JP6324469B2 - Cooling structure of rotating electric machine - Google Patents

Description

  The present invention relates to a cooling structure for a rotating electrical machine that uses cooling oil to cool a heat generating portion.

  In many cases, a rotating electrical machine for driving a vehicle or for assisting an engine is disposed between an engine and a transmission, and a thin flat structure is often employed in accordance with the mounting environment. In this type of rotating electrical machine, the amount of heat generated increases when the coil wound around the stator core is energized, and therefore many structures using various cooling methods such as water cooling and oil cooling are employed.

In Patent Document 1, in a rotating electrical machine that cools by supplying a cooling liquid from above the coil end, the cooling fluid is supplied from the two supply pipes at the same flow rate when the rotating electrical machine is at a low speed, and downstream at a high speed. The supply flow rate from the upstream supply pipe is made larger than the supply flow rate from the supply pipe. Thus, a method is described in which the influence of the swirling flow caused by the rotation of the rotor is reduced, and the deviation in the supply flow rate of the cooling liquid is reduced.
Further, in Patent Document 2, a hole and a groove constituting a cooling oil passage are formed on the left mating surface of the housing by contact, the hole has a supply hole extending in the axial direction, and the groove is in the circumferential direction. And a plurality of notches cut out on the inner peripheral wall facing the distribution groove, and cooling oil drops from the plurality of notches to the coil end are described. ing.

JP 2013-169058 A JP 2014-225969 A

  The above-mentioned patent document 1 aims to improve the cooling state by optimizing the amount of cooling oil scraped and the amount of supplied cooling oil when the rotor rotates, but there are two mechanisms for controlling the oil amount. Since this is necessary, an additional mechanism such as a cooling pipe or an oil pump is required, resulting in an increase in the cost of parts.

  Further, in Patent Document 2, a hole and a groove constituting a cooling oil passage are formed on the left mating surface of the housing by contact, the hole has a supply hole extending in the axial direction, and the groove is in the circumferential direction. And a plurality of cutouts that cut out the inner circumferential wall facing the distribution groove, and cooling oil drops from the plurality of cutouts to the coil ends. In order to realize such a structure, it is necessary to perform complicated processing on the housing, and there is a problem that the processing cost is greatly increased.

  An object of the present invention is to improve the cooling performance without providing a complicated mechanism by adjusting the amount of cooling oil flowing into the housing with a simple structure.

  A cooling structure for a rotating electrical machine according to the present invention includes a stator in which a plurality of divided cores and coils wound around the divided cores are integrated by a hollow frame, and a power feeding that extends radially from the stator and protrudes obliquely upward. In a rotating electrical machine having a terminal, a housing disposed on the outer peripheral side of the stator and having a cooling oil supply port, and a rotor disposed in the stator and discharging cooling oil from the inside in a radial direction by rotation thereof, A flow path is formed in which the gap between the inner peripheral portion of the housing and the outer periphery of the frame is gradually enlarged from the position where the cooling oil is supplied from the upper cooling oil supply port toward the vicinity of the power supply terminal. In addition, in the vicinity of the power supply terminal, the flow path is provided with an opening that is further enlarged in the radial direction in the direction in which the power supply terminal extends. It is.

  According to the present invention, more cooling oil flows into the vicinity of the power supply terminal, and it becomes possible to suppress a local increase in coil temperature, and it is possible to effectively cool a power supply terminal having a high current density. Become.

It is a perspective view which shows the whole structure of the rotary electric machine which concerns on this invention. It is a front view which shows the whole structure of Embodiment 1 which concerns on this invention. It is a perspective view which shows the opening part of the electric power feeding terminal vicinity of Embodiment 1 which concerns on this invention. It is a front view which shows the whole structure of Embodiment 2 which concerns on this invention. It is a graph which shows the temperature of the coil of the up-down and left-right direction of the stator of the rotary electric machine which concerns on this invention. It is sectional drawing which shows the state of the electric power feeding terminal vicinity of the rotary electric machine which concerns on this invention.

FIG. 1 is a perspective view showing a configuration of a rotating electrical machine according to an embodiment of the present invention. As shown in FIG. 1, the rotating electrical machine includes a stator 1 and a rotor 2. A rotor core made of laminated steel plates is disposed on the outer peripheral side of the rotor 2, and a permanent magnet is disposed therein. In addition, the stator 1 is configured by press-fitting a stator core that is also formed of a laminated steel plate on the inner periphery. A predetermined gap is provided between the inner periphery of the stator core and the outer periphery of the rotor core facing the stator core. In addition, a power distribution component is disposed on the end face of the stator core.
Power is supplied from an external harness to the coil wound around the core of the stator 1 via this power distribution component, and the rotor 2 is driven by generating a rotating magnetic field, and the generated torque is transmitted to the drive shaft. It is a mechanism. The stator 1 and the rotor 2 are respectively disposed inside the housing 5.

  As shown in FIG. 1, the stator 1 of the rotating electrical machine of the present invention is configured such that a coil wound in a concentrated manner is stored in a slot formed with a plurality of stator cores aligned. The stator 1 is formed to protrude from the end face of the stator core and constitutes a coil end 11 having a curved shape. The stator 1 around which the coil is wound is integrated by being press-fitted into a frame 12 having a hollow inside. A housing 5 for storing the rotating electrical machine is provided on the outer periphery of the stator 1.

Embodiment 1 FIG.
A first embodiment of the present invention will be described with reference to FIGS. FIG. 2 is a front view showing the overall configuration of the cooling structure for the rotating electrical machine in the first embodiment. FIG. 3 is a perspective view showing an opening near the power supply terminal in the first embodiment.
A cooling structure in the rotating electric machine will be described. There are two mechanisms for supplying the cooling oil, one is a means for ejecting the cooling oil in the radial direction by centrifugal force from the inside of the rotor 2, and the other is an upper portion of the stator 1 as shown in FIG. This is means for cooling the entire outer periphery of the stator 1 by supplying cooling oil from the supply port 8 of the housing 5 as indicated by an arrow A. The cooling oil is stored in a cooling oil reservoir 14 provided at the lower portion of the motor and then discharged to the outside.

  The housing 5 has a uniform space between its inner periphery and the outer periphery of the frame 12 over a wide range. However, as shown by the arrow B indicating the path of the cooling oil 13 in FIG. A flow path that is more open as it goes to the vicinity of the terminal 3 is configured, so that a larger amount of the cooling oil 13 that has entered from the cooling oil supply port 8 flows into the power supply terminal 3 side. Furthermore, as shown in the perspective view of FIG. 3, the opening 6 is greatly enlarged in the radial direction in the direction in which the power supply terminal 3 extends, and has a structure in which more cooling oil flows.

  As indicated by the arrow C on the rotor 2, the range in which the cooling oil is swept up by the rotation of the rotor 2 does not reach the upper part of the motor, so the coil temperature is relatively high in the range near the power supply terminal 3. Although there is a tendency, a large amount of cooling oil is introduced by providing the opening 6 for the above, and a local increase in coil temperature can be suppressed. This also makes it possible to effectively cool the power supply terminal 3 having a high current density.

The cooling structure for a rotating electrical machine according to the first embodiment of the present invention includes a stator 1 in which a plurality of divided cores and coils wound around the divided cores are integrated by a hollow outer peripheral frame 12, and a radial direction from the stator 1. A power supply terminal 3 disposed above the rotating electrical machine extending in a diagonally upward direction, a housing 5 disposed on the outer peripheral side of the stator 1 and having a cooling oil supply port 8, and disposed in the stator 1. In a rotating electrical machine having a rotor 2 that discharges cooling oil from the inside in the radial direction by rotation, the position near which the cooling oil is supplied from the cooling oil supply port 8 at the top of the housing 5 is close to the power supply terminal 3. A gap is formed in which the gap between the inner periphery of the housing 5 and the outer periphery of the frame 12 is gradually enlarged as it goes toward the power supply terminal 3. , The channel is characterized in that an opening 6 which is the feeding terminal 3 are enlarged radially further in the direction of stretching.
In a rotating electrical machine that performs cooling in oil, the coil temperature may vary in the cooling state in the circumferential direction due to the effect of being swept up by the rotation of the rotor. The reason is that there is a part where the cooling oil swept up by the rotation of the rotor is less scattered to the coil. The temperature that is relatively high is in the range where the cooling oil does not reach, and the current that can be energized is increased by uniformly distributing the cooling oil from above to the range so that the cooling state is uniform. , Can increase the maximum output performance. However, if a complicated mechanism is used for distributing the supply from the top, the structure becomes complicated and the cost increases. On the other hand, according to the configuration in the first embodiment of the present invention described above, the opening 6 for storing the power supply terminal 3 is provided in the outer housing 12, and the amount of the cooling oil flowing in is increased. It is possible to improve the cooling performance without providing a simple mechanism and securing the necessary mounting range of structural parts.
That is, the range in which the cooling oil is lifted up by the rotation of the rotor does not reach the upper part of the motor, so the coil temperature tends to be relatively high in the range near the power supply terminal. By providing an opening that gradually widens toward the power supply terminal near the terminal, a large amount of cooling oil flows in, which facilitates the inflow of cooling oil to the vicinity of the power supply terminal and suppresses a local rise in coil temperature. It becomes possible. This also makes it possible to effectively cool a power supply terminal having a high current density.

Embodiment 2. FIG.
A second embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a front view showing the overall configuration of the rotating electrical machine cooling structure according to the second embodiment. FIG. 5 is a graph showing the coil temperatures in the vertical and horizontal directions of the stator of the rotating electrical machine according to the present invention. FIG. 6 is a cross-sectional view showing a state in the vicinity of the power supply terminal of the rotating electrical machine according to the present invention.
As shown in FIG. 4, if the cooling oil that has passed through the opening 6 in the vicinity of the power supply terminal 3 is configured to become narrower again as shown by the arrow D on the downstream side, the cooling oil is added to the narrowed portion. It is possible to suppress a temperature rise at a location where the coil temperature is likely to rise, in particular, due to retention. Such narrowing of the flow path can be realized by means such as providing a guide plate made of an insulating material.

  FIG. 5 shows the results of a coil temperature rise test of a rotating electrical machine when the present invention is implemented. When the opening 6 is provided, the overall coil temperature is reduced, and the distribution of the coil temperature on the upper, lower, left, and right sides is made more uniform, and the rated output can be improved.

  Further, as shown in FIG. 6, since the power feeding terminal 3 is configured at a position that does not overlap the outer peripheral side of the frame 12 in the axial direction, when the cooling oil 13 flows through the outer peripheral portion, the current flows by the power feeding terminal 3 itself. Thus, the cooling performance of the entire stator 1 can be improved. Furthermore, the cooling oil distribution structure using the opening 6 described above can be used more effectively.

In the cooling structure for a rotating electrical machine according to the second embodiment of the present invention, in the configuration of the first embodiment described above, the gradually expanded flow path is formed on the housing on the downstream side of the opening 6. 5 is configured such that the width of the flow path formed by the inner circumference of 5 and the outer circumference of the frame 12 is narrowed.

In the rotating electrical machine cooling structure according to the second embodiment of the present invention, in the configuration of the first embodiment described above, the feeding terminal 3 is arranged at a position that does not overlap the outer peripheral frame 12 in the rotation axis direction. It is characterized by being.
With this configuration, when the cooling oil 13 flows around the outer peripheral portion, the cooling performance of the entire stator 1 can be improved without significantly hindering the flow by the power supply terminal 3 itself, and the opening 6 is used. The cooling oil distribution structure can be used more effectively. Further, the cooling effect in the axial direction by the cooling flow path in the vicinity of the power supply terminal 3 is at a position where the coil end side can be cooled, so that the cooling effect can be enhanced.

Embodiment 3 FIG.
Embodiment 3 according to the present invention will be described with reference to FIGS. 2, 4 and 6 described above.
The power feeding terminal 3 is disposed in the opening 6 as a component of the motor of the present invention. However, as shown in FIGS. A small opening 7 is provided, and auxiliary wiring composed of low voltage wiring 4 such as a temperature sensor is stored in the small opening 7.

  Normally, these parts are often configured outside the motor configuration range, and there are cases where measures such as providing a protrusion on the housing side are necessary to secure the mounting range. Therefore, the opening 6 and the small opening 7 provided for this purpose can be used for the mounting range of the power supply terminal 3 and the low-voltage wiring 4, respectively. Thus, by optimizing the amount of cooling oil with a simple structure, the entire cooling performance can be made uniform.

Space can be used effectively by using the power supply terminal 3 of the motor and the low voltage wiring 4 such as a temperature sensor in each opening.
Further, as shown in FIG. 6, since the opening 6 of the housing extends over the entire area of the frame 5 in the axial direction, more cooling oil can be supplied, and the cooling performance can be further improved.

The cooling structure for a rotating electrical machine according to the third embodiment of the present invention is the power feeding terminal 3 with respect to a vertical plane passing through the central axis of the opening 6 in the configuration of the first or second embodiment. A small opening in which an auxiliary wiring composed of a low voltage wiring 4 used for a temperature sensor or the like is applied by applying a voltage lower than that of the main power supply wiring to which the motor driving voltage applied to the power supply terminal 3 is supplied. 7 is provided.
With this configuration, it is possible to effectively use the space by using each opening portion including the opening portion 6 and the small opening portion 7 as an arrangement position of the auxiliary wiring including the low voltage wiring 4 such as the power supply terminal 3 of the motor and the temperature sensor. .

The rotating electrical machine cooling structure according to the third embodiment of the present invention is the same as that of the first embodiment, the second embodiment, or the previous section, in which the opening 6 of the housing 5 is the shaft of the frame 12. It is characterized by extending over the entire direction.
With this configuration, the opening of the housing 5 extends over the entire area of the frame 12 in the axial direction, so that more refrigerant is supplied and the cooling performance can be improved.

  It should be noted that within the scope of the present invention, a part or all of each embodiment can be freely combined, or each embodiment can be appropriately modified or omitted.

DESCRIPTION OF SYMBOLS 1 Stator, 2 Rotor, 3 Feeding terminal, 4 Low voltage wiring, 5 Housing, 6 Opening part, 7 Small opening part, 8 Cooling oil supply port, 11 Coil end, 12 Frame, 13 Cooling oil, 14 Cooling oil pool, 20 Center A vertical plane that passes through an axis.

Claims (5)

  A stator in which a plurality of split cores and a coil wound around the split core are integrated by a hollow frame, a power supply terminal extending radially from the stator and projecting obliquely upward, and arranged on the outer peripheral side of the stator In a rotating electrical machine having a housing having a cooling oil supply port and a rotor disposed in the stator and discharging cooling oil from the inside in a radial direction by rotation thereof, the cooling oil is supplied from the cooling oil supply port at the top of the housing. Forming a flow path in which the gap between the inner periphery of the housing and the outer periphery of the frame is gradually enlarged toward the vicinity of the power supply terminal from the position where the power is supplied, and in the vicinity of the power supply terminal, A cooling structure for a rotating electrical machine, wherein the flow path is provided with an opening that is further expanded in a radial direction in a direction in which the power supply terminal extends. The gradually expanded flow path is configured such that a flow path width formed by an inner periphery of the housing and an outer periphery of the frame is narrower on the downstream side of the opening. A cooling structure for a rotating electrical machine according to claim 1.   The cooling structure for a rotating electrical machine according to claim 1, wherein the power supply terminal is disposed at a position that does not overlap the frame in a rotation axis direction.   The small opening part by which a low voltage | pressure wiring is arrange | positioned on the opposite side to the said electric power feeding terminal with respect to the perpendicular plane which passes along the central axis of the said opening part is provided. Cooling structure for rotating electrical machines.   The cooling structure for a rotating electrical machine according to any one of claims 1 to 4, wherein the opening of the housing extends over the entire axial direction of the frame.

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