Bushing assembly

Abstract

A bushing assembly according to one embodiment of the present invention is a bushing assembly axially coupled between a rotating shaft of a driving means and a rotating body that rotates by the operation of said rotating shaft, and comprises: a shaft frame axially coupled to said rotating shaft; and a boss frame formed to surround the outer surface of said shaft frame and coupled to said rotating body to transmit power. The boss frame may include: a first boss formed to surround the outer surface of said shaft frame; a second boss arranged in a ring shape on the outside of said first boss with respect to the radial direction of said rotating shaft; and an elastic unit formed of an elastic material that is coupled in a predetermined shape between the outer surface of said first boss and the inner surface of said second boss with respect to said radial direction.

Description

Technology Field

[0001] The present invention relates to a bushing assembly. More specifically, it relates to a bushing assembly capable of effectively transmitting rotational power while maximizing the absorption of vibrations generated between a rotating shaft and a rotating body. Background Technology

[0002] Generally, an air purifier is a home appliance that uses a fan to forcibly draw in and expel air to induce indoor air circulation, while simultaneously filtering contaminated air and supplying purified air back into the room. As a device that contributes to improving indoor air quality and creating a healthy living environment, the demand for such air purifiers has been continuously increasing recently, driven by environmental issues such as fine dust, ultrafine dust, and volatile organic compounds (VOCs). In particular, the importance of air purifiers is becoming even more prominent in enclosed spaces or residential environments where ventilation is difficult.

[0003] Air purifiers generally consist of a filter module, a fan module, and a motor to drive them. Among these components, the fan module plays a pivotal role in drawing in contaminated air, passing it through a filter, and releasing purified air into the room; therefore, the connection structure between the motor and the fan is crucial for maintaining stable rotation. Typically, the fan module is connected directly to the motor shaft or indirectly via a fan bushing, and this connection method has a decisive impact on minimizing vibration and noise that may occur during rotation.

[0004] Conventional fan-motor coupling methods typically utilize metal steel bushings and structurally feature a rigid connection between the impeller and the motor shaft. However, this structure can lead to resonance when the fan rotates at high speeds, particularly when it enters specific natural vibration modes such as torsion mode or tilting mode. This results in an increase in the overall vibration levels of the fan, which in turn causes noise to rise. This phenomenon not only exacerbates user noise sensitivity but can also lead to the accumulation of structural fatigue, reduced fastening rigidity, and decreased durability in the long run, thereby negatively impacting product quality and reliability.

[0005] Recently, consumers tend to use air purifiers for extended periods, and their sensitivity to noise and vibration has increased significantly compared to the past. In particular, even minute vibrations or resonant noise can cause discomfort to users during sleep or in environments requiring silence (e.g., libraries, hospitals, offices). Accordingly, the fan bushing structure of air purifiers needs to go beyond simple mechanical coupling and satisfy complex functions such as vibration mitigation, noise reduction, and ensuring durability.

[0006] Against this backdrop, there is a need for technological development regarding more precise and functional fan bushing structures, moving away from conventional bushing designs focused on simple coupling to effectively dampen vibrations. Prior art literature

[0007] Korean Published Patent No. 10-2022-0091109 (Bushing, impeller and blower fan for rotary assembly, published June 30, 2022) The problem to be solved

[0008] A bushing assembly according to one embodiment of the present invention aims to solve the above problems by proposing a structure that maximizes the absorption of vibrations generated between a rotating shaft and a rotating body, while simultaneously effectively transmitting rotational power.

[0009] In addition, a bushing assembly according to one embodiment of the present invention proposes a structure capable of effectively suppressing vibrations applied in a three-dimensional direction.

[0010] However, the problems to be solved by the present invention are not limited to those mentioned above, and other unmentioned problems may be clearly understood based on the description below. means of solving the problem

[0011] A bushing assembly according to one embodiment of the present invention is a bushing assembly axially coupled between a rotating shaft of a driving means and a rotating body that rotates by the operation of the rotating shaft, and comprises: a shaft frame axially coupled to the rotating shaft; and a boss frame formed to surround the outer surface of the shaft frame and coupled to the rotating body to transmit power. The boss frame may include: a first boss formed to surround the outer surface of the shaft frame; a second boss arranged in a ring shape on the outside of the first boss with respect to the radial direction of the rotating shaft; and an elastic unit formed of an elastic material that is coupled in a preset shape between the outer surface of the first boss and the inner surface of the second boss with respect to the radial direction.

[0012] Alternatively, the second boss may be formed protruding from the inner surface and may include at least one coupling projection formed along the circumferential direction, and the elastic unit may have a coupling groove formed in a recessed shape corresponding to the coupling projection.

[0013] Alternatively, the coupling projection may protrude inward in a T-shape relative to the plane and be spaced apart at equal intervals along the circumferential direction.

[0014] Alternatively, the coupling projection may be formed with a thickness corresponding to the thickness of the second boss based on the thickness direction of the second boss, and the T-shape may include a head portion that is curved with a preset curvature while extending along the circumferential direction; and a support portion that extends along the radial direction from the head portion and is coupled to the inner surface of the second boss.

[0015] Alternatively, the second boss is divided into a first region on the upper side and a second region on the lower side based on the thickness direction, and the coupling projection includes an upper projection formed in the first region and a lower projection formed in the second region, wherein the upper projection and the lower projection may be formed alternately along the circumferential direction.

[0016] Alternatively, the coupling projection may be formed in a downwardly inclined shape with respect to the thickness direction of the second boss, such that one end is coupled to the inner surface and the other end extends along the circumferential direction.

[0017] Alternatively, the first boss may have a plurality of through holes formed along the circumferential direction with respect to a plane, and the elastic unit may be injection molded and joined between the first and second bosses through the through holes. Effects of the invention

[0018] A bushing assembly according to one embodiment of the present invention is intended to solve the above problems and can effectively transmit rotational power while maximizing the absorption of vibrations generated between a rotating shaft and a rotating body.

[0019] In particular, by forming and arranging the coupling projection of the second boss applied to the bushing assembly in a specific shape, vibrations applied in three dimensions can be effectively suppressed. Brief explanation of the drawing

[0020] FIG. 1 is a drawing illustrating a fan module in a state where a bushing assembly is combined according to one embodiment of the present invention. Figure 2 is a vertical cross-sectional view of Figure 1. FIG. 3(a) is a front view of a bushing assembly according to a first embodiment of the present invention, and (b) is a perspective view. FIG. 4 is a perspective view of a second boss in a bushing assembly according to a first embodiment of the present invention. FIG. 5 is an exploded view of a bushing assembly according to a second embodiment of the present invention. Figure 6 (a) is a perspective view of the second boss in Figure 5, and (b) is a plan view. Figure 7 (a) is a perspective view of the second boss of the bushing assembly according to the third embodiment of the present invention, and (b) is a plan view. Specific details for implementing the invention

[0021] Embodiments of the present invention are described below with reference to the attached drawings so that those skilled in the art can easily implement the invention. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein. Furthermore, in order to clearly explain the present invention in the drawings, parts unrelated to the explanation have been omitted, and similar parts throughout the invention are denoted by similar reference numerals.

[0022] In the present invention, when a part is described as being "connected" to another part, this includes not only cases where they are "directly connected," but also cases where other components exist in between, and cases where they are "electrically connected" with other components interposed between them. Furthermore, when a part is described as "including" a component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0023] Hereinafter, a bushing assembly (100) according to the present invention will be described with reference to the drawings. A bushing assembly (100) according to one embodiment of the present invention is a component that is inserted between two rotating bodies to reduce friction and support them to rotate together, and can be used as a bushing that is supported and installed between an impeller, such as a pump or fan, and a motor shaft of a motor.

[0024] Although an example has been described of an embodiment in which a bushing assembly (100) according to one embodiment of the present invention is applied to a fan module of an air purifier, any rotating assembly that requires the effect of reducing vibration and noise by being installed between two rotating members that rotate together (e.g., impeller, fan, etc.) may be subject to the bushing assembly (100) according to one embodiment of the present invention. It should be understood that this is also within the scope of the present invention and is obvious to those skilled in the art. For example, a blower fan to which a bushing according to one embodiment of the present invention is applied may be used in a range hood, home appliance, boiler, ventilation system, etc., but is not limited thereto, and may be used in various products, systems, etc. that require the function of flowing air (including all fluids).

[0025] FIG. 1 is a drawing illustrating a fan module in a state where a bushing assembly is combined according to one embodiment of the present invention.

[0026] The fan module can be understood as a concept comprising a fan frame (10), a motor module (20), and a motor housing (30). The motor module (20) includes a rotation axis to provide rotational power to the fan frame (10).

[0027] The motor module (20) can be accommodated and fixed within the motor housing (30). The fan frame (10) includes a plurality of blades formed in a diagonal direction and is configured to allow air to flow in one direction.

[0028] A bushing assembly according to one embodiment of the present invention may be provided between a fan frame (10) and a motor housing (30) and may reduce vibrations generated when the rotation axis of the motor module (20) and the fan frame (10) rotate. The bushing assembly according to one embodiment of the present invention is not limited to the shape of the fan module shown in FIG. 1.

[0029] FIG. 2 shows a vertical cross-section of FIG. 1. Referring to FIG. 2, the motor module (20) includes a motor body (21) and a rotating shaft (22). The rotating shaft (22) is connected to the motor body (21) and configured to receive rotational power. On the lower side, a shaft end fastening part (23) including a nut and a washer of the rotating shaft (22) is formed, and the shaft end fastening part (23) is fixed to the fan frame (10) so that rotational power can ultimately be transmitted to the fan frame (10). Any known fixing and fastening method can be applied to the motor module (20) and the motor housing (30).

[0030] FIG. 3(a) is a front view of a bushing assembly according to a first embodiment of the present invention, FIG. 3(b) is a perspective view, and FIG. 4 is a perspective view of a second boss of a bushing assembly according to a first embodiment of the present invention.

[0031] A bushing assembly according to a first embodiment of the present invention is described with reference to FIGS. 3 and 4. The rotational axis (22) of the motor module (20) is configured to be axially coupled to the shaft frame (110). To this end, the shaft frame (110) includes a pair of cuts (114) through which a coupling bar (24) can pass.

[0032] The connecting bar (24) extends vertically along the rotation axis (22) to prevent the bushing assembly (100) from coming off when the rotation axis (22) rotates.

[0033] Since the displacement of the rotation axis (22) or bushing assembly (100) in the vertical direction can be changed by the vibration generated, it is preferable that the cut portion (114) be configured with a depth such that the connecting bar (24) can be sufficiently inserted and fixed.

[0034] The shaft frame (110) is formed with a cylindrical upper body (112) into which the lower side of the rotation shaft (22) is inserted, and the aforementioned cut portion (114) is formed on the upper body (112). The shaft frame (110) can be divided into an upper body (112) and a lower body (115) based on the positions of the first and second bosses (111, 120), and the lower side of the rotation shaft (22) can be fixed again by the aforementioned shaft end fastening portion (23) after passing through the lower body (115).

[0035] The bushing assembly (100) includes a boss frame formed to surround the outer surface of the shaft frame (110). The boss frame includes a first boss (111), a second boss (120), and an elastic unit (130). Here, the first and second bosses (111, 120) are preferably formed of a relatively rigid material, such as steel, to stably transmit rotational power, and the elastic unit (130) may be formed of an elastic material to absorb vibration.

[0036] Meanwhile, in one embodiment of the present invention, the drawing shows the shaft frame (110) and the first boss (111) joined as separate parts, but as a possible embodiment, the shaft frame (110) and the first boss (111) may be formed as an integrated unit.

[0037] For a more detailed explanation, refer to FIG. 5. Since the shape of the first boss (111) is configured identically in each embodiment, for convenience, the first boss (111) is described with reference to the exploded view of FIG. 5.

[0038] FIG. 5 is an exploded view of a bushing assembly according to a second embodiment of the present invention.

[0039] The first boss (111) is formed in a ring shape to surround the outer surface of the shaft frame (110), and a plurality of through holes (113) may be formed for injection molding of the elastic unit (130).

[0040] The through holes (113) are generally formed in a circular or elliptical shape and are formed by penetrating perpendicularly to the plane of the first boss (111). The through holes (113) are formed at equal intervals along the circumferential direction of the first boss (111), which is formed in a ring shape, thereby ensuring uniform injection pressure and molding quality overall.

[0041] Referring again to FIG. 3, the elastic unit (130) is formed by injecting an elastic material, such as rubber, silicone, or TPE, through an injection molding machine. At this time, the material injected through the through hole (113) is distributed across both the upper and lower surfaces of the first boss (111), and can form an integrated structure that simultaneously covers both joining surfaces. The elastic unit (130) injected in this manner is fixed between the first boss (111) and the second boss (120), and at the same time, a mechanical interlock structure is formed inside the through hole (113) to prevent detachment or movement even after installation.

[0042] When an elastic material is introduced through the through hole (113) within the injection mold, the molding pressure is naturally distributed vertically, and damping force can be exerted for various vibration frequencies. In addition, it can provide structural advantages that can reduce problems such as shrinkage tolerance, bubble formation, and insufficient filling during injection molding. As such, since the elastic unit (130) is manufactured through injection molding, its shape can be determined according to the embodiment of the second boss.

[0043] In the first embodiment, the second boss (120) is arranged in a ring shape on the outer side of the first boss (111) with respect to the radial direction centered on the rotation axis (22), so that the elastic unit (130) can fill the space between the first and second bosses (111, 120). Accordingly, vibrations transmitted from the fan frame (10) to the second boss (120) and vibrations transmitted from the rotation axis (22) to the first boss (111) can both be dampened.

[0044] The second boss (120) includes a body portion (121) and an inner surface portion (121a) that are generally in the shape of a circular disc (see FIG. 4). A fastening groove (123) for connection with the fan frame (10) may be formed in the body portion (121). The fastening groove (123) is formed in multiple numbers along the circumferential direction of the body portion (121), and a fastening means (e.g., bolt, rivet, etc.) may pass through each of them to be fixed to one side of the fan frame (10). However, this is merely an example, and the second boss (120) and the fan frame (10) may be fixed by filling the fastening groove (123) as the fan frame (10) is injection molded.

[0045] A plurality of connecting protrusions (122) protruding inward are formed on the inner surface portion (121a), and the connecting protrusions (122) are spaced apart along the circumferential direction. Although a structure with six connecting protrusions (122) is shown in FIG. 4, the number and size of the connecting protrusions (122) can be optimally designed by the designer.

[0046] The connecting projection (122) is configured in a 'T-shape' and includes a head portion (1222) extending along the circumferential direction and a support portion (1221) connecting the head portion (1222) and the inner circumferential portion (121a).

[0047] The thickness surface (1222a) of the head portion includes a curved portion with a preset curvature, thereby increasing the contact area with the elastic unit (130). Here, the curvature may be formed as a curvature corresponding to the overall curvature of the body portion (121). Additionally, the thickness surface (1221a) of the support portion may also be formed to include a curved portion.

[0048] In one embodiment of the present invention, the bushing assembly (100) has a structure in which the coupling projection (122) protrudes inward from the inner circumferential portion (121a) of the second boss (120), and thus has the advantage of having a large contact area with the elastic unit (130).

[0049] In addition, the bushing assembly (100) according to one embodiment of the present invention has a structure in which a coupling projection (122) protrudes inward from the inner circumferential portion (121a) and then extends while bending at approximately 90 degrees at one point (in the case of the first embodiment, a 'T-shaped' head portion (1222)). This structure can perform the role of supporting the elastic unit (130) like a hook so that it can maintain its position without leaning to one side at the part where the coupling projection (122) bends when vibration is applied in the radial direction.

[0050] In addition, the bushing assembly (100) according to one embodiment of the present invention is formed with a dual boss structure, thereby ensuring structural stability, and this can maximize the effects of vibration dispersion and load separation compared to a single boss structure.

[0051] Referring again to FIG. 3 (a) and (b), it is preferable that the elastic unit (130) be injection molded so that both the first and second bosses (111, 120) are embedded. The elastic unit (130) is formed to be thicker than the second boss (120) in the thickness direction, and may be formed to protrude by a predetermined thickness above and below the second boss (120), respectively. Accordingly, it can perform the function of an 'elastic pad' that cushions external forces or vibrations applied in the vertical direction.

[0052] Figure 6 (a) is a perspective view of the second boss in Figure 5, and (b) is a plan view.

[0053] With reference to FIGS. 5 and 6, a bushing assembly according to a second embodiment of the present invention will be described. The description will focus on the differences from the first embodiment of the bushing assembly described above, and redundant descriptions will be omitted.

[0054] The second boss (140) generally comprises a body portion (141) and an inner surface portion (141a) in the shape of a circular disc. A fastening groove (143) for connection with the fan frame (10) may be formed in the body portion (141). The fastening grooves (143) are formed in multiple numbers along the circumferential direction of the body portion (141), and a fastening means (e.g., bolt, rivet, etc.) may pass through each of them to be fixed to one side of the fan frame (10). However, this is merely an example, and the second boss (140) and the fan frame (10) may be fixed by filling the fastening groove (143) as the fan frame (10) is injection molded. Based on the thickness direction, the inner surface portion (141a) may be divided into a first region on the upper side and a second region on the lower side. (See FIG. 5)

[0055] In other words, the first region can be understood as the upper perimeter of the inner circumference (141a), and the second region as the lower perimeter of the inner circumference (141a). Here, the first and second regions may be distinguished based on the intermediate height of the thickness, but may vary depending on the designer's choice.

[0056] The connecting projection (142) includes an upper projection (1421) formed in a first region and a lower projection (1422) formed in a second region, wherein the upper projection (1421) and the lower projection (1422) may be formed alternately along the circumferential direction. That is, along the circumferential direction, they may be arranged in the order of upper projection (1421) - lower projection (1422) - upper projection (1421) - lower projection (1422). The shape of the connecting projection (142) may be the same as that of the first embodiment described above, but as shown in FIG. 6, the supporting portion (1421b) may be composed only of a straight portion.

[0057] The upper projection (1421) and the lower projection (1422) can both be configured in a 'T-shape' and can be configured to include a head portion (1421a, 1422a) and a support portion (1421b, 1422b) extending along the circumferential direction. The elastic unit (150) may have recessed coupling grooves (152a, 152b) corresponding to the upper projection (1421) and the lower projection (1422).

[0058] In this way, the bushing assembly according to one embodiment of the present invention can maximize the vibration suppression effect in three dimensions by alternately arranging the coupling protrusions (142) at different heights.

[0059] Specifically, even if an external force pressing from the upper side or an external force pushing up from the lower side is applied to the elastic unit (150), the lower projection (1422) supports the elastic unit (150) so that it cannot detach from the second boss (160) in response to the external force pressing from the upper side, and the upper projection (1421) supports the elastic unit (150) in response to the external force pushing up from the lower side.

[0060] In addition, since the upper projection (1421) and the lower projection (1422) are arranged in alternating positions when viewed from a plane, the radial support structure against external forces is also robust.

[0061] In other words, the structure of this embodiment has the effect of providing a force that withstands vibrations or external forces occurring in the radial direction (axis rotation direction) as well as the vertical direction.

[0062] Figure 7 (a) is a perspective view of the second boss of the bushing assembly according to the third embodiment of the present invention, and (b) is a plan view.

[0063] The second boss (160) of the bushing assembly according to the third embodiment of the present invention is composed of an inclined structure that extends in an overall diagonal shape. The second boss (160) includes a body portion (161) and an inner surface portion (161a) that are generally in the shape of a circular disc. A fastening groove (163) for coupling with the fan frame (10) may be formed in the body portion (161). The fastening groove (163) is formed in multiple numbers along the circumferential direction of the body portion (161), and a fastening means (e.g., bolt, rivet, etc.) may pass through each of them to be fixed to one side of the fan frame (10). However, this is merely an example, and the second boss (160) and the fan frame (10) may be fixed by filling the fastening groove (163) as the fan frame (10) is injection molded.

[0064] Based on the thickness direction of the second boss (160), it is formed in a shape inclined downward, with one end connected to the inner surface portion (161a) and the other end extended along the circumferential direction. Based on the plane, it can be understood as an 'L-shape' (see (B) in FIG. 7) and includes a head portion (1621) and a support portion (1622). Here, the support portion (1622) differs from the first and second embodiments described above in that it is not connected to the center of the head portion (1621) but is connected eccentrically to one side.

[0065] The support member (1622) is coupled to the upper side of the inner circumferential portion (161a), and the head member (1621) extending from the end of the support member (1622) is configured to have a predetermined inclination toward the downward direction. Through this, the contact area with the elastic unit can be maximized, and vibrations applied in the vertical direction can be dispersed more effectively.

[0066] As described above, the bushing assembly according to one embodiment of the present invention is intended to solve the above problems and can effectively transmit rotational power while maximizing the absorption of vibrations generated between the rotating shaft and the rotating body.

[0067] In particular, by forming and arranging the coupling projection of the second boss applied to the bushing assembly in a specific shape, vibrations applied in three dimensions can be effectively suppressed.

[0068] The foregoing description of the present invention is for illustrative purposes only, and those skilled in the art will understand that other specific forms can be easily modified without altering the technical spirit or essential features of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, each component described as a single unit may be implemented in a distributed manner, and components described as distributed may likewise be implemented in a combined form.

[0069] The scope of the present invention is defined by the claims set forth below rather than by the detailed description above, and all modifications or variations derived from the meaning and scope of the claims and equivalent concepts thereof should be interpreted as being included within the scope of the present invention. Explanation of the symbols

[0070] 100: Bushing assembly 110: Axis frame 111: 1st Boss 120, 140, 160: 2nd Boss 130, 150: Elastic unit

Claims

Claim 1 A bushing assembly axially coupled between a rotating shaft of a driving means and a rotating body that rotates by the operation of said rotating shaft, comprising: a shaft frame axially coupled to said rotating shaft; and a boss frame formed to surround the outer surface of said shaft frame and coupled to said rotating body to transmit power, wherein the boss frame comprises: a first boss formed to surround the outer surface of said shaft frame; a second boss arranged in a ring shape on the outside of said first boss with respect to the radial direction of said rotating shaft; and an elastic unit formed of an elastic material that is coupled in a predetermined shape between the outer surface of said first boss and the inner surface of said second boss with respect to said radial direction. Claim 2 In claim 1, the second boss is formed protruding from the inner surface and includes at least one coupling projection formed along the circumferential direction, and the elastic unit has a coupling groove formed by being recessed, which has a shape corresponding to the coupling projection, in a bushing assembly. Claim 3 In paragraph 2, the above-mentioned coupling projections protrude inward in a T-shape relative to a plane and are spaced apart at equal intervals along the circumferential direction, forming a bushing assembly. Claim 4 A bushing assembly according to claim 3, wherein the coupling projection is formed with a thickness corresponding to the thickness of the second boss based on the thickness direction of the second boss, and the T-shape is a head portion that is curved with a preset curvature and extends along the circumferential direction; and a support portion that extends along the radial direction from the head portion and is coupled to the inner surface of the second boss. Claim 5 A bushing assembly according to paragraph 2, wherein the second boss is divided into a first region on the upper side and a second region on the lower side based on the thickness direction, and the coupling projection includes an upper projection formed in the first region and a lower projection formed in the second region, wherein the upper projection and the lower projection are formed alternately along the circumferential direction. Claim 6 A bushing assembly according to paragraph 2, wherein the coupling projection is formed in a downwardly inclined shape with respect to the thickness direction of the second boss, with one end coupled to the inner surface and the other end extended along the circumferential direction. Claim 7 A bushing assembly according to claim 1, wherein the first boss has a plurality of through holes formed along the circumferential direction with respect to a plane, and the elastic unit is injection molded and joined between the first boss and the second boss through the through holes.

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