Anti-loosening mechanism for piston rod and piston rod seat

Abstract

The utility model belongs to the technical field of piston type compressors, and particularly relates to an anti-loosening mechanism for a piston rod and a piston rod seat, which comprises the piston rod, the piston rod seat, a crosshead and a sealing seat, a boss is arranged at the bottom of the hexagonal outer contour of the locknut, one end of the limiting piece is a clamping and pressing end which is clamped and pressed on the outer surface of the boss, the other end of the limiting piece is a positioning end, and the positioning end is connected with the piston rod seat through a positioning screw. The threads are fine threads. The piston rod locking device has the advantages that the piston rod is good in locking effect and simple and compact in structure, threads on the piston rod are not damaged, the piston rod can be disassembled repeatedly, and the service life of parts is prolonged; piston stroke dead points can be conveniently adjusted, compressor cylinder body parts do not need to be disassembled, and the compressor efficiency is guaranteed; and cylinder collision accidents caused by looseness of the piston rod in the operation of the piston compressor are avoided, and the safety is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of piston compressors, and in particular relates to an anti-loosening mechanism for a piston rod and a piston rod seat. Background Art

[0002] A piston compressor relies on the reciprocating motion of a piston to pressurize and transport gas. It is a positive displacement compressor, also known as a "reciprocating piston compressor" or "reciprocating compressor." It primarily consists of a working chamber, transmission components, a body, and auxiliary components. The working chamber, which directly compresses gas, comprises a cylinder, cylinder liner, valve, packing, piston, and piston rod. The piston, driven by the piston rod, reciprocates within the cylinder. The volume of the working chambers on either side of the piston alternates, with the pressure on the side decreasing and gas being discharged through the valve. On the side with the volume increasing, gas is drawn in through the valve due to the pressure decrease. Transmission components, such as the crankshaft, connecting rod, eccentric slider, and swash plate, are used to achieve this reciprocating motion. The crankshaft-connecting rod mechanism, consisting of a crosshead, connecting rod, and crankshaft, is the most commonly used.

[0003] During operation, the piston rod of a piston compressor must withstand significant piston forces and vibrations. A loose piston rod can lead to unstable compressor operation and even cause failure. Therefore, ensuring the stability and anti-loosening properties of the piston rod is crucial for the proper operation of the compressor. The sealing performance between the piston rod and the sealing device has a direct impact on the efficiency and service life of the compressor. A loose piston rod can compromise the integrity of the seal, causing gas leakage, reducing compression efficiency, and potentially accelerating seal wear. In certain applications, such as petrochemicals and refrigeration, the safety of piston compressors is particularly important. A loose piston rod can cause mechanical failure or even lead to safety accidents. Therefore, the design of the anti-loosening device must fully consider safety.

[0004] The connection methods between the piston rod and the crosshead are mainly flange type and threaded type. The industry currently uses a flange type (or connector) structure for piston compressors, which can effectively ensure the stability of the connection between the piston rod and the crosshead. The connection structure is complex and bulky. As long as the fasteners are arranged and selected reasonably, and some anti-loosening measures are adopted for the fasteners, the connection between the piston rod and the crosshead will not loosen under normal circumstances. Threaded connections usually apply a preload to the threaded part through a certain torque. The friction formed by the deformation and compression between the internal and external threads can ensure that the thread is not loose. The convenience and ease of operation are very popular with users. However, for large-diameter piston rods used in large and extra-large piston compressors, due to the large thread pitch and strong deformation resistance of the thread teeth, the preload required for anti-loosening is very large, which will cause a certain degree of damage to the piston rod thread, which is not conducive to subsequent disassembly and maintenance.

[0005] When the piston rod and crosshead connection of a piston compressor loosen during operation, the gap between the piston and cylinder can change, causing the piston to strike the cylinder. This can cause severe vibration and piston rupture in the compressor, or even cracks in the cylinder, rendering it useless. This is particularly true in compressors handling flammable and explosive media, where it can easily lead to serious accidents such as combustion and explosion, resulting in casualties and significant property damage. Therefore, a connection between the piston rod and crosshead that is simple in construction and processing, easy to use, and provides a secure and reliable connection is crucial to completely prevent such accidents. Utility Model Content

[0006] The purpose of the utility model is to provide an anti-loosening mechanism for a piston rod and a piston rod seat, which overcomes the shortcomings of the existing technology and adopts a new piston rod anti-loosening structure. The connection between the piston rod and the crosshead has the advantages of simple processing, convenient use, stable connection and reliable effect, improves the anti-loosening effect and reduces the difficulty of operation. The structure does not require disassembling the cylinder, and the piston can be directly disassembled to replace the seal, which saves maintenance time, reduces workload and is economical.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0008] A piston rod and piston rod seat anti-loosening mechanism includes a piston rod, a piston rod seat, a crosshead and a sealing seat, the piston rod is connected to the piston rod seat through a thread, and is characterized in that a anti-loosening nut is provided at the piston rod thread on the outside of the piston rod seat, and a boss is provided at the bottom of the hexagonal outer contour of the anti-loosening nut, one end of the limiting plate is a clamping end, the clamping end is clamped on the outer surface of the boss, and the other end of the limiting plate is a positioning end, which is connected to the piston rod seat through a positioning screw; the thread is a fine thread.

[0009] Furthermore, the clamping end of the limiting piece is provided with a hexagonal hole matching the hexagonal surface of the anti-loosening nut.

[0010] Furthermore, a slot is formed on the outer side of the hexagonal hole, and the width of the slot is smaller than the distance between opposite sides of the hexagonal hole and larger than the diameter of the piston rod.

[0011] Furthermore, the positioning end is provided with a plurality of positioning holes, and the positioning holes are distributed with equal radius around the axis of the piston rod.

[0012] Furthermore, the number of the positioning holes is 3-4, and the angle between adjacent positioning holes is 10-15°.

[0013] Furthermore, an adjustment window is provided on the sealing seat at the side where the positioning end is located, and a cover plate is provided on the adjustment window, and the cover plate is connected to the sealing seat by screws.

[0014] Furthermore, an observation hole is opened on the cover plate.

[0015] Compared with the prior art, the beneficial effects of the present invention are:

[0016] 1) The piston rod anti-loosening structure is simple and compact, the manufacturing and assembly process is simple, the parts are interchangeable, and the anti-loosening effect is good. After a period of operation test, the anti-loosening effect is significant, and there has never been a loose connection between the piston rod and the crosshead;

[0017] 2) The anti-loosening structure does not damage the threads on the piston rod and can be used for repeated disassembly, extending the service life of the parts;

[0018] 3) The piston travel stop point can be adjusted quickly and conveniently without disassembling the compressor cylinder components, thus ensuring the working efficiency of the compressor;

[0019] 4) Since the piston ring of a piston compressor plays a sealing and lubricating role, it is a wearing part with the greatest loss. Conventional maintenance, disassembly and replacement are relatively complicated. The structure of the utility model can realize the replacement of the seal by directly disassembling the piston without disassembling the cylinder, saving maintenance time, reducing workload, and being economical.

[0020] 5) It eliminates the cylinder collision accident caused by the loose piston rod during the operation of the piston compressor, greatly improving the safety of the piston compressor operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic structural diagram of an embodiment of the utility model;

[0022] Figure 2 yes Figure 1 Sectional view along line AA;

[0023] Figure 3 This is a schematic diagram of the lower structure of the sealing seat in an embodiment of the utility model;

[0024] Figure 4 This is a schematic diagram of the structure of the limiting piece in the embodiment of the utility model;

[0025] In the figure: 1-piston rod, 2-piston rod seat, 3-cross head, 4-sealing seat, 5-thread, 6-lock nut, 7-boss, 8-limiting plate, 9-positioning screw, 10-hexagonal hole, 11-slot, 12-positioning hole, 13-cover plate, 14-screw, 15-observation hole, 16-weight reduction hole. DETAILED DESCRIPTION

[0026] The technical solutions of the present invention will be described clearly and completely below in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0027] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the specific embodiments required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the specific embodiments described below are some implementation methods of the utility model. For ordinary technicians in this field, other specific embodiments can be obtained based on these specific embodiments without paying creative work.

[0028] The components of the embodiments of the present invention generally described and shown in the specific embodiments herein can be arranged and designed in countless different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the specific embodiments is not intended to limit the scope of the claimed invention, but rather represents only selected embodiments of the present invention.

[0029] See Figure 1-4 , is a schematic structural diagram of an embodiment of an anti-loosening mechanism for a piston rod and a piston rod seat of the present invention, comprising a piston rod 1, a piston rod seat 2, a crosshead 3 and a sealing seat 4. The piston rod 1 is connected to the piston rod seat 2 through a thread 5. A anti-loosening nut 6 is provided at the thread 5 of the piston rod 1 on the outside of the piston rod seat 2. A boss 7 is provided at the bottom of the hexagonal outer contour of the anti-loosening nut 6. One end of a limiting piece 8 is a clamping end C, which is clamped on the outer surface of the boss 7. The other end of the limiting piece 8 is a positioning end B, which is connected to the piston rod seat 2 through a positioning screw 9. The thread 5 is a fine thread with an anti-loosening effect.

[0030] The clamping end C of the stopper 8 is provided with a hexagonal hole 10 that matches the hexagonal surface of the locknut 6. A slot 11 is formed on the outside of the hexagonal hole 10. The width of the slot 11 is less than the width across the hexagonal hole 10 and greater than the diameter of the piston rod 1. The stopper 8 is also provided with a weight-reducing hole 16, which helps reduce the weight of the piston compressor's moving parts, facilitates dynamic balancing of the compressor, and ensures balanced operation.

[0031] The positioning end B is provided with a plurality of positioning holes 12, and the positioning holes 12 are distributed with equal radius around the axis of the piston rod 1. The number of positioning holes 12 is 4, and the angle between adjacent positioning holes 12 is 15°. The positioning holes 12 allow the locking nut 6 to be locked at any angle by the limiting plate 8. This setting allows the compressor piston rod 1 to easily adjust the piston stroke stop point or remove the piston to replace wearing parts from the adjustment window without disassembling the compressor cylinder during installation and maintenance, which facilitates the maintenance of the piston compressor and extends the service life of the entire machine. An adjustment window is provided on the sealing seat 4 on the side where the positioning end B is located, and a cover plate 13 is provided on the adjustment window. The cover plate 13 is connected to the sealing seat 4 by screws 14. An observation hole 15 is provided on the cover plate 13, so that the status of the locking nut 6 can be observed at any time.

[0032] When in use, first put the piston rod 1 in place, then tighten the anti-loosening nut 6 on the piston rod seat 2 and apply a pre-tightening force, and finally lock the limiting plate 8 to fix the position of the anti-loosening nut 6 so that it cannot rotate, thereby fundamentally preventing the anti-loosening nut 6 from loosening or coming out. The anti-loosening nut 6 has a large rotational friction resistance, that is, it generates a large anti-loosening friction torque, which plays a role in preventing the anti-loosening between the anti-loosening nut 6 and the piston rod seat 2. The limiting plate 8 strengthens the anti-loosening effect between the anti-loosening nut 6 and the piston rod seat 2, ensuring that the anti-loosening nut 6 and the piston rod seat 2 are integrated into one, forming a self-locking effect, and putting an end to the loosening between the piston rod seat 2 and the anti-loosening nut 6.

[0033] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A piston rod and piston rod seat anti-loosening mechanism, comprising a piston rod, a piston rod seat, a crosshead and a sealing seat, wherein the piston rod is connected to the piston rod seat by a thread, and is characterized in that: A lock nut is provided at the piston rod thread on the outside of the piston rod seat, and a boss is provided at the bottom of the hexagonal outer contour of the lock nut. One end of the limiting plate is a clamping end, which is clamped on the outer surface of the boss, and the other end of the limiting plate is a positioning end, which is connected to the piston rod seat through a positioning screw; the thread is a fine thread.

2. The anti-loosening mechanism of the piston rod and piston rod seat according to claim 1, characterized in that: The clamping end of the limiting piece is provided with a hexagonal hole matching the hexagonal surface of the anti-loosening nut.

3. The anti-loosening mechanism of the piston rod and piston rod seat according to claim 2, characterized in that: A slot is formed on the outer side of the hexagonal hole, and the width of the slot is smaller than the distance between opposite sides of the hexagonal hole and larger than the diameter of the piston rod.

4. The anti-loosening mechanism for a piston rod and a piston rod seat according to claim 1, characterized in that: The positioning end is provided with a plurality of positioning holes, and the positioning holes are distributed with equal radius around the axis of the piston rod.

5. The anti-loosening mechanism for the piston rod and piston rod seat according to claim 4, characterized in that: The number of the positioning holes is 3-4, and the angle between adjacent positioning holes is 10-15°.

6. The anti-loosening mechanism for a piston rod and a piston rod seat according to claim 1, characterized in that: An adjustment window is provided on the sealing seat at the side where the positioning end is located. A cover plate is provided on the adjustment window. The cover plate is connected to the sealing seat through screws.

7. The anti-loosening mechanism for the piston rod and piston rod seat according to claim 6, characterized in that: An observation hole is provided on the cover plate.

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