JP2017223151A - Electric supercharger compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric supercharger compressor capable of reducing the load, which is applied to a lubricant sealed bearing supporting a body of revolution during operation of the bearing.SOLUTION: An electric supercharger compressor comprises: a compressor housing for rotatably accommodating a compressor wheel provided on one end side of a rotation shaft; an electric motor for applying a torque to the rotation shaft; a motor housing for accommodating the electric motor; a lubricant sealed bearing which is provided between the compressor wheel and the electric motor for rotatably supporting the rotation shaft inside which lubricant is enclosed; and a bearing support member which is fixed to at least one of the compressor housing and the motor housing for supporting the lubricant sealed bearing and which has a wheel side facing surface which faces the back face of the compressor wheel with a gap therebetween. The bearing support member has an open hole extending from an opening formed on the wheel side facing surface toward the electric motor along the axial direction of the rotation shaft.SELECTED DRAWING: Figure 1

Description

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

  Improvements in engine fuel efficiency and exhaust gas have been strengthened year by year. As countermeasures, town sizing of engines using supercharging using a supercharger is being promoted. Under such circumstances, an electric supercharged compressor (electric compressor) that drives a compressor using an electric motor generally has a target boost pressure compared to an exhaust turbine supercharger (turbocharger). The arrival time of is fast and excellent in transient response. In recent years, an electric two-stage turbo system in which an electric supercharged compressor is combined with a turbocharger has been proposed, and the electric two-stage turbo system allows a wide range and transient response in a compressor operation map such as an increase in torque at low speed. Can be improved.

  On the other hand, in the electric supercharged compressor, the electric motor generates heat by rotationally driving the compressor. However, heat generated by the electric motor is transferred to a bearing (bearing) that supports the rotating shaft of the compressor wheel. There is a risk that the bearing will be damaged beyond the allowable temperature. For this reason, in order to prevent the bearing from exceeding the permissible temperature due to heat generated by the electric motor, for example, measures such as limiting the rotation speed and driving time of the electric motor are taken. It is a factor that determines the reliability and performance of turbochargers.

  Further, unlike the exhaust turbine supercharger, the electric supercharged compressor has an impeller (compressor wheel) only on one side of the rotating shaft. For this reason, 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 becomes a load on the bearing that supports the rotating body and causes mechanical loss when the rotating body is driven. Therefore, it is also important to improve the reliability and performance of the electric supercharger to reduce the thrust load acting on the rotating body in order to protect the bearing and improve the performance. In the exhaust turbine supercharger, impellers are provided at both ends of the rotating shaft, and the respective thrust loads are offset by mutually opposite thrust loads generated by the impellers on both sides. .

  In this regard, in Patent Document 1, a canceller chamber for canceling the thrust load is formed on the end portion of the rotating shaft where the impeller is not provided, and a gap on the back surface of the impeller and the canceller chamber are provided. The thrust load is reduced by connecting the stationary members that are stationary without moving like a rotating body by a passage portion formed by sewing. More specifically, the compressed air compressed by the compressor leaks from the gap between the outer peripheral end of the impeller and the scroll, and the leaked compressed air is introduced into the canceller chamber by the passage portion. Thus, the compressed air is used as pressurized air for generating a canceller pressure for canceling a thrust load generated in the rotating body. It is also described that 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 is premised on a canceller chamber for canceling a thrust load, and the rotating shaft of the electric supercharged compressor is supported by an air bearing (thrust air bearing). For this reason, the above-mentioned passage part of patent documents 1 cannot be applied to an electric supercharged compressor which does not have a canceller room, or an electric supercharged compressor which adopted a rolling bearing as it is. In addition, the passage portion of Patent Document 1 is formed between stationary members, and guides the compressed air leaking from the gap between the outer peripheral end of the impeller and the scroll first away from the rotating shaft along the radial direction. After that, it has a complicated structure, such as guiding along the axial direction and guiding again toward the rotating shaft along the radial direction. For this reason, 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 is reduced. There is also a concern that the effect of reducing the thrust load and the effect of cooling the bearing may not be sufficiently exhibited.

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

(1) An electric supercharged compressor according to at least one embodiment of the present invention is:
A rotation axis;
A compressor wheel provided on one end of the rotating shaft;
A compressor housing for rotatably housing the compressor wheel;
An electric motor for applying a rotational force to the rotary shaft, provided on the other end side of the rotary shaft from the compressor wheel;
A motor housing that houses the electric motor;
A bearing provided between the compressor wheel and the electric motor for rotatably supporting the rotating shaft, and a lubricant-enclosed bearing in which a lubricant is enclosed;
A bearing support member that is fixed to at least one of the compressor housing and the motor housing and supports the lubricant-enclosed bearing, and is opposed to the wheel side with a gap between the rear surface of the compressor wheel. 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 configuration of (1) above, the compressed air (air) leaking into the gap formed by the back surface side of the compressor wheel and the bearing support portion passes through the through hole of the bearing support member toward the electric motor. Led. Further, the through hole of the bearing support member extends along the axial direction of the rotating shaft, so that the air passage length formed by the through hole is shortened. In other words, the electric supercharged compressor allows compressed air leaking from the intake passage side formed inside the compressor housing to the gap through the through-hole formed in the bearing support member to the electric motor side at a shorter distance. It is configured to escape. Here, a thrust load directed from the back surface of the compressor wheel toward the front surface always acts on the rotating body including the compressor wheel and the rotating shaft of the electric supercharged compressor during operation. According to said structure, the pressure difference in the front side and back side of a compressor wheel can be made smaller, and the thrust load which acts on a rotary body can be reduced more. For this reason, the load by the thrust load of the lubricant enclosure bearing which supports a rotating body can be reduced.

  Further, the electric motor and the lubricant-enclosed bearing on the relatively high temperature side can be cooled by the compressed air on the relatively low temperature side supplied from the through hole of the bearing support member. In particular, the lubricant-enclosed bearing is not supplied from the outside, and the lubricant-enclosed bearing is cooled by the compressed air described above, so that the lubricant-enclosed bearing exceeds the allowable temperature due to the heat generated by the electric motor. Can be suppressed. In addition, since the cooling capability of the lubricant-enclosed bearing is improved in this way, the situation in which the rotational speed and drive time of the electric motor are limited to protect the lubricant-enclosed bearing from the heat of the electric motor that generates heat. Can be suppressed. Therefore, it is possible to improve the performance of the electric supercharged compressor while improving the reliability of the lubricant-enclosed bearing.

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

(3) In some embodiments, in the above configurations (1) to (2),
The opening of the through hole is formed in an outer peripheral side region on the wheel side facing surface.
According to the configuration of the above (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 a region other than the outer peripheral side region of the wheel side facing surface. Can do.

(4) In some embodiments, in the above configurations (1) to (2),
The opening of the through hole is formed on the inner peripheral side of the outer peripheral side region in the wheel side facing surface, and
The through hole extends on the outer peripheral side with respect to the outer peripheral surface of the lubricant-enclosed bearing.
According to the configuration of the above (4), the lubricant-enclosed bearing on the one end side (compressor wheel side) of the rotating body is more directly provided than when 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 is
A diffuser forming portion having a diffuser passage surface defining a diffuser passage with the compressor housing;
A fixed portion having an outer peripheral side connecting portion that is connected to the outer peripheral portion of the diffuser forming portion and extends toward the motor housing, and a clamping portion that is sandwiched between the compressor housing and the motor housing;
An inner peripheral side connecting portion connected to an inner peripheral portion of the diffuser forming portion and extending toward a stator of the electric motor;
A radial support portion extending from the inner peripheral side connection portion toward the lubricant-enclosed bearing and supporting the lubricant-enclosed bearing in a radial direction;
An axial support portion extending from the inner peripheral side connection portion toward the rotation shaft and supporting the lubricant-enclosed bearing in the axial direction,
The wheel side facing surface is formed across the inner peripheral side connecting portion and the axial support portion,
The opening of the through hole is formed on the wheel side facing surface in the inner peripheral side connection portion.

  According to the configuration of (5) above, the bearing support member has a diffuser forming portion having a diffuser passage surface that forms a diffuser passage, and a fixed portion having a portion extending from the outer peripheral portion of the diffuser forming portion toward the motor housing. And a space formed by the inner peripheral side connecting portion extending from the inner peripheral portion of the diffuser forming portion toward the stator, and this space is configured to expand the heat dissipation space by connecting to the heat dissipation space. . The through hole is configured to guide the compressed air to the space formed by the bearing support member. Thereby, the passage length of the compressed air by the through hole can be shortened, and the compressed air is guided from the back gap to the heat radiation space without pressure loss, compared to the case where the above 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 is
A diffuser forming portion having a diffuser passage surface defining a diffuser passage with the compressor housing;
A fixed portion having an outer peripheral side connecting portion that is connected to the outer peripheral portion of the diffuser forming portion and extends toward the motor housing, and a clamping portion that is sandwiched between the compressor housing and the motor housing;
An inner peripheral side connecting portion connected to an inner peripheral portion of the diffuser forming portion and extending toward a stator of the electric motor;
A radial support portion extending from the inner peripheral side connection portion toward the lubricant-enclosed bearing and supporting the lubricant-enclosed bearing in a radial direction;
An axial support portion extending from the inner peripheral side connection portion toward the rotation shaft and supporting the lubricant-enclosed bearing in the axial direction,
The wheel side facing surface is formed across the inner peripheral side connecting 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 (6) above, the bearing support member includes a diffuser forming portion having a diffuser passage surface that forms a diffuser passage, and a fixed portion having a portion extending from the outer periphery of the diffuser forming portion toward the motor housing. And a space formed by the inner peripheral side connecting portion extending from the inner peripheral portion of the diffuser forming portion toward the stator, and this space is configured to expand the heat dissipation space by connecting to the heat dissipation space. . Further, the through hole is formed on the wheel side facing surface of the axial support portion, so that the lubricant-enclosed bearing on one end side (compressor wheel side) of the rotating body can be cooled more directly.

(7) In some embodiments, in the above configurations (1) to (6),
The through hole has a cross-sectional shape having a longitudinal direction in the circumferential direction and a short direction in the radial direction.
According to the configuration of (7) above, it is possible to reduce the time and man-hours required to form the through hole of the bearing support member, and to reduce the manufacturing cost of the through hole.

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

It is a sectional view showing roughly the composition of the electric supercharged compressor concerning one embodiment of the present invention. It is the elements on larger scale 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 supercharging compressor which concerns on other one Embodiment of this invention. It is the elements on larger scale of FIG. It is sectional drawing which shows the cross-sectional shape of the through-hole of the bearing support member which concerns on one Embodiment of this invention, and is a figure corresponding to sectional drawing in the AA cross section of FIG.

Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in the embodiments or shown in the drawings are not intended to limit the scope of the present invention, but are merely illustrative examples. Absent.
For example, expressions expressing relative or absolute arrangements such as “in a certain direction”, “along a certain direction”, “parallel”, “orthogonal”, “center”, “concentric” or “coaxial” are strictly In addition to such an arrangement, it is also possible to represent a state of relative displacement with an angle or a distance such that tolerance or the same function can be obtained.
For example, an expression indicating that things such as “identical”, “equal”, and “homogeneous” are in an equal state not only represents an exactly equal state, but also has a tolerance or a difference that can provide the same function. It also represents the existing state.
For example, expressions representing shapes such as quadrangular shapes and cylindrical shapes represent not only geometrically strict shapes such as quadrangular shapes and cylindrical shapes, but also irregularities and chamfers as long as the same effects can be obtained. A shape including a part or the like is also expressed.
On the other hand, the expressions “comprising”, “comprising”, “comprising”, “including”, or “having” one constituent element are not exclusive expressions for excluding the existence of the other constituent elements.

FIG. 1 is a cross-sectional view schematically showing a 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 the AA cross section of FIG. 2, and shows the cross-sectional shape of the through hole 9 of the bearing support member 5. FIG. 4 is a cross-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 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 a thrust direction. This thrust direction coincides with the direction from the back surface to the front surface of the compressor wheel 2.
Hereinafter, the electric supercharged compressor 1 according to an embodiment of the present invention will be described with reference to FIGS.

  The electric supercharged compressor 1 is provided in an intake passage (not shown) of an internal combustion engine such as a vehicle, for example, and a compressor wheel 2 installed in the intake passage is rotated by an electric motor 7, whereby a cylinder (not This is a device for compressing and feeding the supply air a sucked into the drawing. As shown in FIGS. 1 to 5, a compressor wheel 2 is provided on one end side of the rotating shaft 3, and an electric motor 7 for applying a rotational force to the rotating shaft 3 is provided on the other end side of the rotating shaft 3. Provided. The electric motor 7 is provided on the other end side of the rotating 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 to the other end side of the rotating shaft 3. The

  As shown in FIGS. 1 to 5, the compressor wheel 2 includes a hub portion 21 attached to the rotary shaft 3 and a blade 22 attached on the outer peripheral surface of the hub portion 21. 1 constitutes a 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 (compressor side end) of the rotation shaft 3 is provided in this shaft insertion hole. Is inserted, and the nut 3b is screwed into the threaded portion 3a formed at the end, so that the compressor wheel 2 is connected to the rotary shaft 3. Further, an inverter 76 for controlling the rotation speed of the electric motor 7 is disposed at the other end (inverter side end) of the rotating shaft 3.

  As shown in FIGS. 1 to 5, the rotary shaft 3 includes a lubricant-enclosed bearing 8 (for example, a grease-enclosed type) in which a lubricant is enclosed between the compressor wheel 2 and the electric motor 7. A compressor-side lubricant-enclosed bearing 81 that is a rolling bearing) is provided, and the rotary shaft 3 is rotatably supported by the compressor-side lubricant-enclosed bearing 81. In addition, an inverter-side lubricant-enclosed bearing 82 that is a lubricant-enclosed bearing 8 different from the compressor-side lubricant-enclosed bearing 81 is provided between the inverter 76 and the electric motor 7. That is, the rotating body is supported by the two lubricant-enclosed bearings 8 (81, 82), thereby reducing the shaft 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-enclosed 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 the rotating body that moves during operation, and constitutes a stationary member that is stationary 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 accommodates the compressor wheel 2, a motor housing 6 that accommodates the electric motor 7, and at least one of the compressor housing 4 and the motor housing 6. A bearing support member 5 that is fixed to one side and supports the lubricant-enclosed bearing 8 is configured.

The compressor housing 4 accommodates the compressor wheel 2 and extends in the axial direction of the rotating shaft 3 (hereinafter referred to as the axial direction as appropriate), and the 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 referred to as compressed air as appropriate) flows, the discharge port 41o of the guide cylinder 41 and the scroll part 43 are connected, and scrolling is performed from the discharge port 41o of the guide cylinder 41. And a diffuser portion 42 for guiding compressed air to the portion 43. The diffuser part 42 is a part that converts kinetic energy (dynamic pressure) imparted to the compressed air into pressure energy (static pressure) by decelerating the flow rate of the compressed air. In the embodiment shown in FIGS. 1 to 5, a part of the wall surface of the diffuser passage 42 p formed in the diffuser portion 42 is formed by a diffuser passage surface 5 d (described later) of the bearing support member 5. Further, the guide cylinder 41 is a connection portion with an upstream portion of an intake passage (not shown) of the internal combustion engine, and an intake port 41 i is formed as an inlet for introducing the supply air a into the compressor housing 4. Is done. That is, the supply air a flowing from the upstream side of the intake passage of the internal combustion engine is compressed by passing through the compressor wheel 2 while being guided from the suction port 41 i to the discharge port 41 o by the guide cylinder 41. 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 tube 41, it flows to the downstream portion of the intake passage (not shown).
On the other hand, in the embodiment shown in FIGS. 1 to 5, the motor housing 6 is an integrated housing that also serves as a housing for the electric motor 7 and the inverter 76.

  The compressor housing 4 and the motor housing 6 are connected by bolts or the like, but the internal space of the housing covers the compressor-side lubricant sealed bearing 81 by connecting the compressor housing 4 and the motor housing 6. Is formed. And the bearing support member 5 is installed in the internal space of this 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. The flange portions (4f, 6f) are flat against each other. It has a simple flange surface. Then, the flange portion 4f of the compressor housing 4 and the flange portion 6f of the motor housing 6 are connected to the bolt 15 in a state where a sandwiching portion 52f (described later) formed on the bearing support member 5 is sandwiched between the compressor housing 4 and the motor housing 6. Connected with. Thereby, the bearing support member 5 is fixed to the housing in the internal space of the housing.

  In addition, the bearing support member 5 is fixed to the housing (4, 6) in this manner, the compressor side surface facing the one end side (compressor side end portion side) of the rotating shaft 3, and the other end of the rotating shaft 3. And a motor side surface facing the side (inverter side end portion side). A part of the side surface of the compressor is opposed to the back surface of the compressor wheel 2, and a part of the compressor wheel 2 (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 (back gap S1) is formed between the two. On the other hand, a heat radiation space S <b> 2 is formed between the bearing support member 5 and the electric motor 7. In other words, the heat radiation 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 an 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 inverter side end portion side is formed on the motor side surface of the bearing support member 5 described above. In other words, the through-hole 9 communicates the back gap S <b> 1 and the heat radiation space S <b> 2 between the bearing support member 5 and the electric motor 7. In the embodiment shown in FIGS. 1 to 5, the through-hole 9 is formed in a straight line so as to be parallel to the rotation shaft 3, so that the above-described back gap S <b> 1 and the heat radiation space S <b> 2 communicate with each other at the shortest distance. Is formed. However, the present invention is not limited to this embodiment, and the through hole 9 only needs to have the center line of the passage formed by the through hole 9 along the axial direction of the rotary shaft 3. For example, it is only necessary that the back gap 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 rotation shaft 3. It may extend. The shorter the passage length by the through-hole 9, the smaller the pressure loss and the more advantageous.

  In the electric supercharged compressor 1 having such a configuration, the air supply 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 thereof leaks into the above-described back gap S1 in the vicinity of the discharge port 41o of the guide tube 41. The compressed air that has flowed into the back clearance S1 has a pressure equivalent to that of the compressed air at the discharge port 41o, and the pressure on the back side of the compressor wheel 2 is higher than the pressure on the front side of the compressor wheel 2. . For this reason, a thrust load acts on the rotating body from the high-pressure side toward the low-pressure side (the thrust direction Ds). The thrust load is a load that acts on the lubricant-enclosed bearing 8 (81, 82) that supports the rotating body.

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

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

  The compressed air that has flowed 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 the heat generated by the electric motor 7 is higher than the temperature of the compressed air passing through the through hole 9. For this reason, it becomes possible to cool the electric motor 7 by heat exchange between the relatively low temperature compressed air and the relatively high temperature electric motor 7. Further, by cooling the electric motor 7, the temperature of heat transferred from the electric motor 7 to the lubricant-enclosed bearing 8 (81, 82) is lowered. As a result, the lubricant-enclosed bearing 8 (81, 82) of the electric supercharged compressor 1 of the present embodiment has a lubricant-enclosed bearing 8 (81) than the case where the through-hole 9 is not formed in the bearing support member 5. 82), and the thermal load on the lubricant-enclosed bearing 8 (81, 82) can be reduced.

  In the embodiment shown in FIGS. 1 to 5, a plurality of through holes 9 are provided in the bearing support member 5 as shown in FIG. 3. The plurality of through holes 9 are provided at intervals in the bearing support member 5 along the circumferential direction of the rotating shaft 3. Thereby, the flow area of the flow path formed by the through hole 9 is set to a desired value. The plurality of through holes 9 may or may not be arranged so as to be equally spaced from each other. Moreover, in embodiment shown by FIGS. 1-5, as shown in FIG. 3, the cross section of the through-hole 9 is circular. And the through-hole 9 is formed so that the cross-sectional area of the through-hole 9 may become equal over the full length of the through-hole 9. FIG.

  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 as separate members, or both may be connected by bolts or the like. In the embodiment 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 compressor housing 4, the motor housing 6, and the bearing housing may form the interior of the 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 S <b> 1 formed by the back 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 is an electric motor. Guided towards 7. Further, the through hole 9 of the bearing support member 5 extends along the axial direction of the rotating shaft 3, so that the length of the air passage formed by the through hole 9 is shortened. In other words, the electric supercharged compressor 1 allows the compressed air leaked from the side of the intake passage formed inside the compressor housing 4 to the back gap S1 at a shorter distance by the through hole 9 formed in the bearing support member. It is configured to escape to the electric motor 7 side. Thereby, the pressure difference between the front side and the rear side of the compressor wheel 2 can be further reduced, and the thrust load acting on the rotating body can be further reduced. For this reason, the load by the thrust load of the lubricant enclosure bearing 8 which supports a rotary body can be reduced.

  In addition, the relatively high temperature side compressed air supplied from the through hole 9 of the bearing support member 5 may cool the relatively high temperature side electric motor 7 and the lubricant-enclosed bearing 8 (81, 82). it can. In particular, the lubricant-enclosed bearing 8 is not supplied with lubricating oil from the outside, and the lubricant-enclosed bearing 8 is cooled by the compressed air, so that the lubricant-enclosed bearing 8 (81, 82) is generated by the heat generated by the electric motor 7. Can be prevented from exceeding the allowable temperature. Further, since the cooling capacity of the lubricant-enclosed bearing 8 (81, 82) is improved in this way, the electric motor is protected to protect the lubricant-enclosed bearing 8 (81, 82) from the heat of the electric motor 7 that generates heat. 7 can be prevented from limiting the number of rotations and the driving time. Therefore, it is possible to improve the performance of the electric supercharged compressor 1 while improving the reliability of the lubricant-enclosed bearing 8 (81, 82).

  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 generated. 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 communicates the back gap S1 and the heat radiation space S2. In the present embodiment, the stator 72 of the electric motor 7 includes a stator coil 73 installed around the rotor 71. Further, 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 that is heated 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 said structure, the through-hole 9 of the bearing support member 5 connects the clearance gap (back clearance S1) formed by the back side of the compressor wheel 2, and the bearing support member 5, and the thermal radiation space S2. By cooling the stator 72 which is the main heat generating part of the electric motor 7 by the compressed air being guided to the heat radiation space S2 through the through hole 9, the electric motor 7 can be cooled more effectively. Can do. Moreover, by cooling the electric motor 7, the lubricant-enclosed bearings 8 (81, 82) can be indirectly cooled.

  In some embodiments, as shown in FIGS. 1 to 2, the opening 9 i of the through hole 9 of the bearing support member 5 is formed in the outer peripheral side region of the wheel-side facing surface 5 s of the bearing support member 5. Is done. The outer peripheral side region of the wheel side facing surface 5s is a region on the outer peripheral side in the radial direction of the wheel side facing surface 5s. That is, the supply air a is further compressed as it flows from the front edge side to the rear edge side of the blade 22 of the compressor wheel 2, so that the pressure in the vicinity of the position of the end portion of the compressor wheel 2 (rear edge side) The pressure becomes relatively high. In the present embodiment, the opening 9i of the through hole 9 is formed so that such compressed air is adjacent to the high position in the axial direction. In other words, the distance from the inlet of the back surface gap S1 into which the compressed air flows into the opening 9i serving as the inlet of the through hole 9 is set short, and the pressure when the compressed air flows into the back surface gap S1 is reduced. Compressed air can be guided from the opening 9 i to the through hole 9 in a state where the above is suppressed. For example, the outer peripheral side region of the wheel-side facing surface 5s is between the radial end of the rotating shaft 3 and the radial end of the compressor wheel 2 that is positioned near the discharge port 41o of the guide tube 41. When divided into three equal parts, it may be an area including an area located on the outermost periphery side. And the opening 9i formed in the outer peripheral side area | region of 5s of wheel side opposing surfaces is made into one end part, and the through-hole 9 extends toward the electric motor 7 along an axial direction.

  According to said structure, the thrust load produced in the rotary body of the electric supercharging compressor 1 is reduced rather than the case where the opening 9i of the through-hole 9 is formed in areas other than the outer peripheral side area | region of the wheel side opposing surface 5s. be able to.

  In some other embodiments, as shown in FIGS. 4 to 5, the opening 9 i of the through hole 9 included in the bearing support member 5 is more than the outer peripheral side region of the wheel-side facing surface 5 s of the bearing support member 5. While being formed on the inner peripheral side, the through hole 9 extends on the outer peripheral side from the outer peripheral surface of the lubricant-enclosed 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 an inner peripheral side region (inner peripheral side region) other than the outer peripheral side region in the wheel side facing surface 5s. The The inner peripheral region of the wheel-side facing surface 5s is located closer to the compressor-side lubricant-enclosed bearing 81 than the outer peripheral region. In the present embodiment, the through hole 9 is formed in a portion closer to the compressor side lubricant-enclosed bearing 81 in the bearing support member 5 by forming the opening 9i of the through hole 9 in the inner peripheral side region of the wheel side facing surface 5s. . As a result, the compressed air flows through the through-hole 9, so that the temperature of the portion of the bearing support member 5 that supports the compressor-side lubricant-enclosed bearing 81 (the radial support portion 54 and the axial support portion 55 described later) is reduced. The temperature can be relatively lower than that of the side lubricant-enclosed bearing 81, and the relatively high temperature compressor-side lubricant encapsulated bearing 81 can be cooled.

  In the embodiment shown in FIGS. 1 to 5, a sleeve 34 is provided on the outer peripheral surface of the compressor-side lubricant-enclosed bearing 81. The bearing support member 5 includes a radial support portion 54 (described later) that supports the compressor-side lubricant sealed bearing 81 via the sleeve 34 and an axial direction that supports the compressor-side lubricant sealed bearing 81 in the radial direction. A support portion 55 (described later) is formed of a separate member, and 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 54 and the axial support 55 in the radial direction. Thus, the bearing support member 5 is formed.

  According to said structure, the compressor side lubricant enclosure bearing 81 can be cooled more directly than the case where the opening 9i of the through-hole 9 is formed in the outer peripheral side area | region of 5s of wheel side opposing surfaces.

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 part 51, a fixing part 52, an inner peripheral side connection part 53, a radial support part 54, and An axial support portion 55. All the parts (51 to 55) constituting these bearing support members 5 may be formed as an integral member, or at least a part of the structure is formed as a separate member from other members and connected by bolts or the like. May be integrated. 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 support portion 54 are integrally formed. 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 by a bolt 58.

More specifically, the diffuser forming portion 51 is a portion having a diffuser passage surface 5 d that defines a diffuser passage 42 p between the bearing support member 5 and the compressor housing 4.
The fixed 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, the outer peripheral side connecting portion 52 a extending toward the motor housing 6, the compressor housing 4, and the motor housing 6. A sandwiching portion 52f sandwiched therebetween.
In the embodiment shown in FIGS. 1 to 5, the end portions on the inverter side end portion in the axial direction in the diffuser forming portion 51 and the fixing portion 52 are separated from each other by a distance L <b> 1. In other words, the fixing portion 52 protrudes from the diffuser forming portion 51 toward the inverter side end portion by a distance L1.

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

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

  As described above, when viewed from the diffuser forming portion 51 located closest to the inverter side end portion in the axial direction, the bearing support member 5 has an electric motor in which the fixed portion 52 is in the axial direction from the outer peripheral side of the diffuser forming portion 51. 7 protrudes by a distance L1 along a certain direction 7 and from the inner peripheral side of the diffuser forming portion 51, the radial support portion 54 connected to the inner peripheral side connecting portion 53 is in the direction in which the electric motor 7 is in the axial direction. Along the distance L1. Thus, a space S <b> 3 is formed by the diffuser forming portion 51, the fixing portion 52, the inner peripheral side connection portion 53 and the radial direction support portion 54. Moreover, since said space S3 formed by the bearing support member 5 is continued to said heat dissipation space S2, cooling of an electric motor can be accelerated | stimulated.

  In the embodiment shown in FIGS. 1 to 2, the wheel-side facing surface 5 s is formed across the inner peripheral side connecting portion 53 and the axial support portion 55, and the opening 9 i of the through hole 9 is formed on the inner peripheral side. It is formed on the wheel-side facing surface 5 s in the connection portion 53. Thereby, the passage length of the compressed air by the through-hole 9 can be shortened, and compressed air can be more easily removed from the back surface gap S1 without pressure loss than in 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 5 s is similarly formed across the inner peripheral connection portion 53 and the axial support portion 55, but the opening 9 i of the through hole 9. Is formed on the wheel-side facing surface 5 s of the axial support portion 55. Accordingly, as described above, the through hole 9 is formed in a portion close to the compressor-side lubricant-enclosed bearing 81, and the compressor-side lubricant-enclosed 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 corresponds to the cross-sectional view in the AA cross section of FIG.
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 short direction Hs in the radial direction. When the through hole 9 has such a cross-sectional shape, the passage width by the through hole 9 of the bearing support member 5 can be easily widened. For example, in order to allow a flow rate equivalent to the flow rate that can be flowed by one through-hole 9 having the cross-sectional shape of FIG. 6 to flow through the through-hole 9 having a circular cross-sectional shape shown in FIG. Further, it is necessary to increase the number of through-holes 9 and the number of manufacturing steps increases. However, the cross-sectional shape of FIG. 6 can be easily formed in one step by grooving. Therefore, the time and man-hours required for forming 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 embodiments, and includes forms obtained by modifying the above-described embodiments and forms obtained by appropriately combining these forms.

DESCRIPTION OF SYMBOLS 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 forming part 52 Fixed part 52a Outer peripheral side connection part 52f Nipping part 53 Inner peripheral side connection part 54 Radial support part 55 Axial support part 58 Bolt 6 Motor housing 6f Flange portion 7 Electric motor 71 Rotor 72 Stator 73 Stator coil 76 Inverter 8 Lubricant-enclosed bearing 81 Compressor-side lubricant encapsulated bearing 82 Inverter-side lubricant encapsulated bearing 9 Through hole 9i Opening of through hole

S1 Back gap S2 Heat radiation 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 of the rotating shaft;
A compressor housing for rotatably housing the compressor wheel;
An electric motor for applying a rotational force to the rotary shaft, provided on the other end side of the rotary shaft from the compressor wheel;
A motor housing that houses the electric motor;
A bearing provided between the compressor wheel and the electric motor for rotatably supporting the rotating shaft, and a lubricant-enclosed bearing in which a lubricant is enclosed;
A bearing support member that is fixed to at least one of the compressor housing and the motor housing and supports the lubricant-enclosed bearing, and is opposed to the wheel side with a gap between the rear surface of the compressor wheel. A bearing support member having a surface,
The electric supercharger compressor, wherein the bearing support member has a through hole extending from an opening formed in the wheel side facing surface toward the electric motor along an axial direction of the rotating shaft. . The electric motor is
A rotor fixed to the rotating shaft;
A stator supported by the motor housing around the rotor and for applying a rotational force to the rotor by electromagnetic force;
A heat radiation 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 and the heat dissipation space.   The electric supercharged compressor according to claim 1 or 2, wherein the opening of the through hole is formed in an outer peripheral side region on the wheel side facing surface. The opening of the through hole is formed on the inner peripheral side of the outer peripheral side region in the wheel side facing surface, and
The electric supercharged compressor according to claim 1, wherein the through hole extends on an outer peripheral side with respect to an outer peripheral surface of the lubricant-enclosed bearing. The bearing support member is
A diffuser forming portion having a diffuser passage surface defining a diffuser passage with the compressor housing;
A fixed portion having an outer peripheral side connecting portion that is connected to the outer peripheral portion of the diffuser forming portion and extends toward the motor housing, and a clamping portion that is sandwiched between the compressor housing and the motor housing;
An inner peripheral side connecting portion connected to an inner peripheral portion of the diffuser forming portion and extending toward a stator of the electric motor;
A radial support portion extending from the inner peripheral side connection portion toward the lubricant-enclosed bearing and supporting the lubricant-enclosed bearing in a radial direction;
An axial support portion extending from the inner peripheral side connection portion toward the rotation shaft and supporting the lubricant-enclosed bearing in the axial direction,
The wheel side facing surface is formed across the inner peripheral side connecting portion and the axial support portion,
The electric supercharged compressor according to claim 3, wherein the opening of the through hole is formed in the wheel side facing surface of the inner peripheral side connection portion. The bearing support member is
A diffuser forming portion having a diffuser passage surface defining a diffuser passage with the compressor housing;
A fixed portion having an outer peripheral side connecting portion that is connected to the outer peripheral portion of the diffuser forming portion and extends toward the motor housing, and a clamping portion that is sandwiched between the compressor housing and the motor housing;
An inner peripheral side connecting portion connected to an inner peripheral portion of the diffuser forming portion and extending toward a stator of the electric motor;
A radial support portion extending from the inner peripheral side connection portion toward the lubricant-enclosed bearing and supporting the lubricant-enclosed bearing in a radial direction;
An axial support portion extending from the inner peripheral side connection portion toward the rotation shaft and supporting the lubricant-enclosed bearing in the axial direction,
The wheel side facing surface is formed across the inner peripheral side connecting portion and the axial support portion,
The electric supercharger compressor according to claim 4, wherein the opening of the through hole is formed on the wheel side facing surface of the axial support portion.   The electric supercharging 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 short direction in a radial direction. Machine.

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