JP2020070722A - Electric supercharger - Google Patents

Abstract

To provide an electric supercharger for allowing easy formation of a supply path for lubrication oil.SOLUTION: An electric supercharger 10 includes an oil introduction port 121 provided in a housing 11 and opened to the outside of the housing 11, an oil passage 122 extending from the oil introduction port 121 into a motor housing 12, an oil discharge port 123 communicated with the oil passage 122 and opened in the end face of the motor housing 12, opposite to a closed plate 13, and a fourth supply path 36 for supplying lubrication oil flowing in the oil passage 122 to a first bearing 24 and a second bearing 25. An outside passage 34 as part of the fourth supply path 36 is formed by a plate groove part 44 provided in an opposite face 41a of the closed plate 13, opposite to the motor housing 12, and the end face of the motor housing 12 closing an opening of the plate groove part 44. Part of the plate groove part 44 is opposed to the oil discharge port 123.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electric supercharger.

  For example, as described in Patent Document 1, the electric supercharger includes a rotating shaft, an electric motor that rotates the rotating shaft, and an impeller that is connected to an axial end portion of the rotating shaft. Further, the electric supercharger includes a housing that houses an electric motor and that includes a motor housing that rotatably supports a rotating shaft via a bearing, and a compressor housing that houses an impeller. The compressor housing has a suction port for sucking air, an impeller chamber communicating with the suction port and containing an impeller, a discharge chamber for discharging the air compressed by the impeller, and a communication between the impeller chamber and the discharge chamber. And a diffuser flow path.

  When the electric motor is driven to rotate the rotary shaft, the impeller rotates, and the centrifugal force of the rotating impeller imparts velocity energy to the air sucked from the suction port. Air that has been given a velocity energy and has a high velocity is decelerated in the diffuser flow passage provided at the outlet of the impeller, and the velocity energy of the fluid is converted into pressure energy. Then, the high-pressure air is discharged from the discharge chamber.

  By the way, the bearing that supports the rotating shaft of the electric supercharger tends to reach a high temperature due to the rotating shaft rotating at high speed, and seizure will occur if lubrication is insufficient.Therefore, lubricating oil should be applied between the inner ring and the outer ring of the bearing. It is necessary to lubricate and cool the bearing by supplying it. For this reason, the housing of the electric supercharger of Patent Document 1 has an oil inlet opening to the outside of the housing, an oil passage communicating with the oil inlet, and a supply passage communicating with the oil passage and extending toward the bearing. Have. The supply passage is formed by processing a fine hole in the housing. Then, the lubricating oil introduced into the oil passage from the oil introduction port is supplied to the bearing through the supply passage, whereby the bearing is lubricated.

U.S. Patent Application Publication No. 2014/0056726

However, with the configuration of Patent Document 1 in which the pores formed in the housing of the electric supercharger are used as the lubricating oil supply path, it is troublesome to process the pores.
The present invention has been made to solve the above problems, and an object thereof is to provide an electric supercharger capable of easily forming a lubricating oil supply passage.

  An electric supercharger for solving the above problems includes a rotary shaft, a pair of bearings that rotatably support the rotary shaft, an electric motor that rotates the rotary shaft, and an axial end of the rotary shaft. And a cylindrical motor housing having an opening that opens in the axial direction of the rotating shaft, a housing having a compressor housing that houses the impeller, and a closure that closes the opening of the motor housing. A member, an oil introduction port provided in the housing and opened to the outside of the housing, an oil passage extending from the oil introduction port into the motor housing, the oil passage, and the blockage in the motor housing. An oil discharge port that opens to the end face that faces the member, and a supply that supplies the lubricating oil that flows through the oil passage to the bearing And a part of the supply path is formed by a groove portion provided on an opposing surface of the closing member facing the motor housing, and an end surface of the motor housing closing the opening portion of the groove portion. At least a part of the groove portion faces the oil discharge port.

  According to this, the lubricating oil introduced into the oil passage from the oil introduction port is supplied to the bearing via the oil discharge port and the supply passage. The supply passage is formed by forming a groove in the closing member and closing the opening of the groove of the closing member by the end surface of the motor housing. Therefore, as compared with the case where the entire supply passage is a fine hole, the supply passage can be easily formed.

In the electric supercharger, the groove preferably extends in the circumferential direction of the rotary shaft.
According to this, compared to the case where a plurality of linear grooves are connected to form a groove portion, the path from the oil passage to the bearing can be shortened.

  In the electric compressor, the supply passage is provided in a first passage formed by a groove portion of the closing member and an end surface of the motor housing, and the closing member is provided with the lubricating oil flowing through the first passage. And a second passage for supplying to.

In the electric supercharger, it is preferable that the first passage is arranged at a position where it does not overlap a fixture attached to the closing member when viewed in the axial direction of the rotating shaft.
According to this, the first passage can be provided without changing the arrangement of the fixture.

In the electric supercharger, it is preferable that the supply path is arranged on the side opposite to the electric motor with the bearing in between in the axial direction of the rotating shaft.
When disposing the supply passage between the bearing and the electric motor in the axial direction of the rotary shaft, a space for disposing the supply passage is required between the bearing and the electric motor. On the other hand, by disposing the supply passage on the opposite side of the electric motor across the bearing in the axial direction of the rotary shaft, the space for disposing the supply passage between the bearing and the electric motor becomes unnecessary, The dimension of the motor housing in the axial direction of the rotary shaft can be shortened. Further, since the first passage is formed by the groove portion of the closing member and the end surface of the motor housing, and the second passage is formed in the closing member, the supply passage is arranged on the side opposite to the electric motor with the bearing interposed therebetween. However, the size of the closing member does not increase significantly. Therefore, the electric supercharger can be downsized in the axial direction of the rotating shaft.

  The electric supercharger includes a seal member that seals between the rotating shaft and the closing member, and the closing member is arranged between the motor housing and the compressor housing in an axial direction of the rotating shaft. The supply passage is located on the opposite side of the compressor housing in the axial direction of the rotation shaft with the seal member interposed therebetween, and the first passage has the same height as the rotation shaft in the gravity direction. Alternatively, it preferably extends below the rotation axis.

  When the first passage is located only above the rotary shaft in the direction of gravity, the amount of lubricating oil supplied from the oil passage to the bearing via the oil discharge port and the supply passage becomes excessive and is supplied to the bearing. Lubricating oil may flow out to the compressor housing side. On the other hand, when the first passage extends in the direction of gravity at the same height as the rotating shaft or below the rotating shaft, the amount of lubricating oil supplied to the bearing is unlikely to be excessive. Further, the supply passage is located on the opposite side of the compressor housing with the seal member interposed therebetween. Therefore, it is possible to prevent the lubricating oil supplied to the bearing from flowing out to the compressor housing side.

  According to the present invention, the lubricating oil supply path can be easily formed.

Sectional drawing of the electric supercharger of embodiment. The expanded sectional view of an electric supercharger. Rear view of the plate. The rear view which shows another example of a plate. The rear view which shows another example of a plate. The rear view which shows another example of a plate.

  An embodiment in which the electric supercharger is embodied will be described below with reference to FIGS. 1 to 3. The electric supercharger of the present embodiment is installed in the engine room of an automobile and is used to compress and supply air to the engine.

  As shown in FIG. 1, the housing 11 of the electric supercharger 10 includes a bottomed cylindrical motor housing 12 and a closing plate 13 that closes an opening 12 a of the motor housing 12. The motor housing 12 has a bottom portion 12b and a peripheral wall 12c extending from the bottom portion 12b in a tubular shape. The closing plate 13 includes a first bearing housing portion 13a as a bearing housing portion. A bearing through hole 12h is formed in the bottom portion 12b, and a tubular second bearing accommodating portion 14 is attached to the inside of the bearing through hole 12h. The housing 11 includes a compressor housing 15 connected to the closing plate 13 on the side opposite to the motor housing 12, and a cover 16 closing the bearing through hole 12h of the motor housing 12 from the side opposite to the motor housing 12. Prepare Therefore, the closing plate 13 is located between the motor housing 12 and the compressor housing 15.

  The electric supercharger 10 includes a rotation shaft 17 rotatably supported by the motor housing 12 and the closing plate 13. The rotating shaft 17 passes from the second bearing housing portion 14 into the motor housing 12 and the first bearing housing portion 13 a, penetrates the closing plate 13, and projects into the compressor housing 15. An impeller 18 is connected to one end of the rotating shaft 17 in the axial direction.

  An electric motor 19 for rotating the rotating shaft 17 is housed in the motor housing 12. The electric motor 19 is housed in a motor chamber S that is a space surrounded by the motor housing 12 and the closing plate 13. The opening 12 a of the motor housing 12 is open in the axial direction of the rotary shaft 17. The electric motor 19 is housed in the motor housing 12 through the opening 12 a of the motor housing 12.

  The electric motor 19 includes a tubular stator 20 and a rotor 21 arranged inside the stator 20. A coil 22 is wound around the stator 20. The rotor 21 rotates integrally with the rotating shaft 17 by supplying a current to the coil 22. The stator 20 includes a stator core 23 fixed to the inner peripheral surface of the peripheral wall 12c of the motor housing 12, a first coil end 22a protruding from one end surface of the stator core 23 in the axial direction, which is closer to the impeller 18, and a first coil end 22a. It has the 2nd coil end 22b projected from the other end surface near the 2 bearing accommodation part 14. The first coil end 22a and the second coil end 22b are a part of the coil 22.

  The electric supercharger 10 includes a pair of bearings (a first bearing 24 and a second bearing 25) that rotatably support the rotating shaft 17. The first bearing 24 rotatably supports a portion of the rotating shaft 17 near the impeller 18. The first bearing 24 is housed in the first bearing housing 13a. The first bearing 24 includes a first inner ring 24a fixed to the rotating shaft 17, a first outer ring 24b press-fitted into the inner peripheral surface of the first bearing housing portion 13a, a first inner ring 24a and a first outer ring 24b. A plurality of first balls 24c are arranged between them.

  The second bearing 25 rotatably supports a portion of the rotating shaft 17 that is farther from the impeller 18 than the first bearing 24 in the axial direction of the rotating shaft 17. Therefore, the rotating shaft 17 is rotatably supported by the motor housing 12 and the closing plate 13 via the first bearing 24 and the second bearing 25. The second bearing 25 is housed in the second bearing housing portion 14. The second bearing 25 includes a second inner ring 25a fixed to the rotating shaft 17, a second outer ring 25b press-fitted into the inner peripheral surface of the second bearing housing 14, and a second inner ring 25a and a second outer ring 25b. A plurality of second balls 25c are arranged between them.

  The compressor housing 15 includes a suction port 15a for sucking air (fresh air), an impeller chamber 15b communicating with the suction port 15a and accommodating an impeller 18, and a discharge chamber for discharging air compressed by the impeller 18. 15c and the diffuser flow path 15d which connects the impeller chamber 15b and the discharge chamber 15c.

  When the electric motor 19 is driven to rotate the rotating shaft 17, the impeller 18 rotates, and the centrifugal force of the rotating impeller 18 gives velocity energy to the air sucked from the suction port 15a. The air that has been given a velocity energy and has a high velocity is decelerated by the diffuser flow passage 15d provided at the outlet of the impeller 18, and the velocity energy of the air is converted into pressure energy. Then, the high-pressure air is discharged from the discharge chamber 15c and supplied to an engine (not shown).

  An oil inlet 121 that opens to the outside of the housing 11 and an oil passage 122 that extends from the oil inlet 121 into the motor housing 12 are formed in a portion of the peripheral wall 12c of the motor housing 12 that is located above the gravity direction. There is. The oil supply part 26 can be fitted into the oil inlet 121. The outside of the motor housing 12 and the oil passage 122 communicate with each other via a supply hole 26 a of the oil supply unit 26. The oil passage 122 extends in the axial direction of the rotating shaft 17. An oil discharge port 123 is formed in a portion of the peripheral wall 12c of the motor housing 12 that is located on the upper side in the gravitational direction. The oil discharge port 123 communicates with the oil passage 122 and opens on an end surface of the peripheral wall 12c that faces the closing plate 13. ..

  A first supply passage 31 and a second supply passage 32 that connect the oil passage 122 and the motor chamber S are formed in a portion of the peripheral wall 12c of the motor housing 12 that is located above the gravity direction. The first supply passage 31 and the second supply passage 32 pass through a portion of the peripheral wall 12c below the oil passage 122 in the gravity direction. The first supply path 31 is arranged at a position overlapping with the first coil end 22a in the axial direction of the rotating shaft 17, and the second supply path 32 is located at a position overlapping with the second coil end 22b in the axial direction of the rotating shaft 17. It is located in. Therefore, the first supply path 31 faces the first coil end 22a, and the second supply path 32 faces the second coil end 22b.

A discharge portion 124 that connects the motor chamber S and the outside of the housing 11 is formed in a portion of the peripheral wall 12c of the motor housing 12 that is located below the gravity direction.
A third supply passage 33 communicating with the oil passage 122 is formed in the bottom portion 12b of the motor housing 12. The third supply passage 33 communicates with the first passage portion 33 a extending downward from the oil passage 122 in the direction of gravity and the first passage portion 33 a, and extends toward the second bearing 25 in the axial direction of the rotating shaft 17. It is a pore composed of the extending second passage portion 33b. An end portion of the second passage portion 33b opposite to the first passage portion 33a faces a part of the second bearing 25 between the second inner ring 25a and the second outer ring 25b. The flow passage cross-sectional area of the second passage portion 33b is smaller than the flow passage cross-sectional area of the first passage portion 33a.

  As shown in FIG. 2, the closing plate 13 includes an annular outer plate portion 41 as a plate portion, an inner plate portion 42 located on the inner peripheral side of the outer plate portion 41, an outer plate portion 41, and an inner plate portion. 42 and a connecting portion 43 for connecting with 42. The outer plate portion 41 has a facing surface 41 a facing the end surface of the peripheral wall 12 c of the motor housing 12. The outer plate portion 41 has a plate groove portion 44 as a groove portion that is recessed toward the side opposite to the motor housing 12 on the facing surface 41a.

  As shown in FIG. 3, the plate groove portion 44 has a first plate groove portion 44a and a second plate groove portion 44b connected to the first plate groove portion 44a. The first plate groove portion 44a is formed in the outer plate portion 41 over a half circumference in the circumferential direction of the rotating shaft 17. One end of the first plate groove portion 44a is located on the upper side in the gravity direction and faces the oil discharge port 123 in the axial direction of the rotary shaft 17. The other end of the first plate groove portion 44a is located below the rotating shaft 17 in the gravity direction. That is, the first plate groove portion 44a extends below the rotating shaft 17 in the gravity direction. The second plate groove portion 44b linearly extends from the other end of the first plate groove portion 44a toward the upper side in the gravity direction. As shown in FIG. 2, the outer passage 34 as the first passage is formed by the plate groove portion 44 of the outer plate portion 41 and the end surface of the peripheral wall 12c of the motor housing 12 that closes a part of the opening of the plate groove portion 44. Has been done. Further, the outer plate portion 41 has a plate through hole 41b penetrating in the plate thickness direction.

  As shown in FIG. 3, the inner plate portion 42 has a disk-shaped base portion 421 and three projecting portions 422 that project from the outer peripheral surface of the base portion 421. The inner plate portion 42 has a mounting hole 42a (only one is shown in FIG. 2) in each protruding portion 422. A female screw is formed on the inner peripheral surface of each mounting hole 42a.

  The outer diameter of the base portion 421 is smaller than the diameter of the plate through hole 41b of the outer plate portion 41. The inner plate portion 42 has a first bearing accommodating portion 13a that penetrates the base portion 421 in the plate thickness direction, and a convex portion 42b that protrudes from the inner peripheral surface of the first bearing accommodating portion 13a toward the inner side in the radial direction of the rotating shaft 17. And a deflector portion 42c protruding inward in the radial direction of the rotary shaft 17 from a portion of the inner peripheral surface of the convex portion 42b near the impeller 18. The convex portion 42b is formed over the entire circumference of the inner peripheral surface of the first bearing housing portion 13a. The deflector portion 42c is formed by removing a part of the inner peripheral surface of the convex portion 42b. The inner plate portion 42 is arranged such that the portion where the deflector portion 42c is not formed is located on the lower side in the gravity direction. A part of the end surface of the first outer ring 24b on the impeller 18 side faces the end surface of the convex portion 42b on the electric motor 19 side. The first inner ring 24a and the first outer ring 24b of the first bearing 24 communicate with the inside of the convex portion 42b.

  The closing plate 13 has a discharge passage 45 that penetrates the connecting portion 43 in the plate thickness direction. The discharge passage 45 is located on the lower side in the direction of gravity and is arranged at a position that does not overlap the deflector portion 42c in the circumferential direction of the rotating shaft 17. The discharge path 45 communicates with the motor chamber S.

  As shown in FIG. 2, the connecting portion 43 connects the facing surface 41 a of the outer plate portion 41 and the outer peripheral surface of the inner plate portion 42. In the axial direction of the rotary shaft 17, the outer plate portion 41 is located on the impeller 18 side, and the inner plate portion 42 is located on the electric motor 19 side. Further, the inner plate portion 42 is located inside the plate through hole 41 b of the outer plate portion 41 in the radial direction of the rotating shaft 17. The inner plate portion 42 is located inside the peripheral wall 12c of the motor housing 12 in the radial direction of the rotating shaft 17. The inner peripheral surface of the plate through hole 41b of the outer plate portion 41 and the end surfaces of the inner plate portion 42 and the connecting portion 43 on the impeller 18 side form a retainer housing portion 13b in which a retainer 51 described later is housed. The retainer housing portion 13b communicates with the inside of the convex portion 42b of the first bearing housing portion 13a.

  The closing plate 13 is provided with a first communication passage 35a for communicating the outer passage 34 formed by the second plate groove portion 44b and the end surface of the motor housing 12 with the retainer housing portion 13b. The first communication passage 35a is located below the rotating shaft 17 in the gravity direction. The first communication passage 35a extends linearly in the radial direction of the rotating shaft 17.

  A disc-shaped retainer 51 is accommodated in the retainer accommodating portion 13b. The outer peripheral surface of the retainer 51 faces the inner peripheral surface of the plate through hole 41b of the outer plate portion 41, and the end surface 51a of the retainer 51 on the electric motor 19 side is the end surface of the inner plate portion 42 and the connecting portion 43 on the impeller 18 side. Is facing. The retainer 51 is attached to the inner plate portion 42 of the closing plate 13 by screwing bolts 61 as three fixing members that penetrate the retainer 51 in the plate thickness direction with female screws of the mounting holes 42 a of the inner plate portion 42. It is fixed. The closing plate 13 and the retainer 51 form a closing member that closes the opening 12 a of the motor housing 12.

  The retainer 51 has a recess 51b that is recessed from the end surface 51a on the electric motor 19 side toward the impeller 18 side. The recess 51b has a bottom wall 511 and a cylindrical side wall portion 512 that connects the bottom wall 511 and the end surface 51a on the electric motor 19 side. The retainer 51 has a collar accommodating portion 52 surrounded by the bottom wall 511 and the side wall portion 512 of the recess 51b. The retainer 51 has a retainer through hole 51c that penetrates the bottom wall 511 of the recess 51b.

  A cylindrical seal collar 53 as a seal member is interposed between the inner peripheral surface of the retainer through hole 51c of the retainer 51 and the outer peripheral surface of the rotary shaft 17. The seal collar 53 is attached to a portion of the rotary shaft 17 near the impeller 18, and rotates integrally with the rotary shaft 17. The seal collar 53 has a flange portion 53 a that projects from the outer peripheral surface toward the radial outside of the rotary shaft 17. The collar portion 53 a is housed in the collar housing portion 52. The collar portion 53a constitutes a labyrinth seal that suppresses the lubricating oil supplied to the first bearing 24 from flowing out to the impeller 18 side.

  The retainer 51 has a retainer groove portion 54 that extends linearly in the radial direction of the rotating shaft 17 on the end surface 51 a on the electric motor 19 side. The retainer groove portion 54 extends from the outer peripheral surface of the retainer 51 to the side wall portion 512 of the collar accommodating portion 52. The retainer groove portion 54 and the end faces of the inner plate portion 42 and the connecting portion 43 on the impeller 18 side form a second communication passage 35b. The retainer 51 is arranged such that the second communication passage 35b and the first communication passage 35a of the closing plate 13 communicate with each other in the radial direction of the rotating shaft 17.

  The inside of the first communication passage 35a, the second communication passage 35b, the flange accommodating portion 52, and the convex portion 42b communicates the outer passage 34 with the first inner ring 24a of the first bearing 24 and the first outer ring 24b. The inner passage 35 as a second passage is formed. The outer passage 34 and the inner passage 35 form a fourth supply passage 36 as a supply passage for supplying the lubricating oil flowing in the oil passage 122 to the first bearing 24. The fourth supply path 36 is arranged on the side opposite to the electric motor 19, that is, on the side of the impeller 18 with the first bearing 24 interposed therebetween in the axial direction of the rotating shaft 17. The fourth supply passage 36 is arranged on the opposite side of the compressor housing 15 with the seal collar 53 interposed therebetween in the axial direction of the rotary shaft 17. That is, the fourth supply passage 36 is arranged between the seal collar 53 and the first bearing 24 in the axial direction of the rotary shaft 17.

The operation of this embodiment will be described.
In the electric supercharger 10, the first bearing 24 and the second bearing 25 are likely to become hot due to the rotating shaft 17 that rotates at high speed. Therefore, the first bearing 24 and the second bearing 25 are cooled by supplying the lubricating oil between the first inner ring 24a and the first outer ring 24b and between the second inner ring 25a and the second outer ring 25b. .. Further, the coil 22 of the electric motor 19 also tends to generate heat and become high in temperature, so that it is cooled by the lubricating oil.

  Lubricating oil for cooling the first bearing 24, the second bearing 25, and the coil 22 of the electric motor 19 flows from the outside of the housing 11 into the supply hole 26a of the oil supply portion 26 fitted to the oil introduction port 121. It is introduced into the oil passage 122 via the. A part of the lubricating oil introduced into the oil passage 122 flows into the motor chamber S via the first supply passage 31 and is supplied to the first coil end 22a. The lubricating oil supplied to the first coil end 22a flows downward along the outer peripheral portion of the first coil end 22a in the direction of gravity. Further, a part of the lubricating oil supplied to the oil passage 122 flows into the motor chamber S via the second supply passage 32 and is supplied to the second coil end 22b. The lubricating oil supplied to the second coil end 22b flows downward along the outer peripheral portion of the second coil end 22b in the direction of gravity. As a result, the entire first coil end 22a and the entire second coil end 22b are cooled by the lubricating oil, and the coil 22 of the electric motor 19 is cooled.

  Further, a part of the lubricating oil introduced into the oil passage 122 is supplied to the second bearing 25 via the third supply passage 33. Specifically, the lubricating oil introduced into the oil passage 122 flows into the first passage portion 33a of the third supply passage 33, and then flows from the second passage portion 33b to the second inner ring 25a and the second outer ring 25b of the second bearing 25. It is spouted toward between. At this time, since the flow passage cross-sectional area of the second passage portion 33b is smaller than the flow passage cross-sectional area of the first passage portion 33a, the lubricating oil flows from the second passage portion 33b to the second inner ring 25a and the second outer ring 25b. It is ejected vigorously toward. As a result, the lubricating oil is supplied between the second inner ring 25a and the second outer ring 25b of the second bearing 25, the slidability between the second inner ring 25a and each of the second balls 25c, and the second outer ring 25b. And the second balls 25c have good slidability, and the second bearing 25 is cooled.

  A part of the lubricating oil introduced into the oil passage 122 is supplied to the first bearing 24 via the oil discharge port 123 and the fourth supply passage 36. Specifically, the lubricating oil introduced into the oil passage 122 flows into the outer passage 34 via the oil discharge port 123, flows downward in the gravity direction, and then flows into the inner passage 35. In the inner passage 35, the lubricating oil flows in the order of the first communication passage 35a, the second communication passage 35b, the collar accommodating portion 52, and the convex portion 42b, and then, the first inner ring 24a and the first outer ring of the first bearing 24. And 24b. Thereby, the slidability between the first inner ring 24a and each first ball 24c and the slidability between the first outer ring 24b and each first ball 24c are improved, and the first bearing 24 is cooled. To be done.

  The lubricating oil supplied to the first bearing 24 is discharged into the motor chamber S via the discharge passage 45, and flows in the motor chamber S downward in the gravity direction. The lubricating oil supplied to the first coil end 22a, the second coil end 22b, and the second bearing 25 also flows in the motor chamber S toward the lower side in the direction of gravity. Then, the lubricating oil that has flowed to the lower side in the gravity direction in the motor chamber S is discharged to the outside of the housing 11 via the discharging portion 124 and is collected in the oil pan of the engine as engine oil.

The effects of this embodiment will be described.
(1) The lubricating oil flowing through the oil passage 122 is supplied to the first bearing 24 via the oil outlet 123 and the fourth supply passage 36. The outer passage 34, which is a part of the fourth supply passage 36, forms a plate groove portion 44 in the outer plate portion 41 of the closing plate 13, and opens the opening of the plate groove portion 44 of the outer plate portion 41 into the peripheral wall 12c of the motor housing 12. It is formed by being closed by the end surface of. Therefore, it is possible to easily form the fourth supply passage 36, as compared with the case where the entire fourth supply passage 36 is formed of the fine holes.

  (2) Since the plate groove portion 44 extends in the circumferential direction of the rotary shaft 17, compared with the case where the plate groove portion 44 is formed by connecting a plurality of linear grooves, a path from the oil passage 122 to the inner passage 35. Can be shortened. Therefore, the path from the oil passage 122 to the first bearing 24 can be shortened.

  (3) The outer passage 34 is arranged at a position where it does not overlap with the bolt 61 for fixing the retainer 51 to the closing plate 13 when viewed in the axial direction of the rotating shaft 17. That is, the outer passage 34 extends so as to avoid the bolt 61. Therefore, the outer passage 34 can be provided without changing the arrangement of the bolts 61.

  (4) When the fourth supply passage 36 is arranged between the first bearing 24 and the electric motor 19 in the axial direction of the rotating shaft 17, the fourth supply passage 36 is provided between the first bearing 24 and the electric motor 19. Space is required for placing. On the other hand, in the present embodiment, in the axial direction of the rotating shaft 17, by disposing the fourth supply passage 36 on the side opposite to the electric motor 19 with the first bearing 24 interposed therebetween, the first bearing 24 and the electric motor A space for arranging the fourth supply passage 36 with respect to 19 is unnecessary, and the dimension of the motor housing 12 in the axial direction of the rotating shaft 17 can be shortened. The outer passage 34 is formed by the plate groove portion 44 of the closing plate 13 and the end surface of the peripheral wall 12c of the motor housing 12, and the inner passage 35 is formed by the inner plate portion 42 and the connecting portion 43 of the closing plate 13 and the retainer groove portion 54 of the retainer 51. Formed by and. Therefore, even if the fourth supply path 36 is arranged on the side opposite to the electric motor 19 with the first bearing 24 interposed therebetween in the axial direction of the rotating shaft 17, the dimensions of the closing plate 13 and the retainer 51 are significantly increased. There is nothing. Therefore, the electric supercharger 10 can be downsized in the axial direction of the rotating shaft 17.

  (5) When the outer passage 34 is located only above the rotating shaft 17 in the direction of gravity, the amount of lubricating oil supplied from the oil passage 122 to the first bearing 24 via the fourth supply passage 36 becomes excessive. Therefore, the lubricating oil supplied to the first bearing 24 may flow out to the compressor housing 15 side. On the other hand, since the outer passage 34 of the present embodiment extends below the rotating shaft 17 in the direction of gravity, the amount of lubricating oil supplied to the first bearing 24 is unlikely to be excessive. The fourth supply passage 36 is located on the opposite side of the compressor housing 15 with the seal collar 53 interposed therebetween in the axial direction of the rotary shaft 17. Therefore, it is possible to prevent the lubricating oil supplied to the first bearing 24 from flowing out to the compressor housing 15 side.

This embodiment can be modified and implemented as follows. The present embodiment and the modified examples can be implemented in combination with each other within a technically consistent range.
The motor housing 12 may have a bottomed cylindrical shape in which the opening 12a is open to the second bearing housing 14 side and the bottom 12b is located to the impeller 18 side in the axial direction of the rotating shaft 17. In this case, the oil outlet 123 is arranged on the side of the second bearing accommodating portion 14 in the axial direction of the rotating shaft 17, and the groove and the inner passage 35 are formed in the closing member that closes the opening 12a.

  Further, the motor housing 12 may have a tubular shape that opens on both sides of the rotating shaft 17 in the axial direction. In this case, the oil outlets 123 may be provided on both sides of the rotary shaft 17 in the axial direction, or may be provided on only one side. The groove and the inner passage 35 are formed in the closing member located on the side where the oil discharge port 123 is provided.

The shape of the plate groove portion 44 formed on the outer plate portion 41 of the closing plate 13 may be appropriately changed.
The first plate groove portion 44 a of the plate groove portion 44 may not extend in the circumferential direction of the rotating shaft 17. For example, as shown in FIG. 4, the first plate groove portion 44a of the plate groove portion 44 may be formed by connecting a plurality of (three) straight lines.

  The length of the first plate groove portion 44a of the plate groove portion 44 may be changed as appropriate. For example, as shown in FIG. 5, the first plate groove portion 44 a of the plate groove portion 44 may be formed over the outer plate portion 41 over a quarter of the circumferential direction of the rotary shaft 17.

  The plate groove portion 44 does not have to be linear. For example, as shown in FIG. 6, the plate groove portion 44 may be formed only at a position facing the oil discharge port 123. That is, the entire plate groove portion 44 may face the oil discharge port 123. When the bolts 61 are not located right above the gravity direction, the inner passage 35 may extend straight from the plate groove portion 44 toward the lower side in the gravity direction. In this case, the fourth supply passage 36 is located above the rotating shaft 17 in the gravity direction.

The structure of the inner passage 35 may be appropriately changed as long as the outer passage 34 and the first bearing 24 can be communicated with each other.
○ The retainer 51 may be omitted. That is, the closing member that closes the opening 12a of the motor housing 12 may be only the closing plate 13. In this case, the closing plate 13 may be formed so that the first communication passage 35a directly communicates between the first inner ring 24a and the first outer ring 24b of the first bearing 24.

  The fixture attached to the closing plate 13 is not limited to the bolt 61 for attaching the retainer 51 to the closing plate 13. The fixture attached to the closing plate 13 may be, for example, a bolt that connects the closing plate 13 to the motor housing 12 and integrates the closing plate 13 and the motor housing 12. Also in this case, the outer passage 34 is arranged at a position where it does not overlap with the bolt for integrating the closing plate 13 and the motor housing 12 when viewed in the axial direction of the rotating shaft 17.

The fourth supply passage 36 may be arranged between the first bearing 24 and the electric motor 19 in the axial direction of the rotary shaft 17.
In the closing plate 13, the deflector portion 42c may be omitted. However, it is preferable to provide the deflector portion 42c in order to prevent the lubricating oil supplied to the first bearing 24 from flowing out to the impeller 18 side.

In the closing plate 13, if the lubricating oil after being supplied to the first bearing 24 can be discharged to the motor chamber S, the position of the discharge passage 45 in the circumferential direction of the rotating shaft 17 may be changed appropriately.
The plate groove portion 44 of the closing plate 13 may be formed by subjecting the flat closing plate 13 to groove processing. Further, a convex process for forming the plate groove portion 44 may be applied to the manufacturing die for manufacturing the closing plate 13. In this case, the plate groove portion 44 can be formed at the same time when the closing plate 13 is manufactured.

  The retainer groove portion 54 of the retainer 51 may be formed by subjecting the flat retainer 51 to groove processing. Further, the manufacturing die for manufacturing the retainer 51 may be subjected to convex processing for forming the retainer groove portion 54. In this case, the retainer groove portion 54 can be formed at the same time when the retainer 51 is manufactured.

  The configuration of the motor housing 12 may be changed appropriately. For example, the motor housing 12 may include a main body portion having a concave portion formed on the outer peripheral surface of the peripheral wall 12c of the motor housing 12 of the above-described embodiment, and a lid member attached to the main body portion so as to close the concave portion. Good. In this case, the space defined by the inside of the recess and the lid member serves as the oil passage 122.

The first bearing 24 and the second bearing 25 are not limited to rolling bearings in which rolling elements are balls, and may be, for example, roller bearings in which rolling elements are columnar.
The first bearing accommodating portion 13a that accommodates the first bearing 24 may not be provided in the closing plate 13.

  The configuration of the third supply passage 33 may be appropriately changed as long as the lubricating oil can be supplied from the oil passage 122 to the first bearing 24 via the third supply passage 33. For example, the flow passage cross-sectional area of the second passage portion 33b of the third supply passage 33 may be the same as the flow passage cross-sectional area of the first passage portion 33a. Further, for example, a communication hole communicating with the oil passage 122 may be formed in the motor housing 12, a pipe may be attached to the communication hole, and the inside of the pipe may be used as the third supply passage 33.

  DESCRIPTION OF SYMBOLS 10 ... Electric supercharger, 11 ... Housing, 12 ... Motor housing, 12a ... Opening part, 13 ... Closing plate as a closing member, 15 ... Compressor housing, 17 ... Rotating shaft, 18 ... Impeller, 19 ... Electric motor, 24 ... first bearing as bearing, 25 ... second bearing as bearing, 34 ... outer passage as first passage, 35 ... inner passage as second passage, 36 ... fourth supply passage as supply passage, 41a ... Opposing surface, 44 ... Plate groove portion as groove portion, 53 ... Seal collar as sealing member, 51 ... Retainer as closing member, 61 ... Bolt as fixing tool, 121 ... Oil inlet port, 122 ... Oil passage, 123 ... Oil Vent.

Claims (6)

A rotation axis,
A pair of bearings that rotatably support the rotating shaft,
An electric motor for rotating the rotating shaft,
An impeller connected to the axial end of the rotating shaft,
A cylindrical motor housing having an opening that opens in the axial direction of the rotating shaft, and a housing having a compressor housing that houses the impeller;
A closing member for closing the opening of the motor housing,
An oil inlet provided in the housing and opening to the outside of the housing;
An oil passage extending from the oil inlet into the motor housing,
An oil outlet communicating with the oil passage and opening at an end surface of the motor housing facing the closing member;
A supply passage for supplying the bearing with lubricating oil flowing through the oil passage,
Equipped with
A part of the supply path is formed by a groove portion provided on a facing surface of the closing member facing the motor housing, and an end surface of the motor housing closing an opening portion of the groove portion,
The electric supercharger, wherein at least a part of the groove portion faces the oil discharge port.   The electric supercharger according to claim 1, wherein the groove portion extends in the circumferential direction of the rotating shaft. The supply path is
A first passage formed by the groove portion of the closing member and the end surface of the motor housing;
A second passage which is provided in the closing member and which supplies the lubricating oil flowing in the first passage to the bearing;
The electric supercharger according to claim 1 or 2, further comprising:   The electric supercharger according to claim 3, wherein the first passage is arranged at a position that does not overlap with a fixture attached to the closing member when viewed in the axial direction of the rotating shaft.   The electric supercharger according to claim 3 or 4, wherein the supply path is arranged on the opposite side of the electric motor with the bearing in between in the axial direction of the rotating shaft. A seal member for sealing between the rotary shaft and the closing member,
The closing member is arranged between the motor housing and the compressor housing in the axial direction of the rotating shaft,
The supply passage is located on the opposite side of the compressor housing from the compressor housing in the axial direction of the rotation shaft, and the first passage has the same height as the rotation shaft in the gravity direction, or The electric supercharger according to claim 5, which extends below the rotation shaft.