Sealing device for hydrogen gas sealing and hydrogen gas circulating pump for hydrogen fuel cell

Abstract

The utility model provides a sealing device for hydrogen sealing and a hydrogen circulating pump for a hydrogen fuel cell, which do not need a large occupied space and are low in cost. A sealing device (1) for hydrogen gas sealing is provided with: a reinforcing ring (2) having an annular shape centered on an axis (x); an elastic body part (3) which exposes the outer peripheral surface (21a) of the reinforcing ring (2) and covers the reinforcing ring (2); and an annular member (4) that is disposed on a seal lip (35) on the inner peripheral side of the elastic body part (3) and is made of a fluororesin material.

Description

Technical Field

[0001] The utility model relates to a sealing device for hydrogen sealing and a hydrogen circulation pump for a hydrogen fuel cell. Background Art

[0002] For example, in Chinese Patent Application Publication No. 116447138, a sealing structure assembled in a hydrogen circulation pump of a hydrogen fuel cell is disclosed. Utility Model Content

[0003] Issues to be Solved by Utility Models

[0004] The sealing structure has a complicated structure, thus requiring a large occupied space and being high in cost.

[0005] The present invention has been made in view of the above-mentioned problems, and its object is to provide a low-cost hydrogen sealing device that does not require a large occupied space.

[0006] Means for solving problems

[0007] In order to achieve the above-mentioned purpose, the sealing device for hydrogen sealing involved in the utility model includes: a reinforcement ring, which is ring-shaped with an axis as the center; an elastic body portion, which exposes the outer peripheral surface of the reinforcement ring and covers the reinforcement ring; and an annular component, which is arranged on the sealing lip on the inner peripheral side of the elastic body portion and is made of fluororesin material.

[0008] In the hydrogen sealing sealing device of the utility model, the fluororesin material is PTFE.

[0009] In the hydrogen sealing sealing device involved in the utility model, the elastic body part has: a radial cover covering the inner peripheral surface of the reinforcement ring; an axial cover covering the side surface of the reinforcement ring; and the sealing lip extending from the axial cover along the axial direction of the axis.

[0010] In the hydrogen sealing sealing device according to the present invention, the reinforcement ring is formed of stainless steel.

[0011] The utility model relates to a sealing device for hydrogen sealing, comprising a spring which is arranged on the outer peripheral side of the sealing lip and applies force to the sealing lip toward the inner peripheral side.

[0012] In the hydrogen gas sealing device according to the present invention, the spring is formed of stainless steel.

[0013] The utility model relates to a hydrogen circulation pump for a hydrogen fuel cell, comprising: a rotating shaft, which rotates around an axis; a shell, which has a through hole for inserting the rotating shaft; and a sealing device, which is used to seal between the rotating shaft and the through hole, wherein the sealing device comprises: a reinforcement ring, which is annular with the axis as the center; an elastic body, which exposes the outer peripheral surface of the reinforcement ring embedded in the through hole and covers the reinforcement ring; and an annular component, which is arranged on a sealing lip on the inner peripheral side of the elastic body sliding on the outer peripheral surface of the rotating shaft and is made of a fluororesin material.

[0014] Utility Model Effect

[0015] According to the present invention, a low-cost hydrogen gas sealing device that does not require a large occupied space can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a cross-sectional view schematically showing the structure of a sealing device 1 according to one embodiment of the present invention.

[0017] Figure 2 This is an enlarged end view of one of the sealing devices 1 schematically showing the structure of the sealing device 1 according to one embodiment of the present invention.

[0018] Figure 3 It is a cross-sectional view schematically showing the structure of a hydrogen circulation pump 60 to which the sealing device 1 is applied.

[0019] Figure 4 This is a cross-sectional view showing a usage state of the sealing device 1 according to one embodiment of the present invention.

[0020] Reference numerals:

[0021] 1 sealing device, 2 reinforcing ring, 3 elastic body, 4 annular member, 5 spring, 21 cylindrical portion, 21a outer peripheral surface, 21b inner peripheral surface, 22 flange portion, 22a side surface, 22b side surface, 21c step, 23 first portion, 24 second portion, 25 third portion, 26 fourth portion, 31 radial cover, 32 axial cover, 33 lip portion, 34 lip waist portion, 35 sealing lip, 35a groove, 36 lip front end portion, 37 lip front end portion, 38 sealing side surface, 39 air Body side surface, 60 hydrogen circulation pump, 61 motor housing, 62 pump housing, 62a pump chamber, 62b gear chamber, 63 motor, 64 rotating shaft, 64a outer peripheral surface, 65 rotor, 66 stator, 67, 68, 69 bearings, 70 rotating shaft, 71 bearings, 73, 74 gears, 75, 76 rotors, 77, 78, 79 through holes, 77a inner peripheral surface, 77b end surface, FS first side, SS second side, OC outer peripheral side, IC inner peripheral side, x axis line. DETAILED DESCRIPTION

[0022] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Figure 1 This is a cross-sectional view schematically showing the structure of a sealing device 1 according to one embodiment of the present invention. Figure 1 : is a cross-sectional view of the sealing device 1 along the axis x. As described later, the sealing device 1 involved in the utility model is assembled in, for example, a hydrogen circulation pump or the like for resupplying unreacted hydrogen discharged from a fuel cell stack assembled in a fuel cell vehicle to the fuel cell stack. Specifically, as described later, the sealing device 1 is used in the hydrogen circulation pump or the like to seal between a rotating shaft and a housing having a through hole for inserting the rotating shaft. The sealing device 1 is a sealing device for hydrogen sealing.

[0023] In the drawings, for convenience of explanation, one side in the direction along the axis x (hereinafter referred to as the "axial direction") is defined as a first side FS, and the other side opposite to the one side in the axial direction is defined as a second side SS. As described later, the first side FS is a gas side where a gas such as hydrogen exists, and the second side SS is a liquid side where a liquid such as a lubricant exists. In addition, in a direction orthogonal to the axis x (hereinafter referred to as the "radial direction"), the direction away from the axis x is defined as an outer peripheral side OC, and the direction close to the axis x is defined as an inner peripheral side IC. In addition, the direction around the axis x is defined as a circumferential direction.

[0024] Figure 2 FIG. 1 is an enlarged end view of one side of the sealing device 1 schematically showing the structure of the sealing device 1. Figure 1 and Figure 2 The sealing device 1 includes a reinforcement ring 2 and an elastic body portion 3 formed integrally with the reinforcement ring 2. The reinforcement ring 2 and the elastic body portion 3 are both formed into a circular ring shape centered on the axis x. The reinforcement ring 2 has an annular cylindrical portion 21 extending in the axial direction and an annular flange portion 22 extending from the cylindrical portion 21 to the inner circumference IC on the second side SS. The cylindrical portion 21 is formed as a whole into a cylindrical shape with the axis x as the central axis. In this example, the flange portion 22 is formed by bending the end of the second side SS of the cylindrical portion 21 in the radial direction.

[0025] The cylindrical portion 21 has a first portion 23 formed in a cylindrical shape and a second portion 24 in a truncated cone shape extending from the end portion of the first side FS of the first portion 23 toward the first side FS and the inner circumference IC. The second portion 24 is formed by bending the end portion of the first side FS of the first portion 23 toward the inner circumference IC. The cylindrical portion 21 as a whole has an outer circumferential surface 21a and an inner circumferential surface 21b facing each other in the radial direction. The outer circumferential surface 21a is a surface facing the outer circumferential side OC, and the inner circumferential surface 21b is a surface facing the inner circumferential side IC. The outer circumferential surface 21a extends from the first portion 23 to the second portion 24. Similarly, the inner circumferential surface 21b extends from the first portion 23 to the second portion 24.

[0026] The flange portion 22 has a side surface 22a and a side surface 22b which face each other in the axial direction. The side surface 22a is a surface facing the first side FS, and the side surface 22b is a surface facing the second side SS. The side surface 22b is connected to the outer peripheral surface 21a, and on the other hand, the side surface 22a is connected to the inner peripheral surface 21b. By forming a step 22c on the flange portion 22, steps are also formed on the side surfaces 22a and 22b. The step 22c extends in an annular shape around the axis x. In this example, the flange portion 22 is divided into a third portion 25 on the outer peripheral side OC and a fourth portion 26 arranged on the inner peripheral side IC closer to the first side FS than the third portion 25 by the step 22c.

[0027] The elastomer portion 3 includes a radial cover 31 partially covering the cylindrical portion 21, an axial cover 32 partially covering the flange portion 22, and a sealing portion 33 extending axially from the axial cover 32 toward the first side FS. The radial cover 31 extends axially from the end of the first side FS of the cylindrical portion 21 to the first side FS along the inner peripheral surface 21b of the cylindrical portion 21 of the reinforcement ring 2. In this way, the radial cover 31 covers the cylindrical portion 21 of the reinforcement ring 2 from the inner peripheral side IC. Most of the second portion 24 of the cylindrical portion 21 is buried in the radial cover 31. On the other hand, the reinforcement ring 2 exposes the outer peripheral surface 21a in the region of the first portion 23 of the cylindrical portion 21. In this example, the outer diameter of the outer peripheral surface 21a of the first portion 23 is set to be substantially the same as or smaller than the outer diameter of the outer peripheral surface of the radial cover 31 in the region extending from the cylindrical portion 21 to the first side FS.

[0028] The axial cover 32 extends radially from the end of the second side SS of the radial cover 31. Specifically, the axial cover 32 extends as a whole along the side surface 22a of the flange portion 22 of the reinforcement ring 2. However, in this example, the fourth portion 26 of the flange portion 22 is buried in the axial cover 32. On the other hand, the flange portion 22 exposes the side surface 22b in the region of the third portion 25. Therefore, in this example, the reinforcement ring 2 exposes the outer peripheral surface 21a of the first portion 23 of the cylindrical portion 21 in the radial direction, and exposes the side surface 22b of the third portion 25 of the flange portion 22 in the axial direction. The axial cover 32 is formed integrally with the radial cover 31.

[0029] The sealing portion 33 includes a lip waist portion 34 and a sealing lip 35 extending from the lip waist portion 34 toward the first side FS in the axial direction. The lip waist portion 34 is a portion located near the end portion on the inner circumference side IC of the fourth portion 26 of the flange portion 22 of the reinforcement ring 2. The sealing lip 35 includes a wedge-shaped lip front end portion 36 protruding toward the inner circumference side IC on the inner circumference side IC thereof. The lip front end portion 36 is located on the innermost circumference side IC in a lip front end 37 that describes a circle centered on the axis x in a plane orthogonal to the axis x. The sealing lip 35 is formed so that, in a state of use, the vicinity of the lip front end 37 is in close contact with the outer circumference surface of the rotating shaft in a slidable manner.

[0030] The lip front end portion 36 defines an annular sealing side surface 38 facing the second side SS and an annular gas side surface 39 facing the first side FS, which are connected by the lip front end 37. The sealing side surface 38 is a conical surface in the shape of a truncated cone that decreases in diameter in the axial direction toward the first side FS. In addition, the gas side surface 39 is a conical surface in the shape of a truncated cone that decreases in diameter in the axial direction toward the second side SS. The lip front end 37 is formed at the intersection of the sealing side surface 38 and the gas side surface 39. As described later, the sealing portion 33 is formed integrally with the radial cover 31 and the axial cover 32.

[0031] The lip front end portion 36 has an annular component 4 arranged along the sealing side surface 38 from the lip front end 37. The annular component 4 is formed into an annular shape centered on the axis x. The lip front end 37 is formed by the annular component 4. That is, the annular component 4 is configured to slide on the outer peripheral surface of the rotating shaft. In this example, the annular component 4 extends from the lip front end 37 along the sealing side surface 38 to the vicinity of the lip waist portion 34. The annular component 4 has a substantially uniform thickness in the radial direction. As described later, the annular component 4 is formed integrally with the sealing portion 33, i.e., the elastomer portion 3.

[0032] The sealing device 1 includes an annular spring 5 mounted on an annular groove 35a on the outer peripheral side of the sealing lip 35. The spring 5 is disposed, for example, at a position opposite to the lip front end 37 in the radial direction across the sealing lip 35. The spring 5 applies force to the lip front end 36, i.e., the lip front end 37, toward the inner peripheral side IC. In this way, the spring 5 applies a tightening force of a predetermined magnitude, for example, relative to the outer peripheral surface of the rotating shaft to the lip front end 36, i.e., the lip front end 37. In addition, in this example, the spring 5 is radially opposite to the end of the first side FS of the second portion 24 of the reinforcement ring 2.

[0033] The reinforcement ring 2 is manufactured, for example, by stamping or forging of a metal material. The metal material includes, for example, stainless steel. The elastomer portion 3 is formed, for example, by an elastic resin material. The elastic resin material includes, for example, synthetic rubbers such as nitrile rubber (NBR), hydrogenated nitrile rubber (H-NBR), acrylic rubber (ACM), and fluororubber (FKM). The elastomer portion 3 is formed, for example, by crosslinking (vulcanization) molding using a molding die equipped with the reinforcement ring 2 and the annular component 4. In this way, the elastomer portion 3 and the annular component 4 are formed integrally with the reinforcement ring 2. The annular component 4 is formed, for example, by a fluororesin material. The fluororesin material includes, for example, PTFE (polytetrafluoroethylene). The spring 5 is formed, for example, by a metal material such as stainless steel.

[0034] Next, the operation of the sealing device 1 will be described below. Figure 31 is a cross-sectional view schematically showing the structure of a hydrogen circulation pump 60 as an application object of the sealing device 1. The hydrogen circulation pump 60 is assembled in a hydrogen fuel cell, for example. The hydrogen fuel cell includes, for example: a fuel cell stack that generates electricity by reacting oxygen with hydrogen; an air compressor that supplies oxygen to the fuel cell stack; a high-pressure hydrogen tank that supplies hydrogen to the fuel cell stack; a gas-liquid separation device that separates water discharged from the fuel cell stack from unreacted hydrogen; and a hydrogen circulation pump 60 that supplies unreacted hydrogen to the fuel cell stack. The hydrogen circulation pump 60 is a pump for returning unreacted hydrogen separated from water by the gas-liquid separation device to the fuel cell stack.

[0035] The hydrogen circulation pump 60 has a motor housing 61 and a pump housing 62 mounted on the motor housing 61. A motor 63 is arranged in the motor housing 61. The motor 63 has a rotor 65 fixed to a rotating shaft 64 and a stator 66 fixed to the motor housing 61. The rotating shaft 64 extends from the motor housing 61 to the pump housing 62. One end of the rotating shaft 64 is rotatably supported in the motor housing 61 via a bearing 67, and on the other hand, the other end of the rotating shaft 64 is rotatably supported in the pump housing 62 via a bearing 68. In addition, between one end and the other end, the rotating shaft 64 is supported by a pair of bearings 69, for example. The rotating shaft 64 can rotate around its axis through the magnetic interaction between the permanent magnet of the rotor 65 and the coil of the stator 66.

[0036] A pump chamber 62a and a gear chamber 62b are defined in the pump housing 62. A rotating shaft 70 extending parallel to the rotating shaft 64 is arranged in the pump housing 62. The rotating shaft 70 extends from the gear chamber 62b into the pump chamber 62a. The rotating shaft 70 is supported in the pump housing 62 in a rotatable manner via a pair of bearings 71 and bearings 71 in the gear chamber 62b. Specifically, the rotating shaft 70 is cantilevered by a pair of bearings 71 and bearings 71. In the gear chamber 62b, a gear 73 and a gear 74 are respectively installed on the rotating shaft 64 and the rotating shaft 70. The gear 73 and the gear 74 mesh with each other. As a result, the rotation around the axis of the rotating shaft 64 is transmitted to the rotating shaft 70. In this way, the rotating shaft 70 can rotate around its axis. In addition, a liquid such as a lubricant such as grease is filled in the gear chamber 62b.

[0037] The pump chamber 62a is connected to the fuel cell stack. In the pump chamber 62a, a driving rotor 75 and a driven rotor 76 are respectively installed on the rotating shaft 64 and the rotating shaft 70. The driving rotor 75 is rotated by the rotation of the rotating shaft 64, and the rotating shaft 70 is rotated based on the rotation of the rotating shaft 64, thereby rotating the driven rotor 76. As a result, the unreacted hydrogen sucked into the pump chamber 62a from the fuel cell stack is discharged from the pump chamber 62a toward the fuel cell stack. In this example, the above-mentioned sealing device 1 is applied to the through holes 77, 78 of the pump housing 62 in which the rotating shafts 64, 70 are arranged between the pump chamber 62a and the gear chamber 62b, and the through hole 79 of the pump housing 62 that connects the gear chamber 62b with the space in the motor housing 61.

[0038] Figure 4 2 is a cross-sectional view showing the usage of the sealing device 1. Figure 4 , a scene is shown in which the sealing device 1 is used to seal the through hole 77 between the pump chamber 62a and the gear chamber 62b. Specifically, the sealing device 1 is installed on the inner peripheral surface 77a of the through hole 77 by fitting (pressing). The outer peripheral surface 21a of the first part 23 of the reinforcement ring 2 and the outer peripheral surface of the radial cover 31 of the elastomer portion 3 are in close contact with the inner peripheral surface 77a. In this example, the sealing device 1 further abuts against the end surface 77b of the first side FS of the through hole 77 through the radial cover 31. On the other hand, the lip front end 37 contacts the outer peripheral surface 64a of the rotating shaft 64. If the rotating shaft 64 rotates around the axis x, the lip front end 37 slides on the outer peripheral surface 64a of the rotating shaft 64. In this way, the hydrogen in the pump chamber 62a and the fluid such as the lubricant in the gear chamber 62b are sealed.

[0039] In the sealing device 1 described above, the outer peripheral surface 21a of the first portion 23 of the cylindrical portion 21 of the reinforcement ring 2 is exposed, while the cylindrical portion 21 is covered by the elastic body portion 3 from the inner peripheral side IC. According to such a structure, the sealing device 1 can be easily installed in the through hole 77 by installing it on the inner peripheral surface 77a of the through hole 77 by press-fitting. The sealing device 1 has a simple structure composed of the reinforcement ring 2, the elastic body portion 3 formed integrally with the reinforcement ring 2, and the annular member 4, so the space occupied by the sealing device 1 can be reduced compared with the past. In addition, since the number of parts is small, the assembly cost of the sealing device 1 can be reduced.

[0040] Moreover, the annular component 4 is arranged in the vicinity of the lip front end 37 in the sealing lip 35 of the elastomer portion 3. The annular component 4 is formed of a fluororesin material, namely PTFE. In addition, the reinforcement ring 2 and the spring 5 are formed of metal materials such as stainless steel. For example, when the sealing device 1 is assembled in the hydrogen circulation pump 60, the sealing device 1 is exposed to water (water vapor), hydrogen, etc. The annular component 4, the reinforcement ring 2, and the spring 5 have excellent corrosion resistance and are therefore not affected by corrosion under such conditions. Moreover, since the annular component 4 has excellent wear resistance, even when the lip front end 37 slides on the outer peripheral surface 64a of the rotating shaft 64, the influence of wear can be suppressed.

[0041] The present invention has been described above by the above embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments. It should be understood by those skilled in the art that various changes or improvements can be made to the above embodiments. It can be seen from the description of the claims that the method to which such changes or improvements are made can also be included in the technical scope of the present invention.

[0042] The above-described embodiments are used to facilitate understanding of the present invention, and are not used to limit the interpretation of the present invention. In addition, the above-described embodiments do not limit the objects of use utilized by the present invention, and the present invention may include all of them as its objects of use. The various components and their configurations, materials, conditions, shapes, and sizes possessed by the above-described embodiments are not limited to the illustrated contents, and may be appropriately changed. For example, the present invention includes differences arising from the implementation of manufacturing tolerances, etc. In addition, within the scope of technical non-contradiction, the components shown in different embodiments may be partially replaced or combined with each other. In addition, the various structures may be appropriately and selectively combined in a manner that achieves at least a portion of the above-mentioned topics and effects.

Claims

1. A sealing device for hydrogen sealing, characterized in that: include: A reinforcing ring, which is in a ring shape with the axis as the center; an elastic body portion, exposing the outer peripheral surface of the reinforcement ring and covering the reinforcement ring; as well as The annular member is arranged on the sealing lip on the inner peripheral side of the elastic body portion and is made of a fluororesin material.

2. The hydrogen sealing device according to claim 1, characterized in that: The fluororesin material is PTFE.

3. The hydrogen sealing device according to claim 1 or 2, characterized in that: The elastic body portion has: A radial cover covering the inner circumference of the reinforcement ring; an axial cover covering the side surfaces of the reinforcement ring; and The sealing lip extends from the axial cover in the axial direction of the axis.

4. The hydrogen sealing device according to claim 1, characterized in that: The reinforcement ring is formed of stainless steel.

5. The hydrogen sealing device according to claim 1, characterized in that: include: The spring is disposed on the outer peripheral side of the seal lip and urges the seal lip toward the inner peripheral side.

6. The hydrogen sealing device according to claim 5, characterized in that: The spring is formed from stainless steel.

7. A hydrogen circulation pump for a hydrogen fuel cell, characterized in that: include: Axis of rotation, rotation around an axis; A housing having a through hole for inserting the rotating shaft; as well as A sealing device, used for sealing between the rotating shaft and the through hole, The sealing device comprises: A reinforcing ring, which is ring-shaped with the axis as the center; an elastic body portion, exposing an outer peripheral surface of the reinforcement ring fitted in the through hole and covering the reinforcement ring; as well as The annular member is disposed on a seal lip on the inner peripheral side of the elastic body portion that slides on the outer peripheral surface of the rotating shaft, and is made of a fluororesin material.

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