Non-contact shaft sealing structure of hydrogen circulating pump for fuel cell

Abstract

The utility model relates to the technical field of shaft sealing of hydrogen circulating pumps, in particular to a non-contact type shaft sealing structure of a hydrogen circulating pump for a fuel cell. Comprising a shaft, a shaft sleeve fixed to the shaft, a shell of the hydrogen circulating pump and a sealing assembly. The sealing assembly sleeves the shaft sleeve, is in clearance fit with the shaft sleeve, and is fixed on the shell through interference fit with the shell; the inner ring of the sealing assembly is provided with a first internal thread with the rotating direction opposite to the rotating direction of the shaft. The sealing assembly comprises a first sealing piece and a second sealing piece which are sequentially arranged in the permeation direction of water on the shaft sleeve. The first internal thread is arranged on the inner ring of the first sealing piece, and the inner ring of the second sealing piece is provided with a second internal thread; water is prevented from flowing into the motor end or the pump head end through cooperation of the first sealing piece, the second sealing piece and the breathable water-blocking membrane, and the water-blocking effect can be well achieved through the triple water-blocking structure.

Description

TECHNICAL FIELD

[0001] The utility model relates to hydrogen circulation pump shaft sealing technical field especially relates to a fuel cell hydrogen circulation pump non -contact type's shaft sealing structure. BACKGROUND

[0002] Fuel cell is a kind of clean and high efficiency energy, fuel cell is carried out electrochemical reaction by hydrogen and oxygen (air) such oxidant, and chemical energy is converted into electric energy.As the function of hydrogen circulation pump, the subcomponent of fuel cell system, is to transport the hydrogen that is not completely utilized in fuel cell system back to fuel cell system again, improves the utilization efficiency of hydrogen.The existing hydrogen circulation pump is used in passenger car and commercial vehicle process, and water is generated in the process of electric discharge in the chemical reaction of stack hydrogen and oxygen, part of water flows along with circulation system, when liquid water circulates to hydrogen circulation pump, due to the problem of the internal dynamic sealing effect of hydrogen circulation pump is not ideal, liquid water flows into motor end and pump head end, this phenomenon increases the failure rate of motor and bearing, and influences the service life of hydrogen circulation pump.

[0003] Figure 1 For the shaft sealing structure in the prior art, the oil seal with double lip or single lip directly contacts with the shaft sleeve to seal, the lip material is PTFE or other plastic material with good sealing performance, after hydrogen circulation pump works for a period of time, the characteristics of plastic material appear, long-time wear causes the damage of lip and generates particulate matter, particulate matter is easy to flow into the flow channel of stack and cause blockage, meanwhile, the sealing performance is damaged, liquid water flows into motor end and pump head end, causing the service life of motor and bearing to be shortened, and the existing sealing structure needs to be smeared with grease for lubrication before installation, which does not meet the oil-free requirement of fuel cell. UTILITY MODEL CONTENTS

[0004] The utility model aims at providing a fuel cell hydrogen circulation pump non -contact type's shaft sealing structure to solve the related problems caused by the sealing ring with double lip or single lip directly contacting with the shaft sleeve in the prior art.

[0005] The technical scheme of the utility model is: a fuel cell hydrogen circulation pump non -contact type's shaft sealing structure, comprising: shaft, shaft sleeve fixed on the shaft, hydrogen circulation pump shell, sealing assembly;The sealing assembly is sleeved on the shaft sleeve and matched with the gap of the shaft sleeve, and is fixed on the shell by interference fit with the shell;The inner ring of the sealing assembly is provided with first internal thread with rotation direction opposite to the rotation direction of the shaft.

[0006] Preferably, the sealing assembly comprises a first sealing element and a second sealing element arranged in sequence along the permeation direction of water on the shaft sleeve; the first internal thread is arranged on the inner ring of the first sealing element, and the inner ring of the second sealing element is provided with a second internal thread;

[0007] The body of the second sealing element is provided with a plurality of air holes along the axial direction thereof, and a gas-permeable water-blocking diaphragm is arranged between the first sealing element and the second sealing element to block the plurality of air holes.

[0008] The body of the first sealing element is provided with a plurality of drainage holes at the position opposite to the gas-permeable water-blocking diaphragm, and the outer ring of the first sealing element is concavely provided with an annular drainage groove, and the plurality of drainage holes are in communication with the drainage groove.

[0009] Preferably, the end face of the second sealing element axially close to the first sealing element is protrusively provided with an annular boss, and the orifices of the plurality of air holes are located on the end face of the boss.

[0010] The first sealing element is provided with an annular groove matching the boss, and a water storage groove is concavely arranged on the groove bottom of the annular groove as a starting point, and the drainage holes are arranged on the groove bottom of the annular groove and the water storage groove.

[0011] The gas-permeable water-blocking diaphragm is arranged between the boss and the annular groove.

[0012] Preferably, the first sealing element, the second sealing element and the shell are respectively provided with a first sealing ring and a second sealing ring.

[0013] Preferably, the outer ring of the first sealing element is concavely provided with an annular first mounting groove for mounting the first sealing ring, and the outer ring of the second sealing element is concavely provided with an annular second mounting groove for mounting the second sealing ring.

[0014] Preferably, the first internal thread is a rectangular thread or a triangular thread.

[0015] Preferably, the second internal thread is a fine thread.

[0016] Compared with the prior art, the utility model has the advantages that:

[0017] (1) The non-contact shaft sealing structure of the hydrogen circulating pump for the fuel cell in the embodiment one of the utility model, comprising: a shaft, a shaft sleeve fixed on the shaft, a shell of the hydrogen circulating pump, a sealing assembly; the sealing assembly is sleeved on the shaft sleeve and gap fits with the shaft sleeve, and is fixed on the shell through interference fit with the shell; the inner ring of the sealing assembly is provided with a first internal thread with the rotation direction opposite to that of the shaft; the first internal thread with the rotation direction opposite to that of the shaft on the inner ring of the sealing assembly can block water in the compression cavity body and not flow from the gap between the sealing assembly and the shaft sleeve; the water blocking effect is obvious, and the practicability is strong.

[0018] (2) The utility model discloses a kind of fuel cell hydrogen circulation pumps non-contact shaft seal structure in the second embodiment, sealing assembly includes first sealing piece, second sealing piece sequentially arranged along the permeation direction of water on the sleeve;First internal thread is arranged on the inner ring of first sealing piece, and the inner ring of second sealing piece is provided with second internal thread;Breathable water-blocking diaphragm is clamped between first sealing piece and second sealing piece;Water flows into motor end or pump head end by first sealing piece, second sealing piece, breathable water-blocking diaphragm cooperation prevents, triple water-blocking structure, can very good realize water-blocking effect.

[0019] (3) The utility model discloses a kind of fuel cell hydrogen circulation pumps non-contact shaft seal structure, since sleeve rotates along with shaft, sealing assembly and sleeve gap cooperation, it is non-contact structure, without friction, without holding force, torque is small, power consumption is low, no particulate matter enters the flow channel of electric pile, simultaneously since it is non-contact structure, grease lubrication is not needed, meet the oil-free requirement of fuel cell to hydrogen circulation pump. BRIEF DESCRIPTION OF DRAWINGS

[0020] The utility model will be further described below in connection with the drawings and embodiment:

[0021] Figure 1 For the shaft seal structure in the prior art;

[0022] Figure 2 It is the cross-sectional structure schematic diagram of a kind of fuel cell hydrogen circulation pumps non-contact shaft seal structure described in embodiment one;

[0023] Figure 3 It is the cross-sectional structure schematic diagram of a kind of fuel cell hydrogen circulation pumps non-contact shaft seal structure described in embodiment two;

[0024] Figure 4 It is the explosion structure schematic diagram of first sealing piece, second sealing piece, breathable water-blocking diaphragm described in embodiment two;

[0025] Figure 5 It is the cross-sectional structure schematic diagram of first sealing piece described in embodiment two;

[0026] Figure 6 It is the water flow path schematic diagram of a kind of fuel cell hydrogen circulation pumps non-contact shaft seal structure described in embodiment two;

[0027] Figure 7 It is Figure 6 The enlarged structure schematic diagram of place A in the;

[0028] The components are: 1. Shaft, 2. Bushing, 3. Housing, 4. Sealing assembly, 5. First internal thread, 6. First seal, 7. Drain hole, 8. Drain groove, 9. Ring groove, 10. Water storage tank, 11. Second seal, 12. Second internal thread, 13. Vent hole, 14. Boss, 15. Breathable and water-blocking diaphragm, 16. First mounting groove, 17. Second mounting groove, 18. Compression chamber, 19. Drain through hole. Detailed Implementation

[0029] The present invention will be further described in detail below with reference to specific embodiments:

[0030] In the description of the utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the device 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 on the utility model.

[0031] Example 1

[0032] like Figure 2 As shown, a non-contact shaft seal structure for a hydrogen circulation pump for a fuel cell includes: a shaft 1, a bushing 2 fixed on the shaft 1, a housing 3 of the hydrogen circulation pump, and a sealing assembly 4; the sealing assembly 4 is sleeved on the bushing 2 with a clearance fit and is fixed on the housing 3 by an interference fit; the inner ring of the sealing assembly 4 is provided with a first internal thread 5 whose rotation direction is opposite to that of the shaft 1.

[0033] In this embodiment, after the hydrogen circulation pump is powered on, because the sealing component 4 and the housing 3 are interference-fitted, water entering with hydrogen from the hydrogen circulation pump inlet will not flow in between the sealing component 4 and the housing 3. The first internal thread 5 on the inner ring of the sealing component 4, which rotates in the opposite direction to the rotation direction of the shaft 1, can block water from entering the compression chamber 18 and prevent it from flowing in through the gap between the sealing component 4 and the bushing 2. Since the bushing 2 rotates with the shaft 1, the sealing component 4 and the bushing 2 are clearance-fitted, forming a non-contact structure with no friction, no clamping force, low torque, low power consumption, and no particulate matter entering the stack flow channel. At the same time, because it is a non-contact structure, no grease lubrication is required, thus meeting the oil-free requirement of the fuel cell for the hydrogen circulation pump.

[0034] Example 2

[0035] like Figure 3As shown in the figure, a kind of non-contact shaft sealing structure of hydrogen circulating pump for fuel cell, comprising: shaft 1, fixed on the shaft sleeve 2, the shell 3 of hydrogen circulating pump, sealing assembly 4;Sealing assembly 4 is set on the shaft sleeve 2 and gap fits with shaft sleeve 2, and fixed on the shell 3 by interference fit with shell 3;First internal thread 5 is arranged on the inner ring of sealing assembly 4, and the inner ring of second sealing element 11 is provided with second internal thread 12.

[0036] As shown in the figure, Figure 3 , Figure 4 Sealing assembly 4 includes first sealing element 6, second sealing element 11 arranged in turn along the permeation direction of water on shaft sleeve 2;First internal thread 5 is arranged on the inner ring of first sealing element 6, and the inner ring of second sealing element 11 is provided with second internal thread 12;First internal thread 5 is rectangular thread or triangular thread, and second internal thread 12 is fine thread;A plurality of air holes 13 are formed in the body of second sealing element 11 along the direction of penetration (as shown in the figure, Figure 4 ), and air and water blocking diaphragm 15 is clamped between first sealing element 6 and second sealing element 11 to block a plurality of air holes 13;As shown in the figure, Figure 5 A plurality of drainage holes 7 are formed in the body of first sealing element 6, and annular drainage groove 8 is formed in the outer ring of first sealing element 6, and a plurality of drainage holes 7 are communicated with drainage groove 8. The end face of second sealing element 11 axially close to first sealing element 6 is provided with annular boss 14, and the orifice of a plurality of air holes 13 is located on the end face of boss 14;First sealing element 6 is provided with annular groove 9 matched with boss 14 corresponding to boss 14, and water storage groove 10 is formed in the groove bottom of annular groove 9 as a starting point, and drainage hole 7 is formed in the groove bottom of annular groove 9 and water storage groove 10;Air and water blocking diaphragm 15 is clamped between boss 14 and annular groove 9. In the embodiment, air and water blocking diaphragm 15 is PTFE air permeable diaphragm, and there are many micropores on the PTFE air permeable diaphragm, so the diaphragm is air permeable but not water permeable. Because the flow direction of gas is consistent with the flow direction of water, air and water blocking diaphragm 15 can make gas flow into the motor, so as to ensure the stability of the air pressure in the motor.

[0037] First sealing ring and second sealing ring are respectively arranged between first sealing element 6, second sealing element 11 and shell 3. Annular first mounting groove 16 for mounting first sealing ring is formed in the outer ring of first sealing element 6, and annular second mounting groove 17 for mounting second sealing ring is formed in the outer ring of second sealing element 11.

[0038] In this embodiment, after the hydrogen circulation pump is powered on, because the first seal 6, the second seal 11, and the housing 3 are interference-fitted, water entering with hydrogen from the hydrogen circulation pump's inlet will not flow in between the first seal 6, the second seal 11, and the housing 3; the first internal thread 5 on the inner ring of the sealing assembly 4, whose rotation direction is opposite to that of the shaft 1, can block water from flowing into the compression chamber 18, preventing it from flowing in through the gap between the first seal 6, the second seal 11, and the bushing 2; to ensure a better water-blocking effect, such as Figure 6 , Figure 7 As shown, if water enters the first internal thread 5 of the first seal 6, the water flow is blocked because the breathable water-blocking diaphragm 15 allows air to pass through but not water. After a long period of water accumulation, the water tank 10 accumulates a certain amount of water, and the water flows into the drainage trough 8 from the drain hole 7. Under the action of gravity, the water flows down the drainage trough 8. A drainage through hole 19 is opened on the housing 3 corresponding to the drainage trough 8, which connects to the compression chamber 18. In this way, the water in the drainage trough 8 flows into the compression chamber 18 through the drainage through hole 19, and is finally discharged through the drainage structure of the hydrogen circulation pump itself. In order to ensure a better water blocking effect, if a very small amount of water continues to flow in, the fine thread of the second seal 11 will generate resistance to the water and further block the water. The first seal 6, the second seal 11, and the breathable water-blocking diaphragm 15 work together to prevent water from flowing into the motor end or the pump head end. In this embodiment, since the bushing 2 rotates with the shaft 1, the first seal 6 and the second seal 11 are clearance-fitted with the bushing 2, forming a non-contact structure with no friction, no clamping force, low torque, low power consumption, and no particulate matter entering the stack flow channel. At the same time, since it is a non-contact structure, it does not require grease lubrication, thus meeting the oil-free requirement of the hydrogen circulation pump for fuel cells.

[0039] The above embodiments are only for illustrating the technical concept and features of this utility model, and are intended to enable those skilled in the art to understand the content of this utility model and implement it accordingly. They should not be construed as limiting the scope of protection of this utility model. It is obvious to those skilled in the art that this utility model is not limited to the details of the above exemplary embodiments, and that it can be implemented in other specific forms without departing from the spirit or basic characteristics of this utility model. Therefore, the embodiments should be considered exemplary and non-limiting in all respects. The scope of this utility model is defined by the appended claims rather than the foregoing description, and therefore, all changes falling within the meaning and scope of the equivalents of the claims are intended to be included within this utility model.

Claims

1. A non-contact shaft seal structure for a hydrogen circulation pump for a fuel cell, characterized by The utility model relates to a sealing assembly of hydrogen circulation pump, including: Shaft, the shaft sleeve fixed on the shaft, the casing of hydrogen circulation pump, sealing assembly, sealing assembly is set on the shaft sleeve and cooperates with the shaft sleeve gap, and is fixed on the casing through the interference fit with the casing, the inner ring of sealing assembly is provided with the first internal thread of the rotation direction opposite with the rotation direction of shaft.

2. The non-contact shaft sealing structure for a hydrogen circulation pump of a fuel cell according to claim 1, characterized in that: The sealing assembly includes a first seal and a second seal arranged in sequence along the direction of water penetration on the shaft sleeve; the first internal thread is arranged on the inner ring of the first seal, and the inner ring of the second seal is provided with a second internal thread; A plurality of air holes are formed through the body of the second seal along the axial direction thereof, and a gas-permeable water-blocking diaphragm is clamped between the first seal and the second seal to block the plurality of air holes; A plurality of drainage holes are formed in the body of the first seal opposite to the gas-permeable water-blocking diaphragm, and an annular drainage groove is formed in the outer ring of the first seal; the plurality of drainage holes are in communication with the drainage groove.

3. The non-contact shaft seal structure for a hydrogen circulation pump of a fuel cell according to claim 2, characterized in that: An annular boss is protrusively arranged on the end face of the second seal close to the first seal, and the orifices of the plurality of air holes are located on the end face of the boss; An annular groove is arranged in the first seal corresponding to the boss and in conformance with the boss, a water storage groove is formed in the groove bottom of the annular groove as a starting point, and the drainage holes are formed in the groove bottom of the annular groove and the water storage groove; The gas-permeable water-blocking diaphragm is clamped between the boss and the annular groove.

4. The non-contact shaft sealing structure for a hydrogen circulation pump of a fuel cell according to claim 2, characterized in that: First and second sealing rings are respectively arranged between the first and second seals and the casing.

5. The non-contact shaft sealing structure for a hydrogen circulation pump of a fuel cell according to claim 4, characterized in that: An annular first mounting groove for mounting the first sealing ring is formed in the outer ring of the first seal, and an annular second mounting groove for mounting the second sealing ring is formed in the outer ring of the second seal.

6. The non-contact shaft sealing structure for a hydrogen circulation pump of a fuel cell according to claim 1, characterized in that: The first internal thread is a rectangular thread or a triangular thread.

7. The non-contact shaft sealing structure for a hydrogen circulation pump of a fuel cell according to claim 2, characterized in that: The second internal thread is a fine thread.

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