Terminal box for rotary electric machine

Abstract

To provide a terminal box for a rotary electric machine, which can maintain a distance between an electric wire and a current detector.SOLUTION: A terminal box for a rotary electric machine includes: an electric wire; a current detector; and a support part. The electric wire is electrically connected to a stator winding of the rotary electric machine. The current detector includes a hole forming part which forms a hole through which the electric wire passes and surrounds the electric wire apart from the electric wire, and detects current flowing through the electric wire in the hole. The support part is provided in the hole, supports the electric wire and maintains a distance between the hole forming part and the electric wire in the hole to be constant.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a terminal box for a rotating electric machine. [Background technology]

[0002] A terminal box for a rotating electric machine that is provided in a rotating electric machine has been known. The terminal box for a rotating electric machine includes an electric wire and a current detector that has a hole through which the electric wire passes and that detects a current flowing through the electric wire in the hole. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7435685 [Patent Document 2] Japanese Patent Application Laid-Open No. 2024-8304 Summary of the Invention [Problem to be solved by the invention]

[0004] In this type of terminal box for a rotating electric machine, it is necessary to maintain a distance between the current detector and the electric wire to prevent a high voltage from being induced between the current detector and the electric wire, which may cause insulation breakdown in the current detector or the electric wire. However, for example, if the electric wire is relatively long, the electric wire may sag and come close to the surface of the current detector that forms the hole, making it impossible to maintain a sufficient distance between the current detector and the electric wire.

[0005] One example of a problem to be solved by the present invention is to provide a terminal box for a rotating electric machine that can maintain a distance between an electric wire and a current detector. [Means for solving the problem]

[0006] A terminal box for a rotating electric machine according to an embodiment of the present invention comprises an electric wire electrically connected to a stator winding of a rotating electric machine, a current detector having a first surface that forms a hole through which the electric wire passes and is spaced apart from the outer periphery of the electric wire and surrounds the outer periphery of the electric wire, the current detector detecting the current flowing through the electric wire, and a support portion provided inside the first surface that supports the electric wire and maintains a constant distance between the first surface and the outer periphery of the electric wire. [Effects of the Invention]

[0007] According to the terminal box for a rotating electric machine of the embodiment of the present invention, it is possible to obtain a terminal box for a rotating electric machine that can maintain a distance between the electric wire and the current detector. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating a rotating electrical machine according to an embodiment. [Figure 2] FIG. 2 is a front view showing the internal configuration of the housing of the terminal box of the rotating electric machine according to the embodiment. [Figure 3] FIG. 3 is a side view showing the internal configuration of the housing of the terminal box of the rotating electric machine according to the embodiment. [Figure 4] FIG. 4 is a cross-sectional view showing a current detector in a terminal box according to an embodiment. [Figure 5] FIG. 5 is a cross-sectional view showing a current detector in a terminal box according to a first modified example of the embodiment. [Figure 6] FIG. 6 is a cross-sectional view showing a current detector in a terminal box according to a second modified example of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments will be described with reference to the drawings. In this specification, components according to embodiments and descriptions of the components may be described using multiple expressions. The components and their descriptions are merely examples and are not limited by the expressions in this specification. The components may also be identified by names different from those in this specification. Furthermore, the components may also be described using expressions different from those in this specification.

[0010] The drawings are schematic, and the dimensional relationships and ratios of elements may differ from reality. Furthermore, the drawings may include portions in which the dimensional relationships and ratios differ from one another.

[0011] 1 is a diagram showing a rotating electric machine 1 according to this embodiment. The rotating electric machine 1 according to this embodiment is, for example, a three-phase AC induction rotating electric machine. The rotating electric machine 1 is a motor or a generator. However, the rotating electric machine 1 is not limited to the above.

[0012] 1, a rotating electric machine 1 includes a rotating electric machine main body 2 and a terminal box 3. The terminal box 3 is an example of a terminal box for a rotating electric machine.

[0013] The rotating electrical machine body 2 includes a housing 11 , a stator 12 , a shaft 13 , and a rotor 15 .

[0014] The housing 11 is formed into a box shape from, for example, metal. However, the housing 11 may be formed from other materials. The housing 11 houses the stator 12, a part of the shaft 13, and the rotor 15. The housing 11 is formed, for example, by combining a plurality of members.

[0015] The stator 12 has a stator core and a plurality of stator windings 14. The stator core is fixed to the housing 11. Note that only one stator winding 14 is shown in FIG. 1. The stator core is located radially outside the rotor 15 and is formed in a cylindrical shape surrounding the rotor 15. The stator winding 14 passes through a plurality of slots formed in the stator core and extends in the axial direction, and is fixed to the stator core. The stator winding 14 is electrically connected to a conductive portion 22 (FIG. 2) of the terminal box 3 via an electric wire 4, and power is exchanged between the stator winding 14 and the conductive portion 22 of the terminal box 3.

[0016] Shaft 13 is rotatably supported by housing 11 via two bearings. In other words, the two bearings support shaft 13 rotatably relative to housing 11. Shaft 13 extends through housing 11. One end of shaft 13 is coupled to, for example, various external devices. As a result, the rotation of shaft 13 drives the external devices.

[0017] The rotor 15 is housed inside the housing 11. The rotor 15 is formed in a generally cylindrical shape extending in the axial direction of the shaft 13, and is disposed generally concentrically with the stator 12. The rotor 15 is disposed inside the stator 12 with a gap therebetween. The rotor 15 has, for example, a plurality of permanent magnets. The rotor 15 is coupled to the shaft 13 and rotates integrally therewith.

[0018] The configurations of stator 12 and rotor 15 are not limited to those described above as long as they can generate rotational force using electromagnetic force. For example, rotor 15 may have a rotor core made of a magnetic material and a conductor attached to the rotor core.

[0019] As shown in FIG. 1, the terminal box 3 is located outside the rotating electrical machine body 2 and attached to the housing 11.

[0020] Fig. 2 is a front view showing the internal configuration of the housing 21 of the terminal box 3 of the rotating electric machine 1 of the embodiment. Fig. 3 is a side view showing the internal configuration of the housing 21 of the terminal box 3 of the rotating electric machine 1 of the embodiment.

[0021] 2 and 3, the terminal box 3 includes a housing 21, a conductive part 22, a current detector 23, and a support part 51. The housing 21 is fixed to the housing 11 of the rotating electric machine main body 2. The housing 21 houses the conductive part 22, the current detector 23, and the support part 51.

[0022] The conductive parts 22 and the current detectors 23 are provided corresponding to the three phases, respectively. That is, three conductive parts 22 and three current detectors 23 are provided.

[0023] The conductive part 22 has electric wires 31, 32 and connecting members 34, 35. The electric wires 31, 32 are lead wires (power cables). The electric wire 31 is supported by the housing 21 via a support part 33. The electric wire 31 is electrically connected to the stator winding 14 via an electric wire 4. The electric wire 32 is electrically connected to the electric wire 31 via connecting members 34, 35. One end (upper end) on the upper side of the electric wire 32 is fixed to the connecting member 35, and the other end of the electric wire 32 is electrically connected to an external device such as a power supply device outside the housing 21. The electric wire 32 is wired so as to extend downward from one end and curve toward the horizontal direction. At least a portion of the electric wire 32 extends in a direction intersecting (for example, perpendicular to) the vertical direction.

[0024] Fig. 4 is a cross-sectional view showing the current detector 23 in the terminal box 3 of the embodiment. The current detector 23 is, for example, a known winding type current detector (a CT (Current Transformer) type that converts magnetic flux into current). As shown in Fig. 4, the current detector 23 has a hole forming portion 42a that forms a hole 42b through which the electric wire 32 passes and surrounds the electric wire 32 while being spaced apart from the electric wire 32. The current detector 23 detects the current flowing through the electric wire 32 within the hole 42b.

[0025] For example, current detector 23 has detection unit 41, circuit unit 43, and circuit unit 44. Detection unit 41 detects magnetic flux generated by a current passing through electric wire 32. Circuit unit 43 generates a voltage whose amplitude is proportional to the magnitude of the magnetic flux. Circuit unit 44 detects (measures) the current based on the voltage generated by circuit unit 43. In this way, current detector 23 detects (measures) the current (current value) flowing through electric wire 32 from the magnetic flux (magnetic field) generated by electromagnetic induction caused by the current flowing through electric wire 32.

[0026] The detection unit 41 includes, for example, a case 42, an annular magnetic core (not shown), and a winding (not shown) provided on the magnetic core. The case 42 houses the magnetic core and the winding. The magnetic core is formed in an annular shape around the central axis Ax and is housed in the case 42. The electric wire 32 passes through the inside of the magnetic core.

[0027] As shown in FIG. 4, the case 42 is formed in an annular (circular) shape around the central axis Ax. The case 42 is provided with a hole 42b penetrating the case 42 (terminal box 3). The hole 42b penetrates the case 42 in a direction intersecting (for example, perpendicular to) the vertical direction. The electric wire 32 is inserted in the hole 42b. The electric wire 32 penetrates through the hole 42b. The case 42 has a hole-forming portion 42a that forms the hole 42b and surrounds the electric wire 32 while being spaced apart from the electric wire 32. The hole-forming portion 42a is an annular surface (cylindrical surface) around the central axis Ax. A magnetic core is disposed radially outside the hole-forming portion 42a, and the hole-forming portion 42a is surrounded by the magnetic core. Note that the current detector 23 is not limited to the above.

[0028] The support portion 51 is provided in the hole 42b, supports the electric wire 32, and maintains a constant distance L1 between the hole forming portion 42a and the electric wire 32 in the hole 42b. The support portion 51 is made of an insulating material, such as a material containing glass fiber or rubber. The support portion 51 extends in the extension direction of the hole 42b (the direction along the central axis Ax) and has a generally semicircular cross section that fills the lower half of the hole 42b. The support portion 51 supports the electric wire 32 on the lower side of the electric wire 32. A recess 51a is provided on the upper surface of the support portion 51. A portion of the electric wire 32 is inserted in the recess 51a. That is, the support portion 51 is interposed between the hole forming portion 42a and the electric wire 32 on the vertically lower side of the electric wire 32 (direction D in the figure). The support portion 51 is, for example, interposed between the hole forming portion 42a and the electric wire 32, and is in contact with the hole forming portion 42a and the outer peripheral surface 32a of the electric wire 32. The support portion 51 restricts (prevents) movement of the electric wire 32 within the hole 42b (for example, vertically downward or horizontally).

[0029] The current detector 23 configured as described above detects current when the rotary electric machine 1 is in normal operation, testing, inspection, etc.

[0030] As described above, the terminal box 3 (terminal box for a rotating electric machine) of this embodiment includes the electric wire 32, the current detector 23, and the support portion 51. The electric wire 32 is electrically connected to the stator winding 14 of the rotating electric machine 1. The current detector 23 has a hole forming portion 42a that forms a hole 42b through which the electric wire 32 passes and surrounds the electric wire 32 while being spaced apart from the electric wire 32, and detects the current flowing through the electric wire 32 in the hole 42b. The support portion 51 is provided within the hole 42b, supports the electric wire 32, and keeps the distance L1 constant between the hole forming portion 42a and the electric wire 32 in the hole 42b.

[0031] With this configuration, the hole forming portion 42a can maintain a constant distance L1 between the electric wire 32 and the current detector 23. That is, a predetermined distance L1 can be ensured between the hole forming portion 42a and the electric wire 32 in the hole 42b, preventing a high voltage from being induced between the hole forming portion 42a and the electric wire 32. This can prevent a high voltage from being induced between the current detector 23 and the electric wire 32, thereby preventing a breakdown in the current detector 23 or the electric wire 32.

[0032] The hole 42b and the electric wire 32 extend in a direction intersecting (for example, perpendicular to) the vertical direction. The support portion 51 is interposed between the hole forming portion 42a and the electric wire 32 below the electric wire 32 in the vertical direction (direction D).

[0033] According to this configuration, the hole forming portion 42a can prevent the electric wire 32 from sagging due to gravity.

[0034] Next, a modified example will be described.

[0035] Fig. 5 is a cross-sectional view showing the current detector 23 in the terminal box 3 of the first modified example of the embodiment. As shown in Fig. 5, in this modified example, the support portion 51 is annular and fills the gap between the hole forming portion 42a and the electric wire 32. That is, the support portion 51 is annular (cylindrical) about the central axis Ax, and the support portion 51 is provided with a hole 51b that passes through the support portion 51. The electric wire 32 is inserted into the hole 51b.

[0036] According to this configuration, the hole forming portion 42a can keep the distance L1 between the electric wire 32 and the current detector 23 constant.

[0037] FIG. 6 is a cross-sectional view showing a current detector 23 in a terminal box 3 of a second modified example of the embodiment. As shown in FIG. 6, this modified example differs from the first modified example in that a plurality of (for example, two) electric wires 32 are inserted into the hole 42b of the current detector 23. One of the two electric wires 32 is, for example, a ground wire branched from the other electric wire 32. The support part 51 has a hole 51b formed therein, one for each electric wire 32. That is, the support part 51 has a plurality of holes 51b formed therein. Note that, as the plurality of electric wires 32, electric wires 32 of two or more of the three phases may be inserted into the hole 42b of one current detector 23.

[0038] According to this configuration, the hole forming portion 42a can keep the distance L1 between each electric wire 32 and the current detector 23, and the distance between the plurality of electric wires, constant.

[0039] In the above embodiment, the support portion 51 may be configured to suspend the electric wire 32.

[0040] Although the embodiments of the present invention have been described above, the above embodiments are merely examples and are not intended to limit the scope of the invention. The above embodiments can be implemented in various other forms, and various omissions, substitutions, combinations, and modifications can be made without departing from the spirit of the invention. Furthermore, the specifications of each configuration, shape, and the like (structure, type, direction, format, size, length, width, thickness, height, number, arrangement, position, material, etc.) can be modified as appropriate. [Explanation of symbols]

[0041] 1...rotating electric machine, 3...terminal box (terminal box for rotating electric machine), 14...stator winding, 32...electric wire, 23...current detector, 42a...hole forming portion, 42b...hole, 51...support portion, L1...distance.

Claims

1. an electric wire electrically connected to a stator winding of the rotating electric machine; a current detector having a hole forming portion that forms a hole through which the electric wire passes and is spaced apart from the electric wire and surrounds the electric wire, the current detector detecting a current flowing through the electric wire within the hole; a support portion provided in the hole, supporting the electric wire and maintaining a constant distance between the hole forming portion and the electric wire in the hole; A terminal box for a rotating electric machine comprising:

2. the hole and the electric wire extend in a direction intersecting the vertical direction, The support portion is interposed between the hole forming portion and the electric wire below the electric wire in the vertical direction. The terminal box for a rotating electric machine according to claim 1.

3. The support portion is annular and fills the gap between the hole forming portion and the electric wire.

3. The terminal box for a rotating electric machine according to claim 1 or 2.

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