Super finisher for the threaded part of a ball screw

Abstract

Summary of the Invention Super finisher for the threaded part of a ball screw The present invention relates to an apparatus (100) for superfinishing the threads of a ball screw. The apparatus comprises at least one holder (42, 52), a first interchangeable finishing tool (10) comprising a threaded portion in a working inner recess (10A), a second interchangeable finishing tool (15) comprising a working inner recess (15A) having a threaded portion, a polishing belt (20) reinforced with a slit film configured to pass continuously through the inner recesses (10A, 15A) and form an interface between the finishing tools (10, 15) and the threads (40A) of the ball screw (40), and at least one drive component (44a, 44b) configured to change the angle of the holder to enable linear movement of the finishing tools (10, 15) relative to the ball screw (40). An advantage is that during machining, the apparatus (100) supports the weight of the ball screw, thereby preventing protrusion of the ball screw.

Description

Technical Field

[0001] Field of the Invention Technology The present invention relates to the field of super finishing technology. In particular, it relates to the super finishing treatment of the threads of ball screws.

[0002] Definition of Terms The following terms used in the present invention are generally intended to have the meanings of the following definitions, unless otherwise indicated by the context. Ball screw: In the context of the present invention, the term "ball screw" means, without limitation, a ball screw as a mechanical linear actuator that converts a rotational motion into a linear motion with minimal friction. A ball screw is defined by a cylindrical body having a first end, a second end, and a helical raceway for balls in the longitudinal direction. Super finishing: In the context of the present invention, the term "super finishing" (ultra finishing) means, without limitation, a machining or polishing process that improves the surface roughness to obtain a more precise surface roughness by peeling only the skin layer (1 - 10 μm), thereby improving the anti-friction performance and reducing vibration to a certain extent.

[0003] Background of the Invention Technology A ball screw is a mechanical linear actuator that converts a rotational motion into a linear motion with minimal friction. Conventionally, ball screws have included a helical raceway for balls and a screw shaft that functions as a precision screw. Generally, ball screws are used for automotive steering systems and motion transmissions in machine tools.

[0004] In its manufacture, ball screws require a super-finishing treatment after heat treatment. Conventional finishing methods for ball screws involve manual / semi-automatic processes that are unreliable due to human intervention. For example, ball screws have been manually polished using various abrasives, precision machining, tool grinding methods, and other similar methods. However, using these conventional finishing methods makes the ball screw susceptible to deformation or bending due to its own weight and the forces generated during the machining process. As a result, the threads of the ball screw become uneven in their finished surface, hindering optimal performance. Furthermore, conventional super-finishing methods require a separate attachment to support the weight of the ball screw, which interferes with the machining process. Therefore, there is a need to provide a super finisher for ball screw threads that overcomes the aforementioned disadvantages.

[0005] Purpose of the invention Some of the objectives of the present invention can be adequately expressed by at least one example described herein, which is as follows: One objective of the present invention is to provide a super finisher for the threaded portion of a ball screw. Another object of the present invention is to provide a device for supporting the weight of a ball screw during superfinishing or machining. Another object of the present invention is to provide a device that supports a ball screw while simultaneously performing finishing work on the screw. Another objective of the present invention is to provide a simple and economical device. Another object of the present invention is to provide a device that shortens the setup time of a machine. Other objectives and advantages of the present invention will become even clearer from the following description, which is not intended to limit the scope of the invention.

[0006] summary The present invention provides a super finisher for the threads of a ball screw. The ball screw is defined by a cylindrical body having a first end, a second end, and a longitudinally helical raceway for the ball. The device comprises at least one holder for detachably holding the ball screw, a first interchangeable finishing tool having a first inner recess defining a threaded portion complementing the threads of the ball screw, and a second interchangeable finishing tool having a second inner recess defining a threaded portion complementing the threads of the ball screw. The first and second inner recesses are configured to contact each other during operation to form a hollow cylindrical space, and are configured to clamp and secure the working cylindrical portion of the ball screw within this hollow space. A polishing belt reinforced with a slit film is received by the working portions of the first interchangeable finishing tool and the second finishing tool, passes continuously within the circumferential surface of the hollow space, and interfaces between the finishing tool and the processing cylindrical body portion containing the ball screw, and is configured to allow at least one drive component to change the angle of the holder, thereby changing the angle of the ball screw attached to this drive component relative to the threaded portion of the inner recess. The ball screw is held at or near the center of the holder to allow rotational movement. The first interchangeable finishing tool, the second interchangeable finishing tool, the abrasive belt, and the arm are mounted on sliding support components (54, 56) (longitudinal slides) and move along the longitudinal direction of the threaded portion of the ball screw by complementary screws on the first and second interchangeable finishing tools and screws on the ball screw. The first and second finishing tools and the abrasive belt enable super-finishing treatment of the threads of the ball screw.

[0007] In one embodiment, the first interchangeable finishing tool and the second interchangeable finishing tool are defined by a "C" shaped body.

[0008] In one embodiment, the device includes a pair of arms. Each arm is configured to mount a first interchangeable finishing tool and a second interchangeable finishing tool. The arms are swivel-mounted to the device and support the weight of the ball screw in the operating configuration of the device.

[0009] In one embodiment, the pivot axis of the arm and the axis passing through the center of gravity of the ball screw are parallel in the operating configuration of the device. In another embodiment, the pivot axis of the arm and the axis passing through the center of gravity of the ball screw are on the same plane in the operating configuration of the device. In yet another embodiment, the axis (C) passing through the center of gravity is perpendicular to the axis (M) extending perpendicularly from the pivot axis (P).

[0010] In one embodiment, the operating configuration of the device is configured such that the finishing tool slides back and forth to move the ball screw longitudinally within the hollow section and perform the finishing process on the ball screw.

[0011] In one embodiment, the abrasive material reinforced with a slit film is a nonwoven abrasive tape. The thickness of the abrasive tape reinforced with the slit film ranges from 0.2 mm to 1.0 mm.

[0012] In one embodiment, the drive component is configured to enable alternating clockwise and counterclockwise movement of the ball screw within the recess, and to perform a super-finish treatment on the ball screw threads by causing the first and second finishing tools to reciprocate in the longitudinal direction of the forward and backward movements.

[0013] In one embodiment, the polishing tape reinforced with a slit film has a pitch equal to the pitch defined in the threaded portion of the inner recess of the finishing tool and the pitch defined in the threads of the ball screw. In one embodiment, the device incorporates a gear-driven indexing mechanism. The indexing mechanism is configured to control the movement of a polishing tape reinforced with a slit film between the inner recess of the finishing tool and the effective portion of a ball screw. [Brief explanation of the drawing]

[0014] Brief description of the attached drawing: The apparatus of the present invention for performing a super-finish treatment on the threads of a ball screw will be described below with reference to the accompanying drawings: [Figure 1] Figure 1A shows a conceptual diagram of a conventional device that performs a super-finish treatment on the threads of a ball screw. [Figure 2] Figure 2 shows an equiscale view of a conventional ball screw finisher, including the ball screw as part of the finishing tool. [Figure 3] Figure 3 shows an equal-scale view of the finishing tools used in the conventional apparatus shown in Figures 1 and 2. [Figure 4] Figure 4 shows a conceptual diagram of a replaceable finishing tool of the present invention for a super-finishing device for ball screws according to the present invention, with a ball screw mounted on it, according to an embodiment of the present invention. [Figure 5] Figure 5 shows a conceptual diagram of the interchangeable finishing tool of the present invention for the apparatus according to the present invention, attached to a gripping means, according to an embodiment of the present invention. [Figure 6] Figure 6 shows a conceptual diagram of an abrasive material reinforced with a slit film in a corresponding recess of a replaceable finishing tool according to the present invention, in accordance with an embodiment of the present invention. [Figure 7] Figure 7 shows a conceptual arrangement of a replaceable finishing tool and an abrasive material reinforced with a slit film in a corresponding recess of a ball screw in the apparatus according to the present invention, according to an embodiment of the present invention. [Figure 8] Figure 8 shows a conceptual diagram of an arm equipped with a grasping means and an actuator, according to an embodiment of the present invention. [Figure 9]Figure 9 shows an isometric view of an arm with at least one holder in which a ball screw is mounted and a replaceable finishing tool attached thereto, according to an embodiment of the present invention. [Figure 10] Figure 10 shows an isometric view of a super finisher in which a ball screw is mounted between the centers of a headstock and a tailstock, showing each operating direction示例性 of both the ball screw and the finishing tool, according to the present invention. [Figure 11] Figure 11 shows a plan view of a super finisher in which a ball screw is mounted between the centers of a headstock and a tailstock along a pair of drive components, according to the present invention.

[0015] List of reference numerals 100' Conventional device for performing super finishing 100 Device according to the present invention for performing super finishing on the screw of a ball screw 10 First replaceable finishing tool 10A First recess of the first replaceable finishing tool 15 Second replaceable finishing tool 15A Second recess of the second replaceable finishing tool 20 Polishing belt reinforced with a slit film 30 Gripping means 40 Ball screw 40A Screw of the ball screw 42 Headstock 44a, 44b Drive components 46 Arm 48 Cylindrical hollow portion 50 Actuator 52 Tailstock 54 Long slide 56 Cross slide P Pivot axis of the arm C Axis passing through the center of gravity of the ball screw

[0016] Detailed description of the invention Embodiments of the present invention will be described below with reference to the accompanying drawings. The embodiments described herein will allow a person skilled in this art to fully and completely grasp the scope of the present invention. Numerous details relating to individual components will allow for a complete understanding of the embodiments of the present invention. It will be clear to a person skilled in this art that the details described in the embodiments cannot be interpreted as limiting the scope of the present invention. Some embodiments do not describe in detail well-known processes, well-known apparatus structures, or well-known techniques.

[0017] In this invention, the terms used herein are used solely to describe specific embodiments and should not be considered to limit the scope of the invention. Nouns used herein include multiple things unless the context requires them to be treated as singular. Terms such as "consisting of," "including," "composed of," and "consisting of" are transitional phrases that may include other things and thus define the existence of functions, features, elements, modules, units, or components described herein, but do not exclude the existence or addition of other functions, elements, components, or groups of components.

[0018] When an element is described as “attached,” “engaged,” “connected,” or “linked” to another element, this includes cases where it is directly attached, engaged, connected, or linked to the other element. The term “or” as used herein includes any combination of one or more of the relevant list elements.

[0019] The terms "first," "second," "third," etc., can only be used to distinguish one element or component, region, layer, or section from other components, regions, layers, or sections, and therefore cannot be construed as limiting the scope of the invention. Unless expressly indicated in the invention, the terms "first," "second," "third," etc., do not imply any particular permutation or order.

[0020] In this invention, similar terms such as "bottom," "inside," "outside," "lower side," "below," "down," "up," and "top" may be used to describe the positional relationship between different elements shown in the figure.

[0021] Ball screws require a post-heat treatment and superfinishing process during manufacturing. Conventional apparatus (100') and methods for performing finishing treatment on ball screws (40) typically involve manual or semi-automatic processes, which are unreliable due to human intervention. Examples include manually polishing ball screws using various abrasives, precision machining, tool grinding methods, and other similar methods. Figure 1A shows a conceptual diagram of a conventional finisher for ball screws, Figure 2 shows an equiscale view of a ball screw alongside finishing tools using conventional apparatus for finishing ball screws, and Figure 3 shows an equiscale view of finishing tools used in the conventional apparatuses of Figures 1 and 2.

[0022] However, using conventional methods, ball screws are prone to deformation or bending due to their own weight and the forces generated during the machining process. As a result, the threads of the ball screw have a rough surface finish, impairing optimal performance. Furthermore, conventional methods required a separate attachment, which interfered with the machining process, to support the weight of the ball screw during the superfinishing process.

[0023] To address the aforementioned challenges, the present invention provides an apparatus (100) for performing a superfinish treatment on the threads of a ball screw. The apparatus (100) is manufactured with precision ingenuity to improve the surface quality and precision of the ball screw threads, which are essential for the efficient functioning of mechanical systems in which ball screws are used. The present invention will be described with reference to Figures 4 to 9. The ball screw (40) is defined by a cylindrical body with a first end, a second end, and a longitudinal helical raceway for the balls.

[0024] The apparatus (100) comprises at least one holder (42, 52), a first interchangeable finishing tool (10), a second interchangeable finishing tool (15), a polishing tape belt (20) reinforced with a slit film, and at least one drive component (44a, 44b). Figure 4 shows a conceptual diagram of the interchangeable finishing tool of the present invention for a ball screw apparatus according to the present invention for performing a superfinish treatment on the threads of a ball screw. Figure 5 shows a conceptual diagram of the interchangeable finishing tool of the present invention for the apparatus according to the present invention, mounted on a gripping means.

[0025] The holders (42, 52) are configured to hold the ends, i.e., the first and second ends of the ball screw (40), so that they can move. In one embodiment, the first end is attached to the headstock of the device and the second end is attached to the tailstock (52). Thus, the ball screw (40) is held between the centers of the holders (42, 52), allowing for rotational movement. The first interchangeable finishing tool (10), the second interchangeable finishing tool (15), the abrasive belt (20), and the arm are mounted on a sliding carriage including a longitudinal side (54) and a cross slide (56) along the longitudinal direction of the threaded portion of the ball screw (40) thanks to the complementary threads of the first interchangeable finishing tool (10) and the second interchangeable finishing tool (15) and the thread of the ball screw (40). The complementary threads of the ball screw (40) and the finishing tools (10, 15) allow the finishing tools (10, 15) to move from one end to the other of the ball screw (40) parallel to the sliding bed. In the operating configuration of the device (100), the operation of the finishing tools (10, 15) on the bed makes it possible to super-finish the threads (40A) of the ball screw (40) to the desired length.

[0026] In one embodiment, a ball screw (40) is held between the centers. One end is clamped by a headstock (42) and the other end by a pneumatic tailstock (52).

[0027] Furthermore, the apparatus (100) is equipped with divisible arms. These arms are configured to separate into two independent arms (46) during the process to hold and support the operating cylindrical portion of the ball screw (40). Each arm (46) is actuated by an actuator (50) and is configured to attach at least one gripping means (30). These arms (46) are swivelably mounted to the apparatus (100), and the pivot axis (P) is parallel to or coplanar with the axis (C) passing through the center of gravity of the ball screw (40). In this configuration, the weight of the ball screw (40) is supported, and high-precision control is possible throughout the superfinishing process.

[0028] In one embodiment, each arm (46) separates vertically during operation, optimizing the required space and utilizing the vertical space of the device (100). In one embodiment, the grasping means (30) is slidably attached to or fastened to the operational end of each arm (46).

[0029] In one embodiment, the arm (46) is rotatably attached to the device (100) (P), thereby supporting the weight of the ball screw (40) in the operating configuration of the device (100).

[0030] The gripping means (30) is defined by an opening therein for receiving the finishing tool. The finishing tool is divided into a first interchangeable finishing tool (10) and a second interchangeable finishing tool (15), each part defined by a "C" shaped body structure having a first recess (10A) and a second recess (15A). The first working recess (10A) and the second working recess (15A) of each interchangeable finishing tool (10, 15) are configured with threads.

[0031] In one embodiment, the threaded portions in the recesses (10A, 15A) of the first and second interchangeable finishing tools (10, 15) complement the threads (40A) of the ball screw (40). The first and second inner recesses (10A, 15A) come into contact during operation to form a hollow cylindrical space (48), and the working cylindrical portion of the ball screw (40) is clamped and fixed within the hollow space (48).

[0032] In one embodiment, the first and second inner recesses (10A, 15A) of the first interchangeable finishing tool (10) and the second interchangeable finishing tool (15) are configured to partially cover the working cylindrical portion of the ball screw (40) in the operating configuration of the device (100).

[0033] During machining, the first interchangeable finishing tool (10) and the second interchangeable finishing tool (15) cover a portion of the working cylindrical part of the ball screw (40) and support the ball screw (40). An advantage is that it prevents the ball screw (40) from protruding due to its own weight or the forces generated during machining or superfinishing.

[0034] In one embodiment, the axis (C) passing through the center of gravity is perpendicular to the axis (M) that extends perpendicularly from the pivot axis (P).

[0035] The device consists of an abrasive belt (20) reinforced with a slit film. The abrasive belt (20) is received by the moving parts of the first interchangeable finishing tool (10) and the second finishing tool (15), and is configured to pass continuously through the circumferential surfaces of the first and second inner recesses (10A, 15A) of the first and second finishing tools (10) and the second finishing tool (15). This allows the slit film to form an interface between the threads in the recesses (10A, 15A) of the interchangeable finishing tools (10, 15) and the threads (40A) of the ball screw (40) during machining or superfinishing. The slit film has a constant pitch along its width. This pitch defined on the abrasive belt (20) reinforced with the slit film is equal to the pitch defined in the threads in the inner recesses (10A, 15A) of the finishing tools and the pitch defined in the threads (40A) of the ball screw (40). Figure 6 shows a conceptual diagram of an abrasive belt reinforced with a slit film that fits into corresponding recesses in a replaceable finishing tool of the apparatus according to the present invention, and Figure 7 shows a conceptual connection between the replaceable finishing tool of the apparatus according to the present invention and an abrasive belt reinforced with a slit film that fits into corresponding recesses in a ball screw, according to an embodiment of the present invention.

[0036] In one embodiment, a slit film-reinforced abrasive belt (20) is configured to be driven by gears driven by a gear-driven indexing mechanism at an interface formed between the threaded portion of interchangeable finishing tools (10, 15) and the thread (40A) of a ball screw (40). The indexing mechanism controls the movement of the slit film-reinforced abrasive belt (20)b between the working cylindrical portion, which includes the first and second inner recesses (10A, 15A) of the finishing tools (10, 15) and the thread (40A) of the ball screw (40).

[0037] In one embodiment, the polishing belt (20) reinforced with a slit film is a nonwoven polishing belt.

[0038] In one embodiment, the depth of each slit in the continuous polishing belt (20) reinforced with a slit film is equal to the difference between the larger and smaller diameters of the thread (40A) of the ball screw (40) in the operating configuration of the device (100).

[0039] In one embodiment, the thickness of the polishing belt (20) reinforced with a slit film is in the range of 0.2 mm to 1.0 mm.

[0040] Furthermore, the device (100) incorporates at least one drive component (44a, 44b). The drive component (44a, 44b) is configured to connect to the holder (42) during machining, and is configured such that by changing the angle of the holder (42), the angle of the ball screw (40) attached to the drive component can be changed relative to the threaded portions of the first and second recesses (10A, 15A) of the first and second interchangeable finishing tools (10, 15). A first interchangeable finishing tool (10), a second interchangeable finishing tool (15), and a polishing belt (20) move along the longitudinal direction of the threaded portion of the ball screw (40), and because there are complementary threads on the first interchangeable finishing tool (10) and the second interchangeable finishing tool (15) and the threads of the ball screw (40), the first finishing tool (10), the second finishing tool (15), and the polishing belt (20) enable super-finishing of the threads (40A) of the ball screw (40), thereby super-finishing the ball screw to the required length. Figure 9 shows an equiscale view of an arm with at least one holder and interchangeable finishing tools in which a ball screw is mounted, according to an embodiment of the present invention. Figure 8 shows a conceptual diagram of a gripping means and actuator.

[0041] In one embodiment, the device (100) has only one drive component (44a, 44b) that, in the operating configuration of the device (100), is configured to change the angle of a ball screw (40) and drive a polishing belt (20) which is reinforced with a slit film.

[0042] In another embodiment, the device (100) is equipped with two drive components (44a, 44b), one of which is coupled to a cross slide (56) and the other to a long slide (54). The two drive components (44a, 44b) are configured to rotate at two different speed ratios.

[0043] In another embodiment, the drive components (44a, 44b) facilitate the alternating clockwise and counterclockwise movement of the ball screw (40) within the recesses (10A, 15A), and are configured to perform a superfinish treatment on the thread (40A) of the ball screw (40) by causing the first finishing tool (10) and the second finishing tool (15) to reciprocate in the longitudinal direction of the forward and backward movements. Figure 9 shows an equiscale view of an arm with at least one holder (42) in which the ball screw is mounted and interchangeable finishing tools (10, 15).

[0044] Figure 10 shows a superfinisher featuring a ball screw (40) positioned between the centers of the holder, i.e., the headstock (42) and tailstock (52). The figure further shows the direction of motion of the ball screw (40) as a clockwise or counterclockwise angular displacement, and the longitudinal direction of motion of the finishing tools (10, 15) moving along the threaded portion (40A) of the ball screw (40). This configuration ensures precise control of the finishing process and improves the surface quality of the ball screw (40). The alignment and motion dynamics are configured to optimize the superfinishing treatment of the ball screw (40).

[0045] Figure 11 shows a plan view of the super finisher, which also shows a pair of drive components along with a ball screw mounted between the centers of the headstock and tailstock, as disclosed herein. The pair of drive components consists of a first drive component that works in conjunction with the long slide (54) and a second drive component that works in conjunction with the cross slide (56) of the device (100).

[0046] The foregoing description of embodiments is for illustrative purposes only and is not intended to limit the scope of the invention to that description alone. Individual components of a particular embodiment are generally not limited to that particular embodiment and are interchangeable. Such variations cannot be considered different from the invention, and all such variations are considered to be within the scope of the invention.

[0047] Technological superiority and economic significance The present invention described above has several technical advantages, including, but is not limited to, the realization of a super finisher for the threaded portion of a ball screw: - It supports the weight of the ball screw during machining, thereby preventing the ball screw from bending during the super-finishing process. • Perform finishing work on the threaded portion while the ball screw is being supported. • Simple and economical, and further • Machine setup time is reduced.

[0048] The details of the present invention and its various features and advantages are described below by reference to examples that do not limit their scope. Descriptions of established existing components and processing techniques are omitted to avoid unnecessarily complicating the understanding of the examples of the present invention.

[0049] The descriptions of the above-mentioned specific embodiments sufficiently clarify the general nature of the embodiments of the present invention. Therefore, by applying the existing knowledge, the above-mentioned specific embodiments can be modified or adapted for different uses without deviating from the above-mentioned general concepts. Accordingly, any adaptation / modification should and is intended to be understood as equivalent to and within the scope of the embodiments of the present invention. The usage of phrases and terms used herein is for illustrative purposes only and not for limitation. Accordingly, the embodiments described herein are based on preferred embodiments, and it is recognized that the embodiments described herein can be modified within the intent and scope of the embodiments described herein.

[0050] The use of the expression "at least" or "at least one" suggests the use of one or more elements, components, or quantities, as they may be used in the embodiments of the invention to obtain one or more target substances or results.

[0051] While we have emphasized the different components and parts of the preferred embodiments, many embodiments are possible, and many modifications can be made to the preferred embodiments without deviating from the principles of the invention. It will be obvious to those with expertise in the art that the characteristics of the present invention, the preferred embodiments, and other embodiments can be modified, and it is important to understand that the above explanatory matters are merely for the purpose of illustrating the present invention and should not be interpreted as limiting.

Claims

1. Apparatus (100) for performing a superfinish treatment on the threads of a ball screw, wherein the ball screw (40) is defined by a cylindrical body having a first end and a second end, a longitudinal helical raceway for the ball, and the apparatus (100) comprises: - At least one holder (42) for detachably holding a ball screw (40) - A first interchangeable finishing tool (10) having a first inner recess (10A) that defines a threaded portion complementing the thread (40A) of a ball screw (40). - A second interchangeable finishing tool (15) having a second inner recess (15A), defining a threaded portion that complements the ball screw (40) and the thread (40A) of the first inner recess (10A) and the second inner recess (15A), and further configured to contact each other during operation to form a hollow cylindrical space (48), and to clamp and fix the cylindrical portion of the ball screw (40) during operation inside the hollow space (48). - A polishing belt (20) reinforced with a slit film configured to receive the moving parts of the first interchangeable finishing tool (10) and the second finishing tool (15), a polishing belt (20) reinforced with the slit film configured to pass continuously through the circumferential surface of the hollow portion (48) and to form an interface between the threaded portion of the recess (10, 15) and the moving cylindrical portion including the thread (40A) of the ball screw (40), and further, - At least one drive component (44a, 44b) that is interlocked with the holder (42), the drive component (44a, 44b) is configured to easily change the angle of the holder (42) and thereby facilitate the displacement of the ball screw (40) angle with respect to the threaded portion of the inner recess (10A, 15A), The apparatus is characterized in that the first interchangeable finishing tool, the second interchangeable finishing tool, and the abrasive belt are attached to a sliding support component (54, 56) that moves back and forth along the longitudinal direction of the threaded portion of the ball screw (40) by the first interchangeable finishing tool (10), the second interchangeable finishing tool (15), and the thread (40A) of the ball screw (40), enabling a super-finish treatment on the thread (40A) of the ball screw (40) using the first finishing tool (10), the second finishing tool (15), and the abrasive belt (20).

2. The apparatus (100) according to claim 1, wherein in the operating configuration of the apparatus (100), the finishing tools (10, 15) are configured to slide back and forth on the ball screw (40) to perform the superfinishing treatment on the threads (40A) of the ball screw (40).

3. Apparatus (100) according to claim 1, wherein the drive components (44a, 44b) are configured to enable alternating clockwise and counterclockwise movement of the ball screw (40) within recesses (10A, 15A), causing the first finishing tool (10) and the second finishing tool (15) to reciprocate longitudinally in forward and backward movements, thereby performing a superfinish treatment on the thread (40A) of the ball screw (40).

4. The apparatus (100) according to claim 1, wherein in the operating configuration of the apparatus (100), the hollow portion (48) formed by the inner recesses (10A, 15A) is configured to partially cover the operating cylindrical portion of the ball screw (40).

5. The apparatus (100) claimed in claim 1, wherein the first interchangeable finishing tool (10) and the second interchangeable finishing tool (15) are defined by a "C" type body.

6. The apparatus (100) claimed in claim 5 comprises a pair of arms (46), each of which is configured to mount the first interchangeable finishing tool (10) and the second interchangeable finishing tool (15).

7. The device (100) according to claim 6, wherein the arm (46) is configured to be rotatably attached to the device (100).

8. The apparatus (100) according to claim 6, wherein in the operating configuration of the apparatus (100), the pivot axis (P) of the arm and the axis (C) passing through the center of gravity of the ball screw (40) are parallel.

9. The apparatus (100) claimed in claim 6, wherein the axis (C) passing through the center of gravity is perpendicular to the axis (M) passing perpendicular to the pivot axis (P).

10. The apparatus (100) according to claim 6, wherein in the operating configuration of the apparatus (100), the pivot axis (P) of the arm and the axis (C) passing through the center of gravity of the ball screw (40) are on the same plane.

11. Apparatus (100) according to claim 6, wherein the first interchangeable finishing tool (10) and the second interchangeable finishing tool (15) are configured to be attached to the arm (46) by a gripping means (30).

12. The apparatus (100) according to claim 1, wherein the polishing belt (20) reinforced with the slit film is a nonwoven abrasive.

13. Apparatus (100) according to claim 12, wherein the polishing belt (20) reinforced with the slit film has a pitch equal to the pitch defined in the threaded portion of the inner recess (10A, 15A) of the finishing tool and the pitch defined in the thread (40A) of the ball screw (40).

14. The apparatus (100) according to claim 1, wherein the depth of each slit in the continuous polishing belt (20) reinforced with the slit film in the threaded portion of the finishing tools (10, 15) is equal to the difference between the larger diameter and the smaller diameter, width and pitch of the thread (40A) of the ball screw (40) in the operating configuration of the apparatus (100).

15. The apparatus (100) claimed in claim 1, wherein the apparatus (100) incorporates a gear-driven indexing mechanism configured to control a polishing belt (20) reinforced with a slit film, which moves between the inner recesses (10A, 15A) of the finishing tools (10, 15) and the working part of a ball screw (40).

16. The apparatus (100) according to claim 1, wherein the thickness of the polishing belt (20) reinforced with the slit film is in the range of 0.2 mm to 1.0 mm.

Images