JP2015002565A - Dynamo-electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dynamo-electric machine in which deformation of a rotor can be suppressed, while reducing the eddy current loss.SOLUTION: A rotor 14 is provided, between a pair of magnetic poles 34A, 34B, with a gap 36B for suppressing conduction of a magnetic flux between the pair of magnetic poles 34A, 34B. Furthermore, a rib 38 is formed in the gap 36B. The rib 38 connects the inner peripheral side and outer peripheral side of the rotor 14, and is extending in the radial direction of the rotor 14.

Description

  The present invention relates to a rotating electrical machine including an annular rotor.

  2. Description of the Related Art Conventionally, a rotating electrical machine including an annular rotor provided so as to surround an outer periphery of a cylindrical armature is known. The rotor is provided with magnetic poles in the circumferential direction. In this magnetic pole, for example, a plurality of pairs of magnetic poles (N pole and S pole) are alternately arranged.

  Further, the annular rotor is provided with a support shaft for supporting it. For example, in Patent Document 1, a support shaft is extended from between adjacent magnetic poles in the direction of the rotation center axis of the rotor. Each of the support shafts is bent to the rotation center axis side on the side away from the rotor, and further integrated into a shaft extending in the rotation center axis direction.

  Here, it is known that if a support shaft is provided between all the magnetic poles, eddy current loss occurs as in the case of a cage-type rotating electrical machine. Therefore, in Patent Document 2, an eddy current loss is reduced by providing a support shaft for each magnetic pole pair instead of providing a support shaft for each magnetic pole of the rotor.

JP-A-9-215110 JP 2007-89270 A

  By the way, when providing a support shaft for every magnetic pole pair, in other words, when not providing a support shaft between all the magnetic poles, there exists a possibility that a deformation | transformation of a rotor may arise with the centrifugal force accompanying rotation of a rotor. Therefore, an object of the present invention is to provide a rotating electrical machine that can suppress deformation of a rotor while reducing eddy current loss.

  The present invention relates to a rotating electrical machine. The rotating electrical machine has an annular shape provided so as to surround an outer periphery of a cylindrical armature, and a plurality of rotors each having a pair of magnetic poles arranged alternately in the circumferential direction, and the rotation And a support shaft for supporting the rotor, which is provided between the pair of magnetic poles of the child and extends in the direction of the rotation center axis of the rotor. A gap portion is provided between the pair of magnetic poles and provided on the rotor to suppress conduction of magnetic flux between the pair of magnetic poles. The gap portion includes an inner peripheral side of the rotor and the gap portion. A rib portion extending in the radial direction of the rotor is formed so as to connect the outer peripheral side.

  In the above invention, it is preferable that the rib portion is provided only at an intermediate position of the support shaft adjacent in the circumferential direction of the rotor.

  Further, in the above invention, a plurality of grooves are formed in a circumferential direction on an inner peripheral surface or an outer peripheral surface of the rotor, and a rib part side reference passing through an intermediate position of the pair of magnetic poles from the rotation center axis The plurality of grooves so that an arrangement angle of the groove from the shaft and an arrangement angle of the groove from the support shaft side reference axis passing through an intermediate position of the adjacent magnetic pole pair from the rotation center axis are different. Is preferably formed.

  In the above invention, it is preferable that the groove is formed at a position at an electrical angle of 52 ° from the rib portion side reference axis and at a position at an electrical angle of 12 ° from the support shaft side reference axis.

  According to the present invention, it is possible to suppress deformation of the rotor while reducing eddy current loss.

1 is a configuration diagram of a vehicle equipped with a rotating electrical machine according to the present embodiment. It is a figure which illustrates the rotor of the rotary electric machine which concerns on this embodiment. It is a partially expanded view of the rotor of the rotating electrical machine according to the present embodiment. It is a figure which illustrates the calculation result of the deformation amount of the rotor of the rotary electric machine which concerns on this embodiment. It is a figure which illustrates the calculation result of the stress distribution of the rotor of the rotary electric machine which concerns on this embodiment. It is a figure which shows another example of the rotor of the rotary electric machine which concerns on this embodiment. It is a figure which illustrates the calculation result of the deformation amount of the rotor of the rotary electric machine which concerns on this embodiment. It is a figure which shows another example of the rotor of the rotary electric machine which concerns on this embodiment. It is a partially expanded view of the rotor of the rotating electrical machine according to the present embodiment. It is a figure explaining groove arrangement of a rotor. It is a figure explaining groove arrangement of a rotor. It is a figure explaining groove arrangement of a rotor.

  FIG. 1 illustrates a rotating electrical machine 10 according to this embodiment. In the embodiment shown in FIG. 1, the rotating electrical machine 10 is used as a drive source for a vehicle. The rotating electrical machine 10 may be a so-called hollow rotor type rotating electrical machine, and includes an armature 12, a rotor 14 (rotor), a stator 16 (stator), and a support shaft 18.

  The stator 16 has an annular shape and is provided so as to surround the outer periphery of the rotor 14 through a predetermined air gap. A plurality of phases of windings are assembled to the stator 16 on the inner peripheral surface side in the circumferential direction. An alternating current is supplied to the winding from the power storage device 20 such as a secondary battery via the inverter 22. When an alternating current is supplied, a rotating magnetic field is generated from the winding. The rotor 14 is rotated by this rotating magnetic field.

  The armature 12 has a cylindrical shape and is provided so as to be surrounded by the rotor 14 via a predetermined air gap. A plurality of phases of windings are assembled on the outer peripheral surface of the armature 12 in the circumferential direction. Further, the armature 12 is connected to the drive shaft 26 of the engine 24 and is rotated as the drive shaft 26 rotates. With this rotation, an induced electromotive force is generated in the winding of the armature 12, and an induced current flows through the winding of the armature 12 due to the induced electromotive force, thereby generating a rotating magnetic field. The rotor 14 is rotated by this rotating magnetic field.

  The support shaft 18 is a support member for supporting the rotor 14. As shown in FIG. 2, the support shaft 18 is provided between the magnetic pole pairs 34 of the rotor 14. The support shaft 18 extends in the direction of the rotation center axis C0 of the rotor 14. In the rotating electrical machine 10 according to the present embodiment, the rotation center axis C0 of the rotor 14 coincides with the drive shaft 26, as shown in FIG.

  The support shaft 18 is bent to the rotation center axis C0 side on the side away from the rotor 14, and further integrated with a transmission shaft 28 extending in the direction of the rotation center axis C0. The transmission shaft 28 is connected to a transmission 30 of the vehicle. The rotational drive of the rotor 14 is transmitted to the transmission 30 and the wheels 33 via the support shaft 18 and the transmission shaft 28.

  Further, the support shaft 18 may include a clutch mechanism 31 for coupling with the drive shaft 26. By connecting the drive shaft 26 and the support shaft 18, the armature 12 and the rotor 14 are connected.

  The support shaft 18 is preferably composed of a member that suppresses the conduction of magnetic flux between adjacent magnetic poles 34A and 34B, which will be described later. For example, the support shaft 18 is preferably made of a nonmagnetic material.

  The rotor 14 has an annular shape and is provided so as to surround the outer periphery of the armature 12 through a predetermined air gap. As shown in FIG. 2, the rotor 14 includes a yoke 32, a magnetic pole pair 34, a gap portion 36, and a rib portion 38.

  The yoke 32 is also called a yoke and functions as a magnetic path for the magnetic fluxes of the magnetic poles 34 </ b> A and 34 </ b> B and the interlinkage magnetic flux from the armature 12 and the stator 16.

  Further, as described above, the support shaft 18 is fixed between the magnetic pole pairs 34 of the rotor 14. For this reason, a fixing hole for inserting and fixing the support shaft 18 is provided between the magnetic pole pair 34 of the yoke 32.

  The magnetic pole pair 34 includes a pair of magnetic poles 34A and 34B, and includes, for example, an N pole and an S pole. The magnetic poles 34A and 34B may be composed of permanent magnets. Each of the pair of magnetic poles 34 </ b> A and 34 </ b> B is alternately arranged in the circumferential direction of the rotor 14. For example, the magnetic poles 34A and 34B are configured by forming permanent magnet slots in the circumferential direction of the yoke 32 and fitting the permanent magnets into the slots.

  The gap portion 36 suppresses conduction of magnetic flux between the pair of magnetic poles 34A and 34B. By suppressing the conduction of the magnetic flux between the pair of magnetic poles 34A and 34B, the interlinkage magnetic flux to the armature 12 and the stator 16 can be ensured.

  The gap portion 36 is provided between the pair of magnetic poles 34A and 34B. The gap part 36 is formed in the radial direction intermediate part of the rotor 14, for example, is penetrated in the rotation center axis C0 direction. In other words, the gap portion 36 is formed by thinning the radial intermediate portion of the yoke 32. Further, from the viewpoint of suppressing conduction of magnetic flux between the pair of magnetic poles 34A and 34B, the gap portion 36 may be a gap (air gap) or may be filled with a nonmagnetic material.

  The gap portion 36 may be an end portion of a permanent magnet slot. That is, the circumferential length of the permanent magnet slot may be longer than the circumferential length of the permanent magnet, and both ends of the permanent magnet slot may be formed as the gap portions 36. At this time, the gap portions 36A and 36B are set so that the circumferential length of the gap portion 36B provided between the pair of magnetic poles 34A and 34B is longer than the gap portion 36A on the side to which the support shaft 18 is fixed. It may be formed.

  The rib portion 38 is a reinforcing member for suppressing deformation of the rotor 14 (increasing bending rigidity). As shown in FIG. 3, the rib portion 38 is provided in the gap portion 36 </ b> B and is provided so as to connect the inner peripheral side and the outer peripheral side of the rotor 14. The rib portion 38 extends in the radial direction of the rotor 14.

  By extending the rib portion 38 in the radial direction of the rotor 14, the deformation of the rotor 14 can be effectively suppressed. FIG. 4 shows the result of a simulation in which the amount of deformation in the radial direction of the rotor 14 during rotation is calculated for each part of the rotor 100 according to the prior art and the rotor 14 according to the present embodiment. Yes. 4 is the rotor 100 according to the related art, and the right side is the rotor 14 according to the present embodiment. The rotor 100 according to the related art employs a configuration in which a fixing hole for the support shaft 18 is simply provided between the pair of magnetic poles 34A and 34B.

  Further, in FIG. 4, the magnitude of the deformation amount is represented by the density of the hatching pattern. Here, the denser the hatching pattern, the greater the deformation amount. In the simulation shown in FIG. 4, the same centrifugal force is applied to the rotor 100 according to the prior art and the rotor 14 according to the present embodiment. Further, in the example shown in FIG. 4, the thickness T1 of the rib portion 38 is ½ of the thickness T2 of the wall member 102 of the fixing hole corresponding to the rib portion 38 of the rotor 100 according to the conventional technology. . When attention is paid to the portion surrounded by a broken line in this figure, it can be understood that the deformation amount of the rotor 14 according to the present embodiment is suppressed as compared with the rotor 100 according to the prior art.

  Next, FIG. 5 shows the result of a simulation in which the stress distribution during rotation is calculated for each part of the rotor 100 according to the prior art and the rotor 14 according to the present embodiment. In this figure, as in FIG. 4, the left side of the drawing is the rotor 100 according to the related art, and the right side of the drawing is the rotor 14 according to the present embodiment. Similarly to the simulation of FIG. 4, the same centrifugal force is applied to the rotor 100 according to the conventional technique and the rotor 14 according to the present embodiment. Further, the thickness T1 of the rib portion 38 is set to ½ of the thickness T2 of the wall member 102 corresponding to the rib portion 38 of the rotor 100 according to the related art.

  When attention is paid to the portion of the stress distribution of the rotor 100 according to the prior art, particularly the portion surrounded by the broken line, it is understood that the stress is maximized at a position farthest from the support shaft 18. On the other hand, in the rotor 14 according to the present embodiment, by providing the rib portion 38 extending in the radial direction at a location where the stress is maximum, the stress at the location is reduced.

  From the above simulation results, the rib portion 38 may be provided only at a position where the stress is maximum, that is, at an intermediate position of the support shaft 18 adjacent in the circumferential direction of the rotor 14. In the rotor 100 according to the prior art, since the side wall of the fixing hole of the support shaft 18 becomes the wall member 102, the wall member 102 is provided at two places. And simplification of processing. Furthermore, since only one rib portion 38 is required, the gap portion 36B can be formed large, and the conduction of magnetic flux between the magnetic poles 34A and 34B can be effectively suppressed.

  Note that the present invention is not limited to the above-described embodiment. For example, as shown in FIG. 6, two rib portions 38 may be provided between the pair of magnetic poles 34A and 34B. Also in this case, it is preferable to extend the rib portion 38 in the radial direction of the rotor 14.

  FIG. 7 shows a simulation result obtained by calculating the radial deformation amount of the rotor 14 when the extending direction of the rib portion 38 of the rotor 14 shown in FIG. 6 is changed. The rotor 14 is shown on the left side of the drawing with the ribs 38 extending without being along the radial direction of the rotor 14, and the rotor with the ribs 38 extended in the radial direction of the rotor 14 on the right side of the drawing. 14 is shown. Further, the thicknesses T3 and T4 of the rib portions 38 are the same. Focusing on the portion surrounded by the broken line in this figure, it is understood that the deformation amount of the rotor 14 can be suppressed by extending the rib portion 38 in the radial direction of the rotor 14.

  Further, as shown in FIG. 8, the rib portion 38 may be formed inside the fixing hole of the support shaft 18. Even in this case, it is preferable to extend the rib portion 38 in the radial direction of the rotor 14. The rib portion 38 is preferably provided at an intermediate position between the support shafts 18 adjacent to each other in the circumferential direction of the rotor 14.

  As shown in FIG. 9, in the rotor 14 according to this embodiment, a plurality of grooves 40 are provided in the circumferential direction on the inner circumferential surface or the outer circumferential surface thereof. This groove 40 is provided in order to reduce torque ripple accompanying rotation of the rotor 14. In the present embodiment, the groove 40 is disposed asymmetrically when viewed from the circumferential direction of the magnetic poles 34A and 34B.

  In the rotating electrical machine 10 according to the present embodiment, magnetic characteristics are different on both sides in the circumferential direction of arbitrary magnetic poles 34A and 34B (for example, the magnetic pole 34A in FIG. 3). For example, a relatively small gap portion 36A and a support shaft 18 are provided on the right side of the paper surface of the magnetic pole 34A, and a relatively large gap portion 36B and a rib portion 38 are provided on the right side of the paper surface. Magnetic characteristics (magnetic resistance and magnetic flux passage) are different.

  In the rotor 14 according to this embodiment, the arrangement of the grooves 40 for reducing the torque ripple is asymmetric with respect to the magnetic poles 34A and 34B in accordance with the asymmetry of the magnetic characteristics.

  As shown in FIG. 9, the axis passing from the rotation center axis C0 through the intermediate position between the pair of magnetic poles 34A and 34B is referred to as a rib side reference axis C1. An axis passing from the rotation center axis C0 through the intermediate position of the adjacent magnetic pole pair 34 is referred to as a support shaft side reference axis C2. As shown in FIG. 9, the bisector of the angle formed by the rib side reference axis C1 and the support shaft side reference axis C2 passes through the center of the magnetic pole 34A.

  In this embodiment, each groove 40 is formed so that the arrangement angle α of the groove 40 from the rib side reference axis C1 and the arrangement angle β of the groove 40 from the support shaft side reference axis C2 are different. Yes. Here, the arrangement angle of the groove 40 from the reference axis may refer to the arrangement angle of the center position of the groove 40.

  The effect of torque ripple reduction by varying the arrangement angle will be described with reference to FIGS. FIG. 10 shows a graph of the degree of reduction in torque ripple according to the groove arrangement angle of the rotor 100 according to the prior art. The number of poles of the rotor 14 is 16 (8 pole pairs). Here, the rotor 100 according to the prior art refers to the rotor 100 on the left side of FIG. In addition, the horizontal axis of the graph represents the groove arrangement angle β (mechanical angle) from the reference axis C2, and the vertical axis represents the torque ripple ratio (relative to a predetermined reference value). The plots on the graph indicate the groove arrangement angle α (mechanical angle) from the reference axis C1.

  Furthermore, the straight line on the graph connects plots in which the arrangement angle α and the arrangement angle β are equal. As understood from this graph, in the conventional rotor 100, the torque ripple is most reduced (torque ripple≈20%) because the arrangement angles α and β are equal (α = β = 2.0 °). ) It will be time.

  On the other hand, FIG. 11 shows a graph of the degree of reduction of torque ripple according to the arrangement angle of the groove 40 of the rotor 14 according to the present embodiment. Here, the rotor 14 according to the present embodiment refers to the rotor 14 on the right side in FIG. Further, the horizontal axis, vertical axis, and straight line on the graph are the same as those in FIG. The number of poles of the rotor 14 is 16 (8 pole pairs) as in FIG.

  As understood from this graph, the torque ripple is most reduced (torque ripple≈10%) when the arrangement angles α and β are different (α = 6.5 °, β = 1.5 °). Become. When α (mechanical angle) = 6.5 ° and β (mechanical angle) = 1.5 ° are expressed in terms of electrical angles, respectively, when an 8-pole pair, the mechanical angle is 45 ° and the electrical angle is 360 °. (Electrical angle) = 52 ° and β (electrical angle) = 12 °.

  Thus, in the rotor 14 according to the present embodiment, the torque ripple can be minimized by making the arrangement angles α and β different. Furthermore, as understood when comparing the minimum value of torque ripple in FIG. 10 and FIG. 11, in the rotor 14 according to the present embodiment, the arrangement angles α and β are made different from those of the conventional rotor. Torque ripple can be reduced.

  In FIG. 9, the arrangement angle α (electrical angle) of the groove 40 from the rib side reference axis C1 is 52 °, and the arrangement angle β (electrical angle) of the groove 40 from the support shaft side reference axis C2 is 12 °. An embodiment is illustrated. According to this embodiment, the groove 40 on the reference shaft C2 side on the support shaft side is not disposed before or after the gap portion 36B when viewed from the radial direction of the rotor 14. The gap portion 36B is a portion where the thickness of the yoke 32 is reduced and the strength is relatively low. By not providing the groove 40 at that location, a reduction in the strength of the rotor 14 can be avoided. It becomes possible.

  In the above-described embodiment, the groove 40 is provided only on the outer peripheral surface of the rotor 14, but the present invention is not limited to this configuration. For example, as shown in FIG. 12, the groove 40 may be provided on the inner peripheral surface of the rotor 14 or the groove 40 may be provided only on the inner peripheral surface.

  DESCRIPTION OF SYMBOLS 10 Rotating electric machine, 12 Armature, 14 Rotor, 16 Stator, 18 Support shaft, 20 Power storage device, 22 Inverter, 24 Engine, 26 Drive shaft, 28 Transmission shaft, 30 Transmission, 31 Clutch mechanism, 32 York, 34 Magnetic pole pair, 34A, 34B Magnetic pole, 36A, 36B Gap part, 38 Rib part, 40 groove.

Claims (4)

A circular shape provided so as to surround the outer periphery of the cylindrical armature, and in the circumferential direction, a plurality of pairs of magnetic poles are alternately arranged, and a rotor,
A support shaft for supporting the rotor provided between the magnetic pole pairs of the rotor and extending in the direction of the rotation center axis of the rotor;
With
Between the pair of magnetic poles, a gap is provided on the rotor to suppress conduction of magnetic flux between the pair of magnetic poles.
The rotating electrical machine according to claim 1, wherein a rib portion extending in a radial direction of the rotor is formed in the gap portion so as to connect an inner peripheral side and an outer peripheral side of the rotor. The rotating electrical machine according to claim 1,
The rotating electrical machine according to claim 1, wherein the rib portion is provided only at an intermediate position of the support shaft adjacent in the circumferential direction of the rotor. The rotating electrical machine according to claim 1 or 2,
A plurality of grooves are formed in the circumferential direction on the inner circumferential surface or outer circumferential surface of the rotor,
A support shaft that passes through the intermediate position of the pair of magnetic poles from the rotation center axis and passes through the intermediate position of the adjacent magnetic pole pair from the rotation center axis and the arrangement angle of the groove from the rib side reference axis. The rotating electrical machine, wherein the plurality of grooves are formed so that an arrangement angle of the grooves from a side reference axis is different. The rotating electrical machine according to claim 3,
The rotating electrical machine, wherein the groove is formed at an electrical angle of 52 ° from the rib side reference axis and at an electrical angle of 12 ° from the support shaft side reference axis.

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