KR0139598B1 - Cage rotor for high speed induction motor - Google Patents

Abstract

The cage rotor 10 includes a laminated core 14 fixed to the rotor shaft 12, secondary conductors 18 disposed in a plurality of through holes 16 formed through the laminated core 14, and a chuck layer core. A pair of edge linkages 20 connected to the secondary conductor 18 and a pair of reinforcing members 22 and 23 covering each edge linkage 20 at both axial ends of 14; . The secondary conductor 18 and the edge ring 20 are formed as one by a casting process and are connected to the laminated core 14 and the reinforcing members 22 and 23. The reinforcing members 22 and 23 are annular elements of a high rigidity material, and cylindrical wall portions 26 and 27 surrounding the cylindrical outer circumferential surface of the edge connecting ring 20 and the edge connecting ring 20 and And the multi-hole wall portions 28 and 29, which are sandwiched between the laminated cores 14 and the like, and have a plurality of holes 32 connected to the through holes 16 of the laminated cores 14, and the edge connecting rings ( End wall portions 30, 31, etc., which are in contact with the axially outer end face of 20).

Description

[Name of invention]

Squirrel rotor of high speed induction motor

[Technical Field]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cage rotor of an induction motor, and more particularly to a cage rotor of a high speed induction motor having a reinforcing member that prevents deformation during high speed rotation of a cast molded edge connecting ring.

[Background]

In recent years, in order to improve the capability of a machine tool, the high speed and high output of the spindle motor for spindle drive are advanced.

Induction motors generally used as spindle motors include a cage rotor in which secondary conductors and edge linkages are integrally formed in a laminated core by casting. When the induction motor having such a squirrel rotor is speeded up, there is a risk that the edge linking rings disposed at both ends of the laminated core in the axial direction are bent or destroyed by centrifugal force during the high-speed rotation. Therefore, a cage rotor for high speed rotation is known, in which a separate reinforcing member made of a high rigid material such as iron or stainless steel is disposed on the rotor by surrounding the edge coupling ring to prevent deformation of the edge coupling ring.

The edge link reinforcing member of the conventional high speed cage rotor has an almost L-shape having a cylindrical wall portion in contact with the outer circumferential surface of the cylindrical linkage and an end wall portion in contact with the axial end surface of the edge linkage. It is an annular element having a circumferential cross section. The reinforcing member covers the surface of the edge linking ring, and generally the end wall portion is fixed to the axial end surface of the edge linking ring by fixing means such as a bolt. Therefore, deformation of the edge linkage by the centrifugal force is prevented by the cylindrical wall portion of the reinforcing member. However, in the conventional reinforcing member, the cylindrical wall portion is supported in such a manner that the cylindrical wall portion has only one side at the edge linking part by sandwiching the end wall portion. There was a problem with bending or not supporting the edge ties.

[Initiation of invention]

An object of the present invention is to provide a squirrel-shaped rotor which enables the production of a high-speed induction motor having excellent reliability without the deformation or destruction of the cast-linked edge linkage by the centrifugal force even at a very high speed of rotation of only a few minutes per minute. It is to offer.

In order to achieve the above object, the present invention is a laminate of a rotor shaft and a plurality of magnetic thin plates, and has a plurality of through-holes arranged between both end surfaces of the laminate in the axial direction, and a laminated core and a laminated core fixed to the rotor shaft. It consists of a plurality of secondary conductors arranged in through-holes and a pair of edge linkages connected to the secondary conductors at both ends of the axial core, and are like cylindrical bars of semiconductor and edge linkages formed by a casting process as one. It has a cylindrical wall portion surrounding the surface and a plurality of holes connected to each of the through-holes of the laminated core, and extends the ring inwardly at one end edge of the cylindrical wall to between the edge linkage and the axial end surface of the laminated core. Extends radially inward from the other end edge of the porous wall and the cylindrical wall, Gatchumyeo in the contralateral part end wall in contact with the axially outer surface of the edge connection link, and provides a high-speed squirrel-cage rotor of an induction motor provided with a reinforcing member such as a pair of covering each of the edge connection link.

In the squirrel rotor described above, it is possible to form the secondary conductor and the edge connecting ring of the conductor portion into one by aluminum by a die-cast molding process. In addition, it is preferable that one reinforcing member has a plurality of thin holes serving as an air band in the casting step at the end wall portion.

A reinforcing member is disposed at both ends of the laminated core in axial direction, and many wall portions of the reinforcing member are brought into contact with the axial end faces of the laminated core such that the plurality of holes connect to each of the plurality of through holes of the laminated core. In this state, the laminated core and the reinforcing member are fixed by a jig and casting is performed. At this time, the inlet of the casting is made in the opening of the inner diameter of the reinforcing member. When the conductor part is cast in this manner, the reinforcing member is fixedly held at the laminated core and the conductor part, and the cylindrical wall part is firmly supported at both ends via the porous wall part and the end wall part. Therefore, even at an ultra-high speed rotation of only a few minutes of rotation, the reinforcing member does not deform itself, and prevents deformation and breakage of the edge linkage by centrifugal force.

[Brief Description of Drawings]

The above and other objects, features and advantages of the present invention will be described based on the embodiments shown in the accompanying drawings. In the accompanying drawings,

1 is a cross-sectional view of a cage rotor according to an embodiment of the present invention.

2 is a cross-sectional view of the reinforcing member shown along the line II-II of FIG.

3 is a cross-sectional view showing a manufacturing process of the cage rotor of FIG.

* Explanation of symbols for main parts of the drawings

12: rotor shaft 14: laminated core

16: Through hole 18: Secondary conductor

20: Edge link 22, 23: interpolation member

26, 27: cylindrical wall portion 28, 29: porous wall portion

30, 31: Edge wall part 32: Hole

Best Mode for Carrying Out the Invention

Referring to the drawings, FIG. 1 shows a cage rotor 10 of a high speed flow motor according to an embodiment of the present invention. The cage rotor 10 is a laminate of a rotor shaft 12 and magnetic thin plates, such as a silicon steel sheet, and is adjacent to the outer circumference of the laminated core 14 and the laminated core 14 fixed to the rotor shaft 12. And a plurality of secondary conductors 18 disposed in each of the plurality of through holes 16 formed in the axial direction, and disposed at both ends of the laminated core 14 in the axial direction. And a pair of reinforcing members 22, 23, etc. which are fixed to the edge connecting ring 20 by covering each pair of edge connecting rings 20, which are short-circuited with each other. The plurality of secondary conductors 18 and the pair of edge connecting rings 20 are formed as one by, for example, a casting process such as aluminum die casting, whereby the laminated core 14 and the reinforcing members 22 and 23 are formed. ) Are linked together. In addition, the secondary conductor 18 may be disposed inclined with respect to the axis as is known in order to reduce the torque during the motor operation.

The reinforcing members 22 and 23 are approximately opened radially inward at their inner diameters 24. It is an annular element having a circumferential cross section of the shape of a child, and is formed of a high rigid member such as iron or stainless steel, for example, by cutting. The reinforcing members 22 and 23 are respectively radially inward from the cylindrical wall portions 26 and 27 having an inner diameter substantially equal to the outer diameter of the laminated core 14 and the axial ends of the cylindrical wall portions 26 and 27. And extending wheel-shaped porous wall portions 28 and 29 and end wall portions 30 and 31. The porous wall portions 28 and 29 have a plurality of holes 32 which communicate with the through holes 16 of the laminated core 14, respectively. (See Figure 2). By forming a ring-shaped cavity edge connecting ring 20 surrounded by each wall by a casting process to be described later, the tubular wall parts 26 and 27 of the respective correction members 22 and 23 are edge connecting rings ( 20, the porous wall portions 28 and 29 are narrowly disposed between each axial end surface of the laminated core 14 and the edge connecting ring 20, and the end wall portions 30 and 31 are edge connecting rings. Contact with the axially outer end of 20). In addition, one reinforcing member 22 is provided with an air hole 33 in each portion of the end wall portion 30 facing each of the plurality of holes 32 to stabilize the melt flow during casting.

The manufacturing method of the cage type rotor 10 which has the said structure is demonstrated below with reference to FIG. First, each reinforcing member 22, 23 is arranged in the same center shape on the laminated core 14 in a state where the porous wall portions 28, 29 are in contact with each end surface in the axial direction of the laminated core 14. At this time, the porous walls 28 and 29 are in contact with the end faces of the laminated cores 14 so that the additional holes 32 communicate with each of the plurality of through holes 16 of the laminated cores 14. In this state, the laminated core 14 and each of the reinforcing members 22 and 23 are fixed with the jig 34 shown in FIG. 3 to perform casting.

Here, the reinforcing member 23 allows the laminated core 14 to be held under a predetermined pressure between the respective reinforcing members 22 and 23 by the jig 34, and the inner part of the porous wall portion 29 is maintained. It extends further radially inward beyond the inner peripheral surface of this laminated core 14. This extended part 35 is cut out after a casting process.

In addition, the casting inlet 36 is made in the opening of the inner diameter portion 24 of the reinforcing member 23 as shown.

When casting is performed in this way, for example, castings such as molten aluminum flow into the annular cavities of the reinforcing members 23 that form the casting inlet 36, and then are sandwiched in the holes 32 to form the laminated core 14. Flows into the plurality of through holes 16). In addition, it flows into the annular cavity of the reinforcing member 22, and a plurality of secondary conductors 18 and a pair of edge connecting rings 20 are formed as one.

After casting, the jig 34 is peeled off to remove the extension portion 35 of the porous wall portion 29 of the casting operation and the reinforcing member 23 projecting inwardly from the inner circumferential surface of the laminated core 14. In this way, the rotary shaft 12 (first) is formed by melting, for example, the laminated core 14 and the reinforcing members 22 and 23 integrated by casting of the secondary conductor 18 and the edge connecting ring 20. The cage rotor 10 is formed in FIG. 1 by fixing to 1 degree).

As described above, when the secondary conductor 18 and the edge connecting ring 20 are cast and molded in the cage rotor 10, the lamination cores 14, which are made of a laminate of magnetic thin plates, are fixed to one and the reinforcing members 22 and 23. It is possible to be firmly held in one by the laminated core 14 and the edge linkage (20). At this time, the cylindrical wall portions 26 and 27 of the respective reinforcing members 22 and 23 sandwich the porous wall portions 28 and 29 and the end wall portions 30 and 31 to firmly support both ends. Therefore, the reinforcing members 22 and 23 do not cause their own deformation even at the very high speed of rotation of only a few minutes, and the deformation of the edge linking ring 20 by the centrifugal force can be prevented.

Industrial availability

According to the present invention, since the cylindrical wall portion of the reinforcing member surrounding the outer periphery of the edge linkage is sandwiched by the porous core and the end wall and is firmly supported at both ends by the laminated core and the edge linkage, even at an extremely high speed of rotation of only a few minutes, The reinforcing member itself does not deform, and it is possible to prevent deformation and destruction of the edge linkage by centrifugal force. Therefore, by using the cage rotor according to the present invention, it becomes possible to produce a high speed induction motor having high structural reliability.

Claims (3)

A laminated core comprising a rotor shaft and a plurality of magnetic thin plates, and having a plurality of through holes arranged between both end surfaces of the laminate in the axial direction, and being disposed in the through holes of the laminated cores; A plurality of secondary conductors and a pair of edge connecting rings connected to the secondary conductors at both ends of the laminated core in the axial direction, and a conductor portion formed as one by a casting process, and a cylindrical outer surface of the edge connecting rings And cylindrical wall portion surrounding the; A plurality of holes connected to each of the through-holes of the laminated core and extending radially inward at one end of the tubular shape so as to be held between the edge linkage and the axial end surface of the laminated core. A porous wall portion; A pair of end walls extending radially inward at the other edge connection of the tubular wall, the end wall contacting the axially outer surface of the edge linkage on the opposite side of the multi-hole wall and covering each of the edge links Squirrel rotor of the high-speed induction motor, characterized in that provided with a reinforcing member. The squirrel rotor of claim 1, wherein the secondary conductor and the edge connecting ring of the conductor portion are molded into one by a die cast molding process in aluminum. The squirrel rotor of a high speed induction motor according to claim 1, wherein one of said reinforcing members has a plurality of thin holes that act as air bands in the casting step.