A slewing bearing for ultra-large tonnage crawler machines and a method for controlling the flatness of its inner and outer rings

Abstract

The present invention provides a slewing bearing for an ultra-large tonnage crawler crane. By improving the six-row cylindrical roller combined structure of the existing slewing bearing for an ultra-large tonnage crawler crane, a row of radial rollers is respectively arranged on the inner and outer sides of the middle ring, thereby improving the radial load capacity of the bearing. At the same time, the three rows of axial rollers below are designed to be two rows, and each row of axial rollers is divided into two columns, which is equivalent to lengthening the working length of the single row of axial rollers below, and the axial load capacity of the bearing is also effectively guaranteed. Therefore, the stability of the product operation is significantly improved and the scope of application is wider. The present invention also provides a method for controlling the flatness of the inner and outer rings of the above-mentioned slewing bearing for an ultra-large tonnage crawler crane. The flatness of the plane formed by the outer ring base surface and the inner ring base surface is controlled by controlling the form and position tolerances of each ring, the assembly clearance and the relative height difference of each part of the two rings, thereby ensuring the technical requirements of the flatness of the inner and outer rings of the bearing and improving production efficiency.

Description

Technical Field

[0001] The invention relates to a bearing manufacturing technology, in particular to a turntable bearing for an ultra-large tonnage crawler machine and a method for controlling the flatness of inner and outer rings thereof. Background Art

[0002] Due to their relatively higher load-bearing capacity, operational reliability, and safety, current designs for super-large crawler crane turntable bearings often utilize a six-row cylindrical roller assembly structure. For example, Chinese patent application CN101705965A proposes a roller turntable bearing for super-large crawler cranes. The axial force and overturning moment acting on the turntable bearing are borne by two upper rows and three lower rows of rollers. A row of radial rollers is positioned between the inner raceway of the inner ring and the outer raceway of the second outer ring via a retainer to support radial loads. This six-row cylindrical roller assembly significantly improves the bearing's load-bearing capacity. Compared to earlier three-row cylindrical roller turntable bearings of the same overall dimensions, it offers higher load-bearing capacity while reducing the bearing's height, improving the reliability and safety of crawler crane operations and reducing manufacturing costs.

[0003] However, turntable bearings for ultra-large-tonnage crawler machines are mostly used in heavy-duty construction machinery, which operates in complex environments. In hilly and sloping terrain, the existing single-row radial roller configuration still has a slightly insufficient radial load capacity, hindering the normal operation of the construction machinery. To address this issue, the inventors developed a turntable bearing for crawler machines that can withstand large radial loads. However, after assembly, this bearing requires that the outer and inner ring base surfaces be coplanar, and the flatness of the plane formed by the outer and inner ring base surfaces must be high (generally no more than 0.05mm) to ensure the precise fit between the bearing and the mounting platform.

[0004] Because the reference surfaces of the bearing outer ring and inner ring belong to two separate parts, there are numerous dimensional chains that affect the flatness difference between the two reference surfaces (the two parts are interconnected through dimensional chains such as position and thickness between the inner and outer axial raceways of the center ring). This makes it difficult to meet the technical requirements for the flatness of multiple bearing rings. Therefore, the present invention also provides a method for controlling the flatness of the inner and outer rings of such a turntable bearing. Summary of the Invention

[0005] The present invention provides a turntable bearing for ultra-large tonnage crawler machines. By improving the existing six-row cylindrical roller assembly structure of turntable bearings for ultra-large tonnage crawler machines, a row of radial rollers is provided on the inner and outer sides of the center ring, respectively, thereby increasing the radial load capacity of the bearing. Simultaneously, the three lower rows of axial rollers are divided into two rows, each row of axial rollers being divided into two columns. This effectively increases the working length of the lower single row of axial rollers and effectively ensures the axial load capacity of the bearing. Consequently, the operational stability of the product is significantly improved, extending its applicability. Furthermore, to further enhance operational stability and production efficiency, the present invention also provides a method for controlling the flatness of the inner and outer rings of the turntable bearing for ultra-large tonnage crawler machines. By controlling the geometric and positional tolerances of each ring, the assembly clearance, and the relative height difference between various portions of the two rings, the flatness of the plane formed by the outer and inner ring base surfaces is controlled, thereby ensuring the technical requirements for the flatness of the inner and outer rings of the bearing. This method for controlling the flatness of the inner and outer rings can effectively improve production efficiency.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A turntable bearing for an ultra-large tonnage crawler machine, comprising a first outer ring, a second outer ring, a middle ring, a first inner ring, and a second inner ring, the first outer ring and the second outer ring being connected by one-to-one corresponding connecting holes, and the first inner ring and the second inner ring being also connected by one-to-one corresponding connecting holes, characterized in that: the middle ring is an annular structure as a whole, which is composed of a first annular ring and a second annular ring that are coaxial and solidly integrated, the first annular ring is located on the upper part of the second annular ring, a first annular boss is provided on the lower side of the outer wall of the first annular ring, a first reverse thrust axial raceway is provided on the upper surface of the first annular boss, and a first main thrust axial raceway is provided on the lower surface of the first annular boss; a second annular boss is provided on the lower side of the inner wall of the first annular ring, a second reverse thrust axial raceway is provided on the upper surface of the second annular boss, and a second main thrust axial raceway is provided on the lower surface of the second annular boss;

[0008] The first outer ring and the second outer ring are both sleeved on the outside of the middle ring, and the first outer ring and the second outer ring jointly cover the first annular boss. The first outer ring is located below the second outer ring. First axial rollers are uniformly distributed between the first outer ring and the first main thrust axial raceway, fourth axial rollers are uniformly distributed between the second outer ring and the first reverse thrust axial raceway, and sixth radial rollers are uniformly distributed between the first outer ring and the second outer ring. The rolling surface of the sixth radial roller contacts the outer side surface of the first annular boss.

[0009] The first inner ring and the second inner ring are both located inside the middle ring, and the first inner ring and the second inner ring jointly cover the second annular boss. The first inner ring is located at the lower part of the second inner ring; second axial rollers are evenly distributed between the first inner ring and the second main thrust axial raceway, third axial rollers are evenly distributed between the second inner ring and the second reverse thrust axial raceway, and fifth radial rollers are evenly distributed between the first inner ring and the second inner ring, and the rolling surface of the fifth radial roller is in contact with the inner side surface of the second annular boss.

[0010] The second outer ring has a fourth annular boss on the upper part of its inner side wall, the fourth annular boss is located above the first annular boss, and a fourth axial raceway is provided on the lower surface of the fourth annular boss. The fourth axial roller is installed between the fourth axial raceway and the first reverse thrust axial raceway; the lower part of the inner side wall of the second outer ring has a sixth radial raceway for installing the sixth radial roller.

[0011] The second inner ring has a third annular boss on the upper part of its outer side wall, the third annular boss is located above the second annular boss, and a third axial raceway is provided on the lower surface of the third annular boss. The third axial roller is installed between the third axial raceway and the second reverse thrust axial raceway; the second inner ring has a fifth radial raceway on the lower part of its outer side wall for installing the fifth radial roller.

[0012] The first outer ring has a fifth annular boss on the lower part of its inner side wall, and the fifth annular boss is located below the first annular boss. A first axial raceway is provided on the upper surface of the fifth annular boss, and the first axial roller is installed between the first axial raceway and the first main thrust axial raceway; a seventh annular boss is provided on the upper surface of the first outer ring for placing the sixth radial roller, and the upper surface of the seventh annular boss is higher than the lower surface of the second ring.

[0013] The first inner ring has a sixth annular boss on the lower part of its inner side wall, and the sixth annular boss is located below the second annular boss. A second axial raceway is provided on the upper surface of the sixth annular boss, and the second axial roller is installed between the second axial raceway and the second main thrust axial raceway; an eighth annular boss is provided on the upper surface of the first inner ring for placing the fifth radial roller, and the upper surface of the eighth annular boss is higher than the lower surface of the second ring.

[0014] The first axial rollers are arranged in two groups along the radial direction of the middle ring, and the second axial rollers are also arranged in two groups along the radial direction of the middle ring.

[0015] The first axial roller, the second axial roller, the third axial roller, the fourth axial roller, the fifth radial roller and the sixth radial roller are all provided with retaining frames on their outsides; the upper parts of the two side walls of the first circular ring are respectively provided with sealing lips, and the two sides of the lower end surface of the second circular ring are also respectively provided with sealing lips.

[0016] The present invention also provides a method for controlling the flatness of the inner and outer rings of a turntable bearing for an ultra-large tonnage crawler machine as described above, comprising the following steps: Step A, during the parts processing process before the bearing is assembled, taking the bottom surfaces of the first outer ring and the first inner ring as the base surfaces, controlling the form and position tolerances of the first outer ring, the second outer ring, the middle ring, the first inner ring, and the second inner ring as follows: setting the thickness of the fifth annular boss of the first outer ring to h2, the thickness of the sixth annular boss of the first inner ring to h4, and the mutual difference between h2 and h4 being ≤0.02mm; setting the thickness of the first annular boss of the middle ring to h5, the thickness of the second annular boss of the middle ring to h6, and the mutual difference between h5 and h6 being ≤0.02mm; setting the thickness of the bottom of the first annular boss of the middle ring to h6, and the mutual difference between h5 and h6 being ≤0.02mm; setting the thickness of the bottom of the first annular boss of the middle ring to h7, and the mutual difference between h7 and h8 being ≤0.02mm. The distance from the surface to the lower surface of the middle ring is h7, the distance from the lower surface of the second annular boss of the middle ring to the lower surface of the middle ring is h8, and the difference between h7 and h8 is ≤0.02mm; the distance from the fifth annular boss of the first outer ring to the upper surface of the first outer ring is h1, and the distance from the sixth annular boss of the first inner ring to the upper surface of the first inner ring is h3, and the difference between h1 and h3 is ≤0.05mm; the distance from the lower surface of the fourth annular boss of the second outer ring to the lower surface of the second outer ring is h9, and the distance from the third annular boss of the second inner ring to the lower surface of the second inner ring is h10, and the difference between h9 and h10 is ≤0.05mm. The height difference between the first outer ring and the first inner ring is ≤0.05mm;

[0017] Step B: Set the combination of the first inner ring and the second inner ring as the inner ring set, and the combination of the first outer ring and the second outer ring as the outer ring set. Before assembling the bearing, fit the outer ring set and the inner ring set separately, and test the axial clearance values ​​of the outer ring set and the inner ring set after fitting. If the axial clearance difference of the outer ring set after fitting is greater than 0.10mm, grind the fitting surface of the first outer ring and the second outer ring to ensure that the axial clearance value of the outer ring set of the bearing meets the product design requirements. If the axial clearance difference of the inner ring set after fitting is greater than 0.10mm, grind the fitting surface of the first inner ring and the second inner ring to ensure that the axial clearance value of the outer ring set and the inner ring set of the bearing meet the product design requirements. If the axial clearance difference of the outer ring set and the inner ring set after fitting is both ≤0.10mm, do not perform grinding on the rings, and directly proceed to Step C.

[0018] Step C: Assemble the bearing on a machine tool. After assembly, recheck the axial clearance of the outer ring and the inner ring respectively, and then check the height difference between the base surface of the first outer ring and the base surface of the first inner ring of the bearing. If the height difference between the base surface of the first outer ring and the base surface of the first inner ring of the bearing is greater than 0.05 mm, find the high point of the base surface of the first outer ring or the base surface of the first inner ring, and grind the high point flat on the machine tool to ensure that the height difference between the base surface of the first outer ring and the base surface of the first inner ring of the bearing is ≤ 0.05 mm.

[0019] Step D: After the qualified products are inspected on the machine tool, they are transferred to an external measuring platform to re-inspect the height difference between the base surface of the first outer ring and the base surface of the first inner ring of the bearing.

[0020] In step B, the fitting of the outer ring and the inner ring is performed under isothermal conditions. The fitting process of the outer ring and the axial clearance detection method are as follows: multiple fulcrums are evenly distributed around the circumference in the fitting area, the second outer ring is placed with its bottom surface facing upward and stably on the multiple fulcrums, the fourth axial roller is placed on the fourth axial raceway of the second outer ring, the middle ring is then placed with its bottom surface facing downward and stably above the fourth axial roller, the first axial roller is placed on the first main thrust axial raceway, and finally, the first outer ring is placed with its bottom surface facing upward and its first axial raceway facing downward and stably on the first axial roller, the relative positions of the first outer ring and the second outer ring are adjusted so that the connecting holes on the first outer ring and the second outer ring are aligned one by one, a jack is placed outside each fulcrum, the second outer ring is lifted up with the jack, and the axial clearance of the outer ring is detected using a dial indicator;

[0021] The fitting process of the inner ring and the axial clearance detection method are as follows: multiple fulcrums are evenly distributed in the fitting area according to the circumference, the second inner ring is placed stably on the multiple fulcrums with the bottom surface facing upward, the third axial roller is placed on the third axial raceway of the second inner ring, the middle ring is placed stably with the bottom surface facing upward and the second main thrust axial raceway facing upward above the third axial roller, and the second axial roller is placed on the second main thrust axial raceway of the middle ring; the second axial raceway of the first inner ring is placed stably on the second roller with the second axial raceway facing downward, the relative positions of the first inner ring and the second inner ring are adjusted so that the connecting holes on the first inner ring and the second inner ring are aligned one by one, a jack is placed on the outer side of each fulcrum, the second inner ring is lifted up by the jack, and the axial clearance of the inner ring is detected with a dial indicator.

[0022] The bearing assembly method in step C is as follows: first assemble the outer ring, and then assemble the inner ring together with the outer ring. When assembling the outer ring, the bottom surface of the middle ring faces upward, the second outer ring is at the bottom, and the first outer ring is at the top; when assembling the inner ring, the second inner ring is at the bottom, and the first inner ring is at the bottom; finally, use connecting screws to connect the first outer ring and the second outer ring accordingly, and connect the first inner ring and the second inner ring accordingly.

[0023] The beneficial effects of the present invention are as follows: the turntable bearing for super-large tonnage crawler machines proposed by the present invention has higher radial load capacity and better axial load capacity, can improve the operating stability of crawler engineering machinery on various terrains, and is suitable for heavy-duty crawler engineering machinery working in all terrains; the present invention also provides a method for controlling the flatness of the inner and outer rings of the turntable bearing for super-large tonnage crawler machines mentioned above, which controls the flatness of the plane formed by the outer ring base surface and the inner ring base surface by controlling the form and position tolerances of each ring, the assembly clearance and the relative height difference of each part of the corresponding ring, thereby ensuring the technical requirements for the flatness of the inner and outer rings of the bearing, improving production efficiency, ensuring the smooth installation of the bearing, having strong practicality, simple operation and being suitable for promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the cross-sectional structure of the present utility model.

[0025] Figure 2 It is a schematic diagram of the overall structure of the utility model.

[0026] Figure 3 Schematic diagram of the structure of the first outer ring.

[0027] Figure 4 Schematic diagram of the structure of the first inner ring.

[0028] Figure 5 This is a structural diagram of the middle circle.

[0029] Figure 6 Schematic diagram of the structure of the second outer ring.

[0030] Figure 7 Schematic diagram of the structure of the second inner ring.

[0031] Figure 8 It is a schematic diagram of the installation structure of the present invention.

[0032] Figure 9 This is a schematic diagram of the axial clearance detection after the outer ring is assembled.

[0033] Figure 10 This is a schematic diagram of the axial clearance detection after the inner ring is assembled.

[0034] Figure 11 This is a schematic diagram of the axial clearance test after assembly.

[0035] In the figure: 1, first outer ring; 2, sixth cage; 3, sixth radial roller; 4, first axial roller; 5, first cage; 6, second axial roller; 7, second cage; 8, fifth radial roller; 9, fifth cage; 10, first inner ring; 11, second inner ring; 12, third cage; 13, third axial roller; 14, middle ring; 15, fourth axial roller; 16, fourth cage; 17, second outer ring; 18, mounting platform; 19, first outer ring base surface; 20, first inner ring base surface; 23. Fulcrum, 24. Connecting screw; 25. Second connecting screw; 26. Jack; 27. Dial indicator; 28. First axial raceway; 29. ​​First outer ring fitting surface; 30. Second axial raceway; 31. First inner ring fitting surface; 32. First main thrust axial raceway; 33. Second main thrust axial raceway; 34. First reverse thrust axial raceway; 35. Second reverse thrust axial raceway; 36. Fourth axial raceway; 37. Second outer ring fitting surface; 38. Third axial raceway; 39. Second inner ring fitting surface. DETAILED DESCRIPTION

[0036] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort shall fall within the scope of protection of the present invention.

[0037] like Figure 1-Figure 7 As shown in the figure, the structure of the LY-Z0179-1 six-row cylindrical roller combined slewing bearing developed specifically for a certain user is as follows:

[0038] A turntable bearing for an ultra-large tonnage crawler machine, comprising a first outer ring 1, a second outer ring 17, a middle ring 14, a first inner ring 10 and a second inner ring 11, the first outer ring 1 and the second outer ring 17 being connected by one-to-one connecting holes, and the first inner ring 10 and the second inner ring 11 being also connected by one-to-one connecting holes, the middle ring 14 being an overall annular structure, which is composed of a first annular ring and a second annular ring that are coaxial and solidly integrated, the first annular ring being located on the upper part of the second annular ring, a first annular boss being provided on the lower side of the outer wall of the first annular ring, a first reverse thrust axial raceway 32 being provided on the upper surface of the first annular boss, and a first main thrust axial raceway 34 being provided on the lower surface of the first annular boss; a second annular boss being provided on the lower side of the inner wall of the first annular ring, a second reverse thrust axial raceway 33 being provided on the upper surface of the second annular boss, and a second main thrust axial raceway 35 being provided on the lower surface of the second annular boss;

[0039] The first outer ring 1 and the second outer ring 17 are both sleeved on the outside of the middle ring 14, and the first outer ring 1 and the second outer ring 17 jointly cover the first annular boss. The first outer ring 1 is located below the second outer ring 17. First axial rollers 4 are evenly distributed between the first outer ring 1 and the first main thrust axial raceway 34, fourth axial rollers 15 are evenly distributed between the second outer ring 17 and the first reverse thrust axial raceway 32, and sixth radial rollers 3 are evenly distributed between the first outer ring 1 and the second outer ring 17. The rolling surface of the sixth radial roller 3 contacts the outer side surface of the first annular boss.

[0040] The first inner ring 10 and the second inner ring 11 are both located inside the middle ring 14, and the first inner ring 10 and the second inner ring 11 jointly cover the second annular boss. The first inner ring 10 is located at the lower part of the second inner ring 11; the second axial rollers 6 are evenly distributed between the first inner ring 10 and the second main thrust axial raceway 35, the third axial rollers 13 are evenly distributed between the second inner ring 11 and the second reverse thrust axial raceway 33, and the fifth radial rollers 8 are evenly distributed between the first inner ring 10 and the second inner ring 11. The rolling surface of the fifth radial roller 8 is in contact with the inner side surface of the second annular boss.

[0041] The second outer ring 17 has a fourth annular boss on the upper part of its inner side wall, and the fourth annular boss is located above the first annular boss. A fourth axial raceway 36 is provided on the lower surface of the fourth annular boss, and the fourth axial roller 15 is installed between the fourth axial raceway 36 and the first reverse thrust axial raceway 34; the lower part of the inner side wall of the second outer ring 17 has a sixth radial raceway for installing the sixth radial roller 3.

[0042] The second inner ring 11 has a third annular boss on the upper part of its outer wall, the third annular boss is located above the second annular boss, and a third axial raceway 38 is provided on the lower surface of the third annular boss. The third axial roller 13 is installed between the third axial raceway 38 and the second reverse thrust axial raceway 35; the lower part of the outer wall of the second inner ring 11 has a fifth radial raceway for installing the fifth radial roller 8.

[0043] The first outer ring 1 has a fifth annular boss on the lower part of its inner side wall, and the fifth annular boss is located below the first annular boss. A first axial raceway 28 is provided on the upper surface of the fifth annular boss, and the first axial roller 4 is installed between the first axial raceway 28 and the first reverse thrust axial raceway 32; a seventh annular boss is provided on the upper surface of the first outer ring 1 for placing the sixth radial roller 3, and the upper surface of the seventh annular boss is higher than the lower surface of the second ring.

[0044] The first inner ring 10 has a sixth annular boss on the lower part of its inner side wall, and the sixth annular boss is located below the second annular boss. A second axial raceway 30 is provided on the upper surface of the sixth annular boss, and the second axial roller 6 is installed between the second axial raceway 30 and the second main thrust axial raceway 33; an eighth annular boss is provided on the upper surface of the first inner ring 10 for placing the fifth radial roller 8, and the upper surface of the eighth annular boss is higher than the lower surface of the second ring.

[0045] The first axial rollers 4 are arranged in two groups along the radial direction of the middle ring 14 , and the second axial rollers 6 are also arranged in two groups along the radial direction of the middle ring 14 .

[0046] The first axial roller 4, the second axial roller 6, the third axial roller 13, the fourth axial roller 15, the fifth radial roller 8 and the sixth radial roller 3 are all provided with a retaining frame. Figure 1 、 Figure 2 As shown, a first retaining frame 5 is provided on the outside of the first axial roller 4, a second retaining frame 7 is provided on the outside of the second axial roller 6, a third retaining frame 12 is provided on the outside of the third axial roller 13, a fourth retaining frame 16 is provided on the outside of the fourth axial roller 15, a fifth retaining frame 9 is provided on the outside of the fifth radial roller, and a sixth retaining frame 2 is provided on the outside of the sixth radial roller 3.

[0047] The upper portions of both side walls of the first circular ring are respectively provided with sealing lips, and both sides of the lower end surface of the second circular ring are also respectively provided with sealing lips.

[0048] The rolling axis of the sixth radial roller 3 is parallel to the axis of the middle ring 14 , and the rolling axis of the fifth radial roller 8 is parallel to the axis of the middle ring 14 .

[0049] like Figures 1-11 As shown, taking the LY-Z0179-1 six-row cylindrical roller combined slewing bearing as an example, the method for controlling the flatness of the inner and outer rings during assembly is as follows:

[0050] Step A: During the parts processing before the bearing is assembled, the bottom surfaces of the first outer ring 1 and the first inner ring 10 are used as the base surfaces to control the form and position tolerances of the first outer ring 1, the second outer ring 17, the middle ring 14, the first inner ring 10, and the second inner ring 11. In this embodiment, a cup-type grinding wheel (B250×110×140) is selected during the processing of each ring. Before processing, the grinding wheel runout is detected by a dial indicator after the fulcrum is repaired, and the grinding wheel is dynamically balanced using a grinding wheel dynamic balancer, with a dynamic balance value of 0.84μm. The grinding wheel speed is adjusted to 800r / min, the feed rate to 0.01mm / r, and the workpiece speed to 6r / min. After the product is rotated for tool setting, water spray cooling is turned on, and each bearing ring is processed using a small allowance multiple grinding method.

[0051] In this embodiment, after each ring is processed, the shape and position dimensions of each ring are detected using an electronic digital outside diameter micrometer (0.001mm) and an electronic digital depth micrometer (0.001mm) as follows: h2=74.983-74.995mm, h1=60.106-60.122mm, h4=74.991-75.013mm, h3=60.092-60.121mm, h5=104.978-104.985mm, h6=104.981-105.006mm, h7=55.002-55.015mm, h8=55.015-55.030mm, h9=155.083-155.096mm, h10=155 .071-155.080mm, the difference between h2 and h1 is 0.008mm, the difference between h6 and h7 is 0.003mm, the difference between h7 and h8 is 0.013mm, the difference between h3 and h4 is 0.014mm, the difference between h9 and h10 is 0.012mm, the height difference between the first outer ring 1 and the first inner ring 10 is 0.019mm; it should be noted that: if unqualified dimensions are detected, the workpiece should be reground, and the optimal grinding order is: first outer ring 1→second outer ring 17→middle ring 14→first inner ring 10→second inner ring 11.

[0052] Step B: Before assembling the bearing, strictly control the axial clearance value of the outer ring and the inner ring of the bearing; set the combination of the first inner ring 10 and the second inner ring 11 as the inner ring, and the combination of the first outer ring 1 and the second outer ring 17 as the outer ring. Before assembling the bearing, fit the outer ring and the inner ring separately, and test the axial clearance value of the outer ring and the inner ring after fitting.

[0053] In this embodiment, the outer ring assembly and axial clearance detection are as follows Figure 8As shown, three cylindrical fulcrums 23 are roughly evenly distributed around the circumference and placed in the fitting area. The second outer ring 17 that has been properly ground is placed with its fitting surface 37 facing upward and stably on the cylindrical fulcrum 23. The fourth axial roller 15 is placed on the fourth axial raceway 36 of the second outer ring 17. When placing, at least three fourth axial rollers 15 are placed at each position on the fourth axial raceway 36 corresponding to the connecting hole of the second outer ring 17. Then, the first main thrust axial raceway 32 of the middle ring 14 that has been properly ground is placed upward and stably above the fourth axial roller 15. The first axial roller 4 is placed on the first main thrust axial raceway surface 32 of the middle ring 14. When placing, the first main thrust axial raceway 32 is aligned with the connecting hole of the first outer ring 1. At least three first axial rollers 4 are placed at each corresponding position; finally, the first axial raceway 28 of the first outer ring 1 that has passed the grinding is placed downward and steadily on the first axial roller 4, and the soft belts of the first outer ring 1 and the second outer ring 17 (the soft belt of the raceway of a large turntable bearing is the low hardness area of ​​the raceway) are adjusted to align relative positions according to the requirements of the product drawing. A correction rod is used to assist in the alignment of the mounting holes to ensure that the connecting holes and mounting holes of the first outer ring 1 and the second outer ring 17 are aligned. A jack 26 is placed on the same side of the three cylindrical fulcrums 23, and the second outer ring 17 is lifted up with the jack 26. The axial clearance is checked with the dial indicator 27; in this embodiment, the axial clearance value after the outer ring assembly is assembled is 0.20 mm.

[0054] In this embodiment, the inner ring assembly and axial clearance detection are as follows: Figure 9As shown, three cylindrical fulcrums 23 are roughly evenly distributed around the circumference and placed in the fitting area. The fitting surface 39 of the second inner ring 11 that has been properly ground is placed upward and steadily on the cylindrical fulcrum 23. The third axial roller 13 is placed on the third axial raceway 38 of the second inner ring 11. When placing, at least three third axial rollers 13 are placed at each position on the third axial raceway 38 corresponding to the connecting hole of the second inner ring 11; then the second main thrust axial raceway 33 of the middle ring 14 that has been properly ground is placed upward and steadily above the third axial roller 13, and the second axial roller 6 is placed on the second main thrust axial raceway 33. When placing, at least three third axial rollers 6 are placed at each position on the second main thrust axial raceway 33 corresponding to the connecting hole of the first inner ring 10; finally, the first inner ring 10 that has been properly ground is placed. The second axial raceway 30 is placed downward and stably on the second roller 6. The relative positions of the soft belts of the first inner ring 10 and the second inner ring 11 are adjusted according to the requirements of the product drawing. The correction rod is used to assist in the alignment of the mounting holes to ensure that the connecting holes and mounting holes of the first inner ring 10 and the second inner ring 11 are aligned. The jack 26 is placed on the same side of the three cylindrical fulcrums 23. The second inner ring 11 is lifted up with the jack 26, and the axial clearance is detected with the dial indicator 27. The axial clearance value after the inner ring is assembled is 0.17mm; the axial clearance value of the outer ring is 0.03mm larger than the axial clearance value of the inner ring, which meets the product design requirements; the axial clearance values ​​of the outer and inner rings must be measured after the inner and outer rings are isothermal; preferably, the finished axial rollers are used in the assembly process, and the finished axial rollers placed in each position have the same gauge value.

[0055] Step C: Assemble the bearing on a machine tool. After assembly, recheck the axial clearance of the outer ring and inner ring respectively, and then check the height difference between the base surface of the first outer ring 1 and the base surface of the first inner ring 10 of the bearing. If the height difference between the base surface of the first outer ring 1 and the base surface of the first inner ring 10 of the bearing is greater than 0.05mm, find the high point of the base surface of the first outer ring 1 or the base surface of the first inner ring 10, and grind the high point flat on the machine tool to ensure that the height difference between the base surface of the first outer ring 1 and the base surface of the first inner ring 10 of the bearing is ≤0.05mm.

[0056] In this embodiment, the detection process of the axial clearance between the outer ring and the inner ring after the bearing is assembled and the assembly process are as follows: Figure 1 and Figure 11As shown, the assembly process is to assemble the outer ring first, and then assemble the inner ring together with the outer ring. The specific process is as follows: After each ring is cleaned and tested and qualified, the outer ring is assembled first, and the three cylindrical fulcrums 23 are roughly evenly distributed around the circumference and placed in the assembly area. The second outer ring 17 that has passed the test is placed steadily on the cylindrical fulcrum 23 with the second outer ring fitting surface 37 facing upward. Each connecting hole of the second outer ring 17 corresponds to the fourth axial raceway 36 of the second outer ring 17 and is filled with the fourth axial roller 15 and the fourth cage 16. The first main thrust axial raceway 32 of the middle ring 14 that has passed the test is placed steadily on the fourth Above the axial roller 15, place the first axial roller 4 and the cage 5 on the first main thrust axial raceway 32 of the middle ring 14. Place the first outer ring 1 that has passed the inspection with the first axial raceway 28 facing downward and stably on the first axial roller 4. Adjust the relative position of the soft belts of the first outer ring 1 and the second outer ring 17 according to the product drawing requirements. Use the correction rod to assist in the alignment of the mounting holes to ensure that the connecting holes and mounting holes of the first outer ring 1 and the second outer ring 17 are aligned. Install the connecting screws 24 and pre-tighten them with a torque wrench. The outer ring assembly is complete. Then assemble the inner ring and align the three cylindrical fulcrums 23. The circumference of the second inner ring 11 is evenly distributed and placed in the assembly area. The second inner ring fitting surface 39 of the qualified second inner ring 11 is placed upward and steadily on the cylindrical fulcrum 23. Each connecting hole of the second inner ring 11 corresponds to the second inner ring axial raceway surface 38 and is filled with the third axial roller 13 and the third retainer 12. After that, the second main thrust axial raceway surface 33 of the middle ring 14 of the assembled outer ring is placed upward and steadily above the third axial roller 13. The second main thrust axial raceway surface 33 of the middle ring 14 is filled with the second axial roller 6 and the second retainer 7. The second axial raceway surface 38 of the inner ring 10 that has passed the inspection is placed on the cylindrical fulcrum 23. Place the surface 30 downward and stably on the second axial roller 6. Adjust the relative positions of the soft belts of the first inner ring 10 and the second inner ring 11 according to the requirements of the product drawing. Use a correction rod to assist in the alignment of the mounting holes to ensure that the connecting holes and mounting holes of the first inner ring 10 and the second inner ring 11 are aligned. Install the connecting screws 25 and use a torque wrench to pretighten. The inner ring is assembled; the bearing is assembled; use a jack 26 and a dial indicator 27 to respectively test the axial clearance values ​​of the assembled outer ring and inner ring. The axial clearance value of the outer ring is 0.20mm, and the axial clearance value of the inner ring is 0.17mm.

[0057] In this embodiment, after the bearing is assembled, the flatness of the plane formed by the outer ring and the inner ring is controlled by controlling the height difference between the first outer ring and the first inner ring; specifically, the machine tool fulcrum is leveled, and a micrometer is used to detect runout = 0.008 mm. The machine tool is used as an assembly platform, and a straightedge and a feeler gauge are used to detect the height difference between the base surfaces of the first outer ring 1 and the first inner ring 10 of the bearing at the same position. A total of six positions are detected around the circumference, and the height differences between the base surfaces of the first outer ring 1 and the first inner ring 10 at these six positions are 0.02 mm, 0.01 mm, 0.01 mm, -0.01 mm, 0 mm, and 0.02 mm, respectively. The maximum inside-outside difference detected at each position using a dial indicator is 0.02 mm, and the maximum circumferential runout is 0.02 mm. The flatness of the plane formed by the base surfaces of the first outer ring and the first inner ring detected on the machine tool is 0.04 mm.

[0058] Step D: After the qualified products are inspected on the machine tool, they are transferred to an external measuring platform to re-inspect the height difference between the base surface of the first outer ring 1 and the base surface of the first inner ring 10 of the bearing.

[0059] In this embodiment, the bearings assembled and tested on the machine tool are transported to the three-coordinate measurement room for testing the flatness of the plane formed by the base surfaces of the first outer ring 1 and the first inner ring 10. The first outer ring 1 and the first inner ring 10 are each tested in three layers, with 20 points tested on each layer. The flatness of the plane formed by the first outer ring and the first inner ring, measured by fitting the 120 points in these six layers, is 0.0383mm<0.05mm, which meets the product design requirements. The flatness of the plane formed by the base surfaces of the first outer ring 1 and the first inner ring 10 tested by the machine tool is approximately consistent with the flatness of the plane formed by the outer ring and the inner ring tested by the three-coordinate re-inspection.

[0060] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

[0061] The parts not described in detail in this invention are prior art.

Claims

1. A turntable bearing for an ultra-large tonnage crawler machine, comprising a first outer ring (1), a second outer ring (17), a middle ring (14), a first inner ring (10) and a second inner ring (11), wherein the first outer ring (1) and the second outer ring (17) are connected via one-to-one corresponding connecting holes, and the first inner ring (10) and the second inner ring (11) are also connected via one-to-one corresponding connecting holes, and wherein: The middle ring (14) is an annular structure as a whole, which is composed of a first annular ring and a second annular ring that are coaxial and fixed together. The first annular ring is located on the upper part of the second annular ring. The lower side of the outer wall of the first annular ring has a first annular boss, and the upper surface of the first annular boss is provided with a first reverse thrust axial raceway (34), and the lower surface of the first annular boss is provided with a first main thrust axial raceway (32); the lower side of the inner wall of the first annular ring has a second annular boss, and the upper surface of the second annular boss is provided with a second reverse thrust axial raceway (35), and the lower surface of the second annular boss is provided with a second main thrust axial raceway (33); The first outer ring (1) and the second outer ring (17) are both sleeved on the outside of the middle ring (14), and the first outer ring (1) and the second outer ring (17) jointly cover the first annular boss, and the first outer ring (1) is located at the lower part of the second outer ring (17); the first axial roller (4) is evenly distributed between the first outer ring (1) and the first main thrust axial raceway (32), the fourth axial roller (15) is evenly distributed between the second outer ring (17) and the first reverse thrust axial raceway (34), and the sixth radial roller (3) is evenly distributed between the first outer ring (1) and the second outer ring (17), and the rolling surface of the sixth radial roller (3) is in contact with the outer side surface of the first annular boss; The first inner ring (10) and the second inner ring (11) are both located inside the middle ring (14), and the first inner ring (10) and the second inner ring (11) jointly cover the second annular boss, and the first inner ring (10) is located at the lower part of the second inner ring (11); the second axial rollers (6) are evenly distributed between the first inner ring (10) and the second main thrust axial raceway (33), the third axial rollers (13) are evenly distributed between the second inner ring (11) and the second reverse thrust axial raceway (35), and the fifth radial rollers (8) are evenly distributed between the first inner ring (10) and the second inner ring (11), and the rolling surface of the fifth radial rollers (8) is in contact with the inner side surface of the second annular boss; The second outer ring (17) has a fourth annular boss on the upper portion of its inner side wall, the fourth annular boss is located above the first annular boss, a fourth axial raceway (36) is provided on the lower surface of the fourth annular boss, and the fourth axial roller (15) is installed between the fourth axial raceway (36) and the first reverse thrust axial raceway (34); the second outer ring (17) has a sixth radial raceway on the lower portion of its inner side wall for installing the sixth radial roller (3); The second inner ring (11) has a third annular boss on the upper portion of its outer wall, the third annular boss is located above the second annular boss, and a third axial raceway (38) is provided on the lower surface of the third annular boss. The third axial roller (13) is installed between the third axial raceway (38) and the second reverse thrust axial raceway (35); the second inner ring (11) has a fifth radial raceway on the lower portion of its outer wall for installing the fifth radial roller (8).

2. The turntable bearing for an ultra-large tonnage crawler machine according to claim 1, characterized in that: The first outer ring (1) has a fifth annular boss at the lower portion of its inner side wall, the fifth annular boss is located below the first annular boss, a first axial raceway (28) is provided on the upper surface of the fifth annular boss, and the first axial roller (4) is installed between the first axial raceway (28) and the first main thrust axial raceway (32); a seventh annular boss is provided on the upper surface of the first outer ring (1) for placing the sixth radial roller (3), and the upper surface of the seventh annular boss is higher than the lower surface of the second ring.

3. The turntable bearing for an ultra-large tonnage crawler machine according to claim 1, characterized in that: The first inner ring (10) has a sixth annular boss at the lower part of its inner side wall, and the sixth annular boss is located below the second annular boss. A second axial raceway (30) is provided on the upper surface of the sixth annular boss, and the second axial roller (6) is installed between the second axial raceway (30) and the second main thrust axial raceway (33); an eighth annular boss is provided on the upper surface of the first inner ring (10) for placing the fifth radial roller (8), and the upper surface of the eighth annular boss is higher than the lower surface of the second ring.

4. The turntable bearing for an ultra-large tonnage crawler machine according to claim 1, characterized in that: The first axial rollers (4) are arranged in two groups along the radial direction of the middle ring (14), and the second axial rollers (6) are also arranged in two groups along the radial direction of the middle ring (14).

5. The turntable bearing for an ultra-large tonnage crawler machine according to claim 1, characterized in that: The first axial roller (4), the second axial roller (6), the third axial roller (13), the fourth axial roller (15), the fifth radial roller (8), and the sixth radial roller (3) are all provided with retaining frames on their exteriors; the upper portions of the two side walls of the first circular ring are respectively provided with sealing lips, and the two sides of the lower end surface of the second circular ring are also respectively provided with sealing lips.

6. A method for controlling the flatness of the inner and outer rings of a turntable bearing for an ultra-large tonnage crawler machine as claimed in any one of claims 1 to 5, characterized in that: The following steps are involved: Step A: During the parts processing before the bearing is assembled, the bottom surfaces of the first outer ring (1) and the first inner ring (10) are used as the base surfaces, and the shape and position tolerances of the first outer ring (1), the second outer ring (17), the middle ring (14), the first inner ring (10) and the second inner ring (11) are controlled as follows: the thickness of the fifth annular boss of the first outer ring (1) is set to h2, the thickness of the sixth annular boss of the first inner ring (10) is set to h4, and the mutual difference between h2 and h4 is ≤0.02mm; the thickness of the first annular boss of the middle ring (14) is set to h5, the thickness of the second annular boss is set to h6, and the mutual difference between h5 and h6 is ≤0.02mm; the distance from the lower surface of the first annular boss of the middle ring (14) to the lower surface of the middle ring (14) is set to h7, and the distance from the second annular boss of the middle ring (14) to the lower surface of the middle ring (14) is set to h8. The distance from the lower surface of the annular boss of the first outer ring (1) to the lower surface of the middle ring (14) is h8, and the difference between h7 and h8 is ≤0.02mm; the distance from the fifth annular boss of the first outer ring (1) to the upper surface of the first outer ring (1) is set to h1, and the distance from the sixth annular boss of the first inner ring (10) to the upper surface of the first inner ring (10) is set to h3, and the difference between h1 and h3 is ≤0.05mm; the distance from the lower surface of the fourth annular boss of the second outer ring (17) to the lower surface of the second outer ring (17) is set to h9, and the distance from the third annular boss of the second inner ring (11) to the lower surface of the second inner ring (11) is set to h10, and the difference between h9 and h10 is ≤0.05mm; the height of the first outer ring (1) and the height of the first inner ring (10) are ≤0.05mm; Step B, set the combination of the first inner ring (10) and the second inner ring (11) as the inner ring, and the combination of the first outer ring (1) and the second outer ring (17) as the outer ring. Before assembling the bearing, fit the outer ring and the inner ring separately, and detect the axial clearance value of the outer ring and the inner ring after fitting. If the axial clearance difference of the outer ring after fitting is greater than 0.10mm, grind the fitting surface of the first outer ring (1) and the second outer ring (17) to ensure that the axial clearance value of the outer ring of the bearing meets the product design requirements; if the axial clearance difference of the inner ring after fitting is greater than 0.10mm, grind the fitting surface of the first inner ring (10) and the second inner ring (11) to ensure that the axial clearance value of the outer ring and the inner ring of the bearing meets the product design requirements; if the axial clearance difference of the outer ring and the inner ring after fitting is less than or equal to 0.10mm, do not grind the rings and directly proceed to step C; Step C, assemble the bearing on a machine tool. After the assembly is completed, recheck the axial clearance of the outer ring and the inner ring respectively, and then detect the height difference between the base surface of the first outer ring (1) of the bearing and the base surface of the first inner ring (10); if the height difference between the base surface of the first outer ring (1) and the base surface of the first inner ring (10) of the bearing is greater than 0.05 mm, find the high point of the base surface of the first outer ring (1) or the base surface of the first inner ring (10), grind the high point flat on the machine tool, and ensure that the height difference between the base surface of the first outer ring (1) and the base surface of the first inner ring (10) of the bearing is ≤ 0.05 mm; Step D: After the qualified product is inspected on the machine tool, it is transferred to the external measuring platform to re-inspect the height difference between the base surface of the first outer ring (1) and the base surface of the first inner ring (10) of the bearing.

7. The method for controlling the flatness of the inner and outer rings of a turntable bearing for an ultra-large tonnage crawler machine according to claim 6 is characterized by: In step B, the outer ring and the inner ring are assembled under isothermal conditions; the outer ring assembly process and the axial clearance detection method are as follows: multiple fulcrums are evenly distributed in the assembly area according to the circumference, the second outer ring (17) is placed on the multiple fulcrums with the bottom surface facing upward, and the fourth axial roller (15) is placed on the fourth axial raceway (36) of the second outer ring (17). Then, the middle ring (14) is placed on the fourth axial roller (15) with the bottom surface facing upward and the first reverse thrust axial raceway (34) facing downward. Place the first axial roller (4) on the first main thrust axial raceway (32), and finally place the first outer ring (1) with the bottom facing upward and the first axial raceway (28) facing downward on the first axial roller (4), adjust the relative position of the first outer ring (1) and the second outer ring (17), so that the connecting holes on the first outer ring (1) and the second outer ring (17) are aligned one by one, place a jack on the outside of each fulcrum, use the jack to lift the second outer ring (17), and use a dial indicator to detect the axial clearance of the outer ring; The fitting process of the inner ring and the axial clearance detection method are as follows: multiple fulcrums are evenly distributed in the fitting area according to the circumference, the second inner ring (11) is stably placed on the multiple fulcrums with the bottom surface facing upward, the third axial roller (13) is placed on the third axial raceway (38) of the second inner ring (11), the middle ring (14) is stably placed with the bottom surface facing upward and the second main thrust axial raceway (33) facing upward on the third axial roller (13), and the second main thrust axial raceway (33) of the middle ring (14) is stably placed on the third axial roller (13). Place the second axial roller (6) on the axial raceway (33); place the second axial raceway (30) of the first inner ring (10) downward and steadily on the second roller (6), adjust the relative positions of the first inner ring (10) and the second inner ring (11), align the connection holes on the first inner ring (10) and the second inner ring (11), place a jack on the outer side of each fulcrum, use the jack to lift the second inner ring (11), and use a dial indicator to detect the axial clearance of the inner ring.

8. The method for controlling the flatness of the inner and outer rings of a turntable bearing for an ultra-large tonnage crawler machine according to claim 6 is characterized by: The assembly method of the bearing in step C is as follows: first assemble the outer ring, and then assemble the inner ring together with the outer ring. When assembling the outer ring, the bottom surface of the middle ring (14) faces upward, the second outer ring (17) is at the bottom, and the first outer ring (1) is at the top; when assembling the inner ring, the second inner ring (11) is at the top, and the first inner ring (10) is at the bottom; finally, use connecting screws to connect the first outer ring (1) and the second outer ring (17) correspondingly, and use second connecting screws to connect the first inner ring (10) and the second inner ring (11) correspondingly.

Images