JP2013039012A - Cooling structure of rotary electric machine - Google Patents

Abstract

In a rotating electrical machine installed with a rotating shaft sideways, coolant supplied from above the coil end and dripping through the coil end is returned to the coil end again.
[Solution]
The coolant supplied from the coolant supply port 26 and dropping through the coil end 22 is received by the coolant receiver 28. The coolant receiving member 28 is arranged extending along a part of the inner peripheral surface of the upper end portion 22a of the coil end. The received coolant flows along the coolant receiving member 28, flows out from both ends, and is again applied to the coil end 22. In order to increase the flow velocity at the time of outflow, the flow passage cross-sectional area of the coolant receiving member 28 is large at the top and small at the end.
[Selection] Figure 1

Description

  The present invention relates to a structure for cooling a rotating electric machine, and more particularly to cooling of a coil end.

  An electric motor that converts electrical energy into rotational kinetic energy, a generator that converts rotational kinetic energy into electrical energy, and an electric device that functions as both the motor and the generator are known. Hereinafter, these electric devices are referred to as rotating electric machines.

  A rotating electrical machine that cools with a liquid is known (see Patent Document 1 below). The rotating electrical machine described in the following Patent Document 1 is installed with the rotating shaft sideways, and coolant is supplied from above the coil end. A guide plate is disposed along the inner peripheral surface of the upper half of the coil end (hereinafter referred to as the upper portion), and the guide plate guides the coolant to flow in the circumferential direction.

JP 2011-35992 A

  In the rotating electrical machine described in Patent Document 1, when the amount of coolant supplied is small, the coolant guided by the guide plate provided corresponding to the upper part of the coil end is the coil end upper part. There is a case where the coil end cannot be cooled effectively without touching.

  An object of the present invention is to receive the coolant dripped from the upper part of the coil end so that the received coolant is again applied to the coil end upper part.

  The rotating electrical machine according to the present invention is installed with the rotating shaft sideways, and the coolant is supplied to the coil end from above. A coolant receiving means extending along a part of the inner peripheral surface of the upper portion of the coil end is disposed. The cooling liquid receiving means receives the cooling liquid dripping from the coil end and guides it from the top to the end of the cooling liquid receiving means. The area surrounded by the inner peripheral surface of the coil end and the coolant receiving means is made large at the top of the coolant receiving means and small at the end. As a result, the speed of the coolant flowing while being guided by the coolant receiving means increases at the end.

  The area surrounded by the coil end inner circumferential surface and the coolant receiving means can be gradually reduced from the top to the end of the coolant receiving means.

  Another rotating electrical machine according to the present invention is installed with the rotating shaft sideways, and the coolant is supplied to the coil end from above. A coolant receiving means extending along a part of the inner peripheral surface of the upper portion of the coil end is disposed. The cooling liquid receiving means receives the cooling liquid dripping from the coil end and guides it from the top to the end of the cooling liquid receiving means. The width of the channel through which the coolant flows in the coolant receiving means is wide at the top and narrow at the end. As a result, the speed of the coolant flowing while being guided by the coolant receiving means increases at the end.

  The width of the flow path described above can be gradually reduced from the top to the end of the coolant receiving means.

  At the end of the coolant receiving member, the flow rate of the coolant can be increased, and even when the flow rate is small, the coolant can be sent out toward the coil end, and the coolant can be applied to the coil end.

It is the figure seen from the rotating shaft direction of the rotary electric machine which concerns on this invention. It is a figure which shows the cross section containing the rotating shaft line of the rotary electric machine which concerns on this invention. It is a figure which shows the aspect of the coil conducting wire in the stator of a rotary electric machine, especially a coil end. It is a figure which shows the shape of a cooling fluid receiving member. It is a figure which shows the end surface in the AA sectional view of FIG. 4 of a cooling fluid receiving member. It is a figure which shows the end surface in the BB line cross section of FIG. 4 of a cooling fluid receiving member. It is the figure which looked at the cooling fluid member from the upper part. It is a figure which shows the example of the other shape of a cooling fluid receiving member.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 and 2 are diagrams showing a schematic configuration of a cooling structure for a rotating electrical machine 10 according to the present invention. FIG. 1 is a diagram showing a state of the rotating electrical machine 10 as viewed from the direction of the rotational axis, and FIG. 2 is a cross-sectional view including the rotational axis.

  The rotating electrical machine 10 includes a cylindrical or annular stator 12 and a columnar or disk-shaped rotor 14 disposed coaxially with the cylindrical shape of the stator 12. A rotating shaft 16 passes through the center of the rotor 14. The rotating electrical machine 10 is arranged with the rotating shaft 16 sideways. The stator 12 includes a stator core 18 having irregularities arranged along the circumferential direction on the inner periphery. A coil conductor is housed in a concave portion provided on the inner periphery of the stator core 18, and the coil conductor is wound around the convex portion to form a coil 20 (see FIG. 3). By supplying electric power to the coil 20, a rotating magnetic field is formed in the space inside the stator 12. In other words, the coil 20 is wound around the stator core 18 so that a rotating magnetic field is formed when electric power is supplied.

  The convex portion of the inner periphery of the stator core 18 is also called a tooth, and the concave portion is also called a slot. In the region adjacent to the end face of the stator core 18, a plurality of coil conductors are bundled in a complicated manner. The bundled portion of the coil conducting wire is called a coil end, and hereinafter the coil end is denoted by reference numeral 22.

  In FIG. 1, the coil end 22 is shown in a simplified manner. In practice, the coil end 22 is a complex bundle of coil conductors as illustrated in FIG. There are gaps between the bundled coil conductors and between the coil conductors and the stator core 18. The coil end 22 has an annular shape with a square cross section as a whole, and is positioned adjacent to the cylindrical end surface of the stator core 18. In the following description, the upper part and the lower part of the coil end 22 above the horizontal plane H passing through the rotation axis of the rotating electrical machine 10 are referred to as a coil end upper part 22a and a coil end lower part 22b.

  The rotor 14 has a cylindrical shape as a whole, and is arranged with a slight gap at the inner periphery of the stator 12, particularly at the tip of the tooth. For example, a permanent magnet is embedded in the outer peripheral surface or the vicinity of the outer peripheral surface of the rotor 14 so as to rotate by interacting with a rotating magnetic field formed by the stator 12. It is also possible to provide portions with different reluctance in the circumferential direction of the rotor 14 and to rotate the rotor 14 by interaction with this and the rotating magnetic field. The rotating shaft 16 is fixed to the rotor so as to rotate integrally with the rotor 14. When the rotating electrical machine 10 functions as an electric motor, the rotating shaft 16 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 a current is passed through the coil 20, heat is generated. In the coil conductor in the slot, the generated heat flows to the surrounding stator core. However, the coil end 22 does not have a good heat conductor around it, and the temperature tends to rise. Therefore, efficient cooling of the coil end 22 is desired. In the above-mentioned Patent Document 1, cooling by liquid is performed, and in particular, cooling is performed by applying a liquid to the coil end from above. Since liquid has better thermal conductivity than gas, efficient cooling can be expected. Further, by applying a liquid from above and taking away heat when the liquid flows through the coil end, the amount of the liquid can be reduced as compared with the case where the coil end is immersed in the liquid.

  Also in the cooling of the rotating electrical machine 10, the coil end is cooled by applying liquid from above the coil end 22. When the rotating electrical machine 10 is disposed in a transaxle of an automobile, the cooling liquid can be a lubricating oil or a working fluid of the transaxle. Hereinafter, the liquid for cooling the coil end 22 is referred to as a cooling liquid. The cooling liquid is supplied to the coil end 22 from a cooling liquid supply port 26 that is an opening provided on a side surface of the cooling liquid supply pipe 24 that is supplied by a pump (not shown). The coolant supply ports 26 may be provided at two locations in the extending direction of one coolant supply pipe 24 corresponding to the coil ends 22 at both ends of the stator core 18. At each location, the coolant supply port 26 can be one downward facing as shown in FIG. 1, and two are provided symmetrically with respect to the vertical axis and distributed to the left and right in FIG. Can be hung on the coil end. Although the coolant supply pipe 24 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 this case, the coolant supply port is an opening in which the flow path is opened on the member surface of the case.

  In the cooling structure of the rotating electrical machine 10, the coolant supply port 26 is disposed vertically above the rotation axis of the rotating electrical machine 10 as shown in FIG. 1, and the coolant is applied to the outer peripheral surface of the coil end 22 from here. The position of the coolant supply port 26 may be shifted from the above vertical position, or two or more may be provided. Further, the cooling liquid may be applied to one or a plurality of positions of the coil end 22 from the cooling liquid supply port 26 once through a bowl-shaped guide channel. The coolant applied to the outer peripheral surface of the coil end 22 flows downward along the coil end 22 as indicated by arrows Y1, Y2, and Y3 in FIG.

  As described above, the coil end 22 has a large number of gaps between the coil conductors and between the coil conductors and the stator core. A part of the coolant supplied from the coolant supply port 26 passes through this gap in the coil end upper portion 22a, reaches from the outer peripheral side of the coil end 22 to the inner peripheral side, and drops from here. The coolant dripped from the inner peripheral surface of the coil end upper portion 22a falls on the rotating shaft 16 and prevents the rotating shaft 16 from rotating. In the rotating electrical machine 10, the coolant receiving member 28 is disposed so as to extend along the inner peripheral surface of the coil end upper portion 22 a in order to receive the coolant dripping from the coil end upper portion 22 a.

  4 to 7 are views showing the coolant receiving member 28 alone. 4 is a diagram showing a state viewed from the same direction as FIG. 5 and 6 are views showing the end surfaces of the top and end sections of the coolant receiving member 28. FIG. A cross section at the top is indicated by a line AA in FIG. 4, and this cross section is also a vertical plane including the rotation axis of the rotating electrical machine 10. The cross section of the end is shown by the line BB in FIG. 4, and this cross section is also a plane including the rotation axis of the rotating electrical machine 10. FIG. 7 is a view showing a state in which the coolant receiving member 28 is viewed from above.

  The coolant receiving member 28 includes a receiving part 30 that receives the dropped cooling liquid and a support part 32 that supports the receiving part 30 by suspending it from the stator core 18. The receiving portion 30 extends in an arc along the inner peripheral surface of the coil end 22. The coolant receiving member 28 extends in a circular arc from the highest position of the coil end 22 to a position of about 45 degrees to the left and right. As shown in FIGS. 5 and 6, the receiving portion 30 has two side walls 34, 36, and these side walls 34, 36 are substantially V-shaped in a cross section orthogonal to the direction in which the receiving portion 30 extends in an arc shape. Be placed. A range surrounded by the two side walls 34 and 36 and the inner peripheral surface of the coil end 22 is a flow path of the coolant. The coolant dripped from the coil end 22 is received by the receiving portion 30, further toward the both end portions along the receiving portion 30, and sent from both end portions. Due to the momentum when flowing out from the receiving part 30, the coolant flows out obliquely as shown by the arrow Y4 in FIG. The coolant that flows obliquely is applied to the inner peripheral surface of the coil end 22 and cools the side portion of the coil end 22.

  If the amount of the coolant supplied is small and the speed of the coolant flowing through the receiving portion 30 is slow, the speed of the coolant flowing out from the end of the receiving portion 30 is insufficient and falls before reaching the coil end 22. Even when the supply amount is small, in order to obtain a sufficient flow rate of the cooling liquid, the flow passage cross-sectional area of the receiving portion 30 is large at the top and small at the end. Since the flow path cross-sectional area is small at the end, the flow rate of the coolant passing through this portion is increased, and the coolant reaches the coil end 22.

  Of the side walls 34 and 36 of the receiving portion 30, the side wall (hereinafter referred to as an outer side wall) 34 far from the stator core 18 is disposed in a plane perpendicular to the rotation axis of the rotor, and the other side wall (hereinafter referred to as the inner side wall). 36 is inclined with respect to the rotational axis of the rotor. The inclination direction of the inner side wall 36 is a direction that decreases as the distance from the stator core 18 increases. Accordingly, the received coolant is guided in a direction away from the stator core 18. In the inner side wall 36, the inclination angle θ2 at the end is larger than the inclination angle θ1 at the top of the receiving portion 30 (see FIGS. 5 and 6). Thereby, the width of the channel defined by the outer side wall 34 and the inner side wall 36 is wide at the top and narrow at the end. Further, the channel cross-sectional area at the end is made smaller than the channel cross-sectional area at the top.

  The flow path is disposed on the side surface 38 side of the coil end 22 away from the stator core 18 at the end of the receiving portion 30. As a result, the coolant that has flowed out from the end of the receiving portion 30 is applied to a position far from the rotor 14 on the inner peripheral surface of the coil end 22, and the intrusion into the gap between the rotor 14 and the stator 12 is suppressed.

  The inclination angle of the inner side wall 36 can be changed gradually or continuously from the top to the end. Thereby, the flow of the coolant in the receiving part 30 becomes smooth, which is suitable for accelerating the flow rate of the coolant.

  When the coolant receiving member 28 is mounted on the stator 12, the support portion 32 is substantially U-shaped, and each U-shaped image extends along the outer peripheral surface of the stator core 18 and the two end surfaces in the motor rotation axis direction. Arranged. As a method of mounting the coolant receiving member 28 on the stator, for example, there are the following methods. The coolant receiving member 28 is first manufactured as two parts, that is, two parts divided from the left and right centers in FIG. At this time, the support portion 32 is an elongated plate-like member extending from the top of the inner side wall 36 of the receiving portion 30. The support portion 32 is passed through the gap between the lead wire of the coil end 22 and the stator core 18 from the inner peripheral side to the outer peripheral side of the coil end, and the support portions 32 on both sides are joined on the outer peripheral surface of the stator core 18. Alternatively, the support portions 32 on both sides may be fixed to the stator core 18 respectively.

  FIG. 8 is a diagram showing another example of the shape of the coolant receiving member. The coolant receiver member 40 shown in FIG. 8 has substantially the same shape as the coolant receiver member 28 described above, but is different in that a bottom surface 46 is formed. The coolant receiving member 40 has a bottom surface 46 formed between the two side walls 42 and 44. The bottom surface 46 is parallel to the rotation axis of the rotor. The width of the bottom surface 46 may be the same at the top and end of the coolant receiving member 40, or may be narrow at the end. It may be narrowed gradually or continuously from the top toward the end.

  The coolant receiving members 28 and 40 described above are provided corresponding to both the coil ends on both sides of the stator 12, but only one of them can be disposed. As shown in FIGS. 1 and 4, the receiving portion 30 extends symmetrically. However, if necessary, the receiving portion 30 can be asymmetrical, that is, one of the left and right can be extended longer than the other. .

  DESCRIPTION OF SYMBOLS 10 Rotating electrical machine, 12 Stator, 14 Rotor, 16 Rotating shaft, 18 Stator core, 22 Coil end, 28, Coolant receiving member, 30 Receiving part, 32 Supporting part, 34 Outer side wall, 36 Inner side wall.

Claims (4)

A cooling structure for a rotating electrical machine installed with a rotating shaft sideways,
Liquid supply means for supplying a coolant from above to the coil end of the rotating electrical machine;
A coolant receiving means that extends along a part of the inner peripheral surface of the upper part of the coil end and receives the coolant that drops;
Have
The coolant receiving means guides the coolant received from the top to the end of the liquid receiving means, and the area surrounded by the inner peripheral surface of the coil end and the coolant receiving means is large at the top, Small at the end,
Cooling structure for rotating electrical machines. The cooling structure for a rotating electrical machine according to claim 1,
The area surrounded by the inner peripheral surface of the coil end and the coolant receiving means gradually decreases from the top toward the end.
Cooling structure for rotating electrical machines. A cooling structure for a rotating electrical machine installed with a rotating shaft sideways,
Liquid supply means for supplying a coolant from above to the coil end of the rotating electrical machine;
A coolant receiving means that extends along a part of the inner peripheral surface of the upper part of the coil end and receives the coolant that drops;
Have
The cooling liquid receiving means guides the cooling liquid received from the top of the liquid receiving means toward the end, and the width of the flow path of the cooling liquid of the cooling liquid receiving means is wide at the top, and the end Narrow,
Cooling structure for rotating electrical machines. A cooling structure for a rotating electrical machine according to claim 2,
The width of the flow path gradually decreases from the top toward the end,
Cooling structure for rotating electrical machines.

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