JP2011050179A - Rotor and motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotor along with a motor, capable of reducing torque ripples and also increasing torque. <P>SOLUTION: The rotor 22 which is rotatably supported around an axis includes a cylindrical rotor core 56, and permanent magnets 58 held in openings 57 formed in a circumferential direction of the rotor core at almost equal intervals. In the permanent magnet, a chamfer whose thickness in a radial direction becomes thinner in both sides in the circumferential direction as compared to a center in the circumferential direction. Two grooves 50 are formed between the permanent magnets adjacent in the circumferential direction in the rotor core by leaving a prescribed interval in the circumferential direction. A distance X1 between a deepest part 51 of the groove and an axial center C becomes shorter than a distance X2 between a radial direction farthest part of the adjacent permanent magnet and the axial center. In thickness in the circumferential direction of a magnetic flux passing part sandwiched between the two grooves in the rotor core, thickness W2 of an outer periphery is formed to be thicker than thickness W1 of a radial direction inside. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a rotor and a motor.

  2. Description of the Related Art Conventionally, there has been known a motor including a rotor that is rotatably supported around an axis, a permanent magnet is disposed, and a stator that is disposed to face the rotor and is wound with a coil. Yes. In such a motor, a motor having a higher torque and a higher motor performance has been proposed (for example, see Patent Document 1).

  The permanent magnet type rotor (rotor) of Patent Document 1 includes a rectangular permanent magnet provided on the outer periphery of a rotor yoke (rotor core), a recess provided between adjacent permanent magnets, and a diameter of the recess. And a protrusion provided so as to protrude outward in the direction.

JP 2005-117855 A

  By the way, in the rotor of Patent Document 1 described above, if the permanent magnet is arranged closer to the outer peripheral surface side of the rotor core in order to further increase the torque, the opening of the flux barrier for preventing magnetic flux saturation is large. Thus, there is a problem that torque ripple is likely to occur.

  The present invention has been made in view of the above circumstances, and provides a rotor and a motor that can reduce torque ripple and increase torque.

  In order to solve the above-described problems, the invention described in claim 1 includes a cylindrical rotor core (for example, the rotor core 56 in the embodiment) and openings (for example, substantially equal intervals in the circumferential direction of the rotor core). In the rotor (for example, the rotor 22 in the embodiment) including a permanent magnet (for example, the permanent magnet 58 in the embodiment) held in the opening 57) in the embodiment and supported rotatably around the axis. The permanent magnet is formed with a chamfered portion (for example, a chamfered portion 74 in the embodiment) whose radial thickness is thinner at both sides in the circumferential direction than the central portion in the circumferential direction, and is adjacent to the circumferential direction in the rotor core. Two groove portions (for example, the groove portion 50 in the embodiment) are formed between the permanent magnets at predetermined intervals in the circumferential direction, and the deepest portion (for example, an implementation type) of the groove portion. Is the distance between the radially farthest part of the permanent magnet and the axis center that are close to each other (for example, the distance X1 in the embodiment) between the deepest part 51) and the axis center (for example, the axis center C in the embodiment). The thickness in the circumferential direction of the magnetic flux passage portion (for example, the magnetic flux passage portion 90 in the embodiment) sandwiched between the two groove portions in the rotor core is shorter than (for example, the distance X2 in the embodiment). The thickness of the outer peripheral edge (for example, the thickness W2 in the embodiment) is formed to be thicker than the thickness on the inner side in the direction (for example, the thickness W1 in the embodiment).

  According to the second aspect of the present invention, the radial length between the outer peripheral surface (for example, the outer peripheral surface 90b in the embodiment) and the shaft center in the magnetic flux passage portion of the rotor core is the central portion in the circumferential direction of the magnetic flux passage portion. It is characterized by being gradually shortened from both ends toward the circumferential direction.

  In the invention described in claim 3, a convex portion (for example, the convex portion 91 in the embodiment) protruding in the circumferential direction is formed on the outer peripheral portion (for example, the outer peripheral edge 90 a in the embodiment) of the magnetic flux passage portion of the rotor core. It is characterized by being.

  The invention described in claim 4 is characterized in that the deepest portion of the groove is formed in a U-shape.

  According to a fifth aspect of the present invention, the position corresponding to the chamfered portion of the permanent magnet on the outer peripheral surface of the rotor core is cut out so as to be substantially parallel to the chamfered portion, and the magnetic flux is near the groove portion. Inclined toward the circumferential end of the passage portion, a substantially V-shaped notch (for example, the notch 85 in the embodiment) is formed on the outer peripheral surface of the rotor core.

  According to a sixth aspect of the present invention, a motor (for example, the motor 23 in the embodiment) includes a rotor according to any one of the first to fifth aspects, and a cylindrical stator ( For example, the stator 21) according to the embodiment and a winding wound around a tooth portion of the stator are provided.

  According to the first aspect of the present invention, since the chamfered portion is formed on the permanent magnet, the permanent magnet can be firmly held on the rotor core even if the permanent magnet is arranged close to the outer side in the radial direction of the rotor core. Further, since two groove portions are formed between adjacent permanent magnets in the rotor core, torque ripple can be reduced and torque can be increased by the q groove effect. Further, by forming the groove in the rotor core, the rotor can be reduced in weight, and the responsiveness as a motor can be improved. Further, by reducing the torque ripple, the generation of noise and vibration from the motor can be suppressed. Furthermore, since the minimum value of the torque increases, the current value in the hill hold state decreases. As a result, heat generation in the hill hold state can be reduced. And since the thickness of the circumferential direction of the magnetic flux passage part pinched | interposed into two groove parts was comprised so that the thickness of an outer peripheral edge part might become thicker than the thickness of radial inside, it makes it easy to let magnetic flux pass through a magnetic flux passage part. be able to. That is, since the main magnetic flux passing through the magnetic flux passage portion increases, the motor output can be improved.

  According to the second aspect of the present invention, the shape of the outer circumferential surface of the magnetic flux passage portion is such that the radial length between the outer circumferential surface and the axial center of the rotor core is gradually increased from the circumferential central portion toward both circumferential end portions. Since the length is shortened, the magnetic flux can be more easily passed through the magnetic flux passage portion, and the torque ripple can be further reduced. Moreover, since the main magnetic flux which passes a magnetic flux passage part can be increased, d-axis inductance falls. As a result, the output of the motor can be improved.

  According to the third aspect of the present invention, since the convex portion is formed on the outer peripheral edge portion of the rotor core having a low magnetic flux saturation level, the torque can be further increased.

  According to the invention described in claim 4, since the deepest portion of the groove portion is formed in a U shape, the strength of the rotor core can be ensured and the magnetic flux can be easily passed through the rotor core.

  According to the fifth aspect of the present invention, the torque ripple can be reduced while the reluctance torque is generated by forming the substantially V-shaped notch on the outer peripheral surface of the rotor core. Moreover, since the opening part of a groove part can be narrowed, a torque can be improved more.

  According to the invention described in claim 6, since the chamfered portion is formed in the permanent magnet, the permanent magnet can be firmly held on the rotor core even if the permanent magnet is arranged close to the radial direction outside of the rotor core. In addition, since two grooves are formed in the magnetic flux passage formed between adjacent permanent magnets in the rotor core, a motor capable of reducing torque ripple and increasing torque due to the q groove effect is provided. can do.

It is a schematic structure sectional view of a motor unit in an embodiment of the present invention. It is a front view of the rotor in the embodiment of the present invention. It is the A section enlarged view of FIG. It is a schematic block diagram of the conventional rotor. It is a schematic block diagram of the state which formed the groove part in the conventional rotor. 6 is a graph showing torque characteristics of the rotors of FIGS. 4 and 5. 6 is a graph showing torque characteristics of the rotors of FIGS. 2 and 5.

Next, an embodiment of the present invention will be described with reference to FIGS. In the present embodiment, a motor employed in the vehicle motor unit will be described.
FIG. 1 is a schematic sectional view of a vehicle motor unit. As shown in FIG. 1, a vehicle motor unit (hereinafter referred to as a motor unit) 10 includes a motor 23 including a stator 21 around which a coil 20 is wound and a rotor 22 on which a permanent magnet 58 is disposed. Yes. The motor unit 10 includes a motor housing 11 that houses the motor 23, and a transmission housing that is fastened to one side of the motor housing 11 and that houses a power transmission unit (not shown) that transmits power from the output shaft 24 of the motor 23. 12, and a sensor housing 13 that is fastened to the other side of the motor housing 11 and accommodates the rotation sensor 25 of the motor 23. The motor housing 11 is configured as a motor chamber 36, the mission housing 12 is configured as a mission chamber 37, and the sensor housing 13 is configured as a sensor chamber 38.

  The motor housing 11 is formed in a substantially cylindrical shape so as to cover the entire motor 23. A bearing 26 that rotatably supports one end of the output shaft 24 of the motor 23 is provided on the mission housing 12 side of the boundary between the motor housing 11 and the mission housing 12, and the boundary between the motor housing 11 and the sensor housing 13. On the sensor housing 13 side, a bearing 27 that rotatably supports the other end of the output shaft 24 of the motor 23 is provided.

  Further, a breather passage 35 communicating with each other is formed in the wall portion 31 of the motor housing 11, the wall portion 32 of the transmission housing 12, and the wall portion 33 of the sensor housing 13.

  Further, a water jacket 40 for cooling the motor 23 is provided in the wall portion 31 of the motor housing 11 so as to cover the entire circumference of the stator 21 of the motor 23. The stator 21 is press-fitted into the motor housing 11 and is arranged so as to be in close contact with the inner peripheral surface of the motor housing 11.

  In the mission housing 12, a breather chamber 42 for separating the lubricating oil used in the motor unit 10 is formed. That is, the lubricating oil scattered by the rotation of the power transmission unit (gear) and the motor 23 can be separated in the breather chamber 42, and the lubricating oil leaks to the outside from the breather pipe 39 provided in the breather chamber 42 and communicating with the outside. This can be prevented.

  The breather chamber 42 is formed at a position corresponding to the uppermost part of the motor unit 10. The breather chamber 42 communicates with the breather passage 35 so that high-pressure and high-temperature air in the motor unit 10 can be discharged from the breather pipe 39. Further, the breather chamber 42 communicates with the motor chamber 36, the mission chamber 37, and the sensor chamber 38 via the breather passage 35.

Here, the configuration of the rotor 22 will be described with reference to FIGS. 2 and 3. FIG. 2 is a front view of the rotor, and FIG. 3 is a partially enlarged view of the rotor (A portion in FIG. 2).
As shown in FIG. 2, the rotor 22 includes a rotor core 56 in which a plurality of substantially ring-shaped magnetic plates 55 viewed from the front as viewed from the axial direction are stacked, and openings 57 formed in the rotor core 56 at substantially equal intervals in the circumferential direction. And a permanent magnet 58 held therein, and is rotatably supported by an output shaft (axis line) 24. The rotor 22 is disposed opposite to the stator 21 around which the coil 20 is wound with a predetermined interval. That is, a so-called IPM (Interior Permanent Magnet) motor in which the permanent magnet 58 is embedded in the rotor core 56 is configured.

  As shown in FIG. 3, in this embodiment, the rib 60 is formed so as to divide the opening 57 into two in the direction along the radial direction of the rotor core 56 at the approximate center of the opening 57 in the front view of the rotor core 56. ing. That is, the rib 60 divides the opening into a right opening 57A and a left opening 57B, and the permanent magnet 58 is divided into a right permanent magnet 58A and a left permanent magnet 58B.

  In the following description, the shapes of the opening and the permanent magnet will be described. However, the shapes of the right opening 57A and the left opening 57B and the shapes of the right permanent magnet 58A and the left permanent magnet 58B are both symmetrical via the rib 60. Therefore, only the shape on the right side will be described.

  The right opening 57 </ b> A corresponds to the side surface of the rib 60 and is linearly shown in a front view, and from the end of the rib 60 on the output shaft 24 side (inner diameter side) to the first linear portion 61. A second linear portion 62 extending in a substantially right angle direction, and an arc portion 63 extending in an arc from the end of the rib 60 on the stator 21 side (outer diameter side) along the outer peripheral edge of the rotor core 56; And a linear chamfered portion 64 extending from the end of the arc portion 63 along the outer peripheral edge of the rotor core 56. In addition, between the edge part of the 2nd linear part 62 and the edge part of the chamfering part 64, the notch part 65 for filling for filling an adhesive agent and the flux barrier 67 are formed, and edge parts are connected. . The flux barrier 67 is formed so as to bulge outward in the circumferential direction from the third linear portion 75 (described later in detail) of the right permanent magnet 58A.

  On the other hand, the right permanent magnet 58A includes a first straight portion 71 corresponding to the first straight portion 61 of the right opening 57A, a second straight portion 72 corresponding to the second straight portion 62 of the right opening 57A, and the right opening 57A. The arc portion 73 corresponding to the arc portion 63, the chamfer portion 74 corresponding to the chamfer portion 64 of the right opening 57A, the end portion of the second straight portion 72, and the end portion of the chamfer portion 74 are connected to each other. And a third linear portion 75 extending in a direction substantially perpendicular to the portion 72.

  Further, a notch 85 is formed at a position corresponding to the chamfered portion 74 of the right permanent magnet 58 </ b> A on the outer peripheral surface 56 a of the rotor core 56. The notch 85 is formed in a substantially V shape when viewed from the front, and the straight portion 86 on the rib 60 side is formed so as to be substantially parallel to the chamfered portion 74 of the right permanent magnet 58A. Moreover, the linear part 87 formed continuously with the linear part 86 is formed with an inclination opposite to the linear part 86, and a substantially V-shaped cutout part 85 is formed (to be described in detail later).

  Here, between the adjacent permanent magnets 58 and 58 in the rotor core 56, a groove portion 50 is formed from the outer peripheral surface 56 a of the rotor core 56 toward the axial center C. The groove portion 50 is formed in two places, one in the vicinity of the adjacent permanent magnets 58, 58. A region sandwiched between the groove portions 50 and 50 is configured as a magnetic flux passage portion 90.

  The groove part 50 is formed in a substantially U shape in plan view in the immediate vicinity of the flux barrier 67 in the rotor core 56. Here, the groove portion formed in the vicinity of the right permanent magnet 58A is referred to as a groove portion 50A, and the groove portion formed in the vicinity of the left permanent magnet 58B is referred to as a groove portion 50B. That is, the region sandwiched between the groove portion 50 </ b> A and the groove portion 50 </ b> B in the rotor core 56 is the magnetic flux passage portion 90.

  Convex portions 91 protruding outward in the radial direction are formed on both sides of the outer peripheral edge 90 a of the magnetic flux passage portion 90. That is, the thickness W2 of the outer peripheral edge 90a is formed thicker in the circumferential direction of the magnetic flux passage part 90 than the thickness W1 on the radially inner side. The shape of the convex portion 91 is preferably a substantially rectangular shape in plan view. By making the convex portion 91 substantially rectangular, the area of the convex portion 91 can be as large as possible while ensuring the width of the groove portion 50.

  Further, the radial length between the outer peripheral surface 90 b and the axial center C in the magnetic flux passage portion 90 is gradually shortened from the circumferential central portion of the magnetic flux passage portion 90 toward both circumferential ends. That is, when comparing the length H1 between the circumferential center of the magnetic flux passage 90 and the axial center C and the length H2 between the circumferential end of the magnetic flux passage 90 and the axial center C, H1> H2. In the present embodiment, the outer peripheral surface 90b of the magnetic flux passage portion 90 is curved.

  Moreover, the depth D1 of the groove part 50 is formed with the depth which reduces the short circuit magnetic flux of the adjacent permanent magnets 58 and 58. FIG. Specifically, the distance X1 connecting the shaft center C and the deepest portion 51 of the groove 50 is shorter than the distance X2 between the radially farthest portion of the adjacent permanent magnet 58 and the shaft center C. That is, the depth of the groove 50 is set so that the groove 50 and the permanent magnet 58 wrap in the circumferential direction.

  The width of the groove 50 along the circumferential direction is not particularly limited, but is preferably a width that ensures the strength of the rotor core 56. In addition, it is preferable for the performance of the motor 23 to form the groove portion 50 as close as possible to the permanent magnet 58 side, but the wall thickness W3 between the groove portion 50 and the opening portion 57 is set in consideration of the strength of the rotor core 56. It is necessary to. Further, since the region between the groove 50 and the opening 57 in the rotor core 56 is the place where the magnetic flux is most saturated, a flux barrier 67 is formed in the opening 57 of the permanent magnet 58 on one side and the groove 50 on the other. It is possible to prevent a magnetic flux short circuit from occurring.

  Further, a notch 85 is formed in the outer peripheral surface 56 a of the rotor core 56. The cutout portion 85 is formed in a substantially V shape in plan view, and includes a straight portion 86 and a straight portion 87. The straight portion 86 is formed so as to be substantially parallel to the chamfered portion 74 of the permanent magnet 58. One end side of the linear portion 87 is connected to the end portion of the linear portion 86, and the linear portion 87 is formed toward the convex portion 91 of the magnetic flux passage portion 90 at an inclination angle opposite to the linear portion 86. . The other end side of the linear portion 87 extends to the outer peripheral surface 56 a of the rotor core 56.

  The torque waveforms of the rotor core 56 configured in this way and the conventional rotor core will be compared. FIG. 4 is a configuration diagram of a conventional rotor, and FIG. 5 is a configuration diagram of a rotor in which only a groove portion is formed in a rotor core.

  As shown in FIG. 6, it can be seen that the torque ripple can be reduced by forming the groove in the rotor of FIG. 4 and the rotor of FIG. Moreover, the minimum value of torque can be raised.

  Further, as shown in FIG. 7, it can be seen that the torque ripple can be further reduced by further forming the convex portion 91 in the magnetic flux passage portion 90 in the rotor of FIG. 5 and the rotor of FIG. Further, the minimum value of torque can be further increased.

  According to the present embodiment, the chamfered portion 74 is formed on the permanent magnet 58 and the permanent magnet 58 is formed in a substantially kamaboko shape. The rotor core 56 can be firmly held. In addition, since two groove portions 50 are formed in the magnetic flux passage portion 90 formed between the adjacent permanent magnets 58 and 58 in the rotor core 56, torque ripple can be reduced by the q groove effect and the torque is increased. be able to. Moreover, by forming the groove part 50 in the rotor core 56, the rotor 22 can be reduced in weight and the responsiveness as the motor 23 can be improved. Further, by reducing the torque ripple, the generation of noise / vibration from the motor 23 can be suppressed. Furthermore, since the minimum value of the torque increases, the current value in the hill hold state decreases. As a result, heat generation in the hill hold state can be reduced.

  In addition, the shape of the outer peripheral surface 90b of the magnetic flux passage portion 90 is such that the radial length between the outer peripheral surface 90b and the axial center C of the rotor core 56 gradually decreases from the circumferential central portion toward both circumferential end portions. Therefore, the magnetic flux can be easily passed through the magnetic flux passage portion 90, and the torque ripple can be further reduced. Moreover, since the main magnetic flux which passes the magnetic flux passage part 90 can be increased, d-axis inductance falls. As a result, the output of the motor 23 can be improved.

  Moreover, since the convex part 91 was formed in the outer periphery (outer periphery 90a of the magnetic flux passage part 90) of the rotor core 56 with a low magnetic flux saturation level, a torque can further be raised.

  Further, since the deepest portion 51 of the groove portion 50 is formed in a U shape, the strength of the rotor core 56 can be ensured and the magnetic flux can be easily passed through the rotor core 56.

  Furthermore, by forming a substantially V-shaped cutout 85 on the outer peripheral surface 56a of the rotor core 56, torque ripple can be reduced while generating reluctance torque. Moreover, since the opening part of the groove part 50 can be narrowed, a torque can be improved more.

  Then, by adopting the motor 23 having the rotor 22 using the rotor core 56 formed as described above, it is possible to provide a motor capable of reducing torque ripple and increasing torque. it can.

The present invention is not limited to the above-described embodiment, and includes various modifications made to the above-described embodiment without departing from the spirit of the present invention. That is, the specific structure and shape described in the embodiment are merely examples, and can be changed as appropriate.
For example, in the present embodiment, a case has been described in which a rib is provided on the rotor core and the permanent magnet is divided into two parts, but the permanent magnet may not be divided.
In the present embodiment, the filling notch is formed in the opening. However, if the permanent magnet can be fixed in the opening by other means, the filling notch may not be formed.
Moreover, in this embodiment, although the case where the shape of a notch part was formed in front view substantially V shape was demonstrated, other shapes, such as front view substantially U shape, may be sufficient.

Moreover, in this embodiment, although the case where an adhesive agent was filled in the clearance gap between an opening part and a permanent magnet was demonstrated, what is necessary is just a filler which can hold | maintain a permanent magnet in an opening part.
Moreover, in this embodiment, although the case where the outer peripheral surface in a magnetic flux passage part was made into the curved shape was demonstrated, a taper shape may be sufficient.

  DESCRIPTION OF SYMBOLS 21 ... Stator 22 ... Rotor 23 ... Motor 50 ... Groove part 51 ... Deepest part 56 ... Rotor core 57 ... Opening part 58 ... Permanent magnet 74 ... Chamfering part 85 ... Notch part 90 ... Magnetic flux passage part 90a ... Outer peripheral edge 90b ... Outer peripheral surface 91 ... Convex part C ... axis center X1 ... distance between deepest part of groove part and axis center X2 ... distance between radially farthest part of permanent magnet and axis center W1 ... diameter thickness inside magnetic flux passing part W2 ... magnetic flux passing part The outer peripheral edge thickness

Claims (6)

In a rotor supported by a cylindrical rotor core and a permanent magnet held in openings formed at substantially equal intervals in the circumferential direction of the rotor core, and rotatably supported about an axis,
The permanent magnet is formed with a chamfered portion such that the thickness in the radial direction is thinner on both sides in the circumferential direction than the central portion in the circumferential direction.
Between the permanent magnets adjacent to each other in the circumferential direction in the rotor core, two grooves are formed at predetermined intervals in the circumferential direction,
The distance between the deepest part of the groove and the axial center is shorter than the distance between the radially farthest part of the adjacent permanent magnet and the axial center,
In the rotor core, a thickness of a magnetic flux passage part sandwiched between the two groove parts in the circumferential direction is formed such that the outer peripheral edge part is thicker than the radially inner thickness.   The length in the radial direction between the outer peripheral surface of the magnetic flux passage portion of the rotor core and the axial center is gradually shortened from the circumferential center portion of the magnetic flux passage portion toward both ends in the circumferential direction. The rotor according to claim 1.   The rotor according to claim 1, wherein a convex portion protruding in the circumferential direction is formed on an outer peripheral edge portion of the magnetic flux passage portion of the rotor core.   The deepest part of the said groove part is formed in U shape, The rotor in any one of Claims 1-3 characterized by the above-mentioned.   A position corresponding to the chamfered portion of the permanent magnet on the outer peripheral surface of the rotor core is cut out so as to be substantially parallel to the chamfered portion, and toward the circumferential end of the magnetic flux passing portion in the vicinity of the groove. The rotor according to claim 1, wherein a substantially V-shaped notch is formed on an outer peripheral surface of the rotor core. A rotor according to any one of claims 1 to 5;
A cylindrical stator arranged to surround the rotor;
And a winding wound around a tooth portion of the stator.

Images