Rotating electric machine

Abstract

It suppresses corrosion of metal parts caused by corrosive gases generated by partial electrical discharge, etc. [Solution] The rotating electric machine comprises a case for housing a stator and a rotor, a terminal box communicating with the case, a photocatalyst unit provided inside the terminal box which is activated by light and exhibits the effect of decomposing corrosive gases, and a light source provided inside the terminal box which activates the photocatalyst unit by shining light on it.

Description

Technical Field

[0001] Embodiments of the present invention relate to rotating electrical machines.

Background Art

[0002] In rotating electrical machines such as generators and motors, when the insulation on the surface of the stator winding deteriorates, partial discharge occurs on the deteriorated surface, generating corrosive gases such as ozone and nitrogen oxides. Further, when nitrogen oxides combine with moisture in the air, highly corrosive nitric acid is generated. Then, these corrosive gases accelerate the corrosion of the metal parts constituting the rotating electrical machine, becoming a factor causing deterioration and failure of the rotating electrical machine.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Conventionally, for example, at the time of regular inspection of a rotating electrical machine, a disassembled inspection is performed to diagnose the deterioration state of the insulation of the stator winding, and measures are taken to prevent partial discharge in advance. However, there is still room for improvement in countermeasures for protecting metal parts from corrosive gases generated by partial discharge.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a rotating electrical machine capable of effectively suppressing corrosion of metal parts by corrosive gases generated by partial discharge or the like.

Means for Solving the Problems

[0006] The rotating electric machine according to this embodiment includes a case for housing a stator and a rotor, a terminal box communicating with the case, a photocatalyst unit provided inside the terminal box which is activated by light and exhibits the effect of decomposing corrosive gases, and a light source provided inside the terminal box which activates the photocatalyst unit by shining light on it. [Brief explanation of the drawing]

[0007] [Figure 1] A schematic cross-sectional view showing the internal structure of an example of a rotating electric machine according to one embodiment. [Figure 2] A cross-sectional view showing an enlarged view of the configuration around the terminal box in an example of a rotating electric machine according to one embodiment. [Figure 3] Figure 2 shows an example of the configuration of the terminal box modification of a rotating electric machine according to one embodiment, viewed from the X3 direction. [Modes for carrying out the invention]

[0008] The following describes a rotating electric machine according to one embodiment, with reference to the drawings. The rotating electric machine 10 is used to rotate loads, such as pumps and blowers, which are not shown. Furthermore, the rotating electric machine 10 of this embodiment is assumed to be a relatively high-capacity machine, for example, with a power supply voltage of 2kV or more, which is relatively prone to generating ozone gas due to insulation degradation.

[0009] The rotating electric machine 10 comprises a stator 11, a rotor 12, a rotating shaft 13, a bearing 14, a case 15, a fan 16, a fan cover 17, and a terminal box 20. In the following description, the direction parallel to the center O of the rotating shaft 13 is referred to as the axial direction. The direction perpendicular to the center O is referred to as the radial direction. The end of the rotating shaft 13 to which the load is connected is referred to as the load side, and the end opposite to the load side is referred to as the non-load side. In Figure 1, the left side of the rotating shaft 13 is the load side, and the right side is the non-load side.

[0010] In this embodiment, the stator 11, rotor 12, rotating shaft 13, bearing 14, case 15, fan 16, fan cover 17, and terminal box 20 are each made of metal. That is, the stator 11, rotor 12, rotating shaft 13, bearing 14, case 15, fan 16, fan cover 17, and terminal box 20 are metal parts that can be affected by corrosion from corrosive gases.

[0011] The stator 11, rotor 12, and part of the rotating shaft 13 are housed within a case 15. The stator 11 is fixed to the inside of the case 15. The stator 11 includes, for example, a stator core 111 and stator windings 112. The stator core 111 is, for example, cylindrical and formed by laminating multiple disc-shaped electromagnetic steel sheets. The stator windings 112 are inserted into slots in the stator core 111.

[0012] The rotor 12 is rotatably mounted inside the stator 11 with a gap between it and the stator 11. That is, the rotating electric machine 10 of this embodiment can be configured as, for example, an inner rotor type rotating electric machine. The rotor 12 can be configured with a squirrel-cage conductor, a rotor core and windings, or a rotor core and permanent magnets.

[0013] The rotating shaft 13 is provided through the center of the rotor 12 and is configured to rotate integrally with the rotor 12. Both ends of the rotating shaft 13 are rotatably supported by the case 15 via bearings 14. The bearings 14 can be made of, for example, ball bearings. The case 15 constitutes part of the outer shell of the rotating electric machine 10 and houses the stator 11 and rotor 12 inside.

[0014] The fan 16 is located at the non-load end of the rotating shaft 13 and rotates in conjunction with the rotation of the rotating shaft 13. When the fan 16 rotates, air is blown along the outer surface of the case 15, and heat exchange of air occurs between the inside and outside of the case 15. This cools the stator 11, rotor 12, and rotating shaft 13 inside the case 15. The fan cover 17 is located on the non-load side of the case 15 and covers the fan 16. The fan cover 17, like the case 15, constitutes part of the outer shell of the rotating electric machine 10.

[0015] The terminal box 20 is constructed as a container with an internal space and is, for example, provided on the top of the case 15. However, the terminal box 20 does not necessarily have to be provided on the top of the case 15; for example, it may be provided on the side of the case 15. As shown in Figures 2 and 3, the terminal box 20 has a box portion 21, a lid portion 22, and a connecting portion 23. The box portion 21 and the lid portion 22 are each formed in the shape of a rectangular box that is diagonally and vertically divided into two halves. The box portion 21 constitutes the lower part of the terminal box 20.

[0016] The lid portion 22 constitutes the upper part of the terminal box 20. The lid portion 22 is configured to be openable and closable relative to the box portion 21, and has the function of opening and closing the inside and outside of the terminal box 20. In this embodiment, the lid portion 22 is configured to be detachable from the box portion 21, and is configured to be openable and closable by attaching and detaching it from the box portion 21. The lid portion 22 may also be configured to be opened and closed in a manner that does not involve separation by, for example, a hinge.

[0017] The connection part 23 is connected to the box part 21 and the case 15, and supports the box part 21. As shown in Figure 1, the connection part 23 has a hollow communication part 231 that connects the inside of the terminal box 20 to the inside of the case 15. The lead wires 113 drawn from the stator winding 112 pass through the communication part 231 of the connection part 23, are routed inside the terminal box 20, and extend to the outside of the terminal box 20. If the rotating electric machine 10 is three-phase AC, the rotating electric machine 10 has three lead wires 113.

[0018] The rotating electric machine 10 further includes a support member 31, a photocatalyst section 32, a light source 33, and a light source control section 34. The support member 31 is provided, for example, on the box section 21 of the terminal box 20, and suspends and supports the lead wire 113, for example.

[0019] The photocatalyst section 32 is provided inside the terminal box 20, and exhibits the action of decomposing corrosive gases containing ozone, nitrogen oxides, or nitric acid, etc. by being activated upon receiving light. The photocatalyst section 32 is provided on an element inside the terminal box 20 or on the inner surface of the terminal box 20. In the case of this embodiment, examples of the elements inside the terminal box 20 include the lead wire 113 arranged inside the terminal box 20 and the support member 31 that supports the lead wire 113, etc., but are not limited to these as long as they are housed inside the terminal box 20.

[0020] In FIGS. 1 to 3, the portion where the photocatalyst section 32 is provided is indicated by dotted oblique lines. In the case of this embodiment, the photocatalyst section 32 is provided on the entire inner surface of the terminal box 20, the surface of the support member 31, and the surface of the lead wire 113. The photocatalyst section 32 can be configured using, for example, titanium oxide, zinc oxide, cadmium sulfide, zinc titanate, etc. as raw materials. The photocatalyst section 32 can be provided, for example, by coating a material containing a photocatalyst on the entire inner surface of the terminal box 20, the surface of the support member 31, and the surface of the lead wire 113 using spraying or a brush, etc. Note that the photocatalyst section 32 may be provided on each metal part by, for example, plating.

[0021] The light source 33 is provided inside the terminal box 20, and has the function of activating the photocatalyst section 32 by applying light to the photocatalyst section 32. That is, the light source 33 is set to irradiate ultraviolet rays or visible light for activating the photocatalyst section 32 according to the properties of the photocatalyst section 32. The light source 33 can be configured using, for example, an LED light, a xenon lamp, a black light, etc., according to the characteristics of the photocatalyst section 32.

[0022] The light source 33 is provided in the box portion 21 instead of the lid portion 22. That is, as shown in FIGS. 1 to 3, the light source 33 is provided on the bottom surface 211 inside the terminal box 20, that is, at the lower part inside the terminal box 20. In this case, the light source 33 is provided below the lead wire 113 among the portions routed inside the terminal box 20.

[0023] The light source control unit 34 has a function as a power supply for supplying power to the light source 33 and also has a function as a control device for controlling the irradiation of the light source 33. The light source control unit 34 can be configured by, for example, a separate device independent of the power supply device and the control device of the rotating electric machine 10. The light source control unit 34 is provided, for example, outside the terminal box 20 and on the side surface of the terminal box 20.

[0024] In the case of this embodiment, the light source control unit 34 monitors the operation of the rotating electric machine 10 or synchronizes with the operation of the rotating electric machine 10, and lights the light source 33 constantly or at a predetermined interval during the period when the rotating electric machine 10 is operating. Also, the light source control unit 34 may light the light source 33 for a predetermined period after the rotating electric machine 10 stops. Thereby, the photocatalyst unit 32 is activated by the light irradiated from the light source 33, and corrosive gases such as ozone, nitrogen oxides, and nitric acid present inside the terminal box 20 are decomposed.

[0025] According to the embodiment described above, the rotating electric machine 10 includes the case 15 and the terminal box 20. The case 15 houses the stator 11 and the rotor 12. The terminal box 20 communicates with the case 15. Here, for example, when the insulation on the surface of the stator winding 112 deteriorates, partial discharge occurs on the deteriorated insulation surface, and corrosive gases containing ozone, nitrogen oxides, and nitric acid are generated inside the case 15. Then, the corrosive gas flows into the terminal box 20 from the communication portion 231 between the terminal box 20 and the case 15.

[0026] Therefore, the rotating electric machine 10 of this embodiment includes a photocatalyst unit 32 and a light source 33. The photocatalyst unit 32 is provided inside the terminal box 20 and is activated by light to decompose corrosive gases. The light source 33 is also provided inside the terminal box 20 and has the function of activating the photocatalyst unit 32 by shining light on it.

[0027] In this way, by irradiating the photocatalyst unit 32 with light from the light source 33 and activating it, corrosive gases generated in the case 15 and flowing into the terminal box 20 can be decomposed by the action of the photocatalyst unit 32. As a result, corrosion of metal parts caused by corrosive gases generated by partial discharge, etc., can be effectively suppressed. Furthermore, this eliminates the need for surface treatments such as chromate treatment to protect metal parts inside the terminal box 20, such as terminal blocks, terminal screws, and crimp terminals (not shown), from corrosive gases.

[0028] The terminal box 20 is generally designed to be openable for maintenance, and therefore work can be done relatively easily inside the terminal box 20. By placing the photocatalyst unit 32 and the light source 33 inside the terminal box 20, maintenance of the photocatalyst unit 32 and the light source 33 becomes easier, and it also becomes easier for the customer to add the photocatalyst unit 32 and the light source 33 after the rotating electric machine 10 has been delivered to the customer.

[0029] The photocatalytic unit 32 is provided on the inner surface of the terminal box 20. This allows for a relatively large surface area of ​​the photocatalytic unit 32, thereby widening the area over which the photocatalytic unit 32 is effective, and consequently improving the decomposition capacity of corrosive gases by the photocatalytic unit 32.

[0030] Furthermore, the terminal box 20 has a box portion 21 fixed to the case 15 and a lid portion 22 configured to open and close relative to the box portion 21. The light source 33 is provided in the box portion 21. As a result, since the light source 33 is provided in the box portion 21 and not the lid portion 22, it is not necessary to configure the light source 33 to move in conjunction with the lid portion 22 when the lid portion 22 is opened.

[0031] This disclosure is described in accordance with the embodiments, but it is understood that this disclosure is not limited to such embodiments or structures. This disclosure also includes various modifications and variations within the equivalence. In addition, various combinations and forms, as well as other combinations and forms that include only one, more, or fewer of those elements, fall within the scope and concept of this disclosure. [Explanation of Symbols]

[0032] 10...Rotating electric machine, 11...Stator, 12...Rotor, 15...Case, 20...Terminal box, 21...Box section, 22...Lid section, 32...Photocatalyst section, 33...Light source

Claims

1. A case for housing the stator and rotor, A terminal box communicating with the aforementioned case, A photocatalyst unit is provided inside the terminal box and is activated by light to decompose corrosive gases, A light source provided inside the terminal box for activating the photocatalyst by shining light on it, A rotating electric machine equipped with the following features.

2. The photocatalytic part is provided on the inner surface of the terminal box. The rotating electric machine according to claim 1.

3. The terminal box has a box portion fixed to the case and a lid portion configured to be openable and closable relative to the box portion. The light source is provided in the box portion, The rotating electric machine according to claim 1.

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