JP2001251795A - Permanent magnet rotor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify molding dies and surely restrict diametrical displacement of a permanent magnet, without the need for extra process for forming a pressing part fixing the permanent magnet in iron core punching work. SOLUTION: This rotor relates to a permanent magnet rotor, in which an iron core 4 is formed by laminating a plurality of steel sheets 3 having a plurality of openings 2 for housing a permanent magnet, so that the axes of the openings 2 for housing the permanent magnet to match each other, and a permanent magnet 5 is inserted into the openings 2 for housing the permanent magnet. A central opening 14, having an inner-diameter larger than the diameter of the inner-diameter of the iron core into which the rotor shaft is inserted, is formed in part of the steel sheets 3a forming the iron core and an iron core 16 between the central opening 14 and the opening 2 for housing the permanent magnet is pressed to be deformed from a central opening 14 side, thereby forming a pressing part 17 for the permanent magnet protruding into the opening for housing the permanent magnet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a permanent magnet rotor having a permanent magnet inserted and mounted in a permanent magnet receiving hole formed in an iron core formed by laminating steel plates and used for, for example, a hermetic compressor.

[0002]

2. Description of the Related Art In general, as a rotor of a motor used in a hermetic compressor or the like, a large number of steel plates having permanent magnet receiving holes are arranged so that the permanent magnet receiving holes coincide with each other. 2. Description of the Related Art There is known a permanent magnet rotor in which a core is laminated to form a core, and a permanent magnet is inserted and mounted in a permanent magnet receiving hole of the core. In such a permanent magnet rotor, it is necessary to securely fix the permanent magnet inside the iron core.
There has been proposed an arrangement in which a pressing portion is projected into a permanent magnet receiving hole, and the permanent magnet is pressed in the outer diameter direction by the pressing portion to fix the permanent magnet (Japanese Patent Laid-Open No. 7-1995).
322538).

FIG. 11 is a view showing the structure of the above-mentioned conventional permanent magnet rotor.
Has an iron core 4 in which a large number of steel plates 3 in which four permanent magnet housing holes 2 are formed by punching in the circumferential direction are laminated.
The permanent magnets 5 are inserted into the permanent magnet receiving holes 2 of the iron core 4 so that those having N poles and those having S poles are alternately arranged. 7 are integrally connected.

FIG. 12 is an enlarged plan view of the steel plate 3 constituting the iron core, and is elongated along the edge of the permanent magnet housing hole 2 along the edge of the permanent magnet housing hole 2 on the rotor center side edge 2a. An elongated hole 9 is formed, and the elongated hole 9 and the permanent magnet accommodation hole 2 are formed.
An elongated steel plate portion formed between them protrudes slightly inside the permanent magnet housing hole 2 to form a pressing portion 8 against the permanent magnet 5.

In the drawings, reference numeral 10 denotes a hole for inserting a rivet 7, and 11 denotes a permanent magnet accommodation hole 2 of the laminated steel plate 3.
This is a caulking projection for matching.

When the permanent magnet 5 is inserted into the permanent magnet receiving hole 2, the pressing portion 8 is pressed against the side surface of the permanent magnet 5, and the permanent magnet 5 is pressed and fixed on the inner surface of the permanent magnet receiving hole 2. Is done.

However, in such a structure, the pressing portion is preferably provided on all of the laminated steel plates 3 due to the configuration of the core punching die. In this case, however, the deformation reaction force of the pressing portion 8 is large, A large force is required to insert the permanent magnet, and there are problems such as deformation of the iron core and cracking of the permanent magnet. On the other hand, it is necessary to reduce the width of the pressing portion in order to make the pressing portion weak in deformation reaction force, which makes punching difficult. Further, the permanent magnet receiving hole 2 is formed to form the pressing portion.
, The obstruction of the passage of magnetic flux is hindered, and the characteristics are degraded. Further, there is a problem that an extra punching step is required to provide the above-mentioned elongated hole 9 and that the mold becomes complicated.

It has also been proposed to provide a projection on an end plate for fixing a permanent magnet, and to contact the projection with the permanent magnet to restrict the movement of the permanent magnet in the iron core.

FIG. 13 is a view from the end face of a permanent magnet rotor in which the movement of the permanent magnet is regulated by the protrusion of the end plate, and FIG. 14 is a longitudinal sectional view of the end plate 6. A projection 12 formed by cutting and raising is formed at a position corresponding to the end of the permanent magnet 5, and the projection 12 is pressed against the end face of the permanent magnet 5. FIG.
FIG.

However, in such a device, since the end plate is generally made of a non-magnetic material, there is a problem that the elasticity of the material is small. Also, the distance between the end plate 6 and the end face of the permanent magnet 5 varies considerably depending on the length of the permanent magnet and the lamination of the iron core. When the gap is small, the amount of deformation of the protrusion increases, and the protrusion deforms plastically beyond the elastic deformation region. For this reason, the force with which the protrusion contacts the permanent magnet is reduced.

On the other hand, although mainly radial forces such as centrifugal force due to rotation and electromagnetic force due to driving act on the rotor, the projection 12 of the end plate is pressed against the plane of the end of the permanent magnet. Therefore, the only force that regulates the radial movement of the permanent magnet is the frictional force between the protrusion and the permanent magnet, and the effect of regulating the radial movement of the permanent magnet is small. Therefore, there are problems that the permanent magnet moves in the radial direction and the balance is lost, and the magnet and the protrusion of the iron core or the end plate rub against each other.

In view of the above, the present invention does not require an extra step for providing a pressing portion for fixing a permanent magnet in punching an iron core, simplifies the mold structure, and ensures the radial movement of the permanent magnet. It is an object of the present invention to obtain a permanent magnet rotor that can be regulated to a certain level.

[0013]

The invention according to claim 1 is
A permanent magnet rotor in which a large number of steel plates having a plurality of permanent magnet receiving holes are laminated so that the axes of the permanent magnet receiving holes coincide with each other to form an iron core, and a permanent magnet is inserted and mounted in the permanent magnet receiving hole, On a part of the steel plate constituting the iron core, a center hole having an inner diameter larger than the diameter of the inner diameter portion of the iron core for mounting the rotor shaft mounted on the iron core is formed, and between the center hole and the permanent magnet receiving hole. A permanent magnet pressing portion projecting into the permanent magnet receiving hole is formed by pressing and deforming the iron core portion from the center hole side.

According to a second aspect of the present invention, in the first aspect of the present invention, a narrow portion that is easily deformed is formed in an iron core portion between the center hole and the permanent magnet receiving hole.

The invention according to claim 3 is characterized in that, in the invention according to claim 1, a notch is provided in a core portion between the center hole and the permanent magnet housing hole so as to communicate the two.

According to a fourth aspect of the present invention, an iron core is formed by stacking a plurality of steel plates having a plurality of permanent magnet receiving holes so that the axes of the permanent magnet receiving holes coincide with each other. In a method for manufacturing a permanent magnet rotor in which a permanent magnet is inserted and mounted on a part of the steel plate constituting the iron core,
A center hole having an inner diameter larger than the diameter of the rotor shaft mounted on the core is formed, and in the same step as the pressing of the caulked portion of the laminated core, the core between the center hole and the permanent magnet receiving hole is formed. The portion is pressed and deformed from the center hole side to form a permanent magnet pressing portion.

According to a fifth aspect of the present invention, an iron core is formed by laminating a plurality of steel plates having a plurality of permanent magnet receiving holes so that the axes of the permanent magnet receiving holes coincide with each other. In the method of manufacturing a permanent magnet rotor for inserting and mounting a magnet, a central hole having an inner diameter larger than a diameter of a rotor shaft mounted on the iron core is formed in a part of the steel plates constituting the iron core, and a large number of steel plates are formed. A mandrel is inserted into the rotor insertion hole and the center hole of the laminated core, and the core between the center hole and the permanent magnet receiving hole is pressed and deformed by pushing out a pressing piece built in the mandrel. Features.

According to a sixth aspect of the present invention, an iron core is formed by stacking a plurality of steel plates having a plurality of permanent magnet receiving holes so that the axes of the permanent magnet receiving holes coincide with each other. In a permanent magnet rotor into which a permanent magnet is inserted and mounted, an end plate for closing a permanent magnet accommodating hole is provided on an end surface of the iron core, and a tip end of a projection provided from the end plate is twisted to at least contact the permanent magnet. The contact portion is slanted, and the slanted portion of the protrusion is in contact with the end chamfered portion of the permanent magnet.

The invention according to claim 7 is characterized in that, in the invention according to claim 6, the chamfer angle of the permanent magnet and the angle of the oblique portion of the projection are formed to be the same, and both are abutted on the surface. I do.

The invention according to claim 8 is the invention according to claim 6, characterized in that the protrusion is in contact with a chamfered portion of the permanent magnet on the inner diameter side of the rotor.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a partial longitudinal perspective view of a permanent magnet rotor according to a first embodiment of the present invention.
The permanent magnets 5 are respectively inserted and mounted in the plurality of permanent magnet receiving holes 2 in the iron core 4 configured by laminating.

Some steel plates constituting the iron core 4, for example,
A plurality of steel plates 3a disposed on the upper part of the iron core 4 are formed with a center hole 14 having an inner diameter larger than the inner diameter of the iron core inner diameter portion 13 which comes into contact with the rotor shaft formed on the other steel plates 3. A step 15 is formed in a hole provided in the iron core. Then, the iron core 16 between the center hole 14 and the permanent magnet receiving hole 2 is deformed so as to protrude into the permanent magnet receiving hole 2 by pressing the iron core portion 16 from the inner diameter side, and the permanent magnet pressing portion 17 is formed. Is formed. Thus, the permanent magnet 5 inserted into the permanent magnet receiving hole 2 is pressed and fixed to the inner surface of the permanent magnet receiving hole 2 by the deformation reaction force of the permanent magnet pressing portion 17.

FIG. 2 shows the steel plate 3 constituting the upper part of the iron core 4.
FIG. 3 is a plan view of FIG. 3A, in which a steel plate 3a is formed by punching a center hole 14 having an inner diameter larger than the diameter of an inner core portion 13 (dotted line) for mounting four permanent magnet housing holes 2 and a rotor shaft. Have been. FIG. 3 shows a stack of a plurality of steel plates shown in FIG. 2 stacked on a stack of steel plates formed by punching out the permanent magnet housing 2 and the core inner diameter portion 13, and the stacks are fixed to each other by swaging of the swaging protrusions 11. At this time, a mandrel 18 formed in a shape corresponding to the core inner diameter portion 13 and the center hole 14 as shown in FIG. 4A is inserted into the core inner diameter portion 13 and the center hole 14, and the caulking is performed. Pressing piece 19 built in mandrel 18 at the same time as the process
(FIG. 4B) is extruded radially outward, and the iron core portion 16 is pressed and deformed to form the permanent magnet pressing portion 17.

Thus, in this embodiment, an extra step is not required for punching the iron core, and secure fixing can be performed without generating excessive permanent magnet pressing force. Further, it is not necessary to provide a punched hole for preventing the passage of magnetic flux, and there is no deterioration in characteristics. Furthermore, the core is pressed and deformed after the mandrel for holding is inserted into the portion that comes into contact with the rotor shaft and the large-diameter center hole, so that deformation of the core other than the permanent magnet pressing portion can be prevented.

FIG. 5 is a view showing a second embodiment of the present invention. The steel plate 3a forming the permanent magnet pressing portion 17 includes:
A narrow portion 20 having a predetermined width and a small width is formed between the center hole 14 and the permanent magnet housing hole 2 so as to be easily deformed.

FIG. 6 is a view showing a third embodiment of the present invention. The center hole 14 and the permanent magnet receiving hole 2 are provided in an iron core between the center hole 14 and the permanent magnet receiving hole 2. A notch 21 for communication is provided.

Therefore, in the structure shown in FIGS. 5 and 6, only the necessary portions can be reliably deformed with a weak force to form the permanent magnet pressing portion 17, and the deformation of the core other than the permanent magnet pressing portion 17 can be achieved. Can be prevented.

FIGS. 7 and 8 are views showing a fourth embodiment of the present invention, wherein an end plate 6 mounted on an end face of an iron core 4 in which a large number of steel plates are stacked and closing a permanent magnet accommodation hole 2 is provided. A cut-and-raised protrusion 22 is formed at a portion facing the permanent magnet 5 inserted in the permanent magnet housing hole 2 so as to follow a curve on the inner diameter side of the rotor of the permanent magnet 5. As shown in FIGS. 9 and 10, the cut-and-raised protrusion 22 is twisted so that the tip is inclined, and the tip of the cut-and-raised protrusion 22 rotates the permanent magnet 5 as shown in FIG. It is in contact with the chamfered portion 5a on the child inner peripheral side.

The end face of the permanent magnet is chamfered on both sides, and a protrusion may be brought into contact with both or one of the chamfered portions. A greater effect can be obtained by contact.

As described above, the tip of the cut-and-raised projection is made oblique and is brought into contact with the chamfered portion of the permanent magnet. ) Is applied, and the permanent magnet is pressed laterally against the iron core.

Therefore, even if a centrifugal force or an electromagnetic force acts on the permanent magnet in the lateral direction, the permanent magnet is hardly moved because the permanent magnet is pressed against the iron core.

In FIG. 9, the slope of the projection 22 is in contact with the chamfered corner of the permanent magnet. However, depending on whether the projection is reduced or the chamfer is increased, the projection is formed on the chamfered slope of the permanent magnet. You may make it contact. Furthermore, the angle of the chamfer of the permanent magnet and the angle of the oblique portion of the projection may be the same so that the two abut on the surface.

Further, by contacting the projection with the chamfered portion on the inner peripheral side of the rotor, the permanent magnet is pressed against the outer peripheral side, and the direction of the pressing force by the projection and the direction of the centrifugal force match, so that the permanent magnet is more rigid. In addition, the projection is not subjected to centrifugal force, and the elasticity of the projection can be prevented from being lost due to repeated fatigue.

As described above, in this embodiment,
The permanent magnet can be fixed simply by cutting and raising a projection whose end is obliquely twisted on the end plate, and it is not necessary to provide a magnet holder on the iron core, and it is possible to avoid difficult punching and deterioration of characteristics.
In addition, the movement of the permanent magnet can be more firmly controlled as compared with the case where the projection abuts on the end face of the permanent magnet. In addition, by making the protrusion oblique, even when the width of the protrusion is large or the chamfer of the permanent magnet is small, the protrusion comes into contact with one of the slopes of the protrusion or the permanent magnet. It is possible to reliably control the movement of the permanent magnet without contact.

[0036]

The present invention is constructed as described above.
This eliminates the need for an extra step for providing a pressing portion for fixing the permanent magnet in the punching of the iron core, can reliably restrict the radial movement of the permanent magnet, and does not cause a decrease in motor characteristics. It works.

[Brief description of the drawings]

FIG. 1 is a partially longitudinal perspective view of a permanent magnet rotor of the present invention.

FIG. 2 is a plan view of an iron core steel plate used for the permanent magnet rotor of FIG. 1;

FIG. 3 is a perspective view showing a state in which iron core steel sheets are stacked.

4A is a side view of a permanent magnet pressing portion forming mandrel, and FIG. 4B is a plan view thereof.

FIG. 5 is a plan view of a core steel plate according to a second embodiment of the present invention.

FIG. 6 is a plan view of an iron core steel plate according to a third embodiment of the present invention.

FIG. 7 is a plan view of a permanent magnet rotor according to a fourth embodiment of the present invention.

FIG. 8 is a longitudinal sectional view of a permanent magnet rotor according to a fourth embodiment of the present invention.

FIG. 9 is an enlarged view of the cut-and-raised protrusion of FIG. 8;

10A is a side view of a cut-and-raised projection of an end plate, FIG.
(B) is the front view.

FIG. 11 is a partially exploded perspective view showing the entire configuration of a conventional permanent magnet rotor.

FIG. 12 is an enlarged plan view of an iron core steel plate of the permanent magnet rotor shown in FIG. 11;

FIG. 13 is a plan view of a conventional permanent magnet rotor.

FIG. 14 is a longitudinal sectional view of the permanent magnet rotor of FIG.

FIG. 15 is an enlarged view of a protrusion of FIG. 14;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Permanent magnet rotor 2 Permanent magnet accommodation hole 3 Steel plate 4 Iron core 5 Permanent magnet 6 End plate 7 Rivet 11 Caulking projection 13 Iron core inner diameter part 14 Center hole 15 Stepped part 16 Iron core part 17 Permanent magnet pressing part 18 Mandrel 19 Pressing piece 21 Notch 22 protrusion

Claims (8)

[Claims] An iron core is formed by laminating a plurality of steel plates having a plurality of permanent magnet receiving holes so that the axes of the permanent magnet receiving holes coincide with each other, and inserting a permanent magnet into the permanent magnet receiving hole. In a magnet rotor, a central hole having an inner diameter larger than the diameter of an inner diameter portion of an iron core for mounting a rotor shaft mounted on the iron core is formed in a part of the steel plate constituting the iron core, and the center hole and a permanent magnet are formed. A permanent magnet rotor characterized in that a permanent magnet pressing portion protruding into the permanent magnet receiving hole is formed by pressing and deforming an iron core portion between the receiving hole and the center hole side. 2. The permanent magnet rotor according to claim 1, wherein a narrow portion that is easily deformed is formed in an iron core portion between the center hole and the permanent magnet housing hole. 3. The permanent magnet rotor according to claim 1, wherein a notch is provided in an iron core portion between the center hole and the permanent magnet receiving hole so as to communicate the two. 4. An iron core comprising a plurality of steel plates having a plurality of permanent magnet receiving holes stacked so that the axes of the permanent magnet receiving holes coincide with each other to form an iron core, and a permanent magnet inserted and mounted in the permanent magnet receiving holes. In the manufacturing method of the magnet rotor, in a part of the steel plate constituting the iron core, a center hole having an inner diameter larger than the diameter of the rotor shaft attached to the iron core is formed, and the crimped portion of the laminated iron core is formed. A method for manufacturing a permanent magnet rotor, characterized in that in the same step as pressing, a core portion between the center hole and the permanent magnet receiving hole is pressed and deformed from the side of the center hole to form a permanent magnet pressing portion. 5. An iron core comprising a plurality of steel plates having a plurality of permanent magnet receiving holes stacked so that the axes of the permanent magnet receiving holes coincide with each other to form an iron core, and a permanent magnet inserted and mounted in the permanent magnet receiving holes. In the manufacturing method of the magnet rotor, in a part of the steel plate constituting the iron core, a center hole having an inner diameter larger than the diameter of the rotor shaft mounted on the iron core is formed, and the iron core in which a large number of steel plates are laminated. A permanent magnet, wherein a mandrel is inserted into the rotor insertion hole and the center hole, and a pressing piece incorporated in the mandrel is pushed out to press and deform an iron core between the center hole and the permanent magnet housing hole. Rotor manufacturing method. 6. An iron core comprising a plurality of steel plates having a plurality of permanent magnet receiving holes laminated so that the axes of the permanent magnet receiving holes coincide with each other to form an iron core, and a permanent magnet inserted and mounted in the permanent magnet receiving holes. In the magnet rotor, an end plate for closing the permanent magnet housing hole is provided on the end face of the iron core, and at least a portion that comes into contact with the permanent magnet is inclined by twisting a tip end of a projection protruding from the end plate, and the A permanent magnet rotor, wherein an oblique portion of the projection is in contact with an end chamfer of the permanent magnet. 7. The permanent magnet rotor according to claim 6, wherein the chamfer angle of the permanent magnet and the angle of the oblique portion of the projection are formed to be the same, and both are abutted on the surface. 8. The permanent magnet rotor according to claim 6, wherein said projection is in contact with a chamfered portion of the permanent magnet on the inner diameter side of the rotor.