bushing assembly

Abstract

This utility model relates to the field of mechanical transmission components, and in particular to a bushing assembly. This application provides a bushing assembly with the following technical solution: it includes a disc body, a bushing disposed at the center of the disc body, and a colloid for injection molding the inner edge of the disc body and the outer edge of the bushing together; the inner side of the colloid is injection molded and covers the outer wall of the bushing, and the inner edge of the disc body is injection molded and covers the inner edge of the colloid; the outer edge of the disc body has multiple circumferential cuts to form straight cross-sections on its edge; the side wall of the bushing has a threaded hole communicating with its central shaft hole, and the end of the bushing has two radially arranged notches, which are perpendicular to the threaded hole. This solution has the advantages of improving the bonding strength between the colloid and the metal part, optimizing the uniformity of injection molding filling, enhancing torque transmission stability, and improving the installation flexibility of the bushing.

Description

Technical Field

[0001] This utility model relates to the field of mechanical transmission components, and in particular to a bushing assembly. Background Technology

[0002] As a core component of mechanical transmission systems, the performance of bushing assemblies directly affects the operational accuracy and reliability of equipment. Traditional processes using interference fit between metal discs and bushings have significant drawbacks: the assembly stress generated during press fitting can easily lead to elliptical deformation of the disc, affecting dynamic balance; the hard contact between metals is prone to fretting wear under alternating loads, resulting in increased clearance; and the microscopic pores at the mating surfaces become channels for corrosive media penetration, accelerating the electrochemical corrosion process.

[0003] While existing injection molding connection technology can alleviate the above problems, it still has structural design defects: the edge of the disc lacks an effective torque transmission structure, which leads to circumferential slippage under extreme torque; the connection between the bushing and the drive shaft relies on the traditional keyway structure, which has problems such as keyway stress concentration and poor assembly alignment.

[0004] Furthermore, the structural design of the injection-molded colloid directly affects product performance: colloids with uniform thickness are prone to stress concentration in transition areas, while a lack of optimized fillet design can lead to poor injection flow; the simplistic design of the bushing fixing structure limits installation flexibility and cannot adapt to locking requirements in different directions. These problems severely restrict the reliability of bushing assemblies in high-precision transmission applications.

[0005] To address the aforementioned issues, existing technologies urgently need improvement. Summary of the Invention

[0006] To address the aforementioned problems, the present invention aims to provide a bushing assembly that offers advantages such as improved bonding strength between the colloid and the metal component, optimized injection molding filling uniformity, enhanced torque transmission stability, and improved bushing installation flexibility.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] This application provides a bushing assembly with the following technical solution: it includes a disc body, a bushing disposed at the center of the disc body, and a colloid for injection molding the inner edge of the disc body and the outer edge of the bushing together; the inner side of the colloid is injection molded and covered on the outer wall of the bushing, and the inner edge of the disc body is injection molded and covered within the outer edge of the colloid; the outer edge of the disc body has multiple circumferential cuts to form straight tangents on its edge; the side wall of the bushing is provided with a threaded hole communicating with its central shaft hole, and the end of the bushing is provided with two notches radially, the two notches being arranged perpendicular to the threaded hole.

[0009] Furthermore, this application also proposes that the colloid be constructed into a gradient shape with a large inner edge thickness and a small outer edge thickness.

[0010] Furthermore, this application also proposes that the top surface of the colloid is constructed as an inclined plane, and the inner end of the inclined plane forms a first rounded corner with a radius of 2 mm.

[0011] Furthermore, this application proposes that the bottom surface of the colloid is constructed as a step, the inner corner of the step is constructed as a second rounded corner with a radius of 1 mm, and the sidewall of the step is constructed as a slope.

[0012] Furthermore, this application also proposes that the inner edge of the bottom surface of the colloid is flush with the bottom surface of the bushing, and the outer edge of the bottom surface is recessed to form a step.

[0013] As can be seen from the above, the bushing assembly and its connection structure provided in this application enhance torque transmission stability through the straight sectional surface formed by the disc body cut, improve the bonding strength through the colloid injection molding coating structure, and enhance the installation flexibility by arranging the bushing threaded hole and the notch perpendicularly. It has the advantages of improving the bonding strength between the colloid and the metal parts, optimizing the uniformity of injection molding filling, enhancing torque transmission stability, and improving the installation flexibility of the bushing. Attached Figure Description

[0014] Figure 1 This is a three-dimensional schematic diagram of a bushing assembly provided in this application.

[0015] Figure 2 This is a cross-sectional schematic diagram of a bushing assembly provided in this application. Detailed Implementation

[0016] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0017] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0018] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more, unless otherwise expressly defined.

[0019] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0020] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0021] In existing technologies, bushing assemblies typically employ an interference fit process between a metal disc and the bushing. This method is prone to stress concentration, loosening of the connection, and insufficient sealing. While existing injection molding connection solutions improve stress distribution and sealing, they still suffer from insufficient torque transmission capacity and unreliable connection methods between the bushing and the drive shaft. For example, in high-speed fan drive systems, traditional bushing assemblies may experience micro-displacements between the bushing and the disc during frequent start-stop cycles and load changes, leading to decreased transmission accuracy and abnormal wear.

[0022] To address the aforementioned issues, it is first necessary to eliminate the internal stress introduced by the press-fitting process and simultaneously improve the torsional resistance between the disc and the bushing. Traditional injection-molded materials only achieve unidirectional coverage, failing to effectively transmit torque. By redesigning the edge structure of the disc to create a mechanical interlock with the injection-molded material, the bonding strength can be enhanced. Furthermore, the connection method between the bushing and the drive shaft needs to simplify the installation process and improve reliability. Based on this, it is proposed to provide threaded holes on the sidewall of the bushing to replace key connections, and to design a notch structure at the end of the bushing to create a complementary fit with the drive shaft.

[0023] like Figure 1 and 2 As shown, this application relates to a bushing assembly, including a disc body 1, a bushing 2 disposed at the center of the disc body 1, and a colloid 3 that injection molds the inner edge of the disc body 1 and the outer edge of the bushing 2. The inner side of the colloid 3 covers the outer wall of the bushing 2, and the inner edge of the disc body 1 is covered within the outer edge of the colloid 3. The outer edge of the disc body 1 has multiple circumferential cuts 11 to form straight cross-sections. The side wall of the bushing 2 has threaded holes 21 communicating with the central shaft hole, and the end of the bushing 2 has two radially arranged notches 22 perpendicular to the threaded holes 21. The disc body 1 refers to an annular metal component that bears the transmission force, specifically a stamped steel disc. The cuts 11 on its outer edge are formed into straight cross-sections by laser cutting, milling, or direct punching to increase the contact area and bonding strength with the external plastic component. The bushing 2 refers to a metal sleeve nested in the center of the disc 1. It can be a machined aluminum alloy part, with threaded holes 21 on its sidewalls machined by drilling and tapping for bolt-fixed connection to the drive shaft. The notch 22 refers to symmetrical U-shaped grooves at the end of the bushing 2, which can be machined by wire cutting. These grooves engage with protruding structures on the drive shaft to transmit torque. The colloid 3 refers to a thermoplastic material injection molded, such as nylon or polycarbonate. Its inner and outer sides respectively cover the outer wall of the bushing 2 and the inner edge of the disc 1, forming a two-way interlocking structure to distribute stress.

[0024] Specifically, during injection molding, the colloid 3 melts and fills the gap between the disc 1 and the bushing 2. After cooling and solidification, it forms a bidirectional encapsulation structure, creating a mechanical interlock between the disc 1 and the bushing 2. The straight sectional surface of the outer edge of the disc 1 alters its original circular contour, increasing the contact area and bonding force with the external plastic wheel surface during injection molding of the bushing assembly and the through-flow disc, preventing slippage during high-speed rotation. The threaded hole 21 on the side wall of the bushing 2 allows direct bolt fastening of the drive shaft, eliminating the need for traditional keyway machining. Simultaneously, the two recesses 22 are arranged perpendicularly to the threaded hole 21. When the drive shaft is inserted, its end can be embedded in the recesses 22, forming a circumferential limit and preventing relative rotation caused by bolt loosening.

[0025] Compared to existing technologies, traditional press-fitting processes rely on frictional forces generated by interference fits to transmit torque. This solution, however, utilizes the synergistic effect of the injection-molded colloid 3 and the mechanical structure to transform torque transmission into a dual load-bearing system, combining the shear force of the colloid 3 and the engagement force of the notch 22. In existing injection molding solutions, the colloid 3 only unidirectionally covers the disc 1 or bushing 2, while the bidirectional covering structure of this solution significantly improves connection stability. Furthermore, the combination of the threaded hole 21 and the notch 22 replaces the traditional key connection, reducing processing costs and avoiding transmission failure caused by keyway wear. Through these technical solutions, this application effectively reduces internal stress at the connection between the disc 1 and bushing 2, preventing loosening due to vibration or load changes; the combination of the straight tangent and the injection-molded colloid 3 enhances torque transmission capability, preventing relative slippage during high-speed transmission; the combination of the threaded hole 21 and the notch 22 simplifies the drive shaft installation process, while simultaneously improving connection reliability through the dual action of mechanical engagement and bolt tightening.

[0026] In a further design, the colloid 3 is constructed as a gradient shape with a larger inner edge thickness and a smaller outer edge thickness. The larger inner edge thickness means that the radial cross-sectional thickness of the colloid 3 near the outer wall of the bushing 2 is greater than that of the outer edge region away from the bushing 2. This can be achieved using a tapered gradient structure in the injection mold cavity, with the thickness variation of the colloid 3 controlled by adjusting the inclination angle of the mold inner wall. This design increases the material volume in the critical contact area connecting the bushing 2 and the disc 1, thereby improving the shear resistance of the bonding interface. The smaller outer edge thickness means that the radial cross-sectional thickness of the colloid 3 near the inner edge of the disc 1 decreases away from the bushing 2. This can be achieved through a gradient pressure distribution along the flow path of the molten material during injection molding. This structure avoids stress concentration at the outer periphery of the colloid 3 due to abrupt thickness changes, while ensuring that the inner edge of the disc 1 is fully covered. Specifically, during injection molding, as the molten colloid 3 flows from the outer wall of the bushing 2 to the inner edge of the disc 1, the larger inner edge thickness forms a high-density filling layer around the outer wall of the bushing 2, resulting in a stronger mechanical interlocking effect with the bushing 2 after solidification. The structure with decreasing outer thickness allows the material to form a uniform coating layer in the inner edge region of the disk 1, reducing shrinkage stress caused by thickness differences. When the bushing 2 is subjected to torque, the colloid 3 in the inner thick region preferentially transfers the load to the disk 1, while the outer thin region disperses the torsional stress through the gradually changing cross-sectional stiffness, forming a load transfer path that gradually decreases from the bushing 2 to the disk 1.

[0027] Furthermore, the top surface of the colloid 3 is constructed as a slope 31, with a first rounded corner 311 formed at its inner end. The radius of the first rounded corner 311 is 2mm. The slope 31 refers to a planar structure where the top surface of the colloid 3 forms an inclined angle with the axis of the bushing 2. This can be achieved by setting an inclined cavity during injection molding. This structure guides the molten material to fill evenly along the slope 31, avoiding localized material accumulation or gaps. The first rounded corner 311 refers to the rounded transition structure at the connection between the slope 31 and the outer wall of the bushing 2. This can be achieved by setting a rounded corner feature with a radius of 2mm during mold processing. This rounded structure disperses the stress distribution at the connection, eliminating stress concentration caused by right-angle connections. Specifically, during injection molding, the slope 31 structure causes the molten colloid 3 material to flow in a gradient from the outer wall of the bushing 2 to the inner edge of the disc 1, ensuring complete filling of the interface between the colloid 3 and the metal part. The first arc angle 311 forms a continuous transition between the top surface of the colloid 3 and the outer wall of the bushing 2, eliminating stress concentration points at traditional right-angle connections. After curing, this structure prevents planar contact between the top surface of the colloid 3 and adjacent rotating components, preventing assembly interference. Compared to existing technologies, traditional injection-molded colloid 3 often uses planar or right-angle connection structures, resulting in a single material flow path during injection molding, which easily generates air bubbles, and right angles are prone to stress concentration sources. This solution, through the combined design of the inclined surface 31 and the arc angle, forms a multi-directional flow path during the material filling stage, achieving uniform stress distribution in terms of structural strength. Through the above technical solution, this application effectively solves the problem of incomplete molding caused by structural defects in the injection-molded colloid 3, avoids contact interference between the colloid 3 and surrounding components, significantly reduces the risk of cracking caused by stress concentration, and extends the service life of the bushing assembly under alternating load conditions.

[0028] Furthermore, the bottom surface of the colloid 3 is constructed as a step 32, the inner corner of the step 32 is constructed as a second rounded corner 321 with a radius of 1 mm, and the sidewall of the step 32 is constructed as a slope 322. The step 32 refers to the stepped structure formed by the inward indentation of the outer edge of the bottom surface of the colloid 3, which can be achieved through injection molding. It is used to create space between the bottom surface of the colloid 3 and adjacent components, avoiding assembly interference. The second rounded corner 321 refers to the rounded transition structure at the inner corner of the step 32, which can be achieved through a rounded corner process in the mold. It is used to disperse stress concentration at the connection between the colloid 3 and the bushing 2, reducing the risk of cracking. The slope 322 refers to the inclined surface formed by the sidewall of the step 32 relative to the vertical direction. It can be achieved through mold draft angle design, which is used to improve the flow and filling effect of the molten colloid 3 during injection molding, while reducing the contact area with surrounding components. Specifically, the step 32 structure, through its concave design, creates a gap between the outer edge of the bottom surface of the colloid 3 and adjacent components, preventing collisions during installation. The second rounded corner 321 eliminates stress concentration at right angles through a smooth transition, enhancing the fatigue resistance of the connection between the colloid 3 and the bushing 2. The inclined sidewall 322 guides the material of the colloid 3 to flow along the inclined direction during injection molding, ensuring complete filling of the step 32 area. Simultaneously, the inclined surface 322 structure guides the components to slide into their predetermined positions along the inclined surface during assembly, reducing installation resistance.

[0029] Furthermore, the inner edge of the bottom surface of the colloid 3 is flush with the bottom surface of the bushing 2, while the outer edge of the bottom surface is recessed to form a step 32. The inner edge of the bottom surface being flush with the bottom surface of the bushing 2 means that the area of ​​the colloid 3 near the bottom of the bushing 2 is on the same plane as the bottom of the bushing 2. This can be achieved through the positioning structure of the injection mold. This design creates a continuous support surface between the colloid 3 and the bushing 2, preventing stress concentration due to height differences during axial load transmission. The recessed outer edge forming the step 32 means that the area of ​​the bottom surface of the colloid 3 away from the bushing 2 is recessed inward to form a stepped structure. This can be achieved by adjusting the cavity depth of the injection mold. This structure reduces the volume of the outer periphery of the colloid 3 while ensuring connection strength, reserving assembly space for adjacent components. Specifically, the flush construction of the inner edge of the bottom surface of the colloid 3 with the bottom surface of the bushing 2 creates a seamless support plane. Axial loads can be evenly transmitted to the bushing 2 through this plane, avoiding the risk of cracking of the colloid 3 due to localized stress concentration. The stepped structure 32, formed by the concave outer edge, reduces the material usage by locally thinning the colloid 3 while maintaining the connection strength. Simultaneously, the vertical surface formed by the sidewall of the stepped structure 32 can serve as an assembly reference surface, preventing interference between the edge of the colloid 3 and adjacent components. The stepped transition of the stepped structure 32 also guides the injection melt to fill evenly along the axial and radial directions during molding, improving the bonding density between the colloid 3 and the metal part.

[0030] In summary, the bushing assembly and its connection structure provided in this application enhance torque transmission stability through the straight tangent formed by the cut 11 of the disc body 1, improve the bonding strength through the injection molding of the colloid 3, and enhance installation flexibility through the perpendicular arrangement of the threaded hole 21 and the notch 22 of the bushing 2. It has the advantages of improving the bonding strength between the colloid 3 and the metal parts, optimizing the uniformity of injection molding, enhancing torque transmission stability, and improving the installation flexibility of the bushing 2.

[0031] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0032] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. A bushing assembly, characterized in that: It includes a disc body (1), a bushing (2) disposed at the center of the disc body (1), and a colloid (3) for injection molding to connect the inner edge of the disc body (1) and the outer edge of the bushing (2) together; the inner side of the colloid (3) is injection molded to cover the outer wall of the bushing (2), and the inner edge of the disc body (1) is injection molded to cover the outer edge of the colloid (3); The outer edge of the disc body (1) is provided with multiple cuts (11) along the circumferential direction so that a straight cut surface is formed on its edge; The bushing (2) has a threaded hole (21) connected to its central shaft hole on its side wall. The bushing (2) has two recesses (22) arranged radially at its end. The two recesses (22) are arranged perpendicular to the threaded hole (21).

2. The bushing assembly according to claim 1, characterized in that: The colloid (3) is constructed into a gradient shape with a large inner edge thickness and a small outer edge thickness.

3. The bushing assembly according to claim 1 or 2, characterized in that: The top surface of the colloid (3) is constructed as a slope (31), and the inner end of the slope (31) forms a first rounded corner (311) with a radius of 2 mm.

4. The bushing assembly according to claim 3, characterized in that: The bottom surface of the colloid (3) is constructed as a step (32), the inner corner of the step (32) is constructed as a second rounded corner (321), the radius of the second rounded corner (321) is 1 mm, and the side wall of the step (32) is constructed as a slope (322).

5. The bushing assembly according to claim 4, characterized in that: The inner edge of the bottom surface of the colloid (3) is flush with the bottom surface of the bushing (2), and the outer edge of the bottom surface is recessed to form the step (32).

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