CN223690137U - A type of anti-reverse hydraulic nut - Google Patents

Abstract

The utility model discloses an anti-withdrawal hydraulic nut which comprises a hydraulic cylinder, a piston and a locking nut, wherein an oil cavity of the hydraulic cylinder is connected with an external pump station through a flow channel, the piston is positioned in the oil cavity of the hydraulic cylinder and is in sliding connection with the hydraulic cylinder, the piston is of an annular structure and is provided with internal threads and external threads, the piston is connected with a bolt through the internal threads, the piston is connected with the locking nut through the external threads, and threads for connecting the locking nut and the piston are saw-tooth threads. According to the hydraulic nut disclosed by the utility model, the screw thread for connecting the lock nut and the piston is set as the sawtooth screw thread, and the sawtooth shape can generate friction force with the surface of the matched piece, so that the firmness and the tightness of the screw thread are improved, the sawtooth screw thread can be prevented from loosening or falling off, the service life and the stability of the screw thread are improved, the thread teeth of the sawtooth screw thread are not easy to deform, and the gap between the engaged internal screw thread and the engaged external screw thread is smaller, so that the hydraulic nut has a better anti-withdrawing effect and a good pre-tightening effect.

Description

Anti-withdrawal hydraulic nut

Technical Field

The utility model relates to the field of hydraulic nuts, in particular to an anti-withdrawal hydraulic nut.

Background

The hydraulic nut is used for occasions such as bolts needing to be frequently disassembled and assembled, pretightening of oversized bolts, locking of large workpieces and the like. Such as nuclear power engineering. The principle is that ultra-high pressure oil is utilized to generate a thrust force on the shaft and a tension force on the shaft sleeve, so that the shaft and the shaft sleeve are uniformly connected together under the stress.

Because the working condition of nuclear power engineering is compact, the space is limited, if the mechanical nut is adopted, the hydraulic nut is more suitable because the nut needs a larger space for disassembly and installation, and the pretension is difficult. The nuclear power engineering works in a high-temperature environment and can vibrate during working, so that the nuts used for connection are easy to loosen, radiation is often generated based on the particularity of the nuclear power engineering, therefore, the nuclear power engineering cannot be overhauled frequently, the physical health of workers can be affected, the hydraulic nuts are required to be good in thermal stability, and the hydraulic nuts can be guaranteed to work for 50 years due to good sealing performance.

The hydraulic nut mainly comprises three parts, including pneumatic cylinder, piston, lock nut, the piston is located the pneumatic cylinder, and with pneumatic cylinder sliding connection, be equipped with internal thread and external screw thread on the piston, through internal screw thread and bolted connection, through external screw thread and lock nut connection. The operation steps of the hydraulic nut are as follows:

The method comprises the following steps of 1, pushing a piston in a hydraulic cylinder by utilizing ultra-high pressure oil, directly applying external force to a bolt, and stretching the bolt subjected to the force in an elastic deformation area of the bolt;

And 2, tightening the locking nut after the bolt is stretched, so that the bolt can be locked at the stretched position by the locking nut, and then the hydraulic cylinder is decompressed, and hydraulic oil flows back into the pump station.

In the actual use process of the hydraulic nut, a certain gap exists between the lock nut and the threaded connection part of the piston.

In the step 1, the bolt can be stretched to a length just meeting the pretightening force, and after the hydraulic cylinder is depressurized, the hydraulic cylinder is in a negative pressure state, and a gap exists between the locking nut and the piston, so that the stretched bolt can generate a retraction phenomenon, the actual pretightening force is smaller than the pretightening force preset, the locking precision is reduced, and the locking is unreliable.

Disclosure of Invention

The utility model aims to construct and form an anti-withdrawal hydraulic nut based on the requirements of improving the locking precision of a hydraulic nut assembly bolt and preventing decompression and withdrawal on the basis of the existing hydraulic nut.

The utility model provides a prevent moving back hydraulic nut, includes pneumatic cylinder, piston and lock nut, the oil pocket of pneumatic cylinder passes through the runner and is connected with external pump station, the piston is located the oil pocket of pneumatic cylinder, and with pneumatic cylinder sliding connection, the piston is annular structure and is equipped with internal thread and external screw thread, the piston passes through internal thread and bolted connection, the piston passes through external screw thread and is connected with lock nut, its characterized in that, be used for connecting lock nut with the screw thread of piston is the sawtooth screw thread.

During rotational movement of the serration thread, the serration shape can generate friction with the surface of the mating member, thereby increasing the thread's firmness and tightness. And the sawtooth thread can prevent loosening or falling off, so that the service life and stability of the thread are improved.

Relatively common, the hydraulic nut is usually connected by adopting a pipe thread, the thread of the pipe thread is easier to deform compared with the thread of the sawtooth thread, and the clearance between the engaged internal thread and the engaged external thread is larger, so that the sawtooth thread has better anti-withdrawal effect and good pre-tightening effect when the hydraulic nut is depressurized.

Further, the thread teeth of the sawtooth threads comprise a first thread surface and a second thread surface, the first thread surface forms an included angle of 7 degrees with the rotating shaft, the second thread surface forms an included angle of 45 degrees with the rotating shaft, and the rotating shaft refers to a straight line where the axis line of the rotating shaft of the locking nut is located. Compared with the national standard, the first thread surface and the rotating shaft form an included angle of 3 degrees, the second thread surface and the rotating shaft form an included angle of 30 degrees, the connection strength is better, and the anti-withdrawal effect is better.

Further, the first thread surface arranged on the lock nut is opposite to the first thread surface arranged on the piston, and is propped against when the hydraulic nut is depressurized. Further, an oil cavity and a linkage cavity are arranged on the hydraulic cylinder, the oil cavity is communicated with the linkage cavity, the oil cavity is located above the linkage cavity, and the diameter of the oil cavity is larger than that of the linkage cavity.

Further, the piston comprises an upper part and a lower part, the diameter of the upper part is larger than that of the lower part, a sliding part is arranged on the outer side of the upper part of the piston, the sliding part is in sliding connection with the inner wall of the oil cavity, the external thread of the piston is arranged on the outer side of the upper part of the piston, the external thread of the piston is positioned above the sliding part, the lower part of the piston is in sliding connection with the linkage cavity,

The middle part of the piston is provided with a connecting hole penetrating up and down, the internal thread is arranged on the wall of the connecting hole, the diameter of the connecting hole is equal to that of the bolt,

The piston is provided with a groove which is communicated with the flow passage.

Further, a sealing element is arranged below the sliding element, and the sealing element is a V-shaped spring energy storage ring. Compared with a common O-shaped sealing ring, the V-shaped spring energy storage ring has better sealing effect and longer service life, and can ensure the service life of 50 years.

Further, the lock nut is provided with a plurality of connecting holes for connecting the screwing tool.

Furthermore, the hydraulic nut is made of a non-magnetic material, so that the mechanical performance of the hydraulic nut can be ensured.

The anti-withdrawal hydraulic nut has the beneficial effects that the threads for connecting the locking nut and the piston are set as the saw-tooth threads, and the saw-tooth threads can generate friction force with the surface of the matching piece during rotary motion, so that the firmness and the tightness of the threads are improved, the saw-tooth threads can be prevented from loosening or falling off, the service life and the stability of the threads are improved, the threads of the saw-tooth threads are not easy to deform, and the gap between the engaged internal threads and the engaged external threads is smaller, so that the saw-tooth threads have better anti-withdrawal effect and better pre-tightening effect during pressure relief of the hydraulic nut.

The foregoing description is only an overview of the present utility model, and is intended to be implemented in accordance with the teachings of the present utility model, as well as the preferred embodiments thereof, together with the following detailed description of the utility model, given by way of illustration only, together with the accompanying drawings.

Drawings

For a clearer description of an embodiment of the present utility model or a technical solution in the prior art, the drawings that need to be used in the embodiment will be briefly described, it will be apparent that the drawings in the following description are only some embodiments of the present utility model, and other drawings can be obtained according to these drawings without inventive effort for a person of ordinary skill in the art;

FIG. 1 is a schematic view of the overall structure of one embodiment of the hydraulic nut of the present utility model;

FIG. 2 is a schematic cross-sectional view of FIG. 1;

FIG. 3 is a schematic view of a hydraulic cylinder in one embodiment of the hydraulic nut of the present utility model;

FIG. 4 is an enlarged view of the structure of FIG. 2 at A;

FIG. 5 is a schematic view of the construction of a lock nut in one embodiment of the hydraulic nut of the present utility model;

102, a hydraulic cylinder, 103, an interface, 104, a piston, 105, a lock nut, 106, a connecting hole, 109, a linkage cavity, 110, a runner, 111, an oil cavity, 115, a sliding part, 117, a connecting hole, 120, an annular groove and 121, and a V-shaped spring energy storage ring.

Detailed Description

In order to make the technical problems, technical schemes and beneficial effects solved by the utility model more clear, the utility model is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the utility model.

A back-out preventing hydraulic nut of the present utility model will be further described with reference to the accompanying drawings.

As shown in fig. 1 and 2, the hydraulic nut in this embodiment is made of a non-magnetic material, and includes a hydraulic cylinder 102, a piston 104 and a lock nut 105, where the hydraulic cylinder 102 is connected with a hydraulic oil interface 103, the hydraulic cylinder 102 is connected with an external pump station through the interface 103, the piston 104 is disposed in the hydraulic cylinder 102, the piston 104 is slidably connected with the hydraulic cylinder 102, the piston 104 is connected with the lock nut 105 through threads, and the piston 104 is provided with a self-locking bolt 112.

As shown in fig. 2 and 3, the hydraulic cylinder 102 is provided with an oil cavity 111 and a linkage cavity 109, the oil cavity 111 is communicated with the linkage cavity 109, the diameter of the oil cavity 111 is larger than that of the linkage cavity 109, the oil cavity 111 is located above the linkage cavity 109, a runner 110 is arranged in the hydraulic cylinder 102, the runner 110 comprises a horizontal section and a vertical section, the horizontal section of the runner 110 is connected with the interface 103, the vertical section of the runner 110 is communicated with the oil cavity 111, and the horizontal section of the runner 110 is communicated with the vertical section of the runner 110.

As shown in fig. 2, the piston 104 includes an upper portion and a lower portion, the diameter of the upper portion is larger than that of the lower portion, a connecting hole 106 penetrating up and down is provided in the middle of the piston 104, an internal thread is provided on the wall of the connecting hole 106, the internal thread is used for connecting with a bolt, the diameter of the connecting hole 106 is equal to that of the bolt, and an external thread is provided on the outer side of the upper portion of the piston 104, and the external thread is used for connecting with a lock nut 105.

The thread for connecting the lock nut 105 and the piston 104 is a saw tooth thread, the thread of the saw tooth thread comprises a first thread surface and a second thread surface, the first thread surface forms an included angle of 7 degrees with the rotating shaft (the rotating shaft is a straight line where the rotating shaft axis of the lock nut is located), and the second thread surface forms an included angle of 45 degrees with the rotating shaft.

The lower portion of the piston 104 is slidably connected to the linkage chamber 109.

As shown in fig. 2 and 4, a sliding part 115 is arranged on the outer side of the piston 104, the sliding part 115 is slidably connected with the inner wall of the oil cavity 111, an external thread arranged on the piston 104 is positioned above the sliding part 115, and a V-shaped spring energy storage ring 121 is arranged below the sliding part 115.

The lower end surface of the upper part of the piston 104 is provided with an annular groove 120, and the annular groove 120 is communicated with the flow passage 110.

As shown in fig. 5, six connection holes 117 for connecting the turning tool are provided on the lock nut 105.

When the bolts are installed using the hydraulic nuts,

A. The hydraulic nut is connected with the bolt through the internal thread on the piston 104, the piston 104 positioned in the hydraulic cylinder 102 is pushed by ultra-high pressure oil, and the bolt subjected to the force is stretched in the elastic deformation area of the bolt;

b. Tightening the lock nut 105 locks the bolt in the extended position.

The foregoing description is only a preferred embodiment of the present utility model, but the scope of the present utility model is not limited thereto, and any person skilled in the art, who is within the scope of the present utility model, should make equivalent substitutions or modifications according to the technical solution of the present utility model and the inventive concept thereof, and should be covered by the scope of the present utility model.

Claims (9)

1. The utility model provides a prevent moving back hydraulic nut, includes pneumatic cylinder, piston and lock nut, the oil pocket of pneumatic cylinder passes through the runner and is connected with external pump station, the piston is located the oil pocket of pneumatic cylinder, and with pneumatic cylinder sliding connection, the piston is annular structure and is equipped with internal thread and external screw thread, the piston passes through internal thread and bolted connection, the piston passes through external screw thread and is connected with lock nut, its characterized in that, be used for connecting lock nut with the screw thread of piston is the sawtooth screw thread.

2. The anti-back hydraulic nut according to claim 1, wherein the thread of the sawtooth thread comprises a first thread surface and a second thread surface, the first thread surface forms an included angle of 7 degrees with a rotation axis, the second thread surface forms an included angle of 45 degrees with the rotation axis, and the rotation axis refers to a straight line where the rotation axis of the lock nut is located.

3. The anti-backup hydraulic nut of claim 2, wherein the first threaded surface provided on the lock nut is positioned opposite the first threaded surface provided on the piston and abuts against the first threaded surface when the hydraulic nut is depressurized.

4. The anti-withdrawal hydraulic nut of claim 1, wherein the hydraulic cylinder is provided with an oil cavity and a linkage cavity, the oil cavity is communicated with the linkage cavity, the oil cavity is positioned above the linkage cavity, and the diameter of the oil cavity is larger than that of the linkage cavity.

5. The anti-back hydraulic nut according to claim 1, wherein the piston comprises an upper portion and a lower portion, the diameter of the upper portion is larger than that of the lower portion, a sliding piece is arranged on the outer side of the upper portion of the piston and is in sliding connection with the inner wall of the oil cavity, the external thread of the piston is arranged on the outer side of the upper portion of the piston, the external thread of the piston is located above the sliding piece, and the lower portion of the piston is in sliding connection with the linkage cavity.

6. The anti-withdrawal hydraulic nut of claim 5, wherein a connecting hole penetrating up and down is formed in the middle of the piston, the internal thread is formed in the wall of the connecting hole, and the diameter of the connecting hole is equal to that of the bolt.

7. The anti-backup hydraulic nut of claim 1 wherein the piston is provided with a recess, the recess being in communication with the flow passage.

8. The anti-back hydraulic nut according to claim 5, wherein a sealing element is arranged below the sliding element, and the sealing element is a V-shaped spring energy storage ring.

9. The anti-back hydraulic nut according to claim 1, wherein a plurality of connecting holes for connecting the screwing tool are formed in the locking nut.