JP2016144356A - Rotor for rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cancel shortage in the quantity of a coolant to be supplied in an axial direction of a rotor.SOLUTION: A rotor for a rotary electric machine comprises: an axial discharge passage 28 that extends in an axial direction within a rotor core 22 and is opened on an end face of the rotor core 22; a radial discharge passage 27 that extends in a radial direction within the rotor core 22 and is opened on an outer peripheral surface of the rotor core 22; and a radial connection passage 26 which extends in the radial direction within the rotor core 22, of which one end 26a is connected to a coolant supply passage 25b and another end 26b is connected to the axial discharge passage 28 and the radial discharge passage 27. In a connection part 29 to which the radial connection passage 26, the radial discharge passage 27 and the axial discharge passage 28 are connected, an end portion of the axial discharge passage 28 in the connection part 29 is a tapered part 30 where a cross-sectional area of the passage becomes larger towards the connection part 29. Thus, a coolant from the radial connection passage 26 easily flows into the axial discharge passage 28.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a rotor of a rotating electrical machine, and more particularly to a rotor that cools a stator by discharging a refrigerant supplied from a rotor rotating shaft from an outer peripheral surface of the rotor.

  Various structures have been proposed as a structure for cooling a stator and a rotor of a rotating electrical machine. One of them is a rotor refrigerant flow path that communicates with a refrigerant flow path in the rotating shaft of the rotor and extends in the rotor radial direction in the rotor, and the refrigerant from the refrigerant flow path in the rotating shaft is opened on the outer peripheral surface of the rotor. The structure which discharges from is known (for example, refer patent document 1). In addition to the rotor refrigerant flow path extending in the rotor radial direction, a structure including a rotor refrigerant flow path extending in the rotor axial direction is also known.

JP 2008-228522 A

  The refrigerant in the rotor refrigerant flow path in the rotor radial direction and the rotor axial direction is affected by the centrifugal force of the rotor. Due to the centrifugal force, the amount of refrigerant supplied in the rotor radial direction is larger than the amount of refrigerant supplied in the rotor axial direction, and the amount of refrigerant supplied in the rotor axial direction and rotor radial direction is biased. . For this reason, the amount of refrigerant supplied in the rotor axial direction is insufficient.

  Therefore, an object of the present invention is to provide a rotor of a rotating electrical machine that solves the shortage of the amount of refrigerant supplied in the rotor axial direction.

  The rotor of the rotating electrical machine according to the present invention includes a rotating shaft provided with a refrigerant supply channel therein, a rotor core fixed to the outer periphery of the rotating shaft, an axial direction extending in the rotor core, and an opening at an end surface of the rotor core. An axial discharge passage, a radial discharge passage extending radially in the rotor core and opening on an outer peripheral surface of the rotor core, a radial extension extending in the rotor core, and one end of the refrigerant supply passage A radial connection flow path, the other end of which is connected to the axial discharge flow path and the radial discharge flow path, the radial connection flow path, the axial discharge flow path, and the radial discharge flow In the connection part to which the flow path is connected, in the connection part to which the radial connection flow path, the axial discharge flow path, and the radial discharge flow path are connected, the connection part of the axial discharge flow path The end of Wherein the cross-sectional area of the flow path toward the parts is larger shape.

  ADVANTAGE OF THE INVENTION According to this invention, the bias | inclination of the refrigerant | coolant amount supplied to a rotor axial direction and a rotor radial direction can be suppressed, and the shortage of the refrigerant | coolant amount supplied to a rotor axial direction can be eliminated.

It is sectional drawing which shows schematic structure of a rotary electric machine. It is a cross-sectional view of a rotor, (A) shows the AA cross section of FIG. 1, (B) shows the BB cross section of FIG. 1, (C) shows the CC cross section of FIG. It is a principal part block diagram which shows the modification of a connection part shape. It is a principal part block diagram which shows another modification of a connection part shape, (A) is the figure which formed the recessed part in the downstream of a radial direction connection flow path, (B) is in the upstream of a radial direction discharge flow path. The figure which formed the recessed part is shown, respectively.

  The rotating electrical machine in the embodiment of the present invention is a motor generator mounted on, for example, a hybrid vehicle or an electric vehicle. As shown in FIG. 1, the motor generator 1 includes an annular stator 10 and a rotor 20 disposed therein. A predetermined amount of gap is formed between the inner peripheral surface of the stator 10 and the outer peripheral surface of the rotor 20.

  The stator 10 includes a stator core 11 made of a cylindrical magnetic body, and a stator coil 12 that is wound around a plurality of teeth that protrude from the inner peripheral portion of the stator core 11 and are arranged at equal intervals in the circumferential direction. It has. The stator core 11 is configured by laminating a plurality of electromagnetic steel sheets punched into a substantially annular shape in the axial direction and integrally connecting them. The stator coil 12 includes coil ends 12 a and 12 b that protrude outward from the axial end surface of the stator core 11.

  As shown in FIGS. 1 and 2, the rotor 20 includes a rotating shaft 21, a cylindrical rotor core 22 fixed to the outer periphery of the rotating shaft 21, and a permanent magnet 23 embedded in the rotor core 22. As with the stator core 11, the rotor core 22 is configured by laminating a plurality of electromagnetic steel sheets each punched into a substantially annular shape in the axial direction and integrally connecting them. Further, the rotor core 22 has substantially the same axial length as the stator core 11, and the axial end faces are arranged substantially flush with each other. The permanent magnets 23 are plate-like members having the same length as the axial direction of the rotor core 22, and four permanent magnets 23 are provided at 90 ° intervals in the circumferential direction of the rotor core 22 with the rotary shaft 21 as the center. In FIG. 2, the permanent magnet 23 has a rectangular cross section, but may have a square shape.

  The stator 10 and the rotor 20 are accommodated in a cylindrical case (not shown). In the case, two bearing members that rotatably support the rotating shaft 21 of the rotor 20 are provided on both sides in the axial direction.

  Next, the refrigerant flow path inside the rotor 20 will be described. As the refrigerant, for example, cooling oil such as ATF is used. As shown in FIG. 1, a coolant supply passage 25 that supplies cooling oil to the outside of the rotating shaft 21 is provided inside the rotating shaft 21. The refrigerant supply flow path 25 extends in the radial direction of the rotary shaft 21 from the axial supply flow path 25a and penetrates in the axial direction of the rotary shaft 21 and opens on the outer peripheral surface of the rotary shaft 21. And a radial supply channel 25b. An oil pump (not shown) is connected to one end of the axial supply passage 25a, and cooling oil fed by pressure from the oil pump is supplied. Four radial supply channels 25b are provided radially from the axial supply channel 25a at intervals of 90 degrees in an intermediate portion of the rotor 20 in the axial direction.

  The rotor core 22 is connected to the radial connection flow path 26 whose one end 26 a is connected to the radial supply flow path 25 b and the other end 26 b of the radial connection flow path 26, so that the cooling oil is supplied from the outer peripheral surface of the rotor core 22. The cooling oil is discharged from both the axial end surfaces of the rotor core 22 by branching from the radial discharge channel 27 to be discharged and the other end 26b of the radial connection channel 26 toward both end surfaces of the rotor core 22 in the axial direction. An axial discharge channel 28 is provided. That is, a radial discharge flow path 27 and an axial discharge flow path 28 are connected to the other end 26 b of the radial connection flow path 26, and the outer peripheral surface of the rotor core 22 and the axial direction of the rotor core 22 are connected from this connection portion 29. The flow path is branched in three directions on both end faces of the, and cooling oil is discharged from these three directions.

  The radial discharge flow path 27 is formed on the extension line of the radial connection flow path 26 so as to extend in the radial direction toward the outer peripheral surface of the rotor core 22 in the rotor core 22. 22 is provided with a discharge port 27a that is open on the outer peripheral surface of 22. The axial discharge flow path 28 is formed to extend in the axial direction in the rotor core 22, and includes discharge ports 28 a and 28 b that open at both end faces of the rotor core 22. Moreover, the cross-sectional shape of the radial direction connection flow path 26, the radial direction discharge flow path 27, and the axial direction discharge flow path 28 is each square, and the cross-sectional area is the same.

  A tapered portion 30 is formed at the end of the axial discharge channel 28 toward the connection portion 29 so that the cross-sectional area of the channel increases toward the center of the connection portion 29. The tapered portion 30 has a shape that is gradually inclined toward the radial connection flow path 26.

  The radial discharge flow path 27, the axial discharge flow path 28, and the tapered portion 30 in the rotor core 22 are formed by forming slits in the corresponding electromagnetic steel sheets and laminating the electromagnetic steel sheets. As shown in FIG. 2A, which is a cross section taken along the line AA in FIG. 1, the electromagnetic steel sheet corresponding to the axial discharge flow path 28 has a square slit 28 c serving as the flow path of the axial discharge flow path 28. Is formed. As shown in FIG. 2B which is a BB cross section of FIG. 1, the magnetic steel sheet corresponding to the axial discharge flow path 28 and the tapered portion 30 includes the flow path of the axial discharge flow path 28 and is tapered. A rectangular slit 30 c that is a part of the portion 30 is formed. The slit 30 c has a rectangular shape obtained by extending the slit 28 c toward the upstream side of the radial connection channel 26. In the electromagnetic steel plates adjacent to the upper and lower sides of this electromagnetic steel plate, the tapered portion 30 is formed by sequentially changing the length in the longitudinal direction of the rectangular slit 30c. As shown in FIG. 2C, which is a CC cross section of FIG. 1, in the electrical steel sheet corresponding to the radial connection flow path 26 and the radial discharge flow path 27, a slit 26c continuous from the center to the outer periphery of the electrical steel sheet. In addition, a slit 27c is formed. The radial connection flow path 26 and the radial discharge flow path 27 are formed by stacking a plurality of electromagnetic steel plates having the slits 26c and the slits 27c.

  In order to obtain a smooth taper portion 30, it is necessary to prepare a large number of electromagnetic steel sheets in which slits 30c having slightly different lengths in the longitudinal direction are formed. The number of the electromagnetic steel sheets in which the slits 30c are formed may be reduced. In this case, the number of electromagnetic steel sheets having different slit shapes is small, and the cost can be reduced.

  Next, the flow of cooling oil (refrigerant) in the rotor 20 will be described. In FIG. 1, the flow of the cooling oil is indicated by arrows F1 to F6. As indicated by the arrow F1, the cooling oil pumped by the oil pump is supplied to the axial supply passage 25a of the rotating shaft 21. The cooling oil supplied to the axial supply flow path 25a flows into the radial connection flow path 26 of the rotor core 22 through the radial supply flow path 25b as indicated by an arrow F2.

  The cooling oil that has flowed into the radial connection flow path 26 is accelerated in speed by adding centrifugal force due to rotation of the rotor core 22 to the pumping force of the oil pump. When the cooling oil reaches the tapered portion 30, the cooling oil flows along the tapered shape of the tapered portion 30 and flows into the axial discharge passage 28 as indicated by an arrow F <b> 3. Further, as indicated by an arrow F4, the cooling oil that has collided with the corner of the connection portion 29 also flows into the axial discharge flow path 28. Other cooling oil flows into the radial discharge flow path 27 as indicated by an arrow F5.

  The cooling oil that has flowed into the radial discharge flow path 27 is discharged from the discharge port 27 a of the radial discharge flow path 27 and sprayed onto the stator coil 12 and the stator core 11. Further, as indicated by an arrow F <b> 6, the cooling oil that has flowed into the axial discharge flow path 28 is discharged from the discharge ports 28 a and 28 b of the axial discharge flow path 28, and the radial direction of the rotor core 22 due to the centrifugal force of the rotor core 22. To the coil ends 12 a and 12 b and the stator core 11.

  As described above, the flow of the cooling oil is diffused by the tapered portion 30 in the connection portion 29 of the radial connection flow channel 26, the radial discharge flow channel 27, and the axial discharge flow channel 28. Concentration of the cooling oil is suppressed. For this reason, the bias of the cooling oil flowing into the radial discharge flow path 27 and the axial discharge flow path 28 is suppressed, and the cooling oil can be sufficiently supplied also to the axial discharge flow path 28.

  Further, the flow of the cooling oil can be adjusted by adjusting the taper angle of the taper portion 30 as appropriate, or by changing the shape of the taper portion 30 to, for example, a conical shape, a quadrangular pyramid shape, etc. It is also possible to increase the amount of cooling oil supplied to the discharge flow path 28 as compared to the radial discharge flow path 27.

  Next, a modified example of the shape of the connecting portion 29 of the radial connection flow path 26, the radial discharge flow path 27, and the axial discharge flow path 28 will be described. As shown in FIG. 3, a taper portion 31 is formed at the end portion of the axial discharge flow path 28 toward the connection portion 29 so that the cross-sectional area of the flow path increases toward the center of the connection portion 29. The tapered portion 31 has a shape that is gradually inclined toward the radial discharge channel 27.

  Thus, when the taper part 31 is formed in the vicinity end part of the connection part 29 of the radial direction discharge flow path 27, when cooling oil reaches | attains the taper part 31 from the radial direction connection flow path 26 as shown by arrow F10. In addition to flowing into the radial discharge flow path 27, the cooling oil collides with the tapered surface of the tapered portion 31 and temporarily stays in the connection portion 29. For this reason, as indicated by an arrow F <b> 11, a temporary cooling oil reservoir is formed at the connection portion 29, and the cooling oil in this cooling oil reservoir flows into the axial discharge flow path 28. Therefore, the concentration of the cooling oil in the radial discharge flow path 27 is suppressed, and the bias of the cooling oil flowing into the radial discharge flow path 27 and the axial discharge flow path 28 is suppressed.

  Further, in the modification shown in FIG. 3, the tapered portion 32 is also formed in the discharge port 27 a of the radial discharge flow path 27. As shown by an arrow F12, the cooling oil discharged from the discharge port 27a is diffused by the taper portion 32, so that the cooling oil is prevented from concentrating on a part of the stator coil 12 or the stator core 11 and cooled. It is possible to suppress peeling of the insulating coatings on the stator coil 12 and the stator core 11 due to the concentration of oil.

  In addition, in the connection part 29, you may form the taper parts 30 and 31 in both the downstream of the radial direction connection flow path 26, and the upstream of the radial direction discharge flow path 27, respectively. By providing the taper portions 30 and 31 on both the downstream side and the upstream side of the connection portion 29, a cooling oil pool in which the cooling oil stays is formed in the connection portion 29, and the cooling oil is supplied to the radial discharge passage 27. Concentration is further suppressed. Moreover, the flow of cooling oil can be adjusted more by making the taper angles with the taper parts 30 and 31 into different angles, respectively.

  Further, as shown in FIGS. 4A and 4B, concave-shaped concave portions 33 and 34 may be used instead of the tapered portions 30 and 31. In addition, the recesses 33 and 34 may be formed on both the downstream side of the radial connection flow path 26 and the upstream side of the radial discharge flow path 27 in the connection portion 29. In the taper shape, a plurality of electromagnetic steel plates having different slit lengths are required. However, by using such concave portions 33 and 34, the types of shapes of the electromagnetic steel plates can be reduced and the cost can be reduced.

  DESCRIPTION OF SYMBOLS 1 Motor generator, 10 Stator, 11 Stator core, 12 Stator coil, 12a, 12b Coil end, 20 Rotor, 21 Rotating shaft, 22 Rotor core, 23 Permanent magnet, 25 Refrigerant supply flow path, 25a Axial supply flow path, 25b Radial direction Supply flow path, 26 radial connection flow path, 26c, 27c, 28c slit, 27 radial discharge flow path, 27a, 28a, 28b discharge port, 28 axial discharge flow path, 29 connection section, 30, 31, 32 taper Part, 33, 34 recess.

Claims (1)

A rotating shaft having a refrigerant supply channel therein;
A rotor core fixed to the outer periphery of the rotating shaft;
An axial discharge passage extending in the axial direction in the rotor core and opening in an end surface of the rotor core;
A radial discharge passage extending radially in the rotor core and opening to the outer peripheral surface of the rotor core;
A radially connecting flow path extending in a radial direction in the rotor core, having one end connected to the refrigerant supply flow path and the other end connected to the axial discharge flow path and the radial discharge flow path;
With
In the connection portion where the radial connection flow channel, the axial discharge flow channel, and the radial discharge flow channel are connected, an end portion of the axial discharge flow channel in the connection portion faces the connection portion. A rotor of a rotating electrical machine having a shape in which a cross-sectional area of a flow path is increased.

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