VC roller rotating joint with pressure protection

Abstract

The utility model provides a VC roller rotary joint with pressure protection, which comprises a joint main body and a pressure protection device, the pressure protection device comprises a left shell, a right shell, a double-end valve core and a spring, a hollow core shaft is arranged in the joint main body, and one end of the hollow core shaft extends out of the joint main body to be connected with the left shell; a left inner cavity is formed in the left shell, an oil way is arranged in the hollow mandrel, and the oil way communicates with the left inner cavity. A right inner cavity communicated with the left inner cavity is formed in the right shell, and the right inner cavity is communicated with a roller oil duct of the VC roller; the double-end valve element comprises a valve rod, a left valve head and a right valve head, the left valve head and the right valve head are located at the two ends of the valve rod respectively, the valve rod is movably arranged in the oil passing opening in a penetrating mode, the left valve head and the right valve head are located in the left inner cavity and the right inner cavity respectively, and springs are connected between the left valve head and the left shell and between the right valve head and the right shell in an abutting mode respectively. The double-end valve element axially moves to block the oil passing opening due to the fluctuation change of the oil way pressure so as to protect the rotating connector and the VC roller against damage when the oil pressure fluctuates.

Description

Technical Field

[0001] The utility model belongs to the technical field of metal rolling equipment, in particular to a VC roller rotary joint with pressure protection. Background Art

[0002] The working principle of VC roller is that when the hydraulic oil in the high-pressure hydraulic station is sent into the fluid chamber through the rotary joint under the action of the hydraulic servo control system, the sleeve is expanded, and the deflection generated by the rolling mill during normal operation can be compensated by mechanical convexity. Among them, the rotary joint is a connecting sealing device that inputs the fluid medium from a fixed (stationary) pipeline into the rotating motion equipment and then discharges it from the rotary joint. At present, the rotary joints on the domestic market are mainly used in pressure occasions below 10bar. The ultra-high pressure rotary joints that are truly applied in China with pressures above 1000bar basically rely on imports, but the imported ultra-high pressure rotary joints have the following problems:

[0003] 1. The rotary joint is not equipped with a protection device for hydraulic system pressure fluctuations. When the hydraulic system pressure fluctuates, it will cause damage to the rotary joint or the actuator (VC roller) of the rotary motion equipment;

[0004] 2. The rotary joint is not equipped with a device that allows the actuator of the rotary equipment to continue to work normally after the hydraulic system fails and stops working;

[0005] 3. The internal bearing of the rotary joint is poorly lubricated, with a service life of less than 12 months and premature failure;

[0006] 4. The service life of the internal sealing mechanism of the rotary joint is less than 6 months, and it fails prematurely, resulting in leakage and pollution, and the pressure cannot reach the set value. Utility Model Content

[0007] The utility model aims to provide a VC roller rotary joint with pressure protection, so as to overcome the problems that the existing rotary joint is not provided with a protection device for hydraulic system pressure fluctuation, which is easy to damage the rotary joint and the VC roller, and the internal bearing of the rotary joint is poorly lubricated and the service life of the sealing mechanism is short.

[0008] To achieve the above-mentioned purpose, the solution of the utility model is: a VC roller rotary joint with pressure protection, comprising a joint body and a pressure protection device, the pressure protection device comprising a left shell, a right shell, a double-headed valve core and a spring, a hollow core shaft is provided inside the joint body, one end of the hollow core shaft extends out of the joint body and is connected to the left shell; a left inner cavity is provided inside the left shell, an oil circuit is provided inside the hollow core shaft, and the oil circuit is communicated with the left inner cavity; a right inner cavity is provided inside the right shell that is communicated with the left inner cavity, and the right inner cavity is communicated with the roll oil passage of the VC roller; an oil port is provided at the connection between the left inner cavity and the right inner cavity, the double-headed valve core comprises a valve stem and a left valve head and a right valve head respectively located at both ends of the valve stem, the valve stem is movably arranged in the oil port, the left valve head and the right valve head are respectively located in the left inner cavity and the right inner cavity, and springs are respectively abutted between the left shell and the right shell, and the double-headed valve core moves axially due to the fluctuation of the oil circuit pressure, so that the left valve head or the right valve head blocks the oil port.

[0009] Furthermore, a right nut is threadedly connected in the right inner cavity, a right oil passage cavity communicating with the right inner cavity is arranged inside the right nut, and a spring is abutted between the right nut and the right valve head.

[0010] Furthermore, a left nut is threaded in the left inner cavity, and a gasket is abutted between the left nut and the left side wall of the left inner cavity; the oil passage port includes a first oil passage port and a second oil passage port, and a left oil passage chamber is provided inside the left nut, the left end of the left oil passage chamber is connected with the oil circuit, and the right end is connected with the right inner cavity as the first oil passage port, the left valve head is located in the left oil passage chamber and a spring is abutted between the gasket, and the left valve head is used to block the first oil passage port; the left end of the right inner cavity is connected with the left inner cavity as the second oil passage port, and the right valve head is used to block the second oil passage port.

[0011] Furthermore, the double-headed valve core is composed of a left valve core and a right valve core of the same structure, and the valve stems of the left valve core and the right valve core are relatively abutted.

[0012] Furthermore, an oil passage is provided inside the left valve head and the right valve head, the diameter of the left valve head and the right valve head is larger than the diameter of the valve stem, and a transition section with a gradually decreasing diameter is provided between the left valve head and the right valve head and the valve stem, and a through hole connected to the oil passage is provided on the transition section.

[0013] Furthermore, a bearing is provided between the hollow core shaft and the joint body, and a lubrication channel for lubricating the bearing is provided inside the joint body.

[0014] Furthermore, two bearings are provided, and an oil distribution ring which is fitted on the hollow core shaft is provided between the two bearings. A plurality of first distribution holes are circumferentially distributed on both sides of the oil distribution ring, and the lubrication channel is connected to the first distribution holes.

[0015] Furthermore, a plurality of second distribution holes are circumferentially distributed in the middle of the oil distribution ring, the second distribution holes are connected to the oil circuit inside the hollow core shaft, and the joint body is provided with an oil inlet channel, which is connected to the second distribution holes.

[0016] Furthermore, the mating portion between the oil distribution ring and the hollow core shaft is coated with silicon carbide.

[0017] Furthermore, seals are provided between the two sides of the joint body and the hollow core shaft, between the oil distribution ring and the joint body, between the hollow core shaft and the left housing, and between the left housing and the right housing.

[0018] After adopting the above scheme, the beneficial effects of the utility model are:

[0019] 1. The VC roller rotary joint of the utility model is provided with a pressure protection device, which can prevent the rotary joint and the VC roller from being damaged when the pressure of the hydraulic system fluctuates too much. Specifically, the oil circuit, the left inner cavity, the right inner cavity and the roller oil passage of the VC roller are connected in sequence, and an oil port is provided at the connection between the left inner cavity and the right inner cavity. The valve stem of the double-headed valve core is movably inserted into the oil port. Springs are abutted between the left valve head and the right valve head and the left shell body and the right shell body. After the oil enters the left inner cavity from the oil circuit, it passes through the oil port and the right inner cavity and flows into the roller oil passage of the VC roller. In this process, if the oil circuit pressure rising speed exceeds the set value, the oil pressure pushes the left valve head to move right to block the oil port, thereby realizing self-locking and preventing the rotary joint and the VC roller from being damaged due to excessive fluctuation of the oil pressure rising.

[0020] 2. If the oil circuit pressure drops faster than the set value or the pressure disappears, the oil pressure pushes the right valve head to move left to block the oil port, forming a self-locking state. The pressure in the VC roller remains unchanged and can still work normally. That is, after the hydraulic system fails and stops working, the VC roller can still work normally.

[0021] 3. The joint body is also provided with a lubrication channel for lubricating the bearing, which can remove fine particles generated by internal wear of the bearing and increase the service life of the bearing.

[0022] 4. Seals are provided on the silicon carbide coating between the hollow core shaft and the oil distribution ring, as well as between both sides of the joint body and the hollow core shaft, between the oil distribution ring and the joint body, between the hollow core shaft and the left housing, and between the left housing and the right housing to seal the oil in the oil circuit and lubrication channel to avoid oil leakage and ensure that the pressure part of the oil circuit leaks out and can be maintained at the set value. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The three-dimensional structure entity of the utility model Figure 1 ;

[0024] Figure 2The three-dimensional structure entity of the utility model Figure 2 ;

[0025] Figure 3 It is a left view of the utility model;

[0026] Figure 4 For this utility model Figure 3 Sectional view at AA in the middle;

[0027] Figure 5 For this utility model Figure 3 Sectional view at the middle BB;

[0028] Figure 6 For this utility model Figure 5 Enlarged view of point A in the middle;

[0029] Figure 7 This is a structural schematic diagram of the left valve core (right valve core) of the utility model;

[0030] Figure 8 It is a cross-sectional view of the left valve core (right valve core) of the utility model;

[0031] Fig. 9 It is a structural schematic diagram of the oil distribution ring of the utility model.

[0032] Description of labels:

[0033] 1. Rotary joint; 11. Joint body; 111. Oil inlet channel; 12. Hollow core shaft; 121. Oil circuit; 13. Lubrication channel; 14. Oil circuit distribution ring; 141. First distribution hole; 142. Second distribution hole; 15. Pressure cover; 16. Framework oil seal; 17. Sealing ring; 18. Bearing; 2. Pressure protection device; 21. Left shell; 211. Left inner cavity; 212. Left nut; 213. Left oil chamber; 22. Right shell; 221. Right inner cavity; 223. Right nut; 224. Right oil chamber; 23. Double-headed valve core; 231. Left valve head; 232. Right valve head; 233. Valve stem; 234. Oil passage; 235. Through hole; 24. Spring; 25. First oil port; 26. Second oil port; 27. High-pressure oil inlet; 28. Gasket; 3. Joint; 4. Mounting sleeve. DETAILED DESCRIPTION

[0034] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] like Figure 1-9As shown, the utility model provides a VC roller rotary joint with pressure protection, including a joint body 11 and a pressure protection device, the pressure protection device 2 includes a left shell 21, a right shell 22, a double-headed valve core 23 and a spring 24, a hollow core shaft 12 is provided inside the joint body 11, one end of the hollow core shaft 12 extends out of the joint body 11 and is connected to the left shell 21; a left inner cavity 211 is provided inside the left shell 21, an oil path 121 is provided inside the hollow core shaft 12, and the oil path 121 is communicated with the left inner cavity 211; the inside of the right shell 22 A right inner cavity 221 is provided which is connected to the left inner cavity 211, and the right inner cavity 221 is connected to the roller oil passage of the VC roller (not shown in the figure); an oil port is provided at the connection point between the left inner cavity 211 and the right inner cavity 221, and the double-headed valve core 23 includes a valve stem 233 and a left valve head 231 and a right valve head 232 which are respectively located at both ends of the valve stem 233, and the valve stem 233 is movably arranged in the oil port, and the left valve head 231 and the right valve head 232 are respectively located in the left inner cavity 211 and the right inner cavity 221, and springs 24 are respectively abutted between the left shell 21 and the right shell 22. The joint body 11 is provided with an oil inlet channel 111 connected to the oil circuit 121. The front end of the oil inlet channel 111 is connected to the oil supply system (not shown in the figure) to supply oil to the VC roller. When the rotary joint 1 operates normally, the oil enters the oil circuit from the oil inlet channel, passes through the left inner cavity 211, the oil port, and the right inner cavity 221 in sequence to the roller oil channel of the VC roller.

[0036] The pressure of the oil circuit 121 will fluctuate during oil supply and oil unloading. If the pressure rise rate of the oil circuit 121 exceeds the set value (i.e., the maximum oil pressure fluctuation value allowed when the VC roller can operate normally), the oil pressure pushes the left valve head 231 to move right to block the oil port, achieving self-locking, and preventing the oil pressure from rising and fluctuating too much and causing damage to the rotary joint 1 and the VC roller; on the contrary, if the pressure drop rate of the oil circuit 121 exceeds the set value or the pressure disappears, the oil pressure pushes the right valve head 232 to move left to block the oil port, forming self-locking, and the pressure in the VC roller remains unchanged, and it can still operate normally, preventing the sudden drop or disappearance of the oil pressure from causing the VC roller to interrupt its operation. The following is explained with specific values:

[0037] The pressure rise speed and drop speed of the oil supply system during normal oil supply are set not to exceed 80 bar / s. During the oil supply process, the oil supply system needs to supply oil to 1200 bar at a rising speed less than or equal to 80 bar / s. If the pressure rise speed of the oil circuit 121 exceeds 80 bar / s, the oil will push the double-headed valve core 23 to move right, so that the left valve head 231 blocks the oil port to achieve self-locking; during the oil unloading process, the oil supply system needs to unload the oil pressure from 1200 bar to 0 bar at a dropping speed less than or equal to 80 bar / s. If the pressure drop speed of the oil circuit 121 exceeds 80 bar / s, the oil will push the double-headed valve core 23 to move left, so that the right valve head 232 blocks the oil port to achieve self-locking.

[0038] Key References Figure 4-6 The utility model can adjust the pressure fluctuation setting value of oil supply and oil leakage by changing the compression degree of the spring 24. Specifically, a right nut 223 is threaded in the right inner cavity 221, and a right oil passage chamber 224 connected to the right inner cavity 221 is arranged inside the right nut 223. The right oil passage chamber 224 is used for oil to pass through. A spring 24 is abutted between the right nut 223 and the right valve head 232. Screwing in the right nut 223 can compress the spring 24, so that a larger pressure fluctuation is required to push the double-headed valve core 23. The maximum allowable oil pressure fluctuation value is increased, and a higher oil pressure rise speed and fall speed can be allowed; otherwise, the maximum allowable oil pressure fluctuation value is lowered.

[0039] The left side of the right nut 223 abuts against the spring 24, and the right shell 22 is provided with a joint for connecting the VC roller on the right side of the right nut 223. The hollow interior of the joint is connected with the right oil chamber 224 and the roller oil passage of the VC roller. Since a joint needs to be set on the right side of the right nut 223, the right nut 223 cannot protrude too much from the right shell 22, so the adjustment range of the right nut 223 is limited. A left nut 212 and a gasket 28 can be added to the left inner cavity 211 of the utility model for adjustment.

[0040] Specifically, the left nut 212 is threaded in the left inner cavity 211, and a gasket 28 is abutted between the left nut 212 and the left side wall of the left inner cavity 211; there are two oil passages, including a first oil passage 25 and a second oil passage 26, and a left oil passage chamber 213 is provided inside the left nut 212. The left end of the left oil passage chamber 213 is connected to the oil path 121, and the right end is connected to the right inner cavity 221 as the first oil passage 25. The left valve head 231 is located in the left oil passage chamber 213 and a spring 24 is abutted between the gasket 28. The left valve head 231 is used to block the first oil passage 25; the left end of the right inner cavity 221 is connected to the left inner cavity 211 as the second oil passage 26, and the right valve head 232 is used to block the second oil passage 26. Since the spring 24 is in contact between the gasket 28 and the left valve head 231, the spring 24 can be compressed or stretched by replacing the gasket 28 with different thicknesses, thereby adjusting the maximum allowable oil pressure fluctuation value. Moreover, the adjustment is not affected by the positions of the left nut 212 and the right nut 223, and the adjustment range is larger.

[0041] The left side of the left shell body 21 is used to connect the hollow core shaft 12, and the left inner cavity 211 is arranged on the left and right sides of the left shell body 21. When replacing the gasket 28, it is necessary to disconnect the connection between the left shell body 21 and the right shell body 22 and remove the left nut 212. To facilitate the replacement of the gasket 28, the double-headed valve core 23 can be arranged as a split structure, specifically composed of a left valve core and a right valve core with the same structure. The valve stems 233 of the left valve core and the right valve core are relatively abutted. After disconnecting the connection between the left shell body 21 and the right shell body 22, the left valve core and the right valve core are also separated. At this time, it is convenient to remove the left nut 212 together with the spring 24 and the left valve core inside it, so that the replacement of the gasket 28 is more convenient, and the installation of the left nut 212 and the left valve core is also convenient.

[0042] Key References Figure 7-8 The valve stem 233 of the left valve core is inserted into the first oil passage port 25, and the valve stem 233 of the right valve core is inserted into the second oil passage port 26. The diameters of the left valve head 231 and the right valve head 232 are respectively larger than the diameters of the first oil passage port 25 and the second oil passage port 26, so that the left valve head 231 can block the first oil passage port 25, and the right valve head 232 can block the second oil passage port 26. There is preferably no gap between the left valve head 231 and the left oil passage chamber 213, and there is preferably no gap between the right valve head 232 and the right inner chamber 221, which can limit the axial movement of the left valve core and the right valve core to prevent deviation from affecting the blocking effect. The left valve head 231 and the right valve head 232 are provided with an oil passage 234 inside. The left valve head 231 and the right valve head 232 and the valve stem 233 are transition sections with gradually decreasing diameters. The transition section is provided with a through hole 235 connected to the oil passage 234. When the left valve core and the right valve core do not block the oil passage port, the oil can pass through the left valve head 231 and the right valve head 232 through the oil passage 234 and the through hole 235 to ensure normal oil supply and unloading. The left valve head 231 and the right valve head 232 are hollow inside, which can also reduce the weight of the double-headed valve core 23, making the double-headed valve core 23 responsive and agile, and can quickly close the oil passage port.

[0043] Key References Figure 5 A bearing 18 is provided between the hollow core shaft 12 and the joint body 11 , and a lubrication channel 13 for lubricating the bearing 18 is provided inside the joint body 11 . The lubrication channel 13 can take away fine particles generated by wear inside the bearing 18 , thereby increasing the service life of the bearing 18 .

[0044] Key References Figure 5 and Fig. 9There are two bearings 18, and an oil distribution ring 14 is provided between the two bearings 18, which is matched with the hollow core shaft 12. A plurality of first distribution holes 141 are circumferentially distributed on both sides of the oil distribution ring 14, and the lubrication channel 13 is connected with the first distribution holes 141. The left end of the joint body 11 is provided with an oil inlet and an oil outlet of the lubrication channel 13, and the lubrication channel 13 is divided into two sections. The lubrication channel 13 where the oil inlet is located is preferably arranged above the bearing 18, and the lubrication channel 13 where the oil outlet is located is preferably arranged below the bearing 18. The wheel skating oil flows from the oil inlet into the lubrication channel 13 above the bearing 18, and then flows into the first distribution hole 141 and dispersedly flows into various parts of the bearing 18 to fully lubricate the bearing 18, and then flows into the lubrication channel 13 below the bearing 18 and flows out from the oil outlet.

[0045] A plurality of second distribution holes 142 are circumferentially distributed in the middle of the oil circuit distribution ring 14. The second distribution holes 142 are connected to the oil circuit 121 inside the hollow core shaft 12. The oil inlet channel 111 is connected to the second distribution holes 142. The oil flows into the oil circuit 121 through the second distribution holes 142. The oil circuit distribution ring 14 can separate the oil circuit 121 and the lubrication channel 13.

[0046] Preferably, the mating portion between the oil distribution ring 14 and the hollow core shaft 12 is coated with silicon carbide, which can increase the sealing performance between the oil distribution ring 14 and the hollow core shaft 12 to prevent oil leakage.

[0047] In order to further improve the sealing performance, the utility model also sets seals between the two sides of the joint body 11 and the hollow core shaft 12, between the oil distribution ring 14 and the joint body 11, between the hollow core shaft 12 and the left shell 21, and between the left shell 21 and the right shell 22, so as to seal the oil in the oil circuit 121 and the lubrication channel 13, avoid oil leakage, ensure that the pressure of the oil circuit 121 does not leak, and the oil pressure can be maintained within the set value. The seal can be a sealing ring 17 or other structures. Specifically, the seal between the two sides of the joint body 11 and the hollow core shaft 12 adopts a gland 15, a skeleton oil seal 16 and a sealing ring 17 to install the hollow core shaft 12, and other seals adopt a sealing ring 17. In addition, a sealing ring 17 can also be set between the left nut 212 and the left shell 21, and between the right nut 223 and the right shell 22 to further seal the oil circuit 121.

[0048] Key References Figure 4-5The right side of the left housing 21 is provided with an outer convex part, the left inner cavity 211 is arranged in the outer convex part, the left side of the right housing 22 is provided with an inner concave part matched with the outer convex part, the right inner cavity 221 is arranged on the right side of the right housing 22 and communicates with the inner concave part, and the outer convex part and the inner concave part are arranged to facilitate the connection and alignment between the left housing 21 and the right housing 22, and bolt assembly holes are arranged on both sides of the outer convex part and the inner concave part, and the outer convex part is embedded in the inner concave part and then the left housing 21 and the right housing are locked with bolts to complete the assembly. In addition, a sealing ring 17 can be specifically arranged between the outer convex part and the inner concave part to ensure the sealing between the left housing 21 and the right housing 22.

[0049] Key References Figure 1-5 The utility model also sets a mounting sleeve 4 on the outer periphery of the joint body and the pressure protection device, which has dustproof and protective effects.

[0050] The above description is only a preferred embodiment of the present utility model and is not a limitation on the design of the present invention. Any equivalent changes made based on the key design of the present invention shall fall within the protection scope of the present invention.

Claims

1. A VC roller rotary joint with pressure protection, characterized in that: It comprises a joint body and a pressure protection device, the pressure protection device comprises a left shell, a right shell, a double-headed valve core and a spring, a hollow core shaft is arranged inside the joint body, one end of the hollow core shaft extends out of the joint body and is connected with the left shell; a left inner cavity is arranged inside the left shell, an oil circuit is arranged inside the hollow core shaft, and the oil circuit is communicated with the left inner cavity; a right inner cavity is arranged inside the right shell and is communicated with the left inner cavity, and the right inner cavity is communicated with the roller oil passage of the VC roller; an oil passage is arranged at the connection between the left inner cavity and the right inner cavity, the double-headed valve core comprises a valve stem and a left valve head and a right valve head respectively located at two ends of the valve stem, the valve stem is movably arranged in the oil passage, the left valve head and the right valve head are respectively located in the left inner cavity and the right inner cavity, and springs are respectively abutted between the left shell and the right shell, the double-headed valve core moves axially due to the fluctuation of the oil circuit pressure, so that the left valve head or the right valve head blocks the oil passage.

2. A VC roller rotary joint with pressure protection as claimed in claim 1, characterized in that: A right nut is threadedly connected in the right inner cavity, a right oil passage cavity communicating with the right inner cavity is arranged inside the right nut, and a spring is abutted between the right nut and the right valve head.

3. A VC roller rotary joint with pressure protection as claimed in claim 2, characterized in that: A left nut is threaded in the left inner cavity, and a gasket is abutted between the left nut and the left side wall of the left inner cavity; the oil passage port includes a first oil passage port and a second oil passage port, and a left oil passage chamber is provided inside the left nut. The left end of the left oil passage chamber is connected with the oil circuit, and the right end is connected with the right inner cavity as the first oil passage port. The left valve head is located in the left oil passage chamber and a spring is abutted between the gasket, and the left valve head is used to block the first oil passage port; the left end of the right inner cavity is connected with the left inner cavity as the second oil passage port, and the right valve head is used to block the second oil passage port.

4. A VC roller rotary joint with pressure protection as claimed in claim 3, characterized in that: The double-headed valve core is composed of a left valve core and a right valve core with the same structure, and the valve stems of the left valve core and the right valve core are relatively abutted.

5. A VC roller rotary joint with pressure protection as claimed in claim 4, characterized in that: An oil passage is provided inside the left valve head and the right valve head. The diameter of the left valve head and the right valve head is larger than the diameter of the valve stem. A transition section with a gradually decreasing diameter is provided between the left valve head and the right valve head and the valve stem. A through hole connected to the oil passage is provided on the transition section.

6. A VC roller rotary joint with pressure protection as claimed in claim 1, characterized in that: A bearing is arranged between the hollow core shaft and the joint body, and a lubrication channel for lubricating the bearing is arranged inside the joint body.

7. A VC roller rotary joint with pressure protection as claimed in claim 6, characterized in that: There are two bearings, and an oil distribution ring which is fitted on the hollow core shaft is arranged between the two bearings. A plurality of first distribution holes are circumferentially distributed on both sides of the oil distribution ring, and the lubrication channel is connected with the first distribution holes.

8. A VC roller rotary joint with pressure protection as claimed in claim 7, characterized in that: A plurality of second distribution holes are circumferentially distributed in the middle of the oil distribution ring, and the second distribution holes are connected to the oil circuit inside the hollow core shaft. The joint body is provided with an oil inlet channel, and the oil inlet channel is connected to the second distribution holes.

9. A VC roller rotary joint with pressure protection as claimed in claim 7 or 8, characterized in that: The matching part between the oil distribution ring and the hollow core shaft is coated with silicon carbide.

10. A VC roller rotary joint with pressure protection as claimed in claim 7 or 8, characterized in that: Seals are arranged between the two sides of the joint body and the hollow core shaft, between the oil distribution ring and the joint body, between the hollow core shaft and the left housing, and between the left housing and the right housing.

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