JP2021087315A - Motor and pump - Google Patents

Abstract

To cool an electronic component efficiently.SOLUTION: A motor includes a housing unit having an inner surface and an outer surface, a stator, a rotor, and a heat radiation member. The stator surrounds the outer surface of the housing unit. The rotor is disposed inside with respect to the inner surface of the housing unit. In the radial direction, a gap is formed between the inner surface of the housing unit and the rotor. The heat radiation member is disposed inside with respect to the inner surface of the housing unit together with the rotor.SELECTED DRAWING: Figure 2

Description

The present invention relates to motors and pumps.

An electric water pump may be used as a device for circulating cooling water of an automobile or the like. At that time, it is also necessary to cool the electronic parts for controlling the motor used in the electric water pump.

Japanese Unexamined Patent Publication No. 2012-149603 Japanese Unexamined Patent Publication No. 2004-183595

Among the electronic components, MOS-FET (Metal-Oxide-Semiconductor Field-Effect Transistor) elements and the like generate a particularly large amount of heat, but have not been sufficiently cooled in the past.

The present invention is an example of the above problems, and an object of the present invention is to provide a motor and a pump capable of efficiently cooling electronic components.

A motor according to one aspect of the present invention includes an accommodating portion having an inner peripheral surface and an outer peripheral surface, a stator, a rotor, and a heat radiating member. The stator surrounds the outer peripheral surface of the accommodating portion. The rotor is arranged inside the inner surface of the accommodating portion. In the radial direction, a gap is formed between the inner surface of the accommodating portion and the rotor. The heat radiating member is arranged inside the accommodating portion with respect to the inner surface of the accommodating portion together with the rotor.

According to one aspect of the present invention, electronic components can be efficiently cooled.

FIG. 1 is a perspective view showing an example of the appearance of the water pump according to the embodiment. FIG. 2 is a cross-sectional view taken along the line AA of FIG. FIG. 3 is a front view showing an example of the internal structure of the water pump according to the embodiment. FIG. 4 is a perspective view showing an example of the internal structure of the water pump according to the embodiment. FIG. 5 is a front view showing an example of the internal structure of the water pump according to the embodiment. FIG. 6 is a cross-sectional view taken along the line BB of FIG. FIG. 7 is a partially enlarged view of the vicinity of the heat sink of FIG.

Hereinafter, the motor and the pump according to the embodiment will be described with reference to the drawings. The dimensional relationship of each element in the drawing, the ratio of each element, and the like may differ from the reality. Even between drawings, there may be parts with different dimensional relationships and ratios. In each drawing, in order to make the explanation easy to understand, a three-dimensional Cartesian coordinate system in which the axial direction of the stator 30 described later is the Z-axis positive direction may be illustrated.

FIG. 1 is a perspective view showing an example of the appearance of the water pump according to the embodiment. As shown in FIG. 1, the water pump 1 includes a container 11 having a tubular portion 11a and a bottom portion 11b, and a lid portion 12 covering an opening 11c of the container 11. The container 11 and the lid 12 are made of, for example, a resin member or a metal member. Further, in the axial direction (Z-axis direction side) of the stator 30, the opening 11c of the container 11 is on the opposite side of the bottom 11b. The container 11 and the lid 12 form a housing. The lid portion 12 includes pipes 13 and 14. A part of the motor 2 is housed in the container 11. The motor 2 is, for example, a brushless motor. The motor 2 may include the container 11. The water pump 1 is an example of a pump.

Next, the internal structure of the water pump 1 will be described with reference to FIGS. 2 to 5. FIG. 2 is a cross-sectional view taken along the line AA of FIG. FIG. 3 is a front view showing an example of the internal structure of the water pump according to the embodiment. FIG. 4 is a perspective view showing an example of the internal structure of the water pump according to the embodiment. FIG. 4 shows a view of the internal structure of the water pump shown in FIG. 3 from the lower side (Z-axis negative direction side). FIG. 5 is a front view showing an example of the internal structure of the water pump according to the embodiment. FIG. 5 shows an internal structure in which the stator 30, the terminal 34, the impeller 43, and the bearing 44, which will be described later, are excluded from the internal structure shown in FIG.

As shown in FIG. 2, the motor 2 housed in the container 11 includes a housing portion 20, a stator 30, a shaft 41, a sleeve 42, a rotor 51, a PCB (Printed Circuit Board) 52, and the like. It includes an electronic component 53 and a heat sink 60. Further, the lid portion 12 accommodates the impeller 43. A bearing 64 is provided in the heat sink 60, and a bearing 44 is provided between the recess 43a formed in the impeller 43 and the lid portion 12. The bearing 44 positions the lid 12 with respect to the shaft 41. The heat sink 60 is an example of a heat radiating member.

The shaft 41 is located at the center of the motor 2 in the radial direction and rotatably supports the rotor 51 via the sleeve 42. A part of the shaft 41 (in the embodiment, the end portion 41a on the bottom portion 11b side (Z-axis negative direction side) side) is press-fitted into, for example, a bearing 64 provided in the heat sink 60. Further, the end portion 41a of the shaft 41 is fixed to the motor 2 by being welded to the heat sink 60. That is, the end portion 41a of the shaft 41 is supported by the bearing 64. The bearing 64 is made of, for example, a metal member such as iron. The bearing 64 is fixed to the motor 2 by being press-fitted into the heat sink 60, for example.

Further, the other portion of the shaft 41 (in the embodiment, the end portion 41b on the lid portion 12 side (Z-axis positive direction side) side) is positioned and supported with respect to the lid portion 12 by the bearing 44. The bearing 44 is provided with a plurality of slits 44a arranged in the circumferential direction, and the liquid can flow in and out of the container 11 through the slits 44a. The bearing 44 is made of, for example, a resin member.

The accommodating portion 20 seals the stator 30 with respect to the liquid described later. Further, as shown in FIG. 5, the accommodating portion 20 includes a tubular portion 26 having an outer peripheral surface 21 and an inner peripheral surface 22, and flanges provided on the end portion 26a (on the Z-axis positive direction side) of the tubular portion 26. It has 23 and. The tubular portion 26 having the outer peripheral surface 21 and the inner peripheral surface 22 extends in the rotation axis direction (Z-axis direction) of the motor 2. A heat sink 60, which is the bottom of the accommodating portion 20, is arranged inside the accommodating portion 20 in the radial direction. The tubular portion 26 forms a cup-shaped shape by being in close contact with the heat sink 60. The tubular portion 26 and the heat sink 60 form a cup-shaped shape to prevent the liquid from coming into contact with the stator 30. On the other hand, the inner peripheral surface 22 faces the rotor 51 in the radial direction with a gap G interposed therebetween. The outer peripheral surface 21 is in contact with the stator 30 in the radial direction. The flange 23 faces the lid 12 in the axial direction. The flange 23 is in close contact with the lid portion 12 to ensure airtightness, thereby suppressing the exudation of liquid to the outside of the housing. When the accommodating portion 20 is made of a resin member, the heat sink 60 formed of a metal member is press-fitted into the accommodating portion 20 to fix the heat sink 60 to the accommodating portion 20, and the accommodating portion 20 and the heat sink. The airtightness to the liquid can be ensured at the fixed portion with the 60. Further, if necessary, a part of the accommodating portion 20 formed of the resin member is melted, and the heat sink 60 is inserted into the melted portion and fixed to the liquid in the fixing portion between the accommodating portion 20 and the heat sink 60. The airtightness can be ensured. Further, when the accommodating portion 20 is injection-molded with resin, by integrally forming the accommodating portion 20 together with the metal member forming the heat sink 60, it is possible to improve the airtightness to the liquid in the fixed portion between the accommodating portion 20 and the heat sink 60.

The rotor 51 is formed of a cylindrical magnetic member extending in the Z-axis direction with the shaft 41 as the central axis. The rotor 51 plays the role of a rotor of the motor 2, and is rotatably supported by the shaft 41 via the sleeve 42.

The sleeve 42 is, for example, a metal slide bearing having a shaft 41 as a central axis. The sleeve 42 is fixed to the rotor 51, for example. That is, the sleeve 42 rotates integrally with the rotor 51.

The PCB 52 as a substrate has a wiring 52a for supplying power to and controlling the motor 2. The wiring 52a is formed on the surface of the PCB 52 on the container 11 side (Z-axis negative direction side). An electronic component 53 is connected to the wiring 52a of the PCB 52. The electronic component 53 is electrically connected to the terminal 34 via the wiring 52a. The terminal 34 is electrically connected to the outside via a connector (not shown). Further, the PCB 52 is arranged so as to be separated from the end portion (heat sink 60 side) of the accommodating portion 20 in the axial direction (Z-axis negative direction side).

The electronic component 53 is, for example, a component for controlling the motor 2. The electronic component 53 is, for example, an element such as a MOS-FET (Metal-Oxide-Semiconductor Field-Effect Transistor). The electronic component 53 is provided in contact with the heat sink 60 and is electrically connected to the PCB 52.

The heat sink 60 cools the electronic component 53. The heat sink 60 is provided in close contact with the bottom of the accommodating portion 20. The structure of the heat sink 60 will be described in detail later.

The stator 30 has a cylindrical shape extending in the Z-axis direction around the shaft 41 and surrounding the outer peripheral surface 21 of the accommodating portion 20. The stator 30 plays the role of a stator of the motor 2, and as shown in FIG. 2, the stator 30 has, for example, a rotor 51 having a magnet as a component on the inner peripheral side, and a rotation shaft (shaft) on the rotor 51. It is a stator in an inner rotor type brushless motor to which 41 is coupled.

The stator 30 has a magnetic member (an example of a magnetic material). The magnetic member is formed of, for example, a plate-shaped metal member such as a soft magnetic steel plate such as a silicon steel plate or an electromagnetic steel plate. For example, the stator 30 has a stator core 31 formed by stacking a plurality of plate-shaped metal members in the direction of rotation axis. As shown in FIG. 3, the stator 30 includes a stator core 31, an upper insulator 32 provided on the lid 12 side (Z-axis positive direction side), and a lower portion provided on the container 11 side (Z-axis negative direction side). It has an insulator 33.

Further, a plurality of teeth (not shown) around which a coil (not shown) is wound are formed on the inner peripheral side of the stator 30. The coil is wound around the stator core 31 via, for example, an upper insulator 32 and a lower insulator 33. The upper insulator 32 and the lower insulator 33 are members that electrically insulate the tooth portion of the stator core 31 from the coil wound around the stator core 31, and are formed by, for example, injection molding of an insulating resin. The upper insulator 32 and the lower insulator 33 are formed by, for example, insert molding in which the stator core 31 is embedded therein. The upper insulator 32 covers the stator core 31 from the lid portion 12, that is, from the upper side in the axial direction (the positive direction side of the Z axis). The lower insulator 33 covers the stator core 31 from the container 11 side, that is, from the lower side in the axial direction (the negative side in the Z axis).

A magnetic gap is formed between the plurality of teeth and the rotor 51 shown in FIG. 2, for example, in the gap G between the outer peripheral portion of the rotor 51 and the inner peripheral surface 22 of the accommodating portion 20 surrounded by the teeth. To. That is, the stator 30 forms a magnetic field for rotating the rotor 51 by sequentially energizing the coils wound around the teeth by alternating current supplied from the outside. Further, in the radial direction of the motor 2, a magnetic gap is formed in the gap G between the outer peripheral portion of the rotor 51 and the inner peripheral surface 22 of the accommodating portion 20. As a result, the rotor 51 is rotated by the magnetic field generated by the stator 30.

Further, the lower insulator 33 is provided with, for example, an insertion portion into which the terminal 34 is inserted. The terminal 34 electrically connects the stator 30 and the PCB 52. A conducting wire drawn from the coil is connected to the terminal 34. One end of the terminal 34 is embedded in the insertion portion of the lower insulator 33, and the other end of the terminal 34 is inserted into, for example, an insertion hole provided in the PCB 52. The stator 30 is fixed to the PCB 52 via the terminal 34.

The impeller 43 is fixed to one end on the upper side (Z-axis positive direction side) of the sleeve 42 and rotates together with the sleeve 42. That is, the impeller 43 rotates with the rotation of the rotor 51 shown in FIG. As the impeller 43 rotates, the liquid is sucked from the pipe 13 into the housing, flows through the gap G as shown by the arrow, and is discharged from the pipe 14. That is, in the water pump 1 in this embodiment, the pipe 13 serves as a liquid inlet and the pipe 14 serves as a liquid outlet. Further, the pipes 13 and 14 are connected to the gap G in the accommodating portion 20 via the impeller 43 to form a liquid flow path. The pipe 13 is an example of the first pipe, and the pipe 14 is an example of the second pipe.

As shown in FIG. 4, the PCB 52 is provided apart from the stator 30. The PCB 52 is formed in a ring shape. A part of the heat sink 60 (bottom 60a in the embodiment) is arranged in the opening 52b of the PCB 52. The bottom portion 60a of the heat sink 60 projects from the PCB 52 toward the bottom portion 11b of the container 11. Further, the electronic component 53 is arranged in contact with the contact surface 62 provided on the bottom portion 60a of the heat sink 60. The electronic component 53 is electrically connected to the outside via the wiring 52a formed in the PCB 52. In this embodiment, the configuration including two electronic components 53 will be described, but the number of electronic components 53 provided on the heat sink 60 may be one or three or more.

As shown in FIG. 5, the end portion (Z-axis negative direction side) of the accommodating portion 20 has a first portion 24 in contact with the PCB 52 and a second portion 25 separated from the PCB 52. That is, at the end portion of the accommodating portion 20 on the negative direction side of the Z axis, the first portion 24 is a protruding portion protruding toward the PCB 52.

FIG. 6 is a cross-sectional view taken along the line BB of FIG. As shown in FIG. 6, in the present embodiment, the outer peripheral portion of the heat sink 60 is brought into close contact with the inner peripheral surface 22 of the accommodating portion 20 to ensure airtightness. As a result, the inner peripheral surface 22 and the outer peripheral surface 21 of the accommodating portion 20 are separated from each other. In, the infiltration of liquid into the PCB 52 located below the heat sink 60 is suppressed. Further, as shown in FIG. 6, the lower end portion 42a of the sleeve 42 (Z-axis negative direction) and the upper end portion 64a of the bearing 64 (Z-axis positive direction) face each other with a gap.

The configuration of the heat sink 60 will be described with reference to FIG. FIG. 7 is a partially enlarged view of the vicinity of the heat sink of FIG. As shown in FIG. 7, the heat sink 60 has a plurality of fins 61, a contact surface 62, and a recess 63. The heat sink 60 is made of a metal member such as aluminum having heat dissipation properties. The fin 61 is an example of a part of the heat radiating member, and the contact surface 62 is an example of another part of the heat radiating member.

The fin 61 is formed on the rotor 51 side (Z-axis positive direction side) of the heat sink 60, and forms the bottom of the cup-shaped portion formed by being combined with the accommodating portion 20. That is, the fin 61 is provided at a position inside the accommodating portion 20 in the radial direction and in contact with the flowing liquid in the gap G.

The contact surface 62 is located on the opposite side of the heat sink 60 from the fin 61 in the Z-axis direction, and is a surface on which the electronic component 53 is arranged. The recess 63 is a portion where the bearing 64 is press-fitted and the shaft 41 is welded to be fixed. The recess 63 is provided in the center of the fin 61.

In the heat sink 60 that contacts the surface of the electronic component 53 in the present embodiment, at least a fin 61 that is a part of the heat sink 60 is provided inside the inner peripheral surface 22 of the accommodating portion 20 in the radial direction. As a result, the fin 61 is cooled by touching the flowing liquid in the gap G between the accommodating portion 20 and the rotor 51, so that the heat sink 60 can cool the electronic component 53 more efficiently.

Further, in another example, the electronic components are arranged apart from the PCB and the accommodating portion in order to dissipate heat from the electronic components. On the other hand, in the present embodiment, since the electronic component 53 can be efficiently cooled by the fin 61, the electronic component 53 and the PCB 52 can be provided close to each other.

As described above, the motor 2 according to the embodiment includes an accommodating portion 20 having an outer peripheral surface 21 and an inner peripheral surface 22, a stator 30, a rotor 51, and a heat radiating member 60. The stator 30 surrounds the outer peripheral surface 21 of the accommodating portion 20. The rotor 51 is arranged inside the accommodating portion 20 with respect to the inner surface. In the radial direction, a gap G is formed between the inner surface of the accommodating portion 20 and the rotor 51. The heat radiating member 60 is arranged inside the accommodating portion 20 together with the rotor 51. As a result, the electronic components can be efficiently cooled.

Although the embodiments and modifications of the present invention have been described above, the present invention is not limited to the above embodiments and modifications, and various modifications can be made without departing from the spirit of the present invention. For example, the configuration in which the heat sink 60 covers the entire bottom portion of the accommodating portion 20 has been described, but the present invention is not limited to this. It may be configured to be adhered. In such a configuration, the heat sink 60 forms part of the bottom of the cup-shaped portion rather than the entire bottom.

For example, in the above-described embodiment, the case where the motor 2 is an inner rotor type electric brushless motor used for in-vehicle use has been described, but the motor 2 may be a motor used for other than in-vehicle use, and the outer rotor may be used. It may be a type brushless motor, or it may be another known motor such as a brushed motor or a stepping motor.

Further, the electronic component 53 cooled by the heat sink 60 is not limited to the MOS-FET, and may be an electronic component that generates heat such as a capacitor. Further, the PCB 52 may be further provided with a heat radiating member such as heat radiating silicon separately from the heat sink 60.

Further, the configuration in which the liquid sucked into the pipe 13 from the Z-axis positive direction is discharged from the pipe 14 in the X-axis negative direction has been described, but the present invention is not limited to this, and the liquid sucked from the pipe 14 is discharged from the pipe 13. It may be configured to do so. Further, the motor 2 may be configured to be used not as a water pump but as a pump that sucks gas. Even in this case, the heat sink 60 can effectively cool the electronic component 53 when the fin 61 comes into contact with the gas flowing through the gap G.

As shown in FIG. 6, a gap is provided between the end portion 42a of the sleeve 42 and the end portion 64a of the bearing 64, but the end portion 42a of the sleeve 42 is a bearing due to vibration of the motor 2 or the like. It may come into contact with the end 64a of 64. Therefore, it is preferable that the surface of the end portion 42a of the sleeve 42 that comes into contact with the bearing 64 is minimal. For example, as shown in FIG. 6, the end portion 42a of the sleeve 42 may be curved. Further, the end portion 64a of the bearing 64 preferably has a smooth surface shape.

Moreover, the present invention is not limited by the above-described embodiment. The present invention also includes a configuration in which the above-mentioned components are appropriately combined. Further, further effects and modifications can be easily derived by those skilled in the art. Therefore, the broader aspect of the present invention is not limited to the above-described embodiment, and various modifications can be made.

1 Water pump, 2 motors, 11 containers, 12 lids, 13, 14 pipes, 20 accommodating parts, 21 outer peripheral surfaces, 22 inner peripheral surfaces, 23 flanges, 24 first parts, 25 second parts, 26 cylinders, 30 Stator, 31 stator core, 32 upper insulator, 33 lower insulator, 34 terminals, 41 shaft, 42 sleeve, 43 impeller, 44,64 bearing, 51 rotor, 52 PCB (printed board), 53 electronic components (MOS-FET), 60 Heat sink, 61 fins, 62 contact surfaces, 63 recesses

Claims (7)

An accommodating portion having an inner peripheral surface and an outer peripheral surface,
With the stator
With the rotor
Heat dissipation member and
With
The stator surrounds the outer peripheral surface of the accommodating portion.
The rotor is arranged inside the inner surface of the accommodating portion.
In the radial direction, a gap is formed between the inner surface of the accommodating portion and the rotor.
A motor in which the heat radiating member is arranged inside the accommodating portion together with the rotor. The motor according to claim 1, wherein one or a plurality of electronic components are in contact with the heat radiating member. The motor according to claim 1 or 2, wherein the heat radiating member comes into contact with a gas or liquid inside the accommodating portion with respect to the inner surface. The heat radiating member includes a part that comes into contact with the gas or liquid and another part that comes into contact with the electronic component.
The motor according to claim 3, wherein a part of the heat radiating member is in the accommodating portion. The motor according to claim 4, wherein a plurality of fins are provided in a part of the heat radiating member. A housing with a lid having a pipe and a container
The motor according to any one of claims 1 to 5, wherein the pipe is connected to the gap. The motor according to claim 6 and
The impeller arranged in the lid is provided.
The lid portion includes a second pipe with the pipe as the first pipe.
The first pipe is provided with a suction port for sucking a liquid.
The second pipe is a pump provided with a discharge port for discharging liquid.

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