Rotary joint
Through segmented inner shaft structure and vacuum brazing technology, combined with gap sealing and non-contact sealing, the friction heating and processing difficulty of existing rotary joints in high-speed rotation and multi-gas oil supply scenarios is solved, achieving high efficiency Sealed and long-term high-speed rotary joints.
Patent Information
- Application Number
- CN202420504376.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-15
- Publication Date
- 2025-01-17
- Estimated Expiration
- 2034-03-15
AI Technical Summary
The existing rotary joints have problems such as friction heating, difficult processing and poor sealing in high-speed rotation and multi-gas and oil circuit mixing supply scenarios, which cannot meet the needs of multi-axis CNC machining.
Adopting a segmented inner shaft structure, it is integrated by vacuum brazing, combining gap sealing and non-contact sealing technology, multiple axial and radial channels with different depths are designed, and the sealing groove intervals are increased to achieve high-speed rotation and multi-gas liquid Efficient sealing of channels.
It reduces the difficulty of processing and manufacturing of rotary joints, avoids the risk of heating caused by contact seals, achieves long-term high-speed operation and low leakage performance, and improves sealing and strength.
Smart Images
Figure CN222363543U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the field of mechanical equipment, and particularly relates to a rotary joint. Background Art
[0002] In multi-axis CNC machining, the jig or tooling installed on the rotating table often requires multiple air and oil supply lines to achieve clamping or other actions on the workpiece. The rotary joint is a key component supporting this process.
[0003] The existing rotary joint gas and oil circuit sealing structures include contact seals, mechanical seals and gap seals. Among them, the contact seal uses a Gly ring, an O-ring or other seals to form a closed channel for liquid or gas. This form has a large friction torque and is easily heated by friction during operation. Therefore, it can only meet the requirements of low-speed rotation and cannot be applied to high-speed rotation conditions. In addition, as the gas and oil circuits increase, the shaft rotation resistance will increase. Mechanical seals use dynamic and static ceramic structures for sealing. This structural form can meet the requirements of high-speed rotation, but this structure has certain requirements for the installation space. Rotary joints using this structural form are usually difficult to achieve more channel designs, and are limited by the sealing principle. This type of rotary joint is usually not used for mixed transmission of gas and oil. The gap seal form is to achieve sealing through a small gap between the rotating shafts. This form has great advantages under high-speed rotation conditions, but with the increase in the number of required gas and oil circuits, not only the aspect ratio of the oil circuit is larger, but also the gap control is difficult, making the processing more difficult. Summary of the invention
[0004] The utility model aims to overcome the deficiencies of the prior art and to provide a rotary joint which has a simple structure, is easy to process, and can realize high-speed rotation and mixed supply of multiple gas and oil circuits.
[0005] In order to solve the above technical problems, the utility model is realized through the following technical solutions: a rotary joint, comprising an inner shaft, an outer shaft, a first bearing and a second bearing, the outer shaft is supported on the inner shaft by the first bearing and the second bearing, and the outer shaft and the inner shaft can rotate relatively; there is a clearance fit between the outer shaft and the inner shaft; the inner shaft is formed by fixing a plurality of inner shaft segments, each of which is respectively provided with a different number of axial holes, and the axial holes are connected and combined on the inner shaft to form a plurality of axial inner channels with different depths.
[0006] In the above-mentioned rotary joint, the outer shaft is provided with a plurality of axial outer channels of different depths, the bottom of each axial outer channel is connected to a radial outer channel; the end of each axial inner channel is connected to a radial inner channel, and corresponding to each radial inner channel, a circumferential groove is respectively provided on the outer wall of the inner shaft; the axial inner channel, the radial inner channel, the radial outer channel, and the axial outer channel are connected one-to-one through the circumferential grooves to form a plurality of gas-liquid channels.
[0007] In the above-mentioned rotary joint, each inner shaft segment is also respectively provided with a center hole, and the center holes are interconnected on the inner shaft to form a central air inlet channel; a plurality of circumferential pressure grooves are provided on the outer wall of the inner shaft, and the circumferential pressure grooves and the circumferential grooves are distributed at intervals; the central air inlet channel is respectively connected with the circumferential pressure grooves through a plurality of radial air holes.
[0008] In the above-mentioned rotary joint, the inner shaft segments are centrally positioned by means of a central positioning groove and a central positioning platform, and are angularly positioned by means of an angle positioning hole and a positioning pin; the central positioning groove and the central positioning platform are respectively arranged at the central connection of two adjacent inner shaft segments; the angle positioning hole is arranged on the connection surface of each inner shaft segment, and the positioning pin is arranged in two adjacent angle positioning holes.
[0009] In the above-mentioned rotary joint, the inner shaft segments are connected by brazing, and a plurality of brazing material grooves are respectively arranged on the inner shaft segments, and the brazing material grooves are pre-filled with brazing material.
[0010] In the above-mentioned rotary joint, the solder grooves are respectively concentrically arranged on the inner shaft segment, the outer side of the axial hole of the inner shaft segment and the central positioning platform.
[0011] The above-mentioned rotary joint also includes an end cover, a preload spring and a retaining ring. The end cover is arranged on the end face of the outer shaft, and the second bearing is pressed by the preload spring and the retaining ring; one end of the preload spring is pressed on the end cover, and the other end is pressed on the retaining ring. The retaining ring is sleeved on the inner shaft and contacts the inner ring end face of the second bearing.
[0012] In the above-mentioned rotary joint, both the inner shaft and the outer shaft can be connected to the external rotating device, that is, when the outer shaft is connected to the external rotating device, the outer shaft rotates and the inner shaft does not move; when the inner shaft is connected to the external rotating device, the inner shaft rotates and the outer shaft does not move.
[0013] In the above-mentioned rotary joint, the gas-liquid passage can be passed with gas or liquid.
[0014] In the above-mentioned rotary joint, when the outer shaft rotates, the flow direction of the gas or liquid in the gas-liquid channel is to enter from the axial inner channel, pass through the radial inner channel, the circumferential groove, and the radial outer channel, and then flow out from the axial outer channel; when the inner shaft rotates, the flow direction of the gas or liquid in the gas-liquid channel is to enter from the axial outer channel, pass through the radial outer channel, the circumferential groove, and the radial inner channel, and then flow out from the axial inner channel.
[0015] Compared with the prior art, the utility model has the following beneficial effects: the utility model adopts a segmented inner shaft structure, and after pre-processing the corresponding axial holes, it is combined into one body by vacuum brazing, which not only avoids the processing of internal long and deep holes, but also reduces the processing difficulty caused by the large overhang of the inner shaft, thereby reducing the processing and manufacturing difficulty of key parts of the rotary joint, and the welded inner shaft has good sealing and strength. The inner shaft and the outer shaft adopt non-contact sealing, which can effectively avoid the heating risk caused by contact sealing, no consumables, maintenance-free, and can achieve long-term high-speed operation, and increase the sealing groove interval between multiple gas-liquid channels. After a certain pressure of gas is introduced, leakage can be effectively reduced to ensure the performance of the rotary joint. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 It is a schematic diagram of an end portion provided by an embodiment of the utility model.
[0017] Figure 2 It is a schematic diagram of the internal structure in the AA section direction provided by an embodiment of the utility model.
[0018] Figure 3 It is a schematic diagram of the internal structure in the BB section direction provided by an embodiment of the utility model.
[0019] Figure 4 It is a schematic diagram of the internal structure in the CC section direction provided by an embodiment of the utility model. DETAILED DESCRIPTION
[0020] The present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.
[0021] In the description of the utility model embodiments, it should be noted that the directions or positional relationships indicated by the terms "front", "rear", "left", "right", etc. are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the utility model embodiments and simplifying the description, rather than indicating or implying that the devices or elements referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the utility model embodiments. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.
[0022] Combination Figures 1 to 4As shown, a rotary joint provided by an embodiment of the utility model comprises an outer shaft 1, a first bearing 2, a first inner shaft section 3, a second inner shaft section 4, a third inner shaft section 5, a second bearing 6, a retaining ring 7, a preload spring 8 and an end cover 9. The first inner shaft section 3, the second inner shaft section 4 and the third inner shaft section 5 are sequentially axially connected and welded together to form an inner shaft structure. The outer shaft 1 is supported on the inner shaft structure through the first bearing 2 and the second bearing 6, and is in clearance fit with the inner shaft structure. The outer shaft 1 and the inner shaft structure can rotate relative to each other. Among them, the outer ring of the first bearing 2 is installed in the inner hole of the outer shaft 1, and the inner ring is installed on the first inner shaft section 3; the outer ring of the second bearing 6 is matched with the outer shaft 1, and the inner ring is sleeved on the third inner shaft section 5. The retaining ring 7 is sleeved on the third inner shaft section 5, and the end cover 9 is installed on the end face of the outer shaft 1, and the retaining ring 7 is pressed by the preload spring 8 to press the second bearing 6.
[0023] The outer shaft 1 is provided with a first axial outer channel 11, a second axial outer channel 12, a third axial outer channel 13 and a fourth axial outer channel 14 of different depths. The bottom of the first axial outer channel 11 is connected to a first radial outer channel 15, the bottom of the second axial outer channel 12 is connected to a second radial outer channel 16, the bottom of the third axial outer channel 13 is connected to a third radial outer channel 17, and the bottom of the fourth axial outer channel 14 is connected to a fourth radial outer channel 18. A first axial hole 31 is machined on the first inner shaft segment 3, the bottom of the first axial hole 31 is connected to a first radial inner channel 32, and a first circumferential groove 38 is provided on the outer wall of the first inner shaft segment 3 corresponding to the first radial inner channel 32; a second axial hole 42, a third axial hole 43 and an axial through hole 41 are respectively machined on the second inner shaft segment 4, the bottoms of the second axial hole 42 and the third axial hole 43 are respectively connected to a second radial inner channel 44 and a third radial inner channel 45, corresponding to the second radial inner channel 4 4, a second circumferential groove 416 is provided on the outer wall of the second inner shaft segment 4, corresponding to the third radial inner channel 45, and a third circumferential groove 417 is provided on the outer wall of the second inner shaft segment 4; a first axial through hole 51, a second axial through hole 52, a third axial through hole 53 and a fourth axial hole 54 are respectively processed on the third inner shaft segment 5, and the bottom of the fourth axial hole 54 is connected with the fourth radial inner channel 55, and a fourth circumferential groove 59 is provided on the outer wall of the third inner shaft segment 5 corresponding to the fourth radial inner channel 55. After the first inner shaft segment 3, the fourth inner shaft segment 4 and the third inner shaft segment 5 are welded, the first axial hole 31 is connected with the axial through hole 41 and the first axial through hole 51 to form the first axial inner channel, the second axial hole 42 is connected with the second axial through hole 52 to form the second axial inner channel, the third axial hole 43 is connected with the third axial through hole 53 to form the third axial inner channel, and the fourth axial hole 54 is the fourth axial inner channel.
[0024] When the outer shaft 1 and the inner shaft structure rotate relative to each other, the first axial inner channel, the first radial inner channel 44, the first radial outer channel 15, and the first axial outer channel 11 are connected through the first circumferential groove 38 to form a first gas-liquid channel; the second axial inner channel, the second radial inner channel 44, the second radial outer channel 16, and the second axial outer channel 12 are connected through the second circumferential groove 416 to form a second gas-liquid channel; the third axial inner channel, the third radial inner channel 45, the third radial outer channel 17, and the third axial outer channel 13 are connected through the third circumferential groove 417 to form a third gas-liquid channel; the fourth axial inner channel, the fourth radial inner channel 55, the fourth radial outer channel 18, and the fourth axial outer channel 14 are connected through the fourth circumferential groove 59 to form a fourth gas-liquid channel. The first gas-liquid channel, the second gas-liquid channel, the third gas-liquid channel, and the fourth gas-liquid channel are the working passages of the rotary joint provided in the embodiment of the utility model. The four working passages can be gas passages at the same time, oil passages at the same time, or part of them are gas passages and part of them are oil passages. And the flow direction of the four working channels can be changed according to the usage. When the outer shaft 1 is connected to the external rotating device, the outer shaft 1 rotates and the inner shaft structure is fixed. At this time, the flow direction of each working channel is:
[0025] First gas-liquid channel: first axial through hole 51 → axial hole 41 → first axial hole 31 → first radial inner channel 32 → first circumferential groove 38 → first radial outer channel 15 → first axial outer channel 11;
[0026] Second gas-liquid passage: second axial through hole 52 → third axial hole 42 → second radial inner passage 44 → second circumferential groove 416 → second radial outer passage 16 → second axial outer passage 12;
[0027] The third gas-liquid channel: the third axial through hole 53 → the fourth axial hole 43 → the third radial inner channel 45 → the third circumferential groove 417 → the third radial outer channel 17 → the third axial outer channel 13;
[0028] Fourth gas-liquid channel: fourth axial hole 54 →fourth radial inner channel 55 →fourth circumferential groove 59 →fourth radial outer channel 18 →fourth axial outer channel 14 .
[0029] When the third inner shaft section 5 is connected to the external rotating device, the inner shaft structure rotates, and the outer shaft 1 is fixed. At this time, the flow direction of each working passage is opposite to the above direction, that is:
[0030] First gas-liquid channel: first axial outer channel 11 → first radial outer channel 15 → first circumferential groove 38 → first radial inner channel 32 → first axial hole 31 → axial hole 41 → first axial through hole 51;
[0031] Second gas-liquid passage: second axial outer passage 12 → second radial outer passage 16 → second circumferential groove 416 → second radial inner passage 44 → third axial hole 42 → second axial through hole 52;
[0032] The third gas-liquid channel: the third axial outer channel 13 → the third radial outer channel 17 → the third circumferential groove 417 → the third radial inner channel 45 → the fourth axial hole 43 → the third axial through hole 53;
[0033] Fourth gas-liquid channel: fourth axial outer channel 14 → fourth radial outer channel 18 → fourth circumferential groove 59 → fourth radial inner channel 55 → fourth axial hole 54 .
[0034] When the outer shaft 1 and the inner shaft structure rotate relative to each other, the gap between the outer shaft 1 and the inner shaft structure forms a gap seal, which can effectively prevent the leakage of gas or oil in the four-way working passage. In order to improve the gap sealing effect, a first center hole 30 is provided on the first inner shaft segment 3, a second center hole 40 is provided on the second inner shaft segment 4, and a third center hole 50 is provided on the third inner shaft segment 5. The first center hole 30, the second center hole 40 and the third center hole 50 are interconnected in the axial direction to form a central air intake channel of the inner shaft structure; at the same time, a first circumferential pressure groove 39, a second circumferential pressure groove 418 and a third circumferential pressure groove 51 are respectively provided on the outer walls of the first inner shaft segment 3, the second inner shaft segment 4 and the third inner shaft segment 5. 0, two first circumferential pressure grooves 39 are distributed on both sides of the first circumferential groove 38, two second circumferential pressure grooves 418 are respectively arranged between the second circumferential groove 416 and the third circumferential groove 417 and between the third circumferential groove 417 and the fourth circumferential groove 59, and the third circumferential pressure groove 510 is arranged on one side of the fourth circumferential groove 59, that is, the first circumferential pressure groove 39, the second circumferential pressure groove 418 and the third circumferential pressure groove 510 separate the first circumferential groove 38, the second circumferential groove 416, the third circumferential groove 417 and the fourth circumferential groove 59. The first center hole 30 is connected to the two first circumferential pressure grooves 39 through the first radial air hole 33 and the second radial air hole 34, respectively, the second center hole 40 is connected to the two second circumferential pressure grooves 418 through the third radial air hole 46 and the fourth radial air hole 47, respectively, and the third center hole 50 is connected to the third circumferential pressure groove 510 through the fifth radial air hole 56. After the gas is introduced into the third center hole 50, the gas can enter the first circumferential pressure groove 39, the second circumferential pressure groove 418 and the third circumferential pressure groove 510 through the first radial air hole 33, the second radial air hole 34, the third radial air hole 46, the fourth radial air hole 47 and the fifth radial air hole 56 respectively, thereby effectively reducing the leakage of gas or oil in the above-mentioned four working passages.
[0035] During the processing and manufacturing of this embodiment, the first inner shaft segment 3, the second inner shaft segment 4 and the third inner shaft segment 5 are firstly processed with holes, and then the three are welded together by brazing, which can effectively reduce the difficulty of hole processing. In order to achieve effective brazing, a first center positioning groove 35, a first solder groove 36 and a second solder groove 37 are provided on the first inner shaft segment. The first solder groove 36 is concentrically arranged with the first axial hole 31, the second solder groove 37 is concentrically arranged with the first inner shaft segment 3, and the first center positioning groove 35 is concentrically arranged with the first center hole 30; a first center positioning platform 48 and a third solder groove 49 are provided at one end of the second inner shaft segment 4, and the third solder groove 49 is arranged on the first center positioning platform 48, and the first center positioning platform 48 is positioned and matched with the first center positioning groove 35; a second center positioning groove 410 and a fourth solder groove 411 are provided at the other end of the second inner shaft segment 4. 411, the fifth solder groove 412, the sixth solder groove 413 and the seventh solder groove 414, the fourth solder groove 411 is arranged concentrically with the second axial hole 41, the fifth solder groove 412 is arranged concentrically with the third axial hole 42, the sixth solder groove 413 is arranged concentrically with the fourth axial hole 43, the seventh solder groove 414 is arranged concentrically with the second inner shaft segment 4, and the second center positioning groove 410 is arranged concentrically with the second center hole 40; the third inner shaft segment 5 is provided with a second center positioning platform 57 and an eighth solder groove 58, the eighth solder groove 58 is provided on the second center positioning platform 57, and the second center positioning platform 57 is positioned and matched with the second center positioning groove 410. In order to achieve angular positioning, angle positioning holes are also provided on the respective connecting surfaces of the first inner shaft segment 3, the second inner shaft segment 4 and the third inner shaft segment 5, and the angle positioning is performed respectively by two positioning pins 10.
[0036] Before welding, the first inner shaft segment 3, the second inner shaft segment 4 and the third inner shaft segment 5 are processed respectively, and then solder is placed in the first solder groove 36, the second solder groove 37, the third solder groove 49, the fourth solder groove 411, the fifth solder groove 412, the sixth solder groove 413, the seventh solder groove 414 and the eighth solder groove 58 respectively, and the positioning pin 10 is installed in the corresponding position, and then the first inner shaft segment 3, the second inner shaft segment 4 and the third inner shaft segment 5 are assembled together in turn for vacuum brazing. After welding is completed, the first inner shaft segment 3, the second inner shaft segment 4 and the third inner shaft segment 5 are connected as a whole. At the same time, since the first solder groove 36, the third solder groove 49, the fourth solder groove 411, the fifth solder groove 412, the sixth solder groove 413, and the eighth solder groove 58 are respectively arranged around the first axial inner channel, the second axial inner channel, the third axial inner channel, the fourth axial inner channel and the central air intake channel, they also play a sealing role for the first axial inner channel, the second axial inner channel, the third axial inner channel, the fourth axial inner channel and the central air intake channel after brazing.
[0037] The rotary joint provided in this embodiment has four working passages, but this does not limit the present invention to have only four working circuits. The working circuits of the present invention can be expanded by increasing the number of inner shaft segments and providing corresponding passages and circumferential grooves.
[0038] A rotary joint provided in this embodiment realizes the processing and manufacturing of the inner shaft structure by vacuum brazing. The same method can also be applied to the outer shaft 1, that is, the outer shaft 1 can be processed by segmenting and welding the outer shaft 1, thereby improving the processing accuracy of the outer shaft and reducing the difficulty of processing the internal deep hole.
[0039] Although the utility model is described in detail above, the utility model is not limited thereto, and those skilled in the art can make various modifications according to the principle of the utility model. Therefore, all modifications made according to the principle of the utility model should be understood to fall within the protection scope of the utility model.
Claims
1. A rotary joint, characterized in that: It includes an inner shaft, an outer shaft, a first bearing and a second bearing. The outer shaft is supported on the inner shaft through the first bearing and the second bearing. The outer shaft and the inner shaft can rotate relatively. There is a clearance fit between the outer shaft and the inner shaft. The inner shaft is formed by fixing a plurality of inner shaft segments. Each inner shaft segment is respectively provided with a different number of axial holes. The axial holes are connected and combined on the inner shaft to form a plurality of axial inner channels with different depths.
2. A rotary joint according to claim 1, characterized in that: The outer shaft is provided with a plurality of axial outer channels of different depths, and the bottom of each axial outer channel is connected to a radial outer channel; the end of each axial inner channel is connected to a radial inner channel, and corresponding to each radial inner channel, a circumferential groove is respectively provided on the outer wall of the inner shaft; the axial inner channel, the radial inner channel, the radial outer channel, and the axial outer channel are connected one by one through the circumferential grooves to form a plurality of gas-liquid channels.
3. A rotary joint according to claim 2, characterized in that: Each of the inner shaft segments is also provided with a center hole, which is interconnected on the inner shaft to form a central air intake channel; a plurality of circumferential pressure grooves are provided on the outer wall of the inner shaft, and the circumferential pressure grooves are spaced apart from the circumferential grooves; the central air intake channel is connected with the circumferential pressure grooves through a plurality of radial air holes.
4. A rotary joint according to claim 3, characterized in that: The inner shaft segments are centrally positioned by means of a central positioning groove and a central positioning platform, and are angularly positioned by means of an angle positioning hole and a positioning pin; the central positioning groove and the central positioning platform are respectively arranged at the central connection of two adjacent inner shaft segments; the angle positioning hole is arranged on the connection surface of each inner shaft segment, and the positioning pin is arranged in two adjacent angle positioning holes.
5. A rotary joint according to claim 4, characterized in that: The inner shaft segments are connected by brazing, and a plurality of brazing material grooves are respectively arranged on the inner shaft segments, and the brazing material grooves are pre-filled with brazing material.
6. A rotary joint according to claim 5, characterized in that: The solder grooves are respectively concentrically arranged on the inner shaft segment, the outer side of the axial hole of the inner shaft segment and the central positioning platform.
7. A rotary joint according to claim 6, characterized in that: The rotary joint also includes an end cover, a preload spring and a retaining ring. The end cover is arranged on the end face of the outer shaft, and the second bearing is pressed by the preload spring and the retaining ring. One end of the preload spring is pressed on the end cover, and the other end is pressed on the retaining ring. The retaining ring is sleeved on the inner shaft and contacts the inner ring end face of the second bearing.
8. A rotary joint according to claim 7, characterized in that: Both the inner shaft and the outer shaft can be connected to the external rotating device, that is, when the outer shaft is connected to the external rotating device, the outer shaft rotates and the inner shaft does not move; when the inner shaft is connected to the external rotating device, the inner shaft rotates and the outer shaft does not move.
9. A rotary joint according to claim 8, characterized in that: The gas-liquid channel can be passed with gas or liquid.
10. A rotary joint according to claim 9, characterized in that: When the outer shaft rotates, the flow direction of the gas or liquid in the gas-liquid channel is to enter from the axial inner channel, pass through the radial inner channel, the circumferential groove, and the radial outer channel, and then flow out from the axial outer channel; when the inner shaft rotates, the flow direction of the gas or liquid in the gas-liquid channel is to enter from the axial outer channel, pass through the radial outer channel, the circumferential groove, and the radial inner channel, and then flow out from the axial inner channel.