JP7209148B2 - End plates, rotors of motors and motors on which they are mounted - Google Patents

Description

The present invention relates to a rotor end plate of a motor, a rotor of the motor provided with the end plate, and a motor.

A rotor of an embedded permanent magnet brushless motor (IPM motor) is constructed by inserting permanent magnets into holes formed in a yoke forming a rotor core. The yoke is formed by laminating a plurality of plate-like bodies. A hole having an opening is formed in the yoke. The opening opens in an axial direction including the axis of the shaft, which is the rotation axis. A permanent magnet is inserted into this cavity through the opening. Conventionally, as a method of fixing the permanent magnet and the yoke, there is a method of fixing them with an adhesive or fixing them with the magnetic force of the permanent magnet (see, for example, Patent Document 1).

Also, a configuration is disclosed in which a disk-shaped end plate is provided at the axial end of the yoke to prevent the permanent magnet from protruding in the axial direction (see, for example, Patent Document 2).

JP-A-2007-68318 JP 2007-259583 A

A rotor end plate for a motor according to an aspect of the present invention is a magnet-embedded motor including a rotor in which a plurality of permanent magnets are embedded in a cylindrical rotor yoke. , an end plate attached to at least one end face. The rotor has a rotor yoke in which holes for embedding permanent magnets are respectively formed, a rotating shaft passing through both end faces of the rotor yoke, and at least one plate-like main end plate. ing. The end plate includes a main body that is in annular contact with the end face of the rotor yoke, and a magnet biasing part that extends radially from the annular contact portion of the main body and contacts the permanent magnet. ing.

According to the above configuration, the urging force for urging the permanent magnet axially inward by the magnet urging portion is generated independently of the body portion which is annularly in close contact with the end surface of the yoke. Therefore, sufficient biasing force can be applied to the permanent magnets and the yoke at appropriate locations.

In this way, the present invention has the effect of being able to apply a sufficient biasing force to the permanent magnets and the yoke at appropriate locations.

FIG. 1 is an axial view of a rotor of a motor to which an end plate according to an embodiment of the invention is attached. FIG. 2 is a diagram showing a state in which an end plate is removed from the rotor of the motor shown in FIG. 1; FIG. 3 is a cross-sectional view along AA-AA in FIG. FIG. 4 is a cross-sectional view along BB-BB in FIG. FIG. 5 is an axial view of the rotor of the motor to which the end plate according to the first modification of the embodiment of the present invention is attached. FIG. 6 is an axial view of the rotor of the motor to which the end plate according to the second modification of the embodiment of the invention is attached. FIG. 7 is an axial view of the rotor of the motor to which the end plate according to the third modification of the embodiment of the present invention is attached. FIG. 8 is a CC-CC sectional view shown in FIG. FIG. 9 is an axial view of the rotor of the motor to which the end plate according to the fourth modification of the embodiment of the present invention is attached. FIG. 10 is an axial view of the rotor of the motor to which the end plate according to the fifth modification of the embodiment of the present invention is attached. FIG. 11 is an axial view of the rotor of the motor to which the end plate according to the sixth modification of the embodiment of the invention is attached. FIG. 12 is an axial view of the rotor of the motor to which the end plate according to the seventh modification of the embodiment of the present invention is attached. FIG. 13 is an axial view showing a state in which an end plate is attached to a rotor of a motor having a permanent magnet with an arcuate cross section. FIG. 14 is an axial view showing a state in which an end plate is attached to a rotor of a motor having a permanent magnet with an arcuate cross section. FIG. 15A is a side view of the rotor of the motor to which the end plate is attached according to one embodiment of the present invention. FIG. 15B is a side view of the rotor of the motor to which the end plate is attached according to one embodiment of the present invention. FIG. 15C is a side view of the rotor of the motor to which the end plate is attached according to one embodiment of the present invention. FIG. 16A is a diagram showing another modification of this embodiment. FIG. 16B is a diagram showing another modification of the present embodiment. FIG. 17 is a conceptual diagram of a motor in one embodiment of the present invention.

As will be described later, the rotor end plate of the motor of the present invention includes a main body that is in annular contact with the end surface of the yoke of the rotor, and radially extending from the annular contact portion of the main body. , and a magnet biasing portion that abuts the permanent magnet, thereby imparting a sufficient biasing force to the rotor in place.

That is, the above-described conventional method has the following points to be improved. That is, the method of fixing the yoke and the permanent magnet using an adhesive requires the steps of applying the adhesive to the permanent magnet and drying the applied adhesive. Therefore, the number of man-hours for manufacturing the motor increases.

In addition, various management operations such as management of the amount of adhesive to be applied and management of the process of drying the adhesive are also required. Furthermore, the method of fixing the yoke and the permanent magnet using an adhesive may result in non-uniform adhesive strength.

Moreover, in the configuration in which the disc-shaped end plate is provided at the axial end of the yoke, it may not be possible to apply a sufficient biasing force to the appropriate portions of the yoke and permanent magnets. For example, when a yoke is formed by laminating a plurality of plate-shaped bodies, the plurality of plate-shaped bodies may be fixed to each other by caulking or the like. In this case, it is conceivable to press the axial end portion with an end plate in order to prevent deformation such as a part of the plate-like body from being turned up during or after the yoke is manufactured.

On the other hand, if the axial length of the permanent magnet is shorter than the depth of the hole (the axial length of the yoke), the permanent magnet moves axially in the hole even if the disk-shaped end plate is arranged. Sometimes. Therefore, the permanent magnet is designed so that its axial length is longer than the depth of the cavity. Therefore, even if the disk-shaped end plate is provided at the axial end of the yoke, the disk-shaped end plate contacts the permanent magnet but does not contact the yoke. Therefore, in a mode like Patent Document 2, the permanent magnet and the yoke cannot be pressed together.

Also, each permanent magnet is manufactured with predetermined tolerances. Therefore, when a rotor is constructed using a plurality of permanent magnets, there is a possibility that the plurality of permanent magnets will have different axial lengths within the tolerance range of the permanent magnets. For this reason, when a disk-shaped end plate is provided at the axial end of the yoke, the end plate cannot uniformly apply a biasing force to each permanent magnet.

Therefore, in the embodiment of the present invention, the end plate has a main body that is in annular contact with the end face of the yoke of the rotor, and extends radially from the annular contact portion of the main body so as to come into contact with the permanent magnet. It is set as the structure provided with the magnet biasing part which contacts. As a result, the magnet urging portion acts as a plate spring on the permanent magnet with the body portion that is in close contact with the end surface serving as a base end, so that a sufficient urging force can be applied to the permanent magnet and the yoke at appropriate locations. In particular, if the permanent magnet protrudes from the end face, a more remarkable effect can be obtained.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same reference numerals are given to the same or corresponding elements throughout all the drawings, and duplicate descriptions thereof will be omitted. In addition, when there are a plurality of the same configurations in each figure, one or two of them may be denoted by reference numerals, and other reference numerals may be omitted.

(Embodiment)
FIG. 1 is an axial view of a rotor of a motor to which an end plate according to an embodiment of the present invention is attached, and the end plate is indicated by a solid line. FIG. 2 is a diagram showing the end plate and yoke in the rotor of the motor shown in FIG. 1 with the end plate removed. 3 is an AA-AA cross-sectional view of the end plate in FIG. 1, and FIG. 4 is a BB-BB cross-sectional view of the end plate in FIG. 3 and 4, the lower side is the axially inner side.

A rotor 1 of the motor in this embodiment includes a cylindrical yoke 2 as a rotor yoke. The yoke 2 is held rotatably relative to a cylindrical stator (not shown) attached to the inner wall surface of the outer frame of the motor. The yoke 2 is composed of a plate-like body that is a metal plate processed by press working or the like, and is formed by laminating a plurality of these plate-like bodies. A shaft hole 3 is provided in the center of the yoke 2 . Further, a shaft (S shown in FIGS. 15A to 15C to be described later), which is a rotating shaft including the axis P, is inserted through the shaft hole 3, and the yoke 2 is fixed to the shaft S. In the following description, the direction in which the shaft S extends including the axis P of the shaft S is the axial direction, the direction in which there is no yoke 2 is the axial outward direction, and the opposite direction of the axial outward direction is the axial direction. It is also called axially inward. A radial direction that intersects the shaft S and is centered on the axis P is called a radial direction, and a direction away from the axis P is also called a radial outward direction, and a direction approaching the axis P is also called a radial direction inward. The direction around the axis centered on the axis P of the shaft S is also called the circumferential direction.

In the yoke 2, as shown in FIG. 2, for example, a plurality of holes 4 are arranged circumferentially at regular intervals and are formed so as to penetrate the yoke 2 in the axial direction. Also, in the yoke 2, a portion radially outward of the air hole 4 will be referred to as a yoke outer end portion 15 and will be described. A plurality of yoke outer end portions 15 are also formed so that the intervals in the circumferential direction are arranged at regular intervals. The air holes 4 are opened at both ends of the yoke 2 in the axial direction. The rotor 1 has a plurality of permanent magnets 5 inserted into each of the plurality of holes 4 . In the present embodiment, the permanent magnet 5 is formed in a flat plate shape, and the flat permanent magnet 5 (hereinafter abbreviated as the magnet 5 as appropriate) extends radially from the axis P by a virtual line L (FIG. 2) and the surface of the flat plate are arranged orthogonally. As described above, the motor of the present embodiment is a magnet-embedded motor in which a plurality of permanent magnets 5 are embedded in the yoke 2 of the rotor 1 . Note that the corners of the magnet 5 may be chamfered or rounded. As a result, cracking and chipping of the magnet 5 during manufacturing can be prevented. Also, the magnet 5 is a rare earth magnet formed using a rare earth element such as neodymium, for example. Further, in this embodiment, an example of the rotor 1 having eight holes 4 and eight magnets 5 in total, one for each hole 4, will be described.

One plate-shaped end plate 6 is provided at least at one end in the axial direction of the rotor 1 . That is, the columnar yoke 2 is configured by stacking the plate-like bodies in the stacking direction as described above. An end plate 6 is attached. The end plate 6 is made of an elastically deformable metal plate. The end plate 6 is formed by performing processing such as press working on a metal plate so as to have the following configuration. As shown in FIG. 2, the end plate 6 includes an annular main body portion 7 whose center serves as the shaft hole 3, and a magnet biasing portion 8 and a yoke biasing portion 9 extending radially outward from the main body portion 7 in the radial direction. , is equipped with Such a main body portion 7 is in close contact with the yoke end face 2s, which is the end face of the yoke 2 as shown in FIG. The body portion 7 has a plurality of mounting holes 10 for fixing the body portion 7 and the yoke 2 with a fixing member such as a rivet.

The magnet biasing portion 8 has a plurality of first extending pieces 11 extending radially outward from the body portion 7 , and the first extending pieces 11 are radially arranged at equal intervals in the circumferential direction. Further, a tip portion 13 is formed at a tip portion of each first extending piece 11 on the radially outer side. On the other hand, a permanent magnet 5 is embedded in each of the holes 4 of the yoke 2, and these magnets 5 are configured to protrude slightly from the end face of the yoke 2 respectively. A tip portion 13 of the first extending piece 11 contacts the permanent magnet 5 as a contact portion. As a result, the magnet urging portion 8 acts as a plate spring on the magnet 5 and urges the magnet 5 axially inward, with the body portion 7 in close contact with the end surface of the yoke 2 serving as a base end. That is, the magnet biasing portion 8 applies a force in the plate thickness direction of the end plate 6 toward the yoke 2 so that the magnet 5 protruding from the end face of the yoke 2 is pushed into the hole 4 . The plurality of first extending pieces 11 are provided in the same number (eight) as the number of magnets 5 . The plurality of first extending pieces 11 are provided according to the positions of the plurality of magnets 5 . More specifically, each first extension piece 11 is configured such that the tip portion 13 abuts on the central portion of the axial end face of the corresponding magnet 5 .

For example, the width (length in the circumferential direction) of the contact portion of the first extending piece 11 with the magnet 5 is 1/3 or more and 2/3 or less of the width (length in the circumferential direction) of the magnet 5. be. As a result, the end plate 6 secures a sufficient space for providing the second extension piece 12 while allowing the biasing force of the first extension piece 11 to sufficiently act on the corresponding magnets 5 . can be done.

As shown in FIG. 3 , the first extending piece 11 is formed in the same plane as the main body portion 7 except for the tip portion 13 when it is not in contact with the magnet 5 (natural state). A tip portion 13 of the first extending piece 11 has a shape bent in the axial direction toward the magnet 5 side (axially inward). On the other hand, the length of the magnet 5 is set so that it protrudes from the yoke 2 in the axial direction. Therefore, when the end plate 6 is attached to the yoke 2, that is, when the rotor 1 is completed, the magnet 5 acts to push the abutted tip portion 13 axially outward. Due to this action, the first extending piece 11 is deformed so as to bend outward in the axial direction with respect to the plane formed by the main body portion 7 . The deformed first extension piece 11 functions as a so-called leaf spring, and the restoring force that tries to return to the original plane acts to press the magnet 5 in contact with the magnet 5, and the biasing force is applied to the magnet 5. becomes. Thus, in the completed state of the rotor 1 , the body portion 7 is in surface contact with the end face of the yoke 2 , and the axial tip of the tip portion 13 is in contact with the magnet 5 . The first extending piece 11 is bent axially outward such that the axial distance between the end face of the yoke 2 and the first extending piece 11 increases radially outward.

Moreover, the tip portion 13 of the first extending piece 11 is formed in an arc shape in plan view. That is, the portion of the tip portion 13 that is bent in the axial direction (the portion that protrudes inward in the axial direction of the tip portion 13) has a curved surface that is curved along the circumferential direction, as shown in FIG. ing. As a result, the end plate 6 can increase the rigidity of the distal end portion 13 and also increase the pressing strength at the portion where the first extension piece 11 contacts the magnet 5 . The circular arc at the distal end portion 13 is, for example, a circular arc with the axis P as the center.

The length of the axially inwardly bent portion of the distal end portion 13 of the first extending piece 11 is set so as to absorb variation in the amount of protrusion of the magnet 5 from the yoke 2 in the axial direction. . This variation is caused by tolerances of the magnet 5 . For example, this length is 0.5 mm or more.

Next, the yoke biasing portion 9 has a plurality of second extending pieces 12 radially extending radially outward from the body portion 7 at positions displaced in the circumferential direction from the positions of the plurality of first extending pieces 11 . have. A distal end portion 14 is formed at a radially outward distal end portion of each of the second extending pieces 12 . This tip portion 14 abuts on a yoke outer end portion 15 located radially outward from the hole 4 of the yoke 2 . That is, the plurality of second extension pieces 12 are formed so as not to overlap the plurality of first extension pieces 11 . The length from the axis P to the tip 14 of the second extension piece 12 is longer than the length from the axis P to the tip 13 of the first extension piece 11, and is approximately equal to the radius of rotation of the yoke 2. It will be

When the tip portion 14 of the second extending piece 12 comes into contact with the portion of the yoke 2 radially outward from the hole 4 , the yoke biasing portion 9 rotates the yoke outer end portion 15 , which is that portion, as an axis. direction inward. A plurality of second extending pieces 12 are provided on both sides in the circumferential direction with respect to one first extending piece 11 . That is, as shown in FIG. 1, a pair of second extending pieces 12, that is, two second extending pieces 12 are arranged between a pair of first extending pieces 11 that are closest to each other. Thus, in this embodiment, the yoke biasing portion 9 has 16 second extension pieces 12 . A slit 18 is further formed between the pair of second extension pieces 12, and the pair of second extension pieces 12 including one slit 18 constitutes a second extension pair 12p. there is

The plurality of first extension pieces 11 and the plurality of second extension pieces 12 are provided separately from each other. That is, between each first extension piece 11 and the adjacent second extension piece 12, there is provided a slit 16 extending radially therebetween to form a gap. As a result, in each of the first extension pieces 11 of the magnet biasing portion 8, the tip end portion 13 that abuts the permanent magnet 5 is cut in the yoke biasing portion 9 in the circumferential direction by the slit 16 that is cut in the radial direction. away from Note that the shape of the slit 16 is not particularly limited.

According to the above configuration, the biasing force that biases each magnet 5 axially inward by the magnet biasing portion 8 is generated independently of the main body portion 7 that contacts the yoke 2 . Therefore, a sufficient biasing force can be applied to each magnet 5 and yoke 2 at appropriate locations. Furthermore, a yoke biasing portion 9 is provided separately from the magnet biasing portion 8 . With this configuration, the magnet biasing portion 8 biases each magnet 5 axially inward, the yoke biasing portion 9 biases the yoke outer end portion 15 axially inward, can be generated independently.

In addition, in the above configuration, each of the plurality of magnets 5 is brought into contact with the individual first extension piece 11, thereby generating an urging force that urges each magnet 5 inward in the axial direction. Therefore, the end plate 6 can apply an appropriate urging force to each magnet 5 even when the lengths in the axial direction of the magnets 5 vary.

Further, each of the yoke outer end portions 15 provided corresponding to the holes 4 abuts on the individual second extending pieces 12 . Therefore, each yoke outer end portion 15 is individually biased inward in the axial direction. Therefore, the end plate 6 is properly attached to each yoke outer end 15 with respect to each yoke outer end 15 even if some of the yoke outer ends 15 are lifted (turned up) or the like. power can be given.

In the present embodiment, the yoke biasing portion 9 is disposed at a position overlapping the permanent magnet 5 when viewed in the axial direction, and is in contact with the yoke outer end portion 15 of the yoke 2. It has a shape that does not come into contact with the magnet 5 . More specifically, as shown in FIG. 4, each second extending piece 12 has a bent portion 17, and is bent from the body portion 7 with the bent portion 17 as the bending position. More specifically, when the end plate 6 is not in contact with the yoke 2 (natural state), such a bent portion 17 is positioned at the radially proximal end of the second extending piece 12, or at the proximal end. and the tip. Here, the base end of the second extending piece 12 refers to the point closest to the axis P in the radial direction of the second extending piece 12, and the tip refers to the point farthest from the axis P. As shown in FIG. Moreover, FIG. 4 shows a configuration example in which the bent portion 17 is formed at the proximal end of the second extending piece 12 . In this manner, the yoke biasing portion 9 is configured such that the portions of the second extending pieces 12 on the radially outward side of the bent portions 17 are axially outwardly displaced from the main body portion 7 so as to be separated from the yoke 2 . It has a bent shape. In the case of FIG. 4 , since the bent portion 17 is the base end of the second extending piece 12 , the entire second extending piece 12 is bent outward in the axial direction with respect to the main body portion 7 . Further, the bent portion 17 is located radially inward of the position of the magnet 5 .

A tip portion 14 of the second extending piece 12 is bent toward the yoke 2 side (axially inward), and the tip portion 14 is located outside the yoke 2 radially outward of the hole 4 of the yoke 2 . It is configured to abut the edge 15 . In this case, the position of the tip in the axial direction of the tip portion 14 reaches the planar position of the main body portion 7 in a natural state. Alternatively, in a natural state, the tip of the tip portion 14 is positioned closer to the yoke 2 than the plane position of the main body portion 7 . More preferably, the distal end portion 14 is configured such that the axial position of the distal end portion in the natural state protrudes toward the yoke 2 side by 3 mm or more from the planar position of the main body portion 7 .

Alternatively, the distal end side of the second extending piece 12 from the bent portion 17 may have a shape that curves outward in the axial direction in an arch shape as a whole.

Thereby, the end plate 6 can arrange the second extending piece 12 so as to straddle the magnet 5 regardless of the length of the magnet 5 . Therefore, the end plate 6 can easily secure a contact area in the yoke outer end portion 15 for applying an appropriate biasing force to the yoke biasing portion 9 regardless of the arrangement of the magnets 5 .

In addition, FIG. 1 shows a circular mounting hole 10 having a center 10c and a radius r as an example of the mounting hole. The mounting hole 10 in the main body 7 is provided at a position corresponding to the first extending piece 11 in the circumferential direction (around the axis P), and is used for fixing the main body 7 and the yoke 2. . That is, the mounting hole 10 is provided at a position on an imaginary line segment connecting the circumferential central portion of the first extending piece 11 and the axis P. As shown in FIG. The mounting hole 10 is set at a position radially outwardly spaced from the outer edge of the shaft hole 3 by a predetermined distance.

Further, regarding the slit 16 between the first extending piece 11 and the second extending piece 12 , the boundary between the slit 16 and the main body portion 7 is defined as the base end 16 b of the slit 16 . At this time, the position of the base end 16 b in the radial direction is set between the outer edge of the shaft hole 3 and the position corresponding to the radially inner end of the magnet 5 . More preferably, the proximal end 16b is located at a position defined by a radial distance from the axis P as follows. That is, when the distance to the radially outer side of the mounting hole 10 is Rd1 and the distance to the radially inner side of the distal end portion 13 is Rd2, the distance to the base end 16b is the distance from the center of the axis P. , Rd1 and shorter than Rd2.

In the following description, the distance in the radial direction from the axis P to the target element is referred to as the radial distance, and the position in the radial direction with respect to the target element is indicated by the radial distance.

FIG. 5 is an axial view of the rotor of the motor to which the end plate according to the first modification of the embodiment of the present invention is attached. The end plate 6B indicated by solid lines in FIG. 5 is positioned such that the radial distance Rd16 of the proximal end 16b of the slit 16 is equal to the radial distance Rd10 to the radially inner side of the outer edge of the mounting hole 10. shows an example of In this case, the radial length T of the slit 16 may be T=X+r, as shown in FIG. Here, X is the distance between the position of the center 10c of the mounting hole 10 and the radially outer tip of the tip portion 13, and r is the radius of the mounting hole 10. As shown in FIG. On the other hand, in the end plate 6 shown in FIG. 1, the radial distance of the proximal end 16b of the slit 16 is set to the distance from the center 10c of the mounting hole 10 to a position about X/2 radially outward. If the radial position of the proximal end 16b of the slit 16 is set as described above, the end plate 6 can maintain the rigidity of the end plate as a whole while the biasing force of the first extending piece 11 and the second The radial length of the slit 16 can be obtained so that the urging force of the extension piece 12 can function independently.

As described above, the second extension pair 12p having two second extension pieces 12 is positioned between the first extension pieces 11 adjacent in the circumferential direction. In the second extending pair 12p, the base ends of the two second extending pieces 12 are common, and the bent portion 17 is also common. Also, the slits 18 in the second extension pair 12p are provided between the magnets 5 adjacent in the circumferential direction so as to avoid the magnets 5 . Further, as shown in FIG. 1, for example, one yoke outer end portion 15 corresponds to two second extension pairs 12p adjacent to each other. That is, for example, as shown in FIG. One second extension piece 12 of the other second extension pair 12p is arranged on the other side in the circumferential direction.

FIG. 6 is an axial view of the rotor of the motor to which the end plate according to the second modification of the embodiment of the invention is attached. In the end plate 6C shown in FIG. 6, the circumferential width of the slit 18 between the circumferentially adjacent second extending pieces 12 in the second extending pair 12p is equal to the circumferential width between the circumferentially adjacent magnets 5. A case close to . On the other hand, the end plate 6 shown in FIG. Width shows an example where it is set. By setting the width of the slit 18 in the circumferential direction within the above range, the biasing force exerted by the tip portion 14 on the yoke outer end portion 15 can be reduced while avoiding the contact of the second extending piece 12 with the magnet 5 . can be effectively given.

Also, the first extending piece may be configured to abut on the permanent magnet at a planar portion between the distal end and the proximal end thereof. FIG. 7 is an axial view of the rotor of the motor to which the end plate according to the third modification of the embodiment of the present invention having such a structure is attached. 8 is a cross-sectional view along CC-CC shown in FIG. In FIG. 8, the lower side is the axially inner side.

As shown in FIGS. 7 and 8, the magnet biasing portion 8D of the end plate 6D has a length from the axis P to the tip of the distal end portion 13D of the first extension piece 11D, which is the second extension from the axis P. It is substantially the same as the length to the tip of the tip portion 14 of the protruding piece 12 (length equal to the radius of the yoke 2). That is, in the third modified example, the radial distances to the respective radial ends of the first extending piece 11D, the second extending piece 12 and the yoke 2 are substantially equal. Alternatively, the tip portion 13D of the first extending piece 11D is positioned radially outward from the radially inner end of the permanent magnet 5 and radially inward from the outer circumference of the yoke 2. It may be located at a predetermined position.

Like the first extension piece 11 shown in FIG. 1, the first extension piece 11D is formed in the same plane as the main body portion 7 except for the tip portion 13D in the natural state. The permanent magnet 5 protrudes axially outward from the yoke 2 while being inserted into the air hole 4 . Therefore, the first extension piece 11D contacts the magnet 5 at the radially inner end position of the magnet 5 between the distal end portion 13D and the proximal end thereof, and is elastically deformed axially outward. As a result, the magnet 5 generates a biasing force that biases the first extension piece 11D axially inward. Therefore, even in such a mode, the same effect as in FIG. 1 can be obtained.

Furthermore, the first extending piece 11D of the end plate 6D has a shape in which the tip portion 13D is bent in the direction away from the yoke 2 (outward in the axial direction). As with the tip portion 13 of the first extension piece 11 shown in FIG. 1, the tip portion 13D of the first extension piece 11D is formed in an arc shape in plan view.

In this case, a balance weight (such as a balance putty) may be attached to the distal end portion 13D in a folded configuration. That is, in the configuration where the base end of the first extending piece 11D and the tip portion 13D abut against the permanent magnet 5, the tip portion 13D is provided with a balance weight holding portion that is bent in a direction away from the yoke 2. may Thus, when a balance weight for eliminating eccentricity is attached to the axially outward side of the first extension piece 11D, the tip portion 13D functions as a radially outward movement restraining portion of the balance weight. Therefore, even if the centrifugal force generated by rotating the rotor 1 at high speed is large, the end plate 6D can make it difficult for the balance weight to scatter radially outward.

In the above-described embodiment, the first extension pieces 11 and 11D are configured to abut on the circumferential central portion of the permanent magnet 5, and the second extension pieces 12 are positioned on the left and right sides thereof. As another embodiment, the positions of the first extension pieces 11 and 11D and the position of the second extension piece 12 may be interchanged. FIG. 9 is an axial view of the rotor of the motor to which the end plates according to the fourth modification of the embodiment of the present invention having such a configuration are exchanged.

In the end plate 6E shown in FIG. 9, the second extension piece 12E of the yoke biasing portion 9E is provided so as to cross over the circumferential central portion of the permanent magnet 5 and extend in the radial direction. As a result, the distal end portion 14E of the second extending piece 12E is brought into contact with the circumferential central portion of the yoke outer end portion 15 of the yoke 2 .

Also, the first extension piece 11E of the magnet biasing portion 8E is provided at both sides of the second extension piece 12E in the circumferential direction. That is, two first extending pieces 11E are provided between the second extending pieces 12E adjacent in the circumferential direction. Furthermore, in this modification, a slit 19 is provided between the two first extension pieces 11E, and the slit 19 and the two first extension pieces 11E on both sides of the slit 19 form a first extension as shown in FIG. It constitutes one extension pair 11Ep. In this example, the attachment hole 10 is provided so as to overlap the base end of the second extension piece 12E.

For example, the tip portion 13E is a contact portion of the first extension piece 11E with the magnet 5. As shown in FIG. The width (length in the circumferential direction) of each tip portion 13E is 1/6 or more and 1/3 or less of the width (length in the circumferential direction) of the magnet 5 with which the first extending piece 11E abuts. be. As a result, the end plate 6E can secure a sufficient space for providing the second extending piece 12E while allowing the biasing force of the first extending piece 11E to sufficiently act on the corresponding magnets 5 .

It is preferable that the position of the proximal end of the slit 19 that is closest to the axis P in the radial direction is located radially inward compared to the slit 18 between the second extending pieces 12 in the example of FIG. For example, the proximal end of the slit 19 is provided at a radial position that is approximately the same radial distance as the center of the attachment hole 10 of the main body 7 . Variation in axial length among the plurality of magnets 5 is greater than variation in axial length at the yoke outer end portion 15 . Therefore, the elastic deformation of one first extension piece 11E in the adjacent first extension pieces 11E has a greater influence on the other first extension piece 11E. Therefore, by increasing the radial length of the slit 19, it is possible to prevent the adjacent first extending pieces 11E from affecting each other.

However, the radial length of the slit 19 may be short, for example, when the tolerance of the magnet 5 is kept relatively small. Alternatively, the slit 19 may be eliminated and the adjacent ends of one permanent magnet and another adjacent permanent magnet may be brought into contact with each other by one first extending piece 11E.

FIG. 10 is an axial view of the rotor of the motor to which the end plate according to the fifth modification of the embodiment of the present invention is attached. Like the end plate 6F shown in FIG. 10, instead of having the second extending piece 12 as shown in FIG. may be In other words, the annular outer edge portion of the body portion 7F may be positioned near the outer periphery of the yoke 2 and function as the yoke biasing portion 9F.

In the example shown in FIG. 10, the first extension piece 11F of the magnet biasing portion 8F radially extends radially outward, as in the example shown in FIG. That is, in the body portion 7F, C-shaped slits 21 as shown in FIG. 10 are formed corresponding to the respective first extension pieces 11F. The slits 21 are radially notched on both sides of the first extending piece 11F in the circumferential direction between the first extending piece 11F and the main body portion 7F, and extend from the tip portion 13F of the first extending piece 11F. It is formed by notching in the circumferential direction on the radially outward side. The mounting hole 10 is arranged at a position such that the radial distance of the radial base end of the slit 21 is within the range of the radial distance of the mounting hole 10 . The periphery of the magnet biasing portion 8F is notched in the radial direction and the circumferential direction so that the outer peripheral side, that is, the radially outward side is opened.

In the yoke 2 in which thin plates are laminated using the main body portion 7F as in this modified example, the vicinity of the outer diameter portion of the yoke 2 (a plurality of yoke outer end portions 15) is suppressed over the entire circumference, so that when manufacturing the motor, etc. It is possible to more effectively prevent the thin plate from being turned over.

FIG. 11 is an axial view of the rotor of the motor to which the end plate according to the sixth modification of the embodiment of the invention is attached. Similar to the yoke biasing portion 9F shown in FIG. 10, the yoke biasing portion 9G in the end plate 6G shown in FIG. It is In addition, the first extension piece 11G of the magnet biasing portion 8G extends radially inward from the annular yoke biasing portion 9G (body portion 7G). Therefore, the distal end portion 13G of the first extending piece 11G is positioned radially inward from the proximal end. The magnet biasing portion 8G is notched radially and circumferentially so that the axial center P side, that is, the radially inner side is open.

Also in this modified example, a C-shaped slit 22 as shown in FIG. 11 is formed in the body portion 7G so as to correspond to each first extending piece 11G. The slits 22 are radially notched on both sides of the first extending piece 11G in the circumferential direction between the first extending piece 11G and the main body portion 7G, and extend from the tip portion 13G of the first extending piece 11G. It is formed by notching radially inward in the circumferential direction. The mounting hole 10 is located radially inward from the tip portion 13G of the first extending piece 11G.

10 and 11, the end plates 6F, 6G can apply a sufficient biasing force to at least one of the permanent magnet 5 and the yoke 2 in its proper place.

When the annular yoke biasing portions 9F and 9G as shown in FIGS. 10 and 11 are positioned near the outer diameter of the yoke 2, the shaft hole 3 inside the body portions 7F and 7G is , does not have to be a circle.

By the way, in the above-described embodiment, the plurality of permanent magnets 5 are arranged so that the angles formed by the magnets 5 adjacent to each other in the circumferential direction are all equal. That is, the plurality of magnets 5 are arranged on a virtual line (V1 shown in FIG. 2) defining a virtual polygon when viewed from the axial direction. Alternatively, the plurality of magnets 5 may be arranged on an imaginary line other than a polygon. For example, as such a modified example, the plurality of magnets 5 are composed of a first magnet 5 among the plurality of magnets 5 and a second magnet 5 adjacent to the first magnet 5 in the circumferential direction. The angle to form is acute. Moreover, in the plurality of magnets 5, the angle formed by the second magnet 5 and the third magnet 5 adjacent to the second magnet 5 on the side opposite to the first magnet 5 in the circumferential direction is an obtuse angle. may be arranged as follows. That is, the plurality of magnets 5 may be arranged on a virtual line forming a virtual star when viewed from the axial direction.

FIG. 12 is an axial view of the rotor of the motor to which the end plate according to the seventh modification of the embodiment of the present invention is attached. In the end plate 6H shown in FIG. 12, a plurality of (16 in this example) magnets 5 are arranged on a virtual line V2 defining a virtual star. Further, the end plate 6H is configured such that the tip portion 13H of the first extending piece 11H of the magnet biasing portion 8H abuts against the radially outward end portion of the magnet 5 positioned on the imaginary line V2. It is That is, the first extending piece 11</b>H extends over the radially outward end of the magnets 5 adjacent in the circumferential direction, and is provided so as to straddle the adjacent magnets 5 . The second extending piece 12H of the yoke biasing portion 9H extends further radially outward from the position where the radial distance of the proximal end of the second extending piece 12H is substantially equal to the radial distance to the center of the permanent magnet 5. It is provided so as to extend.

Note that the end plate 6H shown in FIG. 12 is not provided with the attachment hole 10 for fixing to the yoke 2. Instead, in the end plate 6</b>H, the slits 18 between the circumferentially adjacent second extending pieces 12</b>H function as fixing portions to the yoke 2 . For example, the inner diameter side of the slit 18 is formed in an arc shape having a diameter through which the rivet can pass. The end plate 6</b>H is attached to the yoke 2 by fixing rivets (not shown) through the slits 18 to attachment holes 20 formed in the yoke 2 . At this time, the end plate 6H is fixed to the yoke 2 by sandwiching the end plate 6H between the rivet head and the yoke 2 .

Further, the plurality of magnets 5 are not limited to flat permanent magnets, and permanent magnets having an arc-shaped cross section may be used. 13 and 14 are axial views of a rotor of a motor having a permanent magnet with an arc-shaped cross section and an end plate attached to the rotor.

In a rotor 1I shown in FIGS. 13 and 14, a plurality of (eight in this example) permanent magnets 5I having arc-shaped curved surfaces when viewed in the axial direction are arranged so as to protrude radially inward. there is In FIG. 13, an end plate 6Ia configured to hold the ends of circumferentially adjacent permanent magnets 5I with one first extending piece 11H in the same manner as the end plate 6H shown in FIG. installed. Alternatively, the end plate 6Ia may have the same configuration as the end plate 6E shown in FIG.

Further, as shown in FIG. 14, an end plate 6Ib may be attached such that the central portion of each permanent magnet 5I is pressed by one first extending piece 11. As shown in FIG. In addition, in FIG. 14, the end plate 6Ib has the same configuration as the end plate 6G shown in FIG. However, for example, the configuration may be the same as that of each end plate in FIGS.

The end plates 6, 6B to 6H, 6Ia, and 6Ib as described above are attached to at least one end of the yoke 2 in the axial direction. 15A, 15B and 15C are side views of a rotor of a motor to which end plates are attached according to one embodiment of the present invention.

One yoke 2 is attached to the shaft S, as shown in FIG. 15A. End plates 6 shown in FIG. 1 are attached to both sides of the yoke 2 in the axial direction. As shown in FIG. 15B, two yokes 2 are attached to the shaft S so as to be axially connected. A plate-like end plate 23 is interposed between the two yokes 2 . An end plate 6 is attached to the side of each yoke 2 opposite to the side where the end plate 23 is provided. That is, when the two yokes 2 are viewed as one rotor core, end plates 6 are attached to both sides of the rotor core in the axial direction. The plate-shaped end plate 23 has a shape such as a donut shape in which the magnet biasing portion 8 and the yoke biasing portion 9 are not independent.

As shown in FIG. 15C, one yoke 2 is attached to the shaft S, and an end plate 6 is attached only to one axial end of the yoke 2 . A plate-shaped end plate 23 is attached to the other axial end of the yoke 2 . Thus, even if the end plate 6 is provided only at one end in the axial direction, the biasing force generated by the end plate 6 biases the yoke 2 and the permanent magnets 5 independently of each other. be able to.

As another mode, an end plate provided at one axial end of the yoke 2 biases the yoke outer end 15, and an end plate provided at the other axial end of the yoke 2 presses the permanent magnet. 5 can also be configured to be energized.

16A and 16B are diagrams showing other modifications of the present embodiment. 16A shows a view of the rotor viewed from the first end plate side, and FIG. 16B shows a view of the rotor viewed from the second end plate side. A rotor 1J of the motor in this example includes a yoke 2, permanent magnets 5, a first end plate 6Ja, and a second end plate 6Jb. The magnet 5 is inserted into the hole 4 opened at least at one axial end of the yoke 2 . The first end plate 6Ja is provided at one end of the yoke 2 in the axial direction. The second end plate 6Jb is provided at the other end of the yoke 2 in the axial direction.

The first end plate 6Ja includes a first body portion 7Ja and a yoke biasing portion 9J. The first body portion 7Ja is in contact with the yoke 2 and has an annular shape. The yoke biasing portion 9J extends radially outward from the first main body portion 7Ja and contacts the yoke outer end portion 15 to bias the yoke outer end portion 15 axially inward. The second end plate 6Jb includes a second body portion 7Jb and a magnet biasing portion 8J. The second body portion 7Jb is in contact with the yoke 2 and has an annular shape. The magnet biasing portion 8J extends radially outward from the second main body portion 7Jb and biases the magnet 5 axially inward by coming into contact with the magnet 5 .

The magnet biasing portion 8J has a first extending piece 11J extending radially outward from the second main body portion 7Jb. A tip portion 13J of the first extending piece 11J abuts on the magnet 5. As shown in FIG. The yoke biasing portion 9J has a second extending piece 12J extending radially outward from the first main body portion 7Ja. A tip portion 14J of the second extending piece 12J abuts a yoke outer end portion 15 of the yoke 2. As shown in FIG.

According to the above configuration, the biasing force that biases the magnet 5 axially inward is generated by the magnet biasing portion 8J provided on the second end plate 6Jb. A yoke biasing portion 9J provided on the first end plate 6Ja generates a biasing force that biases the yoke outer end portion 15 axially inward. Therefore, according to the above aspect as well, a sufficient biasing force can be applied to the magnet 5 and the yoke 2 at appropriate locations.

Next, a motor including the rotor of the motor according to one embodiment of the present invention described above will be described. The rotor of the motor is attached with the end plate according to the embodiment of the present invention already described.

FIG. 17 is a conceptual diagram of a motor in one embodiment of the present invention. As shown in FIG. 17 , the motor 40 includes a motor rotor 1 , a motor stator 30 and bearings 36 .

A motor stator 30 extends along an axis P included in a shaft S of the motor rotor 1 . A stator 30 of the motor is positioned radially outwardly of the rotor 1 of the motor, facing the rotor 1 of the motor.

The bearing 36 rotatably supports the rotor 1 of the motor.

Furthermore, it demonstrates in detail using drawing.

A motor 40 shown in FIG. 17 is a main part constituting the motor. Normally, the motor is mounted in a case forming the outer shell of the motor 40 and used. Alternatively, the motor is molded with resin so as to cover the motor 40 and used as a molded motor.

A stator 30 of motor 40 includes a stator core 32 and coils 34 . The stator core 32 can be formed by laminating steel plates. The coil 34 is formed by winding an electric wire around the stator core 32 . Distributed winding, concentrated winding, toroidal winding, and the like are known as methods of winding the coil 34 around the stator core 32 .

Furthermore, an insulator made of resin or the like can be inserted between the stator core 32 and the coil 34 . When insulators are used, mutual electrical insulation is ensured between the stator core 32 and the coils 34 .

In this configuration, a predetermined gap exists between the rotor 1 of the motor and the stator 30 of the motor, which face each other.

Next, the motor 40 has bearings 36 . As shown in FIG. 17, in the motor 40 according to the embodiment of the present invention, a pair of bearings 36 are attached to the shaft S so as to sandwich the rotor core 50 therebetween. The rotor core 50 can be formed by stacking steel plates. Rotor core 50 in the present embodiment has a plurality of permanent magnets 5 inside. The rotor core 50 is attached to the shaft S. Depending on the structure of the motor 40, the bearing 36 may have a cantilever structure, that is, only one bearing may be used. The bearing 36 may be attached to a structure forming the outer shell of the motor 40, such as a bracket.

Electric power is supplied from the outside of the motor 40 to the motor 40 that constitutes this configuration. A control current based on the supplied power forms a predetermined current waveform and flows into the coil 34 . A magnetic flux is generated in response to the current flowing into the coil 34 . The rotor 1 of the motor rotates according to the generated magnetic flux. Therefore, the motor 40 can benefit from the effects of the end plate 6 described above.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various improvements, changes, and modifications can be made without departing from the scope of the invention.

For example, the mounting hole 10 of the body portion 7 is provided at a position corresponding to the second extension piece 12 (a position on a virtual line segment connecting the circumferential central portion of the second extension piece 12 and the axis P). Alternatively, the position corresponding to between the first extending piece 11 and the second extending piece 12 (the position on the virtual line segment connecting the circumferential central portion of the second extending piece 12 and the axis P ) may be provided.

Also, the number of permanent magnets 5 (the number of holes 4) is not limited to the above example (8 or 16), and may be larger or smaller.

In the above-described embodiment, the yoke 2 to which the end plates 6, 6B to 6H are attached has a configuration in which the openings of the holes 4 through which the permanent magnets 5 are inserted are provided at both ends in the axial direction. The opening of the hole 4 may be provided only at one axial end of the yoke 2, and the end plates 6, 6B to 6H may be attached to the one axial end of the yoke 2 provided with the opening.

The present invention is useful for applying sufficient biasing force in place to the permanent magnets and yokes.

1, 1I, 1J rotor 2 yoke 2s yoke end surface 3 shaft hole 4 air hole 5, 5I magnet (permanent magnet)
6, 6B, 6C, 6D, 6E, 6F, 6G, 6H, 6Ia, 6Ib, 23 end plate 6Ja first end plate 6Jb second end plate 7, 7F, 7G main body 7Ja first main body 7Jb second main body 8, 8D, 8E, 8F, 8G, 8H, 8J Magnet biasing portion 9, 9E, 9F, 9G, 9H, 9J Yoke biasing portion 10, 20 Mounting hole 10c Center 11, 11D, 11E, 11F, 11G, 11H , 11J First extension piece 11Ep First extension pair 12, 12E, 12H, 12J Second extension piece 12p Second extension pair 13, 13D, 13E, 13F, 13G, 13H, 13J, 14, 14E, 14J Tip Part 15 Yoke Outer End Part 16, 18, 19, 21, 22 Slit 16b Base End 17 Bent Part 30 Stator 32 Stator Core 34 Coil 36 Bearing 40 Motor 50 Rotor Core

Claims (10)

In a magnet-embedded motor including a rotor in which a plurality of permanent magnets are embedded in a cylindrical rotor yoke, an end plate attached to at least one end face of the cylindrical rotor yoke,
The rotor is
the rotor yoke having holes for embedding the permanent magnets therein;
a rotating shaft penetrating through the end faces of the rotor yoke;
Having at least one plate-shaped end plate,
The end plate is
a main body that is in annular contact with the end surface of the rotor yoke;
a magnet urging portion including a plurality of first extending pieces extending radially outward from the annular contact portion of the main body portion, each of the plurality of first extending pieces contacting the permanent magnet; ,
a yoke biasing portion extending outward from the air hole in the radial direction from the main body portion and having a distal end thereof in contact with the end surface of the rotor yoke;
the yoke biasing portion has a plurality of second extending pieces extending radially outward from the body portion;
one of the first extending piece and the second extending piece includes a pair of extending pieces and a first slit provided between the pair of extending pieces,
The plurality of first extending pieces and the plurality of second extending pieces are individually provided at positions displaced from each other in the circumferential direction,
end plate. Each of the first extending pieces has a first distal end bent in the axial direction on the radially outer side,
Each of the second extending pieces has a second tip portion on the outer side in the radial direction, the second tip portion coming into contact with the outer end portion of the rotor yoke,
The length from the axis of the rotating shaft to the second tip is greater than or equal to the length from the axis to the first tip,
An end plate according to claim 1. Each of the first extending pieces has a first distal end bent in the axial direction on the radially outer side,
The first tip portion has a curved surface curved along the circumferential direction,
An end plate according to claim 1. A first tip portion is formed at a radially outward tip portion of the first extending piece,
the main body includes a plurality of circular mounting holes for fixing the main body and the rotor yoke with a fixing member;
The mounting hole is provided at a position on an imaginary line segment connecting the circumferential central portion of the first extending piece and the axis,
An end plate according to claim 1. Each of the second extending pieces has a second distal end that is bent toward the rotor yoke and abuts an outer end of the rotor yoke,
2. The end plate according to claim 1, wherein the length from the axis of said rotating shaft to said second tip is equal to the radius of rotation of said rotor yoke. having a second slit formed between the first extending pieces adjacent to each other in the circumferential direction;
The second slit has a proximal end that is a boundary between the second slit and the main body,
The distance from the axial center of the base end is
greater than the distance from the axis of the rotating shaft to the radially outward side of the mounting hole, and smaller than the distance from the axis to the radially inner side of the first tip,
or equal to the distance from the axial center to the radially inner side of the mounting hole,
5. An end plate according to claim 4 . 2. The end plate according to claim 1, wherein said yoke biasing portion is arranged so as to straddle said permanent magnet without contacting said permanent magnet. The number of the first extending pieces matches the number of the plurality of permanent magnets,
2. The end plate according to claim 1, wherein each first extending piece is provided so as to be positioned in the circumferential center of each permanent magnet. A rotor of a motor, wherein the end plate according to claim 1 is attached to said at least one end surface of said rotor yoke. a rotor of the motor according to claim 9;
a stator of the motor extending along the rotation axis of the rotor of the motor and positioned facing the rotor of the motor;
a bearing that rotatably supports the rotor of the motor;
A motor.

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