Self-supporting lead screw nut mechanism and linear transmission device

Abstract

The invention relates to a self-supporting lead screw nut mechanism and a linear transmission device.The self-supporting lead screw nut mechanism comprises a lead screw and a driving nut, a plurality of rolling bodies are arranged on the two sides of the bottom of the driving nut, and the rolling bodies make contact with a base to form radial supporting; the whole linear motion process of the driving nut is guided only through contact between the rolling body and the base, and the rolling body keeps continuous contact with the base through an axial limiting structure. According to the self-supporting lead screw nut mechanism and the linear transmission device, through a composite supporting guide system formed by the rolling bodies and the base, a guide rod structure is omitted, and efficient transmission of radial loads, precise constraint of motion trails and source inhibition of friction losses are synchronously achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to a mechanical transmission mechanism, in particular to a self-supporting screw nut mechanism for realizing radial support and guidance by rolling bodies and its application device, which is suitable for linear motion control in the fields of automatic equipment, precision instruments and the like. BACKGROUND

[0002] In the field of linear transmission, the traditional screw rod sliding table mechanism always faces the inherent defects of the guide rod system. These structural and functional limitations have long restricted the performance of the equipment and industrial applications: Structural redundancy and space constraints: the guide rod system needs to be arranged in parallel on both sides of the screw rod, forming a redundant mechanical frame. Its large physical size significantly occupies the internal space of the equipment, causing the overall machine volume to be forced to increase, which is particularly prominent in scenes such as precision instruments and medical devices that have extremely high space utilization requirements.

[0003] Essential defects of friction mechanism: the sliding friction pair between the guide rod and the sliding block has a significant impact on the friction resistance due to material properties and surface conditions. The alternating phenomenon of static friction and dynamic friction generated during operation not only causes continuous energy loss, but also causes problems such as speed fluctuation and positioning jitter, which severely restricts the implementation of high-speed precision control scenarios.

[0004] Deformation sensitivity and reliability risk: the demanding installation precision of the guide rod system forms a technical bottleneck. Micro-level assembly deviations can cause motion trajectory deviations, and the difference in thermal expansion coefficients between the screw rod and the guide rod can generate internal stress when the temperature changes. The superimposed effects of the two cause frequent jamming, especially under high load start-stop or long-running working conditions, and the risk of failure rises sharply.

[0005] Systematic imbalance of cost structure: the guide rod assembly needs to be made of high-precision alloy materials, matched with precision ground sliding blocks and special installation bases. This multi-component integrated design increases the overall process cost of material procurement, precision machining and assembly and debugging, forming an economic bottleneck of the transmission mechanism.

[0006] Current technical improvements focus on guide rod layout optimization (such as patent CN212155680U) or friction pair material upgrading, but none of them have broken through the underlying logic of relying on guide rods. International mainstream solutions (such as THK ball guide rod module) still take the guide rod as the core component, which confirms the systematic technical obstacles in eliminating the guide rod. SUMMARY

[0007] Therefore, the present application provides a self-supporting screw nut mechanism, which cancels the guide rod structure through a composite support and guidance system constructed by rolling bodies and a base, and simultaneously realizes efficient transmission of radial load, precise constraint of motion trajectory, and source inhibition of friction loss.

[0008] The application achieves the purpose by the following technical solutions. A self-supporting screw nut mechanism, comprising a screw rod and a driving nut, the driving nut is provided with a plurality of rolling bodies on both sides of the bottom, the rolling bodies are in contact with the base to form radial support, the linear motion of the driving nut is guided by the contact between the rolling bodies and the base throughout the whole process, and the rolling bodies keep continuous contact with the base through axial limiting structure.

[0009] The structure directly bears the radial load through the rolling bodies and replaces the guiding function of the guide rod, eliminating the space occupation and friction loss problems of the traditional guide rod system. The continuous contact between the rolling bodies and the base forms a stable radial support surface, effectively dispersing the radial pressure on the screw rod and preventing the screw rod from being stuck due to radial force. At the same time, the rolling contact mechanism significantly reduces the movement resistance, enabling the driving nut to maintain linear motion precision without a guide rod, simplifying the number of parts in the overall structure, reducing assembly procedures and manufacturing costs.

[0010] Preferably, the bottom of the driving nut is provided with symmetrical accommodating portions on both sides, and the rolling bodies are partially located in the accommodating portions and partially exposed outside the accommodating portions and form rolling pairs with the base.

[0011] The symmetrical accommodating portion design ensures that the rolling bodies are evenly distributed on both sides of the driving nut, maintaining motion balance. The structure of the rolling bodies partially embedded in the accommodating portions provides a reliable positioning reference to prevent the rolling bodies from deviating during operation; the exposed portions form rolling pairs with the base, converting sliding friction into rolling friction, greatly reducing the friction coefficient and significantly lower than sliding friction. This layout maximizes the use of contact area to transfer radial force while avoiding the risk of rolling body falling off, ensuring the stability of the mechanism during high-speed reciprocating motion.

[0012] Preferably, the accommodating portion is a spherical cavity or an arc-shaped guide groove, and the inner contour of the spherical cavity or the arc-shaped guide groove forms a supporting contact with the outer surface of the rolling body.

[0013] The inner contour of the spherical cavity or the arc-shaped guide groove is geometrically matched with the surface of the rolling body, forming a surface contact rather than a point contact supporting structure. This design allows the radial load to be evenly transmitted to the inner wall of the accommodating portion, avoiding local wear caused by stress concentration; at the same time, it limits the degrees of freedom of the rolling body, preventing it from rotating or swinging unexpectedly within the accommodating portion. The inclusiveness of curved surface contact can adapt to rolling bodies of different sizes, improve manufacturing tolerance compatibility, and prolong the service life of the mechanism.

[0014] Preferably, the rolling bodies are distributed in groups along the movement direction of the driving nut, and each group contains at least two rolling bodies.

[0015] The rolling elements in each group form a continuous support line in the movement direction, which can effectively prevent the single-point overload of the rolling elements when the drive nut is subjected to asymmetric radial force. This layout enhances the adaptability of the mechanism to installation errors and prevents movement jamming caused by slight bending of the screw or uneven base, and is particularly suitable for long-stroke high-load scenarios.

[0016] Preferably, the base is provided with a wear-resistant area in contact with the rolling elements.

[0017] The wear-resistant area forms a reinforced layer on the contact surface of the base, which directly resists wear caused by repeated rolling of the rolling elements. This area can effectively extend the service life of the base by increasing the surface hardness and smoothness, reducing the friction coefficient and inhibiting the generation of micro scratches. The wear-resistant area cooperates with the rolling elements to maintain low-friction movement characteristics, avoid movement precision decline or abnormal sound problems caused by base wear, and reduce maintenance frequency.

[0018] Preferably, the axial limiting structure is arranged at the opening end of the accommodating portion, and the axial limiting structure and the accommodating portion jointly define the axial displacement of the rolling elements.

[0019] The axial limiting structure and the accommodating portion form a closed constraint structure to limit the rolling elements within a predetermined active space. This design allows the rolling elements to rotate freely in the radial direction, but strictly limits their axial movement to prevent them from being disengaged due to vibration or impact. The gap between the limiting member and the accommodating portion precisely controls the exposed height of the rolling elements, ensuring uniform distribution of contact pressure with the base, while avoiding excessive compression of the rolling elements to increase rolling resistance.

[0020] Preferably, the rolling elements are surface-reducing rolling elements.

[0021] The surface-reducing treatment forms a low-friction characteristic layer on the working surface of the rolling elements, such as nitriding or DLC coating, which further reduces rolling resistance. This treatment changes the surface molecular structure or adds solid lubricants to make the friction coefficient significantly lower than that of untreated surfaces, reducing power loss. The friction-reducing layer also improves the anti-sticking and grinding ability of the rolling elements, preventing cold welding caused by direct metal contact, and maintaining smooth movement in frequent start-stop or low-speed heavy-load working conditions.

[0022] Preferably, the drive nut is internally provided with a lubrication chamber, and the outlet of the lubrication chamber is communicated to the rolling elements.

[0023] The lubrication chamber directly delivers lubricant to the rolling body to form a continuous oil film protection. This design achieves precise lubrication of the friction pair, reduces waste of lubricant; the oil film separates the rolling body from the accommodating portion and the surface of the base, reduces the contact stress and leads out the friction heat, prevents lubrication failure caused by high temperature. The built-in channel avoids external pollution from entering the friction area, especially suitable for dusty or humid environment, prolongs the maintenance-free period of the mechanism.

[0024] Preferably, the base is provided with guide protrusions on both sides, and the height of the guide protrusions is lower than the central axis of the rolling body.

[0025] The guide protrusions form a physical barrier on both sides of the base, limiting the lateral displacement range of the rolling body. The design that the height of the protrusions is lower than the central axis of the rolling body ensures that the rolling body has enough space to move vertically to adapt to the flatness error of the base, while leaving a limited gap horizontally. This structure prevents the rolling body from being knocked out of the contact area due to lateral impact, and corrects the slight deflection of the drive nut, improving the straightness of the motion trajectory.

[0026] A linear transmission device comprises a screw rod, a driving unit and a transmission component, wherein the transmission component is a driving nut in the self-supporting screw nut mechanism.

[0027] The device completely eliminates the dependence on an independent guide rod system by integrating a self-supporting screw nut mechanism. The rolling body support structure of the driving nut reduces the axial size of the device, making it suitable for installation in compact spaces; the reduction of friction loss reduces the power demand of the driving unit. The device is compatible with motor, hydraulic or manual driving forms, and realizes high-reliability linear transmission in automation equipment, precision instruments and other scenes.

[0028] The beneficial effects of the present application compared with the prior art are: The present application breaks through the traditional guide rod frame, restructures the radial support and motion guide mechanism, and provides full-dimensional technical advantages: 1. Revolutionary simplification of mechanical body: by canceling the guide rod and associated sliding block, support and other components, the mechanical structure is essentially simplified. The direct benefit of reducing the total number of parts is the simplification of assembly process and the improvement of production line debugging efficiency, while reducing the complexity of the supply chain. The optimization of the weight distribution of the whole machine lays a foundation for the improvement of the dynamic performance of the equipment.

[0029] 2. Dimensional leap of tribological performance: the rolling body group replaces the sliding friction pair, completing the qualitative change of the friction mode from the molecular adhesion mechanism to the elastic deformation mechanism. The inherent low friction characteristic of rolling contact improves the energy conversion efficiency of the system, and eliminates the motion discontinuity caused by the crawling effect of the traditional guide rod system, laying a physical foundation for ultra-precision motion control.

[0030] 3. Topology optimization of mechanical load bearing: The innovative multi-rolling element support network disperses radial loads into a distributed stress field. This discretized load bearing pattern completely circumvents the stress concentration risk of traditional lead screws, making the mechanism inherently adaptive to off-load working conditions. Even under the condition of slight bending of the lead screw or deviation of the base flatness, constant motion stability can still be maintained.

[0031] 4. Life cycle value reevaluation: Material cost is reduced at the source due to structural simplification, while the machining precision requirement is relaxed from micrometer level to conventional industrial standard. The superimposed benefits of extended maintenance period and reduced energy consumption make the overall use cost of the device in the whole life cycle restructure the industry benchmark.

[0032] 5. Boundary expansion of engineering adaptability: The fault-tolerant design of curved surface contact is compatible with manufacturing tolerance fluctuations, and the flexible constraint mechanism of the guide convex part adapts to vibration environment challenges. This innate anti-interference ability makes the mechanism exhibit extraordinary robustness in extreme working conditions such as long-stroke heavy-load transportation and space station precision equipment, opening up a new era of transmission technology applications. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0034] Figure 1 It is a three-dimensional structure diagram of a linear transmission device according to an embodiment of the present application.

[0035] Figure 2 It is a three-dimensional structure diagram of a linear transmission device according to an embodiment of the present application.

[0036] Figure 3 It is a front view of a linear transmission device according to an embodiment of the present application.

[0037] Figure 4 It is an exploded view of a drive nut and rolling element according to an embodiment of the present application.

[0038] Label explanation: lead screw 1, drive nut 2, rolling element 3, base 4, accommodating part 21, axial limiting structure 22, wear-resistant area 41, guide convex part 42. DETAILED DESCRIPTION

[0039] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will be combined with the accompanying drawings to make a clear and complete description of the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. The components of the embodiments of the present application described and shown in the accompanying drawings can be arranged and designed in various different configurations.

[0040] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor are within the scope of protection of the present application.

[0041] It should be noted that: similar reference numerals and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. In the description of the embodiments of the present application, it should be understood that the terms "upper", "lower", "left", "right", "vertical", "horizontal" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly used when the product of the present application is used, or the orientation or positional relationship commonly understood by those skilled in the art, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0042] It should be noted that: similar reference numerals and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. In the description of the embodiments of the present application, it should be understood that the terms "upper", "lower", "left", "right", "vertical", "horizontal" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly used when the product of the present application is used, or the orientation or positional relationship commonly understood by those skilled in the art, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0043] The technical solutions in the present application will be described below in combination with the accompanying drawings.

[0044] Embodiment 1

[0045] The present embodiment provides a linear transmission device including a lead screw 1, a driving unit and a transmission component, a self-supporting lead screw nut mechanism including the lead screw 1 and a driving nut 2, a plurality of rolling bodies 3 are arranged on both sides of the bottom of the driving nut 2, the rolling bodies 3 are in contact with the base 4 to form radial support, and the linear motion of the driving nut 2 is guided by the contact between the rolling bodies 3 and the base 4 throughout the whole process. The transmission component is the driving nut 2 in the self-supporting lead screw nut mechanism, and the rolling bodies maintain continuous contact with the base through axial limiting structure.

[0046] The self-supporting screw-nut mechanism directly bears radial load through rolling elements 3 and replaces the guiding function of the guide rod, eliminating the space occupation and friction loss problems of the traditional guide rod system. The continuous contact between the rolling elements 3 and the base 4 forms a stable radial support surface, effectively dispersing the radial pressure received by the screw rod 1 and preventing the screw rod 1 from being stuck due to radial force. At the same time, the rolling contact mechanism significantly reduces the movement resistance, allowing the driving nut 2 to maintain linear motion precision without a guide rod, simplifying the overall structure, reducing the number of parts, and reducing manufacturing costs. The device completely eliminates the dependence on an independent guide rod system by integrating the self-supporting screw-nut mechanism. The rolling element 3 support structure of the driving nut 2 reduces the axial size of the device, making it suitable for compact space installation; the reduction of friction loss reduces the power demand of the driving unit. The device is compatible with motor, hydraulic or manual driving forms, achieving high reliability linear transmission in automated equipment, precision instruments and other scenarios.

[0047] In this embodiment, the driving nut 2 has symmetrical accommodation parts 21 on both sides of the bottom, and the rolling elements 3 are partially located in the accommodation parts 21 and partially exposed outside the accommodation parts 21 and form rolling pairs with the base 4.

[0048] The symmetrical accommodation parts 21 ensure that the rolling elements 3 are evenly distributed on both sides of the driving nut 2, maintaining motion balance. The structure of the rolling elements 3 partially embedded in the accommodation parts 21 provides a reliable positioning reference to prevent the rolling elements 3 from shifting during operation; the exposed part forms a rolling pair with the base 4, converting sliding friction to rolling friction, greatly reducing the friction coefficient, and significantly lower than sliding friction. This layout maximizes the use of contact area to transfer radial force while avoiding the risk of rolling elements 3 falling off, maintaining stability of the mechanism in high-speed reciprocating motion.

[0049] In this embodiment, the accommodation parts 21 are spherical cavities or arc-shaped guide grooves, and the inner contour of the spherical cavities or arc-shaped guide grooves forms a supporting contact with the outer surface of the rolling elements 3.

[0050] The inner contour of the spherical cavities or arc-shaped guide grooves is geometrically matched with the surface of the rolling elements 3, forming a surface contact rather than a point contact supporting structure. This design allows radial load to be evenly transmitted to the inner wall of the accommodation part 21, avoiding local wear caused by stress concentration; at the same time, it limits the degrees of freedom of the rolling elements 3, preventing unexpected rotation or oscillation of the rolling elements 3 in the accommodation part 21. The inclusiveness of curved surface contact can adapt to rolling elements 3 of different sizes, improve manufacturing tolerance compatibility, and prolong the service life of the mechanism.

[0051] In this embodiment, the rolling elements are distributed in groups along the direction of motion, with one group containing two rolling elements.

[0052] The two rolling elements 3 form a two-point support system, ensuring smooth movement of the driving nut under the support of the rolling elements.

[0053] In this embodiment, the base 4 is provided with a wear-resistant area 41 in contact with the rolling body 3.

[0054] The wear-resistant area 41 forms a reinforced layer on the contact surface of the base 4, directly resisting the wear caused by repeated rolling of the rolling body 3. By increasing the surface hardness and smoothness, reducing the friction coefficient and inhibiting the generation of micro scratches, the service life of the base 4 is effectively prolonged. The wear-resistant area 41 cooperates with the rolling body 3 to maintain low-friction movement characteristics, avoid movement precision decline or abnormal sound problems caused by base 4 wear, and reduce maintenance frequency.

[0055] In this embodiment, the axial limiting structure 22 is arranged at the opening end of the accommodating portion 21, and the axial limiting structure 22 cooperates with the accommodating portion 21 to limit the axial displacement of the rolling body 3.

[0056] The axial limiting structure 22 and the accommodating portion 21 form a closed constraint structure to limit the rolling body 3 within a predetermined active space. This design allows the rolling body 3 to rotate freely in the radial direction, but strictly limits its axial movement to prevent the rolling body 3 from being disengaged due to vibration or impact. The cooperation gap between the limiting member 22 and the accommodating portion 21 precisely controls the exposed height of the rolling body 3, ensuring uniform distribution of contact pressure with the base 4, while avoiding excessive compression of the rolling body 3 to increase rolling resistance.

[0057] In this embodiment, the rolling body 3 is a surface friction-reducing treated rolling element.

[0058] The surface friction-reducing treatment forms a low-friction characteristic layer on the working surface of the rolling body 3. Specifically, the rolling body is subjected to nitriding treatment to further reduce rolling resistance. This treatment significantly reduces the friction coefficient compared to untreated surfaces by changing the surface molecular structure or adding solid lubricants, reducing power loss. The friction-reducing layer also improves the rolling body's 3 anti-stick ability, preventing cold welding phenomena caused by direct metal contact, and maintaining smooth movement in frequent start-stop or low-speed heavy-load conditions.

[0059] In this embodiment, the drive nut 2 is provided with a lubrication chamber inside, and the outlet of the lubrication chamber is communicated to the rolling body 3.

[0060] The lubrication chamber directly delivers lubricant to the rolling body 3, forming a continuous oil film protection. This design achieves precise lubrication of the friction pair, reducing lubricant waste; the oil film separates the rolling body 3 from the surface of the accommodating portion 21 and the base 4, reducing contact stress and conducting friction heat, preventing lubrication failure caused by high temperature. The built-in channel avoids external pollution from entering the friction area, especially suitable for dusty or humid environments, prolonging the maintenance-free period of the mechanism.

[0061] In this embodiment, the base 4 is provided with a guide protrusion 42 on both sides, and the height of the guide protrusion 42 is lower than the central axis of the rolling body 3.

[0062] The guide protrusions 42 form a physical barrier on both sides of the base 4, limiting the lateral displacement range of the rolling body 3. The design of the protrusions 42 being lower than the center axis of the rolling body 3 ensures that the rolling body 3 has sufficient space for vertical movement to adapt to the flatness error of the base 4, while retaining a limited gap in the horizontal direction. This structure prevents the rolling body 3 from being knocked out of the contact area due to lateral impact, and corrects the slight deviation of the drive nut 2, improving the straightness of the motion trajectory.

[0063] Example 2: General high-efficiency self-supporting mechanism

[0064] This embodiment shows the engineering optimization form of the basic structure. The drive nut is formed by integral casting process, and the bottom of both sides is symmetrically processed as a precise spherical cavity as a containing part. Each spherical cavity is inserted with an alloy steel rolling body treated by polytetrafluoroethylene immersion. The upper half of the rolling body is in continuous curved surface contact with the inner profile of the spherical cavity, and the exposed part of the lower half is in rolling pair with the hardened stainless steel wear-resistant area of the base. Three groups of support units are arranged along the movement direction of the nut, each group containing two rolling bodies, forming a distributed bearing network.

[0065] The containing part is equipped with a buckle type axial limiting structure at the opening end, with a gap between the inner edge and the rolling body, which not only restricts the axial displacement but also ensures free rotation. The guide protrusions on both sides of the base are designed as flat-top structures, with the top height always lower than the center axis of the rolling body, forming a dual mechanism of horizontal displacement restriction and vertical floating space. The drive nut is provided with an annular lubricating chamber, and the lubricating grease penetrates to the surface of the rolling body through radial micro-holes, forming a self-sustaining oil film system.

[0066] Core advantage realization mechanism: Space optimization and load balancing: three groups of double rolling bodies are arranged in a continuous support line in the movement direction, eliminating the parallel structure redundancy of traditional guide rods. When subjected to eccentric load, the rolling bodies in the same group automatically adjust the contact pressure distribution to avoid unilateral stress on the screw.

[0067] Tribology optimization closed loop: spherical cavity surface contact reduces Hertz stress, hardened base surface suppresses wear, immersion treated rolling body reduces adhesive friction, and lubricating micro-holes continuously supplement oil - four synergies make the friction coefficient decrease.

[0068] Dynamic stability enhancement: the guide protrusions and the axial limiting structure form a composite constraint of "vertical floating + horizontal limiting".

[0069] Full life cycle maintenance simplification: sealed lubricating chamber design blocks external pollutants, and the service life of the base wear-resistant area is improved. Maintenance only needs to supplement the lubricating grease regularly, without the need for precision re-tuning.

[0070] This configuration is suitable for industrial automation scenarios, from light assembly robot arms to medium-sized numerical control machine tool feeding systems, which can be directly adapted.

[0071] Example 3: Extreme working condition strengthening

[0072] Deep optimization for heavy load, high temperature and polluted environment. The driving nut adopts a split heat-resistant alloy structure, the bottom of both sides is processed with a deep arc-shaped guide groove accommodation part, the groove depth design makes the rolling body only expose 1 / 3 of the spherical cap. Three silicon nitride ceramic rolling bodies are built in each group of accommodation parts, the surface is treated with diamond-like coating, and five groups are staggered along the motion direction. The base surface is laser cladded with high-entropy alloy wear-resistant layer, and the contact area with the rolling body forms a micro-convex self-compensating wear surface.

[0073] The axial limiting structure adopts a high-temperature alloy elastic stopper, which forms an axial labyrinth seal with the side wall of the guide groove. The guide convex part on both sides of the base is a double-slope structure, and the slope angle is accurately matched with the envelope trajectory of the rolling body. The lubrication chamber is filled with high-temperature semi-solid lubricating grease, which is targeted delivered to the rolling interface through a heat-resistant capillary tube network. The guide convex part and the base are sintered as a whole, and the thermal expansion coefficient is accurately matched with the rolling body.

[0074] Extreme working condition coping strategy: Heavy load adaptability: The five groups of three rolling bodies form an over-determined support system. When subjected to impact load, the staggered rolling bodies absorb energy through elastic deformation, significantly improving load dispersion capability. The double-slope guide convex part guides the load gradient transmission, avoiding stress mutation.

[0075] High temperature stability: The ceramic rolling body and high-entropy alloy base maintain a stable friction coefficient in a 400℃ environment. Thermal expansion matching design ensures constant contact pressure when temperature fluctuates, eliminating the risk of thermal jamming. The capillary tube network lubrication system forms a carbonized protective film at high temperature, replacing the traditional oil film failure mechanism.

[0076] Polluted environment protection: Deep groove type accommodation part cooperates with labyrinth seal structure to achieve IP67 dustproof standard. The limited exposure design of the rolling body blocks the possibility of hard particle invasion into the friction pair. The self-compensating wear surface can swallow micron-sized abrasive particles to maintain running accuracy.

[0077] Long-term maintenance-free operation: The ceramic-high-entropy alloy friction pair has low wear rate, enabling long-term maintenance-free operation.

[0078] This scheme is specifically for metallurgical equipment, mining machinery and other harsh working conditions, breaking through the environmental limitations while maintaining the advantages of no guide rod.

[0079] Example 4: Ultra-precision compact

[0080] It is designed for nanoscale scenarios such as microelectronic manufacturing and optical focusing. The drive nut is made of aluminum alloy and is processed by numerical control. The bottom of the two sides is a micro-arc-shaped guide groove accommodation part, and the contour precision reaches the level of optical mirror surface. Each group of guide grooves is embedded with two hard alloy micro-rolling bodies coated with molybdenum disulfide on the surface, and seven groups are densely arranged along the motion direction to form a continuous support surface. The base is made of microcrystalline ceramic wear-resistant area with low surface roughness.

[0081] The axial limiting structure is a laser micro-melting flange structure, and the rolling body gap is controlled in microns. The guide convex part adopts a continuous cornice topology, and the top curve is always lower than the rolling body rotation axis. The nanometer porous material with built-in lubrication chamber realizes molecular-level oil film control, and the oil consumption per thousand hours is low.

[0082] The realization principle of nanoscale precision is: Motion smoothness revolution: Seven groups of double rolling bodies form an ultra-dense support array, converting traditional discrete support into quasi-continuous curved surface support. The motion nonlinear error is reduced, and the micro-vibration phenomenon is completely eliminated.

[0083] Friction noise suppression: The micro-arc-shaped guide groove and the mirror surface base form an elastic hydrodynamic lubrication effect. In the micro-feeding working condition, the friction fluctuation amplitude is small, which meets the anti-shake requirements of the optical platform.

[0084] Cross-scale adaptability: The micro-support system is compatible with millimeter-level travel to meter-level travel scenarios. In the application of large-scale lithography machine wafer table, by increasing the number of rolling body groups, the global consistency can be maintained without structural reconstruction.

[0085] This architecture redefines the precision equipment transmission standard and provides basic support for advanced fields such as semiconductor lithography and space telescopes.

[0086] Although embodiments of the present application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A self-supporting screw-nut mechanism, comprising a screw (1) and a drive nut (2), characterized in that: A plurality of rolling bodies (3) are provided on both sides of the bottom of the driving nut (2), and the rolling bodies (3) are in contact with the base (4) to form radial support. The entire linear motion of the driving nut (2) is guided only by the contact between the rolling bodies (3) and the base (4), and the rolling bodies (3) maintain continuous contact with the base (4) through the axial limiting structure (22).

2. The self-supporting screw nut mechanism according to claim 1, characterized in that: Symmetrical receiving portions (21) are provided on both sides of the bottom of the driving nut (2); a portion of the rolling body (3) is located inside the receiving portion (21), and another portion is exposed outside the receiving portion (21) and forms a rolling pair with the base (4).

3. The self-supporting screw nut mechanism according to claim 2, characterized in that: The accommodating portion (21) is a spherical cavity or an arc-shaped guide groove, and its inner contour forms supporting contact with the outer surface of the rolling body (3).

4. The self-supporting screw nut mechanism according to claim 1, characterized in that: The rolling bodies (3) are distributed in groups along the movement direction of the drive nut (2), and each group contains at least two rolling bodies (3).

5. The self-supporting screw-nut mechanism according to claim 1, characterized in that: The base (4) is provided with a wear-resistant area (41) in contact with the rolling body (3).

6. The self-supporting screw-nut mechanism according to claim 2, characterized in that: The axial limiting structure (22) is arranged at the open end of the accommodating portion (21), and the axial limiting structure (22) and the accommodating portion (21) jointly limit the axial displacement of the rolling body (3).

7. The self-supporting screw-nut mechanism according to claim 1, characterized in that: The rolling element (3) is a rolling element with a surface anti-friction treatment.

8. The self-supporting screw-nut mechanism according to claim 1, characterized in that: A lubrication chamber is provided inside the drive nut (2), and an outlet of the lubrication chamber is connected to the rolling body (3).

9. The self-supporting screw-nut mechanism according to claim 1, characterized in that: Guide protrusions (42) are provided on both sides of the base (4), and the height of the guide protrusions (42) is lower than the central axis of the rolling body (3).

10. A linear transmission device comprising a screw rod (1), a drive unit (5) and a transmission component, characterized in that: The transmission component is a driving nut (2) in the self-supporting screw nut mechanism according to any one of claims 1 to 9.

Images