JPS62147935A - Rotor for induction machine - Google Patents

Abstract

PURPOSE:To relax mechanical stress generated in a rotor conductor, and to prevent the breaking of the rotor conductor by storing the rotor conductor in a slot through a liner shorter than both end surfaces of a rotor core only by proper length. CONSTITUTION:Since the entire length of a liner 5 is made properly shorter than entire length in the axial direction of a lot 7 for a rotor core 8, both end surfaces of the liner 5 are positioned on the sides inner than both end surfaces of the rotor core 8 on by the section in the slot 7. Consequently, an air gap 9 approximately equal to the thickness of the liner 5 is formed between a conductor 3 and the inner circumferential surface of the slot 7 between the end surface 5a of the internal liner 5 and the inner side surface of an end ring 4 joined with the conductor. According to said constitution, mechanical stress generated in the rotor conductor 3 is reduced by adjusting length to the slot 7 of the liner 5, thus preventing the breaking of the rotor conductor 3.

Description

[Detailed Description of the Invention] [Technical Field to which the Invention Pertains] The present invention provides an arrangement in which a terminal ring of a rotor conductor housed in a slot of a rotor core through a liner made of brass or the like is connected to both end faces of the rotor core. This invention relates to an induction machine rotor that is mounted in close contact with the rotor of an induction machine. It is desired that the rotor of this building has a structure that can suppress as much as possible the mechanical stress and thermal stress generated in the rotor conductor during operation.

[Prior art and its problems]

For example, in the induction machine 110 and rotor 12 configured as shown in FIG. In addition to adopting sealed slots in the rotor core 8 for the purpose of suppressing this as much as possible,
As illustrated in FIG. 4, end rings 4 provided at both ends of the rotor conductor 30 are generally mounted so as to be in close contact with both end surfaces of the rotor core 80. In this case, the rotor conductor 3 made of steel etc.
slot 7 of the rotor core 8 in which it is stored during operation.
This prevents discharge or electrolytic corrosion from occurring between the trochanter conductor 3 and the inner wall surface of the slot 7, and also prevents the trochanter conductor 3 from moving when it is inserted into the slot 7 or from temperature changes during operation. In order to smoothen the expansion and contraction of the conductor, it is inserted into the slot through a liner 15 which is usually made of brass and has an opening in the axial direction. Since the liner 5 is generally provided in the slot 7, the liner 5 comes into contact with the end ring 4 at both ends of the rotor core 8.

In this case, in general, in an induction machine having a squirrel-cage rotor, the end face of the rotor core of the end ring due to centrifugal force acting on the end rings on both sides of the rotor conductor during operation and expansion and contraction due to temperature changes. Mechanical stress caused by displacement in
Thermal stress occurs in the rotor conductor due to the temperature distribution of the rotor conductor, but in the rotor 12 of a conventional induction machine as illustrated in FIG. In addition, the rotor conductor 3 is attached to the iron core 8.
Because the entire length of the thrower door is restrained by the thrower door via the liner 5, the portion that joins the end ring 4 at the outlet of the thrower door cannot follow the displacement of the end ring 4, so the mechanical stress described above cannot be applied. is concentrated on the rotor conductor 3 near the exit of the thrower door, the conductor 3 becomes fatigued due to the repeated action of the mechanical stress, and the brazing between the conductor 3 and the end ring 4 in particular may cause material deterioration due to etc. This has the disadvantage that there is a risk of breakage near the exit of the narrow thrower door.

[Purpose of the invention]

The above-mentioned 9 in a conventional induction machine having a rotor in which the end rings of the rotor conductor are attached closely to both end faces of the rotor core.
In view of the above drawbacks, the present invention makes the materials and design specifications of the rotor conductor and end ring the same as those of the conventional VJ induction machine, and alleviates the mechanical stress occurring in the rotor conductor by simple means. It is an object of the present invention to provide an induction machine having a rotor which is closely attached to both end faces of a rotor core, which is an end ring of a rotor conductor, and which can prevent breakage of the rotor.

[Key points of the invention]

In order to achieve the above object, the present invention provides the induction machine rotor described above, in which the rotor conductor is accommodated in the slot via a liner that is an appropriate length shorter than both end faces of the rotor core. By doing so, between both end surfaces of the liner and both ends of the slot, a wall gap approximately equal to the thickness of the liner is provided in the axial direction between the rotor conductor and the inner peripheral wall of the slot. It is something that is done like this.

[Embodiments of the invention]

Next, the present invention will be explained in detail based on embodiments shown in the drawings.

For example, in an induction machine 10 and a rotor 2 as illustrated in FIG. In addition to adopting sealed slots in the rotor core 8 for the purpose of minimizing the
Terminal rings 4 provided at both ends of the rotor conductor 30 as illustrated in the figure.
Generally, the rotor core 80 is attached so as to be in close contact with both end faces of the rotor core 80. In this case, the rotor conductor 3 made of steel or the like is prevented from causing electrical discharge or electrolytic corrosion between it and the inner wall surface of the slot 7 of the rotor core 8 in which it is housed during operation,
Further, the movement of the rotor conductor 3 when the rotor conductor 3 is inserted into the slot 7 and the expansion of the conductor 3 due to temperature changes during operation.

In order to smooth the contraction, the liner 5 is usually made of brass and has an opening Y in the axial direction, and is inserted into the slot. Unlike the liner 15 shown in FIG. 1 and FIG. Since it is located inside of both end faces of the rotor core 80, in the darkness between the ghA surface 5a of the internal liner 5 and the end ring 4 1t411u]'i4a connected to the conductor. ,
A gap 9 approximately equal to the thickness of the liner 5 exists between the conductor 3 and the inner peripheral surface of the slot 7, and the free end of the conductor 3 is connected to an end ring, and the other end is connected to the end ring. It resembles a cantilever beam fixed at the end face 5aic of the liner 5 inside the slot 7. At this time, in order to fix the liner 5, which is shorter than the entire axial length of the thrower door, in the thrower door so that its both ends maintain a predetermined distance from both end faces of the rotor core 80, a jig is used to fix the liner 5 in the radial direction of the rotor core 80 after insertion. Punch processing at 60 parts of air duct? so that the liner 5 or the rotor conductor 3 is engaged.

In the case of the induction machine 1 of the present invention constructed as described above, therefore, from the end face 5a of the liner 5 inside the slot 7 of the rotor core 8 to the cantilever beam of the outer rotor conductor 3, The fixed point of the cantilever portion can follow the above-mentioned displacement in the radial direction of the end ring 4 caused by expansion and contraction due to centrifugal force or temperature change. The displacement of the rotor conductor 3 at the end face 5a of the liner 5 can be made more comparable to the displacement of the end ring by adjusting the axial length of the cantilevered portion of the rotor conductor 3. Since it can be made small, the concentrated stress on the conductor 3 at the end face 5a of the liner 5 due to the double edge acting on the end ring 4 can be significantly alleviated, and breakage of the conductor 3 at this portion can be prevented.

In this case, as shown in FIG. 2, two protruding pieces 5b that are approximately parallel to the side surface of the end surface 5a of the liner 5, which is shorter than the axial length of the thrower door of the rotor core 8, are placed near the end surface of the rotor core 8. Providing the liner 5 up to the liner 5 has the advantage that it facilitates the predetermined positioning when the liner 5 is inserted into the thrower door, and also serves as a guide when the conductor 3 is inserted inside the liner 5.

A similar effect can be obtained by adding tapered portions to both ends of the warped liner 5 that reach close to both end faces of the iron core.

〔Effect of the invention〕

As explained above, the present invention is such that the end ring of the rotor conductor, which is housed in the slot of the rotor core through a liner made of brass or the like, is attached to both end faces of the rotor core so as to be closely spaced. 1rvt of the rotor core
By storing the rotor conductor in the slot through a liner that is an appropriate length shorter than the end face,
Without changing the material or design specifications of the rotor conductor or the end ring, it is possible to eliminate the problems that occur in the rotor conductor due to centrifugal force acting on the end ring or expansion and contraction caused by temperature increase. Mechanical stress can be reduced as much as possible by adjusting the length of the liner with respect to the metal rod 4, and there is an effect that folding of the rotor conductor can be prevented.

[Brief explanation of drawings]

FIG. 1 is a schematic vertical cross-sectional view showing an embodiment of the rotor of an induction machine according to the present invention, particularly the P part in FIG. 3, which is related to the present invention, and FIG. A perspective view showing the end of one embodiment of the liner inserted between the conductors is shown in FIG.
The figure is a schematic longitudinal cross-sectional view showing the main parts of an induction machine in general.
The figure represents a schematic vertical cross-sectional view of the P section of FIG. 3, which is related to the present invention, of a rotor of a conventional induction machine. 1... Induction machine, 2... Rotor, 3... Rotor conductor,
4... End ring, 5... Liner, 7... Slot,
8...Rotor core. 7・' ゝ12 Figure 3 Figure 4

Claims (1)

[Claims] 1) An end ring of a rotor conductor housed in a slot of the rotor core via a liner is installed so as to be in close contact with both end faces of the rotor core, in which both end faces of the rotor core are attached. A rotor for an induction machine, characterized in that the rotor conductor is housed in the slot via the liner, which is shorter by an appropriate length.