High-speed heavy-load ball screw assembly with variable-curvature raceway cross section

Abstract

The invention relates to the technical field of guide rails, in particular to a raceway section variable-curvature high-speed heavy-load ball screw pair which comprises a ball screw, a ball nut and balls. The ball nut sleeves the outer side of the ball screw; the ball is arranged in a raceway between the ball screw and the ball nut; the side, close to the bottoms of balls, of the ball screw is provided with a raceway-method section bearing area. Wherein the roller path method section bearing area comprises a first tooth crest arc section, a second type of hyperbolic cosine section, a third bottom groove arc section, a fourth type of hyperbolic cosine section and a fifth tooth crest arc section; the first tooth crest arc section, the second-class hyperbolic cosine section, the third bottom groove arc section, the fourth-class hyperbolic cosine section and the fifth tooth crest arc section are connected in sequence; the fourth-class hyperbolic cosine segment and the second-class hyperbolic cosine segment are symmetrical about the central axis of the ball; and the fifth tooth crest arc section and the first tooth crest arc section are symmetrical about the ball central axis, so that the problem that the precision and the service life of the ball screw pair under the high-speed and heavy-load working condition are limited is solved.

Description

Technical Field

[0001] The present application relates to the field of guide rail technology, and in particular to a high-speed, heavy-load ball screw pair with a variable curvature of the raceway section. Background Art

[0002] High-speed, heavy-duty ball screws are key transmission components in CNC machine tools, aerospace, robotics, and other fields. Their core function is to convert rotational motion into linear motion while simultaneously meeting the requirements of high precision and dynamic response under high-speed, high-load conditions. In these applications, the performance of the transmission components directly determines the equipment's positioning accuracy, operational stability, and service life, placing higher demands on the ball screw's load capacity, impact resistance, and reliability.

[0003] In the prior art, the raceway design of a ball screw pair typically employs a single arc or Gothic-style structure, with point contact between the balls and the raceway. While this design achieves basic transmission functions, under high-pressure conditions, point contact can easily lead to contact stress concentration, causing plastic deformation of the raceway or balls. Furthermore, during the ball's cyclic motion, especially during reversal, impact can generate high-frequency vibrations, further compromising the positioning accuracy and stability of the transmission system.

[0004] In these technologies, the point contact between the balls and raceways, as well as the impact of commutation, limit the accuracy and life of ball screws under high-speed and heavy-load conditions. Optimizing the raceway structure to reduce contact stress and suppress vibration has become a key technical issue in improving ball screw performance. Summary of the Invention

[0005] The present application provides a high-speed and heavy-load ball screw pair with a variable curvature of the raceway section, so as to solve the problem that the accuracy and life of the ball screw pair are limited under high-speed and heavy-load conditions.

[0006] The present application provides a high-speed and heavy-load ball screw pair with a variable curvature of the raceway section, comprising: a ball screw, a ball nut and balls; The ball nut is sleeved on the outside of the ball screw; the balls are arranged in the raceway between the ball screw and the ball nut; the side of the ball screw close to the bottom of the balls has a raceway cross-section bearing area; The bearing area of ​​the raceway cross section includes a first tooth top arc segment, a second type of hyperbolic cosine segment, a third bottom groove arc segment, a fourth type of hyperbolic cosine segment and a fifth tooth top arc segment; The first tooth top arc segment, the second type hyperbolic cosine segment, the third bottom groove arc segment, the fourth type hyperbolic cosine segment and the fifth tooth top arc segment are connected in sequence; the fourth type hyperbolic cosine segment and the second type hyperbolic cosine segment are symmetrical about the center axis of the ball; the fifth tooth top arc segment and the first tooth top arc segment are symmetrical about the center axis of the ball.

[0007] By adopting a raceway cross-section load-bearing area composed of the first tooth top arc segment, the second type of hyperbolic cosine segment, the third bottom groove arc segment, the fourth type of hyperbolic cosine segment and the fifth tooth top arc segment in sequence, and distributing them symmetrically on both sides of the ball center axis, the contact stress distribution between the ball and the raceway can be optimized, and the local stress concentration can be reduced, thereby improving the motion accuracy and fatigue life of the ball screw pair under high-speed and heavy-load conditions.

[0008] Optionally, the second type hyperbolic cosine segment and the fourth type hyperbolic cosine segment are defined by a quasi-hyperbolic cosine curve equation, and the quasi-hyperbolic cosine curve equation is: ; in, x is the horizontal axis, y is the vertical axis, x and y Used to describe the geometric position of the contact point between the ball and the raceway; θ is the rotation parameter, which represents the rotation angle of the hyperbolic cosine curve; k is the scale parameter used to scale the value of the hyperbolic cosine curve to adjust the curvature to match the ball diameter; e is a fixed constant.

[0009] The raceway cross-section curve is defined by a hyperbolic cosine curve equation, where the rotation parameter θ Adjustable curve angle and scale parameters k It can adapt to the curvature requirements of different ball diameters, thereby optimizing the contact trajectory between the ball and the raceway, reducing friction resistance during movement, improving the uniformity of load distribution, and enhancing the running smoothness and transmission efficiency of the ball screw pair.

[0010] Optionally, the adaptability of the raceway decreases monotonically as the contact angle increases; When the contact angle between the ball and the raceway is 45 degrees, the adaptability of the raceway is 0.56; When the contact angle between the ball and the raceway is 60 degrees, the adaptability of the raceway is 0.52.

[0011] By making the raceway adaptability monotonically decrease with increasing contact angle, the adaptability is 0.56 at a contact angle of 45 degrees and 0.52 at a contact angle of 60 degrees. This can optimize the contact characteristics between the ball and the raceway, reduce stress fluctuations at different contact angles, thereby improving the stability of load transfer and reducing friction losses caused by changes in contact angle.

[0012] Optionally, the third bottom groove arc segment is a concave arc curve, and the arc radius formula of the third bottom groove arc segment is: ; in, R g is the arc radius of the third bottom ditch arc segment; D w is the diameter of the ball.

[0013] By using a concave arc curve as the third bottom groove arc segment and making the arc radius R g With ball diameter D w Meeting a specific proportional relationship can optimize the contact shape between the ball and the bottom of the raceway, reduce contact stress concentration, thereby improving load distribution uniformity and reducing friction resistance during ball movement.

[0014] Optionally, the spiral groove formed by the third bottom groove arc segment sweeping at the bottom of the raceway is used to store lubricating oil; the spiral groove extends axially along the raceway and is located at the bottom of the groove on the non-contact side between the ball and the raceway.

[0015] By arranging a spiral groove formed by sweeping the arc segment of the third bottom groove at the bottom of the raceway, and extending it along the axial direction of the raceway and located at the bottom of the groove on the non-contact side between the ball and the raceway, the lubricating oil can be effectively stored, thereby improving the lubrication conditions of the ball screw pair during operation, reducing friction and wear, and reducing the loss of lubricating oil.

[0016] Optionally, the first tooth top circular arc segment is an upward convex circular arc curve, and the arc radius formula of the first tooth top circular arc segment is: ; in, R f is the arc radius of the first tooth top arc segment; D w is the diameter of the ball.

[0017] By using an upward convex arc curve as the first tooth top arc segment and making the arc radius R f With ball diameter D w Maintaining a specific proportional relationship can optimize the contact state between the ball and the top of the raceway, making the load distribution more uniform, thereby reducing the contact stress peak and improving the guidance and stability of the ball movement.

[0018] Optionally, when the average contact stress between the ball and the raceway is ≤80 MPa, the contact center between the ball and the raceway is stabilized at a contact angle of 45 degrees, and the differential slip rate is ≤0.05.

[0019] By controlling the average contact stress between the ball and the raceway to below 80 MPa, the contact center is stably maintained at a contact angle of 45 degrees, and the differential slip rate is limited to within 0.05. This can optimize the stress distribution in the contact area and reduce the sliding friction during ball movement, thereby improving transmission smoothness and extending the service life of the ball screw pair.

[0020] Optionally, when the average contact stress between the ball and the raceway is greater than 80 MPa, the ball is offset toward the ball nut side, the contact center between the ball and the raceway is stabilized at a contact angle position of 45 degrees to 60 degrees, the curvature radius of the bearing area of ​​the raceway cross-section is reduced by 10% to 20%, and the contact area is increased by 15% to 30%.

[0021] When the average contact stress between the ball and the raceway exceeds 80 MPa, by offsetting the ball toward the ball nut side and stabilizing the contact center within the contact angle range of 45 to 60 degrees, while reducing the curvature radius of the bearing area of ​​the raceway section by 10% to 20% and increasing the contact area by 15% to 30%, the stress distribution under high load conditions can be optimized, local stress concentration can be alleviated, and the load-bearing capacity can be improved while maintaining transmission stability.

[0022] Optionally, the raceway cross-section bearing area is arranged symmetrically about the center of the ball.

[0023] By setting the bearing area of ​​the raceway cross section to a structure symmetrically arranged about the ball center, the contact stress distribution between the ball and the raceway can be optimized, making the load transfer more balanced, thereby improving the running smoothness of the ball screw pair and reducing the eccentric wear caused by asymmetric force.

[0024] Optionally, the fifth tooth top circular arc segment is an upward convex circular arc curve, and the arc radius of the fifth tooth top circular arc segment is in the range of 0.1 to 0.15 times the diameter of the ball.

[0025] By setting the fifth tooth top arc segment to an upward convex arc curve and controlling its arc radius within the range of 0.1 to 0.15 times the ball diameter, the contact characteristics between the ball and the top of the raceway can be optimized, making the load distribution more even, thereby reducing contact stress concentration and improving the guiding accuracy and transmission stability of the ball movement.

[0026] From the above technical solution, it can be seen that the present application provides a high-speed and heavy-load ball screw pair with a variable curvature of the rolling section, comprising: a ball screw, a ball nut and a ball; the ball nut is sleeved on the outside of the ball screw; the ball is arranged in the rolling section between the ball screw and the ball nut; the ball screw has a rolling section bearing area on the side close to the bottom of the ball; wherein the rolling section bearing area includes a first tooth top arc segment, a second type hyperbolic cosine segment, a third bottom groove arc segment, a fourth A class hyperbolic cosine segment and a fifth tooth top arc segment; the first tooth top arc segment, the second class hyperbolic cosine segment, the third bottom groove arc segment, the fourth class hyperbolic cosine segment and the fifth tooth top arc segment are connected in sequence; the fourth class hyperbolic cosine segment and the second class hyperbolic cosine segment are symmetrical about the ball center axis; the fifth tooth top arc segment and the first tooth top arc segment are symmetrical about the ball center axis, so as to solve the problem that the accuracy and life of the ball screw pair are limited under high-speed and heavy-load conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0028] Figure 1 A schematic structural diagram of a longitudinal section of a high-speed, heavy-load ball screw pair with a variable curvature raceway section provided in an embodiment of the present application; Figure 2 A schematic structural diagram of a cross section of a high-speed, heavy-load ball screw pair with a variable curvature raceway section provided in an embodiment of the present application; Figure 3 A schematic structural diagram of a high-speed, heavy-load ball screw pair raceway cross section with a variable curvature raceway cross section provided in an embodiment of the present application; Figure 4 A schematic diagram of a basic hyperbolic cosine curve in a high-speed, heavy-load ball screw pair with a variable curvature raceway section provided in an embodiment of the present application; Figure 5 A schematic diagram of a scaled hyperbolic cosine curve in a high-speed, heavy-load ball screw pair with a variable curvature raceway section provided in an embodiment of the present application; Figure 6 Schematic diagram of the rotation curve of a high-speed and heavy-load ball screw pair with a variable curvature raceway section provided in an embodiment of the present application.

[0029] Illustration: Among them, 1-ball screw; 101-first tooth top arc segment; 102-second type hyperbolic cosine segment; 103-third bottom groove arc segment; 104-fourth type hyperbolic cosine segment; 105-fifth tooth top arc segment; 2-ball nut; 3-ball. DETAILED DESCRIPTION

[0030] The following embodiments are described in detail, with examples illustrated in the accompanying drawings. When the following description refers to the drawings, identical numerals in different figures represent identical or similar elements unless otherwise indicated. The embodiments described in the following embodiments are not intended to represent all possible implementations consistent with the present application. They are merely examples of systems and methods consistent with certain aspects of the present application.

[0031] The core function of high-speed, heavy-duty ball screws is to convert rotational motion into linear motion, while also meeting the requirements for high precision and dynamic response under high-speed, high-load conditions. In these applications, the performance of the transmission components directly determines the equipment's positioning accuracy, operational stability, and service life, placing higher demands on the ball screw's load capacity, impact resistance, and reliability.

[0032] In related embodiments, the ball screw pair's raceway design typically employs a single arc or Gothic-style structure, with point contact between the balls and the raceway. While this design achieves basic transmission functionality, under high-pressure conditions, point contact can easily lead to contact stress concentration, causing plastic deformation of the raceway or balls. Furthermore, during the ball's cyclic motion, especially during reversal, impact can generate high-frequency vibrations, further compromising the positioning accuracy and stability of the transmission system.

[0033] To solve the problem of limited accuracy and life of ball screw pairs under high speed and heavy load conditions, see Figure 1-Figure 3 The embodiment of the present application provides a high-speed and heavy-load ball screw pair with a variable curvature of the raceway section, comprising: a ball screw 1, a ball nut 2, and a ball 3; The ball nut 2 is sleeved on the outside of the ball screw 1; the balls 3 are arranged in the raceway between the ball screw 1 and the ball nut 2; the side of the ball screw 1 close to the bottom of the balls 3 has a raceway cross-section bearing area; The bearing area of ​​the raceway cross section includes a first tooth top arc segment 101, a second type hyperbolic cosine segment 102, a third bottom groove arc segment 103, a fourth type hyperbolic cosine segment 104 and a fifth tooth top arc segment 105; The first tooth top arc segment 101, the second type hyperbolic cosine segment 102, the third bottom groove arc segment 103, the fourth type hyperbolic cosine segment 104 and the fifth tooth top arc segment 105 are connected in sequence; the fourth type hyperbolic cosine segment 104 and the second type hyperbolic cosine segment 102 are symmetrical about the center axis of the ball 3; the fifth tooth top arc segment 105 and the first tooth top arc segment 101 are symmetrical about the center axis of the ball 3.

[0034] By adopting a raceway cross-section load-bearing area composed of a first tooth top arc segment 101, a second type of hyperbolic cosine segment 102, a third bottom groove arc segment 103, a fourth type of hyperbolic cosine segment 104 and a fifth tooth top arc segment 105 connected in sequence, and distributing them symmetrically on both sides of the center axis of the ball 3, the contact stress distribution between the ball 3 and the raceway can be optimized, and local stress concentration can be reduced, thereby improving the motion accuracy and fatigue life of the ball screw pair under high-speed and heavy-load conditions.

[0035] In some embodiments, the second type of hyperbolic cosine segment 102 and the fourth type of hyperbolic cosine segment 104 are defined by a quasi-hyperbolic cosine curve equation, and the quasi-hyperbolic cosine curve equation is: ; in, x is the horizontal axis, y is the vertical axis, x and y Used to describe the geometric position of the contact point between the ball 3 and the raceway; θ is the rotation parameter, which represents the rotation angle of the hyperbolic cosine curve; k is a scale parameter used to scale the value of the hyperbolic cosine curve to adjust the curvature to match the diameter of the ball 3; e is a fixed constant, e ≈2.71828.

[0036] The raceway cross-section curve is defined by a hyperbolic cosine curve equation, where the rotation parameter θ Adjustable curve angle and scale parameters k It can adapt to the curvature requirements of different ball 3 diameters, thereby optimizing the contact trajectory between the ball 3 and the raceway, reducing friction resistance during movement, improving the uniformity of load distribution, and enhancing the running stability and transmission efficiency of the ball screw pair.

[0037] It should be noted that the process of forming a quasi-hyperbolic cosine curve includes: The first step is to construct the basic hyperbolic cosine curve, see Figure 4 .

[0038] Specifically, the standard hyperbolic cosine function can be used y=(e x +e -x ） / 2 As a basic curve, this curve has a natural smooth continuity feature. x=0 The minimum value is achieved at the point where the ball screw is placed, and the ball screw extends symmetrically to both sides, showing a gradual growth characteristic. This mathematical characteristic is inherently consistent with the contact mechanics requirements of the ball screw pair.

[0039] The second step is to scale the hyperbolic cosine curve value to adjust the curvature, see Figure 5 .

[0040] Specifically, a scale parameter is introduced on the basic hyperbolic cosine curve k， A scaled hyperbolic cosine curve is formed. k A positive real number scaling factor used to adjust the overall amplitude of the curve. k The value change can not only accurately control the curvature radius of the curve, so that it is consistent with the design requirements of the ball diameter D w Form the best matching relationship, and adjust k The value can change the curvature gradient of the contact area and achieve the optimal distribution of Hertzian contact stress within the allowable range.

[0041] The third step is to rotate the curve and select the appropriate part of the curve. Figure 6 .

[0042] Specifically, the scaled curve is rotated using a rotation matrix. θ Angle rotation, through θ Adjust the curve segment to accurately correspond to the designed contact angle, and only retain the effective working segment where the curvature of the curve changes continuously after rotation. θ≠0 Asymmetric contact area design can be achieved to meet special working conditions.

[0043] In some embodiments, the adaptability of the raceway decreases monotonically as the contact angle increases; When the contact angle between the ball 3 and the raceway is 45 degrees, the adaptability of the raceway is 0.56; When the contact angle between the ball 3 and the raceway is 60 degrees, the adaptability of the raceway is 0.52.

[0044] It should be understood that the adaptability of the raceway ( f rs / f rn ) is the raceway radius of ball screw 1 r s Or the raceway radius of ball nut 2 r n With ball diameter D W The specific formula is as follows: f rs= r s / D W= f rn= r n / D W ; The subscripts s and n represent the ball screw and ball nut, respectively.

[0045] By making the raceway adaptability monotonically decrease with increasing contact angle, the adaptability is 0.56 when the contact angle is 45 degrees and 0.52 when the contact angle is 60 degrees. This can optimize the contact characteristics between the ball 3 and the raceway, reduce stress fluctuations at different contact angles, thereby improving the stability of load transfer and reducing friction losses caused by changes in contact angle.

[0046] In some embodiments, the third bottom groove arc segment 103 is a concave arc curve, and the arc radius formula of the third bottom groove arc segment 103 is: ; in, R g is the arc radius of the third bottom groove arc segment 103; D w is the diameter of ball 3.

[0047] By using a concave arc curve as the third bottom groove arc segment 103 and making the arc radius R g With ball 3 diameter D w Meeting a specific proportional relationship can optimize the contact form between the ball 3 and the bottom of the raceway, reduce contact stress concentration, thereby improving load distribution uniformity and reducing friction resistance when the ball 3 moves.

[0048] In some embodiments, the spiral groove formed by the third bottom groove arc segment 103 sweeping at the bottom of the raceway is used to store lubricating oil; the spiral groove extends axially along the raceway and is located at the bottom of the groove on the non-contact side between the ball 3 and the raceway.

[0049] By providing a spiral groove formed by sweeping the third bottom groove arc segment 103 at the bottom of the raceway, and extending it axially along the raceway and being located at the bottom of the groove on the non-contact side between the ball 3 and the raceway, the lubricating oil can be effectively stored, thereby improving the lubrication conditions of the ball screw pair during operation, reducing friction and wear, and reducing the loss of lubricating oil.

[0050] In some embodiments, the first tooth top circular arc segment 101 is an upward convex circular arc curve, and the arc radius formula of the first tooth top circular arc segment 101 is: ; in, R f is the arc radius of the first tooth top arc segment 101; D w is the diameter of ball 3.

[0051] By using an upward convex arc curve as the first tooth top arc segment 101 and making the arc radius R f With ball 3 diameter D w Maintaining a specific proportional relationship can optimize the contact state between the ball 3 and the top of the raceway, making the load distribution more uniform, thereby reducing the contact stress peak and improving the guidance and stability of the movement of the ball 3.

[0052] In some embodiments, when the average contact stress between the ball 3 and the raceway is ≤80 MPa, the contact center between the ball 3 and the raceway is stabilized at a contact angle of 45 degrees, and the differential slip rate is ≤0.05.

[0053] By controlling the average contact stress between ball 3 and the raceway to below 80 MPa, the contact center is stably maintained at a contact angle of 45 degrees, and the differential slip rate is limited to within 0.05. This can optimize the stress distribution in the contact area and reduce the sliding friction during the movement of ball 3, thereby improving transmission smoothness and extending the service life of the ball screw pair.

[0054] In some embodiments, when the average contact stress between the ball 3 and the raceway is greater than 80 MPa, the ball 3 is offset toward the ball nut 2, the contact center between the ball 3 and the raceway is stabilized at a contact angle of 45 to 60 degrees, the curvature radius of the bearing area of ​​the raceway cross-section is reduced by 10% to 20%, and the contact area is increased by 15% to 30%.

[0055] When the average contact stress between the ball 3 and the raceway exceeds 80 MPa, by offsetting the ball 3 toward the ball nut 2 and stabilizing the contact center within a contact angle range of 45 to 60 degrees, while reducing the curvature radius of the bearing area of ​​the raceway cross-section by 10% to 20% and increasing the contact area by 15% to 30%, the stress distribution under high load conditions can be optimized, local stress concentration can be alleviated, and the load-bearing capacity can be improved while maintaining transmission stability.

[0056] In some embodiments, the raceway cross-section bearing area is symmetrically arranged about the center of the ball 3 .

[0057] By setting the bearing area of ​​the raceway cross section to a structure symmetrically arranged about the center of the ball 3, the contact stress distribution between the ball 3 and the raceway can be optimized, making the load transfer more balanced, thereby improving the running smoothness of the ball screw pair and reducing the eccentric wear caused by asymmetric force.

[0058] It should be understood that in the low-speed, heavy-load section, when the average contact stress between the ball 3 and the raceway is ≤80 MPa, the contact center between the ball 3 and the raceway is stabilized at a contact angle of 45 degrees. In this area, the raceway has a high adaptability, the differential sliding between the ball 3 and the raceway is small, the noise and vibration during high-speed operation are small, and the ball screw pair is suitable for high-speed operation. As the load gradually increases, the ball 3 gradually approaches the side of the ball nut 2, the contact angle gradually increases, the curvature radius of the raceway cross-section of the ball screw 1 gradually decreases, the area of ​​the contact zone increases, the load-bearing capacity of the screw pair increases, and the ball screw pair switches from high-speed, light-load to low-speed, heavy-load. When the contact angle increases to 60 degrees, the adaptability decreases to 0.52. The load-bearing capacity of the low-speed, heavy-load section is 1.7 to 2 times that of the high-speed, light-load section.

[0059] In some embodiments, the fifth tooth top circular arc segment 105 is an upward convex circular arc curve, and the arc radius of the fifth tooth top circular arc segment 105 is in the range of 0.1 to 0.15 times the diameter of the ball 3 .

[0060] By setting the fifth tooth top arc segment 105 to an upward convex arc curve and controlling its arc radius within the range of 0.1 to 0.15 times the diameter of the ball 3, the contact characteristics between the ball 3 and the top of the raceway can be optimized, making the load distribution more uniform, thereby reducing contact stress concentration and improving the guiding accuracy and transmission stability of the ball 3 movement.

[0061] This application specifically takes the 4012-5 end plug ball screw pair as an example to analyze its rated static load calculation under light load and heavy load conditions, mainly involving the following parameters: steel ball diameter D w The ball is 6.35 mm in diameter, the number of ball cycles is i=5, the contact angle is 45 degrees under light load, the adaptability is 0.56, and the rated static load C is 0.56 according to GB / T 17587.5. oa1 The calculation is as follows: .

[0062] in, k 01 is the load factor (related to material and curvature radius), unit: N / mm² ; Z 1 is the number of balls in a single circle (number of rows of load-bearing balls); i is the number of ball circulations; α is the contact angle; D w is the diameter of the steel ball; φ is the lead angle (determined by the screw geometry).

[0063] .

[0064] in, Dpw is the screw pitch diameter (41.5 mm); Z u is the number of invalid balls (here it is 0, i.e. all balls are loaded).

[0065] .

[0066] in, P h is the screw lead.

[0067] ; ; ; .

[0068] in, ρ 11 and ρ 21 is the curvature of the main plane at the contact point between the steel ball and the screw; ρ 12 and ρ 22 is the curvature of the main plane 2 at the contact point between the ball and the screw raceway. Main plane 1 and main plane 2 refer to two mutually perpendicular main curvature planes.

[0069] When the axial load gradually increases, the contact angle gradually increases and the adaptability gradually decreases with the increase of elastic deformation. When the contact angle increases to 60 degrees and the adaptability changes to 0.52, the rated static load C of the 4012-5 end plug ball screw pair is oa2 The calculation is as follows: ; ; .

[0070] It can be seen from the above technical solution that the embodiment of the present application provides a high-speed and heavy-load ball screw pair with a variable curvature of the raceway section, comprising: a ball screw 1, a ball nut 2 and a ball 3; the ball nut 2 is sleeved on the outside of the ball screw 1; the ball 3 is arranged in the raceway between the ball screw 1 and the ball nut 2; the ball screw 1 has a raceway cross-section bearing area on one side close to the bottom of the ball 3; wherein the raceway cross-section bearing area includes a first tooth top arc segment 101, a second type hyperbolic cosine segment 102, a third bottom groove arc segment 103, a fourth type hyperbolic cosine segment 104 and the fifth tooth top arc segment 105; the first tooth top arc segment 101, the second type hyperbolic cosine segment 102, the third bottom groove arc segment 103, the fourth type hyperbolic cosine segment 104 and the fifth tooth top arc segment 105 are connected in sequence; the fourth type hyperbolic cosine segment 104 and the second type hyperbolic cosine segment 102 are symmetrical about the central axis of the ball 3; the fifth tooth top arc segment 105 and the first tooth top arc segment 101 are symmetrical about the central axis of the ball 3, so as to solve the problem that the accuracy and life of the ball screw pair are limited under high-speed and heavy-load conditions.

[0071] Similar parts between the embodiments provided in this application can be referenced to each other. The specific implementation methods provided above are only a few examples under the overall concept of this application and do not constitute a limitation on the scope of protection of this application. For those skilled in the art, any other implementation methods expanded based on the scheme of this application without expending creative work shall fall within the scope of protection of this application.

Claims

1. A high-speed and heavy-load ball screw pair with a variable curvature raceway section, characterized in that: include: A ball screw (1), a ball nut (2), and a ball (3); The ball nut (2) is sleeved on the outside of the ball screw (1); the ball (3) is arranged in a raceway between the ball screw (1) and the ball nut (2); the side of the ball screw (1) close to the bottom of the ball (3) has a raceway cross-section bearing area; The rolling track cross-section bearing area includes a first tooth top arc segment (101), a second type of hyperbolic cosine segment (102), a third bottom groove arc segment (103), a fourth type of hyperbolic cosine segment (104), and a fifth tooth top arc segment (105). The first tooth top circular arc segment (101), the second type hyperbolic cosine segment (102), the third bottom groove circular arc segment (103), the fourth type hyperbolic cosine segment (104) and the fifth tooth top circular arc segment (105) are connected in sequence; the fourth type hyperbolic cosine segment (104) and the second type hyperbolic cosine segment (102) are symmetrical about the central axis of the ball (3); the fifth tooth top circular arc segment (105) and the first tooth top circular arc segment (101) are symmetrical about the central axis of the ball (3).

2. The high-speed and heavy-load ball screw pair with a variable curvature raceway section according to claim 1, characterized in that: The second type of hyperbolic cosine segment (102) and the fourth type of hyperbolic cosine segment (104) are defined by a quasi-hyperbolic cosine curve equation, wherein the quasi-hyperbolic cosine curve equation is: ； in, x is the horizontal axis, y is the vertical axis, x and y Used to describe the geometric position of the contact point between the ball and the raceway; θ is the rotation parameter, which represents the rotation angle of the hyperbolic cosine curve; k is the scale parameter used to scale the value of the hyperbolic cosine curve to adjust the curvature to match the ball diameter; e is a fixed constant.

3. The high-speed and heavy-load ball screw pair with a variable curvature raceway section according to claim 1, characterized in that: The adaptability of the raceway decreases monotonically as the contact angle increases; When the contact angle between the ball (3) and the raceway is 45 degrees, the adaptability of the raceway is 0.56; When the contact angle between the ball (3) and the raceway is 60 degrees, the adaptability of the raceway is 0.

52.

4. The high-speed and heavy-load ball screw pair with a variable curvature raceway section according to claim 1, characterized in that: The third bottom groove arc segment (103) is a concave arc curve, and the arc radius formula of the third bottom groove arc segment (103) is: ； in, R g is the arc radius of the third bottom groove arc segment (103); D w is the diameter of the ball (3).

5. The high-speed and heavy-load ball screw pair with a variable curvature raceway section according to claim 1, characterized in that: The spiral groove formed by the third bottom groove arc segment (103) sweeping the bottom of the raceway is used to store lubricating oil; the spiral groove extends axially along the raceway and is located at the groove bottom on the non-contact side between the ball (3) and the raceway.

6. The high-speed and heavy-load ball screw pair with a variable curvature raceway section according to claim 1, characterized in that: The first tooth top circular arc segment (101) is an upward convex circular arc curve, and the arc radius formula of the first tooth top circular arc segment (101) is: ； in, R f is the arc radius of the first tooth top arc segment (101); D w is the diameter of the ball (3).

7. The high-speed and heavy-load ball screw pair with a variable curvature raceway section according to claim 1, characterized in that: When the average contact stress between the ball (3) and the raceway is ≤80 MPa, the contact center between the ball (3) and the raceway is stabilized at a contact angle position of 45 degrees, and the differential slip rate is ≤0.

05.

8. The high-speed and heavy-load ball screw pair with a variable curvature raceway section according to claim 3, characterized in that: When the average contact stress between the ball (3) and the raceway is greater than 80 MPa, the ball (3) deviates toward the ball nut (2), the contact center between the ball (3) and the raceway is stabilized at a contact angle of 45 to 60 degrees, the curvature radius of the bearing area of ​​the raceway cross section decreases by 10% to 20%, and the contact area increases by 15% to 30%.

9. The high-speed and heavy-load ball screw pair with a variable curvature raceway section according to claim 1, characterized in that: The raceway cross-section bearing area is arranged symmetrically about the center of the ball (3).

10. The high-speed and heavy-load ball screw pair with a variable curvature raceway section according to claim 1, characterized in that: The fifth tooth top circular arc segment (105) is an upward convex circular arc curve, and the circular arc radius of the fifth tooth top circular arc segment (105) is within the range of 0.1 to 0.15 times the diameter of the ball (3).

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