A non-loosening nut

Abstract

A non-loosening nut comprising: a main body (20) containing: body threads (21), spherical seats (22), and guide grooves (23); wherein the body threads (21) are continuous standard thread, the spherical seats (22) are disposed at the root of the body threads (21), the guide grooves (23) within the spherical seats (22), having an axial tilt angle; hemispherical elements (30) containing: hemispherical threads (31), guide pins (32), and inclined surface (33), wherein the hemispherical threads (31) continously engage with the body threads (21); the guide pins (32) are slidably fitted into the guide grooves (23), with their axes deflected by 30 degrees relative to the symmetric center of the hemispherical elements (30); the inclined surface (33) form an initial angle with the bottom end face of the main body (20).

Description

A Non-loosening NutTechnical Field

[0001] The present invention pertains to the field of mechanical fastening technology, specifically relating to a non-loosening nut based on friction-state control and dynamic adjustment of thread angles, along with its working mechanism. It is designed to address anti-loosening requirements for threaded connections under vibration and shock conditions.Background Art

[0002] Conventional threaded pairs are prone to loosening under vibration impacts due to micro-displacement accumulation caused by transitions in friction states (static→dynamic friction).

[0003] Existing anti-loosening nuts primarily rely on additional components (e.g., spring washers, nylon inserts) or structural deformation (e.g., double nuts, wedge threads), which suffer from high assembly complexity, rapid preload decay, and poor reusability. Anti-loosening techniques demonstrate suboptimal performance.Technical Solution

[0004] The present invention resolves these issues by designing hemispherical thread elements with dynamic adjustment capabilities, during preloading, these elements actively regulate friction states and thread lead angles, converting vibrational energy into clamping force enhancement, thereby fundamentally suppressing loosening.Description of Drawings

[0005] Fig.1: External view of the non-loosening but;

[0006] Fig.2: Cross-sectional view of the nut's overall structure;

[0007] Fig.3: Cross-sectional view of the main body;

[0008] Fig.4: External structure of the hemispherical element;

[0009] Fig.5: Decomposed diagram of the hemispherical element's compound motion trajectory;

[0010] Fig.6: Schematic of eccentric compression and the wedge-shaped self-locking zone.Summary of the Invention

[0011] The invention provides a non-loosening nut whose core innovation lies in the compound motion of hemispherical thread elements to achieve friction-state control and dynamic thread lead angle adjustment. the solution is detaild as followings:

[0012] Structural Composition: The non-loosening nut (10) (see Fig.1) comprising a main body (20) and hemispherical elements (30) (see Fig.2):

[0013] Main Body (20) (see Fig.3): Continuous standard threads (21) (herafter "body threads"); Spherical seats (22) at the root of the body threads (21), each incorporating a guide groove (23) with an axial tilt angle α=40°~50°.

[0014] Hemispherical elements (30) (see Fig.4): Hemispherical threads (31) on the side surface, continuously engaging with the body threads (21); Guide pins (32) on the hemispherical surface, slidably fitted into the guide grooves (23), with their axes deflected by 30° relative to the symmetric center of the hemispheres; Inclined surfaces (33) forming an initial angle β=2°~15° with the bottom end face of the main body (20).

[0015] Working Principle: Under preload, the hemispherical elements (30) undergo compound motion (see Fig.5):

[0016] a) Circumferential Rotation (θ=2°~15°): The guide pins (32) slide along the guide grooves (23), driving the hemispherical elements (30) to rotate circumferentially, causing the tail of the hemispherical threads (31) to compress the bolt threads;

[0017] b) Radial Deflection (γ=2°~15°): The inclined surfaces (33) deflect to become parallel to the bottom end face of the main body (20), inducing radial deflection that compresses the apex of the hemispherial threads (31) against the bolt threads. This compound motion creates an eccentric compression state with an eccentricity σ=0.2mm~0.9mm, where σ is positively correlated with the nut's nominal diameter.

[0018] c) Geometric Self-Locking (see Fig.6): Radial deflection γ induces a sudden change in the thread lead angle, forming a wedge-shaped self-locking zone (η=1°~9°) at the tail of the engagement direction to block reverse displacement.

[0019] Friction-State Control Mechanism:

[0020] a) Clearance Elimination: Eccentric compression eliminates clearance the threaded pairs blocking the transition path from static to dynamic friction;

[0021] b) Dynamic Compensation: In vibration enviroments, the compound motion converts vibrational energy into increased compressive stress on the contact surfaces, dynamically compensating for clamping force.

[0022] Material Properties: The hemispherical elements (30) employ gradient-structured material:

[0023] a) Surface Hardened Layer: Hardness HRC60-62, thickness δ=0.3mm~0.5mm, enhancing wear resistance.

[0024] b) Tough Core Layer: Hardness HRC32-35, ensuring impact resistance.Detailed Embodiments

[0025] Embodiment 1: M6 Nominal Diameter Nut

[0026] Parameters: α=48°, β=13°, with preload-release positioning pins embedded in the crescent-shaped notches of the guide pins and guide grooves;

[0027] Motion Relationship: Under preload, θ=13°, γ=11.5°, satisfying sinγ=1-2sin(30°-θ / 2)±0.01, β≧γ;

[0028] Eccentricity: σ=0.26mm, wedge angle η=7°.

[0029] Embodiment 2: M24 Nominal Diameter Nut

[0030] Parameters: α=48°, β=6°, with preload-release positioning pins embedded in the crescent-shaped notches of the guide pins and guide grooves;

[0031] Motion Relationship: Under preload, θ=5.5°, γ=5°, satisfying sinγ=1-2sin(30°-θ / 2)±0.01, β≧γ.

[0032] Eccentricity: σ=0.47mm, wedge angle η=2°

[0033] Embodiment 3: M64 Nominal Diameter Nut

[0034] Parameters: α=45°, β=3°, with preload-release positioning pins embedded in the crescent-shaped notches of the guide pins and guide grooves;

[0035] Motion Relationship: Under preload, θ=3°, γ=2.6°, satisfying sinγ=1-2sin(30°-θ / 2)±0.01, β≧γ;

[0036] Eccentricity: σ=0.67mm, wedge angle η=1.5°Assembly Method

[0037] 1. Nest the hemispherical elements (30) into the spherical seats (22) of the main body (20) with clearance fit;

[0038] 2. Place preload-release positioning pins into the crescent-shaped notches of the guide pins (32);

[0039] 3. Adjust the guide pins (32) to the arc-bottom position of the guide grooves (23), locking the positioning pins centrally in the notches to secure the initial position of the hemispherical elements (30);

[0040] 4. Adjust the angle between the inclined surfaces (33) and the bottom end face of the main body (20) to ensure continuous engagement between the hemispherical threads (31) and the body threads (21).     Final Note

[0041] While the invention has been described in detail with reference to the above embodiments, modifications or equivalent substitutions of certain technical features may still be made by those skilled in the art without departing from the spirit and scope of the invention. All such modifications, substitutions, and improvements shall fall within the protection scope of the present invention.

Claims

1.A non-loosening nut (10) based on friction-state control and dynamic adjustment of thread lead angles, comprising:    a) a main body (20) containing: body threads (21), spherical seats (22), and guide grooves (23); wherein:        the body threads (21) are continuous standard thread, the spherical seats (22) are disposed at the root of the body threads (21), the guide grooves (23) within the spherical seats (22), having an axial tilt angle α=40°~50°;    b) hemispherical elements (30) containing: hemispherical threads (31), guide pins (32), and inclined surface (33), wherein:        the hemispherical threads (31) continously engage with the body threads (21); the guide pins (32) are slidably fitted into the guide grooves (23), with their axes deflected by 30° relative to the symmetric center of the hemispherical elements (30); the inclined surface (33) form an initial angle β=2°~15° with the bottom end face of the main body (20).2.The non-loosening nut according to claim 1, characterized in that: when a preload is applied, the inclined surface (33) of the hemispherical elements (30) deflect by 2°~15° to become parallel to the bottom end face of the main body (20), generating the following compound motion components:   a) The guide pins (32) slide along the guide grooves (23), inducing circumferential rotation of the hemispherical elements (30) by θ=2°~15°;   b) The hemispherical elements (30) undergo radial deflection by γ=2°~15°, wherein γ and θ satisfy sinγ=1-2sin(30°-θ / 2)±0.01, and β≧γ.3.The non-loosening nut according to claim 2, characterized in that:    a) the circumferential rotation θ=2°~15° causes the tail of the hemispherical threads (31) to circumferentially compress the bolt threads (21);   b) the radial deflection γ=2°~15° causes the apex of the hemispherical threads (31) to radially compress the bolt threads;    c) said compound motion forms an eccentric compression state with an eccentricity σ=0.2mm~0.9mm, wherein σ is positively correlated with the nominal diameter of the nut.4.The non-loosening nut according to claim 2, characterized in that: the radial deflection γ=2°~15° induce a sudden changes in the thread lead angle between the hemispherical threads (31) and the continuous body threads (21); the tail of the hemispherical threads (31) in engagement direction axially compresses the bolt threads, forming a wedge-shaped self-locking zone with an angle η=1°~9°.5.The non-loosening nut according to claim 1, characterized in that: the hemispherical elements (30) are made of gradient-structured material comprising:    a) a surface hardened layer with a hardness of HRC60-62 and a thickness δ=0.3mm~0.5mm;    b) a tough core retaining a hardness of HRC32-35.

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