JP6629599B2 - Electric motor - Google Patents

Description

  The embodiment relates to an electric motor.

  There is an electric motor in which a motor main body is housed in a cylindrical frame, and wiring of the motor main body is drawn out of the frame through the frame to the outside of the frame. The frame is provided with a pedestal projecting 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 main body is connected to terminals in the terminal box through the pedestal.

JP-A-10-117458 JP 2009-118602 A

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

The electric motor of the embodiment is a motor-contained, housed, cylindrical frame having conductivity, a pedestal protruding from the outer peripheral surface of the frame, and an insulating packing at a tip end of the pedestal. a terminal box with provided ones in a a conductive, a terminal that is wired to the motor main body through be those provided in the terminal box in the pedestal, metals provided in the pedestal A grounding bracket made of a plate is provided . The grounding bracket is formed by bending a strip-shaped metal plate into a U-shape, and is connected to the frame side plate connected to the frame by screws and to the terminal box by screws. Terminal box side plate, and a connecting plate that connects the base end of the frame side plate and the base end of the terminal box side plate, and the terminal box side plate is configured to be longer than the frame side plate. , The frame The side plate is provided with a screw insertion hole, and the terminal box side plate is provided with a screw insertion hole on the distal end side, and a working hole on the base end side into which a tool for screwing the frame side plate can be inserted. The frame side plate is screwed to the frame from the terminal box side plate side through the work hole, and the terminal box side plate is configured to be screwed to the terminal box from the same direction. .

FIG. 2 is a view showing the first embodiment (a view showing the electric motor in a broken state of a base and a terminal box). Diagram showing the internal configuration of the terminal box Figure showing grounding bracket Figure showing an enlarged view of the mounting state of the grounding bracket

  The motor frame 1 shown in FIG. 1 has a horizontal cylindrical shape with both ends 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. A screw 4 is inserted into each of the two legs 3, and the motor frame 1 is fixed by screwing the two screws 4 to an installation surface.

  A motor body is housed in the motor frame 1. This motor body is composed of a three-phase synchronous reluctance motor, and has a stator and a rotor. The rotor has a horizontal rotation axis fixed to a rotor core, and the stator has a three-phase stator winding wound around the stator core. As shown in FIG. 1, one end of a lead wire 6 is connected to each of these three-phase stator windings, and a crimp terminal 7 is connected to the other end of each of the three-phase lead wires 6. It is connected.

  The stator core is shrink-fitted to the inner peripheral surface of the motor frame 1, and a stud is driven into the stator core from outside the motor frame 1 through the motor frame 1. The stator core is fixed in the motor frame 1 by shrink fitting and studs, and the rotor core is housed in the stator core.

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

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

  A connection seat 11 is fixed to the motor frame 1 as shown in FIG. 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 a female screw is formed on an 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 pedestal 9.

  A terminal block 12 is fixed to the pedestal 9 as shown in FIG. 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 pedestal 9. .

  As shown in FIG. 1, each of the plurality of screws 14 is screwed into a tap hole of the pedestal 9 through the frame side case 15. The frame-side case 15 is interposed between the pedestal 9 and the terminal block 12, and a plurality of screws 14 fix the terminal block 12 to the pedestal 9 together with the frame-side case 15. The frame-side case 15 is made of a conductive metal, and has an opening on one side opposite to the pedestal 9. 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 inside of the pedestal 9 through the opening 16.

  As shown in FIG. 1, a packing 17 is interposed between the pedestal 9 and the frame side case 15. The packing 17 is made of insulating rubber and has a square ring shape. The packing 17 is elastically crushed by the fastening force of the plurality of screws 14 and is in close contact with the pedestal 9 and the frame-side case 15 with elastic restoring force.

  As shown in FIG. 2, a three-phase terminal plate 18 is mounted on the terminal block 12. A tap hole is formed in each of these three-phase terminal plates 18, and each of the three-phase lead wires 6 is screwed into a tap hole of the terminal plate 18 through the crimp terminal 7 from the side opposite to the pedestal 9. It is connected to the terminal plate 18 according to the matching. Each of these three-phase terminal plates 18 is screwed with a screw 20, and each of the three-phase external power lines is connected to the terminal plate 18 via the screw 20. Each of these three-phase terminal plates 18 corresponds to a terminal.

  A terminal box cover 21 is fixed to the frame side case 15 as shown in FIG. The terminal box cover 21 is made of a conductive metal, and a plurality of screws 22 are screwed into the frame-side case 15 through the terminal box cover 21 from the side opposite to the pedestal 9. 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 housed in the terminal box 23, and the other end of each of the plurality of lead wires 6 is a terminal box. Inside 23, it is connected to the terminal plate 18 of the terminal block 12.

Next, a ground structure between the motor frame 1 and the terminal box 23 will be described.
3 is made of conductive metal and has a terminal block side plate 31, a frame side plate 32, and a connection plate 33. The connecting plate 33 has a horizontal plate shape, the terminal block side plate 31 has a rectangular shape pointing downward from one end of the connecting plate 33, and the frame side plate 32 points 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 perpendicular to the connecting plate 33, and the length of the frame side plate 32 in the vertical direction is set smaller than that of the terminal block side plate 31.

  As shown in FIG. 3, the frame side plate 32 is opposed to the base end of the terminal block side plate 31 in parallel, and is inserted into the terminal block side plate 31 at a portion that does not face the frame side plate 32 and has a circular shape. A hole 34 is formed. As shown in FIG. 4, a screw 36 is inserted into the insertion hole 34 from a side opposite to the pedestal 9 via a washer 35. Have been 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 in accordance with being fixed to the pedestal 9.

  An insertion hole 37 is formed in the frame side plate 32 as shown in FIG. The insertion hole 37 has a circular shape, and is arranged 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. The frame side plate 32 is electrically connected to the motor frame 1 in accordance with being fixed to the connection seat 11. That is, the grounding metal fitting 30 brings the terminal box 23 and the motor frame 1 into a conductive state, and the terminal box 23 is grounded via the grounding metal fitting 30 and the motor frame 1.

  As shown in FIG. 3, a circular working hole 40 is formed in the terminal block side plate 31. The work hole 40 is opposed to 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 larger than each of the washer 38 and the head of the screw 39, and the screw 39 can pass through the working hole 40 when the washer 38 is attached. The diameter of the working hole 40 is set larger than the tool. This tool is for screwing the screw 39 into the connection seat 11, and the tool can be inserted into the working hole 40.

  As shown in FIG. 3, a coating layer 41 made of a synthetic resin is formed on the ground metal 30. The coating layer 41 is for preventing rust of the earth metal member 30, and is formed on the surface of the earth metal member 30 except for a contact portion with each of the washer 35, the frame side case 15, the washer 38, and the connection seat 11. This coating layer 41 corresponds to a coating.

According to the first embodiment, the following effects can be obtained.
The motor frame 1 and the terminal box 23 were electrically connected to each other by connecting the grounding metal fittings 30 made of a metal plate. Therefore, deterioration of the coating of the ground wire or breakage of the core wire due to aging does not occur, so that the conduction between the motor frame 1 and the terminal box 23 can be maintained in a healthy state for many years.

  Since each of the terminal box side plate 31 and the frame side plate 32 of the grounding metal 30 is set to be a flat plate crossing the connecting plate 33 at right angles, the entire shape of the grounding metal 30 is bent. Therefore, since the rigidity of the grounding member 30 is increased, it is possible to prevent the grounding member 30 from being deformed by an external force when the grounding member 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 screwed into the connection seat 11 according to 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 pedestal 9 with the frame side case 15 opened. Since the connection can be performed, the connection work of the grounding fitting 30 is simplified.

Since the coating layer 41 is provided on the surface of the earth metal member 30, rust can be prevented from being generated on the earth metal member 30.
In the first embodiment, a motor body different from the three-phase synchronous reluctance motor may be housed in the motor frame 1.

In the first embodiment, the position of the earth box 30 between the terminal box side plate 31 and the frame side plate 32 may be shifted in the circumferential direction.
In the first embodiment, the terminal box side plate 31 of the ground metal 30 is projected upward or downward from the connection plate 33, and the frame side plate 32 of the ground metal 30 is projected upward or downward from the connection plate 33 to the other side. Is 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 30 may intersect the connecting plate 33 at a non-perpendicular angle.
In the first embodiment, a coating made of rubber or an elastomer may be used instead of the coating layer 41.

  Although the embodiment of the present invention has been described above, this embodiment is presented by way of example and is not intended to limit the scope of the invention. These new embodiments can be implemented in other various forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and their equivalents.

  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 bracket, 31 is a terminal box side plate, 32 is a frame side plate, 33 is a connecting plate, 34 is an insertion hole, 36 is a screw, 37 is an insertion hole, 39 is a screw, 40 is a work hole, and 41 is a coating layer (coating).

Claims (2)

A motor-body is housed therein, and a cylindrical frame having conductivity,
A pedestal projecting from the outer peripheral surface of the frame,
A terminal box provided at the end of the pedestal via an insulating packing, and having conductivity,
A terminal provided in the terminal box and wired to the motor main body through the pedestal;
Comprising a metallic plate made of ground metal provided in the pedestal,
The grounding metal is formed by bending a strip-shaped metal plate into a U-shape, and a frame side plate connected to the frame by screwing, a terminal box side plate connected to the terminal box by screwing, Along with having integrally a connecting plate for connecting the base end of the frame side plate and the base end of the terminal box side plate,
The terminal box side plate is configured to be longer than the frame side plate,
The frame side plate is provided with a screw insertion hole,
The terminal box side plate is provided with a screw insertion hole on the distal end side, and is provided with a work hole on the base end side into which a tool for screwing the frame side plate can be inserted,
The electric motor , wherein the frame side plate is screwed to the frame from the terminal box side plate through the work hole, and the terminal box side plate is screwed to the terminal box in the same direction . The electric motor according to claim 1 , wherein a coating for preventing rust of the ground metal is provided on a surface of the ground metal .

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