Wear-resistant shelf body

Abstract

The utility model discloses a kind of wear-resistant upper frame bodies, including support frame, the support frame is connected with arm support bushing, main shaft unit is sleeved in the arm support bushing, the arm support bushing includes interfit groove, wear-resistant spacer is connected in the interfit groove, inner half-ring thread groove is provided on the wear-resistant spacer, outer half-ring thread groove is provided on the end face of interfit groove, the inner half-ring thread groove and outer half-ring thread groove butt joint and form thread hole, fixed screw rod is connected on the thread hole.The utility model provides a kind of wear-resistant upper frame bodies, without replacing entire arm support bushing after wearing, just with wear-resistant spacer, reduce vulnerable parts replacement cost.Meanwhile wear-resistant spacer can be set with different material with arm support bushing, and wear resistance is better.

Description

Technical Field

[0001] This utility model relates to the field of bushing technology, and in particular to a wear-resistant upper frame. Background Technology

[0002] For example, publication number "CN117548170A" discloses "a single-cylinder hydraulic cone crusher," which includes a slip ring cover sealing assembly, an upper frame assembly fixedly mounted on a lower frame assembly, a main shaft assembly mounted on the lower frame assembly, a transmission assembly sealed and fixedly mounted on the lower frame assembly, a piston assembly sealed and fixedly mounted on the lower frame assembly, and a slip ring cover sealing assembly sleeved on the main shaft assembly. The lower end of the slip ring cover sealing assembly is sealed and fixedly connected to the lower frame assembly, and the upper end of the ring cover sealing assembly is sealed and fixedly connected to the main shaft assembly. However, in practical applications, conventional cone crusher boom bushings are machined from castings, and the hardness of the contact surface with the main shaft bushing is not very high. Friction between the main shaft and the boom bushing causes the boom bushing to enlarge, thus requiring replacement of the entire boom bushing. Summary of the Invention

[0003] To address the issue mentioned in the background section that existing technologies require replacing the entire boom bushing after wear, this invention provides a wear-resistant upper frame that eliminates the need to replace the entire boom bushing after wear; only the wear-resistant spacer needs to be replaced, thus reducing the cost of replacing vulnerable parts. Furthermore, the wear-resistant spacer can be made of a different material than the boom bushing, resulting in even better wear resistance.

[0004] To achieve the above objectives, the present invention adopts the following technical solution.

[0005] A wear-resistant upper frame includes a support frame, a boom bushing connected to the support frame, a main shaft unit sleeved inside the boom bushing, the boom bushing including a fitting groove, a wear-resistant spacer connected inside the fitting groove, an inner semi-circular threaded groove provided on the wear-resistant spacer, an outer semi-circular threaded groove provided on the end face of the fitting groove, the inner semi-circular threaded groove and the outer semi-circular threaded groove mating to form a threaded hole, and a fixing screw connected to the threaded hole. In existing technology, the boom bushing and the spindle unit have a line contact, and the boom bushing is equipped with an inclined guide to ensure that the spindle unit has a certain amount of swing space and reduce friction. However, this working mechanism and connection method inevitably lead to increased wear in the line contact area with the spindle unit. After prolonged friction, the boom bushing will wear down, causing the inner diameter of the bushing to increase and the contact area to increase accordingly, thus affecting the working stability of the spindle unit. Therefore, after the above problems occur, the boom bushing needs to be replaced, which incurs significant costs. Therefore, to address the shortcomings of existing technology... In this application, a fitting groove is provided on the boom bushing, and a portion of the boom bushing is hollowed out and replaced with a wear-resistant spacer. This makes the combination of the wear-resistant spacer and the boom bushing in this application the same as the boom bushing in the prior art. The fitting groove is located at the part that rubs against the spindle unit. After the wear-resistant spacer is provided, when the wear-resistant spacer is worn due to friction, the service life of the boom bushing can be extended simply by replacing the wear-resistant spacer. Furthermore, since the boom bushing and the wear-resistant spacer are set separately, the wear-resistant spacer can be made of a different material than the boom bushing. A more wear-resistant material can be selected to improve the wear resistance of the wear-resistant spacer itself and ensure its service life. Furthermore, in this application, the wear-resistant spacer and the boom bushing are respectively provided with an inner half-ring threaded groove and an outer half-ring threaded groove. The axes of the inner and outer ring threaded grooves are parallel to the axis of the boom bushing, so the inner and outer half-ring threaded grooves can be connected to each other, forming a threaded hole. Since the wear-resistant spacer itself is fitted into the fitting groove, the wear-resistant spacer will not be relatively displaced relative to the boom bushing in the radial direction, ensuring the relative stability of the threaded hole. The threaded hole is then connected to a fixing screw, ensuring the stability between the wear-resistant spacer and the boom bushing in the axial direction. Since the connection part is set on the mating surface of the wear-resistant spacer and the boom bushing, the integrity of the inner wall surface of the wear-resistant spacer and the boom bushing near the main spindle unit is ensured, guaranteeing structural strength and preventing uneven stress on the inner wall surface of the boom bushing and the inner wall surface of the wear-resistant spacer during the operation of the main spindle unit.

[0006] Preferably, the boom bushing and wear-resistant spacer are provided with inclined surfaces, and the wear-resistant spacer makes line contact with the main spindle unit. The inclined surfaces on the boom bushing and wear-resistant spacer ensure that the main spindle unit can only contact the wear-resistant spacer, thus allowing the main spindle unit to swing during operation. The inclined surface has a smaller inner diameter at the end closer to the wear-resistant spacer and a larger inner diameter at the end farther from the wear-resistant spacer, thereby controlling the contact area to be on the wear-resistant spacer.

[0007] Preferably, the spindle unit includes a spindle body, on which a spindle bushing is fitted, and the spindle bushing abuts against a wear-resistant spacer. The spindle unit consists of a spindle body and a spindle bushing, wherein the spindle bushing is fitted onto the outside of the spindle body, thereby protecting the spindle body. After the spindle bushing wears out, replacement costs can be minimized by simply replacing the spindle bushing.

[0008] Preferably, the support frame has a stepped surface, and the boom bushing includes an overlapping plate that abuts against the stepped surface. The stepped surface on the support frame supports the overlapping plate, and the overlapping plate on the boom bushing abuts against the stepped surface, thereby ensuring the axial positioning of the boom bushing and guaranteeing its stability and ease of connection.

[0009] Preferably, the overlapping plate is provided with a connecting hole, and a connecting rod is connected to the connecting hole. The connecting rod passes through the overlapping plate and connects to the step surface. The connecting hole on the overlapping plate allows the connecting rod to pass through, thereby connecting the overlapping plate and the step surface together, improving the reliability of the connection.

[0010] Preferably, the support frame includes a lifting base plate, and a sealing component is engaged with the side of the boom bushing near the lifting base plate. The lifting base plate on the support frame creates a constricted structure at the bottom of the connection between the support frame and the boom bushing. The sealing component is connected to the bottom of the boom bushing, and the lifting base plate effectively limits the sealing component, preventing it from detaching from the bottom.

[0011] Preferably, the sealing assembly includes two separately configured sealing units, which are symmetrically arranged along the radial direction of the main shaft unit. The split structure of the sealing assembly, consisting of two separate sealing units, allows each unit to separately seal and block grease above and dust below, improving sealing performance. Furthermore, the two sealing units do not interfere with each other due to relative deformation, ensuring sealing quality. Combining the sealing assembly with two sealing units also reduces the thickness of individual sealing units, improving sealing effectiveness and ensuring the sealing units move smoothly during the rotation of the main shaft unit, thus reducing oil leakage gaps. Moreover, using two sealing units reduces replacement and maintenance costs; if a single sealing unit is damaged, only the corresponding sealing unit needs to be replaced.

[0012] Preferably, the sealing unit includes an engaging portion and a sealing lip. The sealing lip is inclined relative to the boom bushing axis, and the two sealing units are inclined in opposite directions. The engaging portion is configured as an "L"-shaped barb structure. The engaging portion and the sealing lip on the sealing unit are integrally formed. The inclined structure of the sealing lip allows it to adapt to the main shaft unit based on its own elasticity, thereby ensuring the quality of the fit. It can also adapt to the swinging motion of the main shaft unit to change the contact area between the sealing lip and the main shaft unit, ensuring that the two are always in contact. The "L"-shaped structure of the engaging portion ensures the reliability of the connection between the engaging portion and the lifting base plate.

[0013] Preferably, a fixing ring is connected to the supporting base plate, and the fixing ring is provided with a locking hook that can engage and connect the sealing unit. The fixing ring on the supporting base plate, which can engage and connect the sealing unit, ensures that the upper and lower sealing units can be fixed to different substrates respectively, thus guaranteeing the reliability of the sealing unit connection.

[0014] Preferably, a spacer is provided between the two sealing units, and the spacer is fixedly connected to the retaining ring. The spacer between the two sealing units reduces the mutual influence of deformation between them, ensuring the independence of the two sealing units and thus improving the sealing quality. Furthermore, the spacer and the retaining ring are relatively fixed through methods such as fixing rod connection, bolt connection, or integral molding, thereby ensuring that the spacer is fixed in position relative to the retaining ring. This ensures that the upper and lower sides of each sealing unit are fixedly abutted, improving the fixing effect of the sealing units.

[0015] The beneficial effects of this utility model are as follows: (1) Improve the boom bushing of the cone crusher by adding wear-resistant spacers to reduce the replacement cost of vulnerable parts, extend the service life, and shorten the manufacturing cycle. (2) It can improve the sealing effect of the spindle unit, so that the spindle unit can always fit with the sealing unit during the swing process, and can achieve a two-way protection effect. Attached Figure Description

[0016] Figure 1 This is a cross-sectional view of the present invention.

[0017] Figure 2 yes Figure 1 A magnified view of a portion of point A in the middle.

[0018] Figure 3 This is a partial exploded view of this utility model.

[0019] Figure 4 yes Figure 3 A magnified view of a section at point B in the middle.

[0020] In the picture: 1. Support frame; 11. Stepped surface; 12. Supporting base plate; 2 boom bushing, 21 fitting groove, 22 outer semi-circular threaded groove, 23 inclined surface, 24 overlapping plate, 25 connecting hole, 26 connecting rod; 3 spindle unit, 31 spindle body, 32 spindle bushing; 4. Wear-resistant spacer, 41. Inner semi-circular threaded groove, 42. Fixing screw; 5 sealing assembly, 51 sealing unit, 52 engaging part, 53 sealing lip; 6. Fixing ring, 61. Engaging hook, 62. Spacer. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0022] Example 1: like Figure 1 , 3 As shown in Figure 4, a wear-resistant upper frame includes a support frame 1, a boom bushing 2 connected to the support frame 1, a main shaft unit 3 sleeved inside the boom bushing 2, the boom bushing 2 includes a fitting groove 21, a wear-resistant spacer 4 connected inside the fitting groove 21, an inner semi-circular threaded groove 41 provided on the wear-resistant spacer 4, an outer semi-circular threaded groove provided on the end face of the fitting groove 21, the inner semi-circular threaded groove 41 and the outer semi-circular threaded groove are joined to form a threaded hole, and a fixing screw 42 is connected to the threaded hole.

[0023] In the prior art, the boom bushing 2 and the main spindle unit 3 are in line contact, and the boom bushing 2 is provided with an inclined guide to ensure that the main spindle unit 3 has a certain swing space and reduce friction. However, this working mechanism and connection method inevitably leads to increased wear in the area of ​​line contact with the main spindle unit 3. After long-term friction, the boom bushing 2 will wear, causing the inner diameter of the bushing to increase and the contact area to increase accordingly, thus affecting the working stability of the main spindle unit 3. Therefore, after the above problems occur, the boom bushing 2 needs to be replaced, and the replacement of the entire boom bushing 2 will incur significant costs. Therefore, to address the deficiencies in the prior art, this application... The boom bushing 2 is provided with a fitting groove 21. The boom bushing 2 is partially hollowed out and replaced with a wear-resistant spacer 4. This makes the combination of the wear-resistant spacer 4 and the boom bushing 2 in this application the same as the boom bushing 2 in the prior art. The fitting groove 21 is located at the part that rubs against the spindle unit 3. After the wear-resistant spacer 4 is provided, when the wear-resistant spacer 4 is worn due to friction, the service life of the boom bushing 2 can be extended simply by replacing the wear-resistant spacer 4. Furthermore, since the boom bushing 2 and the wear-resistant spacer 4 are set separately, the wear-resistant spacer 4 can be made of a different material than the boom bushing 2. A more wear-resistant material can be selected to improve the wear resistance of the wear-resistant spacer 4 itself and ensure its service life. Furthermore, in this application, the wear-resistant spacer 4 and the boom bushing 2 are respectively provided with an inner semi-circular threaded groove 41 and an outer semi-circular threaded groove. The axes of the inner and outer ring plate threaded grooves are parallel to the axis of the boom bushing 2, so the inner semi-circular threaded groove 41 and the outer semi-circular threaded groove can be connected to each other, forming a threaded hole. Since the wear-resistant spacer 4 is fitted inside the fitting groove 21, the wear-resistant spacer 4 will not undergo relative displacement with respect to the boom bushing 2 in the radial direction, thus ensuring the threaded hole is properly threaded. The perforated holes ensure relative stability, and the threaded holes connect to the fixing screw 42, so that the wear-resistant spacer 4 maintains stability with the boom bushing 2 in the axial direction. Since the connection part is set on the mating surface of the wear-resistant spacer 4 and the boom bushing 2, the integrity of the inner wall surface of the wear-resistant spacer 4 and the boom bushing 2 near the main shaft unit 3 is ensured, the structural strength is guaranteed, and the uneven stress on the inner wall surface of the boom bushing 2 and the inner wall surface of the wear-resistant spacer 4 in contact with the main shaft unit 3 is avoided during the operation of the main shaft unit 3.

[0024] like Figure 2 As shown, inclined surfaces 23 are provided on the boom bushing 2 and the wear-resistant spacer 4, and the wear-resistant spacer 4 is in line contact with the main spindle unit 3. The inclined surfaces 23 on the boom bushing 2 and the wear-resistant spacer 4 ensure that the main spindle unit 3 can only contact the wear-resistant spacer 4, thereby allowing the main spindle unit 3 to swing during operation. The inclined surfaces 23 have a smaller inner diameter at the end closer to the wear-resistant spacer 4 and a larger inner diameter at the end farther from the wear-resistant spacer 4, thus controlling the contact area to be on the wear-resistant spacer 4.

[0025] like Figure 2 As shown, the spindle unit 3 includes a spindle body 31, and a spindle bushing 32 is sleeved on the spindle body 31, with the spindle bushing 32 abutting against the wear-resistant spacer 4. The spindle unit 3 is divided into a spindle body 31 and a spindle bushing 32, wherein the spindle bushing 32 is sleeved on the outside of the spindle body 31, thereby protecting the spindle body 31. After the spindle bushing 32 wears out, the replacement cost can be guaranteed by simply replacing the spindle bushing 32.

[0026] like Figure 2 As shown, the support frame 1 has a stepped surface 11, and the boom bushing 2 includes an overlapping plate 24 that abuts against the stepped surface 11. The stepped surface 11 on the support frame 1 supports the overlapping plate 24, and the overlapping plate 24 on the boom bushing 2 abuts against the stepped surface 11, thereby ensuring the axial positioning of the boom bushing 2 and guaranteeing its stability and ease of connection.

[0027] like Figure 2 , 3 As shown, the overlapping plate 24 is provided with a connecting hole 25, and a connecting rod 26 is connected to the connecting hole 25. The connecting rod passes through the overlapping plate 24 and connects to the step surface 11. The connecting hole 25 on the overlapping plate 24 allows the connecting rod 26 to pass through, thereby connecting the overlapping plate 24 and the step surface 11 together, improving the reliability of the connection.

[0028] Example 2: like Figure 2 As shown, the support frame 1 includes a lifting base plate 12, and a sealing component 5 is engaged with the side of the boom bushing 2 near the lifting base plate 12. The lifting base plate 12 is provided on the support frame 1, wherein the lifting base plate 12 forms a constricted structure at the bottom of the support frame 1 connecting to the boom bushing 2, and the sealing component 5 is connected to the bottom of the boom bushing 2. The lifting base plate 12 can limit the sealing component 5 and prevent the sealing component 5 from falling off from the bottom.

[0029] like Figure 2 , 3As shown, the sealing assembly 5 includes two separately configured sealing units 51, which are symmetrically arranged along the radial direction of the main shaft unit 3. The sealing assembly 5 is configured as a separate structure, consisting of two separately configured sealing units 51. This allows the two sealing units 51 to separately seal and block grease above and dust below, improving sealing performance. Furthermore, the two sealing units 51 do not interfere with each other due to relative deformation, ensuring sealing quality. Because the sealing assembly 5 is composed of two sealing units 51, the thickness of each individual sealing unit 51 is smaller, thereby improving the sealing effect and ensuring the responsiveness of the sealing unit 51 during the rotation of the main shaft unit 3, thus reducing oil leakage gaps. Moreover, using two sealing units 51 reduces replacement and maintenance costs; if a single sealing unit 51 is damaged, only the corresponding sealing unit 51 needs to be replaced.

[0030] like Figure 2 , 3 As shown, the sealing unit 51 includes an engaging portion 52 and a sealing lip 53. The sealing lip 53 is inclined relative to the axis of the boom bushing 2, and the two sealing units 51 are inclined in opposite directions. The engaging portion 52 is configured as an "L"-shaped barb structure. The engaging portion 52 and the sealing lip 53 on the sealing unit 51 are integrally formed. The sealing lip 53 is configured as an inclined structure, which allows it to adapt to the elasticity of the sealing unit 51 to fit the main shaft unit 3, thereby ensuring the fit quality. It can also adapt to the swinging motion of the main shaft unit 3 to change the contact area between the sealing lip 53 and the main shaft unit 3, ensuring that the two are always in contact. The engaging portion 52 is configured as an "L"-shaped structure to ensure the reliability of the connection between the engaging portion 52 and the lifting base plate 12.

[0031] like Figure 2 , 3 As shown, a fixing ring 6 is connected to the supporting base plate 12, and the fixing ring 6 is provided with a locking hook 61 that can engage and connect the sealing unit 51. A spacer 62 is provided between the two sealing units 51, and the spacer 62 is fixedly connected to the fixing ring 6. The fixing ring 6 on the supporting base plate 12 can engage and connect the sealing unit 51, thereby ensuring that the upper and lower sealing units 51 can be fixed on different substrates respectively, ensuring the connection reliability of the sealing units 51. The spacer 62 provided between the two sealing units 51 can reduce the mutual influence of deformation between the sealing units 51, ensure the independence of the two sealing units 51, and thus improve the sealing quality. Furthermore, the spacer 62 and the fixing ring 6 are relatively fixed by means of fixing rod connection, bolt connection, integral molding, etc., so that the spacer 62 can be fixed in position relative to the fixing ring 6, thereby ensuring that the upper and lower sides of each sealing unit 51 can be fixedly abutted, improving the fixing effect of the sealing unit 51.

[0032] In addition to the structural features described above, this embodiment also includes a support frame 1, on which a boom bushing 2 is connected. A main spindle unit 3 is fitted inside the boom bushing 2. The boom bushing 2 includes a fitting groove 21, within which a wear-resistant spacer 4 is connected. The wear-resistant spacer 4 has an inner semi-circular threaded groove 41, and an outer semi-circular threaded groove on the end face of the fitting groove 21. The inner semi-circular threaded groove 41 and the outer semi-circular threaded groove are joined to form a threaded hole, on which a fixing screw 42 is connected. Inclined surfaces 23 are provided on the boom bushing 2 and the wear-resistant spacer 4, and the wear-resistant spacer 4 is in line contact with the main spindle unit 3. The main spindle unit 3 includes a main spindle body 31, on which a main spindle bushing 32 is fitted, and the main spindle bushing 32 abuts against the wear-resistant spacer 4. A stepped surface 11 is provided on the support frame 1, and the boom bushing 2 includes an overlapping plate 24, which abuts against the stepped surface 11. The overlapping plate 24 is provided with a connecting hole 25, and a connecting rod 26 is connected to the connecting hole 25. The connecting rod passes through the overlapping plate 24 and connects to the step surface 11.

[0033] In this application, a fitting groove 21 is provided on the boom bushing 2. The boom bushing 2 is partially hollowed out and replaced with a wear-resistant spacer 4. This makes the combination of the wear-resistant spacer 4 and the boom bushing 2 the same as the boom bushing 2 in the prior art. The fitting groove 21 is located at the part that rubs against the spindle unit 3. After the wear-resistant spacer 4 is provided, when the wear-resistant spacer 4 is worn due to friction, the service life of the boom bushing 2 can be extended simply by replacing the wear-resistant spacer 4. Furthermore, since the boom bushing 2 and the wear-resistant spacer 4 are set separately, the wear-resistant spacer 4 can be made of a different material than the boom bushing 2. A more wear-resistant material can be selected to improve the wear resistance of the wear-resistant spacer 4 itself and ensure its service life. Furthermore, in this application, the wear-resistant spacer 4 and the boom bushing 2 are respectively provided with an inner semi-circular threaded groove 41 and an outer semi-circular threaded groove. The axes of the inner and outer ring plate threaded grooves are parallel to the axis of the boom bushing 2, so the inner semi-circular threaded groove 41 and the outer semi-circular threaded groove can be connected to each other, forming a threaded hole. Since the wear-resistant spacer 4 is fitted inside the fitting groove 21, the wear-resistant spacer 4 will not undergo relative displacement with respect to the boom bushing 2 in the radial direction, thus ensuring the threaded hole is properly threaded. The perforated surface ensures relative stability, and the threaded connection to the fixing screw 42 maintains stability between the wear-resistant spacer 4 and the boom bushing 2 in the axial direction. Since the connection point is located on the mating surface of the wear-resistant spacer 4 and the boom bushing 2, the integrity of the inner wall surfaces of the wear-resistant spacer 4 and the boom bushing 2 near the main spindle unit 3 is ensured, guaranteeing structural strength and preventing uneven stress on the inner wall surfaces of the boom bushing 2 and the wear-resistant spacer 4 during the operation of the main spindle unit 3. Inclined surfaces 23 are provided on the boom bushing 2 and the wear-resistant spacer 4, ensuring that the main spindle unit 3 can only contact the wear-resistant spacer 4, allowing the main spindle unit 3 to swing during operation. The inclined surface 23 has a smaller inner diameter at the end near the wear-resistant spacer 4 and a larger inner diameter at the end away from the wear-resistant spacer 4, thus controlling the contact area to be on the wear-resistant spacer 4. The spindle unit 3 consists of a spindle body 31 and a spindle bushing 32. The spindle bushing 32 is fitted onto the outside of the spindle body 31, thus protecting the spindle body 31. If the spindle bushing 32 wears out, replacement can be achieved simply by replacing the spindle bushing 32, minimizing replacement costs. A stepped surface 11 is provided on the support frame 1, which supports the overlapping plate 24. The overlapping plate 24 on the boom bushing 2 abuts against the stepped surface 11, ensuring the axial positioning of the boom bushing 2 and guaranteeing its stability and ease of connection. A connecting hole 25 is provided on the overlapping plate 24, through which a connecting rod 26 can pass, connecting the overlapping plate 24 to the stepped surface 11, improving the reliability of the connection.

Claims

1. A wear-resistant upper frame, characterized in that, The device includes a support frame, on which a boom bushing is connected. A main shaft unit is fitted inside the boom bushing. The boom bushing includes a fitting groove, in which a wear-resistant spacer is connected. The wear-resistant spacer has an inner semi-circular threaded groove, and an outer semi-circular threaded groove is provided on the end face of the fitting groove. The inner and outer semi-circular threaded grooves are joined to form a threaded hole, and a fixing screw is connected to the threaded hole.

2. The wear-resistant upper frame according to claim 1, characterized in that, The boom bushing and wear-resistant spacer are provided with inclined surfaces, and the wear-resistant spacer is in line contact with the main shaft unit.

3. The wear-resistant upper frame according to claim 1, characterized in that, The spindle unit includes a spindle body, on which a spindle bushing is fitted, and the spindle bushing abuts against a wear-resistant spacer.

4. The wear-resistant upper frame according to claim 1, characterized in that, The support frame is provided with a stepped surface, and the boom bushing includes an overlapping plate that abuts against the stepped surface.

5. A wear-resistant upper frame according to claim 4, characterized in that, The overlapping plate is provided with a connecting hole, and a connecting rod is connected to the connecting hole. The connecting rod passes through the overlapping plate and connects to the step surface.

6. A wear-resistant upper frame according to any one of claims 1-5, characterized in that, The support frame includes a lifting base plate, and the arm bushing is engaged with a sealing component on the side near the lifting base plate.

7. A wear-resistant upper frame according to claim 6, characterized in that, The sealing assembly includes two separately configured sealing units, which are symmetrically arranged along the radial direction of the main shaft unit.

8. A wear-resistant upper frame according to claim 7, characterized in that, The sealing unit includes a locking part and a sealing lip. The sealing lip is inclined relative to the axis of the boom bushing, and the two sealing units are inclined in opposite directions. The locking part is configured as an "L"-shaped barb structure.

9. A wear-resistant upper frame according to claim 7, characterized in that, A fixing ring is connected to the lifting base plate, and the fixing ring is provided with a locking hook that can engage with the sealing unit.

10. A wear-resistant upper frame according to claim 9, characterized in that, A spacer is provided between the two sealing units, and the spacer is fixedly connected to the retaining ring.

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