Motor and fan arrangement

Abstract

A motor and a fan device are provided in which, in a motor of an electromechanical integrated type in which a driver circuit is integrated, flow through flow is prevented even if a shaft comes into contact with a substrate. The motor of the present application includes a motor holder; a shaft of an electrically conductive material fixed to a surface side of the motor holder; a rotor supported by the shaft in a freely rotatable manner; a stator fixed to the surface side of the motor holder on an inner side of the rotor, wound with a plurality of coils that generate a magnetic field for rotating the rotor; a substrate on which a driver circuit that controls generation of a magnetic field using the coils is surface-mounted; and a drive case fixed to a back surface side of the motor holder, forming an accommodation space that accommodates the substrate between the motor holder, a positive wiring of the driver circuit being mounted outside an area on the substrate that coincides with the shaft when the motor is viewed from an axial direction of the shaft.

Description

Technical Field

[0001] This invention relates to a motor and a fan device equipped with the motor. Background Technology

[0002] In recent years, efforts have been made to advance the Sustainable Development Goals (SDGs, the 2030 Agenda for Sustainable Development, selected by the United Nations Summit on September 25, 2015). Along with this, technologies aimed at reducing waste or defective products are known to ensure sustainable production and consumption patterns.

[0003] There are known "mechatronic" motors that integrate the driver circuitry used to drive the motor. Mechatronic motors typically have a shaft, rotor, and stator mounted on the surface of the motor bracket, and a base plate on the back of the motor bracket where the driver circuitry is mounted. Furthermore, such motors are mounted in the engine compartment of vehicles, for example, as motors that drive cooling fans that supply cooling air to radiators (see, for example, Patent Document 1).

[0004] [Existing technical documents]

[0005] [Patent Literature]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2019-108872 Summary of the Invention

[0007] [The problem the invention aims to solve]

[0008] In this type of mechatronic motor, there is a problem that if the motor bracket shaft breaks and contacts the base plate in the event of a vehicle collision, the driver circuit will short-circuit and current will flow through it.

[0009] Therefore, the object of the present invention is to provide a technology that prevents flow through an electromechanical motor in which the driver circuit is integrated, even when the shaft contacts the substrate.

[0010] [Technical means to solve the problem]

[0011] To achieve the aforementioned objective, the present invention provides a motor comprising: a motor bracket; a conductive shaft fixed to a surface side of the motor bracket; a rotor supported by the shaft in a freely rotatable manner; a stator fixed to the surface side of the motor bracket inside the rotor, and having wound with a plurality of coils that generate a magnetic field for rotating the rotor; a substrate with a driver circuit mounted on its surface for controlling the generation of the magnetic field using the coils; and a drive housing fixed to the back side of the motor bracket, forming a receiving space between the drive housing and the motor bracket for receiving the substrate. The motor is characterized in that the positive wiring of the driver circuit is mounted on the outer side of the area on the substrate that coincides with the shaft when the motor is viewed from the axial direction of the shaft.

[0012] [The effects of the invention]

[0013] According to the present invention, in an electromechanical integrated motor in which the driver circuit is integrated, flow can be prevented even if the shaft contacts the substrate. Other issues, structures, and effects will become clear from the description of the following embodiments. Attached Figure Description

[0014] Figure 1 This is a perspective view showing the external appearance of a structural example of a fan device according to an embodiment.

[0015] Figure 2 It is an exploded 3D view of the motor and fan.

[0016] Figure 3 It is an exploded perspective view of the brushless motor, the base plate, and the drive box.

[0017] Figure 4 This is a three-dimensional view of the surface side of the structure of a motor with the rotor yoke removed.

[0018] Figure 5 This is a longitudinal sectional view of the motor.

[0019] Figure 6 It is a schematic circuit diagram of the power system circuits included in the driver circuit.

[0020] Figure 7 This is a plan view of the substrate on which the driver circuitry is mounted.

[0021] [Explanation of Symbols]

[0022] 1: Fan unit

[0023] 2: Motor

[0024] 3: Fan

[0025] 10: Screws

[0026] 11: Brushless Motor

[0027] 12: Driver circuit

[0028] 13: Substrate

[0029] 14: Motor bracket

[0030] 15: Drive box

[0031] 16: Connector Unit

[0032] 17: Adhesive

[0033] 21: Axis

[0034] 22: Bearing

[0035] 23: Rotor

[0036] 24: Stator

[0037] 31: Protrusion portion

[0038] 32: Leaf

[0039] 33: Connecting structural components

[0040] 120: Power system circuit

[0041] 121: Power supply

[0042] 122U, 122V, 122W: Positive-side transistor

[0043] 123U, 123V, 123W: Negative-side transistor

[0044] 124: Motor control IC

[0045] 125: Fuse

[0046] 131: Region

[0047] 132: Region

[0048] 231: Permanent magnet

[0049] 232: Rotor yoke

[0050] 232A: Peripheral wall

[0051] 232B: Inner peripheral wall

[0052] 232C: Connecting Wall

[0053] 241: Stator core

[0054] 242: Insulator

[0055] 243: Coil

[0056] 311: Disc section

[0057] 312: Zhoubi section Detailed Implementation

[0058] Hereinafter, as one aspect of the fan device according to an embodiment of the present invention, a fan device that is installed in a vehicle such as an automobile to cool engine cooling water flowing in the radiator will be described.

[0059] (Overall structure of fan unit 1)

[0060] First, refer to Figure 1 and Figure 2 The overall structure of the fan unit 1 will be described. Figure 1 This is a perspective view of the external structure of a fan device 1 according to an embodiment. Figure 2 This is an exploded perspective view of motor 2 and fan 3.

[0061] like Figure 1 and Figure 2 As shown, the fan unit 1 includes a motor 2 as a drive source and a fan 3 that generates cooling air by rotating the motor 2. The fan unit 1 is installed in the engine compartment, for example, with the motor 2 positioned on the rear side (opposite to the engine) and the fan 3 positioned on the front side (opposite to the radiator).

[0062] The fan 3 is fastened to the motor 2 by a plurality of screws 10. The screws pass through screw holes formed in the boss portion 31, which is the center of the fan 3, from the surface of the fan 3 (and the side opposite to the side facing the motor 2) and are fastened to the rotor yoke 232 of the motor 2. Furthermore, as a fastening component for fastening the fan 3 to the motor 2, screws 10 are not necessarily required. As long as the fan 3 can be fastened to the motor 2, there are no particular restrictions on the number of screws or the type of fastening component.

[0063] The fan 3 includes a boss portion 31 that rotates integrally with the rotor 23 with the shaft 21 as the center of rotation, multiple blades (seven in this embodiment) 32 that extend radially from the outer periphery of the boss portion 31, and multiple connecting members (seven in this embodiment) 33 that connect adjacent blades 32 to each other at the front end side.

[0064] The boss portion 31 includes a disc-shaped disc portion 311 and a cylindrical peripheral wall portion 312 that protrudes from the outer edge of the disc portion 311 toward the motor 2 and is fitted with multiple blades 32. After the fan 3 is installed on the motor 2, the disc portion 311 is opposite to the connecting wall 232C of the rotor yoke 232, and the peripheral wall portion 312 surrounds the outer peripheral wall 232A of the rotor yoke 232.

[0065] (Structure of Motor 2)

[0066] Next, refer to Figures 3-5 The structure of motor 2 will be explained. Figure 3 This is an exploded perspective view of the brushless motor 11, the base plate 13, and the drive box 15. Figure 4 This is a perspective view of the surface side of the structure of motor 2 with the rotor yoke 232 removed. Figure 5 This is a longitudinal sectional view of motor 2.

[0067] like Figures 3-5 As shown, motor 2 is a so-called "mechatronic" electric motor that includes an external rotor type brushless motor 11 and a baseboard 13 on which a driver circuit 12 is mounted.

[0068] The brushless motor 11 is supported by a motor bracket 14. The brushless motor 11 is disposed on one side (surface side) of the motor bracket 14 in the thickness direction. On the other side (back side) of the motor bracket 14 in the thickness direction, a drive housing 15 is secured by a plurality of screws. Thus, a receiving space for a receiving substrate 13 is formed between the back side of the motor bracket 14 and the drive housing 15.

[0069] That is, the substrate 13 is disposed on the opposite side (back side of the motor bracket 14) of the structural components 21 to 24 of the brushless motor 11, separated by the motor bracket 14. Furthermore, the motor bracket 14 and the drive housing 15 are formed of a material with high thermal conductivity (e.g., aluminum, iron, stainless steel, etc.). Moreover, to improve heat absorption, the motor bracket 14 and the drive housing 15 can be made black.

[0070] Furthermore, a connector unit 16, which integrates two connectors for connecting external wiring harnesses, is installed at the end of the motor bracket 14. The brushless motor 11, the driver circuit 12, and the connector unit 16 are electrically connected.

[0071] like Figures 3-5 As shown, the brushless motor 11 includes a shaft 21, a plurality of bearings 22 disposed on the outer periphery of the shaft 21, a rotor 23 supported by the bearings 22 in a manner that allows free rotation around the axis of the shaft 21, and an annular stator 24 that is fixed radially at a predetermined interval from the rotor 23.

[0072] Shaft 21 is a fixed shaft that is fixed to the surface side of motor bracket 14. Hereinafter, in the description related to the structural elements of motor 2, the axial direction of shaft 21 will be simply referred to as "axial direction", the radial direction centered on the axis of shaft 21 will be simply referred to as "radial direction", and the circumferential direction centered on the axis of shaft 21 will be simply referred to as "circumferential direction".

[0073] The rotor 23 includes a plurality of permanent magnets 231 arranged at equal intervals along the circumference in a manner surrounding the outer periphery of the stator 24, and a rotor yoke 232 supporting the plurality of permanent magnets 231 and supported by a shaft 21 in a manner that allows free rotation.

[0074] The rotor yoke 232 is arranged concentrically with the axis of the shaft 21 on the surface of the motor bracket 14. Moreover, the rotor yoke 232 is supported by the shaft 21 in a freely rotatable manner via a plurality of bearings 22. Furthermore, the rotor yoke 232 includes an outer peripheral wall 232A, an inner peripheral wall 232B, and a connecting wall 232C.

[0075] The outer peripheral wall 232A has a cylindrical shape. Furthermore, the outer peripheral wall 232A is located radially outward of the stator 24. Moreover, the outer peripheral wall 232A supports a plurality of permanent magnets 231 on its inner peripheral surface. In other words, the plurality of permanent magnets 231 are fixed to the inner peripheral surface of the outer peripheral wall 232A at predetermined intervals along the circumferential direction.

[0076] The inner peripheral wall 232B has a cylindrical shape. Moreover, the inner peripheral wall 232B is located radially inside the stator 24. Furthermore, the inner peripheral wall 232B is supported by the shaft 21 in a freely rotatable manner via a plurality of bearings 22.

[0077] The connecting wall 232C has a disc-shaped exterior. Furthermore, the connecting wall 232C connects one axial end of the outer peripheral wall 232A and the inner peripheral wall 232B to each other. Moreover, the connecting wall 232C is disposed on the opposite side of the motor bracket 14, separated from the stator 24. Furthermore, the connecting wall 232C is disposed facing the stator 24 at predetermined intervals along the axial direction.

[0078] The stator 24 is housed within a space surrounded by an outer peripheral wall 232A, an inner peripheral wall 232B, a connecting wall 232C, and the surface of the motor bracket 14. Furthermore, the stator 24 is fixed to the surface of the motor bracket 14 radially inward of the plurality of permanent magnets 231. Moreover, the stator 24 is positioned radially spaced from the plurality of permanent magnets 231.

[0079] The stator 24 includes a cylindrical stator core 241, an insulating body 242 mounted on both sides of the axial direction relative to a plurality of teeth protruding radially outward from the stator core 241, and a conductive coil 243 wound on the insulating body 242.

[0080] The stator 24 generates a magnetic field by flowing current through the coil 243. Then, the rotor yoke 232 rotates about the axis of shaft 21 by the attraction and repulsion between the magnetic field generated by the coil 243 and the plurality of permanent magnets 231.

[0081] Then, the motor 2 is positioned in the engine compartment with its shaft 21 facing the direction of travel of the vehicle. Moreover, the motor 2 is a brushless motor 11 facing forward and the drive housing 15 facing rearward in the engine compartment.

[0082] (Structure of driver circuit 12)

[0083] Figure 6 This is a schematic circuit diagram of the power system circuit 120 included in the driver circuit 12. Figure 7 This is a plan view of the substrate 13 on which the driver circuit 12 is mounted. The driver circuit 12 controls the generation of a magnetic field using multiple coils 243. The driver circuit 12 includes multiple electronic components (e.g., transistors, diodes, resistors, etc.) that are surface-mounted on the surface of the substrate 13 opposite to the motor bracket 14. The substrate 13 has, for example, a plate-like shape made of aluminum alloy.

[0084] like Figure 6 As shown, in order to supply current from power supply 121 to the coil 243 of brushless motor 11, power system circuit 120 mainly includes three positive-side transistors 122U, 122V, and 122W; three negative-side transistors 123U, 123V, and 123W; a motor control integrated circuit (IC) 124; and a fuse 125 (hereinafter sometimes collectively referred to as "power system components 121 to 125"). Furthermore, the electronic components supplying current to coil 243 are not limited to the power system components 121 to 125 described above.

[0085] The sources of positive-side transistors 122U, 122V, and 122W are connected in parallel to the positive terminal of power supply 121. Furthermore, the drains of positive-side transistors 122U, 122V, and 122W are connected to the coils 243 of phases U, V, and W, respectively. Finally, the gates of positive-side transistors 122U, 122V, and 122W are connected to the motor control IC 124.

[0086] The sources of negative-side transistors 123U, 123V, and 123W are connected to the coils 243 of phases U, V, and W, respectively. Furthermore, the drains of negative-side transistors 123U, 123V, and 123W are connected in parallel to the negative terminal of power supply 121. Finally, the gates of negative-side transistors 123U, 123V, and 123W are connected to motor control IC 124.

[0087] That is, the wiring from the positive terminal of power supply 121 through positive transistor 122U, positive transistor 122V, and positive transistor 122W to coil 243 is a positive wiring that becomes a positive potential. Moreover, the wiring from coil 243 through negative transistor 123U, negative transistor 123V, and negative transistor 123W to the negative terminal of power supply 121 is a ground (GND) wiring that becomes a ground potential.

[0088] The motor control IC 124 controls the ON and OFF states of transistors 122U, 122V, 122W, 123U, 123V, and 123W (resulting in the supply and blocking of current to coil 243) by controlling the voltage applied to the gates of each transistor 122U, 122V, 122W, 123U, 123V, and 123W. A fuse 125 is positioned between the positive terminal of the power supply 121 and the positive transistors 122U, 122V, and 122W to block wiring when overcurrent flows through the power system circuit 120.

[0089] like Figure 7 As shown, the surface of the substrate 13 includes regions 131 and 132. Furthermore, in the wiring constituting the driver circuit 12, positive wiring and power system components 121 to 125 are disposed in region 131, and GND wiring is disposed in region 132. Moreover, the positive wiring and GND wiring described herein include not only… Figure 6 The wiring of the power system circuit 120 described herein also includes the wiring of the control system (e.g., speed controller, speed converter, voltage controller, etc.).

[0090] and, Figure 7 The symbol ● indicates the position on the base plate 13 that coincides with the shaft 21 when the motor 2 is viewed from the axial direction of the shaft 21 (in other words, the position where the shaft 21 is extended axially). Figure 7 As shown, the extension line of shaft 21 coincides with region 132. That is, the GND wiring of driver circuit 12 is mounted on region 132 on substrate 13 that coincides with shaft 21 when motor 2 is viewed from the axial direction of shaft 21. In other words, the positive wiring of driver circuit 12 and electronic components are mounted on the outside of the region on substrate 13 that coincides with shaft 21 when motor 2 is viewed from the axial direction of shaft 21.

[0091] and, Figure 7 The dashed line indicates the position where the motor 2 coincides with the outer periphery of the stator 24 when viewed from the axial direction of the shaft 21. Furthermore, the power system components 121 to 125 are mounted on the outer side of the area on the base plate 13 that coincides with the stator 24.

[0092] Furthermore, such as Figure 5 As shown, power system components 121 to 125 are in contact with the metal motor bracket 14 via adhesive 17. Furthermore, adhesive 17 ideally has high thermal conductivity.

[0093] According to the described implementation, for example, the following effects are achieved.

[0094] According to the embodiment described above, the GND wiring of the driver circuit 12 is installed on the substrate 13 in the area overlapping with the shaft 21 when the motor 2 is viewed from the axial direction of the shaft 21. Therefore, even if the shaft 21 penetrates the motor bracket 14 and contacts the substrate 13, only the shaft 21 at the same potential contacts the GND wiring, thus preventing overcurrent from flowing through the driver circuit 12. As a result, the fuse 125 is prevented from tripping.

[0095] Furthermore, to prevent current from flowing through the driver circuit 12, it is sufficient to avoid contact between the shaft 21 penetrating the motor bracket 14 and the portion of the driver circuit 12 that is at a positive potential. That is, the portion of the driver circuit 12 that is at a positive potential (typically a positive wiring) when the motor 2 is viewed from the axial direction of the shaft 21 should be mounted on the outside of the area on the substrate 13 that coincides with the shaft 21. Here, no components may be mounted on the area on the substrate 13 that coincides with the shaft 21 when the motor 2 is viewed from the axial direction of the shaft 21, but from the viewpoint of improving the residual copper ratio, it is ideal to mount GND wiring.

[0096] Furthermore, according to the embodiment described above, the power system components 121 to 125 are mounted on the outer side of the area on the base plate 13 that coincides with the stator 24 when the motor 2 is viewed axially from the shaft 21. This reduces the thermal impact on the coil 243 by moving the self-heating power system components 121 to 125 away from the shaft 21. Moreover, since the power system components 121 to 125 can be moved away from the shaft 21, the thermal impact of the shaft 21 on the power system components 121 to 125 can be reduced. This extends the lifespan of the motor 2 and contributes to waste reduction.

[0097] Furthermore, according to the embodiment described above, the power system components 121 to 125 are brought into contact with the metal motor bracket 14 via the adhesive 17, thereby improving heat dissipation. Especially when the motor 2 drives the fan 3, the heat dissipation effect is further improved because the motor bracket 14 is cooled by the cooling air generated by the fan 3. This extends the lifespan of the motor 2 and contributes to waste reduction.

[0098] Furthermore, in the described embodiment, an example of a fan unit 1 being mounted on an engine-driven vehicle was given, but the fan unit 1 can also be mounted on a vehicle driven by a motor, battery, or fuel cell. Moreover, an example of the fan unit 1 being used to supply cooling air to a radiator was described, but its application is not limited to this. Furthermore, in the described embodiment, an example of a fan motor that rotates and drives the fan 3 was given, but its application is not limited to this. Moreover, an example of using a substrate made of aluminum alloy was described, but the substrate 13 can also be made of a resin such as glass epoxy resin.

[0099] The embodiments of the present invention have been described above. Furthermore, the present invention is not limited to the described embodiments and includes various modifications. For example, the embodiments have been described in detail for the purpose of easily understanding the present invention and are not necessarily limited to including all the structures described. Moreover, a part of the structure of this embodiment can be replaced with the structure of other embodiments, and the structure of other embodiments can be added to the structure of this embodiment. Furthermore, a part of the structure of this embodiment can be added to, deleted from, or replaced with other structures.

Claims

1. A motor, comprising: Motor bracket; A conductive shaft is fixed to the surface side of the motor bracket; The rotor is supported by the shaft in a freely rotatable manner; The stator, fixed to the surface side of the motor bracket inside the rotor, is wound with a plurality of coils that generate a magnetic field to rotate the rotor. A substrate, on the surface of which is mounted a driver circuit for controlling the generation of a magnetic field using the coil; as well as The drive housing is fixed to the back side of the motor bracket, forming a receiving space between itself and the motor bracket to accommodate the base plate. The motor is characterized in that: The positive wiring of the driver circuit is mounted on the outside of the area on the substrate that coincides with the shaft when the motor is viewed from the axial direction of the shaft. The grounding wiring of the driver circuit is installed in the area on the substrate that coincides with the shaft when the motor is viewed from the axial direction of the shaft.

2. The motor according to claim 1, characterized in that: The power system component that supplies current to the coils in the driver circuit is mounted on the outside of the region on the substrate that coincides with the stator when the motor is viewed from the axial direction of the shaft.

3. The motor according to claim 2, characterized in that: The power system components are brought into contact with the metal motor bracket via an adhesive.

4. A fan device, characterized in that... include: The motor as described in any one of claims 1 to 3; as well as The fan is driven by the motor to rotate and generate cooling air.

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