JP2012080653A - Dc brushless motor and electrical apparatus using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the following problem: for the purpose of preventing failure due to heat or the like, a conventional DC brushless motor has protective means included in two windings to cut off an electric current upon detection of generated heat; however, the conventional method requires two temperature detection means and there occur variations in detected temperatures because the protective means detects wiring temperatures.SOLUTION: The DC brushless motor includes one protective means provided on the rear of a control board attached with an intelligent power module to reduce the number of parts for highly precise temperature detection, thereby preventing generation of failure or the like in the DC brushless motor.

Description

  The present invention relates to a DC brushless motor using an intelligent power module (hereinafter referred to as IPM) and an electric device using the same, and detects the heat generated by the IPM, thereby detecting the DC brushless motor and the surrounding electric This is to avoid equipment failure.

  As an electric device, for example, an AC motor is used in an integrated air conditioner in which a compressor, a condenser, and an evaporator are housed in the same casing. This AC motor has the advantages that it can be driven directly by an AC power source and that the cost is low due to the small number of parts. However, there is a problem that power consumption is large, and there is a demand for switching to a DC motor with high energy efficiency.

  Some AC motors are provided with a thermal protector that detects abnormal heating of the windings and interrupts the current supplied to the motor. Therefore, when switching such an AC motor to a DC motor, it is necessary to arrange a thermal protector in the DC motor. As described above, an electric device in which a DC motor is provided with a thermal protector is conventionally known (Patent Document 1).

JP-A-2005-143210

  However, in Patent Document 1, there is a winding that is not energized in an abnormal state such as when the DC brushless motor 6 is locked. Therefore, in order to detect the temperature of the coil | winding currently energized, it is necessary to attach a protective device (10, 11) in two places, and there existed a problem that the number of parts increased. There is also a problem that the winding temperature detected by the protective device (10, 11) varies depending on how the windings (U-phase 7, V-phase 8) are wound.

  An object of the present invention is to provide a DC motor that detects abnormal heat generation with one thermal protector and cuts off a power supply current, and an electric device using the DC motor.

  In order to achieve the above object, a DC brushless motor according to the present invention includes a stator having three-phase windings, a rotor having permanent magnets, an inverter for supplying current to the windings, and the inverter disposed. And a control board disposed so as to face one end face of the stator in the axial direction, and detects abnormal heat generation of the inverter in the vicinity of the inverter and supplies it to the inverter The thermal protector which interrupts the generated current is arranged.

  In addition, an electrical device using the brushless motor of the present invention includes a DC brushless motor having a three-phase winding, an inverter that supplies current to the winding, and a control board on which the inverter is disposed, In an electric device comprising: an alternating current supplied from an alternating current power source is converted into a direct current; and at least a direct current power supply that supplies the direct current to the inverter; A thermal protector that cuts off the current is provided, and when the thermal protector detects an abnormal temperature, the thermal protector cuts off the alternating current supplied from the alternating current power source to the direct current supply power source.

  According to the present invention, a single thermal protector can detect abnormal heat generation of the DC brushless motor and cut off the power supply current.

It is an electric circuit diagram of the electric motor of this invention and a component. It is a control board figure of the electric motor of the present invention. It is sectional drawing of the electric motor of this invention. It is sectional drawing of the electric motor of this invention. It is sectional drawing of the electric motor which is another Example of this invention. It is a top view of the electric motor of the present invention. It is a fixed figure of the thermal protector of this invention. It is an electric circuit diagram of the conventional electric motor and components.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a circuit configuration of an electric device such as an integrated air conditioner equipped with a DC motor. The AC power supply 1 is connected to a DC supply power supply (AC / DC converter) 19, an inverter (IPM) 15, and a DC brushless motor 6 in this order. Further, for example, a component 27 such as a compressor is connected to the AC power supply 1 in parallel with a DC supply power supply (AC / DC converter) 19. The control power supply 28 is a circuit that converts the output DC voltage of the DC supply power supply (AC / DC converter) 19 into the power supply voltage of the microcomputer 14. FIG. 2 is a diagram showing both sides of a control board that controls the DC brushless motor. As shown in FIG. 2, an inverter (IPM) 15 is provided on one side of the control board 18, and the thermal protector 12 and the Hall IC 21 are mounted on the opposite side. 3, 4 and 5 are cross-sectional views of the DC brushless motor 6 of the present invention. FIG. 6 is a top view of the DC brushless motor 6 of the present invention. The DC brushless motor 6 of the present invention is a bracket motor provided with a rotor 17, a stator 16, a control board 18, a thermal protector 12 as a protection means, and an IPM 15 as an inverter. Although the control board 18 is installed in the DC brushless motor 6 in this embodiment, the control board 18 may be taken out of the DC brushless motor 6 and handled as separate members.

  As shown in FIG. 4, the stator 16 is configured by winding a winding 162 around a stator core 161 in which steel plates are laminated via an insulator 163. The winding 162 is composed of three phases: a U-phase winding 7, a V-phase winding 8, and a W-phase winding 9, and these three-phase windings are connected as shown in FIG. Connected). In this embodiment, the three-phase windings are Y-connected, but the present invention is not limited to this, and the three-phase windings may be so-called delta connections.

  As shown in FIG. 4, the rotor 17 is disposed on the inner diameter side of the stator 16. The rotor 17 is configured by inserting a shaft 20 on the inner diameter side of a cylindrical rotor core 171 in which steel plates are laminated and attaching a permanent magnet 172 on the outer diameter side. The permanent magnet 172 receives a force from the rotating magnetic field generated by the windings (7, 8, 9) in the stator 16, and the rotor 17 rotates.

  As shown in FIG. 2, an IPM 15, a thermal protector 12, a microcomputer 14, and a Hall IC 21 are mounted on the control board 18. Further, as shown in FIG. 3, the control board 18 is arranged so as to face one end face of the stator in the axial direction.

  The IPM 15 is an inverter that controls electric power, and this inverter is a power module constituted by devices such as a power MOSFET and an insulated gate bipolar transistor (IGBT). Note that a self-protecting function may be incorporated. Since the IPM 15 generates heat when controlling the electric power supplied to the winding, a heat transfer member 24 for releasing the heat is attached. In this embodiment, the case where the heat sink 24 is attached will be described. However, the present invention is not limited to this, and a heat spreader may be attached. The IPM 15 is electrically connected to each of the U-phase winding 7, the V-phase winding 8, and the W-phase winding 9 via lead wires. The direct current rectified by the AC / DC converter 19 is supplied via the cable 26. The IPM 15 supplies current to the U-phase winding 7, the V-phase winding 8, and the W-phase winding 9, and the respective windings, in accordance with a command from the microcomputer 14.

  The thermal protector 12, which is a protection means, cuts off the current flowing through the energization path by opening a contact provided in the thermal protector 12 when the detected temperature is equal to or higher than a preset temperature. .

  The microcomputer 14 controls the IPM 15 on the control board 18. The Hall IC 21 captures the magnetic flux of the permanent magnet 172 in the rotor 17 and detects the position of the rotor 17. The microcomputer 14 controls the IPM 15 based on the position of the rotor 17 detected by the Hall IC.

  The AC / DC converter 19 is a rectifier circuit for converting an alternating current supplied from the alternating current power source 1 into a direct current. The converted direct current is supplied to the three-phase windings (7, 8, 9) via the IPM 15. The AC / DC converter 19 is electrically connected to the thermal protector 12 and the IPM 15 via lead wires.

  In this embodiment, as shown in FIG. 1, the thermal protector 12 is electrically connected to the AC power source 1 and the AC / DC converter 19 by a cable 25.

  As shown in FIG. 2, the thermal protector 12 is disposed on the control board 18, is positioned opposite to the IPM 15 with the control board 18 in between, and is disposed to face the coil end of the winding. Since the coil end is lower than the insulator 163, space can be effectively used by disposing the thermal protector 12 at a position facing the coil end. When arranging, as shown in FIG. 7, the thermal protector 12 is fixed on the control board 18 with an adhesive 23. The adhesive 23 alone is vulnerable to a load from the lateral direction. Therefore, the thermal protector 12 is coated with silicone 22 in order to reinforce against lateral loads.

  By disposing the thermal protector 12 at the above position, the thermal protector 12 can detect the heat generated by the IPM 15 via the control board 18. When the detected temperature of the thermal protector 12 exceeds the set value, the internal contact of the thermal protector 12 is opened. Thereby, the alternating current (power supply current) supplied from the alternating current power supply 1 to the AC / DC converter 19 is cut off. Therefore, since the supply of direct current from the AC / DC converter 19 is cut off, the DC brushless motor 6 stops. Similarly, the component 27 connected in parallel with the AC / DC converter 19 and electrically connected to the thermal protector also stops. As mentioned above, this invention can prevent the failure of the DC brushless motor 6 and the component 27 of an electric equipment.

  In the present embodiment, the thermal protector 12 is disposed at a position opposite to the IPM 15 with the control board 18 in between. However, the present invention is not limited to this position, and the thermal protector 12 is generated at the IPM 15. Any position can be used as long as it can detect heat directly or indirectly. For example, as shown in FIG. 5, the thermal protector 12 may be installed on the heat sink 24 attached to the IPM 15.

  In this embodiment, when the detected temperature of the thermal protector 12 exceeds the set value, the internal contact of the thermal protector 12 is opened. In the present embodiment, the set value is determined based on the safety standard of the IPM 15, but the present invention is not limited to this, and the set value may be changed according to the safety standard of the electronic component to be detected. .

DESCRIPTION OF SYMBOLS 1 AC power supply 2 Power supply switch 3 Filter circuit 4 Rectifier circuit 5 Inverter 6 DC brushless motor 7 U phase winding 8 V phase winding 9 W imaginary winding 10, 11 Protection device 12 Thermal protector 13 Current detection circuit 14 Microcomputer 15 IPM
16 Stator 161 Stator Iron Core 162 Winding 163 Insulator 17 Rotor 171 Rotor Core 172 Permanent Magnet (Magnet)
18 Control board 19 AC / DC converter 20 Shaft 21 Hall IC
22 Silicone 23 Adhesive 24 Heat sink 25 Cable (thermal protector)
26 Cable 27 Component 28 Control power supply

Claims (4)

A stator having three-phase windings;
A rotor having permanent magnets;
An inverter for supplying current to the winding;
The inverter is disposed, and a control board disposed so as to face one end surface of the stator in the axial direction;
DC brushless motor equipped with
A DC brushless motor, wherein a thermal protector that detects abnormal heat generation of the inverter and blocks the current supplied to the inverter is disposed in the vicinity of the inverter. The DC brushless motor according to claim 1,
A heat transfer member that releases heat generated by the inverter;
A DC brushless motor, wherein the thermal protector is disposed so as to be in contact with the heat transfer member. The DC brushless motor according to claim 1,
A DC brushless motor, wherein the thermal protector is disposed at a position opposite to the inverter with the control board interposed therebetween, and opposed to a coil end of the winding. A DC brushless motor having a three-phase winding, an inverter for supplying current to the winding, and a control board on which the inverter is disposed;
A DC supply power source that converts an AC current supplied from an AC power source into a DC current, and supplies the DC current to at least the inverter;
In electrical equipment with
A thermal protector that detects abnormal heat generation of the inverter and cuts off the current flowing through the winding,
If the thermal protector detects an abnormal temperature,
The thermal protector cuts off an alternating current supplied from the alternating current power source to the direct current supply power source.