Self-adaptive variable-attack-angle three-dimensional impeller for centrifugal compressor

Abstract

The utility model relates to a self-adaptive variable-attack-angle three-dimensional impeller for a centrifugal compressor. The self-adaptive variable-attack-angle three-dimensional impeller is characterized in that the three-dimensional impeller structurally comprises an impeller and blade air caps, wherein the blade air caps are arranged at a plurality of blade inlet ends of the impeller and can rotate to change blade inlet mounting angles; the blade hood is provided with a first elastic hoop petal and a second elastic hoop petal which are attached to the surface of the inlet end of an impeller blade, the air inlet side of the blade hood is in a pointed cone shape, the end of the blade hood is connected with a gear shaft, and the impeller is provided with a driving mechanism used for driving the gear shaft to rotate. When the compressor operates under the condition deviating from the design working condition, the attack angle of the impeller can still be kept within a small range, the impeller has the advantages of being high in adjusting speed and reliability, the operating working condition range of the compressor can be widened, and the efficiency of the compressor can be improved.

Description

Technical Field

[0001] This utility model relates to an adaptive variable angle three-dimensional impeller for centrifugal compressors. Background Technology

[0002] Centrifugal compressors, widely used gas booster devices in industry, directly impact the energy efficiency of energy, chemical, and power systems through their aerodynamic performance. The impeller, being the only component of the compressor that performs work on the gas, is responsible for converting input mechanical energy into gas pressure and kinetic energy; therefore, improving impeller efficiency has always been a research hotspot. The impeller blade inlet installation angle is a key geometric constraint for closing the impeller inlet velocity triangle, directly determining the angle of attack characteristics of the airflow entering the impeller channel, significantly affecting impeller efficiency, noise, and stable operating range. This geometric-aerodynamic coupling characteristic dictates that the impeller must not only ensure an angle of attack close to zero at the design point to minimize impact losses, but also maintain a reasonable angle of attack when deviating from the design conditions to avoid significant flow losses.

[0003] Conventional impellers generally employ a fixed impeller blade inlet installation angle design. This geometric parameter is fixed and cannot be adjusted after the impeller is machined. Since the impeller angle of attack is defined as the difference between the impeller blade inlet installation angle and the impeller blade inlet airflow angle, a limitation arises: when the compressor deviates from its design operating conditions, the gas flow direction and the impeller blade inlet installation angle will exhibit uncontrollable angle of attack deviations. Specifically, under high flow conditions, a negative angle of attack occurs, leading to increased flow separation at the suction surface and increased boundary layer losses; while under low flow conditions, a positive angle of attack occurs, inducing flow stall at the pressure surface, causing a sharp drop in efficiency and the risk of instability. This fixed geometric constraint means that conventional impellers consistently face challenges such as poor adaptability to operating conditions and a narrow high-efficiency range, severely restricting the overall performance improvement of the compressor.

[0004] In applications such as hydrogen fuel cell stacks, refrigeration compressors, and turbochargers, compressors need to switch frequently between rated flow, low flow, and high flow conditions. However, conventional impeller compressors perform poorly under low and high flow conditions, which has become one of the challenges restricting the system's transient response and efficient operation across a wide range of conditions. Currently, existing optimization techniques typically adjust the impeller blade profile to improve the compressor's performance under specific operating conditions, but they cannot fundamentally solve the aerodynamic matching problem within a certain operating range. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this utility model is to provide an adaptive variable angle of attack three-dimensional impeller structure for centrifugal compressors and its working method. The impeller can adjust the inlet installation angle of the impeller blades according to the rotational speed, so that the impeller angle of attack can still be kept within a small range when the compressor is running under conditions that deviate from the design conditions. It not only has the characteristics of fast adjustment speed and high reliability, but also can broaden the operating condition range of the compressor and improve the efficiency of the compressor.

[0006] This utility model relates to a three-dimensional impeller structure for a centrifugal compressor with adaptive variable angle of attack. Its features include: an impeller and blade caps mounted on the inlet ends of multiple blades of the impeller, capable of rotating to change the blade inlet angle; the blade caps have a first elastic clamping flap and a second elastic clamping flap that adhere to the surface of the impeller blade inlet end; the air inlet side of the blade cap is conical; a gear shaft is connected to the end of the blade cap; and a drive mechanism for driving the gear shaft to rotate is provided on the impeller.

[0007] Preferably, the driving mechanism is a rack driven by centrifugal force, and the rack meshes with the gear end of the gear shaft for transmission; or the driving mechanism is a gear driven by a motor for rotation, and the gear meshes with the gear end of the gear shaft for transmission.

[0008] Preferably, the blade cap has a countersunk hole along its length for interference fit with the end of the gear shaft. The impeller has a top shaft hole at its center. The top shaft hole has multiple central square grooves corresponding to the blade cap. The bottom of the central square groove has a shaft hole for the end of the gear shaft to pass through. The gear end of the gear shaft extends into the central square groove and meshes with a rack located in the central square groove. The bottom surface of the impeller has multiple T-slots and a drive slider slidably connected in the T-slots. The drive slider drives the rack to move through an intermediate connector. When the impeller rotates at high speed, the centrifugal force drives the slider to move away from the center of the impeller. The intermediate connector and the rack drive the rotation of the gear shaft and the blade cap, thereby changing the blade inlet installation angle.

[0009] Preferably, a return spring is installed in the T-groove. One end of the return spring abuts against the end of the T-groove at the bottom of the impeller, and the other end of the return spring is connected to the hanging ring on the drive slider. The drive slider hinge support on the drive slider is hinged to one end of the drive slider connecting rod. The other end of the drive slider connecting rod is hinged to the long end of the double-headed crank of the double-headed crank. The rotation center of the double-headed crank is rotatably connected to the double-headed crank hinge support. The double-headed crank hinge support is fixed on the impeller. The short end of the double-headed crank is hinged to one end of the slider rack integrated component connecting rod. The other end of the slider rack integrated component connecting rod is hinged to the lower end of the slider rack integrated component. The upper part of the slider rack integrated component is provided with the rack. The drive slider connecting rod, the double-headed crank, the slider rack integrated component connecting rod, and the slider rack integrated component constitute an intermediate connecting member.

[0010] Preferably, the T-slots are arranged in the same direction as the blade tip pointing to the blade root. An impeller bottom cavity is provided above the bottom of the impeller to accommodate the drive slider connecting rod and the double-headed crank. The wall of the impeller bottom cavity is provided with mounting holes for mounting the double-headed crank hinge support. The T-slots, impeller bottom cavity, central square groove and shaft hole of the impeller are evenly arranged in several sets along the circumference.

[0011] Preferably, the blade cap has a torsion angle along the axial direction of the gear shaft, and the torsion angle value is consistent with the angle change value from the blade inlet root to the blade tip, so that the first elastic clamping flap and the second elastic clamping flap of the blade cap can fit tightly against the surface of the blade inlet end.

[0012] Preferably, the aforementioned integrated slider and rack assembly includes a slider and rack integrated assembly hinge support, a vertical square rod, a horizontal rod, and a rack connected in sequence, with a support spring provided between the bottom end of the horizontal rod and the central square groove.

[0013] Preferably, the aforementioned double-ended crank has two straight rod sections, which are bent relative to each other to form an obtuse angle, with the bend located at the center of rotation of the double-ended crank.

[0014] Preferably, a gear washer composed of two halves is coaxially fitted on the shaft end of the gear shaft near the gear end. The gear washer is used to pad the gear shaft to ensure meshing between the gear end and the rack.

[0015] This invention relates to a centrifugal compressor using an adaptive variable angle of attack three-dimensional impeller structure. When the impeller speed increases, the drive slider moves linearly away from the impeller axis in the T-slot, driving the drive slider connecting rod, double-headed crank, slider rack integrated connecting rod, and slider rack integrated component to move. This causes the rack on the slider rack integrated component to drive the gear end of the gear shaft and the blade hood to rotate, changing the impeller blade inlet installation angle, thereby achieving the purpose of reducing the angle of attack and improving the compressor efficiency.

[0016] The beneficial effects of this utility model patent are: fast adjustment speed, high reliability, and simple structure, which helps to broaden the operating range of the compressor and improve its aerodynamic performance; it can automatically adjust the impeller blade inlet installation angle to reduce the angle of attack and flow loss within an operating range higher than the impeller design speed; the drive slider can drive the entire transmission system to respond quickly to changes in impeller speed, so that the impeller blade inlet installation angle always maintains an optimal angle; the overall structure adopts a purely mechanical structure without any electronic components, thus ensuring high reliability and relatively low cost; and it can use the blade cap to quickly test the performance of different blade leading edge geometries, which is beneficial to the research and development of new models; through the above methods, the operating range of the compressor under high speed and high flow conditions can be increased, and the aerodynamic efficiency in this area can be improved; at the same time, it helps to reduce compressor power consumption and accelerate the research and development of new blade leading edge geometries. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings;

[0018] Figure 1 This is a top view schematic diagram of the structure of this utility model;

[0019] Figure 2 This is a schematic diagram of the AA cross-sectional structure of this utility model;

[0020] Figure 3 This is a schematic diagram of the BB cross-sectional structure of this utility model;

[0021] Figure 4 This is a bottom-view perspective view of this utility model;

[0022] Figure 5 yes Figure 4 Enlarged view of section K in the middle;

[0023] Figure 6 This is a 3D view of the connection structure between the gear shaft and the blade wind cap;

[0024] Figure 7 yes Figure 6 The main view;

[0025] Figure 8 yes Figure 2 A partial view;

[0026] Figure 9 yes Figure 3 A partial view;

[0027] Figure 10 yes Figure 1 A partial view;

[0028] Figure 11 It is a 3D diagram of the driving slider;

[0029] Figure 12 It is a 3D view of the driving slider linkage;

[0030] Figure 13 It is a three-dimensional diagram of a double-headed crank;

[0031] Figure 14 It is a three-dimensional view of a double-headed crank hinge support;

[0032] Figure 15 This is a 3D view of the slider-rack integrated connecting rod;

[0033] Figure 16 This is a 3D view of the integrated slider and rack component;

[0034] Figure 17 This is a 3D view of the location of the shaft hole at the top of the impeller;

[0035] Figure 18 It is a 3D view of the central square groove;

[0036] Figure 19 It is a 3D view of the connections, such as intermediate connectors;

[0037] Markings: 1. Impeller; 2. Return spring; 3. Drive slider; 4. Drive slider connecting rod; 5. Double-ended crank; 6. Double-ended crank hinge support; 7. Screw; 8. Slider rack and pinion integrated connecting rod; 9. Slider rack and pinion integrated component; 10. Support spring; 11. Gear shaft; 12. Gear washer; 13. Blade wind cap; 31. Lifting ring; 32. Drive slider hinge support; 33. Rail-holding boss; 51. Long end of double-ended crank; 52. Rotation center of double-ended crank; 53. Short end of double-ended crank; 91 1. Slider rack integrated hinge support; 92. Vertical square rod; 93. Horizontal rod; 94. Rack; 101. End of T-slot at the bottom of the impeller; 102. T-slot; 103. Cavity at the bottom of the impeller; 104. Middle square groove; 105. Shaft hole at the top of the impeller; 106. Boss at the bottom of the impeller; 107. Shaft hole; 108. Mounting hole; 1101. Gear end; 1102. Shaft end; 1301. Root of the blade hood; 1302. Top of the blade hood; 1303. First elastic clamp flap; 1304. Second elastic clamp flap. Detailed Implementation

[0038] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0039] As shown in the figure, the adaptive variable angle three-dimensional impeller structure for centrifugal compressor of this utility model includes an impeller 1, a return spring 2, a drive slider 3, a drive slider connecting rod 4, a double-headed crank 5, a double-headed crank hinge support 6, a screw 7, a slider rack integrated connecting rod 8, a slider rack integrated component 9, a support spring 10, a gear shaft 11, a gear washer 12, and a blade wind cap 13.

[0040] The impeller 1 has a T-shaped groove 102 at its bottom for driving the slider 3 to move, an impeller bottom cavity 103 for accommodating the driving slider connecting rod 4 and the double-headed crank 5, and an impeller bottom boss 106. The impeller 1 has an impeller top shaft hole 105 at its top. The wall of the impeller top shaft hole 105 is evenly distributed with a plurality of central square grooves 104 corresponding to the blade wind cap. The bottom of the central square groove 104 has a shaft hole 107 for passing through the shaft end 1102 of the gear shaft. The gear end 1101 of the gear shaft passes through the shaft hole 107 and extends into the central square groove 104 to mesh with the rack 94 located in the central square groove 104.

[0041] One end of the return spring 2 is fixed to the end 101 of the T-shaped groove at the bottom of the impeller, and the other end of the return spring 2 is connected to the drive slider 3; the other end 32 of the drive slider 3 is connected to one end of the drive slider connecting rod 4, and the other end of the drive slider connecting rod 4 is connected to the double-ended crank 5. The double-ended crank 5 is fixed by the double-ended crank hinge support 6, which is fixed to the impeller 1 by four screws 7. The other end of the double-ended crank 5 is connected to the slider rack integrated connecting rod 8, and the other end of the slider rack integrated connecting rod 8 is connected to the slider rack integrated 9. The integrated rack and pinion 9 transmits power to the gear shaft 11 through the rack 94. The blade hood 13 is fixed on the gear shaft 11 and relies on its own elastic force to fit tightly against the blade inlet end. When the impeller speed increases, the drive slider 3 moves linearly away from the impeller axis and drives the drive slider connecting rod 4, the double-headed crank 5, the integrated rack and pinion connecting rod 8, and the integrated rack and pinion 9 to move. This causes the gear shaft 11 and the blade hood 13 to rotate, changing the impeller blade inlet installation angle and achieving the purpose of reducing the angle of attack and improving the compressor efficiency.

[0042] Specifically, the T-shaped groove 102 at the bottom of the impeller 1, which is used to move the drive slider 3, is oriented in the same direction as the blade tip pointing to the blade root. The impeller bottom cavity 103, which is provided above the bottom of the impeller 1, accommodates the drive slider connecting rod 4 and the double-headed crank 5. The cavity wall is provided with mounting holes 108 (threaded holes) for mounting the double-headed crank hinge support 6. The double-headed crank hinge support 6 is fixed to the mounting holes 108 by several screws 7.

[0043] Several sets of impeller 1, including T-groove 102, impeller bottom cavity 103, middle square groove 104, and shaft hole 107, are evenly arranged along the circumference, with the same number as the number of impeller blades.

[0044] The direction of the shaft hole 107 of the impeller 1 is consistent with the direction of the blade tip pointing to the blade root.

[0045] The impeller bottom boss 106 is for contact and cooperation between the impeller 1 and the other components of the compressor. The impeller bottom boss 106 is integrated with the impeller by welding or integral machining.

[0046] One end of the return spring 2 is fixed to the end 101 of the T-slot at the bottom of the impeller by welding, and the other end is connected to the lifting ring 31 of the drive slider 3 (it can be a fixed connection or a hook connection, as long as it can ensure that the two do not separate).

[0047] The other end of the drive slider 3 is provided with a drive slider hinge support 32 that is hinged to the drive slider connecting rod 4; the drive slider 3 is provided with a rail-holding boss 33 extending to both ends of the bottom of the T-shaped groove 102. The cooperation between the rail-holding boss 33 and the T-shaped groove 102 ensures that the drive slider 3 has only the degree of freedom to move in the horizontal direction along the T-shaped groove 102.

[0048] When the impeller 1 is running at a speed higher than the design speed, the centrifugal force generated by the drive slider 3 is greater than the elastic force of the return spring 2. The drive slider 3 moves away from the axis of the impeller 1 and compresses the return spring 2. When the impeller 1 is running at a speed lower than the design speed, the drive slider 3 moves closer to the axis of the impeller 1, the return spring 2 is reset, and the drive slider 3 returns to its initial position.

[0049] One end of the drive slider connecting rod 4 is hinged to the drive slider 3, and the other end is hinged to the long end 51 of the double-headed crank 5. The double-headed crank 5 and the double-headed crank hinge support 6 are hinged at the rotation center 52 of the double-headed crank. When the impeller 1 operates at a speed higher than the design speed, the double-headed crank can rotate around the double-headed crank hinge support 6 at a certain angle to transmit kinetic energy. The other end of the double-headed crank 5, the short end 53, is hinged to one end of the slider rack integrated connecting rod 8. The other end of the slider rack integrated connecting rod 8 is hinged to the slider rack integrated 9. When the impeller operates at a speed higher than the design speed, the slider rack integrated connecting rod 8 moves with the double-headed crank 5 to transmit kinetic energy.

[0050] The lower end of the integrated slider rack and pinion 9 is hinged to the upper end of the integrated slider rack and pinion rod 8. When the impeller 1 operates at a speed higher than the design speed, it moves with the integrated slider rack and pinion rod 8 to transmit kinetic energy. The other end of the integrated slider rack and pinion 9 is a vertically upward-pointing square rod 92. A horizontal rod 93 perpendicular to the vertical square rod is connected to the top of the vertical square rod 92. A rack 94 perpendicular to the horizontal rod is provided at the end of the horizontal rod 93. The back of the rack 94 of the integrated slider rack and pinion 9 is attached to the vertical wall of the central square groove 104 to ensure the meshing of the rack with the gear end of the gear shaft.

[0051] One end of the support spring 10 is welded to the wall of the shaft hole 105 at the top of the impeller. The other end of the support spring 10 contacts the bottom end of the horizontal rod 93 of the slider rack and pinion assembly 9, so that when the slider is driven and the slider linkage is not pulling the slider rack and pinion assembly, the rack, gear shaft, and blade wind cap can be driven back to their initial state.

[0052] The support spring 10 is used to support the weight of the slider rack assembly 9; it moves with the slider rack assembly 9 when the impeller 1 operates at a speed higher than the design speed.

[0053] A gear washer 12, composed of two identical halves, is coaxially fitted on the end of the gear shaft near the gear end. (The gear washer 12 is shaped like a bushing and is cut into two identical halves along the plane passing through the axis.) The gear washer 12 is used to cushion the axial direction of the gear shaft to ensure meshing between the gear end and the rack 94. The gear washer 12 is made of two halves to facilitate its installation near the gear end, and the two halves can be made of magnetic material to prevent them from falling off the gear shaft.

[0054] The gear end 1101 of the gear shaft 11 meshes with the rack 94 of the slider rack integral part 9, and its shaft end 1102 extending into the impeller 1 is connected to the root 1301 of the blade hood (fixed by welding or key-pin interference fit); when the impeller 1 operates at a speed higher than the design speed, the gear shaft 11 and the blade hood are driven by the rack of the slider rack integral part 9 to rotate a certain angle.

[0055] Specifically, the blade cap 13 is fixed to the shaft end 1102 of the gear shaft 11. The blade cap 13 and the gear shaft 11 are fitted with an interference fit (the shaft end 1102 may have a key, and the hole of the blade cap 13 may have a keyway, with the key and keyway having an interference fit). When the impeller 1 operates at a speed higher than the design speed, the blade cap 13 rotates with the gear shaft 11 at a certain angle to adjust the angle of the impeller 1 blade inlet installation angle, thereby reducing the angle of attack and reducing flow loss.

[0056] The blade cap 13 is provided with a first elastic clamping flap 1303 and a second elastic clamping flap 1304. The first elastic clamping flap 1303 and the second elastic clamping flap 1304 are arc-shaped pieces arranged opposite each other, which have an elastic clamping function.

[0057] The first elastic clamping flap 1303 and the second elastic clamping flap 1304 of the two blades converge toward the geometric center line of the blade cap 13 and adhere to the inlet blade surface of the impeller 1 through elastic force; when the impeller 1 is running at a speed higher than the design speed, the blade cap 13 rotates at a certain angle with the gear shaft, and the first elastic clamping flap 1303 and the second elastic clamping flap 1304 can still adhere to the wall surface of the impeller blade inlet.

[0058] The blade hood 13 has a certain torsional angle along the axial direction of the gear shaft 11, and its value is consistent with the angle change value from the blade inlet root to the blade tip, so that the blade hood can fit tightly against the blade.

[0059] The blade cap 13 has a hole at one end near the gear shaft to accommodate the gear shaft end, and no hole on the side away from the gear shaft end. That is, the blade cap 13 is a countersunk hole for inserting into the gear shaft end.

[0060] The beneficial effects of this utility model patent are: fast adjustment speed and high reliability. It can automatically adjust the impeller blade inlet installation angle according to the rotation speed, so that when the compressor is running under conditions deviating from the design conditions, the impeller angle of attack can still be kept within a small range. It not only has the characteristics of fast adjustment speed and high reliability, but also can broaden the operating condition range of the compressor and improve the efficiency of the compressor. At the same time, it can accelerate the research and development of new impeller blade leading edge geometry by quickly changing and testing different blade cap leading edge geometry.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and not to limit it; although the utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of this utility model or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solution of this utility model, and all such modifications and substitutions should be covered within the scope of the technical solution claimed by this utility model.

Claims

1. A three-dimensional impeller with adaptive variable angle of attack for a centrifugal compressor, characterized in that: The impeller (1) includes a blade cap (13) that is rotatable at the inlet end of multiple blades of the impeller (1) to change the inlet installation angle of the blades; the blade cap (13) has a first elastic clamping flap (1303) and a second elastic clamping flap (1304) that are attached to the surface of the inlet end of the blades of the impeller (1); the air inlet side of the blade cap (13) is conical; the end of the blade cap (13) is connected to a gear shaft (11); the impeller (1) is provided with a drive mechanism for driving the gear shaft to rotate; the blade cap (13) has a countersunk hole along its length for inserting the shaft end (1102) of the gear shaft; the shaft end (1102) has a convex key; the hole of the blade cap (13) has a keyway; the convex key and the keyway are interference fit.

2. The adaptive variable angle three-dimensional impeller for centrifugal compressors according to claim 1, characterized in that: The driving mechanism is a rack (94) driven by centrifugal force, which meshes with the gear end (1101) of the gear shaft (11).

3. The adaptive variable angle three-dimensional impeller for a centrifugal compressor according to claim 1 or 2, characterized in that: The impeller (1) has a top shaft hole (105) at its center. Multiple central square grooves (104) corresponding to the blade caps are evenly distributed on the wall of the top shaft hole (105). The bottom of the central square groove (104) has a shaft hole (107) for the gear shaft end (1102) to pass through. The gear end (1101) of the gear shaft extends into the central square groove (104) and meshes with the rack (94) located in the central square groove (104). Multiple T-shaped grooves (102) and a drive slider (3) slidably connected in the T-shaped grooves are evenly distributed on the bottom surface of the impeller (1). The drive slider (3) drives the rack (94) to move through the intermediate connector. When the impeller is running at high speed, the centrifugal force drives the slider to move away from the center of the impeller. The intermediate connector and the rack drive the rotation of the gear shaft and the blade caps, thereby changing the blade inlet installation angle.

4. The three-dimensional impeller with adaptive variable angle of attack for centrifugal compressors according to claim 3, characterized in that: A return spring (2) is installed in the T-groove. One end of the return spring (2) abuts against the end (101) of the T-groove at the bottom of the impeller. The other end of the return spring (2) is connected to the lifting ring (31) on the drive slider (3). The drive slider hinge support (32) on the drive slider (3) is hinged to one end of the drive slider connecting rod (4). The other end of the drive slider connecting rod is hinged to the long end (51) of the double-headed crank (5). The rotation center (52) of the double-headed crank is rotatably connected to the double-headed crank. On the crank hinge support (6), the double-headed crank hinge support (6) is fixed on the impeller. The short end (53) of the double-headed crank is hinged to one end of the slider rack integral connecting rod (8). The other end of the slider rack integral connecting rod (8) is hinged to the lower end of the slider rack integral (9). The upper part of the slider rack integral (9) is provided with the rack (94). The driving slider connecting rod (4), the double-headed crank (5), the slider rack integral connecting rod (8) and the slider rack integral (9) constitute an intermediate connecting member.

5. The adaptive variable angle of attack three-dimensional impeller for a centrifugal compressor according to claim 4, characterized in that: The T-slot (102) is set in the same direction as the blade tip pointing to the blade root. The bottom cavity (103) of the impeller (1) is provided above the bottom to accommodate the movement of the drive slider connecting rod (4) and the double-headed crank (5). The wall of the bottom cavity (103) of the impeller is provided with a mounting hole (108) for mounting the double-headed crank hinge support (6). The screw (7) passes through the double-headed crank hinge support (6) and is threadedly connected and fixed to the mounting hole (108). The T-slot (102), the bottom cavity (103), the central square groove (104) and the shaft hole (107) of the impeller (1) are evenly arranged in several groups along the circumference.

6. The three-dimensional impeller with adaptive variable angle of attack for a centrifugal compressor according to claim 5, characterized in that: The blade wind cap (13) has a torsion angle along the axial direction of the gear shaft (11). The torsion angle value is consistent with the angle change value from the blade inlet root to the blade tip, so that the first elastic clamping flap (1303) and the second elastic clamping flap (1304) of the blade wind cap can fit tightly against the blade inlet end surface.

7. The three-dimensional impeller with adaptive variable angle of attack for a centrifugal compressor according to claim 6, characterized in that: The integrated slider and rack component (9) includes a slider and rack integrated component hinge support (91), a vertical square rod (92), a horizontal rod (93) and a rack (94) connected in sequence. A support spring (10) is provided between the bottom end of the horizontal rod (93) and the middle square groove (104).

8. The three-dimensional impeller with adaptive variable angle of attack for a centrifugal compressor according to claim 6, characterized in that: The double-headed crank (5) has two straight rod sections, which are bent relative to each other to form an obtuse angle. The bend is located at the rotation center (52) of the double-headed crank.

9. The three-dimensional impeller with adaptive variable angle of attack for a centrifugal compressor according to claim 6, characterized in that: A gear washer (12) composed of two halves is coaxially fitted on the end of the gear shaft near the gear end. The gear washer (12) is used to pad the gear shaft to ensure that the gear end meshes with the rack (94).

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