Crossed roller bearing

Abstract

The utility model relates to the technical field of bearings, in particular to a crossed roller bearing, which at least comprises a bearing inner ring, a bearing outer ring, a plurality of rollers and isolation blocks, a filling hole for filling the rollers is arranged on the bearing inner ring or the bearing outer ring, and the crossed roller bearing further comprises a plug matched with the filling hole. According to the crossed roller bearing disclosed by the utility model, through the special design of the plug and the filling hole, the traditional structural form that the plug is positioned and fixed through a conical pin is changed, the plug can be effectively prevented from moving in any direction in the filling hole, and the repeated positioning precision of the plug which is assembled to the original position after being disassembled is avoided; and the yield of one-time assembly of the bearing is greatly improved. A structural mistake proofing mechanism is constructed, the problem that the plug is reversely installed in the assembling process can be effectively prevented, and the assembling efficiency and the assembling accuracy are improved; and the structural stability after assembly is remarkably improved, and the problem of bearing clamping stagnation or abnormal sound caused by displacement of the plug due to vibration or operation impact is effectively prevented.

Description

TECHNICAL FIELD

[0001] The utility model relates to bearing technical field, concretely relates to a cross roller bearing. BACKGROUND

[0002] Cross roller bearing is widely used in high-precision robot, numerical control machine tool and other fields because it can simultaneously bear radial, axial and overturning moment. The traditional cross roller bearing usually preopens roller filling hole on the bearing inner ring or outer ring, and presets plug matched with the roller filling hole, the plug is provided with radially extending conical hole, the end face of the bearing inner ring or outer ring is provided with pin hole corresponding to the position of the conical hole, for example, the disc rolling bearing disclosed in the Chinese utility model patent with the announcement number CN2607464Y, during assembly, the roller is filled through the roller filling hole, after filling, the plug is placed in the roller filling hole, and the conical pin is inserted into the pin hole and the conical hole from the end face of the bearing, so that the plug is positioned and fixed.

[0003] The traditional cross roller bearing structure and its assembly method have the following technical defects:

[0004] (1) Complicated assembly process: during assembly, the plug and the conical pin need to be assembled first, after assembly, the conical pin and the plug are turned, after turning, the conical pin and the plug are removed for roller filling, after filling, the plug and the conical pin are installed again. Because the conical pin and the plug need to be turned at the same time, there are more turning surfaces, and during assembly, the fitting surface is damaged due to multiple disassembly and assembly, and the precision is reduced.

[0005] (2) Poor precision consistency: the plug and the inner and outer rings are processed respectively, affected by manufacturing tolerance, there is often a gap at the channel after assembly, and the roller will vibrate and produce uneven load during operation.

[0006] (3) Low yield: the assembly size is limited by the superimposed error of multiple part sizes (such as plug, conical pin, pin hole and conical hole), the robustness is poor, assembly interference or looseness is easy to occur, and quality control is difficult.

[0007] (4) Large influence of heat treatment: after heat treatment, the bearing inner and outer rings or the pin hole and the conical hole may be deformed, making it difficult to assemble the plug or the fitting gap to reach the preset precision, further reducing the product qualification rate.

[0008] In addition, the Chinese invention patent with the publication number CN104295598A discloses a rotary bearing with a through hole and a plug. In the disclosed scheme, a through hole for inserting a roller for assembly and maintenance is arranged on one of the rings as the inner ring or the outer ring, and a plug for closing the through hole is arranged. The through hole is a stepped hole, and the plug is a stepped shaft structure matching the stepped hole. In the disclosed scheme, compared with the traditional cross-roller bearing, the structure of the plug is different, and one taper pin structure is less, so that the number of parts and the turning surface are less, and the assembly cumulative error is improved. However, the scheme still has the following technical defects:

[0009] (1) The through hole and the plug are in clearance fit, which is convenient for manual insertion, but also makes it difficult to stably position the plug before assembly is completed. Before the raceway is completely closed or fixed by a pin / screw, the plug is easy to loosen or fall off during handling, turning or slight vibration, thereby potentially interfering with the subsequent assembly process and affecting the assembly efficiency and safety.

[0010] (2) The large diameter section and the small diameter section of the through hole are concentric, and correspondingly, the large diameter section and the small diameter section of the plug are coaxial. In the circumferential direction, there is a lack of anti-rotation design. After assembly is completed, the plug has the possibility of rotating under the action of vibration or stress during work, which may further cause misalignment or interference of the contact surface with the raceway.

[0011] (3) The connection between the plug and the through hole is not provided with a tapered guide section, so that the centering is poor during assembly, especially in the case of small gap fit. The lack of guide taper makes it easy to appear "edge sticking" or "repeated trial assembly", which reduces the assembly efficiency and consistency, increases the assembly difficulty, requires higher proficiency of the operator, and is not conducive to subsequent automatic assembly.

[0012] (4) The large diameter section and the small diameter section of the through hole are concentric, and the large diameter section and the small diameter section of the plug are coaxial, which is a completely symmetrical design. There is a lack of assembly mistake-proofing mechanism, and there is a risk of misassembly. After the raceway is processed, even if the plug is assembled in reverse by 180°, it cannot be identified by appearance or assembly resistance, and the error of "reverse assembly" is easy to occur. Once the plug is assembled in reverse, the raceway surface will have a step misalignment, which seriously affects the running stability of the roller and the overall service life. SUMMARY

[0013] The technical problem to be solved by the utility model is to provide an improved cross-roller bearing to solve the technical defects existing in the structure of the cross-roller bearing in the prior art.

[0014] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a crossed roller bearing, comprising at least an inner bearing ring, an outer bearing ring, and a plurality of rollers and spacers located between the inner and outer bearing rings. The inner or outer bearing ring is provided with a filling hole for loading the rollers. The bearing also includes a plug adapted to the filling hole. The plug comprises a cylindrical section and a lug structure located at one end of the cylindrical section. A first positioning step is formed between the cylindrical section and the lug structure. The projection of the lug structure along the axial direction of the cylindrical section is asymmetrically designed based on the axis of the cylindrical section. The filling hole comprises a circular hole adapted to the cylindrical section and a slot adapted to the lug structure. A second positioning step adapted to the first positioning step is formed between the slot and the circular hole.

[0015] In a preferred embodiment, the lug structure is slightly interference-fitted with the slot.

[0016] In a preferred embodiment, the interference fit between the lug structure and the slot is 5μm–50μm.

[0017] In a preferred embodiment, the lug structure and the slot are fitted with a slight taper.

[0018] In a preferred embodiment, the taper angle between the lug structure and the slot is 0.5°–7°.

[0019] In a preferred embodiment, the lug structure has at least one plane in the circumferential direction.

[0020] In a preferred embodiment, the plug is made of the same material as the bearing inner ring or bearing outer ring with a filling hole.

[0021] Compared with the prior art, the crossed roller bearing of this utility model has the following advantages:

[0022] (1) The first step and the second step achieve precise positioning of the filling hole in the axial direction, which can effectively prevent the plug from moving in the axial direction of the filling hole, and also provide stable support for the subsequent welding process of the plug.

[0023] (2) The projection of the lug structure on the axial direction of the columnar section is based on the structural form of the asymmetric design of the axial direction of the columnar section, which constructs a structural error prevention mechanism, so that the plug can only be installed into the filling hole in the only correct posture, avoiding assembly errors from the source, ensuring the repeatability of the positioning accuracy of the plug after it is removed and reassembled, and greatly improving the pass rate of the cross roller bearing in one assembly.

[0024] (3) The projection of the lug structure on the axial direction of the columnar section is based on the asymmetrical design of the columnar section axis, which realizes the circumferential locking fit between the plug and the filling hole, eliminates the risk of plug rotation, significantly improves the structural stability after assembly, and effectively prevents the problem of bearing jamming or abnormal noise caused by the displacement of the plug due to vibration or running impact.

[0025] (4) The lug structure of the plug and the slot of the filling hole are slightly interference fit, which ensures reliable fixation without affecting the operability during the assembly process, and also facilitates the simulation assembly and fit adjustment before subsequent heat treatment.

[0026] (5) The lug structure of the plug is matched with the small taper of the slot of the filling hole, which has the functions of guiding assembly, initial positioning and self-locking. After the taper angle is less than the friction self-locking angle, the plug will not loosen on its own after pressing. The combination of taper fit design and interference fit design makes the plug stable before welding and significantly improves the process robustness.

[0027] (6) The combination of step positioning and interference fit between the plug and the filling hole can effectively prevent the plug from moving axially and rotating out of place. At the same time, the tapered fit design further enhances the self-centering ability of the plug during insertion, which can effectively prevent the plug from moving in any direction in the filling hole, thereby improving the overall positioning accuracy.

[0028] (7) The special design of the plug and filling hole changes the traditional structure of fixing the plug by the tapered pin, reduces the number of traditional turning surfaces, and makes the disassembly process more streamlined. The assembly personnel only need to press the plug into the positioning to complete the assembly, which significantly shortens the assembly cycle and reduces labor costs. There is no need to process additional structures such as tapered pin holes on the plug and bearing ring, which effectively reduces the processing steps, reduces the complexity of the mold and the difficulty of CNC programming, and is suitable for mass production.

[0029] (8) The overall structure of the plug and filling hole after assembly is heat treated. Based on the special structural design of the plug and filling hole, it can effectively adapt to the geometric changes during heat treatment and processing. The plug fit has good tolerance compensation ability and shows higher pass rate and reliability in actual manufacturing.

[0030] (9) The special design of the plug and filling hole enhances the modularity and standardization of the bearing structure, making it very suitable for integration into automated assembly lines and helping to improve the production efficiency and consistency of the robotics or precision equipment industry. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the bearing outer ring in this embodiment;

[0032] Figure 2 for Figure 1A partially enlarged schematic diagram of part A shown;

[0033] Figure 3 This is a schematic diagram of the plug structure in this embodiment;

[0034] Figure 4 for Figure 3 A schematic diagram of the axial projection of the plug shown;

[0035] Figure 5 This is a schematic diagram of the structure of the bearing outer ring and plug after assembly and machining in this embodiment;

[0036] Figure 6 for Figure 5 The diagram shows a cross-sectional view of BB.

[0037] Figure 7 for Figure 6 A partially enlarged schematic diagram of part D is shown below;

[0038] Figure 8 for Figure 5 A magnified view of part C shown. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0040] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0041] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an integral connection, or a detachable connection; they can refer to the internal connection of two components; they can refer to a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0042] This embodiment of a crossed roller bearing includes at least an inner bearing ring, an outer bearing ring 10, and a plurality of rollers and spacers located between the inner and outer bearing rings. Wherein, as... Figure 1 , Figure 2As shown, the outer ring 10 of the bearing is provided with a filling hole 20 for filling rollers, such as... Figures 5-8 As shown, a plug 30 is fitted into the filling hole 20. The plug 30 is made of the same material as the outer ring of the bearing. It should be noted that the inner ring, rollers, and spacer block are standard components of a crossed roller bearing, and their specific structures will not be described in detail in this embodiment.

[0043] In this embodiment, the structure of the plug 30 is as follows: Figure 3 , Figure 4 As shown, it includes a columnar segment 31 and a lug structure 32 located at one end of the columnar segment 31, with a first positioning step 33 formed between the columnar segment 31 and the lug structure 32.

[0044] As a special feature of this embodiment, wherein, as Figure 3 , Figure 4 As shown, the projection of the lug structure 32 onto the axial direction of the columnar segment 31 is based on an asymmetrical design of the axis of the columnar segment 31. It should be noted that, in this embodiment, the specific shape of the asymmetry is not limited.

[0045] In this embodiment, the structure of the bearing ring is described using the outer ring 10 as an example. For example, Figure 1 , Figure 2 As shown, the outer ring 10 of the bearing is provided with a filling hole 20 that is adapted to the plug 30. The filling hole 20 includes a circular hole 21 adapted to the columnar section 31 and a slot 22 adapted to the lug structure 32. Furthermore, a second positioning step 12 adapted to the first positioning step 33 is formed between the slot 22 and the circular hole 21.

[0046] As a special feature of this embodiment, the lug structure 32 and the slot 22 are in a slight interference fit. Preferably, the interference fit is 5–20 μm.

[0047] As a special feature of this embodiment, the lug structure 32 and the slot are fitted with a small taper. Preferably, the taper angle α is 0.5°–7°.

[0048] As a preferred embodiment, in this case, Figure 3 , Figure 4 As shown, the lug structure has at least one plane 34 in its circumferential direction, and in this embodiment, four planes 34 are provided. Correspondingly, the circumferential wall of the slot 22 is provided with a planar structure adapted to the aforementioned planes 34. In this embodiment, the provision of planes 34 increases the stability between the plug and the filling hole in the circumferential direction, effectively preventing the problem of bearing jamming or abnormal noise caused by displacement of the plug due to vibration or operational impact.

[0049] In this embodiment, as Figures 5-8 As shown, a groove 11 for accommodating the roller is machined at the free end of the cylindrical section 31 of the plug 30 by turning.

[0050] In this embodiment, the plug and the bearing outer ring are fixed together by welding. Preferably, laser welding is used. After welding, the plug and the bearing outer ring form a single unit.

[0051] It should be noted that in this embodiment, the example of setting the filling hole on the outer ring of the bearing is used for illustration. Those skilled in the art should understand that the filling hole can also be set on the inner ring of the bearing.

[0052] In summary, the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A crossed roller bearing, comprising at least an inner bearing ring, an outer bearing ring, and a plurality of rollers and spacers located between the inner and outer bearing rings, wherein the inner or outer bearing ring is provided with a filling hole for loading the rollers, and further comprising a plug adapted to be installed in the filling hole, characterized in that, The plug includes a cylindrical section and a lug structure located at one end of the cylindrical section. A first positioning step is formed between the cylindrical section and the lug structure. The projection of the lug structure in the axial direction of the cylindrical section is based on an asymmetrical design of the axis of the cylindrical section. The filling hole includes a circular hole adapted to the cylindrical section and a slot adapted to the lug structure. A second positioning step adapted to the first positioning step is formed between the slot and the circular hole.

2. The roller bearing according to claim 1, characterized in that, The lug structure is slightly interference-fitted with the slot.

3. The roller bearing according to claim 2, characterized in that, The interference fit between the lug structure and the slot is 5μm–50μm.

4. The roller bearing according to any one of claims 1-3, characterized in that, The lug structure and the slot are fitted with a small taper.

5. The roller bearing according to claim 4, characterized in that, The taper angle between the lug structure and the slot is 0.5°–7°.

6. The roller bearing according to any one of claims 1-3 or 5, characterized in that, The lug structure has at least one plane in its circumferential direction.

7. The roller bearing according to any one of claims 1-3 or 5, characterized in that, The plug is made of the same material as the inner or outer ring of the bearing with a filling hole.

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