Crosshead hydraulic connecting and fastening device of BOG compressor

Abstract

The invention relates to the technical field of compressor equipment, in particular to a crosshead hydraulic connecting and fastening device of a BOG compressor, which comprises a thrust ring, a positioning ring, a pressure body, a locking nut and a follow-up ring. The crosshead is located at one end of the piston rod, and the thrust ring, the positioning ring and the pressure body are sequentially arranged on the piston rod and are coaxial. And an oil cavity is arranged in the pressure body. And a pressure piston and a sealing ring are arranged in the oil cavity. The locking nut is connected with the pressure body in a sleeved mode and matched with the pressure body in a threaded mode, and the locking nut is in ball hinge with the follow-up ring. According to the crosshead hydraulic connecting and fastening device of the BOG compressor, after the pressure of the oil cavity is relieved, the required connecting pre-tightening force is achieved between the piston rod and the crosshead, and if the locking nut has the tendency of axial deviation, the locking nut will promote the follow-up ring to rotate relative to the locking nut, the stress of the locking nut is balanced, and the service life of the follow-up ring is prolonged. Therefore, the piston rod is prevented from being bent, and normal use of the piston rod is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of compressor equipment, and in particular to a crosshead hydraulic connection and fastening device of a BOG compressor. Background Art

[0002] BOG compressor is a kind of equipment specially used to process boil-off gas (BOG) generated in liquefied natural gas (LNG) storage tanks. Most BOG compressors use oil-free lubricated reciprocating compressors, and their working principle is the same as that of ordinary reciprocating compressors. The difference is that the inlet of the BOG compressor inhales low-temperature gas, so the first-stage cylinder, piston and other structures of the compressor must be resistant to low temperatures and prevent icing to ensure the normal use of the BOG compressor.

[0003] As an important component connecting the piston rod and the connecting rod, the crosshead is subjected to complex forces such as alternating loads and inertia force generated by the reciprocating motion of the piston during the operation of the compressor. Traditional BOG compressor crossheads and piston rods are mostly connected by threaded connections. During the installation process, the nut is tightened manually using tools to tightly connect the crosshead and the piston rod. However, this connection method is not strong enough and can easily cause the piston rod to break.

[0004] Chinese patent CN2758526Y discloses a crosshead hydraulic connection and fastening device, including a thrust ring, a spiral ring, an adjustment ring, a pressure body, a locking nut, an oil pump high-pressure joint, a sealing ring and a pressure piston. During installation, after the piston rod is connected to the crosshead through the hydraulic connection and fastening device, the high-pressure oil is used to force the tail of the piston rod to produce elastic tensile deformation, and then the locking nut is screwed to the end of the crosshead to achieve mechanical positioning. After that, the high-pressure oil is depressurized, and the piston rod will slowly recover after the high-pressure oil is depressurized. The preload force generated by the elastic deformation of the piston rod acts on the connecting thread between the pressure body and the locking nut, preventing the pressure body and the locking nut from rotating relative to each other, so that the required connection preload force is achieved between the piston rod and the crosshead, completing the fastening connection between the piston rod and the crosshead.

[0005] However, due to the errors between the parts, when the high-pressure oil is released and the piston rod recovers to apply force to the connecting thread between the pressure body and the locking nut, the locking nut may produce axial deviation and apply force in the opposite direction of the piston rod through the pressure body in addition to the axial direction of the piston rod, causing the piston rod to produce axial deviation and even causing the piston rod to bend, affecting the normal use of the piston rod and shortening the service life of the piston rod. Summary of the invention

[0006] The present invention provides a crosshead hydraulic connection and fastening device for a BOG compressor, so as to solve the problem that when the existing crosshead hydraulic connection and fastening device connects the piston rod and the crosshead, due to the error between the parts, the locking nut may cause the piston rod to produce axial deviation, thereby affecting the normal use of the piston rod.

[0007] A crosshead hydraulic connection and fastening device for a BOG compressor of the present invention adopts the following technical scheme: a crosshead hydraulic connection and fastening device for a BOG compressor, used for connecting a crosshead and a piston rod, comprising a thrust ring, a positioning ring, a pressure body, a locking nut and a follower ring; the crosshead is located at one end of the piston rod, the thrust ring, the positioning ring and the pressure body are sequentially arranged on the piston rod along a first direction and are coaxial, and the first direction is the axial direction of the piston rod; the thrust ring is located on a side of the pressure body close to the crosshead in the first direction, the thrust ring abuts against the crosshead, the positioning ring is threadedly matched with the crosshead and abuts against the thrust ring, An adjusting ring is sleeved on the positioning ring, and the adjusting ring is threadedly matched with the positioning ring; an oil chamber is arranged in the pressure body, and a pressure piston and a sealing ring are arranged in sequence in the oil chamber along a first direction, the pressure piston is located on the side of the sealing ring close to the positioning ring in the first direction, and the pressure piston abuts against the positioning ring; an oil pump joint is provided on the pressure body, and the oil pump joint is connected with the oil chamber; a follower ring and a locking nut are arranged in sequence and coaxially in the first direction, the follower ring is located on the side of the locking nut close to the crosshead in the first direction and can abut against the crosshead, the locking nut is sleeved with the pressure body and threadedly matched with the pressure body, and the locking nut is hinged to the follower ring.

[0008] Furthermore, a limit plate is coaxially and fixedly arranged on the follower ring, the limit plate is an arc-shaped plate, and in the radial direction of the piston rod, the limit plate is located between the locking nut and the pressure body, and the limit plate is threadedly matched with the pressure body.

[0009] Furthermore, a slide groove is provided on the inner circumferential wall surface of the locking nut, a limiting plate is installed in the slide groove, and a thread on the limiting plate can be connected with a thread on the inner circumferential wall surface of the locking nut.

[0010] Furthermore, the piston rod includes a first rod body and a second rod body, which are arranged sequentially in the first direction and fixedly connected, the first rod body is an elastic rod, and the diameter of the first rod body is smaller than the diameter of the second rod body, the thrust ring, the positioning ring and the pressure body are all installed on the first rod body, and the second rod body is provided with a shoulder at one end close to the first rod body in the first direction, and the pressure body abuts against the shoulder.

[0011] Furthermore, three positioning bosses are sequentially arranged on the first rod body at intervals along the first direction.

[0012] Furthermore, the thrust ring includes two ring bodies, both of which are semi-annular structures, and the two ring bodies are installed on the piston rod through a first elastic member.

[0013] Furthermore, the first elastic member is an annular spring.

[0014] Furthermore, it also includes a manual ultra-high pressure oil pump, which is connected to the oil pump connector through a hose.

[0015] Furthermore, an oil circuit is provided on the pressure body, and the oil pump connector is connected with the oil chamber through the oil circuit.

[0016] Furthermore, the adjusting ring and the positioning ring are connected via screws.

[0017] The beneficial effects of the present invention are as follows: a crosshead hydraulic connection and fastening device of a BOG compressor of the present invention cooperates by arranging a thrust ring, a positioning ring, a pressure body, a locking nut and a follower ring. After the oil chamber is depressurized, the preload force generated by the deformation of the piston rod will act on the connecting thread between the pressure body and the locking nut, so that the relative rotation of the pressure body and the locking nut is hindered, thereby achieving the required connection preload force between the piston rod and the crosshead, and if the locking nut has a tendency to axially deviate, the locking nut will prompt the follower ring to rotate relative to the locking nut, balance the force on the locking nut, prevent the locking nut from axially deviating, and further prevent the piston rod from bending, thereby ensuring the normal use of the piston rod. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is a schematic diagram of the overall structure of an embodiment of a crosshead hydraulic connection and fastening device of a BOG compressor of the present invention; Figure 2 It is a front view of the overall structure of an embodiment of a crosshead hydraulic connection and fastening device for a BOG compressor of the present invention; Figure 3 for Figure 2 Sectional view along AA; Figure 4 for Figure 3 The enlarged view of point B in the middle; Figure 5 for Figure 4 Enlarged view of point C in the middle; Figure 6 A schematic diagram of a follower ring of an embodiment of a crosshead hydraulic connection and fastening device for a BOG compressor of the present invention; Figure 7A schematic diagram of a locking nut of an embodiment of a crosshead hydraulic connection and fastening device for a BOG compressor of the present invention; Figure 8 It is a schematic diagram of a piston rod of an embodiment of a crosshead hydraulic connection and fastening device of a BOG compressor of the present invention.

[0020] In the figure: 100, crosshead; 200, piston rod; 210, first rod body; 220, second rod body; 230, positioning boss; 300, thrust ring; 310, first elastic member; 400, positioning ring; 500, pressure body; 510, oil chamber; 520, pressure piston; 530, sealing ring; 540, oil pump joint; 600, locking nut; 610, slide groove; 700, follower ring; 710, limit plate; 800, adjusting ring. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] An embodiment of a crosshead hydraulic connection and fastening device of a BOG compressor of the present invention is as follows: Figures 1 to 8 shown.

[0023] A crosshead hydraulic connection and fastening device for a BOG compressor is used to connect a crosshead 100 and a piston rod 200, and includes a thrust ring 300, a positioning ring 400, a pressure body 500, a locking nut 600, and a follower ring 700. The crosshead 100 is located at one end of the piston rod 200. The thrust ring 300, the positioning ring 400, and the pressure body 500 are sequentially arranged on the piston rod 200 along a first direction and are coaxial. The first direction is the axial direction of the piston rod 200. The thrust ring 300 is located on the side of the pressure body 500 close to the crosshead 100 in the first direction. The thrust ring 300 abuts against the crosshead 100, the positioning ring 400 is threadedly matched with the crosshead 100 and abuts against the thrust ring 300, and the positioning ring 400 is sleeved with an adjusting ring 800, and the adjusting ring 800 is threadedly matched with the positioning ring 400. An oil chamber 510 is provided in the pressure body 500. A pressure piston 520 and a sealing ring 530 are sequentially provided in the oil chamber 510 along a first direction. The pressure piston 520 is located on a side of the sealing ring 530 close to the positioning ring 400 in the first direction. The pressure piston 520 abuts against the positioning ring 400. An oil pump connector 540 is provided on the pressure body 500. The oil pump connector 540 is connected to the oil chamber 510.

[0024] The follower ring 700 and the locking nut 600 are sequentially arranged in the first direction and are coaxial. The follower ring 700 is located on a side of the locking nut 600 close to the crosshead 100 in the first direction and can abut against the crosshead 100. The locking nut 600 is sleeved with the pressure body 500 and threadedly matched with the pressure body 500. The locking nut 600 and the follower ring 700 are ball-jointed.

[0025] Specifically, the adjusting ring 800 and the positioning ring 400 are connected by screws.

[0026] In this embodiment, the thrust ring 300, the positioning ring 400, the pressure body 500, the locking nut 600 and the follower ring 700 are arranged to cooperate. When the piston rod 200 is connected to the cross head 100, the sealing ring 530 and the pressure piston 520 are first installed in the oil chamber 510 of the pressure body 500, and the locking nut 600 and the follower ring 700 are screwed into the pressure body 500. Then, the pressure body 500 is installed on the piston rod 200.

[0027] Then screw the adjusting ring 800 into the positioning ring 400 and tighten it with screws. Install the positioning ring 400 on the piston rod 200 so that the positioning ring 400 abuts against the pressure piston 520. Then install the thrust ring 300 on the piston rod 200. Then screw the positioning ring 400 into the crosshead 100 until the adjusting ring 800 abuts against the crosshead 100. Figure 3 and Figure 4 As shown, at this time, the preliminary connection between the crosshead 100 and the piston rod 200 is completed.

[0028] Then, pressure is applied to the oil chamber 510 through the oil pump connector 540. Figure 3 and Figure 4 As shown, the pressure piston 520 will apply pressure to the left, and the pressure body 500 will apply pressure to the right, forcing the piston rod 200 to deform, and then the locking nut 600 is rotated to drive the follower ring 700 to approach the crosshead 100 through the locking nut 600 until the follower ring 700 abuts against the crosshead 100.

[0029] Then the oil chamber 510 is depressurized. After the pressure is released, the piston rod 200 will slowly recover after the high-pressure oil is depressurized. The preload force generated by the deformation of the piston rod 200 will act on the connecting thread between the pressure body 500 and the locking nut 600, so that the relative rotation of the pressure body 500 and the locking nut 600 is hindered, thereby achieving the required connection preload force between the piston rod 200 and the crosshead 100, and if the locking nut 600 tends to deviate axially, the locking nut 600 will prompt the follower ring 700 to rotate relative to the locking nut 600, balance the force on the locking nut 600, prevent the locking nut 600 from axially deviating, and further prevent the piston rod 200 from bending, thereby ensuring the normal use of the piston rod 200.

[0030] In this embodiment, a crosshead hydraulic connection and fastening device for a BOG compressor further includes a manual ultra-high pressure oil pump, which is not shown in the figure. The manual ultra-high pressure oil pump is connected to the oil pump connector 540 through a hose.

[0031] Specifically, an oil circuit is provided on the pressure body 500 , and the oil pump connector 540 is connected to the oil chamber 510 through the oil circuit.

[0032] When in use, connect the hose of the manual ultra-high pressure oil pump to the oil pump connector 540, then turn the handle of the manual ultra-high pressure oil pump to raise the pressure of the manual ultra-high pressure oil pump to 150Mpa. Figure 3 and Figure 4 As shown, at this time, the pressure piston 520 will press to the left, and the pressure body 500 will press to the right.

[0033] In this embodiment, the thrust ring 300 includes two ring bodies, both of which are semi-annular structures, and the two ring bodies are installed on the piston rod 200 through the first elastic member 310. The first elastic member 310 is an annular spring.

[0034] In this embodiment, the piston rod 200 includes a first rod body 210 and a second rod body 220, which are sequentially arranged in the first direction and fixedly connected, and the first rod body 210 and the second rod body 220 are an integrally formed structure. The first rod body 210 is an elastic rod, and the diameter of the first rod body 210 is smaller than the diameter of the second rod body 220. The thrust ring 300, the positioning ring 400 and the pressure body 500 are all installed on the first rod body 210. The second rod body 220 is provided with a shoulder at one end close to the first rod body 210 in the first direction, and the pressure body 500 abuts against the shoulder.

[0035] Furthermore, three positioning bosses 230 are provided on the first rod body 210, and the three positioning bosses 230 are arranged in sequence along the first direction on the first rod body 210, and the thrust ring 300 is installed on the positioning boss 230 on the side away from the second rod body 220 in the first direction, that is, on the positioning boss 230 at the end. The remaining two positioning bosses 230 are used to assist the positioning of the adjustment ring 800 and the pressure body 500.

[0036] In a further embodiment, a limit plate 710 is coaxially and fixedly arranged on the follower ring 700, and the limit plate 710 is an arc-shaped plate. In the radial direction of the piston rod 200, the limit plate 710 is located between the locking nut 600 and the pressure body 500, and the limit plate 710 is threadedly matched with the pressure body 500.

[0037] Specifically, a slide groove 610 is opened on the inner wall surface of the locking nut 600, and the limit plate 710 is installed in the slide groove 610, and the thread on the limit plate 710 can be connected with the thread on the inner wall surface of the locking nut 600, so that when the locking nut 600 is screwed into the pressure body 500, it will not affect the installation of the locking nut 600 on the pressure body 500.

[0038] In this embodiment, a limit plate 710 is provided. When the follower ring 700 rotates relative to the locking nut 600, the follower ring 700 will drive the limit plate 710 to rotate synchronously, so that the thread on the limit plate 710 is misaligned with the thread on the pressure body 500, so that the limit plate 710 and the pressure body 500 are locked, preventing the limit plate 710 and the pressure body 500 from rotating relative to each other, and indirectly limiting the locking nut 600 from rotating relative to the limit plate 710, thereby further improving the connection tightness of the crosshead 100 and the piston rod 200.

[0039] In combination with the above embodiments, the specific working process is as follows: When connecting the piston rod 200 to the crosshead 100, first install the sealing ring 530 and the pressure piston 520 in the oil chamber 510 of the pressure body 500, and screw the locking nut 600 and the follower ring 700 into the pressure body 500. Then, the pressure body 500 is installed on the first rod body 210 of the piston rod 200, and the pressure body 500 is abutted against the shoulder of the second rod body 220 of the piston rod 200.

[0040] Then, the adjusting ring 800 is screwed into the positioning ring 400 and locked by screws. The positioning ring 400 is installed on the first rod body 210 of the piston rod 200 so that the positioning ring 400 abuts against the pressure piston 520. Then, the two ring bodies are locked and installed on the piston rod 200 using the first elastic member 310, and the installation of the thrust ring 300 is completed.

[0041] Then, the adjusting ring 800 is screwed to screw the positioning ring 400 into the crosshead 100 until the adjusting ring 800 abuts against the crosshead 100. Figure 3 and Figure 4 As shown, at this time, the preliminary connection between the crosshead 100 and the piston rod 200 is completed.

[0042] Connect the hose of the manual ultra-high pressure oil pump to the oil pump connector 540, then turn the handle of the manual ultra-high pressure oil pump to raise the pressure of the manual ultra-high pressure oil pump to 150Mpa, and apply pressure to the oil chamber 510 through the oil pump connector 540. Under the action of high pressure oil, Figure 3 and Figure 4As shown, the pressure piston 520 will apply pressure to the left, and the pressure body 500 will apply pressure to the right, forcing the piston rod 200 to deform, and then the locking nut 600 is rotated to drive the follower ring 700 to approach the crosshead 100 through the locking nut 600 until the follower ring 700 abuts against the crosshead 100.

[0043] Then the oil chamber 510 is depressurized. After the pressure is released, the preload force generated by the deformation of the piston rod 200 will act on the connecting thread between the pressure body 500 and the locking nut 600, so that the relative rotation of the pressure body 500 and the locking nut 600 is hindered, thereby achieving the required connection preload force between the piston rod 200 and the crosshead 100, and if the locking nut 600 tends to deviate axially, the locking nut 600 will prompt the follower ring 700 to rotate relative to the locking nut 600, balance the force on the locking nut 600, prevent the locking nut 600 from deviating axially, and further prevent the piston rod 200 from bending, thereby ensuring the normal use of the piston rod 200.

[0044] And when the follower ring 700 rotates relative to the locking nut 600, the follower ring 700 will drive the limit plate 710 to rotate synchronously, so that the thread on the limit plate 710 is misaligned with the thread on the pressure body 500, so that the limit plate 710 and the pressure body 500 are bitten into each other, preventing the limit plate 710 and the pressure body 500 from rotating relative to each other, and indirectly limiting the rotation of the locking nut 600 relative to the limit plate 710, further improving the connection tightness of the crosshead 100 and the piston rod 200.

[0045] 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, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A crosshead hydraulic connection and fastening device for a BOG compressor, used to connect a crosshead and a piston rod, characterized in that: It includes a thrust ring, a positioning ring, a pressure body, a locking nut and a follower ring; the crosshead is located at one end of the piston rod, and the thrust ring, the positioning ring and the pressure body are sequentially arranged on the piston rod along a first direction and are coaxial, and the first direction is the axial direction of the piston rod; the thrust ring is located on the side of the pressure body close to the crosshead in the first direction, the thrust ring abuts against the crosshead, the positioning ring is threadedly matched with the crosshead and abuts against the thrust ring, and an adjusting ring is sleeved on the positioning ring, and the adjusting ring is threadedly matched with the positioning ring; an oil chamber is provided in the pressure body, and a pressure piston and a sealing ring are sequentially arranged in the oil chamber along the first direction, the pressure piston is located on the side of the sealing ring close to the positioning ring in the first direction, and the pressure piston abuts against the positioning ring; an oil pump joint is provided on the pressure body, and the oil pump joint is connected to the oil chamber; the follower ring and the locking nut are sequentially arranged in the first direction and are coaxial, the follower ring is located on the side of the locking nut close to the crosshead in the first direction and can abut against the crosshead, the locking nut is sleeved with the pressure body and threadedly matched with the pressure body, and the locking nut is hinged to the follower ring.

2. The crosshead hydraulic connection and fastening device of a BOG compressor according to claim 1, characterized in that: A limit plate is coaxially and fixedly arranged on the follower ring. The limit plate is an arc-shaped plate. In the radial direction of the piston rod, the limit plate is located between the locking nut and the pressure body, and the limit plate is threadedly matched with the pressure body.

3. The crosshead hydraulic connection and fastening device of a BOG compressor according to claim 2, characterized in that: A slide groove is provided on the inner circumferential wall surface of the locking nut, a limiting plate is installed in the slide groove, and the thread on the limiting plate can be connected with the thread on the inner circumferential wall surface of the locking nut.

4. The crosshead hydraulic connection and fastening device of a BOG compressor according to claim 1, characterized in that: The piston rod includes a first rod body and a second rod body, which are arranged in sequence in a first direction and fixedly connected. The first rod body is an elastic rod, and the diameter of the first rod body is smaller than the diameter of the second rod body. The thrust ring, the positioning ring and the pressure body are all installed on the first rod body. A shoulder is provided at one end of the second rod body close to the first rod body in the first direction, and the pressure body abuts against the shoulder.

5. The crosshead hydraulic connection and fastening device of a BOG compressor according to claim 4, characterized in that: Three positioning bosses are arranged on the first rod body in sequence and at intervals along the first direction.

6. The crosshead hydraulic connection and fastening device of a BOG compressor according to claim 1, characterized in that: The thrust ring comprises two ring bodies, both of which are semi-annular structures, and the two ring bodies are mounted on the piston rod through a first elastic member.

7. A crosshead hydraulic connection and fastening device for a BOG compressor according to claim 6, characterized in that: The first elastic member is an annular spring.

8. The crosshead hydraulic connection and fastening device of a BOG compressor according to claim 1, characterized in that: It also includes a manual ultra-high pressure oil pump, which is connected to the oil pump connector through a hose.

9. A crosshead hydraulic connection and fastening device for a BOG compressor according to claim 8, characterized in that: An oil circuit is provided on the pressure body, and an oil pump connector is communicated with the oil chamber through the oil circuit.

10. The crosshead hydraulic connection and fastening device of a BOG compressor according to claim 1, characterized in that: The adjusting ring and the positioning ring are connected by screws.

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