High speed high pressure swivel

Abstract

The application relates to the technical field of fluid transmission and sealing, in particular to a high-speed and high-pressure rotary joint which comprises a stationary shell, a rotating main shaft and a sealing assembly. The inner wall of the stationary shell is provided with a spiral internal cooling liquid channel, the rotating main shaft is provided with a central fluid pipeline and a lubricant storage cavity, the sealing assembly is composed of a dynamic ring and a static ring to form end face sealing, lubricant is transported to a sealing interface through a radial delivery hole, and the cooling liquid channel forms a forced cooling loop. The application can realize stable sealing and heat dissipation under high-speed and high-pressure working conditions.

Description

Technical Field

[0001] This utility model belongs to the field of fluid transmission and sealing technology, specifically a high-speed high-pressure rotary joint. Background Technology

[0002] High-speed, high-pressure rotary joints are key components used to achieve continuous fluid medium transfer between stationary fluid pipelines and rotating equipment. They are widely used in industrial fields such as aerospace, precision machining, energy equipment, and automated production lines. These joints ensure the stable delivery of media such as hydraulic oil, coolant, or gas while the equipment rotates at high speeds, meeting the functional requirements of power transmission, temperature control, or pressure maintenance in rotating systems.

[0003] High-speed, high-pressure rotary joints typically consist of a housing, rotor, sealing components, bearings, and lubrication structures. They achieve dynamic sealing of high-pressure fluids through a precisely fitted rotary sealing interface. In actual operation, the joint must simultaneously withstand high rotational speeds and system pressures, thus placing high demands on sealing reliability, operational stability, and service life. To improve performance, multi-stage sealing designs, high-precision machining processes, and special material matching are often employed to reduce leakage risks and minimize friction and wear.

[0004] However, during long-term operation, the sealing components of existing high-speed high-pressure rotary joints are subjected to continuous high pressure and high-speed shearing, which can easily lead to increased interface wear and significant heat accumulation, resulting in a gradual decline in sealing performance. Under extreme working conditions, this may affect the stability of fluid transmission. Therefore, there is still room for further improvement in their durability under the conditions of high speed and high working pressure. Utility Model Content

[0005] This invention provides a high-speed, high-pressure rotary joint, which aims to solve the problem of increased wear and significant heat accumulation in the sealing components of existing rotary joints under long-term high-speed and high-pressure conditions due to continuous high pressure and high-speed shearing action, thereby improving the sealing performance stability and working durability of the device.

[0006] To achieve the above objectives, this utility model provides the following technical solution: The high-speed, high-pressure rotary joint includes a stationary housing, a rotating spindle, and a sealing assembly, wherein: The stationary housing has a through-hole accommodating cavity, and one end of the stationary housing is provided with a mounting flange for fixing. The shell wall of the stationary housing has a main working fluid inlet and a main working fluid outlet. On the inner wall of the stationary housing, in the area adjacent to the sealing assembly, a spiral internal coolant channel is integrally formed.

[0007] The rotating spindle passes through the inner cavity of the stationary housing and is rotated with the inner wall of the stationary housing by means of a bearing assembly; a central fluid pipe is provided at the axis of the rotating spindle, which is connected to the main working fluid inlet and the main working fluid outlet; an independent lubricant storage cavity is provided inside the rotating spindle.

[0008] The sealing assembly is fitted onto the outer periphery of the rotating spindle and housed within the receiving cavity of the stationary housing. The sealing assembly includes a dynamic ring seal and a stationary ring seal. The dynamic ring seal rotates synchronously with the rotating spindle, while the stationary ring seal is fixed within the receiving cavity of the stationary housing. The end faces of the dynamic and stationary ring seals are in contact with each other, forming a dynamic sealing interface. The lubricant storage cavity of the rotating spindle is connected to the dynamic sealing interface through multiple radial delivery channels.

[0009] Optionally, the internal coolant channel includes a spiral groove surrounding the inner wall of the receiving cavity, and a coolant inlet and a coolant outlet respectively opened on the outer wall of the stationary outer shell; the coolant inlet and coolant outlet are respectively connected to the two ends of the spiral groove to form an independent forced cooling circulation loop.

[0010] Optionally, the bearing assembly includes a first bearing and a second bearing spaced apart along the axial direction of the rotating spindle, both of which are angular contact ball bearings; the first bearing and the second bearing are mounted back-to-back between the rotating spindle and the stationary housing to simultaneously bear radial loads and bidirectional axial loads, thereby improving the operating rigidity of the rotating spindle.

[0011] Optionally, the sealing assembly further includes a pressure compensation mechanism, which includes a balance piston disc integrally formed with the rotating spindle and a pressure compensation chamber formed by the inner wall of the stationary housing, the balance piston disc, and the outer wall of the rotating spindle. The pressure compensation chamber is connected to the main working fluid inlet through a pressure-inducing channel. The axial force generated by the high-pressure working fluid acting on the effective pressure-bearing area of ​​the balance piston disc is opposite in direction to the axial force of the fluid acting on the dynamic ring seal.

[0012] Optionally, the dynamic ring seal includes a metal base ring and a wear-resistant sealing ring embedded in the end face of the metal base ring; the metal base ring is fixedly connected to the outer wall of the rotating main shaft by an anti-rotation pin. The stationary ring seal includes a stationary ring seat and a wear-resistant friction pair ring embedded in the end face of the stationary ring seat; the stationary ring seat is fixed in the receiving cavity of the stationary housing by a positioning step.

[0013] Optionally, the lubricant storage cavity is a sealed annular cavity located near the sealing assembly on the rotating spindle; the radial delivery channel is a microporous structure extending obliquely from the bottom of the annular cavity to the outer surface of the rotating spindle. When the rotating spindle rotates, the lubricant is delivered to the dynamic sealing interface through the microporous structure under the action of centrifugal force.

[0014] Optionally, an isolation bushing is provided in the receiving cavity of the stationary housing between the sealing assembly and the bearing assembly; the isolation bushing is fixed to the inner wall of the stationary housing, and a gap is maintained between its inner hole and the outer wall of the rotating main shaft; multiple annular leakage collection grooves are formed on the outer circumferential surface of the isolation bushing, and the annular leakage collection grooves are connected to the outside of the stationary housing through a leakage discharge hole.

[0015] Optionally, end caps are fixedly connected to both ends of the stationary shell, and an outer protective seal is provided between the end caps and the rotating main shaft; the outer protective seal is a non-contact labyrinth seal structure, which includes multiple stationary labyrinth teeth integrally formed with the end caps and multiple rotating labyrinth teeth integrally formed with the rotating main shaft, wherein the stationary labyrinth teeth and the rotating labyrinth teeth are interlaced but do not contact each other.

[0016] Optionally, a number of heat dissipation fins are integrally formed on the outer wall of the stationary shell, in the area facing the internal coolant channel. The heat dissipation fins are evenly distributed along the circumference of the stationary shell to increase the heat exchange area between the stationary shell and the external environment.

[0017] The high-speed, high-pressure rotary joint provided by this utility model has the following beneficial effects: This high-speed, high-pressure rotary joint utilizes a spiral-shaped internal coolant channel on the inner wall of the stationary housing to create a forced cooling circuit adjacent to the dynamic sealing interface. During operation, the heat generated by friction at the sealing interface and by the shearing effect of the high-pressure fluid is rapidly carried away by the circulating coolant, significantly suppressing temperature rise in the sealing components and slowing down aging and performance degradation of the sealing material due to high temperatures. Furthermore, by designing a lubricant storage chamber and centrifugal radial delivery channels inside the rotating spindle, continuous and self-lubricating lubrication of the dynamic sealing interface is achieved, forming a stable lubricating film between the contact surfaces of the rotating and stationary rings, greatly reducing the coefficient of friction and wear rate. The introduction of a pressure compensation mechanism effectively balances most of the axial fluid force acting on the seal, reducing the specific pressure on the sealing end face, further delaying the wear process of the end face, and extending the service life of the sealing assembly. Attached Figure Description

[0018] Figure 1 This is a cross-sectional view of the overall structure of the high-speed high-pressure rotary joint of this utility model; Figure 2This is a partial enlarged view of the sealing assembly and cooling structure according to an embodiment of this application; Figure 3 This is a schematic diagram of the rotating spindle and lubrication supply structure of this utility model; Figure 4 This is a schematic diagram of the pressure compensation mechanism according to an embodiment of this application; Figure 5 This is a schematic diagram of the connection structure between the outer protective seal and the end cap of this utility model; Explanation of reference numerals in the attached figures: 1. Stationary housing; 2. Rotating spindle; 3. Sealing assembly; 4. Mounting flange; 5. Main working fluid inlet; 6. Main working fluid outlet; 7. Internal coolant passage; 8. Central fluid conduit; 9. Lubricant storage chamber; 10. Dynamic ring seal; 11. Stationary ring seal; 12. Radial delivery channel; 13. Balance piston disc; 14. Pressure compensation chamber; 15. Pressure tapping channel; 16. Isolation bushing; 17. End cap; 18. Outer protective seal. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0020] Please see Figures 1 to 5 This invention provides a high-speed, high-pressure rotary joint, which is applied in industrial equipment requiring the transfer of high-pressure fluid between stationary and rotating components, such as machine tool spindles, rotary tables, or continuous casting equipment. This embodiment improves the internal structure of the rotary joint, particularly in sealing, cooling, and lubrication, thereby enhancing the operational stability and durability of the device under long-term high-speed, high-pressure conditions.

[0021] Please see Figure 1 This utility model provides a technical solution: a high-speed, high-pressure rotary joint, which includes a stationary housing 1, a rotating spindle 2, and a sealing assembly 3. The rotating spindle 2 passes through the interior of the stationary housing 1 and is rotatably connected to the stationary housing 1 through a bearing assembly. The sealing assembly 3 is disposed between the stationary housing 1 and the rotating spindle 2, forming a dynamic seal for the fluid channel.

[0022] Specifically, please refer to Figure 1 and Figure 2The stationary housing 1 is a hollow cylindrical structure with a through-hole internal cavity. A mounting flange 4 is integrally formed at one end of the stationary housing 1, with multiple bolt holes. This structure secures the rotary joint to the external equipment frame. A main working fluid inlet 5 and a main working fluid outlet 6 are respectively formed on the shell wall of the stationary housing 1, and these two ports are connected to external high-pressure fluid pipelines. On the inner wall of the stationary housing 1, adjacent to the installation location of the sealing assembly 3, a spiral internal coolant channel 7 is integrally formed. This internal coolant channel 7 is a continuous spiral groove, directly machined into the inner wall of the stationary housing 1, and its depth and width are determined according to the preset coolant flow rate and heat exchange requirements. A coolant inlet and a coolant outlet are also correspondingly formed on the outer wall of the stationary housing 1, and these two ports are connected to the two ends of the spiral groove, thus forming an independent, forced-circulation coolant circuit. Coolant enters through the coolant inlet, flows along the spiral-shaped internal coolant channel 7, surrounds the area where the sealing assembly 3 is located, and finally flows out through the coolant outlet. In addition, on the outer wall of the stationary casing 1, in the area directly opposite the internal coolant channel 7, several circumferentially evenly distributed heat dissipation fins are integrally formed. These heat dissipation fins increase the contact area between the stationary casing 1 and the outside air, helping to dissipate the heat absorbed by the internal coolant channel 7.

[0023] Please see Figure 1 and Figure 3 The rotating main shaft 2 is a stepped shaft structure, which is integrally inserted into the accommodating cavity of the stationary housing 1. A bearing assembly forms a rotational fit between the rotating main shaft 2 and the inner wall of the stationary housing 1. This bearing assembly includes a first bearing and a second bearing spaced apart along the axial direction of the rotating main shaft 2; both bearings are angular contact ball bearings. The first and second bearings are installed back-to-back between the rotating main shaft 2 and the stationary housing 1 with their inner and outer rings facing each other. This installation method enhances the rigidity of the bearing assembly, enabling it to simultaneously withstand radial loads and axial loads from both directions, maintaining a high degree of coaxiality and operational stability of the rotating main shaft 2 during high-speed rotation. A through-flow central fluid conduit 8 is provided at the axis of the rotating main shaft 2. This central fluid conduit 8 is the core channel for the main working fluid to flow inside the rotary joint. The central fluid conduit 8 connects to the main working fluid inlet 5 and the main working fluid outlet 6 through a specific space within the cavity of the stationary housing 1. Inside the rotating spindle 2, near the sealing assembly 3, there is a separate, sealed annular cavity, which is the lubricant storage cavity 9. This lubricant storage cavity 9 is pre-filled with liquid lubricant.

[0024] Please see Figure 1 , Figure 2 and Figure 3The sealing assembly 3 is fitted around the outer periphery of the rotating spindle 2 and housed within the receiving cavity of the stationary housing 1, with its axial position adjacent to the internal coolant channel 7. The sealing assembly 3 includes a rotating ring seal 10 and a stationary ring seal 11. The rotating ring seal 10 rotates synchronously with the rotating spindle 2, while the stationary ring seal 11 is fixed within the receiving cavity of the stationary housing 1. The rotating ring seal 10 includes a metal base ring and a wear-resistant sealing ring embedded in the end face of the metal base ring. The wear-resistant sealing ring is made of silicon carbide or hard alloy. The metal base ring is interference-fitted with the outer wall of the rotating spindle 2 through its inner hole and is fixedly connected to the outer wall of the rotating spindle 2 by an anti-rotation pin. One end of the anti-rotation pin is inserted into the pin hole of the metal base ring, and the other end is inserted into the pin groove of the outer wall of the rotating spindle 2. This connection eliminates relative rotation between the two. The stationary ring seal 11 includes a stationary ring seat and a wear-resistant friction pair ring embedded in the end face of the stationary ring seat. This wear-resistant friction pair ring is also made of silicon carbide or hard alloy and is paired with the wear-resistant sealing ring of the rotating ring seal 10. The stationary ring seat engages with a positioning step within the cavity of the stationary housing 1 via its outer diameter and is fixed by an axial preload, thus remaining stationary within the stationary housing 1. The end face of the wear-resistant sealing ring of the rotating ring seal 10 and the end face of the wear-resistant friction pair ring of the stationary ring seal 11 are in close contact and precision ground to form a dynamic sealing interface. This dynamic sealing interface adheres tightly under the action of high-pressure working fluid, preventing leakage of high-pressure fluid from the gap between the stationary housing 1 and the rotating main shaft 2.

[0025] Please see Figure 3 The lubricant storage chamber 9 of the rotating spindle 2 is connected to the aforementioned dynamic sealing interface through multiple radial delivery channels 12. The radial delivery channels 12 are microporous structures extending radially outward from the bottom of the lubricant storage chamber 9 towards the outer surface of the rotating spindle 2. The outlets of these micropores are precisely located near the mating surface between the dynamic ring seal 10 and the rotating spindle 2. When the rotating spindle 2 rotates at high speed, the lubricant in the lubricant storage chamber 9 is thrown radially outward under centrifugal force and pressed into these inclined radial delivery channels 12, ultimately being delivered to the dynamic sealing interface, forming a lubricating oil film between the mating surfaces of the dynamic ring seal 10 and the stationary ring seal 11.

[0026] Please see Figure 1 and Figure 4In this embodiment, the sealing assembly 3 further includes a pressure compensation mechanism. This pressure compensation mechanism includes a balance piston disc 13 integrally formed with the rotating main shaft 2, and an annular pressure compensation chamber 14 formed by the inner wall of the stationary housing 1, the end face of the balance piston disc 13, and the outer wall of the rotating main shaft 2. A pressure-inducing channel 15 is provided on the shell wall of the stationary housing 1. One end of the pressure-inducing channel 15 is connected to the fluid region near the main working fluid inlet 5, and the other end is connected to the pressure compensation chamber 14. High-pressure working fluid enters the pressure compensation chamber 14 through the pressure-inducing channel 15 and acts on the effective pressure-bearing area of ​​the balance piston disc 13. Since the pressure direction of the balance piston disc 13 is opposite to the direction of the axial force of the high-pressure working fluid directly acting on the dynamic ring seal 10, the axial thrust acting on the balance piston disc 13 offsets most of the fluid axial force acting on the dynamic ring seal 10, reducing the contact pressure of the dynamic sealing interface.

[0027] Please see Figure 1 Within the accommodating cavity of the stationary housing 1, an isolation bushing 16 is provided between the sealing assembly 3 and the bearing assembly. This isolation bushing 16 is an annular component, its outer diameter fixedly connected to the inner wall of the stationary housing 1, and its inner bore maintaining a small radial clearance with the outer wall of the rotating main shaft 2. Multiple annular leakage collection grooves are formed on the outer circumferential surface of the isolation bushing 16. These collection grooves communicate with the outside of the stationary housing 1 through a leakage discharge hole on the housing wall. If a minor leak occurs in the sealing assembly 3, the leaked fluid will enter the leakage collection grooves and be discharged through the leakage discharge hole, without entering the area where the bearing assembly is located.

[0028] Please see Figure 1 and Figure 5 The stationary housing 1 has end caps 17 bolted to both ends. An outer protective seal 18 is provided between the end caps 17 and the rotating main shaft 2. This outer protective seal 18 is a non-contact labyrinth seal structure. Its specific structure includes multiple stationary labyrinth teeth integrally formed with the end caps 17 and multiple rotating labyrinth teeth integrally formed with the rotating main shaft 2. The stationary and rotating labyrinth teeth are interlaced radially and axially but do not physically contact each other, forming a series of tortuous, narrow gaps. This structure hinders external contaminants such as dust and moisture from entering the rotary joint and also limits the outward leakage of internal lubricating grease.

[0029] In this invention, the working steps of the device are as follows: 1. First, connect the external high-pressure fluid source to the main working fluid inlet 5 via pipeline, and connect the downstream equipment to the main working fluid outlet 6. Simultaneously, connect the external cooling system to the coolant inlet and outlet on the stationary housing 1. The rotating spindle 2 is then driven to begin rotation by the external power source.

[0030] 2. High-pressure working fluid enters from the main working fluid inlet 5, flows through the inner cavity of the stationary housing 1, enters the central fluid pipe 8 of the rotating main shaft 2, rotates with the rotating main shaft 2, and finally flows out from the main working fluid outlet 6, completing the fluid transfer. In the fluid channel, the dynamic ring seal 10 rotates with the rotating main shaft 2, and its end face is tightly fitted with the end face of the fixed static ring seal 11, forming a dynamic seal to prevent high-pressure fluid from leaking outward.

[0031] 3. Simultaneously, the coolant is driven by an external pump and enters the internal coolant channel 7 of the stationary housing 1 from the coolant inlet. The coolant is forced to circulate within the spiral channel. In the area adjacent to the sealing assembly 3, it absorbs the heat generated by the friction between the dynamic ring seal 10 and the stationary ring seal 11, as well as the heat generated by the shearing of the high-pressure fluid in the gap. Subsequently, the coolant carrying heat flows out from the coolant outlet, enters the external cooling system to cool down, and then circulates again.

[0032] 4. During the high-speed rotation of the main shaft 2, the lubricant in its internal lubricant storage chamber 9 is subjected to centrifugal force and is forced into multiple radial conveying channels 12, and is continuously conveyed to the dynamic sealing interface between the dynamic ring seal 10 and the stationary ring seal 11 to form a lubricating film and reduce friction.

[0033] 5. A portion of the high-pressure working fluid is introduced into the pressure compensation chamber 14 via the pressure channel 15. The fluid pressure acts on the balance piston disc 13, generating a thrust that is opposite in direction to the axial force exerted by the fluid on the dynamic ring seal 10. These two forces cancel each other out, reducing the net axial force applied to the dynamic sealing interface.

[0034] 6. If a minute leak occurs in the sealing assembly 3, the leaked fluid will be captured by the annular leak collection groove on the isolation bushing 16 and discharged to the outside of the machine body through the leak discharge hole. The outer protective seal 18 at the end cap 17 continuously prevents external contaminants from entering the interior of the rotary joint.

[0035] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A high-speed, high-pressure rotary joint, characterized in that: It includes a stationary housing (1), a rotating spindle (2), and a sealing assembly (3), wherein: The stationary housing (1) has an inner cavity, and a mounting flange (4) is provided at one end of the stationary housing (1). The main working fluid inlet (5) and the main working fluid outlet (6) are provided on the shell wall of the stationary housing (1). A spiral internal coolant channel (7) is integrally formed on the inner wall of the stationary housing (1) in the area adjacent to the sealing assembly (3). The rotating spindle (2) passes through the inner cavity of the stationary outer shell (1) and forms a rotational fit with the inner wall of the stationary outer shell (1) by means of a bearing assembly. A central fluid pipe (8) is provided at the axis of the rotating spindle (2). The central fluid pipe (8) is connected to the main working fluid inlet (5) and the main working fluid outlet (6). A lubricant storage cavity (9) is provided inside the rotating spindle (2). The sealing assembly (3) is fitted around the outer periphery of the rotating spindle (2) and housed in the receiving cavity of the stationary housing (1). The sealing assembly (3) includes a dynamic ring seal (10) that rotates synchronously with the rotating spindle (2) and a stationary ring seal (11) fixed in the receiving cavity of the stationary housing (1). The end faces of the dynamic ring seal (10) and the stationary ring seal (11) fit together to form a dynamic sealing interface. The lubricant storage cavity (9) of the rotating spindle (2) is connected to the dynamic sealing interface through multiple radial delivery channels (12).

2. The high-speed high-pressure rotary joint according to claim 1, characterized in that: The internal coolant channel (7) includes a spiral groove surrounding the inner wall of the receiving cavity, and a coolant inlet and a coolant outlet respectively opened on the outer wall of the stationary outer shell (1); the coolant inlet and the coolant outlet are respectively connected to the two ends of the spiral groove.

3. The high-speed high-pressure rotary joint according to claim 1, characterized in that: The sealing assembly (3) further includes a pressure compensation mechanism, which includes a balance piston disk (13) integrally formed with the rotating main shaft (2) and a pressure compensation chamber (14) formed by the inner wall of the stationary housing (1), the balance piston disk (13) and the outer wall of the rotating main shaft (2); the pressure compensation chamber (14) is connected to the main working fluid inlet (5) through a pressure channel (15).

4. The high-speed high-pressure rotary joint according to claim 1, characterized in that: The lubricant storage cavity (9) is an annular cavity located on the rotating spindle (2) near the sealing assembly (3); the radial delivery channel (12) is a microporous structure that extends obliquely from the bottom of the annular cavity to the outer surface of the rotating spindle (2).

5. The high-speed high-pressure rotary joint according to claim 1, characterized in that: The dynamic ring seal (10) includes a metal base ring and a wear-resistant sealing ring embedded in the end face of the metal base ring. The metal base ring is fixedly connected to the outer wall of the rotating main shaft (2) by an anti-rotation pin. The static ring seal (11) includes a static ring seat and a wear-resistant friction pair ring embedded in the end face of the static ring seat. The static ring seat is fixed in the receiving cavity of the stationary outer shell (1) by a positioning step.

6. The high-speed high-pressure rotary joint according to claim 1, characterized in that: The bearing assembly includes a first bearing and a second bearing spaced apart along the axial direction of the rotating main shaft (2). Both the first bearing and the second bearing are angular contact ball bearings and are installed back-to-back between the rotating main shaft (2) and the stationary housing (1).

7. The high-speed high-pressure rotary joint according to claim 1, characterized in that: In the accommodating cavity of the stationary housing (1), an isolation bushing (16) is provided between the sealing assembly (3) and the bearing assembly; the isolation bushing (16) is fixed to the inner wall of the stationary housing (1), and multiple annular leakage collection grooves are opened on its outer circumferential surface, and the annular leakage collection grooves are connected to the outside of the stationary housing (1) through a leakage discharge hole.

8. The high-speed high-pressure rotary joint according to claim 1, characterized in that: The two ends of the stationary shell (1) are respectively fixedly connected with end caps (17), and an outer protective seal (18) is provided between the end caps (17) and the rotating main shaft (2); the outer protective seal (18) is a non-contact labyrinth seal structure, which includes a plurality of stationary labyrinth teeth integrally formed with the end caps (17) and a plurality of rotating labyrinth teeth integrally formed with the rotating main shaft (2), and the stationary labyrinth teeth and the rotating labyrinth teeth are interlocked.

Images