JPH09294347A - Laminated core for rotating electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the cost without spoiling the productivity, to make it possible to prevent the deterioration of the characteristic, and to prevent the deformation of a shaft at the time of press fit. SOLUTION: Core segments R1, R2 having at least two kinds of shaft supporting holes H1, H2 and a plurality of teeth T are laminated, and a shaft S is inserted into the shaft supporting holes H1, H2 by press fitting. One kind of core segments R1 are utilized for press fitting, and the other core segment R2 is made to have the same dimension as the shaft S or slightly larger. It becomes possible to reduce the cogging torque, by making markings by recessions in the periphery to make it possible to tell the press fit parts from a loose inserted part from the outside.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a laminated core for a rotary electric machine, and more particularly, to a structure in which the shaft is prevented from being deformed when being assembled into an assembly by press fitting the shaft.

[0002]

2. Description of the Related Art Conventionally, a laminated core structure in which thin silicon steel plates are laminated in multiple layers and a shaft is press-fitted into a central bearing hole is widely used as a rotor core used in a rotary electric machine such as a small direct current motor. That is, as shown in FIG. 5, bearing holes HH smaller than the diameter of the shaft SS are formed in all the core pieces RR in the laminated core pieces RR in the same manner. Axis S
S was pressed in.

[0003]

However, in a thin cylindrical motor used as a vibration notification source for a recent wireless communication device or the like, since the shaft diameter is about 0.8 mm, the core piece RR made of a silicon steel plate is used. When several tens of layers are stacked and press-fitted, the press-fitted portion becomes long for a small diameter shaft, and the shaft is bent due to variations in the bearing holes. For this reason, there is also a method of loosely fitting the shaft into the bearing hole and fixing the shaft with an anaerobic adhesive, but this results in poor productivity.

Therefore, the present invention intends to provide a laminated core assembly structure which is advantageous in terms of cost without impairing productivity, has no deterioration of characteristics, and is free from deformation of the shaft during press fitting. Is.

[0005]

In order to solve the above problems, the present invention is characterized in that a plurality of core pieces are provided with a press-fitting portion and a loose fitting portion, which facilitates bending deformation of the shaft. Can be prevented.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, core pieces made of a thin silicon steel plate having a bearing hole at the center are laminated in multiple layers,
A shaft is mounted by press-fitting the shaft into the shaft-receiving hole. At least two types of shaft-receiving holes are provided to prevent deformation of the shaft, one core piece is used for press-fitting, and the other core piece is used as the shaft. It is the same size as or slightly loosely fitted.

[0007] The other core piece may be arranged in an intermediate portion and the one core piece may be arranged in both end portions thereof, or, conversely, the one core piece may be arranged in an intermediate portion and the other core piece It is effective to arrange the core pieces of the above at both ends thereof.

It is effective to provide markings on the radially outer peripheral surface of the tooth so that the press-fitting portion and the loosely fitting portion can be distinguished from each other, or to form the markings in the recesses to reduce the cogging torque. Is.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the structure of an embodiment of the present invention will be described with reference to a longitudinal sectional view of a main part shown in FIG. The figure shows a rotor core R of an ultra-thin tubular DC motor, in which 18 core pieces made of a 0.35 t silicon steel plate are laminated as magnetic plates, and the outer diameter of the salient poles (teeth) T is about 4 mm. A stainless steel shaft S having a shaft diameter of 0.8 mm and an actual power of 0.797 mm is attached to the center.

In this concrete structure, the diameter of the bearing holes H1 of the six core pieces R1 on each of both ends is about 0.785 mm, and the bearing holes H2 of the six core pieces R2 of the intermediate portion.
Has a diameter of about 0.8 mm. Since the general shaft diameter is about 0.797 mm, it is press-fitted and supported in the bearing holes H1 of the core pieces R1 on both ends, and loosely fitted in the bearing holes H2 in the middle portion.

As shown in the plan view of FIG. 2, the outer periphery of the salient pole (teeth) T is provided with recesses 1 and 2 for marking and cogging torque reduction, one at each end and one at the core piece R1. The core piece R2 for the intermediate portion is provided at two places. Incidentally, this marking may be provided in the inner shaft mounting hole as shown by an imaginary line in FIG. As a result, which part of the core is the core can be clearly determined from the outside as shown in the perspective view of FIG. 3, and the core provided inside can be determined with or without the end face.

A method of manufacturing such a laminated core assembly can be achieved by punching out a hoop material of a silicon steel plate with an appropriate layout. That is, the core piece R1 having a bearing hole of 0.785 mm and the core piece R1 having a bearing hole of 0.8 mm
Can be achieved by alternately punching out a predetermined number of sheets and combining them.

Further, as shown in FIG. 4, the core pieces R1 ... Are brought in the middle part and the bearing holes H1 are used for press-fitting, and the bearing holes H2 of the core piece R2 are loosely fitted on both end sides to be laminated. In order to prevent unevenness, the outer diameter portions of the salient poles (teeth) T of all the core pieces are all welded in the axial direction by the number of salient poles. By doing so, even if the laminated core is coated with an insulating coating such as epoxy, the shaft S
Since the coating does not adhere to, it is possible to prevent dimensional variation in the axial direction when assembling each member.

In the above embodiment, the shaft diameter of 0.8 mm is shown, but it is needless to say that it can be applied to other laminated cores having a shaft diameter of 1 to 2 mm and a large number of laminated layers. Also,
In the above description, all of them have teeth, but it goes without saying that they can be applied to slotless laminated cores without teeth.

[0015]

As described above, according to the present invention, at least two types of bearing holes are provided, and one core piece is used for press fitting,
Since the other core piece is configured to have the same size as or slightly loosely fitted to the shaft, bending deformation of the shaft at the time of press fitting can be easily prevented. Further, by arranging the other core piece in the middle part and arranging the one core piece in both end parts, there is no fear that the laminated core pieces will come apart.

Further, if one core piece is arranged in the middle part and the other core piece is arranged in both end parts, axial dimensional variation due to coating burr when the insulating coating is applied to the laminated core. Can be prevented. And by providing markings on the radial outer peripheral surface of the tooth, it is possible to easily distinguish between the press-fitting portion and the loose fitting portion,
Further, if the marking is formed in the recess, the cogging torque can be reduced.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an essential part of an embodiment of a laminated core for a rotary electric machine according to the present invention.

FIG. 2 is a plan view of the embodiment, in which (a) is a press-fitted portion,
(B) has shown the loose fitting part.

FIG. 3 is a perspective view of the same embodiment.

FIG. 4 is a cross-sectional view of a main part of another embodiment of the laminated core for a rotary electric machine of the present invention.

FIG. 5 is a longitudinal sectional view of a main part of a conventional laminated core for a rotating electric machine.

[Explanation of symbols]

 R, RR core R1 press fit part R2 loose fitting part T teeth S, SS shaft H, HH shaft bearing hole H1 shaft bearing hole smaller in diameter H2 shaft bearing hole equivalent to or slightly larger than shaft H2

Claims (5)

[Claims] 1. A laminated core for a rotary electric machine, comprising: laminating a plurality of core pieces made of a thin magnetic plate having a bearing hole at the center in a multi-layer, and pressing the shaft into the bearing hole to prevent deformation of the shaft. At least two bearing holes for cutting
A laminated core for a rotating electric machine, which is configured to have one kind of core piece for press-fitting and the other core piece to have the same size as or slightly loosely fitted to the shaft. 2. The laminated core for a rotary electric machine according to claim 1, wherein the other core piece is arranged in an intermediate portion, and the one core piece is arranged in both end portions thereof. 3. The laminated core for a rotary electric machine according to claim 1, wherein the one core piece is arranged in an intermediate portion, and the other core piece is arranged in both end portions thereof. 4. The laminated core for a rotating electric machine according to claim 2, wherein the marking is provided so that the intermediate portion and both end portions can be distinguished from each other. 5. The laminated core for a rotary electric machine according to claim 4, wherein the marking has a plurality of teeth, and the marking is formed in a recess in order to reduce cogging torque.