JPH06133481A - Rotating electric machine - Google Patents

Abstract

PURPOSE:To ensure a balance over a long period by forming continuous holes, which are made to communicate with a passage for allowing cooling air to flow from one end to the other end of a rotor, in an annular weight groove into which a balance weight is inserted to balance a rotor core, thereby preventing the deposition of dust in the weight groove. CONSTITUTION:A rotor made up of a rotor core 5, a rotor bar 9, a short-circuit ring 8 and a core presser 6, or the like, is rotated n a stator 2 of a rotating electric machine. A balance weight is attached to an annular insertion groove 6b in order to balance the rotor. To cool the rotor core 5, a passage 13 is formed for allowing cooling air to flow from one end to the other end of the rotor 5 by means of a fan. A number of continuous holes 6c communicating with the passage 13 are formed in the balance weight insertion groove 6b. Air in the continuous hole 6c is sucked out into the passage 13 by setting an air velocity in the continuous hole 6c lower than that in the passage 13. Thereby, the deposition of dust in the balance weight insertion groove can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary electric machine, and more particularly to the structure of a balance weight insertion groove into which a balance weight for balancing the rotor is inserted.

[0002]

2. Description of the Related Art FIG.
14-31 is a cross-sectional view showing a conventional rotary electric machine shown in No. 89-9378, and FIG. 8 is a cross-sectional view showing the structure of the iron core pressing portion shown in FIG. 7. In the figure, reference numeral 1 is a cylindrical stator frame, and an air intake hole is provided in the outer peripheral portion on one end side in the longitudinal direction.
1a is provided with air discharge holes 1b on the other end side, and both ends of the stator frame 1 are closed by end plates 1c and 1d. Reference numeral 2 is a stator core attached to the stator frame 1, 3 is a stator winding attached to the stator core 2, and 4 is a stator frame 1.
A rotor shaft 5 rotatably supported by a rotor core 5 attached to the rotor shaft 4 has a ventilation hole 5a. Reference numeral 6 denotes an iron core retainer attached to one end of the rotor iron core 5, which is a ventilation hole 5a.
An annular balance weight insertion groove 6b and a plurality of communication holes 6c connected to the balance weight insertion groove 6b are formed on one end side of the outer peripheral portion. Reference numeral 7 denotes an iron core receiver attached to the other end of the rotor iron core 5, which has an opening 7a connected to the ventilation opening 5a. Has been formed. 8 is an end ring, 9 is a rotor bar attached to the rotor iron core 5, both ends of which are connected to the end ring 8, 10 is a balance weight attached to the iron retainer 6 and iron core receiver 7, and 11 is a balance weight. The fan is attached to the rotor shaft 4, and its outer peripheral portion is arranged so as to face the air discharge hole 1b. The rotor 12 is formed by the above 4 to 11, and the first flow path 13 is formed by the above 5a to 7a. 14
Is a dust cover provided by closing the air intake hole 1a. In addition, the second flow path 14 is provided between the stator 2 and the rotor 12.
Are formed.

Next, the operation will be described. When the rotating electric machine is driven, the rotating fan 11 discharges the air inside the stator frame 1 from the air discharge hole 1b, and the inside of the stator frame 1 becomes a negative pressure, and the dust cover 13 from the air intake hole 1a. The air that has passed through is taken in, flows from one end to the other end of the second flow path 15 between the stator core 2 and the rotor 12, and the first flow path 13, and is fixed by the fan 11. It is discharged to the outside of the child frame 1. Here, since the rotor 12 is formed by integrating a plurality of parts as described above, a rotational imbalance occurs. If the rotor 12 has a rotational imbalance, abnormal vibration and noise are generated during operation of the rotating electric machine, which eventually leads to mechanical damage. Therefore, the rotor 12 is mounted on a balance machine to achieve dynamic balance. As for this dynamic balance, as shown in FIG. 8, the balance weights 10 are attached to the balance weight insertion grooves 6b in an amount corresponding to the amount of imbalance at that time. Due to its nature, a plurality of balance weights 10 are arranged in one place, and as shown in FIG. 9, insert the balance weights 10a, 10b into which axially divided two and threaded holes are provided on the divided surfaces. It is fixed to the balance weight insertion groove 6b by inserting it into the groove 6b and screwing the screw 10c into the screw hole of the dividing surface. Therefore, even if the rotor 12 rotates at a high speed, the rotor 12 can rotate without losing the balance. In addition,
Fine dust 16 gradually accumulates in the space formed between the balance weights 10 in the balance weight insertion groove 6b, but this dust 16 is dissipated to the outside of the balance weight insertion groove 6b by a centrifugal force through the communication hole 6c. It

[0004]

Since the conventional rotary electric machine has the balance weight insertion groove 6b configured as described above, the fine dust 16 contained in the cooling air taken in through the dust cover 13 by the fan 11 is After being accumulated in the balance weight insertion groove 6b, it is discharged from the communication hole 6c by the centrifugal force acting by the rotation of the rotor 12, but dust 16 is shown in FIG. As shown in the figure, there is a problem in that, when the balance weight is inserted in the balance weight insertion groove 6b for a long period of time, the balance is disturbed by the apparent specific gravity of the dust and the rotor becomes unbalanced, causing a failure.

The present invention has been made to solve the above-mentioned problems, and prevents dust in the cooling air taken in by the fan from accumulating in the balance weight insertion groove, and for long-term operation. Also aims to obtain a rotating electric machine that can maintain the balance of the rotor.

[0006]

A rotary electric machine according to the present invention has a balance weight insertion groove provided with a communication hole for communicating with a passage of cooling air introduced from one end of the rotary electric machine and discharged from the other end. is there.

[0007]

The communication hole of the rotating electric machine according to the present invention draws the dust that has entered the balance weight insertion groove into the passage of the cooling air introduced from one end of the rotating electric machine and discharged from the other end.

[0008]

EXAMPLES Example 1. Embodiment 1 of the present invention will be described below with reference to the drawings. 1 is a front view showing, in a sectional view, a portion of a rotor showing a balance weight insertion groove of a rotary electric machine according to Embodiment 1 of the present invention, and FIG. 2 is a sectional view taken along line II-II in FIG. In the figure, 2 is a stator core, 3 is a stator winding, 5 is a rotor core, 6 is a core holder, 6a is an opening,
6b is a balance weight insertion groove, 8 is an end ring, and 9 is a rotor bar, all of which are the same as conventional ones. 6c is opening 6a
A plurality of communication holes are provided to connect the balance weight insertion groove 6b with the balance weight insertion groove 6b. The balance weight 10 is mounted in the same manner as the conventional one, as shown in FIG.

Next, the operation will be described. When the rotating electric machine is driven, the cooling air flowing in from the air intake port 1a flows into the first flow path 13, the balance weight insertion groove 6b and the communication hole 6c as shown by the arrow in the figure, as in the conventional case. Depending on the ratio of the cross-sectional areas of the first flow path 13 and the communication hole 6c, the first flow path 13
Since the flow velocity of the cooling air flowing through the connecting hole 6c is higher than the flow velocity of the cooling air flowing through the connecting hole 6c, the cooling air flowing through the connecting hole 6c is the first flow path.
It is drawn into the cooling air flowing through 13. Therefore, the fine dust contained in the cooling air is drawn into the first flow path 13 through the communication hole 6c and is discharged to the outside through the air discharge hole 1b without accumulating in the balance weight insertion hole 6b.

Embodiment 2. FIG. 4 is a partial cross-sectional view of a rotary electric machine showing a balance weight insertion groove and a communication hole of a rotary electric machine according to Embodiment 2 of the present invention, in which a communication hole 6c is provided at a predetermined angle with respect to the first flow path 13. Since the flow path resistance of the communication hole 6c is reduced as compared with the above embodiment, the flow velocity of the cooling air flowing through the communication hole 6c can be increased and the number of processing steps for the communication hole 6c can be reduced.

Embodiment 3. In the above embodiment, the communication hole
The cooling air flowing through 6c is drawn in by the cooling air flowing through the first flow path 13, but as shown in FIG. 5, the cooling air flows through the communication hole 6c from the other end of the iron core pusher 6 toward the outer periphery. Even if the cooling air flowing in the balance weight insertion groove 6b is drawn in by the cooling air flowing through the second flow path 15, the same effect as that of the above embodiment can be obtained.

Embodiment 4. 6 is a partial sectional view of a rotary electric machine showing a balance weight insertion hole and a communication hole of a rotary electric machine according to Embodiment 4 of the present invention, in which a communication hole 6c is formed by connecting the balance weight insertion hole 6b and the outer circumference of the iron core retainer 6. Even if the cooling air that flows into the balance weight insertion groove 6b is drawn in by the cooling air that flows through the second flow path 15, the flow path resistance of the communication hole 6c is reduced compared to the above embodiment, so that it flows through the communication hole 6c. The effect that the flow velocity of the cooling air is increased and the man-hour for processing the communication hole 6c can be reduced is obtained.

[0013]

As described above, according to the present invention, the balance weight insertion groove is provided with the communication hole communicating with the passage of the cooling air introduced from one end of the rotating electric machine and discharged from the other end. Therefore, dust is not accumulated in the balance weight insertion groove, and the effect of ensuring balance of the rotor over a long period of time can be obtained.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a rotary electric machine showing a balance weight insertion groove and a communication hole of the rotary electric machine according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a cross-sectional view showing mounting of the balance weight in FIG.

FIG. 4 is a partial cross-sectional view of a rotary electric machine showing a balance weight insertion groove and a communication hole of the rotary electric machine according to the second embodiment of the present invention.

FIG. 5 is a partial sectional view of a rotary electric machine showing a balance weight insertion groove and a communication hole of the rotary electric machine according to a third embodiment of the present invention.

FIG. 6 is a partial cross-sectional view of a rotary electric machine showing a balance weight insertion groove and a communication hole of the rotary electric machine according to Embodiment 4 of the present invention.

FIG. 7 is a cross-sectional view showing a conventional rotary electric machine.

8 is a partial cross-sectional view showing a balance weight insertion groove in the rotary electric machine of FIG.

9 is an exploded view showing details of balance weights in the rotary electric machine of FIG. 7.

10 is a cross-sectional view showing a state in which dust is accumulated in a balance weight insertion groove in the rotary electric machine of FIG.

[Explanation of symbols]

 1 Stator frame 2 Stator 6b Balance weight insertion hole 6c Communication hole 12 Rotor 13 First flow path (passage) 15 Second flow path (passage) 16 Dust

Claims (1)

[Claims] 1. A rotary electric machine having an annular balance weight insertion groove formed on an outer peripheral portion of an iron core of a rotor, into which a balance weight is inserted, wherein the balance weight insertion groove is introduced from one end of the rotary electric machine and the other end. A rotating electric machine, characterized in that it communicates with a passage for cooling air discharged from the casing through a communication hole.