阅读说明：本技术 大型lng卸料臂用旋转接头 (Rotary joint for large LNG unloading arm ) 是由 黄琳 韩力 尹云 高飞 郗厚岩 苏华 于 2019-09-24 设计创作，主要内容包括：本发明涉及低温流体输送技术领域,尤其涉及大型LNG装卸臂用的旋转接头。本发明内圈法兰的底面开有真空槽和静密封槽,内圈法兰底面与内圈底面采用螺栓把合在一起,中间静密封槽内放置静密封垫；内圈内表面与隔温环固定在一起,形成隔温腔；内圈开有次密封槽放置次密封圈；内圈外表面加工有两道滚道凹槽；外圈内表面加工有两道滚道凹槽；外圈套装于内圈的外部,使得内圈和外圈上的滚道凹槽组成两个具有一定缝隙的圆形滚道,并且分别安装有偏心夹持滚道；偏心夹持滚道内部安装有滚珠；外圈法兰法兰底面与外圈底面采用螺栓把合。本发明的技术方案解决了现有技术中的现有旋转接头结构已经不能补偿其瞬时温度对结构的影响,导致液态LNG无法正常输送的问题。(The invention relates to the technical field of cryogenic fluid delivery, in particular to a rotary joint for a large LNG loading and unloading arm. The bottom surface of the inner ring flange is provided with a vacuum groove and a static sealing groove, the bottom surface of the inner ring flange and the bottom surface of the inner ring are combined together by adopting bolts, and a static sealing gasket is arranged in the middle static sealing groove; the inner surface of the inner ring is fixed with the heat insulation ring to form a heat insulation cavity; the inner ring is provided with a secondary sealing groove for placing a secondary sealing ring; two raceway grooves are processed on the outer surface of the inner ring; two raceway grooves are processed on the inner surface of the outer ring; the outer ring is sleeved outside the inner ring, so that the raceway grooves on the inner ring and the outer ring form two circular raceways with certain gaps, and are respectively provided with an eccentric clamping raceway; the eccentric clamping roller path is internally provided with a ball; the bottom surface of the flange of the outer ring and the bottom surface of the outer ring are fastened by bolts. The technical scheme of the invention solves the problem that the influence of the instantaneous temperature on the structure cannot be compensated by the existing rotary joint structure in the prior art, so that the liquid LNG cannot be normally conveyed.)

1. The utility model provides a large-scale LNG rotary joint for unloading arm which characterized in that, large-scale LNG unload that rotary joint for arm includes: the device comprises an inner ring flange (1), an inner ring (3), a heat insulation ring (4), an outer ring (5), an eccentric clamping raceway (7), balls (8), an outer ring flange (9) and a ball plug (13);

The bottom surface of the inner ring flange (1) is provided with a vacuum groove and a static sealing groove, the bottom surface of the inner ring flange (1) and the bottom surface of the inner ring (3) are combined together by bolts, and a static sealing gasket (2) is arranged in the middle static sealing groove;

the inner surface of the inner ring (3) is fixed with the heat insulation ring (4) to form a heat insulation cavity, so that the influence of low temperature in the tube on the ball roller path is reduced; the inner ring (3) is provided with a secondary sealing groove for placing a secondary sealing ring (15); two raceway grooves are processed on the outer surface of the inner ring (3);

Two raceway grooves are machined on the inner surface of the outer ring (5); the outer ring (5) is sleeved outside the inner ring (3), so that the raceway grooves on the inner ring (3) and the outer ring (5) form two circular raceways with certain gaps, and are respectively provided with an eccentric clamping raceway (7);

A ball (8) is arranged in the eccentric clamping roller path (7);

The bottom surface of the outer ring flange (9) is provided with a groove for placing a movable sealing ring (11) and a groove for placing a static sealing ring (10), and the bottom surface of the outer ring flange (9) and the bottom surface of the outer ring (5) are closed by bolts.

2. the swivel joint for a large-scale LNG unloading arm according to claim 1, wherein the eccentric clamping raceway (7) is divided into an inner part and an outer part, the inner part and the outer part are oval and are respectively embedded in a raceway groove on the outer surface of the inner ring (3) and a raceway groove on the inner surface of the outer ring (5).

3. The swivel joint for a large-scale LNG unloading arm according to claim 2, wherein the outer surface of the outer ring (5) is provided with two nitrogen drying holes (6) which are located between two raceway grooves; two nitrogen drying holes (6) are distributed on the outer surface of the outer ring (5) at 180 degrees.

4. the swivel joint for a large LNG discharging arm according to claim 3, characterized in that the two rows of raceway grooves of the outer ring (5) are respectively provided with round holes for placing balls and are provided with ball plugs (13) for facilitating the mounting and dismounting of the balls (8); a sealing ring is arranged between the ball plug (13) and the outer ring (5).

5. The swivel joint for a large LNG unloading arm according to claim 1, wherein the outer ring flange (9) is provided with a dynamic seal check hole (12) at the dynamic seal ring seating groove and a secondary seal check hole (16) at the secondary seal ring seating groove for double check of leakage of the low-temperature LNG.

6. the swivel joint for a large-scale LNG unloading arm according to claim 2, wherein the waterproof sealing ring (14) is tightly fitted and tightly pressed at the gap between the upper surface of the inner ring (3) and the lower surface of the outer ring (5) to prevent external moisture and dust from entering the raceway.

Technical Field

The invention relates to the technical field of cryogenic fluid delivery, in particular to a rotary joint for a large LNG loading and unloading arm.

Background

in recent years, the proportion of LNG in the global natural gas supply in China has increased rapidly, and more low-temperature discharge arms are in butt joint with marine pipelines at many ports and docks for fluid discharge. The rotary joint is used as an indispensable component of the low-temperature discharging arm, and plays a vital role in ensuring the normal work of the whole machine and reducing the influence of the discharging arm on the ship body and the sea waves. The conventional ball type rotary joint is mainly used in a working state of a product in a normal-temperature working environment in a mode of directly connecting an inner ring, an outer ring and balls. At present, a rotary joint applied to an LNG discharging arm is mainly in a single-layer dynamic sealing structure form, and a ball and a rotary joint body are directly connected, so that the rotary joint is mainly suitable for products with small conveying pipe diameters. In the case of a large LNG loading arm, the existing rotary joint structure cannot compensate the influence of the instantaneous temperature on the structure, so that the liquid LNG cannot be normally transported.

the existing low-temperature fluid loading and unloading arm rotary joint comprises:

CN201610046430.6 a rotary joint special for ultra-low temperature fluid loading and unloading arm, the rotary joint special for loading and unloading arm described in this patent is a ball and body direct contact type, and the ball is hollow, and the arrangement form of nitrogen purging line is different. Because large-scale rotary joint atress condition is abominable, ball and body direct contact structure make the body wearing and tearing easily, if change can only change the body, the cost increases. And the hollow structure of the ball bearing has the same external dimension and bears smaller force ratio, and the deformation in low-temperature environment is uneven and is easy to damage.

The rotary joint described in the patent of CN201720507375.6 rotary joint and the loading and unloading arm using the same adopts a non-ball type in which the rotary core and the housing are relatively rotatable. Because the large rotary joint has larger load and is under the condition of low-temperature medium transportation, if a non-ball type is adopted as sliding friction, the acting force is obviously increased compared with the rolling friction force of a ball type, and the blocking phenomenon is easy to occur under the low-temperature working condition.

aiming at the problems in the prior art, a novel rotary joint for a large LNG unloading arm is researched and designed, so that the problem in the prior art is very necessary to be solved.

disclosure of Invention

According to the existing rotary joint structure that has proposed above, the influence of its instantaneous temperature to the structure can not be compensated yet, leads to the technical problem that liquid LNG can't normally carry, and provides a rotary joint for large-scale LNG unloading arm. The invention realizes the stable and reliable transmission and convenient replacement of the low-temperature fluid mainly through the design of an eccentric clamping raceway, the design of a nitrogen drying line, the design of dynamic seal arrangement and the design of a heat insulation cavity.

The technical means adopted by the invention are as follows:

The utility model provides a large-scale LNG rotary joint for unloading arm which characterized in that, large-scale LNG unload that rotary joint for arm includes: the inner ring flange, the inner ring, the heat insulation ring, the outer ring, the eccentric clamping raceway, the ball, the outer ring flange and the ball plug; the bottom surface of the inner ring flange is provided with a vacuum groove and a static sealing groove, the bottom surface of the inner ring flange and the bottom surface of the inner ring are combined together by bolts, and a static sealing gasket is arranged in the middle static sealing groove; the inner surface of the inner ring is fixed with the heat insulation ring to form a heat insulation cavity, so that the influence of low temperature in the pipe on the ball roller path is reduced; the inner ring is provided with a secondary sealing groove for placing a secondary sealing ring; two raceway grooves are processed on the outer surface of the inner ring; two raceway grooves are processed on the inner surface of the outer ring; the outer ring is sleeved outside the inner ring, so that the raceway grooves on the inner ring and the outer ring form two circular raceways with certain gaps, and are respectively provided with an eccentric clamping raceway; the eccentric clamping roller path is internally provided with a ball; the bottom surface of the outer ring flange is provided with a groove for placing a dynamic sealing ring and a groove for placing a static sealing ring, and the bottom surface of the outer ring flange and the bottom surface of the outer ring are closed by bolts.

Furthermore, the eccentric clamping raceway is divided into an inner part and an outer part, the inner part and the outer part are elliptic and are respectively embedded in a raceway groove on the outer surface of the inner ring and a raceway groove on the inner surface of the outer ring.

Furthermore, two nitrogen drying holes are formed in the outer surface of the outer ring and are positioned between the two raceway grooves; two nitrogen drying holes are distributed on the outer surface of the outer ring at 180 degrees.

furthermore, circular holes for placing balls are formed in the two rows of raceway grooves of the outer ring respectively and are matched with ball plugs, so that the balls are convenient to mount and dismount; and a sealing ring is arranged between the ball plug and the outer ring.

Furthermore, the outer ring flange is provided with a dynamic seal detection hole at the position of the dynamic seal ring mounting groove and a secondary seal detection hole at the position of the secondary seal ring mounting groove, and the outer ring flange is used for double detection of leakage of low-temperature LNG.

Furthermore, a gap between the upper surface of the inner ring and the lower surface of the outer ring is tightly attached to and tightly pressed with a waterproof sealing ring, so that external moisture and dust are prevented from entering the raceway.

The working principle of the invention is as follows:

The inner ring flange and the inner ring are relatively fixed, and the outer ring flange are relatively fixed. The inner ring and the outer ring can rotate relatively through the balls. The movable sealing ring and the secondary sealing ring are both arranged between two surfaces which slide relatively, and sealing is realized by pressing the sliding surface. The dynamic seal detection hole and the secondary seal detection hole are respectively arranged in the outer ring flange and close to the outer sides of the dynamic seal ring and the secondary seal ring, and detection of two-stage sealing is achieved.

When the low-temperature fluid LNG flows into the outer ring flange from the main pipeline and flows out of other pipelines through the inner ring flange, the inner ring flange and the inner ring can rotate relative to the outer ring and the outer ring flange through the balls to realize the rotation around the axial direction when external force is applied.

When the ball is extruded and deformed by external force and the inner and outer parts of the eccentric clamping raceway, and the hardness difference between the eccentric clamping raceway and the ball forces the original round and elliptical contact to be changed into round and approaching to round contact, so that the stress area is increased, and the stress condition is improved.

Nitrogen is blown in from the nitrogen drying line, passes through the balls and is blown out from the nitrogen drying line on the other side, and therefore the balls are prevented from freezing and rotating inflexibly due to the existence of moisture around the balls.

compared with the prior art, the invention has the following advantages:

1. According to the rotary joint for the large LNG discharging arm, the stress condition between the ball and the roller path is improved due to the special design of the eccentric clamping roller path, and the service life of the structure is prolonged;

2. According to the rotary joint for the large LNG discharging arm, the eccentric clamping roller path is arranged between the inner ring and the outer ring, and the hardness difference design of the roller path and the balls is adopted, so that the roller path is weaker than the balls and the inner ring and the outer ring, the roller path is replaced preferentially, the cost is reduced, and the rotary joint is convenient to disassemble;

3. According to the rotary joint for the large LNG discharging arm, when fluid is transmitted, the multi-layer sealing design of double dynamic sealing and static sealing and the design of waterproof sealing and heat insulation of the heat insulation cavity are realized, the leakage rate is reduced, and the working safety is improved;

4. According to the rotary joint for the large LNG discharging arm, the balls are enabled to rotate flexibly without freezing under the low-temperature condition through the design of the nitrogen drying line;

5. The rotary joint for the large LNG discharging arm provided by the invention realizes the detection of whether the low-temperature fluid leaks or not through two dynamic seal detections, and ensures the reliability of the structure.

In conclusion, the technical scheme of the invention solves the problem that the existing rotary joint structure in the prior art cannot compensate the influence of the instantaneous temperature on the structure, so that the liquid LNG cannot be normally conveyed.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a top view of the present invention;

Fig. 3 is a schematic diagram of the use state of the present invention mounted on an LNG unloading arm.

In the figure: 1. the device comprises an inner ring flange 2, a static sealing gasket 3, an inner ring 4, a heat insulation ring 5, an outer ring 6, a nitrogen drying hole 7, an eccentric clamping raceway 8, a ball 9, an outer ring flange 10, a static sealing ring 11, a dynamic sealing ring 12, a dynamic sealing detection hole 13, a ball plug 14, a waterproof sealing ring 15, a secondary sealing ring 16 and a secondary sealing detection hole.

Detailed Description

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

The relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

In the description of the present invention, it is to be understood that the orientation or positional relationship indicated by the directional terms such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal" and "top, bottom", etc., are generally based on the orientation or positional relationship shown in the drawings, and are used for convenience of description and simplicity of description only, and in the absence of any contrary indication, these directional terms are not intended to indicate and imply that the device or element so referred to must have a particular orientation or be constructed and operated in a particular orientation, and therefore should not be considered as limiting the scope of the present invention: the terms "inner and outer" refer to the inner and outer relative to the profile of the respective component itself.

Spatially relative terms, such as "above … …," "above … …," "above … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial relationship to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary term "above … …" can include both an orientation of "above … …" and "below … …". The device may be otherwise variously oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

It should be noted that the terms "first", "second", and the like are used to define the components, and are only used for convenience of distinguishing the corresponding components, and the terms have no special meanings unless otherwise stated, and therefore, the scope of the present invention should not be construed as being limited.

As shown in the figures, the invention provides a rotary joint for a large LNG unloading arm, which is characterized in that the rotary joint for the large LNG unloading arm comprises: the device comprises an inner ring flange 1, an inner ring 3, a heat insulation ring 4, an outer ring 5, an eccentric clamping raceway 7, balls 8, an outer ring flange 9 and a ball plug 13; the bottom surface of the inner ring flange 1 is provided with a vacuum groove and a static sealing groove, the bottom surface of the inner ring flange 1 and the bottom surface of the inner ring 3 are combined together by bolts, and a static sealing gasket 2 is arranged in the middle static sealing groove; the inner surface of the inner ring 3 is fixed with the heat insulation ring 4 to form a heat insulation cavity, so that the influence of low temperature in the pipe on the ball roller path is reduced; the inner ring 3 is provided with a secondary sealing groove for placing a secondary sealing ring 15; two raceway grooves are machined on the outer surface of the inner ring 3; two raceway grooves are processed on the inner surface of the outer ring 5; the outer ring 5 is sleeved outside the inner ring 3, so that the raceway grooves on the inner ring 3 and the outer ring 5 form two circular raceways with certain gaps, and are respectively provided with an eccentric clamping raceway 7; a ball 8 is arranged in the eccentric clamping roller path 7; the bottom surface of the outer ring flange 9 is provided with a groove for placing a dynamic seal ring 11 and a groove for placing a static seal ring 10, and the bottom surface of the outer ring flange 9 and the bottom surface of the outer ring 5 are closed by bolts.

the eccentric clamping raceway 7 is divided into an inner part and an outer part, the inner part and the outer part are elliptic and are respectively embedded in a raceway groove on the outer surface of the inner ring 3 and a raceway groove on the inner surface of the outer ring 5.

The outer surface of the outer ring 5 is provided with two nitrogen drying holes 6 which are positioned between the two raceway grooves; two nitrogen drying holes 6 are distributed on the outer surface of the outer ring 5 at 180 degrees.

the two rows of raceway grooves of the outer ring 5 are respectively provided with round holes for placing balls and are provided with ball plugs 13, so that the balls 8 can be conveniently mounted and dismounted; a sealing ring is arranged between the ball plug 13 and the outer ring 5.

The outer ring flange 9 is provided with a dynamic seal detection hole 12 at the position of the dynamic seal ring mounting groove and a secondary seal detection hole 16 at the position of the secondary seal ring mounting groove, and is used for double detection of leakage of low-temperature LNG.

And a waterproof sealing ring 14 is tightly attached and tightly sleeved at a gap between the upper surface of the inner ring 3 and the lower surface of the outer ring 5, so that external moisture and dust are prevented from entering the raceway.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.