Center swivel joint
By adopting a combined structure of sealing ring and bimetallic sheet in the center slewing joint, the problem of degradation of sealing performance is solved, and reliable sealing is achieved during high temperatures or long-term use is achieved to ensure the normal operation of the hydraulic equipment.
Patent Information
- Application Number
- CN202422459794.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-11
- Publication Date
- 2025-08-12
- Estimated Expiration
- 2034-10-11
AI Technical Summary
The existing center swing joints have degraded sealing performance during long-term use or in high-temperature environments, resulting in hydraulic oil leakage and unable to transmit sufficient hydraulic energy, affecting the normal operation of the equipment.
It adopts a multi-layer sealing structure, including a sealing ring and a bimetallic sheet, which uses the bimetallic sheet to deform due to different expansion coefficients at high temperatures, providing a radial top support for the sealing ring to ensure the sealing effect; combining bolt connection and gasket design, a reliable housing and spindle connection is achieved.
Effectively prevent hydraulic oil leakage, ensure that hydraulic equipment reliably transmits hydraulic energy during high temperatures or long-term work, and ensures the normal operation of the equipment.
Smart Images
Figure CN223215972U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of hydraulic equipment, and in particular to a center rotary joint. Background Art
[0002] Center swivel joints are widely used in construction machinery such as cranes and excavators. They are a device that integrates multiple oil circuits to transport the hydraulic oil and electrical system of the construction machinery to the actuators on the construction machinery.
[0003] In existing technologies, a central rotary joint typically consists of a sleeve, a fixed body, and a seal. The sleeve is fixed to the rotary platform and rotates with it, while the fixed body, housed within the sleeve, remains stationary on the chassis. Multiple hydraulic oil lines are routed during the rotation process, ensuring reliable hydraulic operation of the equipment through the flow of hydraulic oil as the equipment rotates.
[0004] However, after long-term use or in a high-temperature environment, the sealing performance of the seal will be reduced, which will lead to a decrease in the sealing between the sleeve and the fixed body. This will cause the hydraulic oil to leak from between the sleeve and the fixed body, and it will be impossible to transmit sufficient hydraulic energy to the equipment, causing the equipment to malfunction. Utility Model Content
[0005] In order to overcome the deficiencies of the prior art, the present application provides a central rotary joint.
[0006] The present application is implemented by the following technical solution: a central rotary joint, comprising a shell and a main shaft, one end of the main shaft being fixed on a base, the other end of the main shaft being passed through the inner side of the shell, the top of the shell being connected to the hydraulic equipment, a plurality of annular transverse oil passages being provided on the inner wall of the shell, a plurality of vertical oil passages being provided on the inner side of the main shaft, one of the vertical oil passages being connected to one of the transverse oil passages, and another of the vertical oil passages being connected to another of the transverse oil passages; a sealing ring is provided above and below any of the transverse oil passages, the sealing ring being clamped on the inner wall of the shell and sleeved on the outer wall of the main shaft, a plurality of through holes being provided in the sealing ring, a bimetallic strip being provided in the through hole, and the bimetallic strip being protruding toward the axial direction of the sealing ring.
[0007] By adopting the above technical solution, the sealing ring itself can play a sealing role to prevent the hydraulic oil from leaking in the lateral oil channel. Furthermore, a bimetallic strip is arranged in the perforation of the sealing ring. The characteristic that the bimetallic strip will produce different degrees of deformation after being heated due to different expansion coefficients is utilized to realize the supporting effect of the bimetallic strip on the sealing ring, thereby causing the sealing ring to expand radially, thereby ensuring that the sealing effect of the sealing ring is continuous and reliable.
[0008] Optionally, a connecting plate is provided at the bottom of the hydraulic equipment, and the connecting plate is connected to the top of the shell by a first bolt. The shell is also provided with a notch, and a positioning plate is provided in the notch. The top of the positioning plate is fitted with the bottom of the connecting plate, the positioning plate is connected to the main shaft by a second bolt, and the main shaft is connected to the base by a third bolt.
[0009] By adopting the above technical solution, the cooperation between the connecting plate and the first bolt realizes a reliable connection between the housing and the hydraulic equipment, and the cooperation between the positioning plate and the second bolt realizes a reliable connection between the positioning plate and the main shaft. At the same time, under the limiting action of the connecting plate, the installation position of the positioning plate and the main shaft is also fixed.
[0010] Optionally, a plurality of valve ports are provided on the outer wall of the shell, the number of the valve ports is consistent with the number of the vertical oil channels, the valve ports are connected with the transverse oil channels, the valve ports, transverse oil channels and vertical oil channels are connected in sequence to form a hydraulic oil channel, and the hydraulic oil flows forward or reverse in the hydraulic oil channel.
[0011] By adopting the above technical solution, it is ensured that the hydraulic oil can flow reliably between the housing and the main shaft, so that the hydraulic equipment can perform hydraulic operations while rotating.
[0012] Optionally, a plurality of cavities are further provided in the sealing ring, and the plurality of cavities correspond one-to-one to the plurality of perforations and are interconnected. A plurality of countersunk holes are provided on the inner wall of the cavity away from the perforations, one end of the countersunk hole is connected to the cavity, and the other end of the countersunk hole is close to the inner wall of the sealing ring. A push rod is passed through the countersunk hole, one end of the push rod is inserted into the countersunk hole, and the other end of the push rod is connected to the outer wall of the bimetallic strip.
[0013] By adopting the above technical solution, when the bimetallic strip is bent and deformed, it will form a supporting effect on the push rod, and the push rod will promote the radial expansion of the sealing ring, thereby improving the sealing effect of the sealing ring on the main shaft and the housing.
[0014] Optionally, the top of the bimetallic strip is flush with the top of the sealing ring, and the bottom of the bimetallic strip is flush with the bottom of the sealing ring. The top and bottom of the bimetallic strip are both provided with pressing plates, and a receiving groove for placing the sealing ring is provided on the inner wall of the shell, and the pressing plate is clamped in the receiving groove.
[0015] By adopting the above technical solution, after the sealing ring is installed, the inner wall of the accommodating groove will form an axial extrusion on the sealing ring, which will also form an extrusion effect on the pressure plate, thereby achieving an interference fit between the sealing ring and the shell. Furthermore, the pressure exerted on the pressure plate will be transmitted to the bimetallic strip, so that the bimetallic strip is in a tensioned state, which can improve the sensitivity of the bimetallic strip to deformation to a certain extent.
[0016] Optionally, a boss is provided at the lower portion of the main shaft, the third bolt is passed through the boss, the shell is mounted on the top of the boss, a gasket is provided between the bottom of the shell and the top of the boss, a plurality of convex rings are provided on the top of the gasket, the plurality of convex rings are coaxially arranged and spaced apart along the radial direction of the gasket, and there is a distance between two adjacent convex rings.
[0017] By adopting the above technical solution, the cooperation between the boss and the third bolt realizes the reliable assembly of the main shaft and the base, and at the same time, realizes the bearing effect on the shell; further, with the cooperation of the gasket and the convex ring, the bottom of the shell and the top of the convex ring can be reliably sealed without affecting the normal rotation of the shell.
[0018] Compared with the existing technology, the present application realizes reliable sealing between the housing and the main shaft by setting up multiple sealing rings and utilizing the elastic deformation of the bimetallic strip to radially support the sealing ring, thereby ensuring that the hydraulic oil can flow reliably in the hydraulic oil channel formed by the valve port, the horizontal oil channel and the vertical oil channel, and effectively preventing the leakage of the hydraulic oil at high temperature or after long-term operation. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 It is a schematic diagram of the structure of this application;
[0020] Figure 2 It is a cross-sectional view of the internal structure of the sealing ring;
[0021] Figure 3 This is a reference diagram of the assembly status of the gasket and the convex ring;
[0022] In the figure: 1. Housing; 11. Notch; 12. Positioning plate; 13. Second bolt; 14. Valve port; 15. Accommodation groove; 2. Main shaft; 21. Third bolt; 22. Boss; 221. Gasket; 222. Raised ring; 3. Hydraulic oil channel; 31. Horizontal oil channel; 32. Vertical oil channel; 4. Sealing ring; 41. Perforation; 42. Bimetallic sheet; 420. Pressing sheet; 43. Cavity; 44. Countersunk hole; 45. Push rod; 5. Connecting plate; 50. First bolt. DETAILED DESCRIPTION
[0023] Below, the present application is further described in conjunction with the accompanying drawings and specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.
[0024] like Figure 1-3 As shown, a central rotary joint includes a housing 1 and a main shaft 2. The lower part of the main shaft 2 is provided with a boss 22. The upper end of the main shaft 2 is inserted into the inner side of the housing 1. The bottom of the housing 1 is mounted on the top of the boss 22. A third bolt 21 is screwed on the boss 22. The third bolt 21 is screwed into the base, thereby achieving a reliable connection between the main shaft 2 and the base. A positioning plate 12 is provided on the top of the main shaft 2, and the positioning plate 12 and the main shaft 2 are connected by a second bolt 13. A notch 11 is provided on the top of the housing 1. The positioning plate 12 is adaptively arranged in the notch 11 and can rotate in the notch 11. Furthermore, a connecting plate 5 is provided at the bottom of the hydraulic equipment. The connecting plate 5 covers the notch 11 and is connected to the top of the housing 1 by a first bolt 50. In this way, the base is connected to the main shaft 2 and remains relatively stationary, and the housing 1 is connected to the hydraulic equipment and can rotate around the axis of the main shaft 2.
[0025] A gasket 221 is provided between the bottom of the housing 1 and the top of the boss 22. A plurality of raised rings 222 are provided on top of the gasket 221. The raised rings 222 are coaxially arranged and spaced radially apart from each other, with a distance between adjacent raised rings 222. The raised rings 222 are disposed between the housing 1 and the gasket 221. Under the downward pressure of gravity on the housing 1, the raised rings 222 deform to a certain extent, causing each raised ring 222 to form an independent seal, achieving a reliable seal between the housing 1 and the boss 22. Furthermore, the contact area between the raised rings 222 and the housing 1 is small, which does not hinder the normal rotation of the housing 1. In other words, with the gasket 221 and the raised rings 222 working together, the housing 1 can rotate reliably without leaking hydraulic oil between the housing 1 and the boss 22.
[0026] A number of annular transverse oil passages 31 are provided on the inner wall of the shell 1, and a number of vertical oil passages 32 are provided on the inner side of the main shaft 2. Each vertical oil passage 32 is connected to a corresponding transverse oil passage 31. At the same time, a number of valve ports 14 are provided on the outer wall of the shell 1, and each valve port 14 is also connected to a corresponding transverse oil passage 31. In this way, the valve ports 14, the transverse oil passages 31 and the vertical oil passages 32 are connected in sequence to form a hydraulic oil passage 3. When the hydraulic oil flows forward in the hydraulic oil passage 3, the hydraulic oil flows from the oil supply equipment in the base to the hydraulic equipment that needs oil. When the hydraulic oil flows reversely in the hydraulic oil passage 3, the hydraulic oil flows from the hydraulic equipment to the oil supply equipment in the base, thereby ensuring that the hydraulic equipment can reliably perform hydraulic operation.
[0027] A receiving groove 15 is provided on the inner wall of the housing 1, both above and below each transverse oil passage 31. The grooves 15 are connected and annular. A sealing ring 4 is fitted within the groove 15 and sleeved onto the outer wall of the main shaft 2. The presence of a sealing ring 4 above and below the transverse oil passage 31 ensures that hydraulic oil flowing within the hydraulic oil passage 3 does not leak between the housing 1 and the outer wall of the main shaft 2. Furthermore, the sealing ring 4 is provided with a plurality of through-holes 41 axially extending through the sealing ring 4. Furthermore, the sealing ring 4 is provided with a plurality of cavities 43, which correspond one-to-one with the plurality of through-holes 41 and are interconnected. A bimetallic strip 42 is adaptively provided in the through-hole 41. The top of the bimetallic strip 42 is flush with the top of the sealing ring 4, and the bottom of the bimetallic strip 42 is flush with the bottom of the sealing ring 4 and fits with the outer wall of the main shaft 2. A pressing piece 420 is provided on the top and bottom of the bimetallic strip 42. When the sealing ring 4 is placed in the accommodating groove 15, the inner wall of the accommodating groove 15 will form an extrusion effect on the sealing ring 4 and the pressing piece 420, so that the sealing ring 4 can be connected to the housing 1 in an interference fit state, thereby preventing the sealing ring 4 from falling off during the relative rotation of the housing 1 and the main shaft 2. Furthermore, after the sealing ring 4 is installed, the squeezing effect of the inner wall of the accommodating groove 15 on the pressure sheet 420 can put the bimetallic strip 42 in a tensioned state. In this way, when in a high temperature environment and after being used for a long time, the bimetallic strip 42 will gradually heat up. Since the expansion coefficients of the two metals of the bimetallic strip 42 are inconsistent and through the reasonable setting of the assembly direction of the bimetallic strip 42, the bimetallic strip 42 can bend toward the inner wall of the sealing ring 4 after being heated, thereby forming a supporting effect on the sealing ring 4, which also enables the sealing ring 4 to produce a certain shape, thereby improving the fit tightness between the sealing ring 4 and the main shaft 2, and effectively improving the sealing effect of the sealing ring 4 on the main shaft 2 and the housing 1.
[0028] A plurality of countersunk holes 44 are provided on the inner wall of the cavity 43 away from the through-hole 41. One end of the countersunk hole 44 is communicated with the cavity 43, and the other end of the countersunk hole 44 is close to the inner wall of the sealing ring 4 (that is, the countersunk hole 44 will not penetrate the sealing ring 4 in the radial direction). A push rod 45 is passed through the countersunk hole 44. One end of the push rod 45 is inserted into the countersunk hole 44 and close to the inner wall of the sealing ring 4 (that is, close to the main shaft 2). The other end of the push rod 45 is connected to the bimetallic strip 42 and is in a movably connected state (that is, the end of the push rod 45 and the bimetallic strip 42 can rotate relative to each other). When the bimetallic strip 42 is bent and deformed, it pushes the push rod 45 to move toward the main shaft 2. In this way, the push rod 45 will form a pushing effect on the sealing ring 4, causing the sealing ring 4 to deform slightly, so that the sealing ring 4 can be more tightly fitted on the outer wall of the main shaft 2, ensuring that the hydraulic oil will only flow in the hydraulic oil channel 3 and will not leak to the outside of the housing 1 and the main shaft 2, significantly improving the sealing effect of the sealing ring 4, and ensuring that the hydraulic equipment can reliably perform hydraulic operations while rotating.
[0029] The above-mentioned embodiments are only preferred embodiments of the present application and cannot be used to limit the scope of protection of the present application. Any non-substantial changes and replacements made by technicians in this field based on the present application shall fall within the scope of protection required by the present application.
Claims
1. A center rotary joint, characterized in that: The invention comprises a housing (1) and a main shaft (2), one end of the main shaft (2) is fixed on a base, the other end of the main shaft (2) is passed through the inner side of the housing (1), the top of the housing (1) is connected to the hydraulic equipment, a plurality of annular transverse oil passages (31) are provided on the inner wall of the housing (1), a plurality of vertical oil passages (32) are provided on the inner side of the main shaft (2), one of the vertical oil passages (32) is communicated with one of the transverse oil passages (31), and another of the vertical oil passages (32) is communicated with another of the transverse oil passages (31); A sealing ring (4) is provided above and below any of the transverse oil passages (31). The sealing ring (4) is clamped on the inner wall of the housing (1) and sleeved on the outer wall of the main shaft (2). A plurality of through holes (41) are provided in the sealing ring (4). A bimetallic strip (42) is provided in the through holes (41). The bimetallic strip (42) can protrude toward the axial direction of the sealing ring (4).
2. A center rotary joint according to claim 1, characterized in that: A connecting plate (5) is provided at the bottom of the hydraulic equipment, and the connecting plate (5) is connected to the top of the housing (1) by a first bolt (50). The housing (1) is also provided with a notch (11), and a positioning plate (12) is provided in the notch (11). The top of the positioning plate (12) is fitted with the bottom of the connecting plate (5), the positioning plate (12) is connected to the main shaft (2) by a second bolt (13), and the main shaft (2) is connected to the base by a third bolt (21).
3. A central rotary joint according to claim 1, characterized in that: A plurality of valve ports (14) are provided on the outer wall of the housing (1), the number of the valve ports (14) being consistent with the number of the vertical oil passages (32), the valve ports (14) being connected to the transverse oil passages (31), the valve ports (14), the transverse oil passages (31) and the vertical oil passages (32) being connected in sequence to form a hydraulic oil passage (3), and the hydraulic oil flows in the hydraulic oil passage (3) in a forward or reverse direction.
4. A central rotary joint according to claim 3, characterized in that: The sealing ring (4) is further provided with a plurality of cavities (43), and the plurality of cavities (43) correspond to the plurality of perforations (41) one by one and are interconnected. A plurality of countersunk holes (44) are provided on the inner wall of the cavity (43) away from the perforation (41). One end of the countersunk hole (44) is connected with the cavity (43), and the other end of the countersunk hole (44) is close to the inner wall of the sealing ring (4). A push rod (45) is passed through the countersunk hole (44), and one end of the push rod (45) is inserted into the countersunk hole (44), and the other end of the push rod (45) is connected to the outer wall of the bimetallic strip (42).
5. A center rotary joint according to claim 4, characterized in that: The top of the bimetallic strip (42) is flush with the top of the sealing ring (4), and the bottom of the bimetallic strip (42) is flush with the bottom of the sealing ring (4). A pressing piece (420) is provided on the top and bottom of the bimetallic strip (42). A receiving groove (15) for accommodating the sealing ring (4) is provided on the inner wall of the housing (1), and the pressing piece (420) is clamped in the receiving groove (15).
6. A central rotary joint according to claim 2, characterized in that: A boss (22) is provided at the lower portion of the main shaft (2), the third bolt (21) is passed through the boss (22), the housing (1) is mounted on the top of the boss (22), a gasket (221) is provided between the bottom of the housing (1) and the top of the boss (22), a plurality of convex rings (222) are provided on the top of the gasket (221), the plurality of convex rings (222) are coaxially arranged and spaced apart along the radial direction of the gasket (221), and a distance exists between two adjacent convex rings (222).