JP2015198515A - motor structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor structure in which a motor is appropriately cooled.SOLUTION: A motor structure S includes: a motor 1 including a rotor 11 and an annular stator core 12; a cylindrical stator holder 2 holding the stator core 12; a cylindrical motor housing 2 including a cooling water flow channel 3a and surrounding an outer circumferential surface of the stator holder 2; and a resin member 4 interposed between the stator holder 2 and the motor housing 3. A linear expansion coefficient of the motor housing 3 is greater than a linear expansion coefficient of the stator holder 2, and the resin member 4 is a thermosetting resin that is thermally set at a temperature higher than a temperature upper limit value of cooling water with drive of the motor 1, and is filled into a gap between the stator holder 2 and the motor housing 3 and is set.

Description

  The present invention relates to a motor structure including a motor.

An inner rotor type motor is known in which a rotor is arranged on the radial inner side of a stator. For example, this motor generates a rotating magnetic field by supplying three-phase AC power via a coil wound around a stator core, and rotates the rotor.
Incidentally, since the motor generates heat due to copper loss and iron loss during driving of the motor, it is required to release the generated heat to the outside and keep the motor at an appropriate temperature.

  For example, Patent Literature 1 describes a cylindrical case that has a cooling passage through which cooling water flows and is disposed on the radially outer side of the stator core. The inner peripheral surface of the case and the outer peripheral surface of the stator core are in surface contact, and heat generated by the motor is sequentially dissipated to the stator core, the case, and the cooling water.

JP 2012-1000052 A1

In the technique described in Patent Document 1, an undivided integrated stator core (made of iron) and a case (made of aluminum) arranged on the radially outer side of the stator core are in contact as described above.
Here, the linear expansion coefficient representing the degree of expansion / contraction with respect to temperature change differs between iron, which is a constituent material of the stator core, and aluminum, which is a constituent material of the case. That is, since aluminum has a larger linear expansion coefficient than iron, the case described above is easier to expand and contract than the stator core.

Then, in the technique described in Patent Document 1, there is a possibility that a gap is generated between the case and the stator core at a high temperature, or excessive stress is generated in each member at a low temperature, so that the heat dissipation of the motor may not be performed appropriately. There is sex.
It is conceivable that the case is also made of iron in accordance with the stator core, and the linear expansion coefficient of both is the same. However, in this case, there is a problem that the weight of the case is increased and the weight of a vehicle or the like on which the motor is mounted is increased.

  Then, this invention makes it a subject to provide the motor structure which cools a motor appropriately.

  As means for solving the above problems, a motor structure according to the present invention includes a motor having a rotor, an annular stator core disposed on the radially outer side of the rotor, and holding the stator core. A cylindrical stator holder whose peripheral surface is in close contact with the outer peripheral surface of the stator core, a cylindrical housing having a refrigerant flow path through which refrigerant flows, and surrounding the outer peripheral surface of the stator holder, the stator holder, and the housing A linear expansion coefficient of the housing is larger than a linear expansion coefficient of the stator holder, and the resin member is more than a temperature upper limit value of the refrigerant accompanying the driving of the motor. Is a thermosetting resin that is thermoset at a high temperature, and is filled and cured between the stator holder and the housing.

  According to such a configuration, the resin member filled between the stator holder and the housing (gap) is thermally cured at a temperature higher than the temperature upper limit value of the refrigerant accompanying the driving of the motor. Here, as the “temperature upper limit value” of the refrigerant, for example, the temperature at which the rated operation of the motor is continued and the temperature rise of the refrigerant flowing through the refrigerant channel converges can be used. When the refrigerant boils as the rated operation continues, the boiling point of the refrigerant is set to the “temperature upper limit value”.

Since the linear expansion coefficient of the housing is larger than the linear expansion coefficient of the stator holder, an annular gap between the stator holder and the housing is widened during thermosetting, and the thermosetting resin is thermoset in this state. The
After the above-described thermosetting, the temperature of the refrigerant (that is, the temperature of the housing, the resin member, and the stator holder) becomes lower than the upper temperature limit value of the refrigerant. Further, due to the magnitude relationship of the linear expansion coefficient, the degree of contraction accompanying the temperature drop is greater in the housing than in the stator holder. Then, since the distance (radial direction) between the stator holder and the housing is reduced as compared with that during thermosetting during the driving of the motor, the resin member is always compressed by the stator holder and the housing.

  That is, even if the distance between the housing and the stator holder changes due to the difference in linear expansion coefficient, the resin member follows this change and keeps in close contact with the housing and the stator holder. Further, the outer peripheral surface of the stator core and the inner peripheral surface of the stator holder are in close contact with each other. Therefore, the heat generated by the motor is radiated to the refrigerant flowing through the refrigerant flow path via the stator holder, the resin member, and the housing. Thus, by interposing a resin member between the housing and the stator holder, the heat conductivity of the motor structure can be increased and the motor can be appropriately cooled.

  In addition, the outer diameter of the stator holder, so that the compression rate of the resin member is less than the fracture compression rate of the resin member at the lower temperature limit value of the refrigerant set based on the environmental temperature of the cold region, and It is preferable that an inner diameter of the housing is set.

  According to such a configuration, it is possible to prevent the resin member from being excessively compressed exceeding the fracture compression ratio and being damaged, and as a result, it is possible to suppress a decrease in the cooling performance of the motor structure. In addition, the “temperature lower limit value” of the refrigerant is appropriately set in consideration of a case where the motor is used in a low temperature environment such as an air temperature of −40 ° C., for example.

  Moreover, it is preferable that the linear expansion coefficient of the stator holder is substantially equal to the linear expansion coefficient of the stator core, and the material constituting the housing is aluminum.

According to such a configuration, since the linear expansion coefficient of the stator holder is approximately equal to the linear expansion coefficient of the stator core, the degree of expansion / contraction of both becomes equal with the temperature change. Therefore, the stress acting on the stator core and the stator holder can be suppressed.
Further, since the housing is made of aluminum lighter than the steel plate (iron), the weight of the motor structure can be made relatively small.

  The stator core preferably includes a plurality of divided cores arranged in an annular shape.

  According to such a configuration, the plurality of divided cores are held by the stator holder in a state of being arranged in an annular shape. Further, for example, the split core may be fixed to the stator holder by press-fitting, and it is not necessary to polish the outer peripheral surface of the split core. Furthermore, as described above, since the resin member is interposed between the stator holder and the housing, it is not necessary to polish the inner peripheral surface of the housing. Therefore, the manufacturing process of the motor structure can be simplified.

  Moreover, it is preferable that a heat conductive additive is added to the thermosetting resin.

  According to such a configuration, since the heat conductive additive is added to the thermosetting resin, the heat conductivity between the stator holder and the housing is increased, and thus the cooling performance of the motor structure is improved. Can do.

  ADVANTAGE OF THE INVENTION According to this invention, the motor structure which cools a motor appropriately can be provided.

It is a sectional side view of the motor structure concerning one embodiment of the present invention. It is a front view of a motor structure in the state where a sensor housing was removed. It is a disassembled perspective view of a motor structure. (A) is explanatory drawing which shows the relationship between the outer diameter of a stator holder in this embodiment, the thickness of a resin member, the internal diameter of a motor housing, and the temperature of each member, (b) is a stator in a comparative example. It is explanatory drawing which shows the relationship between the outer diameter of a holder, the internal diameter of a motor housing, and the temperature of each member.

<Embodiment>
<Configuration of motor structure>
FIG. 1 is a side sectional view of a motor structure according to the present embodiment. The motor structure S supplies three-phase AC power to the winding C wound around the stator core 12 to rotate the rotor 11 and cool the motor 1. For example, the motor structure S is mounted on a hybrid vehicle.
The motor structure S includes a motor 1 having a rotor 11 and a stator core 12, a cylindrical stator holder 2 that holds the stator core 12, a cylindrical motor housing 3 that surrounds the outer peripheral surface of the stator holder 2, and a stator holder 2. And a resin member 4 interposed between the motor housing 3 and the motor housing 3.

(motor)
The motor 1 includes a rotor 11 and an annular stator core 12 disposed on the radially outer side of the rotor 11.
The rotor 11 is formed by laminating a plurality of magnetic steel plates in the axial direction (direction along the central axis X of the motor 1), and has a cylindrical shape. Near the radial center of the rotor 11, a hole h1 into which the cylindrical motor shaft F is press-fitted is formed along the axial direction. A plurality of permanent magnets M (see FIG. 2) are embedded near the outer peripheral edge of the rotor 11.
Near both ends of the motor shaft F protrudes from the rotor 11, and bearings R1, R2 are installed at the protruding portions.

FIG. 2 is a front view of the motor structure with the sensor housing removed.
The stator core 12 has a plurality of divided cores 121 arranged in an annular shape, and is arranged on the radially outer side of the rotor 11. The split core 121 includes a yoke 121a that has a fan shape when viewed from the front, and a tooth 121b that extends radially inward from the yoke 121a, and is configured by laminating plate-shaped magnetic steel plates along the axial direction. The
In the state where the divided cores 121 are arranged in an annular shape, the yokes 121a adjacent in the circumferential direction are in close contact with each other. On the other hand, the teeth 121b adjacent in the circumferential direction are separated by a predetermined interval so that the winding C wound around each tooth 121b does not interfere.

  The stator core 12 is configured by winding the winding C around the teeth 121b of each of the split cores 121 (for example, concentrated winding), closely contacting the yoke 121a in the circumferential direction, and arranging the split cores 121 in an annular shape. Since the winding C can be wound before the split core 121 is assembled in this way, a relatively large diameter winding C can be wound around the teeth 121b, or the space factor of the winding C can be increased. . That is, the copper loss of the motor 1 can be reduced by using the split stator core 12.

(Stator holder)
FIG. 3 is an exploded perspective view of the motor structure. As will be described later, the resin member 4 shown in FIG. 3 is formed by pouring a liquid silicone resin between the stator holder 2 and the motor housing 3 and thermosetting the resin. It is substantially integrated with the housing 3.
The stator holder 2 is a member that holds the stator core 12 and has a cylindrical shape. The stator holder 2 has a cylindrical portion 2 a whose inner peripheral surface is in close contact with the outer peripheral surface of the stator core 12, and a flange portion 2 b that is abutted against the front wall of the motor housing 3.

The cylindrical portion 2a has a relatively thin cylindrical shape, and a stator core 12 in which a plurality of divided cores 121 are annularly arranged is press-fitted into the cylindrical portion 2a. That is, the outer peripheral surface of the stator core 12 and the inner peripheral surface of the cylindrical portion 2a are in close contact.
The length of the cylindrical portion 2a in the axial direction is set so that the outer peripheral surface (entire surface) of the stator core 12 can be in close contact with the inner peripheral surface of the cylindrical portion 2a. Thereby, the heat transfer area between the cylindrical portion 2a and the stator core 12 can be ensured to the maximum.

  The stator holder 2 is preferably formed of a material (for example, iron) common to the stator core 12. As a result, the stator core 12 and the stator holder 2 expand to the same extent at high temperatures, and the stator core 12 and the stator holder 2 contract to the same extent at low temperatures, so that the close contact state between them is maintained.

The flange portion 2b is a portion that abuts against the front wall of the motor housing 3, and extends radially outward from the front end of the cylindrical portion 2a. When the stator holder 2 is inserted into the opening H of the motor housing 3, the flange portion 2 b comes into contact with the vicinity of the edge of the opening H, and the movement of the stator holder 2 is restricted.
When the stator core 12 is attached to the motor housing 3, the flange portion 2b is provided with a plurality (five) of insertion holes h2 through which the bolts B are inserted. In addition, the location where the insertion hole h2 is provided in the circumferential direction among the flange portions 2b extends radially outward from the other locations.

(Motor housing)
The motor housing 3 (housing) accommodates the motor 1 and the stator holder 2 and has a cylindrical shape.
The inner diameter of the motor housing 3 is slightly larger than the outer diameter of the cylindrical portion 2 a of the stator holder 2, and the motor housing 3 surrounds the outer peripheral surface of the stator holder 2. That is, a cylindrical space is provided between the inner peripheral surface of the motor housing 3 and the outer peripheral surface of the stator holder 2. This cylindrical space is filled with a silicone resin that is a constituent material of the resin member 4 to be described later.

The motor housing 3 is made of aluminum, for example. Thus, the motor structure S can be reduced in weight by using the motor housing 3 made of aluminum.
The stator holder 2 is made of iron as described above. That is, since the linear expansion coefficient of aluminum (about 22 [ppm / K]) is larger than the linear expansion coefficient of iron (about 12.1 [ppm / K]), the motor housing 3 and the stator holder 2 The distance becomes larger.
Therefore, in the present embodiment, a resin member 4 described later is interposed between the motor housing 3 and the stator so that the heat transfer between the motor housing 3 and the stator holder 2 is maintained in a high state regardless of the temperature change. It was made to intervene.

In the motor housing 3, a female screw h <b> 3 that engages with the bolt B described above is provided at a location corresponding to the flange portion 2 b.
Further, the motor housing 3 has a cooling water passage 3a (refrigerant passage) through which cooling water (refrigerant) flows. The cooling water flow path 3a is formed so that the cooling water reaches the entire motor housing 3 (axial direction and circumferential direction).

A tube joint J1 is installed at the inlet of the cooling water passage 3a, and a tube joint J2 is installed at the outlet. And a cooling water pump (not shown) drives, and cooling water is pumped through the cooling water flow path 3a.
The cooling water flowing through the cooling water flow path 3a absorbs heat from the stator holder 2 and rises in temperature, and the raised cooling water is discharged to the outside through the tube joint J2. As a result, the motor 1 can be dissipated and cooled to keep the motor 1 at an appropriate temperature.

(Resin member)
As described above, the resin member 4 is a thermosetting resin that fills a cylindrical space between the stator holder 2 and the motor housing 3. In order to make the explanation easy to understand, in FIG. 1, the thickness of the resin member 4 (for example, less than 1 mm) is shown to be thicker than the actual thickness.
The resin member 4 is formed by pouring a liquid resin (for example, silicone resin) between the stator holder 2 and the motor housing 3 and heating and curing the resin.

As the resin member 4, it is preferable to use a material that is thermally cured at a temperature (curing temperature T _sol : see FIG. 4) higher than the temperature upper limit value T _Max (see FIG. 4) of the cooling water flowing through the cooling water channel 3a. . As the above-mentioned “temperature upper limit value T _Max ”, for example, the temperature when the rated operation of the motor 1 is continued and the temperature rise of the cooling water converges can be used.
In this embodiment, the boiling point of the cooling water (boiling point 120 ° C. during pressurization) is used as the “temperature upper limit value T _Max ” of the cooling water. Further, as the resin member 4, a silicone resin that is thermoset at 150 ° C. higher than the boiling point of the cooling water was used.

As described above, since the aluminum motor housing 3 is more easily expanded and contracted than the iron stator holder 2, the stator holder 2 and the motor housing 3 are at a curing temperature T _sol that is higher than when the motor 1 is driven. The distance (gap) is relatively large. In this state, the resin member 4 is formed by thermosetting the liquid resin poured into the gap between the stator holder 2 and the motor housing 3.

  When the distance between the stator holder 2 and the motor housing 3 is reduced with the subsequent temperature decrease, the resin member 4 is compressed by both. Accordingly, the inner peripheral surface of the resin member 4 is in close contact with the outer peripheral surface of the stator holder 2 regardless of the temperature change of the motor 1, and the state in which the outer peripheral surface of the resin member 4 is in close contact with the inner peripheral surface of the motor housing 3 can be maintained. .

  In addition, it is preferable to improve the heat conductivity of the resin member 4 by adding a heat conductive additive (for example, silver, aluminum, platinum) to the liquid silicone resin. As a result, the thermal conductivity between the stator holder 2 and the motor housing 3 can be enhanced, and consequently the cooling performance of the motor structure S can be enhanced.

Further, the outer diameter of the stator holder 2 and the motor are set so that the compression rate of the resin member 4 is less than the fracture compression rate at the lower limit value T _min (see FIG. 4) of the cooling water flowing through the cooling water flow path 3a. It is preferable to set the inner diameter of the housing 3. The aforementioned “temperature lower limit value T _min ” is set in advance in consideration of the possibility that the motor structure S is used in a cold region (for example, an air temperature of −40 ° C.).

In a cold region where the environmental temperature is low, the shrinkage of the motor housing 3 made of aluminum becomes significant, and the force for compressing the resin member 4 interposed between the stator holder 2 and the motor housing 3 also increases.
As described above, the resin member 4 is broken and damaged by setting the outer diameter of the stator holder 2 and the inner diameter of the motor housing 3 (that is, setting the clearance between the stator holder 2 and the motor housing 3). Can be prevented.

(Other equipment)
The sensor housing G1 houses a sensor A for detecting the rotation angle of the rotor 11, and the gear housing G2 houses a speed reducer (not shown) that transmits power from the motor shaft F. The sensor housing G <b> 1 is installed on the front side of the motor housing 3, and the gear housing G <b> 2 is installed on the rear side of the motor housing 3.

<Assembly procedure of motor structure>
The winding C is wound around the teeth 121b of each divided core 121 (see FIG. 2), and the divided core 121 is annularly arranged in the circumferential direction to constitute the stator core 12. In this state, the yoke 121a of the split core 121 is in close contact with another yoke 121a adjacent in the circumferential direction.
Next, the stator core 12 is press-fitted into the stator holder 2 while pressurizing the stator core 12 in the axial direction by a press-fitting machine (not shown). As a result, the stator core 12 is held by the stator holder 2 with its outer peripheral surface being in close contact with the inner peripheral surface of the stator holder 2.

  Next, the stator holder 2 holding the stator core 12 is installed in the motor housing 3. That is, the insertion hole h2 (see FIG. 3) of the stator holder 2 and the female screw h3 (see FIG. 3) of the motor housing 3 are aligned in the circumferential direction, and the stator holder 2 is assembled to the motor housing 3 from the front side. Then, the flange portion 2b of the stator holder 2 comes into contact with the front wall (near the opening H) of the motor housing 3. Further, the bolt B is screwed into the female screw h3 through the insertion hole h2, and the stator holder 2 is fixed to the motor housing 3.

  In this state, a cylindrical gap is formed between the outer peripheral surface of the stator holder 2 and the inner peripheral surface of the motor housing 3. Moreover, one side (front side in FIG. 3) of the cylindrical gap is closed by the flange portion 2b, and the other side (rear side in FIG. 3) is opened.

  Next, the motor housing 3 or the like is placed so that the side where the cylindrical gap is open faces upward, and silicone resin is poured into the gap and filled. Since the silicone resin is liquid, the silicone resin spreads over the entire cylindrical gap. In addition, since the flange portion 2b positioned on the lower side in the vertical direction is in contact (crimped) with the motor housing 3, the silicone resin does not leak down.

Next, the motor structure S (excluding the rotor 11) is put in a curing furnace (not shown) to thermally cure the silicone resin, and the resin member 4 is formed. For example, the silicone resin is thermoset at about 150 ° C. to become rubbery. At this time, the temperature of the stator holder 2 and the motor housing 3 is also 150 ° C., and the gap between them is wider than when the temperature is low.
In addition, since the liquid level of the silicone resin descends according to the spread of the gaps described above, for example, when the temperature of each member reaches 140 ° C., an insufficient amount of silicone resin is added and further heated and thermally cured. May be. Further, the stator holder 2 and the motor housing 3 may be preheated to, for example, 140 ° C., and when the gap between the two spreads, the silicone resin may be filled at once and thermally cured.

  Further, the motor structure S is taken out by lowering the temperature in the furnace. With the above-described temperature decrease, the gap between the stator holder 2 and the motor housing 3 is contracted more than at the time of thermosetting. As a result, the resin member 4 is compressed by the stator holder 2 and the motor housing 3.

  Next, the motor housing 3 is assembled to the gear housing G2 in which the rotor 11 and the like are installed, and further the sensor housing G1 is assembled to the motor housing 3. In this state, the rotor 11 is arranged on the radially inner side of the stator.

<About heat transfer with temperature change>
FIG. 4A is an explanatory diagram showing the relationship between the outer diameter of the stator holder, the thickness of the resin member, the inner diameter of the motor housing, and the temperature of each member in the present embodiment. Hereinafter, as an example, a case where the stator holder 2 is made of iron and the motor housing 3 is made of aluminum will be described.

  As shown by the solid line in FIG. 4A, the outer diameter of the stator holder 2 and the inner diameter of the motor housing 3 increase linearly as the temperature rises. Further, since aluminum has a larger linear expansion coefficient than iron, the motor housing 3 has a greater degree of expansion / contraction due to temperature change than the stator holder 2. Therefore, the distance (gap) between the stator holder 2 and the motor housing 3 increases as the temperature of the motor 1 increases.

Further, when the motor structure S is used, the temperature of the cooling water existing in the cooling water flow path 3a is equal to or higher than the above-described temperature lower limit value T _min (for example, −40 ° C.) and the temperature upper limit value T _Max (for example, 120). It varies within the “operating temperature range” that is less than or equal to ° C. Since the cooling water passage 3a, the resin member 4, and the stator holder 2 are close to each other in the radial direction, the temperature of the resin member 4 and the stator holder 2 is substantially equal to the temperature of the cooling water.

When the silicone resin is thermally cured at a curing temperature T _sol higher than the temperature upper limit value T _Max to form the resin member 4, the temperature of each member is lowered to a predetermined temperature T1 included in the use temperature range. The effect is played. That is, since the motor housing 3 is more easily contracted than the stator holder 2, the resin member 4 receives a radially inward force from the motor housing 3 and a radially outward force from the stator holder 2.

  Since the resin member 4 is compressed in this way, the resin member 4 comes into close contact with the outer peripheral surface of the stator holder 2 and the inner peripheral surface of the motor housing 3. That is, in the operating temperature range of the motor structure S, the resin member 4 is always maintained in a compressed state regardless of the temperature change of the motor 1.

Incidentally, the linear expansion coefficient of the silicone resin constituting the resin member 4 is about 130 [ppm / K], which is larger than the linear expansion coefficient of aluminum (for example, 22 [ppm / K]). That is, if attention is paid only to the material, the resin member 4 is more easily contracted than the motor housing 3.
However, when the temperature is lowered after the resin member 4 is thermally cured, the degree of the distance between the stator holder 2 and the motor housing 3 being narrowed is greater than the degree of the resin member 4 being contracted, as will be described below. .

The thickness (radial direction) of the resin member 4 at the time of curing is L1 ₀ [m], the temperature change based on the curing temperature T _sol is ΔT (<0) [K], and the linear expansion coefficient of the silicone resin is α1. [Ppm / K]. When the temperature of the resin member 4 is lowered after thermosetting, the thickness (radial direction) L1 [m] of the resin member 4 is expressed by the following (Formula 1).
L1 = L1 ₀ (1 + α1 · ΔT) (Formula 1)

Here, even if the linear expansion coefficient α1 is a relatively large value, since the thickness L1 ₀ of the resin member 4 is very small (for example, less than 1 mm), the change (shrinkage) from the thickness L1 to the thickness L1 ₀ ) Is relatively small.
On the other hand, the thickness (radial direction) of the motor housing 3 is much larger than that of the resin member 4. Therefore, even if the linear expansion coefficient of aluminum constituting the motor housing 3 is a relatively small value, the degree of contraction of the motor housing 3 is relatively large. That is, the degree to which the distance between the stator holder 2 and the motor housing 3 is reduced with the difference in the linear expansion coefficient is larger than the degree to which the resin member 4 is contracted.
As a result, the resin member 4 is always compressed by the stator holder 2 and the motor housing 3 in the operating temperature range of the motor structure S.

FIG. 4B is an explanatory diagram showing the relationship between the outer diameter of the stator holder, the inner diameter of the motor housing, and the temperature of each member in the comparative example. In the comparative example, the resin member 4 is not interposed between the stator holder 2 and the motor housing 3.
As described above, the degree of expansion of the aluminum motor housing 3 is larger than that of the iron stator holder 2. Therefore, in the case of the comparative example, when each member becomes equal to or higher than the temperature T _A (<T _Max ), a gap is formed between the stator holder 2 and the motor housing 3. As a result, the heat transfer between the stator holder 2 and the motor housing 3 may be significantly reduced.
Further, when each member is at a temperature T _B (> T _min ) or less, the fastening allowance of the stator core 12 becomes too large, and an excessive stress may be generated in the stator core.

<Effect>
According to the present embodiment, the resin member 4 is formed by thermosetting the silicone resin at a curing temperature T _sol higher than the temperature upper limit value T _Max of cooling water or the like, and further, the stator holder 2 and the motor housing 3 are contracted. The resin member 4 was compressed by using the difference in degree. Accordingly, it is possible to maintain the state in which the outer peripheral surface of the stator holder 2 and the resin member 4 are brought into close contact with each other and the inner peripheral surface of the motor housing 3 and the resin member 4 are brought into close contact regardless of the temperature change.
Therefore, heat generated in the motor 1 is radiated to the cooling water with high efficiency through the stator holder 2, the resin member 4, and the motor housing 3. Thereby, the cooling performance of the motor structure S can be improved, and the motor 1 can be kept at an appropriate temperature.

Further, for example, when the stator is installed in the motor housing 3 by shrink fitting, it is necessary to prepare a special jig for fixing each divided core 121 or to polish the outer peripheral surface of the stator. The manufacturing cost will increase.
On the other hand, in the present embodiment, the split core 121 may be press-fitted into the stator holder 2, and the motor structure S can be manufactured easily and at a lower cost than when shrink fitting is performed. Further, since each divided core 121 is held by the stator holder 2, the installation work after the divided core 121 is press-fitted into the stator holder 2 can be easily performed.

Further, by configuring the stator holder 2 with a material common to the stator core 12 made of iron, the linear expansion coefficients of both can be made equal. Furthermore, since the outer peripheral surface of the stator core 12 and the inner peripheral surface of the stator holder 2 are in close contact with each other by the press-fitting described above, high heat conductivity can be maintained between the stator core 12 and the stator holder 2 regardless of temperature changes.
Moreover, the strength of the motor structure S can be increased by providing the stator holder 2 that holds the plurality of split cores 121. Further, by securing the strength with the stator holder 2, the motor housing 3 made of aluminum having a relatively low strength can be used, and the motor structure S can be reduced in weight.

Further, the outer diameter of the stator holder 2 and the inner diameter of the housing are set so that the compressibility of the resin member 4 at the cooling water temperature lower limit T _min is less than the fracture compressibility. Thereby, it is possible to prevent the resin member 4 from being excessively compressed beyond the fracture compression ratio and being damaged, and as a result, it is possible to suppress a decrease in the cooling performance of the motor structure S.

≪Modification≫
As described above, the motor structure S according to the present invention has been described in the above embodiment, but the present invention is not limited to these descriptions, and various modifications can be made.
For example, in the embodiment, the case where the motor housing 3 made of aluminum is used has been described. However, the present invention is not limited to this. For example, you may comprise the motor housing 3 with the aluminum alloy which mixed copper, manganese, magnesium, zinc, etc. in aluminum.

  Moreover, although the said embodiment demonstrated the case where a silicone resin was used as the resin member 4, it is not restricted to this. For example, a thermosetting resin such as an epoxy resin or a thermosetting polyimide may be used as the resin member 4.

  In the above embodiment, the case where the stator holder 2 made of iron that is the same material as the stator core 12 (that is, the same linear expansion coefficient) is used has been described. However, the stator holder 2 is made of a material different from the stator core 12. Also good. In order to prevent excessive stress from being generated in the stator core 12 and the stator holder 2 in accordance with the temperature change, it is preferable that both are made of materials having substantially the same linear expansion coefficient.

  In the embodiment, the case where the water-cooled motor housing 3 is used has been described. However, for example, an oil-cooled motor housing 3 may be used. That is, the motor 1 may be cooled by passing insulating oil (refrigerant) through the refrigerant flow path.

  Moreover, although the said embodiment demonstrated the case where the stator core 12 was comprised by arrange | positioning the some division | segmentation core 121 cyclically | annularly, it is not restricted to this. In other words, instead of the split stator core 12, an integral stator core having a cylindrical shape may be used. Even in this case, heat transfer can be improved by bringing the inner peripheral surface of the stator holder 2 into close contact with the outer peripheral surface of the stator core 12 and further interposing the resin member 4 between the stator holder 2 and the motor housing 3.

  Moreover, although embodiment demonstrated the case where the motor structure S was installed in a hybrid vehicle, it is not restricted to this. For example, you may mount in other types of vehicles, such as an electric vehicle and a fuel cell vehicle. In addition to the four-wheeled vehicle, the motor structure S may be installed in a moving body such as a two-wheeled vehicle or a three-wheeled vehicle, or in a stationary system.

S motor structure 1 motor 11 rotor 12 stator core 2 stator holder 3 motor housing (housing)
3a Cooling water channel (refrigerant channel)
4 resin member 121 split core 121a yoke 121b teeth C coil

Claims (5)

A motor having a rotor and an annular stator core disposed on the radially outer side of the rotor;
A cylindrical stator holder that holds the stator core and has an inner peripheral surface closely contacting the outer peripheral surface of the stator core;
A cylindrical housing having a refrigerant flow path through which the refrigerant flows, and surrounding an outer peripheral surface of the stator holder;
A resin member interposed between the stator holder and the housing,
The linear expansion coefficient of the housing is larger than the linear expansion coefficient of the stator holder,
The resin member is a thermosetting resin that is thermoset at a temperature higher than a temperature upper limit value of the refrigerant that accompanies driving of the motor, and is filled and cured between the stator holder and the housing. Motor structure. The outer diameter of the stator holder and the housing so that the compression rate of the resin member is less than the fracture compression rate of the resin member at the lower temperature limit value of the refrigerant set based on the environmental temperature in a cold region The motor structure according to claim 1, wherein an inner diameter of the motor structure is set. The linear expansion coefficient of the stator holder is substantially equal to the linear expansion coefficient of the stator core,
The motor structure according to claim 1 or 2, wherein the material constituting the housing is aluminum. The motor structure according to any one of claims 1 to 3, wherein the stator core includes a plurality of divided cores arranged in an annular shape. The motor structure according to any one of claims 1 to 4, wherein a heat conductive additive is added to the thermosetting resin.

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