Shock absorbers for drilling rigs

Abstract

The present invention relates to a buffer shock absorber for a drilling rig, and belongs to the technical field of shock absorbers. It comprises a connecting sleeve installed on the drilling rig, a telescopic sleeve being slidably connected to the connecting sleeve, a reset spring being mounted on the telescopic sleeve, the two ends of the reset spring respectively abutting against two opposite surfaces of the telescopic sleeve and the connecting sleeve, a buffer compression cavity is further provided in the connecting sleeve, a piston is slidably connected in the buffer compression cavity, the piston is connected to the telescopic sleeve, and the buffering force of the telescopic sleeve can be adjusted by controlling the pressure of the medium in the buffer compression cavity; the buffer compression cavity is respectively connected to the central tube cavity of the connecting sleeve and the telescopic sleeve, and when the telescopic sleeve is compressed, the buffer compression cavity compresses the medium through the piston to buffer the telescopic sleeve. The present invention provides a buffer shock absorber for a drilling rig, which can adjust different buffering forces according to different working occasions.

Description

Technical Field

[0001] The invention relates to a buffer shock absorber for a drilling rig, and belongs to the technical field of shock absorbers. Background Art

[0002] Drilling rigs are widely used in mining, oil, gas, water wells, geological exploration, and other fields. During the drilling process, friction, impact, and vibration between the drill bit and the formation generate significant mechanical stress and vibration, which not only affects drilling efficiency but can also damage the equipment and pose safety risks to operators. Therefore, developing effective shock absorbers is crucial for improving drilling rig performance and extending its lifespan.

[0003] For water well drilling rigs, high-pressure impact drilling is used. The drilling geology is more complex and the environment is more severe. The drill rod (drill bit) is connected to the gearbox main shaft, and the rebound and impact force are large, and the vibration frequency is high, which can easily cause damage to the bearings, oil seals and other components in the gearbox, further causing serious wear of the drill rig's slider, reducing the service life of the drill rig and increasing maintenance costs.

[0004] Currently, shock absorbers for drilling rigs usually use springs, air compression, or hydraulic principles to absorb and reduce vibration. Their basic working principles include:

[0005] Spring buffer: use the elastic deformation of the spring to absorb impact energy and reduce vibration transmission.

[0006] Hydraulic shock absorption: absorbs vibration energy through the flow and compression of liquid, and usually has good damping characteristics.

[0007] Gas cushioning (such as the Chinese invention patent with publication number CN105804671A): uses the compressibility of gas to reduce vibration and is suitable for applications requiring a larger stroke.

[0008] The existing technology is unable to adjust the buffer force in real time according to different working scenarios (such as exploration, drilling, etc.), resulting in serious damage to the spring and the drilling rig. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a buffer shock absorber for a drilling rig, which can adjust different buffer forces according to different working occasions.

[0010] The buffer shock absorber for a drilling rig of the present invention comprises a connecting sleeve mounted on the drilling rig, a telescopic sleeve being slidably connected to the connecting sleeve, a return spring being mounted on the telescopic sleeve, and two ends of the return spring respectively abutting against two opposite surfaces of the telescopic sleeve and the connecting sleeve;

[0011] A buffer compression cavity is provided in the connecting sleeve, a piston is slidably connected in the buffer compression cavity, and the piston is connected to the telescopic sleeve. The buffering force of the telescopic sleeve is adjusted by controlling the medium pressure in the buffer compression cavity.

[0012] The buffer compression cavity is communicated with the central tube cavity of the connecting sleeve and the telescopic sleeve respectively. When the telescopic sleeve is compressed, the buffer compression cavity compresses the medium through the piston to buffer the telescopic sleeve.

[0013] Furthermore, the connecting sleeve consists of a first connecting sleeve and a second connecting sleeve, the first connecting sleeve and the second connecting sleeve are detachably connected, a buffer compression cavity is provided in the first connecting sleeve, and the telescopic sleeve passes through the second connecting sleeve and is connected to the piston located in the buffer compression cavity of the first connecting sleeve.

[0014] Furthermore, the telescopic sleeve is provided with a spline shaft section, and the second connecting sleeve is provided with a key groove matching the spline shaft section.

[0015] Furthermore, the return spring is a compression spring, which is sleeved on the telescopic sleeve, with one end of the compression spring resting against the positioning ring on the telescopic sleeve and the other end resting against the second connecting sleeve.

[0016] Furthermore, after the reset spring is reset, at least a portion of the protective sleeve is sleeved onto the positioning ring.

[0017] Furthermore, a protective sleeve is sheathed on the outside of the return spring, and the protective sleeve is detachably connected to the second connecting sleeve.

[0018] Furthermore, a sealing member is provided on the outer cylindrical surface of the piston.

[0019] Furthermore, a support ring is provided on the outer cylindrical surface of the piston.

[0020] Furthermore, the telescopic sleeve is provided with an anti-loosening structure for the piston.

[0021] Furthermore, a sealing structure is provided between the telescopic sleeve and the piston.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] Traditional shock absorbers rely on fixed damping coefficients (e.g., pure springs or hydraulic structures) and are unable to adapt to changes in formation hardness (soft rock vs. hard rock) or drilling techniques (e.g., high-frequency vibration during exploration vs. high-torque impact during drilling). This invention intelligently controls the pressure of the medium (e.g., gas or liquid) within the buffer compression chamber to achieve nonlinear dynamic adjustment of the buffer force in response to external loads. This prevents "rigid rebound" of the drill bit in soft rock and suppresses "stress overshoot" in hard rock, broadening its adaptability to various operating conditions.

[0024] Existing technologies mostly use a single buffering mode (such as pure mechanical springs or independent pneumatic damping), which makes it difficult to take into account both high-frequency micro-vibrations and extreme impact loads. This invention innovatively combines the synergistic effects of mechanical elastic deformation (compression springs) and gas compression energy storage to form a two-stage energy dissipation path:

[0025] Initial buffer: The compression spring quickly absorbs high-frequency micro-vibrations and reduces the instantaneous impact when the drill bit contacts the formation;

[0026] End buffer: The buffer compression chamber provides large stroke damping under extreme loads to avoid drilling rig resonance or structural failure.

[0027] Traditional shock absorbers, due to their single buffering mode, are prone to compression spring fatigue fracture (in soft rock conditions) or pneumatic seal failure (in hard rock conditions). This invention uses dynamic pressure regulation to limit the compression spring stress amplitude to the elastic deformation range (σ < 0.5σ_s). This, coupled with a self-compensating seal structure within the buffer compression chamber, extends the compression spring replacement cycle from approximately 10 days to 12-15 months under extreme operating conditions. This eliminates the compression spring from becoming a consumable part requiring frequent replacement, reducing maintenance costs by 65%. (Measured data: a certain drilling rig operated continuously for 2000 hours without any problems.) BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a structural diagram of embodiment 1 of the present invention;

[0029] Figure 2 is a full cross-sectional view of Example 1 of the present invention;

[0030] Figure 3 yes Figure 2 A partial enlarged view of the middle A;

[0031] Figure 4 This is a schematic diagram of the split structure of Example 1 of the present invention;

[0032] Figure 5 This is a schematic structural diagram of the first connecting sleeve in accordance with Embodiment 1 of the present invention;

[0033] Figure 6 1 is a schematic diagram of the piston structure of Example 1 of the present invention;

[0034] Figure 7 This is a schematic structural diagram of the second connecting sleeve in accordance with Embodiment 1 of the present invention;

[0035] Figure 8 2 is a schematic structural diagram of a telescopic sleeve according to embodiment 1 of the present invention;

[0036] In the picture:

[0037] 1. Connecting sleeve; 11. First connecting sleeve; 12. Second connecting sleeve;

[0038] 2. Telescopic sleeve; 21. Spline shaft segment; 22. Positioning ring; 23. Anti-loosening groove;

[0039] 3. Protective cover;

[0040] 4. Return spring;

[0041] 5. Piston; 51. Seal; 52. Support ring; 53. Sealing structure;

[0042] 6. Anti-loosening structure; 61. Round nut; 62. Anti-loosening plate;

[0043] 7. Buffer compression cavity. DETAILED DESCRIPTION

[0044] Example 1

[0045] like Figures 1 to 8 As shown, the buffer shock absorber for drilling rigs described in the present invention includes a connecting sleeve 1 installed with the drilling rig, and a threaded section is provided on the connecting sleeve 1. The drill rod is removed in advance and connected to the drill rod installation part of the drilling rig through the thread on the connecting sleeve 1.

[0046] The connecting sleeve 1 is slidably connected to the telescopic sleeve 2, and a reset spring 4 is installed on the telescopic sleeve 2. The two ends of the reset spring 4 are respectively against the two opposite surfaces of the telescopic sleeve 2 and the connecting sleeve 1. The reset spring 4 can be directly compressed by the telescopic sleeve 2, so that the telescopic sleeve 2 has an elastic buffering effect.

[0047] Existing products can be cushioned by closed air chambers, but this application Figure 2 As shown, a buffer compression chamber 7 is provided in the connecting sleeve 1, and a piston 5 is slidably connected in the buffer compression chamber 7. The piston 5 is connected to the telescopic sleeve 2. The buffering force of the telescopic sleeve 2 is adjusted by controlling the medium pressure in the buffer compression chamber 7. When the medium is gas, the buffering force is adjusted in real time by controlling the gas pressure in the buffer compression chamber 7. This solves the pain point that traditional shock absorbers cannot adapt to different formation hardness (such as soft rock, hard rock) or drilling processes (exploration / drilling), significantly reduces the risk of spring fatigue fracture or drill rod damage due to overload, and extends the life of the equipment.

[0048] The buffer compression cavity 7 is respectively connected to the central tube cavity of the connecting sleeve 1 and the telescopic sleeve 2. When the telescopic sleeve 2 is compressed, the buffer compression cavity 7 compresses the medium through the piston 5 to buffer the telescopic sleeve 2, and the medium in the buffer compression cavity 7 is compressed. When the return spring 4 is a spring, the synergistic effect of the spring elastic deformation and gas compression is combined to form a "mechanical + pneumatic" two-stage buffer system:

[0049] Initial buffer: The compression spring quickly absorbs high-frequency micro-vibrations and reduces the instantaneous impact when the drill bit contacts the formation;

[0050] End buffer: The buffer compression chamber provides large stroke damping under extreme loads to avoid drilling rig resonance or structural failure.

[0051] The connecting sleeve 1 consists of a first connecting sleeve 11 and a second connecting sleeve 12. The first connecting sleeve 11 and the second connecting sleeve 12 are detachably connected. The first connecting sleeve 11 and the second connecting sleeve 12 are connected by threads. The threaded connection has better stability and can also be connected by rotating the buckle. The two end faces can be locked by rotating after abutting each other, which can achieve quick assembly, but the stability is not as good as the threaded connection.

[0052] A buffer compression cavity 7 is provided in the first connecting sleeve 11 , and the telescopic sleeve 2 passes through the second connecting sleeve 12 and is connected to the piston 5 located in the buffer compression cavity 7 of the first connecting sleeve 11 .

[0053] The telescopic sleeve 2 is provided with a spline shaft section 21, and the second connecting sleeve 12 is provided with a keyway to match the spline shaft section 21. The sliding fit between the spline shaft section and the second connecting sleeve ensures radial positioning accuracy while allowing axial expansion and contraction, solving the problem of easy sticking of traditional shock absorbers.

[0054] The return spring 4 is a compression spring. The return spring 4 can be a metal return spring, a rubber return spring or a plastic return spring. The compression spring is sleeved on the telescopic sleeve 2, with one end against the positioning ring 22 on the telescopic sleeve 2 and the other end against the second connecting sleeve 12.

[0055] After the reset spring 4 is reset, at least a portion of the protective cover 3 is sleeved onto the positioning ring 22 , effectively preventing external debris from entering the working area of ​​the reset spring 4 .

[0056] A protective sleeve 3 is sheathed on the outside of the reset spring 4. The protective sleeve 3 and the second connecting sleeve 12 are detachably connected. The protective sleeve 3 and the second connecting sleeve 12 are connected by threads. The threaded connection has better stability and can also be connected by rotating the buckle. The two end faces can be locked by rotating after they are abutted against each other, which can achieve quick assembly, but the stability is not as good as the threaded connection.

[0057] A seal 51 is provided on the outer cylindrical surface of the piston 5. A modular design is achieved by arranging the piston 5 in conjunction with the seal 51. The seal 51 can be installed on the outer cylindrical surface of the piston 5 using a hole-use combined sealing ring. The piston 5 is made of high-hardness material (such as aluminum alloy, cast iron) and has an optimized piston surface treatment to reduce friction loss between the piston and the cylinder wall. The aluminum alloy piston 5 is lightweight and corrosion-resistant, while the cast iron piston 5 has high strength and wear resistance, meeting performance requirements under different working conditions.

[0058] A support ring 52 is further provided on the outer cylindrical surface of the piston 5 . The support ring 52 is made of a highly wear-resistant material, which can better ensure the coaxiality of the piston 5 during movement and avoid excessive wear of the seal 51 .

[0059] The telescopic sleeve 2 is also provided with an anti-loosening structure 6 for the piston 5. The anti-loosening structure 6 includes a round nut 61, and an anti-loosening sheet 62 is installed inside the round nut 61. Figure 8 As shown, a corresponding anti-loosening groove 23 is opened on the threaded section at the end of the telescopic sleeve 2. During installation, the teeth of the inner ring of the anti-loosening plate 62 are placed in the anti-loosening groove 23. When the round nut 61 is screwed in, the teeth on the outside of the anti-loosening plate 62 are pressed into the groove of the outer ring of the round nut 61, thereby preventing the round nut 61 from loosening, thereby preventing the piston 5 from loosening in the event of high-frequency vibration.

[0060] A sealing structure 53 is provided between the telescopic sleeve 2 and the piston 5. The sealing structure 53 is a sealing ring. An optical axis section is provided on the inner side of the threaded section at the end of the telescopic sleeve 2. An annular groove is provided on the optical axis section. A sealing ring is installed in the annular groove, thereby sealing the gap between the piston 5 and the telescopic sleeve 2, thereby avoiding leakage of the threaded connection between the piston 5 and the telescopic sleeve 2.

[0061] Working process or working principle:

[0062] During installation, install the sealing ring into the annular groove in advance, install the seal 51 and the support ring 52 on the piston 5, then put the spring sleeve on the telescopic sleeve 2, and slide the second connecting sleeve 12 along the spline shaft section 21. At this time, one end of the second connecting sleeve 12 is against the spring, and the piston 5 is threadedly installed on the threaded section of the telescopic sleeve 2, and then the anti-loosening plate 62 is installed on the threaded section, and finally the round nut 61 is screwed in to lock it. Finally, the first connecting sleeve 11 and the protective sleeve 3 are respectively installed on the two ends of the second connecting sleeve 12.

[0063] The description of the direction and relative position relationship of the structure in the present invention, such as the description of front, back, left, right, up and down, does not constitute a limitation of the present invention and is only for the convenience of description.

Claims

1. A buffer shock absorber for a drilling rig, comprising a connecting sleeve (1) mounted on the drilling rig, a telescopic sleeve (2) slidably connected to the connecting sleeve (1), a return spring (4) mounted on the telescopic sleeve (2), two ends of the return spring (4) respectively abutting against two opposite surfaces of the telescopic sleeve (2) and the connecting sleeve (1), characterized in that: A buffer compression cavity (7) is provided in the connecting sleeve (1), a piston (5) is slidably connected in the buffer compression cavity (7), and the piston (5) is connected to the telescopic sleeve (2). The buffering force of the telescopic sleeve (2) is adjusted by controlling the medium pressure in the buffer compression cavity (7); The buffer compression cavity (7) is respectively connected to the central tube cavity of the connecting sleeve (1) and the telescopic sleeve (2); when the telescopic sleeve (2) is compressed, the buffer compression cavity (7) compresses the medium through the piston (5) to provide shock absorption and buffering for the telescopic sleeve (2).

2. The shock absorber for drilling rig according to claim 1, characterized in that: The connecting sleeve (1) consists of a first connecting sleeve (11) and a second connecting sleeve (12). The first connecting sleeve (11) and the second connecting sleeve (12) are detachably connected. A buffer compression cavity (7) is provided in the first connecting sleeve (11). The telescopic sleeve (2) passes through the second connecting sleeve (12) and is connected to a piston (5) located in the buffer compression cavity (7) of the first connecting sleeve (11).

3. The buffer shock absorber for drilling rig according to claim 2, characterized in that: The telescopic sleeve (2) is provided with a spline shaft section (21), and the second connecting sleeve (12) is provided with a keyway matching the spline shaft section (21).

4. The shock absorber for drilling rig according to claim 2, characterized in that: The return spring (4) is a compression spring, which is sleeved on the telescopic sleeve (2), with one end of the compression spring resting against the positioning ring (22) on the telescopic sleeve (2) and the other end resting against the second connecting sleeve (12).

5. The shock absorber for drilling rig according to claim 4, characterized in that: After the reset spring (4) is reset, at least a portion of the protective sleeve (3) is sleeved onto the positioning ring (22).

6. The shock absorber for drilling rig according to claim 2, characterized in that: A protective sleeve (3) is sleeved on the outside of the return spring (4), and the protective sleeve (3) is detachably connected to the second connecting sleeve (12).

7. The shock absorber for drilling rig according to claim 1, characterized in that: A sealing member (51) is provided on the outer cylindrical surface of the piston (5).

8. The shock absorber for drilling rig according to claim 7, characterized in that: A support ring (52) is provided on the outer cylindrical surface of the piston (5).

9. The shock absorber for drilling rig according to claim 7, characterized in that: An anti-loosening structure (6) for the piston (5) is provided on the telescopic sleeve (2).

10. The shock absorber for drilling rig according to claim 7, characterized in that: A sealing structure (53) is provided between the telescopic sleeve (2) and the piston (5).

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