Fixed structure

Abstract

The present invention provides a fixing structure that suppresses creep deformation and loosening of a fastening member caused by vibration and improves the fixing holding force. The fixing structure (1) comprises: a stator (2); a housing (3) having an opposing surface (31) opposing the stator (2); and a fixing member (4) fixing the stator (2) and the housing (3), wherein the fixing member (4) comprises an embedded member (5) embedded in the housing (3) and a fastening member (6) fixing the stator (2) to the embedded member (5), wherein the embedded member (5) comprises a supporting surface (55) abutting against the stator (2), wherein at least the supporting surface (55) of the embedded member (5) is formed of a metal material having a damping capacity greater than a specified value, and wherein the supporting surface (55) is located closer to the stator (2) than the opposing surface (31) of the housing (3).

Description

Technical Field

[0001] The present invention relates to a fixing structure. Background Art

[0002] Conventionally, in a fixing structure in which a plurality of members are fixed using fastening members, various technologies have been proposed for improving the fixing and holding force between the plurality of members.

[0003] For example, Patent Document 1 (Japanese Patent Application Laid-Open No. 2017-115907) discloses a fixing structure comprising: an anchor bolt and a nut for fastening an object with a right-hand thread; and a locking bolt that contacts the nut axially to prevent the nut from loosening relative to the anchor bolt. The anchor bolt comprises a male threaded body and a small-diameter female threaded portion, smaller than the male threaded body and recessed at the threaded end of the male threaded body. The locking bolt comprises a small-diameter male threaded portion that screws into the small-diameter female threaded portion with a left-hand thread.

[0004] According to the technology described in Patent Document 1, the small-diameter male thread of the anti-loosening member and the small-diameter female thread of the anchor bolt are threaded in a reversed relationship relative to the threaded engagement between the anchor bolt and nut. Therefore, the anti-loosening member reliably prevents relative loosening of the nut. Furthermore, the anchor bolt, nut, and anti-loosening member do not have overlapping right-hand and left-hand threads along the axial direction. Therefore, even if right-hand and left-hand threads are mixed in the anchor bolt, nut, and anti-loosening member, these components can be manufactured separately and simply. Summary of the Invention

[0005] Summary of the Invention

[0006] Problems to be solved by the invention

[0007] However, the technology described in Patent Document 1 can cause creep deformation in the female thread of the object being fastened to the anchor bolt when tightening torque (axial force) is high. This creep deformation can cause the anchor bolt (fastening member) to loosen. Furthermore, in a vibrating environment, for example, in addition to creep deformation, the vibration can also cause fastening members such as locking members and nuts to loosen.

[0008] Therefore, an object of the present invention is to provide a fixing structure that suppresses creep deformation and loosening of a fastening member caused by vibration and improves fixing and holding force.

[0009] Solutions to Problems

[0010] The fixing structure of the present invention is constructed as follows.

[0011] (1) A fixing structure according to one embodiment of the present invention (e.g., fixing structure 1 in the embodiment) comprises: a first member (e.g., stator 2 in the embodiment); a second member (e.g., housing 3 in the embodiment) having an opposing surface (e.g., opposing surface 31 in the embodiment) opposing to the first member; and a fixing member (e.g., fixing member 4 in the embodiment) for fixing the first member to the second member, the fixing member having an embedded member (e.g., embedded member 5 in the embodiment) embedded in the second member and a fastening member (e.g., fastening member 6 in the embodiment) for fixing the first member to the embedded member, the embedded member having a supporting surface (e.g., supporting surface 55 in the embodiment) abutting against the first member, at least the supporting surface in the embedded member being formed of a metal material having a damping capacity greater than or equal to a specified value, the supporting surface being located closer to the first member than the opposing surface of the second member.

[0012] (2) In the fixing structure of the above-mentioned solution (1), the vibration isolation coefficient of the metal material may be 30% or more, and the entire embedded member may be formed of the metal material.

[0013] (3) In the fixing structure of the above-mentioned aspect (1) or (2), a gap (for example, the gap S in the embodiment) may be provided between the facing surface of the second member and the first member.

[0014] (4) In the fixing structure of any one of the above schemes (1) to (3), the fastening member can pass through the first member, and the embedded member can have: a male thread portion formed on the outer periphery of the portion embedded in the second member (for example, the male thread portion 53 in the embodiment); and a female thread portion for the fastening member to be screwed (for example, the female thread portion 54 in the embodiment).

[0015] (5) In the fixing structure of the above-mentioned aspect (4), the fixing member may include a gasket (for example, gasket 7 in the embodiment) interposed between the first member and the end portion of the fastening member on the opposite side to the second member.

[0016] (6) In the fixing structure of any one of the above schemes (1) to (5), the embedded member may have: an embedded portion embedded in the second member (for example, the embedded portion 51 in the embodiment); and a flange portion connected to the end portion on the first member side of the embedded portion and having an outer diameter larger than the outer diameter of the embedded portion (for example, the flange portion 52 in the embodiment), and the second member may have a receiving portion for receiving the flange portion (for example, the receiving portion 33 in the embodiment).

[0017] (7) In the fixing structure of any one of the above-mentioned aspects (1) to (6), the first member may be a stator, and the second member may be a housing for accommodating the stator.

[0018] (8) In the fixing structure of the above-mentioned aspect (7), the stator may be formed in an annular shape, and the embedded member may be embedded in the housing along the axial direction of the stator.

[0019] Effects of the Invention

[0020] According to the scheme of (1), the fixing member has an embedded member embedded in the second member and a fastening member that fixes the first member to the embedded member, so that the first member and the second member are fixed via the embedded member and the fastening member. The fastening member is fastened to the second member via the embedded member. Thus, by, for example, setting the material and shape of the embedded member to avoid creep deformation between the second member and the embedded member, the generation of creep deformation in the second member can be suppressed compared to the existing technology in which the fastening member is directly fastened to the second member. In particular, when the second member is formed of a material softer than the fastening member (such as aluminum), by fastening the fastening member to the second member via the embedded member, the creep deformation of the portion (embedded member) that fastens the fastening member can be suppressed, thereby increasing the axial force of the fastening member. Thus, creep deformation, loosening of the second member, etc. can be suppressed, the decrease in the axial force of the fastening member can be suppressed, and the fixing retention force of the fixing member can be increased. For example, the first member and the fastening member can be fastened while the embedding member is embedded in the second member. Therefore, the fixing and holding force of the fixing member can be improved without complicating the work during manufacturing.

[0021] The embedded member has a supporting surface that abuts the first member. The supporting surface is formed from a metal material with a damping capacity greater than a specified value, thereby suppressing sliding of the first member relative to the embedded member. This prevents loosening of the fastening member, for example, even in a vibrating environment. The supporting surface is located closer to the first member than the opposing surface of the second member, concentrating the axial force between the supporting surface and the first member rather than between the opposing surface and the first member. This further suppresses loosening of the fastening member and improves the fixing and holding force.

[0022] Therefore, it is possible to provide a fixing structure that suppresses creep deformation and loosening of the fastening member due to vibration and improves the fixing and holding force.

[0023] Because the first member can be prevented from sliding with a simple structure, there's no need to increase the axial force of high-force bolts, or increase the number of fastening members required to maintain the required holding force, as is conventionally done. In other words, compared to conventional methods, the first and second members can be secured using fewer fastening members and lower strength. This simplifies the fastening process and reduces manufacturing costs.

[0024] Furthermore, since a gap can be formed between the first and second components, a cooling medium can flow through this gap. This allows the first component to be actively cooled by the cooling medium. Since the support surface is located closer to the first component than the opposing surface of the second component, the embedded component can be exposed. This allows the exposed embedded component to be directly cooled by the cooling medium, suppressing thermal expansion of the embedded component.

[0025] According to the scheme of (2), the entire embedded component is formed of a metal material having a damping capacity greater than that specified, so that the damping performance of the embedded component can be improved. As a result, it can become a fixed component with high vibration reduction efficiency that suppresses the transmission of vibration from the first component to the second component or the transmission of vibration from the second component to the first component. The portion of the embedded component that is embedded in the second component can ensure a larger friction coefficient with the second component. Similarly, the portion of the embedded component that is fastened to the fastening component can ensure a larger friction coefficient with the fastening component. As a result, it is possible to suppress sliding between the first component, the second component, and the fastening component relative to the embedded component, and suppress loosening of the fastening component.

[0026] According to the solution (3), a gap is provided between the opposing surface of the second member and the first member. As a result, the first member contacts only the supporting surface of the embedded member, concentrating the axial force between the supporting surface and the first member. This provides a fixing structure that further suppresses loosening of the fastening member and enhances the fixing and holding force.

[0027] According to the scheme of (4), the embedded member has a male thread portion formed on the outer periphery of the portion embedded in the second member and a female thread portion for the fastening member to be screwed in. By screwing the female thread portion of the fastening member and the female thread portion of the embedded member into the second member, the first member and the second member are fastened and fixed via the fastening member and the embedded member. In this way, by sandwiching the embedded member between the fastening member and the second member, the occurrence of creep deformation of the second member can be suppressed compared to the existing technology in which the fastening member is directly fastened to the second member. In the case where the embedded member is formed of a material with higher strength than the second member, the creep deformation of the female thread portion of the embedded member for the fastening member to be screwed in can be suppressed. As a result, the creep deformation of the second member and the embedded member when the fastening member is tightened can be suppressed, the decrease in the axial force of the fastening member can be suppressed, and the fixing and retaining force of the first member and the second member can be improved.

[0028] According to the solution (5), the fixing member includes a gasket, which is sandwiched between the end of the fastening member opposite the second member and the first member. Therefore, when the first and second members are fastened together, the first member is clamped in the axial direction by the gasket and the embedded member. This allows the axial force of the fastening member to effectively act on the first member, firmly securing the first member to the embedded member.

[0029] According to the scheme of (6), the embedded component has an embedded portion and a flange portion. The flange portion is connected to the end portion on the first member side of the embedded portion and has an outer diameter larger than the outer diameter of the embedded portion. Therefore, the embedded component can be positioned in the embedding direction by the contact between the flange portion and the second member. When the embedded portion is embedded in the second member, the flange portion is exposed on the surface of the second member. Thus, for example, when embedding the embedded component in the second member, the flange portion can be grasped and operated. Since the surface on the first member side of the flange portion can be set as the supporting surface, the area of ​​the supporting surface can be expanded compared to the case where the flange portion is not provided and the surface on the first member side of the embedded portion is set as the supporting surface. Thus, the friction between the supporting surface of the embedded component and the first member can be increased, further suppressing the sliding of the first member. Since the surface pressure acting on the supporting surface is reduced, the buckling and deformation of the first member can be suppressed, and the decrease in the axial force of the fixing member can be suppressed. Thus, the positioning of the embedded component can be facilitated, the sliding of the first member can be suppressed, and the loosening can be suppressed.

[0030] The second member includes a receiving portion for accommodating the flange. By adjusting the depth of the receiving portion and the thickness of the flange, the flange thickness can be ensured, and the support surface can be made to protrude a desired height from the opposing surface toward the first member. This makes it easy to create a gap of a desired size between the first and second members. By setting the gap to a size that maximizes vibration reduction efficiency, for example, it is possible to further enhance damping performance and suppress loosening of the fastening member caused by vibration.

[0031] According to the embodiment of (7), the first member is the stator, and the second member is the housing for housing the stator. The stator is fixed to the housing via the fixing member.

[0032] When applied to the stator of a rotating electrical machine, such as one installed in an automobile, vibrations may sometimes be generated in the stator due to the rotation of the rotor or the flow of current to the stator coils. Conventional mounting structures have presented challenges such as creep deformation of the housing due to thermal cycling, transmission of vibrations from the stator to the housing, and radio noise caused by leakage current from the stator to the housing via the fastening members.

[0033] The fixing structure of the present invention, particularly when fixing a stator prone to vibration to a housing, can suppress loosening of the fastening member caused by vibration and securely fix the stator to the housing. Even when the housing is formed of a material such as aluminum, the housing and stator can be fixed via embedded members formed of a metal material with higher strength than aluminum. Furthermore, creep deformation caused by hot and cold cycles can be suppressed. This can suppress creep deformation and loosening of the housing, inhibit a decrease in the axial force of the fastening member, and improve the fixing and retaining force between the housing and the stator.

[0034] Therefore, it is possible to provide a fixing structure that suppresses creep deformation and loosening of the fastening member due to vibration and improves the fixing and holding force.

[0035] The fastened portion of the housing is formed by an embedded component that is a separate part from the housing. This facilitates quality control of the fastened portion of the housing and reduces quality standards for the housing, thereby reducing manufacturing costs. Furthermore, since the embedded component, which has a higher electrical resistance than aluminum, is interposed between the fastening component securing the stator and the housing, leakage current from the stator to the housing is suppressed. This also reduces the generation of radio noise. This creates a structure that suppresses vibration and noise and is optimal for securing the stator to the housing.

[0036] According to the embodiment (8), the embedded member is embedded in the housing along the axial direction of the stator. Thus, the embedded member can be embedded in the bolt hole, for example, formed in the housing in the prior art. This provides a preferred fixing structure, particularly when fixing the stator to the housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a perspective view showing a part of the rotating electrical machine according to the embodiment.

[0038] Figure 2 It is a side view of the rotating electrical machine showing the fixing structure according to the embodiment.

[0039] Figure 3 yes Figure 2 Cross-sectional view along line III-III.

[0040] Figure 4 It is a perspective view of the embedded member according to the embodiment. DETAILED DESCRIPTION

[0041] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0042] (Implementation Method)

[0043] (Rotating Electric Machine)

[0044] Figure 1 1 is a perspective view showing a portion of the rotating electrical machine 10 according to the embodiment. Figure 1 , only a portion of the stator 2 formed in an annular shape is shown.

[0045] The rotating electric machine 10 is, for example, a travel motor mounted on a hybrid vehicle or electric vehicle. However, the structure of the present invention is not limited to travel motors and can also be applied to a power generation motor, motors for other purposes, and rotating electric machines 10 (including generators) other than those for vehicles.

[0046] The rotating electrical machine 10 includes a stator 2 (a first member in this section of the present invention), a housing 3 (a second member in this section of the present invention), and a rotor (not shown).

[0047] The stator 2 is formed in an annular shape centered on the axis C. The stator 2 includes a stator core 21 and a coil 22. In the following description, the direction along the axis C of the stator 2 is sometimes simply referred to as the axial direction, the direction perpendicular to the axis C is sometimes referred to as the radial direction, and the direction around the axis C is sometimes referred to as the circumferential direction.

[0048] The stator core 21 is formed in an annular shape with the axis C as the center. The stator core 21 is a laminated core formed by laminating a plurality of steel plates in the axial direction of the axis C. Bolt insertion holes 25 (see FIG. 25 ) are formed on the outer periphery of the stator core 21 so as to penetrate the stator core 21 in the axial direction. Figure 3 A fastening member 6 described later is inserted into the bolt insertion hole 25 . A plurality of bolt insertion holes 25 are provided along the circumferential direction of the stator core 21 .

[0049] Coil 22 is disposed on the inner periphery of stator core 21 and is assembled to stator core 21 by being inserted into slots 23 extending axially through stator core 21. Coil 22 may be, for example, a plurality of divided conductors. A magnetic field is generated in stator 2 by supplying current to coil 22 from a current supply unit (not shown).

[0050] The housing 3 is arranged on one side in the axial direction relative to the stator 2. The housing 3 is formed into a bottomed cylindrical shape centered on the axis C. The housing 3 is formed of a metal material such as aluminum. The housing 3 has a bottom 30 and a frame 35.

[0051] The bottom portion 30 is formed in a disk shape with the axis C as the center.

[0052] The frame portion 35 protrudes from the outer periphery of the bottom portion 30 toward the stator 2 in the axial direction. The frame portion 35 is formed over the entire periphery of the bottom portion 30. The end surface of the frame portion 35 facing the stator 2 is set to be aligned with the end surface 2a of the stator 2 (see Figure 2 ) The housing 3 has an opposing surface 31 that faces the end surface 2a of the stator 2. The housing 3 is fixed to the stator 2 by a fixing member 4, which will be described in detail later, with the opposing surface 31 of the housing 3 facing the end surface 2a of the stator 2. The opposing surface 31 has a receiving portion 33 and a fastening hole 32 formed therein.

[0053] The housing portion 33 is recessed axially from the facing surface 31. The housing portion 33 is formed into a circular shape when viewed from the axial direction. Multiple housing portions 33 are provided at intervals along the circumferential direction. Each housing portion 33 is provided at a position coaxial with the bolt insertion hole 25 of the stator 2 when the stator 2 and the housing 3 are facing each other.

[0054] The fastened hole 32 is formed from the bottom surface 33a of the receiving portion 33 (see Figure 3 ) is recessed in the axial direction. The fastened hole 32 is provided coaxially with the receiving portion 33. The diameter of the fastened hole 32 is smaller than the diameter of the receiving portion 33. A female thread is formed on the inner periphery of the fastened hole 32.

[0055] A rotor (not shown) is arranged radially inward of the stator 2, with a slight gap therebetween. The rotor is mounted so as to be rotatable about the axis C relative to the housing 3. The rotor is provided with permanent magnets (not shown). When current is applied to the coils 22 of the stator 2 to generate a magnetic field in the stator 2, a magnetic force acts between the stator 2 and the permanent magnets of the rotor, causing the rotor to rotate about the axis C relative to the stator 2.

[0056] (Fixed structure)

[0057] (Fixed component)

[0058] Figure 2 It is a side view of the rotating electrical machine 10 showing the fixing structure 1 according to the embodiment. Figure 3 yes Figure 2 Cross-sectional view along line III-III.

[0059] The rotating electrical machine 10 includes a fixing structure 1 for fixing a housing 3 and a stator 2. The fixing structure 1 includes the housing 3 and the stator 2 described above, and a fixing member 4.

[0060] The fixing member 4 fixes the stator 2 to the housing 3. The fixing member 4 includes an embedded member 5 and a fastening member 6.

[0061] (Buried components)

[0062] Figure 4 It is a perspective view of the embedded member 5 according to the embodiment.

[0063] The embedded member 5 is embedded in the housing 3 to secure the stator 2. The embedded member 5 is formed from a metal material having a damping capability greater than or equal to a specified value. A metal material having a damping capability greater than or equal to a specified value is a metal material with a vibration damping coefficient of 30% or greater. In this embodiment, the embedded member 5 is formed from a vibration-damping sintered material. The vibration-damping sintered material is a sintered material formed by impregnating a resin material within the pores within a sintered material containing iron. Specifically, the vibration-damping sintered material includes metal materials such as iron, nickel, copper, molybdenum, and cobalt. The vibration-damping sintered material has higher damping performance than the aluminum housing 3 and is less likely to transmit vibrations from the stator 2, which is fastened to the embedded member 5, to the housing 3. In other words, the vibration-damping sintered material attenuates the vibrations by converting vibration energy into heat energy due to the resin material arranged in the pores expanding or compressing in response to vibrations from the stator 2. The resin material disposed in the pores of the vibration-damping sintered material generates friction between the resin material and the metal material, thereby converting the vibration energy into heat energy. The embedded member 5 includes an embedded portion 51, a flange portion 52, and a support surface 55.

[0064] The embedded portion 51 is formed into a bottomed cylindrical shape with one end portion being closed. A male thread portion 53 is formed on the outer periphery of the embedded portion 51. Figure 3 As shown, the male thread portion 53 of the embedded portion 51 is threadedly engaged with the female thread formed in the fastened hole 32 of the housing 3. As a result, the embedded portion 51 is embedded in the housing 3 along the axial direction of the axis C. A female thread portion 54 is formed on the inner circumference of the embedded portion 51. Both the male thread portion 53 and the female thread portion 54 are threaded in a right-handed manner.

[0065] The flange portion 52 is connected to the axial end portion of the embedded portion 51 on the stator 2 side. The flange portion 52 is formed into a cylindrical shape coaxial with the embedded portion 51. A female thread portion 54 is formed on the inner circumference of the flange portion 52, which is continuous with the female thread portion 54 of the embedded portion 51. The outer diameter of the flange portion 52 is larger than the outer diameter of the embedded portion 51. The flange portion 52 is housed in the housing portion 33 of the housing 3. When the flange portion 52 is housed in the housing portion 33, the flange portion 52 abuts against the bottom surface 33a of the housing portion 33.

[0066] like Figure 4As shown, the outer periphery of the flange portion 52 located on the stator 2 side of the flange portion 52 is formed into a hexagonal shape when viewed from the axial direction. It should be noted that the outer periphery of the flange portion 52 may be formed into a hexagonal shape as a whole.

[0067] The end surface of the flange portion 52 on the stator 2 side in the axial direction is provided as a support surface 55. Figure 3 As shown, the end face 2a of the stator 2 abuts against the support surface 55. The support surface 55 contains hard particles. Examples of the hard particles are silicon carbide, aluminum oxide, tungsten carbide, and the like. As a result, the support surface 55 of the embedded member 5 has a greater coefficient of friction with the stator 2 than the portion of the embedded member 5 other than the support surface 55. When the embedded member 5 is embedded in the housing 3, the support surface 55 is parallel to the opposing surface 31 of the housing 3 and is located axially closer to the stator 2 than the opposing surface 31. Consequently, a gap S is provided between the stator 2 and the opposing surface 31 of the housing 3.

[0068] (Fasteners)

[0069] The fastening member 6 is, for example, a bolt. The fastening member 6 is inserted into the stator 2 from the stator 2 side toward the housing 3 side in the axial direction. The fastening member 6 axially penetrates the stator core 21. The fastening member 6 secures the stator 2 to the embedded member 5. The fastening member 6 has a body portion 61 and a head portion 62.

[0070] The body portion 61 is inserted into the bolt insertion hole 25 of the stator core 21. A male thread is formed on the end portion of the body portion 61 on the housing 3 side. The male thread of the body portion 61 is screwed into the female thread portion 54 of the embedded member 5.

[0071] The head portion 62 abuts against the other axial end surface 2b of the stator core 21 via the spacer 7. Specifically, the spacer 7 is sandwiched between the other axial end surface 2b of the stator core 21 and the head portion 62 of the fixing member 4. The outer diameter of the spacer 7 is larger than that of the head portion 62. Like the embedded member 5, the spacer 7 is formed of a vibration-damping sintered material.

[0072] The rotating electric machine 10 thus formed is formed by fixing the stator 2 to the embedded member 5 using the fastening member 6 relative to the housing 3 in a state where the embedded member 5 is embedded, thereby fixing the stator 2 to the housing 3. In other words, the stator 2 is not in direct contact with the housing 3, but is fixed to the housing 3 via the embedded member 5.

[0073] (Action, effect)

[0074] Next, the operation and effects of the above-mentioned fixing structure 1 will be described.

[0075] According to the fixing structure 1 of this embodiment, the fixing member 4 includes an embedded member 5 embedded in the housing 3 (the second member in this section of the Summary of the Invention) and a fastening member 6 that secures the stator 2 to the embedded member 5 (the first member in this section of the Summary of the Invention). Therefore, the stator 2 is secured to the housing 3 via the embedded member 5 and the fastening member 6. The fastening member 6 is fastened to the housing 3 via the embedded member 5. Thus, by, for example, selecting the material and shape of the embedded member 5 to prevent creep deformation between the housing 3 and the embedded member 5, creep deformation in the housing 3 can be suppressed compared to conventional techniques in which the fastening member 6 is directly fastened to the housing 3. In particular, when the housing 3 is formed of a material softer than the fastening member 6 (e.g., aluminum), fastening the fastening member 6 to the housing 3 via the embedded member 5 can suppress creep deformation in the portion (the embedded member 5) to which the fastening member 6 is fastened, thereby increasing the axial force of the fastening member 6. This can suppress creep deformation, loosening of the housing 3, and the like, and can also suppress a decrease in the axial force of the fastening member 6, thereby improving the fixing and holding force of the fixing member 4. For example, since the stator 2 and the fastening member 6 can be fastened while the embedded member 5 is embedded in the housing 3, the fixing and holding force of the fixing member 4 can be improved without complicating the manufacturing process.

[0076] The embedded member 5 has a support surface 55 that contacts the stator 2. This support surface 55 is formed from a metal material (vibration-damping sintered material) with a damping capacity exceeding a specified level. This prevents slippage of the stator 2 relative to the embedded member 5. This prevents loosening of the fastening member 6, even in a vibrating environment. Because the support surface 55 is located closer to the stator 2 than the opposing surface 31 of the housing 3, the axial force is concentrated between the support surface 55 and the stator 2, rather than between the opposing surface 31 and the stator 2. This further prevents loosening of the fastening member 6 and enhances its holding force.

[0077] Therefore, it is possible to provide the fixing structure 1 that suppresses creep deformation and loosening of the fastening member 6 due to vibration and improves the fixing and holding force.

[0078] Because the stator 2 can be prevented from sliding using a simple structure, there is no need to increase the axial force using high-axial-force bolts to prevent the stator 2 from sliding, nor to increase the number of fastening members 6 to maintain the fixing force, as is conventionally done. In other words, compared to the prior art, the stator 2 and the housing 3 can be fixed using lower-strength fastening members 6 and a smaller number of fastening members. This simplifies the fastening process and reduces manufacturing costs.

[0079] Furthermore, since a gap S can be formed between the stator 2 and the housing 3, a cooling medium can flow through this gap. This allows the cooling medium to actively cool the stator 2. Since the support surface 55 is located closer to the stator 2 than the opposing surface 31 of the housing 3, the embedded component 5 can be exposed. This allows the exposed embedded component 5 to be cooled directly by spraying the cooling medium, thereby suppressing thermal expansion of the embedded component 5.

[0080] The support surface 55 has hard particles, which further increases the friction coefficient between the support surface 55 and the stator 2. This further suppresses slippage of the stator 2 relative to the embedded member 5 and provides a strong fixing and holding force.

[0081] The entire embedded component 5 is formed of a metal material (vibration-damping sintered material) having a damping capacity greater than or equal to a specified value, thereby improving the damping performance of the embedded component. This allows the embedded component 4 to be a high-efficiency fixing component 4 that suppresses the transmission of vibration from the stator 2 to the housing 3 or from the housing 3 to the stator 2. The portion of the embedded component 5 (embedded portion 51) embedded in the housing 3 can ensure a high coefficient of friction with the housing 3. Similarly, the portion of the embedded component 5 to which the fastening component 6 is fastened can ensure a high coefficient of friction with the fastening component 6. This suppresses sliding between the stator 2, the housing 3, and the fastening component 6 relative to the embedded component 5, and suppresses loosening of the fastening component 6.

[0082] A gap S is provided between the facing surface 31 of the housing 3 and the stator 2. As a result, the stator 2 contacts only the support surface 55 of the embedded member 5, concentrating the axial force between the support surface 55 and the stator 2. This further suppresses loosening of the fastening member 6 and improves the fixing and holding force of the fixing structure 1.

[0083] The embedded member 5 includes a male threaded portion 53 formed on the outer periphery of the portion embedded in the housing 3 and a female threaded portion 54 into which the fastening member 6 is threadedly engaged. The fastening member 6 is threadedly engaged with the female threaded portion 54 of the embedded member 5, and the female threaded portion 54 of the embedded member 5 is threadedly engaged with the housing 3, thereby fastening the stator 2 to the housing 3 via the fastening member 6 and the embedded member 5. Thus, by sandwiching the embedded member 5 between the fastening member 6 and the housing 3, creep deformation of the housing 3 can be suppressed compared to the conventional technique of directly fastening the fastening member 6 to the housing 3. When the embedded member 5 is formed of a material having a higher strength than the housing 3, creep deformation of the female threaded portion 54 of the embedded member 5 into which the fastening member 6 is threaded can be suppressed. This suppresses creep deformation of the housing 3 and the embedded member 5 when the fastening member 6 is fastened, and reduces the reduction in the axial force of the fastening member 6, thereby improving the fixing and retaining force between the stator 2 and the housing 3.

[0084] The fixing member 4 includes a gasket 7, which is interposed between the end (head 62) of the fastening member 6 on the side opposite the housing 3 and the stator 2. Therefore, when the stator 2 is fastened to the housing 3, the stator 2 is clamped in the axial direction by the gasket 7 and the embedded member 5. This allows the axial force generated by the fastening member 6 to effectively act on the stator 2, firmly securing the stator 2 to the embedded member 5.

[0085] The embedded member 5 includes an embedded portion 51 and a flange portion 52. The flange portion 52 is connected to the end portion of the embedded portion 51 on the stator 2 side and has an outer diameter larger than the outer diameter of the embedded portion 51. Therefore, the embedded member 5 can be positioned in the embedding direction by the contact between the flange portion 52 and the housing 3. When the embedded portion 51 is embedded in the housing 3, the flange portion 52 is exposed on the surface of the housing 3. Thus, for example, when embedding the embedded member 5 in the housing 3, the flange portion 52 can be grasped to perform operations. Since the surface of the flange portion 52 on the stator 2 side can be set as the support surface 55, the area of ​​the support surface 55 can be increased compared to the case where the flange portion 52 is not provided and the surface of the embedded portion 51 on the stator 2 side is set as the support surface 55. As a result, the friction between the support surface 55 of the embedded member 5 and the stator 2 can be increased, further suppressing the sliding of the stator 2. Since the surface pressure acting on the support surface 55 is reduced, buckling and deformation of the stator 2 can be suppressed, and the reduction in the axial force of the fixing member 4 can be suppressed. This facilitates positioning of the embedded member 5, suppresses slippage of the stator 2, and suppresses looseness.

[0086] The housing 3 includes a receiving portion 33 for accommodating the flange 52. Therefore, by adjusting the depth of the receiving portion 33 and the thickness of the flange 52, the thickness of the flange 52 can be ensured, and the support surface 55 can be made to protrude a desired height from the opposing surface 31 toward the stator 2. This facilitates the formation of a gap S of a desired size between the stator 2 and the housing 3. By setting the size of the gap S to a value that maximizes vibration reduction efficiency, for example, it is possible to further enhance damping performance and suppress loosening of the fastening member 6 caused by vibration.

[0087] In the present embodiment, the fixing structure 1 is provided as a fixing structure 1 for fixing the stator 2 to the housing 3 .

[0088] When the fixing structure 1 is applied to the stator 2 of a rotating electrical machine 10 mounted on an automobile, as in this embodiment, vibrations may be generated in the stator 2 due to the rotation of the rotor or the flow of current to the coils 22 of the stator 2. Conventional fixing structures 1 have presented problems such as creep deformation of the housing 3 due to thermal cycling, transmission of vibrations from the stator 2 to the housing 3, and radio noise caused by leakage current from the stator 2 to the housing 3 via the fastening member 6.

[0089] The fixing structure 1 of the present invention, particularly when securing a stator 2, which is prone to vibration, to a housing 3, can suppress loosening of the fastening member 6 caused by vibration, thereby firmly securing the stator 2 to the housing 3. Even when the housing 3 is formed of a material such as aluminum, the housing 3 and stator 2 can be secured via the embedded member 5 formed of a vibration-damping sintered material having a higher strength than aluminum. Furthermore, creep deformation caused by thermal cycling can be suppressed. This suppresses creep deformation and loosening of the housing 3, reduces the decrease in the axial force of the fastening member 6, and improves the securing force between the housing 3 and the stator 2.

[0090] Therefore, it is possible to provide the fixing structure 1 that suppresses creep deformation and loosening of the fastening member 6 due to vibration and improves the fixing and holding force.

[0091] The fastened portion of the housing 3 is formed by an embedded member 5, a separate component from the housing 3. This facilitates quality control of the fastened portion of the housing 3 and relaxes quality standards for the housing 3, thereby reducing manufacturing costs. Furthermore, since the embedded member 5, which has a higher electrical resistance than aluminum, is interposed between the fastening member 6 securing the stator 2 and the housing 3, leakage current from the stator 2 to the housing 3 is suppressed. This also reduces the generation of radio noise. This results in a fixing structure 1 that suppresses vibration and noise and is ideal for securing the stator 2 to the housing 3.

[0092] The embedded member 5 is embedded in the housing 3 along the axial direction of the stator 2. This allows the embedded member 5 to be embedded in a conventional bolt hole formed in the housing 3, for example. This provides a particularly preferred fixing structure 1 for fixing the stator 2 to the housing 3.

[0093] It should be noted that the technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

[0094] For example, in this embodiment, the embedded member 5 is entirely formed of a vibration-damping sintered material, but this is not limiting. It suffices that at least the portion of the embedded member 5 corresponding to the support surface 55 be formed of the vibration-damping sintered material. Portions other than the support surface 55 may be formed of a metal material other than the vibration-damping sintered material, for example. However, from the perspective of further suppressing the transmission of vibration, the structure of this embodiment entirely formed of the vibration-damping sintered material is superior.

[0095] The fastening member 6 may axially penetrate the embedded member 5. In this case, it is preferable to provide a space for suppressing the contact between the fastening member 6 protruding in the axial direction from the embedded member 5 and the housing 3.

[0096] The metal materials used to form the vibration-damping sintered material and the hard particles are not limited to the above-described embodiments. Hard particles do not need to be provided on the support surface 55. Specifically, if the friction coefficient between the stator 2 and the embedded member 5 is sufficiently high to prevent slippage of the stator 2 due to the vibration-damping sintered material, the support surface 55 can be formed of the vibration-damping sintered material without providing hard particles.

[0097] The rotation direction when tightening the female screw portion 54 and the male screw portion 53 of the embedded member 5 is sufficient as long as the female screw portion 54 and the male screw portion 53 are the same, and a left-hand screwing form may be used.

[0098] In this embodiment, the fixing structure 1 is used to secure the stator 2 to the housing 3. However, the components secured by the fixing structure 1 are not limited to the housing 3 and the stator 2. For example, the fixing structure 1 can secure the housing 3 or casing of the rotating electrical machine 10 to the casing of a speed reducer. It can also be used to secure vehicle-mounted components such as the rotating electrical machine 10 and a generator to the vehicle body. The fixing structure 1 can also be applied to mechanical components other than those mounted on the vehicle.

[0099] Furthermore, within the scope not departing from the gist of the present invention, the components in the above-described embodiments may be appropriately replaced with well-known components, and the above-described embodiments may be appropriately combined.

[0100] Explanation of symbols

[0101] 1 Fixed structure

[0102] 2. Stator (first component)

[0103] 3. Shell (second component)

[0104] 4 Fixed components

[0105] 5. Embedded components

[0106] 6 Fastening components

[0107] 7 Gasket

[0108] 31 Opposite surface

[0109] 33 Containment Department

[0110] 51 Buried Department

[0111] 52 flange

[0112] 53 Male thread

[0113] 54 female thread

[0114] 55 Support surface

[0115] S Gap

Claims

1. A fixing structure, characterized in that: have: first component; a second member having an opposing surface opposed to the first member; and a fixing member fixing the first member and the second member, The fixing member has: an embedded member embedded in the second member; as well as a fastening member for fixing the first member to the embedded member, The embedded member has a support surface that abuts against the first member, At least the support surface of the embedded member is formed of a metal material having a vibration damping capability greater than a predetermined value, and the support surface has hard particles. The support surface is located closer to the first member than the opposing surface of the second member. The embedded component has: an embedded portion embedded in the second member; and a flange portion connected to an end portion of the embedded portion on the first member side and having an outer diameter larger than an outer diameter of the embedded portion, The second member has a housing portion for housing the flange portion, and in a state where the flange portion is housed in the housing portion, the flange portion abuts against a bottom surface of the housing portion.

2. The fixing structure according to claim 1, characterized in that: The metal material has a vibration isolation coefficient of 30% or more, and the embedded member is entirely formed of the metal material.

3. The fixing structure according to claim 1 or 2, characterized in that: A gap is provided between the facing surface of the second member and the first member.

4. The fixing structure according to claim 1, characterized in that: The fastening member penetrates the first member, The embedded component has: a male thread portion formed on an outer peripheral portion of a portion buried in the second member; as well as A female threaded portion for threading the fastening member.

5. The fixing structure according to claim 4, characterized in that: The fixing member includes a spacer interposed between the first member and an end portion of the fastening member on the opposite side to the second member.

6. The fixing structure according to claim 1, characterized in that: The first component is a stator, The second member is a housing for accommodating the stator.

7. The fixing structure according to claim 6, characterized in that: The stator is formed into a ring shape, The embedded member is embedded in the housing along the axial direction of the stator.

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