A hydrogen rotary joint suitable for low temperature environment

Abstract

The present invention provides a hydrogen rotary joint suitable for low-temperature environments, comprising: a core shaft, a housing, a front bearing, a rear bearing, a first oil seal, a second oil seal, an O-ring, and a Gly ring; a gas inlet is formed on the side wall of the housing, an annular channel groove is formed on the inner wall of the housing at the gas inlet position, and a plurality of sealing ring mounting grooves are provided on both sides of the channel groove; a front bearing and a rear bearing are respectively mounted on the core shaft, the housing is sleeved on the core shaft and supported by the front bearing and the rear bearing; an O-ring and a Gly ring are provided between the front bearing and the rear bearing, and a first oil seal and a second oil seal are respectively provided on the outer sides of the front bearing and the rear bearing; a first flow channel hole is formed on the side wall surface of the core shaft located within the housing, and a second flow channel hole is formed on the side wall surface located outside the housing, and the two flow channel holes are connected by a radial flow channel. The present invention has a low leakage rate, reliable operation, and wide applicability.

Description

Technical Field

[0001] The invention relates to a hydrogen rotary joint applicable to a low-temperature environment, and belongs to the field of rotary joints and hydrogen applications. Background Art

[0002] Conventional rotary joints are mostly suitable for media such as lubricating oil and cooling water. Research on rotary joints at home and abroad is mostly focused on operation under high temperature, high speed and high pressure conditions. There is less research on rotary joints for combustible gases, especially combustible gases that are prone to leakage, such as hydrogen. In particular, there are no related products from domestic and foreign manufacturers for hydrogen rotary joints that can be used in low temperature environments.

[0003] As a clean energy source, hydrogen has broad application prospects in promoting energy conservation and emission reduction, adjusting the energy industry structure, and addressing global climate change. Therefore, the development of hydrogen rotary joints is of great significance to promoting the promotion of hydrogen use. Summary of the Invention

[0004] The technical problem to be solved by the present invention is: for low-pressure hydrogen with a working pressure not exceeding 0.1MPa and a working temperature ranging from room temperature to low temperature of -20°C, the present invention provides a hydrogen rotary joint with high safety performance.

[0005] The technical solution adopted by the present invention is: a hydrogen rotary joint applicable to low temperature environment, comprising: a core shaft, a housing, a front bearing, a rear bearing, a first oil seal, a second oil seal, an O-ring and a Gly ring;

[0006] The side wall of the shell is provided with a gas inlet, the inner wall of the shell is provided with an annular channel groove at the gas inlet position, and a plurality of sealing ring mounting grooves are provided on both sides of the channel groove;

[0007] The front bearing and the rear bearing are respectively installed on the core shaft, and the housing is sleeved on the core shaft and supported by the front bearing and the rear bearing; an O-ring and a Gly ring are provided between the front bearing and the rear bearing, and a first oil seal and a second oil seal are respectively provided on the outer sides of the front bearing and the rear bearing;

[0008] A first flow channel hole is opened on the side wall surface of the core shaft located in the shell, and a second flow channel hole is opened on the side wall surface located outside the shell. The two flow channel holes are connected through a radial flow channel.

[0009] Furthermore, a first leakage detection hole and a second leakage detection hole are respectively provided on the housing at the front bearing cavity and the rear bearing cavity, and a gas concentration detector is installed at the first leakage detection hole and the second leakage detection hole to detect the leakage rate of hydrogen.

[0010] Furthermore, during operation, the core shaft is connected to the rotating device, the shell is connected to the fixed device, hydrogen enters from the gas inlet on the shell, flows in through the first flow channel hole on the core shaft, and flows out from the second flow channel hole on the core shaft.

[0011] Furthermore, the grid rings are symmetrically arranged on both sides of the channel groove of the shell.

[0012] Furthermore, the O-rings are symmetrically arranged on both sides of the channel groove of the housing, and the O-rings are respectively located between the Gly ring and the front bearing, and between the Gly ring and the rear bearing.

[0013] Furthermore, the gas entering the housing is sealed by the Gly ring, the O-ring, the first oil seal and the second oil seal.

[0014] Furthermore, the hydrogen rotary joint applicable to low temperature environments further includes a shaft retaining ring, the outer side of the rear bearing is limited by the shaft retaining ring, and the shaft retaining ring is located between the rear bearing and the second oil seal.

[0015] Furthermore, the materials of the O-ring and Gly ring are nitrile, EPDM or fluorosilicone rubber.

[0016] Furthermore, the core shaft has an inner hole along the central axis for installing a conductive slip ring or passing a wire.

[0017] Furthermore, the cylindricity of the core shaft for mounting the Gly ring and the O-ring meets grade 7 precision, and the surface roughness Ra value is not greater than 0.4 μm.

[0018] The advantages of the present invention compared with the prior art are:

[0019] (1) The present invention provides a hydrogen rotary joint, which is used in the fuel supply system of the Winter Olympics. It has a low leakage rate, reliable operation, and wide applicability: the hydrogen rotary joint proposed in the present invention can ensure a low leakage rate at both normal temperature and low temperature (-20°C) environments, and has a wide applicable temperature range; at the same time, since hydrogen is the smallest molecule in nature and has stronger permeability than other gases, the rotary joint is not only suitable for hydrogen, but can also be extended to other gas media, and has a wide range of applicable media.

[0020] (2) There are no hydrogen rotary joints in the domestic and foreign markets, and there are not even mature rotary joints that are applicable to combustible gases. Therefore, the hydrogen rotary joint proposed in the present invention fills the technical gap of domestic hydrogen sealed rotary joints and is a major technological innovation in the design and application of flammable and explosive rotary joints. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the structure of hydrogen rotary joint;

[0022] Among them: 1-core shaft, 2-first oil seal, 3-front bearing, 4-O-ring, 5-housing, 6-rear bearing, 7-shaft retaining ring, 8-second oil seal, 9-Glay ring, 10-first leakage observation hole, 11-second leakage observation hole

[0023] Figure 2 This is the appearance diagram of the hydrogen rotary joint. DETAILED DESCRIPTION

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0025] like Figure 1 、 2 As shown, a hydrogen rotary joint suitable for low-temperature environments includes: a core shaft 1, a housing 5, a front bearing 3, a rear bearing 6, a first oil seal 2, a second oil seal 8, an O-ring 4 and a Gly ring 9.

[0026] A gas inlet is provided in the sidewall of the housing 5, and an annular channel groove is provided on the inner wall of the housing 5 at the gas inlet location. The core shaft 1 is equipped with a front bearing 3 and a rear bearing 6, which support the housing 5 for stable rotation. After gas enters the rotary joint cavity through the gas inlet on the housing 5, it is first sealed by a Gly ring 9. If the Gly ring 9 fails, it is sealed by an O-ring 4. If the O-ring 4 fails, hydrogen leaks into the bearing cavities on both sides. The bearing cavities on both sides are respectively provided with a first leak detection hole 10 and a second leak detection hole 11. Gas concentration detectors can be installed through the first and second leak detection holes 10 and 11 to measure the hydrogen leakage rate, thereby detecting Gly ring and O-ring failure and determining the leakage of the seals. To prevent hydrogen from escaping into the atmosphere, a first oil seal 2 and a second oil seal 8 are installed on the outside of the front and rear bearings 3 and 6, respectively, isolating them from the outside air and ensuring the stable performance of the rotary joint. The outer side of the rear bearing 6 is limited by a shaft retaining ring 7 , and the shaft retaining ring 7 is located between the rear bearing 6 and the second oil seal 8 .

[0027] A first flow channel hole is formed on the side wall surface of the core shaft 1 located within the housing 5 (i.e., the inner surface of the core shaft), and a second flow channel hole is formed on the side wall surface located outside the housing 5 (i.e., the outer surface of the core shaft). The two flow channel holes are connected by a radial flow channel. The interior of the core shaft 1 is a hollow structure, with oil seals installed on both sides of the front and rear bearings, and an O-ring 4 and a Gly ring 9 installed between the two bearings. During operation, the core shaft 1 is connected to the rotating equipment, and the housing 5 is connected to the fixed equipment. During operation, hydrogen enters the rotary joint from the fixed housing 5, flows in through the flow channel hole on the inner surface of the core shaft, and flows out from the outer surface of the core shaft. Gly rings 9 and O-rings 4 are symmetrically provided at both ends of the channel groove of the housing 5. An inner hole is machined in the center of the rotary joint core shaft 1 for installing a conductive slip ring and other functions for passing wires.

[0028] Considering the high risk of leakage of small-molecule hydrogen, the hydrogen rotary joint utilizes a combined O-ring 4 and Glyd ring 9 to ensure good airtightness. To accommodate operating conditions ranging from ambient temperature to -30°C, the sealing ring must be cold-resistant and maintain high flexibility even in low-temperature environments. Materials such as nitrile, EPDM, or fluorosilicone rubber are recommended. To ensure smooth operation and a secure seal, the cylindricity of the elastomer (O-ring 4 and Glyd ring 9) mounting area on the core shaft 1 must meet GB / T 1184-1996d Grade 7 precision, with a surface roughness Ra value no greater than 0.4μm. To ensure good protection in outdoor working environments or dusty production workshops, the hydrogen rotary joint is equipped with an oil seal to isolate it from external dust and water mist. Because hydrogen is a flammable and explosive gas, it can explode when exposed to open flames when its volume content in air reaches 4% to 74.2%. Therefore, the hydrogen rotary joint is equipped with a leak detection hole, which, when combined with a hydrogen leak detection device, allows online monitoring of the joint's sealing condition.

[0029] The hydrogen rotary joint provided by the present invention, suitable for low-temperature environments, has been tested using helium for airtightness at ambient temperatures of 30°C, 0°C, -10°C, -15°C, and -20°C. At a medium pressure of 100kPa, the static airtightness test showed a pressure drop of less than 0.5% per hour. At a medium pressure of 100kPa and a rotational speed of 15RPM, the dynamic rotary airtightness test also achieved a pressure drop of less than 0.5% per hour at all temperatures. The protection level reaches IP65, meeting the requirements for use. This rotary joint is used in the fuel supply system of the Winter Olympics and has a low leakage rate and reliable operation.

[0030] Parts of the present invention that are not described in detail belong to the common knowledge of those skilled in the art.

Claims

1. A hydrogen rotary joint suitable for low temperature environment, characterized in that: include: A core shaft (1), a housing (5), a front bearing (3), a rear bearing (6), a first oil seal (2), a second oil seal (8), an O-ring (4) and a Gly ring (9); The side wall of the shell (5) is provided with a gas inlet, and the inner wall of the shell (5) is provided with an annular channel groove at the position of the gas inlet, and a plurality of sealing ring mounting grooves are respectively provided on both sides of the channel groove; The core shaft (1) is respectively mounted with a front bearing (3) and a rear bearing (6), and the housing (5) is sleeved on the core shaft (1) and supported by the front bearing (3) and the rear bearing (6); an O-ring (4) and a grid ring (9) are provided between the front bearing (3) and the rear bearing (6), and the O-ring (4) is located on the side of the grid ring (9) away from the annular channel groove on the inner wall of the housing (5); a first oil seal (2) and a second oil seal (8) are respectively provided on the outer sides of the front bearing (3) and the rear bearing (6); The core shaft (1) has a first flow channel hole on its side wall surface located in the shell (5), and a second flow channel hole on its side wall surface located outside the shell (5), and the two flow channel holes are connected through a flow channel along the radial direction; A first leakage detection hole (10) and a second leakage detection hole (11) are respectively provided on the housing (5) at the front bearing cavity and the rear bearing cavity, and a gas concentration detector is installed at the first leakage detection hole (10) and the second leakage detection hole (11) to detect the leakage rate of hydrogen; The core shaft (1) has an inner hole along the central axis for installing a conductive slip ring or passing a wire; The grid rings (9) are symmetrically arranged on both sides of the channel groove of the housing (5); The O-shaped sealing rings (4) are symmetrically arranged on both sides of the channel groove of the housing (5), and the O-shaped sealing rings (4) are respectively located between the grid ring (9) and the front bearing (3), and between the grid ring (9) and the rear bearing (6).

2. A hydrogen rotary joint suitable for low temperature environments according to claim 1, characterized in that: During operation, the core shaft (1) is connected to the rotating device, the shell (5) is connected to the fixed device, hydrogen enters from the gas inlet on the shell (5), flows in through the first flow channel hole on the core shaft (1), and flows out from the second flow channel hole on the core shaft (1).

3. The hydrogen rotary joint applicable to low temperature environment according to claim 1, characterized in that: The gas entering the housing (5) is sealed by the Gly ring (9), the O-ring (4), the first oil seal (2) and the second oil seal (8).

4. The hydrogen rotary joint applicable to low temperature environment according to claim 1, characterized in that: It also includes a shaft retaining ring (7), the outer side of the rear bearing (6) is limited by the shaft retaining ring (7), and the shaft retaining ring (7) is located between the rear bearing (6) and the second oil seal (8).

5. The hydrogen rotary joint applicable to low temperature environment according to claim 1, characterized in that: The materials of the O-ring (4) and the grid ring (7) are nitrile, EPDM or fluorosilicone rubber.

6. The hydrogen rotary joint applicable to low temperature environment according to claim 1, characterized in that: The cylindricity of the core shaft (1) used for mounting the Gly ring (9) and the O-ring (4) meets the 7th grade precision, and the surface roughness Ra value is not greater than 0.4 μm.

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