Hydrogen circulating pump with pressure balance system structure

Abstract

The application relates to the technical field of hydrogen circulating pumps, in particular to a hydrogen circulating pump with a pressure balance system structure, which comprises a transmission shaft, a rotor component, a driving motor, a gear component and a pressure balance component; wherein the transmission shaft comprises a driving shaft and a driven shaft; the rotor component, the driving motor and the gear component are sequentially distributed along the axial direction of the transmission shaft and are sequentially arranged in a gas compression cavity, a motor cavity and a gear cavity; the pressure balance component is arranged between the gas compression cavity and the motor cavity and balances the pressure in the gas compression cavity and the motor cavity. The motor cavity is arranged between the gas compression cavity and the gear cavity, and the pressure balance component is arranged, so that the pressure difference problem caused by the dynamic sealing failure of the structure is solved while the static sealing of the structure is ensured, dynamic pressure balance is realized, internal medium flow caused by the pressure difference is avoided, and the working performance of the structure is maximally guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydrogen circulating pumps, in particular to a hydrogen circulating pump with a pressure balance system structure. BACKGROUND

[0002] The hydrogen circulating pump is a key component of a hydrogen fuel cell engine, and plays an important role in improving fuel utilization and ensuring hydrogen safety (hydrogen overflow in the external environment causes unsafe factors).

[0003] At present, in the hydrogen energy fuel industry, the hydrogen circulating pump still needs to be further improved, mainly in the following aspects:

[0004] Firstly, the sealing between the internal cavities of the hydrogen circulating pump is sealed by a sealing element. Static sealing has a certain effect, but there is still a certain amount of leakage. Dynamic sealing is accompanied by wear of the sealing element, and the leakage between the cavities is uncontrollable. Thus, a pressure difference condition is generated between the cavities, which is conducive to the leakage of lubricating oil and the flow of water or water vapor, thereby adversely affecting the lubricating effect of the gear box lubricating oil and the insulation performance of the motor.

[0005] Secondly, the traditional hydrogen circulating pump transmission structure adopts gear transmission, and the gear box is located between the gas compression cavity and the motor cavity. There is a certain amount of lubricating oil in the gear box. The gear box and the gas compression cavity are sealed by a sealing element. However, the sealing element has a high risk of failure under high-speed operation or harsh operating conditions, thereby increasing the risk of gear box oil leakage into the gas compression cavity. Therefore, dynamic sealing technology is a major problem. Once the lubricating oil leaks into the gas compression cavity, it will contaminate the compressed gas, which will cause damage to the hydrogen fuel cell stack, thereby affecting the efficiency and service life of the fuel cell stack. Under harsh operating conditions, the temperature of the gas compression cavity rises very high, and the heat will be directly transferred to the gear box, thereby increasing the temperature rise of the gear. The lubricating and cooling effect of the lubricating oil under high temperature conditions will decrease sharply, thereby increasing the risk of mechanical failure of the gear box.

[0006] In summary, the above-mentioned problems are caused by defects in the structure design of the hydrogen circulating pump. The present application provides a hydrogen circulating pump with a pressure balance system structure to solve the problems in the prior art. SUMMARY

[0007] The purpose of the present application is to provide a hydrogen circulating pump with a pressure balance system structure to solve the problem of mutual interference between the gas compression cavity and the gear cavity in the prior art, and to solve the problem of performance affected by the pressure difference condition in the structure.

[0008] The technical solution of the present application is: a hydrogen circulating pump with a pressure balance system structure, comprising:

[0009] A transmission shaft, comprising a driving shaft and a driven shaft;

[0010] A rotor member, a driving motor and a gear member are sequentially arranged along the axial direction of the transmission shaft and are sequentially arranged in the gas compression cavity, the motor cavity and the gear cavity;

[0011] A pressure balance member is arranged between the gas compression cavity and the motor cavity to balance the pressure in the gas compression cavity and the motor cavity.

[0012] Preferably, the gas compression cavity is formed with a low-pressure cavity and a high-pressure cavity, and the pressure balance member comprises a first one-way valve and a second one-way valve;

[0013] The first one-way valve is arranged between the low-pressure cavity and the motor cavity and is arranged in the first air port to realize one-way flow of gas from the motor cavity to the low-pressure cavity;

[0014] The second one-way valve is arranged between the high-pressure cavity and the motor cavity and is arranged in the second air port to realize one-way flow of gas from the high-pressure cavity to the motor cavity.

[0015] Preferably, the first one-way valve and the second one-way valve are not synchronous, the first one-way valve has a triggered calibration value Fmax, and the second one-way valve has a triggered calibration value Fmin;

[0016] The first one-way valve opens when the pressure in the motor cavity is higher than Fmax and closes when the pressure in the motor cavity is lower than Fmax;

[0017] The second one-way valve opens when the pressure in the motor cavity is lower than Fmin and closes when the pressure in the motor cavity is higher than Fmin.

[0018] Preferably, the low-pressure cavity and the high-pressure cavity are arranged on the opposite sides of the middle axis of the driving shaft and the driven shaft; and / or,

[0019] The middle axis of the first air port and the second air port is perpendicular to the middle axis of the driving shaft and the driven shaft.

[0020] Preferably, the gas compression cavity and the gear cavity are arranged on the opposite sides of the motor cavity, and the distance between the gas compression cavity and the gear cavity is increased by the motor cavity in a balanced state of dynamic pressure.

[0021] Preferably, the driving shaft and the driven shaft are arranged in the same length and sequentially penetrate the gas compression cavity, the motor cavity and the gear cavity, respectively;

[0022] The motor cavity comprises a first chamber for the main shaft to pass through and a second chamber for the driven shaft to pass through; the driving motor is installed in the first chamber and connected with the main shaft; the second chamber is connected with the first chamber to expand the working space of the driving motor.

[0023] Preferably, the transmission shaft, the rotor member, the driving motor, the gear member and the pressure balance member are installed in the casing; the casing comprises a rotor shell, a motor shell and a gear box; the gas compression cavity is formed in the rotor shell and capped by a flange; the motor cavity is formed in the motor shell and capped by the rotor shell; the gear cavity is formed in the gear box and capped by the motor shell;

[0024] The first vent and the second vent are arranged on the rotor shell between the gas compression cavity and the motor cavity, parallel to the axial direction of the transmission shaft, and the first one-way valve and the second one-way valve are installed in the first vent and the second vent respectively.

[0025] Preferably, bearings are installed on the flange, the rotor shell and the gear box for the transmission shaft to be installed; an oil seal is arranged between the transmission shaft and the motor shell, a first gas seal is arranged between the transmission shaft and the rotor shell, and a second gas seal is arranged between the transmission shaft and the flange.

[0026] The sealing forms of the oil seal, the first gas seal and the second gas seal are static sealing between relatively static combined surfaces at the outer rings and dynamic sealing between relatively moving combined surfaces.

[0027] Preferably, the rotor member comprises a main rotor and a driven rotor rotating synchronously, the main rotor is connected with the main shaft, and the driven rotor is connected with the driven shaft.

[0028] The gear member comprises a main gear and a driven gear meshing with each other, the main gear is connected with the main shaft, and the driven gear is connected with the driven shaft.

[0029] Compared with the prior art, the application has the following advantages:

[0030] (1) The motor cavity is arranged between the gas compression cavity and the gear cavity, and the pressure balance member is arranged to ensure the static sealing of the structure and solve the pressure difference problem caused by the failure of dynamic sealing in the structure, so as to realize dynamic pressure balance and avoid the internal medium flow caused by the pressure difference, thereby maximizing the working performance of the structure.

[0031] (2) The seal in the hydrogen circulation pump is mainly realized by a sealing element, and the sealing element includes an oil seal, a first gas seal, and a second gas seal. The static seal has a certain sealing effect, but a certain amount of leakage is inevitable under severe operating conditions. The dynamic seal is uncontrollable due to the wear of the sealing element and the leakage between the cavities, and then the pressure difference between the cavities is generated, and the pressure difference further causes the leakage of lubricating oil and the flow of water or water vapor. Therefore, when the sealing element fails, the dynamic pressure balance between the cavities is ensured by the pressure balance component, which can effectively reduce the leakage of lubricating oil and the flow of water or water vapor caused by the pressure difference. At the same time, during the dynamic pressure balance, the gas flow formed in the motor cavity can bring better cooling effect to the inside of the motor cavity.

[0032] (3) The gas compression cavity and the gear cavity are arranged away from each other, so that when the sealing element fails, the lubricating oil in the gear cavity does not directly leak into the gas compression cavity, thereby avoiding the problem of pollution of the circulating gas in the hydrogen fuel cell stack, and avoiding the risk of failure of the hydrogen fuel cell stack in the hydrogen energy fuel cell field.

[0033] (4) Because the temperature of the gas compression cavity rises very high under operating conditions, the gear box and the gas compression cavity are arranged away from each other, so that the heat in the gas compression cavity is not directly transmitted to the gear box, the lubrication and cooling effect of the mechanical parts in the gear box is improved, the reliability of the mechanical parts is improved, and the replacement and maintenance cost and frequency of the lubricating oil in the gear box are reduced.

[0034] (5) Because the rotor member and the gear member are located at the two ends, the driving shaft and the driven shaft need to be arranged with the same length. Because the driving motor is connected with the driving shaft, the space corresponding to the aligned position of the driven shaft is connected with the space where the driving motor is installed, the working space of the driving motor is expanded, and the temperature rise and noise problem of the driving motor is improved. BRIEF DESCRIPTION OF DRAWINGS

[0035] The application will be further described below in combination with the drawings and embodiments:

[0036] Figure 1 It is a sectional view of the hydrogen circulation pump with a pressure balance system structure according to the application;

[0037] Figure 2 It is another sectional view of the hydrogen circulation pump with a pressure balance system structure according to the application and Figure 1 It is another sectional view of the hydrogen circulation pump with a pressure balance system structure according to the application and

[0038] Figure 3 It is a sectional view of the casing according to the application;

[0039] Figure 4 It is a sectional view of the rotor casing according to the application and perpendicular to the transmission shaft.

[0040] Wherein: 1, the shell, 11, rotor shell, 111, the first vent, 112, the second vent, 12, motor shell, 121, partition, 13, gear box, 14, flange, 15, front cover;

[0041] 2, drive shaft, 21, the driving shaft, 22, driven shaft;

[0042] 3, rotor member, 31, the driving rotor, 32, driven rotor;

[0043] 4, drive motor;

[0044] 5, gear member, 51, the driving gear, 52, driven gear;

[0045] 6, pressure balance member, 61, the first check valve, 62, the second check valve;

[0046] 7, bearing;

[0047] 8, seal, 81, oil seal, 82, the first gas seal, 83, the second gas seal;

[0048] 01, gas compression cavity, 011, low pressure cavity, 012, high pressure cavity, 02, motor cavity, 021, the first chamber, 022, the second chamber, 03, gear cavity. DETAILED DESCRIPTION

[0049] The content of the application is further described in detail below in combination with specific embodiments:

[0050] As shown in Figure 1 , Figure 2 , a hydrogen circulation pump with pressure balance system structure, comprising a shell 1, drive shaft 2, rotor member 3, drive motor 4, gear member 5 and pressure balance member 6.

[0051] As shown in Figure 3As shown, housing 1 houses the drive shaft 2, rotor assembly 3, drive motor 4, gear assembly 5, and pressure balancing assembly 6. Its structure includes a rotor housing 11, a motor housing 12, and a gearbox 13, all arranged and fixedly connected along a predetermined first direction. A gas compression chamber 01 is formed within the rotor housing 11 and sealed by a flange 14. The gas compression chamber 01 contains a low-pressure chamber 011 and a high-pressure chamber 012. A motor cavity 02 is formed within the motor housing 12 and sealed by the end of the rotor housing 11 furthest from the flange 14. The gearbox 13 has a gear cavity 03, which is sealed by the motor housing 12 at the end away from the rotor housing 11. In this embodiment, the rotor housing 11 between the gas compression cavity 01 and the motor cavity 02 is provided with a first vent 111 and a second vent 112, with the central axis direction parallel to the axis of the transmission shaft 2. The first vent 111 is located on one side of the low-pressure cavity 011 and is directly connected to the low-pressure cavity 011, while the second vent is located on one side of the high-pressure cavity 012 and is directly connected to the high-pressure cavity 012.

[0052] The drive shaft 2 includes a driving shaft 21 and a driven shaft 22 arranged in parallel. The driving shaft 21 and the driven shaft 22 are of equal length and their axial directions are parallel to the first direction. They pass through the gas compression chamber 01, the motor chamber 02, and the gear chamber 03, which are distributed along the axial direction of the drive shaft 2, respectively. Bearings 7 are installed on the flange 14, the rotor housing 11, and the gearbox 13 for mounting the drive shaft 2. An oil seal 81 is provided between the drive shaft 2 and the motor housing 12, a first gas seal 82 is provided between the drive shaft 2 and the rotor housing 11, and a second gas seal 83 is provided between the drive shaft 2 and the flange 14. The oil seal 81, the first gas seal 82, and the second gas seal 83 constitute the sealing element 8 inside the hydrogen circulation pump. The sealing forms are divided into static sealing between relatively stationary mating surfaces at the outer ring and dynamic sealing between relatively moving mating surfaces. In this embodiment, since the drive shaft 2 passes through the flange 14, a front cover 15 is provided on the outer end face of the flange 14 to prevent the ends of the driving shaft 21 and the driven shaft 22 from being exposed.

[0053] like Figure 1 As shown, the rotor component 3, the drive motor 4, and the gear component 5 are distributed sequentially along the axial direction of the transmission shaft 2 and are sequentially housed in the gas compression chamber 01, the motor chamber 02, and the gear chamber 03.

[0054] The rotor component 3 is located in the gas compression chamber 01 and includes a driving rotor 31 and a driven rotor 32. The driving rotor 31 is connected to the driving shaft 21, and the driven rotor 32 is connected to the driven shaft 22. The driving rotor 31 and the driven rotor 32 move synchronously to achieve gas compression. Under harsh working conditions, the temperature rise in the gas compression chamber 01 is very high. Therefore, the gear chamber 03 is located far away from the gas compression chamber 01 to avoid the heat in the gas compression chamber 01 being directly transferred to the gearbox 13. This improves the lubrication and cooling effect of the mechanical components in the gearbox 13, enhances the reliability of the mechanical components, and reduces the cost and frequency of lubricant replacement and maintenance in the gearbox 13.

[0055] The drive motor 4 is disposed in the motor cavity 02. The motor cavity 02 includes a first chamber 021 through which the drive shaft 21 passes and a second chamber 022 through which the driven shaft 22 passes. A partition 121 is provided between the first chamber 021 and the second chamber 022. The partition 121 forms a space between its end biased towards the rotor housing 11 and the end face of the rotor housing 11, thereby realizing the communication between the first chamber 021 and the second chamber 022. The drive motor 4 is installed in the first chamber 021. The presence of the second chamber 022 expands the working space of the drive motor 4, which is more conducive to improving the temperature rise and noise problems of the drive motor 4.

[0056] Gear component 5 is disposed within gear cavity 03, including driving gear 51 and driven gear 52. Driving gear 51 is connected to driving shaft 21, and driven gear 52 is connected to driven shaft 22. Gear cavity 03 contains lubricating medium to prevent tooth surface wear, scratches, sintering, etc., thereby extending its service life and improving transmission efficiency. Generally, liquid lubricating oil or solid grease is used. Since gear cavity 03 is disposed far from gas compression chamber 01, compared with the traditional structure in which gear cavity 03 and gas compression chamber 01 are adjacent, even if the seal 8 fails under harsh working conditions, the lubricating medium in gear cavity 03 can be prevented from directly leaking into gas compression chamber 01 to a certain extent. Thus, in the field of hydrogen fuel cells, the risk of hydrogen fuel cell stack failure is avoided.

[0057] Combination Figure 1 , Figure 2 , Figure 4 As shown, the pressure balancing component 6 is disposed between the gas compression chamber 01 and the motor chamber 02 to balance the pressure in the gas compression chamber 01 and the motor chamber 02; in this embodiment, the low-pressure chamber 011 and the high-pressure chamber 012 are respectively disposed on opposite sides of the plane containing the central axes of the drive shaft 21 and the driven shaft 22; the plane containing the central axes of the first vent 111 and the second vent 112 is perpendicular to the plane containing the central axes of the drive shaft 21 and the driven shaft 22.

[0058] The pressure balance component 6 comprises a first one-way valve 61 and a second one-way valve 62; the first one-way valve 61 and the second one-way valve 62 are not synchronous, the first one-way valve 61 has a triggered calibration value Fmax, and the second one-way valve 62 has a triggered calibration value Fmin.

[0059] The first one-way valve 61 is arranged between the low-pressure cavity 011 and the motor cavity 02 and is built in the first air port 111, the first one-way valve 61 is opened when the pressure in the motor cavity 02 is higher than Fmax, realizing one-way flow of gas from the motor cavity 02 to the low-pressure cavity 011, and is closed when the pressure in the motor cavity 02 is lower than Fmax.

[0060] The second one-way valve 62 is arranged between the high-pressure cavity 012 and the motor cavity 02 and is built in the second air port 112, the second one-way valve 62 is opened when the pressure in the motor cavity 02 is lower than Fmin, realizing one-way flow of gas from the high-pressure cavity 012 to the motor cavity 02, and is closed when the pressure in the motor cavity 02 is higher than Fmin.

[0061] Therefore, based on the arrangement of the first one-way valve 61 and the second one-way valve 62, and the formation of the low-pressure cavity 011 and the high-pressure cavity 012 in the gas compression cavity 01, the gas pressure in the motor cavity 02 can be maintained between Fmin and Fmax, and the leakage problem caused by the pressure difference is reduced to a certain extent.

[0062] In the present application, since the gas compression cavity 01 and the gear cavity 03 are arranged on the opposite side of the motor cavity 02, the motor cavity 02 can not only increase the distance between the gas compression cavity 01 and the gear cavity 03, but also balance the dynamic pressure. In actual working process, the leakage of lubricating oil in the structure, the flow of water or water vapor mainly comes from: (1) the failure of the sealing element; (2) the pressure difference between the cavities; the former is inevitable and uncontrollable under operating conditions, and the latter is caused based on the former, therefore, by arranging the pressure balance component 6, the dynamic pressure balance in the structure is realized, the leakage of lubricating oil, the flow of water or water vapor is reduced to a certain extent, and the lubricating effect of the lubricating oil in the gear box 13 and the insulation performance of the driving motor 4 are ensured.

[0063] The above examples are only for illustrating the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and to implement it, and cannot limit the protection scope of the present application. For those skilled in the art, it is obvious that the present application is not limited to the details of the above exemplary embodiments, and the present application can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application, therefore, no matter from which point of view, the examples should be regarded as exemplary and non-limiting, the scope of the present application is defined by the appended claims rather than the above description, therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present application.

Claims

1. A hydrogen circulation pump with a pressure balance system structure, characterized by, The utility model relates to a kind of gas compressor, including: Transmission shaft, the transmission shaft includes driving shaft and driven shaft; Rotor component, drive motor and gear component, sequentially distributed along the axial direction of transmission shaft, and sequentially built-in gas compression cavity, motor cavity and gear cavity; Pressure balance component, the pressure balance component is arranged between the gas compression cavity and the motor cavity, and the pressure balance component balances the pressure in the gas compression cavity and motor cavity; The low-pressure cavity and high-pressure cavity are formed in the gas compression cavity, and the pressure balance component includes first one-way valve and second one-way valve; The first one-way valve is arranged between the low-pressure cavity and the motor cavity, and built-in first air port, realize the one-way flow of gas from motor cavity to low-pressure cavity; The second one-way valve is arranged between the high-pressure cavity and the motor cavity, and built-in second air port, realize the one-way flow of gas from high-pressure cavity to motor cavity; The first one-way valve and the second one-way valve are not synchronous action, the first one-way valve has the trigger calibration value Fmax, and the second one-way valve has the trigger calibration value Fmin; The first one-way valve opens when the pressure in the motor cavity is higher than Fmax, and closes when the pressure in the motor cavity is lower than Fmax;The second one-way valve opens when the pressure in the motor cavity is lower than Fmin, and closes when the pressure in the motor cavity is higher than Fmin, so that the air pressure in the motor cavity is kept between Fmin~Fmax.

2. The hydrogen circulation pump with a pressure balance system structure according to claim 1, characterized in that: The low-pressure cavity and the high-pressure cavity are arranged on the opposite side of the middle axis of the driving shaft and the driven shaft;And / or, The middle axis of the first air port and the second air port is perpendicular to the middle axis of the driving shaft and the driven shaft.

3. The hydrogen circulating pump with a pressure balance system structure according to claim 1, characterized in that: The gas compression cavity and the gear cavity are arranged on the opposite side of the motor cavity, and the distance between the gas compression cavity and the gear cavity is increased by the motor cavity under the balanced dynamic pressure.

4. The hydrogen circulating pump with a pressure balance system structure according to claim 3, characterized in that: The driving shaft and the driven shaft are equal in length, and sequentially penetrate the gas compression cavity, the motor cavity and the gear cavity respectively; The motor cavity includes a first chamber for the driving shaft to penetrate, and a second chamber for the driven shaft to penetrate;The drive motor is installed in the first chamber and connected with the driving shaft;The second chamber is communicated with the first chamber, and the working space of the drive motor is expanded.

5. The hydrogen circulating pump with a pressure balance system structure according to claim 4, characterized in that: The transmission shaft, rotor component, drive motor, gear component and pressure balance component are installed in the shell;The shell includes rotor shell, motor shell and gear box;The gas compression cavity is formed in the rotor shell and sealed by flange plate;The motor cavity is formed in the motor shell and sealed by rotor shell;The gear cavity is formed in the gear box and sealed by motor shell; The first air port and the second air port are arranged on the rotor shell between the gas compression cavity and the motor cavity, and the middle axis direction is parallel to the axial direction of the transmission shaft, and the first one-way valve and the second one-way valve are installed respectively.

6. The hydrogen circulating pump with a pressure balance system structure according to claim 5, characterized in that: The flange, the rotor shell and the gear box are provided with bearings for mounting the transmission shaft; the transmission shaft and the motor shell are provided with an oil seal, the transmission shaft and the rotor shell are provided with a first gas seal, and the transmission shaft and the flange are provided with a second gas seal; The sealing forms of the oil seal, the first gas seal and the second gas seal are static sealing between relatively static combined surfaces and dynamic sealing between relatively moving combined surfaces.

7. The hydrogen circulating pump with a pressure balance system structure according to claim 6, characterized in that: The rotor member comprises a driving rotor and a driven rotor which rotate synchronously, the driving rotor is connected with the driving shaft, and the driven rotor is connected with the driven shaft. The gear member comprises a driving gear and a driven gear which engage with each other, the driving gear is connected with the driving shaft, and the driven gear is connected with the driven shaft.

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