JP2008121477A - Electric turbocharger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric supercharger including a cooling structure capable of efficiently cooling a stator of a rotating electrical machine over the whole circumferences. <P>SOLUTION: Lubricating oil 400 supplied to a bearing portion of a shaft of the electric supercharger is diffused toward coil winding 330 of the stator by centrifugal force caused by a rotation of a rotor 340. An oil reflection wall 380 is disposed at a position separated toward a radial direction from the rotor 340 such that a part of the lubricating oil 410 diffused by the rotation of the rotor 340 directly arrives at the coil winding 330, and a part of the rest of the lubricating oil 411 is reflected toward the rotor 340. The lubricating oil 420 reflected by the oil reflection wall 380 is again diffused by the rotation of the rotor 340, thereby it becomes possible to supply the lubricating oil acting as a coolant on the coil winding 330 over the whole circumferences of the stator. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electric supercharger, and more particularly to a cooling structure for a rotating electrical machine that rotates a supercharger.

  In order to improve the output of the engine, there is known a supercharger that compresses and supercharges air supplied to the engine by rotation of a compressor wheel. In particular, an electric supercharger including a rotating electric machine (hereinafter also referred to as “assist motor” or simply “motor”) that applies a rotational force to a compressor wheel is known.

  In such an electric supercharger, when the air compressed in the compressor does not reach a desired supercharging pressure, such as in a low engine speed range, the supercharging pressure of the compressor is forcibly driven by driving an assist motor. Is controlled to be raised. At this time, since the assist motor of the electric supercharger is used up to an ultra high speed rotation range (for example, on the order of 100,000 rpm), it is required to cool the motor efficiently and at low cost. Further, in the electric supercharger, the temperature of the assist motor is likely to rise due to the exhaust of the internal combustion engine, so that the necessity for motor cooling is further increased.

For example, Japanese Utility Model Publication No. 4-54467 (Patent Document 1) discloses a motor cooling structure that can withstand such ultra-high-speed rotation, and a motor rotor (rotor) that supplies lubricating oil supplied to a bearing of a rotating shaft (turbine shaft). A cooling structure for a turbine generator is disclosed in which the rotor is cooled and the stator of the motor is cooled by oil diffused by the centrifugal force of the rotor.
Japanese Utility Model Publication No. 4-54467

  However, in the cooling structure disclosed in Patent Document 1, the cooling of the stator is performed using the lubricating oil diffused by the rotor as the refrigerant, so that it is difficult to supply the refrigerant (lubricating oil) over the entire circumference of the stator. . In other words, in an electric motor or generator with the same rotation direction, a region where it is difficult to supply the lubricant occurs due to the positional relationship between the portion where the lubricant is supplied from the bearing portion to the rotor and the rotor rotation direction. End up. Specifically, it is difficult to supply the refrigerant (lubricating oil) to the stator portion in the rotor reverse rotation direction when viewed from the rotor portion to which the lubricating oil is supplied.

  The present invention has been made to solve such problems, and an object of the present invention is a cooling structure capable of efficiently cooling the stator of the rotating electrical machine of the electric supercharger over the entire circumference. It is providing the electric supercharger provided with.

The electric supercharger according to the present invention includes a supercharger, a rotating electrical machine, lubricating oil supply means, and a reflecting wall. The supercharger is configured to compress intake air of the internal combustion engine by rotating using exhaust gas of the internal combustion engine. The rotating electrical machine includes a rotor connected to a rotating shaft of a supercharger and a stator provided to face the rotor from a direction orthogonal to the rotating shaft. The lubricating oil supply means supplies lubricating oil to the bearing portion of the rotating shaft. The reflecting wall is provided at a position separated from the rotating shaft and the rotor in a direction perpendicular to the rotating shaft, and a part of the lubricating oil diffused by the centrifugal force accompanying the rotation of the rotating shaft and the rotor is directed toward the rotating shaft and the rotor. A part of the lubricating oil that is configured to be reflected and diffused by the rotation of the rotating shaft and the rotor is provided in such a shape as to reach the coil winding wound around the stator.

  According to the electric supercharger, since the lubricating oil reflected by the reflecting wall is diffused again toward the coil winding of the stator by the centrifugal force of the rotating shaft and the rotor, the lubricating oil of the stator in the circumferential direction is reduced. The reach is expanded. Thereby, compared with the configuration in which the lubricating oil is supplied to the stator by the centrifugal force of the rotating shaft and the rotor without providing a reflecting wall, the rotor rotation direction is seen from the portion where the lubricating oil is supplied from the bearing portion to the rotor. Lubricating oil that acts as a refrigerant can be easily supplied to the coil windings in the reverse rotation direction. As a result, it is possible to efficiently cool the coil winding around the entire circumference of the stator of the rotating electrical machine without complicating the cooling structure.

  Preferably, the reflection wall is provided so as to be non-parallel to the direction of the rotation axis and to protrude in a direction approaching the rotation axis.

  By adopting such a configuration, it becomes easy to supply the lubricating oil (refrigerant) to the coil winding over the entire circumference of the stator by enhancing the reflection effect of the lubricating oil by the reflecting wall.

  Preferably, the reflecting wall is provided so that a radial width dimension at a portion relatively far from the coil winding is wider along a direction of the rotation axis than a portion relatively near the coil winding. .

  By setting it as such a structure, the lubricating oil which does not directly hit coil winding among the lubricating oil diffused by the rotating shaft and the rotor can be reflected toward the rotating shaft and the rotor by the reflecting wall. And since the reflected lubricating oil is diffused again by the centrifugal force of the rotating shaft and the rotor, the amount of lubricating oil (refrigerant) finally supplied to the coil winding can be increased. As a result, the cooling effect of the rotating electrical machine can be enhanced.

  Alternatively, preferably, the reflection wall protrudes from the surface in a direction intersecting with the rotation axis of the inner wall of the housing that houses the rotating electrical machine, and the reflecting wall is parallel to the rotation axis of the inner wall of the housing. In the region where the lubricating oil diffused with the rotation of the rotating shaft and the rotor reaches, a surface portion whose tangential direction is not parallel to the rotating shaft is provided.

  By adopting such a configuration, the lubricant that has reached the inner wall surface (upper surface) of the casing without directly hitting the coil winding of the lubricant diffused by the rotating shaft and the rotor is removed from the upper surface side of the coil winding. It can be dropped on the side opposite to the rotor facing surface. Thereby, it is possible to cool the upper surface side of the coil winding, and the cooling effect of the coil winding is increased.

  Preferably, the electric supercharger further includes a refrigerant path and a lubricating oil container. The refrigerant path is provided inside a housing that houses the rotating electrical machine. The lubricating oil storage portion is provided with an introducing portion for introducing lubricating oil, an accumulating portion for accumulating the introduced lubricating oil, and a discharging portion for discharging the accumulated lubricating oil toward the rotating electrical machine, and , Configured integrally with the housing. The lubricating oil storage unit is configured so that the lubricating oil in the storage unit can exchange heat with the refrigerant in the refrigerant path. Further, the introduction portion is provided in a region of the inner wall of the housing where the lubricant diffused with the rotation of the rotation shaft and the rotor reaches, and the discharge portion is the rotation shaft and the rotor of the rotating electrical machine. The lubricating oil is provided so as to be discharged toward a portion different from a portion where the lubricating oil diffused with the rotation of the oil reaches.

By adopting such a configuration, the lubricating oil that has reached the inner wall surface (upper surface) of the casing without directly hitting the coil winding out of the lubricating oil diffused by the rotating shaft and the rotor is contained in the lubricating oil from the introduction portion. It can introduce | transduce into a part and can cool by heat exchange with the refrigerant | coolant (for example, cooling water) in a refrigerant path. And since it becomes possible to supply the cooled lubricating oil to the upper surface side of a coil winding from a lubricating oil accommodating part, the cooling effect of a coil winding increases.

  Preferably, the electric supercharger further includes an annular unit. The annular unit is disposed outside the rotating electrical machine and is configured to be rotatable around the rotation axis by an actuator. And the reflection wall is provided so that it may protrude on the surface facing the rotary electric machine of an annular unit.

  More preferably, the electric supercharger further includes phase control means for operating the actuator so as to change the rotational phase of the annular unit in accordance with the operating state of the electric supercharger. For example, the phase control means operates the actuator so as to change the rotational phase of the annular unit according to the temperature of the coil winding. Alternatively, the phase control means operates the actuator so as to change the rotational phase of the annular unit according to the rotational speed of the rotor.

  With this configuration, the rotational phase of the annular unit can be changed by operating the actuator, so that the position of the reflecting wall (rotational phase) is optimal for cooling the coil winding. Can be adjusted. In particular, by automatically changing the rotational phase of the annular unit according to the operating state of the electric supercharger, for example, the measured temperature of the coil winding and the rotational speed of the rotor, the automatic positioning of the reflecting wall is optimal for cooling the coil winding. Control becomes possible. Thereby, even if the driving | running state of an electric supercharger changes, it becomes possible to cool a coil winding efficiently each time.

  More preferably, the electric supercharger further includes atomization means. In order to atomize the lubricating oil diffused with the rotation of the rotating shaft and the rotor by the reflecting wall, the atomizing means moves the actuator so that the annular unit periodically reciprocates in the forward rotation direction and the reverse rotation direction. Operate.

  With such a configuration, the atomizing means can be actuated in a timely manner to atomize the lubricating oil diffused by the rotating shaft and the rotor. Thereby, the cooling effect of the coil winding which used lubricating oil as a refrigerant | coolant can further be improved.

  Preferably, the electric supercharger further includes pressure control means. The pressure control means changes the supply pressure of the lubricating oil by the lubricating oil supply means in accordance with the operating state of the electric supercharger.

  By adopting such a configuration, the diffusion angle of the lubricating oil diffused by the centrifugal force of the rotating shaft and the rotor can be varied by changing the lubricating oil supply amount by changing the lubricating oil supply pressure to the bearing portion. It can be. Thereby, the cooling effect of a coil winding can be heightened by adjusting a diffusion angle to an optimal angle according to a motor driving | running state.

  Preferably, in the bearing portion, the lubricating oil flowing out from the bearing portion to the rotating shaft is relatively in a region on the opposite side of the rotating direction from the rotating direction side region of the rotating shaft across the vertical direction in the circumferential direction of the rotating shaft. It has a structure that increases in number.

  By adopting such a configuration, it acts as a refrigerant on a portion where the lubricating oil is difficult to reach due to the rotation of the rotating shaft and the rotor, that is, a portion rotating in the direction opposite to the rotor rotating direction as viewed from the lubricating oil supply portion from the bearing portion. It becomes easy to supply lubricating oil. Therefore, it is possible to efficiently cool the coil windings around the stator of the rotating electrical machine by increasing the lubricating oil supplied to the coil windings in the reverse rotation direction without complicating the cooling structure. It becomes.

  Preferably, the clearance of the bearing portion with respect to the casing of the rotating electrical machine is set larger on the side closer to the rotating electrical machine than on the side farther from the rotating electrical machine.

  With such a configuration, a larger amount of the lubricating oil supplied to the bearing portion is supplied to the rotating electrical machine side (inside the housing). Therefore, the cooling effect of the rotating electrical machine using this lubricating oil as a refrigerant can be reduced. Can be increased. In addition, it is possible to reduce the leakage of lubricating oil to the outside of the housing.

  According to the electric supercharger according to the present invention, a cooling structure capable of efficiently cooling the stator of the rotating electrical machine over the entire circumference can be realized.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following, the same or corresponding parts in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated in principle.

[Embodiment 1]
FIG. 1 is a configuration diagram of an engine system equipped with an electric supercharger according to an embodiment of the present invention.

  Referring to FIG. 1, the engine system includes an engine 100, an electric supercharger 200, an intercooler 162, an engine ECU (Electronic Control Unit) 250, and a supercharger ECU 50. The engine system according to the present embodiment is mounted on a vehicle such as an automobile. Engine ECU 250 and supercharger ECU 50 may be integrated into one ECU. In the present embodiment, engine ECU 250 and supercharger ECU 50 are connected so that they can communicate in both directions.

  Air sucked from the suction port 150 is filtered by the air cleaner 152. The air filtered by the air cleaner 152 flows to the electric supercharger 200 through the intake passage 156. The air flowing through the electric supercharger 200 is compressed by the compressor 202, then flows through the intake passage 160, and is cooled by the intercooler 162. The air cooled by the intercooler 162 flows through the intake passage 102 and is taken into the engine 100.

  An air flow meter 154 that detects the amount of intake air is provided in the middle of the intake passage 156. Air flow meter 154 transmits a signal representing detected intake air amount Q to engine ECU 250.

  The intercooler 162 cools the air that has been compressed by the compressor 202 and has risen in temperature. Since the volume of the cooled air is smaller than that before cooling, more air is sent into the engine 100.

  Further, a bypass passage 158 that bypasses the intake passage 156 and the intake passage 160 is provided, and an air bypass valve 164 that adjusts the flow rate of the air flowing through the bypass passage 158 is provided in the middle of the bypass passage 158. Air bypass valve 164 operates in accordance with a control signal received from engine ECU 250.

A throttle valve 166 that adjusts the flow rate of air flowing through the intake passage 102 is provided in the middle of the intake passage 102. The throttle valve 166 is driven by a throttle motor 168. Throttle motor 168 is driven in accordance with a control signal received from engine ECU 250.

  An intake pipe pressure sensor 170 and an intake air temperature sensor 172 are provided in the intake passage 102. The intake pipe pressure sensor 170 detects the pressure of air in the intake passage 102. Intake pipe pressure sensor 170 transmits a signal representing the detected air pressure to engine ECU 250. The intake air temperature sensor 172 detects the temperature of air in the intake passage 102. Intake air temperature sensor 172 transmits a signal representing the detected air temperature to engine ECU 250.

  Engine 100 includes a cylinder head (not shown) and a cylinder block 112. The cylinder block 112 is provided with a plurality of cylinders in the vertical direction of the drawing in FIG. In each cylinder, a piston 114 is slidable in the vertical direction of the drawing. Piston 114 is connected to crankshaft 120 via connecting rod 116. A piston 114, connecting rod 116 and crankshaft 120 form a crank mechanism.

  A combustion chamber 108 is formed at the upper part of the piston 114. The combustion chamber 108 is provided with a spark plug 110 and a fuel injection injector 106 toward the combustion chamber 108. In the present embodiment, engine 100 is described as being a direct injection engine, but is not particularly limited to a direct injection engine. For example, engine 100 may be an internal combustion engine, and may be a port injection type engine or a diesel engine.

  In the cylinder head, an intake passage 102 and an exhaust passage 130 are provided so as to be connected to the combustion chamber 108, respectively. An intake valve 104 is provided between the intake passage 102 and the combustion chamber 108. An exhaust valve 128 is provided between the exhaust passage 130 and the combustion chamber 108. The intake valve 104 and the exhaust valve 128 are driven by a camshaft (not shown) that rotates in conjunction with the crankshaft 120.

  The air flowing through the intake passage 102 is sucked into the combustion chamber 108 by opening the intake valve 104 when the piston 114 descends. The air flowing into the combustion chamber 108 is mixed with the fuel injected from the fuel injection injector 106. When the intake valve 104 is closed and the piston 114 rises to near the top dead center, the air mixed with fuel is ignited and burned in the spark plug 110. Piston 114 is pushed down by the pressure by combustion. At this time, the vertical motion of the piston 114 is converted into the rotational motion of the crankshaft 120 via the crank mechanism. When the piston 114 is lowered to near the bottom dead center, the exhaust valve 128 is opened.

  When the piston 114 rises again, the air combusted in the combustion chamber 108, that is, the exhaust gas, flows through the exhaust passage 130. The air that has flowed through the exhaust passage 130 drives the turbine 204 of the electric supercharger 200 and then flows through the exhaust pipe 180 and is guided to the catalyst 182. The exhaust gas is purified by the catalyst 182 and then discharged outside the vehicle.

  A pulley (not shown) is provided at one end of the crankshaft 120. The pulley is connected to a pulley provided on the rotating shaft of the alternator 126 via a belt 124. The alternator 126 is operated by the rotation of the crankshaft 120 to generate power.

The timing rotor 118 is provided on the crankshaft 120 and rotates together with the crankshaft 120. A plurality of protrusions are provided on the outer periphery of the timing rotor 118 at predetermined intervals. The crank position sensor 122 is provided to face a protrusion of a timing rotor (not shown). When the timing rotor 118 rotates, the air gap between the projection of the timing rotor 118 and the crank position sensor 122 changes, so that the magnetic flux passing through the coil portion of the crank position sensor 122 increases and decreases, and an electromotive force is generated in the coil portion. . Crank position sensor 122 transmits a signal representing the electromotive force to engine ECU 250. Engine ECU 250 detects the crank angle based on the signal transmitted from crank position sensor 122.

  Further, the vehicle is provided with a vehicle speed sensor (not shown) on the wheel, and detects the rotation speed (wheel speed) of the wheel. The vehicle speed sensor transmits a signal representing the detection result to engine ECU 250. Engine ECU 250 calculates the vehicle speed from the rotational speed of the wheel. Engine ECU 250 performs arithmetic processing based on signals transmitted from each sensor such as intake pressure, intake air temperature, intake air amount, wheel speed, accelerator depression amount, maps and programs stored in memory, and engine 100 performs desired processing. The devices are controlled so as to be in an operating state.

  The electric supercharger 200 includes a compressor 202, a turbine 204, a shaft 210, and a rotating electrical machine 216 as an assist motor. As the rotating electrical machine 216, basically any type of motor or motor generator can be applied, but in the following, the rotating electrical machine 216 is also simply referred to as a motor 216.

  A compressor wheel (also referred to as a compressor rotor, a compressor blade, etc.) 206 is accommodated in the housing of the compressor 202. The compressor wheel 206 compresses (supercharges) the air filtered by the air cleaner 152.

  A turbine wheel (also referred to as a turbine rotor, a turbine blade, or the like) 208 is accommodated in the housing of the turbine 204. The turbine wheel 208 is rotated by exhaust gas.

  The compressor wheel 206 and the turbine wheel 208 are provided at both ends of the shaft 210, respectively. That is, when the turbine wheel 208 is rotated by the exhaust gas, the compressor wheel 206 is also rotated.

  Further, a motor 216 having a shaft 210 as a rotation axis is provided between the compressor wheel 206 and the turbine wheel 208. The shaft 210 is rotatably supported by the housing of the motor 216. The motor 216 includes a rotor 340 mounted on the shaft 210 and a stator provided so as to surround the rotor 340.

  The motor 216 applies a rotational force to the shaft 210 when the rotor 340 is rotated by electric power supplied from a supercharger EDU (Electronic Drive Unit) 60 in accordance with a control signal of the supercharger ECU 50. The supercharger EDU 60 uses the power supplied from the high voltage battery 40 to supply power to the motor 216 according to the control signal input from the supercharger ECU 50.

  The motor 216 is provided with a hall sensor (not shown), and the rotor position (phase) detected by the hall sensor is transmitted to the supercharger ECU 50. Typically, the motor 216 is configured by a three-phase brushless DC motor, and the supercharger EDU 60 is based on the rotational phase detected by the Hall sensor 205 and has an alternating current with an appropriate phase for each phase of the three-phase brushless DC motor. It is composed of an inverter that supplies current.

The high voltage battery 40 is electrically connected to the DC / DC converter 30. The DC / DC converter 30 is electrically connected to the alternator 126 described above. Therefore, the electric power generated by the alternator 126 is boosted to an appropriate voltage by the DC / DC converter 30 and then supplied to the high voltage battery 40. Thereby, the high voltage battery 40 is charged. Further, the electric power generated in the alternator 126 is supplied to the low voltage battery 20. Thereby, the low voltage battery 20 is charged. The low voltage battery 20 supplies electric power to the engine ECU 250, the supercharger ECU 50, and the like.

  The supercharger ECU 50 performs arithmetic processing based on the information transmitted from the engine ECU 250, the signal transmitted from the rotor position sensor, and the map and program stored in the memory. The devices are controlled so as to be in an operating state.

  In the electric supercharger 200 having the above-described configuration, after the air mixed with fuel is burned in the engine 100, the exhaust gas is guided into the turbine 204 from the exhaust passage 130. The exhaust gas then rotates the turbine wheel 208 and the rotational force is transmitted to the shaft 210. Thereafter, the exhaust gas flows through the exhaust pipe 180 and is guided to the catalyst 182. The exhaust gas guided to the catalyst 182 is exhausted outside the vehicle in a purified state.

  On the other hand, the air taken from outside the vehicle to be supplied to the engine 100 is filtered by the air cleaner 152, then flows through the intake passage 156 and is guided into the compressor 202. The air is compressed (supercharged) by a compressor wheel 206 that rotates integrally with the shaft 210. The compressed air is guided to the intercooler 162 and is sucked into the combustion chamber 108 through the intake passage 102 of the engine 100 in a cooled state.

  Further, supercharger ECU 50 determines that the air compressed in compressor 202 does not reach a desired supercharging pressure in the low engine speed range of engine 100 (for example, the engine speed is equal to or lower than a predetermined engine speed). In some cases, the motor 216 is driven to control the boost pressure of the compressor 202 to be forcibly increased.

  Here, the motor 216 of the electric supercharger is used up to an ultra-high speed rotation range (for example, on the order of 100,000 rpm), and the temperature easily rises due to the exhaust of the internal combustion engine. Is needed. Below, the cooling structure of the motor 216, especially the cooling structure of the stator coil winding (coil end) will be described.

FIG. 2 is a diagram illustrating a cooling structure for the electric supercharger according to the first embodiment of the present invention.
FIG. 2 shows the structure of the upper surface side (oil supply side) in the cross-sectional view along the rotation axis direction and the vertical direction of the electric supercharger 200. A similar structure is also provided over the entire circumference of the motor 216 except for the structure related to the lubricant supply in the housing 300.

  Referring to FIG. 2, the motor 216 is stored in a housing 300 having a cylindrical motor housing portion. Motor 216 includes a stator core 320, a stator including coil winding 330 wound around stator core 320, and rotor 340.

  As described with reference to FIG. 1, the rotor 340 is attached to the shaft 210 provided with the compressor wheel 206 and the turbine wheel 208 at both ends. In the drawing, the rotation axes of the shaft 210 and the rotor 340 are indicated by alternate long and short dash lines.

  The inner wall surface of the housing 300 includes a wall surface 310 (also referred to as a side wall surface 310) in a direction intersecting the rotation axis of the shaft 210 and a wall surface 312 (hereinafter also referred to as an upper wall surface 312) in a direction parallel to the rotation axis. The housing 300 is provided with a lubricating oil path 305 for introducing the lubricating oil 400, and the lubricating oil 400 is supplied to the bearing 350 through the lubricating oil path 305. The bearing 350 is provided as a “bearing portion” that is attached to the shaft 210 and supports the shaft 210 that is rotatably attached to the housing 300. Note that engine oil is generally used as the lubricating oil 400. The supply path of the lubricating oil 400 including the lubricating oil path 305 corresponds to the “lubricating oil supply means” in the present invention.

  The lubricating oil supplied to the bearing 350 flows out to the shaft 210 and the rotor 340 after being used for lubricating the bearing portion. Then, the lubricating oil 400 is diffused by the centrifugal force accompanying the rotation of the shaft 210 and the rotor 340. As a result, the lubricating oil diffused to each part of the motor 216 acts as a refrigerant to cool the part. In particular, by diffusing the lubricating oil to the stator winding 330 wound around the stator core 320, the coil winding 330 can be cooled by this lubricating oil.

  An oil reflecting wall 380 is provided on the side wall surface 310 of the housing 300. As shown in FIG. 3, the oil reflecting wall 380 is provided in a slit shape on the entire circumference of the motor 216. As understood from FIGS. 2 and 3, the oil reflecting wall 380 is provided over the entire circumference in the rotor circumferential direction at a position separated from the shaft 210 and the rotor 340 in a direction (radial direction) perpendicular to the rotation axis. .

  Here, referring to FIG. 4, the diffusion state of the lubricating oil in the cooling structure in which the oil reflecting wall 380 is not disposed will be described as a comparative example. FIG. 4 shows a cross-sectional view of the motor 216 along the direction perpendicular to the rotation axis.

  Referring to FIG. 4, coil windings 330 are wound corresponding to the respective teeth 335, and the lubricating oil 400 is diffused by the centrifugal force accompanying the rotation of the rotor 340, so that the refrigerant is supplied to the coil windings 330. As a lubricating oil is supplied.

  However, in the system in which the lubricating oil that is simply dropped onto the bearing 350 and dropped by gravity is wound up and diffused by the rotor 340, the region 500 in which the lubricating oil can be diffused is limited when viewed in the motor circumferential direction. That is, in the circumferential direction of the motor, the lubricating oil 410 can be diffused in a region on the rotor rotational direction side as viewed from the portion 505 where the lubricating oil 400 is supplied to the rotor 340, whereas the rotational direction opposite to the rotor rotational direction (hereinafter referred to as the rotational direction) , Referred to as “reverse rotation direction”), it is difficult to diffuse the lubricating oil.

  On the other hand, FIG. 5 shows a diffusion state of the lubricating oil in the cooling structure according to the first embodiment in which the oil reflecting wall 380 is arranged. FIG. 5 is a cross-sectional view showing the same portion as FIG.

  Referring to FIG. 5, by providing oil reflecting wall 380, the lubricating oil diffused by the rotation of shaft 210 and rotor 340 reaches part of coil winding 330 directly as indicated by reference numeral 410. On the other hand, the remaining part is reflected by the oil reflecting wall 380 as indicated by reference numeral 411 and reaches the rotor 340 again, and further from that point by the centrifugal force generated by the shaft 210 and the rotor 340 as indicated by reference numeral 420. Diffused.

  Thereby, compared with the comparative example shown in FIG. 4, the area | region which can supply lubricating oil by rotation of the shaft 210 and the rotor 340 can be expanded to the motor circumferential direction whole region. Therefore, according to the cooling structure according to the first embodiment provided with the oil reflecting wall 380, the lubricating oil supplied to the bearing 350 can be supplied as a refrigerant to the coil winding 330 over the entire circumference of the stator. As a result, the coil winding 330 can be cooled over the entire circumference, and the cooling capacity of the motor 216 can be improved.

In the cooling structure according to the first embodiment, the range in which the lubricating oil can be supplied as viewed in the circumferential direction of the motor varies depending on the interval (position), size, and shape of the oil reflecting wall 380. . Therefore, even at the maximum number of rotations of the motor 216 that is assumed, a position, size, and shape that does not prevent the part of the lubricating oil diffused by the rotation of the shaft 210 and the rotor 340 from reaching the coil winding 310. Therefore, it is necessary to provide the oil reflecting wall 380.

  Further, as shown in FIG. 6, the oil reflecting wall 380 may be provided so as to protrude in a direction approaching the rotation axis with an angle Ψ (Ψ ≠ 0) downward with respect to the rotation axis direction. There is (Ψ ≠ 0). FIG. 6 shows a part of a sectional view similar to FIG.

  By providing the oil reflecting wall in this manner, the oil reflecting effect by the oil reflecting wall 380 is further enhanced, and it becomes easy to supply the lubricating oil as the refrigerant to the coil winding 330 over the entire circumference of the stator.

[Modification of Embodiment 1]
FIG. 7 is a perspective view of the inner wall surface of the housing provided with the oil reflecting wall according to the modification of the first embodiment, as compared with FIG.

  Referring to FIG. 7, in the modification of the first embodiment, oil reflecting wall 380 is provided in a shape such that circumferential width dimension W varies along the rotation axis direction. Specifically, the width dimension W is wide on the side close to the inner wall surface 310, that is, on the side far from the coil winding 330, while the width dimension W is designed to be narrow on the side close to the coil winding 330.

  FIG. 8 is a conceptual diagram showing a comparison of the diffusion state of the lubricating oil in the cooling structure of the first embodiment and its modification. FIG. 8 shows a part of a sectional view similar to FIG. FIG. 8A shows the diffusion state of the lubricating oil in the cooling structure of the first embodiment, and FIG. 8B shows the diffusion state of the lubricating oil in the cooling structure of the modified example of the first embodiment. Indicated.

  Referring to FIG. 8A, according to the oil reflecting wall having the shape shown in FIG. 3 having a uniform width dimension W along the rotation axis direction, the oil is diffused by the rotation of the shaft 210 and the rotor 340. As indicated by reference numeral 414, the lubricating oil reaches the coil winding 330 on the side close to the coil winding 330, whereas it is indicated by reference numeral 412 near the inner wall surface 310, that is, on the side far from the coil winding 330. Is diffused without reaching the coil winding 330 directly.

  On the other hand, according to the oil reflecting wall having the shape shown in FIG. 7 according to the modification of the first embodiment, the lubricating oil diffused by the rotation of the shaft 210 and the rotor 340 is closer to the coil winding 330. Then, as in FIG. 8A, the coil winding 330 is reached as indicated by reference numeral 414. Furthermore, in the vicinity of the inner wall surface 310, that is, on the side far from the coil winding 330, the lubricating oil 412 that does not reach the coil winding 330 shown in FIG. Can be reflected again to the rotor side.

  As a result, the amount of lubricating oil (refrigerant) finally supplied to the coil winding 330 can be increased, so that the cooling capacity of the coil winding 330 can be increased.

  FIG. 9 is a top view of the oil reflecting wall showing variations in the shape of the oil reflecting wall 380.

  FIG. 9A shows the shape of the oil reflecting wall 380 shown in FIG. 3 having a uniform width W and protruding in a direction along the rotation axis for comparison. On the other hand, as shown in FIGS. 9B to 9D, the width dimension W can be changed along the rotation axis direction, and the protruding direction can be made non-parallel to the rotation axis direction. Note that the shape of the oil reflecting wall 380 affects the diffusion form of the lubricating oil due to the rotation of the shaft 210 and the rotor 340. Therefore, it depends on the maximum rotational speed of the motor 216, the lubricating oil supply pressure (amount) to the bearing portion, and the like. The best one will be different. For this reason, it is preferable to design with an appropriate shape for each motor.

[Embodiment 2]
In the following, variations of the cooling structure of the electric supercharger will be sequentially described. That is, the overall configuration of the engine system shown in FIG. 1 is the same in each embodiment described below.

  In the second embodiment, a cooling structure that processes the upper wall surface 312 of the housing 300 to allow cooling of the upper surface side of the coil winding 330 will be described.

  FIG. 10 is a diagram illustrating a cooling structure for the electric supercharger according to the second embodiment of the present invention. 10 is a cross-sectional view of the same portion as FIG.

  Referring to FIG. 10, R surface machining is performed on a region 315 of the upper wall surface 312 of the housing 300 where the lubricating oil 412 that has not been supplied directly to the coil winding 330 reaches. As a result, the lubricating oil 412 wraps around the upper surface of the coil winding 330 along the R surface that is non-parallel to the rotation axis direction, and is dropped from the portion toward the coil winding 330 by gravity.

  As a result, not only the lower surface side (the inner side with respect to the rotation axis) of the coil winding 330 cooled by the lubricating oil 414 diffused by the rotation of the shaft 210 and the rotor 340 but also the upper surface side (the rotation shaft) of the coil winding 330. It is possible to cool the outer side as well.

  FIG. 11 is a diagram showing a variation of the cooling structure for the electric supercharger according to the second embodiment of the present invention.

  For comparison, FIG. 11A shows a structure in which a region parallel to the rotation axis is formed without particularly processing the region 315 of the upper wall surface 312. In this case, the lubricating oil 414 that has reached the region 315 does not generate a force toward the inner side (coil winding 330 side) along the rotation axis direction, and the lubricating oil 414 drops again by gravity, so the coil winding A cooling effect of 330 cannot be obtained.

  On the other hand, as shown in FIGS. 11B and 11C, in addition to the R surface processing, the region 315 of the upper wall surface 312 is subjected to processing such as chamfering and is not parallel to the rotation axis direction. By forming the surface portion, the lubricating oil 414 that has reached the region 315 can be guided to the coil winding 330 side. As a result, similarly to the cooling structure shown in FIG. 10, the upper surface side of the coil winding 330 can be cooled. That is, the lower surface side of the coil winding 330 to which the lubricating oil diffused by the rotation of the shaft 210 and the rotor 340 arrives by providing a surface portion whose tangential direction is not parallel to the rotation axis in the region 315 of the upper wall surface 312. In addition, it is possible to supply lubrication not only to the upper surface side of the coil winding 330, but also to improve the cooling capacity of the coil winding.

[Modification of Embodiment 2]
FIG. 12 is a diagram illustrating a cooling structure for the electric supercharger according to a modification of the second embodiment. FIG. 12 is a cross-sectional view showing a portion similar to FIG.

Referring to FIG. 12, in the cooling structure according to the modification of the second embodiment, the lubricating oil corresponding to the “lubricating oil storage portion” is reached in region 315 where lubricating oil 412 not directly supplied to coil winding 330 reaches. A flow path 316 is provided. The lubricating oil flow path 316 is provided at a joint portion between the portion constituting the side wall surface 310 of the housing 300 and the portion constituting the upper wall surface 312, and is provided on the protrusion 317 that defines the lubricating oil flow passage 316. The lubricating oil 412 is guided into the lubricating oil flow path 316 by the introduction hole 318. The lubricating oil passage 316 is connected to the cooling water passage 30 in the housing 300.
6, the lubricating oil in the lubricating oil passage 316 is cooled by exchanging heat with the cooling water in the cooling water passage 306 via the housing 300. Further, the lubricating oil in the lubricating oil flow path 316 is dropped from the discharge hole 319 provided on the upper surface of the coil winding 330 and supplied to the upper surface of the coil winding 330.

  As a result, the lubricating oil that has not been directly supplied to the coil winding 330 is cooled by heat exchange with the cooling water in the lubricating oil flow path 316 and supplied to the upper surface of the coil winding 330. Thereby, since it becomes possible to supply the cooled lubricating oil as a refrigerant to the upper surface of the coil winding 330, it becomes possible to enhance the cooling effect of the upper surface portion of the coil winding.

[Embodiment 3]
In the third embodiment, a cooling structure capable of extending the lubricating oil supply range to the stator by improving the structure of the bearing 350 will be described.

  FIG. 13 is a diagram illustrating a cooling structure for the electric supercharger according to the third embodiment of the present invention. FIG. 13 is a cross-sectional view showing the same part as in FIG.

  Referring to FIG. 13, the bearing 350 is disposed so as to have a clearance with respect to the housing 300, and the thrust 350 in the thrust direction (rotating axis direction) is prevented from being displaced at both ends in the rotating axis direction. A bearing retainer 354 is provided.

FIG. 14 is a front view illustrating the shape of the bearing retainer.
As shown in FIG. 14A, the bearing retainers 354 provided at both ends of the bearing 350 normally have an opening 356 in the lower part in the vertical direction. The lubricating oil 400 flows out of the opening 356 and reaches the shaft 210 and the rotor 340, and is diffused by the centrifugal force accompanying the rotation of the shaft 210 and the rotor 340.

  In the cooling structure according to the third embodiment, as shown in FIG. 14 (b) or (c), when viewed in the circumferential direction, the region AR1 on the rotor rotation direction side sandwiches the vertical direction in which the lubricating oil 400 is dropped. In addition, the lubricant oil flowing out from the bearing 350 to the shaft 210 or the rotor 340 becomes relatively large in the region AR2 on the reverse rotation direction side with respect to the vertical direction.

  For example, as shown in FIG. 14B, by providing an opening 357 in a slit shape or a continuous shape (not shown) in the area AR2, the amount of lubricating oil flowing out from the opening 357 is increased, and the area AR2 In particular, the amount of lubricating oil in the vicinity of the rotor reverse rotation direction of the dripping portion of the lubricating oil 400 can be increased.

  Alternatively, as shown in FIG. 14C, the bearing retainer 354 is formed with an asymmetrical diameter, and an opening 358 is provided by increasing the inner diameter in the region AR2, and the region AR2 is formed by lubricating oil flowing out from the opening 358. The amount of lubricating oil in can be increased.

  FIG. 15 is a conceptual diagram illustrating a diffusion state of the lubricating oil in the cooling structure according to the third embodiment. FIG. 15 is a cross-sectional view showing the same portion as FIG. 4 and FIG.

  As shown in FIG. 15, the structure shown in FIG. 14B or 14C increases the amount of lubricating oil supplied to the rotor reverse rotation direction portion, so that the lubricating oil is less likely to reach by rotor rotation. Lubricating oil as a refrigerant can be sufficiently supplied also to the coil winding 330 on the reverse rotation direction side (region AR2 side in FIG. 14).

  As a result, when viewed in the circumferential direction of the motor, the region where the lubricating oil can be supplied to the coil winding 330 by the rotation of the shaft 210 and the rotor 340 can be expanded, and the lubricating oil supplied to the bearing 350 can be The refrigerant can be supplied to the coil winding 330 over the circumference.

  The effect of the structure of the third embodiment can be further expanded by combining with the oil reflecting wall shown in the first embodiment and its modification. However, even if the bearing structure according to the third embodiment is used alone without being combined with the oil reflecting wall, the region in which the lubricating oil can be supplied to the coil winding 330 can be expanded when viewed in the motor circumferential direction. It is possible to confirm that it can contribute to the improvement of the cooling performance.

[Embodiment 4]
In the fourth embodiment, a cooling structure that efficiently uses lubricating oil supplied to the bearing 350 for motor cooling will be described.

  FIG. 16 is a diagram illustrating a cooling structure for the electric supercharger according to the fourth embodiment of the present invention. FIG. 16 is a cross-sectional view similar to FIG.

  Referring to FIG. 16, the lubricating oil 400 supplied to the bearing 350 flows out to the motor side (inner side) and the housing side (outer side). Therefore, it is preferable that the outflow of lubricating oil from the outside used for motor cooling is increased while suppressing the outflow of lubricating oil from the outside that leads to oil leakage from the housing 300. Therefore, in the cooling structure according to the fourth embodiment, the shape of bearing 350 # is not uniform.

  Specifically, as shown in FIG. 17, by providing a taper in the cross-sectional shape of the bearing 350 #, increasing the diameter on the outer side (outside the housing) and decreasing the diameter on the inner side (motor side), The clearance between bearing 350 # and housing 300 is designed to be narrow on the outside and large on the inside.

  As a result, oil leakage to the outside of the housing 300 is prevented, lubricant oil is prevented from flowing out to the compressor wheel 206 and the turbine wheel 208, and the amount of lubricating oil used for motor cooling is increased to improve cooling performance. It becomes possible. Note that the taper (diameter difference) provided in the bearing 350 # can generate the above-described difference in the amount of lubricating oil even in the order of several μm, so that the above-described effects can be achieved without excessive generation of thrust force. It is possible to enjoy.

[Embodiment 5]
FIG. 18 is a diagram illustrating a cooling structure for the electric supercharger according to the fifth embodiment. 18 is a cross-sectional view of the same portion as FIG.

  As can be understood by comparing FIG. 18 with FIG. 2, in the cooling structure according to the fifth embodiment, the oil reflecting wall 380 is not provided directly on the inner wall surface of the housing, but is an annular unit independent of the housing 300. 700. Since the structure of other parts is the same as that of the first embodiment (FIG. 2), detailed description will not be repeated.

  As shown in FIG. 19, the annular unit 700 is provided with an oil reflecting wall 380 in the shape of a slit as in FIG. In addition, as shown in FIG. 6 or FIG.9 (b)-(d), the optimal dimension and shape can be suitably selected for the oil reflecting wall 380. FIG.

The annular unit 700 has an operation end 600 that can be moved up and down by an actuator (not shown).
Are linked by a link mechanism 605. Accordingly, the annular unit 700 is movable in the rotational direction by moving the operation end up and down by the actuator. That is, since the rotational phase of the annular unit 700, that is, the position (phase) of the oil reflecting wall 380 can be made variable by the operation of the actuator, the lubricating oil diffused with the rotation of the shaft 210 and the rotor 340 is It is possible to adjust the phase to be optimally supplied to the coil winding 330. Thereby, the cooling performance of the motor 216, in particular, the coil winding 330 of the stator is enhanced.

[Modification of Embodiment 5]
In the modification of the fifth embodiment, a configuration for automatically controlling the rotational phase of the annular unit 700 as described above, that is, the position of the oil reflecting wall 380 will be described.

FIG. 20 is a diagram illustrating a cooling structure for the electric supercharger according to a modification of the fifth embodiment.
As can be understood by comparing FIG. 20 with FIG. 18, in the cooling structure for the electric supercharger according to the modification of the fifth embodiment, the supercharger ECU 50 causes the actuator 610 to move the operation end 600 of the link mechanism up and down. To control the operation. Accordingly, it is possible to control the vertical position of the operation end 600, that is, the rotational phase of the annular unit 700, according to an instruction from the supercharger ECU 50.

  Further, the coil winding 330 is provided with a temperature sensor 680, and the output signal of the temperature sensor 680 is input to the supercharger ECU 50 in the same manner as the output signal of the rotor position sensor 670 provided in the stator. Thus, supercharger ECU 50 can detect the coil winding temperature of coil winding 330 and the rotational speed of rotor 340. Since the structure of other parts is the same as that of the fifth embodiment (FIG. 18), detailed description will not be repeated.

  FIG. 21 is a flowchart for explaining a first example of automatic control of the rotation phase of the annular unit 700 by the supercharger ECU 50, that is, the oil reflection wall position (phase).

  Referring to FIG. 21, supercharger ECU 50 initially sets counter value n = 1 in step S100, and acquires coil winding temperature Tn of the stator based on the output of temperature sensor 680 in step S110.

  Further, the supercharger ECU 50 changes the oil reflection wall phase by a predetermined amount Δθ in step S120, and increments (+1) the counter value n in step S130.

  When a predetermined time has elapsed from steps S120 and S130, supercharger ECU 50 acquires stator coil winding temperature Tn based on the output of temperature sensor 680 in step S140. As a result, the coil winding temperature after the oil reflection wall phase is changed in step S120 is obtained.

  In step S150, supercharger ECU 50 compares coil winding temperature Tn-1 at the previous oil reflection wall phase with coil winding temperature Tn at the current oil reflection wall phase. The supercharger ECU 50 recognizes that the phase change direction of the oil reflecting wall is an appropriate direction for increasing the cooling direction of the coil winding temperature when the coil winding temperature decreases (when YES is determined in step S150). Then, the process returns to step S120 again. As a result, the oil reflection wall phase Δθ is further changed Δθ in the same direction.

On the other hand, when the coil winding temperature rises after the phase change of the oil reflecting wall (when NO is determined in step S150), the supercharger ECU 50 further changes the phase of the oil reflecting wall in the same direction. Recognizing that the coil winding temperature will rise, the oil reflection wall phase is maintained as it is.

  Through a series of processes in steps S100 to S150, the oil reflection wall phase can be set to a phase corresponding to the minimum point of the coil winding temperature change with respect to the phase change of the oil reflection wall. That is, it becomes possible to obtain an optimum oil reflection wall phase by trial and error under the current state of the electric supercharger.

  Therefore, by executing a series of processes of steps S100 to S150 every time a predetermined condition such as the passage of a certain period of time, the number of rotations of the motor, or the change of the coil winding temperature over a certain level is established, the coil winding temperature is measured. The phase of the oil reflecting wall is automatically controlled to the optimum cooling value of the coil winding 330, so that the coil winding can be efficiently cooled every time the operating state of the electric supercharger changes.

  FIG. 22 is a flowchart for explaining a second example of the automatic control of the rotational phase of the annular unit 700 by the supercharger ECU 50, that is, the oil reflection wall position (phase).

  Referring to FIG. 22, supercharger ECU 50 acquires rotor rotational speed Nt based on the output of rotor position sensor 670 in step S200. Then, in step S210, the supercharger ECU 50 refers to a map 655 shown in FIG. 23 to obtain an optimum oil reflection wall phase corresponding to the current rotor rotational speed Nt, and further, this oil reflection wall phase. The actuator 610 is controlled so that the vertical position of the operation end 600 corresponding to is obtained.

  Since the magnitude of the centrifugal force changes as the rotor rotational speed changes, the diffusion mode of the lubricating oil by the shaft 210 and the rotor 340 changes. For this reason, the oil reflection wall phase optimum for cooling the coil winding changes in accordance with the rotor rotational speed.

  Referring to FIG. 23, an optimum oil reflection wall phase in each rotor rotation speed range is obtained in advance according to the flowchart shown in FIG. 21 to set the oil reflection wall phase in each rotor rotation speed range. A map 655 can be created in advance. The oil reflection wall phase can be mapped as the vertical position of the operation end 600.

  Thus, during operation of the electric supercharger, by referring to the map 655 in step S210 of FIG. 22, an oil reflection wall phase optimum for cooling the coil winding is set according to the current rotor rotational speed. Thus, even if the operating state of the electric supercharger changes, the coil winding can be efficiently cooled each time.

  FIG. 24 is a flowchart for explaining a second example of automatic control of the rotational phase of the annular unit 700, that is, the oil reflection wall position (phase) by the supercharger ECU 50.

  Referring to FIG. 24, supercharger ECU 50 determines in step S220 whether or not a predetermined condition for atomizing the lubricant is satisfied. This predetermined condition can be determined so as to be satisfied when, for example, a certain time elapses or the coil winding temperature rises above a predetermined threshold.

Then, when the predetermined condition is satisfied (when YES is determined in step S220), supercharger ECU 50 periodically causes operation end 600 of the link mechanism to reciprocate up and down in step S230. As a result, the annular unit 700 provided with the oil reflecting wall also periodically reciprocates in the forward direction and the reverse direction. Therefore, the lubricating oil is wound up and diffused by the oil reflecting wall 380 by the shaft 210 and the rotor 340. Can be atomized. By supplying the atomized lubricating oil to the coil winding 330, the cooling effect of the coil winding 330 using the lubricating oil as a refrigerant can be enhanced.

  Note that the processing according to the procedure shown in FIGS. 21, 22, and 24 is realized, for example, by executing a program stored in advance by the supercharger ECU 50. That is, in the fifth embodiment, the supercharger ECU 50 constitutes “phase control means” and “atomization means” in the present invention.

[Embodiment 6]
In the sixth embodiment, a cooling structure that automatically controls the lubricating oil supply pressure will be described.

FIG. 25 is a diagram illustrating a cooling structure for the electric supercharger according to the sixth embodiment.
25 is compared with FIG. 20, in the cooling structure of the electric supercharger according to the sixth embodiment, the oil reflecting wall 380 protrudes from the inner wall surface 310 of the housing 300, as in the first embodiment (FIG. 2). Provided. The oil reflecting wall 380 is provided in a slit shape as in FIG. As for the oil reflecting wall 380, as shown in FIG. 6 or FIGS. 9B to 9D, the optimum size and shape can be appropriately selected.

  As a result, compared with the cooling structure of FIG. 20 (Embodiment 5), the arrangement of the annular unit 700 and the operation end 600, the link mechanism 605, and the actuator 610 for operating the annular unit 700 is omitted.

  On the other hand, in the sixth embodiment, the lubricating oil supply pressure of the oil pump 690 that supplies the lubricating oil is controlled based on an instruction from the supercharger ECU 50. When engine oil is used as the lubricating oil, a control configuration in which the instruction from the supercharger ECU 50 is reflected in the instruction from the engine ECU 250 that controls the oil pump for the engine oil can be adopted. Since the structure of other parts is the same as in FIG. 20, detailed description will not be repeated.

  By changing the lubricating oil supply pressure by the oil pump 690, the amount of the lubricating oil 400 supplied to the bearing 350 also changes, and accordingly, the diffusion angle of the lubricating oil wound up by the rotation of the shaft 210 and the rotor 340 also changes. Come. Therefore, in the cooling structure for the electric supercharger according to the sixth embodiment, the diffusion of the lubricating oil is performed without fixing the phase of the oil reflecting wall 380, that is, without newly providing a control member such as a link mechanism or an actuator. The cooling state can be adjusted according to the situation by controlling the angle.

  FIG. 26 is a flowchart illustrating automatic control of the lubricating oil supply pressure in the electric turbocharger cooling structure according to the sixth embodiment.

  Referring to FIG. 26, supercharger ECU 50 initially sets counter value n = 1 in step S300, and acquires coil winding temperature Tn of the stator based on the output of temperature sensor 680 in step S310.

  Further, the supercharger ECU 50 changes (increases or decreases) the lubricant supply pressure by a predetermined value in step S320, and increments (+1) the counter value n in step S330.

  When a predetermined time has elapsed from steps S320 and S330, supercharger ECU 50 acquires stator coil winding temperature Tn based on the output of temperature sensor 680 in step S340. Thereby, the coil winding temperature after changing the lubricant supply pressure in step S320 is obtained.

  In step S350, supercharger ECU 50 compares coil winding temperature Tn-1 at the previous lubricating oil supply pressure with coil winding temperature Tn at the current lubricating oil supply pressure. The supercharger ECU 50 recognizes that the change direction of the lubricating oil supply pressure is an appropriate direction for increasing the cooling direction of the coil winding temperature when the coil winding temperature decreases (when YES is determined in step S350). Then, the process returns to step S320 again. Thereby, the lubricating oil supply pressure is further changed by a predetermined value in the same direction.

  On the other hand, when the coil winding temperature has risen after the change in the lubricant supply pressure (when NO in step S350), the supercharger ECU 50 further changes the lubricant supply pressure in the same direction, Recognizing that the winding temperature will rise, maintain the lubricant supply pressure as it is.

  Through a series of processes in steps S300 to S350, the lubricant supply pressure corresponding to the minimum point of the coil winding temperature change with respect to the change of the lubricant supply pressure can be set. That is, it becomes possible to obtain the optimum lubricating oil supply pressure under the current state of the electric supercharger by trial and error.

  Accordingly, by executing a series of processes in steps S300 to S350 each time a predetermined condition such as the passage of a certain period of time, the motor rotation speed, or the change of the coil winding temperature over a certain level is satisfied, based on the actual measurement of the coil winding temperature. The lubricating oil supply pressure is automatically controlled to the optimum cooling value of the coil winding 330, so that the coil winding can be efficiently cooled each time the operating state of the electric supercharger changes. As in FIG. 23, the optimum lubricating oil supply pressure with respect to the operating state of the electric supercharger (typically the rotor rotational speed) is obtained in advance and mapped, so that the modification of the fifth embodiment can be obtained. Similarly, the lubricating oil supply pressure can be set appropriately each time according to the current operating state of the electric supercharger.

  As described above, in the cooling structure of the electric supercharger according to the sixth embodiment, the diffusion angle of the lubricating oil diffused by the shaft 210 and the rotor 340 is controlled by the automatic control of the lubricating oil supply pressure without providing a special actuator. Thus, the optimum cooling state can be automatically obtained. As a result, the cooling effect of the coil winding can be enhanced.

  Note that the processing according to the procedure shown in FIG. 26 is realized, for example, by executing a program stored in advance by supercharger ECU 50. That is, in the sixth embodiment, the supercharger ECU 50 constitutes the “pressure control means” in the present invention.

  In addition, for each of the plurality of embodiments described above, it is confirmed that it can be appropriately combined and executed as necessary unless the combination is structurally or logically inconsistent. To be described.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 is a configuration diagram of an engine system on which an electric supercharger according to an embodiment of the present invention is mounted. It is a figure explaining the cooling structure of the electric supercharger by Embodiment 1 of this invention. FIG. 3 is a perspective view of an inner wall surface of a housing provided with an oil reflecting wall shown in FIG. 2. It is a conceptual diagram explaining the spreading | diffusion state of the lubricating oil in the cooling structure which has not arrange | positioned the oil reflective wall shown as a comparative example. It is a conceptual diagram explaining the spreading | diffusion state of the lubricating oil in the cooling structure by Embodiment 1 which has arrange | positioned the oil reflecting wall. It is a figure explaining the variation of arrangement | positioning of an oil reflecting wall. FIG. 6 is a perspective view of a housing inner wall surface provided with an oil reflecting wall according to a modification of the first embodiment. It is a conceptual diagram which shows the comparison of the spreading | diffusion state of the lubricating oil in Embodiment 1 and its modification. It is a top view explaining the variation of the shape of an oil reflective wall. It is a figure explaining the cooling structure of the electric supercharger by Embodiment 2 of this invention. It is a figure which shows the variation of the cooling structure of the electric supercharger by Embodiment 2. FIG. It is a figure explaining the cooling structure of the electric supercharger by the modification of Embodiment 2 of this invention. It is a figure explaining the cooling structure of the electric supercharger by Embodiment 3 of this invention. It is a front view explaining the shape of the bearing retainer shown in FIG. FIG. 10 is a conceptual diagram illustrating a diffusion state of lubricating oil in a cooling structure according to a third embodiment. It is a figure explaining the cooling structure of the electric supercharger by Embodiment 4 of this invention. It is an enlarged view of the bearing part in FIG. FIG. 10 is a diagram illustrating a cooling structure for an electric supercharger according to a fifth embodiment. It is a perspective view of the annular unit shown in FIG. FIG. 10 is a diagram illustrating a cooling structure for an electric supercharger according to a modification of the fifth embodiment. It is a flowchart explaining the 1st example of the automatic control of the rotation phase (oil reflection wall position) of an annular unit. It is a flowchart explaining the 2nd example of the automatic control of the rotation phase (oil reflection wall position) of an annular unit. It is a conceptual diagram which shows an example of the phase setting map of the oil reflection wall with respect to rotor rotation speed. It is a flowchart explaining the 3rd example of automatic control of the rotation phase (oil reflection wall position) of an annular unit. It is a figure explaining the cooling structure of the electric supercharger by Embodiment 6 of this invention. It is a flowchart explaining the automatic control of the lubricating oil supply pressure by Embodiment 6 of this invention.

Explanation of symbols

20 Low-voltage battery, 30 Converter, 40 High-voltage battery, 50 Supercharger ECU, 60 Supercharger EDU, 100 Engine, 102, 156, 160 Intake passage, 104 Intake valve, 106 Fuel injection injector, 108 Combustion chamber, 110 Spark plug 112 cylinder block, 114 piston, 116 connecting rod, 118 timing rotor, 120 crankshaft, 122 crank position sensor, 124 belt, 126 alternator, 128 exhaust valve, 130 exhaust passage, 150 inlet, 152 air cleaner, 154 air flow meter, 158 Bypass passage, 162 Intercooler, 164 Air bypass valve, 166 Throttle valve, 168 Throttle motor, 170 Intake pipe pressure sensor, 172 Intake temperature sensor, 180 Exhaust pipe, 182 catalyst, 200 electric supercharger, 202 compressor, 204 turbine, 205
Hall sensor, 206 Compressor wheel, 208 Turbine wheel, 210 shaft, 216 Rotating electric machine (motor), 250 Engine ECU, 300 Housing, 305 Lubricating oil path, 306 Cooling water path, 310 Coil winding, 310 Side wall surface (housing), 312 Upper wall surface (housing), 315 region (reaching lubricant), 316 lubricating oil flow path, 317 protrusion, 318 introduction hole, 319 discharge hole, 320 stator core, 330 coil winding, 330 stator core, 335 teeth, 340 rotor, 350
Bearing, 356-358 Opening, 380 Oil reflecting wall, 400, 410-414, 420 Lubricating oil, 600 Operation end, 605 Link mechanism, 610 Actuator, 655 Map, 670 Rotor position sensor, 680 Temperature sensor, 690 Oil pump , 700 annular unit, n counter value, Nt rotor speed, Tn coil winding temperature, W width dimension (oil reflection wall).

Claims (13)

A supercharger configured to compress intake air of the internal combustion engine by rotating using exhaust gas of the internal combustion engine;
A rotating electrical machine having a rotor connected to a rotating shaft of the supercharger and a stator provided to face the rotor from a direction orthogonal to the rotating shaft;
Lubricating oil supply means for supplying lubricating oil to the bearing portion of the rotating shaft;
A part of the lubricating oil provided at a position separated from the rotating shaft and the rotor in a direction perpendicular to the rotating shaft and diffused by a centrifugal force accompanying the rotation of the rotating shaft and the rotor is used for the rotating shaft and the rotor. And a reflecting wall for reflecting toward the
The electric supercharger, wherein the reflecting wall is provided in a shape such that a part of the lubricating oil diffused by the rotation of the rotating shaft and the rotor reaches a coil winding wound around the stator.   The electric supercharger according to claim 1, wherein the reflection wall is provided so as to protrude in a direction that is not parallel to the direction of the rotation axis and approaches the rotation axis.   The reflection wall is provided so that a radial width dimension at a portion relatively far from the coil winding is wider along a direction of the rotation axis than a portion relatively near the coil winding. The electric supercharger according to claim 1. The reflection wall is provided to protrude from a surface in a direction intersecting the rotation axis of an inner wall of a housing that houses the rotating electrical machine,
Of the surface in the direction parallel to the rotation axis of the inner wall of the housing, the direction of the tangent is the rotation axis and the region where the lubricant diffused with the rotation of the rotation axis and the rotor reaches. The electric supercharger according to claim 1, wherein a non-parallel surface portion is provided. A refrigerant path provided inside a housing that houses the rotating electrical machine;
The housing provided with an introduction part for introducing the lubricating oil, an accumulation part for accumulating the introduced lubricating oil, and a discharge part for discharging the accumulated lubricating oil toward the rotating electrical machine; And further comprising an integrally configured lubricating oil container,
The lubricating oil storage unit is configured to exchange heat between the lubricating oil in the storage unit and the refrigerant in the refrigerant path,
The introduction part is provided in a region of the inner wall of the housing where the lubricant oil diffused with the rotation of the rotating shaft and the rotor reaches,
The discharge unit is provided to discharge the lubricating oil toward a portion of the rotating electrical machine that is different from a portion where the lubricant diffused as the rotating shaft and the rotor rotate. The electric supercharger according to claim 1. An annular unit disposed outside the rotating electrical machine and configured to be rotationally movable around the rotation axis by an actuator;
The electric supercharger according to claim 1, wherein the reflecting wall is provided so as to protrude on a surface of the annular unit facing the rotating electrical machine.   The electric supercharger according to claim 6, further comprising a phase control unit that operates the actuator so as to change a rotation phase of the annular unit according to an operating state of the electric supercharger.   The electric supercharger according to claim 7, wherein the phase control means operates the actuator so as to change a rotational phase of the annular unit according to a temperature of the coil winding.   The electric supercharger according to claim 7, wherein the phase control unit operates the actuator so as to change a rotation phase of the annular unit according to a rotation speed of the rotor.   Actuate the actuator so that the annular unit periodically reciprocates in the forward and reverse rotation directions in order to atomize the lubricating oil diffused with the rotation of the rotating shaft and the rotor by the reflecting wall. The electric supercharger according to claim 6, further comprising an atomizing means for causing the electric supercharger.   The electric supercharger according to claim 1, further comprising pressure control means for changing a supply pressure of the lubricating oil by the lubricating oil supply means in accordance with an operating state of the electric supercharger.   In the bearing portion, the lubricating oil flowing out from the bearing portion to the rotating shaft is a region on the opposite side of the rotating direction from the rotating direction region of the rotating shaft across the vertical direction in the circumferential direction of the rotating shaft. The electric supercharger according to any one of claims 1 to 11, wherein the electric supercharger has a structure that is relatively large.   12. The electric overload according to claim 1, wherein a clearance of the bearing portion with respect to the casing of the rotating electrical machine is set larger on a side closer to the rotating electrical machine than on a side far from the rotating electrical machine. Feeder.

Images