JP5452892B2 - Permanent magnet motor - Google Patents

Description

  The present invention relates to a permanent magnet motor.

Conventionally, a permanent magnet that is supported rotatably around an axis, and includes a rotor portion in which a permanent magnet is disposed, and a stator portion that is disposed to face the periphery of the rotor portion and is wound with a coil. An electric motor is known. Here, as a configuration of the rotor portion, a configuration in which a permanent magnet is embedded in a rotor core on which magnetic plate materials are laminated is known. In the rotor portion having such a configuration, a method is generally employed in which a permanent magnet is inserted into an opening formed in the rotor core, and a gap between the rotor core and the permanent magnet is filled with an adhesive or the like. However, when the gap between the opening of the rotor core and the permanent magnet is large, the position of the permanent magnet is not stable, and the magnetic flux varies, which may adversely affect the performance of the motor. In order to solve such a problem, there has been proposed one in which the variation in the position of the permanent magnet is suppressed (see, for example, Patent Document 1).
The motor in which the permanent magnets of Patent Document 1 are embedded is provided with a groove portion on the wall surface of the permanent magnet embedding hole, and an adhesive layer for fixing the rotor core body and the permanent magnet to the groove portion.
JP-A-11-191939

  By the way, in the motor of Patent Document 1 described above, since the adhesive for fixing the permanent magnet and the rotor core is filled and fixed only in the groove portion, the permanent magnet may not be fixed to the rotor core reliably. In addition, since the outer dimensions of the permanent magnet and the permanent magnet hole are configured to substantially coincide with each other, there is a problem that the assemblability when the permanent magnet is assembled to the rotor core is poor.

  Therefore, the present invention has been made in view of the above circumstances, and provides a permanent magnet motor that can hold a permanent magnet on a rotor core without deteriorating motor performance and has good assemblability. Is.

In order to solve the above problems, the invention described in claim 1 is a rotor core (for example, the rotor core 56 in the embodiment) in which a plurality of magnetic plate materials (for example, the magnetic plate material 55 in the embodiment) are stacked, and the rotor core. And a permanent magnet (for example, the permanent magnet 58 in the embodiment) held in the opening (for example, the opening 57 in the embodiment) formed around the axis (for example, the output shaft 24 in the embodiment). Permanently provided with a rotor portion that is rotatably supported (for example, the rotor portion 22 in the embodiment) and a stator portion (for example, the stator portion 21 in the embodiment) disposed so as to surround the rotor portion. magnet motor (e.g., motor 23 in the embodiment) in the opening, the ribs along the radial direction of the rotor core (e.g., exemplary type Are divided into two right side opening portion (e.g., the right side opening 57A in the embodiment) left side opening portion (e.g., the right side opening 57B in the embodiment) by the rib 60) in said permanent magnet, said right side opening And a right permanent magnet (for example, the right permanent magnet 58A in the embodiment) and a left permanent magnet (for example, the right permanent magnet 58B in the embodiment) respectively held in the left and right openings, and the right opening and the An adhesive that holds the right permanent magnet and the left permanent magnet in the right opening and the left opening at the circumferential end on the opposite side of the rib on the radially inner portion of each of the left openings. filling notches the inlet (e.g., filling notches 65 in the embodiment) with is formed, the right side opening And the radially outer portion of each of the left side openings, on the opposite side of the filling notch, through the right side opening and the left side opening, respectively, in the circumferential direction opposite to the ribs A taper portion (for example, a taper portion 64 in the embodiment) in which the distance from the radially inner portion becomes smaller toward the end portion is formed, and the right permanent magnet, the left permanent magnet, and the right opening portion are formed. And the radially outer portion of each of the left side openings are a first contact point in the vicinity of the rib (for example, the first contact point 81 in the embodiment) and a second contact point in the tapered portion (for example, in the embodiment). The second contact point 82) is configured to come into contact at two points, and radially outside each of the right permanent magnet and the left permanent magnet, and the right opening and the left opening. The side portion is separated from the first contact point and the second contact point.

  According to a second aspect of the present invention, a flux barrier (for example, the flux barrier 67 in the embodiment) is formed at both ends in the circumferential direction of the rotor core in the opening, and the notch for filling and the flux barrier are It is characterized by being configured to be partitioned by a contact portion (for example, the boundary point 68 in the embodiment) between the permanent magnet and the rotor core.

According to the first aspect of the present invention, after the permanent magnet is inserted into the opening of the rotor core, the adhesive is uniformly distributed in the gap between the permanent magnet and the opening by injecting the adhesive from the notch for filling. The permanent magnet can be reliably held on the rotor core. In addition, since the notch for filling is formed at both ends on the inner peripheral side of the opening, it is possible to press the permanent magnet against the outer peripheral side of the opening with the pressure when the adhesive is injected. In addition, since the distance between the permanent magnet and the stator portion can be reduced, variations in torque characteristics can be suppressed. Furthermore, by forming the notch for filling at both ends on the inner peripheral side of the opening, it is possible to suppress the occurrence of irreversible demagnetization due to anti-demagnetization and the occurrence of irreversible demagnetization due to heat generation.
Moreover, since the rib is provided in the opening, the strength of the rotor core (opening) can be improved. Therefore, the opening can be enlarged and a larger permanent magnet can be provided. As a result, it is possible to increase the torque and output of the permanent magnet motor. Moreover, by providing the rib, each permanent magnet can be held radially outward at the circumferential center position (rib side) of the opening. Therefore, the assemblability can be further improved, and the permanent magnet can be reliably held on the outer peripheral side of the rotor core.

  According to the invention described in claim 2, by forming the flux barriers at both ends of the opening, it is possible to prevent magnetic flux leakage of the permanent magnet and improve the performance of the motor. In addition, by partitioning the notch for filling and the flux barrier with a permanent magnet, when the adhesive is injected into the notch for filling, the adhesive efficiently spreads to the gap between the permanent magnet and the rotor core. can do. Further, since the size of the opening is surely larger than the size of the permanent magnet, it can be easily assembled.

Next, an embodiment of the present invention will be described with reference to FIGS. In the present embodiment, a permanent magnet motor employed in a vehicle power train will be described.
FIG. 1 is a schematic sectional view of a power train for a vehicle. As shown in FIG. 1, a vehicle power train (hereinafter referred to as a power train) 10 includes a motor housing 11 that houses a motor (permanent magnet motor) 23 having a stator portion 21 and a rotor portion 22, and the motor housing 11. A transmission housing 12 that houses a power transmission unit (not shown) that transmits power from the output shaft 24 of the motor 23, and a rotation sensor 25 of the motor 23 that is fastened to the other side of the motor housing 11. And a sensor housing 13 for housing the sensor. The mission housing 12 includes a common housing 12A fastened to the motor housing 11 and a gear housing 12B fastened to the common housing 12A. 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, in the wall portion 31 of the motor housing 11, a water jacket 40 for cooling the motor 23 is provided on the inner peripheral side of the breather passage 35 so as to cover the entire stator portion 21 of the motor 23. . The stator portion 21 is shrink-fitted into the motor housing 11 and is disposed so as to be in close contact with the inner peripheral surface of the motor housing 11.

  A breather chamber 51 for separating the lubricating oil used in the powertrain 10 is formed in the mission housing 12. 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 51, and the lubricating oil leaks to the outside from the breather pipe 39 provided in the breather chamber 51 and communicating with the outside. This can be prevented.

  The breather chamber 51 is formed at a position corresponding to the uppermost portion of the power train 10. The breather chamber 51 communicates with the breather passage 35 so that high-pressure and high-temperature air in the power train 10 can be discharged from the breather pipe 39. Further, the breather chamber 51 communicates with the motor chamber 36, the mission chamber 37, and the sensor chamber 38 via the breather passage 35.

  Here, the structure of the rotor part 22 is demonstrated using FIG. 2, FIG. 2 is a plan view of the rotor portion, and FIG. 3 is an enlarged view of a portion A in FIG. As shown in FIGS. 2 and 3, the rotor unit 22 includes a rotor core 56 in which a plurality of magnetic plate materials 55 are stacked, and a permanent magnet 58 held in an opening 57 formed in the rotor core 56, and an output shaft. (Axis) 24 is rotatably supported. The rotor portion 22 is disposed to face the stator portion 21 around which the coil is wound with a predetermined interval.

  In the present 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 a plan view of the rotor core 56. 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 57A corresponds to the side surface of the rib 60, and is substantially perpendicular to the first straight portion 61 from the end on the output shaft 24 side of the rib 60 and the first straight portion 61 shown linearly in plan view. From the extended second linear portion 62, the arc-shaped arc portion 63 extending from the end of the rib 60 on the stator portion 21 side along the outer peripheral edge of the rotor core 56, and the end of the arc portion 63 And a linear taper portion 64 further extending 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 taper 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 from the third linear portion 75 (described later in detail) of the right permanent magnet 58A. Further, the filling notch 65 is formed so as to bulge from the end of the second linear portion 62 toward the inner peripheral side of the rotor core 56. Note that the boundary between the arc portion 63 and the taper portion 64 is defined as a switching point 66.

  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. An arc portion 73 corresponding to the arc portion 63, a taper portion 74 corresponding to the taper portion 64 of the right opening 57A, and an end portion of the second linear portion 72 and an end portion of the taper portion 74 are connected to each other. And a third linear portion 75 extending in a direction substantially perpendicular to the portion 72. A boundary between the arc portion 73 and the taper portion 74 is defined as a switching point 76.

  Here, when the right permanent magnet 58A is inserted into the right opening 57A, the right permanent magnet 58A comes into contact with the right permanent magnet 58A at two points on the outer peripheral edge side of the rotor core 56 in the right opening 57A, that is, the arc portion 63 and the taper portion 64. It is configured as follows. Specifically, the first contact point 81 near the boundary between the first straight line portion 61 and the arc portion 63 in the right opening 57A, and the second contact point 82 near the end opposite to the switching point 66 in the taper portion 64. The right opening 57A and the right permanent magnet 58A are in contact with each other. The right permanent magnet 58 </ b> A and the right opening 57 </ b> A are configured to abut at a boundary point 68 between the filling notch 65 and the flux barrier 67.

  Then, the right permanent magnet 58A is inserted into the right opening 57A and the adhesive is pumped and filled from the filling notch 65, so that the adhesive is spaced from the filling notch 65 to the right permanent magnet 58A and the rotor core 56. The right permanent magnet 58A is fixed in the right opening 57A. Further, the filling notch 65 is provided at the inner peripheral end of the right opening 57A, and the right permanent magnet 58A is held on the outer peripheral side of the right opening 57A on the rib 60 side by injecting adhesive from there. The other openings 57 can be held at substantially the same position.

  According to the present embodiment, after the right permanent magnet 58A is inserted into the right opening 57A of the rotor core 56, the adhesive is injected from the filling notch 65, so that the right permanent magnet 58A and the right opening 57A are in contact with each other. The adhesive spreads evenly across the gap, and the right permanent magnet 58A can be reliably held on the rotor core 56. Further, since the filling notch 65 is formed at the inner peripheral end of the right opening 57A, when the adhesive is injected, the right permanent magnet 58A can be pressed against the outer periphery of the right opening 57A by the pressure.

  Further, by providing the rib 60 in the opening 57, each permanent magnet 58 (58A, 58B) can be held radially outward at the circumferential center position (rib 60 side) of both the openings 57A, 57B. Therefore, the assemblability can be improved and the permanent magnet 58 can be reliably held on the outer peripheral side of the rotor core 56. Furthermore, since the distance between the permanent magnet 58 and the stator portion 21 can be reduced, variation in torque characteristics can be suppressed. Furthermore, by forming the filling notches 65 at both ends on the inner peripheral side of the opening 57, it is possible to suppress the occurrence of irreversible demagnetization due to anti-demagnetization and the occurrence of irreversible demagnetization due to heat generation.

  Moreover, since the rib 60 is provided, the strength of the rotor core 56 (opening 57) can be improved. Therefore, the opening 57 can be enlarged, and a larger permanent magnet 58 can be provided. As a result, the motor 23 can be increased in torque and output.

  And by forming the flux barrier 67 at both ends of the opening 57, the magnetic flux leakage of the permanent magnet 58 can be prevented, and the performance of the motor 23 can be improved. In addition, by partitioning the filling notch 65 and the flux barrier 67 with the permanent magnet 58, when the adhesive is injected into the filling notch 65, the adhesive is efficiently attached to the permanent magnet 58 and the rotor core 56. It can be made to spread across the gap. Further, since the size of the opening 57 is surely larger than the size of the permanent magnet 58, it can be easily assembled.

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 this embodiment, although the description of the case where the flux barrier is provided on both sides of the open mouth, flux barriers need not be provided.
Further, in the present embodiment, the rotor core has an opening for embedding the permanent magnet and an opening for inserting the output shaft. However, an opening for reducing the weight of the rotor core may be formed. Good.

It is a schematic structure sectional view of a power train in an embodiment of the present invention. It is a top view of the rotor part in the embodiment of the present invention. It is the A section enlarged view of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 21 ... Stator part 22 ... Rotor part 23 ... Motor (permanent magnet electric motor) 24 ... Output shaft (axis) 55 ... Magnetic plate material 56 ... Rotor core 57 ... Opening part 58 ... Permanent magnet 60 ... Rib 65 ... Notch part for filling 67 ... Flux Barrier 68 ... Boundary point (contact part)

Claims (2)

A rotor core comprising a plurality of magnetic plate members laminated and a permanent magnet held in an opening formed in the rotor core, and a rotor portion supported rotatably around an axis;
In a permanent magnet electric motor comprising a stator portion disposed so as to surround the rotor portion,
The opening is divided into a right opening and a left opening by ribs along the radial direction of the rotor core ,
The permanent magnet is composed of a right permanent magnet and a left permanent magnet held in the right opening and the left opening, respectively.
The right side permanent magnet and the left side permanent magnet are placed on the radially inner end of each of the right side opening and the left side opening at the circumferential end opposite to the rib, and the right side opening and the left side opening. A notch for filling that serves as an inlet for the adhesive to be held in the part is formed,
The radially outer portion of each of the right side opening and the left side opening is opposite to the rib on the opposite side of the right side opening and the left side opening with respect to the notch for filling. As it goes to the circumferential end on the side, a taper portion is formed in which the distance between the radially inner portion is reduced ,
The right permanent magnet and the left permanent magnet, and the radially outer portion of each of the right opening and the left opening are two points: a first contact point in the vicinity of the rib and a second contact point in the tapered portion. Configured to contact with
The right permanent magnet and the left permanent magnet, and the radially outer portion of each of the right opening and the left opening are separated from each other between the first contact point and the second contact point. Permanent magnet motor characterized by A flux barrier is formed at both ends in the circumferential direction of the rotor core in the opening,
The permanent magnet motor according to claim 1, wherein the filling notch and the flux barrier are configured to be partitioned by a contact portion between the permanent magnet and the rotor core.

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