JP2015095908A - Electric motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric motor which cools heat generation and overheating occurring during the operation of the electric motor with a coolant thereby preventing the performance deterioration of a driving force and damage, such as burning of a coil, and achieving stability performance and high durability.SOLUTION: An electric motor includes: first passages 3 installed in a housing cylinder part 1 of the electric motor and second passages 4 formed in cooling covers 9 disposed at both ends of a stator 10 and connected with the first passages 3. A coolant flows through the first passages 3 and the second passages 4. A coolant passage, which circulates between an electric motor inner part and a coolant supply device at an electric motor outer part via an inflow port 2 and a discharge port 6 provided at the first passage 3, is formed in the electric motor inner part to improve the cooling function and prevent temperature rise of the electric motor which is caused by heat generated by the stator 10.

Description

  The present invention relates to an electric motor having a cooling water flow path in order to absorb and cool heat generated by operation.

  In the electric motor in operation, when the load increases, heat generation increases, and the temperature of the electric motor rises. As a result, the performance of the electric motor may deteriorate. In particular, in the case of a vehicle-mounted motor, a decrease in the performance of the motor affects the running performance, steering performance, braking performance, etc. of the vehicle, and imposes a heavy burden on the driver.

  As a measure for cooling an electric motor, Patent Document 1 discloses that in a drive motor for an electric vehicle, a cylindrical cooling water flow path is formed inside a housing, an inlet and a discharge port are provided to circulate the cooling water, and the motor is A cooling structure is described.

  Patent Document 2 has a structure in which a cooling jacket through which a refrigerant passes is installed between a cylindrical frame and a stator core, and the refrigerant jacket includes a plurality of micro flow channel channels formed concentrically with the frame. A cooling device for a rotating electrical machine is described.

Japanese Patent Laid-Open No. 10-2011178 JP 2010-1110025 A

In the cooling structures shown in Patent Documents 1 and 2, only heat is absorbed from the outer periphery of the stator, a sufficient cooling effect cannot be obtained, and a decrease in the performance of the motor may be unavoidable.
An object of the present invention is to provide an electric motor that efficiently absorbs and cools heat generated from the periphery of a stator and can be stably operated without causing a performance degradation.

  In order to solve the above problems, the structural feature of the invention according to claim 1 is that a housing having a cylindrical portion in which a first flow path having an inlet and an outlet is formed, and an inner circumference of the housing A stator having a plurality of slots for storing coils fixed to a surface and separated from a stator core by an insulator, a rotor disposed with a gap on an inner peripheral surface of the stator, and an internal And a cooling cover disposed in contact with the end face of the stator core at both ends of the stator.

  When configured as described above, the cooling water flowing through the first flow path formed inside the cylindrical portion of the housing absorbs and cools heat from the outer periphery of the stator, and in the cooling cover. The cooling water flowing through the formed second flow path can absorb heat from both ends of the stator and cool it.

In order to solve the above-described problem, the structural feature of the invention according to claim 2 is that the housing cylindrical portion includes an outer cylinder and an inner cylinder, and is provided on at least one of the inner circumference of the outer cylinder and the outer circumference of the inner cylinder. A groove is formed, and the groove forms the first flow path by press-fitting the inner cylinder into the outer cylinder.
If comprised as mentioned above, a 1st flow path can be easily formed in the inside of a housing cylindrical part. With this structure, the shape of the first channel can be easily processed, and the channel cross-sectional shape and the channel path shape can be processed into various shapes.

In order to solve the above-described problem, a structural feature of the invention according to claim 3 is that the second flow path is formed so as to go around the slots on the end face of the stator core.
If comprised as mentioned above, the flow path length of the cooling water which adjoins the said stator core end surface can be taken large, and the heat absorption from the end surface of the said stator core can be performed effectively.

In order to solve the above-mentioned problem, the structural feature of the invention according to claim 4 is that the cooling cover is composed of two plates having the same shape, and the two plates are joined in the thickness direction. It is joined by a surface, a groove is formed in at least one of the joining surfaces, and the groove constitutes the second flow path by joining the joining surface.
If comprised as mentioned above, members other than two plates which comprise the said cooling cover are not required, but a flow path can be easily formed in the said cooling cover.

In order to solve the above-mentioned problem, the structural feature of the invention according to claim 5 is that the cooling cover is composed of two plates having the same shape, and the two plates are joined in the thickness direction. And joining the two joint surfaces after disposing a pipe member constituting the second flow path in a groove formed in at least one of the joint surfaces and being bent according to the groove shape. .
If comprised as mentioned above, since the pipe member has already formed the said 2nd flow path by itself, joining work can be performed easily, without considering the sealing performance of a junction part.

In order to solve the above-mentioned problem, the structural feature of the invention according to claim 6 is that the tube member that is bent so as to go around each slot of the end face of the stator core and constitutes the second flow path. The cooling cover is embedded by molding or injection molding.
If comprised as mentioned above, the said cooling cover can be manufactured easily and efficiently. Moreover, since the adhesiveness between the tube member forming the second flow path and the cooling cover main body portion is high, the thermal conductivity is good and effective cooling can be performed.

In order to solve the above problems, a structural feature of the invention according to claim 7 is that the cooling cover is made of a resin material having thermal conductivity and electrical insulation.
If comprised as mentioned above, the heat | fever of the said stator can be efficiently conducted to the cooling water in a 2nd flow path, and the said insulator is interposed between the said cooling cover and the said winding. Even in the case of contact without any problem, electrical insulation between the winding and the stator core can be ensured. Further, by using a resin material, the cooling cover can be easily and inexpensively manufactured by injection molding or the like.

  As described above, according to the present invention, it is possible to efficiently absorb and cool the heat generated from the periphery of the stator, and to provide an electric motor capable of stable operation without causing performance degradation. Become.

It is the schematic which shows the axial direction cross section of the electric motor in the 1st Embodiment of this invention. It is a perspective view which shows the structure of the stator core in the 1st Embodiment of this invention, a coil, and a cooling cover. It is a perspective view of the outer periphery of the inner cylinder of the housing cylindrical part in which the groove | channel was formed in the 1st Embodiment of this invention. It is a thickness direction side view of a cooling cover in a 1st embodiment of the present invention. It is the schematic of the groove | channel formed in one joining surface of the two board | plates which comprise the cooling cover in the 1st Embodiment of this invention, and its surface. It is a perspective view of the outer periphery of the inner cylinder of the housing cylindrical part in which the groove | channel was formed in the 2nd Embodiment of this invention. It is a shape external view of the pipe member which comprises the 2nd flow path in the 3rd Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is an axial sectional view of an electric motor according to a first embodiment of the present invention.

  The electric motor is rotatably supported by the housing via the housing, the stator 10 fixed to the inner periphery of the housing cylindrical portion 1, the bearings 14a and 14b disposed in the housing, and the bearings 14a and 14b. The rotating shaft 13 and the rotor 11 fixed to the outer periphery of the rotating shaft 13 at a position corresponding to the stator 10 are provided.

The housing includes a cylindrical housing cylindrical portion 1, a disk-shaped housing side plate 15 fixed to one end of the housing cylindrical portion 1, and a disk-shaped housing side plate 16 fixed to the other end of the housing cylindrical portion 1. Has been.
A stator 10 is provided on the inner periphery of the housing cylindrical portion 1, and a rotor 11 is disposed on the inner periphery side with a constant interval. A bearing 14 a is attached to the housing side plate 15, and a bearing 14 b is attached to the housing side plate 16.

  FIG. 2 shows the configuration of the stator 10. The stator 10 includes a stator core 17, an insulator, a coil 12, and a cooling cover 9. A slot 18 is provided in the stator core 17. The insulator disposed in the slot performs an insulating function between the stator core 17 and the coil 12 wound around the cooling cover 9 and the stator core 17 between the slots.

  The cooling cover 9 has a slot 22 having the same shape as the slot 18, is disposed in contact with both end faces of the stator core 17, and has a function of absorbing and cooling the heat of the stator core 17 from both ends. In order to enhance the function, a sealing / adhesive material having high thermal conductivity can be applied or sandwiched between the adhesive surfaces so as to improve the adhesion between the cooling cover 9 and the end face of the stator core 17. The cooling cover 9 has the second flow path 4 through which cooling water flows.

As shown in FIG. 1, the housing cylindrical portion 1 has a first flow path 3 through which cooling water flows. The first flow path 3 is provided with an inflow port 2 and a discharge port 6 that penetrate the outer diameter surface of the outer cylinder 7.
Piping members 30a and 30b are installed at the inflow port 2 and the discharge port 6, and pipes connecting the cooling water supply device outside the electric motor are connected.

The housing cylindrical portion 1 has a double structure including an outer cylinder 7 and an inner cylinder 8, and the outer cylinder 7 and the inner cylinder 8 are press-fitted with an interference. Grooves are provided on both the inner circumference of the outer cylinder 7 or the outer circumference of the inner cylinder 8, and by pressing the inner cylinder 8 into the outer cylinder 7, both grooves are overlapped to form a single space. One flow path 3 is formed. It is also possible to install the groove only on the inner periphery of the outer cylinder 7 or only on the outer periphery of the inner cylinder 8.
If comprised as mentioned above, the 1st flow path 3 can be easily formed in the inside of the housing cylindrical part 1. FIG. With this structure, the shape of the first channel 3 can be easily processed, and the channel cross-sectional shape and the channel path shape can be processed into various shapes.

FIG. 3 is a perspective view of the inner cylinder 8 of the housing cylindrical portion 1 and the groove 25 formed in the outer periphery 26 thereof.
The groove 25 is formed on the outer periphery 26 of the inner cylinder 8 in a coil shape concentric with the inner cylinder 8 and extending in the axial direction. When the inner cylinder 8 is press-fitted into the outer cylinder 7, the groove 25 is One flow path 3 is formed.

  In order to enhance the sealing performance of the press-fitting surfaces of the outer cylinder 7 and the inner cylinder 8, it is possible to apply an adhesive or the like having a sealing property to the press-fitting surfaces in advance.

  The first flow path 3 is provided with a connection flow path 5 that penetrates the inner periphery of the inner cylinder 8, and the cooling cover 9 disposed at both ends of the stator 10 via the connection flow path 5. It is connected to the second flow path 4 provided inside.

  FIG. 4 is a side view in the thickness direction of the cooling cover 9. The cooling cover 9 is formed by stacking and joining two plates of the same shape in the thickness direction. The outer diameter of the cooling cover 9 is the same as the outer diameter of the stator core 17, and is arranged in contact with both ends of the stator core 17 to constitute a part of the stator 10.

  The cooling cover 9 is made of a resin material having thermal conductivity and electrical insulation. For this reason, even if it is a case where it contacts without passing through the said insulator between the cooling cover 9 and the coil 12, the electrical insulation between the coil 12 and the stator core 17 can be ensured. Further, by using a resin material, the cooling cover can be easily and inexpensively manufactured by injection molding or the like.

FIG. 5 is a plan view of one joining surface 21 a of the cooling cover 9.
A groove 20 is formed in the joint surface 21 a so as to surround the periphery of the slot 22 of the cooling cover 9 corresponding to the slot 18 of the stator core 17. The groove 20 has both ends reaching the outer diameter surface of the cooling cover 9 after going around each slot 22.
If comprised as mentioned above, the flow path length of the cooling water which adjoins a stator core end surface can be taken large, and the heat absorption from the end surface of a stator core can be performed effectively.

A groove similar to the groove 20 is formed at a position corresponding to the groove 20 on the other bonding surface 21b, and both the grooves are overlapped to form the second flow path 4 by closely bonding both the bonding surfaces. . It is also possible to provide a groove for forming the flow channel only on either one of the joint surfaces.
The second flow path 4 has both ends reaching the outer periphery of the cooling cover 9, which are connected to the connection flow path 5 connected to the first flow path 3 provided in the inner cylinder 8 of the housing cylindrical portion 1. 19

Next, the assembly process of the motor will be described.
First, the inner cylinder 8 of the housing cylindrical portion 1 is press-fitted into the outer cylinder 7 to constitute the housing cylindrical portion 1. At this time, the inner cylinder 8 and the outer cylinder 7 are positioned in the circumferential direction and the axial direction so that after press-fitting, grooves provided in the inner cylinder 8 and the outer cylinder 7 overlap to form one flow path. ing. Thereafter, the housing side plate 15 is joined to one end face of the housing cylindrical portion 1.

Next, the cooling cover 9 is disposed in contact with both ends of the stator core 17, and after inserting the insulators into all the slots 18 and 22, coils are wound to form the stator 10. At this time, the cooling cover 9 is placed at both ends of the stator core 17 so that the connection ports 19 at both ends of the second flow path 4 installed on the outer circumferences of the two cooling covers 9 coincide with each other in the circumferential direction. Deploy.
The formed stator 10 is press-fitted into the inner cylinder 8 of the housing cylindrical portion 1. At this time, the circumferential direction of the stator 10 is such that the connection ports 19 provided at both ends of the second flow path 4 of the cooling cover 9 are connected to the connection flow paths 5 provided in the inner cylinder 8 of the housing cylindrical portion 1. And adjust the axial position.

After the rotor 11 is mounted on the rotating shaft 13 and the bearings 14a and 14b are mounted on the rotating shaft 13 portions on both sides of the rotor 11, the rotor 11 is inserted inside the stator 10, and the bearing 14a is mounted on the housing side plate 15. Installing. After the housing side plate 16 is inserted into the rotary shaft 13, the housing side plate 16 is attached to the bearing 14 b and joined to the end surface of the housing cylindrical portion 1.
By assembling the electric motor, the first flow path 3, the connection flow path 5, the second flow path 4, the inflow port 2, and the discharge port 6 are all connected to form a cooling water circulation flow path.

Next, the flow of cooling water will be described.
The cooling water is introduced from the cooling water supply device outside the electric motor into the electric motor through the external inlet 2 of the electric motor. The cooling water that has entered the first flow path 3 from the inflow port 2 enters the second flow path 4 via the connection flow path 5, goes through the second flow path 4, and then returns to the first flow path 3. It is discharged out of the electric motor from the discharge port 6 connected to the first flow path, and returns to the cooling water supply device via an external pipe.

Next, a conduction / absorption path of heat generated by the electric motor will be described.
During operation of the electric motor, heat generated when a current flows through the coil 12 is conducted to the stator core 17. The heat conducted from the outer periphery of the stator core 17 to the housing cylindrical portion 1 is absorbed by the cooling water flowing through the first flow path 3 installed in the housing cylindrical portion 1. The heat transmitted to the end face of the stator core 17 is absorbed by the cooling water flowing through the second flow path 4 installed in the cooling cover 9. In addition to heat absorption from the outer periphery of the stator core 17, heat generated from both ends of the stator core 17 can effectively absorb heat generated from the coil 12 during operation of the electric motor.

The first flow path 3 of the housing cylindrical portion 1 described above can form various flow paths and cross-sectional shapes.
FIG. 6 is a perspective view of the outer periphery 28 of the inner cylinder in which the groove 27 forming the first flow path is formed in the second embodiment.
The grooves 27 are linearly and parallel to the axial direction on the outer periphery 28 of the inner cylinder, and grooves arranged at substantially equal intervals in the circumferential direction are connected to the adjacent flow paths at both ends, and reciprocate in the axial direction. However, the groove 27 is formed as a whole. When the inner cylinder is press-fitted into the outer cylinder, the groove 27 forms the first flow path circulating in the housing cylindrical portion.

  A groove similar to that formed in the inner cylinder can be formed on the inner diameter surface of the outer cylinder. In this case, when the inner cylinder is press-fitted into the outer cylinder, both grooves overlap with each other so as to face the joint surface, thereby forming a first flow path having a flow path cross section obtained by combining the respective groove cross sections.

The second flow path 4 formed in the cooling cover 9 described above can be formed in various ways.
FIG. 7 is an external view of the shape of the tube member 23 constituting the second flow path according to the third embodiment. The tube member 23 is formed by bending the tube material in accordance with the shape of the groove around the outer periphery of the slot formed on at least one joint surface of the two plates of the cooling cover.
The molded pipe member 23 is inserted and arranged in the groove, and then constitutes the second flow path as a part of the cooling cover 9 formed by joining the joining surfaces.

  According to the present embodiment, by using the bent dedicated pipe member 23 as the second flow path, it is not necessary to consider the sealing performance of the joining surface of the cooling cover, and the joining operation can be easily performed. And processability is improved.

In the fourth embodiment, the cooling cover may be formed by bending the tube member 23 into a shape that surrounds the outer periphery of the slot on the end face of the stator core, and then embedding by molding or injection molding. it can. According to this method, the cooling cover provided with the 2nd flow path 4 can be manufactured cheaply and efficiently.
According to this embodiment, since the adhesiveness between the tube member 23 forming the second flow path and the main body portion of the cooling cover is good, the thermal conductivity is improved and the cooling performance is improved.

  Further, in both the first channel and the second channel, the channel length, the channel cross-sectional area, and the like can be arbitrarily set in accordance with the size of the electric motor to be applied and the heat generation amount.

According to the configuration of the present invention, it is possible to provide an electric motor that can efficiently absorb and cool the heat generated from the periphery of the stator and can be stably operated without causing a performance degradation.
In particular, it can be widely applied to a motor with a large load, and is particularly useful as a motor for driving a car.

1: housing cylindrical portion, 2: inlet, 3: first flow path, 4: second flow path,
5: Connection flow path, 6: Discharge port, 7: Outer cylinder, 8: Inner cylinder, 9: Cooling cover,
10: Stator, 11: Rotor, 12: Coil, 13: Rotating shaft,
14a, 14b: bearing, 15, 16: housing side plate, 17: stator core,
18: Slot, 19: Connection port, 20: Groove, 21a, 21b: Joining surface,
22: slot, 23: pipe member, 24: connection port, 25: groove, 26: outer periphery,
27: groove, 28: outer periphery, 30a, 30b: piping member

Claims (7)

A housing having a cylindrical portion in which a first flow path having an inflow port and a discharge port is formed;
A stator having a plurality of slots for storing coils fixed to an inner peripheral surface of the housing and separated from a stator core by an insulator;
A rotor disposed with a gap in the inner peripheral surface of the stator and a second flow path connected to the first flow path are formed inside, and at both ends of the stator, end faces of the stator core A cooling cover placed in contact with the
An electric motor comprising:   The cylindrical portion of the housing includes an outer cylinder and an inner cylinder. A groove is formed on at least one of the inner peripheral surface of the outer cylinder and the outer peripheral surface of the inner cylinder, and the groove is formed by press-fitting the inner cylinder into the outer cylinder. The electric motor according to claim 1, wherein a first flow path is formed.   3. The electric motor according to claim 1, wherein the second flow path is formed so as to go around the slots on the end face of the stator core.   The cooling cover is composed of two plates having the same shape, and the two plates are bonded to each other at bonding surfaces facing each other in the thickness direction, and a groove is formed on at least one of the bonding surfaces. 4. The electric motor according to claim 1, wherein the groove forms the second flow path by bonding. 5.   The cooling cover includes two plates having the same shape, and the two plates are bonded to each other at bonding surfaces facing each other in the thickness direction, and are formed into grooves formed in at least one of the bonding surfaces. 4. The electric motor according to claim 1, wherein the joint surfaces are joined after arranging the pipe members that are bent together to form the second flow path. 5.   The tube member that is bent so as to surround each slot on the end face of the stator core and that constitutes the second flow path includes the cooling cover that is embedded by molding or injection molding. The electric motor according to claim 1 or 3.   The electric motor according to claim 1, wherein the cooling cover is made of a resin material having thermal conductivity and electrical insulation.

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