Outer circulation combined insertion pipe type reverser assembly of ball screw pair

Abstract

The invention belongs to the technical field of ball screws, and relates to a ball screw pair outer circulation combined insertion pipe type reverser assembly which comprises a screw nut, an inner hole of the screw nut is connected with a screw in a threaded fit mode, the screw nut is provided with a ball return raceway, and the ball return raceway comprises at least one lower half raceway, at least one upper half raceway and at least one lower half raceway, the two ends of the lower half roller path are respectively and smoothly communicated with pipe insertion holes formed in the lead screw nut; the number of the inverters is consistent with that of the lower half raceways, the inverters are correspondingly matched with the corresponding lower half raceways, and upper half raceways constructed on the inner walls of the inverters are matched with the corresponding lower half raceways and form a closed ball movement route with the spiral raceways on the surface of the lead screw; the sleeve is arranged on the lead screw nut in a sleeving mode so that the reverser can be limited in the radial direction. The assembly difficulty of the reverser can be reduced, the impact and clamping stagnation risks during ball reversing are reduced, single-side raceway stress concentration is avoided, the overall bearing capacity is improved, the fatigue life is prolonged, and the maintenance cost is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of ball screws, and relates to a ball screw pair outer circulation combined plug-in type reverser component. Background Art

[0002] The ball screw pair is a common transmission device used for the conversion between rotary motion and linear motion, or for positioning. It consists of a screw and nut with a spiral raceway, multiple balls, and a reverser. The rolling of the balls between the screw spiral raceway and the nut spiral raceway enables efficient transmission and positioning. The ball screw pair has the characteristics of high precision, large load capacity, low friction, and high efficiency. Therefore, it is widely used in mechanical equipment, such as CNC machine tools, automated production lines, aerospace equipment, and automobiles.

[0003] The reverser in the ball screw pair is a device that realizes the circular motion of the balls in the spiral raceway. The quality of its working performance will directly affect the transmission quality. At present, the reverser has the problems of high noise, poor durability, and difficult installation and maintenance. It is necessary to design a reverser that is easy to assemble and has good smoothness. Summary of the invention

[0004] In view of the above problems, the present invention provides a ball screw pair external circulation combined insert-tube reverser assembly, which can reduce the difficulty of assembling the reverser, reduce the impact and jamming risks during ball reversing, avoid stress concentration on one side of the raceway, improve the overall load-bearing capacity and fatigue life, and reduce maintenance costs.

[0005] According to the technical solution of the present invention: a ball screw pair external circulation combined plug-in type reverser assembly includes a screw nut, the inner hole thread of the screw nut is matched to connect the screw, and the screw nut is provided with a return ball raceway, characterized in that the return ball raceway includes:

[0006] At least one lower half raceway, which is spirally arranged on the circumferential surface of the screw nut, and the two ends of the lower half raceway are smoothly connected with the insertion holes arranged on the screw nut;

[0007] The reverser has the same number as the lower half raceway and is matched with the corresponding lower half raceway. The upper half raceway of the reverser inner wall is matched with the corresponding lower half raceway and forms a closed ball movement route with the spiral raceway on the surface of the screw.

[0008] The sleeve is sleeved on the lead screw nut to form a radial limit for the reverser.

[0009] As a further improvement of the present invention, both ends of the deflector are provided with an integrally connected cylindrical insert, and after the deflector is matched with the lower raceway, the end surface of the insert is supported on the positioning step provided on the inner wall of the insert hole;

[0010] The positioning step is provided with a radially extending notch to form a positioning groove, and the outer end surface of the insert tube is constructed with an integrally connected ball guide structure, and the ball guide structure is cooperatively arranged in the positioning groove.

[0011] As a further improvement of the present invention, the working surface of the ball guide structure is in an arc shape.

[0012] As a further improvement of the present invention, the reverser has integrally connected anti-twist structures on both sides in the width direction, and the anti-twist structures are cooperated with the limiting parts respectively arranged on both sides of the lower half raceway to prevent the reverser from torsional deformation.

[0013] As a further improvement of the present invention, the curve of the upper half raceway is divided into three sections, wherein the middle section is an elliptical arc, and the two ends are modified polynomial transition sections, and the curves at the two ends are symmetrical about the middle section;

[0014] The transition sections at both ends use a fifth-order polynomial (t∈[-1,-k]U[k,1]):

[0015]

[0016] Where R is the radius of gyration and is related to the lead P of the screw: (η≈1.1~1.3 is the margin coefficient), H is the maximum height of the return bead groove, k controls the range ratio of the ellipse segment, and the length of the ellipse segment L e =2kR, γ is the lateral polynomial term to adjust the lateral impact of the ball at the entrance / exit, β is the longitudinal quintic term to adjust the normal acceleration of the ball when it cuts into the thread;

[0017] Middle elliptical arc segment (t∈[-k, k]):

[0018]

[0019] Where λ∈(0,0.15) is the ellipse correction coefficient, which controls the curvature transition and implies the ellipse equation:

[0020] The technical effects of the present invention are: 1) The upper and lower raceways are connected to form a continuous ball return path, reducing the impact and jamming risks during ball reversing, and the ball guide structure assists the ball to smoothly enter the insert tube to avoid deviation of the motion trajectory. 2) The split design allows the upper half of the raceway to be disassembled or replaced separately, reducing maintenance costs. 3) The upper and lower raceways jointly bear the ball pressure, avoiding stress concentration on one side of the raceway, and improving the overall load-bearing capacity and fatigue life. 4) The ball return curve combines the advantages of polynomials and sine functions through segmented design, achieving a balance between dynamic performance and manufacturing feasibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is an exploded view of the present invention.

[0022] Figure 2 It is a front view of the reverser of the present invention.

[0023] Figure 3 It is a perspective view of the reverser of the present invention.

[0024] Figure 4 It is a front view of the screw nut of the present invention.

[0025] Figure 5 for Figure 4 AA section view.

[0026] Figure 6 It is a stereoscopic view of the screw nut of the present invention.

[0027] Among them, the figure markings are: 1. nut; 2. reverser; 3. screw; 4. sleeve; 5. upper raceway; 6. anti-torsion structure; 7. insert tube; 8. ball guide structure; 9. lower raceway; 10. limit part; 11. insert tube hole; 12. positioning groove; 13. positioning step. DETAILED DESCRIPTION

[0028] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings.

[0029] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. The described embodiment is only a part of the embodiment of the present invention, not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of the present invention.

[0030] like Figure 1-6 As shown, the present invention is a ball screw pair external circulation combined plug-in type reverser assembly, including a screw nut 1, the inner hole thread of the screw nut 1 is connected to the screw 3, the screw nut 1 is provided with a ball return raceway, the ball return raceway includes at least one lower half raceway 9, which is spirally arranged on the circumferential surface of the screw nut 1, and the two ends of the lower half raceway 9 are smoothly connected with the plug-in hole 11 arranged on the screw nut 1.

[0031] Each lower half raceway 9 is respectively provided with a deflector 2, and the upper half raceway 5 of the inner wall structure of the deflector 2 cooperates with the corresponding lower half raceway 9 to form a ball return raceway; the upper half raceway 5, the lower half raceway 9 and the spiral raceway on the surface of the screw 3 form a closed ball movement route.

[0032] In order to achieve radial limitation of the reverser 2, a sleeve 4 is sleeved on the screw nut 1. It can be understood that in order to ensure a reliable fastening connection between the sleeve 4 and the screw nut 1, the sleeve 4 and the screw nut 1 adopt an interference fit, and the sleeve 4 covers all the reversers 2.

[0033] Furthermore, both ends of the deflector 2 are provided with an integrally connected cylindrical insert 7. After the deflector 2 is matched with the lower raceway 9, the end face of the insert 7 is supported on the positioning step 13 provided on the inner wall of the insert hole 11 to achieve reliable positioning of the deflector 2.

[0034] Furthermore, an integrally connected anti-twist structure 6 is constructed on both sides of the width direction of the reverser 2, and the anti-twist structure 6 is arranged on the limiting parts 10 respectively arranged on both sides of the lower half raceway 9 to prevent the reverser 2 from torsional deformation. The anti-twist structure 6 is a positioning piece integrally connected to the reverser 2.

[0035] In order to guide the balls to flow back into the raceway of the lead screw 3 during operation, a radially extending notch is provided on the positioning step 13 to form a positioning groove 12, and an integrally connected ball guide structure 8 is constructed on the outer end surface of the insert tube 7, and the ball guide structure 8 is cooperatively arranged in the positioning groove 12. It can be understood that the working surface of the ball guide structure 8 is in an arc shape.

[0036] The curve of the upper raceway 5 is divided into three sections, wherein the middle section is an elliptical arc, and the two ends are modified polynomial transition sections, and the curves at the two ends are symmetrical about the middle section;

[0037] The transition sections at both ends use a fifth-order polynomial (t∈[-1,-k]U[k,1]):

[0038]

[0039] Where R is the radius of gyration and is related to the lead P of the screw: is the margin coefficient, H is the maximum height of the bead return groove, k controls the range ratio of the ellipse segment, and L is the length of the ellipse segment. e =2kR, γ is the lateral polynomial term to adjust the lateral impact of the ball at the entrance / exit, β is the longitudinal quintic term to adjust the normal acceleration of the ball when it cuts into the thread;

[0040] Middle elliptical arc segment (t∈[-k, k]):

[0041]

[0042] Where λ∈(0, 0.15) is the ellipse correction coefficient, which controls the curvature transition and implies the ellipse equation:

[0043] like Figure 1-6As shown, during assembly, the present invention installs the insert tube 7 of the reverser 2 in the insert tube hole 11 of the screw nut 1 from the outside to the inside. At this time, the anti-torsion structure 6 of the reverser 2 is constrained by the limiting portion 10 of the screw nut 1 to prevent the reverser 2 from torsional deformation, and the lower half raceway 9 of the screw nut 1 and the upper half raceway 5 of the reverser 2 together constitute the return ball raceway of the external circulation combined insert tube type reverser; then the sleeve 4 is tightly sleeved on the screw nut 1 to cover all the reversers 2 on the surface of the screw nut 1 to prevent the reverser 2 from falling off during the operation of the ball screw pair.

[0044] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A ball screw pair external circulation combined plug-in type reverser assembly, comprising a screw nut (1), the inner hole thread of the screw nut (1) is matched to connect the screw (3), the screw nut (1) is provided with a ball return raceway, characterized in that: The ball return track comprises: At least one lower half raceway (9) is spirally arranged on the circumferential surface of the screw nut (1), and both ends of the lower half raceway (9) are smoothly connected to the insertion holes (11) arranged on the screw nut (1); The reverser (2) has the same number as the lower half raceway (9) and is matched with the corresponding lower half raceway (9). The upper half raceway (5) of the inner wall structure of the reverser (2) is matched with the corresponding lower half raceway (9) and forms a closed ball movement route with the spiral raceway on the surface of the lead screw (3); The sleeve (4) is sleeved on the lead screw nut (1) to form a radial limit for the reverser (2).

2. The ball screw pair external circulation combined plug-in type reverser assembly according to claim 1, characterized in that: The two ends of the deflector (2) are respectively provided with an integrally connected cylindrical insert (7). After the deflector (2) and the lower raceway (9) are correspondingly matched, the end surface of the insert (7) is supported on a positioning step (13) provided on the inner wall of the insert hole (11); The positioning step (13) is provided with a radially extending notch to form a positioning groove (12); the outer end surface of the insert tube (7) is constructed with an integrally connected ball guide structure (8); the ball guide structure (8) is cooperatively arranged in the positioning groove (12).

3. The ball screw pair external circulation combined plug-in type reverser assembly as claimed in claim 2, characterized in that: The working surface of the ball guide structure (8) is in an arc shape.

4. The ball screw pair external circulation combined plug-in type reverser assembly according to claim 1, characterized in that: The reverser (2) is provided with integrally connected anti-twist structures (6) on both sides in the width direction, and the anti-twist structures (6) are arranged on the limiting parts (10) respectively arranged on both sides of the lower half raceway (9) to prevent the reverser (2) from twisting and deforming.

5. The ball screw pair external circulation combined plug-in type reverser assembly according to claim 1, characterized in that: The curve of the upper raceway (5) is divided into three sections, wherein the middle section is an elliptical arc, and the two ends are modified polynomial transition sections, and the curves at the two ends are symmetrical about the middle section; The transition sections at both ends use a fifth-order polynomial (t∈[-1,-k]U[k,1]): Where R is the radius of gyration and is related to the lead P of the screw: (η≈1.1~1.3 is the margin coefficient), H is the maximum height of the return bead groove, k controls the range ratio of the ellipse segment, and the length of the ellipse segment L e =2kR, γ is the lateral polynomial term to adjust the lateral impact of the ball at the entrance / exit, β is the longitudinal quintic term to adjust the normal acceleration of the ball when it cuts into the thread; Middle elliptical arc segment (t∈[-k, k]): Where λ∈(0,0.15) is the ellipse correction coefficient, which controls the curvature transition and implies the ellipse equation:

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