motor

Abstract

This technology provides a way to suppress the inflow of foreign matter into the motor. [Solution] The cover portion 6 has a through hole 62 through which the shaft 30 is inserted, and a wall portion 64 that protrudes from the through hole 62 to the first end side D1 and covers the outer circumferential surface of the shaft 30 in an annular shape. The blade portion 5 has a cylindrical fitting cylinder portion 55 that fits onto the shaft 30, a disc-shaped base portion 54 that extends radially outward from the first end side D1 of the fitting cylinder portion 55, and a blade hub portion 56 that protrudes from the radially outward side of the base portion 54 to the outward side of the second end side D2 and covers the fitting cylinder portion 55 in an annular shape. With the fitting cylinder portion 55 fitted onto the shaft 30, the tip P1 of the blade hub portion is located at the second end side D2, which is further than the tip P2 of the wall portion.

Description

Technical Field

[0001] This disclosure relates to a motor.

Background Art

[0002] The motor is covered by a bracket. A shaft hole is formed in the upper part of the bracket, and a bearing is provided inside the lower part thereof. A shaft is rotatably held by the bearing. The shaft is exposed outside the bracket from the shaft hole. Also, a stator core is arranged inside the bracket (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] There is a gap between the shaft hole and the shaft, and foreign matters such as dust and water may flow into the bracket through the gap, which may have an adverse effect on the stator core, bearing, etc. Therefore, it is required to suppress the inflow of foreign matters.

[0005] This disclosure has been made to solve the above problems, and an object thereof is to provide a technique for suppressing the inflow of foreign matters into the motor.

Means for Solving the Problems

[0006] To solve the above problems, a motor according to one aspect of the present disclosure comprises a shaft that extends axially and is rotatable about an axis, with axial and radial directions defined with respect to the axis, and a first end and a second end defined as the two ends in the axial direction; a rotor yoke that rotates integrally with the shaft, having a cylindrical stator core that covers the outer surface of the shaft; a hollow cylindrical portion that covers the stator core in an annular manner; a fixed end that extends from the first end of the cylindrical portion to the outer surface of the shaft and covers the first end surface of the stator core; a stator base that faces the second end of the cylindrical portion and covers the second end surface of the stator core; a cup-shaped cover portion fixed to the stator base and covering the rotor yoke; and a blade portion that is positioned on the first end side of the fixed end and rotates integrally with the shaft. The cover portion has a through hole through which the shaft is inserted and a wall portion that protrudes from the through hole toward the first end and covers the outer surface of the shaft in an annular manner. The blade portion includes a cylindrical fitting cylinder portion that fits onto the shaft, a disc-shaped base portion that extends radially outward from the first end of the fitting cylinder portion, a blade hub portion that protrudes from the radially outward side of the base portion toward the second end and covers the fitting cylinder portion in an annular shape, and a blade that protrudes radially outward from the blade hub portion. When the fitting cylinder portion is fitted onto the shaft, the tip of the protrusion of the blade hub portion is located toward the second end than the tip of the protrusion of the wall portion. [Effects of the Invention]

[0007] According to this disclosure, it is possible to suppress the inflow of foreign matter into the motor. [Brief explanation of the drawing]

[0008] [Figure 1] This is a side view showing the configuration of the motor according to the embodiment. [Figure 2] Figure 1 is an exploded perspective view showing the motor after it has been disassembled. [Figure 3] This is a schematic side cross-sectional view of the motor shown in Figure 1. [Figure 4] Figure 3 is a disassembled side cross-sectional view showing the motor after it has been disassembled. [Modes for carrying out the invention]

[0009] Hereinafter, embodiments for implementing this disclosure will be described with reference to the attached drawings. The embodiments described below all represent preferred specific examples of this disclosure. Therefore, the numerical values, shapes, materials, components, arrangement and connection configurations of components, as well as the steps (processes) and the order of steps shown in the following embodiments are examples and are not intended to limit this disclosure. Accordingly, among the components in the following embodiments, those components that are not described in the independent claims representing the highest-level concept of this disclosure will be described as arbitrary components. In addition, substantially identical components are denoted by the same reference numerals in each figure, and redundant explanations are omitted or simplified.

[0010] Furthermore, while terms including ordinal numbers such as "first" and "second" are used to describe various components, these terms are used solely to distinguish one component from others, and do not limit the components themselves.

[0011] The configuration of the motor 10 according to this embodiment will be explained with reference to Figures 1 to 4. Figure 1 is a side view showing the configuration of the motor 10, and Figure 2 is an exploded perspective view showing the motor 10 disassembled. Hereinafter, for convenience, the direction along the axis S will be called the "axial direction," the direction of the diameter R of a circle centered on the axis S on a plane perpendicular to the axis S will be called the "radial direction," and the direction of the circumference of the said circle will be called the "circumferential direction." Here, with respect to the "radial direction," the direction approaching the axis S will be called the inner radial direction, and the direction away from the axis S will be called the outer radial direction. Also, the plane perpendicular to the axial direction will be called the "axial orthogonal plane." Furthermore, the first end side D1 and the second end side D2 are defined as the two ends in the axial direction. The first end side D1 may be called the upper side, and the second end side D2 may be called the lower side. Such directional notation does not restrict the orientation of the motor 10, and the motor 10 can be used in any orientation.

[0012] As shown in Figure 1, in the motor 10, the blade section 5, cover section 6, and stator base 26 are arranged in order from the first end D1 to the second end D2. As shown in Figure 2, the rotor yoke 40 is positioned between the cover section 6 and the stator base 26, and the stator 2 (stator unit 25) is positioned between the rotor yoke 40 and the stator base 26. The motor 10 is also equipped with a shaft 30, which extends axially and is rotatable about axis S. The blade section 5 and rotor yoke 40 rotate integrally with the shaft 30. In other words, the blade section 5, rotor yoke 40, and shaft 30 constitute a rotating body (rotor 4).

[0013] Figure 3 is a schematic side cross-sectional view of the motor 10. This figure shows a cross-section obtained by cutting the motor 10 through a plane passing through axis S. Figure 4 is an exploded side cross-sectional view showing the motor 10 disassembled.

[0014] The motor 10 mainly comprises a stator 2, a rotor 4, a cover 6, a shaft 30, a first bearing 31, a second bearing 32, and a circuit board (not shown). The stator 2, the cover 6, and the circuit board constitute a stationary body.

[0015] The rotor 4 is rotatably supported relative to the stator 2 via a first bearing 31 and a second bearing 32. The first bearing 31 and the second bearing 32 are located inside the stator core 21 and rotatably support the shaft 30. The rotor 4 mainly comprises the shaft 30, a cup-shaped rotor yoke 40, and a blade portion 5 that is detachable from the rotor yoke 40.

[0016] The shaft 30 extends cylindrically in the axial direction along the axis S. The rotor yoke 40 has a hollow cylindrical portion 41 that covers the stator core 21 in an annular shape, and a fixed end portion 42 that extends from the first end D1 of the cylindrical portion 41 to the outer circumferential surface of the shaft 30 and covers the surface of the first end D1 of the stator core 21. A cylindrical end portion 43 is also provided at the second end D2 of the cylindrical portion 41.

[0017] The rotor yoke 40 is formed by resin molding such as injection molding using a plastic such as polyamide resin mixed with magnetic powder (hereinafter referred to as "magnetic resin"). The rotor 4 of the embodiment is manufactured by insert molding in which the molten magnetic resin (hereinafter referred to as "molten resin") is poured into a molding die containing the shaft 30. By insert molding, the shaft 30 and the rotor yoke 40 are integrated.

[0018] The rotor yoke 40 is a plastic magnet with high residual magnetic flux density and axial anisotropy. The rotor yoke 40 is insert molded while applying a magnetic field for axial anisotropy. A predetermined number of drive magnetic poles are provided on the inner peripheral surface of the cylindrical portion 41 of the rotor yoke 40 by magnetization treatment. Due to the characteristics of the axial anisotropic magnet, no magnetic poles are formed on the outer peripheral surface of the cylindrical portion 41. Therefore, the embodiment does not include a back yoke.

[0019] The stator 2 mainly includes a stator core 21, a first insulator 22, a second insulator 23, a winding 24, a stator base 26, a stator base support portion 28, and a stator unit support portion 29. The stator core 21 has a cylindrical shape and covers the outer peripheral surface of the shaft 30. The first insulator 22 is disposed above the stator core 21, and the second insulator 23 is disposed below the stator core 21. The first insulator 22 and the second insulator 23 sandwich the stator core 21 from both sides in the axial direction. The first insulator 22 and the second insulator 23 are resin members formed by mold molding.

[0020] The winding 24 is wound around the stator core 21 via the first insulator 22 and the second insulator 23. The stator core 21, the first insulator 22, the second insulator 23, the winding 24, and the substrate are integrated to form a stator unit 25. In the embodiment, four windings 24 are provided at intervals of 90° in the circumferential direction.

[0021] The stator base 26 is a disk-shaped member that supports the stator unit 25. The stator base 26 faces the second end side D2 of the cylindrical portion 41 and covers the surface of the second end side D2 of the stator core 21.

[0022] The stator base support portion 28 and the stator unit support portion 29 are members that integrate the stator unit 25 and the stator base 26 by engaging with each other. Here, the stator base support portion 28 is provided below the second insulator 23. Also, the stator unit support portion 29 is provided above the stator base 26. When the stator base support portion 28 and the stator unit support portion 29 engage, the stator unit 25 and the stator base 26 are integrated. Note that the stator base support portion 28 may be formed integrally with the second insulator 23. Also, the stator unit support portion 29 may be formed integrally with the stator base 26.

[0023] The substrate is a substantially semicircular printed circuit board that extends along a plane orthogonal to the axial direction. A Hall element and a drive circuit (both not shown) are mounted on the substrate. The Hall element outputs a detection signal that is approximately proportional to the magnetic flux density of the magnetic flux when the magnetic flux from the drive magnetic pole of the cylindrical portion 41 passes through the Hall element. The drive circuit supplies a drive current to the winding 24 based on the detection signal of the Hall element. The lower portion of the second insulator 23 is fixed to the substrate.

[0024] The cover portion 6 has a cup shape with a wide second end side D2 and a narrow first end side D1, and the edge of the second end side D2 is fixed to the stator base 26. The cover portion 6 covers the rotor yoke 40 when fixed to the stator base 26. A through hole 62, which is a circular opening, is provided at the first end side D1 of the cover portion 6. The through hole 62 is disposed on the first end side D1 with respect to the fixed end portion 42 of the rotor yoke 40 and the shaft 30 is inserted therethrough. Further, a wall portion 64 protruding from the through hole 62 to the first end side D1 is provided, and the wall portion 64 annularly covers the outer peripheral surface of the shaft 30.

[0025] The blade portion 5 is attached to the shaft 30 that protrudes from the through hole 62 to the first end side D1. Therefore, the blade portion 5 is positioned at the first end side D1 rather than the fixed end 42. The blade portion 5 is arranged in the following order from the inside to the outside in the radial R direction: fitting cylinder portion 55, base portion 54, blade hub portion 56, and blade 57. The fitting cylinder portion 55 is cylindrical and fits onto the shaft 30. The surface of the second end side D2 of the fitting cylinder portion 55 contacts the surface of the first end side D1 of the fixed end 42 inside the wall portion 64. The base portion 54 is disc-shaped and extends outward in the radial R direction from the first end side D1 of the fitting cylinder portion 55.

[0026] The blade hub portion 56 protrudes from the outside of the base portion 54 in the radial R direction toward the second end D2. Therefore, the blade hub portion 56 covers the fitting cylinder portion 55 in an annular shape. When the fitting cylinder portion 55 is fitted onto the shaft 30, the fitting cylinder portion 55, the through hole 62, and the blade hub portion 56 are arranged in order toward the outside in the radial R direction. Also, when the fitting cylinder portion 55 is fitted onto the shaft 30, the tip of the protrusion of the blade hub portion 56 (hereinafter referred to as "blade hub portion tip P1") is located at the second end D2, which is further away from the tip of the protrusion of the wall portion 64 (hereinafter referred to as "wall portion tip P2"). Furthermore, a blade 57 is provided on the blade hub portion 56, and the blade 57 protrudes outward from the blade hub portion 56 in the radial R direction.

[0027] The cylindrical portion 41 of the rotor yoke 40 is provided with a first inflow suppression wall 44 that protrudes cylindrically from the cylindrical end 43 at the second end D2 further toward the second end D2. The first inflow suppression wall 44 suppresses the inflow of foreign matter into the rotor yoke 40 from the gap between the rotor yoke 40 and the stator base 26. The stator base 26 is also provided with a second inflow suppression wall 70 that protrudes cylindrically from the stator base 26 toward the first end D1. The second inflow suppression wall 70 suppresses the inflow of foreign matter into the rotor yoke 40 from the gap between the rotor yoke 40 and the stator base 26. Here, the second inflow suppression wall 70 and the first inflow suppression wall 44 are arranged in order toward the outside in the radial R direction. Furthermore, the tip of the protrusion of the second inflow suppression wall 70 (hereinafter referred to as "second inflow suppression wall tip P3") is located at the first end D1 than the tip of the protrusion of the first inflow suppression wall 44 (hereinafter referred to as "first inflow suppression wall tip P4").

[0028] This section describes the path through which foreign matter enters the motor 10. In Figure 3, the path through which foreign matter enters is indicated as the inflow path U. The inflow path U enters the space enclosed by the fitting cylinder 55, the base 54, and the blade hub 56 from the outside of the motor 10 through the gap between the blade hub 56 and the wall 64, passes through the gap between the wall 64 and the fitting cylinder 55, and proceeds to the space between the cover 6 and the rotor yoke 40. In doing so, the inflow path U avoids the tip P1 of the blade hub and then the tip P2 of the wall, resulting in a complex path that meanders between the first end D1 and the second end D2.

[0029] The inflow path U, which has advanced into the space between the cover portion 6 and the rotor yoke 40, enters the interior of the rotor yoke 40 by passing between the first inflow suppression wall 44 and the second inflow suppression wall 70. Here again, the inflow path U avoids the tip P3 of the second inflow suppression wall and then the tip P4 of the first inflow suppression wall, so it becomes a complex path by meandering between the first end side D1 and the second end side D2. Because the inflow path U is complex, it becomes difficult for foreign matter to enter the interior of the rotor yoke 40. In addition, since the first bearing 31 and the second bearing 32, which require the most protection, are located inside the rotor yoke 40, the first bearing 31 and the second bearing 32 are less susceptible to the effects of foreign matter.

[0030] The operation of the motor 10 is described below. When a drive current is supplied from the drive circuit to the winding 24 based on the detection signal from the Hall element, a magnetic field corresponding to the drive current is generated around the stator core 21. Due to the interaction between this magnetic field and the drive magnetic poles of the rotor yoke 40, a rotational torque is generated in the rotor yoke 40, and the shaft 30 rotates around the axis S in accordance with this torque. As the shaft 30 rotates, the blades 5 connected to the shaft 30 also rotate. In other words, when a drive current is supplied from the drive circuit to the winding 24, the rotor 4 rotates.

[0031] In this embodiment, with the fitting cylinder portion 55 fitted onto the shaft 30, the tip P1 of the blade hub portion 56 is located at the second end D2 of the wall portion 64, thus making the inflow path U2 more complex. Furthermore, because the inflow path U is complex, the inflow of foreign matter into the motor 10 can be suppressed. In addition, since the tip P1 of the blade hub portion and the tip P2 of the wall portion protrude alternately, a U-shaped gap is formed when viewed in cross-section from the outside in the radial R direction. In other words, the intrusion path of foreign matter is further complicated, thus further suppressing the inflow of foreign matter. Here, "alternately" means that a part of the wall portion 64 and a part of the blade hub portion 56 overlap.

[0032] Furthermore, since the fitting cylinder portion 55 is located inside the wall portion 64, the gap between the wall portion 64 and the shaft 30 can be narrowed. Also, because the gap between the wall portion 64 and the shaft 30 is narrow, the inflow of foreign matter can be suppressed. In addition, since the first bearing 31 and the second bearing 32 are arranged inside the stator core 21, the influence of foreign matter on the first bearing 31 and the second bearing 32 can be suppressed. Furthermore, since the first inflow suppression wall 44 is provided, the inflow of foreign matter can be suppressed. Furthermore, since the second inflow suppression wall 70 is provided, the inflow of foreign matter can be suppressed. Furthermore, since the tip P3 of the second inflow suppression wall is located on the first end side D1 than the tip P4 of the first inflow suppression wall, the tip P3 of the second inflow suppression wall and the tip P4 of the first inflow suppression wall can be made to protrude alternately. Furthermore, since the tip P3 of the second inflow suppression wall and the tip P4 of the first inflow suppression wall protrude alternately, the intrusion of foreign matter can be suppressed.

[0033] An overview of one aspect of this disclosure is as follows: (Item 1) The axial (S) direction and radial (R) direction are defined with respect to the axis (S), and the first end (D1) and second end (D2) are defined as the two ends of the axial (S) direction. A shaft (30) extending in the direction of the axis (S) and rotatable about the axis (S), A cylindrical stator core (21) covers the outer surface of the shaft (30), A rotor yoke (40) having a hollow cylindrical portion (41) that covers the stator core (21) in an annular shape, and a fixed end portion (42) that extends from the first end side (D1) of the cylindrical portion (41) to the outer circumferential surface of the shaft (30) and covers the surface of the first end side (D1) of the stator core (21), and which rotates integrally with the shaft (30), A stator base (26) is provided, which faces the second end (D2) of the cylindrical portion (41) and covers the surface of the second end (D2) of the stator core (21), A cup-shaped cover portion (6) is fixed to the stator base (26) and covers the rotor yoke (40), The system includes a vane portion (5) positioned on the first end side (D1) of the fixed end (42) and rotating integrally with the shaft (30), The cover portion (6) is, The shaft (30) has a through hole (62) through which it is inserted, The shaft (30) has a wall portion (64) that protrudes from the through hole (62) toward the first end (D1) and covers the outer circumferential surface of the shaft (30) in an annular shape, The aforementioned blade portion (5) is A cylindrical fitting tube portion (55) that fits onto the shaft (30), A disc-shaped base portion (54) extending outward in the radial (R) direction from the first end side (D1) of the fitting cylindrical portion (55), A wing hub portion (56) protrudes from the outer side of the base portion (54) in the radial (R) direction toward the second end side (D2) and covers the fitting cylinder portion (55) in an annular manner, The hub portion (56) for the blade has a blade (57) that protrudes outward in the radial (R) direction, A motor (10) in which, with the fitting cylinder portion (55) fitted onto the shaft (30), the tip of the protrusion of the blade hub portion (56) is located further towards the second end (D2) than the tip of the protrusion of the wall portion (64).

[0034] (Item 2) The motor (10) described in item 1, wherein the fitting cylinder portion (55) is fitted onto the shaft (30), and the fitting cylinder portion (55), the wall portion (64), and the blade hub portion (56) are arranged in order toward the outside in the radial (R) direction.

[0035] (Item 3) The system further includes bearings (31, 32) that rotatably support the shaft (30), The bearings (31, 32) are located inside the stator core (21) of the motor (10) described in item 1.

[0036] (Item 4) The rotor yoke (40) is The cylindrical portion (41) further has a first inflow suppression wall (44) that protrudes cylindrically from the second end side (D2) to the second end side (D2), The motor (10) according to item 1, wherein the first inflow suppression wall (44) suppresses the inflow of foreign matter from the gap between the rotor yoke (40) and the stator base (26) into the inside of the rotor yoke (40).

[0037] (Item 5) The stator base (26) is It has a second inflow-restricting wall (70) that protrudes cylindrically from the first end side (D1), The motor (10) according to item 4, wherein the second inflow suppression wall (70) suppresses the inflow of foreign matter into the inside of the rotor yoke (40) from the gap between the rotor yoke (40) and the stator base (26).

[0038] (Item 6) The second inflow-restricting wall (70) and the first inflow-restricting wall (44) are arranged in order toward the outer side in the radial (R) direction. The motor (10) according to item 5, wherein the tip of the protrusion of the second inflow suppression wall (70) is located closer to the first end (D1) than the tip of the protrusion of the first inflow suppression wall (44).

[0039] The present disclosure has been explained above based on examples. These examples are illustrative, and it will be understood by those skilled in the art that various modifications are possible for each component or combination of processing steps, and that such modifications are also within the scope of the present disclosure. [Explanation of Symbols]

[0040] D1 First end, P1 Tip of hub section for blades, 2 Stator, D2 Second end, P2 Tip of wall section, P3 Tip of second inflow suppression wall, 4 Rotor, P4 Tip of first inflow suppression wall, 5 Blade section, 6 Cover section, 10 Motor, 21 Stator core, 22 First insulator, 23 Second insulator, 24 Winding, 25 Stator unit, 26 Stator base, 28 Stator base support section, 29 Stator unit support section, 30 Shaft, 31 First bearing, 32 Second bearing, 34 Washer, 35 Circumferential groove, 40 Rotor yoke, 41 Cylindrical section, 42 Fixed end, 43 Cylindrical end, 44 First inflow suppression wall, 54 Base section, 55 Fitting cylinder section, 56 Hub section for blades 57 blade, 62 through hole, 64 wall section, 70 second inflow suppression wall.

Claims

1. The axial and radial directions are defined with respect to the axis, and the first end and second end are defined as the two ends in the axial direction. A shaft extending in the axial direction and rotatable about the axis, A cylindrical stator core covering the outer surface of the shaft, A rotor yoke having a hollow cylindrical portion that covers the stator core in an annular shape, and a fixed end portion that extends from the first end of the cylindrical portion to the outer circumferential surface of the shaft and covers the first end surface of the stator core, and which rotates integrally with the shaft, A stator base facing the second end of the cylindrical portion and covering the second end surface of the stator core, A cup-shaped cover portion fixed to the stator base and covering the rotor yoke, It comprises a vane portion positioned on the first end side of the fixed end and rotating integrally with the shaft, The aforementioned cover portion is A through hole through which the aforementioned shaft is inserted, It has a wall portion that protrudes from the through hole toward the first end and covers the outer surface of the shaft in an annular manner, The aforementioned wing portion is, A cylindrical fitting tube portion that fits onto the aforementioned shaft, A disc-shaped base portion extending radially outward from the first end of the fitting cylinder portion, A hub portion for blades that protrudes from the radially outer side of the base toward the second end and covers the fitting cylinder portion in an annular manner, It has a blade that protrudes radially outward from the hub portion for the blade, A motor in which, with the fitting cylinder portion fitted onto the shaft, the tip of the protrusion of the vane hub portion is located closer to the second end than the tip of the protrusion of the wall portion.

2. The motor according to claim 1, wherein, with the fitting cylinder portion fitted onto the shaft, the fitting cylinder portion, the wall portion, and the blade hub portion are arranged in order toward the radially outward direction.

3. The system further includes a bearing that rotatably supports the aforementioned shaft, The motor according to claim 1, wherein the bearing is disposed inside the stator core.

4. The rotor yoke is The cylindrical portion further has a first inflow suppression wall that protrudes cylindrically from the second end side to the second end side, The motor according to claim 1, wherein the first inflow suppression wall suppresses the inflow of foreign matter from the gap between the rotor yoke and the stator base into the inside of the rotor yoke.

5. The stator base is, It has a second inflow suppression wall that protrudes cylindrically toward the first end, The motor according to claim 4, wherein the second inflow suppression wall suppresses the inflow of foreign matter from the gap between the rotor yoke and the stator base into the inside of the rotor yoke.

6. The second inflow-restricting wall and the first inflow-restricting wall are arranged in order toward the radially outward direction. The motor according to claim 5, wherein the tip of the protrusion of the second inflow suppression wall is located closer to the first end than the tip of the protrusion of the first inflow suppression wall.

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