Cushion pad and mechanical seal wash pipe assembly

Abstract

The invention relates to the technical field of top driving devices, in particular to a buffer pad and a mechanical seal wash pipe assembly.The buffer pad comprises a first buffer part and a second buffer part, and the second buffer part is arranged on the surface, corresponding to the buffer direction, of the first buffer part; the first buffering piece has an elastic state and a limit state in the process of compressing in the buffering direction; in the elastic state, the rigidity of the first buffer piece is lower than that of the second buffer piece; and in a limit state, the rigidity of the first buffer piece is higher than that of the second buffer piece. Through cooperation of the first buffer part and the second buffer part, the buffer pad has the two-stage buffer capacity, the whole buffer pad can adapt to vibration or impact under different pressures, the pressure adapting range of the buffer pad is guaranteed, and the pressure adapting range of the wash pipe is widened.

Description

Technical Field

[0001] The invention relates to the technical field of top drive devices, and in particular to a buffer pad and a mechanical seal flush pipe assembly. Background Art

[0002] The existing mechanical flush pipe uses the pressure of drilling fluid and compensation spring to ensure that the end faces of a set of relatively rotating sealing rings (dynamic ring and static ring) are always tightly fitted to achieve rotary sealing. In order to ensure that the sealing ring has a long service life, the material of the sealing ring should have the characteristics of high hardness, wear resistance, high temperature resistance and good thermal conductivity. Ceramic materials are usually used, but the disadvantage of ceramic materials is low impact toughness. During drilling operations, the drill string is often subjected to axial impact and vibration, which may cause damage to the dynamic ring and static ring and lead to seal damage.

[0003] Based on this, a spring can be arranged in the punch tube as a buffer pad to withstand axial impact and vibration and promote close fit between the dynamic ring and the static ring.

[0004] However, in the actual drilling operation, it was found that when there is a large change in the pressure of the mud pipe inside the punch pipe, the spring cannot adapt. Specifically, due to the punch pipe structure, the pressure inside the mud pipe will cause the floating mud pipe to generate axial pressure. The higher the internal mud pressure, the higher the axial pressure of the floating pipe. The axial force will be transmitted to the buffer pad through the static ring and the dynamic ring. During drilling operations, when the mud pressure is high, the stiffness of the buffer pad needs to be higher, otherwise it will be completely compressed and will not play a buffering role. However, when the mud pressure is low, the stiffness of the buffer pad needs to be lower, otherwise it will not play a buffering role, and the dynamic ring and the static ring will vibrate and separate due to excessive elastic force. Summary of the invention

[0005] The purpose of the present invention is to overcome the problem in the prior art that when the pressure of the mud pipe inside the flushing pipe changes greatly, the existing buffer pad is difficult to adapt, and to provide a buffer pad and a mechanical seal flushing pipe assembly.

[0006] In a first aspect, the present invention provides a buffer pad, comprising a first buffer component and a second buffer component, wherein the second buffer component is arranged on the surface of the first buffer component corresponding to the buffering direction; the first buffer component has an elastic state and an extreme state during compression along the buffering direction; in the elastic state, the stiffness of the first buffer component is lower than that of the second buffer component; in the extreme state, the stiffness of the first buffer component is higher than that of the second buffer component.

[0007] Preferably, the first buffer member has at least one elastic section along the buffering direction, and the elastic section includes two plate-like parts and a connecting part, and one end of the two plate-like parts is connected to the connecting part; in the elastic state, the other end of the two plate-like parts in each of the elastic sections is opened along the buffering direction; in the extreme state, the other end of the two plate-like parts in each of the elastic sections is closed along the buffering direction.

[0008] Preferably, the first buffer component and the second buffer component are both annular structures.

[0009] Preferably, the first buffer component has an elastic section along the buffering direction, and the cross-sectional shape of the first buffer component in the elastic state is V-shaped; the V-shaped opening direction of the first buffer component faces the inner side of the first buffer component; the second buffer component is a structure covering both sides and the outer side of the first buffer component along the buffering direction.

[0010] Preferably, in the limit state, all adjacent plate-shaped parts are in close contact with each other, and the cross-sectional shape of the first buffer member is a square.

[0011] Preferably, the first buffer component is made of metal, and the second buffer component is made of polymer or composite material.

[0012] Preferably, the first buffer member is made of stainless steel or spring steel; the second buffer member is made of cloth-reinforced rubber or polyurethane.

[0013] In a second aspect, the present invention provides a mechanical seal flush tube assembly, comprising a dynamic ring and a lower nut, and also comprising a buffer device, wherein the buffer device comprises a floating ring and a buffer pad as described in any of the above schemes; the floating ring is slidably matched with the lower nut, the floating ring is connected to the dynamic ring, the buffer pad is arranged between the floating ring and the lower nut, and the dynamic ring can abut against the static ring under the elastic action of the buffer pad.

[0014] Preferably, the lower nut is provided with a countersunk hole, and the buffer pad is arranged in the countersunk hole; under the limit state, the cross-sectional shape of the buffer pad is consistent with the cross-sectional shape of the countersunk hole.

[0015] Preferably, it also includes a stationary ring, an upper nut, a mud pipe, and a floating compensation device; the mud pipe is fixedly connected to the upper nut; the floating compensation device is sleeved on the pipe mouth of the mud pipe, the floating compensation device is fixedly connected to the stationary ring, the floating compensation device is elastically connected to the upper nut, and the stationary ring abuts against the dynamic ring under the action of elasticity.

[0016] Preferably, the floating compensation device includes a floating cylinder sleeve, a spring, a guide rod, a sealing ring and a guide ring; a plurality of the guide rods are fixed to the upper nut, the floating cylinder sleeve is slidably connected to the guide rods, and the spring is provided between the floating cylinder sleeve and the upper nut; the floating cylinder sleeve is sleeved on the pipe mouth of the mud pipe, the sealing ring and the two guide rings are provided between the inner wall of the floating cylinder sleeve and the outer wall of the pipe mouth of the mud pipe, and the sealing ring is located between the two guide rings.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. The buffer pad provided by the present invention is mainly buffered by the first buffer with lower rigidity when the mud pressure is low so that the first buffer cannot be compressed to the limit state, ensuring that the buffer pad can play a buffering role, and at this time, the first buffer is difficult to provide too much elastic force, and it is difficult to cause the dynamic ring and the static ring to separate due to vibration of excessive elastic force, thereby improving the coordination between the dynamic ring and the static ring under low pressure. When the mud pressure is high, so that the first buffer is compressed to the limit state under the action of pressure, the first buffer is not easy to produce further elastic deformation, and its rigidity increases suddenly, and it cannot provide buffering between the dynamic ring and the static ring. At this time, the second buffer is mainly used for buffering, and through the compression of the second buffer, the dynamic ring and the static ring can still cooperate with each other under high pressure.

[0019] Through the cooperation of the first buffer component and the second buffer component, the buffer pad has a two-level buffering capability, which enables the entire buffer pad to adapt to vibrations or impacts under different pressures, thereby ensuring the buffer pad's adaptable pressure range and further improving the flushing tube's adaptable pressure range.

[0020] 2. The present invention provides a mechanical seal flush pipe assembly. When the flush pipe works in a low pressure section or the impact downhole is weak, the first stage elastic buffer works. When the flush pipe works in a high pressure section or the impact downhole is severe, the second stage elastic buffer works. The characteristics of the buffer ensure that the flush pipe can adapt to a wide pressure range, which can meet both normal drilling and severe vibrations of surface drilling. The two-stage elastic characteristics of the buffer pad achieve a buffering effect while avoiding excessive elastic potential energy. When the elastic potential energy is released, the dynamic ring and the static ring are separated, resulting in sealing failure. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the structure of a buffer pad according to Embodiment 1 of the present invention;

[0022] Figure 2 It is a partial cross-sectional schematic diagram of a cushion according to Embodiment 1 of the present invention;

[0023] Figure 3 This is a schematic diagram of the overall cross section of a cushion according to Embodiment 1 of the present invention;

[0024] Figure 4 This is an overall forward schematic diagram of the mechanical seal flushing pipe assembly of Embodiment 2 of the present invention;

[0025] Figure 5 It is a schematic diagram of the overall lateral internal structure of the mechanical seal flushing pipe assembly of Example 2 of the present invention;.

[0026] Numbers in the figure: 1-buffer pad, 11-first buffer member, 111-plate-like portion, 112-connecting portion, 12-second buffer member, 2-floating ring, 3-lower nut, 31-countersink, 4-dynamic ring, 5-static ring, 6-upper nut, 7-mud pipe, 81-floating cylinder sleeve, 82-screw, 83-spring, 84-guide rod, 85-sealing ring, 86-guide ring. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below in conjunction with specific embodiments. However, this should not be understood as the scope of the above subject matter of the present invention being limited to the following embodiments, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

[0028] Unless otherwise specified, in the description of the specific embodiments of the present invention, the terms indicating the orientation or position relationship such as "up", "down", "left", "right", "center", "inside", "outside", etc. are all based on the expression of the orientation or position relationship shown in the drawings, or are the orientation or position relationship when the invented product / equipment / device is usually used. These terms of orientation or position relationship are only for the convenience of describing the scheme of the present invention or simplifying the description in the specific embodiments, so as to facilitate the technicians to quickly understand the scheme, and do not indicate or imply that a specific device / component / element must have a specific orientation, or be constructed and operated in a specific position relationship, and therefore cannot be understood as a limitation on the present invention.

[0029] In addition, if the terms "horizontal", "vertical", "overhanging", "parallel" and the like appear, it does not mean that the corresponding devices / components / elements are required to be absolutely horizontal or vertical or overhanging or parallel, but may be slightly tilted or have deviations. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but may be slightly tilted. Alternatively, it can be simplified to mean that the corresponding devices / components / elements are set in directions such as "horizontal", "vertical", "overhanging", "parallel", etc., and can have an error / deviation of ±10% relative to the corresponding direction setting, more preferably an error / deviation within ±8%, more preferably an error / deviation within ±6%, more preferably an error / deviation within ±5%, and more preferably an error / deviation within ±4%. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its role in the scheme of the present invention.

[0030] In addition, the expressions “first”, “second”, “third”, etc., which appear in the terms, are merely used to distinguish the description of the same or similar components and should not be understood as emphasizing or implying the relative importance of specific components.

[0031] In addition, in the description of the embodiments of the present invention, "several", "plurality" and "a number" represent at least 2. It can be any number such as 2, 3, 4, 5, 6, 7, 8, 9, and even more than 9.

[0032] In addition, in the description of the technical solution of the present invention, unless otherwise clearly specified / defined / restricted, the terms "set", "install", "connect", "connected", "provided with", "laid", and "arranged" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection, and can be welding, riveting, bolting, threading, and other commonly used connection means in the field. This connection can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection, or an indirect connection through an intermediate medium, and it can be the internal connection of two elements.

[0033] Example 1

[0034] like Figure 1-3 As shown, the present invention provides a buffer pad 1, comprising a first buffer member 11 and a second buffer member 12, wherein the second buffer member 12 is arranged on a surface of the first buffer member 11 corresponding to a buffering direction;

[0035] Among them, for the surface of the first buffer component 11 corresponding to the buffering direction, for example, when the buffering direction is a vertical direction, the surface of the first buffer component 11 corresponding to the buffering direction is the top surface and the bottom surface of the first buffer component 11, and when the buffering direction is a left and right direction, the surface of the first buffer component 11 corresponding to the buffering direction is the left surface and the right surface of the first buffer component 11.

[0036] The first buffer member 11 has an elastic state and a limit state during compression along the buffering direction;

[0037] Among them, the first buffer member 11 can be a spring. Taking the spring as an example, when the compression amount of the spring has not reached its designed maximum value (that is, there is still a gap between the elastic units of each section of the spring), the spring is in an elastic state. At this time, the stiffness of the spring is relatively constant; when the compression amount of the spring reaches its designed maximum value (that is, the elastic units of each section of the spring are abutted against each other), the spring is in a limit state. At this time, the spring at the compression limit can be regarded as a block structure without any gaps, and it is difficult to continue to compress. At this time, the stiffness of the spring increases sharply.

[0038] In an elastic state, the stiffness of the first buffer component 11 is lower than that of the second buffer component 12 ; in an extreme state, the stiffness of the first buffer component 11 increases suddenly, so that the stiffness of the first buffer component 11 is higher than that of the second buffer component 12 .

[0039] Among them, stiffness refers to the ability of a component to resist elastic deformation when subjected to force, and is a representation of the ease of elastic deformation of a component. Under the same pressure, the lower the stiffness, the greater the displacement of the elastic deformation of the component. Based on this, when the force to be buffered is small so that the buffer pad 1 remains in an elastic state, the stiffness of the first buffer 11 is lower than that of the second buffer 12, and the displacement of the first buffer 11 is greater than that of the second buffer 12. At this time, the first buffer 11 is mainly used for buffering; when the force to be buffered is large so that the buffer pad 1 passes through the elastic state and enters the limit state, the stiffness of the first buffer 11 is higher than that of the second buffer 12, and the displacement of the first buffer 11 is less than that of the second buffer 12. At this time, the second buffer 12 is mainly used for buffering.

[0040] Therefore, when the mud pressure is so low that the first buffer component 11 cannot be compressed to the limit state, the first buffer component 11 is in an elastic state, and is mainly buffered by the first buffer component 11 with lower rigidity, ensuring that the buffer pad 1 can play a buffering role. At this time, it is difficult for the first buffer component 11 to provide excessive elastic force, and it is difficult to cause the dynamic ring 4 and the static ring 5 to separate due to vibration due to excessive elastic force, thereby improving the coordination between the dynamic ring 4 and the static ring 5 under low pressure.

[0041] When the mud pressure is high and the first buffer component 11 is compressed to the limit state under the action of pressure, the first buffer component 11 is not easy to produce further elastic deformation, and its stiffness increases suddenly, and it is unable to provide buffering between the dynamic ring 4 and the static ring 5. At this time, the second buffer component 12 is mainly used for buffering. Through the compression of the second buffer component 12, the dynamic ring 4 and the static ring 5 can still cooperate with each other under high pressure.

[0042] Through the cooperation of the first buffer member 11 and the second buffer member 12, the buffer pad 1 has a two-level buffering capability, which enables the entire buffer pad 1 to adapt to vibrations or impacts under different pressures, thereby ensuring the buffer pad 1 adapts to the pressure range, thereby improving the pressure range that the flushing tube adapts to.

[0043] Among them, the buffer pad 1 may also include multiple unit components. In this case, the multiple unit components are arranged at intervals around the circumference to jointly withstand axial impact and vibration; but it is more preferred that the buffer pad 1 can be an annular structure, that is, the first buffer component 11 and the second buffer component 12 are both annular structures.

[0044] The first buffer member 11 and the second buffer member 12 under the annular structure can provide a more comprehensive buffering effect on the dynamic ring 4 and the static ring 5, and compared with a plurality of relatively spaced buffer pads 1, the buffer pad 1 under the annular structure has a higher supporting strength and is more adaptable to drilling operations.

[0045] In one or more embodiments, the first buffer member 11 may have at least one elastic section along the buffering direction, wherein the elastic section includes two plate-like portions 111 and a connecting portion 112 , and one end of the two plate-like portions 111 is connected to the connecting portion 112 .

[0046] In the elastic state, the other ends of the two plate-like parts 111 in each elastic segment are opened along the buffering direction, that is, there is a distance between the other ends of the two plate-like parts 111 along the buffering direction, and the two plate-like parts form a V shape.

[0047] In the limit state, the other ends of the two plate-like parts 111 in each elastic segment are closed along the buffering direction, that is, the other ends of the two plate-like parts 111 abut against each other along the buffering direction.

[0048] At this time, the cross-sectional shape of the first buffer member 11 in the elastic state can be V-shaped (i.e. one elastic segment), N-shaped (i.e. two elastic segments), or W-shaped (i.e. three elastic segments), or a structure consisting of more elastic segments.

[0049] Among them, in the elastic state, if the buffer pad 1 is under pressure, the two plate-like parts 111 of each elastic segment of the first buffer component 11 gradually elastically deform from an open state to a closed state; in the extreme state, the two plate-like parts 111 of the first buffer component 11 have been closed, and if the buffer pad 1 is under pressure, the first buffer component 11 is not easy to deform further. Therefore, the stiffness of the first buffer component 11 in the extreme state increases sharply, and it is difficult to meet the buffering requirements, so the second buffer component 12 is used for buffering.

[0050] Among them, it is more preferred that the first buffer member 11 has only one elastic section along the buffering direction, the cross-sectional shape of the first buffer member 11 in the elastic state is V-shaped, and the V-shaped opening direction of the first buffer member 11 faces the inner side of the first buffer member 11.

[0051] Thus, it is convenient to arrange the second buffer member 12 on the first buffer member 11. Specifically, the second buffer member 12 can directly cover the two sides and the outer side of the first buffer member 11 along the buffering direction. In this case, the second buffer member 12 covering the two sides and the outer side of the first buffer member 11 along the buffering direction can be an integrated structure, or can be formed by splicing together the partial components covering the outer side of the first buffer member 11 and the partial components covering different sides of the first buffer member 11 to form the required second buffer member 12.

[0052] In one or more embodiments, in the limit state, all adjacent plate-shaped parts 111 are closely abutted against each other, and the cross-sectional shape of the first buffer member 11 is a square, so that the buffer pad 1 is subjected to pressure in the buffering direction, and when the first buffer member 11 is compressed to the limit, the extrusion force between the second buffer member 12 and the first buffer member 11 can be parallel to the buffering direction, thereby reducing the possible deflection of the second buffer member 12 during the buffering process and improving the buffering effect of the second buffer member 12.

[0053] In one or more embodiments, the material of the first buffer member 11 may be a metal material with elastic properties, preferably stainless steel or spring steel. The rigidity of stainless steel itself can withstand the pressure during mechanical flushing drilling operations, and it is not easy to corrode in the mud pipe 7, and has a sufficient service life.

[0054] The material of the second buffer 12 can be a polymer or composite material with elastic characteristics, preferably, cloth-reinforced rubber or polyurethane. The cloth-reinforced rubber is an existing composite material, which is laminated by rubber and cloth, has strong compressive resistance, and can play a role in buffering the dynamic ring 4 and the static ring 5 when the mud pressure is high. It also has good wear resistance, oil resistance, corrosion resistance, high temperature resistance, pressure resistance and other characteristics, and has a sufficient service life.

[0055] Example 2

[0056] like Figure 4-5 As shown, the present invention provides a mechanical seal flushing pipe assembly, including a moving ring 4 and a lower nut 3, and also includes a buffer device, wherein the buffer device includes a floating ring 2 and a buffer pad 1 as described in any one of the embodiments 1;

[0057] The floating ring 2 is designed as a hollow shaft with a flange structure. The hollow shaft of the floating ring 2 is inserted into the inner hole of the lower nut 3 and can slide axially; the flange of the floating ring 2 is designed with a pin hole, and the dynamic ring 4 is designed with a pin hole of the same diameter. The floating ring 2 is connected to the dynamic ring 4 through a lower positioning pin, and the lower positioning pin passes through the pin hole and is connected and fixed to the lower nut 3 to ensure that the dynamic ring 4 and the floating ring 2 rotate synchronously with the lower nut 3. The buffer pad 1 is arranged between the floating ring 2 and the lower nut 3, and the flange of the floating ring 2 is placed on the buffer pad. The dynamic ring 4 can abut against the static ring 5 under the elastic action of the buffer pad 1.

[0058] When the punch pipe works in the low pressure section or the impact downhole is weak, the first-stage elastic buffer pad 1 works, and when the punch pipe works in the high pressure section or the impact downhole is severe, the second-stage elastic buffer pad 1 works. The characteristics of the buffer pad 1 ensure that the punch pipe can adapt to a wide pressure range, which can meet both normal drilling and severe vibration of surface drilling. The two-stage elastic characteristics of the buffer pad can achieve the buffering effect and avoid excessive elastic potential energy. When the elastic potential energy is released, the dynamic ring 4 and the static ring 5 are separated, and the seal fails.

[0059] In one or more embodiments, the lower nut 3 is provided with a countersunk hole 31, and the buffer pad 1 is arranged in the countersunk hole 31; in the limit state, the cross-sectional shape of the buffer pad 1 is consistent with the cross-sectional shape of the countersunk hole 31. Therefore, when the pressure is relatively high, the buffer pad 1 can be sealed in the countersunk hole 31, thereby further improving the sealing performance of the flushing pipe.

[0060] Based on this, the first buffer member 11 may be made of stainless steel, thereby reducing corrosion caused by contact with mud during plugging; the second buffer member 12 may be made of cloth-reinforced rubber, which can provide stronger sealing and pressure resistance.

[0061] In one or more embodiments, the mechanical seal flushing pipe assembly also includes a stationary ring 5, an upper nut 6, a mud pipe 7, and a floating compensation device; the mud pipe 7 is fixedly connected to the upper nut 6; the floating compensation device is sleeved on the pipe mouth of the mud pipe 7, the floating compensation device is fixedly connected to the stationary ring 5, the floating compensation device is elastically connected to the upper nut 6, and the stationary ring 5 abuts against the dynamic ring 4 under the action of elasticity.

[0062] In one or more examples, the floating compensation device may include a floating cylinder sleeve 81, a screw 82, a spring 83, a guide rod 84, a sealing ring 85 and a guide ring 86; multiple guide rods 84 are fixed to the upper nut 6, and the floating cylinder sleeve 81 is slidably connected to the guide rod 84; one end of multiple screw rods 82 is connected to the upper nut 6, and the other end passes through the floating cylinder sleeve 81 and is threadedly connected with a nut to prevent the floating cylinder sleeve 81 from detaching from the guide rod 84; the spring 83 is provided between the floating cylinder sleeve 81 and the upper nut 6, and the spring 83 is sleeved outside the screw 82. The floating cylinder sleeve 81 is pushed by the spring 83 to push the static ring 5 to press the dynamic ring 4.

[0063] The floating cylinder sleeve 81 is sleeved on the pipe mouth of the mud pipe 7, and the sealing ring 85 and the two guide rings 86 are arranged between the inner wall of the floating cylinder sleeve 81 and the outer wall of the pipe mouth of the mud pipe 7, and the sealing ring 85 is located between the two guide rings 86. The two guide rings 86 restrict the sliding direction of the floating cylinder sleeve 81, so that the pressure transmitted to the stationary ring 5, the dynamic ring 4 and the buffer pad 1 can be distributed along the axial direction, thereby improving the force stability of the buffer pad 1 during the buffering process, thereby further improving the buffering effect of the buffer pad 1.

[0064] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A cushion, characterized in that: It comprises a first buffer member (11) and a second buffer member (12), wherein the second buffer member (12) is arranged on a surface of the first buffer member (11) corresponding to a buffering direction; The first buffer (11) has an elastic state and a limit state during compression along the buffering direction; In an elastic state, the first buffer member (11) has a lower rigidity than the second buffer member (12); In a limit state, the first buffer member (11) has a higher rigidity than the second buffer member (12).

2. A cushion according to claim 1, characterized in that: The first buffer member (11) has at least one elastic section along the buffering direction, the elastic section comprising two plate-shaped parts (111) and a connecting part (112), one end of the two plate-shaped parts (111) being connected to the connecting part (112); In the elastic state, the other ends of the two plate-shaped parts (111) in each elastic segment are opened along the buffering direction; In the limit state, the other ends of the two plate-shaped parts (111) in each elastic segment are closed along the buffering direction.

3. A cushion according to claim 2, characterized in that: The first buffer member (11) and the second buffer member (12) are both annular structures.

4. A cushion according to claim 3, characterized in that: The first buffer member (11) has an elastic section along the buffering direction, and the cross-sectional shape of the first buffer member (11) in the elastic state is V-shaped; The V-shaped opening direction of the first buffer member (11) faces the inner side of the first buffer member (11); The second buffer component (12) is a structure covering both sides and the outer side of the first buffer component (11) along the buffering direction.

5. A cushion according to any one of claims 2 to 4, characterized in that: In the limit state, all adjacent plate-shaped parts (111) are tightly abutted against each other, and the cross-sectional shape of the first buffer member (11) is a square.

6. A cushion according to any one of claims 2 to 4, characterized in that: The material of the first buffer component (11) is metal, and the material of the second buffer component (12) is polymer or composite material.

7. A cushion according to claim 6, characterized in that: The material of the first buffer (11) is stainless steel or spring steel; the material of the second buffer (12) is cloth-reinforced rubber or polyurethane.

8. A mechanical seal flushing pipe assembly, comprising a moving ring (4) and a lower nut (3), characterized in that: It also includes a buffer device, which includes a floating ring (2) and a buffer pad as described in any one of claims 1 to 7; The floating ring (2) is slidably matched with the lower nut (3), the floating ring (2) is connected to the dynamic ring (4), the buffer pad (1) is arranged between the floating ring (2) and the lower nut (3), and the dynamic ring (4) can abut against the static ring (5) under the elastic action of the buffer pad (1).

9. A mechanical seal flushing pipe assembly according to claim 8, characterized in that: The lower nut (3) is provided with a countersunk hole (31), and the buffer pad (1) is arranged in the countersunk hole (31); In the limit state, the cross-sectional shape of the buffer pad (1) is consistent with the cross-sectional shape of the counterbore (31).

10. The mechanical seal flushing pipe assembly according to claim 8, characterized in that: It also includes a stationary ring (5), an upper nut (6), a mud pipe (7), and a floating compensation device; The mud pipe (7) is fixedly connected to the upper nut (6); The floating compensation device is sleeved on the pipe mouth of the mud pipe (7), the floating compensation device is fixedly connected to the static ring (5), the floating compensation device is elastically connected to the upper nut (6), and the static ring (5) abuts against the dynamic ring (4) under the action of elasticity.

11. A mechanical seal flushing pipe assembly according to claim 10, characterized in that: The floating compensation device comprises a floating cylinder sleeve (81), a spring (83), a guide rod (84), a sealing ring (85) and a guide ring (86); A plurality of guide rods (84) are fixed to the upper nut (6), the floating cylinder sleeve (81) is slidably connected to the guide rods (84), and the spring (83) is provided between the floating cylinder sleeve (81) and the upper nut (6); The floating cylinder sleeve (81) is sleeved on the pipe mouth of the mud pipe (7), and the sealing ring (85) and two guide rings (86) are provided between the inner wall of the floating cylinder sleeve (81) and the outer wall of the pipe mouth of the mud pipe (7), and the sealing ring (85) is located between the two guide rings (86).

Images