A rotor bow based on NURBS type double curvature variable cross-section line

Abstract

The utility model discloses a rotor bow based on NURBS type double curvature variable cross section type line belongs to steel wire rope manufacturing equipment rotor part technical field, and this rotor bow main part is NURBS type double curvature bending section, and the cross section width is gradually increased from the center to both ends along the length direction, each section is composed of elliptical streamline, intermediate horizontal line section and upper three point arc line compound, and the smooth continuous axial symmetry profile is formed. The main body both ends pass through lofting stretching transition section and equal cross section end portion fairing link. Through the coupling design of variable cross section geometry and double curvature bending structure, improve high -speed rotation dynamic balance, restrain eddy current and flutter, reduce vibration noise and optimize stress distribution, thereby promote the working stability of stranding machine and steel wire rope stranding quality.

Description

Technical Field

[0001] This utility model relates to the technical field of rotor components for wire rope manufacturing equipment, specifically to a rotor bow based on a NURBS-type double curvature variable cross-section profile. Technical Background

[0002] Twisting machines are key equipment in the production of metal products such as wire ropes and cables. The high-speed stability of their rotor system directly determines the twisting quality and production efficiency of the products. As the core component of the rotor, the rotor bow's structural design directly affects the equipment's vibration level, noise level, and energy consumption.

[0003] Currently, most rotor bows used both domestically and internationally are straight or curved structures with uniform cross-sections or simple tapered variations. These traditional designs have inherent drawbacks under high-speed conditions: First, their aerodynamic shape and mass distribution are difficult to achieve optimal dynamic balance, easily leading to strong vibrations due to uneven centrifugal force, generating high-decibel noise and affecting bearing life; second, the uniform cross-section design, when subjected to alternating bending stress, results in uneven stress distribution, easily forming fatigue cracks near fixed points, posing safety hazards; third, traditional designs have high eddy current resistance, increasing drive energy consumption. These problems severely restrict further improvements in the performance of high-speed twisting machines.

[0004] To address the shortcomings of the existing technologies, this utility model aims to provide a novel rotor bow structure solution. By incorporating a NURBS-type double curvature variable cross-section profile design, it optimizes the mass distribution and aerodynamic shape from the source, thereby completely solving the vibration, noise, and fatigue problems at high speeds and meeting the higher requirements of high-end wire rope manufacturing equipment. Utility Model Content

[0005] The technical problem to be solved by this utility model is to overcome the defects of existing rotor bows, such as large vibration, high noise, large aerodynamic resistance and energy consumption, and easy fatigue damage when running at high speed, and to provide a high-speed, low-energy-consumption rotor bow based on NURBS-type hyperbolic variable cross-section profile.

[0006] To achieve the above technical objectives, the following technical solution is adopted.

[0007] This utility model provides a rotor bow based on a NURBS-type hyperbolic variable cross-section profile, including a rotor bow body and a plate body included in the rotor bow body. The rotor bow body is a plate-shaped component that bends and extends along the central axis of symmetry. The rotor bow body is an integral NURBS-type hyperbolic bending section, with a lofted stretching transition section and a constant cross-section end section symmetrically arranged at both ends.

[0008] The main body of the rotor bow has a cross-sectional width that gradually increases from the center to both ends along its length. The cross-section of the main body of the rotor bow is an axisymmetric composite profile, which is composed of a horizontal line segment at the bottom, elliptical streamlines at both ends, and a bow guide groove at the top formed by three circular arcs or elliptical arcs.

[0009] Furthermore, the profile of any cross-section on the NURBS-type hypercurvature curved segment is a quasi-elliptical streamline, and the total width changes smoothly with the position of the cross-section.

[0010] Furthermore, the cross-sectional widths at both ends of the lofting and stretching transition section are different, and a smooth transition is achieved between the lofting and stretching method and the bending section and the end section with equal cross-section, thereby ensuring the continuous curvature of the overall shape and the assembly adaptability.

[0011] Furthermore, the plate has a nominally uniform thickness structure, with the thickness remaining essentially constant within the process tolerance range to meet the requirements for high-speed rotational stiffness and mass distribution.

[0012] Furthermore, the plate is made of a high-strength alloy material, preferably titanium alloy or manganese steel, and is heat-treated to meet the requirements for strength, toughness and fatigue resistance.

[0013] Furthermore, the rotor bow has positioning holes at both ends for mounting onto the flywheel disc of the twisting machine.

[0014] Furthermore, several sets of guide ring positioning holes are provided in the middle of the rotor bow length direction for installing guide rings to precisely limit the position of the steel cord; each set of guide ring positioning holes is symmetrically arranged with respect to the length center, and the hole spacing is symmetrically and non-linearly increasing along the length direction, gradually increasing from the middle to both ends; the guide ring mounting part is provided with guide ring mounting groove and smooth transition area to reduce local stress concentration.

[0015] Furthermore, the guide ring is installed in the guide ring mounting groove. The guide ring has a symmetrical structure, and its lower surface fits the contour of the upper surface of the rotor bow at the installation position. Its upper surface is a quasi-elliptical streamline that smoothly transitions with the surrounding composite cross section. The lower part of the guide ring is provided with a steel cord channel groove, in which a hard alloy liner is tightly embedded. The shape of the liner is formed by the contour of the channel groove offset inward at equal intervals. The liner material is selected from WC-Co or ceramic to improve wear resistance and guiding stability.

[0016] The beneficial effects of this utility model are as follows: through the coupled design of variable cross-section geometry and NURBS-type hyperbolic bending structure, and supplemented by the smooth transition of the lofted stretching transition section to the constant cross-section end section and the continuous curvature profile of the composite cross-section, it can improve dynamic balance, suppress eddy currents and flutter, reduce aerodynamic drag and vibration noise, and optimize stress distribution under high-speed working conditions; in conjunction with the symmetrical incremental arrangement of guide ring positioning holes and the wear-resistant guiding structure of the guide ring or liner, it further stabilizes the steel cord path and tension, reduces wear and improves fatigue life, thereby improving the working stability of the twisting machine and the twisting quality of the wire rope, and achieving a comprehensive effect of low resistance, low noise and long service life. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the rotor bow according to an embodiment of the present utility model;

[0018] Figure 2 This is a schematic diagram of the cross-sectional structure at the central axis of symmetry (section AA) of this utility model;

[0019] Figure 3 This is a schematic diagram of the cross-sectional structure at the end point (BB section) of the large circular arc segment of this utility model;

[0020] Figure 4 This is a schematic diagram of the cross-sectional structure at the end point (CC section) of the lofting and stretching section of this utility model;

[0021] Figure 5 This is a partial structural schematic diagram of the guide ring mounting location of this utility model;

[0022] 1. Plate body; 2. Bow guide groove; 3. Lower horizontal line segment; 4. Elliptical streamline; 5. Positioning hole; 6. Guide ring positioning hole; 7. Guide ring mounting groove; 8. Smooth transition zone; 9. Guide ring; 10. Hard alloy liner. Detailed Implementation

[0023] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be understood that the embodiments described herein are for illustrative purposes only and are not intended to limit the scope of protection. Other embodiments that can be obtained by those skilled in the art without inventive effort based on the concept of the present invention should be included within the scope of the claims of the present invention.

[0024] See Figures 1-4As shown, this utility model provides a rotor bow based on a NURBS-type hyperbolic variable cross-section profile, including a rotor bow body and a plate 1 included in the rotor bow body. The rotor bow body is a plate-shaped component that bends and extends along a central axis of symmetry. The rotor bow body is a NURBS-type hyperbolic curved section, with a lofted stretching transition section and a constant cross-section end section symmetrically connected to its two ends in sequence. The smooth transition between each section is achieved through a continuous curvature to achieve a smooth connection of the shape. Positioning holes 5 are provided at both ends of the rotor bow for assembly and positioning with the flywheel disc of a twisting machine.

[0025] Along its length, the cross-sectional width of the rotor bow gradually increases from the center to both ends. The cross-section is an axisymmetric composite profile, composed of a lower horizontal line segment 3, left and right half-elliptical streamlines 4, and an upper three-point circular arc. A bow guide groove 2 is provided in the middle of the plate 1 along its thickness direction. The groove bottom is arc-shaped and smoothly connected to the composite profile with a continuous curvature G2 / G3, thereby maintaining the guiding function while reducing local stress concentration. Any cross-sectional profile on the NURBS-type hypercurvature bending section is a quasi-elliptical streamline 4, with its total width smoothly varying with the location of the cross-section.

[0026] Example 1:

[0027] like Figure 5 As shown, several sets of guide ring positioning holes 6 are arranged symmetrically with respect to the length center along the middle of the rotor bow. The hole spacing is symmetrically and non-linearly increasing along the length direction, gradually increasing from the middle to both ends, to match the gradual transition of the path and tension of the steel cord during high-speed twisting. The guide ring positioning holes 6 are located on both sides of the guide ring mounting groove 7. A smooth transition zone 8 is provided between the mounting groove 7 and the plate 1 to reduce stress concentration caused by local geometric abrupt changes.

[0028] The guide ring 9 has a symmetrical structure and is installed in the guide ring mounting groove 7. Its lower surface fits the contour of the upper surface of the rotor bow at the installation position. The upper surface of the guide ring 9 is a quasi-elliptical streamline 4 and smoothly transitions with the surrounding composite cross section.

[0029] The lower part of the guide ring 9 is provided with a steel cord channel groove, which has an arc-shaped profile and corresponds to the bow guide groove 2; a hard alloy liner 10 is tightly embedded in the channel groove, and the shape of the liner 10 is formed by the channel groove profile offset inward at equal intervals.

[0030] The inner lining material 10 is either WC-Co or ceramic.

[0031] The material of plate 1 is titanium alloy, and it undergoes appropriate heat treatment to meet the requirements of strength, rigidity and fatigue resistance under high-speed rotation; a nominal equal thickness structure is adopted to take into account dynamic balance and consistency of processing and assembly.

[0032] Example 2

[0033] See Figure 1This embodiment provides a high-speed, low-energy-consumption rotor bow based on a NURBS-type hyperbolic variable cross-section profile.

[0034] Without altering the aforementioned structural relationships and functional roles, a set of reproducible example parameters are provided: overall length L = 917 mm; length of the main body NURBS-type hyperbola bending section L1 = 570.26 mm; length of the end-spreading and stretching transition section L2 = 82.87 mm; length of the constant cross-section end section L3 = 90 mm. At three typical cross-sections: center section at AA: total cross-sectional width W1 = 16.0 mm; end of the bending section at BB: total cross-sectional width W2 = 22.45 mm; end of the spread section / start of the constant cross-section at CC: total cross-sectional width W3 = 24.0 mm; the width increase from BB to CC is achieved through spread stretching, ensuring the continuous curvature and smooth shape of the contour.

[0035] The composite cross-section profile has the same shape at points AA, BB, and CC, differing only in total width: the lower horizontal segment 3 has an example length of 6.4 mm; the left and right half-ellipse 4 has a major semi-axis of a = 4.8 mm and a minor semi-axis of b = 0.85 mm, with its inner endpoints tangent to both ends of the lower horizontal segment 3; the upper three-point arc is tangent to the upper ends of the left and right half-ellipses, forming a continuous curvature; the bottom of the bow guide groove 2 uses three-point defined arcs: (−3.3, 0.85), (3.3, 0.85), (0, 0.25), in mm, with its left and right endpoints tangent to the upper ends of the left and right half-ellipses; the nominal thickness of plate 1 is t = 1.70 mm.

[0036] Guide ring arrangement: 12 sets of guide ring positioning holes 6 are set in the middle of the length direction, with the length center as the plane of symmetry; the hole spacing increases symmetrically from the middle to both ends according to a non-linear law, matching the twisting tension and path transition of the steel cord. The lower channel groove of the guide ring 9 corresponds to the bow guide groove 2, and a hard alloy liner 10 is embedded in the groove, which is selected as WC-Co, HRA≥88.

[0037] The NURB double curvature section and the lofted stretching section are generated in 3D CAD using G2 / G3 smoothing constraints; the composite section tri-curve is constructed by horizontal line segments, semi-ellipses, and three-point arcs using tangent / curvature continuity constraints; the guide groove and the outer contour normal curvature are continuous; the key dimensions of the total width gradually increasing trajectory, guide groove position, and hole spacing are inspected using gauges / coordinate measuring machines; the guide ring mounting groove 7 and the transition zone are subjected to stress-relief chamfering and polishing; the inner liner 10 is assembled using interference fit / adhesive bonding / brazing to ensure that the channel dimensions and surface roughness meet the requirements for steel cord passage.

[0038] The implementation principle of this utility model embodiment is as follows: by designing the continuous curvature shape and composite section consistency of the NURBS-type double curvature bending section, the lofted stretching transition section and the equal cross-section end section, the width gradually increases while the shape remains constant while maintaining the guiding function. This improves dynamic balance, suppresses eddy currents and flutter, reduces vibration noise and aerodynamic drag, and optimizes stress distribution under high-speed conditions. Combined with the symmetrically increasing hole spacing of the guide ring 9 and the wear-resistant inner liner 10, the path and tension of the steel cord are further stabilized, wear is reduced and fatigue life is improved, which is consistent with the technical effects of the utility model content and claims.

Claims

1. A rotor bow based on a NURBS-type hypercurvature variable cross-section profile, comprising a rotor bow body and a plate (1) included in the rotor bow body, characterized in that: The main body of the rotor bow is a plate-shaped component that bends and extends along the central axis of symmetry. The whole is a NURBS-type double curvature bending section, with a lofted stretching transition section and a constant cross-section end section symmetrically arranged at both ends. The main body of the rotor bow has a cross-sectional width that gradually increases from the center to both ends along its length. The cross-section of the main body of the rotor bow is an axisymmetric composite profile, which is composed of the horizontal line segment (3) at the bottom, the elliptical streamlines (4) at both ends, and the bow guide groove (2) at the top, which is composed of three circular arcs or elliptical arcs.

2. The rotor bow based on a NURBS-type hypercurvature variable cross-section profile according to claim 1, characterized in that: The profile of any cross section on the NURBS-type hyperbola bending segment is an elliptical streamline (4), and the total width changes smoothly with the position of the cross section.

3. The rotor bow according to claim 2, characterized in that: The cross-sectional widths at both ends of the lofting and stretching transition section are different, and the transition is smooth to the constant width of the equal cross-section end section through the lofting and stretching method.

4. The rotor bow according to claim 3, characterized in that: The plate (1) is provided with a bow guide groove (2) in the middle, the bottom of which is arc-shaped and connected to the axisymmetric composite profile with a smooth and continuous curvature.

5. The rotor bow based on a NURBS-type hypercurvature variable cross-section profile according to claim 4, characterized in that: The rotor bow is provided with positioning holes (5) at both ends for mounting to the flywheel disc of the twisting machine.

6. The rotor bow based on a NURBS-type hypercurvature variable cross-section profile according to claim 5, characterized in that: Several sets of guide ring positioning holes (6) are provided in the middle along the length of the rotor bow for installing guide rings (9) to precisely limit the position of the steel cord; the guide ring positioning holes (6) are arranged symmetrically with respect to the central axis of symmetry.

7. The rotor bow based on a NURBS-type hypercurvature variable cross-section profile according to claim 6, characterized in that: The spacing between the positioning holes (6) of each group of guide rings is symmetrically and non-linearly increasing along the length direction, gradually increasing from the middle to both ends.

8. The rotor bow based on a NURBS-type hypercurvature variable cross-section profile according to any one of claims 6-7, characterized in that: The guide ring (9) is installed in the guide ring mounting groove (7). The guide ring (9) has a symmetrical structure. Its lower surface fits the upper surface contour of the rotor bow of the mounting part. Its upper surface is an elliptical streamline (4) and smoothly transitions with the axisymmetric composite contour. A smooth transition area (8) is provided between the mounting part and the plate (1).

9. The rotor bow based on a NURBS-type hypercurvature variable cross-section profile according to any one of claims 6-7, characterized in that: The lower part of the guide ring (9) is provided with a steel cord channel groove, which has an arc-shaped profile and corresponds to the bow guide groove (2).

10. The rotor bow based on a NURBS-type hypercurvature variable cross-section profile according to claim 9, characterized in that: The steel cord channel groove is tightly fitted with a hard alloy liner (10), the shape of which is formed by the channel groove outline offset inward at equal intervals.

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