JP2003047221A - Conductor termination ring holding configuration of cage rotor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conductor termination ring holding configuration of cage rotor which can increase strength of a termination ring by centrifugal force and can also prevent stress applied on reinforcing materials by thermal expansion of the termination ring. SOLUTION: This cage rotor comprises a stacked core 12 which is formed by stacking a plurality of magnetic thin plates and is fixed to a rotating shaft 11, a plurality of through-holes 14 formed in the axial direction in proximity to the external circumferential surface of the stacked core 12, a conductor which is formed integrally with the casting process of the termination rings which terminate conductor bars 15 at both end portions in the axial direction of a plurality of conductor bars 15 allocated in the through-holes 14 and stacked core 12 and are mutually coupled and a reinforcing member 17 which covers the termination rings 16 to prevent deformation thereof. The reinforcing member is formed of aluminum alloy having higher strength and also has almost L-shape cross-section. Moreover, this reinforcing member is integrated with the stacked core 12 and termination rings 16 when the conductor part is casted in order to cover the termination rings 16 keeping the predetermined interval toward the diameter direction from the external circumference of a rotating shaft 11.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for holding a conductor short-circuit ring of a cage rotor. 2. Description of the Related Art Conventionally, a structure for holding a conductor short-circuiting ring of a cage rotor is shown in FIG. 2. In FIG. 2, reference numeral 10 denotes a rotor, 11 denotes a rotating shaft, and 12 denotes a rotating shaft 11. A laminated core formed by laminating a plurality of magnetic thin plates fitted and fixed on the laminated core; 13, a central hole formed between both end surfaces in the axial direction of the laminated core; A plurality of through holes formed in the axial direction at substantially regular intervals, a plurality of conductor rods 15 disposed in each of the through holes 14, a plurality of conductor rods 16 disposed at both axial ends of the laminated core 12. A pair of short-circuit rings that mechanically and electrically connect 15 to each other, and a pair of reinforcing members 21 that cover each short-circuit ring. The plurality of conductor rods 15 and the pair of short-circuit rings 16 constitute a conductor portion, and are integrally formed from a highly conductive metal material such as aluminum through a casting process such as die casting. Thereby, the laminated structure of the laminated core 12 is integrally fixed and the laminated core 1 is fixed.
2 and each reinforcing member 21 are integrally connected. further,
The reinforcing member 21 is formed of an annular element having a substantially L-shaped peripheral section that is open to the outside, and is formed from a highly rigid material such as iron or stainless steel by machining such as cutting or cutting. Each reinforcing member 21 has an inner diameter that is substantially the same as the diameter of the center hole 13 of the laminated core 12, and the cylindrical inner wall 1 that contacts the rotating shaft 11.
8, an annular end wall 19 extending radially outward from one axial end edge of the cylindrical inner wall 18 to exhibit an outer diameter substantially equal to the outer diameter of the laminated core 12, and an axial other end of the cylindrical inner wall 18 An annular locking wall 20 is provided integrally extending from the edge to the outside in the radial direction until the outer diameter of the plurality of through holes 14 of the laminated core 12 is smaller than or equal to the diameter defined by the innermost part in the radial direction. In such a configuration, when a conductor portion composed of a plurality of conductor rods 15 and a pair of short-circuit rings 16 is integrated by casting, each reinforcing member 21 is fixedly supported on the laminated core 12 via the annular locking wall 20. And is fixedly supported on the rotating shaft 11 through the cylindrical inner wall 18, particularly in the radial direction. As a result, the annular end wall 19 of the reinforcing member 21 covers the axially outer end face of the short-circuit ring 16, and the short-circuit ring 16 bends due to centrifugal force at the time of high-speed rotation, such as turning up of the inner peripheral edge part. (For example, see Japanese Patent Application Laid-Open No. 9-280).
No. 64). However, in the prior art, when the rotor 10 rotates at high speed, the rotor 10 rotates due to centrifugal force acting on the rotor 10 or various losses such as iron loss and copper loss generated in the motor. There is a problem in that the temperature of the armature 10 rises and the thermal expansion of the short-circuit ring 16 causes stress on the reinforcing member 21 due to the difference between the linear expansion coefficient of the short-circuit ring 16 and the linear expansion coefficient of the reinforcing member 21. As a result, the reinforcing member 2
When a stress is applied to No. 1, there is a fear that the short-circuit ring 16 may be bent or broken. Further, the structure in which the reinforcing member 21 is directly fixed to the rotating shaft 11 has a problem that when the rotor 10 thermally expands in the axial direction, an excessive force is generated in the reinforcing member 21 and the rotating shaft 10 is bent. SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and has been made to increase the strength of a short-circuit ring due to centrifugal force, and to prevent a stress from being applied to a reinforcing member due to thermal expansion of the short-circuit ring. An object of the present invention is to provide a holding structure for a conductor short-circuit ring of a child. [0004] In order to solve the above-mentioned problems, a cage short-circuit ring holding structure for a cage rotor according to the present invention comprises a rotating shaft and a plurality of magnetic short-circuiting rings fixed to the rotating shaft. A laminated core formed by laminating thin plates; a plurality of through holes formed in the axial direction in proximity to the outer peripheral surface of the laminated core; a plurality of conductor rods disposed in the through holes and an axis of the laminated core The conductor rods are short-circuited at both ends in the direction, and are constituted by a pair of short-circuit rings connected to each other and integrally formed by a casting process, and the short-circuit rings are covered to prevent deformation of the short-circuit rings. In a cage rotor provided with a pair of reinforcing members, the reinforcing members have a substantially L-shaped cross section made of a high-strength aluminum alloy, and have a predetermined distance from an outer periphery of the rotating shaft in a radial direction. And wrap the short-circuit ring. That is, the conductor portion is formed integrally with the laminated core and the short-circuit ring at the time of casting. An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view showing a structure of a conductor short-circuit ring of a cage rotor according to an embodiment of the present invention. Constituent elements of the present invention that are the same as those in the related art are given the same reference numerals, and description thereof is omitted. Only different points will be described. The difference between the present invention and the conventional one is as follows.
That is, the reinforcing member 17 has a substantially L-shaped cross section made of a high-strength aluminum alloy instead of the conventional reinforcing member 21 and is spaced from the outer periphery of the rotating shaft 11 in the radial direction by a predetermined distance. The point is that the conductor portion is integrally molded with the laminated core 12 and the short-circuit ring 16 so as to surround the short-circuit ring 16. Specifically, the inner diameter of the cylindrical inner wall 18 constituting the reinforcing member 17 is larger than the diameter of the center hole 13 of the laminated core 12 and smaller than the inner diameter of the through hole 14. This is obviously different in that the reinforcing member 17 has a shape that does not contact the rotating shaft 11. Next, an example of a manufacturing process of the cage rotor will be described. First, a plurality of magnetic thin plates punched in a disk shape are provided so as to have respective openings corresponding to the center hole 13 and the through-hole 14, and are temporarily fixed to each other by, for example, caulking to form the laminated core 12. Then, the substantially L-shaped horizontal portion of the reinforcing member 17 is concentrically arranged on the laminated core 12 in a state of being in contact with each end face in the axial direction of the laminated core 12. At this time, when casting is performed in a state where such a rotor 10 is accommodated in a mold having a casting space (not shown), a predetermined radial direction is formed on both end surfaces in the axial direction of the laminated core 12 from the outer periphery of the rotating shaft 10. A reinforcing member provided so as to wrap the short-circuit ring at an interval
As a result, the conductor rods 15 are formed in the plurality of through-holes 14 formed in the laminated core 12 in the axial direction, and short-circuits are formed at both axial ends of the laminated core 12 as annular spaces that open radially outward. A ring 16 is formed. Accordingly, the reinforcing member 17 according to the present invention is used.
Has a substantially L-shaped cross-section made of a high-strength aluminum alloy, and has a laminated core 12 and a short-circuit when the conductor portion is cast so as to wrap the short-circuit ring 16 at a predetermined distance from the outer periphery of the rotating shaft 11. Since the reinforcing member 17 and the short-circuit ring 16 have the same linear expansion coefficient because they are formed integrally with the ring 16, it is possible to prevent stress from being applied to the reinforcing member due to thermal expansion of the short-circuit ring during high-speed rotation. it can. In addition, since aluminum alloy has a lower specific gravity than iron and stainless steel, an increase in inertia can be reduced, which is advantageous for stable high-speed rotation. In addition, there is no need to fix the reinforcing member 3 to the rotating shaft because excessive force is not applied in thermal expansion, and the problem that excessive force is generated in the reinforcing member when the rotor expands in the axial direction and the shaft is bent is also solved. can do. As described above, according to the present invention, the reinforcing member of the present invention has a substantially L-shaped cross section made of a high-strength aluminum alloy, and has the outer periphery of the rotating shaft 11. Is formed integrally with the laminated core 13 and the short-circuit ring at the time of casting the conductor portion so as to wrap the short-circuit ring at a predetermined distance from the reinforcing member. It is possible to prevent stress from being applied to the reinforcing member due to thermal expansion of the short-circuit ring. In addition, since aluminum alloy has a lower specific gravity than iron and stainless steel, an increase in inertia can be reduced, which is advantageous for stable high-speed rotation. In addition, there is no need to fix the reinforcing member 3 to the rotating shaft because excessive force is not applied in thermal expansion, and the problem that excessive force is generated in the reinforcing member when the rotor expands in the axial direction and the shaft is bent is also solved. can do.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing a structure of a conductor short-circuit ring of a cage rotor according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing the structure of a conventional short-circuiting ring of a cage rotor. [Description of Signs] 10 Rotor 11 Rotary shaft 12 Laminated core 13 Center hole 14 Through hole 15 Conductor bar 16 Short-circuit ring 17 Reinforcement member

Claims (1)

Claims: 1. A rotating shaft, a laminated core fixed to the rotating shaft and formed by laminating a plurality of magnetic thin plates, and an axially penetratingly formed close to an outer peripheral surface of the laminated core. A plurality of through-holes, a plurality of conductor rods arranged in the through-hole, and a short-circuit between the conductor rods at both axial ends of the laminated core, and a pair of short-circuit rings connected to each other. In a cage rotor including a conductor portion integrally formed by a casting process and a pair of reinforcing members that cover the short-circuit ring and prevent deformation of the short-circuit ring, the reinforcing member is made of a high-strength aluminum alloy. Having a configured substantially L-shaped cross-section, and wrapping the short-circuit ring at a predetermined interval in the radial direction from the outer periphery of the rotating shaft,
A structure for holding a conductor short-circuiting ring of a cage rotor, wherein the conductor-forming portion is formed integrally with the laminated core and the short-circuiting ring during casting of the conductor portion.