JP2005318679A - Rotor structure of rotary electric machine, rotary electric machine, and power mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the generation of vibration or noise by improving the bending rigidity of a shaft. <P>SOLUTION: A rotor shaft 72 has a resolver 80 mounted at one end as a rotary position detection sensor, a planetary gear mounted at the other end, and both the ends having different inner diameters Ba, Bb and a flange 72a formed to support a rotor core 74. In the rotor shaft 72, stepped parts 72b, 72c are formed into cylindrical shapes having uniform inner diameters Bc larger than the inner diameters Ba, Bb of both the ends from both the ends toward an inside. Thus, sectional secondary moment to the bend of the rotor shaft 72 can be increased, and bending rigidity can be improved while increasing weight and suppressing a size increase. Accordingly, the vibration of the rotor shaft 72 accompanied by the drive of the motor and the rotation of the planetary gear can be suppressed. As a result, the generation of vibration or noise based on the rotor shaft 72 can be suppressed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  TECHNICAL FIELD The present invention relates to a rotating electrical machine, and more specifically, a rotor structure of a rotating electrical machine having a hollow rotor shaft in which a flange portion that supports a rotor core is formed and both ends are formed to have different diameters by a predetermined member attached to the end portion. The present invention also relates to a rotating electrical machine including a rotor shaft using this rotor structure, and a power mechanism that outputs power from the rotating electrical machine to a drive shaft via a planetary gear mechanism.

Conventionally, as a rotor structure of this type of rotating electrical machine, a structure including a rotor shaft formed with a flange portion that supports a rotor core has been proposed (for example, see Patent Document 1). In this rotor structure, a hollow rotor shaft is used to reduce the weight.
JP 2003-191761 A

  By the way, the rotor shaft is restricted in its shape, particularly the diameter, by a member to which a sensor for detecting the rotation state is attached or a planetary gear mechanism is attached. For this reason, it is necessary to design the shape of the rotor shaft within the range of this constraint. Sometimes the bending rigidity is insufficient, and vibration is generated by driving the rotating electrical machine or rotating the planetary gear mechanism to support the rotor shaft. It is transmitted to the case of the rotating electrical machine through the bearing and appears as vibration and noise. It is also possible to cope with this by changing the material of the rotor shaft to one that increases bending rigidity, improving the accuracy of the tooth surface of the planetary gear mechanism to be connected, or improving the rigidity of the case. However, the weight is increased or the size is increased, and the cost is disadvantageous.

  The rotor structure of a rotating electrical machine, the rotating electrical machine, and the power mechanism of the present invention are intended to provide a rotor shaft of a rotating electrical machine that can suppress generation of vibration and noise while suppressing an increase in weight and an increase in size. .

  The rotor structure of the rotating electrical machine, the rotating electrical machine, and the power mechanism of the present invention employ the following means in order to achieve the above-described object.

The rotor structure of the first rotating electrical machine of the present invention is:
A rotor structure of a rotating electrical machine having a hollow rotor shaft formed with a different diameter at both ends by a predetermined member attached to the end portion and having a flange portion supporting the rotor core,
The gist is that a stepped portion is formed in a portion inward from the both ends so that a portion on the inner side of the both ends of the rotor shaft has a substantially uniform diameter larger than the diameter of the both ends. .

  In the rotor structure of the first rotating electric machine according to the present invention, the flange portion that supports the rotor core is formed, and both ends of the hollow rotor shaft that are formed at different diameters by a predetermined member that is attached to the end portion. A stepped portion is formed at a portion directed inward from both ends so that the inner portion has a cylindrical shape having a substantially uniform diameter larger than the diameters at both ends. Therefore, since the cross-sectional secondary moment can be increased, the bending rigidity can be improved while suppressing an increase in weight and an increase in size. As a result, the generation of vibration and noise based on the rotor shaft can be suppressed.

  In the rotor structure of the first rotating electric machine according to the present invention, the flange portion may be formed at a substantially center inside the both ends.

The rotor structure of the second rotating electrical machine of the present invention is
A rotor structure of a rotating electrical machine having a hollow rotor shaft formed with a different inner diameter at both ends by a predetermined member attached to the end portion and having a flange portion supporting the rotor core,
A step portion having an inner diameter extending in the axial direction from the both ends toward the center is formed at a predetermined portion inside the both ends of the rotor shaft, and the flange portion is formed in the vicinity of the step portion. The gist of the invention is that the rotor shaft is formed so as to have a tapered outer diameter from the smaller end portion to the flange portion.

  In the rotor structure of the second rotating electric machine according to the present invention, a flange portion that supports the rotor core is formed, and both ends of the hollow rotor shaft that are formed at different diameters by a predetermined member attached to the end portion are formed. A step part with an inner diameter extending in the axial direction from both ends toward the center is formed at a predetermined inner part, and a flange part is formed in the vicinity of the step part, and a taper is formed from the end of the both ends having the smaller inner diameter to the flange part. The rotor shaft is formed to have an outer diameter. Therefore, since the cross-sectional secondary moment with respect to the bending of the flange portion can be increased, the bending rigidity can be improved while suppressing an increase in weight and an increase in size. As a result, the generation of vibration and noise based on the rotor shaft can be suppressed.

  In the rotor structure of the second rotating electrical machine of the present invention, the tapered outer diameter may be formed with an inclination of approximately 45 degrees with respect to the axial direction of the rotor shaft.

  Further, in the rotor structure of the second rotating electrical machine of the present invention, the thickness inside the both ends of the rotor shaft may be formed to be thicker than the thickness at the both ends.

  In the rotor structure of the first or second rotating electric machine according to the present invention, the predetermined member is a planetary gear in which a case and a drive shaft of the rotating electric machine are respectively connected to two of the three rotating elements. The rotor shaft may be connected to the other rotating element of the planetary gear mechanism at the end.

  In the rotor structure of the first or second rotating electric machine according to the present invention, the predetermined member may be a rotation detector that detects a rotation state of the rotor shaft.

The rotating electrical machine of the present invention is
The gist of the present invention is to provide a rotor shaft using the rotor structure of the first or second rotating electrical machine according to any one of the above aspects.

  Since the rotating electrical machine of the present invention includes the rotor shaft using the rotor structure of the first or second rotating electrical machine of the present invention according to any one of the above-described aspects, the first or second rotating electrical machine of the present invention. The same effect as that produced by this rotor structure, for example, the effect of suppressing the generation of vibration and noise based on the rotor shaft can be obtained.

The power mechanism of the present invention is
A power mechanism that outputs power from the rotating electrical machine of the present invention to a drive shaft via a planetary gear mechanism,
The rotor shaft of the rotating electrical machine and the drive shaft are connected to two of the three rotating elements of the planetary gear mechanism, respectively, and the other rotating element is supported non-rotatably in the case of the power mechanism. The summary is as follows.

  Since the power mechanism of the present invention includes the above-described rotating electrical machine of the present invention, the same effect as that produced by the rotating electrical machine of the present invention can be achieved.

  Next, the best mode for carrying out the present invention will be described using examples.

  FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 10 equipped with a power mechanism 20 using a rotor structure of a rotating electrical machine as an embodiment of the present invention. FIG. It is a block diagram which shows an outline. As shown in the figure, the hybrid vehicle 10 of the embodiment includes an engine 12, a first planetary gear 30 connected to a crankshaft 14 of the engine 12 via a damper 22, and a motor MG1 connected to the first planetary gear 30. The second planetary gear 35 as a reduction gear connected to the first planetary gear 30 and the motor MG2 attached to the second planetary gear 35 are provided.

  As shown in FIG. 2, the power mechanism 20 of the embodiment mainly includes a damper 22, a motor MG1, a first planetary gear 30, a second planetary gear 35, a motor MG2, a counter gear 42, a differential gear 44, and the like. These are housed in a case 50. The case 50 is configured such that a first case 52 that accommodates the motor MG1 and a second case 54 that accommodates the motor MG2 are coupled by a fastening component such as a bolt 56. The case 50 is filled with lubricating oil for lubricating the first planetary gear 30, the second planetary gear 35, the bearings, and the like, and the oil is picked up by the rotation of the counter gear 42, the differential gear 44, and the like. It is supplied to each part.

  As shown in FIG. 1, the first planetary gear 30 meshes with the sun gear 31 of the external gear, the ring gear 32 of the internal gear disposed concentrically with the sun gear 31, and meshes with the ring gear 32. A planetary gear mechanism is provided that includes a plurality of pinion gears 33 and a carrier 34 that holds the plurality of pinion gears 33 so as to rotate and revolve. The sun gear 31, the ring gear 32, and the carrier 34 perform a differential action. . In the first planetary gear 30, the crankshaft 26 of the engine 22 is connected to the carrier 34, and the motor MG <b> 1 is connected to the sun gear 31. The ring gear 32 of the first planetary gear 30 is mechanically connected to the drive wheels 16a and 16b via a counter gear 42 and a differential gear 44 as a reduction mechanism.

  Similarly to the first planetary gear 30, the second planetary gear 35 is meshed with the sun gear 36 and the ring gear 37 of the internal gear disposed concentrically with the sun gear 36, and meshed with the ring gear 37. A planetary gear mechanism including a plurality of pinion gears 38 and a carrier 39 that holds the plurality of pinion gears 38 so as to rotate and revolve. The sun gear 36, the ring gear 37, and the carrier 39 are used as rotating elements to perform differential action. Yes. In the second planetary gear 35, the motor MG2 is connected to the sun gear 36, and the ring gear 32 of the first planetary gear 30 is connected to the ring gear 37, respectively. The carrier 39 of the second planetary gear 35 is supported by the second case 54 of the case 50 so that its rotation is prohibited.

  As shown in FIG. 2, the motor MG1 is configured as a synchronous generator motor including a rotor 46 on which a permanent magnet is attached and a stator 48 around which a three-phase coil is wound. The support walls 62 and 64 of the first case 52 are rotatably supported via bearings 63 and 65.

  Similarly to the motor MG1, the motor MG2 is configured as a synchronous generator motor including a rotor 70 to which a permanent magnet is attached and a stator 78 around which a three-phase coil is wound. The rotor 70 of the motor MG2 is The second case 54 is rotatably supported by support walls 66 and 68 via bearings 67 and 69.

  FIG. 3 is an enlarged view showing the rotor 70 of the motor MG2 of FIG. 2 using the rotor structure of the rotating electrical machine of the embodiment. As shown in the figure, the rotor 70 of the motor MG2 includes a hollow rotor shaft 72 having a substantially uniform thickness as a rotating shaft, and a rotor core 74 supported by a flange portion 72a formed at the approximate center of the rotor shaft 72. Is provided. The rotor core 74 is configured by laminating a plurality of thin annular magnetic steel plates 74a punched by pressing or the like. At both ends of the rotor core 74 in the stacking direction, presser plates 76a that press and hold the electromagnetic steel plates 74a and the permanent magnets 74b in the left-right direction in the figure in a state where the permanent magnets 74b are inserted into slots (not shown) formed in the rotor core 74. , 76b are attached.

  The rotor shaft 72 of the rotor 70 is mounted with the sun gear 36 of the second planetary gear 35 and has a rotational position for detecting the rotational position of the rotor shaft 72 at the end opposite to the sun gear 36 (right side of the bearing 69 in the drawing). A resolver 80 as a detection sensor is attached. For this reason, the inner diameters Ba and Bb at both ends of the rotor shaft 72 are restricted by the sun gear 36, the resolver 80, and the bearings 67 and 69 and are different (see FIG. 3). Further, the rotor shaft 72 has a step portion 72b having a relatively large step so as to form a cylindrical shape having a uniform inner diameter Bc larger than the inner diameters Ba and Bb from the both ends to the inner side. A small step 72c is formed. As a result, the moment of inertia of the section with respect to the bending of the rotor shaft 72 can be increased, and the bending rigidity is improved. For manufacturing the rotor shaft 72, for example, an upper mold and a lower mold that form the outer surface shape of the rotor shaft 72 and a core that forms the inner surface shape of the rotor shaft 72 are prepared. Put the upper mold on top of each other, tighten the lower mold and the upper mold, pour molten aluminum into the spout formed at one end of the mold, and remove the mold when the aluminum has cooled and solidified. This can be done by taking a child.

  FIG. 4 shows a graph showing the relationship between the frequency and the sound pressure level when the rotor structure of the rotating electrical machine of FIG. 3 is used, by comparison with the case where another rotor structure is used. FIG. 4A shows the relationship between the frequency and the sound pressure level in the planetary gear noise of the second planetary gear 35, and FIG. 4B shows the relationship between the frequency and the sound pressure level in the motor noise of the motor MG2. As another rotor structure, the rotor structure shown in FIG. 7 was used. The rotor shaft 272 of the rotor 270 in the rotor structure of FIG. 7 is formed with a stepped portion 272b having an inner diameter Bc larger than the inner diameter Ba of one end (resolver 80 side) of the rotor shaft 272 and the other end (second planetary gear). 35), a stepped portion 272c is formed to have an inner diameter Bd that is larger than the inner diameter Bb and smaller than the inner diameter Bc, and a stepped portion 272d that connects the inner diameter Bc and the inner diameter Bd is formed at the center of the rotor shaft 272. A flange portion 274a is formed on 274d. As shown in FIG. 4, when the rotor structure of FIG. 3 is used, the planetary gear noise and the motor noise are both about 500 to 3500 Hz in a frequency band of about 5 dB at maximum as compared with the case of using the rotor structure of FIG. It was confirmed that it could be suppressed.

  According to the rotor structure of the rotating electrical machine of the embodiment described above, a step is formed on the inner side from both ends of the hollow rotor shaft 72 while the thickness thereof is substantially uniform, while the inner diameters Ba and Bb are different from each other toward the inner side. By forming the portions 72b and 72c, a cylindrical shape having a uniform inner diameter Bc larger than the inner diameters Ba and Bb at both ends can be obtained, so that the secondary moment can be increased and the weight of the rotor shaft 72 can be increased. The bending rigidity can be improved. As a result, vibration and noise can be suppressed.

  In the rotor structure of the rotating electric machine according to the embodiment, the stepped portions 72b and 72c are formed inwardly from both ends of the rotor shaft 72 to thereby form a cylindrical rotor shaft having a uniform inner diameter Lb larger than inner diameters La and Lc at both ends. However, the shape of the rotor shaft may be formed such that the bending rigidity of the flange portion is improved. FIG. 5 is a configuration diagram showing an outline of a configuration of a rotor 170 using a rotor structure of a rotating electrical machine according to a modification. In addition, the same code | symbol is attached | subjected about the structure same as the rotor structure of the rotary electric machine of an Example among the rotor structures of the rotary electric machine of a modification, Since the description overlaps, it abbreviate | omits. As shown in the figure, the rotor shaft 172 of the rotor 170 has inner diameters Ba and Bb at both ends of the rotor shaft 172 extended toward the center to form a stepped portion 172b near the center and a flange portion near the stepped portion 172b. 172a is formed. Furthermore, the rotor shaft 172 is formed with a tapered portion 172c so that the outer diameter gradually increases from the end portion with the smaller inner diameter (the end portion on the second planetary gear 35 side) to the flange portion 172a. . By forming the tapered portion 172c, it is possible to improve the bending rigidity with respect to the bending of the flange portion 172a to the right side in the figure, so that vibration and noise based on the rotor shaft 172 can be suppressed. In the modification, if the thickness Wc inside the both ends of the rotor shaft 172 is made larger than the thickness Wa, Wb at both ends, the thickness Wd of the flange portion 172a is made thicker inside than both ends of the rotor shaft 172. It was assumed to be formed larger than Wc. FIG. 6 shows a graph showing the relationship between the frequency and the sound pressure level when using the rotor structure of the rotating electrical machine of the modified example of FIG. 5 in comparison with the case where another rotor structure is used. FIG. 6A shows the relationship between the frequency and the sound pressure level in the planetary gear noise of the second planetary gear 35, and FIG. 6B shows the relationship between the frequency and the sound pressure level in the motor noise of the motor MG2. As another rotor structure, the above-described rotor shaft 272 shown in FIG. 7 was used. As shown in FIG. 6, even when the rotor structure of FIG. 5 is used, both planetary gear noise and motor noise can be suppressed in a frequency band of about 500 to 3500 Hz compared to the case of using the rotor structure of FIG. confirmed. In this modification, when the thickness Wc inside the both ends of the rotor shaft 172 is made larger than the thickness Wa, Wb at both ends, the thickness Wd of the flange portion 172a is made thicker than both ends of the rotor shaft 172. The thickness is larger than the thickness Wc. However, the present invention is not limited to this. For example, the entire thickness except for the tapered portion 172c may be substantially uniform.

  In the rotor structure of the rotating electric machine according to the embodiment, the second planetary gear 35 is attached to one end of the both ends of the rotor shaft 72 and the resolver 80 is attached to the other end, but one of the second planetary gear 35 and the resolver 80 is attached. It is good also as what applies to what is not. Moreover, as long as it is a member which gives restrictions so that the diameter of the both ends of the rotor shaft 72 may differ, it is good also as what applies to the rotor shaft which attached the other member.

  In the embodiment, the rotor structure of the rotor shaft 70 of the motor MG2 in the power mechanism 20 mounted on the hybrid vehicle 10 has been described. However, the flange portion that supports the rotor core is formed as the rotor shaft of the rotating electrical machine, and the members are attached to both ends. Of course, it can be applied as a rotor structure of a rotor shaft of any rotating electrical machine as long as the hollow ends are formed to have different diameters.

  The best mode for carrying out the present invention has been described with reference to the embodiments. However, the present invention is not limited to these embodiments, and various modifications can be made without departing from the gist of the present invention. Of course, it can be implemented in the form.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 10 equipped with a power mechanism 20 using a rotor structure of a rotating electrical machine as an embodiment of the present invention. It is a block diagram which shows the outline of a structure of the power mechanism 20 of an Example. It is an enlarged view which expands and shows the rotor 70 of motor MG2 of FIG. 2 using the rotor structure of the rotary electric machine of an Example. It is a graph which shows the relationship between the frequency when using the rotor structure of the rotary electric machine of an Example, and a sound pressure level. It is a block diagram which shows the outline of a structure of the rotor 170 of motor MG2 using the rotor structure of the rotary electric machine of a modification. It is a graph which shows the relationship between a frequency when using the rotor structure of the rotary electric machine of a modification, and a sound pressure level. It is a block diagram which shows the outline of a structure of the rotor 270 of motor MG2 using the rotor structure of another rotary electric machine.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Hybrid vehicle, 12 Engine, 14 Crankshaft, 16a, 16b Drive wheel, 20 Power mechanism, 22 Damper, 30 1st planetary gear, 31 Sun gear, 32 Ring gear, 33 Pinion gear, 34 Carrier, 35 2nd planetary gear, 36 Sun gear, 37 Ring gear, 38 pinion gear, 39 carrier, 42 counter gear, 44 differential gear, 46 rotor, 48 stator, 50 case, 52 first case, 54 second case, 56 bolt, 62, 64, 66, 68 support wall, 63, 65, 67, 69 Bearing, 70, 170, 270 Rotor, 72, 172, 272 Rotor shaft, 72a Flange, 72b, 72c, 172b, 272b, 272c, 272d Stepped portion, 172 Tapered portion, 74 a rotor core, 74a electromagnetic steel, 74b permanent magnet, 76a, 76 b pressing plate, 80 resolver, MG1, MG2 motor.

Claims (9)

A rotor structure of a rotating electrical machine having a hollow rotor shaft formed with a different diameter at both ends by a predetermined member attached to the end portion and having a flange portion supporting the rotor core,
A rotor structure for a rotating electrical machine, in which a stepped portion is formed at a portion inward from the both ends so as to form a cylindrical shape having a substantially uniform diameter larger than the diameter at both ends of the rotor shaft. .   The rotor structure for a rotating electrical machine according to claim 1, wherein the flange portion is formed at a substantially center inside the both ends. A rotor structure of a rotating electrical machine having a hollow rotor shaft formed with a different inner diameter at both ends by a predetermined member attached to the end portion and having a flange portion supporting the rotor core,
A step portion having an inner diameter extending in the axial direction from the both ends toward the center is formed at a predetermined portion inside the both ends of the rotor shaft, and the flange portion is formed in the vicinity of the step portion. A rotor structure of a rotating electrical machine, wherein the rotor shaft is formed so as to have a tapered outer diameter from the end portion with the smaller diameter to the flange portion.   The rotor structure of a rotating electrical machine according to claim 3, wherein the tapered outer diameter is formed with an inclination of approximately 45 degrees with respect to the axial direction of the rotor shaft.   The rotor structure for a rotating electrical machine according to claim 3 or 4, wherein the rotor shaft is formed such that a thickness inside the both ends of the rotor shaft is thicker than a thickness at both ends. A rotor structure for a rotating electrical machine according to any one of claims 1 to 5,
The predetermined member is a planetary gear mechanism in which a case of the rotating electrical machine and a drive shaft are connected to two of the three rotating elements, respectively.
The rotor shaft is a rotor structure of a rotating electrical machine in which an end portion is connected to another rotating element of the planetary gear mechanism.   The rotor structure for a rotating electrical machine according to claim 1, wherein the predetermined member is a rotation detector that detects a rotation state of the rotor shaft.   A rotary electric machine comprising a rotor shaft using the rotor structure of the rotary electric machine according to any one of claims 1 to 7. A power mechanism that outputs power from the rotating electrical machine according to claim 8 to a drive shaft via a planetary gear mechanism,
The rotor shaft of the rotating electrical machine and the drive shaft are connected to two of the three rotating elements of the planetary gear mechanism, respectively, and the other rotating element is supported non-rotatably in the case of the power mechanism. A power mechanism.

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