JP2017127155A - Electric motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric motor capable of maintaining a conduction state between a frame and a terminal box.SOLUTION: An electric motor in an embodiment includes: a conductive cylindrical frame 1 in which a motor body is stored; a pedestal base 9 which protrudes from the outer peripheral surface of the frame 1; a conductive terminal box 23 which is disposed on the front end of the pedestal base 9 being interposed by an insulative packing 17; a plurality of terminals 7 which are disposed in the terminal box 23 and wired to the motor body through the pedestal base 9; and a metal plate earth metal fitting which is disposed in the pedestal base 9 which maintains a conduction state between the terminal box 23 and the frame 1.SELECTED DRAWING: Figure 1

Description

  The embodiment relates to an electric motor.

  Some electric motors have a motor body housed in a cylindrical frame, and the wiring of the motor body is drawn out of the frame through the frame. The frame is provided with a pedestal protruding from the outer peripheral surface, and the wiring of the motor body is inserted into the pedestal. A terminal box is provided at the tip of the pedestal via an insulating packing. Terminals are provided in the terminal box, and the wiring of the motor body is connected to the terminals in the terminal box through the pedestal.

Japanese Patent Laid-Open No. 10-117458 JP 2009-118602 A

  In the case of the above-described conventional electric motor, a ground wire is accommodated in the pedestal, and the frame and the terminal box are electrically connected to each other by connecting the ground wire with the ground wire. Therefore, there is a possibility that the coating of the ground wire is deteriorated or the core wire is disconnected due to secular change, and it is difficult to keep the conduction between the frame and the terminal box in a healthy state for many years.

  The electric motor of the embodiment includes a motor main body and a conductive cylindrical frame, a pedestal protruding from the outer peripheral surface of the frame, and an insulating packing at the front end of the pedestal. A terminal box having electrical conductivity, a terminal box provided in the terminal box and wired in the motor body through the pedestal, and provided in the pedestal. There are "connection plate" and "a terminal box side plate connected to the terminal box that is provided at one end of the connection plate" and "is provided at the other end of the connection plate. The terminal box side plate and the frame side plate intersect each other with respect to the connecting plate. The metal plate has a metal plate having a frame side plate connected to the frame.

The figure which shows Example 1 (The figure which shows an electric motor in the fracture | rupture state of a base and a terminal box) Diagram showing the internal configuration of the terminal box Illustration showing the grounding bracket Figure showing an enlarged view of the grounding bracket installation

  The motor frame 1 shown in FIG. 1 has a horizontal cylindrical shape with both end faces opened, and corresponds to a frame. The motor frame 1 is formed by casting conductive aluminum and has a plurality of cooling fins 2. Two legs 3 are fixed to the motor frame 1. Each of these legs 3 has conductivity, and projects downward from the outer peripheral surface of the motor frame 1. Screws 4 are inserted into the both legs 3, and the motor frame 1 is fixed by screwing both screws 4 to the installation surface.

  A motor body is accommodated in the motor frame 1. The motor body is a three-phase synchronous reluctance motor and has a stator and a rotor. The rotor is formed by fixing a horizontal rotating shaft to the rotor core, and the stator is formed by winding a three-phase stator winding around the stator core. As shown in FIG. 1, one end portion of the lead wire 6 is connected to each of these three-phase stator windings, and a crimp terminal 7 is connected to the other end portion of each of the three-phase lead wires 6. It is connected.

  The stator core is shrink-fitted on the inner peripheral surface of the motor frame 1, and a rivet is driven into the stator core from the outside of the motor frame 1 through the motor frame 1. This stator core is fixed in the motor frame 1 by shrink fitting and scissors, and the rotor core is accommodated in the stator core.

  As shown in FIG. 1, two brackets 8 are fixed to the motor frame 1. Each of these brackets 8 is formed by pouring molten cast iron into a mold. One bracket 8 covers one end surface of the motor frame 1 from the axial direction, and the other bracket 8 is the motor frame 1. Is covered from the axial direction. Each of these brackets 8 is provided with a bearing. One bearing rotatably supports one end portion of the rotating shaft, and the other bearing rotatably supports the other end portion of the rotating shaft.

  As shown in FIG. 1, a pedestal 9 is fixed to the motor frame 1. The pedestal 9 has a hollow shape, and the cross section is set to a square shape. The pedestal 9 is made of a conductive metal and protrudes horizontally from the outer peripheral surface of the motor frame 1. An opening 10 is formed in the motor frame 1. The opening 10 connects the inside of the base 9 to the motor frame 1, and the other end of the three-phase lead wire 6 is drawn into the base 9 from the motor frame 1 through the opening 10.

  As shown in FIG. 1, a connection seat 11 is fixed to the motor frame 1. The connection seat 11 is made of a conductive metal and is electrically connected to the motor frame 1. The connection seat 11 has a cylindrical shape, and an internal thread is formed on the inner peripheral surface of the connection seat 11. The connection seat 11 protrudes horizontally from the outer peripheral surface of the motor frame 1 and is disposed in the base 9.

  As shown in FIG. 1, a terminal block 12 is fixed to the pedestal 9. The terminal block 12 is made of an insulating and flame retardant synthetic resin and has a plurality of mounting seats 13. Each of the plurality of mounting seats 13 has a cylindrical shape protruding from the outer peripheral surface of the terminal block 12, and a screw 14 is inserted into each of the plurality of mounting seats 13 from the side opposite to the base 9. .

  As shown in FIG. 1, each of the plurality of screws 14 is screwed into the tap hole of the base 9 through the frame side case 15. The frame side case 15 is interposed between the base 9 and the terminal base 12, and a plurality of screws 14 fix the terminal base 12 to the base 9 together with the frame side case 15. The frame-side case 15 is made of a conductive metal, and one surface on the side opposite to the base 9 is open. An opening 16 is formed in the frame side case 15, and the three-phase lead wire 6 is inserted into the frame side case 15 from the pedestal 9 through the opening 16.

  A packing 17 is interposed between the base 9 and the frame side case 15 as shown in FIG. The packing 17 is made of insulating rubber and has a quadrangular ring shape. The packing 17 is elastically crushed by the fastening force of the plurality of screws 14, and is in close contact with each of the base 9 and the frame side case 15 with elastic restoring force.

  As shown in FIG. 2, a three-phase terminal plate 18 is attached to the terminal block 12. Each of these three-phase terminal plates 18 is formed with a tap hole, and each of the three-phase lead wires 6 is screwed into a tap hole of the terminal plate 18 through a crimping terminal 7 from the side opposite to the base 9. It is connected to the terminal board 18 according to the match. Each of these three-phase terminal boards 18 is screwed with screws 20, and each of the three-phase external power supply lines is connected to the terminal board 18 via the screws 20. Each of these three-phase terminal boards 18 corresponds to a terminal.

  As shown in FIG. 1, a terminal box cover 21 is fixed to the frame side case 15. The terminal box cover 21 is made of a conductive metal, and the frame is formed by screwing each of the plurality of screws 22 from the opposite side of the base 9 to the frame side case 15 through the terminal box cover 21. It is joined to the side case 15. The frame side case 15 and the terminal box cover 21 constitute a hollow terminal box 23, the terminal block 12 is accommodated in the terminal box 23, and the other end of each of the plurality of lead wires 6 is a terminal box. 23 is connected to the terminal plate 18 of the terminal block 12.

Next, the ground structure between the motor frame 1 and the terminal box 23 will be described.
3 is made of a conductive metal and has a terminal block side plate 31, a frame side plate 32, and a connecting plate 33. The connecting plate 33 has a horizontal flat plate shape, the terminal block side plate 31 has a rectangular shape directed downward from one end of the connecting plate 33, and the frame side plate 32 is directed downward from the other end of the connecting plate 33. It has a rectangular shape. Each of the terminal block side plate 31 and the frame side plate 32 is substantially orthogonal to the connecting plate 33, and the frame side plate 32 is set to have a smaller vertical dimension than the terminal block side plate 31.

  As shown in FIG. 3, the frame side plate 32 faces the base end portion of the terminal block side plate 31 in parallel, and is inserted into the terminal block side plate 31 at a portion not facing the frame side plate 32 in a circular shape. A hole 34 is formed. As shown in FIG. 4, a screw 36 is inserted into the insertion hole 34 from the opposite side of the base 9 through a washer 35, and the screw 36 is screwed into the tap hole of the base 9 through the frame side case 15. Are combined. The screw 36 fixes the terminal block side plate 31 to the pedestal 9, and the terminal block side plate 31 is electrically connected to the frame side case 15 according to being fixed to the pedestal 9.

  As shown in FIG. 3, an insertion hole 37 is formed in the frame side plate 32. The insertion hole 37 has a circular shape and is disposed at a higher position than the insertion hole 34 of the terminal block side plate 31. As shown in FIG. 4, a screw 39 is inserted into the insertion hole 37 via a washer 38, and the screw 39 is screwed into the connection seat 11 of the motor frame 1. The screw 39 fixes the frame side plate 32 to the connection seat 11, and the frame side plate 32 is electrically connected to the motor frame 1 in accordance with being fixed to the connection seat 11. In other words, the grounding metal 30 is a conductive state between the terminal box 23 and the motor frame 1, and the terminal box 23 is grounded via the grounding metal 30 and the motor frame 1.

  As shown in FIG. 3, a circular work hole 40 is formed in the terminal block side plate 31. The work hole 40 faces the insertion hole 37 of the frame side plate 32 from the horizontal direction, and the center of the work hole 40 and the center of the insertion hole 37 are arranged on a common horizontal line HL. The diameter of the working hole 40 is set to be larger than that of each of the washer 38 and the head of the screw 39, and the screw 39 is allowed to pass through the working hole 40 with the washer 38 attached. The diameter of the working hole 40 is set larger than that of the tool. This tool is for screwing the screw 39 into the connection seat 11, and the tool can be inserted into the work hole 40.

  As shown in FIG. 3, a coating layer 41 made of a synthetic resin is formed on the ground metal fitting 30. The coating layer 41 serves to prevent the earth metal fitting 30 from rusting, and is formed on the surface of the earth metal fitting 30 other than the contact portions with respect to the washer 35, the frame side case 15, the washer 38, and the connection seat 11. The coating layer 41 corresponds to a film.

According to the said Example 1, there exists the following effect.
The motor frame 1 and the terminal box 23 were electrically connected to each other according to the connection between the motor frame 1 and the terminal box 23 by a metal plate ground metal fitting 30. Therefore, since the coating of the ground wire is not deteriorated or the core wire is not broken due to secular change, the conduction between the motor frame 1 and the terminal box 23 can be kept healthy for many years.

  Since each of the terminal box side plate 31 and the frame side plate 32 of the ground metal 30 is set in a flat plate shape that intersects the connection plate 33 at a right angle, the entire shape of the ground metal 30 is bent. Accordingly, since the rigidity of the grounding metal 30 is increased, it is possible to prevent the grounding metal 30 from being deformed by an external force when the grounding metal 30 is connected to the connection seat 11 and the terminal box 23.

  Since the work hole 40 is provided in the terminal box side plate 31, the screw 39 is inserted into the connection seat 11 from the work hole 40 through the insertion hole 37 of the frame side plate 32 with the washer 38 attached, and the tool is inserted into the work hole 40. The screw 39 can be tightened into the connection seat 11 in accordance with the insertion. Accordingly, the operation of connecting the terminal box side plate 31 to the terminal box 23 with the screws 36 and the operation of connecting the frame side plate 32 to the motor frame 1 with the screws 39 are performed from the side opposite to the base 9 in the opened state of the frame side case 15. Since it can be performed, the connection work of the ground metal fitting 30 is simplified.

Since the coating layer 41 is provided on the surface of the grounding metal 30, it is possible to prevent rusting from occurring in the grounding metal 30.
In the first embodiment, a motor body different from the three-phase synchronous reluctance motor may be accommodated in the motor frame 1.

In the first embodiment, the position between the terminal box side plate 31 and the frame side plate 32 of the ground metal fitting 30 may be shifted in the circumferential direction.
In the first embodiment, the terminal box side plate 31 of the ground metal fitting 30 is protruded upward or downward from the connection plate 33, and the frame side plate 32 of the ground metal fitting 30 is protruded from the connection plate 33 upward or downward. Also good.

In the first embodiment, at least one of the terminal box side plate 31 and the frame side plate 32 of the ground metal fitting 30 may intersect the connecting plate 33 at a non-right angle.
In the first embodiment, instead of the coating layer 41, a film made of rubber or elastomer may be used.

  As mentioned above, although the Example of this invention was described, this Example is shown as an example and is not intending limiting the range of invention. These novel 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. These embodiments and modifications thereof are included in the scope and gist of the invention and are also included in the invention described in the claims and the equivalent scope thereof.

  1 is a motor frame (frame), 9 is a pedestal, 17 is packing, 18 is a terminal plate (terminal), 23 is a terminal box, 30 is a grounding metal fitting, 31 is a terminal box side plate, 32 is a frame side plate, 33 is a connecting plate, Reference numeral 34 denotes an insertion hole, 36 denotes a screw, 37 denotes an insertion hole, 39 denotes a screw, 40 denotes a work hole, and 41 denotes a coating layer (film).

Claims (3)

A motor main body is housed, and has a cylindrical frame having conductivity,
A pedestal protruding from the outer peripheral surface of the frame;
A terminal box having electrical conductivity, which is provided at the tip of the pedestal via an insulating packing,
A terminal provided in the terminal box, the terminal wired in the motor body through the pedestal;
Provided in the pedestal, the "connecting plate" and "the terminal box side plate provided at one end of the connecting plate and connected to the terminal box" and "other than the connecting plate A metal plate grounding metal fitting having a frame side plate provided at an end and connected to the frame,
Each of the terminal box side plate and the frame side plate intersects the connecting plate. The terminal box side plate and the frame side plate are opposed to each other,
The frame side plate is provided with an insertion hole into which a screw for connecting the frame side plate to the frame is inserted,
The terminal box side plate is inserted with a work hole for inserting a screw of the frame side plate through an insertion hole of the frame side plate through the terminal box side plate and a screw for connecting the terminal box side plate to the terminal box. The electric motor according to claim 1, wherein an insertion hole is provided.   3. The electric motor according to claim 1, wherein a coating for preventing rusting of the grounding metal is provided on a surface of the grounding metal.

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