JP2015224600A - Electric supercharger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric supercharger which enables simplification of a structure for cooling multiple bearings having different tendencies of temperature rise.SOLUTION: An electric supercharger 101 includes: an electric motor 30; a compressor wheel 21 which is rotationally driven by the electric motor 30 through a shaft 22; a housing 10 which houses the electric motor 30; and a first bearing 23 and a second bearing 24 which are disposed in the housing 10 and rotatably support the shaft 22. The first bearing 23 is disposed between the compressor wheel 21 and the second bearing 24. The housing 10 includes multiple heat radiation fins 40 which protrude to the outer side at the exterior side of a side wall 13a extending along an axial direction of the shaft 22. The heat radiation fins 40 include: first fins 41 positioned at the first bearing 23 side; and second fins 42 positioned at the second bearing 24 side. The first fins 41 protrude from the side wall 13a further than the second fins 42.

Description

  The present invention relates to an electric supercharger.

  In the turbocharger, only the compressor wheel or both the compressor wheel and the turbine wheel rotate at a high speed, which causes the bearings of the rotating shafts of the compressor wheel and the turbine wheel to generate heat, resulting in reduced slidability and durability. Cooling of the bearing is necessary.

  For example, Patent Document 1 describes a supercharger in which a turbine wheel is attached to one end of a turbine shaft and a compressor wheel is attached to the other end. This supercharger has, in its housing, a bearing space including a turbine shaft and its two bearings, and a cooling water jacket surrounding the outer periphery of the bearing space. The cooling water jacket includes a cooling coolant therein. The cooling coolant cools the bearing through a wall portion between the cooling water jacket and the bearing space. Further, a plurality of fins protruding toward the inside of the cooling water jacket are formed on the wall portion, and the plurality of fins enhance the cooling action on the bearing. Further, the cooling water jacket extends between the bearing close to the turbine and the turbine, and receives the heat from the turbine to suppress the temperature rise of the bearing close to the turbine having severe temperature conditions.

JP 2009-79497 A

  In the supercharger of Patent Document 1, a cooling water jacket is employed, and a cooling water jacket is interposed between the turbine and the bearing, thereby suppressing the temperature rise of two bearings having different temperature rising trends. This complicates the structure of the turbocharger, and further requires piping and a water pump for circulating the coolant for cooling in the cooling water jacket, so that the structure around the turbocharger is also complicated and costly. There is a problem of increasing. Such a problem is not limited to the supercharger disclosed in Patent Document 1, but also includes a bearing cooling structure described in Patent Document 1 in which an electric supercharger that supercharges by rotating a compressor wheel by a rotating electric machine such as a built-in electric motor. It also occurs when adopting.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide an electric supercharger that simplifies a structure for cooling a plurality of bearings having different temperature rising tendencies. .

  In order to solve the above-described problems, an electric supercharger according to the present invention includes a rotating electrical machine, a compressor wheel that is rotationally driven by the rotating electrical machine, a housing that houses the rotating electrical machine, a housing disposed in the housing, and a compressor A first bearing and a second bearing that rotatably support a rotating shaft of a rotating electrical machine that rotationally drives the wheel, the first bearing being disposed between the compressor wheel and the second bearing, and the housing being a rotating shaft A plurality of radiating fins projecting outwardly on the outer side of the side wall extending along the axial direction of the first, and the plurality of radiating fins are positioned on the first bearing side in the axial direction of the rotary shaft It includes a fin and a second fin located on the second bearing side in the axial direction of the rotating shaft, and the first fin protrudes from the side wall more than the second fin.

The first fin and the second fin may form a contour with a step at a boundary between each other.
The first fins arranged in the axial direction of the rotary shaft may be reduced in thickness in the axial direction of the rotary shaft from the first bearing toward the second bearing.
The first fins arranged in the axial direction of the rotary shaft may reduce the amount of protrusion from the side wall from the first bearing toward the second bearing.
The first fin and the second fin may extend along the circumferential direction of the rotation axis on the side wall.
The rotating electrical machine includes a coil to which electric power is applied and a stator provided on the side wall between the first bearing and the second bearing, and a rotor provided on the rotating shaft, and the first fin has the rotating shaft The second fin may be provided from the stator to the second bearing in the axial direction of the rotary shaft.
The first fin and the second fin may have a tapered shape that extends in the axial direction of the rotation axis from the protruding end toward the side wall.

  According to the electric supercharger according to the present invention, it is possible to simplify the structure for cooling a plurality of bearings having different temperature rising tendencies.

It is a typical section side view showing the composition of the electric supercharger concerning Embodiment 1 of this invention. It is a typical section side view showing the composition of the electric supercharger concerning Embodiment 2 of this invention. It is a typical section side view showing the composition of the electric supercharger concerning Embodiment 3 of this invention. It is a typical section side view showing the composition of the electric supercharger concerning Embodiment 4 of this invention. It is a typical side view which shows the modification of the fin of the electric supercharger of FIG.

Hereinafter, an electric supercharger according to an embodiment of the present invention will be described with reference to the accompanying drawings.
Embodiment 1 FIG.
Referring to FIG. 1, an electric supercharger 101 according to Embodiment 1 of the present invention includes a supercharging unit 1 for supercharging inhaled gas (which is air in the present embodiment), and a supercharging unit. And a drive unit 2 for driving 1 using an electric motor 30 which is a rotating electrical machine. The electric supercharger 101 is mounted on, for example, a vehicle equipped with a fuel cell that requires air supply without mounting an internal combustion engine, and supercharges air and supplies it to the fuel cell.

  The supercharging unit 1 includes a compressor wheel 21 that supercharges intake air by rotating, a shaft 22 that can rotate integrally with the compressor wheel 21, and a metal compressor that houses the compressor wheel 21 by being assembled with each other. A cover 11 and a seal plate 12 are provided. Here, the shaft 22 constitutes a rotation axis.

The shaft 22 extends from the inside of the compressor cover 11 to the drive unit 2 through the seal plate 12. At this time, the seal plate 12 extends in the radial direction of the shaft 22.
Inside the compressor cover 11 and the seal plate 12 are a wheel chamber 15 that rotatably accommodates the compressor wheel 21 and a suction passage 16 that extends from the wheel chamber 15 in the axial direction of the shaft 22 and opens to the outside. And an annular discharge passage 17 that communicates with the wheel chamber 15 and extends around the compressor wheel 21 and opens to the outside.

The drive unit 2 includes a metal bottomed cylindrical motor case 13 and a metal end cover 14 that closes the opening of the motor case 13. The motor case 13 and the end cover 14 form a motor chamber 18 that houses the electric motor 30 therein.
The compressor cover 11 and the seal plate 12 have the same outer diameter in the radial direction of the shaft 22. The outer diameter of the compressor cover 11 and the seal plate 12 is larger than the outer diameter of the end cover 14 in the radial direction of the shaft 22. Is also significantly larger.
The compressor cover 11, the seal plate 12, the motor case 13, and the end cover 14 form a housing 10 for the electric supercharger 101.

The motor case 13 includes a cylindrical side wall 13a and an end wall 13b that forms a bottom portion that closes an end of the side wall 13a. The end cover 14 closes the opening of the side wall 13a. A seal plate 12 is fixed to an end wall 13 b extending in the radial direction of the shaft 22. An end wall through hole 13b1 that opens toward the motor chamber 18 and the seal plate 12 is formed through the center of the end wall 13b.
The seal plate 12 is formed with a plate through hole 12a that is adjacent to and communicates with the end wall through hole 13b1.
The shaft 22 extends into the motor chamber 18 through the plate through hole 12a and the end wall through hole 13b1. The shaft 22 extends in the axial direction along the axial direction of the side wall 13 a of the motor case 13.

  An outer peripheral surface 22 a of the shaft 22 is supported by a first bearing 23 and a second bearing 24 such as a ball bearing provided in the motor chamber 18 so as to be rotatable in the circumferential direction. The first bearing 23 supports the shaft 22 near the end wall 13b, and the second bearing 24 supports the shaft 22 near the end 22b on the end cover 14 side.

The first bearing 23 has a cylindrical shape with a flange surrounding the outer periphery thereof, is supported and fixed by a first bearing frame 25 fixed to the end wall 13b, and is positioned adjacent to the end wall through hole 13b1. The first bearing 23 has an outer diameter larger than the inner diameter of the end wall through hole 13b1, and closes the end wall through hole 13b1.
The second bearing 24 has a cylindrical shape with a flange surrounding the outer periphery thereof, and is supported and fixed by a second bearing frame 26 fixed to the end cover 14.

A cylindrical rotor core 32 is provided on the outer peripheral surface 22 a of the shaft 22 so as to rotate integrally with the shaft 22 between the first bearing 23 and the second bearing 24 in the motor chamber 18. A permanent magnet 33 is embedded in the rotor core 32 along the outer peripheral surface thereof. The rotor core 32 and the permanent magnet 33 constitute a rotor 31 that is a rotor.
Further, a cylindrical stator core 35 is provided in the motor chamber 18 so as to surround the outer periphery of the rotor core 32. The stator core 35 is fixed to the side wall 13 a of the motor case 13. Further, a winding is wound in the stator core 35, and this winding forms a coil 36 and protrudes from both ends of the stator core 35. The stator core 35 and the coil 36 constitute a stator 34 that is a stator.
When electric power is supplied to the winding, a rotating magnetic field is generated from the coil 36, and the rotor magnet 32 is rotationally driven together with the shaft 22 and the compressor wheel 21 by the action of the rotating magnetic field received by the permanent magnet 33.

  The shaft 22, the rotor 31, and the stator 34 as described above constitute an electric motor 30. The shaft 22 also serves as the rotation shaft of the compressor wheel 21 and the electric motor 30.

  The end wall 13b of the motor case 13 is formed with a plurality of pressure adjusting holes 13b2 that open toward the motor chamber 18 and the seal plate 12. The pressure adjustment hole 13b2 allows the air in and out of the motor chamber 18 to enter and exit, and suppresses the pressure difference between the inside and outside of the motor chamber 18. Thereby, leakage of the grease enclosed in the first bearing 23 is prevented.

A plurality of radiating fins 40 are integrally formed on the outer peripheral side of the cylindrical side wall 13a of the motor case 13 for improving the cooling efficiency of the motor case 13 by ambient air.
Each radiating fin 40 has an annular plate shape that surrounds the side wall 13a and extends in the circumferential direction, and protrudes radially outward from the side wall 13a. The plurality of radiating fins 40 are arranged in a line along the axial direction of the side wall 13 a and the shaft 22.

The plurality of heat radiating fins 40 are formed in two types of shapes, and are constituted by a plurality of first fins 41 and second fins 42 having different shapes.
The first fin 41 is disposed between the end portion 35 a of the stator core 35 on the end cover 14 side and the seal plate 12, and the second fin 42 is disposed between the end portion 35 a of the stator core 35 and the end cover 14. ing.

The first fin 41 has an outer diameter close to the seal plate 12 without projecting radially outward from the seal plate 12.
The second fin 42 has an outer diameter close to the end cover 14 without projecting radially outward from the end cover 14.
Therefore, the first fin 41 has an outer diameter that is significantly larger than that of the second fin 42. Thereby, the fins 41 and 42 form the outline with the level | step difference in radial direction by making the edge part 35a position of the stator core 35 which is a boundary of the some 1st fin 41 and the some 2nd fin 42 into a boundary. .

Further, the cylindrical end surface 41 a on the radially outer side of the first fin 41 has a greater thickness in the axial direction of the shaft 22 than the cylindrical end surface 42 a on the radially outer side of the second fin 42.
Furthermore, tapered side surfaces 41b and 41c are formed on both sides of the end surface 41a of the first fin 41 in the axial direction of the shaft 22 so as to be inclined from the end surface 41a toward the side wall 13a in the axial direction. Yes. On both sides of the end surface 42a of the second fin 42 in the axial direction of the shaft 22, tapered side surfaces 42b and 42c are formed so as to be inclined from the end surface 42a toward the side wall 13a in the axial direction. The side surface 41b and the side surface 42b are parallel to each other, and the side surface 41c and the side surface 42c are parallel to each other.

The angle formed between the side surfaces 41b and 41c of the adjacent first fin 41, the angle formed between the side surface 41c of the adjacent first fin 41 and the side surface 42b of the second fin 42, and the adjacent second fin 42. The angles formed between the side surfaces 42b and 42c are the same, and are set so as to satisfy the draft angle of the mold used for casting the motor case 13.
Accordingly, the first fin 41 has an outer diameter and a thickness that are significantly larger than those of the second fin 42, that is, has a larger cross section in the axial direction and the radial direction of the shaft 22 than the second fin 42. ing. In addition, by making the 2nd fin 42 into the above structures, the axial direction length of the motor case 13 is shorter than the case where the 2nd fin 42 is made into the same shape as the 1st fin 41. FIG.

The electric supercharger 101 as described above operates as described below.
Referring to FIG. 1, in the electric supercharger 101, when electric power is applied to the coil 36 of the electric motor 30 by a power source (not shown), the rotor 31 is rotationally driven by the rotating magnetic field generated by the coil 36, whereby the shaft 22 and the compressor wheel 21 are driven to rotate at high speed.

The compressor wheel 21 rotating at high speed compresses or supercharges the air sucked from the suction passage 16 and discharges it from the discharge passage 17.
At this time, the air that is heated by being compressed raises the temperature of the compressor wheel 21, the shaft 22, the compressor cover 11, and the seal plate 12. The heat transmitted from the shaft 22 and the seal plate 12 raises the temperature of the end wall 13b of the motor case 13 and the first bearing 23. Moreover, the temperature of the first bearing 23 and the second bearing 24 is increased by the rotation of the shaft 22. As a result, the first bearing 23 tends to be hotter than the second bearing 24.
Furthermore, the coil 36 through which the current flows also generates heat, and the stator core 35 rises in temperature.
Therefore, in the motor chamber 18, the temperature increases around the second bearing 24, the stator core 35, and the first bearing 23, and the temperatures are around the second bearing 24, around the stator core 35, and around the first bearing 23. It becomes high in order.

  Outside air is configured to be introduced around the electric supercharger 101, and the introduced outside air exchanges heat with the radiating fins 40 on the side wall 13 a of the motor case 13, so that the radiating fins 40 and the side walls are exchanged. Cool 13a. As a result, the air in the motor chamber 18 and the stator core 35 are cooled by exchanging heat with the side wall 13 a, and the cooled air cools the first bearing 23, the second bearing 24, the stator core 35, and the coil 36.

  In the heat radiating fin 40, the first fin 41 has a larger outer diameter and thickness than the second fin 42, and therefore has a larger contact area with the surrounding air than the second fin 42. And has a large heat dissipation. For this reason, in the motor chamber 18, the internal air and the stator core 35 are sufficiently cooled by receiving a high cooling action in the region extending from the first bearing 23 to the stator core 35, and the internal air in the region extending from the stator core 35 to the second bearing 24. However, the cooling effect is lower than that in the region extending from the first bearing 23 to the stator core 35, but is sufficiently cooled. Thereby, the 1st bearing 23, the stator core 35, the coil 36, and the 2nd bearing 24 are fully cooled.

  In addition, in order to cool the internal air around the first bearing 23 and the stator core 35 having different temperature rising tendency via the side wall 13a and the first fin 41 of the motor case 13, the circumference of the first bearing 23 and the stator core 35 are cooled. There is a temperature difference in the internal air with the surroundings. Further, a temperature difference of the internal air is generated between the periphery of the stator core 35 and the periphery of the second bearing 24. As a result, an internal air flow (natural convection) along the axial direction of the shaft 22 occurs in the motor chamber 18, and this natural convection cools the first bearing 23, the stator core 35, the coil 36, and the second bearing 24. Increase efficiency.

  As described above, the electric supercharger 101 according to the first embodiment of the present invention includes the electric motor 30, the compressor wheel 21 that is rotationally driven by the electric motor 30, the housing 10 that houses the electric motor 30, and the housing 10 And a first bearing 23 and a second bearing 24 that rotatably support a shaft 22 of an electric motor 30 that is disposed therein and that rotationally drives the compressor wheel 21. The first bearing 23 is disposed between the compressor wheel 21 and the second bearing 24. The housing 10 has a plurality of radiating fins 40 projecting outward on the outside of the side wall 13 a extending along the axial direction of the shaft 22. The plurality of radiating fins 40 include a first fin 41 located on the first bearing 23 side in the axial direction of the shaft 22 and a second fin 42 located on the second bearing 24 side in the axial direction of the shaft 22. The first fin 41 protrudes from the side wall 13 a more than the second fin 42. And in the electric supercharger 101, the 1st fin 41 and the 2nd fin 42 form the outline with a level | step difference in the boundary between each other.

  At this time, the first bearing 23 which is closer to the compressor wheel 21 and is easily affected by the heat of the supercharged air of the compressor wheel 21 has a tendency to rise in temperature than the second bearing 24. The surrounding air exchanges heat with the side wall 13a to release heat, and the released heat is released by exchanging heat with the surrounding air through the first fin 41 having a larger protruding amount than the second fin 42. The Similarly, the heat of the air around the second bearing 24 is released to the outside through the side wall 13 a and the second fin 42. Thereby, the first bearing 23 receives a cooling action higher than that of the second bearing 24 due to the surrounding air. Accordingly, both the first bearing 23 and the second bearing 24 having different temperature rising tendencies are effectively cooled. And this cooling effect | action can be achieved by the simple structure which provided the 1st fin 41 and the 2nd fin 42 from which protrusion amount differs in the side wall 13a. Further, by suppressing the protruding amount of the second fin 42 that does not require a high heat exchange amount, the length of the second fin 42 in the axial direction on the side wall 13a can be reduced, and the electric supercharger 101 can be downsized. In particular, when the motor case 13, the first fin 41, and the second fin 42 are integrally formed by casting, the side surfaces of the first fin 41 and the second fin 42 need to have a tapered shape that satisfies the draft. The low head of the second fin 42 greatly contributes to the miniaturization of the electric supercharger 101.

  Further, in the electric supercharger 101, the first fin 41 and the second fin 42 extend along the circumferential direction of the shaft 22 on the side wall 13 a of the motor case 13. Thereby, since the 1st fin 41 and the 2nd fin 42 extend so that the 1st bearing 23 and the 2nd bearing 24 may be enclosed, respectively, the fin and surrounding air around the 1st bearing 23 and the 2nd bearing 24 The contact area of the first bearing 23 and the second bearing 24 can be improved.

  In the electric supercharger 101, the electric motor 30 includes a coil 36 to which electric power is applied and a stator 34 provided on the side wall 13 a of the motor case 13 between the first bearing 23 and the second bearing 24, and a shaft. The first fin 41 is provided from the first bearing 23 to the stator core 35 of the stator 34 in the axial direction of the shaft 22, and the second fin 42 is a stator core in the axial direction of the shaft 22. 35 to the second bearing 24. Thereby, cooling by the high cooling effect | action of the stator core 35 and the coil 36 is attained via the 1st fin 41 and the side wall 13a. Therefore, the temperature rise in the motor chamber 18 is suppressed, and the first bearing 23 and the second bearing 24 can be effectively cooled.

  Further, in the electric supercharger 101, the first fin 41 and the second fin 42 each have a tapered shape that extends in the axial direction of the shaft 22 from the projecting end faces 41a and 42a toward the side wall 13a of the motor case 13. Have. By configuring the taper shapes of the first fin 41 and the second fin 42 to satisfy the draft angle of the mold, the motor case 13 and the first fin 41 and the second fin 42 can be integrally formed by casting. . Thereby, the structure of the motor case 13 including the first fin 41 and the second fin 42 can be simplified.

Embodiment 2. FIG.
The electric supercharger 201 according to Embodiment 2 of the present invention is such that, in the electric supercharger 101 according to Embodiment 1, the thickness of the first fin decreases from the first bearing 23 toward the second bearing 24. It is what I did.
In the following embodiments, the same reference numerals as those in the previous drawings are the same or similar components, and thus detailed description thereof is omitted.

Referring to FIG. 2, the electric supercharger 201 is a motor including an electric motor 30, a shaft 22, a first bearing 23, and a second bearing 24 in the same manner as the electric supercharger 101 according to the first embodiment. A case 13 is provided.
The motor case 13 has a plurality of heat dissipating fins 240 integrally formed on the outer peripheral side of the side wall 13a in the same manner as the electric supercharger 101 according to the first embodiment.
The plurality of heat radiation fins 240 are configured by a plurality of first fins 241 and second fins 242 arranged in a line along the axial direction of the side wall 13 a and the shaft 22.

The second fin 242 is disposed between the end portion 35a of the stator core 35 and the end cover 14, and has the same configuration as the second fin 42 of the electric supercharger 101 according to the first embodiment.
The first fin 241 is disposed between the end portion 35a of the stator core 35 and the seal plate 12, and has a configuration similar to the first fin 41 of the electric supercharger 101 according to the first embodiment. However, the plurality of first fins 241 having the same outer diameter arranged in the axial direction of the shaft 22 are reduced in thickness in the axial direction from the first bearing 23 toward the second bearing 24. That is, the axial length of the end surfaces 241 a of the plurality of first fins 241 decreases from the first bearing 23 toward the second bearing 24.

Therefore, in the first fin 241, the fin located at the end wall 13b of the motor case 13 and the first bearing 23 closest to the compressor wheel 21 in the axial direction of the shaft 22 has the largest contact area with the ambient air. As the end wall 13b and the first bearing 23 move toward the second bearing 24, the fins reduce the contact area with the ambient air. As a result, the first fin 241 has a cooling capacity corresponding to the temperature rise tendency of the first bearing 23 and the stator 34. Then, by gradually reducing the thickness of the first fin 241 along the axial direction, the number of the first fins 241 is smaller than that of the first fin 41 of the electric supercharger 101 according to Embodiment 1 in FIG. Although the number of the first fins 241 is the same as that of the first fins 41, the axial length occupied by the first fins 241 on the side wall 13a is reduced as compared with the case of the first fins 41. Can do.
Moreover, since the other structure and operation | movement of the electric supercharger 201 which concern on Embodiment 2 of this invention are the same as that of Embodiment 1, description is abbreviate | omitted.

And according to the electric supercharger 201 in the second embodiment, the same effect as the electric supercharger 101 in the first embodiment can be obtained.
Furthermore, in the electric supercharger 201, the first fins 241 arranged in the axial direction of the shaft 22 reduce the thickness in the axial direction of the shaft 22 from the first bearing 23 toward the second bearing 24. The length occupied by the fins 241 in the axial direction can be reduced, and the electric supercharger 201 can be downsized. In the electric supercharger 201, the second fin 242 may also be configured so that the thickness in the axial direction of the shaft 22 decreases from the first bearing 23 toward the second bearing 24.

Embodiment 3 FIG.
In the electric supercharger 301 according to Embodiment 3 of the present invention, the amount of protrusion of the first fin and the second fin is changed from the first bearing 23 to the second bearing 24 in the electric supercharger 101 according to Embodiment 1. It is designed to be smaller as it goes.

Referring to FIG. 3, the electric supercharger 301 is a motor including an electric motor 30, a shaft 22, a first bearing 23, and a second bearing 24 in the same manner as the electric supercharger 101 according to the first embodiment. A case 13 is provided.
The motor case 13 has a plurality of heat dissipating fins 340 integrally formed on the outer peripheral side of the side wall 13a in the same manner as the electric supercharger 101 according to the first embodiment.
The plurality of heat radiation fins 340 are configured by a plurality of first fins 341 and second fins 342 arranged in a line along the axial direction of the side wall 13 a and the shaft 22.

The first fin 341 is disposed between the end portion 35a of the stator core 35 and the seal plate 12, and has a configuration similar to the first fin 41 of the electric supercharger 101 according to the first embodiment. The second fin 342 is disposed between the end 35 a of the stator core 35 and the end cover 14, and has a configuration similar to the second fin 42 of the electric supercharger 101 according to the first embodiment.
However, the plurality of first fins 341 having the same thickness (thickness on the side wall 13 a side) aligned in the axial direction of the shaft 22 has an outer diameter that decreases from the first bearing 23 toward the second bearing 24. . Further, the plurality of second fins 342 having the same thickness (thickness on the side wall 13 a side) aligned in the axial direction of the shaft 22 have an outer diameter that decreases from the first bearing 23 toward the second bearing 24. . Therefore, the first fin 341 and the second fin 342 form a truncated cone-shaped contour having an outer diameter at a constant rate from the seal plate 12 toward the end cover 14.

For this reason, in the 1st fin 341 and the 2nd fin 342, a contact area with surrounding air reduces as it goes to the end cover 14 from the seal plate 12.
Accordingly, the first fin 341 and the second fin 342 have a cooling capacity corresponding to the temperature rise tendency of the first bearing 23, the stator 34 and the second bearing 24. Then, by gradually reducing the outer diameters of the first fin 341 and the second fin 342 along the axial direction, the motor case 13 becomes lighter than the electric supercharger 101 according to the first embodiment.
Moreover, since the other structure and operation | movement of the electric supercharger 301 which concern on Embodiment 3 of this invention are the same as that of Embodiment 1, description is abbreviate | omitted.

And according to the electric supercharger 301 in the third embodiment, the same effect as the electric supercharger 101 in the first embodiment can be obtained.
Further, in the electric supercharger 301, the first fins 341 arranged in the axial direction of the shaft 22 reduce the amount of protrusion from the side wall 13 a of the motor case 13 from the first bearing 23 toward the second bearing 24. The case 13 can be reduced in weight, and the cost is reduced.

Embodiment 4 FIG.
The electric supercharger 401 according to the fourth embodiment of the present invention is the electric supercharger 201 according to the second embodiment, in which the protruding amounts of the first fin and the second fin are changed from the first bearing 23 to the second bearing 24. It is designed to be smaller as it goes.

Referring to FIG. 4, an electric supercharger 401 is a motor including an electric motor 30, a shaft 22, a first bearing 23, and a second bearing 24 in the same manner as the electric supercharger 201 according to the second embodiment. A case 13 is provided.
Similarly to the electric supercharger 201 according to the second embodiment, the motor case 13 has a plurality of heat radiation fins 440 integrally formed on the outer peripheral side of the side wall 13a.
The plurality of heat radiating fins 440 are configured by a plurality of first fins 441 and second fins 442 arranged in a line along the axial direction of the side wall 13 a and the shaft 22.

The first fin 441 is disposed between the end portion 35a of the stator core 35 and the seal plate 12, and has a configuration similar to the first fin 241 of the electric supercharger 201 according to the second embodiment. The second fin 442 is arranged between the end portion 35a of the stator core 35 and the end cover 14, and has a configuration similar to the second fin 242 of the electric supercharger 201 according to the second embodiment.
However, the plurality of first fins 441 and second fins 442 arranged in the axial direction of the shaft 22 have an outer diameter that decreases from the first bearing 23 toward the second bearing 24. That is, the first fin 441 and the second fin 442 form a frustoconical contour whose outer diameter is made constant from the seal plate 12 toward the end cover 14.

As a result, the first fin 441 and the second fin 442 that reduce the contact area with the surrounding air from the seal plate 12 toward the end cover 14 increase the temperature of the first bearing 23, the stator 34, and the second bearing 24. Cooling capacity corresponding to the trend. The motor case 13 is lighter than the electric supercharger 201 according to the second embodiment.
Moreover, since the other structure and operation | movement of the electric supercharger 401 which concern on Embodiment 4 of this invention are the same as that of Embodiment 2, description is abbreviate | omitted.
And according to the electric supercharger 401 in the fourth embodiment, the same effect as the electric supercharger 201 in the second embodiment can be obtained.

In the electric superchargers 101 to 401 according to the first to fourth embodiments, the radiation fins 40, 240, 340, and 440 include a plurality of annular plate-shaped first fins 41, 241, 341, 441, and second fins. 42, 242, 342, and 442 are included, but not limited thereto.
The first fins 41, 241, 341, 441 and the second fins 42, 242, 342, 442 are not continuous annular, but the first fins 541 and the second fins of the heat dissipating fins 540 of the electric supercharger 501 of FIG. As in the case of 542, the ring may be divided into a plurality of sections along the radial direction. Furthermore, the division positions of the first fin 541 and the second fin 542 may be different in the circumferential direction as shown in FIG. 5 between adjacent fins, or may be the same in the circumferential direction. Thereby, the turbulent flow of air is generated around the first fin 541 and the second fin 542, and the heat exchange efficiency between the first fin 541 and the second fin 542 and the air is improved.
Further, the divided first fin 541 and second fin 542 may be shifted from each other in the axial direction of the shaft 22 without being arranged on the same circumference. Thereby, turbulent flow is more likely to occur in the air around the first fin 541 and the second fin 542.
Alternatively, the plurality of first fins 41, 241, 341, 441 may be continued in a spiral shape, and the plurality of second fins 42, 242, 342, 442 may be continued in a spiral shape. As a result, air turbulence is generated around the fins.

  In the electric superchargers 101 to 401 according to the first to fourth embodiments, the first fins 41, 241, 341, 441 and the second fins 42, 242, 342, 442 of the radiating fins 40, 240, 340, 440 are Although extending perpendicular to the axial direction of the shaft 22, the shaft 22 may be inclined at an angle with respect to the axial direction. Furthermore, although the 1st fin 41,241,341,441 and the 2nd fin 42,242,342,442 extended in parallel mutually, it does not need to be parallel. As a result, air turbulence is generated around the fins.

In the electric superchargers 101 to 401 according to the first to fourth embodiments, the first fins 41, 241, 341, and 441 of the radiation fins 40, 240, 340, and 440 are connected to the end portions of the stator core 35 from the first bearing 23. Although extending to 35a, it may extend from the first bearing 23 to the middle of the stator core 35.
In the electric superchargers 301 and 401 according to the third and fourth embodiments, the first fins 341 and 441 and the second fins 342 and 442 of the radiating fins 340 and 440 are all from the first bearing 23 to the second bearing 24. However, only one of the first fins 341 and 441 and the second fins 342 and 442 may be configured to reduce the amount of protrusion. .

In the electric superchargers 101 to 401 according to the first to fourth embodiments, the two bearings 23 and 24 are provided. However, the present invention is not limited to this, and three or more bearings may be provided. Good.
Further, the above-described cooling structure of the bearings 23 and 24 in the electric superchargers 101 to 401 of the first to fourth embodiments is not to cool the bearing by immersing it in the lubricating oil or to cool it with the flowing lubricating oil. Any supercharger that uses and cools can be used.

  DESCRIPTION OF SYMBOLS 10 Housing, 13 Motor case, 13a Side wall (side wall of housing), 21 Compressor wheel, 22 Shaft (rotary shaft), 23 1st bearing, 24 2nd bearing, 30 Electric motor (rotary electric machine), 31 Rotor (rotor) , 34 Stator (stator), 35 Stator core, 36 Coil, 40, 240, 340, 440 Radiation fin, 41, 241, 341, 441 First fin, 42, 242, 342, 442 Second fin, 101, 201, 301,401 Electric supercharger.

Claims (7)

Rotating electrical machinery,
A compressor wheel driven to rotate by the rotating electrical machine;
A housing that houses the rotating electrical machine;
A first bearing and a second bearing that are disposed in the housing and rotatably support a rotating shaft of the rotating electrical machine that rotationally drives the compressor wheel;
The first bearing is disposed between the compressor wheel and the second bearing;
The housing has a plurality of heat dissipating fins protruding outward on the outside of the side wall extending along the axial direction of the rotating shaft,
The plurality of heat dissipating fins include a first fin located on the first bearing side in the axial direction of the rotating shaft, and a second fin located on the second bearing side in the axial direction of the rotating shaft,
The first fin is an electric supercharger that protrudes from the side wall more than the second fin.   The electric supercharger according to claim 1, wherein the first fin and the second fin form a contour with a step at a boundary between them.   The electric supercharging according to claim 1 or 2, wherein the first fins arranged in the axial direction of the rotary shaft have a thickness in the axial direction of the rotary shaft that decreases from the first bearing toward the second bearing. Machine.   The electric overload according to any one of claims 1 to 3, wherein the first fins arranged in the axial direction of the rotating shaft reduce a protruding amount from the side wall from the first bearing toward the second bearing. Feeder.   The electric supercharger according to any one of claims 1 to 4, wherein the first fin and the second fin extend along a circumferential direction of the rotation shaft on the side wall. The rotating electrical machine includes a stator including a coil to which electric power is applied and provided on the side wall between the first bearing and the second bearing, and a rotor provided on the rotating shaft,
The first fin is provided from the first bearing to the stator in the axial direction of the rotating shaft,
The electric supercharger according to any one of claims 1 to 5, wherein the second fin is provided from the stator to the second bearing in an axial direction of the rotating shaft.   The electric motor according to any one of claims 1 to 6, wherein the first fin and the second fin have a tapered shape that extends in an axial direction of the rotary shaft from the protruding end portion toward the side wall. Turbocharger.

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