CN205714846U - A kind of single-stage direct-drive supercharged centrifugal air compressor of vehicle fuel battery engine - Google Patents

Abstract

The utility model relates to a single-stage direct-drive supercharged centrifugal air compressor for a vehicle fuel cell engine. The air compressor is driven to rotate by a motor, and includes a stator, a main shaft, and a rotor fixed in the middle of the main shaft. A volute is arranged at one end and a fixed The impeller connected to one end of the main shaft inside the volute drives the rotor to rotate at a super high speed through a driver, and the two ends of the main shaft are supported by simply supported beam support structures. Compared with the prior art, the utility model adopts a high-power motor ultra-high-speed direct-drive centrifugal impeller intake pressurization method, a high-efficiency permanent magnet synchronous motor, an oil-free lubricated air foil dynamic pressure bearing and a rotor-spindle- The impeller structure is integrated design, the impeller diameter is small, the overall structure is simple, compact, small in size, light in weight, easy to install and disassemble, which can meet the air supply requirements of the current full working condition vehicle fuel cell engine without increasing the size of the fuel cell In the case of the engine volume, the volume specific power of the fuel cell engine is increased.

Description

A single-stage direct-drive supercharged centrifugal air compressor for a vehicle fuel cell engine

technical field

The utility model relates to the technical field of fuel cell engines, in particular to a high-power ultra-high-speed single-stage supercharged centrifugal air compressor for vehicle fuel cell engines.

Background technique

Air compressors are widely used in aerospace, automobiles, pipeline transportation, food packaging and other fields. In addition, air compressors are one of the key components in the auxiliary air supply assembly of new energy fuel cell vehicles. Pressure and flow directly affect the stoichiometric ratio, air humidification characteristics, and water heat management characteristics in fuel cell engines, which in turn affect the voltage output of the fuel cell stack and the power output of the fuel cell engine.

Since the power of high-power vehicle fuel cell engines is in the hundreds of kilowatts class, high-power air compressors with high pressure ratio and high flow rate that meet the air supply requirements of fuel cell engines under all working conditions have become one of the design trends. The air compressor is directly driven by a motor, which consumes the power of the fuel cell vehicle engine itself. In order to improve the effective power output of the engine and reduce the parasitic power consumption of the air compressor, high-efficiency air compressor technology has attracted widespread attention. Moreover, due to the ultra-high-speed operation of the air compressor, the rotor bears more and more centrifugal force as the speed increases. The permanent magnet material in the rotor generally has a compressive strength of about 1000MPa, and a tensile strength of about 80MPa. Tensile failure of permanent magnets by centrifugal force. However, in order to meet the high pressure ratio and large flow air supply output requirements, that is, the high power output of the motor, to ensure that the motor has sufficient torque output, the motor rotor is required to have a sufficiently large diameter. It can be seen from the above that the motor rotor-spindle structure size Design requirements are high. In addition, in order to increase the output power of the centrifugal compressor, the rotor speed of the centrifugal air compressor generally needs to be operated at an ultra-high speed above 100,000 rpm. Require. Moreover, the inevitable oil leakage of traditional oil-lubricated bearings will enter the interior of the fuel cell engine and affect the electrochemical reaction of the fuel cell. Therefore, oil-free lubricated bearing supports are the best choice for air compressors. To sum up, from the perspective of the selection of the main shaft diameter, the bearing lubrication method, the bearing support distance, the oil-free air intake requirements of the fuel cell engine itself, and the low-temperature cold start requirements of the fuel cell engine at minus 30 degrees, the existing It is difficult for traditional bearings to meet the performance requirements and use requirements of fuel cell engine air compressors. Even if special bearings can meet the requirements, it will also bring about the problem of rotor dynamics stability. hotspots and difficulties. Long-term ultra-high-speed operation of the air compressor will cause the risk of damage to bearings and other supporting components, increasing the difficulty of fault monitoring and diagnosis. The ultra-high-speed rotor will also cause wind wear on the rotor surface, which in turn will cause heat dissipation and cooling problems. Finally, as a part of the vehicle's fuel cell engine, the air compressor is required to be compact in size and high in structural strength.

Utility model content

The purpose of this utility model is to overcome the defects of the above-mentioned prior art and provide a kind of air supply system that can meet the actual demand of high pressure and wide flow range of the 60-80kW high-power fuel cell engine, and has the advantages of compact structure and high efficiency. , small size, light weight, fast response and other characteristics of single-stage supercharged centrifugal air compressor for vehicle fuel cell engines.

The purpose of the utility model can be achieved through the following technical solutions: a single-stage direct-drive supercharged centrifugal air compressor for a vehicle fuel cell engine, the air compressor is driven to rotate by a motor, and the air compressor includes Motor stator, main shaft, rotor fixed in the middle of the main shaft, a volute arranged at one end, an impeller fixed inside the volute and connected to one end of the main shaft, and a driver, the driver drives the motor rotor to rotate at a super high speed, and the two ends of the main shaft pass through The beam support structure provides support. The permanent magnet of the high-power motor adopts a structure with a pair of poles and a large gap with the stator of the motor, and the rotation speed can reach a predetermined high rotation speed when the frequency is increased.

The rotary shaft of the air compressor adopts a simply supported beam support structure of double-sided radial air foil bearings and single-sided axial air foil thrust bearings, and uses a driver to directly drive the motor to drive the rotor-main shaft-impeller integrated structure to rotate at ultra-high speed , realize the high-speed rotation of the centrifugal impeller, and realize the intake boost of the fuel cell engine through the impeller volute. At the same time, by controlling the motor driver, directly adjust the motor rotor speed, adjust the output air pressure and flow, change the stoichiometric ratio of the fuel cell stack air, improve the hydrogen-oxygen electrochemical reaction efficiency on the fuel cell membrane electrode, and improve the efficiency of the fuel cell. engine power output.

The utility model adopts the supercharging mode of the single-stage impeller volute, and has a simple structure. The natural air is introduced through the volute inlet, and after being compressed by the high-speed rotation of the impeller, it flows out through the air outlet to realize the function of ultra-high-speed rotating supercharging. The performance index can reach high pressure ratio (2.5bar) and high flow rate (100g/s), meeting the air flow supply demand in a wide range of 60-80kW high-power vehicle fuel cell engines. The overall structure of the air compressor adopts a unidirectional arrangement of output loads, that is, a motor is arranged in the middle of the overall structure of the air compressor, including the motor stator and rotor, and the motor unilaterally rotates the load output. It adopts a single impeller volute structure, and the impeller passes through the main shaft- The rotor structure is connected to form an integrated structure. The impeller-main shaft-rotor structure is supported by simply supported beams, and the rotating system (main shaft, motor rotor and impeller) is supported by bearings and bearing seats to ensure its high-speed and stable rotation. The driver is used to directly drive the motor to drive the rotor-spindle-impeller integrated structure to rotate at a super high speed, so as to realize the super high speed rotation of the centrifugal impeller to generate high-pressure air. At the same time, by controlling the motor driver, directly adjust the motor rotor-main shaft-impeller speed, according to the demand of the fuel cell engine, adjust the output air pressure and flow, change the stoichiometric ratio of the fuel cell stack air, and improve the hydrogen on the fuel cell membrane electrode , Oxygen electrochemical reaction, improve fuel cell engine performance.

The simply supported beam support structure includes a radial air foil bearing a at the impeller end of the main shaft, a radial air foil bearing b and an axial air foil dynamic pressure thrust bearing at the other end of the main shaft. The radial air foil bearing a is fixed on the outside of the main shaft by uniformly distributed circumferential screws, the axial air foil thrust bearing is fixed on the outside of the main shaft in the form of a sleeve, and the radial air foil Bearing b is fixed on the outer side of the axial air foil thrust bearing by using circumferentially uniform screws.

The form of axial force balance is provided by double-sided radial air foil radial bearing support and single-sided axial air foil thrust bearing. The foil is located between the shaft and the bearing. When the main shaft rotates at a high speed, the foil is compressed to generate a high-pressure air film and the main shaft is suspended between the air foil bearings. The non-direct contact between the main shaft and the bearing can greatly reduce the distance between the bearing and the shaft. The friction of the motor improves the working efficiency of the motor. The axial air foil thrust bearing is fixed on the main shaft in the form of a sleeve, which is convenient for disassembly, positioning and replacement.

One end of the axial air foil thrust bearing is provided with a protrusion, which is located between the two thrust bearing foil discs, and the protrusion and the two thrust bearing foil discs rotate at a super high speed When the compressed gas fits. Such a design can avoid axial movement of the entire shafting.

One end of the main shaft connected to the axial air foil thrust bearing is provided with a fixed plug, which is used to prevent the deformation of the bearing plate in the axial air foil thrust bearing during high-speed rotation when the main shaft rotates at high speed. To ensure the clearance of the foil in the axial air foil thrust bearing.

The main shaft adopts the whole shaft stepped shaft, that is, the main shaft is integrally formed without segmentation, and the diameter of the main shaft at the place where the rotor is installed is smaller than the diameter of the main shaft where the radial air foil bearing a is installed; except for the place where the impeller is installed, the main shaft Both adopt hollow spindle to reduce the weight of the spindle. The main shaft adopts the form of a whole shaft without segmentation, which reduces the number of ultra-high-speed rotating parts and improves the rigidity of the main shaft, reducing the deflection and deformation of the high-speed main shaft and the difficulty of dynamic balance check. The main shaft adopts a stepped form to facilitate the installation and positioning of the permanent magnet of the motor rotor. At the same time, it is arranged on both sides with the thrust bearing to achieve the function of balancing the center of mass of the rotating parts. Most of the main shaft is hollowed out to reduce the mass of rotating parts and improve the rotor dynamics.

The rotor adopts a three-layer arrangement of stainless steel main shaft, electrical steel, and permanent magnets from the inside to the outside, and carbon fibers are wound outside the permanent magnets, and the two ends of the rotor are magnetically isolated by filling glue. Winding the carbon fiber outside the permanent magnet prevents the permanent magnet from breaking due to centrifugal force under high-speed rotation. The glue filling is to pour a certain thickness of high-viscosity coagulation glue on both ends of the permanent magnet under the premise of fixing the permanent magnet, so as to ensure the strength and magnetic isolation performance.

The driver includes a low-voltage signal connector and a three-phase cable, and the motor controls the speed of changing the direction of the magnetic field generated by the stator of the motor through the driver, thereby controlling the rotation speed of the main shaft.

The motor adopts a permanent magnet synchronous motor, and the permanent magnet synchronous motor adopts a pair of extremely high-frequency operation modes, so that the high speed required by the high performance of the air compressor can be achieved.

The air compressor also includes a water cooling system, the water cooling system includes a casing and a water cooling jacket, the water cooling jacket is arranged outside the main shaft, the casing is arranged outside the water cooling jacket, and the air compressor When the machine is running, cold water is passed between the shell and the water-cooling jacket to dissipate heat.

Compared with the prior art, the beneficial effects of the utility model are reflected in the following aspects:

1. The high-power motor is used to directly drive the impeller to rotate at high speed. The rated power of the motor is 15Kw, and the maximum can reach 100,000rpm. It avoids the use of additional mechanical speed-up mechanisms such as speed-up speeders. , to avoid many problems such as gear meshing vibration noise, lubrication and wear; the air compressor of the utility model can meet the high pressure ratio and large flow air supply and use requirements of 60-80Kw high-power fuel cell engines, and can improve the efficiency of existing fuel cell engines. power output;

2. The centrifugal air compressor can easily adjust the impeller speed, and then change the outlet pressure and flow of the air compressor, which can meet the needs of frequent changes in the working conditions of fuel cell vehicles;

3. Adopt a new type of air foil bearing, double-sided radial support air foil bearing and single-side axial air foil thrust bearing arrangement, compact and simple, increase product reliability and safety, and avoid ultra-high-speed conditions The risk of damage to the rotating parts meets the oil-free working conditions of the gas supply system of the fuel cell engine; it is also conducive to improving the dynamic balance effect of the rotor and the stability of the rotor dynamics. At the same time, it is also beneficial to reduce processing difficulty and processing cost, and is conducive to industrialization

4. The bearing housings at both ends of the utility model and the air foil bearings adopt a tight fit method and are fixed by circumferentially uniform screws. The axial air foil thrust bearing and the main shaft adopt an interference fit method, which fully meets the requirements of the strength level of the vehicle.

5. The surface of the rotor of this utility model is wound with high-strength, light-weight carbon fiber, and an interference fit is adopted between the carbon fiber and the permanent magnet. When rotating at ultra-high speed, the permanent magnet is radially compressed by the carbon fiber winding and the interference. The safety and reliability of the rotor permanent magnet material under the condition of high-speed rotation are guaranteed by structural locking.

6. The magnetic isolation design method of filling glue on both sides of the permanent magnet of the rotor of the utility model not only optimizes the thermal expansion and deformation of the high-speed rotor, but also has the effect of preventing the magnetic flux leakage of the permanent magnet.

Description of drawings

Fig. 1 is the external structure schematic diagram of the present utility model;

Fig. 2 is the overall structural representation of the utility model;

Fig. 3 is a schematic diagram of the rotor-main shaft-impeller integrated structure in Fig. 2 .

Among them, 1 is the volute, 2 is the end cover of the right end motor, 3 is the connecting bolt, 4 is the water cooling jacket, 5 is the casing, 6 is the motor stator, 7 is the low-voltage signal connector, 8 is the metal waterproof connector, and 9 is the three-phase Cable, 10 is the axial air foil bearing seat at the left end, 11 is the end cover of the motor at the left end, 12 is the pre-tightening nut, 13 is the impeller, 14 is the volute and impeller end cover, 15 is the radial air foil bearing a, 16 17 is the motor winding, 18 is the rotor, 19 is carbon fiber, 20 is the radial air foil bearing b, 21 is the axial air foil thrust bearing, 22 is the left end thrust bearing foil plate A, 23 is Thrust bearing foil plate B at the left end, 24 is the bearing fixing plug, 25 is the bearing foil at the right end, 26 is the rotor glue filling colloid A, 27 is the rotor glue filling glue B, and 28 is the left end bearing foil.

detailed description

The following is a detailed description of the embodiments of the present utility model. This embodiment is implemented on the premise of the technical solution of the present utility model, and detailed implementation methods and specific operating procedures are provided, but the protection scope of the present utility model is not limited to the following the described embodiment.

Example

A single-stage turbocharged centrifugal air compressor for a vehicle fuel cell engine, its structure is shown in Figure 1 and Figure 2, the air compressor is connected to a motor, driven by the motor to rotate, the air compressor includes a main shaft 16, a fixed The rotor 18 in the middle of the main shaft 16, the motor stator 6, the volute 1, and the impeller 13 arranged inside the volute 1 and connected to one end of the main shaft 16, the volute 1 is connected to the right end motor end cover 2, and fixed by the connecting bolt 3, The impeller 13 is fixed to the main shaft through the pre-tightening nut 12, and is bonded with high-strength glue to ensure the safety of the high-speed operation of the impeller; motor windings 17 are arranged on both sides of the motor stator 6, and the motor windings 17 are connected to the low-voltage by the three-phase cable 9. The signal connector 7 is connected to the motor, and the three-phase cable 9 is provided with a metal waterproof connector 8 . The air compressor also includes a casing 4 and a water cooling jacket 5. The water cooling jacket 5 is arranged on the outside of the main shaft 16, and the casing 4 is arranged on the outside of the water cooling jacket 5. Cold water acts as a heat sink.

Both ends of the main shaft are supported by a simply supported beam support structure, wherein the rotor-main shaft-impeller integrated structure is shown in Figure 3, the simply supported beam support structure includes a radial air foil bearing a15 arranged at the impeller end of the main shaft 16 and The radial air foil bearing b20 and the axial air foil thrust bearing 21 arranged at the other end of the main shaft 16, the radial air foil bearing a15 is fixed on the outer side of the main shaft 16 by uniformly distributed circumferential screws, and the axial air foil thrust bearing The thrust bearing 21 is fixed on the outer side of the main shaft 16 in the form of a shaft sleeve, the radial air foil bearing b20 is fixed on the outer side of the axial air foil thrust bearing 21 by uniformly distributed circumferential screws, and the radial air foil bearing a15 is connected to the radial The air foil bearing b20 is respectively provided with a right end bearing foil 25 and a left end bearing foil 28 , these two foils generate a high-pressure air film when the main shaft 16 rotates at high speed so that the main shaft 16 is suspended between the air foil bearings. The end of the axial air foil thrust bearing 21 away from the impeller 13 is provided with a protrusion, and the protrusion is located between the left end thrust bearing foil disk A22 and the left end thrust bearing foil disk B23 to avoid the axial Movement; one end of the main shaft 16 connected to the axial air foil thrust bearing 21 is provided with a bearing fixing plug 24, which is used to prevent the deformation of the bearing plate in the radial axial air foil thrust bearing during high-speed rotation, so as to Guarantee the clearance of the foil in the radial axial air foil thrust bearing 21.

In the middle of the main shaft 16, there is also a rotor 18 corresponding to the motor stator 6. The rotor adopts a three-layer concentric winding arrangement of stainless steel main shaft, electrical steel, and permanent magnets from the inside to the outside, and carbon fiber 19 is wound outside the rotor 18. , the two ends of the rotor are magnetically separated by potting, forming the rotor potting colloid A26 and the rotor potting colloid B27 respectively.

The radial air foil bearing b20 is installed on the left end axial air foil bearing seat 10, the radial air foil bearing a15 is installed on the right end axial air foil bearing seat, and the right end axial air foil bearing seat and the worm gear There is a volute and an impeller end cover 14 between the shells, which are used to resist the axial air foil bearing seat at the right end, and a left end motor end cover 11 is provided at the leftmost end of the air compressor to resist the axial air foil bearing seat at the left end. The specific structure of the sheet bearing seat 10, the bearing fixing plug 24 and the left end thrust bearing foil disc B23 is shown in FIG. 2 .

The motor is connected to the motor winding 17 parts through the low-voltage signal connector 7 and the three-phase cable 9, the motor stator 6 is driven through the motor control, and the tangential torque generated by the winding magnetic force line drives the rotor 18 to run at a high speed, and then the rotor-spindle drives the impeller to rotate at a high speed , the motor realizes the high-speed rotating compressed air of the centrifugal impeller through the different speed control of the rotor 18, and achieves the gas load output with high pressure ratio and large flow rate. Input according to different conditions can meet the air flow supply demand in a wide range of high-power vehicle fuel cell engines.

Claims (8)

1. A single-stage direct-drive supercharged centrifugal air compressor of a vehicle fuel cell engine, the air compressor is driven to rotate by a motor, and it is characterized in that the air compressor includes a motor stator, a main shaft, and is fixed on The rotor in the middle of the main shaft, the volute at one end, the impeller fixed inside the volute and connected to one end of the main shaft, and the driver for driving the rotor to rotate at high speed, and the two ends of the main shaft are supported by a simply supported beam support structure. 2. A single-stage direct-drive supercharged centrifugal air compressor for a vehicle fuel cell engine according to claim 1, wherein the simply supported beam support structure includes a radial air compressor arranged at the end of the main shaft impeller The foil bearing a, the radial air foil bearing b and the axial air foil dynamic pressure thrust bearing arranged at the other end of the main shaft, the radial air foil bearing a is fixed on the main shaft with circumferentially uniform screws The outer side of the axial air foil thrust bearing is fixed on the outer side of the main shaft in the form of a shaft sleeve, and the radial air foil bearing b is fixed on the axial air foil thrust bearing b by circumferentially uniformly distributed screws Push the outside of the bearing. 3. A single-stage direct-drive supercharged centrifugal air compressor for a vehicle fuel cell engine according to claim 2, wherein a protrusion is provided at one end of the axial air foil thrust bearing , the protrusion is located between the two thrust bearing foil discs, and the protrusion cooperates with the compressed gas when the two thrust bearing foil discs rotate at a super high speed. 4. A single-stage direct-drive supercharged centrifugal air compressor for a fuel cell engine for vehicles according to claim 2, wherein one end of the main shaft connected to the axial air foil thrust bearing is provided with a There are retaining plugs to prevent deformation of the axial air foil thrust bearing during high speed rotation. 5. A single-stage direct-drive supercharged centrifugal air compressor for a vehicle fuel cell engine according to claim 1, wherein the main shaft is an integral stepped shaft, and the main shaft at the rotor is installed The diameter is smaller than the diameter of the main shaft where the radial air foil bearing a is installed; the main shaft is a hollow main shaft except for the place where the impeller is installed. 6. The single-stage direct-drive supercharged centrifugal air compressor of a vehicle fuel cell engine according to claim 1, wherein the rotor adopts stainless steel main shaft, electrical steel, permanent The magnets are arranged in three layers, and carbon fibers are wound outside the permanent magnets. 7. A single-stage direct-drive supercharged centrifugal air compressor for a vehicle fuel cell engine according to claim 1, wherein the driver includes a low-voltage signal connector and a three-phase cable, and the motor passes through the driver Controlling the changing speed of the direction of the magnetic field generated by the stator of the motor, thereby controlling the rotational speed of the main shaft. 8. A single-stage direct-drive supercharged centrifugal air compressor for a vehicle fuel cell engine according to claim 1, wherein said air compressor also includes a water cooling system, and said water The cooling system includes a shell and a water-cooling jacket, and the water-cooling jacket is arranged on the outside of the motor stator.