JP6572834B2 - Rotating electric machine with cooling structure - Google Patents

Description

  The present invention relates to a rotating electrical machine.

  The rotating electrical machine includes a rotor having a permanent magnet therein, and a stator that is disposed on the outer peripheral side of the rotor and in which a coil is wound around a stator core. When mechanical power is obtained by operating the rotating electrical machine as a motor, a current is passed through the coil to apply a rotational force to the rotor. In addition, when the electric power is generated by the rotating electrical machine and the electric power is obtained, the rotor is rotated by the external rotational force, and the current generated in the coil is taken out.

  When this mechanical power or electric power is obtained, the coils in the stator and the permanent magnets in the rotor generate heat. Considering the endurance temperature of the insulating material that covers the coil and the demagnetization of the permanent magnet that increases with temperature, the coil and permanent magnet must be kept below a certain temperature, and it is necessary to cool the rotating electrical machine that contains them. There is.

  The rotating electrical machine may be cooled by a liquid cooling method using a liquid such as cooling water or oil as a cooling medium.

  Patent Document 1 discloses that the coolant is directly supplied from the coolant supply port to the outer peripheral surface of the coil or the stator core.

JP 2012-191809 A

  However, since the coolant supplied in Patent Document 1 flows along the outer peripheral surface of the stator, there is a problem that it is difficult to cool the rotor inside the stator.

  Accordingly, the stator core is provided with a flow path that communicates the inner peripheral surface and the outer peripheral surface of the stator core, and the cooling liquid supplied to the outer peripheral surface of the stator core is supplied to the rotor located on the inner peripheral side of the stator core to solve the above-described problems. It is possible to do.

  However, when cooling liquid is supplied to the outer peripheral surface of the stator, most of the supplied cooling liquid flows vigorously along the outer peripheral surface of the stator, so that a flow from the outer peripheral surface of the stator to the inner peripheral surface is generated in the cooling liquid. Hard to do. For this reason, the cooling liquid cannot be efficiently supplied to the flow path connecting the outer peripheral surface and the inner peripheral surface of the stator, and sufficient cooling liquid cannot be supplied to the rotor located on the inner peripheral side of the stator. As a result, there arises a problem that the rotor cannot be sufficiently cooled.

  The present invention is for solving the above-described problems, and provides a rotating electrical machine having a cooling structure capable of sufficiently cooling a rotor.

A cylindrical stator having a hollow portion;
A rotating electrical machine that is disposed on the inner peripheral side of the hollow portion of the stator and that rotates about a rotation axis, and that is supplied to the outer peripheral surface of the stator and flows along the outer peripheral surface of the stator In
The stator has a communication channel that connects the inner peripheral surface of the stator and the outer peripheral surface of the stator;
A protrusion that protrudes from the outer peripheral surface of the stator and that forms a trough that retains the coolant flowing along the outer peripheral surface of the stator with the outer peripheral surface of the stator , and
Opening of the communication passage formed in the outer circumferential surface of the stator, the valley formed by the outer peripheral surface and the projecting portion of the stator, and the outer peripheral surface of the stator than the protrusion A rotating electrical machine characterized by being provided on the upstream side of a flow of coolant flowing along .

In the rotating electrical machine of the present invention, a cylindrical stator having a hollow portion, a communication channel that communicates the outer peripheral surface and the inner peripheral surface of the stator, and a flow that protrudes from the outer peripheral surface of the stator and flows along the outer peripheral surface of the stator. And a protrusion that forms a trough for retaining the coolant with the outer peripheral surface of the stator . Furthermore, the opening of the communication flow path formed on the outer peripheral surface of the stator is in the valley formed by the outer peripheral surface of the stator and the protruding portion, and the coolant flowing along the outer peripheral surface of the stator rather than the protruding portion . It is provided upstream of the flow .
Therefore, after the coolant supplied to the outer peripheral surface of the rotating electrical machine flows along the outer peripheral surface, it collides with the projecting portion, stays in the valley formed by the outer peripheral surface of the stator and the projecting portion, and cools through the communication channel. A flow from the outer peripheral surface of the stator toward the inner peripheral surface is generated in the liquid. As a result, it becomes easy to supply to the opening part of the flow path which connects the outer peripheral surface and the inner peripheral surface of the stator.
Therefore, the rotating electrical machine of the present invention can efficiently supply the coolant supplied to the outer peripheral surface of the stator to the rotor on the inner peripheral side of the stator, thereby sufficiently cooling the rotor.

It is a figure which shows the stator of the rotary electric machine which concerns on this invention. It is a figure which shows the cross section containing the rotating shaft line X of the rotary electric machine which concerns on this invention. FIG. 3 is a view showing a cross section orthogonal to the rotation axis X of the stator of the rotating electrical machine according to the present invention. It is a figure which shows the other example of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  A rotating electrical machine including the cooling structure according to the first embodiment will be described with reference to FIGS. As shown in FIG. 2, the rotating electrical machine 10 includes a cylindrical stator 100 and a columnar rotor 400 disposed coaxially with the cylindrical shape of the stator 100. A rotation shaft 403 passes through the center of the rotor 400. A stator 100 shown in FIGS. 1 and 3 includes a stator core 101 in which irregularities are arranged along the circumferential direction on the inner periphery. A coil is housed in a concave portion (hereinafter referred to as a slot) provided on the inner periphery of the stator core 101, and this coil is wound around a convex portion (hereinafter referred to as a tooth) to form a coil 300. By supplying electric power to the coil 300, a magnetic field for rotating the rotor is formed in the space inside the stator 100.

  On the outer periphery of the stator core 101, three projecting portions 104 extending outward from the outer peripheral edge are provided. A through hole is formed in the protruding portion 104. Bolts pass through these through holes to bind the stacked steel plates. The number of protrusions 104 and the number of through holes may be other than three.

Further, the stator core 101 is provided with three communication flow paths (hereinafter referred to as flow paths) 105 that communicate the inner peripheral surface and the outer peripheral surface of the stator core 101. 105a, 105b, and 105c are formed as flow path inlets on the outer surface of the stator core. In the present embodiment, channel outlets 106a, 106b, and 106c are formed at the tips of the teeth 102 as outlets of the channel inlets 105a, 105b, and 105c, respectively. In addition, a coolant supply pipe 200 that supplies a coolant toward the outer peripheral surface of the stator core 101 at a certain distance from the stator core 101 is provided.

  The rotor 400 has a cylindrical shape as a whole, and is disposed with a slight gap at the inner periphery of the stator 100, particularly at the tip of the teeth 102. In the rotor 400, a permanent magnet 402 is embedded in the outer peripheral surface of the rotor core 401 or in the vicinity of the outer peripheral surface. It is also possible to provide portions with different reluctance in the circumferential direction of the rotor core 401, and to rotate the rotor 400 by interaction with this and the rotating magnetic field. The rotating shaft 403 is fixed to the rotor 400 so as to rotate integrally with the rotor 400. When the rotating electrical machine 10 functions as an electric motor, the rotating shaft 403 serves as an output shaft that outputs the rotational force generated by the rotor to the outside. When the rotating electrical machine 10 functions as a generator, the external rotating force is input to the rotating electrical machine. It becomes the input shaft for.

  When the rotating electrical machine 10 is disposed in a transaxle of an automobile, the coolant can be a transaxle lubricating oil or hydraulic fluid. The coolant is supplied to the outer peripheral surface of the stator core 101 from a coolant supply port 201 that is supplied by a pump (not shown) and is an opening at the end of the coolant supply pipe 200. Although the coolant supply pipe 200 is shown in a tubular form in the drawing, it may be a flow path formed by making a hole in a case (for example, a transaxle case) that houses the rotating electrical machine 10.

  In the cooling structure of the rotating electrical machine 10, the coolant supply port 201 is arranged vertically above the rotation axis of the stator 100 as shown in FIG. 3, and supplies coolant to the outer peripheral surface of the stator core 101 from here. The position of the coolant supply port 201 may be shifted from the above-described vertical upper position, or two or more may be provided.

  When a current is passed through the coil 300, the coil 300 generates heat. In the coil in the slot 103, the generated heat is transmitted to the surrounding stator core 101. Further, in the high-speed rotation region of the rotating electrical machine, the permanent magnet generates heat due to the eddy current generated in the permanent magnet 402, and the heat is transmitted to the surrounding rotor core 401. Therefore, efficient cooling of the rotating electrical machine 10 including the stator core 101 and the rotor core 401 is required.

  The coolant supplied to the outer peripheral surface of the stator core 101 flows along the outer peripheral surface of the stator core 101 in the direction of the broken arrow in FIGS. The cooling liquid supplied from the cooling liquid supply port 201 is not concentratedly supplied to the flow path inlet 105 b located directly below the cooling liquid supply port 201 but is supplied while diffusing to the outer peripheral surface of the stator core 101. . Therefore, if only 105b is formed as the flow path inlet, the coolant supplied to the outer peripheral surface of the stator core 101 off the flow path inlet 105b is not supplied to the flow path 105, and the rotor core 401 is sufficiently supplied. May not be able to cool. Therefore, it is conceivable to improve the cooling performance of the rotor 400 by forming a plurality of flow path inlets on the outer peripheral surface of the stator core 101. However, since the coolant flowing along the outer peripheral surface of the stator core 101 vigorously flows along the outer peripheral surface of the stator, a flow from the outer peripheral surface of the stator core 101 toward the inner peripheral surface is unlikely to occur in the coolant. Therefore, the coolant cannot be efficiently supplied to the flow path that connects the outer peripheral surface and the inner peripheral surface of the stator core 101, and the rotor 400 may not be sufficiently cooled.

    Therefore, in the cooling structure of the rotating electrical machine 10 according to the first embodiment of the present invention, the coolant supplied from the coolant supply pipe 200 to the outer peripheral surface of the stator core 101 is shown in FIGS. 1 and 3 along the outer periphery of the stator core. The trough formed by the protrusion 104 and the outer peripheral surface of the stator core 101 is paid attention to the fact that it flows in the direction indicated by the broken line arrow and stays in the trough formed by the outer periphery of the protrusion 104 and the stator core 101. The channel inlets 105a and 105c are formed in the shaded area shown in FIG.

  By causing the protrusion 104 to retain the coolant flowing along the outer peripheral surface of the stator core, a flow from the outer peripheral surface of the stator toward the inner peripheral surface is generated in the coolant. As a result, the coolant that can be supplied to the flow path inlets 105a and 105c can be increased as compared with the case where the flow path inlet is in the valley, that is, the coolant that can be supplied to the rotor 400 can be increased. And the cooling performance of the rotor 400 is improved.

  In the first embodiment of the present invention, the channel outlets 106a, 106b, and 106c are provided at the tip of the teeth 102 as an optimal configuration for improving the cooling performance of the rotor 400. It is good also as a structure which is provided in 103 and is supplied to the rotor 400 after the coil 300 is cooled.

  If the flow path inlets 105a and 105c are formed in the valley formed by the protrusion 104 and the outer peripheral surface of the stator core, and upstream of the coolant flow from the protrusion 104, the shape of the flow path 105 is as shown in FIG. It is not limited to the shape shown, For example, a linear shape may be sufficient. Further, the number of flow paths may be increased or decreased. For example, the channel inlet 105b and the channel outlet 106b may not be provided.

  A rotating electrical machine having the cooling structure according to the second embodiment will be described with reference to FIG.

  In 2nd Embodiment, the cooling guide is used as the protrusion part 500 instead of using the protrusion part 101 which binds the steel plates laminated | stacked like the 1st Embodiment of this invention. The protrusion 500 controls the flow of the coolant flowing on the outer peripheral surface of the stator core 18.

4 is shown in FIG. 4 while controlling the flow of the coolant on the outer peripheral surface of the stator core 101 by providing the flow path inlet 10 5 d in the trough formed by the protruding portion 500 and the outer peripheral surface of the stator core 101. The cooling performance of the rotor 400 that is not present can be improved. In addition, you may use the rib for reinforcing a stator core as a protrusion part of a stator core.

  As described above, the main features of the cooling structure for a rotating electrical machine according to the embodiment of the present invention are the flow path that connects the inner peripheral surface and the outer peripheral surface of the stator, and the protruding portion that protrudes from the outer peripheral surface of the stator. Provided, the opening of the flow path formed in the outer peripheral surface of the stator is provided in the valley formed by the outer peripheral surface of the stator core and the protruding portion, and on the upstream side of the cooling liquid flow from the protruding portion. .

  By providing the above-described features of the present invention, the coolant can be efficiently supplied to the rotor.

DESCRIPTION OF SYMBOLS 10 Rotating electrical machine, 100 Stator, 101 Stator core, 102 Teeth, 103 slot, 104 Protrusion part, 105 flow path (communication flow path) , 200 Cooling liquid supply pipe, 201 Cooling liquid supply port, 300 coils, 400 rotor, 401 rotor core, 402 permanent magnet, 403 axis of rotation

Claims (1)

A cylindrical stator having a hollow portion;
A rotating electrical machine that is disposed on the inner peripheral side of the hollow portion of the stator and that rotates about a rotation axis, and that is supplied to the outer peripheral surface of the stator and flows along the outer peripheral surface of the stator In
The stator has a communication channel that connects the inner peripheral surface of the stator and the outer peripheral surface of the stator;
A protrusion that protrudes from the outer peripheral surface of the stator and that forms a trough that retains the coolant flowing along the outer peripheral surface of the stator with the outer peripheral surface of the stator , and
Opening of the communication passage formed in the outer circumferential surface of the stator, the valley formed by the outer peripheral surface and the projecting portion of the stator, and the outer peripheral surface of the stator than the protrusion A rotating electrical machine characterized by being provided on the upstream side of the flow of the coolant flowing along .

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