Fan unit

Abstract

To provide a motor in which liquid drops having entered a space around a shaft can be discharged with a simple structure.SOLUTION: A motor includes a motor bracket, a shaft, a rotor yoke, a bearing, and a stator around which a coil that generates a magnetic field for rotating the rotor yoke is wound. The rotor yoke has a cylindrical outer circumferential wall that is disposed radially outside the stator and that has an inner circumferential surface supporting a plurality of permanent magnets, a cylindrical inner circumferential wall that is disposed radially inside the stator and that is supported by the bearing in a rotatable manner with respect to the shaft, and a disk-shaped connection wall for connecting, at the other end side in the axial direction of the shaft, an end of the outer circumferential wall and an end of the inner circumferential wall. An axial direction groove that extends in the axial direction and is open to the other end side of the shaft is formed in the outer circumferential surface of the bearing and / or the inner circumferential surface of the inner circumferential wall.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention Ha, Fu This relates to a fan device. [Background technology]

[0002] In recent years, efforts have been made to promote the Sustainable Development Goals (2030 Agenda for Sustainable Development, adopted at the United Nations Summit on September 25, 2015, hereafter referred to as "SDGs"). Accordingly, technologies that aim to reduce waste and defective products in order to ensure sustainable production and consumption patterns have become well known.

[0003] An outer rotor brushless motor, which rotates a rotor yoke located outside the stator, is used, for example, as a fan motor to drive an in-vehicle cooling fan. Motors used in this type of application require the drainage of liquid droplets (e.g., rainwater) that may have entered the motor.

[0004] To address this issue, a motor is known in which a through hole communicating with a drainage channel formed inside the motor is formed in the bearing holder to drain droplets that have entered the space around the shaft (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6132877 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the technology of Patent Document 1 requires the formation of drainage channels in the gaps between the bracket, stator, and rotor, which makes the motor structure complex and the drainage channels longer, making it difficult to discharge droplets.

[0007] Therefore, an object of the present invention is to provide a device that can drain droplets that have entered the space around the shaft with a simple configuration. Fan unit The purpose is to provide [Means for solving the problem]

[0008] In order to achieve the above object, the present invention provides a motor comprising: a motor bracket; a shaft having one axial end fixed to the motor bracket; a rotor yoke supporting a plurality of permanent magnets spaced at predetermined intervals in the circumferential direction; a bearing supporting the rotor yoke rotatably relative to the shaft; and a stator fixed to the motor bracket inside the plurality of permanent magnets and wound with a coil that generates a magnetic field for rotating the rotor yoke. and a fan rotated by the driving force of the motor, The rotor yoke has a cylindrical outer peripheral wall that is disposed radially outward from the stator and supports the plurality of permanent magnets on its inner peripheral surface, a cylindrical inner peripheral wall that is disposed radially inward from the stator and is supported by the bearing so as to be rotatable relative to the shaft, and a disk-shaped connecting wall that connects ends of the outer peripheral wall and the inner peripheral wall at the other axial end side of the shaft, and an axial groove that extends in the axial direction and is open to the other end side of the shaft is formed on at least one of the outer peripheral surface of the bearing and the inner peripheral surface of the inner peripheral wall. The fan is fixed to the connecting wall and rotates, and a surface of the fan that contacts the connecting wall is formed with a plurality of radial grooves that extend radially to avoid a mounting position with the connecting wall. . [Effects of the Invention]

[0009] According to the present invention, droplets that have entered the space around the shaft can be drained with a simple configuration. Problems, configurations, and effects other than those described above will become clear from the following description of the embodiments. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is an external perspective view showing an example of the configuration of a fan device according to an embodiment; [Figure 2] FIG. 2 is an exploded perspective view of the motor and the fan. [Figure 3]FIG. 2 is a perspective view of the motor as viewed from the front side. [Figure 4] FIG. 2 is a perspective view showing the configuration of the motor with the rotor yoke removed. [Figure 5] FIG. 4 is a cross-sectional view taken along line VV in FIG. [Figure 6] FIG. 2 is an exploded perspective view of components around the shaft. [Figure 7] 1A and 1B are perspective views of a rotor yoke as viewed from the front side and the back side, respectively. [Figure 8] 10A and 10B are diagrams showing variations in the shape of the back surface side of the boss portion. [Figure 9] FIG. 2 is a cross-sectional view of the fan and rotor yoke. DETAILED DESCRIPTION OF THE INVENTION

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A fan device mounted on a vehicle such as an automobile to cool engine coolant flowing through a radiator will be described below as one aspect of a fan device according to an embodiment of the present invention.

[0012] (Overall configuration of fan device 1) First, the overall configuration of a fan device 1 will be described with reference to Figures 1 and 2. Figure 1 is an external perspective view showing an example of the configuration of a fan device 1 according to an embodiment. Figure 2 is an exploded perspective view of a motor 2 and a fan 3 disassembled.

[0013] 1 and 2, the fan device 1 includes a motor 2 as a drive source and a fan 3 that is rotated and driven by the motor 2 to generate cooling air. The fan device 1 is disposed, for example, in an engine room so as to face a radiator. For example, when the vehicle body is positioned on a horizontal plane, the fan device 1 is disposed in the engine room so that the shaft 21 of the motor 2 extends horizontally. However, if the vehicle body tilts, the extension direction of the shaft 21 also tilts from the horizontal direction.

[0014] (Motor 2 configuration) Next, the configuration of the motor 2 will be described with reference to Figs. 3 to 7. Fig. 3 is an external perspective view of the motor 2 as seen from the front side. Fig. 4 is a perspective view showing the configuration of the motor 2 with the rotor yoke 232 removed. Fig. 5 is a cross-sectional view taken along line VV in Fig. 3.

[0015] As shown in Figures 3 to 5, motor 2 is a so-called "mechanically integrated" electric motor that includes an outer rotor type brushless motor 201 and a driver circuit 202 that controls brushless motor 201 (more specifically, the generation of a magnetic field by coil 243).

[0016] The brushless motor 201 is supported by a plate-shaped motor bracket 203. The brushless motor 201 is disposed on one side (front surface side) of the motor bracket 203 in the thickness direction.

[0017] 5, a driver bracket 204 is fastened to the other side (rear side) in the thickness direction of the motor bracket 203 by a plurality of screws 205. As a result, an accommodation space 206 is formed between the motor bracket 203 and the driver bracket 204. The driver circuit 202 is accommodated in this accommodation space 206.

[0018] In addition, a connector unit 207, which combines two connectors to which an external harness is connected, is attached to an end of the motor bracket 203. The brushless motor 201, the driver circuit 202, and the connector unit 207 are electrically connected to one another via the motor bracket 203.

[0019] As shown in Figures 4 and 5, brushless motor 201 has shaft 21, bearings 22A and 22B provided on the outer periphery of shaft 21, rotor 23 rotatably supported around the axis of shaft 21 via bearings 22A and 22B, and annular stator 24 wound with coil 243 that generates a magnetic field for rotating rotor 23.

[0020] The shaft 21 is a fixed shaft with one axial end fixed to the motor bracket 203. In the following description of the components of the motor 2, the axial direction of the shaft 21 will be simply referred to as the "axial direction," the radial direction centered on the axis of the shaft 21 will be simply referred to as the "radial direction," and the circumferential direction centered on the axis of the shaft 21 will be simply referred to as the "circumferential direction."

[0021] 6 is an exploded perspective view of components around the shaft 21. As shown in FIG.

[0022] The shaft 21 has a generally cylindrical outer shape and mainly includes a first shaft portion 211, a second shaft portion 212, and a flange portion 213.

[0023] The first shaft portion 211 and the second shaft portion 212 are portions that extend in opposite directions with a flange portion 213 in between. An inner ring of a bearing 22A is fitted onto the first shaft portion 211. An inner ring of a bearing 22B is fitted onto the second shaft portion 212. In other words, the bearings 22A and 22B are arranged spaced apart in the axial direction.

[0024] The flange portion 213 is a disk-shaped portion that protrudes radially outward and continues in the circumferential direction between the first shaft portion 211 and the second shaft portion 212. That is, the diameter of the flange portion 213 is set to be larger than the diameters of the first shaft portion 211 and the second shaft portion 212. The flange portion 213 functions as a spring seat against which one end of the coil spring 52 abuts.

[0025] Bearings 22A and 22B are ball bearings including an inner ring, an outer ring, a plurality of balls arranged between the inner ring and the outer ring, and a retainer that maintains the circumferential spacing of the plurality of balls. Bearings 22A and 22B are radial bearings that support a load in the radial direction. The inner ring of bearing 22A is fitted onto shaft 21, and the outer ring is fitted into inner circumferential wall 232B. The inner ring of bearing 22B is fitted onto shaft 21, and the outer ring is fitted into inner circumferential wall 232B. As a result, bearings 22A and 22B support rotor yoke 232 rotatably relative to shaft 21.

[0026] The coil spring 52 is fitted onto the first shaft portion 211 between the bearing 22A and the flange portion 213. The coil spring 52 biases the bearing 22A toward the fan 3. As a result, the flange portion 213 is pressed against the bearing 22A.

[0027] 5, the rotor 23 has a plurality of permanent magnets 231 arranged at equal intervals in the circumferential direction so as to surround the outer periphery of the stator 24, and a rotor yoke 232 that covers the stator 24 and the plurality of permanent magnets 231. The rotor yoke 232 is arranged on the front surface side of the motor bracket 203 so as to be concentric with the axis of the shaft 21. The rotor yoke 232 is rotatably supported on the shaft 21 via bearings 22A and 22B.

[0028] 7 is a perspective view of rotor yoke 232 as viewed from the front side (A) and the back side (B). As shown in FIGS. 5 and 7, rotor yoke 232 includes an outer peripheral wall 232A, an inner peripheral wall 232B, and a connecting wall 232C.

[0029] The outer peripheral wall 232A has a cylindrical outer shape. The outer peripheral wall 232A is disposed radially outward of the stator 24. The inner peripheral surface of the outer peripheral wall 232A supports a plurality of permanent magnets 231. 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 in the circumferential direction.

[0030] The inner circumferential wall 232B has a cylindrical outer shape and is disposed radially inward of the stator 24. The inner circumferential wall 232B is rotatably supported by the shaft 21 via bearings 22A and 22B.

[0031] The connecting wall 232C has a disk-shaped outer shape. The connecting wall 232C connects the axial ends of the outer peripheral wall 232A and the inner peripheral wall 232B. More specifically, as shown in Fig. 5, the connecting wall 232C connects the outer peripheral wall 232A and the inner peripheral wall 232B on the other axial end side of the shaft 21 (i.e., the side opposite the motor bracket 203).

[0032] Furthermore, a plurality of (three in this embodiment) axial grooves 233 are formed in the rotor yoke 232. The axial grooves 233 extend in the axial direction on the inner circumferential surface of the inner circumferential wall 232B. The axial grooves 233 are formed at a plurality of positions spaced apart in the circumferential direction (at 120° intervals in this embodiment). However, the number and intervals of the axial grooves 233 are not limited to the above example; for example, six axial grooves 233 may be formed at 60° intervals.

[0033] 5, the axial groove 233 is recessed radially outward from the inner circumferential surface of the inner circumferential wall 232B. One end of the axial groove 233 (the end on the motor bracket 203 side) is located between the pair of bearings 22A and 22B. The other end of the axial groove 233 (the end on the connecting wall 232C side) is open.

[0034] As a result, a gap is formed between the outer circumferential surface of bearing 22A and the inner circumferential surface of inner circumferential wall 232B by axial groove 233. As a result, the space formed between bearings 22A, 22B, shaft 21, and inner circumferential wall 232B (hereinafter referred to as "space around shaft 21") is communicated with the outside of motor 2 (fan 3 side) through axial groove 233. In other words, liquid droplets that have entered the space around shaft 21 are discharged to the outside of motor 2 through axial groove 233.

[0035] The stator 24 is housed in a space surrounded by the outer peripheral wall 232A, the inner peripheral wall 232B, the connecting wall 232C, and the motor bracket 203. The stator 24 is fixed to the surface side of the motor bracket 203, radially inward of the multiple permanent magnets 231. The stator 24 faces the multiple permanent magnets 231 across a predetermined radial gap.

[0036] As shown in Figures 4 and 5, the stator 24 has a cylindrical stator core 241, insulating insulators 242 attached to both axial sides of a plurality of teeth protruding radially outward from the stator core 241, and a conductive coil 243 wound around the insulator 242.

[0037] The stator 24 generates a magnetic field when a current flows through the coil 243. Then, the rotor yoke 232 rotates around the axis of the shaft 21 due to attractive and repulsive forces generated between the magnetic field generated by the coil 243 and the plurality of permanent magnets 231.

[0038] (Fan 3 configuration) As shown in Figures 1 and 2, the fan 3 has a boss portion 31 that rotates integrally with the rotor 23 with the axis of the shaft 21 as its center of rotation, a plurality of blades 32 (seven in this embodiment) that extend radially from the outer periphery of the boss portion 31, and a plurality of connecting members 33 (seven in this embodiment) that connect adjacent blades 32 at their tips.

[0039] Boss portion 31 includes a disk-shaped disk portion 311 and a cylindrical peripheral wall portion 312 that protrudes from the outer edge of disk portion 311 toward motor 2 and has a plurality of blades 32 attached thereto. When fan 3 is attached to motor 2, disk portion 311 faces connecting wall 232C of rotor yoke 232, and peripheral wall portion 312 surrounds outer peripheral wall 232A of rotor yoke 232.

[0040] Fig. 8 is a diagram showing variations in the shape of the back surface (surface facing the connecting wall 232C) of the boss portion 31. As shown in Fig. 8, the disk portion 311 is formed with a plurality of screw holes 313 and a plurality of radial grooves 314A, 314B.

[0041] The plurality of screw holes 313 penetrate the disk portion 311 in the thickness direction in a ring-shaped region of the disk portion 311 that abuts against the connecting wall 232C. The screw holes 313 are formed at predetermined intervals (120° intervals in this embodiment) in the circumferential direction. However, the number of screw holes 313 and the intervals in the circumferential direction are not limited to the above example.

[0042] 2, the fan 3 is fastened to the rotor yoke 232 by screws 10 threaded into the screw holes 313. In this embodiment, in consideration of the rotational balance of the fan 3, three screws 10 are attached at equal intervals on a circumference centered on the rotation center of the fan 3. Note that it is not necessary to use three screws 10 as fastening members for fastening the fan 3 to the motor 2; there are no particular limitations on the number of screws 10 or the type of fastening members as long as the fan 3 can be fastened to the motor 2.

[0043] The plurality of radial grooves 314A, 314B are formed on a surface of the disk portion 311, in a ring-shaped region that abuts against the connecting wall 232C, on the side facing the connecting wall 232C of the fan 3. The plurality of radial grooves 314A, 314B are formed radially, avoiding the screw holes 313 (i.e., the attachment positions with the connecting wall 232C). More specifically, the plurality of radial grooves 314A, 314B extend radially, passing between the screw holes 313 that are adjacent in the circumferential direction.

[0044] As one example, as shown in Fig. 8(A), the radial grooves 314A may be provided so as to extend linearly in the radial direction. As another example, as shown in Fig. 8(B), the radial grooves 314B may be curved radially outward in the direction opposite (i.e., clockwise) to the rotation direction of the fan 3 (counterclockwise in the example of Fig. 8(B)).

[0045] 9 is a cross-sectional view of the fan 3 and the rotor yoke 232. As indicated by the arrows in FIG. 9, liquid droplets that have entered the space around the shaft 21 are discharged through the axial groove 233 into the space between the fan 3 and the rotor yoke 232 (i.e., the side opposite the motor bracket 203). Next, the liquid droplets in the space between the fan 3 and the rotor yoke 232 are discharged radially outward through the radial grooves 314A and 314B by the centrifugal force generated by the rotation of the fan 3 and the rotor yoke 232.

[0046] Furthermore, radially outward of the ring-shaped region where the disk portion 311 and the connecting wall 232C abut, there is an axial gap between the fan 3 and the rotor yoke 232. Therefore, liquid droplets discharged from the radial grooves 314A and 314B by centrifugal force are discharged through this gap to the outside of the fan device 1. On the other hand, liquid droplets that have entered this gap from the outside of the fan device 1 may enter the inner circumferential wall 232B through the radial grooves 314A and 314B and the axial groove 233.

[0047] Therefore, the fan device 1 further includes a narrow portion 315. The narrow portion 315 is disposed between the fan 3 and the connecting wall 232C, radially outward of the radial grooves 314A and 314B. The narrow portion 315 is also selectively disposed on an extension line of the radial grooves 314A and 314B in the circumferentially continuous gap between the fan 3 and the connecting wall 232C. As a result, the gap between the fan 3 and the connecting wall 232C is narrower on the extension line of the radial grooves 314A and 314B than in other areas. However, the narrow portion 315 does not completely close the gap between the fan 3 and the connecting wall 232C, but rather maintains a certain degree of gap.

[0048] As a result, it is possible to prevent droplets from entering radial grooves 314A and 314B from outside fan device 1. On the other hand, centrifugal force acts on droplets discharged from radial grooves 314A and 314B, causing them to bypass narrow portion 315 and be discharged to the outside of fan device 1.

[0049] The narrow portion 315 may be attached to the fan 3 or to the rotor yoke 232. The specific shape of the narrow portion 315 is not particularly limited, and may be a wall, a pillar, a rib, or the like.

[0050] According to the above embodiment, for example, the following advantageous effects are achieved.

[0051] According to the above embodiment, simply by providing the axial groove 233, it is possible to drain droplets that have entered between the shaft 21 and the inner circumferential wall 232B to the side opposite the motor bracket 203 of the motor 2. This makes it possible to drain droplets that have entered the space around the shaft 21 with a simple configuration. As a result, rusting of the shaft 21, bearings 22A and 22B, and coil spring 52 can be prevented, thereby extending the life of the fan device 1 and contributing to a reduction in waste.

[0052] Furthermore, according to the above embodiment, by providing the axial grooves 233 at a plurality of positions spaced apart in the circumferential direction, it is possible to properly discharge droplets in the space around the shaft 21 regardless of the posture at the time of installation of the motor 2. However, if the posture at the time of installation of the motor 2 is fixed, the axial grooves 233 may be provided only below the shaft 21.

[0053] Furthermore, according to the above embodiment, by providing the radial grooves 314A and 314B, it is possible to efficiently discharge the droplets discharged through the axial groove 233 to the outside of the fan device 1. When the fan 3 rotates both clockwise and counterclockwise, by forming the radial groove 314A in a straight line as shown in FIG. 8(A), it is possible to discharge the droplets regardless of the rotation direction of the fan 3. On the other hand, when the fan 3 rotates in only one direction, by curving the radial groove 314B in the direction opposite to the rotation direction of the fan 3 as shown in FIG. 8(B), it is possible to discharge the droplets inside and prevent the intrusion of droplets from the outside.

[0054] Furthermore, according to the above embodiment, by selectively providing narrow portions 315 on the extension lines of the radial grooves 314A and 314B, it is possible to prevent the intrusion of droplets without interfering with the discharge of droplets due to the action of centrifugal force.

[0055] In the above embodiment, an example has been described in which the axial grooves 233 are formed in the inner circumferential surface of the inner circumferential wall 232B, but the position of the axial grooves 233 is not limited to the above example. As another example, the axial grooves 233 extending in the axial direction may be formed in the outer circumferential surface of the bearing 22A that contacts the inner circumferential wall 232B. In other words, it is sufficient that the axial grooves 233 are formed in at least one of the outer circumferential surface of the bearing 22A and the inner circumferential surface of the inner circumferential wall 232B.

[0056] In the above embodiment, the use of the fan device 1 is described as an example of supplying cooling air to a radiator, but the use of the fan device 1 is not limited to this. In the above embodiment, the use of the motor 2 is described as an example of a fan motor that rotates and drives the fan 3, but the use of the motor 2 is not limited to this.

[0057] The above describes an embodiment of the present invention. However, the present invention is not limited to the above embodiment and includes various modifications. For example, the above embodiment has been described in detail to clearly explain the present invention, and is not necessarily limited to an embodiment including all of the described configurations. Furthermore, it is possible to replace part of the configuration of this embodiment with the configuration of another embodiment, or to add the configuration of another embodiment to the configuration of this embodiment. Furthermore, it is possible to add, delete, or replace part of the configuration of this embodiment with other configurations. [Explanation of symbols]

[0058] 1: Fan device 2: Motor 3: Fan 10,205:Screw 21: Shaft 22A, 22B: Bearings 23: Rotor 24: Stator 31: Boss Department 32: Feather 33: Connecting member 52: Coil spring 201: Brushless motor 202: Driver circuit 203: Motor bracket 204: Driver bracket 206: Containment space 207: Connector unit 211: First shaft 212: Second shaft 213: Flange part 231: Permanent magnet 232: Rotor yoke 232A: Outer wall 232B: Inner wall 232C: Connecting wall 233: Axial groove 241: Stator core 242: Insulator 243: Coil 311: Disc section 312: Peripheral wall part 313: screw hole 314A, 314B: Radial groove 315: Narrow part

Claims

1. A motor bracket; a shaft having one axial end fixed to the motor bracket; a rotor yoke that supports a plurality of permanent magnets at predetermined intervals in the circumferential direction; a bearing that rotatably supports the rotor yoke relative to the shaft; a motor including a stator fixed to the motor bracket inside the plurality of permanent magnets and wound with a coil that generates a magnetic field for rotating the rotor yoke; a fan rotated by the driving force of the motor, The rotor yoke is a cylindrical outer wall disposed radially outward of the stator and supporting the plurality of permanent magnets on an inner peripheral surface thereof; a cylindrical inner peripheral wall disposed radially inward of the stator and supported by the bearing so as to be rotatable relative to the shaft; a disk-shaped connecting wall that connects ends of the outer circumferential wall and the inner circumferential wall at the other axial end side of the shaft, an axial groove extending in the axial direction and opening toward the other end side of the shaft is formed on at least one of the outer circumferential surface of the bearing and the inner circumferential surface of the inner circumferential wall; the fan is fixed to the connecting wall and rotates; A fan device, characterized in that a surface of the fan that abuts against the connecting wall is formed with a plurality of radial grooves that extend radially to avoid a mounting position with the connecting wall.

2. The fan device according to claim 1, the rotor yoke is rotatably supported on the shaft by a pair of the bearings spaced apart in the axial direction, The axial groove extends in the axial direction on the inner surface of the inner wall, with one axial end positioned between the pair of bearings and the other axial end open to the connecting wall side.

3. The fan device according to claim 1, The fan device is characterized in that the axial grooves are formed at a plurality of positions spaced apart in the circumferential direction.

4. The fan device according to claim 1, The fan device is characterized in that the radial grooves extend linearly in the radial direction.

5. The fan device according to claim 1, The fan device, wherein the radial grooves are curved radially outward in a direction opposite to the rotation direction of the fan.

6. The fan device according to claim 1, a narrowed portion that narrows a gap between the fan and the connecting wall, the narrowed portion being located radially outward of the radial groove and on an extension of the radial groove;

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