Roller isolation structure and differential planetary roller screw pair

Abstract

The utility model relates to high accuracy transmission technical field, specifically disclose a kind of roller isolation structure and differential planetary roller screw pair. Wherein, the roller isolation structure includes roller and isolation circle, the roller at least includes the first meshing section and the second meshing section sequentially, the outer diameter of the first meshing section is greater than the outer diameter of the second meshing section, the middle part of the first meshing section is provided with light pole section;The isolation circle includes accommodating cavity and opening, the wrap angle of accommodating cavity is greater than 180 °, and the wall thickness of isolation circle is greater than the maximum radial dimension of the first meshing section to the radial height of light pole section. In the above structure, the isolation circle on each roller is configured, the separation between rollers is realized, the function of traditional integral cage is replaced, the light pole section of roller can be directly clamped from radial, the assembly difficulty in narrow space is greatly reduced, especially beneficial to the manufacture and assembly of miniaturization, high-density integrated product, and the assembly convenience and assembly efficiency are greatly improved.

Description

Technical Field

[0001] This utility model relates to the field of high-precision transmission technology, specifically to a roller isolation structure and a differential planetary roller screw pair. Background Technology

[0002] Differential planetary roller screw pairs are linear transmission mechanisms with high precision and high load-bearing capacity, widely used in robotics, aerospace, and precision transmission equipment. They achieve small lead and high-resolution linear displacement through the differential motion of multiple rollers between the screw and nut.

[0003] Traditional differential planetary roller screw assemblies have rollers with adjacent first and second engagement sections, and these sections have a significant diameter difference. The first engagement section meshes with the external thread of the screw, while the second engagement section meshes with the zero-lead internal thread of the nut. Additionally, the nut contains a clearance section to accommodate the first engagement section. To prevent the rollers from stacking or colliding during operation, a ring-shaped cage is typically placed between the rollers, with roller positioning holes corresponding to each roller.

[0004] However, this traditional form of differential planetary roller screw pair has the following technical limitations:

[0005] (1) The cage is an integral ring structure. Due to the large diameter difference between the clearance section inside the nut and the zero-lead internal thread, the assembly is difficult, especially in miniaturized or micro-miniaturized designs with limited radial space.

[0006] (2) The clearance between the cage and the roller is difficult to control precisely, which affects the transmission accuracy and reliability.

[0007] (3) The cage needs to be equipped with a central through hole for the lead screw to pass through and circumferentially distributed roller positioning holes. In order to meet its own structural strength requirements, sufficient radial space needs to be reserved. This structure restricts the development of differential planetary roller screw pairs in the direction of smaller dimensions. Summary of the Invention

[0008] The technical problem to be solved by this utility model is to overcome the technical shortcomings of existing differential planetary roller screw pairs, such as high assembly difficulty, poor transmission accuracy and reliability, and the cage structure restricting the development of differential planetary roller screw pairs towards smaller sizes.

[0009] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a roller isolation structure, characterized in that it includes a roller and an isolation ring, wherein the roller includes at least a first meshing section and a second meshing section arranged sequentially, the outer diameter of the first meshing section is larger than the outer diameter of the second meshing section, and a smooth rod section is provided in the middle of the first meshing section;

[0010] The isolation ring includes a receiving cavity that is clearance-fitted with the optical rod section and an opening for the optical rod section to enter the receiving cavity. The containment angle of the receiving cavity is greater than 180°, and the wall thickness of the isolation ring is greater than the maximum radial dimension of the first meshing section to the radial height of the optical rod section.

[0011] In a preferred embodiment, the difference between the wall thickness of the isolation ring and the maximum radial dimension of the first engagement section to the radial height of the polished rod section is not less than 0.05 mm.

[0012] In a preferred embodiment, the insulating ring is made of an elastic material.

[0013] In a preferred embodiment, the outer wrap angle of the insulating ring is greater than the inner wrap angle.

[0014] In a preferred embodiment, the outer wrap angle of the insulating ring is 270°~330°, and the inner wrap angle is 200°~240°.

[0015] In a preferred embodiment, the opening is provided with a transition section, the wall thickness of which gradually decreases from the end position of the inner ring corner to the end position of the outer ring corner.

[0016] In a preferred embodiment, the opening is provided with a rounded corner between the end position of the outer ring corner and the transition section.

[0017] This utility model also discloses a differential planetary roller screw pair, which includes at least a nut, a screw, and multiple sets of the roller isolation structures, wherein the roller isolation structures are disposed between the nut and the screw; and the opening faces the screw.

[0018] The roller isolation structure and differential planetary roller screw pair of this utility model achieve separation between rollers through isolation rings configured on each roller, replacing the function of the traditional integral cage. The open design ensures normal meshing between the first engagement section and the external thread of the screw drive, while achieving the following beneficial effects:

[0019] (1) The isolation ring adopts a side opening design, which can be directly inserted into the roller rod section from the radial direction, eliminating the axial insertion and precision alignment process required by the traditional cage, greatly reducing the assembly difficulty in narrow space, and is particularly beneficial to the manufacturing and assembly of miniaturized, high-density integrated products. Its assembly convenience and assembly efficiency are greatly improved.

[0020] (2) The isolation ring and the smooth rod section are fitted with a clearance, and the containment cavity wrap angle is greater than 180°, which can reliably isolate each roller and effectively prevent the rollers from colliding and stacking during the movement, thereby ensuring a smooth and reliable transmission process and improving the overall transmission accuracy and reliability.

[0021] (3) Compared with the traditional cage structure which requires a central through hole and circumferential roller positioning hole, the isolation ring is directly embedded in the gap between the roller smooth rod section and the nut clearance section, which greatly saves radial installation space and makes the structure more compact, providing the possibility for further miniaturization and lightweight design of the product.

[0022] (4) The design of the opening facing the lead screw, combined with the optional elastic material and the transition rounded corner structure, allows the isolation ring to be effectively locked after installation and is easy to operate during disassembly, which greatly facilitates the later maintenance and parts replacement.

[0023] (5) An innovative structure with an outer ring wrap angle greater than the inner ring wrap angle is adopted. On the one hand, the large outer ring wrap angle ensures the overall strength and stability of the isolation ring, and on the other hand, the small inner ring wrap angle reduces the assembly difficulty. The structure is scientifically designed, taking into account both strength and assembly convenience, and achieving an effective unity of reliability and ease of assembly and disassembly.

[0024] (6) By adjusting the inner and outer wrap angles of the isolation ring, the difference in wall thickness and the opening transition structure, the ease of assembly and working stability can be further balanced to meet the application requirements of different loads, speeds and precision requirements, and show good engineering adaptability and design freedom. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the internal structure of the differential planetary roller screw pair shown in Example 1;

[0026] Figure 2 for Figure 1 The diagram shows a cross-sectional view (AA).

[0027] Figure 3 for Figure 1 A schematic diagram of the three-dimensional state structure shown;

[0028] Figure 4 This is a three-dimensional structural diagram of the isolation ring in Example 1;

[0029] Figure 5 for Figure 4 A schematic diagram of the front view of the isolation ring shown;

[0030] Figure 6 This is a schematic diagram of the roller structure in Example 1;

[0031] Figure 7 This is a schematic diagram of the nut structure in Example 1;

[0032] Figure 8 This is a schematic diagram of the internal partial structure of the differential planetary roller screw pair shown in Example 2;

[0033] Figure 9 This is a schematic diagram of the roller structure in Example 2.

[0034] Among them, 10-isolation ring, 11-accommodating cavity, 12-opening, 13-inner ring, 14-outer ring, 15-transition section, 16-rounded corner; 20-roller, 21-first engagement section, 22-second engagement section, 23-polished rod section; 30-nut, 31-clearance section, 32-zero lead internal thread section; 40-lead screw. Detailed Implementation

[0035] 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.

[0036] 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.

[0037] 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.

[0038] Example 1

[0039] This embodiment describes a differential planetary roller screw pair, such as... Figures 1-3 As shown, it includes a nut 30, a lead screw 40, and multiple sets of roller isolation structures disposed between the lead screw 40 and the nut 30. The lead screw 40 has a transmission external thread on its outer periphery.

[0040] In this embodiment, the structure of the nut 30 is as follows: Figure 7As shown, its inner circumference is provided with a clearance section 31 and zero-lead internal thread sections 32 adjacent to both sides of the clearance section 31. The inner diameter of the clearance section 31 is larger than the maximum inner diameter of the zero-lead internal thread section 32, and the diameter difference between the two is relatively large.

[0041] As a special feature of this embodiment, the roller isolation structure includes rollers 20 and isolation rings 10 disposed on the rollers 20. The structure of the rollers 20 is as follows: Figure 6 As shown, it includes a first engagement section 21 that meshes with the external transmission thread and a second engagement section 22 adjacent to both sides of the first engagement section 21. The second engagement section 22 has a zero-lead external thread section for meshing with a zero-lead internal thread section 32. The first engagement section 21 is located within the clearance section 31 of the nut 30.

[0042] As a special feature of this embodiment, a smooth rod section 23 is provided in the middle of the first engagement section 21, and an isolation ring 10 is fitted on the smooth rod section 23.

[0043] As a special feature of this embodiment, the structure of the isolation ring 10 is as follows: Figures 4-5 As shown, it includes a receiving cavity 11 that is clearance-fitted with the optical rod section 23 and an opening 12 for the optical rod section 23 to enter the receiving cavity 11. Figure 2 As shown, the enclosing angle of the accommodating cavity 11 is greater than 180°, and the opening 12 faces the lead screw 40.

[0044] In this embodiment, the insulating ring 10 is typically made of a material with a certain degree of elasticity, such as engineering plastics, resins, or metallic elastic materials, to facilitate radial insertion of the insulating ring into the roller guide section. In this embodiment, a wear-resistant, low-friction, or high-strength material is preferably selected. Of course, in this embodiment, there are no restrictions on the specific material used; those skilled in the art can select from existing materials according to design requirements.

[0045] In this embodiment, the wall thickness of the isolation ring 10 is greater than the maximum radial dimension of the first meshing section to the radial height of the guide rod section 23. With this setting, since the accommodating cavity 11 of the isolation ring 10 and the guide rod section 23 are in clearance fit, even if the isolation ring and the guide rod section are not concentric, effective isolation between adjacent rollers can be ensured, preventing collisions and stacking between adjacent rollers.

[0046] In this embodiment, the difference between the wall thickness of the isolation ring 10 and the maximum radial dimension of the first meshing section to the radial height of the polished rod section 23 is usually not less than 0.05 mm, and can be designed accordingly according to different loads, speeds and accuracy requirements.

[0047] In this embodiment, there is a gap between the outer wall of the isolation ring 10 and the inner wall of the clearance section 31 to prevent friction and interference when the nut 30 moves linearly relative to the lead screw 40.

[0048] As a special feature of this embodiment, such as Figure 4 , Figure 5 As shown, the wrap angle of the outer ring 14 of the insulating ring 10 is larger than that of the inner ring 13. Typically, the outer ring wrap angle is 270°~330°, and the inner ring wrap angle is 200°~240°. The purpose of this design is to ensure the overall strength and stability of the insulating ring by utilizing the large wrap angle of the outer ring, while reducing assembly difficulty by utilizing the small wrap angle of the inner ring. The structural design is scientific, balancing strength and assembly convenience, and achieving an effective balance between reliability and ease of assembly and disassembly.

[0049] As a special feature of this embodiment, a transition section 15 is provided at the opening 12. The wall thickness of the transition section 15 gradually decreases from the end position of the inner ring corner to the end position of the outer ring corner. The purpose of this arrangement is to guide the assembly and disassembly of the insulating ring and the smooth rod section, facilitating the convenient assembly and disassembly of the insulating ring and the smooth rod section.

[0050] As a special feature of this embodiment, the opening 12 is provided with a fillet 16 between the termination position of the outer ring wrap angle and the transition section. The purpose of this setting is that, during the operation of the differential planetary roller screw pair, even if the isolating ring deflects, the position where it contacts the transmission external thread on the screw is at the fillet 16, with a small contact area and less friction, thereby ensuring transmission accuracy.

[0051] Example 2

[0052] The differential planetary roller screw pair in this embodiment, such as Figure 8 , Figure 9 As shown, the difference from Embodiment 1 is that the roller 20 and the nut 30 have different structural forms.

[0053] Specifically, in this embodiment, the roller 20 includes a second engagement section 22 that engages with the zero-lead internal thread section 32 of the nut 30, and a first engagement section 21 adjacent to both sides of the second engagement section 22. The first engagement section 21 is used to engage with the external thread on the lead screw. Furthermore, a smooth rod section 23 for fitting the isolation ring 10 is provided in the middle of the two first engagement sections 21.

[0054] Accordingly, the nut 30 is provided with a zero-lead internal thread section 32 and clearance sections 31 adjacent to both sides of the zero-lead internal thread section 32.

[0055] 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 roller isolation structure, characterized in that, It includes rollers and a separator ring. The rollers include at least a first meshing section and a second meshing section arranged in sequence. The outer diameter of the first meshing section is larger than the outer diameter of the second meshing section. A smooth rod section is provided in the middle of the first meshing section. The isolation ring includes a receiving cavity that is clearance-fitted with the optical rod section and an opening for the optical rod section to enter the receiving cavity. The containment angle of the receiving cavity is greater than 180°, and the wall thickness of the isolation ring is greater than the maximum radial dimension of the first meshing section to the radial height of the optical rod section.

2. The roller isolation structure according to claim 1, characterized in that, The difference between the wall thickness of the isolation ring and the maximum radial dimension of the first meshing section to the radial height of the polished rod section is not less than 0.05 mm.

3. The roller isolation structure according to claim 1, characterized in that, The insulating ring is made of an elastic material.

4. The roller isolation structure according to claim 1, characterized in that, The outer wrap angle of the isolation ring is greater than the inner wrap angle.

5. The roller isolation structure according to claim 4, characterized in that, The outer wrap angle of the isolation ring is 270°~330°, and the inner wrap angle is 200°~240°.

6. The roller isolation structure according to claim 4 or 5, characterized in that, The opening is provided with a transition section, the wall thickness of which gradually decreases from the end position of the inner ring corner to the end position of the outer ring corner.

7. The roller isolation structure according to claim 6, characterized in that, The opening is provided with a rounded corner between the end position of the outer ring corner and the transition section.

8. A differential planetary roller screw pair, characterized in that, It includes at least a nut, a lead screw, and a plurality of roller isolation structures as described in any one of claims 1-7, wherein the roller isolation structure is disposed between the nut and the lead screw; and the opening faces the lead screw.

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