JP2009118686A - Cooling structure of rotating electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling structure of a rotating electric machine in which parts to be cooled can be cooled efficiently by supplying many coolants to a permanent magnet when the permanent magnet is likely to generate heat, and by supplying the coolant to a coil when the coil is likely to generate heat, in accordance with an operation state of the rotating electric machine. <P>SOLUTION: The cooling structure of the rotating electric machine M which cools the rotating electric machine M equipped with a stator S and a rotor R by circulating the coolants therethrough includes: the permanent magnet PM provided to one of the stator S and the rotor R; the coil C provided to the other one of the stator S and the rotor R; a first flow passage l1 through which the coolants cooling the permanent magnet PM are circulated; a second flow passage l2 through which the coolants cooling the coil C are circulated; and a circulation switching means 10 for switching the circulation states of coolants in the first flow passage l1 and second flow passage l2 based on one or both the number of rotations and the output torque of the rotating electric machine M. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rotating electrical machine cooling structure in which a refrigerant is circulated and cooled in a rotating electrical machine including a stator and a rotor.

  Conventionally, a rotating electrical machine has been used as one of driving power sources over various devices. Since such a rotating electrical machine is often required to have a large output, the amount of heat generated from each part of the rotating electrical machine, particularly from a coil or a permanent magnet, becomes large. Causes of such heat generation of the rotating electrical machine include copper loss and iron loss. Copper loss is a loss that always occurs when a current flows through a coil, regardless of the magnitude of the current, and increases in proportion to the square of the current flowing through the coil. On the other hand, iron loss consists of hysteresis loss and eddy current loss, and is generated when a magnetic material is placed in an alternating magnetic field. The hysteresis loss is a loss when the magnetic domain of the iron core changes the direction of the magnetic field by an alternating magnetic field, and the eddy current loss is a loss caused by the eddy current generated when the magnetic flux is changed inside the conductor. Since these losses are dissipated as thermal energy, that is, Joule heat, the coils and permanent magnets of the rotating electrical machine generate heat. When such heat generation proceeds excessively, in the coil, there is a possibility that the insulating varnish that insulates the coil conductors from each other and the insulating paper that insulates each phase coil from each other may break down. On the other hand, in the permanent magnet, irreversible demagnetization occurs in which the magnetic force reduced by heating does not recover even when the temperature is lowered, and the function of the rotating electrical machine may be reduced.

  From such circumstances, as a technique for cooling coils and permanent magnets that have been provided in rotating electrical machines so far, a refrigerant is circulated through the rotor core of a rotor provided with permanent magnets, and this refrigerant is further injected into the coils by a rotational centrifugal force. Thus, there is a motor cooling circuit that sequentially cools the permanent magnet and the coil (for example, Patent Document 1). In addition, as a technique for cooling the coil and the stator core having the coil, the refrigerant is injected from the case side of the motor, that is, from the outer side of the stator to the coil end, and also to the stator core according to the increase in the rotational speed of the rotating electrical machine. There is also a cooling device that circulates and cools the refrigerant (for example, Patent Document 2).

Japanese Patent Laid-Open No. 9-182374 JP 2006-353051 A

  In the motor cooling circuit disclosed in Patent Document 1, the refrigerant after cooling the permanent magnet, that is, the refrigerant warmed by the heat dissipated from the permanent magnet is injected into the coil by the rotating centrifugal force. Therefore, although the refrigerant injected into the coil has a uniform temperature and amount, the temperature is already high, so the coil cannot be efficiently cooled. Moreover, in the cooling device disclosed in Patent Document 2, when the coil end is cooled, the refrigerant is injected from above in the direction of gravity. Therefore, since the refrigerant heated by the heat of the portion near the injection port reaches the portion far from the injection port where the refrigerant is injected, that is, the portion located in the downward direction of gravity, the temperature cannot be uniformly cooled. Unevenness is likely to occur. In addition, when cooling the stator core, the refrigerant is circulated through the cooling pipe embedded in the upper part of the motor case. Therefore, the efficiency is higher on the far side (center side) than on the side closer to the cooling pipe (outer side). There was a problem that it could not be cooled well.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to efficiently switch a portion that needs to be cooled by making it possible to switch the circulation state of the refrigerant according to the operating state of the rotating electrical machine. An object of the present invention is to provide a cooling structure for a rotating electrical machine that can be cooled.

  In order to achieve the above-described object, a characteristic structure of a cooling structure for a rotating electric machine according to the present invention is a structure in which a refrigerant is circulated and cooled in a rotating electric machine including a stator and a rotor, and is provided in one of the stator and the rotor. A permanent magnet, a coil provided on the other of the stator and the rotor, a first flow path through which a refrigerant for cooling the permanent magnet flows, a second flow path through which a refrigerant for cooling the coil flows, and the rotation And a flow switching unit that switches a flow state of the refrigerant to each of the first flow path and the second flow path based on one or both of the rotation speed and the output torque of the electric machine.

  With such a characteristic configuration, the flow switching unit supplies a large amount of refrigerant to the permanent magnet side, for example, in a state where the permanent magnet easily generates heat, based on one or both of the rotational speed and the output torque of the rotating electrical machine. In a state in which the coil is likely to generate heat, by allowing the refrigerant to be switched so that the refrigerant is supplied to the coil side, it is possible to efficiently cool the portion that needs to be cooled. In addition, the first flow path through which the refrigerant for cooling the permanent magnet flows and the second flow path through which the refrigerant for cooling the coil flow are provided separately (separately from the refrigerant supply side to each flow path. The refrigerant is not directly warmed by the heat of the other of the permanent magnet and the coil before the one of the permanent magnet and the coil that needs to be cooled is cooled. Can be cooled. Moreover, since the site | part which needs cooling can be selected and cooled in this way, the quantity of a refrigerant | coolant required for cooling can be restrained small. Therefore, since the discharge capacity required for the pump for circulating the refrigerant is smaller than that for cooling both the permanent magnet and the coil at the same time, the pump can be reduced in size, weight, and cost. Can do.

  The distribution switching means includes a first state in which the refrigerant flows through the first flow path when the rotation speed of the rotating electrical machine is equal to or higher than a predetermined switching rotation speed, and the rotation speed of the rotating electrical machine is less than the switching rotation speed. In this case, it is preferable that the second state in which the refrigerant flows through the second flow path is switched.

  Here, when the rotational speed of the rotating electrical machine is high, the exchange of magnetic flux across the permanent magnet increases, and hysteresis loss, eddy current loss, that is, iron loss increases, and the permanent magnet often tends to generate heat. Therefore, it is preferable to cool the permanent magnet. On the other hand, when the rotational speed of the rotating electrical machine is low, it is often desirable to obtain a high output torque. In such a case, it is preferable to cool the coil because the current flowing through the coil increases and the copper loss increases and the coil is likely to generate heat. In this configuration, the switching rotation number for switching between the first state in which the refrigerant for cooling the permanent magnet flows in the first flow path and the second state in which the refrigerant for cooling the coil flows in the second flow path is set in advance. . Therefore, a large amount of refrigerant can be supplied to the permanent magnet side when the rotational speed of the rotating electrical machine at which the permanent magnet easily generates heat is equal to or higher than the switching rotational speed. On the other hand, when the rotational speed of the rotating electrical machine at which the coil easily generates heat is less than the switching rotational speed, the refrigerant can be supplied to the coil side. Thus, with this configuration, it is possible to efficiently cool a portion that needs to be cooled according to the operating state of the rotating electrical machine.

  Alternatively, the flow switching means may be configured such that when the output torque of the rotating electrical machine is less than a predetermined switching torque, the first state where the refrigerant flows through the first flow path, and the output torque of the rotating electrical machine is equal to or higher than the switching torque. It is preferable that the second state in which the refrigerant flows through the second flow path is switched to the second state.

  Here, when the output torque is desired to be obtained by the rotating electrical machine, it is preferable to cool the coil because the current flowing through the coil increases and the copper loss increases and the coil is likely to generate heat. On the other hand, when the rotational speed of the rotating electrical machine is high, the exchange of magnetic flux across the permanent magnet increases, and hysteresis loss, eddy current loss, that is, iron loss increases, and the permanent magnet often tends to generate heat. It is preferable to cool the permanent magnet. In this configuration, a switching torque for switching between a first state in which the refrigerant that cools the permanent magnet flows in the first flow path and a second state in which the refrigerant that cools the coil flows in the second flow path is set in advance. Therefore, when the output torque of the rotating electrical machine at which the coil is likely to generate heat is equal to or higher than the switching torque, the refrigerant can be supplied to the coil side. On the other hand, when the output torque of the rotating electrical machine at which the permanent magnet easily generates heat is less than the switching torque, a large amount of refrigerant can be supplied to the permanent magnet side. Thus, with this configuration, it is possible to efficiently cool a portion that needs to be cooled according to the operating state of the rotating electrical machine.

  Alternatively, the flow switching means may supply refrigerant to the first flow path in the first region on one side of the switching boundary line based on the switching boundary line defined by the relationship between the rotational speed of the rotating electrical machine and the output torque. In the second state on the other side of the switching boundary line, the refrigerant is preferably circulated through the second flow path in the first state of circulation.

  With such a configuration, the distribution switching means is responsive to the first region or the second region in which the operating state of the rotating electrical machine is determined by a switching boundary defined by the relationship between the rotational speed of the rotating electrical machine and the output torque. The refrigerant distribution state between the first flow path and the second flow path can be switched. Therefore, according to both the rotational speed and output torque of the rotating electrical machine, a large amount of refrigerant is supplied to the permanent magnet side when the permanent magnet easily generates heat, and a refrigerant is supplied to the coil side when the coil easily generates heat. Thus, it is possible to efficiently cool a portion that needs to be cooled.

  Further, for example, the switching boundary is defined as a relationship between the rotational speed of the rotating electrical machine and the output torque at which the ratio of the temperature increase amount of the permanent magnet and the temperature increase amount of the coil is a predetermined value. It is also suitable.

  If it is such a structure, according to the heat_generation | fever state of a permanent magnet and a coil, it will become possible to cool more appropriately.

  Further, in the first state, it is preferable that the refrigerant is circulated to the second channel in addition to the first channel.

  With such a configuration, in the first state, the flow switching means circulates the refrigerant in the second flow path as well as in the first flow path, so that the coil is further cooled while reliably cooling the permanent magnet in the first state. Can be cooled.

  Here, it is preferable that the refrigerant flows from the axial center of the rotor to the first flow path and the second flow path.

  With such a configuration, it is possible to distribute the refrigerant to the first flow path and the second flow path using the centrifugal force accompanying the rotation of the rotor from the rotor axis, and supply the refrigerant concentrically to each part. . Therefore, since the refrigerant without temperature unevenness can be circulated through the permanent magnets and coils provided in the rotating electrical machine, the rotating electrical machine can be effectively cooled.

  The rotor is preferably provided with a flow path for circulating a refrigerant in the rotor core.

  With such a configuration, the rotor can be uniformly cooled from the inside.

  The flow switching means preferably includes a control valve, and the control valve is preferably controlled by centrifugal force generated by rotation of the rotating electrical machine.

  With such a configuration, since the control valve is controlled so that the flow state of the refrigerant to each of the first flow path and the second flow path can be switched by centrifugal force, the flow according to the rotation speed of the rotating electrical machine It is possible to switch the state.

  Alternatively, the flow switching means may include a control valve, and the control valve may be controlled by hydraulic pressure of hydraulic oil.

  With such a configuration, the control valve is controlled so that the flow state of the refrigerant to each of the first flow path and the second flow path can be switched by the hydraulic pressure of the hydraulic oil. It is possible to freely switch the distribution state according to one or both of the torques.

  Preferably, the coil is provided in a stator, and the permanent magnet is provided in a rotor.

  The above configuration can also be applied to a motor having a configuration in which a coil is provided in a stator and a permanent magnet is provided in a rotor, such as a permanent magnet type synchronous motor.

In addition, the coil is provided in a stator, the permanent magnet is provided in a rotor,
The refrigerant flowing through the first flow path cools the coil after flowing through the rotor core and cooling the permanent magnet, and the refrigerant flowing through the second flow path passes through the rotor core without flowing through the rotor core. It is preferable that the coil is cooled.

  If it is such a structure, a coil can be cooled with the refrigerant | coolant after cooling the permanent magnet distribute | circulated to the 1st flow path. Therefore, the coil can be cooled to some extent even in a state where the refrigerant is circulated through only the first flow path.

  The output torque of the rotating electrical machine is preferably calculated based on the coil current of the coil.

  With such a configuration, the output torque of the rotating electrical machine can be calculated based on the current instruction value flowing through the coil or the current value actually flowing through the coil.

1. First Embodiment Hereinafter, a cooling structure of a rotating electrical machine M that circulates and cools a cooling liquid to the rotating electrical machine M including a stator S and a rotor R according to the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view along a rotation axis A of a rotating electrical machine M that employs a cooling structure according to the present embodiment. As shown in FIG. 1, the rotating electrical machine M is configured such that the stator S and the rotor R are housed in a space formed by the case main body MC1 and a cover MC2 that covers the opening of the case main body MC1. The stator S is fixed to the case body MC1.

  The rotating electrical machine M according to the present embodiment acquires rotational power by the electromagnetic action of the coil C and the permanent magnet PM. Since the acquisition of the rotational power is a known technique, a description thereof will be omitted. In the present embodiment, description will be made assuming that the coil C is provided in the stator S and the permanent magnet PM is provided in the rotor R. Note that the cooling liquid in the following description corresponds to the refrigerant in the claims of the present application. As this cooling liquid, it is preferable to use a general cooling oil suitable for cooling the rotating electrical machine, but it is not limited to this.

  The rotor R is held in a case of the rotation axis A, and the rotation axis A is rotatably supported with respect to the case main body MC1 and the case MC2 via a support bearing BRG. FIG. 2 is a view showing a cross section of the rotary shaft A and the rotor R. FIG. However, the case main body MC1 and the stator S are omitted. As shown in FIG. 2, the rotor R is provided with a plurality of permanent magnets PM. Further, the rotor R includes a plurality of flow paths Rl for circulating a coolant in the rotor core. By allowing the coolant to flow through the flow path Rl in the rotor core, the permanent magnet PM can be cooled. In the flow path Rl, the coolant flows through the first flow path due to the centrifugal force generated by the rotation of the rotary shaft A from the coolant supply port in provided at the center of the rotary shaft A, that is, the centrifugal force generated by the rotation of the rotor R. and the distribution port B11 (details will be described later).

  Returning to FIG. 1, the rotating shaft A includes a connecting portion A <b> 1 for connecting to a conduction shaft (not shown) at one end, and outputs the driving force generated by the rotating electrical machine M to the outside of the rotating electrical machine M. Is configured to be possible. In such a case, the rotating electrical machine M functions as an electric motor. In addition, the rotating electrical machine M can function as a generator that generates power by the driving force transmitted from the outside to the rotating electrical machine M.

  The stator S is configured to include a stator core SC that is fixed to the case body MC1, and the coil ends CE of the coil C wound around the stator core SC are positioned outside both axial ends of the stator core SC. Yes. Although details are omitted, the stator core SC is configured by laminating a large number of ring-shaped steel plates p in the axial direction of the rotation axis A.

  The coil C is formed by winding a conducting wire around the stator core SC. The coil C is impregnated with an insulating varnish that insulates the conducting wires from each other, and is fixed in an insulated state. By this insulating varnish, the thermal conductivity between the stator core SC and the coil C is improved, and heat dissipation is improved.

  The above is the outline of the structure of the rotating electrical machine M that employs the cooling structure of the rotating electrical machine according to the present invention. Hereinafter, the cooling structure of the stator S by the coolant adopted in the rotating electrical machine M, and the rotor R The cooling structure will be described.

  The rotating electrical machine M includes a first flow path 11 through which a cooling liquid for cooling the permanent magnet PM flows, and a second flow path 12 through which a cooling liquid for cooling the coil C flows. Here, the rotating electrical machine M is supplied with the cooling liquid from the cooling liquid supply path in provided in the shaft center of the rotating shaft A by operating a pump (not shown). In order to cool the permanent magnet PM and the coil C, the cooling liquid supplied from the cooling liquid supply path in is supplied to one of the first flow path l1 and the second flow path l2. As described above, in the present embodiment, the permanent magnet PM is provided in the rotor R, and the coil C is provided in the stator S. Therefore, as shown in FIGS. 1 and 2, the first flow path 11 is formed so as to go from the coolant supply path in to the flow path Rl in the rotor core. As shown in FIG. 3, the second flow path 12 is formed so as to go from the coolant supply path in to the coil end CE of the stator S fixed to the inner surface of the case body MC1.

  As described above, the coolant supplied to the coolant supply path in is supplied to each part of the rotating electricity M including the first flow path 11 and the second flow path 12 by the centrifugal force generated by the rotation of the rotation shaft A. . Therefore, the first flow path 11 and the second flow path 12 are provided so as to penetrate linearly from the inner peripheral surface to the outer peripheral surface along the radial direction of the hollow rotation axis A. Further, the first flow path 11 is arranged such that the opening of the flow path Rl is positioned on the radially outer side of the rotation axis A with respect to the first flow path 11 so that the coolant is easily supplied to the flow path Rl in the rotor core. It is preferable to be provided. Further, the second flow path 12 cools the coil end CE by being injected by the centrifugal force from the second flow path 12 to the coil end CE, so that the cooling liquid easily reaches the coil end CE. It is preferable that the coil end CE is provided so as to be located radially outside the rotation axis A with respect to the second flow path 12.

  Between the first flow path 11 and the second flow path 12 and the coolant supply path in, flow switching as a flow switching means for switching the flow state of the coolant to each of the first flow path l1 and the second flow path l2. Part 10 is provided. The flow switching unit 10 includes a first control valve B1, a second control valve B2, a first spring sp1, and a second spring sp2. The first control valve B1, the second control valve B2, the first spring sp1, and the second spring sp2 are configured to form a set of these four types of parts. In FIG. 2, although shown as one set, it is not limited to this. For example, it is naturally possible to provide a plurality of sets along the circumferential direction of the rotation axis A. Here, the circulation state includes a state where the coolant is flowing and a state where the coolant is not flowing, and specifically corresponds to a state where the coolant flows and a state where the coolant does not flow. Therefore, the flow switching unit 10 switches between the state in which the coolant flows and the state in which the coolant does not flow for each of the first flow path 11 and the second flow path 12.

  The first control valve B1 has a communication port B1l that allows the coolant supply path in and the first flow path l1 to communicate with each other, and is arranged so as to be urged radially inward by the first spring sp1. Established. Here, FIG. 1 illustrates a state in which the first spring sp1 is contracted (hereinafter referred to as a contracted state) due to the centrifugal force accompanying the rotation of the rotating shaft A. When the first spring sp1 as shown in FIG. 1 is in a contracted state, the coolant flows from the coolant supply path in to the first flow path l1, but the coolant supply path in and the second flow path l2 Is closed by the first control valve B1, so that the coolant does not flow from the coolant supply path in to the second flow path l2.

  The second control valve B2 is a control valve that switches the flow state of the coolant through the communication port B2l formed between the first flow path 11 and the flow path Rl in the rotor core. Like the one spring sp1, it is arranged to be urged radially inward of the rotation axis A. Here, in FIG. 1, the second spring sp2 is also in a contracted state. When the second spring sp2 is in the contracted state as shown in FIG. 1, the first flow path 11 and the flow path Rl in the rotor core are in communication with each other, and the cooling liquid supplied to the cooling liquid supply path in The centrifugal force generated by the rotation (the force indicated by the white arrow) is able to flow through the flow path Rl in the rotor core. Therefore, as indicated by the broken line v, the coolant supplied from the coolant supply path in reaches the rotor R, and the permanent magnet PM provided in the rotor R is cooled. In addition, the coolant that flows through the flow path Rl in the rotor core and cools the permanent magnet PM is then coiled by the centrifugal force generated by the rotation of the rotary shaft A from the flow path Rl in the rotor core as indicated by the broken line w. Injected into CE. Therefore, the coil C is also cooled. Note that the state in which the flow switching unit 10 circulates the coolant through the first flow path 11 as described above is defined as the first state.

  Here, as described above, the cooling liquid is supplied to each part using the centrifugal force generated by the rotation of the rotating shaft A. Therefore, it is possible to distribute and inject the coolant uniformly to each part of the rotating electrical machine M.

  FIG. 3 is different from the first state shown in FIG. 1 in that the centrifugal force due to the rotation of the rotating shaft A is small and the first spring sp1 and the second spring sp2 are extended (hereinafter referred to as the extended state). Is shown. Note that FIG. 3 mainly shows only the upper part of the cross section of the rotating electrical machine M. When the first spring sp1 is in the extended state, a gap 100 is formed between the first control valve B1 and the inner wall of the coolant supply path in. Therefore, the coolant supplied to the coolant supply path in can pass through the gap 100 and be supplied to the first flow path l1 and the second flow path l2. Of course, the coolant can also be supplied to the first flow path 11 and the second flow path 12 from the communication port B11 provided in the first control valve B1.

  Further, when the second spring sp2 is in the extended state, the second control valve B2 is in contact with the outer peripheral surface of the rotary shaft A on the radially inner side of the rotary shaft A and closes the communication port B21, so that the first flow path 11 is provided. And the flow path Rl in the rotor core are closed. Therefore, the coolant does not flow through the first flow path 11. Therefore, the coolant supplied to the coolant supply path in is circulated only to the second flow path 12 without being supplied to the flow path Rl in the rotor core. The coolant flowing through the second flow path 12 is jetted onto the coil end CE as shown by the broken line x by the centrifugal force generated by the rotation of the rotating shaft A, thereby cooling the coil end CE. Therefore, the coil C is cooled. Thus, the state in which the circulation switching unit 10 circulates the coolant through the second flow path 12 is defined as the second state.

  Next, control of the first control valve B1 and the second control valve B2 will be described. The first control valve B1 and the second control valve B2 are controlled by a centrifugal force generated by the rotation of the rotating electrical machine M. As the rotation axis A rotates, centrifugal force around the rotation axis A acts on the rotor R, the rotation axis A, and the like. This centrifugal force similarly acts on the first control valve B1 and the second control valve B2. Here, the centrifugal force is a force in the direction toward the outside as viewed from the center of rotation (the force in the direction of the white arrow in FIG. 1), and the mass of each of the first control valve B1 and the second control valve B2 and each valve. It is proportional to the distance from the axis and increases in proportion to the square of the rotational speed. Therefore, the first control valve B1 and the second control valve B2 receive a force in the outward direction due to the centrifugal force. When the centrifugal force is larger than the urging force of the first spring sp1 and the urging force of the second spring sp2, as shown in FIG. 1, in the first control valve B1, the first spring sp1 A force acts so as to abut against the inner wall of the coolant supply path in against the urging force. In the second control valve B2, a force acts in a direction away from the rotation axis A against the urging force of the second spring sp2.

  On the other hand, when the centrifugal force is smaller than the urging force of the first spring sp1 and the urging force of the second spring sp2, as shown in FIG. 3, the first control valve B1 In accordance with the urging force, a force directed radially inward of the rotation axis A acts. Even in the second control valve B2, a force directed radially inward of the rotary shaft A acts according to the urging force of the second spring sp2. Thus, the first control valve B1 and the second control valve B2 are controlled by the urging force of the first spring sp1 and the urging force of the second spring sp2 and the centrifugal force generated by the rotation of the rotating electrical machine M. Here, the spring constant of the first spring sp1 and the spring constant of the second spring sp2 are equal to the urging force of the spring due to the centrifugal force acting on each of the first control valve B1 and the second control valve B2 at substantially the same rotational speed. As determined respectively. Accordingly, the first control valve B1 and the second control valve B2 can operate simultaneously to switch the flow state of the first flow path 11 and the second flow path 12. In this case, from the viewpoint of ensuring the cooling of the permanent magnet PM and the coil C, it is preferable that the first control valve B1 and the second control valve B2 are not in a state in which neither coolant flows.

  As described above, the first state and the second state are switched by the distribution switching unit 10. In the present embodiment, switching is performed depending on whether or not the rotational speed of the rotating electrical machine M is equal to or higher than a predetermined switching rotational speed. That is, when the rotational speed of the rotating electrical machine M is equal to or higher than the predetermined switching rotational speed, the first state where the coolant flows through the first flow path l1 is set, and the rotational speed of the rotating electrical machine M is less than the predetermined switching rotational speed. In the second state, the coolant is circulated through the second flow path 12.

  In the present embodiment, a switching rotational speed for switching between the first state and the second state is set in advance. This switching speed is determined by the weight of the first control valve B1 and the second control valve B2, the positions where the respective valves are provided, and the spring constants of the springs of the respective valves. That is, the weights of the first control valve B1 and the second control valve B2, the positions where the respective valves are provided, and the respective positions so that the flow states of the first flow path 11 and the second flow path 12 are switched at a desired number of revolutions. A spring constant of a spring included in the valve is set.

  FIG. 4 illustrates a switching map between the first state and the second state according to the present embodiment. The switching rotational speed is set to coincide with the rotational speed indicated in the switching map. When the rotational speed of the rotating electrical machine M is high, the exchange of magnetic flux across the permanent magnet PM increases, and hysteresis loss, eddy current loss, that is, iron loss increases, and the permanent magnet PM tends to easily generate heat. . According to the present embodiment, as shown in FIG. 4, when the rotational speed of the rotating electricity M is higher than the switching rotational speed, a large amount of coolant is supplied to the permanent magnet PM side to cool the permanent magnet PM. Can do. On the other hand, when the rotational speed of the rotating electrical machine M is low, it is often desirable to obtain a high output torque. In such a case, the current flowing through the coil is increased, the copper loss is increased, and the coil is likely to generate heat. According to this embodiment, as shown in FIG. 4, when the rotational speed of the rotating electricity M is less than the switching rotational speed, the coolant can be supplied to the coil C side to cool the coil C. Therefore, it is possible to efficiently cool a portion that needs to be cooled according to the operating state of the rotating electrical machine M.

2. Second Embodiment Next, a second embodiment of the cooling structure for the rotating electrical machine M according to the present invention will be described. In the second embodiment, the control valve B that constitutes the flow switching unit 10 that switches the flow state of the cooling liquid to each of the first flow path 11 and the second flow path 12 is controlled by hydraulic pressure. Different from one embodiment. Since the configuration other than the distribution switching unit 10 is the same as that of the first embodiment, the distribution switching unit 10 will be mainly described here.

  FIG. 5 is a diagram (an enlarged view of a main part of the invention) showing a first state according to the second embodiment. The control valve B in the present embodiment is provided so as to be positioned in the first flow path 11 and the second flow path l2, and the communication port B1l and the second flow path 12 for communicating the first flow path l1 are communicated. A communication port B21 for forming a state is formed. In addition, the control valve B is provided with a hydraulic chamber 30 to which hydraulic oil is supplied from the hydraulic control unit 20 at one end, and a spring sp at the other end. The control valve B in this embodiment is controlled by the hydraulic pressure of the hydraulic oil and the biasing force of the spring sp.

  Here, also in the present embodiment, the first state is a state in which the coolant flows through the first flow path 11, and the second state is a state in which the coolant flows through the second flow path 12. In the first state shown in FIG. 5, the hydraulic pressure of the hydraulic oil supplied to the hydraulic chamber 30 is increased by the hydraulic control unit 20 and becomes stronger than the urging force of the spring sp. As a result, the control valve B is moved in the left direction in the figure. Accordingly, the communication port B11 of the control valve B communicates with the first flow path 11 and the centrifugal force generated by the rotation of the rotating shaft A causes the coolant to flow from the coolant supply path in to the first flow path 11 as indicated by the broken line v. To flow to the flow path Rl in the rotor core. Therefore, the permanent magnet PM provided in the rotor R is cooled. In addition, the coolant that flows through the flow path Rl in the rotor core and cools the permanent magnet PM is then coiled as indicated by the broken line w by the centrifugal force generated by the rotation of the rotary shaft A from the flow path Rl in the rotor core. It is injected into the end CE. Therefore, the coil C is also cooled.

  On the other hand, the second state in the present embodiment is shown in FIG. In the second state, the hydraulic pressure of the hydraulic oil supplied to the hydraulic chamber 30 by the hydraulic control unit 20 becomes weaker than the biasing force of the spring sp, and the control valve B is moved in the right direction in the figure by the biasing force of the spring sp. . Therefore, the communication port B2l of the control valve B communicates with the second flow path l2, and the coolant flows from the coolant supply path in to the second flow path as indicated by the broken line x due to the centrifugal force generated by the rotation of the rotary shaft A. It is injected to the coil end CE via l2. Therefore, the coil C is cooled.

  Also in this embodiment, the first state and the second state are switched by the distribution switching unit 10. In the present embodiment, switching is performed depending on whether or not the output torque of the rotating electrical machine M is equal to or higher than a predetermined switching torque. Here, the output torque of the rotating electrical machine M is preferably calculated based on the coil current flowing through the coil C. As for this coil current, a control unit (not shown) of the rotating electrical machine M can calculate an output torque based on a current instruction value to be passed through the coil C calculated according to an output required for the rotating electrical machine M. . Alternatively, it is possible to measure the current value actually flowing through the coil C during operation of the rotating electrical machine M and calculate the output torque based on the measurement result.

  In the present embodiment, a switching torque for switching between the first state and the second state is set in advance. This switching torque is determined in advance based on the switching map shown in FIG. FIG. 7 illustrates a switching map between the first state and the second state according to the present embodiment. Then, the hydraulic control unit 20 supplies hydraulic pressure to the hydraulic chamber 30 so that the distribution state between the first state and the second state is switched when the output torque obtained by calculation as described above becomes a predetermined switching torque. Is switched between a high pressure state in which the pressure is supplied and a low pressure state in which the hydraulic pressure is not supplied. In the present embodiment, the first state is as shown in FIG. 5 when the hydraulic pressure is supplied to the hydraulic chamber 30, and the second state is shown as shown in FIG. 6 when the hydraulic pressure is not supplied to the hydraulic chamber 30.

  As shown in FIG. 7, when the output torque of the rotating electrical machine M is high, the coil C often tends to generate heat. According to the present embodiment, when the output torque of the rotating electrical machine M is higher than the switching torque, the refrigerant can be supplied to the coil C side and the coil C can be cooled. On the other hand, when the output torque of the rotating electrical machine M is small, the permanent magnet PM is likely to generate heat. According to this embodiment, when the output torque of the rotating electrical machine M is less than the switching torque, a large amount of refrigerant can be supplied to the permanent magnet PM side to cool the permanent magnet PM. Therefore, it becomes possible to cool efficiently the site | part which needs cooling.

3. Third Embodiment Next, a third embodiment of the cooling structure for the rotating electrical machine M according to the present invention will be described. In the third embodiment, the control valve B switches the flow state of the first flow path 11, and the second flow path 12 is different from the above-described embodiment in that the coolant flows regardless of the control of the control valve B. Since the configuration other than the distribution switching unit 10 is the same as that of the first embodiment, the distribution switching unit 10 will be mainly described here.

  FIG. 8 is a diagram (an enlarged view of a main part of the invention) showing a first state according to the third embodiment. The control valve B in the present embodiment functions as a control valve that switches a coolant flow state between the coolant supply path in and the first flow path l1. The control valve B is formed such that the surface on the side in contact with the inner wall of the coolant supply path in has a predetermined angle θ with the rotation axis A, and is biased by the spring sp. Also in this embodiment, the centrifugal force indicated by the white arrow acts on the control valve B. Here, as described above, the contact surface of the control valve B is formed so as to have a predetermined angle θ with the rotation axis A, so that the control valve B faces outward in the radial direction of the rotation axis A. The component force in the direction along the inner wall surface inclined by the angle θ of the centrifugal force acting as a force becomes the force for moving the control valve B. The control valve B in this embodiment is controlled by the balance between the force in the direction along the inclined inner wall surface, which is a component of the centrifugal force, and the biasing force of the spring sp.

  In the first state shown in FIG. 8, the centrifugal force corresponding to the white arrow acts on the control valve B as the rotary shaft A rotates. Here, since the control valve B is formed so that the surface that contacts the inner wall of the coolant supply path in has an angle θ, the control valve B tries to move along the inner wall surface inclined by centrifugal force. When the force to be applied becomes larger than the biasing force of the spring sp, the control valve B moves in the left direction in the figure. As a result, the control valve B is opened, the coolant supply path in and the first flow path 11 are communicated, and the coolant is cooled as shown by the broken line v due to the centrifugal force generated by the rotation of the rotating shaft A. It circulates from the supply path in to the flow path Rl in the rotor core via the first flow path l1. Therefore, the permanent magnet PM provided in the rotor R is cooled. In addition, the coolant that flows through the flow path Rl in the rotor core and cools the permanent magnet PM is then coiled as indicated by the broken line w by the centrifugal force generated by the rotation of the rotary shaft A from the flow path Rl in the rotor core. It is injected into the end CE. Therefore, the coil C is also cooled.

  Furthermore, in the present embodiment, a control valve for controlling the flow state of the cooling liquid is not provided between the second flow path 12 and the cooling liquid supply path in, so that the control valve is supplied from the cooling liquid supply path in. The coolant is circulated through the second flow path 12 in addition to the first flow path 11 as indicated by the broken line x by the centrifugal force generated by the rotation of the rotating shaft A, and is injected into the coil end CE. Therefore, the coil C is also cooled by the coolant passing through the second flow path 12.

  On the other hand, the 2nd state which concerns on 3rd embodiment is shown in FIG. 9 (enlarged view of the principal part of invention). In the second state, the centrifugal force becomes weaker than the biasing force of the spring sp, and the control valve B moves in the right direction in the figure by the biasing force of the spring sp along the inner wall surface. Therefore, the control valve B is in a closed state, and the coolant does not flow from the coolant supply path in to the first flow path l1. In addition, since no control valve for controlling the flow state of the coolant is provided between the second flow path 12 and the coolant supply path in, the cooling is performed in the second state as in the first state described above. The coolant supplied from the liquid supply path in flows through the second flow path 12 as indicated by the broken line x by the centrifugal force generated by the rotation of the rotary shaft A, and is injected into the coil end CE. Therefore, the coil C is cooled.

  Also in this embodiment, the first state and the second state are switched by the distribution switching unit 10 at a predetermined switching speed. This switching rotational speed is set so as to coincide with the switching rotational speed shown in the switching map shown in FIG. 4 as in the first embodiment. Note that the switching rotational speed in the present embodiment is also determined by the weight of the control valve B, the position where the control valve B is provided, and the spring constant of the spring sp, as in the first embodiment. That is, the weight of the control valve B, the position where the control valve B is provided, and the spring constant of the spring sp are set so that the flow state of the first flow path 11 is switched at a predetermined switching speed.

4). Fourth Embodiment Next, a fourth embodiment of the cooling structure for the rotating electrical machine M according to the present invention will be described. The fourth embodiment differs from the third embodiment described above in that the control valve B that switches the flow state of the first flow path 11 is controlled by hydraulic pressure. Since the configuration other than the distribution switching unit 10 is the same as that of the first embodiment, the distribution switching unit 10 will be mainly described here.

  FIG. 10 is a diagram (an enlarged view of the main part of the invention) showing a first state according to the fourth embodiment. The control valve B in the present embodiment is provided in the first flow path l1 and is formed with a communication port B1l for bringing the first flow path l1 into a communication state. In addition, the control valve B is provided with a hydraulic chamber 30 to which hydraulic oil is supplied from the hydraulic control unit 20 at one end, and a spring sp at the other end. The control valve B in this embodiment is controlled by the hydraulic pressure of the hydraulic oil and the biasing force of the spring sp.

  Here, also in the present embodiment, the first state is a state in which the coolant flows through the first flow path 11, and the second state is a state in which the coolant flows through the second flow path 12. In the first state shown in FIG. 10, the hydraulic pressure of the hydraulic oil supplied to the hydraulic chamber 30 by the hydraulic control unit 20 is increased and becomes stronger than the urging force of the spring sp. As a result, the control valve B can be moved in the left direction in the figure. Accordingly, the communication port B11 of the control valve B communicates with the first flow path 11 and the centrifugal force generated by the rotation of the rotating shaft A causes the coolant to flow from the coolant supply path in to the first flow path 11 as indicated by the broken line v. To flow to the flow path Rl in the rotor core. Therefore, the permanent magnet PM provided in the rotor R is cooled. In addition, the coolant that flows through the flow path Rl in the rotor core and cools the permanent magnet PM is then coiled as indicated by the broken line w by the centrifugal force generated by the rotation of the rotary shaft A from the flow path Rl in the rotor core. It is injected into the end CE. Therefore, the coil C is also cooled.

  Further, also in the present embodiment, a control valve for controlling the flow state of the cooling liquid is not provided between the second flow path 12 and the cooling liquid supply path in, so that the control valve is supplied from the cooling liquid supply path in. The coolant is circulated through the second flow path 12 in addition to the first flow path 11 as indicated by the broken line x by the centrifugal force generated by the rotation of the rotating shaft A, and is injected into the coil end CE. Therefore, the coil C is also cooled by the coolant passing through the second flow path 12.

  On the other hand, the second state according to the fourth embodiment is shown in FIG. In the second state, the hydraulic pressure of the hydraulic oil supplied to the hydraulic chamber 30 by the hydraulic control unit 20 is reduced and becomes weaker than the urging force of the spring sp. Therefore, the control valve B is moved in the right direction in the figure by the biasing force of the spring sp. As a result, the control valve B is closed, and the coolant does not flow from the coolant supply path in to the first flow path 11. Moreover, since the control valve which controls the distribution | circulation state of a cooling fluid is not provided between the 2nd flow path 12 and the cooling fluid supply path in, like the above-mentioned 1st state, from the cooling fluid supply path in The supplied coolant flows through the second flow path 12 as indicated by the broken line x by the centrifugal force generated by the rotation of the rotation shaft A, and is injected into the coil end CE. Therefore, the coil C is cooled.

  Also in this embodiment, the first state and the second state are switched by the distribution switching unit 10 with a predetermined switching torque. This switching is performed by the hydraulic control unit 20 based on the switching map shown in FIG. 5 as in the second embodiment. That is, the hydraulic pressure control unit 20 switches the hydraulic pressure supplied to the hydraulic chamber 30 when the output torque calculated from the current flowing through the coil C becomes a predetermined switching torque, so that the distribution state of the first state and the second state Switch.

5). Other Embodiments (1) In the above embodiment, the coil C is provided in the stator S and the permanent magnet PM is provided in the rotor R. However, the scope of application of the present invention is not limited to this. Of course, it is also possible to configure so that the coil C is provided in the rotor R and the permanent magnet PM is provided in the stator S. If it is such a structure, the structure of the 1st flow path 11 and the 2nd flow path 12 will also be changed according to arrangement | positioning of the coil C and the permanent magnet PM.

(2) In the above embodiment, the control valve B (including the first control valve B1 and the second control valve B2) has been described as being either in the open state or the closed state. However, the scope of application of the present invention is not limited to this. For example, it is of course possible to adopt a configuration in which the opening degree is adjusted and an intermediate state is set instead of either the valve open state or the valve closed state.

(3) In the above-described embodiment, the control valve B (including the first control valve B1 and the second control valve B2) is switched between the rotation speed of the rotating electrical machine M and a preset switching rotational speed, It demonstrated that it was performed by the distribution switching part 10 according to output torque and the preset switching torque. However, the scope of application of the present invention is not limited to this. Based on the switching boundary line cl defined by the relationship between the rotational speed of the rotating electrical machine M and the output torque, in the first region α1 on one side of the switching boundary line cl, the first state in which the coolant flows through the first flow path l1. Naturally, it is possible to control the second region α2 on the other side of the switching boundary line cl to be in the second state in which the coolant flows through the second flow path l2.

  At this time, for example, it is preferable that the switching boundary line cl as shown in FIG. 12 is a substantially right-up line in which the output torque gradually increases as the rotational speed of the rotating electrical machine M increases. In this case, it is preferable that the high rotation / low torque side of the switching boundary line cl is the first region α1, and the low rotation / high torque side of the switching boundary line cl is the second region α2.

  More specifically, the switching boundary line cl is defined as the relationship between the rotational speed of the rotating electrical machine M and the output torque such that the ratio of the temperature rise amount of the permanent magnet PM and the temperature rise amount of the coil C becomes a predetermined value. It is suitable that it is such. FIG. 12 shows the switching boundary line cl defined in this way. With such a configuration, the distribution switching unit 10 divides the operating state of the rotating electrical machine M by the switching boundary line cl defined by the relationship between the temperature increase amount of the permanent magnet PM and the temperature increase amount of the coil C. In order to switch the circulation state of the coolant in the first flow path 11 and the second flow path 12 in accordance with the first region α1 or the second region α2, it is permanent according to both the rotational speed of the rotating electrical machine M and the output torque. In a state where the temperature rise of the magnet PM is large, a large amount of coolant is supplied to the permanent magnet PM side, and in a state where the temperature rise of the coil C is large, the coolant is supplied to the coil C side. Cooling is possible. Therefore, it becomes possible to cool appropriately according to the heat generation state of the coil C and the permanent magnet PM. In such a case, it may be applied to the configuration of hydraulic control as in the second embodiment and the fourth embodiment described above, and controlled using a switching map as shown in FIG. Note that the temperature increase amount is preferably defined as the temperature increase amount per unit time.

Here, similarly to each of the above-described embodiments, for example, when the coil C is provided in the stator S and the permanent magnet PM is provided in the rotor R, the switching boundary line cl satisfies the following expression (1). It is preferable to determine.
[(Copper loss + stator iron loss) / coil heat capacity] = [rotor iron loss / magnet heat capacity] (1)
The copper loss is a loss generated as Joule heat when a current is passed through the coil C, and the stator iron loss includes eddy current loss and hysteresis loss of the iron plate constituting the stator S. The rotor iron loss includes eddy current loss of the iron plate constituting the rotor R, hysteresis loss, and eddy current loss of the magnet. The coil heat capacity is the heat capacity of the coil C, and the magnet heat capacity is the heat capacity of the permanent magnet PM.

  When the switching boundary line cl is determined so that the above expression (1) is established, [(copper loss + stator iron loss) / coil heat capacity]> [rotor iron loss / magnet heat capacity], that is, [stator S (coil C) In the case of [temperature increase amount]> [temperature increase amount of rotor R (permanent magnet PM)], the flow switching unit 10 may actively cool the coil C by switching the flow state of the coolant to the second state. it can. On the other hand, [(copper loss + stator iron loss) / coil heat capacity] <[rotor iron loss / magnet heat capacity], that is, [temperature rise of stator S (coil C)] <[temperature rise of rotor R (permanent magnet PM)] In the case of amount, the flow switching unit 10 can actively cool the permanent magnet PM by switching the flow state of the coolant to the first state. Therefore, the rotating electrical machine M can be appropriately cooled according to the heat generation state of the permanent magnet PM and the coil C.

  Further, the switching boundary line cl can be determined by an experiment performed in advance. Such a determination method is preferably performed as follows. First, the rotating electrical machine M is operated by appropriately changing the rotational speed and output torque of the rotating electrical machine M. At that time, the temperature rise amount of the permanent magnet PM and the temperature rise amount of the coil C are measured in accordance with the change in the rotational speed of the rotating electrical machine M and the output torque. It is preferable to determine the switching boundary line cl based on the relationship between the rotational speed of the rotating electrical machine M, the output torque, the temperature rise amount of the permanent magnet PM, and the temperature rise of the coil C measured in this way. Then, a switching map as shown in FIG. 12 is created based on the switching boundary line cl determined by the experiment, and the flow switching unit 10 switches the flow state of the coolant according to the switching map, whereby the rotating electrical machine M is changed. It becomes possible to cool appropriately.

  Here, in the above embodiment, the switching boundary line cl is the relationship between the rotational speed of the rotating electrical machine M and the output torque such that the ratio of the temperature rise amount of the permanent magnet PM and the temperature rise amount of the coil C becomes a predetermined value. As explained as defined. The ratio between the temperature increase amount of the permanent magnet PM and the temperature increase amount of the coil C being a predetermined value is not limited to 1. The predetermined value may be changed to another value according to the configuration or operating status of the rotating electrical machine M, or the predetermined value may have a range.

(4) In the second embodiment and the fourth embodiment, the control valve B has been described as being controlled by the output torque. However, the scope of application of the present invention is not limited to this. As in the first embodiment and the third embodiment, it is naturally possible to control by the number of rotations of the rotating electrical machine M. In such a case, it is good to control using a switching map as shown in FIG.

  The present invention can be used for various known rotating electrical machines that include a stator and a rotor and require cooling.

The schematic diagram which shows the 1st state of the cooling structure of the rotary electric machine which concerns on 1st embodiment of this invention. The figure which shows typically the cross section of the rotating shaft and rotor which concern on this invention The schematic diagram which shows the 2nd state of the cooling structure of the rotary electric machine which concerns on 1st embodiment of this invention. The figure which shows the switching map of the 1st state switched according to the rotation speed of the rotary electric machine which concerns on this invention, and a 2nd state. The schematic diagram which shows the 1st state of the cooling structure of the rotary electric machine which concerns on 2nd embodiment of this invention. The schematic diagram which shows the 2nd state of the cooling structure of the rotary electric machine which concerns on 2nd embodiment of this invention. The figure which shows the switching map of the 1st state switched according to the output torque of the rotary electric machine which concerns on this invention, and a 2nd state. The schematic diagram which shows the 1st state of the cooling structure of the rotary electric machine which concerns on 3rd embodiment of this invention. The schematic diagram which shows the 2nd state of the cooling structure of the rotary electric machine which concerns on 3rd embodiment of this invention. The schematic diagram which shows the 1st state of the cooling structure of the rotary electric machine which concerns on 4th embodiment of this invention. The schematic diagram which shows the 2nd state of the cooling structure of the rotary electric machine which concerns on 4th embodiment of this invention. The figure which shows the switching map of the 1st state and 2nd state switched according to the rotation speed and output torque of the rotary electric machine which concern on this invention.

Explanation of symbols

10: Distribution switching unit (distribution switching means)
A: Rotating shaft A1: Connecting part B: Control valve B1: First control valve B11: Communication port B2: Second control valve B21: Communication port BRG: Support bearing C: Coil CE: Coil end in: Coolant supply path 11 : First flow path l2: second flow path M: rotating electrical machine M1: case body p: steel plate PM: permanent magnet R: rotor Rl: flow path in the rotor core: stator SC: stator core sp: spring sp1: first spring sp2 : Second spring

Claims (13)

A cooling structure for a rotating electrical machine that cools a rotating electrical machine including a stator and a rotor by circulating a refrigerant,
A permanent magnet provided on one of the stator and the rotor;
A coil provided on the other of the stator and the rotor;
A first flow path through which a refrigerant for cooling the permanent magnet flows;
A second flow path through which a refrigerant for cooling the coil flows;
Based on one or both of the rotational speed and output torque of the rotating electrical machine, flow switching means for switching the refrigerant flow state to each of the first flow path and the second flow path,
A cooling structure for a rotating electrical machine.   The flow switching means includes a first state in which the refrigerant flows through the first flow path when the rotational speed of the rotating electrical machine is equal to or higher than a predetermined switching rotational speed, and the rotational speed of the rotating electrical machine is less than the switching rotational speed. The cooling structure for a rotating electrical machine according to claim 1, wherein the state is switched to a second state in which the refrigerant flows through the second flow path.   The flow switching means includes a first state in which the refrigerant flows through the first flow path when the output torque of the rotating electrical machine is less than a predetermined switching torque, and the output switching torque when the output torque of the rotating electrical machine is greater than or equal to the switching torque. The cooling structure for a rotating electrical machine according to claim 1, wherein the second state is switched to a second state in which the refrigerant flows through the second flow path.   The distribution switching means distributes the refrigerant to the first flow path in the first region on one side of the switching boundary line based on the switching boundary line defined by the relationship between the rotation speed of the rotating electrical machine and the output torque. 2. The cooling structure for a rotating electrical machine according to claim 1, wherein the first state is set to a second state in which the refrigerant flows through the second flow path in the second region on the other side of the switching boundary line.   5. The switching boundary line is defined as a relationship between a rotational speed of the rotating electrical machine and an output torque at which a ratio of a temperature increase amount of the permanent magnet and a temperature increase amount of the coil becomes a predetermined value. Cooling structure for rotating electrical machines.   The cooling structure for a rotating electrical machine according to any one of claims 2 to 5, wherein in the first state, the refrigerant flows to the second flow path in addition to the first flow path.   The cooling structure for a rotating electrical machine according to any one of claims 1 to 6, wherein the refrigerant flows from the axis of the rotor to the first flow path and the second flow path.   The cooling structure for a rotating electrical machine according to any one of claims 1 to 7, wherein the rotor includes a flow path for circulating a refrigerant in the rotor core. The flow switching means includes a control valve,
The cooling structure for a rotating electrical machine according to any one of claims 1 to 8, wherein the control valve is controlled by a centrifugal force generated by the rotation of the rotating electrical machine. The flow switching means includes a control valve,
The cooling structure for a rotating electric machine according to any one of claims 1 to 8, wherein the control valve is controlled by hydraulic pressure of hydraulic oil.   The cooling structure for a rotating electrical machine according to any one of claims 1 to 10, wherein the coil is provided in a stator, and the permanent magnet is provided in a rotor. The coil is provided in a stator, the permanent magnet is provided in a rotor,
The refrigerant flowing through the first flow path cools the coil after flowing through the rotor core and cooling the permanent magnet,
The cooling structure for a rotating electrical machine according to claim 8, wherein the refrigerant flowing through the second flow path cools the coil without flowing through the rotor core.   The cooling structure for a rotating electrical machine according to any one of claims 1 to 12, wherein an output torque of the rotating electrical machine is calculated based on a coil current of the coil.

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