JP2019004608A - Totally-enclosed rotary electric machine and drain mechanism - Google Patents

Abstract

To secure a drain function and a flame propagation preventing function without removing a drain plug in a totally-enclosed rotary electric machine.SOLUTION: A totally-enclosed rotary electric machine has a rotator, a stator, a frame, two bearings, a bearing bracket forming a closed space together with the frame, and a drain mechanism 100 provided on a base plate 40b of the frame and draining condensed water produced within the closed space. The drain mechanism 100 has a frame through-hole 140 formed on the base plate 40b of the frame, and a moving part 110, provided within the frame through-hole 140, which can shift between a first state where the condensed water within the frame can be drained in normal times and a second state where the closed space is blocked from the outside when pressure within the closed space rises, mutually.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a fully closed rotating electrical machine and a drainage mechanism thereof.

  In a fully-closed rotating electrical machine having a cooler, each of a frame, a bearing bracket, and a cooler cover is generally a component that forms a closed space together with each other.

  The through-hole part of the bearing bracket of the rotating body such as the rotor shaft, the connection part between the frame and the bearing bracket, or the connection part between the frame and the cooler cover are sealed, but the leakage amount is completely It is not zero. Therefore, outside air flows into this closed space for a long period of time.

  When the outside air flows into the closed space, the cooling gas in the closed space is cooled by the cooler, so the relative humidity rises, and the excess water vapor in the flowing outside air condenses and becomes condensed water. Accumulated in a closed space. Since this condensed water eventually accumulates at the lower part of the frame, a drain plug is generally provided at the lower part of the frame in order to discharge the condensed water to the outside of the rotating electrical machine.

  In general, including other fields, for the drain plug, for example, an example in which scattering is prevented when draining (see Patent Document 1), or an example in which the drain plug is detachable (see Patent Document 2). Etc. are known.

JP 11-337291 A JP2013-167410A

  On the other hand, in the case of a rotating electrical machine, there are cases where specific conditions should be considered.

  First, the first function required for the drain plug is a drainage function. That is, it is necessary that the condensed water accumulated in the rotating electrical machine can be drained appropriately.

  Furthermore, when the rotating electrical machine is a pressure-proof explosion-proof rotating electrical machine, a second function required for the drain plug is a flame propagation preventing function. That is, when an explosion occurs in the machine, it is necessary to prevent the propagation of flame from the inside of the rotating electrical machine to the outside.

  For this reason, normally, the drain plug was attached to clear the second condition, and drainage was performed by removing the drain plug each time. However, since the drain plug is provided at the bottom of the frame, it is not easy to remove.

  Therefore, an object of the present invention is to ensure a drainage function and a flame propagation prevention function without removing a drain plug in a fully enclosed rotating electrical machine.

  In order to achieve the above-mentioned object, a fully-closed rotating electrical machine according to the present invention has a rotor shaft that extends in the direction of the rotation axis and is rotatably supported, and a rotor core that is attached to the outer side in the radial direction of the rotor shaft. A stator having a rotor, a cylindrical stator core provided radially outside the rotor core, and a stator winding penetrating through the stator core in the rotational axis direction; and the rotation A frame containing a core and the stator and having a bottom plate, two bearings rotatably supporting the rotor shaft, and fixedly supporting the bearings and connected to the frame to form a closed space together with the frame A bearing bracket to be formed, and a drainage mechanism that is provided on a bottom plate of the frame and discharges condensed water generated in the closed space, and the drainage mechanism is formed on the bottom plate of the frame. A ram through-hole, a first state that is provided in the frame through-hole and is capable of discharging condensed water in the frame at a normal time, and when the pressure in the closed space is higher than the normal pressure And a movable part capable of shifting between a second state in which the frame through-hole is closed to block the closed space from the outside.

  The present invention also provides a fully-enclosed rotating electrical machine including a rotor, a stator, a rotor iron core, a frame that houses the stator and a bottom plate, and a bearing bracket that forms a closed space together with the frame. A drainage mechanism that is provided on the bottom plate of the frame and discharges condensed water generated in the closed space, and is provided in the frame through-hole formed in the bottom plate of the frame and in the frame through-hole. Sometimes when the condensate in the frame can be discharged, and when the pressure in the closed space rises above the normal pressure, the frame through hole is closed to connect the inside and outside of the closed space. And a movable part capable of shifting between the second states to be blocked.

  ADVANTAGE OF THE INVENTION According to this invention, in a fully enclosed rotary electric machine, a drainage function and a flame propagation prevention function can be ensured, without removing a drain plug.

It is an elevation sectional view showing the composition of the fully closed type rotary electric machine concerning an embodiment. It is an elevation sectional view showing the composition of the drainage mechanism of the fully closed type rotary electric machine concerning an embodiment. It is an elevation sectional view showing a frame penetration hole formed in the bottom of the frame in the fully closed type rotating electrical machine according to the embodiment.

  Hereinafter, with reference to the drawings, a fully closed rotary electric machine and a drain plug according to an embodiment of the present invention will be described. Here, the same or similar parts are denoted by common reference numerals, and redundant description is omitted.

  FIG. 1 is an elevational sectional view showing a configuration of a fully-closed rotating electrical machine according to the embodiment. The fully closed rotating electrical machine 200 includes a rotor 10, a stator 20, and a frame 40.

  The rotor 10 includes a rotor shaft 11 that extends horizontally in the direction of the rotation axis, and a rotor core 12 that is attached to the outer side in the radial direction of the rotor shaft 11. An inner fan 15 is attached to the rotor shaft 11.

  The stator 20 has a cylindrical stator core 21 provided on the outer side in the radial direction of the rotor core 12 and a stator winding 22 that penetrates in the vicinity of the inner surface in the radial direction of the stator core 21 in the rotational axis direction. .

  The frame 40 surrounds these radial directions so as to accommodate the stator 20 and the rotor core 12. Bearing brackets 45a and 45b are provided on both sides in the rotation axis direction of the frame 40, and the bearings 31 and 32 are fixedly supported. A cooling unit 60 is formed at a portion other than the bottom of the frame 40. A plurality of fins (not shown) are provided on the outer surface of the frame 40.

  The cooling unit 60 has one or a plurality of ventilation paths 61. Each ventilation path 61 extends in the axial direction and is sandwiched between an inner wall 61g and an outer wall 61h. The cross section of each ventilation path 61 may be, for example, a rectangle, an ellipse, or a shape expanded in the circumferential direction. Each ventilation path 61 communicates with the atmosphere inside the machine, that is, the atmosphere on the side where the rotor core 12 and the stator 20 are provided, through the ventilation path inlet opening 61a and the ventilation path outlet opening 61b. . The number of the air passages 61 and the expansion in the circumferential direction of each of the air passages 61 or the spread in the circumferential direction of the plurality of air passages 61 are the height dimension of the air passage 61, that is, the distance between the inner wall 61g and the outer wall 61h. In addition, it may be set according to the required cooling capacity.

  The frame 40 and the bearing brackets 45a and 45b are combined with each other to form a closed space 40a. The interior of the machine and the ventilation path 61 constitute a closed space 40a, and the closed space 40a is filled with a cooling gas. The cooling gas is driven by the inner fan 15 and circulates in the closed space 40a. The cooling gas driven by the inner fan 15 flows into the ventilation path 61 via the ventilation path inlet opening 61a. In the ventilation path 61, the cooling gas is cooled by outside air through the outer wall 61h, and then flows into the machine through the ventilation path outlet opening 61b. The cooling gas flowing into the machine cools the rotor core 12 and the stator 20 and then flows into the inner fan 15 again.

  The drainage mechanism 100 is provided on the bottom of the frame 40, that is, the bottom plate 40b.

  FIG. 2 is an elevational cross-sectional view illustrating the configuration of the drainage mechanism of the fully-closed rotating electrical machine according to the embodiment. FIG. 3 is an elevational sectional view showing a frame through hole formed in the bottom of the frame.

  As shown in FIG. 3, the frame through-hole 140 formed in the bottom plate 40b of the frame 40 has a stepped structure with its center formed vertically downward. That is, the diameter gradually decreases from the top to the bottom.

  In the uppermost stage, a large-diameter hole 141 is formed and reaches the flat portion 141a. In the lower stage, a medium-diameter hole 142 is formed. The medium diameter hole 142 reaches the flat portion 142a at the lower side. In the lower stage, a small-diameter hole 143 is formed.

  From the lower end of the small diameter hole 143, a tapered hole 144 whose diameter decreases as it goes downward is formed. A small diameter hole 145 is formed from the lower end of the tapered hole 144 to the lower end of the through hole 140 in a certain shape.

  As shown in FIG. 2, the drainage mechanism 100 has a movable part 110, a spring 120, and a head presser 130 provided in a frame through hole 140 formed in the bottom plate 40b.

  The movable portion 110 includes a columnar portion 111 that extends in the axial direction in a columnar shape, a cone-shaped body portion 112 that is provided first from one end portion of the columnar portion 111 and decreases in diameter toward the tip, and the columnar portion 111. And a disk-shaped head 113 connected so as to align the central axis at one end. The movable part 110 is provided so that the cone part 112 is on the lower side and the axis is vertical.

  The angle of inclination of the cone of the cone portion 112 is equal to the angle of inclination of the tapered hole 144. When the movable portion 110 moves to the lowermost position, the outer surface of the cone portion 112 has a tapered hole. The frame through-hole 140 is closed in surface contact with the inner surface of 144.

  The spring 120 is provided so as to be sandwiched between the lower surface of the head 113 of the movable portion 110 and the two surfaces of the flat portion 142a.

  The head presser 130 includes a cylindrical portion 131 and a flange portion 132 that extends in the radial direction from the upper end of the cylindrical portion 131. The flange portion 132 is attached to the bottom plate 40b with, for example, a plurality of bolts (not shown) so that the lower surface thereof is in close contact with the radially outer portion of the frame through hole 140. At least one drain passage 132a is formed in the flange portion 132, and the upper surface of the bottom plate 40b communicates with the inside of the frame through hole 140.

  At this time, the lower end of the cylindrical portion 131 is in a state of suppressing the head portion 113 of the movable portion 110. The spring 120 is in a compressed state. Further, the cone portion 112 does not contact the tapered hole 144, and a gap is formed between the outer surface of the cone portion 112 and the inner surface of the tapered hole 144. This state is referred to as a first state.

  In the drainage mechanism 100 in the first state as described above, the condensed water that is normally generated in the frame 40 and finally falls to the bottom plate 40b is discharged from the drain passage 131 formed in the flange portion 132. Then, it flows into the frame through hole 140, passes through the gap between the conical body portion 112 and the tapered hole 144, and flows out downward from the small diameter hole 145.

  Here, when there is an explosion in the machine of the fully-closed rotating electric machine 200, a pressure difference is generated between the machine and the outside, so that the range surrounded by the head presser 130 of the head 113 of the movable part 110 is generated. The differential pressure is applied, and a force due to the differential pressure acts in the direction in which the spring 120 pressing the movable part 110 against the head presser 130 is compressed.

  As a result, the movable portion 110 moves downward, the outer surface of the conical body portion 112 and the inner surface of the tapered hole 144 come into contact with each other, and the inside of the frame 40 is isolated from the outside. This state is called a second state. When an explosion occurs in the aircraft, the flame generated in the aircraft does not propagate outside the frame 40 by shifting to the second state.

  When the flame in the machine converges and the pressure in the machine returns to a normal state, the movable body 110 rises to a position where it comes into contact with the head presser 130 by the restoring force of the spring 120 and returns to the first state. Again, a drainage channel is secured. That is, the first state and the second state can shift to each other.

As described above, according to the present invention, the first state having the drainage function and the second state having the flame propagation preventing function can be realized with the drainage mechanism 100 attached.
[Other Embodiments]
As mentioned above, although embodiment of this invention was described, embodiment is shown as an example and is not intending limiting the range of invention. For example, in the embodiment, the case where the present invention is applied to a horizontal type rotary electric machine has been described. However, the present invention is not limited to this.

  Furthermore, the embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention.

  The embodiments and the modifications thereof are included in the scope of the invention and the scope of the invention, and are also included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 10 ... Rotor, 11 ... Rotor shaft, 11a ... Coupling part, 12 ... Rotor iron core, 15 ... Inner fan, 20 ... Stator, 21 ... Stator iron core, 22 ... Stator winding, 31, 32 ... Bearing 40 ... Frame, 40a ... Closed space, 40b ... Bottom plate, 45a, 45b ... Bearing bracket, 60 ... Cooling part, 61 ... Ventilation path, 61a ... Ventilation path inlet opening, 61b ... Ventilation path outlet opening, 61g ... Inner wall, 61h ... outer wall, 100 ... drainage mechanism, 110 ... movable part, 111 ... cylindrical part, 112 ... cone part, 113 ... head, 120 ... spring, 130 ... head presser, 131 ... cylindrical part, 132 ... flange Part, 132a ... drain passage, 140 ... frame through hole, 141 ... large diameter hole, 141a ... flat part, 142 ... medium diameter hole, 142a ... flat part, 143 ... small diameter hole, 144 ... taper hole, 145 ... small diameter hole , 200 All closed-form rotary electric machine

Claims (4)

A rotor having a rotor shaft that extends in the direction of the rotation axis and is rotatably supported; and a rotor core that is attached to a radially outer side of the rotor shaft;
A stator having a cylindrical stator core provided radially outside the rotor core, and a stator winding penetrating the stator core in the direction of the rotation axis;
A frame that houses the rotor core and the stator and has a bottom plate;
Two bearings rotatably supporting the rotor shaft;
A bearing bracket that fixedly supports each of the bearings and is connected to the frame to form a closed space together with the frame;
A drainage mechanism that is provided on the bottom plate of the frame and discharges the condensed water generated in the closed space;
With
The drainage mechanism is
A frame through hole formed in the bottom plate of the frame;
The frame through hole provided in the frame through hole in a first state in which the condensed water in the frame can be discharged normally and when the pressure in the closed space is higher than the normal pressure. A movable part capable of shifting between the second states that block the inside and outside of the closed space by blocking
A fully-enclosed rotating electrical machine characterized by comprising: The frame through hole has a tapered hole whose diameter decreases as it goes down,
The movable part is formed in a conical shape with a reduced diameter as the lower part goes downward so as to face the tapered hole,
The drainage mechanism is
A spring for acting a restoring force to move the movable part vertically upward;
A head retainer that prevents the movable part from moving upward;
The fully-closed rotary electric machine according to claim 1, further comprising:   The fully enclosed rotating electrical machine according to claim 2, wherein an outer surface of a conical portion at a lower portion of the movable portion is formed so as to be in surface contact with an inner surface of a tapered hole of the frame through hole. Provided on the bottom plate of the frame of the fully-closed rotating electrical machine, comprising: a rotor, a stator, a frame containing the rotor core and the stator and having a bottom plate; and a bearing bracket that forms a closed space together with the frame. A drainage mechanism for discharging condensed water generated in the closed space,
A frame through hole formed in the bottom plate of the frame;
The frame through hole provided in the frame through hole in a first state in which the condensed water in the frame can be discharged normally and when the pressure in the closed space is higher than the normal pressure. A movable part capable of shifting between the second states that block the inside and outside of the closed space by blocking
A drainage mechanism characterized by comprising:

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