A multi-medium rotary joint

Abstract

The application relates to the field of fluid transmission and sealing, in particular to a multi-medium rotary joint which comprises a fixed core shaft and a rotary bushing rotatably sleeved on the fixed core shaft, at least two independent medium conveying channels are arranged between the fixed core shaft and the rotary bushing, a sealing ring is arranged on the outer circumferential surface of the fixed core shaft in the axial direction, the two medium conveying channels are sealed and separated by the sealing ring, a pressure relief assembly is arranged between the fixed core shaft and the rotary bushing, and the pressure relief assembly is used for directing the gas between the fixed core shaft and the rotary bushing to discharge. The rotary joint can realize the simultaneous conveying of gas and liquid, and the gas and the liquid do not interfere with each other in the conveying process, liquid leakage to the turntable is effectively avoided, other components are prevented from being damaged, and the service life of the equipment is prolonged.

Description

Technical Field

[0001] This application relates to the field of fluid transmission and sealing, and in particular to a multi-media rotary joint. Background Technology

[0002] In the industrial manufacturing sector, CNC machine tools are developing rapidly, playing a crucial role in improving production efficiency and machining accuracy. As a key component of CNC machine tools, the performance of the servo rotary table directly affects machining quality and efficiency. The rotary joint plays an indispensable role, enabling gas transfer between rotating parts; its performance significantly impacts the overall performance of the CNC machine tool servo rotary table. The effective application of rotary joints allows for more stable and efficient operation of the CNC machine tool servo rotary table, thereby improving machining accuracy and production efficiency, reducing production costs, and meeting the manufacturing industry's demand for high-quality, high-precision products. Existing technologies offer various solutions for achieving multi-channel gas and liquid pressure transmission. Existing multi-channel rotary joints generally consist of a fixed part and a rotating part. The fixed part is typically a mandrel, and the rotating part is a bushing fitted over the mandrel. The mandrel and bushing can rotate relative to each other. By providing partial channels on both the mandrel and bushing, after installation, these channels connect one-to-one, forming multiple independent media transport channels for conveying gases or liquids. For sealing the media transport channels of a multi-channel rotary joint, sealing rings are typically used. For conveying gases, rubber rings are commonly used, providing excellent gas sealing but unable to withstand high pressures. For conveying liquids, such as oil, sealing rings made of materials like PTFE or polyurethane are generally chosen. These sealing rings are very effective at sealing oil but less effective at sealing gases.

[0003] However, existing multi-channel rotary joints still have significant shortcomings in practical applications. These mainly manifest in the lack of effective control and isolation measures between channels when simultaneously conveying different media. They cannot simultaneously convey gas and liquid. If air and hydraulic oil are simultaneously conveyed in adjacent media channels, excessive pressure in the media channels, coupled with poor sealing between channels, can cause gas to slowly leak into adjacent hydraulic oil channels. This can lead to malfunctions and damage to the tooling fixtures on the turntable due to gas ingress. Simultaneously, hydraulic oil leakage can cause the hydraulic oil channels to become empty, preventing pressure buildup when the hydraulic channels are reused and hindering the tooling fixtures' operation. Therefore, existing multi-channel rotary joints cannot achieve simultaneous gas and liquid conveying. Utility Model Content

[0004] In order to enable the rotary joint to simultaneously transport gas and liquid without interference between them during the transport process, effectively prevent liquid leakage to the turntable and damage to other components, and thus extend the service life of the equipment, this application provides a multi-media rotary joint.

[0005] This application provides a multi-media rotary joint, including a fixed mandrel and a rotating bushing rotatably sleeved on the fixed mandrel. At least two independent media delivery channels are provided between the fixed mandrel and the rotating bushing. Sealing rings are axially spaced on the outer circumferential surface of the fixed mandrel, and the two media delivery channels are sealed and separated by the sealing rings. A pressure relief assembly is provided between the fixed mandrel and the rotating bushing, and the pressure relief assembly is used to directionally discharge the gas between the fixed mandrel and the rotating bushing. By adopting the above technical solution, at least two independent medium conveying channels set between the fixed mandrel and the rotating bushing can be used to convey different gases. The two medium conveying channels are sealed and separated by sealing rings axially spaced on the outer circumference, achieving a preliminary seal. Due to the increased pressure between the fixed mandrel and the rotating bushing during the conveying process, a large amount of gas accumulates. The gas will compress the sealing rings on both sides, causing deformation and reducing the sealing performance of the sealing rings. The pressure relief component cleverly designed in this application can directionally discharge the gas existing between the fixed mandrel and the rotating bushing, thereby reducing the pressure between the fixed mandrel and the rotating bushing. This ensures that the sealing rings maintain good sealing performance during operation, effectively preventing gas leakage between different medium conveying channels. This avoids the problem of gas leakage into the hydraulic oil channel causing malfunction and damage to the tooling fixture, as well as the problem of hydraulic oil leakage preventing the hydraulic channel pressure from being established. Preferably, the pressure relief assembly includes pressure relief grooves and a pressure relief discharge channel. The pressure relief grooves are axially spaced on the outer circumferential surface of the fixed mandrel. Each pressure relief groove has a pressure relief hole at its bottom. The pressure relief discharge channel is located at the center of the fixed mandrel. Both the pressure relief grooves and the pressure relief holes are connected to the pressure relief discharge channel, allowing gas between the fixed mandrel and the rotating bushing to be directionally discharged through the pressure relief discharge channel. By adopting the above technical solution, the pressure relief grooves are axially spaced on the outer circumferential surface of the fixed mandrel, and pressure relief holes are provided at the bottom of the grooves. The pressure relief discharge channel is located at the center of the fixed mandrel, and both the pressure relief grooves and the pressure relief holes are connected to the pressure relief discharge channel. When gas accumulates between the fixed mandrel and the rotating bushing to a high pressure, the gas first enters the pressure relief groove, then enters the pressure relief discharge channel through the pressure relief hole at the bottom of the groove. This effectively directs the gas between the fixed mandrel and the rotating bushing out through the pressure relief discharge channel, preventing gas accumulation between them and ensuring the sealing between the channels is maintained due to excessive pressure. This ensures that the multi-media rotary joint can stably achieve simultaneous gas-liquid transport. Preferably, the pressure relief discharge channel is linearly arranged, with one end penetrating the end face of the rotating bushing away from the fixed mandrel. By adopting the above technical solution, the linear arrangement of the pressure relief discharge channel, with one end penetrating the end face of the rotating bushing away from the fixed mandrel, reduces the resistance encountered by the gas during discharge, allowing for smoother gas flow.Meanwhile, the end face of the rotating bushing away from the fixed mandrel provides a clear and direct discharge path for the gas, preventing gas accumulation inside and thus achieving the effect of directional discharge of gas between the fixed mandrel and the rotating bushing through the channel. Preferably, each pressure relief groove extends along the outer circumferential surface of the fixed mandrel in a complete annular trajectory. By adopting the above technical solution, each pressure relief groove extends along the outer circumferential surface of the fixed mandrel in a complete annular trajectory, allowing gas at all circumferential positions between the fixed mandrel and the rotating bushing to collect in the pressure relief groove. Because the annular pressure relief groove has no breaks, regardless of the circumferential position from which the gas enters the gap between the fixed mandrel and the rotating bushing, it can smoothly flow into the pressure relief groove and then be directionally discharged through the pressure relief hole and pressure relief discharge channel, improving the efficiency of gas collection and discharge, ensuring normal discharge of gas between the fixed mandrel and the rotating bushing, and avoiding the problem of gas accumulation compressing and deforming the sealing ring. Preferably, the cross-sectional shape of each pressure relief groove is trapezoidal, with the larger diameter end of the trapezoid facing the inner wall of the rotating bushing. By adopting the above technical solution, the cross-sectional shape of the pressure relief groove is set to trapezoidal with the large-diameter end facing the inner wall of the rotating bushing. Since the large-diameter end is close to the inner wall of the rotating bushing, the contact area between the gas and the fixed mandrel and the rotating bushing is increased, making it easier for the gas to flow into the pressure relief groove. This facilitates the directional discharge of gas from the channel, enhancing the gas discharge effect of the pressure relief assembly and improving the safety and stability of the multi-media rotary joint. Preferably, the outer circumferential surface of the fixed mandrel is provided with sealing grooves spaced axially, and the inner circumferential surface of the rotating bushing is provided with a groove corresponding to the sealing groove. The sealing ring is embedded in the sealing groove and abuts against the bottom of the groove. By adopting the above technical solution, with sealing grooves spaced axially on the outer circumferential surface of the fixed mandrel and a groove corresponding to the sealing groove on the inner circumferential surface of the rotating bushing, and the sealing ring embedded in the sealing groove and abutting against the bottom of the groove, this arrangement allows the sealing ring to be stably installed within the space formed by the sealing groove and the groove. When the fixed mandrel and the rotating bushing rotate relative to each other, the sealing ring comes into tight contact with the bottom of the groove, effectively preventing the medium in the medium conveying channel from leaking out through the gap between the fixed mandrel and the rotating bushing. This significantly improves the sealing performance between the medium conveying channels of the multi-medium rotary joint, preventing gas leakage into adjacent hydraulic oil channels that could cause malfunctions in the tooling fixture, and also avoiding the problem of hydraulic channel pressure not being established due to liquid leakage. Preferably, the pressure relief hole is positioned away from the medium conveying channel and is not connected to it. By adopting the above technical solution, by positioning the pressure relief hole away from the medium conveying channel and not connecting it, the free flow of medium between the two can be avoided due to the pressure relief hole being connected to the medium conveying channel. If the pressure relief hole is connected to the medium conveying channel, when venting the gas between the fixed mandrel and the rotating bushing, the medium normally conveyed in the medium conveying channel may also be vented, affecting the normal conveying and use of the gas.By positioning the two components separately and ensuring they are not connected, it is guaranteed that when excess gas is directionally discharged through the pressure relief hole and pressure relief discharge channel, it will not interfere with the normal transport of the medium within the medium transport channel, thus ensuring the independence of each channel of the multi-medium rotary joint and the stability of the transport. Preferably, the number of medium transport channels is four, and the four medium transport channels are evenly arranged around the fixed mandrel. By adopting the above technical solution, setting the number of medium transport channels to four and evenly circling the fixed mandrel, compared with a smaller number of medium transport channels, it is possible to transport more types or larger flow rates of media simultaneously. Furthermore, the evenly circling layout makes the distribution of each medium transport channel around the fixed mandrel more balanced, improving the transport capacity and efficiency of the multi-medium rotary joint for different media. Preferably, each medium transport channel is provided with an inlet and an outlet. By adopting the above technical solution, each media conveying channel is equipped with an inlet and an outlet. The inlet allows media such as gas or liquid to be introduced into the media conveying channel, while the outlet allows the media to be output from the media conveying channel. This enables smooth flow of the media within the media conveying channel, meeting the conveying needs of the multi-media rotary joint for different media. Preferably, the pressure relief discharge channel is equipped with a discharge port. By adopting the above technical solution, since the pressure relief discharge channel is equipped with a discharge port, when gas between the fixed mandrel and the rotating bushing enters the pressure relief assembly, it will enter the pressure relief discharge channel through the pressure relief groove and pressure relief hole, and finally be discharged directionally through the discharge port, preventing gas from accumulating between the fixed mandrel and the rotating bushing.

[0006] In summary, this application has the following beneficial technical effects: Because sealing rings are axially spaced on the outer circumference of the fixed mandrel, and the two media conveying channels are sealed and separated by these sealing rings, a pressure relief component is provided between the fixed mandrel and the rotating bushing. This pressure relief component can directionally discharge the gas between the fixed mandrel and the rotating bushing from the channel, so that the gas will not accumulate between the channels. This avoids the pressure increase in the channel caused by gas accumulation, which would squeeze and deform the sealing rings. It effectively blocks the leakage paths of gas and liquid, realizes effective control and isolation of the conveying of different media, avoids gas leakage into the hydraulic oil channel or hydraulic oil leakage, and prevents tooling fixtures from being damaged due to gas entry and the problem of hydraulic channel pressure not being able to be established. Attached Figure Description

[0007] Figure 1 This is an exploded view of a multi-medium rotary joint according to this application; Figure 2 This is a front view of a multi-media rotary joint according to this application; Figure 3 yes Figure 2 AA cross-section view; Figure 4This is a structural diagram of the fixed mandrel of a multi-media rotary joint according to this application; Figure 5 This is a structural diagram of the rotating bushing of a multi-media rotary joint according to this application.

[0008] Explanation of reference numerals in the attached drawings: 1. Fixed mandrel; 2. Rotating bushing; 3. Medium conveying channel; 4. Sealing ring; 11. Sealing groove; 12. Pressure relief groove; 13. Pressure relief hole; 14. Pressure relief discharge channel; 141. Discharge port; 21. Groove; 31. Inlet; 32. Outlet. Detailed Implementation

[0009] The following is in conjunction with the appendix Figure 1-5 This application will be described in further detail.

[0010] This application provides an embodiment of a multi-media rotary joint, referring to... Figure 1 It includes a fixed mandrel 1, a rotating bushing 2, and a pressure relief assembly. The rotating bushing 2 is sleeved on the fixed mandrel 1 and can rotate relative to the fixed mandrel 1. Multiple independent media conveying channels 3 for conveying different media are provided between the fixed mandrel 1 and the rotating bushing 2. The pressure relief assembly provided between the fixed mandrel 1 and the rotating bushing 2 is used to directionally discharge the gas between the fixed mandrel 1 and the rotating bushing 2 from the channels. This can effectively control and isolate the conveying of different media, avoid mutual leakage and interference between gas and liquid, and realize the simultaneous conveying of gas and liquid.

[0011] Reference Figure 2 and Figure 3 Specifically, in this embodiment, the fixed mandrel 1 and the rotating bushing 2 are each provided with partial channels. After the mandrel and bushing are installed, the partial channels of the mandrel and the partial channels of the bushing can be connected one-to-one to form independent media conveying channels 3 for conveying gas or liquid. In this embodiment, the outer circumferential surface of the fixed mandrel 1 is provided with axially spaced sealing grooves 11, and sealing rings 4 are embedded in the sealing grooves 11. Each pair of independent media conveying channels 3 is sealed and separated by the sealing rings 4. In this embodiment, there are four media conveying channels 3, which are evenly arranged around the fixed mandrel 1, thus making reasonable use of space and achieving efficient conveying of multiple media. Each media conveying channel 3 is provided with an inlet 31 and an outlet 32. The inlet 31 is for the inflow of media, and the outlet 32 ​​is for the outflow of media. The inlet 31 and outlet 32 ​​can be circular openings for easy connection to external pipelines. The number of media conveying channels 3 can be adjusted according to actual needs, and the shapes of the inlet 31 and outlet 32 ​​can also be square or other shapes.

[0012] Reference Figure 4 and Figure 5Specifically, the inner circumferential surface of the rotating bushing 2 is provided with a groove 21 corresponding to the sealing groove 11. The sealing ring 4 is embedded in the sealing groove 11 and abuts against the bottom of the groove 21, thus forming a good sealing effect. Both the sealing groove 11 and the groove 21 are annular grooves. The depth and width of the sealing groove 11 are determined according to the size of the sealing ring 4 to ensure that the sealing ring 4 can be stably installed. Alternatively, the sealing groove 11 can also be a groove with a square cross section or other shapes. When gas and liquid are transported in different medium transport channels 3, the sealing ring 4 can prevent gas and liquid from leaking between adjacent medium transport channels 3, confining different media within their respective channels so that they do not cross-flow and interfere with each other during operation.

[0013] Specifically, the pressure relief assembly includes a pressure relief groove 12, a pressure relief hole 13, and a pressure relief discharge channel 14. The pressure relief assembly can promptly discharge excess gas between the fixed mandrel 1 and the rotating bushing 2, preventing gas from compressing the sealing ring 4 and causing deformation, ensuring that the sealing ring 4 maintains good sealing performance during operation, thereby guaranteeing stable pressure in each channel. Specifically, the pressure relief groove 12 and pressure relief hole 13 are both connected to the pressure relief discharge channel 14. The pressure relief grooves 12 are located on the outer circumferential surface of the fixed mandrel 1 and are spaced apart along the axial direction. Each pressure relief groove 12 extends along the outer circumferential surface of the fixed mandrel 1 in a complete annular trajectory, thus collecting gas between the fixed mandrel 1 and the rotating bushing 2 from all directions. In particular, the cross-sectional shape of each pressure relief groove 12 is trapezoidal, with the larger diameter end of the trapezoid facing the inner wall of the rotating bushing 2. This shape facilitates gas inflow. Alternatively, the cross-sectional shape of the pressure relief groove 12 can also be rectangular or other shapes.

[0014] The pressure relief hole 13 is located at the bottom of the pressure relief groove 12 and is a circular through hole used to introduce gas from the pressure relief groove 12 into the pressure relief discharge channel 14. The pressure relief hole 13 is positioned away from the medium conveying channel 3 and is not connected to it, thus preventing gas from flowing into the medium conveying channel 3 and causing interference. Alternatively, the pressure relief hole 13 can also be square or other shapes. The pressure relief discharge channel 14 is located at the axis of the fixed mandrel 1, is linear, and one end of it passes through the end face of the rotating bushing 2 away from the fixed mandrel 1. The pressure relief discharge channel 14 is used to directionally discharge gas between the fixed mandrel 1 and the rotating bushing 2, and its interior is a cylindrical channel to facilitate gas flow. The pressure relief discharge channel 14 is provided with a discharge port 141, located on the end face of the rotating bushing 2 away from the fixed mandrel 1, for discharging gas to the outside. Alternatively, the pressure relief discharge channel 14 can also be a curved channel or other forms.

[0015] When the fixed mandrel 1 and rotating bushing 2 are operating normally, gas and liquid are simultaneously and stably transported. During this process, gas begins to accumulate between the fixed mandrel 1 and rotating bushing 2, creating a high-pressure environment. The gas between the fixed mandrel 1 and rotating bushing 2 compresses the sealing ring 4, causing it to deform. Therefore, the gas flows sequentially through the pressure relief groove 12, the pressure relief hole 13, and then into the pressure relief discharge channel 14, finally being discharged directionally to the outside from the discharge port 141. In this way, leaked gas will not accumulate between the fixed mandrel 1 and rotating bushing 2, and will not affect the gas and liquid transport within the media transport channel 3, further ensuring the stable transport of gas and liquid within their respective media transport channels 3, achieving simultaneous gas and liquid transport without interference or leakage. Even under particularly severe conditions, if a very small amount of gas or liquid leaks into the gap between the fixed mandrel 1 and rotating bushing 2 due to excessive pressure or other factors, this leaked gas will be collected by the pressure relief groove 12 and will not leak to the turntable.

[0016] The implementation principle of this embodiment is as follows: This multi-media rotary joint uses a sealing ring 4 to seal and separate different media conveying channels 3. Combined with a pressure relief component to maintain the good sealing performance of the sealing ring 4, it can prevent leakage between different media. When there is excess gas between the fixed spindle 1 and the rotating bushing 2, the gas flows into the pressure relief groove 12, then enters the pressure relief discharge channel 14 through the pressure relief hole 13, and finally is discharged directionally through the discharge port 141. This effectively controls and isolates the conveying of different gases, avoiding problems such as gas leakage into the hydraulic oil channel and hydraulic oil leakage in existing rotary joints. It achieves simultaneous gas and liquid conveying, improves the performance and stability of the multi-media rotary joint, and meets the requirements of simultaneous multi-channel gas and liquid pressure conveying in CNC machine tool servo rotary tables.

[0017] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A multi-medium rotary joint, comprising a fixed mandrel (1) and a rotating bushing (2) rotatably sleeved on the fixed mandrel (1), wherein at least two independent media conveying channels (3) are provided between the fixed mandrel (1) and the rotating bushing (2), and sealing rings (4) are provided axially spaced on the outer circumferential surface of the fixed mandrel (1), characterized in that, The two media conveying channels (3) are sealed and separated by the sealing ring (4). A pressure relief assembly is provided between the fixed mandrel (1) and the rotating bushing (2). The pressure relief assembly is used to directionally discharge the gas between the fixed mandrel (1) and the rotating bushing (2).

2. The multi-media rotary union of claim 1, wherein, The pressure relief assembly includes a pressure relief groove (12) and a pressure relief discharge channel (14). The pressure relief groove (12) is axially spaced on the outer peripheral surface of the fixed mandrel (1). The pressure relief groove (12) has a pressure relief hole (13) at the bottom. The pressure relief discharge channel (14) is located at the axis of the fixed mandrel (1). The pressure relief groove (12) and the pressure relief hole (13) are connected to the pressure relief discharge channel (14) to directionally discharge the gas between the fixed mandrel (1) and the rotating bushing (2) through the pressure relief discharge channel (14).

3. The multi-media rotary union of claim 2, wherein, The pressure relief channel (14) is arranged in a straight line, and one end of it passes through the end face of the rotating bushing (2) away from the fixed spindle (1).

4. The multi-media rotary union of claim 2, wherein, Each of the pressure relief grooves (12) extends along the outer circumferential surface of the fixed mandrel (1) in a complete annular trajectory.

5. The multi-media rotary union of claim 4, wherein, Each of the pressure relief grooves (12) has a trapezoidal cross-sectional shape, with the larger diameter end of the trapezoid facing the inner wall of the rotating bushing (2).

6. The multi-media rotary union of claim 1, wherein, The outer circumferential surface of the fixed mandrel (1) is provided with sealing grooves (11) spaced apart along the axial direction. The inner circumferential surface of the rotating bushing (2) is provided with a groove (21) corresponding to the sealing groove (11). The sealing ring (4) is embedded in the sealing groove (11) and abuts against the bottom of the groove (21).

7. The multi-media rotary union of claim 2, wherein, The pressure relief hole (13) is positioned away from the medium conveying channel (3), and the pressure relief hole (13) is not connected to the medium conveying channel (3).

8. The multi-media rotary union of claim 1, wherein, The number of the media conveying channels (3) is four, and the four media conveying channels (3) are evenly arranged around the fixed mandrel (1).

9. The multi-media rotary union of claim 1, wherein, Each of the media conveying channels (3) is provided with an inlet (31) and an outlet (32).

10. The multi-media rotary union of claim 2, wherein, The pressure relief discharge channel (14) is provided with a discharge port (141).

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