JP2016200020A - Cooling structure of supercharger with electric motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiency cool a coil of an electric motor which is attached to a shaft for connecting a compressor of a supercharger to a turbine.SOLUTION: Fig. 4 for explaining a route of an oil pipe 32 is equivalent to one in which a core of a stator 22 indicated in Fig.1 is deployed while attention is paid to a portion of teeth 34. As indicated in the Fig.4, the oil pipe 32 is arranged at a periphery of the portion of the teeth 34 in a one-stroke-of pen shape. Specifically, the oil pipe 32 is arranged in parallel with side faces of the teeth 34, arranged so as to be folded along end faces at the end faces of the teeth 34 at a turbine 14 side (T-side), and also arranged so as to be transited to the end faces of the adjacent teeth 34 while being folded at the end faces of the teeth 34 at a compressor 12 side (C-side). A lubricant flowing in the oil pipe 32 alternately flows at the C-side and the T-side, and is finally discharged from the T-side.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a cooling structure for a supercharger with an electric motor.

  Conventionally, for example, Japanese Unexamined Patent Application Publication No. 2007-309101 discloses a supercharger cooling structure including an electric motor attached to a shaft connecting a compressor and a turbine. An electric motor according to this cooling structure includes a rotor mounted on a shaft, a stator provided so as to surround the rotor, wound with a coil, and a housing for housing the rotor and the stator, and an engine. When the rotation speed is low or the exhaust pressure is low, the shaft is auxiliary rotated by supplying current to the coil and exciting it.

  In addition, the electric motor according to this cooling structure includes an oil passage for flowing lubricating oil in the housing. The lubricating oil flowing through the oil passage is supplied to the shaft, and the supplied lubricating oil scatters in the housing as the shaft rotates and acts as a refrigerant to cool the components of the motor. Here, the oil passage is branched into two in the housing, and an oil scattering portion for scattering the lubricating oil toward the coil is provided at one outlet portion of the branch passage. Therefore, according to this cooling structure, the coil that is heated at the time of current supply can be particularly cooled by the lubricating oil from the oil scattering portion.

JP 2007-309101 A JP 2008-115731 A JP 2008-121466 A

  However, the above-described oil passage is formed on both the compressor side surface and the turbine side surface of the housing, and the turbine side surface thereof is heated by exhaust heat. For this reason, the lubricating oil flowing in the oil passage on the side surface of the turbine is also heated. If the high temperature lubricating oil flows into the oil scattering portion, the temperature of the coil that would otherwise be cooled may be increased by the lubricating oil scattered from here. Further, if the temperature of the coil rises, it becomes easy to reach the heat generation limit temperature of the coil, which causes a problem that the auxiliary rotation time of the shaft by the electric motor is shortened.

  The present invention has been made in view of the above-described problems. That is, it aims at efficiently cooling the coil of the electric motor attached to the shaft which connects the compressor and turbine of a supercharger.

To achieve the above object, the present invention provides a cooling structure for a supercharger with an electric motor,
A rotor mounted on a shaft connecting the turbocharger compressor and turbine;
A stator provided so as to surround the rotor, a plurality of teeth arranged at predetermined intervals along an inner circumference, and extending in a direction parallel to the central axis of the shaft, and wound around each of the teeth. A stator having a plurality of rotated coils;
A housing that houses the rotor and the stator;
An oil passage formed on the compressor side of the housing for supplying lubricating oil to the shaft;
An oil pipe connected to the oil passage, the oil pipe being disposed so as to pass through a side surface of the tooth extending in a direction parallel to the central axis and across all of the end surface on the turbine side of the tooth. When,
It is characterized by providing.

  According to the present invention, the coil can be cooled by heat exchange with the lubricating oil flowing through the oil pipe passing through the side surface of the tooth extending in the direction parallel to the central axis of the shaft. Further, the end portion on the turbine side of the coil can also be cooled by heat exchange with the lubricating oil flowing through the oil pipe arranged so as to cross all of the side surfaces of the teeth on the turbine side. Since the lubricating oil flowing through the oil pipe is supplied from the oil passage on the compressor side of the housing, the influence of the exhaust heat is small, and the temperature is lower than the lubricating oil flowing through the oil passage on the turbine side of the housing. Therefore, compared with the case where lubricating oil is supplied from the turbine side oil passage, the coil of the motor can be efficiently cooled.

It is a figure for demonstrating the schematic structure of the supercharger to which the cooling structure which concerns on embodiment of this invention was applied. FIG. 3 is a diagram for explaining a schematic configuration of a motor 18. FIG. 3 is a diagram for explaining a schematic configuration of a motor 18. FIG. 4 is a diagram for explaining a route of an oil pipe 32. It is a figure for demonstrating schematic structure of the supercharger 40 to which the conventional cooling structure was applied. FIG. 5 is a diagram for explaining another arrangement example of the oil pipe 32. FIG. 5 is a diagram for explaining another arrangement example of the oil pipe 32. FIG. 5 is a diagram for explaining another arrangement example of the oil pipe 32.

  FIG. 1 is a diagram for explaining a schematic configuration of a supercharger to which a cooling structure according to an embodiment of the present invention is applied. A turbocharger 10 shown in FIG. 1 includes a compressor 12 that compresses intake air of an internal combustion engine (not shown) mounted on a vehicle or the like, a turbine 14 that is rotationally driven using the energy of the exhaust gas of the internal combustion engine, A shaft 16 connecting the compressor 12 and the turbine 14 and a rotating electrical machine 18 as an assist motor are provided. Although the rotary electric machine 18 can basically be applied to any type of motor or motor generator, the rotary electric machine 18 is also referred to as a motor 18 below.

  The motor 18 includes a rotor 20 attached to the shaft 16, a stator (such as an electromagnetic steel plate) 22 disposed so as to surround the rotor 20, and a coil 24 wound around the stator 22. It is stored in. An oil passage 30 for supplying lubricating oil (for example, engine oil) to the bearing 28 is formed in the housing 26. The oil passage 30 is formed on both side surfaces of the compressor 12 side (hereinafter also simply referred to as “C side”) and the turbine 14 side (hereinafter also simply referred to as “T side”). The inlet of the T-side oil passage 30 is closed, and both oil passages 30 are connected by a single oil pipe 32 (details will be described later). Lubricating oil flowing through the C-side oil passage 30 is supplied to the T-side oil passage 30 via an oil pipe 32.

  2 to 3 are diagrams for explaining a schematic configuration of the motor 18. “Arrow A” in both figures is a schematic view in the housing 26 as viewed from the direction A in FIG. 1, and “CC” in both figures is in the housing 26 as viewed in the direction CC from “Arrow A”. In these schematic views, “arrow B” in both figures corresponds to a schematic view inside the housing 26 as seen from the direction B in FIG. For convenience of describing the position of the oil pipe 32, the coil 24 is omitted in FIG.

  As shown in FIGS. 2 to 3, a plurality of teeth 34 (six in this embodiment) are formed around the rotor 20 at a predetermined interval. The teeth 34 constitute the core of the stator 22 shown in FIG. 1, and are parallel to the central axis of the rotor 20 (the central axis of the shaft 16) as indicated by “CC” in FIGS. 2 to 3. It is formed to extend in any direction. 2 and 3, an oil pipe 32 is disposed in the longitudinal direction of the side surface of the tooth 34, and the coil 24 is wound so as to cover the oil pipe 32. . 2 and 3, the oil pipe 32 is disposed in the short direction of the end surface on the T side of the tooth 34, and the coil 24 is wound so as to cover the oil pipe 32. ing. On the other hand, as shown in “arrow A” in FIGS. 2 and 3, the coil 24 is wound so as to directly cover the C-side end face of the tooth 34.

  FIG. 4 is a diagram for explaining the path of the oil pipe 32, and corresponds to a diagram in which the core of the stator 22 shown in FIG. As shown in FIG. 4, the oil pipe 32 is arranged in a single stroke around the teeth 34. Specifically, the oil pipe 32 is disposed in parallel with the side surface of the tooth 34. The oil pipe 32 is arranged so as to be folded back along the end surface at the T-side end surface of the tooth 34. Further, the oil pipe 32 is disposed so as to be folded back at the C-side end face of the tooth 34 and transferred to the end face of the adjacent tooth 34. The arrows shown in the figure indicate the flow direction of the lubricating oil by such pipe arrangement. That is, the lubricating oil flowing through the oil pipe 32 flows alternately between the C side and the T side, and is finally discharged from the T side. The discharged lubricating oil flows into the T-side oil passage 30.

  The effect of the cooling structure according to the present embodiment will be described with reference to FIG. FIG. 5 is a diagram for explaining a schematic configuration of a supercharger 40 to which a conventional cooling structure is applied. The basic configuration of the supercharger 40 is the same as that of the supercharger 10 in FIG. However, in the supercharger 40, the oil pipe 32 is not provided, and the T-side oil passage 30 is not closed. That is, the oil passage 30 is independent on the C side and the T side, and the lubricating oil flowing through the C side and T side oil passages 30 is supplied to the bearing 28 separately.

  In FIG. 5, the lubricating oil separately supplied to the bearing 28 from the oil passage 30 on the C side and the T side is scattered in the housing 26 as the shaft 16 rotates (see the arrow in FIG. 5), and acts as a refrigerant. Then, the stator 22 and the coil 24 are cooled. However, as shown in the figure, when heat from the turbine 14 moves and the lubricating oil flowing through the T-side oil passage 30 rises in temperature, the end face of the T-side coil 24 (which should be cooled originally) Hereinafter, the temperature of the “T-side coil end” may increase. Further, if the temperature of the T-side coil end increases, the temperature of the entire coil 24 increases, so that the heat generation limit temperature of the coil 24 is reached, and as a result, the assist time of the shaft 16 by the motor 18 is shortened. Such a problem will occur.

  In this regard, according to the configuration of the supercharger 10 described above, the coil 24 can be cooled by heat exchange with the lubricating oil flowing through the oil pipe 32. Further, the T-side coil end can also be cooled by heat exchange with the lubricating oil flowing through the oil pipe 32 disposed on the T-side end face of the tooth 34. Since the lubricating oil flowing through the oil pipe 32 is supplied from the oil passage 30 on the C side, the influence of the exhaust heat is small and lower than the lubricating oil flowing through the oil passage 30 on the T side of the supercharger 40. is there. Therefore, the temperature of the T-side coil end can be efficiently cooled as compared with the case where the lubricating oil is supplied from the T-side oil passage 30 of the supercharger 40. In addition, the assist time of the shaft 16 by the motor 18 can be extended.

  By the way, in the said embodiment, the one oil pipe 32 was arrange | positioned on the side surface of the teeth 34. FIG. However, the number of oil pipes 32 and the arrangement method thereof are not limited to this, and various modifications are possible. 6 to 8 are diagrams for explaining other arrangement examples of the oil pipe 32. For convenience of explanation, the coil 24 is omitted as in FIG. In the example shown in FIG. 6, one oil pipe 32 is arranged to draw a circle on the end surface on the T side of the tooth 34. FIG. 7 is a view for explaining the path of the oil pipe 32 of FIG. 6 and corresponds to a developed view focusing on the teeth 34 as in FIG. As shown in FIG. 7, the oil pipe 32 is disposed in parallel with one of the side surfaces of the teeth 34, and the end surface on the T side of the teeth 34 is disposed along all the end surfaces. The arrows shown in the figure indicate the flow direction of the lubricating oil by such pipe arrangement. That is, the lubricating oil flowing through the oil pipe 32 flows from the C side to the T side, does not return to the C side, flows along the T side end surface of the teeth 34, and is finally discharged from the T side.

  FIG. 8 is a view for explaining the path of other oil pipes 32. 8 (a) to 8 (c), one oil pipe 32 is disposed in parallel with a part of the side surface of the tooth 34, and is folded back at a part of the end surface on the C side of the tooth 34 so as to be adjacent. It arrange | positions so that it may move to the end surface of the teeth 34 of this. In FIG. 8D, six oil pipes 32 are arranged in parallel with the side surfaces of all the teeth 34. 8E to 8H, two or three oil pipes 32 are arranged in parallel to the side surface of the tooth 34. As shown in these drawings, as long as the oil pipe 32 is disposed in parallel with a part of the side surface of the tooth 34 and the oil pipe 32 is disposed along the entire end surface on the T side of the tooth 34. The number of oil pipes 32 and the arrangement method thereof can be variously modified.

10, 40 Supercharger 12 Compressor 14 Turbine 16 Shaft 18 Rotating electric machine (motor)
20 Rotor 22 Stator 24 Coil 26 Housing 28 Bearing 30 Oil passage 32 Oil pipe 34 Teeth

Claims (1)

A rotor mounted on a shaft connecting the turbocharger compressor and turbine;
A stator provided so as to surround the rotor, a plurality of teeth arranged at predetermined intervals along an inner circumference, and extending in a direction parallel to the central axis of the shaft, and wound around each of the teeth. A stator having a plurality of rotated coils;
A housing that houses the rotor and the stator;
An oil passage formed on the compressor side of the housing for supplying lubricating oil to the shaft;
An oil pipe connected to the oil passage, the oil pipe being disposed so as to pass through a side surface of the tooth extending in a direction parallel to the central axis and across all of the end surface on the turbine side of the tooth. When,
A cooling structure for a supercharger with an electric motor.

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