Composite locknut
Technical Field
The utility model belongs to the technical field of the nut, concretely relates to compound locknut.
Background
The screw connection has been widely used in the industries of automobiles, machine tools, aerospace, railways and the like because of the advantages of compact structure, easy assembly and disassembly, large connecting force, reusability and the like. The traditional threaded connection meets the self-locking condition under the conditions of static load action and small temperature change, the unscrewing torque between threads is smaller than the self-locking torque, the connection system is in a balanced state, effective locking can be realized, and generally, an additional anti-loosening method is not required to be introduced to prevent loosening. However, when the structure is subjected to impact and vibration, particularly to dynamic load in a transverse circulation mode, the pretightening force of the threaded connection is easy to gradually reduce, and finally, the problems of connection failure in the modes of loosening, disengaging, dropping and the like are caused. In safety and critical applications, such failures can be catastrophic.
In general, the durability of a mechanical structure is proportional to the number of bolted connections, and with the development of modern manufacturing industry, the problem of avoiding loosening of a threaded connection structure during operation has become one of the core problems of the design of the threaded connection structure at present. Therefore, it is critical to design and use a secure and reliable threaded coupling anti-loosening method. Although there are many methods for preventing loosening of threaded fasteners, there are four general methods: the first is friction anti-loosening, which mainly depends on increasing friction force; the second is mechanical anti-loosening, which is to use a pin, a gasket and a steel wire to clamp a nut; the third is rivet punching anti-loosing, mainly to rivet and weld the thread pair; the fourth is the structure anti-loose, such as Hard Lock locknut, Down's screw anti-loose, ST2 type locknut, SLB screw anti-loose, etc.
The first type of friction locking is the most widely used locking method, which generates a positive pressure between the thread pairs that is not changed by an external force, thereby obtaining a friction force that can prevent the thread pairs from rotating relative to each other. This friction can be achieved by axial or simultaneous two-way compression of the thread pairs. Such as an elastic washer, a double nut, a self-locking nut, a nylon insert locking nut and the like. The anti-loosening mode is convenient for disassembling the nut, but under the conditions of impact, vibration and variable load, the bolt can cause the pretightening force to be reduced due to loosening, the lost pretightening force is slowly increased along with the increase of the vibration times, the nut can be finally loosened and the thread coupling can be failed, and the increase of the friction force by increasing the positive pressure between the thread pairs is limited.
The second way is to use a stop to directly limit the relative rotation of the thread pairs. Such as the use of cotter pins, tandem wires, and stop washers. This kind of mode causes the dismantlement inconvenient, and its locking mode does not have the pretightning force moreover, when the bolt pine moves back to locking position, locking mode could take place the effect promptly. Thus, this approach is not anti-loosening in nature, but rather anti-drop.
The third mode is riveting and anti-loosening, which adopts the methods of punching, welding, bonding and the like after screwing, so that the screw pair loses the characteristics of the kinematic pair and is connected into non-detachable connection. The disadvantage of this method is that the bolt can only be used once and is difficult to remove, and the bolt pair must be destroyed to be removed. The application range is very limited.
The most classical anti-loose structure in the fourth structure is a Japanese Hard Lock anti-loose nut, which is improved by combining the anti-loose principle of a double nut and a convex-concave nut. The upper nut is a concave nut, the lower nut is a convex nut, the center slightly shifts during processing, eccentric processing is achieved, the effect of driving a wedge into a gap is achieved, loosening of threads is prevented, different corresponding eccentric amounts exist for different sizes and materials, manufacturing and production are troublesome, and efficiency is low.
SUMMERY OF THE UTILITY MODEL
An object of the utility model is to overcome not enough among the prior art, a compound locknut is provided, moreover, the steam generator is simple in structure, wedge reinforcement structure and the spring structure that will have logical groove combine together, the axial pretightning force is unchangeable and radial pretightning force is multiplied and is increased, the wedge structure that leads to the groove in the area makes nut and bolt actual area of contact show the increase, too big local wear and destruction between the check surface when avoiding dismantling, used repeatedly many times, spring structure can provide invariable lasting pretightning force, vibrations are better with the big occasion locking effect of temperature variation.
The utility model provides a following technical scheme:
a composite locknut comprises a taper nut, a taper sleeve and a spring structure;
the taper nut comprises a rotary sleeve, a connecting sleeve and an inner taper sleeve which are sequentially connected, the outer surface of the inner taper sleeve is a conical surface, and a plurality of through grooves extending along the axial direction of the inner taper sleeve are formed in the inner taper sleeve;
the tapered sleeve is internally provided with a tapered groove and a spring groove which are communicated, the tapered groove is matched with the inner tapered sleeve, and the spring groove is internally provided with a plurality of spring structures.
Preferably, the inner surfaces of the rotary sleeve, the connecting sleeve and the inner taper sleeve are provided with internal threads matched with the external threads of the bolt rod.
Preferably, the outer surface of the rotating sleeve is hexagonal.
Preferably, the outer surface of the connecting sleeve is an arc surface.
Preferably, the through grooves are uniformly distributed along the circumferential direction of the inner taper sleeve.
Preferably, the upper surface of the spring groove protrudes out of the conical surface groove and forms an annular limiting table, and the inner diameter of the limiting table is smaller than the outer diameter of the inner taper sleeve.
Preferably, the spring structure is a disc spring, and the outer diameter of the disc spring is smaller than the inner diameter of the end face of the spring groove.
Preferably, the taper angles of the outer surface of the inner taper sleeve and the inner surface of the tapered groove are both 3 to 15 °.
Compared with the prior art, the beneficial effects of the utility model are that:
(1) the inner taper sleeve of the taper nut is matched with the taper groove of the taper sleeve and the matching surface is a taper surface, so that a wedge-shaped force increasing structure is formed, the radial pretightening force of the thread is increased in multiples under the condition that the axial pretightening force is kept unchanged, the radial gap causing impact load and fatigue damage is eliminated, the radial contact area of the bolt and the nut is also obviously increased, and the threaded connection force is increased;
(2) the inner taper sleeve of the taper nut is provided with a plurality of through grooves extending along the axial direction of the inner taper sleeve, so that the inner taper sleeve can deform along the radial direction within a certain range, the laminating area of the inner taper sleeve and the bolt is increased, the threaded connection force is increased, the anti-loosening effect is realized, the overlarge local abrasion and damage between locking surfaces during disassembly are avoided, and the taper nut can be repeatedly used for many times;
(3) the spring groove of the taper sleeve is internally provided with a plurality of spring structures, when the taper sleeve is used, the lower end surface of each spring structure is contacted with the upper end surface of a fastening object, when the taper nut is screwed, the spring structures can always keep the radial pretightening force and the axial pretightening force of the thread, so that the thread pretightening is not influenced by adverse factors such as vibration, thermal expansion, cold contraction and the like, the anti-loosening effect is realized, and the connection failure of the nut and the bolt is prevented;
(4) the utility model provides a compound locknut, the component is small in quantity, simple structure, and it is convenient to make, with low costs, is convenient for produce and use.
Drawings
FIG. 1 is a schematic structural view of a composite locknut;
FIG. 2 is a schematic structural view of a taper nut;
FIG. 3 is an axial cross-sectional view of the taper nut;
FIG. 4 is an axial cross-sectional view of the taper sleeve;
FIG. 5 is a cross-sectional axial view of the composite locknut;
fig. 6 is a sectional view of the composite locknut;
labeled as: 1. a taper nut; 1-1, rotating sleeve; 1-2, inner taper sleeve; 1-3, connecting sleeves; 1-4, through grooves; 1-5, internal threads; 2. a taper sleeve; 2-1, a conical groove; 2-2, spring grooves; 2-3, a limit table; 2-4, end faces of the spring grooves; 3. a bolt; 3-1, bolt bar; 3-2, bolt head; 4. a spring structure; 5. and (5) fastening the object.
Detailed Description
The present invention will be further described with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.
It should be noted that, in the description of the present invention, the terms "front", "rear", "left", "right", "upper", "lower", "inner", "outer", etc. indicate the directions or positional relationships based on the directions or positional relationships shown in the drawings, and are only for convenience of description of the present invention but do not require the present invention to be constructed and operated in a specific direction, and thus, should not be construed as limiting the present invention.
As shown in fig. 1-6, a composite locknut comprises a taper nut 1, a taper sleeve 2 and a spring structure 4; the taper nut 1 comprises a rotary sleeve 1-1, a connecting sleeve 1-3 and an inner taper sleeve 1-2 which are connected in sequence, the outer surface of the inner taper sleeve 1-2 is a conical surface, and a plurality of through grooves 1-4 extending along the axial direction of the inner taper sleeve 1-2 are arranged on the inner taper sleeve 1-2; the tapered sleeve 2 is internally provided with a tapered groove 2-1 and a spring groove 2-2 which are communicated, the tapered groove 2-1 is matched with the inner tapered sleeve 1-2, and a plurality of spring structures 4 are arranged in the spring groove 2-2.
As shown in figures 2 and 3, the inner surfaces of the rotary sleeve 1-1, the connecting sleeve 1-3 and the inner taper sleeve 1-2 are provided with inner threads 1-5 matched with the outer threads of the bolt rod 3-1. The outer surface of the rotating sleeve 1-1 is a hexagonal surface, so that external force application is facilitated to rotate. The outer surface of the connecting sleeve 1-3 is a cambered surface, so that stress concentration is avoided, collision damage in the installation process is also prevented, and the service life is prolonged. The through grooves 1-4 are uniformly distributed along the circumferential direction of the inner taper sleeve 1-2, so that the inner taper sleeve 1-2 is uniformly deformed along the radial direction in a certain range, and the attaching area of the inner taper sleeve 1-2 and the bolt rod 3-1 is increased.
As shown in figure 4, the upper surface of the spring groove 2-2 protrudes out of the conical surface groove 2-1 and forms an annular limiting table 2-3, the inner diameter of the limiting table 2-3 is smaller than the outer diameter of the inner taper sleeve 1-2, and the lower end surface of the inner taper sleeve 1-2 is clamped on the upper end surface of the limiting table 2-3 during installation. The spring structure 4 is a disc spring, and the outer diameter of the disc spring is smaller than the inner diameter of 2-4 parts of the end face of the spring groove, so that the disc spring is convenient to mount.
As shown in FIG. 5, the taper angles of the outer surface of the inner taper sleeve 1-2 and the inner surface of the tapered groove 2-1 are each 3-15 deg..
As shown in fig. 5 and 6, during installation, a bolt rod 3-1 of a bolt 3 sequentially passes through a fastening object 5, a spring structure 4, a taper sleeve 2 and a taper nut 1, so that the upper end surface of the bolt head 3-2 is in contact with the lower end surface of the fastening object 5, the spring structure 4 is clamped in a spring groove 2-2 of the taper sleeve 2, the lower end surface of the spring structure 4 is in contact with the upper end surface of the fastening object 5, the upper end surface of the spring structure 4 is in contact with the upper surface of the spring groove 2-2, and an inner taper sleeve 1-2 of the taper nut 1 is clamped in a taper groove 2-1 of the taper sleeve 2.
As shown in fig. 5 and 6, in the working state, the rotating sleeve 1-1 of the taper nut 1 is rotated, and the taper nut 1 moves downwards, so that the outer surface of the inner taper sleeve 1-2 is contacted with the inner surface of the taper groove 2-1; and continuing to rotate the rotating sleeve 1-1 of the taper nut 1, driving the taper sleeve 2 to move downwards by the taper nut 1 until the bottom of the end face of the spring groove 2-2 is contacted with the upper end face of the fastening object 5, and applying a locking torque to meet the standard requirement during rotation. At the moment, the inner taper sleeve 1-2 of the taper nut 1 is subjected to the axial force given by the locking moment and the elastic force of the spring structure 4 and also subjected to the inclined plane reaction force (which can be decomposed into the axial force and the radial force) given by the taper sleeve 2, and the radial force is a plurality of times of the axial force, so that the internal thread of the taper nut 1 is tightly attached to the external thread on the bolt rod 3; meanwhile, the inner taper sleeve 1-2 deforms along the radial direction in a certain range in the installation process, and the attaching area of the inner taper sleeve 1-2 and the bolt rod 3-1 is increased, so that the threaded connection force is increased, and the anti-loose locking effect is achieved.
The utility model provides a compound locknut has adopted the principle of inflation screw, will have wedge reinforcement structure and the spring structure that leads to the groove and combine together, and the axial pretightning force is unchangeable and radial pretightning force increases at double. Different from other traditional structures, due to the existence of the through groove, the front end of the inner taper sleeve in a cantilever state is easy to generate overall deformation under the action of radial pretightening force, and meanwhile, the internal thread is matched with the external thread of the bolt rod (the thread shape and the thread pitch are completely consistent), so that the axial gap and the radial gap between the nut and the bolt are effectively eliminated (the radial gap is the main reason for generating thread loosening), the actual contact area between the nut and the bolt is obviously increased, the reliability of thread locking is improved, overlarge local abrasion and damage between locking surfaces during disassembly can be avoided, and the locking force can be continuously used without obvious change after 30 times of disassembly; the spring structure can provide constant and lasting pretightening force, and the anti-loosening effect is better on occasions with large vibration and temperature change.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be considered as the protection scope of the present invention.