Ball screw pair with combined reverser

Abstract

The invention relates to the technical field of end plug type ball screw pairs, and provides a ball screw pair with a combined reverser, which comprises a lead screw and a nut, the nut is sleeved on the lead screw, the inner wall of the nut is provided with two reverser grooves which are respectively arranged at the two ends of the nut, the ball screw pair also comprises a reverser substrate and a reverser plug-in, the reverser base part comprises a clamping groove, a ball receding groove and a guide convex circle. The reverser plug-in comprises a clamping protrusion and a receding convex circle. When the reverser base part and the reverser plug-in part are combined, the clamping protrusions are inserted into the clamping grooves so that detachable fixing of the reverser base part and the reverser plug-in part can be achieved, and a continuous ball channel is formed between the reverser base part and part of the roller path of the reverser plug-in part and the interior of the nut in an aligned and matched mode. Through the split type mounting and dismounting design, sufficient passing space is provided for the balls, the problem of ball interference during nut dismounting and mounting is solved, it is guaranteed that the balls return smoothly, operation noise is reduced, the ball mounting space is optimized, and maintenance and overhaul are facilitated.

Description

Technical Field

[0001] The present application relates to the technical field of end-plug type ball screw pairs, and in particular to a ball screw pair with a combined return device. Background Art

[0002] The traditional ball screw pair is an integral return device. Due to the guide convex circle of the return device, it needs to be installed in the nut first, and then the nut is filled with balls using a guide sleeve. Finally, the installed nut assembly is passed onto the ball screw. The end of the ball screw must have a through raceway to ensure the smooth entry of the nut assembly. For scenarios with strict dustproof requirements on the screw end, the solution can only be solved by subsequent methods such as inserting a sleeve, and neither accuracy nor rigidity can be guaranteed.

[0003] There are also combined return assembly components on the market to solve the problem of blocked screw ends, but none of them have space for ball installation. This method requires installing the balls first and then installing the return assembly. Due to interference, only 2-3 balls can be installed. The impact noise of the ball circulation is large and affects the service life of the ball screw pair. Summary of the Invention

[0004] In order to solve the problem that the combined return device assembly in the prior art has no ball installation space, the number of balls installed is small, the impact noise is large, and the service life of the ball screw pair is affected.

[0005] The present application provides a ball screw pair with a combined return device, comprising: A lead screw, a surface of which is provided with a spiral groove, wherein the spiral groove is provided in the middle of the lead screw; a nut, sleeved on the lead screw, with a return groove provided on its inner wall, two return grooves being provided at both ends of the nut, and the return grooves being communicated with the spiral channel; The return device assembly is composed of a return device base member and a return device plug-in member which are separately arranged; There are two return device assemblies, which are arranged oppositely in the return device grooves at both ends of the nut; The return device base comprises: a clamping groove, a ball bearing clearance groove and a guide convex circle; The clamping groove is provided on the top of the return device base, the ball bearing clearance groove is provided at one end close to the clamping groove and communicates with the clamping groove, and the guide convex circle is fixed on the side of the return device base facing away from the clamping groove; The return device plug-in comprises: a locking convex and a yielding convex circle; The locking protrusion is arranged in the middle of the return device plug-in, and the relief convex circle is fixed on the end of the bottom of the return device plug-in away from the locking protrusion; When the return device base and the return device plug-in are assembled, the return device base is inserted into the return device groove of the nut, and the guide convex circle extends into the spiral groove of the lead screw; When the return device base and the return device plug-in are assembled, the return device base is inserted into the return device groove of the nut, and the guide convex circle extends into the spiral groove of the lead screw; The latching protrusion of the return device plug-in is inserted into the latching groove to realize the detachable fixation of the return device base and the return device plug-in, and the axes of the raceways of the two opposite return device components are collinear to form a continuous ball channel.

[0006] In a feasible implementation, the diameter of the ball installation space formed by the cooperation between the ball clearance groove and the wall surface of the return device groove is larger than the ball diameter by 0.15mm-0.2mm; The center radius R of the raceway of the return device assembly composed of the return device base and the return device plug-in unit satisfies the relationship: R>1.5Dw; Where Dw is the ball diameter.

[0007] In a feasible implementation, the return device base further includes: a first component positioning ear; The first component positioning ear is located on the top of the return device base and away from the ball clearance groove; The first component positioning ear is provided with a first axial positioning protrusion on the surface of the return device base member close to the slot.

[0008] In a feasible implementation, the return device plug-in further includes: a second component positioning ear; The second component positioning ear is located at an end of the return device plug-in away from the locking protrusion and the relief protrusion; The second component positioning ear is provided with a second axial positioning protrusion close to the return device plug-in and facing away from the relinquishing convex circle.

[0009] In a feasible implementation, the first axial positioning protrusion and the second axial positioning protrusion are both point-shaped protrusions; The first axial positioning protrusion and the second axial positioning protrusion form an axial interference fit of 0.1mm-0.3mm with the inner hole of the nut using an elastic retaining ring.

[0010] In a feasible implementation, when the return device base and the return device plug-in are combined, the first axial positioning protrusions and the second axial positioning protrusions are orthogonally distributed; The first component positioning ear located on the return device base contacts the axial inner wall of the nut; the second component positioning ear located on the return device plug-in contacts the radial inner wall of the nut; The first axial positioning protrusion and the second axial positioning protrusion form a bidirectional constraint structure to limit the radial displacement and angular deflection of the return device assembly.

[0011] In a feasible implementation, the return device base further includes a first return flow positioning column, and the return device plug-in further includes a second return flow positioning column; The first reflux positioning column is fixed to one end of the bottom of the return device base away from the clamping groove and close to the ball clearance groove, and the first reflux positioning column is a columnar protrusion; The second reflux positioning column is fixed to the bottom of the return device plug-in on a side away from the second component positioning ear; The axial direction of the first reflux positioning column is parallel to the assembly direction of the second reflux positioning column. When the return device base and the return device plug-in are combined, the first reflux positioning column and the second reflux positioning column are combined and inserted into the nut reflux hole countersunk groove.

[0012] In a feasible implementation, the return device plug-in further includes: a retaining ring limiting wall; The retaining ring limiting wall is fixed to the middle part of the return device plug-in at one end facing away from the clamping protrusion, and the retaining ring limiting wall is a wall-shaped structure perpendicular to the mounting surface; When the return device base member is combined with the return device plug-in unit, the retaining ring limiting wall contacts the outer ring of the elastic retaining ring for the external hole.

[0013] In a feasible implementation, the guide convex circle is a cylindrical protrusion, and the guide convex circle is fixed to an end of the return device base member close to the top and away from the clamping groove; When the return device assembly is assembled on the lead screw, the guide cam extends into the spiral channel of the lead screw, and the axis of the guide cam is perpendicular to the axis of the lead screw.

[0014] In a feasible implementation, a disassembly slot is provided on the top of the return device plug-in; The disassembly groove is arranged at one end of the return device plug-in away from the yield convex circle. The disassembly groove is a groove structure that passes through the surface of the return device plug-in. The depth direction of the disassembly groove is perpendicular to the installation surface of the return device plug-in.

[0015] The present application provides a ball screw pair with a combined return device, which achieves higher transmission efficiency and longer service life through optimized structural design. The combined return device is designed with step-by-step installation and disassembly, and the end plug nut is more convenient to disassemble and assemble on the end of the non-through screw, while meeting the use scenarios with strict dust protection requirements at the end. The combination of the ball clearance groove and the return device groove wall provides sufficient installation space for the balls, solving the interference problem of the balls during assembly and disassembly. The center radius size of the return device assembly raceway ensures smooth ball return and reduces operating noise. The design of the component positioning ear and axial positioning protrusion ensures that the return device assembly is accurately positioned on the nut and is stable and reliable, and maintains an appropriate interference with the elastic retaining ring for the hole, effectively avoiding axial movement and vibration noise. The overall design not only increases the number and stability of ball installation, but also significantly reduces the impact noise of the ball circulation, extends the operating life of the ball screw pair, and optimizes the ball installation space, facilitating maintenance and repair, showing a wide range of application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings are incorporated into and constitute a part of this specification, illustrate embodiments consistent with the implementation of the present invention, and together with the description, serve to explain the principles of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the implementation of the present invention. For those skilled in the art, other drawings can be derived from these drawings without inventive effort.

[0017] Figure 1 1 is a schematic structural diagram of a ball screw pair with a combined return device exemplarily shown in an embodiment of the present application; Figure 2 1 is a schematic diagram of an installation method of a return device base member and a ball installation space formed after installation, as exemplified in an embodiment of the present application; Figure 3 1 is a front structural diagram of a return device base member exemplarily shown in an embodiment of the present application; Figure 4 1 is a schematic diagram of the back structure of the return device base member exemplarily shown in an embodiment of the present application; Figure 5 1 is a front structural diagram of a return device plug-in exemplarily shown in an embodiment of the present application; Figure 6 1 is a schematic diagram of the back structure of the return device plug-in exemplarily shown in an embodiment of the present application; Figure 7 1 is an exploded schematic diagram of a return device assembly exemplarily shown in an embodiment of the present application; Figure 8 1 is a schematic diagram of the assembly of a return device assembly exemplarily shown in an embodiment of the present application; Figure 91 is a schematic diagram of a raceway of a return device assembly exemplarily shown in an embodiment of the present application; Figure 10 Schematic diagram of the raceway radius of the return device assembly exemplarily shown in an embodiment of the present application; Figure 11 Schematic diagram of the internal state of the return device assembly in the ball screw pair, exemplarily shown in an embodiment of the present application; Figure 12 This is a schematic diagram of an embodiment of the present application showing an example of a ball being installed in a ball screw pair.

[0018] Description of the accompanying drawings: 10-returner assembly; 20-nut; 30-screw; 1-returner base; 2-returner plug-in; 11-slot; 12-guide cam; 13-ball clearance groove; 14-first return positioning column; 15-first component positioning ear; 16-first axial positioning protrusion; 21-slot; 22-clearance cam; 23-second component positioning ear; 24-second axial positioning protrusion; 25-retaining ring limiting wall; 26-disassembly groove; 27-second return positioning column; 201-returner groove; 202-ball installation space; 203-raceway. DETAILED DESCRIPTION

[0019] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that the present invention will be more comprehensive and complete and to fully convey the concepts of the example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to provide a thorough understanding of the implementation of the example embodiments of the present invention.

[0020] Traditional ball screw pairs feature an integral return element. Due to the return element's convex guide, the nut must be installed first. The nut is then filled with balls using a guide sleeve, and the nut assembly is then threaded onto the ball screw. This requires a through raceway at the end of the screw. For applications with strict dust protection requirements at the screw end, this can only be addressed with subsequent sleeve insertion, making it difficult to guarantee accuracy and rigidity. Currently, there are modular return element assemblies on the market that address the issue of blocked screw ends, but these lack space for ball installation, requiring the balls to be installed first and then the return element. This can lead to interference with the installation of only 2-3 balls, resulting in high ball circulation noise and impact, impacting the operating life.

[0021] To solve the above problems, refer to Figures 1-8 As shown, this embodiment provides a ball screw pair with a combined return device, including a screw 30, a nut 20 and a return device assembly 10.

[0022] The surface of the lead screw 30 is provided with a spiral groove, which is located in the middle of the lead screw 30. The nut 20 is sleeved on the lead screw 30, and its inner wall is provided with two return grooves 201, which are respectively provided at both ends of the nut 20 and communicate with the spiral groove.

[0023] The returner assembly 10 consists of a separate returner base 1 and a returner insert 2. There are two returner inserts, positioned opposite each other in the returner slot 201 at either end of the nut 20. The returner base 1 includes a latching slot 11, a ball bearing clearance groove 13, and a guide protrusion 12. The latching slot 11 is located at the top of the returner base 1. The ball bearing clearance groove 13 is located near and connected to the latching slot 11. The guide protrusion 12 is fixed to the side of the returner base 1 facing away from the latching slot 11. The returner insert 2 includes a latching protrusion 21 and a clearance protrusion 22. The latching protrusion 21 is located in the middle of the returner insert 2, and the clearance protrusion 22 is fixed to the bottom end of the returner insert 2, away from the latching protrusion 21.

[0024] The lead screw 30, as the core driving component, contacts the balls through a spiral groove and supports the nut 20, converting rotational motion into linear motion. The nut 20, which fits over the lead screw 30, serves as the actuator. Its interior forms a kinematic connection with the lead screw 30 via the balls, and its exterior is connected to equipment such as a workbench to achieve linear motion. The returner assembly 10, mounted within the nut 20, guides the balls in circulation, forming an infinitely looped closed path. The retaining groove 11 of the returner base 1 mates with the retaining protrusion 21 of the returner insert 2, enabling removable fixation. The ball clearance groove 13 and the wall surface of the returner groove 201 of the nut 20 form a ball installation space 202, facilitating ball assembly and passage. The guide protrusion 12 extends into the spiral groove of the lead screw 30, ensuring smooth ball rolling and minimizing impact noise. The retaining protrusion 21 of the returner insert 2 mates with the retaining groove 11 of the returner base 1, forming a ball raceway 203 when the returner insert 2 and returner base 1 are assembled. The axes of the raceways 203 of the two opposing return assembly assemblies 10 on the nut 20 are collinear, and combined with the spiral groove on the lead screw 30, a ball channel capable of continuous circulation is formed.

[0025] As the lead screw 30 rotates, the inclined surface of the spiral raceway forces the balls to roll. The balls move forward along the spiral raceway, simultaneously pushing the nut 20 to move linearly along the axial direction of the lead screw 30. When the balls reach the end of the nut 20, they enter the channel of the return assembly 10. The return assembly 10 guides the balls around the lead screw 30, looping back to the starting end of the raceway 203 and re-entering the load zone, ensuring continuous transmission.

[0026] Traditional integral returners require a through raceway at the end of the lead screw 30 due to the guide convexity to ensure smooth insertion of the nut 20, making it difficult to meet the requirements for dust protection at the end. This solution, through the combined returner assembly 10, solves the problem of convenient assembly and disassembly of the end plug nut 20 on the lead screw 30 with a non-through end, while also meeting the requirements for dust protection at the end.

[0027] The ball screw pair with a combined return device in this embodiment has effectively solved the technical problems existing in traditional integral return devices and existing combined return devices through structural design improvements. The design of the combined return device assembly 10 allows the nut 20 to be assembled without relying on the end of the screw 30 to pass through the raceway, adapting to the use scenario with strict dust protection requirements at the end, while avoiding the problem of reduced accuracy and rigidity caused by the sleeve treatment. The matching structure of the detachable return device base 1 and the nut return device groove 201 forms an independent ball installation space 202, which solves the problem of insufficient installation of balls due to interference during the assembly process, ensures the integrity of the number of balls, and thus improves transmission efficiency and operational stability. In addition, the setting of the guide cam 12 and the yield cam 22 optimizes the rolling path of the balls, reduces the impact and noise during the ball circulation process, and further improves the service life of the ball screw pair. The detachable fixing method of the slot 11 and the cam 21 not only enhances the assembly convenience of the return device assembly 10, but also provides convenience for subsequent maintenance and inspection. The overall structure improves the convenience of disassembly and assembly of the end plug ball screw pair when the end is not through, ensuring the smoothness and reliability of operation, while meeting the strict requirements of dust prevention at the end and improving the applicability of the product.

[0028] In some embodiments of the present application, reference Figure 9 and Figure 10 As shown, during assembly, the return device base 1 is first placed, and the ball clearance groove 13 on the return device base 1 and the wall surface of the nut return device groove 201 form a clearance groove larger than the diameter size of 0.15mm-0.2mm, which is convenient for the ball assembly to pass through. For example, if the ball diameter is 5mm, the ball installation space 202 has a diameter range of 5.15mm-5.2mm. This size ensures that the ball can pass smoothly during the assembly and disassembly process. After the ball assembly is completed, the return device plug-in 2 is inserted. At this time, the channel for ball installation is closed, and the partial raceways of the return device base 1 and the return device plug-in 2 are combined into a complete ball raceway 203. The ball runs in the raceway 203, and the center radius R of the raceway 203 satisfies the relationship: R>1.5Dw, where Dw is the ball diameter. Taking the ball diameter of 5mm as an example, the center radius R of the raceway 203 needs to be greater than 7.5mm.

[0029] The large center radius of raceway 203 ensures a consistent ball trajectory within the return element 10, reducing friction and impact during movement and increasing the ball screw's DN value (the product of rotational speed and lead). As the balls move through the ball screw, they smoothly pass through this channel and achieve reverse motion.

[0030] During the implementation process, during assembly, the return device base 1 is first fixed to the return device groove 201 of the nut 20, and then the balls are placed in the ball clearance groove 13 on the return device base 1. The balls enter the spiral channel from the ball clearance groove 13. After the required number of balls are loaded, the return device plug-in 2 is inserted, so that the return device base 1 and the return device plug-in 2 cooperate to form a complete raceway 203, and finally form a closed circulation system with the spiral channel of the screw 30, realizing the full process requirements of smooth assembly, stable circulation and efficient return of the balls, and ensuring the normal operation of the ball screw pair.

[0031] This solution further improves the performance of the returner assembly 10 by precisely controlling the diameter of the ball mounting space 202 and the center radius of the returner assembly's raceway 203. The rational design of the ball mounting space 202 diameter prevents ball jamming during assembly and disassembly; accurate control of the center radius of the returner assembly's raceway 203 ensures smooth and stable ball movement, reduces friction and impact, and improves the overall performance of the ball screw assembly. By optimizing the design of the ball mounting space 202 diameter and the center radius of the returner assembly's raceway 203, the applicability and reliability of the returner assembly 10 are enhanced, meeting the high performance requirements of ball screws for high-end equipment.

[0032] In some embodiments of this application, continue to refer to Figure 1 As shown, the return device base 1 also includes a first component positioning ear 15, which is located at the top of the return device base 1 and away from the ball clearance groove 13; the first component positioning ear 15 is provided with a first axial positioning protrusion 16 on the surface of the return device base 1 having the card groove 11 close to the return device base 1, which is used to interference fit with an external component such as a nut 20 to prevent axial movement of the component.

[0033] During installation, the first assembly positioning lug 15 and the first axial positioning protrusion 16 engage with corresponding structures within the nut 20. When the returner base 1 is inserted into the returner groove 201 on the nut 20, the first assembly positioning lug 15 is located in the corresponding position of the returner groove 201 on the nut 20, and the first axial positioning protrusion 16 contacts the hole-use elastic ring fixed in the nut 20, forming an axial interference fit.

[0034] This embodiment ensures the axial positioning accuracy of the return mechanism base member 1 on the nut 20, avoiding operational noise caused by return mechanism vibration. The addition of the first component positioning lug 15 and the first axial positioning protrusion 16 further improves the positioning accuracy and stability of the return mechanism base member 1 on the nut 20.

[0035] The contact between the first assembly positioning lug 15 and the axial inner wall of the nut 20, as well as the interference fit between the first axial positioning protrusion 16 and the hole-mounting elastic ring, ensure the axial positioning reliability of the return mechanism base 1, effectively preventing axial movement and noise caused by vibration. This ensures the reliability and stability of the return mechanism assembly 10 in high-speed, high-precision motion applications, meeting the high performance requirements of ball screw pairs in high-end equipment.

[0036] In some embodiments of this application, continue to refer to Figure 3 As shown, the return device plug-in 2 also includes a second component positioning ear 23, which is located at the end of the return device plug-in 2 away from the locking protrusion 21 and the clearance protrusion 22; the second component positioning ear 23 is close to the side of the return device plug-in 2 facing away from the clearance protrusion 22 and is provided with a second axial positioning protrusion 24, which is used to interference fit with an external component such as a nut 20 to further prevent axial movement of the component.

[0037] During installation, the second assembly positioning lug 23 and the second axial positioning protrusion 24 engage with corresponding structures within the nut 20. When the returner insert 2 is assembled with the returner base 1, the second assembly positioning lug 23 is located in the corresponding position of the returner groove in the main body of the nut 20, and the second axial positioning protrusion 24 contacts the hole-use elastic ring fixed in the nut 20, forming an axial interference fit.

[0038] It can be understood that the second component positioning ear 23 and the second axial positioning protrusion 24 work together with the first component positioning ear 15 and the first axial positioning protrusion 16 to form an all-round positioning of the return assembly 10 on the nut 20, ensuring the stability and reliability of the return assembly 10.

[0039] This embodiment adds a second assembly positioning lug 23 and a second axial positioning protrusion 24, which complement the first assembly positioning lug 15 and the first axial positioning protrusion 16, thereby ensuring the full positioning of the return assembly 10 on the nut 20. This effectively prevents axial play and radial displacement of the assembly under high-speed, high-precision motion conditions, thereby improving the overall performance of the return assembly 10.

[0040] In some embodiments of the present application, the first axial positioning protrusion 16 and the second axial positioning protrusion 24 are both dot-shaped protrusions, respectively located on the surfaces of the first component positioning ear 15 and the second component positioning ear 23, near the center of the return device base 1 and the return device insert 2. These dot-shaped protrusions are used to form an axial interference fit of 0.1mm-0.3mm with the hole-use elastic ring fixed in the nut 20 to prevent axial movement of the components.

[0041] During assembly, when the returner base 1 and returner insert 2 are respectively inserted into the returner slot 201 on the nut 20, the first axial positioning protrusion 16 and the second axial positioning protrusion 24 respectively contact the hole-mounted circlip mounted in the nut 20, forming an interference fit. This dot-shaped protrusion ensures that even if the axial precision of the returner slot in the nut 20 varies by ±0.1mm, the axial interference between the positioning protrusion and the hole-mounted circlip is maintained within 0.1mm-0.3mm, effectively preventing axial movement of the returner assembly 10.

[0042] This embodiment further improves the axial positioning accuracy and stability of the return assembly 10 on the nut 20 by precisely controlling the shape and position of the first axial positioning protrusion 16 and the second axial positioning protrusion 24, as well as their matching relationship with the elastic retaining ring used in the inner hole of the nut 20. The design of the dot-shaped protrusions makes the fit more precise and reliable, while the control of the interference fit ensures that a stable axial positioning effect can be maintained even in the presence of machining errors. By further optimizing the design and matching relationship of the axial positioning protrusions, the axial positioning accuracy and stability of the return assembly 10 on the nut 20 are improved, axial movement and the resulting operating noise are effectively prevented, and the overall performance and service life of the ball screw pair are improved.

[0043] In some embodiments of the present application, when the returner base 1 and returner insert 2 are assembled, the first axial positioning protrusions 16 and the second axial positioning protrusions 24 are arranged orthogonally. Specifically, the first component positioning ears 15 on the returner base 1 contact the axial inner wall of the nut 20, while the second component positioning ears 23 on the returner insert 2 contact the radial inner wall of the nut 20. This orthogonal distribution allows the first axial positioning protrusions 16 and the second axial positioning protrusions 24 to form a bidirectional constraint structure, effectively limiting radial displacement and angular deflection of the returner assembly 10.

[0044] This bidirectional constraint structure precisely secures the position of the return assembly 10 on the nut 20. The orthogonal arrangement of the first axial positioning protrusions 16 and the second axial positioning protrusions 24 limits radial displacement and angular deflection of the return assembly 10, ensuring its secure positioning on the nut 20. This also reduces operating noise caused by assembly vibration and improves the overall performance of the ball screw assembly.

[0045] This solution forms a bidirectional constraint structure for the return element 10 through the orthogonally distributed first axial positioning protrusions 16 and second axial positioning protrusions 24. This structure effectively limits the radial displacement and angular deflection of the return element 10, improves the positioning accuracy and stability of the return element 10 on the nut 20, effectively prevents radial displacement and angular deflection, reduces operating noise, and improves the overall performance and service life of the ball screw pair.

[0046] In some embodiments of the present application, reference Figure 1 and Figure 4 As shown, the deflector base 1 also includes a first return locating post 14, and the deflector insert 2 also includes a second return locating post 27. The first return locating post 14 is fixed to the bottom of the deflector base 1, away from the retaining slot 11 and near the ball bearing clearance groove 13. The first return locating post 14 is a cylindrical protrusion that provides basic positioning support. The second return locating post 27 is fixed to the bottom of the deflector insert 2, away from the second component positioning ear 23, and together with the first return locating post 14, accurately positions the return system.

[0047] The axial direction of the first reflux positioning column 14 is parallel to the assembly direction of the second reflux positioning column 27. When the return device base 1 and the return device plug-in 2 are combined, the first reflux positioning column 14 and the second reflux positioning column 27 are combined and inserted into the reflux hole countersunk groove of the nut 20.

[0048] Specifically, the first reflux positioning post 14 ensures the stability of the return element 1 during assembly by maintaining its fixed axial orientation, and provides a reference for subsequent insertion of the nut 20 into the return hole countersunk groove. The second reflux positioning post 27 serves as a positioning component for the return element 2, assisting in aligning the return element 2 with the return element 1. When the return element 1 and return element 2 are assembled, the axial directions of their reflux positioning posts are parallel, ensuring that they can be smoothly combined and accurately inserted into the return hole countersunk groove of the nut 20, thereby achieving connectivity for the entire return system.

[0049] Specifically, during the installation process, the return device base 1 is first inserted into one side of the return hole countersunk groove of the nut 20 through the first return positioning column 14, and then the return device plug-in 2 is inserted into the other side along the same axial direction through the second return positioning column 27, ensuring the smooth transition of the ball during the reverse movement, reducing impact and noise, and improving the operating stability of the ball screw pair.

[0050] Because the two assembly directions are parallel, they can be quickly docked without additional adjustments during assembly. This linkage method effectively reduces the accumulation of errors during assembly, while improving overall assembly efficiency and resolving the assembly difficulties caused by inaccurate positioning in traditional structures.

[0051] It is understandable that in traditional ball screw designs, inaccurate return positioning or an uneven transition can cause excessive impact and noise to the balls during the return motion, thus affecting the overall performance of the ball screw. In this embodiment, the insertion of the first and second return positioning posts 14 and 27 ensures a smooth transition of the balls during the return motion, reducing impact and noise, and improving the operational stability and reliability of the ball screw. This design also simplifies the assembly process and enhances production efficiency.

[0052] In some embodiments of the present application, reference Figure 5 As shown, the returner insert 2 also includes a retaining ring retaining wall 25. This wall-like structure is fixed to the middle end of the returner insert 2, facing away from the retaining protrusion 21, and is perpendicular to the mounting surface. When the returner base 1 and the returner insert 2 are assembled, the retaining ring retaining wall 25 contacts the outer ring of the elastic retaining ring used in the external hole.

[0053] It is understandable that when the ball screw pair is working, the balls circulate at high speed along the spiral groove of the screw 30 and the ball channel in the nut 20, which will produce periodic impacts on the return device. Especially during acceleration and load changes, the impact will cause the components to vibrate, resulting in the ball circulation being stuck and the noise increasing. Long-term vibration will also aggravate the fatigue loss of components.

[0054] The retaining ring limiting wall 25 is a fixed wall structure on the return device plug-in 2 that is perpendicular to the mounting surface. Its function is to form a tight fit with the elastic retaining ring in the external hole. This tight fit can effectively absorb the energy caused by the impact of the ball, suppress the vibration of the return device, ensure that the return device is always correctly aligned with the raceway, and maintain the smoothness of the ball circulation.

[0055] Furthermore, when the ball screw pair is overloaded, the impact force exerted by the balls on the return mechanism assembly 10 increases dramatically, potentially causing the second assembly positioning lugs 23 on the return mechanism insert 2 to break or deform. If the second assembly positioning lugs 23 fail, the return mechanism insert 2 loses radial restraint and may move radially perpendicular to the axis of the screw 30, disrupting the alignment between the return mechanism and the raceway. This prevents the balls from properly entering or exiting the raceway, leading to jamming and damage to the screw 30 or nut 20.

[0056] The retaining ring limiting wall 25 serves as a second radial retaining structure on the return device insert 2. Its combination with the elastic retaining ring in the external hole replaces the failed second component positioning ear 23, limiting radial movement of the return device insert 2. Even if the second component positioning ear 23 is damaged, the retaining ring limiting wall 25 can still maintain the relative position of the return device base 1 and the return device insert 2, preventing the return device from failing to align with the raceway. This provides a second layer of protection for ball circulation and improves system reliability during overloads.

[0057] This embodiment plays a protective role in the return device structure of the ball screw pair by designing a retaining ring limiting wall 25. When the return device base 1 is combined with the return device plug-in 2, the retaining ring limiting wall 25 cooperates with the elastic retaining ring of the external hole to effectively suppress the vibration caused by external impact, thereby maintaining the stability of the return device. In addition, under overload conditions, the second component positioning ear 23 may be damaged due to excessive force, thereby causing radial movement of the return device. The presence of the retaining ring limiting wall 25 can provide an additional limiting function, forming a double protection for the return device, and preventing further damage or operation deviation caused by the failure of the second component positioning ear 23. The reliability and service life of the ball screw pair under complex working conditions are ensured.

[0058] In some embodiments of the present application, the guide cam 12 is a cylindrical protrusion, which is fixed at one end of the return device base 1 close to the top and away from the slot 11 to achieve docking with the spiral channel of the ball screw pair.

[0059] When the returner assembly 10 is assembled to the ball screw pair, the guide cam 12 extends into the spiral channel of the screw 30, with the axis of the guide cam 12 perpendicular to the axis of the screw 30. This effectively guides the ball's trajectory within the channel, preventing operational instability caused by deviation. Specifically, the guide cam 12 provides precise guidance, ensuring that the ball maintains a stable motion path during high-speed operation, thereby resolving the technical problem of ball jamming or wear caused by insufficient guidance.

[0060] Furthermore, when the balls roll along the ball path of the screw 30 to the returner area, the cylindrical structure of the guide convex circle 12 exerts a lateral restraining force on the balls, allowing them to move along a predetermined trajectory when entering the raceway 203 of the returner assembly 10, thus avoiding confusion in the ball's movement direction and ensuring stable operation of the ball screw assembly. The balls then complete the circulation loop through the opposing returner assembly 10.

[0061] This embodiment provides convenience for the disassembly and assembly of the end plug nut 20 on the screw 30 with a non-through end through the guide cam 12 of the return device base 1, while ensuring smooth operation and reliability, improving the applicability of the ball screw pair, meeting the use requirements of special scenarios such as strict dust prevention requirements at the end of the screw 30, and ensuring smooth operation and low noise characteristics.

[0062] In some embodiments of the present application, reference Figure 5 As shown, a disassembly groove 26 is provided on the top of the return device plug-in 2, and is provided at the end of the return device plug-in 2 away from the yield convex circle 22. The disassembly groove 26 is a groove structure that passes through the surface of the return device plug-in 2, and the depth direction of the disassembly groove 26 is perpendicular to the installation surface of the return device plug-in 2, which facilitates the installation and disassembly operations of the return device plug-in 2, thereby improving maintenance efficiency.

[0063] Specifically, the removal slot 26 facilitates disassembly of the return mechanism assembly 10. When disassembly and maintenance are required, any hook-shaped tool can be inserted into the removal slot 26 to conveniently remove the return mechanism insert 2. After removing the return mechanism insert 2, the balls are removed, and the return mechanism base 1 is rotated and removed. The nut 20 is then disengaged from the ball screw assembly. This avoids the time wasted and component damage associated with traditional disassembly methods.

[0064] This embodiment solves the problem of inconvenient disassembly of the conventional return device assembly 10 by adding a disassembly slot 26, thereby improving maintenance efficiency. The beneficial effect is that it reduces the risk of damage to the assembly during disassembly, extends the service life of the assembly, and also reduces maintenance costs and time costs.

[0065] In combination with the above embodiments, it can be seen that when the combined return device of the present application is used, the return device base is inserted into the return device groove on the nut. During the insertion process, ensure that the ball clearance groove at the bottom of the return device base and the return device groove wall on the nut form a ball installation space that is larger than the ball diameter of 0.15mm. Figure 11 As shown, the guide convex circle of the return device base member enters the ball screw pair channel. At this time, the first component positioning ear of the return device base member should be located at the corresponding position of the return device groove of the nut.

[0066] Reference Figure 12As shown, the ball installation space formed is then used to install the required number of balls to ensure that the balls can circulate smoothly between the ball screw and the return device base. Align the retaining protrusion of the return device plug-in with the retaining groove of the return device base to achieve a detachable interlocking connection, so that the return device plug-in is fixed to the return device base. The return device plug-in and the partial raceway of the return device base are combined to form a complete ball raceway to ensure smooth passage of the balls. A circlip is used to fit into the hole on the nut, so that the circlip has interference contact with the first and second axial positioning protrusions on the return device base and the return device plug-in, as well as the ball screw specifications, to ensure that the return device assembly is firmly and stably mounted on the nut.

[0067] When disassembly maintenance is required, use any hook-shaped tool to insert the disassembly slot on the top of the return unit plug-in and remove the return unit plug-in. After pouring out the balls, rotate and remove the return unit base to separate the nut from the ball screw.

[0068] In summary, the ball screw pair with a combined return device provided in this application achieves higher transmission efficiency and longer service life through optimized structural design. The combined return device adopts a step-by-step installation and disassembly design, making the end plug nut more convenient to disassemble and assemble on the end of the non-through screw, while also meeting the use scenarios with strict dust protection requirements at the end. The combination of the ball clearance groove and the return device groove wall provides sufficient passage space for the balls, solving the interference problem during assembly and disassembly. The center radius size of the return device assembly raceway ensures smooth ball return and reduces operating noise. The design of the component positioning ears and axial positioning protrusions ensures that the return device assembly is accurately positioned on the nut and is stable and reliable, maintaining an appropriate interference with the elastic ring used in the hole, effectively avoiding axial movement and vibration noise. The overall design not only increases the number and stability of ball installation, but also significantly reduces the impact noise of ball circulation, extends the operating life of the ball screw pair, and optimizes the ball installation space, facilitating maintenance and repair, showing a wide range of application prospects.

[0069] Those skilled in the art will readily conceive of other embodiments of the present disclosure after considering the disclosure of the specification and examples. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art that are not disclosed in this disclosure.

Claims

1. A ball screw pair with a combined return device, characterized in that: include: A lead screw (30) having a spiral groove on its surface, wherein the spiral groove is provided in the middle of the lead screw (30); A nut (20) is sleeved on the lead screw (30), and a return groove (201) is provided on the inner wall of the nut (20), wherein two return grooves (201) are provided at both ends of the nut (20), and the return grooves (201) are communicated with the spiral channel; The return device assembly (10) is composed of a return device base member (1) and a return device plug-in member (2) which are separately arranged; There are two returner assemblies (10), which are arranged oppositely in the returner slots (201) at both ends of the nut (20); The return device base (1) comprises: a clamping groove (11), a ball bearing clearance groove (13) and a guide convex circle (12); The clamping groove (11) is provided on the top of the return device base (1), the ball bearing clearance groove (13) is provided at one end close to the clamping groove (11) and is in communication with the clamping groove (11), and the guide convex circle (12) is fixed on the side of the return device base (1) facing away from the clamping groove (11); The return device plug-in (2) comprises: a locking convex portion (21) and a relief convex portion (22); The clamping protrusion (21) is arranged in the middle of the return device plug-in (2), and the relief convex circle (22) is fixed to an end of the bottom of the return device plug-in (2) away from the clamping protrusion (21); When the return device base (1) and the return device plug-in unit (2) are combined, the return device base (1) is inserted into the return device groove (201) of the nut (20), and the guide convex circle (12) extends into the spiral groove of the lead screw (30); The protrusion (21) of the return device plug-in (2) is inserted into the slot (11) to achieve detachable fixation of the return device base (1) and the return device plug-in (2), and the axes of the raceways (203) of the two opposite return device assemblies (10) are collinear to form a continuous ball channel.

2. The ball screw pair with a combined return device according to claim 1, characterized in that: The ball mounting space (202) formed by the cooperation between the ball yielding groove (13) and the wall surface of the return device groove (201) has a diameter greater than the ball diameter by 0.15 mm to 0.2 mm; The center radius R of the raceway (203) of the return device assembly formed by the return device base (1) and the return device plug-in (2) satisfies the relationship: R>1.5Dw; Where Dw is the ball diameter.

3. The ball screw pair with a combined return device according to claim 1, characterized in that: The return device base (1) further comprises: a first component positioning ear (15); The first component positioning ear (15) is located at the top of the return device base (1) and away from the ball clearance groove (13); A first axial positioning protrusion (16) is provided on the surface of the first component positioning ear (15) close to the return device base (1) having the clamping groove (11).

4. The ball screw pair with a combined return device according to claim 3, characterized in that: The return device plug-in (2) further includes: a second component positioning ear (23); The second component positioning ear (23) is located at an end of the return device plug-in (2) away from the locking protrusion (21) and the clearance protrusion (22); The second component positioning ear (23) is provided with a second axial positioning protrusion (24) on a side of the return device plug-in (2) facing away from the relief convex circle (22).

5. The ball screw pair with a combined return device according to claim 4, characterized in that: The first axial positioning protrusion (16) and the second axial positioning protrusion (24) are both point-shaped protrusions; The first axial positioning protrusion (16) and the second axial positioning protrusion (24) form an axial interference fit of 0.1mm-0.3mm with the inner hole of the nut (20) using an elastic retaining ring.

6. The ball screw pair with a combined return device according to claim 4, characterized in that: When the return device base (1) and the return device plug-in unit (2) are combined, the first axial positioning protrusion (16) and the second axial positioning protrusion (24) are orthogonally distributed; A first component positioning ear (15) located on the return device base (1) contacts the axial inner wall of the nut (20); a second component positioning ear (23) located on the return device plug-in (2) contacts the radial inner wall of the nut (20); The first axial positioning protrusion (16) and the second axial positioning protrusion (24) form a bidirectional constraint structure, limiting the radial displacement and angular deflection of the return device assembly (10).

7. The ball screw pair with a combined return device according to claim 4, characterized in that: The return device base (1) further includes a first return flow positioning column (14), and the return device plug-in (2) further includes a second return flow positioning column (27); The first reflux positioning column (14) is fixed to an end of the bottom of the return device base (1) away from the clamping groove (11) and close to the ball clearance groove (13), and the first reflux positioning column (14) is a columnar protrusion; The second reflux positioning column (27) is fixed to a side of the bottom of the return device plug-in (2) away from the second component positioning ear (23); The axial direction of the first reflux positioning column (14) is parallel to the assembly direction of the second reflux positioning column (27). When the return device base (1) and the return device plug-in unit (2) are combined, the first reflux positioning column (14) and the second reflux positioning column (27) are combined and inserted into the reflux hole countersunk groove of the nut (20).

8. The ball screw pair with a combined return device according to claim 1, characterized in that: The return device plug-in (2) further includes: a retaining ring limiting wall (25); The retaining ring limiting wall (25) is fixed to one end of the middle part of the return device plug-in (2) facing away from the clamping protrusion (21), and the retaining ring limiting wall (25) is a wall-shaped structure perpendicular to the installation surface; When the return device base (1) is combined with the return device plug-in unit (2), the retaining ring limiting wall (25) contacts the outer ring of the elastic retaining ring of the external hole.

9. The ball screw pair with a combined return device according to claim 1, characterized in that: The guide convex circle (12) is a cylindrical protrusion, and the guide convex circle (12) is fixed to one end of the return device base (1) close to the top and away from the clamping groove (11); When the return device assembly (10) is assembled on the lead screw (30), the guide cam (12) extends into the spiral channel of the lead screw (30), and the axis of the guide cam (12) is perpendicular to the axis of the lead screw (30).

10. The ball screw pair with a combined return device according to claim 1, characterized in that: The top of the return device plug-in unit (2) is provided with a disassembly slot (26); The disassembly groove (26) is provided at one end of the return device plug-in (2) away from the convex circle (22), and the disassembly groove (26) is a groove structure penetrating the surface of the return device plug-in (2), and the depth direction of the disassembly groove (26) is perpendicular to the installation surface of the return device plug-in (2).

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