quadrangle or a cylinder does not only represent a shape such as a quadrangle or a cylinder in a geometrically strict sense, but also an uneven portion or a chamfer within a range in which the same effect can be obtained. The shape including parts and the like is also shown.
On the other hand, the expressions “comprising”, “comprising”, “comprising”, “including”, or “having” one element are not exclusive expressions excluding the existence of other elements.

FIG. 1 is a sectional view schematically showing the configuration of an electric supercharged compressor 1 according to an embodiment of the present invention. FIG. 2 is a partially enlarged view of FIG. FIG. 3 is a view showing a cross section taken along the line AA in FIG. 2, and shows a cross-sectional shape of the through hole 9 of the bearing support member 5. FIG. 4 is a sectional view schematically showing the configuration of the electric supercharged compressor 1 according to another embodiment of the present invention. FIG. 5 is a partially enlarged view of FIG. In the following description, the direction of the thrust load generated when the rotating body including the compressor wheel 2 and the rotating shaft 3 described later is rotated is referred to as the thrust direction. This thrust direction corresponds to the direction from the back surface to the front surface of the compressor wheel 2.
Hereinafter, the electric supercharged compressor 1 according to the embodiment of the present invention will be described with reference to FIGS. 1 to 5.

  The electric supercharged compressor 1 is provided in, for example, an intake passage (not shown) of an internal combustion engine such as a vehicle, and a compressor wheel 2 installed in the intake passage is rotated by an electric motor 7 so that a cylinder (not It is a device for compressing and feeding the supply air a drawn into the drawing. As shown in FIGS. 1 to 5, a compressor wheel 2 is provided on one end side of the rotary shaft 3, and an electric motor 7 for applying a rotational force to the rotary shaft 3 is provided on the other end side of the rotary shaft 3. It is provided. The electric motor 7 is provided on the other end side of the rotary shaft 3 with respect to the compressor wheel 2, and the compressor wheel 2 and the electric motor 7 are arranged in this order from one end side of the rotary shaft 3 to the other end side. It

  As shown in FIGS. 1 to 5, the compressor wheel 2 includes a hub portion 21 attached to the rotating shaft 3 and a blade 22 attached on the outer peripheral surface of the hub portion 21, and the electric supercharged compressor. 1 to form the rotating body. In the embodiment shown in FIGS. 1 to 5, a shaft insertion hole is provided on the rotation center axis of the hub portion 21 of the compressor wheel 2, and one end of the rotary shaft 3 (end on the compressor side) is provided in the shaft insertion hole. The compressor wheel 2 is connected to the rotary shaft 3 by inserting the nut 3b into the threaded portion 3a formed at the end of the compressor wheel 2a. Further, an inverter 76 for controlling the number of rotations of the electric motor 7 is arranged at the other end (end portion on the inverter side) of the rotating shaft 3.

  Further, as shown in FIGS. 1 to 5, the rotary shaft 3 has a lubricant-filled bearing 8 (for example, a grease-filled type bearing) having a lubricant filled therein between the compressor wheel 2 and the electric motor 7. A compressor-side lubricant-containing bearing 81, which is a rolling bearing, is provided, and the rotary shaft 3 is rotatably supported by the compressor-side lubricant-containing bearing 81. An inverter-side lubricant-containing bearing 82, which is a lubricant-containing bearing 8 different from the compressor-side lubricant-containing bearing 81, is provided between the inverter 76 and the electric motor 7. That is, the rotating body is supported by the two lubricant-filled bearings 8 (81, 82), which reduces the axial vibration of the rotating shaft 3.

  The rotating body including the compressor wheel 2 and the rotating shaft 3, the electric motor 7, and the lubricant-filled bearing 8 (81, 82) are housed inside the housing of the electric supercharged compressor 1. The housing of the electric supercharged compressor 1 is different from a rotating body that moves during operation, and constitutes a stationary member in a stationary state in order to rotatably support the rotating body around the rotating body. As shown in FIGS. 1 to 5, the stationary member includes a compressor housing 4 that rotatably houses the compressor wheel 2, a motor housing 6 that houses an electric motor 7, and at least the compressor housing 4 and the motor housing 6. The bearing support member 5 is fixed to one side and supports the lubricant-filled bearing 8.

The compressor housing 4 accommodates the compressor wheel 2 and extends in the axial direction of the rotary shaft 3 (hereinafter, appropriately referred to as the axial direction), and a compressed supply discharged from the discharge port of the guide cylinder 41. The scroll part 43 forming a spiral chamber into which air a (hereinafter, appropriately referred to as compressed air) is connected to the discharge port 41o of the guide cylinder 41 and the scroll part 43, and the scroll is performed from the discharge port 41o of the guide cylinder 41. And a diffuser section 42 for guiding compressed air to the section 43. The diffuser portion 42 is a portion that reduces the flow velocity of the compressed air to convert the kinetic energy (dynamic pressure) applied to the compressed air into pressure energy (static pressure). In the embodiment shown in FIGS. 1 to 5, a part of the wall surface of the diffuser passage 42p formed in the diffuser portion 42 is formed by the diffuser passage surface 5d (described later) of the bearing support member 5. Further, the guide cylinder 41 is a connecting portion with an upstream side portion of an intake passage (not shown) of the internal combustion engine, and has an intake port 41i serving as an inlet for introducing the supply air a into the compressor housing 4. To be done. That is, the supply air a flowing from the upstream side in the intake passage of the internal combustion engine is compressed by passing through the compressor wheel 2 while being guided by the guide cylinder 41 from the intake port 41i to the discharge port 41o. After that, after passing through the diffuser portion 42 and the scroll portion 43 in this order from the discharge port 41o of the guide cylinder 41, it flows to the downstream side portion of the intake passage (not shown).
On the other hand, the motor housing 6 is an integral housing that also serves as a housing for the electric motor 7 and the inverter 76 in the embodiment shown in FIGS.

  The compressor housing 4 and the motor housing 6 are connected to each other by bolts or the like. By connecting the compressor housing 4 and the motor housing 6, the internal space of the housing is covered so as to cover the compressor-side lubricant-filled bearing 81. Is formed. Then, the bearing support member 5 is installed in the internal space of the housing. More specifically, the compressor housing 4 is formed with a flange portion 4f, and the motor housing 6 is formed with a flange portion 6f, and the respective flange portions (4f, 6f) are in flat contact with each other. It has a simple flange surface. The flange portion 4f of the compressor housing 4 and the flange portion 6f of the motor housing 6 are fastened to each other by the bolt 15 with the holding portion 52f (described later) formed on the bearing support member 5 sandwiched between the compressor housing 4 and the motor housing 6. Connected by. As a result, the bearing support member 5 is fixed to the housing in the internal space of the housing.

  Further, the bearing support member 5 is fixed to the housing (4, 6) in this way, and the compressor side surface facing the one end side (the compressor side end side) of the rotating shaft 3 and the other end of the rotating shaft 3. Side (the side of the inverter side end) of the motor. Then, a part of the compressor side surface faces the back surface of the compressor wheel 2, and this part (the wheel side facing surface 5s) and the back surface of the compressor wheel 2 (the hub portion 21 of the compressor wheel 2). A gap (a back face gap S1) is formed between them. On the other hand, a heat radiation space S2 is formed between the bearing support member 5 and the electric motor 7. In other words, the heat dissipation space S2 is formed between the motor side surface of the bearing support member 5 and the surface of the electric motor 7 facing the compressor side end.

  The bearing support member 5 has a through hole 9 extending toward the electric motor 7 along the axial direction of the rotary shaft 3, and the opening 9i of the through hole 9 located on the compressor side end portion side. Is formed on the wheel-side facing surface 5s of the bearing support member 5 described above. Further, the opening 9o of the through hole 9 on the side of the end portion on the inverter side is formed on the side surface of the motor of the bearing support member 5 described above. In other words, the through hole 9 connects the back surface gap S1 and the heat radiation space S2 between the bearing support member 5 and the electric motor 7 to each other. In the embodiment shown in FIGS. 1 to 5, the through hole 9 is linearly formed so as to be parallel to the rotating shaft 3, and communicates the above-described back clearance S1 and the heat dissipation space S2 with the shortest distance. Is formed in. However, the present invention is not limited to this embodiment, and the through hole 9 may have a center line of the passage formed by the through hole 9 along the axial direction of the rotating shaft 3. For example, it suffices that the back clearance S1 and the heat radiation space S2 can be communicated with each other by the through hole 9 penetrating the bearing support member 5, and the through hole 9 has an angle of 0 to 45 degrees with respect to the rotating shaft 3. You may extend it. The shorter the passage length of the through hole 9, the smaller the pressure loss, which is advantageous.

  In the electric supercharged compressor 1 having such a configuration, the supply air a is gradually compressed from the front edge side to the rear edge side of the blade 22 when passing through the compressor wheel 2. Further, when the supply air a compressed by passing through the compressor wheel 2 flows toward the scroll portion, a part of the supply air a leaks to the above-described back surface gap S1 near the discharge port 41o of the guide cylinder 41. The compressed air that has flowed into the rear surface gap S1 has a pressure equivalent to that of the compressed air at the discharge port 41o, and the pressure on the rear surface side of the compressor wheel 2 is higher than the pressure on the front surface side of the compressor wheel 2. . Therefore, a thrust load acts on the rotating body in the direction from the high pressure side to the low pressure side (the above thrust direction Ds). Then, this thrust load becomes a load that acts on the lubricant-containing bearing 8 (81, 82) that supports the rotating body.

  However, in this embodiment, as described above, the through hole 9 is formed in the bearing support member 5, and the compressed air flowing into the back surface clearance S1 flows through the through hole 9 toward the electric motor 7. become. In other words, the compressed air flowing into the back surface gap S1 is released from the back surface gap S1 by the through hole 9 of the bearing support member 5 without staying in the back surface gap S1. As a result, the pressure in the rear surface gap S1 is reduced, so that the pressure difference between the pressure on the rear surface side and the pressure on the front surface side of the compressor wheel 2 is reduced. As a result, in the electric supercharged compressor 1 of the present embodiment, the thrust load acting on the rotating body is reduced as compared with the case where the through hole 9 is not formed in the bearing support member 5, and the lubricant is enclosed by the thrust load. The load on the bearing 8 (81, 82) can be reduced.

  Further, the through hole 9 is formed so as to penetrate through the bearing support member 5, so that the compressed air in the back surface gap S1 is guided to the electric motor 7 in a shorter distance. That is, by reducing the pressure loss when the compressed air passes through the through hole 9, the pressure on the back side of the compressor wheel 2 is further reduced. As a result, the thrust load acting on the rotating body is further reduced, and the load on the lubricant-containing bearing 8 (81, 82) caused by the thrust load is reduced.

  Moreover, the compressed air flowing through the through hole 9 of the bearing support member 5 is directed to the electric motor 7. At this time, the temperature due to heat generation of the electric motor 7 is higher than the temperature of the compressed air passing through the through hole 9. Therefore, it is possible to cool the electric motor 7 by exchanging heat between the relatively low temperature compressed air and the relatively high temperature electric motor 7. Further, as the electric motor 7 is cooled, the temperature of the heat transferred from the electric motor 7 to the lubricant-filled bearing 8 (81, 82) is lowered. As a result, the lubricant-filled bearing 8 (81, 82) of the electric supercharged compressor 1 of the present embodiment has a lubricant-filled bearing 8 (81) more than when the through hole 9 is not formed in the bearing support member 5. , 82) can be reduced, and the heat load on the lubricant-filled bearing 8 (81, 82) can be reduced.

  In the embodiment shown in FIGS. 1 to 5, as shown in FIG. 3, the bearing support member 5 is provided with a plurality of through holes 9. In addition, the plurality of through holes 9 are provided in the bearing support member 5 at intervals along the circumferential direction of the rotating shaft 3. Thereby, the flow passage area of the flow passage formed by the through hole 9 is set to a desired value. The plurality of through holes 9 may or may not be arranged at equal intervals. Further, in the embodiment shown in FIGS. 1 to 5, the through hole 9 has a circular cross section, as shown in FIG. The through holes 9 are formed so that the cross sectional areas of the through holes 9 are equal over the entire length of the through holes 9.

  In the embodiment shown in FIGS. 1 to 5, the motor housing 6 is an integral housing that also serves as a housing for the electric motor 7 and the inverter 76. However, the present invention is not limited to this embodiment, and in some other embodiments, the motor housing 6 and the inverter housing may be formed by separate members, and both may be connected by bolts or the like. Further, in the embodiments shown in FIGS. 1 to 5, the bearing support member 5 is an insert member inserted between the compressor housing 4 and the motor housing 6, but in some other embodiments. The bearing support member 5 may be a bearing housing. That is, the interior of the housing may be formed by the compressor housing 4, the motor housing 6, and the bearing housing. In this case, the bearing housing has a portion having the same function as the bearing support member 5.

  According to the above configuration, the compressed air (air) leaking into the back surface gap S1 formed by the back surface side of the compressor wheel 2 and the bearing support member 5 passes through the through hole 9 of the bearing support member 5 and the electric motor. Guided towards 7. Further, the through hole 9 of the bearing support member 5 extends along the axial direction of the rotary shaft 3 so that the passage length of the air formed by the through hole 9 is shortened. That is, in the electric supercharged compressor 1, the compressed air leaking from the intake passage side formed inside the compressor housing 4 to the back surface gap S1 through the through hole 9 formed in the bearing support member can be shortened. It is configured to be released to the electric motor 7 side. As a result, the pressure difference between the front surface side and the rear surface side of the compressor wheel 2 can be further reduced, and the thrust load acting on the rotating body can be further reduced. Therefore, the load due to the thrust load of the lubricant-containing bearing 8 that supports the rotating body can be reduced.

  Further, the electric motor 7 and the lubricant-filled bearing 8 (81, 82) on the relatively high temperature side can be cooled by the compressed air on the relatively high temperature side supplied from the through hole 9 of the bearing support member 5. it can. In particular, the lubricant-filled bearing 8 is not supplied with lubricating oil from the outside, and the lubricant-filled bearing 8 is cooled by the above compressed air to generate heat from the electric motor 7 to cause the lubricant-filled bearing 8 (81, 82). It is possible to suppress the situation where the temperature exceeds the allowable temperature. Further, since the cooling capacity of the lubricant-containing bearing 8 (81, 82) is improved in this way, the electric motor is protected in order to protect the lubricant-containing bearing 8 (81, 82) from the heat of the electric motor 7 that generates heat. It is possible to suppress a situation in which the rotation speed of 7 and the driving time are limited. Therefore, the performance of the electric supercharged compressor 1 can be improved while improving the reliability of the lubricant-filled bearing 8 (81, 82).

  Further, in some embodiments, as shown in FIGS. 1 to 5, the electric motor 7 is supported by the rotor 71 fixed to the rotating shaft 3 and the motor housing 6 around the rotor 71, and electromagnetic force is applied. And a stator 72 for applying a rotational force to the rotor 71. A heat radiation space S2 is formed between the stator 72 and the bearing support member 5, and the through hole 9 connects the back surface gap S1 and the heat radiation space S2. In the present embodiment, the stator 72 of the electric motor 7 is configured to include a stator coil 73 installed around the rotor 71. Moreover, since electric power is supplied to the stator 72 side, the stator 72 generates heat. A heat radiating space S2 is formed adjacent to the stator 72 whose temperature is raised by heat generation, and the compressed air in the back surface gap S1 is supplied through the through hole 9 toward the heat radiating space S2.

  According to the above configuration, the through hole 9 of the bearing support member 5 communicates the gap formed by the back face side of the compressor wheel 2 and the bearing support member 5 (back face gap S1) with the heat radiation space S2. Compressed air is introduced into the heat dissipation space S2 through the through holes 9 to cool the stator 72, which is the main heat generating point of the electric motor 7, and thus to more effectively cool the electric motor 7. You can Further, by cooling the electric motor 7, the lubricant-filled bearing 8 (81, 82) can be indirectly cooled.

  In some embodiments, as shown in FIGS. 1 and 2, the opening 9i of the through hole 9 of the bearing support member 5 is formed in the outer peripheral region of the wheel-side facing surface 5s of the bearing support member 5. To be done. The outer peripheral region of the wheel-side facing surface 5s is a radial outer peripheral region of the wheel-side facing surface 5s. That is, the supply air a is further compressed as it flows from the leading edge side to the trailing edge side of the blades 22 of the compressor wheel 2, so that the pressure near the position of the end of the compressor wheel 2 (the trailing edge side) is smaller than that at the leading edge side. The pressure is relatively high. In this embodiment, the opening 9i of the through hole 9 is formed so as to be adjacent to such a position where the compressed air is high in the axial direction. In other words, the distance from the inlet of the back surface gap S1 into which the compressed air flows to the opening 9i serving as the inlet of the through hole 9 is set to be short, and the pressure when the compressed air flows into the back surface gap S1 is reduced. The compressed air can be guided from the opening 9i to the through hole 9 in a state in which the above is suppressed. For example, the outer peripheral region of the wheel-side facing surface 5s is located between the radial end of the rotary shaft 3 and the radial end of the compressor wheel 2 that is located near the discharge port 41o of the guide cylinder 41. It may be a region including a region located on the outermost side when divided into three equal parts. Then, the through hole 9 extends toward the electric motor 7 along the axial direction with the opening 9i formed in the outer peripheral side region of the wheel side facing surface 5s as one end.

  According to the above configuration, the thrust load generated on the rotating body of the electric supercharged compressor 1 is reduced as compared with the case where the opening 9i of the through hole 9 is formed in a region other than the outer peripheral region of the wheel-side facing surface 5s. be able to.

  In some other embodiments, as shown in FIGS. 4 to 5, the opening 9i of the through hole 9 included in the bearing support member 5 is larger than the outer peripheral side region in the wheel side facing surface 5s of the bearing support member 5. The through hole 9 is formed on the inner peripheral side and extends on the outer peripheral side of the outer peripheral surface of the lubricant-containing bearing 8. For example, when the outer peripheral side region is defined as described above, the opening 9i of the through hole 9 is formed in the inner peripheral side region (inner peripheral side region) other than the outer peripheral side region in the wheel side facing surface 5s. It The inner peripheral region of the wheel-side facing surface 5s is located closer to the compressor-side lubricant-containing bearing 81 than the outer peripheral region thereof. In the present embodiment, by forming the opening 9i of the through hole 9 in the inner peripheral region of the wheel-side facing surface 5s, the through hole 9 is formed in a portion of the bearing support member 5 closer to the compressor-side lubricant-filled bearing 81. . As a result, the temperature of the portion of the bearing support member 5 (the radial support portion 54 and the axial support portion 55, which will be described later) that supports the compressor-side lubricant-containing bearing 81 is reduced by the compressed air flowing through the through hole 9. The temperature can be made relatively lower than that of the side lubricant-containing bearing 81, and the relatively high temperature compressor-side lubricant-containing bearing 81 can be cooled.

  In the embodiment shown in FIGS. 1 to 5, the sleeve 34 is provided on the outer peripheral surface of the compressor-side lubricant-containing bearing 81. Further, the bearing support member 5 includes a radial direction support portion 54 (described later) that supports the compressor-side lubricant-containing bearing 81 via the sleeve 34 and an axial direction that supports the compressor-side lubricant-containing bearing 81 in the radial direction. The supporting portion 55 (described later) is formed as a separate member, and the both are connected by a bolt 58. The through hole 9 extends toward the electric motor 7 along the axial direction between the bolt 58 and the sleeve 34 that connect the radial support portion 54 and the axial support portion 55 in the radial direction. Thus, the bearing support member 5 is formed.

  According to the above configuration, the compressor-side lubricant-containing bearing 81 can be cooled more directly than in the case where the opening 9i of the through hole 9 is formed in the outer peripheral region of the wheel-side facing surface 5s.

Next, the bearing support member 5 of the embodiment shown in FIGS. 1 to 5 will be described in more detail.
In some embodiments, as shown in FIGS. 2 and 5, the bearing support member 5 includes a diffuser forming portion 51, a fixing portion 52, an inner peripheral side connecting portion 53, a radial direction supporting portion 54, And an axial support portion 55. All of the parts (51 to 55) forming the bearing support member 5 may be formed as an integral member, or at least a part of the structure is formed as a member different from other members and connected by bolts or the like. It may be integrated as a result. In the embodiment shown in FIGS. 1 to 5, the diffuser forming portion 51, the fixing portion 52, the inner peripheral side connecting portion 53, and the radial direction supporting portion 54 are integrally formed, and are different from this. The bearing support member 5 is configured by connecting (fixing) the axial support portion 55 formed as a member to the radial support portion 54 with a bolt 58.

More specifically, the diffuser forming portion 51 is a portion of the bearing support member 5 having a diffuser passage surface 5d that defines a diffuser passage 42p with the compressor housing 4.
The fixing portion 52 is a portion of the bearing support member 5 that is connected to the outer peripheral portion of the diffuser forming portion 51, and extends to the motor housing 6 from the outer peripheral side connecting portion 52 a, the compressor housing 4, and the motor housing 6. And a pinching portion 52f that is pinched between the two.
In the embodiment shown in FIGS. 1 to 5, the end portions of the diffuser forming portion 51 and the fixing portion 52 on the side of the inverter side end portion in the axial direction are separated from each other by the distance L1. In other words, the fixed portion 52 projects from the diffuser forming portion 51 by the distance L1 toward the inverter side end portion.

The inner peripheral side connecting portion 53 is a portion of the bearing supporting member 5 connected to the inner peripheral portion of the diffuser forming portion 51, and is a portion extending toward the stator 72. In the embodiment shown in FIGS. 1 to 5, the inner peripheral side connecting portion 53 is provided so as to be displaced from the diffuser forming portion 51 toward the inverter side end portion in the axial direction, and the diffuser forming portion 51 of the diffuser forming portion 51 is provided. A step is formed between the diffuser passage surface 5d and the compressor side surface portion of the bearing support member 5 formed by the inner peripheral side connection portion 53. The back surface of the compressor wheel 2 is located at the step portion, and the inner peripheral side connection portion 53 forms a part of the outer peripheral side of the wheel side facing surface 5s. The wheel-side facing surface 5s is constituted by the inner peripheral side connecting portion 53 and the radial direction supporting portion 54 described later.
Further, the end portions of the diffuser forming portion 51 and the inner peripheral side connecting portion 53 on the side of the axial side inverter side end portion are separated from each other by a distance L1. In other words, the inner peripheral side connecting portion 53 projects from the diffuser forming portion 51 by the distance L1 toward the end portion on the inverter side. The radial support portion 54 and the axial support portion 55 are connected to the inner peripheral side connection portion 53, respectively.

  The radial support portion 54 is a portion of the bearing support member 5 extending from the inner peripheral side connection portion 53 toward the compressor-side lubricant-filled bearing 81, and supports the compressor-side lubricant-filled bearing 81 in the radial direction. . In the embodiment shown in FIG. 5, the radial support portion 54 supports the compressor-side lubricant-containing bearing 81 via the sleeve 34 described above.

  The axial support portion 55 is a portion of the bearing support member 5 that extends from the inner peripheral side connection portion 53 toward the rotary shaft 3, and supports the compressor-side lubricant-containing bearing 81 in the axial direction. In the embodiment shown in FIGS. 1 to 5, the axial support portion 55 forms a part of the wheel-side facing surface 5s on the outer peripheral side. The wheel-side facing surface 5s is configured by the inner peripheral side connecting portion 53 and the radial direction supporting portion 54 described above. Further, the axial support portion 55 extends to the sleeve 35 provided on the rotary shaft 3, and the end portion of the axial support portion 55 on the inverter side end portion supports the outer ring of the compressor side lubricant-containing bearing 81. are doing.

  As described above, in the bearing support member 5, when viewed from the diffuser forming portion 51 located closest to the end portion on the inverter side in the axial direction, the fixing portion 52 is arranged in the axial direction from the outer peripheral side of the diffuser forming portion 51. 7, the radial direction support portion 54 connected to the inner peripheral side connecting portion 53 extends from the inner peripheral side of the diffuser forming portion 51 in the axial direction of the electric motor 7. Along which the distance L1 is projected. Thereby, the diffuser forming portion 51, the fixing portion 52, the inner peripheral side connecting portion 53, and the radial direction supporting portion 54 form a space S3. Further, since the space S3 formed by the bearing support member 5 is continuous with the heat radiation space S2, cooling of the electric motor can be promoted.

  In the embodiment shown in FIGS. 1 and 2, the wheel-side facing surface 5s is formed over the inner peripheral side connecting portion 53 and the axial support portion 55, and the opening 9i of the through hole 9 is formed on the inner peripheral side. It is formed on the wheel-side facing surface 5s of the connecting portion 53. As a result, the passage length of the compressed air through the through hole 9 can be further shortened, and the compressed air can be discharged from the back surface gap S1 with less pressure loss as compared with the case where the space S3 is not formed in the bearing support member 5. It can be guided to the heat dissipation space S2.

  On the other hand, in the embodiment shown in FIGS. 4 to 5, the wheel-side facing surface 5s is similarly formed over the inner peripheral side connecting portion 53 and the axial direction supporting portion 55, but the opening 9i of the through hole 9 is formed. Is formed on the wheel-side facing surface 5s of the axial support portion 55. As a result, as described above, the through hole 9 is formed in the portion near the compressor-side lubricant-containing bearing 81, and the compressor-side lubricant-containing bearing 81 can be cooled more directly.

Hereinafter, some other embodiments of the cross-sectional shape of the through hole 9 of the bearing support member 5 will be described with reference to FIG. FIG. 6 is a cross-sectional view for explaining the cross-sectional shape of the through hole 9 of the bearing support member 5 according to another embodiment of the present invention, and is a view corresponding to the cross-sectional view taken along the line AA in FIG. 2.
As shown in FIG. 6, the through hole 9 of the bearing support member 5 may have a cross-sectional shape having a longitudinal direction Hl in the circumferential direction and a lateral direction Hs in the radial direction. Since the through hole 9 has such a cross-sectional shape, the passage width of the through hole 9 of the bearing support member 5 can be easily widened. For example, in order to allow the flow rate equivalent to the flow rate that can be flowed by one through hole 9 having the cross-sectional shape in FIG. 6 to be flowed in the through hole 9 having a circular cross-sectional shape shown in FIG. It is necessary to further increase the number of through holes 9, which increases the number of manufacturing steps. However, the cross-sectional shape of FIG. 6 can be easily formed in one step by groove processing. Therefore, the time and man-hours required to form the through hole 9 of the bearing support member 5 can be reduced, and the manufacturing cost of the through hole 9 can be reduced.

  The present invention is not limited to the above-described embodiment, and includes a modified form of the above-described embodiment and a combination of these forms as appropriate.

1 Supercharged compressor 15 Bolt 2 Compressor wheel 21 Hub part 22 Blade 3 Rotating shaft 3a Screw part 3b Nut 34 Sleeve 35 Sleeve 4 Compressor housing 4f Flange part 41 Guide cylinder 41i Suction port 41o Discharge port 42 Diffuser part 42p Diffuser passage 43 Scroll Part 5 Bearing support member 5d Diffuser passage surface 5s Wheel side facing surface 51 Diffuser formation part 52 Fixed part 52a Outer peripheral side connection part 52f Clamping part 53 Inner peripheral side connection part 54 Radial direction support part 55 Axial direction support part 58 Bolt 6 Motor housing 6f Flange 7 Electric motor 71 Rotor 72 Stator 73 Stator coil 76 Inverter 8 Lubricant-filled bearing 81 Compressor-side lubricant-filled bearing 82 Inverter-side lubricant-filled bearing 9 Through-hole 9i Through-hole opening

S1 Back clearance S2 Radiating space S3 Space Ds Thrust direction Hl Longitudinal direction Hs Short direction a Air supply

Claims (7)

A rotation axis,
A compressor wheel provided on one end side of the rotating shaft,
A compressor housing that rotatably accommodates the compressor wheel,
An electric motor provided on the other end side of the rotary shaft with respect to the compressor wheel, for applying a rotational force to the rotary shaft,
A motor housing that houses the electric motor;
A bearing for rotatably supporting the rotating shaft, provided between the compressor wheel and the electric motor, wherein the lubricant-enclosed bearing has a lubricant enclosed therein,
A bearing support member that is fixed to at least one of the compressor housing and the motor housing and that supports the lubricant-filled bearing, and that opposes the rear surface of the compressor wheel with a gap between them. A bearing support member having a surface ,
A sleeve provided on the rotary shaft at a position closer to the compressor wheel than the lubricant-filled bearing ,
The wheel side facing surface is configured to extend to the sleeve,
The bearing support member has a through hole that extends from an opening formed in the wheel-side facing surface toward the electric motor along the axial direction of the rotating shaft. . The electric motor is
A rotor fixed to the rotating shaft,
A stator that is supported by the motor housing around the rotor and that applies a rotational force to the rotor by an electromagnetic force,
A heat dissipation space is formed between the stator and the bearing support member,
The electric supercharged compressor according to claim 1, wherein the through hole communicates the gap with the heat radiation space.   The electric supercharged compressor according to claim 1 or 2, wherein the opening of the through hole is formed in an outer peripheral region of the wheel-side facing surface. The opening of the through hole, while being formed on the inner peripheral side of the outer peripheral side region in the wheel-side facing surface,
The electric supercharged compressor according to claim 1 or 2, wherein the through hole extends on an outer peripheral side of an outer peripheral surface of the lubricant-filled bearing. The bearing support member,
A diffuser forming portion having a diffuser passage surface that defines a diffuser passage between the compressor housing and the compressor housing;
A fixed part having an outer peripheral side connecting part connected to an outer peripheral part of the diffuser forming part and extending toward the motor housing, and a sandwiching part sandwiched between the compressor housing and the motor housing,
An inner peripheral side connecting part that is connected to an inner peripheral part of the diffuser forming part and extends toward the stator of the electric motor;
A radial support portion extending from the inner peripheral side connection portion toward the lubricant-filled bearing and supporting the lubricant-filled bearing in a radial direction;
An axial support portion that extends from the inner peripheral side connection portion toward the rotation shaft and that axially supports the lubricant-filled bearing,
The wheel-side facing surface is formed over the inner peripheral side connection portion and the axial support portion,
The electric supercharged compressor according to claim 3, wherein the opening of the through hole is formed on a surface of the inner peripheral side connection portion that faces the wheel side. The bearing support member,
A diffuser forming portion having a diffuser passage surface that defines a diffuser passage between the compressor housing and the compressor housing;
A fixed part having an outer peripheral side connecting part connected to an outer peripheral part of the diffuser forming part and extending toward the motor housing, and a sandwiching part sandwiched between the compressor housing and the motor housing,
An inner peripheral side connecting part that is connected to an inner peripheral part of the diffuser forming part and extends toward the stator of the electric motor;
A radial support portion extending from the inner peripheral side connection portion toward the lubricant-filled bearing and supporting the lubricant-filled bearing in a radial direction;
An axial support portion that extends from the inner peripheral side connection portion toward the rotation shaft and that axially supports the lubricant-filled bearing,
The wheel-side facing surface is formed over the inner peripheral side connection portion and the axial support portion,
The electric supercharged compressor according to claim 4, wherein the opening of the through hole is formed in a surface of the axial support portion that faces the wheel side.   The electric supercharged compression according to any one of claims 1 to 6, wherein the through hole has a cross-sectional shape having a longitudinal direction in a circumferential direction and a lateral direction in a radial direction. Machine.

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