JP2004297947A - Rotor for motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotor for a motor of which a core plate is surely fixed, and dimension precision and mechanical strength of a rotor core are raised, with a structure simple enough to suppress cost increase. <P>SOLUTION: The rotor for a motor comprises a motor output shaft 2. It also comprises a cylindrical rotor core 3 where disc-like core plates 8 are laminated, which is composed of a through hole 14 in which the motor output shaft 2 is inserted, a plurality of insert holes 10 where a permanent magnet 7 is inserted, and a partition groove 11 formed to prevent magnetic shorting that can occur between the insert holes 10. It also comprises a fixing frame 4 composed of a pair of disc part 5 which sandwiches the rotor core 3 from upper and lower end surfaces, and a skeleton 6 that engages with the partition groove 11 formed vertically from the disc part 5 for fixing the core plate 8. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a motor, and more particularly, to a structure of a motor rotor (rotor core).
[0002]
[Prior art]
Conventionally, a motor configured to arrange a rotor having a permanent magnet inside a stator core on which a winding coil is mounted and to input an electric pulse to the winding coil of the stator core to rotate the rotor is generally used. Have been. The rotor of such a motor is configured such that a rotating shaft as an output shaft for rotating power and a rotor core to which a permanent magnet is fixed rotate integrally. The rotor core has a rotating shaft at the center of rotation and a permanent magnet near the outer peripheral end. The rotor core rotates according to a magnetic field change generated by the stator core, and outputs power from the rotating shaft.
[0003]
In such a motor, since a plurality of permanent magnets provided near the outer peripheral end of the rotor core are provided in a very narrow range so as to surround the entire circumference of the rotor core, each permanent magnet works so as to cancel each other's magnetic flux. In some cases, the formation of a favorable magnetic field is hindered, and the rotation reaction of the rotor core is dulled. Therefore, a configuration has been put to practical use in which grooves are provided at the outer peripheral end of the rotor core so as to partition the permanent magnets provided on the rotor core from each other to prevent a magnetic short circuit between the respective permanent magnets (for example, See Patent Document 1.).
[0004]
By the way, a rotor core is generally formed by laminating a plurality of magnetic materials such as electromagnetic steel plates as a core plate. The laminated core plates are usually fixed by caulking or welding using rivets. However, when the core plate is fixed by caulking, local stress concentration and deformation occur due to physical force, and when the core plate is fixed by welding, welding heat causes any local stress concentration and deformation. In addition to a decrease in mechanical strength, magnetic characteristic deterioration may occur.
[0005]
On the other hand, as a technique for solving such a problem, as shown in a configuration example of a conventional motor rotor (rotor core) in FIG. 4, when a laminated core in which a plurality of core plates 34 are laminated is permanently fixed. The laminated core in which the magnet 33 is embedded is sandwiched between a pair of end plates 32, and the inner ring 32c of the end plate and the corresponding pin 32b are press-fitted and fixed in the through hole 34a and the pin insertion through hole 34b at the center of the laminated core. A technique has been proposed in which a rotor core is formed, and a shaft 25 is press-fitted and fixed in a through hole 32a at a central portion of an end plate 32 so that the shaft 25 is integrally attached to a rotor (for example, Patent Document 2). reference.).
[0006]
[Patent Document 1]
JP 2001-286110 A (paragraphs 0025 to 0028, FIG. 1)
[Patent Document 2]
JP 2000-184645 A (paragraphs 0023 to 0033)
[0007]
[Problems to be solved by the invention]
However, in the technique described in Patent Document 2 described above, it is necessary to form a dedicated through hole 34b for penetrating the pin 32b at the same position on each core plate. Therefore, when manufacturing the rotor core, a process of processing the through hole with high accuracy is required, and there is a problem that the cost increases.
[0008]
Further, in this technique, the entire rotor core is fixed by sandwiching the laminated core plates 34 between the pair of end plates 32 into which the shaft 25 is press-fitted. That is, since the strength of the entire rotor core depends on the frictional force acting on the contact portion between the inner ring 32c of the pair of end plates and the shaft 5, the fixing force tends to be insufficient, and the dimensional accuracy of the rotor core and the mechanical It is difficult to secure strength.
[0009]
SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and aims to improve the dimensional accuracy and mechanical strength of a rotor core while ensuring that a core plate can be securely fixed by a simple structure that suppresses an increase in cost. It is an object of the present invention to provide a motor rotor that can be used.
[0010]
[Means for Solving the Problems]
For this reason, the motor rotor according to the first aspect of the present invention includes a motor output shaft, a through hole through which the motor output shaft is inserted, a plurality of insertion holes into which permanent magnets are inserted, and the insertion hole. A cylindrical rotor core formed by laminating disk-shaped core plates each having a partition groove formed so as to prevent a magnetic short circuit that can occur between holes, and a pair of disk-shaped members that sandwich the rotor core from upper and lower end surfaces. And a frame formed in a vertical direction from the disc-shaped portion and fitted to the partition groove to fix the core plate.
[0011]
It is preferable that the fixing frame is made of a non-magnetic material. In this case, a magnetic short circuit that can occur between the insertion holes of the permanent magnets can be effectively prevented, and the surrounding magnetic field environment is not adversely affected.
According to a second aspect of the present invention, the rotor for a motor according to the present invention is characterized in that the frame portion is provided so as to connect the pair of disc-shaped portions.
[0012]
According to a third aspect of the present invention, in the motor rotor of the present invention, the fixing frame is fixed to the rotating shaft.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an exploded configuration diagram showing the configuration of the motor rotor. FIG. 2 is an assembly configuration diagram showing the configuration of the motor rotor.
As shown in FIGS. 1 and 2, a motor rotor (rotor) 1 according to the present embodiment mainly includes a rotating shaft (motor output shaft) 2, a rotor core 3, and a fixing frame 4. . The rotor core 3 has a cylindrical shape formed by laminating a plurality of disc-shaped core plates (here, electromagnetic steel plates) 8. The electromagnetic steel plate 8 is provided with a through hole 14 at the center thereof for penetrating the rotating shaft 2, and a plurality of insertion holes 10 for inserting the permanent magnets 7 are uniformly arranged on the entire outer periphery near the outer peripheral end. Is formed. Further, a partition groove 11 is formed at an outer peripheral end of each electromagnetic steel sheet 8 so as to partition the peripheral edges of the plurality of insertion holes 10 from each other, so that a magnetic short circuit between the permanent magnets 7 is prevented. The plurality of electromagnetic steel sheets 8 all have the same shape, and the insertion holes 10 and the partition grooves 11 are provided so as to be evenly arranged on the respective circumferences with respect to the center of the electromagnetic steel sheet 8. Then, the electromagnetic steel sheets 8 are stacked so that the insertion holes 10 and the partition grooves 11 are vertically aligned, and the rotor core 3 is formed.
[0014]
The rotating shaft 2 is a rotating shaft of the motor rotor, and is configured as an output shaft of a motor that is inserted through the rotor core 3 and rotates integrally, and outputs the rotating force. Further, the rotating shaft 2 is provided with a frame pin hole 12 for fixing the fixing frame 4.
The fixing frames 4 are provided in pairs on upper and lower end surfaces of the rotor core 3. The pair of fixing frames 4 are fixed to the rotating shaft 2 and joined to the upper and lower end surfaces of the rotor core 3 to clamp the rotor core 3, and the electromagnetic steel plates 8 are fixed by fitting into the partition grooves. And a plurality of frame portions (rib-like structures) 6. The skeleton 6 is provided in a vertical direction from the disc 5 so as to connect the pair of discs 5 to each other. Note that the fixing frame 4 is made of a non-magnetic material, and here, ceramic is used.
[0015]
With the configuration as described above, according to the motor rotor of the present embodiment, it is assembled as follows, and the following effects are obtained.
First, a plurality of electromagnetic steel sheets 8 are stacked so that the insertion holes 10 and the partition grooves 11 are vertically aligned. The plurality of electromagnetic steel sheets 8 all have the same shape, and the insertion holes 10 and the partition grooves 11 are evenly provided on the respective circumferences with respect to the center of the electromagnetic steel sheet 8, so that the lamination is easy and the lamination is easy. No deviation occurs.
[0016]
Next, the permanent magnet 7 is inserted into the insertion hole 10 to form the rotor core 3. Since there is no lamination displacement, the permanent magnet 7 can be easily inserted. Further, a partition groove 11 is formed at the outer peripheral end of the rotor core 3. Since the partition grooves 11 are formed so as to partition the respective permanent magnets 7, it is possible to prevent a magnetic short circuit between the respective permanent magnets 7.
[0017]
Subsequently, the rotor core 3 is passed through the rotating shaft 2, and the rotor core 3 is held by the fixed frame 4. At this time, the frame 6 of the fixing frame 4 is fitted into the partition groove 11 formed on the outer peripheral end of the rotor core 3, and the rotor core 3 is fixed by the frame 6. Since the frame portion 6 is provided in the vertical direction from the disc-shaped portion 5 so as to connect between the pair of disc-shaped portions 5 of the fixed frame 4, the rotor core 3 can be securely fixed. Further, the outer peripheral end of the rotor core 3 on which a large centrifugal force acts can be fixed by the frame portion 6 over the entire cross section perpendicular to the rotating shaft 2, and the electromagnetic steel sheet 8 can be held effectively. In addition, since the partition groove 11 is for preventing a magnetic short circuit of the permanent magnet 7, there is no need to separately prepare a hole or a groove for fitting the frame portion 6 in advance, and the cost does not increase. The performance of the rotor core 3 does not decrease.
[0018]
Further, since the rotor core 3 is not fixed by press-fitting of the frame 6, but is fixed by fitting the partitioning groove 11 and the frame 6 and clamping by the fixing frame 4, unnecessary stress or deformation to the rotor core 3 is generated. In addition, the frame 6 can fix the rotor core 3 even at the outer peripheral end of the rotor core 3.
In addition, since the fixed frame 4 is made of a non-magnetic material, the magnetic field formed by the rotor core is not disturbed, and the fixed frame itself is magnetized by the permanent magnet 7 to adversely affect the surrounding magnetic field environment. There is no fear of giving.
[0019]
Finally, the disc-shaped portion 5 of the fixing frame 4 is fixed to the rotating shaft 2 using the frame pins 9. The fixing by the frame pins 9 is performed by press-fitting. However, since the object to be press-fitted is the rotary shaft 2, unnecessary stress and deformation are not applied to the rotor core 3, and the dimensional accuracy and mechanical strength of the rotor core 3 can be increased. Further, it is possible to securely press-fit the rotor core 3 to the rotary shaft 2 without giving unnecessary stress or deformation to the rotor core 3. In addition, since the frame pins 9 are pressed into the rotating shaft 2 and fixed instead of simply pressing the fixing frame 4 into the rotating shaft 2, the fixing frame 4 and the rotating shaft 2 are firmly connected. Can be fixed.
[0020]
As described above, one embodiment of the present invention has been described, but the present invention is not limited to such an embodiment, and can be variously modified and implemented without departing from the gist of the present invention.
For example, in the above-described embodiment, a plurality of insertion holes 10 for inserting the permanent magnets 7 near the outer peripheral end of the electromagnetic steel plate 8 and a partition that partitions the permanent magnets 7 inserted into the plurality of insertion holes 10 from each other. The grooves 11 are formed so as to be evenly arranged on the outer peripheral end. For example, as shown in FIG. 3, each of the insertion holes 10 ′ is slightly inside the outer peripheral end of the electromagnetic steel plate 8 ′, one on each side. May be arranged so as to form the partition groove 11 ′. In the case of such a configuration, the partition groove 11 ′ is formed slightly inside the outer peripheral end of the electromagnetic steel plate 8 ′ and the entire circumference of the partition groove 11 ′ is surrounded by the electromagnetic steel plate 8 ′. The rigidity of the periphery can be further increased, and the electromagnetic steel sheet 8 'can be firmly held by fitting the frame portion into the partition groove 11'.
[0021]
【The invention's effect】
As described in detail above, according to the motor rotor of the present invention, since the electromagnetic steel sheet is held at the outer peripheral end by the fixing frame, displacement and breakage of the electromagnetic steel sheet due to centrifugal force are prevented. The rotor core can be fixed most firmly. In addition, a magnetic short circuit inside the rotor core can be prevented.
[0022]
Further, according to the motor rotor of the present invention, since the frame portion is provided so as to connect the pair of disc-shaped portions, the motor rotor can be securely fixed. In particular, since the outer peripheral end of the motor rotor on which a large centrifugal force acts can be fixed in all cross sections perpendicular to the rotation axis, the electromagnetic steel sheet can be held effectively.
[0023]
According to the third aspect of the present invention, since the fixing frame is fixed to the rotating shaft, the fixing frame does not apply unnecessary stress or deformation to the rotor core, and the dimension of the rotor core is reduced. Accuracy and mechanical strength can be increased.
[Brief description of the drawings]
FIG. 1 is an exploded configuration diagram illustrating a configuration of a motor rotor as one embodiment of the present invention.
FIG. 2 is an assembly configuration diagram showing a configuration of a motor rotor as one embodiment of the present invention.
FIG. 3 is a partial configuration diagram showing a configuration of an electromagnetic steel plate in a motor rotor as a modification of one embodiment of the present invention.
FIG. 4 is a configuration example of a conventional motor rotor, and is an overall configuration diagram showing the configuration.
[Explanation of symbols]
1 rotor (rotor for motor)
2 Rotating shaft (motor output shaft)
3 rotor core 4 fixing frame 5 disc-shaped part 6 skeleton part (rib-shaped structure)
7 Permanent magnet 8, 8 'Magnetic steel sheet (core plate)
9 Frame Pin 10, 10 'Insertion Hole 11, 11' Partition Groove 12 Frame Pin Hole 13 Frame Pin Hole 14 Through Hole

Claims (3)

Motor output shaft,
The motor output shaft includes a through hole, a plurality of insertion holes into which permanent magnets are inserted, and a partition groove formed to prevent a magnetic short circuit that may occur between the insertion holes. A cylindrical rotor core formed by laminating disk-shaped core plates;
A fixing frame including a pair of disk-shaped portions for holding the rotor core from upper and lower end surfaces, and a frame portion formed in a vertical direction from the disk-shaped portion and fitted in the partition groove to fix the core plate; A rotor for a motor, characterized in that: The motor rotor according to claim 1, wherein the frame portion is provided so as to connect the pair of disc-shaped portions. 3. The motor rotor according to claim 1, wherein the fixing frame is fixed to the rotating shaft.

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