A rotary joint and a crane

Abstract

This utility model discloses a rotary joint and a crane, relating to the field of hydraulic oil conveying technology. The rotary joint includes an oil delivery shaft, an oil supply sleeve, and an oil distribution sleeve. The oil delivery shaft has at least two independent oil delivery channels inside. The oil supply sleeve is rotatably fitted onto the first end of the oil delivery shaft and has oil supply channels corresponding to the corresponding oil delivery channels, which are connected to each other. The oil distribution sleeve is rotatably fitted onto the second end of the oil delivery shaft and has oil distribution channels corresponding to the corresponding oil delivery channels, which are connected to each other. The oil delivery shaft is used to convey hydraulic oil between the oil supply sleeve and the oil distribution sleeve. The pipe connected to the oil supply sleeve and the rotating mechanism connected to the oil distribution sleeve can both rotate coaxially relative to the oil delivery shaft, which can improve the problem in related technologies where the rotary joint is subjected to a counter-torque, causing fatigue stress in the connected fixed pipe, resulting in loosening or damage.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic oil delivery technology, and in particular to a rotary joint and a crane. Background Technology

[0002] A rotary joint, also known as a hydraulic central rotary joint or center rotary joint, is a hydraulic component installed at the connection between the grab bucket and the boom of a crane (or excavator). While the grab bucket can rotate continuously 360°, it provides a continuous, non-tangled hydraulic circuit to the hydraulic cylinders that drive the opening and closing of the grab bucket. In related technologies, rotary joints employ a two-stage structure, allowing only hydraulic oil transmission between the two stages of the mechanism. The rotary joint bears a counter-torque, which, over long-term operation, may cause fatigue stress in the connected fixed pipes, leading to loosening or damage.

[0003] Therefore, how to provide a rotary joint and a crane that improves the shortcomings of the aforementioned related technologies is a technical problem that needs to be solved by those skilled in the art. Utility Model Content

[0004] The purpose of this invention is to provide a rotary joint and a crane that can improve the problem in related technologies where a rotary joint subjected to a counter-torque causes fatigue stress in the connected fixed pipe, resulting in loosening or damage.

[0005] To achieve the above objectives, this utility model provides a rotary joint, comprising:

[0006] The oil supply shaft has at least two independent oil supply channels inside.

[0007] The oil supply bushing is rotatably fitted onto the first end of the oil supply shaft. The oil supply bushing has an oil supply channel that corresponds to the oil supply channel, and the oil supply channel is connected to the corresponding oil supply channel.

[0008] The oil distribution sleeve is rotatably fitted onto the second end of the oil supply shaft. The oil distribution sleeve has an oil distribution channel that corresponds one-to-one with the oil supply channel. The oil distribution channel is connected to the corresponding oil supply channel. The oil supply shaft is used to transport hydraulic oil between the oil supply sleeve and the oil distribution sleeve.

[0009] In one possible implementation, each oil distribution channel includes multiple oil distribution ports, and all oil distribution ports of the same oil distribution channel are evenly arranged in the circumferential direction of the oil distribution sleeve.

[0010] In one possible implementation, the oil delivery channel includes an oil delivery axial section extending in the direction of the rotation axis of the oil distribution bushing, and a first oil delivery extension section communicating with one end of the oil delivery axial section, the first oil delivery extension section extending to the outer circumferential surface of the oil delivery shaft body.

[0011] The oil supply channel includes an oil supply axial section extending in the direction of the rotation axis of the oil distribution sleeve, and an oil supply extension section connected to one end of the oil supply axial section. The oil supply extension section extends to the inner circumferential surface of the oil supply sleeve and is connected to the first oil delivery extension section.

[0012] In one possible implementation, the first oil delivery extension and / or oil supply extension is an annular groove.

[0013] In one possible implementation, the oil delivery channel further includes a second oil delivery extension section connected to the other end of the oil delivery axial section. The second oil delivery extension section extends to the outer circumferential surface of the oil delivery shaft body. The second oil delivery extension section is an annular groove, and the oil distribution port penetrates the outer circumferential surface and the inner circumferential surface of the oil distribution sleeve to connect with the second oil delivery extension section.

[0014] In one possible implementation, the oil delivery channel further includes a second oil delivery extension section connected to the other end of the oil delivery axial section. The second oil delivery extension section extends to the outer circumferential surface of the oil delivery shaft. The oil distribution channel includes an annular oil distribution groove body opened on the inner circumferential surface of the oil distribution bushing. The oil distribution groove body is connected to the second oil delivery extension section and the oil distribution port.

[0015] In one possible implementation, a first limiting member is connected to the first end of the oil delivery shaft. The first limiting member has a first limiting surface on the side facing the oil supply sleeve. The oil delivery shaft has a second limiting surface perpendicular to the rotation axis of the oil distribution sleeve. The second limiting surface is located on the side of the oil supply sleeve away from the first limiting surface. The first limiting surface and the second limiting surface are used to restrict the movement of the oil supply sleeve relative to the oil delivery shaft in the rotation axis direction of the oil distribution sleeve.

[0016] In one possible implementation, a second limiting member is further included connected to the second end of the oil delivery shaft. The second limiting member has a third limiting surface on the side facing the oil distribution sleeve. The oil delivery shaft has a fourth limiting surface perpendicular to the rotation axis of the oil distribution sleeve. The fourth limiting surface is located on the side of the oil distribution sleeve away from the third limiting surface. The third and fourth limiting surfaces are used to restrict the movement of the oil distribution sleeve relative to the oil delivery shaft in the rotation axis direction of the oil distribution sleeve.

[0017] In one possible implementation, a plurality of first sealing grooves are provided between the oil supply shaft and the oil supply bushing, and a first sealing element is provided in the first sealing groove.

[0018] Several second sealing grooves are provided between the oil distribution bushing and the oil supply bushing, and second sealing elements are provided in the second sealing grooves.

[0019] Based on the foregoing, this application also provides a crane, including a rotary joint as described in any of the above claims.

[0020] Compared with the prior art, the technical solution provided by this utility model has at least the following beneficial effects: the first end of the oil supply shaft is rotatably fitted with an oil supply sleeve, and the second end of the oil supply shaft is rotatably fitted with an oil distribution sleeve. The oil supply channel of the oil supply sleeve corresponds one-to-one with and is connected to the oil supply channel of the oil supply shaft, and the oil distribution channel of the oil distribution sleeve corresponds one-to-one with and is connected to the oil supply channel of the oil supply shaft, so that hydraulic oil is transported between the oil supply sleeve and the oil distribution sleeve. The pipe connected to the oil supply sleeve and the rotating mechanism connected to the oil distribution sleeve can both rotate coaxially relative to the oil supply shaft. When the rotating mechanism drives the oil distribution sleeve to rotate relative to the oil supply shaft, the oil supply sleeve and the pipe eliminate torque by rotating relative to the oil supply shaft, which improves the problem in the related technology that the rotary joint bears a counter-torque, causing the connected fixed pipe to generate fatigue stress and become loose or damaged. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the structure of the rotary joint provided in an embodiment of the present utility model;

[0023] Figure 2 A cross-sectional view of the rotary joint provided in an embodiment of this utility model;

[0024] Figure 3 for Figure 1 The main view;

[0025] Figure 4 for Figure 1 The right view;

[0026] Figure 5 for Figure 1 The left view.

[0027] in:

[0028] 100-Oil supply shaft, 110-Oil supply channel, 111-Oil supply shaft section, 112-First oil supply extension section, 113-Second oil supply extension section, 120-Second limiting surface, 130-Fourth limiting surface;

[0029] 200-oil supply bushing, 210-oil supply channel, 211-oil supply axial section, 212-oil supply extension section;

[0030] 300 - oil distribution bushing, 310 - oil distribution port, 320 - oil distribution groove body;

[0031] 400 - First limiting component;

[0032] 500 - Second limiting component;

[0033] 600 - First sealing groove;

[0034] 700 - Second sealing groove. Detailed Implementation

[0035] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0036] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] In the description of this utility model, it should be understood that the terms "inner" and "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the position or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations of this utility model.

[0038] The purpose of this invention is to provide a rotary joint and a crane that can improve the problem in related technologies where a rotary joint subjected to a counter-torque causes fatigue stress in the connected fixed pipe, resulting in loosening or damage.

[0039] Please see Figures 1 to 5To achieve the above objectives, this utility model provides a rotary joint, including an oil supply shaft 100, an oil supply sleeve 200, and an oil distribution sleeve 300. The oil supply shaft 100 has at least two independent oil supply channels 110 inside, and has a first end and a second end opposite to each other. The oil supply sleeve 200 is rotatably sleeved on the first end of the oil supply shaft 100, and has an oil supply channel 210 corresponding to each of the oil supply channels 110. The oil supply channels 210 are connected to the corresponding oil supply channels 110, and the different oil supply channels 210 are independent of each other. The oil distribution sleeve 300 is rotatably sleeved on the second end of the oil supply shaft 100, and has an oil distribution channel corresponding to each of the oil supply channels 110. The oil distribution channels are connected to the corresponding oil supply channels 110, and the different oil distribution channels are independent of each other. The oil supply shaft 100 is used to transport hydraulic oil between the oil supply sleeve 200 and the oil distribution sleeve 300. The oil supply shaft 100, the oil supply bushing 200, and the oil distribution bushing 300 are coaxially arranged.

[0040] The first end of the oil supply shaft 100 is rotatably fitted with an oil supply sleeve 200, and the second end of the oil supply shaft 100 is rotatably fitted with an oil distribution sleeve 300. The oil supply channel 210 of the oil supply sleeve 200 corresponds to and is connected to the oil supply channel 110 of the oil supply shaft 100. The oil distribution channel of the oil distribution sleeve 300 corresponds to and is connected to the oil supply channel 110 of the oil supply shaft 100. This allows hydraulic oil to be transported between the oil supply sleeve 200 and the oil distribution sleeve 300. The pipe connected to the oil supply sleeve 200 and the rotating mechanism connected to the oil distribution sleeve 300 can both rotate coaxially relative to the oil supply shaft 100. When the rotating mechanism drives the oil distribution sleeve 300 to rotate relative to the oil supply shaft 100, the oil supply sleeve 200 and the pipe eliminate torque by rotating relative to the oil supply shaft 100. This improves the problem in related technologies where the rotary joint is subjected to a counter-torque, causing the connected fixed pipe to develop fatigue stress and become loose or damaged.

[0041] It should be noted that the oil delivery shaft 100 is connected to the fixed body, the oil distribution sleeve 300 is connected to the rotating mechanism, and the oil supply sleeve 200 can be connected to another rotating mechanism so that it can rotate relative to the oil delivery shaft 100 around the axis of the oil delivery shaft 100 under the drive of the other rotating mechanism. In this way, hydraulic oil transmission of the three-stage mechanism rotating coaxially can be realized. The rotating mechanism connected to the oil distribution sleeve 300 and the other rotating mechanism connected to the oil supply sleeve 200 can rotate relative to the oil delivery shaft 100 at different rotational speeds, so that the three-stage mechanism rotating coaxially can adapt to different rotational speeds.

[0042] In one possible implementation, each oil distribution channel includes multiple oil distribution ports 310. All oil distribution ports 310 of the same oil distribution channel are evenly arranged circumferentially on the oil distribution sleeve 300. After being transported to the oil distribution channel along the oil delivery channel 110 of the oil delivery shaft 100, the hydraulic oil is distributed into multiple paths through the oil distribution ports 310, controlling multiple hydraulic actuators to achieve simultaneous operation. This simplifies the structure, reduces costs, and improves reliability. It can overcome the problems in the prior art where rotary joints do not have their own oil distribution device and require an additional oil distribution device, resulting in low integration, complex structure, high risk of oil leakage, and high cost.

[0043] It is understood that the oil supply channel 110, oil delivery channel 210, and oil distribution channel are one-to-one and each has two sections. The oil distribution ports 310 of the two oil distribution channels are also one-to-one, and one set of corresponding oil distribution ports 310 in the two oil distribution channels can be used to connect to a hydraulic actuator for hydraulic oil to enter and exit the hydraulic actuator. Specifically, when hydraulic oil enters an oil delivery channel 110 from one oil supply channel 210, and then enters the corresponding oil distribution channel, it enters the hydraulic actuator through one oil distribution port 310 of the oil distribution channel. At this time, the hydraulic oil in the hydraulic actuator itself enters another oil delivery channel 110 from one oil distribution port 310 of the other oil distribution channel, and is discharged to the outside of the rotary joint from the other oil supply channel 210. That is, the two oil supply channels 210 are used for hydraulic oil entry and exit respectively. When one oil supply channel 210 is used for hydraulic oil entry, the remaining oil supply channel 210 is used for hydraulic oil exit. The hydraulic actuator can be, but is not limited to, a cylinder actuator, to achieve hydraulic oil diversion for multiple cylinder actuators via the oil distribution bushing 300.

[0044] In one possible implementation, the oil delivery channel 110 includes an oil delivery axial section 111 extending in the direction of the rotation axis of the oil distribution sleeve 300, and a first oil delivery extension 112 communicating with one end of the oil delivery axial section 111. The oil delivery axial section 111 is located inside the oil delivery shaft body 100, and the first oil delivery extension 112 extends to the outer circumferential surface of the oil delivery shaft body 100. The oil supply channel 210 includes an oil supply axial section 211 extending in the direction of the rotation axis of the oil distribution sleeve 300, and an oil supply extension 212 communicating with one end of the oil supply axial section 211. The oil supply extension 212 extends to the inner circumferential surface of the oil supply sleeve 200. In the corresponding oil delivery channel 110 and oil supply channel 210, the oil supply extension 212 corresponds to the first oil delivery extension 112 in position and communicates with the first oil delivery extension 112. Among them, the first oil delivery extension 112 of the two oil delivery channels 110 is isolated from each other in the direction of rotation axis of the oil distribution sleeve 300, and the oil supply extension 212 of the two oil supply channels 210 is also isolated in the direction of rotation axis of the oil distribution sleeve 300.

[0045] Furthermore, the first oil delivery extension 112 and / or the oil supply extension 212 are annular grooves, that is, including the following three cases: the first oil delivery extension 112 is an annular groove; the oil supply extension 212 is an annular groove; and both the first oil delivery extension 112 and the oil supply extension 212 are annular grooves. When the first oil delivery extension 112 is an annular groove, the oil supply extension 212 is a radially extending groove, so that the oil supply sleeve 200 can be rotated to any angle relative to the oil delivery shaft 100, and the oil supply extension 212 is always connected to the first oil delivery extension 112; when the oil supply extension 212 is an annular groove, the first oil delivery extension 112 is a radially extending groove, so that the oil supply sleeve 200 can be rotated to any angle relative to the oil delivery shaft 100, and the oil supply extension 212 is always connected to the first oil delivery extension 112; in addition, both the first oil delivery extension 112 and the oil supply extension 212 can be annular grooves, which can also achieve the same result of the oil supply sleeve 200 being rotated to any angle relative to the oil delivery shaft 100, and the oil supply extension 212 being always connected to the first oil delivery extension 112.

[0046] In one possible implementation, the oil delivery channel 110 further includes a second oil delivery extension 113 communicating with the other end of the oil delivery axial section 111. The second oil delivery extension 113 extends to the outer circumferential surface of the oil delivery shaft body 100. The second oil delivery extension 113 is an annular groove, and the oil distribution port 310 penetrates the outer circumferential surface and the inner circumferential surface of the oil distribution sleeve 300 to communicate with the second oil delivery extension 113. The second oil delivery extensions 113 of the two oil delivery channels 110 are isolated from each other in the direction of the rotation axis of the oil distribution sleeve 300, and the oil distribution ports 310 of the two oil supply channels 210 are also isolated from each other in the direction of the rotation axis of the oil distribution sleeve 300. The oil distribution port 310 is a through hole that extends radially and penetrates the oil distribution sleeve 300. The second oil delivery extension section 113 adopts an annular groove, which means that when the oil distribution sleeve 300 is rotated to any angle relative to the oil delivery shaft 100, all the oil distribution ports 310 in the same oil distribution channel located in the circumferential direction of the annular groove are connected to the second oil delivery extension, so as to divert the hydraulic oil passing through the second oil delivery extension section 113 or to merge the hydraulic oil flowing into the oil distribution channel from the hydraulic actuator.

[0047] In another possible embodiment, the oil delivery channel 110 further includes a second oil delivery extension 113 connected to the other end of the oil delivery axial section 111. The second oil delivery extension 113 extends to the outer circumferential surface of the oil delivery shaft 100. Each oil distribution channel includes an annular oil distribution groove 320 formed on the inner circumferential surface of the oil distribution sleeve 300. The oil distribution groove 320 connects the second oil delivery extension 113 and the oil distribution port 310. The second oil delivery extensions 113 of the two oil delivery channels 110 are isolated in the direction of the rotation axis of the oil distribution sleeve 300, and the oil distribution grooves 320 of the two oil supply channels 210 are also isolated in the direction of the rotation axis of the oil distribution sleeve 300. When the oil distribution groove 320 adopts an annular structure, all oil outlets 310 in the same oil distribution channel are connected to the oil distribution groove 320. This ensures that the oil distribution sleeve 300 can rotate to any angle relative to the oil delivery shaft 100, and that the oil distribution groove 320 can always be connected to the second oil delivery extension 113, thus maintaining communication between the second oil delivery extension 113 and the oil outlets 310. It should be noted that when the oil distribution groove 320 adopts an annular structure, the second oil delivery extension 113 can be configured as a radially extending groove or an annular groove.

[0048] In one possible implementation, the rotary joint further includes a first limiting member 400 connected to the first end of the oil supply shaft 100. The first limiting member 400 has a first limiting surface on the side facing the oil supply sleeve 200. The oil supply shaft 100 has a second limiting surface 120 perpendicular to the rotation axis direction of the oil distribution sleeve 300. The second limiting surface 120 is located on the side of the oil supply sleeve 200 away from the first limiting surface. The first limiting surface and the second limiting surface 120 are used to restrict the movement of the oil supply sleeve 200 relative to the oil supply shaft 100 in the rotation axis direction of the oil distribution sleeve 300. Specifically, the oil supply sleeve 200 is fitted onto the first end of the oil delivery shaft 100. After the oil distribution sleeve 300 moves into position along its rotation axis, a first limiting member 400 is installed at the first end of the oil delivery shaft 100. The outer diameters of both the first and second limiting surfaces 120 are larger than the inner diameter of the oil supply sleeve 200, thereby restricting the movement of the oil supply sleeve 200 relative to the oil delivery shaft 100 along the rotation axis of the oil distribution sleeve 300. The first limiting member 400 has a first connecting hole, and the first end of the oil delivery shaft 100 has a second connecting hole. A first connecting member connects to the first and second connecting holes, thus fixing the first limiting member 400 relative to the oil delivery shaft 100. The first and second connecting holes can be, but are not limited to, threaded holes, and the first connecting member can be, but is not limited to, a screw.

[0049] In one possible implementation, the rotary joint further includes a second limiting member 500 connected to the second end of the oil delivery shaft 100. The second limiting member 500 has a third limiting surface on the side facing the oil distribution sleeve 300. The oil delivery shaft 100 has a fourth limiting surface 130 perpendicular to the rotation axis direction of the oil distribution sleeve 300. The fourth limiting surface 130 is located on the side of the oil distribution sleeve 300 away from the third limiting surface. The third limiting surface and the fourth limiting surface 130 are used to restrict the movement of the oil distribution sleeve 300 relative to the oil delivery shaft 100 in the rotation axis direction of the oil distribution sleeve 300. Specifically, the oil distribution sleeve 300 is fitted onto the first end of the oil delivery shaft 100. After the oil distribution sleeve 300 moves into position along its rotation axis, a second limiting member 500 is installed at the second end of the oil delivery shaft 100. The outer diameters of the third and fourth limiting surfaces 130 are both larger than the inner diameter of the oil supply sleeve 200, thereby restricting the movement of the oil distribution sleeve 300 relative to the oil delivery shaft 100 along its rotation axis. The second limiting member 500 has a third connecting hole, and the second end of the oil delivery shaft 100 has a fourth connecting hole. A second connecting member connects to the third and fourth connecting holes, thus fixing the second limiting member 500 relative to the oil delivery shaft 100. The third and fourth connecting holes can be, but are not limited to, threaded holes, and the second connecting member can be, but is not limited to, a screw.

[0050] In one possible implementation, a plurality of first sealing grooves 600 are provided between the oil supply shaft 100 and the oil supply sleeve 200, and a first sealing element is provided in each of the first sealing grooves 600. The first sealing grooves 600 are located between the two oil supply extensions 212 and between the end faces of the oil supply extensions 212 and the oil supply sleeve 200, and are used to prevent hydraulic oil leakage from the two oil supply extensions 212, while preventing dust from entering the oil supply extensions 212 and contaminating the hydraulic oil. The first sealing element may include a main seal and a secondary seal. The sealing effect is improved by the combination of the main seal and the secondary seal to meet the rotational operation under high pressure conditions and to prevent dust from entering. A plurality of second sealing grooves 700 are provided between the oil distribution sleeve 300 and the oil supply sleeve 200, and a second sealing element is provided in each of the second sealing grooves 700. The second sealing groove 700 is located between the two oil distribution channels and between the end faces of the oil distribution channels and the oil distribution bushing 300. It is used to prevent hydraulic oil leakage from the two oil distribution channels and to prevent dust from entering the oil distribution channels and contaminating the hydraulic oil. The second seal can also include a main seal and a secondary seal. The combination of the main seal and the secondary seal improves the sealing effect to meet the rotational operation under high pressure conditions and prevent dust from entering.

[0051] Based on the above, this application also provides a crane, including a rotary joint as described in any of the above claims. The crane further includes multiple grabs, each grab connected to a hydraulic actuator. Each grab's hydraulic actuator is connected to a set of oil ports 310, wherein each set of oil ports 310 is one of two oil distribution channels, allowing the hydraulic actuator to communicate with two oil supply channels 210. When one oil supply channel 210 is inlet to control the grab's "opening," the other oil supply channel 210 is used for oil discharge; when the other oil supply channel 210 is inlet to control the grab's "closing," the aforementioned oil supply channel 210 is used for oil discharge. The grab's gripping or dropping of heavy objects is achieved through the inflow and outflow of hydraulic oil. The crane also possesses all the beneficial effects of the aforementioned rotary joint. The remaining structure of the crane can be referred to in the prior art, and will not be elaborated here.

[0052] It should be noted that in this specification, relational terms such as first and second are used only to distinguish one entity from several other entities, and do not necessarily require or imply any such actual relationship or order between these entities.

[0053] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0054] This article uses specific examples to illustrate the principles and implementation methods of this utility model. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made to this utility model without departing from the principles of this utility model, and these improvements and modifications also fall within the protection scope of this utility model.

Claims

1. A rotary joint, characterized in that, include: The oil supply shaft (100) has at least two independent oil supply channels (110) inside. An oil supply bushing (200) is rotatably sleeved on the first end of the oil supply shaft (100). The oil supply bushing (200) is provided with an oil supply channel (210) that corresponds one-to-one with the oil supply channel (110). The oil supply channel (210) is connected to the corresponding oil supply channel (110). The oil distribution sleeve (300) is rotatably sleeved on the second end of the oil supply shaft (100). The oil distribution sleeve (300) is provided with an oil distribution channel that corresponds one-to-one with the oil supply channel (110). The oil distribution channel is connected to the corresponding oil supply channel (110). The oil supply shaft (100) is used to transport hydraulic oil between the oil supply sleeve (200) and the oil distribution sleeve (300).

2. The rotary joint according to claim 1, characterized in that, Each of the oil distribution channels includes multiple oil distribution ports (310), and all the oil distribution ports (310) of the same oil distribution channel are evenly arranged in the circumferential direction of the oil distribution sleeve (300).

3. The rotary joint according to claim 2, characterized in that, The oil delivery channel (110) includes an oil delivery axial section (111) extending in the direction of the rotation axis of the oil distribution sleeve (300) and a first oil delivery extension section (112) communicating with one end of the oil delivery axial section (111). The first oil delivery extension section (112) extends to the outer circumferential surface of the oil delivery shaft body (100). The oil supply channel (210) includes an oil supply axial section (211) extending in the direction of the rotation axis of the oil distribution bushing (300) and an oil supply extension section (212) communicating with one end of the oil supply axial section (211). The oil supply extension section (212) extends to the inner circumferential surface of the oil supply bushing (200) and is communicating with the first oil delivery extension section (112).

4. The rotary joint according to claim 3, characterized in that, The first oil delivery extension (112) and / or the oil supply extension (212) are annular grooves.

5. The rotary joint according to claim 3, characterized in that, The oil delivery channel (110) also includes a second oil delivery extension (113) connected to the other end of the oil delivery axial section (111). The second oil delivery extension (113) extends to the outer circumferential surface of the oil delivery shaft (100). The second oil delivery extension (113) is an annular groove. The oil distribution port (310) penetrates the outer circumferential surface and the inner circumferential surface of the oil distribution bushing (300) to connect to the second oil delivery extension (113).

6. The rotary joint according to claim 3, characterized in that, The oil delivery channel (110) also includes a second oil delivery extension (113) connected to the other end of the oil delivery axial section (111). The second oil delivery extension (113) extends to the outer circumferential surface of the oil delivery shaft (100). Each oil distribution channel includes an annular oil distribution groove (320) opened on the inner circumferential surface of the oil distribution sleeve (300). The oil distribution groove (320) is connected to the second oil delivery extension (113) and the oil distribution port (310).

7. The rotary joint according to any one of claims 1-6, characterized in that, It also includes a first limiting member (400) connected to the first end of the oil delivery shaft (100). The first limiting member (400) has a first limiting surface on the side facing the oil supply sleeve (200). The oil delivery shaft (100) has a second limiting surface (120) perpendicular to the rotation axis direction of the oil distribution sleeve (300). The second limiting surface (120) is located on the side of the oil supply sleeve (200) away from the first limiting surface. The first limiting surface and the second limiting surface (120) are used to restrict the movement of the oil supply sleeve (200) relative to the oil delivery shaft (100) in the rotation axis direction of the oil distribution sleeve (300).

8. The rotary joint according to any one of claims 1-6, characterized in that, It also includes a second limiting member (500) connected to the second end of the oil delivery shaft (100). The second limiting member (500) has a third limiting surface on the side facing the oil distribution sleeve (300). The oil delivery shaft (100) has a fourth limiting surface (130) perpendicular to the rotation axis of the oil distribution sleeve (300). The fourth limiting surface (130) is located on the side of the oil distribution sleeve (300) away from the third limiting surface. The third limiting surface and the fourth limiting surface (130) are used to restrict the movement of the oil distribution sleeve (300) relative to the oil delivery shaft (100) in the rotation axis direction of the oil distribution sleeve (300).

9. The rotary joint according to any one of claims 1-6, characterized in that, A plurality of first sealing grooves (600) are provided between the oil delivery shaft body (100) and the oil supply bushing (200), and a first sealing element is provided in the first sealing groove (600); A plurality of second sealing grooves (700) are provided between the oil distribution bushing (300) and the oil supply bushing (200), and a second sealing element is provided in the second sealing groove (700).

10. A crane, characterized in that, Includes the rotary joint as described in any one of claims 1-9.

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