JP2018091301A - Electric supercharger - Google Patents

Abstract

An electric supercharger capable of achieving both cooling of a motor and lubrication of a ball bearing is realized. An electric supercharger according to an embodiment of the present invention is an electric supercharger in which a rotating shaft of a motor is supported on a housing by a ball bearing. The electric supercharger 1 includes an oil supply mechanism 6. The oil supply mechanism 6 includes an oil supply unit 6a, a first supply channel 6b through which oil is supplied from the oil supply unit 6a, and a first supply channel 6b. Connected to the supply flow path 6b, connected to the second supply flow path 6c for supplying oil from the first supply flow path 6b to the motor 5, and to the first supply flow path 6b, the first supply flow path 6b. A third supply channel 6d for supplying oil to the ball bearing 12 and a supply port 6e formed in the third supply channel 6d for supplying compressed air to the third supply channel 6d. [Selection] Figure 2

Description

  The present invention relates to an electric supercharger, for example, an electric supercharger in which a rotating shaft of a motor is supported on a housing by a ball bearing.

  A general electric supercharger is configured to rotate a turbine fixed to the tip of a rotating shaft of a motor to supply intake air. Such an electric supercharger generates heat due to the loss of each part and the temperature rises, so if it is not cooled, it will exceed the melting limit of the motor coil, resin parts, etc., and defects such as defective insulation will occur There is. Therefore, for example, the motor is cooled by supplying oil to the motor.

  By the way, Patent Document 1 discloses a ball bearing that can obtain a good lubrication state by supplying a mixture of compressed air and oil into the ball bearing.

JP 2001-59524 A

  When the oil for cooling the motor is used to lubricate the ball bearing that supports the rotating shaft of the motor, the motor cooling becomes insufficient if the oil supply amount is reduced in order to exert the performance of the ball bearing. . On the other hand, if the amount of oil required to cool the motor is secured, the optimum supply of the ball bearing will be greatly exceeded, so that the original performance of the ball bearing cannot be achieved and the friction of the ball bearing increases. End up. Therefore, it is difficult to achieve both the cooling of the motor and the lubrication of the ball bearing in a general electric supercharger.

  This invention is made | formed in view of such a problem, and implement | achieves the electric supercharger which can be compatible with cooling of a motor and lubrication of a ball bearing.

An electric supercharger according to an aspect of the present invention is an electric supercharger in which a rotating shaft of a motor is supported on a housing by a ball bearing,
The electric supercharger includes an oil supply mechanism,
The oil supply mechanism is
An oil supply,
A first supply channel through which oil is supplied from the oil supply unit;
A second supply flow path connected to the first supply flow path for supplying the oil from the first supply flow path to the motor;
A third supply flow path connected to the first supply flow path for supplying the oil from the first supply flow path to the ball bearing;
A supply port that is formed in the third supply flow path and supplies compressed air to the third supply flow path;
Have
With such a configuration, it is possible to suppress the supply of excessive oil to the ball bearing while supplying oil to the motor in a supply amount necessary for cooling the motor. Therefore, it becomes possible to achieve both cooling of the motor and lubrication of the ball bearing.

  ADVANTAGE OF THE INVENTION According to this invention, the electric supercharger which can be compatible with cooling of a motor and lubrication of a ball bearing is realizable.

It is a figure which shows typically the flow of the oil and air to the electric supercharger of Embodiment 1. FIG. 1 is a cross-sectional view schematically showing an electric supercharger according to a first embodiment. 2 is a partial cross-sectional view schematically showing a ball bearing in the electric supercharger according to Embodiment 1. FIG. FIG. 3 is an enlarged cross-sectional view showing the vicinity of the right ball bearing of the electric supercharger according to the first embodiment. FIG. 3 is a perspective view schematically showing a bearing holder on the right side of the electric supercharger according to the first embodiment. FIG. 4 is a different perspective view schematically showing a bearing holder on the right side of the electric supercharger according to the first embodiment. FIG. 3 is an enlarged cross-sectional view of the vicinity of a left ball bearing of the electric supercharger according to the first embodiment. 2 is a perspective view schematically showing a left bearing holder of the electric supercharger according to Embodiment 1. FIG. FIG. 3 is a different perspective view schematically showing a left bearing holder of the electric supercharger according to the first embodiment. It is sectional drawing which shows typically the electric supercharger of Embodiment 2. FIG. FIG. 6 is a partial cross-sectional view schematically showing a ball bearing of a second embodiment. It is a figure which shows typically the flow of the oil and air to the electric supercharger of different embodiment. Furthermore, it is a figure which shows typically the flow of the oil and air to the electric supercharger of different embodiment.

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiment. In addition, for clarity of explanation, the following description and drawings are simplified as appropriate.

<Embodiment 1>
FIG. 1 is a diagram schematically showing the flow of oil and air to the electric supercharger of the present embodiment. FIG. 2 is a cross-sectional view schematically showing the electric supercharger of the present embodiment. FIG. 3 is a partial cross-sectional view schematically showing a ball bearing in the electric supercharger of the present embodiment. FIG. 4 is an enlarged sectional view showing the vicinity of the right ball bearing of the electric supercharger according to the present embodiment. FIG. 5 is a perspective view schematically showing a bearing holder on the right side of the electric supercharger of the present embodiment. FIG. 6 is a different perspective view schematically showing the right bearing holder of the electric supercharger of the present embodiment. FIG. 7 is an enlarged sectional view showing the vicinity of the left ball bearing of the electric supercharger according to the present embodiment. FIG. 8 is a perspective view schematically showing a left bearing holder of the electric supercharger of the present embodiment. FIG. 9 is a different perspective view schematically showing the left bearing holder of the electric supercharger of the present embodiment.

  Here, in the following description, in order to clarify the explanation, as shown in FIG. 2, the vertical direction and the left-right direction of the electric supercharger are defined, but these directions depend on the usage form of the electric supercharger. It is changed as appropriate.

  The electric supercharger 1 of this embodiment is suitable as a compressor for an air supply system of an FC (fuel cell) system, and supplies compressed air to the stack 3 via an intercooler 2 as shown in FIG. To do. Here, in FIG. 1, the flow of oil is indicated by solid arrows, and the flow of air is indicated by broken arrows. However, although the electric supercharger 1 of this Embodiment is comprised as a compressor of the air supply system of FC system, it can be used similarly as another compressor.

  As shown in FIG. 2, the electric supercharger 1 includes a housing 4, a motor 5, and an oil supply mechanism 6. The housing 4 communicates the first accommodating portion 4a that accommodates the motor 5 and the like, the air intake port 4b, the exhaust port 4c that discharges air taken in from the intake port 4b, and the intake port 4b and the exhaust port 4c. A first flow path 4d is provided.

  The motor 5 includes a rotor 7 and a stator 8. As shown in FIG. 2, the rotor 7 includes a magnet 7a, a cylindrical body 7b, and an end plate 7c. The magnet 7 a is formed in a cylindrical shape with a penetrating portion extending in the left-right direction of the rotor 7. Cylindrical body 7b is formed in a cylindrical shape with a penetrating portion extending in the left-right direction of rotor 7, and magnet 7a is press-fitted into the penetrating portion of cylindrical body 7b so that compressive stress is applied to magnet 7a. Yes. The end plate 7c has a penetrating portion having an inner diameter substantially equal to the penetrating portion of the magnet 7a, and is fitted into the penetrating portion of the cylindrical body 7b so as to sandwich the magnet 7a from the left-right direction of the magnet 7a.

  A rotating shaft 9 extending in the left-right direction of the electric supercharger 1 is passed through the magnet 7 a and the end plate 7 c of the rotor 7. The rotor 7 is rotatably supported by the housing 4 via the rotating shaft 9 while being accommodated in the first accommodating portion 4 a of the housing 4.

  In the present embodiment, a washer 10, a spacer 11, a ball bearing 12, and a bearing holder 13 are passed through the rotary shaft 9 so as to sandwich the rotor 7 from the left and right directions of the electric supercharger 1. A rotating shaft 9 is rotatably supported by the housing 4. As a result, the rotor 7 is rotatably supported by the housing 4 via the rotary shaft 9.

  Further, a preload spring 14 and a sealing material 15 are arranged so as to sandwich the rotor 7, the left and right washers 10, the left and right spacers 11, the left and right ball bearings 12, and the left and right bearing holders 13 from the left and right directions of the electric supercharger 1. Yes. Then, preload is introduced into the rotor 7, the left and right washers 10, the left and right spacers 11, the left and right ball bearings 12, and the left and right bearing holders 13 by the preload spring 14 compressed in the first housing portion 4 a of the housing 4. ing. Thereby, the rotor 7, the left and right washers 10, the left and right spacers 11, the left and right ball bearings 12, and the left and right bearing holders 13 are pressed against the flange portion 9 a of the rotating shaft 9, and as a result, provided on the rotating shaft 9. Yes.

  Here, the ball bearing 12 of the present embodiment is an angular ball bearing in which a ball 12d held by a cage 12c is interposed between an inner ring 12a and an outer ring 12b, as shown in FIG.

  A resolver 16 for detecting the rotation angle of the rotor 7 is provided on the right side portion of the rotation shaft 9. Incidentally, in the present embodiment, the resolver 16 is accommodated in the second accommodating portion 4e formed in the housing 4, but the arrangement of the resolver 16 is not limited.

  The left portion of the rotating shaft 9 (the portion on the left side of the flange portion 9 a of the rotating shaft 9) protrudes into the first flow path 4 d of the housing 4. A turbine 17 disposed in the first flow path 4 d of the housing 4 is provided on the left side portion of the rotating shaft 9. Therefore, when the rotating shaft 9 rotates, the air sucked from the intake port 4 b of the housing 4 is compressed by the turbine 17, exhausted from the exhaust port 4 c of the housing 4, and supplied to the stack 3 through the intercooler 2. Incidentally, the rotating shaft 9 of the present embodiment rotates in the direction of arrow A in FIG.

  The stator 8 is disposed so as to surround the rotor 7, and is fixed to the housing 4 in a state of being accommodated in the first accommodating portion 4 a of the housing 4. The stator 8 includes a stator core 8a and a stator coil 8b. The stator core 8a is formed by laminating a plurality of magnetic steel plates 8c, and the rotor 7 passes through the stator core 8a. The stator coil 8b is wound around a predetermined tooth formed on the stator core 8a.

  The oil supply mechanism 6 cools the motor 5 and lubricates the ball bearing 12. The oil supply mechanism 6 includes an oil supply unit 6a, a first supply channel 6b, a second supply channel 6c, a third supply channel 6d, and a supply port 6e.

  The oil supply part 6a is provided with a pump, and sends out oil accumulated in an oil pan 4f formed below the first housing part 4a in the housing 4 to the oil cooling part 6f. Here, ATF (Automatic transmission fluid) generally used for lubricating the ball bearing 12 is suitable as the oil.

  The oil cooling part 6f cools the oil sent from the oil supply part 6a and supplies it to the first supply flow path 6b. The first supply channel 6 b is a second channel 4 g formed in the housing 4. The second flow path 4g is formed so as to extend substantially in the left-right direction of the housing 4 above the first housing part 4a in the housing 4, and the right end part is connected to the oil cooling part 6f. .

  The second supply channel 6 c supplies oil to the motor 5 from the first supply channel 6 b. The second supply channel 6 c is a third channel 4 h formed in the housing 4. In the present embodiment, the two third flow paths 4h extend substantially in the vertical direction of the housing 4, and the upper ends of the respective third flow paths 4h are both ends of the second flow path 4g. The lower end of the housing 4 reaches the first accommodating portion 4a.

  The third supply channel 6d supplies oil to the ball bearing 12 from the first supply channel 6b. The third supply flow path 6 d includes a fourth flow path 4 i formed in the housing 4 and a communication path 13 a formed in the bearing holder 13.

  In the present embodiment, the two fourth flow paths 4 i extend in the substantially vertical direction of the housing 4. The upper end portion of the right fourth flow channel 4i is connected between the connection portion of the second flow channel 4g with the right third flow channel 4h and the right end portion of the second flow channel 4g, and the lower end. The part reaches the bearing holder 13 on the right side. The upper end portion of the left fourth channel 4i is connected to the left end portion of the second channel 4g, and the lower end portion reaches the left bearing holder 13.

  Here, the right and left bearing holders 13 are different in configuration between the right and left bearing holders. In the following description, for the sake of clarity, the right bearing holder will be described with reference numeral 18 and the left bearing holder will be described with reference numeral 19.

  As shown in FIG. 4, the right bearing holder 18 includes a cylindrical body 18a, a flange portion 18b, and a communication path 18c (13a). The cylindrical body 18a accommodates the right ball bearing 12 inside the cylindrical body 18a. The flange portion 18b protrudes from the inner peripheral surface of the cylindrical body 18a, and is in contact with the right ball bearing 12 so that the pushing force of the preload spring 14 can be transmitted to the right ball bearing 12.

  As shown in FIGS. 5 and 6, the communication path 18 c includes a through portion 18 d and a first groove portion 18 e. The penetrating portion 18 d penetrates the cylindrical body 18 a substantially in the vertical direction and communicates with the fourth flow path 4 i on the right side in the housing 4. The first groove portion 18e is formed on the left side surface of the flange portion 18b, and extends substantially downward from the through portion 18d so as to be continuous with the through portion 18d.

  In the present embodiment, a second groove 18f is formed on the outer peripheral surface of the cylindrical body 18a. The second groove portion 18 f extends in the circumferential direction of the cylindrical body 18 a and is continuous with the fourth channel 4 i on the right side in the housing 4. As a result, the oil supplied from the right fourth channel 4i in the housing 4 enters between the housing 4 and the cylinder 18a of the right bearing holder 18 via the second groove 18f, and the right bearing The damper function in the radial direction of the holder 18 is exhibited. In this embodiment, in order to effectively use the path between the fourth flow path 4i on the right side and the bearing holder 18 on the right side in the housing 4 that has already been established, in this embodiment, the through-hole 18d is replaced with the second groove 18f. Is formed.

  As shown in FIG. 7, the left bearing holder 19 includes a cylindrical body 19a, a first flange portion 19b, a second flange portion 19c, and a communication path 19d (13a). The cylindrical body 19 a accommodates the left ball bearing 12 and the sealing material 15. The first flange portion 19 b protrudes from the inner peripheral surface of the cylindrical body 19 a so as to block the left ball bearing 12 and the sealing material 15. The first flange portion 19b is in contact with the left ball bearing 12 so as to receive the left ball bearing 12 pushed by the preload spring 14.

  The second flange portion 19 c protrudes from the outer peripheral surface of the cylindrical body 19 a and is in contact with the housing 4 so as to apply a reaction force to the left ball bearing 12 pushed by the preload spring 14. As shown in FIGS. 8 and 9, the communication path 19d includes a through portion 19e and a first groove portion 19f. The penetrating portion 19 e penetrates the cylindrical body 19 a substantially in the vertical direction and communicates with the left fourth channel 4 i in the housing 4. The first groove portion 19f is formed on the right side surface of the first flange portion 19b, and extends substantially downward from the through portion 19e so as to be continuous with the through portion 19e.

  In the present embodiment, a second groove portion 19g is formed on the outer peripheral surface of the cylindrical body 19a. The second groove portion 19 g extends in the circumferential direction of the cylindrical body 19 a and is continuous with the left fourth channel 4 i in the housing 4. As a result, the oil supplied from the left fourth channel 4i in the housing 4 enters between the housing 4 and the cylindrical body 19a of the left bearing holder 19 through the second groove 19g, and the left bearing The damper function in the radial direction of the holder 19 is exhibited. In this embodiment, in order to effectively utilize the path between the left fourth flow path 4i and the left bearing holder 19 in the housing 4 that has already been established, the through hole 19e is formed in the second groove 19g. Is formed.

  As shown in FIG. 2, the supply port 6e is formed in the third supply channel 6d in order to supply compressed air from the outside to the third supply channel 6d. In the present embodiment, the supply port 6e is formed in the fourth flow path 4i of the housing 4, and the air compressed by the electric supercharger 1 is supplied via the intercooler 2 as shown in FIG. It is supplied from the port 6e to the fourth channel 4i. Thereby, the cost increase by adding the supply source of compressed air can be suppressed.

  In such an electric supercharger 1, the oil supplied from the oil supply unit 6 a is supplied to the motor 5 through the second flow path 4 g and the third flow path 4 h of the housing 4. Thereby, the motor 5 is cooled and the temperature rise of the motor 5 can be suppressed. On the other hand, the oil supplied from the oil supply unit 6 a is supplied to the ball bearing 12 through the second flow path 4 g and the fourth flow path 4 i of the housing 4 and the communication path 13 a of the bearing holder 13. At this time, since compressed air is supplied to the fourth flow path 4 i of the housing 4, an air-fuel mixture of compressed air and oil is supplied to the ball bearing 12. As a result, the oil can be supplied to the ball bearing 12 while the oil is supplied to the motor 5 with the supply amount necessary for cooling the motor 5. Therefore, the electric supercharger 1 of the present embodiment can achieve both cooling of the motor 5 and lubrication of the ball bearing 12. In FIGS. 4 and 7, the flow of the air-fuel mixture is indicated by solid arrows.

<Embodiment 2>
FIG. 10 is a cross-sectional view schematically showing the electric supercharger of the present embodiment. FIG. 11 is a partial cross-sectional view schematically showing the ball bearing of the present embodiment. In addition, since the electric supercharger of this Embodiment is set as the structure substantially the same as the electric supercharger of Embodiment 1, the overlapping description is abbreviate | omitted and it demonstrates using the same code | symbol for the same member. . Incidentally, in FIG. 11, in order to simplify the drawing, the cage 12c is omitted.

  When the ball bearing 12 is an angular ball bearing, band wear may occur due to the preload introduced. Therefore, it is preferable to make a difference between the rotation speed of the inner ring 12a of the ball bearing 12 and the rotation speed of the ball 12d.

  Therefore, the electric supercharger 21 of the present embodiment makes a difference between the rotation speed of the inner ring 12a of the ball bearing 12 and the rotation speed of the balls 12d by the air-fuel mixture supplied from the fourth flow path 4i of the housing 4. It is set as the structure which can be made to produce.

  Specifically, as shown in FIG. 10, the outer ring 12 b of the ball bearing 12 is formed with a through portion 12 e that communicates with the communication path 13 a of the bearing holder 13. At this time, the communication path 13 a of the bearing holder 13 is a through portion that penetrates the cylindrical body of the bearing holder 13 in the substantially vertical direction, and communicates with the fourth flow path 4 i of the housing 4.

  As shown in FIG. 11, the penetrating portion 12e is inclined toward the rotational direction of the inner ring 12a (ie, in the direction of arrow A in FIG. 2) from the outer diameter side to the inner diameter side of the outer ring 12b of the ball bearing 12. Yes. Thereby, air-fuel mixture can be supplied to the ball 12d so that the rotation of the ball 12d is accelerated, and band wear of the ball bearing 12 can be suppressed. At this time, in the electric supercharger 21 of the present embodiment, the third supply flow path 6d is configured by the fourth flow path 4i of the housing 4, the communication path 13a of the bearing holder 13, and the penetrating portion 12e of the ball bearing 12. Will do.

  The present invention is not limited to the above-described embodiment, and can be changed as appropriate without departing from the spirit of the present invention.

  For example, in the above embodiment, the air compressed by the electric superchargers 1 and 21 is supplied to the fourth flow path 4i of the housing 4 via the intercooler 2, but as shown in FIG. The exhaust from the stack 3 may be supplied to the fourth flow path 4 i of the housing 4. As shown in FIG. 13, when the electric superchargers 1 and 21 include the expander 31, the exhaust from the stack 3 is compressed by the expander 31 and supplied to the fourth flow path 4 i of the housing 4. May be. In this case, an auxiliary driving force can be applied to the motor 5 by the expander 31.

DESCRIPTION OF SYMBOLS 1 Electric supercharger 2 Intercooler 3 Stack 4 Housing, 4a 1st accommodating part, 4b Inlet, 4c Exhaust, 4d 1st flow path, 4e 2nd accommodating part, 4f Oil pan, 4g 2nd Flow path, 4h third flow path, 4i fourth flow path 5 motor 6 oil supply mechanism, 6a oil supply section, 6b first supply flow path, 6c second supply flow path, 6d third supply flow Road, 6e Supply port, 6f Oil cooling part 7 Rotor, 7a Magnet, 7b Cylindrical body, 7c End plate 8 Stator, 8a Stator core, 8b Stator coil, 8c Magnetic steel plate 9 Rotating shaft, 9a Flange part 10 Washer 11 Spacer 12 Ball bearing , 12a inner ring, 12b outer ring, 12c cage, 12d ball, 12e penetrating part 13 bearing holder, 13a communication path 14 preload spring 15 sealing material 16 resolver 1 Turbine 18 Right bearing holder, 18a cylinder, 18b flange, 18c communication path, 18d penetrating part, 18e first groove, 18f second groove 19 Left bearing holder, 19a cylinder, 19b first flange 19c 2nd flange part, 19d Communication path, 19e Penetration part, 19f 1st groove part, 19g 2nd groove part 21 Electric supercharger 31 Expander

Claims (1)

An electric supercharger in which a rotating shaft of a motor is supported by a housing by a ball bearing;
The electric supercharger includes an oil supply mechanism,
The oil supply mechanism is
An oil supply,
A first supply channel through which oil is supplied from the oil supply unit;
A second supply flow path connected to the first supply flow path for supplying the oil from the first supply flow path to the motor;
A third supply flow path connected to the first supply flow path for supplying the oil from the first supply flow path to the ball bearing;
A supply port that is formed in the third supply flow path and supplies compressed air to the third supply flow path;
Having an electric supercharger.

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