Axial flow compressor driven by motor

Abstract

The invention discloses a motor-driven axial flow compressor which comprises a casing, and a low-pressure compressor unit formed by alternately arranging low-pressure working wheel blade grids and low-pressure rectifier blade grids in sequence is arranged in the casing; a fixed cover at the front end of the casing is provided with an air inlet guide blade grid, the rear end of the casing is provided with a casing flow channel splitting piece through a fixed air outlet guide blade grid, and a gap is reserved between the outer edge of the casing flow channel splitting piece and the inner wall of the rear end of the casing; a transmission shaft driven by a motor is arranged in the casing in a penetrating mode, and the low-pressure working wheel blade grid is fixedly arranged on the transmission shaft in a sleeving mode. The low-pressure working wheel blade grids and the low-pressure rectifier blade grids which are alternately arranged in sequence jointly form an inner duct in the blade areas of the low-pressure working wheel blade grids and the low-pressure rectifier blade grids; in each low-pressure working wheel blade grid and each low-pressure rectifier blade grid, the space shape between every two adjacent blades forms a curve type expansion channel. The invention has the characteristics of high efficiency, large flow, large supercharge ratio and low cost, so that the application requirements of civil products and small and medium-sized aircrafts can be met.

Description

Technical Field

[0001] The invention belongs to the technical field of electric fans, and in particular relates to an axial flow compressor driven by a motor. Background Art

[0002] Electric fans are used in household electrical appliances such as vacuum cleaners, sweepers, electric fans, hair dryers, violent fans, industrial air blowers, blowers, cooling fans, ventilation equipment, wind-powered fire extinguishers, etc. At present, various types of electric fans available on the market can be divided into axial flow fans and centrifugal fans according to their structural forms.

[0003] The characteristic of axial flow fan is that the airflow enters from the axial direction, and is discharged along the axial direction after the fan works and boosts the pressure. The advantages are high efficiency and large flow rate, but the disadvantage is that because there is only one stage of fan, the boost ratio of general civilian products is very low, and the boost ratio is between 0-2. Even if the axial flow fan adopts the air inlet rectifying blade group or the air outlet rectifying blade group, its essence is still a single-stage fan working and boosting, and its boost ratio is limited.

[0004] The characteristic of centrifugal fans is that the airflow enters from the axial direction, and after being pressurized by the fan, it is discharged radially along the left and right sides by centrifugal force, so the direction of the airflow has a turning angle of approximately 90 degrees. The pressure ratio of centrifugal fans is slightly larger than that of axial fans. The pressure ratio of single-stage centrifugal fans in general civilian products is between 1-3, which is not high, and still has the disadvantages of low efficiency and small flow.

[0005] The axial flow compressor principle is widely used in gas turbines (including aircraft engines). The efficiency, flow rate and compression ratio of the axial flow compressor are excellent, but as one of the most sophisticated mechanical products in the contemporary era, it involves a variety of disciplines such as pneumatics, thermal engineering, structure and strength, control, testing, manufacturing technology and materials. It has extremely high requirements for design, materials and processes, and the cost is also extremely high, which is unaffordable for general civilian products. Summary of the invention

[0006] In view of the shortcomings of the prior art, the present invention provides an axial flow compressor driven by an electric motor. By drawing on the principles of axial flow compressors, the present invention optimizes the structural design, rationally selects materials, and improves the processing and molding process. While improving the efficiency, flow rate and compression ratio, the design and manufacturing costs are reduced to meet the application requirements of civil products and small and medium-sized aircraft.

[0007] In order to solve the above technical problems and achieve the above technical effects, the present invention is implemented through the following technical solutions:

[0008] An axial flow compressor driven by a motor comprises a casing, wherein a low-pressure compressor unit is arranged in the casing, wherein the low-pressure compressor unit is composed of at least one group of low-pressure working wheel blades and low-pressure rectifier blades arranged in sequence, wherein the low-pressure working wheel blades of the same group are in front and the low-pressure rectifier blades are in the back, forming a first stage of the low-pressure compressor unit; an air inlet guide blade is arranged at the front fixed cover of the casing as an air inlet of the axial flow compressor; an air outlet guide blade is arranged at the rear end of the casing as an air outlet of the axial flow compressor, and the air outlet guide blade is fixedly connected to the inner wall of the casing;

[0009] All of the low-pressure rectifier blades are fixedly connected to the inner wall of the casing, and a transmission shaft driven by a motor is inserted into the casing. All of the low-pressure working wheel blades are fixedly sleeved on the transmission shaft and driven by the motor to rotate in the casing; the low-pressure working wheel blades and the low-pressure rectifier blades arranged alternately in sequence together form an airflow channel connecting the axial flow compressor air inlet and the axial flow compressor air outlet in the blade areas of the two, serving as the inner channel of the axial flow compressor; in each of the low-pressure working wheel blades and each of the low-pressure rectifier blades, the space shape between two adjacent blades forms a curved expansion channel in which the airflow outlet area is larger than the airflow inlet area, and the curved expansion channel can reduce the speed of the incoming subsonic airflow and increase the pressure.

[0010] Furthermore, a centrifugal fan or a turbine group is also provided in the casing, the low-pressure compressor group is located at the front part of the casing, the centrifugal fan or the turbine group is located at the rear part of the casing, the centrifugal fan or the turbine group is fixedly sleeved on the transmission shaft, and is driven by the motor to realize rotation in the casing; the low-pressure working wheel blades and the low-pressure rectifier blades arranged alternately in sequence and the centrifugal fan or the turbine group together form an airflow channel connecting the axial flow compressor air inlet and the axial flow compressor air outlet in the blade area of ​​the three, which serves as the inner channel of the axial flow compressor.

[0011] Further, the motor is arranged in front of or behind the casing;

[0012] When the motor is located in front of the casing, the motor is a single-output shaft motor, and the output shaft of the motor is drivingly connected to the front end of the transmission shaft;

[0013] When the motor is located at the rear of the casing, the motor is a single-output shaft motor, and the output shaft of the motor is drivingly connected to the rear end of the transmission shaft.

[0014] Furthermore, a high-pressure compressor unit and a speed change mechanism are also arranged in the casing, the low-pressure compressor unit is located at the front part of the casing, the high-pressure compressor unit is located at the rear part of the casing, and the speed change mechanism is located at the middle part of the casing;

[0015] The high-pressure compressor unit is composed of at least one group of high-pressure impeller blades and high-pressure rectifier blades arranged in sequence, with the high-pressure impeller blades in the front and the high-pressure rectifier blades in the back, forming one stage of the high-pressure compressor unit;

[0016] The transmission shaft is divided into two sections, one section is arranged in the rear part of the casing, and the other section is arranged in the front part of the casing; the rear end of the transmission shaft of the rear section is connected to the output shaft of the motor, the front end of the transmission shaft of the rear section is connected to the rear end of the speed change mechanism, and the rear end of the transmission shaft of the front section is connected to the front end of the speed change mechanism;

[0017] All the high-voltage rectifier leaves are fixedly connected to the rear inner wall of the casing, and all the high-voltage working wheel leaves are fixedly sleeved on the transmission shaft located at the rear section, and are driven by the transmission shaft located at the rear section to realize rotation in the casing;

[0018] All the low-voltage rectifier leaves are fixedly connected to the front inner wall of the casing, and all the low-voltage working wheel leaves are fixedly sleeved on the transmission shaft located at the front section, and are driven by the transmission shaft located at the front section to realize rotation in the casing;

[0019] In each of the high-pressure impeller blades and each of the high-pressure rectifier blades, the space between two adjacent blades forms a curved expansion channel in which the airflow outlet area is larger than the airflow inlet area, and the curved expansion channel can reduce the speed of the incoming subsonic airflow and increase the pressure;

[0020] The outer diameter of the speed change mechanism is smaller than the inner diameter of the middle part of the casing, and the gap between the outer edge of the speed change mechanism and the inner wall of the middle part of the casing constitutes an airflow channel; the low-pressure working wheel blades and the low-pressure rectifier blades, which are arranged alternately in sequence, jointly constitute an airflow front channel connecting the air inlet of the axial flow compressor and the airflow channel in the blade area of ​​both; the high-pressure working wheel blades and the high-pressure rectifier blades, which are arranged alternately in sequence, jointly constitute an airflow rear channel connecting the airflow channel and the air outlet of the axial flow compressor in the blade area of ​​both; the airflow front channel, the airflow channel and the airflow rear channel are connected in sequence to form the inner channel of the axial flow compressor.

[0021] Furthermore, a large fan is arranged in front of the casing, and the large fan and the outside of the casing are jointly covered by a cylindrical cover, the cover is coaxial with the casing, the large fan is fixedly sleeved on the front end of the transmission shaft of the front section, and is driven by the motor to rotate in the cover, and the gap between the outer wall of the casing and the inner wall of the cover constitutes an external airflow channel, which serves as an external duct of the axial flow compressor.

[0022] Further, the motor is arranged at the front, rear or inner center of the casing;

[0023] When the motor is located in front of the casing, the motor is a single-output-shaft motor, and the output shaft of the motor is in driving connection with the front end of the transmission shaft of the front section;

[0024] When the motor is located at the rear of the casing, the motor is a single-output shaft motor, and the output shaft of the motor is drivingly connected to the rear end of the transmission shaft at the rear section;

[0025] When the motor is located at the inner center of the casing, the motor is a dual-output shaft motor, the front end output shaft of the motor is transmission-connected to the rear end of the speed change mechanism, the front end of the speed change mechanism is transmission-connected to the rear end of the transmission shaft of the front section, and the rear end output shaft of the motor is transmission-connected to the front end of the transmission shaft of the rear section.

[0026] Furthermore, the low-pressure rectifier blades and the high-pressure rectifier blades have the same structure, and are both composed of a stator outer ring, a stator inner ring, and stator blades uniformly connected between the stator inner ring and the stator outer ring; the low-pressure rectifier blades and the high-pressure rectifier blades are both fixedly arranged in the casing by a tight fit between their respective stator outer rings and the inner wall of the casing, and all the stator outer rings are arranged in sequence to form the rectifier outer ring wall of the axial flow compressor;

[0027] The low-pressure impeller blades and the high-pressure impeller blades have the same structure, and are both composed of a rotor inner ring, a rotor outer ring, a rotor connecting plate connected between the rotor inner ring and the rotor outer ring, and rotor blades uniformly arranged on the outer surface of the rotor outer ring; the low-pressure impeller blades and the high-pressure impeller blades are rotatably arranged in the casing by means of a fixed sleeve connection between the rotor inner ring and the transmission shaft, and all the rotor blades are in a clearance fit relationship with the outer ring wall of the rectifier;

[0028] The outer diameter of the stator outer ring of the same stage is larger than the outer diameter of the rotor outer ring of the same stage, and the outer diameter of the stator inner ring of the previous stage is larger than the outer diameter of the stator inner ring of the next stage, and the outer diameter of the rotor outer ring of the previous stage is larger than the outer diameter of the rotor outer ring of the next stage. All the rotor outer rings and all the stator inner rings are arranged alternately in sequence to form the rectifier inner ring wall of the axial flow compressor. The gap between the rectifier inner ring wall and the rectifier outer ring wall gradually decreases from front to back, thereby forming the inner channel with a large air inlet and a small air outlet.

[0029] Furthermore, the low-pressure working wheel blade, the high-pressure working wheel blade, the low-pressure rectifier blade and the high-pressure rectifier blade are all designed with a combined blade group; wherein,

[0030] The low-pressure impeller blade and the high-pressure impeller blade are both composed of a female rotor and a male rotor that are tightly engaged front and back; the male rotor includes an annular plate, the central hole wall of the annular plate serves as the inner ring of the rotor, and a plurality of forward arc-shaped mounting plates extending forward are arranged at equal angles on the outer wall of the annular plate, the curvature of each forward arc-shaped mounting plate is the same as the curvature of the annular plate, and a rotor blade is arranged on the outer wall of each forward arc-shaped mounting plate; the female rotor includes an annular ring, the outer diameter of the annular ring is equal to the outer diameter of the annular plate, and a plurality of backward arc-shaped mounting plates extending backward are arranged at equal angles on the outer wall of the annular ring, the curvature of each backward arc-shaped mounting plate is the same as the curvature of the annular ring, and a rotor blade is arranged on the outer wall of each backward arc-shaped mounting plate; the space between two adjacent forward arc-shaped mounting plates The distance between the two adjacent backward arc-shaped mounting plates corresponds to the width of one of the backward arc-shaped mounting plates, and the distance between the two adjacent backward arc-shaped mounting plates corresponds to the width of one of the forward arc-shaped mounting plates; the female rotor and the male rotor are spliced ​​front and back by the staggered engagement of the backward arc-shaped mounting plates and the forward arc-shaped mounting plates, and are tightly fixed by the tight fit of the backward arc-shaped mounting plates and the annular plates and the tight fit of the forward arc-shaped mounting plates and the annular rings; after the female rotor and the male rotor are tightly engaged, the forward arc-shaped mounting plates and the backward arc-shaped mounting plates staggered in sequence constitute the outer ring of the rotor; the orientations of all the rotor blades are consistent, and the shape of the space between two adjacent rotor blades constitutes a curved expansion channel whose airflow outlet area is larger than the airflow inlet area, and the curved expansion channel can reduce the speed of the incoming subsonic airflow and increase the pressure;

[0031] The low-voltage rectifier leaf and the high-voltage rectifier leaf are both composed of a female stator and a male stator that are tightly engaged front and back; the female stator includes an inner ring plate as the inner ring of the stator and an outer ring plate as the outer ring of the stator, and a plurality of inner front tooth blocks are arranged at equal angles on the outer wall of the inner ring plate, and the curvature of each inner front tooth block is the same as that of the inner ring plate, and a plurality of outer front tooth blocks are arranged at equal angles on the inner wall of the outer ring plate, and the curvature of each outer front tooth block is the same as that of the outer ring plate, and a stator blade is fixedly connected between each inner front tooth block and a corresponding outer front tooth block; the male stator includes an inner hoop with a diameter slightly smaller than that of the inner ring plate and an outer hoop with a diameter slightly smaller than that of the outer ring plate, and a plurality of inner rear tooth blocks are arranged at equal angles on the front end surface of the inner hoop, and the curvature of each inner rear tooth block is the same as that of the inner hoop, and a plurality of outer rear tooth blocks are arranged at equal angles on the front end surface of the outer hoop Tooth blocks, the curvature of each outer rear tooth block is the same as the curvature of the outer ring hoop, and a stator blade is fixedly connected between each inner rear tooth block and the corresponding outer rear tooth block; a circle of the inner front tooth blocks can be staggered and embedded with a circle of the inner rear tooth blocks, and a circle of the outer front tooth blocks can be staggered and embedded with a circle of the outer rear tooth blocks; the female stator and the male stator are front-to-back engaged by the staggered engagement of the inner front tooth blocks and the inner rear tooth blocks and the staggered engagement of the outer front tooth blocks and the outer rear tooth blocks, and are tightly fixed by the tight fit of the inner rear tooth blocks and the inner ring plate and the tight fit of the outer rear tooth blocks and the outer ring plate; after the female stator and the male stator are tightly engaged, the directions of all the rotor blades are consistent, and the space shape between two adjacent rotor blades constitutes a curved expansion channel with an airflow outlet area larger than an airflow inlet area, and the curved expansion channel can reduce the speed of the incoming subsonic airflow and increase the pressure.

[0032] Furthermore, a slot is provided on the inner wall of the stator outer ring corresponding to the installation position of the rotor blade to change the circumferential and axial pressure gradients near the inner wall of the stator outer ring, thereby suppressing the leakage of vortex at the tip of the rotor blade and improving the stall margin and surge.

[0033] Furthermore, a grate seal structure for reducing inter-stage backflow loss and air leakage loss is provided on the inner wall of the inner channel between the rotor blades and the stator blades.

[0034] The beneficial effects of the present invention are:

[0035] The present invention draws on the principle of axial flow compressors widely used in gas turbines (including aircraft engines). In view of the lower design indicators of civilian products, an electric motor is used to drive the compressor instead of the expansion work of high-temperature and high-pressure gas in the combustion chamber in the turbine group. By optimizing the structural design, selecting suitable materials, and improving the processing and molding technology, it not only has the characteristics of high efficiency, large flow rate, and high compression ratio of traditional axial flow compressors, but also greatly reduces the production and manufacturing costs, so that it is controlled within the acceptable range of civilian products.

[0036] The present invention is expected to greatly promote the competitiveness of various products in the international market due to its excellent performance and efficiency, and can be widely used in vacuum cleaners, sweepers, electric fans, hair dryers, violent fans, industrial air blowers, blowers, cooling fans, ventilation equipment, wind-powered fire extinguishers, model airplanes and other civilian electrical products (excluding toys and teaching instruments) as well as power components of small and medium-sized aircraft.

[0037] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. The specific implementation of the present invention is given in detail by the following embodiments and their accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0039] Figure 1 It is an external stereoscopic diagram of the rear motor-single duct-axial flow compressor (low pressure) in Example 1 of the present invention;

[0040] Figure 2 It is a three-dimensional cross-sectional view of the rear motor-single duct-axial flow compressor (low pressure) in Example 1 of the present invention;

[0041] Figure 3 It is a three-dimensional cross-sectional exploded view of the rear motor-single duct-axial flow compressor (low pressure) in Example 1 of the present invention;

[0042] Figure 4 It is an axial cross-sectional view of the rear motor-single duct-axial flow compressor (low pressure) in Example 1 of the present invention;

[0043] Figure 5 It is an assembly diagram of the combined working wheel leaf of the present invention;

[0044] Figure 6 It is an assembly diagram of the combined rectifier Ye Shan of the present invention;

[0045] Figure 7 It is a schematic diagram of the shape of the gap between two adjacent blades in the impeller blade and the rectifier blade of the present invention;

[0046] Figure 8 It is a working principle diagram of the multi-stage axial flow compressor of the present invention;

[0047] Fig. 9 A schematic diagram of the position of the slots of the present invention;

[0048] Fig.10 It is a structural schematic diagram of the comb teeth air sealing structure of the present invention;

[0049] Fig.11 It is an axial cross-sectional view of the rear motor-single duct-axial flow centrifugal hybrid compressor (low pressure) in Example 2 of the present invention;

[0050] Fig.12 It is an axial cross-sectional view of the rear motor-single duct-axial flow compressor (low pressure + high pressure) in Example 3 of the present invention;

[0051] Fig.13 It is an axial cross-sectional view of the rear motor-dual duct-axial flow compressor (low pressure + high pressure) in Example 4 of the present invention;

[0052] Fig.14 It is an axial cross-sectional view of the front motor-single duct-axial flow compressor (low pressure) in Example 5 of the present invention;

[0053] Fig.15 It is an axial cross-sectional view of the front motor-single duct-axial flow compressor (low pressure + high pressure) in Example 6 of the present invention;

[0054] Fig.16 It is an axial cross-sectional view of the front motor-dual duct-axial flow compressor (low pressure + high pressure) in Example 7 of the present invention;

[0055] Fig.17 It is an axial cross-sectional view of a mid-mounted motor-single duct-axial flow compressor (low pressure + high pressure) in Example 8 of the present invention;

[0056] Fig.18 It is an axial cross-sectional view of the mid-mounted motor-dual duct-axial flow compressor (low pressure + high pressure) in Example 9 of the present invention;

[0057] Fig.19 The figure is a schematic diagram of the position of the shock absorbing boss on the working wheel blade of the present invention. DETAILED DESCRIPTION

[0058] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings so that the purpose, features and advantages of the invention can be more clearly understood. It should be understood that the embodiments shown in the accompanying drawings are not intended to limit the scope of the present invention, but are only intended to illustrate the essential spirit of the technical solution of the present invention.

[0059] References throughout the specification to "one embodiment" or "an embodiment" indicate that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of "in one embodiment" or "in an embodiment" in various places throughout the specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any manner in one or more embodiments.

[0060] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. It should be noted that the term "or" is generally employed in its sense including "and / or" unless the context clearly dictates otherwise.

[0061] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0062] Example 1 A rear motor-single duct-axial flow compressor (low pressure)

[0063] See also Figure 1-4 As shown, a rear motor-single duct-axial flow compressor (low pressure) includes a casing 1, in which a low-pressure compressor unit is arranged, and the low-pressure compressor unit is mainly composed of two parts: a rotating rotor and a stationary stator. The rotor part is called a low-pressure impeller blade 2, and the stator part is called a low-pressure rectifier blade 3. The low-pressure compressor unit includes at least one group of the low-pressure impeller blade 2 and the low-pressure rectifier blade 3. The low-pressure impeller blade 2 in the same group is in front, and the low-pressure rectifier blade 3 is in the back, forming a basic unit of the low-pressure compressor unit, which is called a "stage". In this embodiment, the low-pressure compressor unit is a three-stage low-pressure compressor unit, which is composed of three groups of low-pressure impeller blades 2 and low-pressure rectifier blades 3 arranged in sequence.

[0064] The front fixed cover of the casing 1 is provided with an air inlet guide vane 4, which serves as the air inlet of the axial compressor. The rear end of the casing 1 is provided with an air outlet guide vane 5, which serves as the air outlet of the axial compressor. The air outlet guide vane 5 is fixedly connected to the inner wall of the casing 1. A single-output-shaft motor 7 is provided at the rear of the casing 1. A transmission shaft 8 is provided on the axis of the casing 1. The rear end of the transmission shaft 8 passes through the air outlet guide vane 5 and the casing flow channel split part 6 and is transmission-connected to the output end of the motor 7.

[0065] When the diameter of the motor 7 is smaller than the diameter of the casing 1, the casing 1 can adopt a straight-through flow channel structure. When the diameter of the motor 7 is larger than the diameter of the casing 1, the casing 1 can adopt a split flow channel structure with the rear end diffusing outward, and a casing flow channel splitting piece 6 is provided on the rear side of the air outlet guide leaf 5, and the outer diameter of the casing flow channel splitting piece 6 is smaller than the inner diameter of the rear end of the casing 1, thereby splitting the air flow channel. The casing of conventional axial flow compressors is mostly a HALF structure, which is high in cost and low in precision. The present invention splits the air flow channel design so that the casing can adopt an integrated injection molding process, improve installation accuracy, and reduce product costs.

[0066] According to the application scenario requirements, the motor 7 can be selected from a micro motor of less than 750 watts, a small motor of 750 watts to 7.5 kilowatts, or a medium-sized motor of 7.5 watts to 110 kilowatts. The type and size of the motor are defined by referring to the motor power size of GB / T 755, GB / T14711, GB / T 12350, GB / T 1032, GB / 18613 and the international standard IEC60034-1.

[0067] The three low-pressure rectifier blades 3 are composed of a stator outer ring, a stator inner ring, and stator blades uniformly connected between the stator inner ring and the stator outer ring. The three low-pressure rectifier blades 3 are fixedly arranged in the casing 1 by means of a tight fit (such as an interference fit) between the corresponding stator outer ring and the inner wall of the casing 1, and the three stator outer rings are arranged in sequence to form the rectifier outer ring wall of the axial flow compressor.

[0068] The three low-pressure impeller blades 2 are composed of a rotor inner ring, a rotor outer ring, a rotor connecting plate connected between the rotor inner ring and the rotor outer ring, and rotor blades uniformly arranged on the outer surface of the rotor outer ring. The three low-pressure impeller blades 2 are rotatably arranged in the casing 1 by means of a fixed sleeve connection between the corresponding rotor inner ring and the transmission shaft 8, and the three rotor blades are in a clearance fit relationship with the outer ring wall of the rectifier. The motor 7 drives the three low-pressure impeller blades 2 to rotate in the casing 1 through the transmission shaft 8.

[0069] The low-pressure working wheel blades 2 and the low-pressure rectifier blades 3, which are arranged alternately in sequence, together form an airflow channel connecting the air inlet of the axial flow compressor and the air outlet of the axial flow compressor in the blade area of ​​the two, as the inner channel 9 of the axial flow compressor. In order to form the inner channel 9 with a large air inlet and a small air outlet, the outer diameter of the stator outer ring of the same level in the present invention is greater than the outer diameter of the rotor outer ring of the same level, and the outer diameter of the stator inner ring of the previous level is greater than the outer diameter of the stator inner ring of the next level, and the outer diameter of the rotor outer ring of the previous level is greater than the outer diameter of the rotor outer ring of the next level. All the rotor outer rings and all the stator inner rings are arranged alternately in sequence to form the inner ring wall of the rectifier of the axial flow compressor, and the gap between the inner ring wall of the rectifier and the outer ring wall of the rectifier gradually decreases from front to back, thereby forming the inner channel 9 with a large air inlet and a small air outlet.

[0070] In order to further improve the efficiency, pressure ratio and other technical indicators of the compressor, a higher blade consistency must be used, but high consistency will cause the blade to be unable to be injection molded and to have undercuts. Therefore, the low-pressure impeller blade 2 and / or the low-pressure rectifier blade 3 of the present invention adopt a combined blade group design, that is, segmented molding and then assembled into a whole. The combined blade group can solve the problem of being unable to be injection molded due to too small a gap or undercuts.

[0071] Take the low-pressure working wheel Ye Shan 2 as an example, see Figure 5As shown, the low-pressure impeller blade 2 is composed of a female rotor and a male rotor that are tightly engaged front and back. The male rotor includes an annular plate 16, the central hole wall of the annular plate 16 serves as the inner ring of the rotor, and a plurality of forward arc-shaped mounting plates 17 extending forward are arranged at equal angles on the outer wall of the annular plate 16, the curvature of each forward arc-shaped mounting plate 17 is the same as that of the annular plate 16, and a rotor blade 18 is arranged on the outer wall of each forward arc-shaped mounting plate 17. The female rotor includes an annular ring 19, the outer diameter of the annular ring 19 is equal to the outer diameter of the annular plate 16, and a plurality of backward arc-shaped mounting plates 20 extending backward are arranged at equal angles on the outer wall of the annular ring 19, the curvature of each backward arc-shaped mounting plate 20 is the same as that of the annular ring 19, and a rotor blade 18 is arranged on the outer wall of each backward arc-shaped mounting plate 20. The spacing between two adjacent forward arc-shaped mounting plates 17 corresponds to the width of one backward arc-shaped mounting plate 20, and the spacing between two adjacent backward arc-shaped mounting plates 20 corresponds to the width of one forward arc-shaped mounting plate 17; the female rotor and the male rotor are assembled front and back by staggered engagement of the backward arc-shaped mounting plates 20 and the forward arc-shaped mounting plates 17, and are tightly fixed by tight fit between the backward arc-shaped mounting plates 20 and the annular plate 16 and the forward arc-shaped mounting plates 17 and the annular ring 19. After the female rotor and the male rotor are tightly engaged, the forward arc-shaped mounting plates 17 and the backward arc-shaped mounting plates 20 arranged in sequence form the outer ring of the rotor, and all the rotor blades 18 are oriented in the same direction.

[0072] Take the low voltage rectifier Ye Shan 3 as an example, see Figure 6As shown, the low-voltage rectifier Ye Shan 3 is composed of a female stator and a male stator that are tightly engaged front and back; the female stator includes an inner ring plate 23 as the inner ring of the stator and an outer ring plate 24 as the outer ring of the stator, and a plurality of inner front tooth blocks 25 are arranged at equal angles on the outer wall of the inner ring plate 23, and the curvature of each inner front tooth block 25 is the same as that of the inner ring plate 23, and a plurality of outer front tooth blocks 26 are arranged at equal angles on the inner wall of the outer ring plate 24, and each of the inner front tooth blocks 26 is arranged at equal angles. The curvature of the outer front tooth block 26 is the same as that of the outer ring plate 24, and a stator blade 27 is fixedly connected between each of the inner front tooth blocks 25 and the corresponding outer front tooth block 26; the male stator includes an inner hoop 28 with a diameter slightly smaller than that of the inner ring plate 23 and an outer hoop 29 with a diameter slightly smaller than that of the outer ring plate 24, and a plurality of inner rear tooth blocks 30 are arranged at equal angles on the front end surface of the inner hoop 28, and the curvature of each inner rear tooth block 30 is the same as that of the outer ring plate 24. The inner hoop 28 has the same curvature, and a plurality of outer rear tooth blocks 31 are arranged at equal angles on the front end surface of the outer hoop 29, and the curvature of each outer rear tooth block 31 is the same as that of the outer hoop 29. A stator blade 27 is fixedly connected between each inner rear tooth block 30 and a corresponding outer rear tooth block 31; a circle of the inner front tooth blocks 25 can be staggered with a circle of the inner rear tooth blocks 30, and a circle of the outer front tooth blocks 26 can be staggered with a circle of the outer rear tooth blocks 3 1 interlaced engagement; the female stator and the male stator are engaged front and rear through the interlaced engagement of the inner front tooth block 25 and the inner rear tooth block 30 and the interlaced engagement of the outer front tooth block 26 and the outer rear tooth block 31, and are tightly fixed through the tight fit of the inner rear tooth block 30 and the inner ring plate 23 and the tight fit of the outer rear tooth block 31 and the outer ring plate 24; after the female stator and the male stator are tightly engaged, the directions of all the rotor blades 18 are consistent.

[0073] See also Figure 7-8 As shown, in each of the low-pressure working wheel blades 2 and each of the low-pressure rectifier blades 3, the space shape between two adjacent blades constitutes a curved expansion channel, and the airflow outlet area of ​​the curved expansion channel is larger than the airflow inlet area. According to gas mechanics, when a subsonic airflow flows through an expansion channel, the speed of the airflow decreases and the pressure increases. In the low-pressure working wheel blades 2, the airflow obtains the mechanical work of the rotor blades, and while increasing the pressure (including total pressure and static pressure), the absolute kinetic energy is also increased. In the subsequent low-pressure rectifier blades 3, the airflow gradually decelerates under the action of the stator blades, converting the kinetic energy into an increase in static pressure, and changing the direction of the airflow flow to meet the needs of the next stage. For a multi-stage compressor, the airflow flows through one stage after another in sequence, repeating the above process, and the pressure of the gas is gradually increased.

[0074] The single-stage compression ratio (ratio of the pressure after the stage to the pressure before the stage) of a subsonic compressor is generally about 1.2-1.5, but after the airflow passes through multiple stages of supercharging, it can reach an extremely high compression ratio. According to tests, for example, the compression ratio of a three-stage axial flow compressor is about 3-4, and the compression ratio of a multi-stage axial flow compressor with more than three stages can reach 6-10. If there is market demand for certain products and the cost allows, a compression ratio of 10-20 can even be obtained, and the outlet wind speed can reach more than 200 meters per second. It should be noted that the above refers to the compression ratio values ​​under subsonic conditions. Supersonic designs can use shock waves to increase the compression ratio, but the shock waves will cause great noise and vibration.

[0075] See also Fig. 9 As shown, a circle of evenly distributed slots 21 are axially provided on the inner wall of the stator outer ring corresponding to the installation position of the rotor blades, thereby changing the circumferential and axial pressure gradients near the inner wall of the casing 1, suppressing the leakage vortex at the tip of the rotor blades, thereby improving the stall margin and surging of the axial compressor. Fig.10 As shown, a grate seal structure 22 is provided on the inner wall of the inner channel 9 between the rotor blades and the stator blades, thereby reducing interstage backflow loss and leakage loss. The slots 21 and the grate seal structure 22 can be injection molded together with the stator outer ring.

[0076] Since the intake speed of civil electrical appliances driven by motors is low, the operating speed change is small, and the total boost is relatively low, the surge problem of axial compressors is not as serious as that of gas turbines (including aircraft engines). Therefore, the present invention does not design unnecessary complex and expensive surge control structures such as exhaust devices, rotatable inlet guide vanes, rotatable stator vanes, etc., but retains the casing treatment and grate seal gas structure with limited cost increase and injection molding, and is equipped with a series of low-cost means such as appropriate subsonic blade design, flexible motor speed adjustment, etc. to control the surge of axial compressors, greatly reducing the cost of products.

[0077] The stator and casing of conventional axial compressors are usually fastened by bolts, which is very costly. The stator (rectifier blade) of the present invention is directly tightly matched with the casing, and the rotor (working wheel blade) is directly tightly matched with the motor shaft, without any bolt fasteners, which greatly reduces the cost.

[0078] In view of the low working temperature of civil products and the continuous working time generally calculated in minutes, the material requirements do not need to be too strict. The working temperature at 6 times the pressure ratio is only about 150°C, so the present invention uses a nylon carbon fiber mixed material, which greatly reduces the cost.

[0079] The blades of conventional axial compressors are basically mortise and tenon structures, and the cost of processing and assembling thousands of blades one by one is extremely high. The present invention appropriately reduces the blade density and adjusts the hub shape to eliminate the undercut shape of the product during injection molding, so that the rotor (working wheel blades) and stator (rectifier blades), casing, inlet guide vanes, etc. can all adopt the injection molding process, greatly reducing product costs.

[0080] In summary, the present invention is based on the design principle of axial flow compressor and, according to the performance characteristics of civil electrical appliances, makes corresponding design, structure, material, process and other improvement measures on the premise of maintaining most of its performance and efficiency, and makes every effort to significantly reduce the cost so that the cost can be borne by civil electrical appliances.

[0081] Example 2: Rear motor-single duct-axial flow centrifugal mixed compressor (low pressure)

[0082] On the basis of Example 1, a centrifugal fan 10 is additionally provided inside the casing 1, thereby forming a rear motor-single duct-axial flow centrifugal hybrid compressor (low pressure).

[0083] See also Fig.11 As shown, the low-pressure compressor unit is located at the front part of the casing 1, and the centrifugal fan 10 is located at the rear part of the casing 1. The centrifugal fan 10 is fixedly mounted on the transmission shaft 8 and driven by the motor 7 to realize rotation in the casing 1. The low-pressure working wheel blades 2, the low-pressure rectifier blades 3 and the centrifugal fan 10, which are arranged alternately in sequence, together form an airflow channel connecting the air inlet of the axial flow compressor and the air outlet of the axial flow compressor in the blade area of ​​the three, serving as the inner channel 9 of the axial flow compressor. This embodiment combines an axial flow compressor and a centrifugal compressor. The centrifugal compressor has the advantages of a high single-stage compression ratio and a wide working range. The axial flow compressor and the centrifugal compressor can be combined to have the advantages of both.

[0084] Example 3: Rear motor - single duct - axial compressor (low pressure + high pressure)

[0085] On the basis of Example 1, a high-pressure compressor unit and a speed change mechanism 11 are additionally provided inside the casing 1, thereby forming a rear motor-single duct-axial flow compressor (low pressure + high pressure).

[0086] See also Fig.12 As shown, the low-pressure compressor unit is located at the front portion of the casing 1 , the high-pressure compressor unit is located at the rear portion of the casing 1 , and the speed change mechanism 11 is located at the middle portion of the casing 1 .

[0087] The structure of the high-pressure compressor unit is the same as that of the low-pressure compressor unit, and is also mainly composed of two parts: a rotating rotor and a stationary stator. The rotor part is called a high-pressure impeller blade 12, and the stator part is called a high-pressure rectifier blade 13. The high-pressure compressor unit includes at least one group of the high-pressure impeller blade 12 and the high-pressure rectifier blade 13. The high-pressure impeller blade 12 in the same group is in front, and the high-pressure rectifier blade 13 is in the back, forming a basic unit of the high-pressure compressor unit, which is called a "stage". In this embodiment, the high-pressure compressor unit is a three-stage high-pressure compressor unit, which is composed of three groups of high-pressure impeller blades 12 and high-pressure rectifier blades 13 arranged in sequence.

[0088] Slightly different from the transmission shaft 8 in Example 1, the transmission shaft 8 in this embodiment is divided into two sections, one section is arranged through the rear part of the casing 1, and the other section is arranged through the front part of the casing 1; the rear end of the rear section of the transmission shaft 8 is connected to the output shaft of the motor 7, the front end of the rear section of the transmission shaft 8 is connected to the rear end of the speed change mechanism 11, and the rear end of the front section of the transmission shaft 8 is connected to the front end of the speed change mechanism 11.

[0089] The high-pressure rectifier blade 13 has the same structure as the low-pressure rectifier blade 3, and is composed of a stator outer ring, a stator inner ring, and stator blades uniformly connected between the stator inner ring and the stator outer ring. The three low-pressure rectifier blades 3 are fixedly arranged at the front of the casing 1 by means of a tight fit between the corresponding stator outer rings and the inner wall of the casing 1, and the corresponding stator outer rings of the three low-pressure rectifier blades 3 form the rectifier outer ring wall of the low-pressure compressor unit after being arranged in sequence. The three high-pressure rectifier blades 13 are fixedly arranged at the rear of the casing 1 by means of a tight fit between the corresponding stator outer rings and the inner wall of the casing 1, and the corresponding stator outer rings of the three high-pressure rectifier blades 13 form the rectifier outer ring wall of the high-pressure compressor unit after being arranged in sequence.

[0090] The high-pressure impeller blades 12 have the same structure as the low-pressure impeller blades 2, and are both composed of a rotor inner ring, a rotor outer ring, a rotor connecting plate connected between the rotor inner ring and the rotor outer ring, and rotor blades uniformly arranged on the outer surface of the rotor outer ring. The three low-pressure impeller blades 2 are rotatably arranged at the front of the casing 1 by means of a fixed sleeve connection between the corresponding rotor inner ring and the front section of the transmission shaft 8, and the rotor blades corresponding to the three low-pressure impeller blades 2 are in a clearance fit relationship with the outer ring wall of the rectifier of the low-pressure compressor unit. The three high-pressure impeller blades 12 are rotatably arranged at the rear of the casing 1 by means of a fixed sleeve connection between the corresponding rotor inner ring and the rear section of the transmission shaft 8, and the rotor blades corresponding to the three high-pressure impeller blades 12 are in a clearance fit relationship with the outer ring wall of the rectifier of the high-pressure compressor unit. The motor 7 drives the three high-pressure working wheel leaves 12 and the three low-pressure working wheel leaves 2 to rotate in the casing 1 at the same time through the transmission shaft 8 at the rear section, the speed change mechanism 11 and the transmission shaft at the front section.

[0091] The outer diameter of the speed change mechanism 11 is smaller than the inner diameter of the middle part of the casing 1, and the gap between the outer edge of the speed change mechanism 11 and the inner wall of the middle part of the casing 1 constitutes an airflow middle channel. The low-pressure impeller blades 2 and the low-pressure rectifier blades 3, which are arranged alternately in sequence, together constitute an airflow front channel connecting the air inlet of the axial flow compressor and the airflow middle channel in their blade areas. The high-pressure impeller blades 12 and the high-pressure rectifier blades 13, which are arranged alternately in sequence, together constitute an airflow rear channel connecting the airflow middle channel and the air outlet of the axial flow compressor in their blade areas. The airflow front channel, the airflow middle channel and the airflow rear channel are connected in sequence to form the inner channel 9 of the axial flow compressor.

[0092] The high-voltage impeller blades 12 and / or the high-voltage rectifier blades 13 may also be designed as a combined blade set, that is, they are formed in sections and then assembled into a whole.

[0093] Taking the high pressure working wheel Ye Shan 12 as an example, see Figure 5As shown, the high-pressure impeller blade 12 is composed of a female rotor and a male rotor that are tightly engaged front and back. The male rotor includes an annular plate 16, the central hole wall of the annular plate 16 serves as the inner ring of the rotor, and a plurality of forward arc-shaped mounting plates 17 extending forward are arranged at equal angles on the outer wall of the annular plate 16, the curvature of each forward arc-shaped mounting plate 17 is the same as that of the annular plate 16, and a rotor blade 18 is arranged on the outer wall of each forward arc-shaped mounting plate 17. The female rotor includes an annular ring 19, the outer diameter of the annular ring 19 is equal to the outer diameter of the annular plate 16, and a plurality of backward arc-shaped mounting plates 20 extending backward are arranged at equal angles on the outer wall of the annular ring 19, the curvature of each backward arc-shaped mounting plate 20 is the same as that of the annular ring 19, and a rotor blade 18 is arranged on the outer wall of each backward arc-shaped mounting plate 20. The spacing between two adjacent forward arc-shaped mounting plates 17 corresponds to the width of one backward arc-shaped mounting plate 20, and the spacing between two adjacent backward arc-shaped mounting plates 20 corresponds to the width of one forward arc-shaped mounting plate 17; the female rotor and the male rotor are assembled front and back by staggered engagement of the backward arc-shaped mounting plates 20 and the forward arc-shaped mounting plates 17, and are tightly fixed by tight fit between the backward arc-shaped mounting plates 20 and the annular plate 16 and the forward arc-shaped mounting plates 17 and the annular ring 19. After the female rotor and the male rotor are tightly engaged, the forward arc-shaped mounting plates 17 and the backward arc-shaped mounting plates 20 arranged in sequence form the outer ring of the rotor, and all the rotor blades 18 are oriented in the same direction.

[0094] Taking the high voltage rectifier Ye Shan 13 as an example, see Figure 6As shown, the high-voltage rectifier Ye Shan 13 is composed of a female stator and a male stator that are tightly engaged front and back; the female stator includes an inner ring plate 23 as the inner ring of the stator and an outer ring plate 24 as the outer ring of the stator, and a plurality of inner front tooth blocks 25 are arranged at equal angles on the outer wall of the inner ring plate 23, and the curvature of each inner front tooth block 25 is the same as that of the inner ring plate 23, and a plurality of outer front tooth blocks 26 are arranged at equal angles on the inner wall of the outer ring plate 24, each of which is arranged at equal angles. The curvature of the outer front tooth block 26 is the same as that of the outer ring plate 24, and a stator blade 27 is fixedly connected between each of the inner front tooth blocks 25 and the corresponding outer front tooth block 26; the male stator includes an inner hoop 28 with a diameter slightly smaller than that of the inner ring plate 23 and an outer hoop 29 with a diameter slightly smaller than that of the outer ring plate 24, and a plurality of inner rear tooth blocks 30 are arranged at equal angles on the front end surface of the inner hoop 28, and the curvature of each inner rear tooth block 30 is the same as that of the outer ring plate 24. The inner hoop 28 has the same curvature, and a plurality of outer rear tooth blocks 31 are arranged at equal angles on the front end surface of the outer hoop 29, and the curvature of each outer rear tooth block 31 is the same as that of the outer hoop 29. A stator blade 27 is fixedly connected between each inner rear tooth block 30 and a corresponding outer rear tooth block 31; a circle of the inner front tooth blocks 25 can be staggered with a circle of the inner rear tooth blocks 30, and a circle of the outer front tooth blocks 26 can be staggered with a circle of the outer rear tooth blocks 3 1 interlaced engagement; the female stator and the male stator are engaged front and rear through the interlaced engagement of the inner front tooth block 25 and the inner rear tooth block 30 and the interlaced engagement of the outer front tooth block 26 and the outer rear tooth block 31, and are tightly fixed through the tight fit of the inner rear tooth block 30 and the inner ring plate 23 and the tight fit of the outer rear tooth block 31 and the outer ring plate 24; after the female stator and the male stator are tightly engaged, the directions of all the rotor blades 18 are consistent.

[0095] The blade structures of the high-voltage impeller blade 12 and the high-voltage rectifier blade 13 are the same as the blade structures of the low-voltage impeller blade 2 and the low-voltage rectifier blade 3. Figure 7-8As shown, in each of the high-pressure working wheel blades 12 and each of the high-pressure rectifier blades 13, the space shape between two adjacent blades constitutes a curved expansion channel, and the airflow outlet area of ​​the curved expansion channel is larger than the airflow inlet area. According to gas mechanics, when a subsonic airflow flows through an expansion channel, the speed of the airflow decreases and the pressure increases. In the high-pressure working wheel blades 12, the airflow obtains the mechanical work of the rotor blades, and while increasing the pressure (including total pressure and static pressure), the absolute kinetic energy is also increased. In the subsequent high-pressure rectifier blades 13, the airflow gradually decelerates under the action of the stator blades, converting the kinetic energy into an increase in static pressure, and changing the direction of the airflow flow to meet the needs of the next stage. For a multi-stage compressor, the airflow flows through one stage after another in sequence, repeating the above process, and the pressure of the gas is gradually increased.

[0096] See also Fig. 9 As shown, a circle of evenly distributed slots 21 are axially provided on the inner wall of the casing 1 corresponding to the installation position of the high-pressure impeller blade 12, thereby changing the circumferential and axial pressure gradients near the inner wall of the casing 1, suppressing the leakage vortex at the tip of the rotor blade, thereby improving the stall margin and surging of the axial flow compressor. Fig.10 As shown, a grate gas sealing structure 22 is provided on the inner wall of the casing 1 between the high-voltage impeller blade 12 and the high-voltage rectifier blade 13, thereby reducing interstage backflow loss and gas leakage loss. The slot 21 and the grate gas sealing structure 22 can be injection molded together with the casing 1.

[0097] The embodiments of the present invention are not limited to a dual-rotor structure, but may also adopt a three-rotor structure design, that is, through three compressor units connected in series, they are divided into a low-pressure compressor unit, a medium-pressure compressor unit and a high-pressure compressor unit. Through a speed change device, each compressor unit is adapted to a different rotational speed, which can achieve higher compression efficiency, a larger total compression ratio and a wider stable operating range.

[0098] Example 4: Rear motor - dual duct - axial compressor (low pressure + high pressure)

[0099] On the basis of Example 3, a rear motor-double duct-axial flow compressor (low pressure + high pressure) is formed by adding a large fan 14 in front of the casing 1 and jointly covering the large fan 14 and the outside of the casing 1 with a cylindrical cover 15.

[0100] See also Fig.13As shown, the cover 15 is coaxial with the casing 1, and the large fan 14 is fixedly sleeved on the front end of the transmission shaft 8 at the front section, and is driven by the motor 7 to realize rotation in the cover 15. The large fan 14 can directly replace the air intake guide vane 4 set at the front section of the casing 1 in Example 3. The gap between the outer wall of the casing 1 and the inner wall of the cover 15 constitutes an outer airflow channel, which serves as an outer duct 23 of the axial flow compressor. Similar to an aviation turbofan engine, part of the airflow goes through the outer duct, and part of the airflow and the axial flow compressor go through the inner duct together.

[0101] Example 5: Front motor - single duct - axial compressor (low pressure)

[0102] On the basis of Example 1, the motor 7 is arranged from the rear to the front of the casing 1, thereby forming a front motor-single duct-axial flow compressor (low pressure).

[0103] See also Fig.14 As shown, different from the rear motor method of embodiment 1, the motor 7 of this embodiment is located in front of the casing 1, and the output shaft of the motor 7 is drivingly connected to the front end of the transmission shaft 8.

[0104] Example 6: Front motor - single duct - axial flow compressor (low pressure + high pressure)

[0105] On the basis of Example 3, the motor 7 is arranged from the rear to the front of the casing 1, thereby forming a front motor-single duct-axial flow compressor (low pressure + high pressure).

[0106] See also Fig.15 As shown, different from the rear motor method of embodiment 3, the motor 7 of this embodiment is located in front of the casing 1, and the output shaft of the motor 7 is drivingly connected to the front end of the transmission shaft 8 of the front section.

[0107] Example 7: Front motor - dual duct - axial flow compressor (low pressure + high pressure)

[0108] On the basis of Example 4, the motor 7 is arranged from the rear to the front of the casing 1, thereby forming a front motor-double duct-axial flow compressor (low pressure + high pressure).

[0109] See also Fig.16 As shown, different from the rear motor method of embodiment 4, the motor 7 of this embodiment is located in front of the casing 1, and the output shaft of the motor 7 is drivingly connected to the front end of the transmission shaft 8 of the front section.

[0110] Example 8: Mid-mounted motor - single duct - axial flow compressor (low pressure + high pressure)

[0111] On the basis of Example 3 or Example 6, the motor 7 is arranged from the rear or front of the casing 1 to the inside, thereby forming a mid-mounted motor-single duct-axial flow compressor (low pressure + high pressure).

[0112] See also Fig.17 As shown, different from the rear motor of embodiment 3 and the front motor of embodiment 6, the motor 7 of this embodiment is changed from a single output shaft motor to a dual output shaft motor, the motor 7 is located in the center of the casing 1, the front output shaft of the motor 7 is connected to the rear end of the speed change mechanism 11, the front end of the speed change mechanism 11 is connected to the rear end of the transmission shaft 8 of the front section, and the rear output shaft of the motor 7 is connected to the front end of the transmission shaft 8 of the rear section. The front output shaft of the motor 7 drives the rotation of all the low-pressure working wheel leaves 2 through the speed change mechanism 11 and the transmission shaft 8 of the front section, and the rear output shaft of the motor 7 drives the rotation of all the high-pressure working wheel leaves 12 through the transmission shaft 8 of the rear section.

[0113] Example 9: Mid-mounted motor - dual duct - axial flow compressor (low pressure + high pressure)

[0114] On the basis of Example 4 or Example 7, the motor 7 is arranged from the rear or front of the casing 1 to the inside, thereby forming a mid-mounted motor-double duct-axial flow compressor (low pressure + high pressure).

[0115] See also Fig.18 As shown, unlike the rear motor of embodiment 4 and the front motor of embodiment 7, the motor 7 of this embodiment is changed from a single output shaft motor to a dual output shaft motor, the motor 7 is located in the center of the casing 1, the front output shaft of the motor 7 is connected to the rear end of the speed change mechanism 11, the front end of the speed change mechanism 11 is connected to the rear end of the transmission shaft 8 of the front section, and the rear output shaft of the motor 7 is connected to the front end of the transmission shaft 8 of the rear section. The front output shaft of the motor 7 drives the rotation of all the low-pressure working wheel leaves 2 and the large fan 14 through the speed change mechanism 11 and the transmission shaft 8 of the front section, and the rear output shaft of the motor 7 drives the rotation of all the high-pressure working wheel leaves 12 through the transmission shaft 8 of the rear section.

[0116] Example 10 Front motor-single duct-axial flow turbine hybrid compressor (low pressure)

[0117] On the basis of Example 5, a turbine group is added inside the casing 1 to form a front motor-single duct-axial turbine hybrid compressor (low pressure).

[0118] Inside the casing 1, the low-pressure compressor unit works on the gas, and then the gas works on the turbine unit, and the heat of the front motor 7 is used to mix the exhaust gas of the low-pressure compressor unit to work on the turbine unit. The present invention is an electrically driven compressor without a combustion chamber. The efficiency of the motor is generally above 90%, and can reach 98% at most. Under normal circumstances, the cost-effectiveness of using the heat of the motor to mix the exhaust gas of the compressor to work on the turbine is not high, but it does not completely rule out installing a turbine behind the motor, using the heat of the motor to mix the exhaust gas of the compressor to work on the turbine, and increasing the motor shaft power.

[0119] Example 11 Axial Flow Compressor Driven by Large or Extra Large Motor

[0120] Although the drone, helicopter, and large turbofan transport aircraft industries are booming, there is still a serious lack of heavy-load aircraft. Compared with propeller blades, the diameter of the propeller blades is generally around 12 meters when the takeoff weight is 10 tons. Under the same power, the outer diameter of the electric-driven axial compressor is only about one-tenth of the propeller diameter, but the cost is almost the same. Because the boost pressure is relatively high, the flight speed is faster, and the size and convenience are incomparable, which is suitable for designing aircraft with large load capacity.

[0121] Compared with turbofan aircraft engines, although the electric drive thrust is only a fraction of that of turbofan aircraft engines at the same diameter, the flight speed is relatively low. However, at the same power, the cost of an electric drive compressor is only about one percent of that of a turbofan aircraft engine, and heavy-duty aircraft design can be achieved by stacking the number of electric drive compressors. In summary, in the field of heavy-duty aircraft that do not pursue speed, electric drive axial flow compressors are small in size, moderate in flight speed, and extremely low in cost, and have broad market prospects!

[0122] Specifically, in the industrial design and production of large or extra-large electric-driven axial compressors (or axial-flow centrifugal hybrid compressors), although there are extremely high requirements in aerodynamics, thermal engineering, structure and strength, control, testing, manufacturing technology and materials, the basic structural layout is still similar to that of small and medium-sized electric-driven compressors. According to the application scenario requirements, the motor 7 can select a large motor of 110 kW to 1000 kW or an extra-large motor of 1000 kW and above.

[0123] In view of the relatively low speed and pressure ratio requirements of heavy-duty aircraft, the load standard of a single blade can be appropriately reduced, and the injection molding process can still be considered to reduce the cost by hundreds of times. However, after all, the blade load and working conditions of large compressors are incomparable to those of small and medium-sized compressors. The moving blades are prone to flutter and cause damage to the compressor (the stationary blades have inner and outer ring structures that are relatively strong), see Fig.19 As shown, it is possible to consider designing a shock-absorbing boss 32 near the tip of the moving blade, and the cost will hardly increase.

[0124] If the aircraft has higher requirements for high and low temperatures during operation, aluminum alloy die-casting technology can be used (titanium alloy and stainless steel are too expensive); if the aircraft has higher requirements for the boost ratio, a low-pressure + high-pressure dual-rotor compressor can be used; if the compressor has a wide operating range, in order to eliminate surge, gradually add steel belt exhaust devices, adjustable angle inlet guide vanes, adjustable angle stator blades and other measures; if in order to improve efficiency and reduce leakage losses, add wear-resistant coatings on the inner wall of the casing, but the cost will also increase sharply.

[0125] The essence of this invention is to simplify the design of the extremely high-end axial compressor and greatly reduce the cost so that it can be accepted by civilian products. The core difficulty lies in the design of the compressor assembly. As long as the cost can be properly controlled, given the excellent large flow, high efficiency and ultra-high pressure ratio of the axial compressor, perhaps many incredible products can be realized.

[0126] For example, an axial flow compressor with a low-pressure compressor unit and a high-pressure compressor unit can have a compression ratio of 6-10, which can reach or exceed the pressure of a small air compressor. This axial flow compressor can be used to produce handheld ultra-high-pressure air blowers, which can replace small air compressors in many application scenarios. This is equivalent to opening up a whole new market.

[0127] For example, if an axial flow compressor with a low-pressure compressor unit and a high-pressure compressor unit is used, and the compression ratio is increased to 10-20 through material and process optimization, the outlet wind speed can reach about 200 meters per second. This axial flow compressor can be used in blower-type fire extinguishers.

[0128] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An axial flow compressor driven by a motor, characterized in that: The invention comprises a casing (1), wherein a low-pressure compressor unit is arranged in the casing (1), wherein the low-pressure compressor unit is composed of at least one group of low-pressure working wheel blades (2) and low-pressure rectifier blades (3) arranged in sequence, wherein the low-pressure working wheel blades (2) of the same group are in front and the low-pressure rectifier blades (3) are in the rear, forming a first stage of the low-pressure compressor unit; the front end fixed cover of the casing (1) is provided with an air inlet guide blade (4) serving as an air inlet of the axial flow compressor; the rear end of the casing (1) is provided with an air outlet guide blade (5) serving as an air outlet of the axial flow compressor, and the air outlet guide blade (5) is fixedly connected to the inner wall of the casing (1); All of the low-pressure rectifier blades (3) are fixedly connected to the inner wall of the casing (1); a transmission shaft (8) driven by a motor (7) is inserted into the casing (1); all of the low-pressure working wheel blades (2) are fixedly sleeved on the transmission shaft (8) and driven by the motor (7) to rotate in the casing (1); the low-pressure working wheel blades (2) and the low-pressure rectifier blades (3) arranged alternately in sequence together form an airflow channel connecting the axial flow compressor air inlet and the axial flow compressor air outlet in the blade areas of the two, serving as the inner channel (9) of the axial flow compressor; in each of the low-pressure working wheel blades (2) and each of the low-pressure rectifier blades (3), the space shape between two adjacent blades forms a curved expansion channel with an airflow outlet area larger than an airflow inlet area, and the curved expansion channel can reduce the speed of the incoming subsonic airflow and increase the pressure.

2. The motor-driven axial flow compressor according to claim 1, characterized in that: A centrifugal fan (10) or a turbine group is also arranged in the casing (1), the low-pressure compressor group is located at the front part of the casing (1), and the centrifugal fan (10) or the turbine group is located at the rear part of the casing (1). The centrifugal fan (10) or the turbine group is fixedly sleeved on the transmission shaft (8) and driven by the motor (7) to realize rotation in the casing (1); the low-pressure working wheel blades (2) and the low-pressure rectifier blades (3) arranged alternately in sequence and the centrifugal fan (10) or the turbine group together form an air flow channel connecting the axial flow compressor air inlet and the axial flow compressor air outlet in the blade area of ​​the three, which serves as the inner channel (9) of the axial flow compressor.

3. The motor-driven axial flow compressor according to claim 1 or 2, characterized in that: The motor (7) is arranged in front of or behind the casing (1); When the motor (7) is located in front of the casing (1), the motor (7) is a single-output-shaft motor, and the output shaft of the motor (7) is in driving connection with the front end of the transmission shaft (8); When the motor (7) is located at the rear of the casing (1), the motor (7) is a single-output-shaft motor, and the output shaft of the motor (7) is drivingly connected to the rear end of the transmission shaft (8).

4. The motor-driven axial flow compressor according to claim 1, characterized in that: The casing (1) is also provided with a high-pressure compressor unit and a speed change mechanism (11), wherein the low-pressure compressor unit is located at the front portion of the casing (1), the high-pressure compressor unit is located at the rear portion of the casing (1), and the speed change mechanism (11) is located at the middle portion of the casing (1); The high-pressure compressor unit is composed of at least one group of high-pressure impeller blades (12) and high-pressure rectifier blades (13) arranged in sequence, with the high-pressure impeller blades (12) in the front and the high-pressure rectifier blades (13) in the rear, forming one stage of the high-pressure compressor unit; The transmission shaft (8) is divided into two sections, one section passing through the rear part of the casing (1), and the other section passing through the front part of the casing (1); the rear end of the transmission shaft (8) of the rear section is connected to the output shaft of the motor (7), the front end of the transmission shaft (8) of the rear section is connected to the rear end of the speed change mechanism (11), and the rear end of the transmission shaft (8) of the front section is connected to the front end of the speed change mechanism (11); All the high-voltage rectifier blades (13) are fixedly connected to the rear inner wall of the casing (1), and all the high-voltage working wheel blades (12) are fixedly sleeved on the transmission shaft (8) located at the rear section, and are driven by the transmission shaft (8) located at the rear section to realize rotation in the casing (1); All the low-voltage rectifier blades (3) are fixedly connected to the front inner wall of the casing (1), and all the low-voltage working wheel blades (2) are fixedly sleeved on the transmission shaft (8) located at the front section, and are driven by the transmission shaft (8) located at the front section to realize rotation in the casing (1); In each of the high-pressure impeller blades (12) and each of the high-pressure rectifier blades (13), the space between two adjacent blades forms a curved expansion channel in which the airflow outlet area is larger than the airflow inlet area, and the curved expansion channel can reduce the speed of the incoming subsonic airflow and increase the pressure; The outer diameter of the speed change mechanism (11) is smaller than the inner diameter of the middle part of the casing (1), and the gap between the outer edge of the speed change mechanism (11) and the inner wall of the middle part of the casing (1) constitutes an airflow middle channel; the low-pressure working wheel blades (2) and the low-pressure rectifier blades (3) arranged alternately in sequence jointly constitute an airflow front channel connecting the air inlet of the axial flow compressor and the airflow middle channel in their blade areas; the high-pressure working wheel blades (12) and the high-pressure rectifier blades (13) arranged alternately in sequence jointly constitute an airflow rear channel connecting the airflow middle channel and the air outlet of the axial flow compressor in their blade areas; the airflow front channel, the airflow middle channel and the airflow rear channel are connected in sequence to form an inner channel (9) of the axial flow compressor.

5. The motor-driven axial flow compressor according to claim 4, characterized in that: A large fan (14) is arranged in front of the casing (1), and the large fan (14) and the outside of the casing (1) are jointly covered by a cylindrical cover (15). The cover (15) is coaxial with the casing (1). The large fan (14) is fixedly sleeved on the front end of the transmission shaft (8) of the front section, and is driven by the motor (7) to realize rotation in the cover (15). The gap between the outer wall of the casing (1) and the inner wall of the cover (15) constitutes an external airflow channel, which serves as an outer duct (23) of the axial flow compressor.

6. The motor-driven axial flow compressor according to claim 4 or 5, characterized in that: The motor (7) is arranged at the front, rear or inner center of the casing (1); When the motor (7) is located in front of the casing (1), the motor (7) is a single-output-shaft motor, and the output shaft of the motor (7) is in driving connection with the front end of the transmission shaft (8) at the front section; When the motor (7) is located at the rear of the casing (1), the motor (7) is a single-output-shaft motor, and the output shaft of the motor (7) is in driving connection with the rear end of the transmission shaft (8) at the rear section; When the motor (7) is located at the center of the casing (1), the motor (7) is a dual-output shaft motor, the front output shaft of the motor (7) is transmission-connected to the rear end of the speed change mechanism (11), the front end of the speed change mechanism (11) is transmission-connected to the rear end of the transmission shaft (8) at the front section, and the rear output shaft of the motor (7) is transmission-connected to the front end of the transmission shaft (8) at the rear section.

7. The motor-driven axial flow compressor according to claim 1, characterized in that: The low-pressure rectifier blade (3) and the high-pressure rectifier blade (13) have the same structure, and are both composed of a stator outer ring, a stator inner ring, and stator blades uniformly connected between the stator inner ring and the stator outer ring; the low-pressure rectifier blade (3) and the high-pressure rectifier blade (13) are both fixedly arranged in the casing (1) by means of a tight fit between the stator outer ring and the inner wall of the casing (1), and all the stator outer rings are arranged in sequence to form the rectifier outer ring wall of the axial flow compressor; The low-pressure impeller blades (2) and the high-pressure impeller blades (12) have the same structure, and are both composed of a rotor inner ring, a rotor outer ring, a rotor connecting plate connected between the rotor inner ring and the rotor outer ring, and rotor blades uniformly arranged on the outer surface of the rotor outer ring; the low-pressure impeller blades (2) and the high-pressure impeller blades (12) are both rotatably arranged in the casing (1) by means of a fixed sleeve connection between their respective rotor inner rings and the transmission shaft (8), and all the rotor blades are in a clearance fit relationship with the outer ring wall of the rectifier; The outer diameter of the stator outer ring of the same stage is greater than the outer diameter of the rotor outer ring of the same stage, and the outer diameter of the stator inner ring of the previous stage is greater than the outer diameter of the stator inner ring of the next stage, and the outer diameter of the rotor outer ring of the previous stage is greater than the outer diameter of the rotor outer ring of the next stage. All the rotor outer rings and all the stator inner rings are arranged alternately in sequence to form the rectifier inner ring wall of the axial flow compressor. The gap between the rectifier inner ring wall and the rectifier outer ring wall gradually decreases from front to back, thereby forming the inner channel (9) with a large air inlet and a small air outlet.

8. The motor-driven axial flow compressor according to claim 7, characterized in that: The low-pressure working wheel blade (2), the high-pressure working wheel blade (12), the low-pressure rectifier blade (3) and the high-pressure rectifier blade (13) all adopt a combined blade group design; wherein, The low-pressure impeller blade (2) and the high-pressure impeller blade (12) are both composed of a female rotor and a male rotor that are tightly engaged front and back. The male rotor includes an annular plate (16). The central hole wall of the annular plate (16) serves as the inner ring of the rotor. A plurality of forward arc-shaped mounting plates (17) extending forward are arranged at equal angles on the outer wall of the annular plate (16). The curvature of each forward arc-shaped mounting plate (17) is the same as that of the annular plate (16), and the outer wall of each forward arc-shaped mounting plate (17) is The mother rotor comprises an annular ring (19), the outer diameter of the annular ring (19) is equal to the outer diameter of the annular plate (16), a plurality of backward arc-shaped mounting plates (20) extending backward are arranged at equal angles on the outer wall of the annular ring (19), the curvature of each backward arc-shaped mounting plate (20) is the same as the curvature of the annular ring (19), and a rotor blade (18) is arranged on the outer wall of each backward arc-shaped mounting plate (20); adjacent two front The spacing between the two adjacent backward arc-shaped mounting plates (17) corresponds to the width of one of the backward arc-shaped mounting plates (20), and the spacing between two adjacent backward arc-shaped mounting plates (20) corresponds to the width of one of the forward arc-shaped mounting plates (17); the female rotor and the male rotor are assembled front and back by staggered engagement of the backward arc-shaped mounting plates (20) and the forward arc-shaped mounting plates (17), and the rearward arc-shaped mounting plates (20) and the annular plate (16) are tightly fitted together by the tight fit between the backward arc-shaped mounting plates (20) and the annular plate (16) and the tight fit between the forward arc-shaped mounting plates (17). 7) is tightly fitted with the annular ring (19) to achieve tight fixation; after the female rotor and the male rotor are tightly clamped, the forward arc-shaped mounting plate (17) and the backward arc-shaped mounting plate (20) arranged in sequence and staggered form the outer ring of the rotor; the orientations of all the rotor blades (18) are consistent, and the shape of the space between two adjacent rotor blades (18) forms a curved expansion channel with an airflow outlet area larger than an airflow inlet area, and the curved expansion channel can reduce the speed of the incoming subsonic airflow and increase the pressure; The low-voltage rectifier leaf (3) and the high-voltage rectifier leaf (13) are both composed of a female stator and a male stator that are tightly engaged front and back; the female stator includes an inner ring plate (23) as the inner ring of the stator and an outer ring plate (24) as the outer ring of the stator, a plurality of inner front tooth blocks (25) are arranged at equal angles on the outer wall of the inner ring plate (23), and the curvature of each inner front tooth block (25) is the same as that of the inner ring plate (23); a plurality of outer front tooth blocks (26) are arranged at equal angles on the inner wall of the outer ring plate (24), and the curvature of each outer front tooth block (26) is the same as that of the inner ring plate (23). The outer ring plate (24) has the same curvature, and a stator blade (27) is fixedly connected between each inner front tooth block (25) and a corresponding outer front tooth block (26); the male stator comprises an inner hoop (28) with a diameter slightly smaller than the inner ring plate (23) and an outer hoop (29) with a diameter slightly smaller than the outer ring plate (24); a plurality of inner rear tooth blocks (30) are arranged at equal angles on the front end surface of the inner hoop (28); the curvature of each inner rear tooth block (30) is the same as that of the inner hoop (28); and ... A plurality of outer rear tooth blocks (31) are provided, the curvature of each outer rear tooth block (31) being the same as the curvature of the outer hoop (29), and a stator blade (27) is fixedly connected between each inner rear tooth block (30) and a corresponding outer rear tooth block (31); a circle of the inner front tooth blocks (25) can be staggered and engaged with a circle of the inner rear tooth blocks (30), and a circle of the outer front tooth blocks (26) can be staggered and engaged with a circle of the outer rear tooth blocks (31); the female stator and the male stator are staggered and engaged with each other through the staggered engagement of the inner front tooth blocks (25) and the inner rear tooth blocks (30) and the staggered engagement of the outer front tooth blocks (26). The staggered engagement of the block (26) and the outer rear tooth block (31) realizes front-to-back engagement, and the tight fit of the inner rear tooth block (30) and the inner ring plate (23) as well as the tight fit of the outer rear tooth block (31) and the outer ring plate (24) realizes tight fixation; after the female stator and the male stator are tightly engaged, the orientations of all the rotor blades (18) are consistent, and the spatial shape between two adjacent rotor blades (18) forms a curved expansion channel with an airflow outlet area larger than an airflow inlet area, and the curved expansion channel can reduce the speed of the incoming subsonic airflow and increase the pressure.

9. The motor-driven axial flow compressor according to claim 7, characterized in that: A slot (21) is provided on the inner wall of the stator outer ring corresponding to the installation position of the rotor blade, which is used to change the circumferential and axial pressure gradients near the inner wall of the stator outer ring, suppress the leakage vortex at the tip of the rotor blade, and thus improve the stall margin and surge.

10. The motor-driven axial flow compressor according to claim 7, characterized in that: A comb-teeth gas sealing structure (22) for reducing inter-stage backflow loss and air leakage loss is arranged on the inner wall of the inner channel (9) between the rotor blades and the stator blades.

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