JP3882721B2 - Cooling structure for rotating electrical machine and method for manufacturing the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cooling structure for a rotating electrical machine that efficiently cools a stator of a rotating electrical machine (such as a motor, a generator, or a motor / generator) and a method for manufacturing the same.
[0002]
[Prior art]
In a rotating electrical machine (for example, a motor, a generator, a motor / generator, etc.), in order to cool the stator efficiently, the inside of the stator slot (groove portion in which the stator coil is accommodated) is used as a refrigerant passage, and the stator coil Technologies have been proposed that allow direct cooling. As a method of forming such a refrigerant passage, a mold is disposed on the inner peripheral side of the stator and inside the slot, and a resin material is injected and filled into a space defined by the stator core and the mold, and then cured. A method of making the inside of the slot a refrigerant passage by closing the slot opening is disclosed (for example, see Patent Document 1).
[0003]
[Patent Document 1]
JP-A-4-364343
[Problems to be solved by the invention]
However, in the above-described prior art, after the filled resin material is cured, the molds arranged on the inner peripheral side of the stator and the inside of the slot must be extracted. However, the workability of pulling out the long and narrow mold disposed inside the slot is poor, and there is a possibility that the stator core may be damaged or the mold itself may be deformed if it is forcibly removed.
[0005]
The present invention has been made paying attention to such conventional problems, and aims to provide a cooling structure for a rotating electrical machine and a method for manufacturing the same without damaging the stator core and at low manufacturing costs. Yes.
[0006]
[Means for Solving the Problems]
The present invention solves the above problems by the following means. In addition, in order to make an understanding easy, although the code | symbol corresponding to embodiment of this invention is attached | subjected, it is not limited to this.
[0007]
The present invention is a cooling structure for a rotating electrical machine having a rotor (2) and a stator (3) disposed around the rotor and fixed to the case by a case fixing member (20), the stator (3 ) Surrounds the teeth portion from the periphery with a stator core (3a) having a plurality of tooth portions (6) and a slot portion (7) between the teeth portions, and a projection portion near the opening portion of the slot portion. (35) a teeth surrounding member (31), a stator coil (3b) wound around the teeth surrounding member, and an abutment portion of the slot portion provided in contact with the protrusion of the teeth surrounding member closes and the slot portion, a slot closure member which refrigerant in the refrigerant passage can be Tsuryu (22), by crimping the slot closure member with the protrusion of the tooth enclosing member Characterized in that it comprises a constant closing member fixing means (23).
[0008]
[Action / Effect]
According to the present invention, the slot opening portion between the teeth of the stator is closed by the slot closing member, and the slot closing member is crimped and fixed to the protruding portion of the teeth surrounding member by the closing member fixing means. Since the refrigerant passage is used as a refrigerant passage, the refrigerant passage can be formed without damaging the stator.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings.
(First embodiment)
1 and 2 are cross-sectional views showing a rotating electrical machine according to the first embodiment of the present invention. 1 is a view taken in the direction of arrows I-I in FIG. 2, and FIG. 2 is a view taken in the direction of arrows II-II in FIG.
This rotating electrical machine includes a case 1, a rotor 2, and a stator 3, and functions as, for example, a motor, a generator, a motor / generator, or the like.
[0010]
The case 1 includes a cylindrical portion 1a and side plate portions 1b and 1c that close openings at both ends in the axial direction of the cylindrical portion 1a. The side plate portions 1b and 1c are cylindrical portions by bolts or the like (not shown). It is fixed to 1a.
[0011]
The rotor 2 is accommodated inside the case 1. The rotor 2 is composed of a cylindrical rotor core 2a and a rotating shaft 2b penetratingly disposed on the central axis of the rotor core 2a. Both ends of the rotating shaft 2b are respectively provided with side plate portions 1b via bearings 4, respectively. 1c is supported. Therefore, the rotor 2 is rotatable with respect to the case 1. A magnet 8 is provided near the outer peripheral surface of the rotor 2.
[0012]
The stator 3 is disposed in the case 1 so as to surround the outer periphery of the rotor 2. The stator 3 includes a cylindrical stator core 3a that surrounds the outer periphery of the rotor 2 and a stator coil 3b. The stator 3 is fixed to the case 1 by a cylindrical portion 20.
[0013]
Next, the stator 3 will be described in more detail with reference to FIG. 3 (a view taken along the line III-III in FIG. 1).
[0014]
The stator core 3a includes a ring-shaped back core 5 extending along the cylindrical portion 1a and teeth 6 protruding radially inward from the back core 5. An insulating cap 31 is attached to the teeth 6, and from above. The stator coil 3b is concentratedly wound. Here, the insulating cap 31 is a teeth surrounding member that surrounds the teeth 6 from the periphery. The insulating cap 31 has an insulating performance and prevents conduction between the core 30 and the stator coil 3b. In the present embodiment, the insulating cap 31 is provided on the peripheral side portion of the tooth 6 as shown in FIG. 3, but it may also be formed on the rotor facing surface of the tooth 6.
[0015]
The stator core 3 a can be divided for each tooth 6. For this reason, the concentrated winding operation | work of the stator coil 3b to the teeth 6 can be performed easily. Between adjacent teeth 6, a groove-like slot 7 extending in the rotation axis direction (normal direction to FIG. 3) is formed. Inside the slot 7, the stator coil 3b wound around the tooth 6 is accommodated. The stator 3 is press-fitted (shrink-fitted or the like) into the cylindrical portion 1 a of the case 1, so that the stator 3 is fixed to the case 1. Since the back cores 5 of the adjacent split cores are brought into close contact with each other by this press-fitting, the magnetic performance is the same as that of the integrated stator core even in the stator core 3a having the split structure as in this embodiment.
[0016]
Returning to FIG. 1 again, a structure for cooling the stator coil 3b will be described. A cylindrical portion 20 extends from one end face of the stator 3 to the side plate portion 1b. In the present embodiment, the cylindrical portion 20 is formed integrally with the stator 3 (insulating cap 31). An annular first coolant chamber 11 is defined by the outer peripheral surface of the cylindrical portion 20, the inner peripheral surface of the cylindrical portion 1 a, the side surface of the side plate portion 1 b, and one end surface of the stator 3. The distal end of the cylindrical portion 20 is supported by the side plate portion 1 b via an annular seal member 21. The opposite side of the stator 3 has the same structure, and an annular second coolant chamber 13 is formed. Cooling oil is supplied from the oil supply port 14 penetrating the side plate portion 1b to the first coolant chamber 11, flows through the refrigerant passage 15 provided inside the stator 3, and is supplied to the second coolant chamber 13 on the opposite side. Then, the oil is discharged from the oil discharge port 16 penetrating the side plate portion 1c.
[0017]
An insulating cap 31 that prevents a short circuit between the stator core 3 a and the stator coil 3 b is provided on the end surface of the stator core 3 a, and the surface of the insulating cap 31 is the end surface of the stator 3.
[0018]
Again, the refrigerant passage 15 will be described in detail with reference to FIG. The refrigerant passage 15 is a part of the slot 7, and the opening on the radially inner peripheral side of the slot 7 is closed with a resin plate (slot closing member) 22 and a resin mold layer (closing member fixing means) 23. The space formed in this manner is a refrigerant passage 15. Originally, the slot 7 is a groove-like space opened at both axial end portions and the radially inner peripheral side, only the radially inner peripheral side opening portion is closed, and both end portions remain open. The first coolant chamber 11 and the second coolant chamber 13 and the refrigerant passage 15 communicate with each other through the opening at both ends.
[0019]
Next, a method for manufacturing the stator 3 (particularly the resin mold layer 23) will be described with reference to FIGS.
[0020]
First, a large number of substantially T-shaped electromagnetic steel sheets are laminated to form a split core 30 (having a part of the back core 5 and one tooth 6) (split core forming step).
[0021]
And the insulation cap (teeth surrounding member) 31 which covers the teeth 6 from the front and back of the split core 30 is attached (tooth surrounding process). In the present embodiment, the insulating cap 31 has a two-part structure as shown in FIG. The insulating cap 31 is formed with an end face insulating portion 32, a tooth insulating portion 33, a back core insulating portion 34, and a protruding portion 35. The end surface insulating portion 32 prevents a short circuit between the end surface of the tooth 6 and the stator coil. Teeth insulating portion 33 is formed continuously with end surface insulating portion 32 and prevents a short circuit between the side surface of teeth 6 (the surface on the slot 7 side) and the stator coil. The back core insulating portion 34 is provided over the entire circumference of the insulating cap 31 and prevents a short circuit between the side surface (the surface on the slot 7 side) of the back core 5 and the stator coil. The protruding portion 35 is formed in parallel with the back core insulating portion 34 over the entire circumference of the insulating cap 31. In FIG. 4, the insulating cap 31 has a structure that can be divided into two in the front-rear direction by the teeth insulating portion 33. However, for example, the insulating cap 31 may have a structure that can be divided in the left-right direction by the end surface insulating portion 32. Moreover, the structure which can be divided | segmented into three or more divisions may be sufficient.
[0022]
As the material of the insulating cap 31, an epoxy resin, a polyester resin, or the like can be used. Various binders can be mixed as needed to change the strength or linear expansion coefficient (the length of the object changes due to temperature changes under a constant pressure). When it occurs, the ratio) is adjusted. In particular, if the linear expansion coefficient of the insulating cap 31 is adjusted to be substantially equal to the linear expansion coefficient of the core 30, the thermal stress can be reduced and the reliability of the parts can be improved.
[0023]
In the next step, a stator coil is wound around the split core 30 with the insulating cap 31 attached thereto to form a split stator (split stator forming step). At this time, the stator coil is wound around the end surface insulating portion 32 and the teeth insulating portion 33 of the insulating cap 31. Since the back core insulating part 34 and the protrusion 35 are formed above and below the end face insulating part 32 and the tooth insulating part 33, the stator coil is prevented from being collapsed, and the winding work can be facilitated. In FIG. 5, only three turns of the stator coil are shown in order to avoid the drawing becoming complicated, but in actuality, several tens of turns are wound.
[0024]
In the next step, a plurality (12 in this embodiment) of divided stators are arranged in an annular shape and assembled into a cylindrical stator 3, and the assembled stator 3 is press-fitted into the cylindrical portion 1a (stator insertion step). ). FIG. 5 shows a state in which the stator 3 is press-fitted into the cylindrical portion 1a.
[0025]
In the next step, a plate (slot closing member) 22 is disposed in the opening of the slot 7 and a cylindrical mold (molding mold) that is in close contact with the inner peripheral surface of the stator 7 (tip surface of the teeth 6). 40 is arranged on the inner periphery of the stator (blocking member / mold mold arranging step). In addition, the state which has arrange | positioned the plate 22 and the metal mold | die 40 in FIG. 6 is shown.
[0026]
In the next step, the mold resin is filled into the space 41 defined by the side surface of the insulating cap 31, the plate 22 and the mold 40 (mold resin filling step). At this time, a filling pressure acts on the inner peripheral side (rotor side) surface 22 a of the plate 22, and the seal surface 22 b of the plate 22 is pressed against the protruding portion 35 of the insulating cap 31 by this pressure. For this reason, the filling resin does not leak into the slot 7. In this way, the slot 7 is closed and the refrigerant passage 15 is formed.
[0027]
When the mold resin is filled as described above, the mold 40 is pulled out and removed after the mold resin is hardened (mold removal process). The resin filled in the space 41 and cured is the resin mold layer 23 of FIG. At this time, the plate 22 is used as a part of the refrigerant passage 15 without being pulled out. For this reason, the refrigerant passage can be formed without damaging the stator. Further, it is possible to simultaneously form the cylindrical portion 20 in the step of forming the resin mold layer 23, and FIG. 1 of the present embodiment illustrates the case where the resin mold layer 23 and the cylindrical portion 20 are integrated. is doing.
[0028]
According to the present embodiment, the resin plate is used as a means for preventing the mold resin to be filled to form the refrigerant passage from flowing into the coil side, and after filling the resin, the refrigerant passage is not pulled out. Therefore, the refrigerant passage can be formed without damaging the stator.
[0029]
Further, in the conventional method, the mold resin filled from the gap between the mold and the stator core is easily leaked. Therefore, in order to prevent such leakage, the mold had to be finished with high accuracy. However, according to this embodiment, since the plate is pressed from the rotating shaft (rotor) side toward the stator core side, the adhesion of the plate to the stator core is improved, and leakage of the filling mold resin can be prevented. Therefore, the accuracy of the mold can be relaxed, and the required accuracy of the workpiece itself is also lowered, so that mass production is possible, cost can be reduced, and mass productivity is improved.
[0030]
Furthermore, in order to hold the resin plate near the tip of the teeth portion of the stator core, for example, it is conceivable that the tip of the teeth portion is widened to form the resin plate holding portion. However, since the teeth part is an electromagnetic steel plate, if it does so, magnetic flux leaks from the teeth part toward the rotor core, and electromagnetic performance deteriorates. However, according to the present embodiment, the size of the stator core (tooth portion) itself does not change, and a resin insulating cap is provided, and the plate is held by the insulating cap, so while maintaining good electromagnetic performance, A low-cost and high-performance cooling structure can be obtained.
[0031]
In addition, if the insulating cap of the stator core tip portion is provided so as to surround the tip portion of the teeth portion of the stator core, the stator core is more firmly joined.
The insulating cap may be made of a material that is compatible with the material at the time of final molding. Here, specifically, “compatible” means that the material should have high bonding strength. By doing so, since the resin mold to be molded in the subsequent process is bonded to the insulating cap, the bonding surface at the stator core is eliminated and the bonding surface between the resins is eliminated, so that the bonding strength can be improved. Further, if the material is made of a material having a thermal expansion coefficient close to that of the electromagnetic steel sheet (stator core), cracks due to thermal stress can be prevented. Further, the material of the plate (slot closing member) 22 is the same as that of the resin mold layer (closing member fixing means) 23 or a material having a high bonding strength, so that the reliability can be further improved.
[0032]
Furthermore, in the present embodiment, since the insulating cap formed in advance is formed on the stator core, the manufacturing cost can be kept low.
[0033]
In addition, since the shape of the insulating cap extends to the opposing surfaces of the coil and the stator, it is possible to prevent the coolant from leaking from the gap between the stacked surfaces of the stator core.
[0034]
(Second Embodiment)
FIG. 7 is a cross-sectional view showing a rotating electrical machine according to the second embodiment of the present invention.
[0035]
In each embodiment described below, the same reference numerals are given to portions that perform the same functions as those of the first embodiment described above, and redundant descriptions are omitted as appropriate.
[0036]
In the first embodiment, the case where the cylindrical portion 20 is formed integrally with the stator 3 (insulating cap 31) has been described as an example. However, in this embodiment, the cylindrical portion 20 includes the stator 3 (insulating cap 31). It is formed separately. In this case, for example, as shown in FIG. 7, the cylindrical portion 20 may be attached to the side plate portions 1 b and 1 c by welding or the like, and an annular seal member 51 may be sandwiched between the cylindrical portion 20 and the stator 3.
[0037]
According to the present embodiment, the cylindrical portion 20 can be easily and reliably fixed to the side plate portions 1b and 1c.
[0038]
(Third embodiment)
FIG. 8 is a diagram showing a split core according to the third embodiment of the present invention. 8A is an overall perspective view, and FIG. 8B is a cross-sectional view.
[0039]
In the previous embodiment, the insulating cap 31 was previously formed in a two-divided structure. However, in this embodiment, the split core 30 is resin-molded to provide an end face insulating portion 32, a tooth insulating portion 33, and a back core insulation. The part 34 and the protrusion part 35 are formed directly. That is, in this embodiment, after obtaining the split core 30 by laminating the electromagnetic steel sheets, the first resin mold is performed to form the insulating cap 31 and the state shown in FIG. Molding is performed to form the resin mold layer 23. The material used is a mixture of unsaturated polyester with a binder adjusted for strength and linear expansion. In some cases, PPS resin or the like may be used.
[0040]
Normally, the bonding strength between the resin and the stator core (metal) is not high, but in the present embodiment, since the teeth 6 have a shape that expands on the tip side, the resin portion and the stator core portion are firmly bonded. It is also effective to intentionally increase the unevenness of the bonding surface and improve the bonding strength.
[0041]
Further, as shown in FIG. 8B, if the resin mold layer covers the entire teeth portion of the stator core, the stator core is more firmly joined. In consideration of manufacturing cost or the like, it may be determined whether to cover the entire surface or a part of the surface.
[0042]
According to this embodiment, since the plate is formed after the stator mold is held by the resin mold at the front end portion of the stator core, it is possible to more reliably prevent the deterioration of electromagnetic performance such as magnetic flux leaks from the tooth portion toward the rotor core. .
[0043]
Further, since the teeth 6 have a shape that expands on the tip side, the bonding strength between the resin portion and the stator core portion is high.
[0044]
It should be noted that the present invention is not limited to the embodiment described above, and various modifications and changes can be made within the scope of the technical idea, and it is obvious that these are equivalent to the present invention.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a rotating electrical machine according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view showing the rotating electrical machine according to the first embodiment of the present invention.
3 is a view taken in the direction of arrows III-III in FIG.
FIG. 4 is a diagram illustrating a method for manufacturing a stator.
FIG. 5 is a view showing a state in which a stator is press-fitted into a cylindrical portion.
FIG. 6 is a view showing a state in which a plate and a mold are arranged.
FIG. 7 is a cross-sectional view showing a rotating electrical machine according to a second embodiment of the present invention.
FIG. 8 is a diagram showing a split core according to a third embodiment of the present invention.
[Explanation of symbols]
1 Case 2 Rotor 3 Stator 3a Stator Core 3b Stator Coil 5 Back Core 6 Teeth 7 Slot 15 Refrigerant Passage 22 Plate 23 Resin Mold Layer 31 Insulating Cap 35 Protrusion 40 Mold

Claims (13)

A rotating electrical machine cooling structure having a rotor and a stator disposed around the rotor and fixed to the case by a case fixing member,
The stator is
A stator core having a plurality of tooth portions and a slot portion between the tooth portions;
A teeth surrounding member that surrounds the teeth portion from the periphery and has a protrusion near the opening of the slot portion;
A stator coil wound around the teeth surrounding member;
A slot closing member that is provided in contact with the protrusion of the teeth enclosing member, closes the opening of the slot, and makes the slot a refrigerant passage through which a refrigerant can flow;
A cooling structure for a rotating electrical machine, comprising: a closing member fixing means for pressing and fixing the slot closing member to a protrusion of the teeth surrounding member. 2. The rotating electrical machine according to claim 1, wherein the teeth surrounding member is a member having a shape formed in advance in accordance with the teeth portion, and is mounted on the teeth portion to form the stator. Cooling structure. The cooling structure for a rotating electric machine according to claim 1, wherein the teeth surrounding member is formed by covering the teeth portion with a mold resin. The cooling structure for a rotating electrical machine according to any one of claims 1 to 3, wherein the teeth surrounding member is formed on an entire circumference so as to surround the teeth portion. 5. The rotation according to claim 1, wherein the teeth surrounding member is formed on substantially the entire surface or a part of the opposing surfaces of the stator coil and the stator core. 6. Electric cooling structure. The cooling structure for a rotating electric machine according to any one of claims 1 to 5, wherein the teeth surrounding member is formed of an insulating material. The teeth surrounding member is formed of the same material as the material of the closing member fixing means or a material having a high bonding strength with the material of the closing member fixing means. The cooling structure for a rotating electric machine according to any one of the above. 8. The rotating electrical machine according to claim 1, wherein the teeth surrounding member is made of a material having a linear expansion coefficient substantially equal to a linear expansion coefficient of the stator core. Cooling structure. The cooling structure for a rotating electrical machine according to any one of claims 1 to 8, wherein the teeth surrounding member is formed integrally with the case fixing member. The cooling structure for a rotating electric machine according to any one of claims 1 to 8, wherein the teeth surrounding member is formed separately from the case fixing member. The rotating electrical machine according to any one of claims 1 to 10, wherein the closing member fixing means is formed of a material having a linear expansion coefficient substantially equal to that of the stator core. Cooling structure. 12. The cooling structure for a rotating electrical machine according to claim 1, wherein surfaces of the teeth portion and the tooth surrounding member that are in contact with each other are uneven surfaces. A split core forming step of stacking a plurality of electromagnetic steel sheets to form one split core;
A teeth surrounding step of surrounding the teeth portion of the divided core formed in the divided core forming step with a teeth surrounding member having a protrusion ,
A divided stator forming step of forming a divided stator by winding a stator coil around the teeth surrounding member provided in the teeth surrounding step;
A plurality of split stators formed in the split stator forming step are arranged in an annular shape to form a cylindrical stator, and a stator insertion step of inserting the stator into the case;
A closing member for disposing a slot closing member for closing the slot opening portion in a slot opening portion between the teeth portions of the stator inserted in the case in the stator insertion step, and disposing a mold on the inner periphery of the stator. Mold mold placement process;
By filling the molding resin into a gap of a slot closure member and a mold arranged in the closing member, the mold arrangement step, by the filling pressure, thereby pressure wearing the slot closure member with the protrusion of the tooth enclosing member Then, a mold resin filling step in which the slot portion between the teeth portions is a cooling passage through which a cooling medium can pass,
A method of manufacturing a cooling structure for a rotating electrical machine, comprising: a mold removing process for extracting and removing the mold after the mold resin filled in the mold resin filling process is cured.

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