JPS6271459A - Rotor for squirrel-cage type induction motor - Google Patents

Abstract

PURPOSE:To increase the strength of an end ring, and to prevent the deformation of the end ring by using for a prolonged term by fitting a retaining ring on the outer circumferential side of the end ring while fixing the retaining ring to a buried member buried to the end ring. CONSTITUTION:In a rotor with a cage type conductor in which a rotor bar 13 and end rings 19 are cast integrally by an aluminum alloy, retaining rings 20 for holding the strength of the end rings are fitted to the outer edge sections of the end rings 19. The retaining rings 20 are fastened to buried members 18 partially buried into the end rings 19 by bolts 21, etc. Accordingly, the end rings 19 can be reinforced, thus preventing the deformation of the end rings 19 even by using for a prolonged term at a high temperature and high revolution.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a rotor for a squirrel cage induction motor whose end ring is cast from an aluminum alloy.

[Technical background of the invention and its problems]

In general, squirrel cage induction motors that are used in situations where the starting and stopping are severe, that is, where the inertial force of the load is large, or in high-speed rotation, are known to use rotors whose end rings are cast from aluminum alloy. There is.

However, since the end ring portion of the rotor becomes extremely hot, the strength of the aluminum alloy that constitutes the end ring decreases, and the end ring is deformed by centrifugal force during high-speed rotation.

That is, as shown in FIG. 7, the aluminum alloy
It is known that when the temperature exceeds 100°C, the strength decreases rapidly. On the other hand, although various cooling methods have been developed, the internal temperature of an N-motor is usually 100 to 120 degrees Celsius.
The temperature may exceed 150°C in some cases. In particular, in recent years, induction motors have been used as electric motors to drive vehicles, but in this case, due to limited space, it is necessary to make them smaller and lighter, or to increase the capacity within the same size. The design is such that the temperature always exceeds 150°C. Therefore, there was a problem in that the end ring was deformed.

Therefore, we created a wedge-shaped notch on the end face of the rotor core.
The rotor was constructed by covering these notches with casting at the same time as the rotor bar and end ring were cast.
22) 49>, and as shown in FIG. 8, a rotor has been proposed in which, in addition to the rotor bar 1, a reinforcing bar 2 is integrally cast with an end ring 3.3. In addition, in this figure, 4 is a rotating shaft, and 5 is a laminated iron core.

However, even with this structure, the material covering the wedge-shaped notch and the material of the reinforcing bar 2 are different from the end ring 3.
, 3 is the same aluminum alloy, and its strength decreases at high temperatures, making it impossible to obtain a sufficient reinforcing effect. Therefore, if the end ring 3.3 is used for a long period of time at high temperature and high rotation, a creep phenomenon occurs and the end ring 3.3 becomes deformed.

For this reason, it has recently been thought that it is effective to prevent deformation by fitting a retaining ring around the end ring to maintain its strength. No method of attachment has yet been proposed.

[Purpose of the invention]

The present invention was made based on the above circumstances, and its purpose is to be able to reinforce the end ring and thereby prevent the end ring from deforming even when used for a long period of time at high temperatures and high rotations. The object of the present invention is to provide a rotor for a squirrel-cage induction motor that can perform the following functions.

[Summary of the invention]

In order to achieve the above object, the present invention is characterized in that a retaining ring that maintains strength is fitted onto the end ring, and the retaining ring is fixed to an embedded member that is at least partially embedded within the end ring. That is.

[Embodiments of the invention]

A first embodiment of the present invention will be described below with reference to FIG.

Reference numeral 11 in FIG. 1 is a laminated core fitted into the center of the rotating shaft 12, and a plurality of rotor bar through holes 14 for constructing the rotor bar 13 are formed by casting near the outer periphery of the laminated core 11. It is provided. Further, a plurality of stud through holes 15 are provided between the rotor bar through hole 14 of the laminated core 11 and the rotating shaft 12, and the stud through holes 15 are made of a material stronger than aluminum alloy, such as 520C. Or through hole 15 by 5US304 etc.
A stud (embedded member) 16 formed to have a diameter equal to or slightly smaller than the outer diameter of is inserted.

Both ends of this stud 16 are threaded, and a female threaded connecting member (embedded member) 18.18 is screwed into the threaded portion 17.17. Tightening is fixed from the side.

A rotor bar 13 and end rings 19, 19 are integrally cast in the laminated core 11 from an aluminum alloy. That is, the rotor bar through hole 1
4 is formed with a lower tar bar 13, and end rings 19.19 are provided on both end surfaces of the laminated core 11 to connect threaded portions 17.17 of the studs 16 and connecting members 18.18.
It is formed in a state where it is embedded.

In addition, a retaining ring 20.20 for maintaining strength is fitted into the end ring 19.19, and this retaining ring 20.20
is a holding f that fits on the outer peripheral surface of the end ring 19.19.
i520a, 20a, and a retaining portion 20b that covers the end face of the end ring 19, 19 to prevent the retaining portions 20a, 20a from coming off.

20b and is integrally formed with a cross-sectional shape. Then, the connecting member i is connected to the retaining portions 20b and 20b
Tightening is fixed by bolts 2)° and 2) on s and is.

According to the above configuration, the end ring 19.1 is
Even if the temperature of the end ring 19.19 increases and its strength decreases, and the end ring 19.19 tries to deform outward due to centrifugal force due to high-speed rotation, the end ring 19.19 retains the retaining ring 20.2.
0 is fitted, so that deformation can be prevented.

In addition, this retaining ring 20.20 is fixed to a connecting member 18.18 cast in the end ring 19.19 with a bolt 2)°2) while connected to the stud 16. The retaining ring will not come off due to vibration, environment, or operation.

Therefore, deformation of the end ring 19.19 due to the creep phenomenon can be suppressed, so when considering rotors of the same size, not only reliability is improved, but the rotation speed can also be increased. It can be used at high temperatures, that is, 150°C or higher, which was the conventional limit for use. For this reason, small l! You can improve your ranking.

FIG. 2 shows a second embodiment of the present invention. In this embodiment, the retaining ring 20Φ retaining part 20a and the retaining part 20b are separated, which improves the productivity. It looks like this.

FIG. 3 shows a third embodiment of the present invention. In this embodiment, the length of the stud 16 is such that it protrudes outward from the end ring 19, and the retaining ring 20 is directly connected to the threaded portion 17 of the stud 16. It is attached by a nut 22.

FIG. 4 shows a fourth embodiment of the present invention. In this embodiment, a balance weight mounting groove 23 is provided in the retaining ring 20, and a balance weight 24 is attached to the balance way 1 to the mounting groove 23 with set screws. 25, so that balance can be maintained at the retaining ring 20 portion.

FIG. 5 shows a fifth embodiment of the present invention. In this embodiment, the retaining ring 20 is provided with cooling fins 26, which dissipate the heat generated from the end ring 19 and cool it. Efficiency can now be improved.

FIG. 6 shows a sixth embodiment of the present invention, in which the present invention is applied to a rotor that does not require consideration of tightening the iron core 11 from both sides. That is, a seat (embedded member) 27 is cast into the end ring 19, and the retaining ring 20 is attached to the seat 27 with a port 28.
Fixed by

As described above, the same effects as in the first embodiment can be obtained in the second to sixth embodiments.

[Effects of the Invention] As explained above, according to the present invention, the end ring can be reinforced, thereby preventing deformation of the end ring even when used for a long period of time at high speed and wet conditions. It produces a immersive effect such as

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a first embodiment of the invention, FIG. 2 is a sectional view showing a second embodiment of the invention, and FIG. 3 is a sectional view showing a third embodiment of the invention. , FIG. 4 is a sectional view showing a fourth embodiment of the invention, FIG. 5 is a sectional view showing a fifth embodiment of the invention, and FIG. 6 is a sectional view showing a sixth embodiment of the invention. Figure 7 shows the temperature, tensile strength, yield strength, and
FIG. 8, which is a diagram showing the relationship with elongation, is a sectional view showing a conventional example. DESCRIPTION OF SYMBOLS 11... Laminated iron core, 12... Rotating shaft, 13... Rotor bar, 16... Embedded member (stat), 18...
・Embedded member (connecting member), 19... End ring, 2
0... Retaining ring, 27... Embedded member (mounted on seat). Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 2 Prisoner Figure 3 Figure 4 Figure 6 Degrees (0C) Figure 7 Figure 8

Claims (4)

[Claims] (1) A device comprising a laminated core fixed to a rotating shaft, a rotor bar fixed to the laminated core in the direction of lamination, and an end ring integrally cast from an aluminum alloy at the end of the rotor bar, wherein the end ring A rotor for a squirrel-cage induction motor, characterized in that a retaining ring that maintains strength is fitted onto the outside of the rotor, and the retaining ring is fixed to an embedded member at least partially embedded in the end ring. (2) The cage-shaped guide according to claim 1, wherein the embedded member is configured by providing a stud that passes through the laminated core and a connecting member that connects the stud and the retaining ring. rotor of an electric motor. (3) A rotor for a squirrel-cage induction motor according to claim 1, wherein the embedded member is a stud that penetrates the laminated core. (4) A rotor for a squirrel cage induction motor according to claim 1, wherein the embedded member is constituted by a mounting seat that is substantially entirely embedded in the end ring.