Shaft sleeve mounting structure, arm section, folding arm support and mechanical equipment with folding arm support

Abstract

The invention relates to the field of mechanical equipment, and discloses a shaft sleeve mounting structure, an arm section, a folding arm support and mechanical equipment with the same. The first shaft sleeve (1) and the second shaft sleeve (2) are installed on the first component in a mutually spaced mode, and the shaft sleeve flitch plate (3) is connected with the first shaft sleeve (1) and the second shaft sleeve (2) and attached to the surface of the first component so that the second component can be connected with the first component in a pivoted mode through a pivoting shaft penetrating through the first shaft sleeve (1). And the first component can be driven to pivot relative to the second component by a driving assembly which is pivotally connected to the second shaft sleeve (2). The shaft sleeve mounting structure can remarkably reduce the change range and the load in the load direction of the shaft hole, effectively improves the bearing state of the shaft hole, and is particularly suitable for preventing the fiber composite material arm support from being crushed and cracked in the weak direction at the position of the arm support shaft hole.

Description

Technical Field

[0001] The present invention relates to mechanical equipment such as engineering machinery, and in particular to a sleeve mounting structure for pivotally connecting a first component to a second component. In addition, the present invention also relates to a boom section and a foldable boom, and mechanical equipment having the foldable boom. Background Art

[0002] In various types of mechanical equipment such as engineering machinery and fire fighting equipment, it is common to use mutually cooperating pivot shafts and sleeves to pivotally connect different parts to each other, and use a drive unit such as an oil cylinder to drive one part to rotate relative to another part pivotally connected to it, so as to achieve construction or operation purposes such as material transportation. Typically, as an important component of engineering machinery such as concrete pump trucks, the foldable boom includes a plurality of boom sections pivotally connected to each other through a pivot shaft, and boom cylinders are connected between adjacent boom sections, so that the boom cylinders can drive the adjacent boom sections to pivot relative to each other, thereby facilitating the delivery of concrete to a predetermined position through a delivery pipe.

[0003] In view of the development goal of lightweight boom, the existing technology proposes a solution of using fiber composite materials to manufacture the boom body. Compared with the steel materials (including high-strength steel) of traditional booms, fiber composite materials have the advantages of high specific strength, high specific modulus, good fatigue resistance, good damage safety, good damping and vibration reduction performance, and strong designability, which makes it achieve remarkable results in the lightweight design and manufacturing of booms.

[0004] However, fiber composite materials used in the manufacture of booms will cause new problems. For example, due to the anisotropy of fiber composite materials, when the boom posture changes with the working conditions, the direction and size of the shaft hole load will change significantly at the same time, which can easily cause the weak direction of the fiber composite material to be crushed and cracked. For another example, fiber composite materials also have problems such as poor wear resistance and inability to weld with metal sleeves. When the boom posture changes with the working conditions, the sleeve rotates with the pivot shaft in the boom shaft hole, causing the shaft hole to be worn and the hole diameter to become larger and larger, causing the connection between the sleeve and the shaft hole to loosen, affecting the service life of the boom. Summary of the invention

[0005] The purpose of the present invention is to overcome the problem in the prior art that the boom (especially a fiber composite boom) is easily crushed and cracked at the axis hole position due to the fact that the size and direction of the boom shaft hole load change significantly with the boom posture. A sleeve mounting structure, boom section and folding boom are provided that can be used for the boom. When the boom posture changes with the working conditions, the sleeve mounting structure, boom section and folding boom can significantly reduce the variation range of the boom shaft hole load direction and the load size, thereby significantly improving the load-bearing state of the boom shaft hole.

[0006] In order to achieve the above-mentioned objectives, on one hand, the present invention provides a sleeve mounting structure for pivotally connecting a first component to a second component, the sleeve mounting structure comprising a first sleeve and a second sleeve installed to the first component at intervals from each other, and a sleeve plate connecting the first sleeve and the second sleeve and abutting against the surface of the first component, so as to allow the second component to be pivotally connected to the first component by a pivot axis passing through the first sleeve, and enable the first component to be driven by a driving assembly pivotally connected to the second sleeve to pivot relative to the second component.

[0007] Preferably, the first component is a box-type structure, the first sleeve and the second sleeve extend through the side walls of the box-type structure respectively, and the sleeve plates are connected to both sides of the side walls respectively and fit the wall surfaces thereof.

[0008] Preferably, the first sleeve and the second sleeve have outer peripheral surfaces of a rotating body or a non-rotating body respectively, and the first component is formed with shaft holes respectively interference-fitted with the outer peripheral surfaces.

[0009] Preferably, the first component has a main body made of a fiber composite material, and the first sleeve, the second sleeve and the sleeve plate are made of a metal material.

[0010] Preferably, a metal lining plate is embedded in the position of the first component for mounting the first sleeve and the second sleeve.

[0011] The second aspect of the present invention provides an arm section having a first sleeve for pivotally connecting to an adjacent arm section and a second sleeve for transmission connection to an arm cylinder, wherein a sleeve plate is connected between the first sleeve and the second sleeve and is in contact with the side wall surface of the arm section.

[0012] Preferably, the arm section has a main body made of a fiber composite material, and the first shaft sleeve, the second shaft sleeve and the shaft sleeve plate are made of a metal material.

[0013] Preferably, the first sleeve, the second sleeve and the sleeve plate are made of carbon steel, alloy steel, aluminum alloy, magnesium alloy or titanium alloy, and / or, weight-reducing holes are formed on the sleeve plate.

[0014] The third aspect of the present invention provides a foldable arm frame, comprising a first arm section and a second arm section pivotally connected to each other and a driving assembly connected between the first arm section and the second arm section, wherein the first arm section has a first shaft sleeve and a second shaft sleeve installed at intervals from each other, and the second arm section has a pivot shaft passing through the first shaft sleeve, and the driving assembly is pivotally connected to the second shaft sleeve to be able to drive the first arm section to pivot relative to the second arm section around the pivot shaft, wherein a shaft sleeve plate is connected between the first shaft sleeve and the second shaft sleeve and is in contact with the side wall surface of the first arm section.

[0015] Preferably, the first arm section and the second arm section respectively have a main body made of a fiber composite material, and the first shaft sleeve, the second shaft sleeve and the shaft sleeve plate are made of a metal material.

[0016] Preferably, the driving assembly comprises a boom cylinder and a first link respectively pivotally mounted to the second boom section and a second link pivotally connected to the second bushing, the boom cylinder and the second link respectively being hinged to the first link.

[0017] A fourth aspect of the present invention provides a mechanical equipment having the above-mentioned bushing mounting structure or foldable boom.

[0018] Through the above technical scheme, the sleeve installation structure, arm section and folding boom of the present invention connect the first sleeve for pivotally connecting the adjacent components (arm section) and the second sleeve for pivotally connecting the driving assembly (arm cylinder) into one body through the sleeve plate, and the load from the corresponding pivot shaft borne by either the first sleeve or the second sleeve is associated with the other, so that the two sets of shaft holes for installing the first sleeve and the second sleeve share the load transmitted by the pivot shaft, thereby improving the load-bearing state of the shaft hole. Tests have proved that when applied to a folding boom, when the boom posture changes, the sleeve installation structure and arm section provided by the present invention can significantly reduce the range of change and load size of the boom shaft hole load direction, thereby significantly improving the load-bearing state of the boom shaft hole. This can effectively prevent crushing and cracking in the weak direction for the fiber composite boom, thereby significantly reducing the risk of the boom structure being easily damaged due to the anisotropy of the fiber composite material, which is conducive to the development and application of boom lightweight technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a partial view of a boom section according to a preferred embodiment of the present invention, which includes a shaft sleeve mounting structure provided by the present invention;

[0020] Figure 2 is the cross section of the fiber composite boom;

[0021] Figure 3 yes Figure 1 A cross-sectional view of the center sleeve mounting structure;

[0022] Figure 4 It is a partial view of a boom section in the prior art, which includes shaft sleeves that are independent of each other;

[0023] Figure 5 It is a schematic diagram for representing the boom posture of a foldable boom, wherein there is an inter-arm angle between the first boom section and the second boom section;

[0024] Figure 6 It is a schematic diagram of the coordinate system used to represent the load direction of the boom shaft hole;

[0025] Figure 7 It is the relationship curve between the boom posture and the load direction of the boom shaft hole;

[0026] Figure 8 It is the relationship curve between the boom posture and the load size of the boom shaft hole;

[0027] Fig. 9 It is a three-dimensional diagram of the welded parts of the shaft sleeve and the shaft sleeve plate;

[0028] Fig.10 yes Fig. 9 Cross-sectional view of a weldment.

[0029] Description of Reference Numerals

[0030] 1-first bushing; 2-second bushing; 3-sleeve plate; 31-weight-reducing hole; 32-weld; 4-first arm section; 41-fiber composite material layer; 42-metal lining plate; 5-second arm section; 6-arm cylinder; 7-first connecting rod; 8-second connecting rod; a-first pivot connection point; b-second pivot connection point; α-angle between arms. DETAILED DESCRIPTION

[0031] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0032] As mentioned above, one aspect of the present invention provides a sleeve mounting structure for pivotally connecting a first component to a second component, and other aspects of the present invention provide a boom section, a folding boom, and mechanical equipment including the sleeve mounting structure or the folding boom. It should be understood that although this article mainly uses the folding boom as an application object to exemplify the implementation method and technical effect of the provided sleeve mounting structure, the sleeve mounting structure can be used to pivotally connect other different components other than the boom section to each other. Therefore, the first component and the second component described in the present invention can not only be the first boom section and the second boom section in the folding boom described later, but also can be other components in various types of mechanical equipment that are pivotally connected and can be driven to pivot relative to each other. In this case, the mechanical equipment described in the present invention can be engineering machinery, fire-fighting equipment, etc., such as a concrete pump truck and a high-rise fire truck.

[0033] Reference Figures 1 to 3As shown, according to a preferred embodiment of the present invention, a sleeve mounting structure for pivotally connecting a first component to a second component comprises a first sleeve 1 and a second sleeve 2 installed to the first component at intervals, and a sleeve plate 3 connecting the first sleeve 1 and the second sleeve 2 and fitting with the surface of the first component. Figure 5 As shown, the first component and the second component here can be the first arm section 4 and the second arm section 5 adjacent to each other in the foldable arm frame, wherein the first arm section 4 and the second arm section 5 can be pivotally connected to each other at the first pivot connection point a where the first shaft sleeve 1 is installed, and the second pivot connection point b where the second shaft sleeve 2 is installed can be used to pivotally connect the driving component, and the driving component can drive the first arm section 4 to pivot relative to the second arm section 5 to present different arm frame postures. The shaft sleeve plate 3 can be fitted with the surface of the first arm section 4. When the first arm section 4 is set as a box-type arm, the inner and outer wall surfaces of the first arm section 4 can respectively have shaft sleeve plates 3 connecting the first shaft sleeve 1 and the second shaft sleeve 2.

[0034] Thus, through the above-mentioned sleeve mounting structure, the second component can be pivotally connected to the first component by passing through the pivot shaft of the first sleeve 1, and the first component can be driven by the driving assembly pivotally connected to the second sleeve 2 to pivot relative to the second component. Since the sleeve mounting structure connects the first sleeve 1 used for pivotally connecting adjacent components (the second component, the second arm section 5) and the second sleeve 2 used for pivotally connecting the driving assembly (the boom cylinder) as a whole through the sleeve plate 3, the load from the corresponding pivot shaft borne by either the first sleeve 1 or the second sleeve 2 is associated with the other, so that the two sets of shaft holes on which the first sleeve 1 and the second sleeve 2 are installed share the load transmitted by the pivot shaft, thereby improving the load-bearing state of the shaft holes. Relatively speaking, in the case of Figure 4 In the prior art shown, the two groups of arm shaft holes of the arm section are independent of each other, and the arm shaft hole at the first pivot connection point a and the first shaft sleeve 1 installed therein, and the arm shaft hole at the second pivot connection point b and the second shaft sleeve 2 installed therein each independently bear the load transmitted by the pivot shaft. When the arm posture changes, the load size and direction of the arm shaft hole will change significantly, which may easily cause the arm to be crushed and cracked at the shaft hole position, especially for the fiber composite material arm, due to the anisotropy of its fiber composite material, it has a weak direction with low load-bearing capacity. The shaft sleeve installation structure of the present invention effectively improves the load-bearing state of the shaft hole through the shaft sleeve plate.

[0035] against Figure 1 The shaft sleeve installation structure provided by the present invention is shown Figure 4 The prior art shown, the inventor based on Figure 5The foldable boom model shown in the figure tests and compares the load direction and load magnitude of the boom shaft hole under different boom postures. Specifically, the simulation software Abaqus is used to model and extract the magnitude and direction of the boom shaft hole support force at the first pivot connection point a and the first pivot connection point b. Among them, the angle between the first boom section 4 and the second boom section 5 is the inter-arm angle α, which is used to represent the boom posture; Figure 6 The coordinate system shown is the reference coordinate system representing the load direction of the boom shaft hole. The specific test process is as follows:

[0036] A 1:1 scale model of a real pump truck is selected to construct a mesh model, in which the arm and connecting rod are meshed with shell elements, the pin (pivot shaft) and the bushing are meshed with solid elements, and the concrete pipe is meshed with beam elements. The assembly relationship between the pin and the arm and connecting rod is modeled using the contact properties of hard contact and sliding friction. The load of the worst load condition of the real vehicle is extracted, and the input load for the simulation calculation is determined after multiplying by the dynamic load coefficient, including the concentrated force and bending moment formed by the wind load, and the concentrated force, bending moment and torque formed by the deadweight of the front structural parts. Submit the calculation and output the magnitude and direction of the reaming force of the arm reaming in the result file. Similarly, adjusting the arm posture (angle between arms) can obtain the magnitude and direction of the arm reaming force under different postures.

[0037] Test results such as Figure 7 and Figure 8 When the angle α between the arms changes from 30° to 240°, the Figure 4 The existing sleeve installation structure shown in the figure has a load direction of the arm shaft hole at the first pivot connection point a (i.e. Figure 7 The reaming force direction shown in the figure changes from 172.7° to 283.4°, with a range of 110.7°. The load size of the boom shaft hole (i.e. Figure 8 The reaming force shown in the figure varies in the range of 113.3 tons to 210.6 tons; under the same working conditions (the same test conditions and range of motion), the bushing installation structure provided by the present invention is adopted, and the load direction of the boom shaft hole at the first pivot connection point a changes from 224.6° to 252.8°, with a range of 28.2°, and the load size of the boom shaft hole varies in the range of 113 tons to 121.9 tons. It can be seen that when the boom posture changes, the bushing installation structure provided by the present invention changes the load-bearing mode of the boom shaft hole, which can significantly reduce the range of variation and load size of the load direction of the boom shaft hole, thereby significantly improving the load-bearing state of the boom shaft hole. For a fiber composite boom, this can effectively prevent crushing and cracking in the weak direction, thereby significantly reducing the risk of the boom structure being easily damaged due to the anisotropy of the fiber composite material, which is conducive to the development and application of boom lightweight technology.

[0038] Continue to refer to Figures 1 to 3As shown, the present invention provides a boom section, here the first boom section 4, which has a first sleeve 1 for pivoting to an adjacent boom section (such as the aforementioned second boom section 5) and a second sleeve 2 for transmission connection to the boom cylinder, and a sleeve plate 3 that fits the side wall surface of the boom section is connected between the first sleeve 1 and the second sleeve 2. It should be understood that the boom cylinder is usually transmission-connected to the second sleeve 2 through a connecting rod, which will be described in detail in the subsequent description of the foldable boom. As the aforementioned sleeve installation structure, the boom section, as a specific implementation form of the sleeve installation structure, has the same technical effect as it, and will not be repeated here.

[0039] Combination Figures 1 to 3 , Figure 5 As shown, the present invention also provides a foldable boom, wherein: Figure 5 Only two arm sections in the foldable boom are schematically shown, namely the first arm section 4 and the second arm section 5, which are pivotally connected to each other at the first pivot connection point a, and a driving assembly is connected between the two. The first arm section 4 has a first sleeve 1 and a second sleeve 2 installed at intervals from each other, and the second arm section 5 has a pivot shaft passing through the first sleeve 1, and the driving assembly is pivotally connected to the second sleeve 2 so as to be able to drive the first arm section 4 to pivot relative to the second arm section 5 around the pivot shaft, and a sleeve plate 3 that fits the side wall surface of the first arm section 4 is connected between the first sleeve 1 and the second sleeve 2. According to the above, the foldable boom can make the load direction and load size of the boom shaft hole change within a small range under different boom postures, thereby significantly improving the load-bearing state of the boom shaft hole.

[0040] During operation, the load borne by the boom mainly comes from the gravity of the front structural member, and its effect can be decomposed into a first component force parallel to the line between the first pivot connection point a and the first pivot connection point b and a second component force perpendicular to the first component force. For the bushing installation structure of the prior art, the magnitude and direction of the force borne by the boom shaft hole at the first pivot connection point a and the first pivot connection point b will change significantly within the range of the arm angle required by the operating specifications; while the bushing installation structure provided by the present invention can be used to offset the force components borne by the first bushing 1 and the second bushing 2 along the line direction thereof, so that the boom shaft hole at the first pivot connection point a and the first pivot connection point b mainly bears the force component perpendicular to the direction, and the magnitude and direction of the force component will only change within a relatively small range when the arm angle changes, especially the magnitude of the force can be kept basically constant, so that the effect of improving the load-bearing state is significant.

[0041] As mentioned above, the first component and the second component used for being pivotally connected by the sleeve mounting structure of the present invention can be components in various mechanical equipment that are pivotally connected and can be driven to pivot relative to each other. Figure 2 and Figure 3 As shown, the first component and the second component can be a box-type structure such as adjacent arm sections of a concrete pump truck boom, and the box-type structure has a hollow cavity surrounded by side walls, wherein the first shaft sleeve 1 and the second shaft sleeve 2 extend through the side walls of the box-type structure respectively, and shaft sleeve plates 3 that fit the wall surfaces are connected to the two sides of the side walls respectively. In addition, the shaft holes (and the shaft sleeves mounted thereon) on the two opposite side walls are aligned with each other so that the pivot shaft passes through the shaft sleeves on the two side walls and is pivotally connected.

[0042] In the above-mentioned sleeve mounting structure, arm section and folding boom, the first component of the sleeve mounting structure, the first arm section 4, can have a main body made of fiber composite material, and the second component, the second arm section 5 pivotally connected thereto, can also have a main body made of fiber composite material, thereby making the corresponding functional module (such as the boom) lightweight, and the first sleeve 1, the second sleeve 2 and the sleeve plate 3 can be made of metal material so as to be connected as a whole by welding or the like. For example, the first sleeve 1, the second sleeve 2 and the sleeve plate 3 can be made of carbon steel, alloy steel, aluminum alloy, magnesium alloy or titanium alloy, among which alloy steel is preferred. Figure 2 and Figure 3 As shown, the arm section may have a composite material layer 41 made of fiber composite material, and a metal lining plate 42 is embedded in the position for mounting the first bushing 1 and the second bushing 2 so as to withstand relatively large compressive stress at this location.

[0043] It is understandable that, although the bushing mounting structure of the present invention is advantageous for solving the problem of fragile arm structures due to anisotropy of fiber composite materials, the bushing mounting structure does not exclude its use in arms or other pivoting components made of traditional materials.

[0044] During the manufacturing process, first, the fiber composite arm can be marked and positioned, and the arm shaft hole can be formed by spiral milling and other machining methods at the position of the fiber composite arm shaft hole for the installation of the shaft sleeve. Fig. 9 and Fig.10 As shown, the first sleeve 1, the second sleeve 2 and the sleeve plate 3 are cut by flame cutting, laser cutting or the like to obtain blanks; then, the first sleeve 1, the second sleeve 2 and the sleeve plate 3 are machined by turning, milling or the like; then, the first sleeve 1 and the second sleeve 2 are welded to one of the sleeve plates 3 to form a welded part of the sleeve and the sleeve plate; then, the welding machine can be finely processed to obtain a sleeve structure suitable for installation in the arm support shaft hole and to make the sleeve plate 3 fit the arm support surface.

[0045] In a preferred embodiment of the present invention, the first sleeve 1 and the second sleeve 2 may respectively have an outer peripheral surface of a rotating body or an outer peripheral surface of a non-rotating body, such as an outer contour cross section with a circular, elliptical, oval, polygonal or other shapes. Accordingly, the first component or the first arm section 4 may be formed with an axial hole corresponding thereto, and the two may be assembled together by interference fit. Since the first sleeve 1 and the second sleeve 2 are connected as a whole through the sleeve plate 3, the sleeve can be prevented from rotating in the axial hole in the installed state, thereby preventing the axial hole from being worn, and significantly improving the service life. As a result, the outer peripheral surface of the first sleeve 1 and the second sleeve 2 and the axial hole for installing them can be formed as a circular surface, and do not have to be formed into a special-shaped shape with an outer contour cross section such as a polygon.

[0046] The first sleeve 1 and the second sleeve 2 can be fixedly connected to the sleeve plate 3 by welding, riveting, etc., for example, Figure 3 As shown in the figure, the first sleeve 1 and the second sleeve 2 are connected to the sleeve plates 3 on both sides by welding, and a weld 32 is formed. The sleeve plate 3 can have an outer rim in an elliptical shape, a dumbbell shape, etc., which can be determined according to design requirements. Among them, a weight reduction hole 31 can be formed in the middle part of the sleeve plate 3.

[0047] Reference Figure 5 As shown, as a typical application mode, the driving assembly for pivotally connecting the second sleeve 2 may have a first link 7 and a second link 8 that are transmission-connected between the boom cylinder 6 and the second sleeve 2, and the first link 7 may be configured to have multiple hinge points. Specifically, the driving assembly includes a boom cylinder 6 and a first link 7 that are pivotally mounted to the second arm section 5, respectively, and a second link 8 that is pivotally connected to the second sleeve 2, wherein the boom cylinder 6 and the second link 8 are hinged to the first link 7, respectively. Thus, when the boom cylinder 6 is retracted, it can apply a pulling force to the first arm section 4 at the second pivot connection point b through the first link 7 and the second link 8, so that the first arm section 4 rotates relative to the second arm section 5 around the first pivot connection point a.

[0048] The foldable boom provided by the present invention can not only improve the bearing state of the fiber composite boom shaft hole, reduce the bearing load of the fiber composite boom shaft hole, and solve the problem of easy crushing and cracking of the shaft hole, but also solve the problems of easy rotation of the fiber composite boom shaft sleeve and easy wear of the shaft hole, thereby significantly improving the service life of the fiber composite boom shaft hole.

[0049] Another aspect of the present invention provides a mechanical equipment having the above-mentioned shaft sleeve mounting structure or foldable boom, and the foldable boom may be, for example, a boom of a concrete pump truck or a high-rise fire truck.

[0050] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various specific technical features in any suitable manner. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations. However, these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A sleeve mounting structure for pivotally connecting a first component to a second component, characterized in that: The sleeve mounting structure comprises a first sleeve (1) and a second sleeve (2) which are mounted to the first component at intervals from each other, and a sleeve plate (3) which connects the first sleeve (1) and the second sleeve (2) and fits with the surface of the first component, so as to allow the second component to be pivotally connected to the first component via a pivot axis passing through the first sleeve (1), and enable the first component to be driven by a driving assembly pivotally connected to the second sleeve (2) to pivot relative to the second component.

2. The shaft sleeve installation structure according to claim 1, characterized in that: The first component is a box-type structure, the first shaft sleeve (1) and the second shaft sleeve (2) respectively extend through the side wall of the box-type structure, and the shaft sleeve plates (3) that fit the wall surface are respectively connected to both sides of the side wall.

3. The shaft sleeve installation structure according to claim 1, characterized in that: The first shaft sleeve (1) and the second shaft sleeve (2) respectively have a rotating body or a non-rotating body outer peripheral surface, and the first component is formed with an axial hole that is interference-fitted with the outer peripheral surface.

4. The shaft sleeve installation structure according to claim 1, characterized in that: The first component has a main body made of a fiber composite material, and the first shaft sleeve (1), the second shaft sleeve (2) and the shaft sleeve plate (3) are made of a metal material.

5. The shaft sleeve installation structure according to claim 1, characterized in that: A metal lining plate (42) is embedded in the position of the first component for mounting the first shaft sleeve (1) and the second shaft sleeve (2).

6. A boom section, characterized in that: The arm section comprises a first shaft sleeve (1) for pivotally connecting to an adjacent arm section and a second shaft sleeve (2) for transmission connection to an arm frame cylinder; a shaft sleeve plate (3) which is in contact with the side wall surface of the arm section is connected between the first shaft sleeve (1) and the second shaft sleeve (2).

7. The arm section according to claim 6, characterized in that: The arm section has a main body made of a fiber composite material, and the first shaft sleeve (1), the second shaft sleeve (2) and the shaft sleeve plate (3) are made of a metal material.

8. The arm section according to claim 6, characterized in that: The first shaft sleeve (1), the second shaft sleeve (2) and the shaft sleeve plate (3) are made of carbon steel, alloy steel, aluminum alloy, magnesium alloy or titanium alloy, and / or a weight-reducing hole (31) is formed on the shaft sleeve plate (3).

9. A foldable arm frame, comprising a first arm section (4) and a second arm section (5) pivotally connected to each other and a driving assembly connected between the first arm section (4) and the second arm section (5), characterized in that: The first arm section (4) has a first shaft sleeve (1) and a second shaft sleeve (2) installed at a distance from each other, the second arm section (5) has a pivot shaft passing through the first shaft sleeve (1), the driving assembly is pivotally connected to the second shaft sleeve (2) so as to be able to drive the first arm section (4) to pivot relative to the second arm section (5) around the pivot shaft, wherein a shaft sleeve plate (3) is connected between the first shaft sleeve (1) and the second shaft sleeve (2) and is in contact with the side wall surface of the first arm section (4).

10. The foldable boom according to claim 9, characterized in that: The first arm section (4) and the second arm section (5) respectively have a main body made of a fiber composite material, and the first shaft sleeve (1), the second shaft sleeve (2) and the shaft sleeve plate (3) are made of a metal material.

11. The foldable boom according to claim 9, characterized in that: The driving assembly comprises a boom cylinder (6) and a first connecting rod (7) respectively pivotally mounted to the second boom section (5), and a second connecting rod (8) pivotally connected to the second bushing (2); the boom cylinder (6) and the second connecting rod (8) are respectively hinged to the first connecting rod (7).

12. A mechanical device, characterized in that: The mechanical equipment has a bushing mounting structure according to any one of claims 1 to 5 or a foldable boom according to any one of claims 9 to 11.

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