JP2016116407A - Rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve workability of an operation to replace an earth brush of a rotary electric machine.SOLUTION: A rotary electric machine 100 has: a rotor 10 having a rotor shaft 11 and a rotor core 12; a stator 20 having a stator core 21 and a stator coil 22; and grounding devices 38, 40 for preventing static electricity from being accumulated in the rotator 10. The grounding devices 38, 40 each have an earth brush fixed stationarily to the rotor shaft 11 in a pressed state; a support bracket stationarily supporting the earth brush on the rotor shaft 11 in a pressed state; a brush presser supported rotatably on the support bracket and pressing the earth brush against the rotor shaft 11; and a driving support part 44 formed to move the support bracket between an installation place and a radially outer side.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a rotating electrical machine having a ground brush.

  In a rotor shaft of a rotating electrical machine, a voltage called a shaft voltage is generated between the shaft end face or the bearings. The generation factors of the shaft voltage include electromagnetic induction action due to magnetomotive force and magnetic path imbalance, electrostatic induction action, and electrostatic charge accumulation.

  Even when driven by a sine wave power supply, the shaft voltage is somewhat generated depending on the above-mentioned action and the capacity of the rotating electrical machine. There is a tendency to increase.

  When the shaft voltage is increased in a rotating electrical machine, current flows due to discharge or energization through an oil film or a grease film, which may cause damage to the shaft or the bearing.

  For this reason, in a rotating electrical machine in which a situation in which the shaft voltage becomes high is likely to occur, a grounding device is provided in the vicinity of one of the two bearings. The grounding device includes an earth brush that is stationaryly supported and contacts the rotor shaft, and a holding portion that is stationaryly supported and presses the earth brush against the rotor shaft (Patent Document 1). The holding part is held by the bracket, and measures are taken to drop the current to the bearing bracket (ground) so that the current does not flow to the bearing.

Japanese Utility Model Publication No. 63-97358

  The ground brush is worn because it maintains a pressure-bonded state on the rotating rotor shaft. For this reason, it is necessary to replace it when a predetermined wear amount is reached.

  In the case of a rotating electrical machine having an external fan, the grounding device provided in the vicinity of the bearing near the external fan is provided in the space between the frame and the external fan cover. For this reason, an opening for taking in and out for accessing the grounding device and taking in and out the earth brush is formed in the outer fan cover.

  Therefore, when exchanging the earth brush, the earth brush is taken out via the opening for taking in and out, and the earth brush for exchanging is inserted. Also, the removal and attachment of the earth brush is done by inserting a hand through the opening for taking in and out. For this reason, there existed a subject that workability | operativity was not good and there was a possibility of hurting a hand depending on the case and it was necessary to improve workability | operativity.

  Accordingly, an object of the present invention is to improve the workability of replacing the earth brush in a rotating electrical machine.

  In order to achieve the above-described object, a rotating electrical machine according to the present invention includes a rotor shaft that is rotatably supported and extends in the axial direction at the center of the rotating shaft, and a rotor core provided outside the rotor shaft. A stator having a rotor, a stator core disposed radially outside the rotor shaft, a stator coil provided in a slot formed in the stator core, and static electricity to the rotor An earthing brush that is fixedly fixed to the rotor shaft in a pressure-bonded state, and a support bracket that statically supports the earth brush on the rotor shaft in a pressure-bonded state. And a brush presser that is rotatably supported by the support bracket and presses the earth brush so that the earth brush is crimped to the rotor shaft; Serial to the support bracket and the installation location and the driving support part that is movably formed between the radially outer, characterized in that it has a.

  ADVANTAGE OF THE INVENTION According to this invention, workability | operativity of the replacement | exchange operation | work of an earth brush can be improved in a rotary electric machine.

It is a longitudinal cross-sectional view of the rotary electric machine which concerns on embodiment. It is a fragmentary longitudinal cross-section which shows the grounding apparatus part of the II-II arrow of FIG. FIG. 3 is a partial cross-sectional view showing a grounding device portion taken along line III-III in FIG. 2. It is a conceptual diagram for demonstrating a structure and operation | movement of the drive support part of the grounding apparatus of the rotary electric machine which concerns on embodiment.

  Hereinafter, a squirrel-cage induction motor according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a longitudinal sectional view of a rotating electrical machine according to an embodiment. The rotating electrical machine 100 includes a rotor 10, a stator 20, a frame 31, an outer fan side bearing 32, a coupling side bearing 33, an outer fan fan 35, and an outer fan cover 37.

  The rotor 10 includes a rotor shaft 11, a rotor core 12, a rotor bar 13, and a short-circuit ring 14. The rotor shaft 11 is rotatably supported around the main shaft and extends in the main shaft direction. The rotor core 12 has a central opening formed through the rotor shaft 11 in the center, and has a cylindrical shape in which, for example, ferromagnetic silicon steel plates are laminated in the main axis direction. Further, the rotor core 12 is formed with through holes (not shown) spaced in the circumferential direction on the outer side in the radial direction of the central opening and in the vicinity of the outer side in the radial direction of the rotor core 12.

  The rotor bar 13 is a conductor and is provided in each of the through holes. The short-circuit ring 14 is an annular conductor that electrically connects the rotor bars 13 protruding from both axial ends of the rotor core 12.

  The stator 20 has a stator core 21 and a stator coil 22. The stator core 21 is mainly made of a ferromagnetic material, is provided on the radially outer side of the rotor core 12, and faces the rotor core 12 with a gap. The stator coil 22 includes a conductor housed in a slot (not shown) formed in the stator core 21 and extending in the main axis direction, and a connection portion outside the stator core 21.

  The frame 31 houses the rotor core 12 and the stator 20. A coupling side bearing 33 on the coupling 11a side, which is a coupling portion between the outer fan side bearing 32 and a rotating machine (not shown), rotatably supports both sides of the rotor shaft 11 in the main axis direction. The outer fan side bearing 32 and the coupling side bearing 33 are each fixedly fixed by a frame 31.

  An outer fan fan 35 is attached to the outer side in the axial direction of the portion of the rotor shaft 11 supported by the outer fan side bearing 32. A part of the frame 31 and the outer fan fan 35 are covered with an outer fan cover 37. A part of the outer fan cover 37 on the suction side of the outer fan fan 35 is formed with a suction port 37b for the atmospheric gas for cooling. Further, the outer fan cover 37 is provided with a handling opening 37a for handling a ground brush of a support bracket 43 (FIGS. 2 and 3) described later, and a cover is occupied except during handling.

  A coupling side grounding device 38 is provided between the coupling side bearing 33 and the coupling portion 11a. An outer fan side grounding device 40 is provided between the outer fan fan 35 and the outer fan side bearing 32. The outer fan side grounding device 40 has a drive support portion 44. The drive support portion 44 will be described with reference to FIG.

  FIG. 2 is a partial longitudinal sectional view showing a grounding device portion taken along line II-II in FIG. 3 is a partial cross-sectional view showing a grounding device portion taken along line III-III in FIG. The outer fan side grounding device 40 includes a ground brush 41, a brush press 42, a support bracket 43, and a drive support portion 44.

  The ground brush 41 is stationary and fixed by a support bracket 43. One surface of the ground brush 41 is pressure-bonded to the surface of the rotor shaft 11 by a brush presser 42 fixedly supported by the support bracket 43. In the rotating state of the rotor shaft 11, the sliding state between the surface of the earth brush 41 and the surface of the rotor shaft 11 is maintained.

  The drive support unit 44 includes a movement support unit 45 and a drive unit 46 that moves and drives the support bracket 43 that is fixedly supported by the movement support unit 45. The movement support portion 45 extends radially outward from the vicinity of the surface of the rotor shaft 11 and reaches the vicinity of the handling opening 37a of the outer fan cover 37 (FIG. 1). The movement support unit 45 incorporates a rotation shaft 45a that rotates about an axis extending in the axial direction. The rotation shaft 45 a is formed with a screw and is driven to rotate by the drive unit 46.

  FIG. 4 is a conceptual diagram for explaining the configuration and operation of the drive support portion 44. The movement support unit 45 includes a rotary shaft 45a, a bearing 45b, a second gear for deceleration 45c, and an axial direction movement transmission unit 45d. In order to replace the ground brush 41, the support bracket 43 holding the ground brush 41 is moved outward in the radial direction. This moving direction is referred to as a brush moving direction.

  The rotating shaft 45a extends in the brush moving direction, and both ends thereof are pivotally supported by bearings 45b so as to be rotatable without moving in the brush moving direction. The rotating shaft 45a is configured to be rotatable in both forward and reverse directions. A male screw is formed in a portion sandwiched between both bearings 45b of the rotary shaft 45a. The second reduction gear 45c is provided outside the bearing on one side of the rotating shaft 45a.

  A through hole through which the rotation shaft 45a passes is formed in the axial direction movement transmission portion 45d. A female screw corresponding to the male screw formed on the rotary shaft 45a is formed at a portion of the through hole facing the rotary shaft. The axial direction movement transmission part 45 d is coupled to the support bracket 43. The support bracket 43 is configured to be movable only in the brush moving direction by a guide portion (not shown). For this reason, due to the rotation of the rotation shaft 45a, the axial direction movement transmission portion 45d and the support bracket 43 coupled thereto move in the brush movement direction without rotating in a plane perpendicular to the brush movement direction.

  The drive unit 46 includes a drive motor 46a and a first reduction gear 46b. The drive motor 46a can rotate in either forward or reverse direction, and rotates the first reduction gear 46b. The first reduction gear 46b transmits the rotation to the second reduction gear 45c and rotates the rotary shaft 45a. In addition, although the case where the drive motor 46a is reversed in order to reverse the rotation direction of the rotating shaft 45a has been shown, the present invention is not limited to this. For example, at the time of reverse rotation, the system may be switched to a system via a gear (not shown) between the first reduction gear 46b and the second reduction gear 45c.

  In this embodiment, in order to move the support bracket 43 that holds the earth brush 41 between the mounting position near the surface of the rotor shaft 11 and the inner surface of the outer fan cover 37, a rotating shaft or the like on which a male screw is formed is used. Although the case of the method used was shown, it is not limited to this. For example, any method that can move, including a method using a caterpillar, may be used.

  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. The embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope 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 core, 13 ... Rotor bar, 14 ... Short-circuit ring, 15 ... Inner fan, 20 ... Stator, 21 ... Stator core, DESCRIPTION OF SYMBOLS 22 ... Stator coil, 31 ... Frame, 32 ... Outer fan side bearing, 33 ... Coupling side bearing, 35 ... Outer fan fan, 37 ... Outer fan cover, 37a ... Handling opening, 37b ... Suction port, 38 ... Coupling Side grounding device, 40 ... Outer fan side grounding device, 41 ... Ground brush, 42 ... Brush presser, 43 ... Support bracket, 44 ... Drive support, 45 ... Moving support, 45a ... Rotating shaft, 45b ... Bearing, 45c ... Second gear for reduction, 45d ... Axial direction movement transmission part, 46 ... Drive part, 46a ... Drive motor, 46b ... First gear for reduction, 100 ... Rotary electric machine

Claims (3)

A rotor having a rotor shaft that is rotatably supported and extends in the axial direction at the center of the rotation axis, and a rotor core provided outside the rotor shaft;
A stator having a stator core disposed radially outside the rotor shaft, and a stator coil provided in a slot formed in the stator core;
A grounding device for preventing static electricity from accumulating on the rotor;
With
The grounding device is
An earth brush that is stationary and fixed to the rotor shaft in a crimped state;
A support bracket for stationaryly supporting the earth brush on the rotor shaft in a pressure-bonded state;
A brush presser that is rotatably supported by the support bracket and presses the earth brush so that the earth brush is crimped to the rotor shaft;
A drive support portion formed so as to be movable between an installation location and the radially outer side of the support bracket;
A rotating electric machine comprising: The drive support portion is
A moving support portion that movably supports the support bracket and extends radially outward;
A drive unit for moving and driving the support bracket along the moving support unit;
The rotating electrical machine according to claim 1, comprising: The movement support portion is configured to restrain the support bracket to be movable in the longitudinal direction by a built-in axially extending rotary shaft.
The rotating electrical machine according to claim 2, wherein the driving unit rotationally drives the rotating shaft.

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