Multi-gas passage sealed rotary joint

Abstract

The rotary joint comprises a rotary joint shell, a rotary main shaft and a sealing structure, the rotary joint shell is of a rod-shaped structure with the hollow interior and one open end, a plurality of gas cavities are formed in the rotary joint shell, a gas source connector is formed in the side wall of the rotary joint shell in the length direction, and the sealing structure is arranged in the gas cavities; two adjacent air source interfaces are sealed, the rotating main shaft sequentially penetrates through the multiple sealing structures and rotates relative to the rotating joint shell, multiple air source through holes are formed in the side wall of the rotating main shaft, the multiple air source through holes are communicated to the bottom of the rotating main shaft, the multiple air source through holes are communicated with the multiple air source interfaces, and the multiple air source interfaces are communicated with the rotating main shaft. A sealing structure is arranged between every two adjacent layered connector shells, every two vertically adjacent gas cavities are sealed, and therefore pipelines, connected with an external gas source, of each gas source connector on the rotary connector are not communicated with one another; and the gas source interface connected with the external gas source does not generate the condition of gas overflow.

Description

Technical Field

[0001] The present application relates to the field of semiconductor polishing technology, and in particular to a rotary joint with multiple gas passage seals. Background Art

[0002] The semiconductor grinding head is a key component in semiconductor grinding equipment. It is mainly used to press the wafer onto the grinding pad and drive the wafer to rotate in the CMP process to achieve micro-grinding of the wafer. During the grinding process, the slurry composed of abrasive particles will be placed between the wafer and the grinding pad. Through the friction of abrasives, frictional heat and chemical reactions, the surface of the wafer will be flattened and smoothed. The rotary joint connected to the semiconductor grinding head is a specially designed mechanism for transmitting gas (under pressure or vacuum) from a fixed inlet to a rotating outlet during the semiconductor grinding process. The rotary joint connects to multiple external gas sources to transport gas at the same time. When the interfaces on the rotary joint are not all connected to the external gas source, the interfaces will be connected to the outside and inside of the rotary joint, resulting in reduced air tightness inside the rotary joint. Utility Model Content

[0003] In view of this, the present application proposes a rotary joint with multiple gas passage seals, in which the multiple gas chambers are relatively sealed to improve the overall air tightness.

[0004] According to one aspect of the present application, there is provided a rotary joint with multiple gas passage seals, comprising: a rotary joint housing, a rotating main shaft and a sealing structure;

[0005] The rotary joint shell is a rod-shaped structure which is hollow inside and open at one end, and is provided with a plurality of gas chambers inside, and a plurality of gas source interfaces connected to the gas chambers are opened on the side wall of the rotary joint shell along the length direction, and the sealing structure is arranged inside the gas chamber to seal two adjacent gas source interfaces, and the rotating main shaft is a rod-shaped structure, which passes through the plurality of sealing structures in sequence through the mounting hole and can rotate relative to the rotary joint shell, and a plurality of gas source through holes are provided on the side wall of the rotating main shaft in sequence along the axial length direction, and the plurality of gas source through holes are connected to the bottom of the rotating main shaft, and the plurality of gas source through holes correspond to and are connected to the plurality of gas source interfaces one by one.

[0006] In a possible implementation, the rotary joint housing is a layered structure, including a top cover and a plurality of layered joint housings;

[0007] The layered joint shell is a hollow annular structure, the gas chamber includes a first gas chamber and a second gas chamber that are connected, and the first gas chamber and the second gas chamber are hollow structures, the cross-sectional diameter of the first gas chamber is larger than the cross-sectional diameter of the second gas chamber, and the first gas chamber and the end surface of the layered joint shell are located on the same plane;

[0008] A first positioning pin is provided at a position adjacent to the first gas chamber and the second gas chamber, and a second positioning pin is provided at an end surface of the layered joint housing away from the first gas chamber;

[0009] Both end surfaces of the layered joint shell are provided with connecting bolt holes, and any two layered joint shells can be detachably connected;

[0010] The top cover is arranged on the top of the plurality of detachably connected layered joint housings and is sealed and connected.

[0011] In a possible implementation, the sealing structure includes: a first anti-rotation portion, a second anti-rotation portion and a rotating portion;

[0012] The first anti-rotation part is an annular structure with a preset thickness, one end of which is a sealing end and the other end is a rotating end. The end surface of the rotating end of the first anti-rotation part is coated with graphite. The sealing end of the first anti-rotation part matches the second gas chamber and is embedded in the interior of the second gas chamber. A fixing plate is arranged around the middle of the first anti-rotation part along the circumferential direction. The fixing plate abuts against the interior of the first gas chamber. A positioning pin hole is provided on the plate surface of the fixing plate. When the opening position of the positioning pin hole corresponds to the position of the first positioning pin, the first anti-rotation part is coaxially arranged with the layered joint housing.

[0013] The second anti-rotation part has the same structure as the first anti-rotation part, and is disposed inside the first gas chamber, and a positioning pin hole provided at a sealing end of the second anti-rotation part is sleeved on the second positioning pin;

[0014] The rotating part is a ring-shaped structure with thickness, which is arranged inside the first gas chamber and between the first stop part and the second stop part. The side wall is provided with a through gas source connection hole and a mounting hole. When the rotating main shaft is bolted to the rotating part through the mounting hole, the gas source through hole corresponds to the gas source connection hole. Both end faces of the rotating part are coated with silicon carbide, and rotate with the rotating end of the first stop part and the rotating end of the second stop part respectively.

[0015] In a possible implementation, the outer side wall of the sealing end of the first anti-rotation portion is attached to the side wall of the second gas chamber;

[0016] The cross-sectional diameter of the inner side wall of the first anti-rotation portion is greater than the cross-sectional diameter of the rotating main shaft.

[0017] In one possible implementation, a first sealing groove is formed on an outer side wall of the sealing end of the first rotation-stopping portion. The first sealing groove is an annular groove arranged along the circumferential direction of the sealing end of the first rotation-stopping portion, and a sealing ring is provided inside the first sealing groove.

[0018] In one possible implementation, a second sealing groove is provided on the inner side wall of the rotating part. The second sealing groove is an annular groove arranged along the circumferential direction of the rotating part. There are two second sealing grooves, which are respectively arranged above and below the air source connecting hole, and a sealing ring is embedded inside.

[0019] In a possible implementation, any of the connected gas source through holes, the gas source connecting holes, and the gas source interfaces are located on the same plane.

[0020] In a possible implementation, the number of the anti-rotation pin holes opened on the fixing plate is more than two, any adjacent anti-rotation pin holes have the same spacing angle, and the anti-rotation pin holes are connected to the edge position of the fixing plate.

[0021] In one possible implementation, the fixing plate and the first anti-rotation portion are integrally formed.

[0022] In a possible implementation, the method further includes a rotating bearing;

[0023] The rotating bearing is arranged at the bottom of the plurality of detachably connected layered joint shells, and the bottom of the plurality of detachably connected layered joint shells is connected to the outer ring of the rotating bearing, and the side wall of the rotating main shaft is connected to the inner ring of the rotating bearing.

[0024] The beneficial effects of the rotary joint with multiple gas passages sealed in the embodiment of the present application are as follows: the bottom of the semiconductor grinding head connection device is connected to the grinding head to grind the semiconductor, and the connection device can stably output gas to assist grinding while ensuring that the grinding head is in a rotating state relative to the connection device by connecting to an external gas source. Specifically, the rotary joint shell is a hollow structure with an opening at one end, and the side wall is provided with a plurality of gas source interfaces connected to an external gas source along the length direction. The bottom of the rotating main shaft of the columnar structure is fixedly connected to the grinding head, and the side wall of the rotating main shaft is provided with gas source through holes corresponding to the gas source interfaces along the length direction, and the gas source through holes are connected to the bottom of the rotating main shaft with a gas source outlet, and the gas source outlet is connected to the through hole of the grinding head for gas transmission. During use, the bottom of the rotating spindle is connected to the grinding head, so that the bottom of the rotating spindle is aligned with the through hole of the grinding head, and then the rotating joint shell is fixed with a bracket, and the grinding head is turned on for grinding. The grinding head will drive the rotating spindle to rotate relative to the rotating joint shell inside the rotating joint shell, and the rotating joint shell is connected to the external gas source, and the gas is transmitted through the rotating spindle. When the connecting device is fixed as a whole, the grinding head can be kept in a rotating state, and the external gas can be connected through the connecting device without affecting the normal rotation and grinding of the grinding head. By providing a sealing structure between the interiors of two adjacent layered joint shells, the upper and lower adjacent gas chambers are sealed, so that each gas chamber is not connected to each other, so that the pipelines connected to the external gas source of each gas source interface on the rotating joint are not connected to each other, and the external gas source connected to each gas source interface is not affected. When the gas source interfaces of the rotating joint are not all connected to the external gas source, the gas source interface connected to the external gas source will not have gas overflow.

[0025] Other features and aspects of the present application will become apparent from the following detailed description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments, features, and aspects of the present application and, together with the description, serve to explain the principles of the present application.

[0027] Figure 1 A cross-sectional schematic diagram showing a rotary joint with multiple gas passage seals according to an embodiment of the present application;

[0028] Figure 2 A schematic diagram showing the structure of a rotary joint with multiple gas passage seals according to an embodiment of the present application;

[0029] Figure 3 A partial cross-sectional schematic diagram showing a rotary joint with multiple gas passage seals according to an embodiment of the present application;

[0030] Figure 4A front view schematic diagram showing a sealing structure of a rotary joint with multiple gas passages sealed according to an embodiment of the present application;

[0031] Figure 5 A schematic top view of the sealing structure of a rotary joint with multiple gas passages sealed according to an embodiment of the present application is shown;

[0032] Figure 6 A schematic diagram of a layered joint housing of a rotary joint with multiple gas passage seals according to an embodiment of the present application is shown;

[0033] Figure 7 A schematic cross-sectional view of a layered joint housing of a rotary joint with multiple gas passage seals according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0034] Various exemplary embodiments, features and aspects of the present application will be described in detail below with reference to the accompanying drawings. The same reference numerals in the accompanying drawings represent elements with the same or similar functions. Although various aspects of the embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless otherwise specified.

[0035] Among them, it needs to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the utility model or simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the utility model.

[0036] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0037] The word “exemplary” is used exclusively herein to mean “serving as an example, example, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.

[0038] In addition, in order to better illustrate the present application, numerous specific details are given in the following specific embodiments. It should be understood by those skilled in the art that the present application can also be implemented without certain specific details. In some examples, methods, means, components and circuits well known to those skilled in the art are not described in detail in order to highlight the subject matter of the present application.

[0039] See also Figure 1 and Figure 2 The rotary joint with multiple gas passage seals of the embodiment of the present application includes: a rotary joint shell 100, a rotating main shaft 200 and a sealing structure 300. The rotary joint shell 100 is a rod-shaped structure with a hollow interior and an open end, and is provided with multiple gas chambers inside. The side wall of the rotary joint shell 100 is provided with multiple gas source interfaces 170 connected to the gas chambers along the length direction. The sealing structure 300 is arranged inside the gas chamber to seal two adjacent gas source interfaces 170. The rotating main shaft 200 is a rod-shaped structure, which passes through multiple sealing structures 300 in sequence through the mounting holes and can rotate relative to the rotary joint shell 100. The side wall of the rotating main shaft 200 is provided with multiple gas source through holes 210 in sequence along the axial length direction. The multiple gas source through holes 210 are connected to the bottom of the rotating main shaft 200, and the multiple gas source through holes 210 correspond to and are connected to the multiple gas source interfaces one by one.

[0040] In this embodiment, the bottom of the semiconductor grinding head connection device is connected to the grinding head to grind the semiconductor, and the connection device is connected to an external gas source, and can stably output gas to assist grinding while ensuring that the grinding head is in a rotating state relative to the connection device. Specifically, the rotary joint housing 100 is a hollow structure with an opening at one end, and the side wall is provided with a plurality of gas source interfaces 170 connected to an external gas source along the length direction. The bottom of the rotating main shaft 200 of the columnar structure is fixedly connected to the grinding head, and the side wall of the rotating main shaft 200 is provided with a gas source through hole 210 corresponding to the gas source interface 170 along the length direction, and the gas source through hole 210 is connected to the bottom of the rotating main shaft 200 with a gas source outlet, and the gas source outlet is connected to the through hole of the grinding head for gas transmission. During use, the bottom of the rotating spindle 200 is connected to the grinding head, so that the bottom of the rotating spindle 200 is aligned with the through hole of the grinding head, and then the rotating joint housing 100 is fixed with a bracket, and the grinding head is turned on for grinding. The grinding head will drive the rotating spindle 200 to rotate relative to the rotating joint housing 100 inside the rotating joint housing 100, and the rotating joint housing 100 is connected to the external gas source, and the gas is transmitted through the rotating spindle 200, so that the connection device is fixed as a whole, so that the grinding head can be kept in a rotating state, and the external gas can be connected through the connection device without affecting the normal rotation and grinding of the grinding head. By providing a sealing structure 300 between the interiors of two adjacent layered joint housings, the upper and lower adjacent gas chambers are sealed, so that each gas chamber is not connected to each other, so that the pipelines of each gas source interface 170 on the rotating joint connected to the external gas source are not connected to each other, and the external gas source connected to each gas source interface 170 is not affected. When the gas source interface 170 of the rotary joint is not fully connected to the external gas source, the gas source interface 170 connected to the external gas source will not overflow.

[0041] It should be noted that the semiconductor polishing head is a key component in the chemical mechanical polishing (CMP) equipment, which is used to polish and shape the surface of semiconductor wafers and other components. CMP equipment plays a vital role in the manufacturing process of semiconductor equipment, and the polishing head is a key tool for achieving high-precision polishing. The design of the polishing head is very sophisticated, usually including a polishing head body and a protective structure. The polishing head body is used to carry the wafer and drive it to move on the surface of the polishing pad to achieve the purpose of polishing and shaping. The protective structure is connected to the periphery of the polishing head body to collect foreign particles, reduce the risk of the wafer being scratched by particles, and thus improve the quality of wafer polishing. During polishing, the polishing head presses the wafer against the polishing pad and drives the wafer to rotate, while the polishing pad rotates in the opposite direction. The slurry (composed of abrasive particles) is placed between the wafer and the polishing pad to achieve the polishing effect. Variables that affect the CMP process include the pressure applied by the polishing head, the flatness of the wafer, the rotation speed of the wafer and the polishing pad, the chemical composition of the slurry and the abrasive particles, the temperature, and the material and abrasiveness of the polishing pad.

[0042] A through connecting bolt hole 123 and an installation bolt hole 124 are opened on the end face of the layered joint shell along the axial length direction, and in two adjacent layered joint shells, the connecting bolt hole 123 passing through the upper layered joint shell is aligned with the installation connecting bolt hole 123 of the lower layered joint shell, and the plurality of layered joint shells are fixed to a top cover 160 in sequence to form a rotating joint shell 100 with a plurality of gas chambers inside and an opening at one end for placing the rotating main shaft 200.

[0043] In one embodiment, see Figure 1 and Figure 2 A rotary joint housing 100 is composed of a plurality of layered joint housings and a top cover 160. There are five layered joint housings. The five layered joint housings are all annular structures with a preset thickness, and a through hole is provided in the axial direction to install the rotating main shaft 200. The two end faces of the five layered joint housings are provided with through connection bolt holes 123 for fixing the plurality of layered joint housings, and the top cover 160 is arranged on the top of the plurality of layered joint housings for sealing, forming a columnar structure with a hollow interior and an open end. The five layered joint housings are respectively the first joint housing 110, the second joint housing 120, the third joint housing 130, the fourth joint housing 140 and the fifth joint housing 150 connected in sequence. Among them, the top end surface of the first joint shell 110 is fixedly connected to the top cover 160, and one end of the rotating joint shell 100 is sealed inside the chassis. The second joint shell 120, the third joint shell 130 and the fourth joint shell 140 have the same structure and are located between the first joint shell 110 and the second joint shell 120. The bottom end surface of the fifth joint shell 150 is provided with a bearing mounting hole, which can be fixed to the rotating joint shell 100 with a bearing, so that the rotating main shaft 200 can rotate relative to the rotating shell.

[0044] In this embodiment, the sealing structure 300 includes: a first stop part 320, a second stop part 330 and a rotating part 310, wherein the structure of the second stop part 330 is the same as that of the first stop part 320, and the rotating part 310 must cooperate with the two stop parts at the same time to be able to rotate relative to the rotary joint shell 100. Specifically, the first stop part 320 is an annular structure with a preset thickness, one end of which is a sealing end 332 and the other end of which is a rotating end 331. The sealing end 332 of the first stop part 320 matches the second gas chamber 122 of the layered joint shell, and the projected cross-sectional diameter of the first stop part 320 is smaller than the cross-sectional diameter of the first chamber. The first stop part 320 can be disposed inside the first gas chamber 122 of the layered joint shell, and the sealing end 332 of the first stop part 320 can be embedded in the second gas chamber 122 of the layered joint shell, while the rotating end 331 of the first stop part 320 is located inside the first gas chamber 121, and is used to cooperate with the rotating part 310 to realize the rotation of the rotating main shaft 200 relative to the rotating joint shell 100.

[0045] Among them, a fixing plate 334 is provided in the middle position of the outer wall of the first stop part 320 along the circumferential direction, the fixing plate 334 is an annular plate structure, and the plate surface of the fixing plate 334 is perpendicular to the length direction of the first stop part 320, and the fixing plate is closer to the rotating end 331 of the first stop part 320 than the sealing end 332 of the first stop part 320, and the cross-sectional diameter of the fixing plate 334 is larger than the cross-sectional diameter of the second gas chamber 122, so that the first stop part 320 can be clamped in the second gas chamber 122, and the rotating end 331 is located inside the first gas chamber 121. Inside the first gas chamber 121, more than two positioning pins are provided on the annular side wall adjacent to the second gas chamber 122. The more than two positioning pins are arranged at equal intervals in the circumferential direction, and the fixing plate 334 of the first stop part 320 is provided with positioning pin holes with a shape and position matching the positioning pins. The first stop part 320 can be fixed relative to the first gas chamber 121, so that the first stop part 320 is limited in the circumferential direction and cannot rotate in the circumferential direction.

[0046] The shape and structure of the second stopper 330 are the same as those of the first stopper 320, and a fixing plate 334 of the same structure is arranged on the outer side wall. A stopper pin is arranged in the circumferential direction inside the connection groove 125 on the top end face of the layered joint shell, and the stopper pin arranged in the connection groove 125 is the same as the stopper pin arranged in the first gas chamber 121, and both are arranged at equal intervals in the circumferential direction. In addition, the cross-sectional diameter of the connection groove 125 of the annular structure is larger than the cross-sectional diameter of the fixing plate 334 on the second stopper 330, so that the sealing end 332 of the second stopper 330 can be embedded in the second gas chamber 122 of the layered joint shell, and the fixing plate 334 abuts against the end face of the connection groove 125, and the stopper pin arranged on the connection groove 125 passes through the stopper pin hole 3341 of the fixing plate 334 of the second stopper 330, so that the second stopper 330 can be limited to rotate in the circumferential direction.

[0047] In this embodiment, the rotating part 310 is a columnar structure with a preset thickness, and a through hole is opened along the length direction. The through hole matches the rotating main shaft 200, so that the main shaft of the rotating shaft passes through the through hole opened in the rotating part 310, and a through fixing hole is opened on the side wall of the rotating part 310, and a matching fixing groove is opened on the side wall of the rotating main shaft 200. A fixing rod with a rod-like structure is passed through the fixing hole and embedded in the fixing groove to fix the rotating part 310 and the rotating main shaft 200. The rotating part 310 can rotate together with the rotating main shaft 200 inside the first gas chamber 121. Specifically, the rotating part 310 has a preset thickness. When the five layered joint shells are fixed, after two adjacent layered joint shells are fixed, the rotating end 331 of the first stop part 320 and the rotating end 331 of the second stop part 330 abut against each other, and the first stop part 320 and the second stop part 330 are restricted from rotating in the circumferential direction due to the presence of the stop pin and the stop pin hole 3341. Therefore, the rotating part 310 fixedly connected to the rotating main shaft 200 can rotate in the circumferential direction relative to the first stop part 320 and the second stop part 330.

[0048] A gas source communication hole is provided on the side wall of the rotating part 310 . After the rotating part 310 is fixed to the rotating main shaft 200 , the gas source communication hole is aligned with the gas source through hole 210 to transmit gas.

[0049] Example 1

[0050] Before the second joint shell 120 and the third joint shell 130 are fixed, the first stop part 320 is first arranged inside the second joint shell 120, so that the sealing end 332 of the first stop part 320 is embedded in the second gas chamber 122 of the second joint shell 120, and the first stop part 320 is fixed through the fixing plate 334 so that the rotating end 331 of the first stop part 320 is located inside the first gas chamber 121, and the fixing plate 334 is sleeved on the matching stop pin through the stop pin hole 3341 to limit the circumferential rotation of the first stop part 320. The second anti-rotation part 330 is arranged inside the connection groove 125 on the top end surface of the third joint housing 130, and the sealing end 332 of the second anti-rotation part 330 is embedded in the second gas chamber 122 of the third joint housing 130. The fixing plate 334 abuts against the connection groove 125 of the third joint housing 130, and is fixed by using the anti-rotation pin and the anti-rotation pin hole 3341 opened on the second anti-rotation pin fixing plate 334, so as to limit the second anti-rotation part 330 from rotating in the circumferential direction relative to the third joint housing 130. The rotating part 310 is placed inside the first gas chamber 121 of the second joint housing 120, so that the rotating main shaft 200 passes through the first gas chamber 121 of the third joint housing 130, the through hole of the second anti-rotation pin, the through hole of the rotating part 310, the through hole of the first anti-rotation pin and the first gas chamber 121 of the second joint housing 120 in sequence, and the rotating part 310 and the rotating main shaft 200 are fixed by a rod-shaped fixing rod. Finally, bolts are used to pass through the connection bolt holes 123123 opened on the top end surface of the second joint housing 120 to the installation bolt holes 124 on the top end surface of the third joint housing 130, thereby completing the connection between the second joint housing 120 and the third joint housing 130. At this time, the first anti-rotation part 320, the rotating part 310, and the second anti-rotation part 330 are sequentially arranged between the second joint housing 120 and the third joint housing 130, and the rotating end 331 of the first anti-rotation part 320 abuts against one end surface of the rotating part 310, and the rotating end 331 of the second anti-rotation part 330 abuts against the other end surface of the rotating part 310.

[0051] Among them, the rotating part 310 can rotate in the circumferential direction relative to the rotating end 331 of the first stop part 320 and the rotating end 331 of the second stop part 330, so that the rotating main shaft 200 can be fixed inside the rotating joint shell 100 relative to the rotating joint shell 100, and the rotating main shaft 200 can also rotate in the circumferential direction relative to the rotating joint shell 100.

[0052] In a specific embodiment, the end faces of the rotating ends 331 of the first rotation stopper 320 and the second rotation stopper 330 are coated with graphite, and the two end faces of the rotating part 310 are coated with silicon carbide, so that when the two end faces of the rotating part 310 rotate relative to the rotating ends 331 of the first rotation stopper 320 and the second rotation stopper 330, a good sealing performance can be maintained. Specifically, this is mainly attributed to their unique physical and chemical properties and the interaction between them.

[0053] First, graphite has the characteristics of high temperature resistance, good electrical and thermal conductivity, excellent self-lubrication, stable chemical properties and high plasticity. This makes graphite stable in a variety of extreme environments and not easy to deform or damage. At the same time, the powdery nature of graphite can produce a sealing ring effect, effectively preventing impurities from entering the sealing end 332 surface, thereby improving the sealing performance. Secondly, silicon carbide is a material with great hardness, and its Mohs hardness is second only to diamond, and has excellent thermal conductivity. In addition, silicon carbide also has high thermal stability and high temperature strength, and can maintain its original performance at high temperatures. More importantly, silicon carbide is a wear-resistant material with high toughness and chemical inertness, so it has excellent corrosion resistance and is particularly suitable for occasions with corrosive media at high temperatures. When graphite and silicon carbide are in contact, the sealing performance of the two materials is very good, and the thermal conductivity of the materials is also fully utilized, thereby improving the self-heating performance. This combination makes the sealing structure 300 perform well in high temperature, high pressure, corrosion resistance and wear resistance, so it has good sealing performance.

[0054] In a specific embodiment, the outer wall of the sealing end 332 of the first stop portion 320 is attached to the side wall of the second gas chamber 122, and the cross-sectional diameter of the inner wall of the first stop portion 320 is larger than the cross-sectional diameter of the rotating main shaft 200, so that a gap is reserved between the first stop portion 320 and the rotating main shaft 200, forming a second gas chamber 122 surrounded by the rotating main shaft 200.

[0055] In a specific embodiment, a first sealing groove 321 is provided on the outer side wall of the sealing end 332 of the first stop portion 320. The first sealing groove 321 is an annular groove, which is arranged in the circumferential direction of the sealing end 332 of the first stop portion 320, and a sealing ring is provided inside the first sealing groove 321 for sealing the position where the first gas chamber 121 is connected to the second gas chamber 122 to prevent gas from flowing between the first stop portion 320 and the inner side wall of the layered joint shell.

[0056] In a specific embodiment, a second sealing groove 314 is provided on the inner side wall of the rotating part 310. The second sealing groove 314 is an annular groove and is arranged along the circumferential direction of the rotating part 310. There are two second sealing grooves 314, which are respectively arranged above and below the gas source connection hole 313, and a sealing ring is embedded inside. The two second sealing grooves 314 are respectively provided at the upper and lower positions of the gas source connection hole 313, and the passage of gas passing through the gas source connection hole 313 and the gas source through hole 210 is sealed inside the rotating part 310, so as to prevent gas from flowing between the inner side wall of the rotating part 310 and the outer side wall of the rotating main shaft 200.

[0057] In a specific embodiment, any connected gas source through hole 210, gas source connection hole 313 and gas source interface 170 are located on the same plane. After the rotating part 310 is fixedly installed with the layered joint housing, the gas source connection hole 313 is aligned with the gas source through hole 210 and is coaxially arranged, and the gas source interface 170, the gas source connection hole 313 and the gas source through hole 210 connected to the same gas chamber are in a straight line, which is convenient for the transmission of external gas.

[0058] In a specific embodiment, there are more than two stop pin holes 3341 opened on the fixing plate 334, and the first stop part 320 can be fixed inside the layered joint shell through the fixing plate 334, and any adjacent spacing angles are the same, ensuring that the force on the fixing plate 334 on the first stop part 320 is more uniform, and the stop pin holes 3341 opened on the fixing plate 334 are connected to the edge position of the fixing plate, which is convenient for aligning the stop pin holes 3341 on the fixing plate 334 with the stop pins provided in the first gas chamber 121.

[0059] In one specific embodiment, the fixing plate 334 and the first anti-rotation portion 320 are integrally formed.

[0060] In a specific embodiment, a rotating bearing is further included, which is arranged at the bottom of a plurality of detachably connected layered joint shells, and the bottom of the plurality of detachably connected layered joint shells is connected to the outer ring of the rotating bearing, and the side wall of the rotating main shaft 200 is connected to the inner ring of the rotating bearing. The rotating bearing has the function of relatively fixing the rotating main shaft 200 and the rotating joint shell 100, so that the rotating main shaft 200 can rotate more smoothly relative to the rotating joint shell 100, and can seal the bottom opening of the rotating joint shell 100. Among them, the bottom of the fifth joint shell 150 located at the bottom is provided with a bearing mounting hole, which matches the size of the rotating bearing.

[0061] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A rotary joint with multiple gas passage seals, suitable for connecting a grinding head, characterized in that: include: Rotary joint housing, rotating spindle and sealing structure; The rotary joint shell is a rod-shaped structure which is hollow inside and open at one end, and is provided with a plurality of gas chambers inside, and a plurality of gas source interfaces connected to the gas chambers are opened on the side wall of the rotary joint shell along the length direction, and the sealing structure is arranged inside the gas chamber to seal two adjacent gas source interfaces, and the rotating main shaft is a rod-shaped structure, which passes through the plurality of sealing structures in sequence and can rotate relative to the rotary joint shell, and a plurality of gas source through holes are provided on the side wall of the rotating main shaft in sequence along the axial length direction, and the plurality of gas source through holes are connected to the bottom of the rotating main shaft, and the plurality of gas source through holes correspond to and are connected to the plurality of gas source interfaces one by one.

2. The multi-gas passage sealed rotary joint according to claim 1, characterized in that: The rotary joint housing is a layered structure, including a top cover and a plurality of layered joint housings; The layered joint shell is a hollow annular structure, the gas chamber includes a first gas chamber and a second gas chamber that are connected, and the first gas chamber and the second gas chamber are hollow structures, the cross-sectional diameter of the first gas chamber is larger than the cross-sectional diameter of the second gas chamber, and the first gas chamber and the end surface of the layered joint shell are located on the same plane; A first positioning pin is provided at a position adjacent to the first gas chamber and the second gas chamber, and a second positioning pin is provided at an end surface of the layered joint housing away from the first gas chamber; Both end surfaces of the layered joint shell are provided with connecting bolt holes, and any two layered joint shells can be detachably connected; The top cover is arranged on the top of the plurality of detachably connected layered joint housings and is sealed and connected.

3. The multi-gas passage sealed rotary joint according to claim 2, characterized in that: The sealing structure comprises: a first anti-rotation part, a second anti-rotation part and a rotating part; The first anti-rotation part is an annular structure with a preset thickness, one end of which is a sealing end and the other end is a rotating end. The end surface of the rotating end of the first anti-rotation part is coated with graphite. The sealing end of the first anti-rotation part matches the second gas chamber and is embedded in the interior of the second gas chamber. A fixing plate is arranged around the middle of the first anti-rotation part along the circumferential direction. The fixing plate abuts against the interior of the first gas chamber. A positioning pin hole is provided on the plate surface of the fixing plate. When the opening position of the positioning pin hole corresponds to the position of the first positioning pin, the first anti-rotation part is coaxially arranged with the layered joint housing. The second anti-rotation part has the same structure as the first anti-rotation part, and is disposed inside the first gas chamber, and a positioning pin hole provided at a sealing end of the second anti-rotation part is sleeved on the second positioning pin; The rotating part is a ring-shaped structure with thickness, which is arranged inside the first gas chamber and between the first stop part and the second stop part. The side wall is provided with a through gas source connection hole and a mounting hole. When the rotating main shaft is bolted to the rotating part through the mounting hole, the gas source through hole corresponds to the gas source connection hole. Both end faces of the rotating part are coated with silicon carbide, and rotate with the rotating end of the first stop part and the rotating end of the second stop part respectively.

4. The multi-gas passage sealed rotary joint according to claim 3, characterized in that: The outer side wall of the sealing end of the first anti-rotation portion is attached to the side wall of the second gas chamber; The cross-sectional diameter of the inner side wall of the first anti-rotation portion is greater than the cross-sectional diameter of the rotating main shaft.

5. The multi-gas passage sealed rotary joint according to claim 4, characterized in that: A first sealing groove is formed on the outer side wall of the sealing end of the first anti-rotation part. The first sealing groove is an annular groove arranged along the circumferential direction of the sealing end of the first anti-rotation part, and a sealing ring is arranged inside the first sealing groove.

6. The multi-gas passage sealed rotary joint according to claim 4, characterized in that: A second sealing groove is provided on the inner side wall of the rotating part. The second sealing groove is an annular groove arranged along the circumferential direction of the rotating part. There are two second sealing grooves, which are respectively arranged above and below the air source connecting hole, and a sealing ring is embedded inside.

7. The multi-gas passage sealed rotary joint according to claim 3, characterized in that: The arbitrarily connected gas source through holes, the gas source connecting holes and the gas source interfaces are located on the same plane.

8. The multi-gas passage sealed rotary joint according to claim 3, characterized in that: There are more than two anti-rotation pin holes on the fixing plate, and any adjacent ones have the same spacing angle, and the anti-rotation pin holes are connected to the edge of the fixing plate.

9. The multi-gas passage sealed rotary joint according to claim 3, characterized in that: The fixing plate and the first anti-rotation portion are integrally formed.

10. The multi-gas passage sealed rotary joint according to claim 2, characterized in that: Also includes a rotary bearing; The rotating bearing is arranged at the bottom of the plurality of detachably connected layered joint shells, and the bottom of the plurality of detachably connected layered joint shells is connected to the outer ring of the rotating bearing, and the side wall of the rotating main shaft is connected to the inner ring of the rotating bearing.

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