JP2011114986A - Cooling structure of electric motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling structure of electric motor having high cooling performance and capable of suppressing loss due to acceleration of oil. <P>SOLUTION: A coolant pathway 12b located on an end plate 12 includes a supply hole 16, which is formed on the inner circumferential side of a radial direction of the end plate 12 and receives a supplied coolant (oil); a first flow pathway R1, which is formed in the outer circumferential direction of the radius direction from the supply hole 16; and a discharge hole 21, formed closer to the inner circumferential side than to the outermost circumferential portion 17 of the first flow pathway R1 in a radial direction and discharges the coolant (oil). The coolant pathway 12b from the supply hole 16 up to the discharge hole 21 is bent. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a motor cooling structure, and more particularly to a motor cooling structure for cooling a rotor (rotor) and a stator (stator).

  Electric motors are widely used as power sources for industrial machines and vehicles. Particularly, when used as a driving power source for vehicles, the motors are required to be small in size, high in output, or high in efficiency. Further, when the electric motor is operated, each part generates heat due to internal loss due to the action of electric resistance, magnetic field and the like, and the temperature rises. The difference between the temperature of the part that generates heat and the ambient temperature is called temperature rise. If this value becomes too high, the maximum output of the motor is often limited by the temperature rise of the motor. Therefore, in order to increase the output or efficiency of the electric motor, it is necessary to improve the cooling performance for suppressing the temperature rise of the electric motor.

  Thus, the cooling performance of the electric motor affects the output performance, efficiency, and durability of the electric motor. In view of these demands, there have conventionally been electric motors having a cooling structure for cooling a rotor (rotor) magnet and a stator (stator) coil end using a refrigerant. Depending on the motor installation environment and operating environment, etc., the cooling structure of the motor can be an air cooling system using air using a fan as a refrigerant, a water cooling system using a liquid such as water or oil, or an oil cooling system. The circulating refrigerant supply method is adopted. In such a circulating refrigerant supply method using a liquid as a circulating refrigerant, a flow path is provided together with a stator and a rotor, and these flow paths are driven by a power source such as an internal combustion engine or another electric motor. In addition, there are some provided with a flow path (cooling structure) using the centrifugal force of the rotor, which is used in combination with such a pump type or provided separately.

  Patent Documents 1 to 4 describe an electric motor having a cooling structure for cooling such a rotor and a coil end. A rotating electrical machine (electric motor) described in Patent Literature 1 includes a rotating shaft provided rotatably, a core body fixed to the rotating shaft, a permanent magnet embedded in the core body, and an axial end surface of the core body. And an end plate provided opposite to the end plate. A first refrigerant passage through which a refrigerant can flow is formed in the rotating shaft. A second refrigerant passage communicating with the first refrigerant passage is formed between the end plate and the axial end surface of the core body. Inside the second refrigerant passage, a partition wall that divides the second refrigerant passage in the circumferential direction, and a path wall that guides the refrigerant introduced into the second refrigerant passage to the outer peripheral edge region of the axial end surface where the permanent magnet is disposed Is formed. Since it is comprised in this way, the residence of the refrigerant | coolant in the outer surface of a rotor is suppressed.

  Patent Document 2 also describes a rotating electric machine (electric motor) that cools a cooling target portion including a permanent magnet provided on a stator with a refrigerant. This rotating electrical machine includes a shaft provided rotatably, a housing hole capable of housing a permanent magnet, and a rotor fixed to the shaft including a permanent magnet housed in the housing hole. Further, a stator having a coil facing the rotor is provided, and an end plate provided at an end portion in the axial direction of the rotor. Then, a cooling medium passage formed on the end plate and passing through the axial end portion of the permanent magnet through which the refrigerant can flow, and located on the outer peripheral side of the rotor from the inner diameter direction end portion of the permanent magnet, includes the permanent magnet. It is located inward in the radial direction of the rotor with respect to the target portion, and includes a discharge hole that communicates with the refrigerant passage and can discharge the refrigerant. Since it is comprised in this way, the refrigerant | coolant sprayed on a coil end is reduced.

  Further, the motor cooling device described in Patent Document 3 is provided with a plurality of cooling channels through which a cooling liquid for cooling the motor generator is circulated, and the cooling liquid is supplied to the plurality of cooling channels. In the cooling device including two jackets provided with liquid supply ports, the cooling liquid supply ports are communicated with the upper portions of the plurality of cooling channels. With this configuration, the motor cooling device improves the cooling efficiency.

  Patent Document 4 describes a liquid-cooled rotary electric machine in which a rotor is disposed inside a stator via a bearing member and the stator is cooled by supplying a circulating refrigerant. In this liquid-cooled rotary electric machine, an impeller that rotates as the rotary shaft rotates is attached to the end of the rotary shaft of the rotor, and a sealed space that contacts the impeller is formed. A coolant such as water or oil is stored in the sealed space, and the coolant in the sealed space is discharged toward the groove portion through the discharge side pipe by the rotation of the impeller and after the cooling is finished, The refrigerant returning from the stator side is sucked into the sealed space. The discharged refrigerant cools the stator core as it flows through the groove. The cooled refrigerant is sucked into the sealed space side of the refrigerant reservoir through the suction side pipe. And since the inner ring | wheel part of a bearing member is cooled by the refrigerant | coolant in sealed space via an edge part, a temperature difference with an outer ring | wheel part becomes small. Such a configuration and action eliminates the need to consider operating conditions. Moreover, it is a space and economically advantageous structure.

JP 2009-118713 A JP 2009-27837 A JP 2004-194362 A JP 2007-49850 A

  As described above, in order to suppress the heat generation that affects the operation and performance of the motor, it is necessary to cool the stator (rotor) of the motor and the like in order to effectively perform the cooling. For this, it is desirable to control the behavior or flow of the refrigerant with good cooling efficiency in consideration of the retention of the refrigerant in the flow path. Furthermore, even in the case of controlling the behavior of such a refrigerant, those having good workability are advantageous in terms of cost and productivity. Considering these points, the inventions of Patent Documents 1 to 4 are considered. In the invention of Patent Document 1, the discharge holes are arranged on the outermost peripheral side in the radial direction of the end plate, and the retention of oil on the outer peripheral side is prevented. Although it is trying to suppress, the flow of the refrigerant from the flow path to the discharge hole due to the centrifugal force is slow in the vicinity of the outermost peripheral surface by simply providing the discharge hole on the outermost peripheral side. For this reason, it is insufficient to prevent the stagnation in the vicinity of the outermost peripheral surface, and the refrigerant mainly flows inside, so that the cooling near the outermost peripheral portion of the end plate cannot be performed efficiently.

  Further, in Patent Document 2, since the discharge hole is provided on the inner peripheral side of the end plate, it is effective for circulating the oil to the outermost peripheral part and cooling the outer peripheral part of the rotor, Although the amount of oil sprayed on the coil end can be reduced, the shape of the end plate is complicated and the workability is lowered, so that the productivity is lowered and the manufacturing cost is increased.

  Furthermore, in patent document 3, since the oil path is provided in the stator side and this oil path meanders, cooling efficiency is high. However, since it is provided on the stator side, oil must be supplied using a pump or the like.

  And in patent document 4, the structure for cooling becomes complicated and the number of parts will also increase. As described above, the motor cooling structure provided for cooling the coil ends of the rotor and the stator still has room for improvement in order to improve the cooling performance and productivity of the motor.

  The present invention has been made paying attention to the above technical problem, and relates to a cooling structure for an electric motor that cools heat from a stator (stator) or a rotor (rotor) with a refrigerant. An object of the present invention is to provide a motor cooling structure that can improve the cooling performance of the motor by improving the flow of the motor.

  In order to achieve the above object, the invention of claim 1 includes a rotating shaft provided with a rotor having a magnetic pole, and a stator that surrounds the rotating shaft in a cylindrical shape and changes the magnetic pole by a change in current. An end plate is provided at an end portion of the cylindrical portion and the rotor in the axial direction, and a groove is formed in the end plate, and an axial direction between a wall surface of the end plate and an end surface of the rotor is formed. A cooling passage for an electric motor comprising a cooling passage provided between the supply plate, the cooling passage, and a supply hole provided on a radially inner periphery side of the end plate, to which a cooling medium is supplied, and from the supply hole A first flow path provided in a radially outer peripheral direction, and a discharge hole for discharging a refrigerant provided on an inner peripheral side from the outermost peripheral portion of the first flow path in the radial direction, The refrigerant passage from the supply hole to the discharge hole is bent. And it is characterized in Rukoto.

  The invention according to claim 2 is the invention according to claim 1, wherein the refrigerant passage communicates with an outermost peripheral portion of the first flow path and is provided in a circumferential direction, and the second flow A third channel provided in an inner circumferential side of the third channel, which is communicated with an end of the channel opposite to the end communicated with the first channel, and an inner circumference of the third channel And a fourth flow path provided in a circumferential direction opposite to the position of the third flow path, the supply hole is provided at one end of the refrigerant passage, and the discharge hole Is a cooling structure for an electric motor, which is provided at the other end of the refrigerant passage.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the fourth flow path is communicated with an end portion of the fourth flow path opposite to the end section that is communicated with the third flow path. A fifth flow path provided in the direction of the inner peripheral side and a fifth flow path provided in the circumferential direction on the side opposite to the position of the fifth flow path are communicated with the inner peripheral end of the fifth flow path. An electric motor cooling structure including six flow paths.

  According to the first aspect of the present invention, the flow of oil in the outer peripheral portion that needs to be cooled can be made smooth to improve the cooling efficiency in the vicinity of the outer peripheral portion. Further, since the discharge hole is provided on the inner peripheral side, the oil discharge speed can be reduced to suppress the acceleration loss due to the oil.

  According to the invention of claim 2, the oil flow in the outer peripheral portion requiring cooling can be made smooth to improve the cooling efficiency in the vicinity of the outer peripheral portion. Further, since the discharge hole is provided on the inner peripheral side, the oil discharge speed can be reduced to suppress the acceleration loss due to the oil.

  According to the invention of claim 3, the flow of oil in the outer peripheral portion that needs to be cooled can be made smooth, and the cooling efficiency in the vicinity of the outer peripheral portion can be improved. Further, since the discharge hole is provided on the inner peripheral side, the oil discharge speed can be reduced to suppress the acceleration loss due to the oil.

It is a fragmentary sectional view showing the end plate in the structural example (Example 1) of the cooling structure of the electric motor which concerns on this invention. It is a fragmentary sectional view showing the end plate in other composition examples (example 2) of the cooling structure of the electric motor concerning this invention. It is a fragmentary sectional view showing the end plate in the other example of composition (example 3) of the cooling structure of the electric motor concerning this invention. It is an upper section showing the composition of the electric motor concerning this invention. It is a fragmentary sectional view showing the composition of the rotor of the electric motor concerning this invention.

  Next, structural examples (Examples 1 to 3) of the present invention will be described with reference to the drawings. The motor cooling structure according to the present invention is used as a power source for a hybrid vehicle or an electric vehicle, and can be used for an electric motor that continuously operates for traveling of the vehicle. In addition to such vehicles, the present invention can also be applied to an electric motor that cools the heat generated by continuous operation with a refrigerant. In the electric motor to which the electric motor cooling structure of the present invention is applied, the stator (stator) is provided in a cylindrical shape on the outer peripheral side of the rotor (rotor), and the stator is provided with a stator winding. In addition, the present invention can be applied to a configuration in which both end portions (coil ends) in the axial direction of the stator winding protrude or protrude from both end portions in the axial direction of the rotor. Typical examples according to the type of motor include three-phase squirrel-cage induction motor, three-phase winding induction motor, single-phase induction motor, synchronous motor, brushless synchronous motor, reluctance motor, permanent magnet synchronous motor ( PM motor), hysteresis motor, and series motor (single-phase series commutator motor). The electric motor that can be the subject of the present invention has both a function as a motor driven by power supply (power running function) and a function as a generator that converts mechanical energy into electric energy (regenerative function). ing. Hereinafter, an example of the configuration of an electric motor (motor) that can be targeted for the electric motor cooling structure of the present invention will be described. Moreover, the motor used as the object of this invention is demonstrated as a motor rotated by supplying an alternating current as an example.

  FIG. 4 shows the internal components of this motor, and the main components, ie, the stator (stator) 1 and the rotor (rotor) 2 are shown in the same positional relationship as in the state where they are arranged inside the motor. Has been. The stator 1 has a cylindrical shape, and an inner peripheral surface thereof is disposed to face an outer peripheral surface of the cylindrical rotor 2, and the rotor 2 is enclosed and accommodated in a cylindrical shape. ing. A gap between the inner peripheral surface of the stator 1 and the outer peripheral surface of the rotor 2 is an air gap 3. The air gap 3 determines the magnetic attractive force acting between the stator 1 and the rotor 2, and the dimension is set according to the size of the motor. A casing (housing) 4 is provided on the outer peripheral side of the stator 1, and the stator 1 is accommodated in the casing 4. The stator 1 is configured as an electromagnet having a coil 7 around which a conductive wire such as a lead wire is wound together with a stator core 6 in which a plurality of electromagnetic steel plates 5 are arranged and laminated. The coil 7 wound around the stator iron core (stator core) 6 is folded back at both ends of the coil 7 at positions extending from the length of the stator iron core 6 in the axis A1 direction. 7 coil end 7a. The coil end 7a is provided with an insulating coating 7b. And this stator 1 is arrange | positioned at several places in the casing 4 in the periphery shape. For example, when this motor is a three-phase AC motor, the casing 4 is provided with three circumferentially spaced intervals.

  A conductive wire (not shown) connected to the coil 7 is electrically connected to an inverter (not shown), and is electrically connected from the inverter to a battery (not shown) by another conductive wire (not shown). Has been. For example, when this motor is a three-phase AC motor, a terminal box (not shown) having a U terminal, a V terminal, and a W terminal is provided on the casing 4, and a lead wire from the inverter is connected to each of them. It becomes the composition to be done. In addition, in the inverter, the operation of the driver's accelerator pedal and brake pedal (both not shown) is detected by a sensor (not shown), and the operation status is displayed to the inverter via an electronic control device (not shown). Information is communicated as an electrical signal. When the inverter receives this electric signal, the inverter instructs the battery the amount of electric power, converts the direct current from the battery into an alternating current, and supplies the motor with electric power.

  On the other hand, the rotor 2 has a configuration in which a rotating shaft 8 is inserted into a hole 2a provided in the center portion in the radial direction. The rotary shaft 8 rotates about the axis A1 as an axis, has a predetermined length in the direction of the axis A1, and can transmit power to a power transmission element (not shown). Further, a positioning rib 9 is provided on one side of the rotating shaft 8 (in the positive x-axis direction in FIG. 4) with which one end surface of the rotor 2 abuts. Furthermore, a rotor mounting tool 10 is attached so that the other end face of the rotor 2 abuts on the other side of the rotating shaft 8 (x-axis negative direction in FIG. 4). The positioning rib 9 and the rotor fixture 10 are sandwiched between both end faces of the rotor 2 to define the position of the rotor 2 in the axis A1 direction.

  The rotating shaft 8 is supported at both ends by bearing members (not shown) such as ball bearings and bearing metals. A shaft channel 11 is formed in the rotary shaft 8 in a hollow shape. Furthermore, a hole 11 a for supplying a refrigerant (hereinafter referred to as oil as an example) to a supply hole 16 of the end plate 12 described later is communicated from the inner peripheral surface of the shaft flow path 11 to the outer peripheral surface of the rotary shaft 8. ing. The oil supplied to the shaft flow path 11 is configured such that oil stored in a refrigerant reservoir such as an oil pan (not shown) circulates by an oil pressure caused by a centrifugal force of a pump (not shown) or the rotor 2. Yes.

  The rotor 2 assembled to such a rotating shaft 8 has end plates (end plates) 12 which are end portions of the rotor 2 in contact with the positioning rib 9 and the rotor mounting tool 10 at both ends. Yes. Further, the rotor 2 is sandwiched between the end plates 12 in the axial direction, and is arranged in contact with the outer peripheral surface of the rotating shaft 8. A core (rotor core) 14 is provided. The end plate 12 has a structure that prevents a plurality of electromagnetic steel plates 13 having a laminated structure of the rotor iron cores 14 from being sandwiched and dispersed. These are fixed by a method such as caulking or press-fitting and rotate integrally with the rotating shaft 8. Since the end plate 12 is fastened in this way, the rotor iron core 14 is also configured to rotate integrally with the end plate 12. Note that the end plate 12 and the plurality of electromagnetic steel plates 13 may be configured such that a fastening member such as a screw or a bolt is inserted and fastened to both the members 12 and 13 and rotated integrally.

  Further, as shown in FIG. 5, a plurality of permanent magnet groups 15 are provided in the vicinity of the outer periphery of the rotor core 14 in a circumferential shape. In other words, the plurality of permanent magnet groups 15 are configured to be embedded in the rotor iron core 14 in a circumferential shape. A plurality of permanent magnet groups 15 are arranged in a circumferential shape so that the magnetic poles formed by the permanent magnet groups 15 configured as described above are alternately different from the magnetic poles adjacent to each other in the circumferential direction. Are lined up.

  Here, the end plate (end plate) 12 provided at both ends of the rotor 2 and sandwiching the rotor iron core 14 in which the permanent magnet group 15 is embedded will be described. Further, since the end plates 12 are provided at both ends of the rotor 2 and the two end plates 12 are formed as mirror surfaces, only one of them will be described. Therefore, one of the other end plates 12 has a structure that is mirror-targeted with one end plate 12 described below. A groove 12a described later is formed in the end plate 12 to constitute a flow path (refrigerant passage 12b) for circulating oil, and the distributed oil is discharged from a discharge hole 21 described later, and the coil end 7a. And the coil end 7a is cooled. Therefore, the positional relationship between the end plate 12 and the coil end 7a is configured such that the position of the discharge hole 21 of the end plate 12 described later and the position of the coil end 7a overlap in the direction of the axis A1.

  As described above, the end plate 12 is formed by press molding, for example, so that the communicating groove 12a is formed on one surface, and the groove 12a serves as a flow path to form the refrigerant passage 12b. In other words, since the groove 12 a is provided, the partition walls 18, 19, and 20 are formed in the space inside the end plate 12 to form a flow path through which oil passes. The refrigerant passage 12b thus formed is provided with a supply hole 16 through which a hole 11a provided in the rotary shaft 8 communicates. The first flow path R1 is provided from the supply hole 16 toward the outer peripheral side in the radial direction. The first flow path R1 is a flow path from reaching the outermost peripheral surface 17 to bending (or bending) along the circumferential direction. In other words, since the groove 12a is formed as described above, the first flow path R1 is formed by the wall surface 12c forming the space inside the end plate 12 and the partition wall surface 18a of the partition wall 18. Since the first flow path R1 is formed in this way, the cross section thereof is rectangular, but the groove 12a may be formed by, for example, press molding or the like, and the cross section may be various shapes such as semicircular, semielliptical, or triangular. The flow path may have a shape, and the flow path shown below formed on the end plate 12 may be a flow path having various shapes such as a semicircular shape, a semi-elliptical shape, or a triangular shape. .

  The first flow path R1 is provided with a second flow path R2 from a portion bent in the circumferential direction, and the second flow path R2 is extended to a certain length along the circumferential direction. The second flow path R2 is a flow path that extends to a certain length and is bent toward the inner peripheral side in the radial direction. In other words, the second flow path R <b> 2 is formed by the wall surface (outermost peripheral surface) 17 forming the space inside the end plate 12 and the partition wall surface 19 a of the partition wall 19. Further, the third flow path R3 is provided from a portion where the second flow path R2 is bent toward the inner peripheral side in the radial direction, and the third flow path R3 has a certain length toward the inner peripheral side in the radial direction. Has been extended. The third flow path R3 is a flow path that extends to a certain length and extends to a certain length toward the inner peripheral side in the radial direction and bends. In other words, the third flow path R <b> 3 is formed by the wall surface 12 d forming the space inside the end plate 12 and the side wall surface 19 b of the partition wall 19.

  Further, the fourth flow path R4 is provided from a portion where the third flow path R3 is bent in the circumferential direction, and the fourth flow path R4 has a certain length so as to fold back the second flow path R2 along the circumferential direction. It has been extended. The fourth flow path R4 is a flow path that extends to a certain length in the circumferential direction opposite to the position where the third flow path R3 is located and is bent toward the inner peripheral side in the radial direction. In other words, the fourth flow path R4 is formed by the partition wall surface 19c of the partition wall 19 and the partition wall surface 20a of the partition wall 20. Further, the fourth flow path R4 is provided with a fifth flow path R5 from a portion bent toward the inner peripheral side in the radial direction, and the fifth flow path R5 has a certain length toward the inner peripheral side in the radial direction. It has been extended. The fifth flow path R5 is a flow path extending to a certain length and bending in the circumferential direction. In other words, the fifth flow path R5 is formed by the partition wall surface 18b of the partition wall 18 and the side wall surface 20b of the partition wall 20.

  The fifth flow path R5 is provided with a sixth flow path R6 from a portion bent in the circumferential direction, and the sixth flow path R6 has a certain length so as to fold the fourth flow path R4 along the circumferential direction. It has been extended. The sixth channel R6 is a channel extended to a certain length in the circumferential direction opposite to the position where the fifth channel R5 is located. In other words, the sixth flow path R <b> 6 is formed by the wall surface 12 e forming the space inside the end plate 12 and the partition wall surface 20 c of the partition wall 20. A discharge hole 21 for discharging oil is provided in the vicinity of the end portion of the sixth flow path R6 opposite to the position where the fifth flow path R5 is located. As described above, the discharge hole 21 is provided at the other end of the refrigerant passage 12b when the position of the supply hole 16 in the refrigerant passage 12b is one end. The oil discharged from the discharge hole 21 is blown to the coil end 7a and returned to a refrigerant reservoir such as an oil pan (not shown). In addition, in the first flow path R1 to the sixth flow path R6 formed in the end plate 12 in this way, a thin plate-like or sheet-like seal member (see FIG. 6) that abuts the surface on the side where the groove 12a is formed. (Not shown) may be attached to the rotor 2 so that the flow path is maintained in a liquid-tight state. The oil may be cooled by providing fins, fans, or the like between the refrigerant reservoir and the supply hole 16 or between the discharge hole 21 and the refrigerant reservoir.

  The operation, action, and effect of the motor (motor) and the motor cooling structure of the present invention configured as described above (Example 1) of the present invention will be described below. When the driver operates an accelerator pedal (not shown) or the like, electric power is supplied from a battery to a motor (not shown) by an inverter (not shown). A current due to the electric power supplied to the motor is supplied to the coil 7 of the stator 1. Since a current flows through the coil 7 of the stator 1, a magnetic field is generated in the stator 1 from the coil 7 and the plurality of electromagnetic steel plates 5. The stator 1 is provided in several places in the casing 4, and the magnetic field generated in the plurality of stators 1 is switched and changed in synchronization with the rotation state of the rotor 2. The change in the magnetic field due to this synchronous switching is performed so that the rotor 2 rotates. Thus, current flows through the coil 7 and the rotating shaft 8 of the motor rotates.

  In the motor, an electric current is passed through the coil 7, the rotating shaft 8 rotates, and the power of the rotating shaft 8 is transmitted from various power transmission elements to the wheels to drive the vehicle. When the vehicle is driven in this way, the rotating shaft 8 is continuously rotated and continuously operated. When the motor is continuously operated, as described above, it is necessary to cool the heat generating portion so that heat exceeding the heat rating of the motor is not generated. In the present invention, the rotor is cooled by the refrigerant passage 12b provided in the end plate 12, and the coil end 7a is sprayed with oil to be cooled. The operation will be described below.

  Since the motor is continuously operated as described above, the rotary shaft 8 is also continuously rotated. Since the rotor core 14 rotates together with the rotating shaft 8, the end plate 12 also rotates together. Thus, since the end plate 12 rotates, the centrifugal force acts on the oil inside the end plate 12. Since centrifugal force acts on the oil inside the end plate 12, the oil supplied to the inside of the shaft flow path 11 of the rotating shaft 8 is discharged from the hole 11 a of the rotating shaft 8. The oil discharged from the hole 11a of the rotating shaft 8 is supplied from the supply hole 16 of the end plate 12 to the refrigerant passage 12b. The oil supplied to the refrigerant passage 12b circulates from the radially inner periphery side to the outer periphery side in the first flow path R1. Since the first flow path R1 is bent in the circumferential direction and communicated with the second flow path R2, the oil flows in the second flow path R2 along the circumferential direction by changing the flow direction.

  The oil that has flowed through the second flow path R2 flows through the third flow path R3 that is bent from the second flow path R2 radially inward. The oil flows through the third flow path R3, moves inward in the radial direction, and enters the fourth flow path R4 bent to the opposite side to the position communicating with the third flow path R3 in the circumferential direction. Circulate. The oil flows through the fourth flow path R4 and flows in the circumferential direction opposite to the position communicating with the third flow path R3. The oil that has flowed through the fourth flow path R4 flows into the fifth flow path R5 and moves to the radially inner peripheral side. The oil that has flowed through the fifth flow path R5 flows through a sixth flow path R6 that is bent in the circumferential direction on the side opposite to the fifth flow path R5. As described above, when oil flows from the first flow path R1 to the sixth flow path R6, the oil absorbs heat generated in the rotor 2. And the oil which distribute | circulated 6th flow path R6 is discharged from the discharge hole 21 provided in the terminal part vicinity of 6th flow path R6. The oil discharged from the discharge hole 21 is blown to the coil end 7a, cools the coil end 7a, and is collected in a refrigerant reservoir such as an oil pan (not shown).

  As described above, the oil flows from the first flow path R1 to the sixth flow path R6, whereby the rotor 2 is cooled. At this time, the oil flowing from the first flow path R1 passes through the second flow path R2 and flows into the third flow path R3, so that the third flow path R3 draws oil from the outer peripheral side in the radial direction to the inner peripheral side. Since the structure is made to circulate, the flow rate of oil flowing through the second flow path R2 increases near the outermost peripheral surface 17. Since the flow rate of the oil flowing through the second flow path R2 increases in the vicinity of the outermost peripheral surface 17, the oil flow in the vicinity of the outermost peripheral surface 17 that needs to be cooled becomes smooth, and the cooling effect is improved. In other words, since the third flow path R3 is configured to circulate oil from the outer peripheral side to the inner peripheral side in the radial direction, the flow of oil near the outermost peripheral surface 17 of the end plate 12 may stay. Therefore, the oil flow is smooth through the refrigerant passage 12b, and the cooling effect of the rotor 2 is improved. Therefore, the permanent magnet group 15 embedded in the outer periphery of the rotor core 14 of the rotor 2 shown in FIG. 5 can be efficiently cooled.

  In addition, since the discharge hole 21 is provided near the end of the sixth flow path R6 and is disposed on the inner peripheral side of the end plate 12, the oil discharge speed is reduced to reduce or suppress the acceleration loss due to oil. it can. Further, since the discharge hole 21 is provided near the end portion of the sixth flow path R6 and the arrangement is on the inner peripheral side of the end plate 12, the momentum of the oil sprayed on the coil end 7a is weakened. Damage to the insulating coating 7b of the end 7a can be reduced. Furthermore, the first flow path R1 to the sixth flow path R6 provided in the end plate 12 are formed with a groove 12a that is press-formed and communicated with one surface of the end plate 12, so that the partition plates 18, 19, 20 and the end plate 12 are connected. And the end surface of the rotor iron core 14. Thus, the groove | channel 12a bent in the end plate 12 is formed, and it has the structure where the refrigerant path 12b is provided between the wall surface of the end plate 12 and the end surface of the rotor iron core 14 in the axis line A1 direction. Therefore, the rigidity of the end plate 12 is increased, oil leaks between the end plate 12 and the rotor 2, and torque loss due to entering the air gap 3 between the stator 1 and the rotor 2 can be suppressed. . Furthermore, since the end plate 12 that can constitute the first flow path R1 to the sixth flow path R6 in this way has a shape that is easy to manufacture and can be manufactured by press molding, the workability is good. The cost can be reduced and the manufacturing process can be simplified, and the productivity is improved.

  Here, another configuration example (Example 2) of the end plate 12 having the above-described configuration example will be described. FIG. 2 shows an end plate 22 which is another configuration example of the end plate 12 having the configuration example described above. The configuration of the second embodiment is the same as the configuration example having the end plate 12 described above except for the configuration of the end plate 22. Therefore, the description of the configuration other than the end plate 22 is omitted. Like the end plate 12, the end plate 22 is formed with a groove 22a to form a flow path (refrigerant passage 22b) for circulating oil, and the distributed oil is discharged from a discharge hole 27 described later, The coil end 7a is sprayed to cool the coil end 7a. Therefore, the positional relationship between the end plate 22 and the coil end 7a is configured such that the position of the discharge hole 27 of the end plate 22 described later and the position of the coil end 7a overlap in the direction of the axis A1.

  As described above, the end plate 22 is formed by press molding, for example, so that the communicating groove 22a is formed on one surface, and the groove 22a serves as a flow path to form the refrigerant passage 22b. In other words, since the groove 22a is provided, the partition walls 25 and 26 are formed in the space inside the end plate 22 to form a flow path through which oil passes. The refrigerant passage 22b formed in this way is provided with a supply hole 23 through which a hole 11a provided in the rotary shaft 8 communicates. The first flow path L1 is provided from the supply hole 23 toward the outer peripheral side in the radial direction. The first flow path L1 is a flow path from reaching the outermost peripheral surface 24 to bending along the circumferential direction. In other words, since the groove 22a is formed as described above, the first flow path L1 is formed by the wall surface 22c that forms the space inside the end plate 22 and the partition wall surface 25a of the partition wall 25. Since the first flow path L1 is formed in this way, the cross section thereof is rectangular. However, the groove 22a may be formed by, for example, press molding or the like, and the cross section may be various shapes such as semicircular, semielliptical, or triangular. Similarly, the following flow paths formed on the end plate 22 may be flow paths having various shapes such as a semicircular shape, a semi-elliptical shape, or a triangular shape. .

  A second flow path L2 is provided from a portion where the first flow path L1 is bent in the circumferential direction, and the second flow path L2 is extended to a certain length along the circumferential direction. The second flow path L2 is a flow path that extends to a certain length and is bent toward the inner peripheral side in the radial direction. In other words, the second flow path L <b> 2 is formed by the wall surface (outermost peripheral surface) 24 that forms a space inside the end plate 22 and the partition wall surface 26 a of the partition wall 26. Further, the third flow path L3 is provided from a portion where the second flow path L2 is bent toward the inner peripheral side in the radial direction, and the third flow path L3 has a certain length toward the inner peripheral side in the radial direction. Has been extended. The third flow path L3 is a flow path that extends to a certain length and extends to a certain length toward the inner peripheral side in the radial direction and bends. In other words, the third flow path L <b> 3 is formed by the wall surface 22 d forming the space inside the end plate 22 and the side wall surface 26 b of the partition wall 26.

  Further, the fourth flow path L4 is provided from the portion where the third flow path L3 is bent in the circumferential direction, and the fourth flow path L4 has a certain length so that the second flow path L2 is folded back along the circumferential direction. It has been extended. The fourth flow path L4 is a flow path that extends to a certain length in the circumferential direction opposite to the position where the third flow path L3 is located and is bent toward the inner peripheral side in the radial direction. In other words, the fourth flow path L <b> 4 is formed by the wall surface 22 e forming the space inside the end plate 22 and the partition wall surface 26 c of the partition wall 26. A discharge hole 27 for discharging oil is provided in the vicinity of the end of the fourth flow path L4 opposite to the position where the third flow path L3 is located. As described above, the discharge hole 27 is provided at the other end of the refrigerant passage 22b, assuming that the position of the supply hole 23 in the refrigerant passage 22b is one end. The oil discharged from the discharge hole 27 is blown to the coil end 7a and returned to a refrigerant reservoir such as an oil pan (not shown). In addition, in the first flow path L1 to the fourth flow path L4 formed in the end plate 22 in this way, a thin plate-like or sheet-like seal member (see FIG. 5) that abuts the surface on the side where the groove 22a is formed. (Not shown) may be attached to the rotor 2 so that the flow path is maintained in a liquid-tight state. The oil may be cooled by providing fins, fans, or the like between the refrigerant reservoir and the supply hole 23 or between the discharge hole 27 and the refrigerant reservoir.

  The operation, action, and effect of the electric motor (motor) and the electric motor cooling structure of the present invention configured as described above in another structural example (second embodiment) of the present invention will be described below. The operation of the motor and the oil until the rotation shaft 8 of the motor is rotated and continuously operated until the oil is supplied from the supply hole 23 through the refrigerant passage 22b of the end plate 22 from the hole 11a of the rotation shaft 8 is described above. Since it is the same as that of a structural example (Example 1), description is abbreviate | omitted. The oil supplied to the refrigerant passage 22b flows from the radially inner periphery side to the outer periphery side in the first flow path L1. Since the first flow path L1 is bent in the circumferential direction and communicated with the second flow path L2, the oil flows in the second flow path L2 along the circumferential direction by changing the flow direction.

  The oil flowing through the second flow path L2 flows through the third flow path L3 bent from the second flow path L2 inward in the radial direction. The oil flows through the third flow path L3, moves inward in the radial direction, and enters the fourth flow path L4 bent to the side opposite to the position communicating with the third flow path L3 in the circumferential direction. Circulate. The oil flows through the fourth flow path L4 and flows in the circumferential direction opposite to the position communicating with the third flow path L3. As described above, when oil flows from the first flow path L1 to the fourth flow path L4, the oil absorbs heat generated in the rotor 2. And the oil which distribute | circulated the 4th flow path L4 is discharged from the discharge hole 27 provided in the terminal part vicinity of the 4th flow path L4. The oil discharged from the discharge hole 27 is blown to the coil end 7a, cools the coil end 7a, and is collected in a refrigerant reservoir such as an oil pan (not shown).

  As described above, the oil flows from the first flow path L1 to the fourth flow path L4, whereby the rotor 2 is cooled. At this time, the oil flowing from the first flow path L1 passes through the second flow path L2 and flows into the third flow path L3, so that the third flow path L3 draws oil from the outer peripheral side in the radial direction to the inner peripheral side. Since it is structured to circulate, the flow rate of oil flowing through the second flow path L2 increases near the outermost peripheral surface 24. Since the flow velocity of the oil flowing through the second flow path L2 increases near the outermost peripheral surface 24, the oil flow near the outermost peripheral surface 24 that needs to be cooled becomes smooth, and the cooling effect is improved. In other words, since the third flow path L3 has a structure in which oil is circulated from the outer peripheral side to the inner peripheral side in the radial direction, the oil flow in the vicinity of the outermost peripheral surface 24 of the end plate 22 may stay. Therefore, the oil flow is smooth through the refrigerant passage 22b, and the cooling effect of the rotor 2 is improved. Therefore, the permanent magnet group 15 embedded in the outer periphery of the rotor core 14 of the rotor 2 shown in FIG. 5 can be efficiently cooled.

  In addition, since the discharge hole 27 is provided near the end of the fourth flow path L4 and is disposed on the inner peripheral side of the end plate 22, the oil discharge speed is reduced to reduce or suppress the acceleration loss due to the oil. it can. Further, since the discharge hole 27 is provided near the end portion of the fourth flow path L4 and the arrangement is on the inner peripheral side of the end plate 22, the momentum of the oil sprayed on the coil end 7a is weakened. Damage to the insulating coating 7b of the end 7a can be reduced. Further, the first flow path L1 to the fourth flow path L4 provided in the end plate 22 are formed with grooves 22a that are press-formed and communicated with one surface of the end plate 22, and the partition walls 25 and 26 and the wall surface of the end plate 22 are formed. And the end face of the rotor iron core 14. Thus, the groove | channel 22a bent in the end plate 22 is formed, and it has the structure where the refrigerant path 22b is provided between the wall surface of the end plate 22 and the end surface of the rotor iron core 14 in the axis line A1 direction. Thus, the rigidity of the end plate 22 is increased, oil leaks from between the end plate 22 and the rotor 2, and torque loss due to entering the air gap 3 between the stator 1 and the rotor 2 can be suppressed. . Furthermore, the end plate 22 that can form the first flow path L1 to the fourth flow path L4 in this way has a shape that is easy to manufacture and can be manufactured by press molding, so that the workability is good. The cost can be reduced and the manufacturing process can be simplified, and the productivity is improved.

  Here, another configuration example (Example 3) of the end plate 12 having the configuration example described above will be described. FIG. 3 shows an end plate 28 which is another configuration example of the end plate 12 having the above-described configuration example. The configuration of the third embodiment is the same as the configuration example having the end plate 12 described above except for the configuration of the end plate 28. Therefore, the description other than the end plate 28 with the same reference numerals is omitted. Since the end plate 28 is obtained by modifying the end plate 12 with respect to the partition walls 19 and 20, the configuration of the partition walls 19 and 20 will be described.

  The shape of the partition walls 19 and 20 of the end plate 28 is formed by bending the front end portions 29 and 30 on the open end side. The distal end portion 29 of the partition wall 19 is bent along the wall surface 12d that forms a space inside the end plate 28 in the radially inner circumferential direction. In other words, the partition wall surface 29a of the tip portion 29 of the partition wall 19 faces the wall surface 12d forming the space inside the end plate 28, the partition wall surface 29b faces the partition wall surface 20a of the partition wall 20, and the partition wall surface 29 c is formed to face the partition wall surface 30 a of the tip end portion 30 of the partition wall 20. The tip portion 30 of the partition wall 20 is bent along the partition wall surface 18b of the partition wall 18 in the radial outer peripheral direction. In other words, the partition wall surface 30a of the tip end portion 30 of the partition wall 20 faces the partition wall surface 29c of the tip end portion 29 of the partition wall 19 as described above, the partition wall surface 30b faces the partition wall surface 19c of the partition wall 19, and the partition wall surface. 30 c is formed to face the partition wall surface 18 b of the partition wall 18. The size of the bent tip portions 29 and 30 of the partition walls 19 and 20 of the end plate 28, that is, the portion of the partition walls 19 and 20 to be bent depends on the flow velocity in the vicinity of the outermost peripheral surface 17 of the second flow path R2. It is appropriate and is set so as to appropriately reduce the discharge speed of oil discharged from the discharge hole 21.

  Since the tip portions 29 and 30 on the open end side of the partition walls 19 and 20 are bent as described above, the third flow path R3 has the partition wall surface 29a of the tip portion 29 of the partition wall 19 inside the end plate 28. It is configured to face the wall surface 12d forming the space. The fourth flow path R4 has a partition wall surface 29b facing the partition wall surface 20a of the partition wall 20, a partition wall surface 29c facing the partition wall surface 30a of the tip end portion 30 of the partition wall 20, and the partition wall surface 30b. And a portion that faces the partition wall surface 19c. The fifth flow path R <b> 5 is configured such that the partition wall surface 30 c faces the partition wall surface 18 b of the partition wall 18. About other 1st flow path R1, 2nd flow path R2, and 6th flow path R6, it is the same as that of the above-mentioned structural example (Example 1). In addition, the configuration other than the above is the same as the above-described configuration example (Example 1).

  The operation, action, and effect of the electric motor (motor) and the electric motor cooling structure of the present invention configured as described above in another configuration example (third embodiment) of the present invention will be described below. The operation of the motor and oil until the rotating shaft 8 of the motor rotates and continuously operates until oil is supplied from the supply hole 16 through the refrigerant passage 28b of the end plate 28 from the hole 11a of the rotating shaft 8 is described above. Since it is the same as that of a structural example (Example 1), it abbreviate | omits. The oil supplied to the refrigerant passage 28b circulates from the radially inner periphery side to the outer periphery side in the first flow path R1. Since the first flow path R1 is bent in the circumferential direction and communicated with the second flow path R2, the oil flows in the second flow path R2 along the circumferential direction by changing the flow direction.

  The oil that has flowed through the second flow path R2 flows through the third flow path R3 that is bent from the second flow path R2 radially inward. The oil flows through the third flow path R3, moves inward in the radial direction, and enters the fourth flow path R4 bent to the opposite side to the position communicating with the third flow path R3 in the circumferential direction. Circulate. The oil flows through the fourth flow path R4 and flows in the circumferential direction opposite to the position communicating with the third flow path R3. The oil that has flowed through the fourth flow path R4 flows into the fifth flow path R5 and moves to the radially inner peripheral side. The oil that has flowed through the fifth flow path R5 flows through a sixth flow path R6 that is bent in the circumferential direction on the side opposite to the fifth flow path R5. As described above, when oil flows from the first flow path R1 to the sixth flow path R6, the oil absorbs heat generated in the rotor 2. And the oil which distribute | circulated 6th flow path R6 is discharged from the discharge hole 21 provided in the terminal part vicinity of 6th flow path R6. The oil discharged from the discharge hole 21 is blown to the coil end 7a, cools the coil end 7a, and is collected in a refrigerant reservoir such as an oil pan (not shown).

  As described above, the oil flows from the first flow path R1 to the sixth flow path R6, whereby the rotor 2 is cooled. At this time, the oil flowing from the first flow path R1 passes through the second flow path R2 and flows into the third flow path R3, so that the third flow path R3 draws oil from the outer peripheral side in the radial direction to the inner peripheral side. Since the structure is made to circulate, the flow rate of oil flowing through the second flow path R2 increases near the outermost peripheral surface 17. Since the flow rate of the oil flowing through the second flow path R2 increases in the vicinity of the outermost peripheral surface 17, the oil flow in the vicinity of the outermost peripheral surface 17 that needs to be cooled becomes smooth, and the cooling effect is improved. In other words, since the third flow path R3 is configured to circulate oil from the outer peripheral side in the radial direction to the inner peripheral side, the flow of oil near the outermost peripheral surface 27 of the end plate 28 may stay. Therefore, the oil flow is smooth through the refrigerant passage 28b, and the cooling effect of the rotor 2 is improved. Therefore, the permanent magnet group 15 embedded in the outer periphery of the rotor core 14 of the rotor 2 shown in FIG. 5 can be efficiently cooled.

  In the end plate 28 of the other configuration (Example 3), the shape of the partition walls 19 and 20 is formed by bending the tip end portions 29 and 30 on the open end side. And the dimensions of the bent tip portions 29 and 30 of the partition walls 19 and 20 of the end plate 28 are such that the flow velocity in the vicinity of the outermost peripheral surface 17 of the second flow path R2 is appropriate, and the oil discharged from the discharge hole 21 Since the discharge speed is set to be appropriately reduced, the oil flow in the vicinity of the outermost peripheral surface 17 can be further adjusted.

  In addition, since the discharge hole 21 is provided near the end of the sixth flow path R6 and is disposed on the inner peripheral side of the end plate 28, the oil discharge speed is reduced to reduce or suppress the acceleration loss due to oil. it can. Further, since the discharge hole 21 is provided near the end portion of the sixth flow path R6, and the arrangement is on the inner peripheral side of the end plate 28, the momentum of the oil sprayed on the coil end 7a is weakened. Damage to the insulating coating 7b of the end 7a can be reduced. Furthermore, the first flow path R1 to the sixth flow path R6 provided in the end plate 28 are formed with grooves 28a that are press-formed and communicated with one surface of the end plate 28, so that the partition walls 18, 19, 20 and the tip portion 29 are formed. 30 and the wall surface of the end plate 28 and the end face of the rotor iron core 14. Thus, the groove 28a bent in the end plate 28 is formed, and the refrigerant passage 28b is provided between the wall surface of the end plate 28 and the end surface of the rotor core 14 in the direction of the axis A1. Therefore, the rigidity of the end plate 28 is increased, and the oil loss from the gap between the end plate 28 and the rotor 2 and the torque loss due to entering the air gap 3 between the stator 1 and the rotor 2 can be suppressed. . Furthermore, the end plate 28 that can form the first flow path R1 to the sixth flow path R6 in this way has a shape that is easy to manufacture and can be manufactured by press molding, so that the workability is good. The cost can be reduced and the manufacturing process can be simplified, and the productivity is improved.

  In the configuration examples (Examples 1 to 3) described above, the rotor 2 is a permanent magnet. However, the rotor 2 may be an electromagnet. Further, as described above, the stator 1 is provided in a cylindrical shape on the outer peripheral side of the rotor 2, and the stator 1 is provided with the coil (stator winding) 7, and the coil (stator winding) is provided. ) 7 can be applied to an electric motor having a configuration in which both end portions (coil end 7a) in the direction of the axis A1 project (extend) from both ends in the direction of the axis A1 of the rotor.

  DESCRIPTION OF SYMBOLS 12 ... End plate, 12b ... Refrigerant passage, 16 ... Supply hole, 17 ... Outermost periphery part, 21 ... Discharge hole, R1 ... 1st flow path.

Claims (3)

A rotating shaft provided with a rotor having magnetic poles, a cylindrical portion having a stator that surrounds the rotating shaft in a cylindrical shape and changes the magnetic poles by a change in current, and an end portion in the axial direction of the rotor A cooling structure for an electric motor comprising an end plate, a groove formed in the end plate, and a refrigerant passage provided between a wall surface of the end plate and an end surface of the rotor in an axial direction. In
The refrigerant passage includes a supply hole for supplying a refrigerant provided on an inner peripheral side in a radial direction of the end plate;
A first flow path provided in a radial direction from the supply hole;
A discharge hole for discharging the refrigerant provided on the inner peripheral side from the outermost peripheral portion of the first flow path in the radial direction,
The cooling structure for an electric motor, wherein the refrigerant passage from the supply hole to the discharge hole is bent.   The refrigerant passage is opposite to the second flow passage provided in the circumferential direction so as to communicate with the outermost peripheral portion of the first flow passage, and the end portion of the second flow passage communicated with the first flow passage. A third flow path that communicates with the end portion on the side and is provided in the radially inner circumferential direction, and communicates with the inner circumferential side of the third flow path, opposite to the position of the third flow path. A fourth flow path provided in the circumferential direction, wherein the supply hole is provided at one end of the refrigerant passage, and the discharge hole is provided at the other end of the refrigerant passage. The cooling structure for an electric motor according to claim 1, wherein the cooling structure is an electric motor.   A fifth channel provided in an inner peripheral side in the radial direction, communicated with an end of the fourth channel that is opposite to the end communicated with the third channel; 3. A sixth flow path provided in the circumferential direction opposite to the position of the fifth flow path, communicated with an end portion on the inner peripheral side of the flow path, according to claim 1 or 2. The electric motor cooling structure as described.

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