Gas compressor with width-adjustable diffuser

Abstract

The compressor comprises a machine shell body, an impeller and a pneumatic executing mechanism, the machine shell body comprises a fixing frame, a pressing shell, a diffuser plate and a back plate, the back plate is fixedly connected to the pressing shell, the diffuser plate is slidably connected to the back plate and located on the side close to the pressing shell, the pressing shell is provided with an air inlet and an air outlet, and the air inlet and the air outlet are communicated with the impeller. The impeller is rotationally connected in the pressure shell, and the back plate, the pressure shell and the diffusion plate are fixedly connected to the fixing frame through the back plate; a diffusion gap is formed between the diffusion plate and the pressure shell; the pneumatic executing mechanism is installed on the fixing frame, the output end of the pneumatic executing mechanism is connected with the diffusion plate, an air pipe is led out of an air outlet of the pressing shell, and the end, away from the pressing shell, of the air pipe is communicated with the pneumatic executing mechanism so that the pneumatic executing mechanism can drive the back plate to slide to be close to or away from the pressing shell to adjust the diffusion gap. Through the arrangement of the driving execution mechanism and the air pipe, automatic adjustment of the diffusion gap is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of turbochargers, and in particular to a compressor with an adjustable diffuser width. Background Art

[0002] In recent years, with the upgrade of engine emission standards, the requirements for supercharger performance have become increasingly higher, especially for automotive engines, which pay more attention to low-speed high torque and good fuel economy performance, which puts forward more stringent requirements for the performance improvement of superchargers at corresponding operating points. As an important part of the supercharger, the improvement of compressor efficiency can effectively improve the performance of the entire supercharger. Therefore, it is very important to improve the performance of the compressor.

[0003] At present, in addition to improving the performance of the compressor by optimizing the fluid dynamics design of the compressor impeller and the compressor casing, the compressor performance can also be optimized by matching the structural parameters of the compressor impeller and the compressor casing. The structural parameters that affect the compressor performance include the impeller inlet and outlet diameters, the impeller outlet blade height and the diffuser width, the diffuser inlet and outlet ratio, etc. Once the compressor state is determined, the only thing that can be adjusted is the diffuser width. In the existing design, a movable plate is generally set to adjust the diffuser width. The movable plate is limited and adjusted by screws, but this method can only be adjusted manually and cannot be adjusted automatically.

[0004] In summary, there is an urgent need for a compressor with an adjustable diffuser width to solve or at least partially solve the problems existing in the prior art. Summary of the invention

[0005] The present invention aims to provide a compressor with adjustable diffuser width, aiming to solve the problem that the existing design cannot automatically adjust the diffuser width. The specific technical solution is as follows:

[0006] A compressor with adjustable diffuser width comprises a casing body, an impeller and a pneumatic actuator, wherein the casing body comprises a fixing frame, a compression shell, a diffuser plate and a back plate, wherein the back plate is fixedly connected to the compression shell, the diffuser plate is slidably connected to the back plate and is located on a side close to the compression shell, the compression shell is provided with an air inlet and an air outlet, the impeller is rotatably connected in the compression shell, the back plate, the compression shell and the diffuser plate are all fixedly connected to the fixing frame via the back plate; a diffuser gap is arranged between the diffuser plate and the compression shell; the pneumatic actuator is mounted on the fixing frame, the output end of the pneumatic actuator is connected to the diffuser plate, an air pipe is led out from the air outlet of the compression shell, and the end of the air pipe away from the compression shell is connected to the pneumatic actuator so that the pneumatic actuator drives the back plate to slide close to or away from the compression shell to adjust the size of the diffuser gap.

[0007] Preferably, the pneumatic actuator includes a cylinder, a crank, a shift fork and a push rod, which are connected in sequence, a first end of the cylinder is hinged to a fixed frame, a second end of the cylinder is hinged to an input end of the crank, the crank is hinged to the fixed frame, an output end of the crank is fixedly connected to the shift fork, an end of the shift fork away from the crank is fixedly connected with a latch, a drive groove is radially arranged on the push rod, the latch is movably connected in the drive groove, an end of the push rod away from the shift fork passes through a back plate and is fixedly connected to a diffuser plate, and the push rod is arranged parallel to a sliding direction of the diffuser plate.

[0008] Preferably, the pneumatic actuator includes a cylinder, a crank, a shift fork and a push rod, which are connected in sequence, the first end of the cylinder is hinged to a fixed frame, the second end of the cylinder is hinged to an input end of the crank, the crank is hinged to the fixed frame, the output end of the crank is fixedly connected to the shift fork, a drive groove is provided at one end of the shift fork away from the crank and the drive groove is arranged along the length direction of the shift fork; a pin is provided on the push rod, the pin is slidably connected in the drive groove, one end of the push rod away from the shift fork passes through the back plate and is fixedly connected to the diffuser plate, and the push rod is arranged parallel to the sliding direction of the diffuser plate.

[0009] Furthermore, the cylinder includes a cylinder body, a piston rod and an elastic member, the cylinder body is hinged on a fixed frame, the piston rod is slidably connected in the cylinder body, and one end of the piston rod away from the cylinder body is hinged on a crank; a cavity is provided between the cylinder body and the piston rod, and the air pipe is connected to the cavity; the elastic member is arranged on a side away from the cavity, and a first end of the elastic member abuts against the cylinder body, and a second end of the elastic member abuts against the piston rod.

[0010] Furthermore, two push rods are arranged, and the two push rods are symmetrically arranged along the axis of the impeller. Two pins are arranged on the fork. The first end of the fork is connected to one of the push rods through one of the pins, and the second end of the fork is connected to the other push rod through the other pin.

[0011] Furthermore, the crank comprises a driving arm, a driven arm and a locking assembly, the driving arm is telescopically arranged in the driven arm, or the driven arm is telescopically arranged in the driving arm, and the locking assembly is used to lock the driving arm and the driven arm.

[0012] Furthermore, the locking assembly includes a screw, the screw passes through the driven arm and is rotatably connected to the driving arm, the screw is threadedly connected to the driven arm, and the screw is arranged along the telescopic direction of the driving arm.

[0013] Furthermore, the locking assembly also includes a locking nut, which is threadedly connected to the screw, and one side of the locking nut abuts against the driven arm.

[0014] Furthermore, a slider is provided on the pressure diffuser plate, a slide groove is provided on the back plate, and the slider is slidably connected in the slide groove.

[0015] Furthermore, a guide surface is provided at one end of the diffuser plate close to the impeller, and the guide surface is arranged toward the impeller.

[0016] The application of the technical solution of the present invention has the following beneficial effects:

[0017] When the pressure at the diffuser gap increases, the pressure at the corresponding outlet will also increase, causing the pressure delivered by the air pipe to the pneumatic actuator to increase, and the pneumatic actuator will push the diffuser plate toward the compression shell to reduce the diffuser gap, thereby reducing the energy loss caused by turbulence in the gas at the diffuser gap. Conversely, when the pressure at the diffuser gap decreases, the pressure at the corresponding outlet will decrease accordingly, causing the pressure delivered by the air pipe to the pneumatic actuator to decrease, and the pneumatic actuator will push the diffuser plate away from the compression shell to increase the diffuser gap. Automatic adjustment of the diffuser gap is achieved by setting the drive actuator and the air pipe.

[0018] In addition to the objects, features and advantages described above, the present invention has other objects, features and advantages. Figure 1-Figure 7 , the present invention is further described in detail. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings constituting a part of this application are used to provide a further understanding of the present invention. 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:

[0020] Figure 1 This is one of the overall structural schematic diagrams of a compressor with adjustable diffuser width according to the present invention;

[0021] Figure 2 This is the second schematic diagram of the overall structure of a compressor with adjustable diffuser width according to the present invention;

[0022] Figure 3 yes Figure 2 Magnified view at A in the middle;

[0023] Figure 4 It is a schematic diagram of the internal structure of a compressor with adjustable diffuser width according to the present invention;

[0024] Figure 5 yes Figure 4 Magnified view at B in the middle;

[0025] Figure 6 It is a cross-sectional view of a crank in a compressor with adjustable diffuser width according to the present invention;

[0026] Figure 7 It is a cross-sectional view of a cylinder in a compressor with adjustable diffuser width according to the present invention;

[0027] Among them, 1. casing body; 11. fixing frame; 12. compression shell; 121. air inlet; 122. air outlet; 123. air pipe; 13. pressure diffuser plate; 131. slider; 132. guide surface; 14. back plate; 15. pressure diffuser gap; 2. impeller; 3. pneumatic actuator; 31. cylinder; 311. cylinder body; 312. piston rod; 313. cavity; 314. elastic member; 32. crank; 321. driving arm; 322. driven arm; 323. locking assembly; 3231. screw; 3232. locking nut; 33. fork; 331. latch; 34. push rod; 341. driving slot. DETAILED DESCRIPTION

[0028] In order to facilitate the understanding of the present invention, the present invention will be described more fully below, and preferred embodiments of the present invention are provided. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0030] Example:

[0031] See also Figure 1-Figure 7 The present embodiment provides a compressor with an adjustable diffuser width, comprising a casing body 1, an impeller 2 and a pneumatic actuator 3. The casing body 1 comprises a fixing frame 11, a compression casing 12, a diffuser plate 13 and a back plate 14. The back plate 14 is detachably fixedly connected to the compression casing 12 by bolts. The diffuser plate 13 is slidably connected to the back plate 14 along the central axis direction of the compression casing 12 and is located on a side close to the compression casing 12. The compression casing 12 has an air inlet 121 and an air outlet 122. The impeller 2 is rotatably connected to the compression casing 12. The back plate 14, the compression casing 12 and the back plate 14 are detachably fixedly connected to the compression casing 12 by bolts. The diffuser plate 13 is slidably connected to the back plate 14 along the central axis direction of the compression casing 12 and is located on a side close to the compression casing 12. The compression casing 12 has an air inlet 121 and an air outlet 122. The impeller 2 is rotatably connected to the compression casing 12. The shell 12 and the diffuser plate 13 are fixedly connected to the fixed frame 11 through the back plate 14; a diffuser gap 15 is set between the diffuser plate 13 and the compression shell 12; the pneumatic actuator 3 is installed on the fixed frame 11, the output end of the pneumatic actuator 3 is connected to the diffuser plate 13, and an air pipe 123 is led out from the air outlet 122 of the compression shell 12. The end of the air pipe 123 away from the compression shell 12 is connected to the pneumatic actuator 3, so that the pneumatic actuator 3 drives the back plate 14 to slide close to the compression shell 12 or away from the compression shell 12 to adjust the size of the diffuser gap 15.

[0032] Research has found that when the diffuser gap 15 is larger, the higher the pressure at the diffuser gap 15, the easier it is to generate turbulence. When turbulence occurs here, it will cause greater gas resistance, resulting in increased power consumption. Properly reducing the diffuser gap 15 here can effectively reduce the generation of turbulence, which is beneficial to reducing power consumption here. When the pressure at the diffuser gap 15 is high, the gap needs to be controlled to be relatively small, and when the pressure at the diffuser gap 15 is low, the diffuser gap 15 needs to be increased accordingly.

[0033] Specifically, one side of the back plate 14 is fixedly connected to the compression shell 12 by bolts, and the other side of the back plate 14 is fixedly connected to the fixing frame 11 by bolts. It should be noted that the back plate 14, the diffuser plate 13 and the compression shell 12 corresponding to the position of the diffuser plate 13 constitute a diffuser, and the width of the diffuser refers to the width of the diffuser gap 15.

[0034] It can be known that when the impeller 2 is working, the impeller 2 sucks the gas at the air inlet 121 of the compression shell 12. Driven by the impeller 2, the air is thrown out from the outer periphery of the impeller 2 and enters the air outlet 122 from the pressure diffuser gap 15 and then discharged. It should be noted that when the pressure at the pressure diffuser gap 15 rises, the pressure at the corresponding air outlet 122 will also rise, thereby increasing the pressure delivered to the pneumatic actuator 3 by the air pipe 123, thereby pushing the pressure diffuser plate 13 toward the compression shell 12 through the pneumatic actuator 3, reducing the pressure diffuser gap 15, thereby reducing the energy loss caused by turbulence of the gas at the pressure diffuser gap 15. On the contrary, when the pressure at the pressure diffuser gap 15 drops, the pressure at the corresponding air outlet 122 drops accordingly, thereby reducing the pressure delivered to the pneumatic actuator 3 by the air pipe 123, and pushing the pressure diffuser plate 13 toward the direction away from the compression shell 12 through the pneumatic actuator 3, thereby increasing the pressure diffuser gap 15. By driving the actuator and the air pipe 123, automatic adjustment of the diffusion gap 15 is achieved.

[0035] Preferably, the pneumatic actuator 3 includes a cylinder 31, a crank 32, a shift fork 33 and a push rod 34, and the cylinder 31, the crank 32, the shift fork 33 and the push rod 34 are connected in sequence, the first end of the cylinder 31 is hinged to the fixed frame 11, the second end of the cylinder 31 is hinged to the input end of the crank 32, the crank 32 is hinged on the fixed frame 11, the output end of the crank 32 is fixedly connected to the shift fork 33, the shift fork 33 is fixedly connected with a pin 331 at one end away from the crank 32, a driving groove 341 is radially arranged on the push rod 34, the pin 331 is movably connected in the driving groove 341, the end of the push rod 34 away from the shift fork 33 passes through the back plate 14 and is fixedly connected to the diffuser plate 13, and the push rod 34 is arranged parallel to the sliding direction of the diffuser plate 13.

[0036] It can be known that when the gas pressure rises, the gas discharged from the gas outlet 122 of the compression shell 12 is delivered to the cylinder 31 through the gas pipe 123, and the cylinder 31 drives the crank 32 to rotate, and the crank 32 drives the shift fork 33 to shift the push rod 34 to move, and the push rod 34 pushes the diffuser plate 13 to move, so that the diffuser gap 15 becomes smaller. Through the setting of the crank 32, the linear motion of the cylinder 31 is converted into rotation, and through the setting of the crank 32, the shift fork 33, the push rod 34, the latch 331 and the driving slot 341, the rotational motion of the crank 32 is converted into the linear motion of the push rod 34.

[0037] It should be noted that, in another embodiment of the present application, the driving groove 341 is arranged on the shift fork 33, and the latch pin 331 is arranged on the push rod 34. Only the installation positions are swapped, but the functions are basically the same and will not be described again here.

[0038] Furthermore, the cylinder 31 includes a cylinder body 311, a piston rod 312 and an elastic member 314. The cylinder body 311 is hinged on the fixed frame 11, the piston rod 312 is slidably connected in the cylinder body 311, and the end of the piston rod 312 away from the cylinder body 311 is hinged on the crank 32; a cavity 313 is provided between the cylinder body 311 and the piston rod 312, and the air pipe 123 is connected to the cavity 313; the elastic member 314 is arranged on the side away from the cavity 313, and the first end of the elastic member 314 abuts on the cylinder body 311, and the second end of the elastic member 314 abuts on the piston rod 312.

[0039] Specifically, the air pipe 123 is connected to the cylinder body 311 , and the air pipe 123 is communicated with the inside of the cylinder body 311 , and air is supplied to the inside of the cylinder body 311 through the air pipe 123 .

[0040] It can be known that when the gas enters the cavity 313 between the cylinder body 311 and the piston rod 312 from the air pipe 123, the volume of the cavity 313 increases, and the gas pushes the piston rod 312 to move toward the outside of the cylinder body 311. As the cylinder body 311 moves, the piston rod 312 compresses the elastic member 314. The elastic member 314 is compressed, and the elastic member 314 applies a reaction force to the piston rod 312. As the piston rod 312 moves, the compression amount of the elastic member 314 increases, and the reaction force applied by the elastic member 314 to the piston rod 312 also increases, until the pressure applied by the gas to the piston rod 312, the force of the crank 32 reacting on the piston rod 312, and the elastic force of the elastic member 314 are balanced, at which time the piston rod 312 stops moving, thereby ventilating the cylinder body 311 through the air pipe 123 and controlling the piston rod 312, and then controlling the moving distance of the diffuser plate 13 through the piston rod 312. It should be noted that when the pressure at the diffuser increases, the pressure at the air outlet 122 of the compressor shell 12 also increases, and the value of the pressure increase at the air outlet 122 of the compressor shell 12 is greater than the value of the pressure increase at the diffuser.

[0041] It is worth noting that in the present embodiment, the elastic member 314 is a spring. In other embodiments of the present application, the elastic member 314 may also be a reed, a gas spring or other structures or components that can deform and accumulate elastic potential energy.

[0042] Furthermore, two push rods 34 are arranged, and the two push rods 34 are symmetrically arranged along the axis of the impeller 2. Two pins 331 are arranged on the fork 33. The first end of the fork 33 is connected to one of the push rods 34 through one of the pins 331, and the second end of the fork 33 is connected to the other push rod 34 through the other pin 331.

[0043] It can be known that the diffuser plate 13 is an annular pressure plate. Two push rods 34 are arranged in an annular direction along the axis of the impeller 2. The two push rods 34 are connected to the annular diffuser plate 13, so that the fork 33 drives the two push rods 34 to move simultaneously, so that the diffuser plate 13 is evenly stressed and the sliding of the diffuser plate 13 is more stable and smooth.

[0044] Furthermore, the crank 32 includes a driving arm 321 , a driven arm 322 and a locking assembly 323 . The driving arm 321 is telescopically arranged in the driven arm 322 . The locking assembly 323 is used to lock the driving arm 321 and the driven arm 322 .

[0045] It can be known that the driving arm 321 is telescopically arranged in the driven arm 322. By adjusting the relative positions of the driving arm 321 and the driven arm 322, the driving arm 321 and the driven arm 322 are locked by the locking assembly 323 after adjustment, so as to adjust the length of the crank 32. When the crank 32 is longer, the force arm of the cylinder 31 is longer, and the force of pushing the push rod 34 by plugging and unplugging is greater, and the moving distance of the pressure diffuser 13 is longer, and vice versa. The moving distance of the pressure diffuser 13 can be adjusted by adjusting the length of the crank 32.

[0046] It should be noted that in some other embodiments of the present application, the slave arm 322 can also be telescopically arranged inside the driving arm 321 .

[0047] Furthermore, the locking assembly 323 includes a screw 3231 , which passes through the driven arm 322 and is rotatably connected to the driving arm 321 . The screw 3231 is threadedly connected to the driven arm 322 , and the screw 3231 is arranged along the telescopic direction of the driving arm 321 .

[0048] It can be known that the screw 3231 is connected to the driving arm 321 for relative rotation, and the screw 3231 is threadedly connected to the driven arm 322. When the screw 3231 is rotated, the screw 3231 moves along the length direction of the driven arm 322 and pushes the driving arm 321 to extend or retract into the driven arm 322, thereby adjusting the length of the crank 32.

[0049] Furthermore, the locking assembly 323 also includes a locking nut 3232, which is threadedly connected to the screw 3231, and one side of the locking nut 3232 abuts against the driven arm 322. It should be noted that in order to increase the anti-vibration performance, an elastic pad can be further provided between the nut and the driven arm 322, the elastic pad is coaxially sleeved on the screw 3231, the first end of the elastic pad abuts against the locking nut 3232, and the second end of the elastic pad abuts against the outer surface of the driven arm 322.

[0050] It is known that, although the screw 3231 has a certain self-locking function, the screw 3231 may rotate under the interference of external force or under the action of vibration, thereby causing the length of the rocker arm to change. By setting the locking nut 3232, the locking nut 3232 is threadedly connected to the screw 3231. When the screw 3231 needs to be locked, the screw 3231 is tightened so that the side wall of the locking nut 3232 is pressed against the outer surface of the driven arm 322. The force of the locking nut 3232 pressing against the driven arm 322 reacts on the locking nut 3232, so that a large static friction force is generated between the locking nut 3232 and the screw 3231, and a large static friction force is also generated between the screw 3231 and the driven arm 322, thereby preventing the screw 3231 from loosening.

[0051] Furthermore, a slider 131 is provided on the pressure diffuser plate 13 , and a slide groove is provided on the back plate 14 , and the slider 131 is slidably connected in the slide groove.

[0052] Specifically, the pressure diffuser 13 is an annular plate, the slider 131 is an annular slider 131, the slider 131 is fixedly connected to the pressure diffuser 13, the slide groove is an annular groove, and two sliders 131 are provided, the two sliders 131 are coaxially arranged, and two corresponding slide grooves are also arranged, the two sliders 131 are correspondingly slidably connected in the two slide grooves, and the outside of the slider 131 is tightly matched with the inner wall of the slide groove. It can be known that through the cooperation of the slider 131 and the slide groove, the pressure diffuser 13 can slide smoothly relative to the back plate 14, and secondly, the cooperation of the slider 131 and the slide groove forms a labyrinth seal to reduce the leakage of high-pressure gas (it should be noted that the high-pressure gas here refers to the gas pressure higher than the pressure of the gas at the air inlet 121).

[0053] Furthermore, a guide surface 132 is provided at one end of the diffuser plate 13 close to the impeller 2 , and the guide surface 132 is arranged toward the impeller 2 .

[0054] Specifically, the guide surface 132 is formed by chamfering the diffuser plate 13. Due to the existence of the guide surface 132, the diffuser gap 15 formed between the guide surface 132 and the inner wall of the compression shell 12 is larger on the side close to the impeller 2 and smaller on the side away from the impeller 2, so that the gas delivered from the impeller 2 is guided under the action of the trumpet-shaped mouth, and the kinetic energy of the gas delivered from the impeller 2 is converted into pressure energy.

[0055] The working principle of the present invention is as follows:

[0056] When the impeller 2 rotates, the gas at the air inlet 121 of the compression shell 12 is pumped out to the diffusion gap 15, and flows outward through the diffusion gap 15, converting the kinetic energy of the gas into static pressure energy, slowing down the flow rate, increasing the pressure, and being discharged from the air outlet 122 on the compression shell 12. When the speed of the impeller 2 increases, the pressure of the gas pumped out from the diffuser gap 15 increases, and the pressure at the air outlet 122 also increases. The gas at the air outlet 122 is transmitted to the cylinder 31 through the air pipe 123, and pushes the piston rod 312 to move. The piston rod 312 pushes the crank 32 to rotate, and the crank 32 pushes the push rod 34 through the fork 33 to drive the diffuser plate 13 to move toward the direction close to the compression shell 12, so that the diffuser gap 15 becomes smaller. The elastic member 314 is compressed during the movement of the piston rod 312. As the compression amount of the elastic member 314 increases, the force of the elastic member 314 reacting on the piston rod 312 also increases, until the elastic force of the elastic member 314, the pressure applied to the piston rod 312 by the gas, and the resistance of the crank 32 are balanced, and the diffuser plate 13 stops moving. When the gas pressure decreases, the pressure applied by the gas to the piston rod 312 decreases, and the elastic member 314 pushes the piston rod 312 to move back, and the piston rod 312 drives the crank 32 to rotate in the opposite direction, and drives the push rod 34 through the fork 33 to pull the diffuser plate 13 in a direction away from the compression shell 12, thereby increasing the diffuser gap 15. The diffuser gap 15 is automatically adjusted by the arrangement of the cylinder 31, the crank 32, the fork 33 and the push rod 34.

[0057] 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. A compressor with adjustable diffuser width, characterized in that: It comprises a casing body (1), an impeller (2) and a pneumatic actuator (3). The casing body (1) comprises a fixing frame (11), a compression shell (12), a pressure diffuser (13) and a back plate (14); the back plate (14) is fixedly connected to the compression shell (12); the pressure diffuser (13) is slidably connected to the back plate (14) and is located on a side close to the compression shell (12); the compression shell (12) has an air inlet (121) and an air outlet (122); the impeller (2) is rotatably connected in the compression shell (12); the back plate (14), the compression shell (12) and the pressure diffuser (13) are all fixedly connected to the fixing frame (11) via the back plate (14); A diffusion gap (15) is provided between the diffusion plate (13) and the compression shell (12); The pneumatic actuator (3) is mounted on the fixing frame (11), the output end of the pneumatic actuator (3) is connected to the diffuser plate (13), an air pipe (123) is led out from the air outlet (122) of the compression shell (12), and the end of the air pipe (123) away from the compression shell (12) is connected to the pneumatic actuator (3), so that the pneumatic actuator (3) drives the back plate (14) to slide close to the compression shell (12) or away from the compression shell (12) to adjust the size of the diffuser gap (15).

2. The compressor with adjustable diffuser width according to claim 1, characterized in that: The pneumatic actuator (3) comprises a cylinder (31), a crank (32), a shift fork (33) and a push rod (34), wherein the cylinder (31), the crank (32), the shift fork (33) and the push rod (34) are connected in sequence. The first end of the cylinder (31) is hinged to the fixed frame (11), and the second end of the cylinder (31) is hinged to the input end of the crank (32). The crank (32) is hinged on the fixed frame (11), and the output end of the crank (32) is fixedly connected to the shift fork (33). One end of the shift fork (33) away from the crank (32) is fixedly connected with a latch (331), a driving groove (341) is radially arranged on the push rod (34), the latch (331) is movably connected in the driving groove (341), one end of the push rod (34) away from the shift fork (33) passes through the back plate (14) and is fixedly connected to the diffuser plate (13), and the push rod (34) is arranged parallel to the sliding direction of the diffuser plate (13).

3. The compressor with adjustable diffuser width according to claim 1, characterized in that: The pneumatic actuator (3) comprises a cylinder (31), a crank (32), a shift fork (33) and a push rod (34), wherein the cylinder (31), the crank (32), the shift fork (33) and the push rod (34) are connected in sequence. The first end of the cylinder (31) is hinged to the fixed frame (11), and the second end of the cylinder (31) is hinged to the input end of the crank (32). The crank (32) is hinged on the fixed frame (11), and the output end of the crank (32) is fixedly connected to the shift fork (33). A driving groove (341) is provided at one end of the shift fork (33) away from the crank (32), and the driving groove (341) is arranged along the length direction of the shift fork (33); a latch (331) is provided on the push rod (34), and the latch (331) is slidably connected in the driving groove (341); one end of the push rod (34) away from the shift fork (33) passes through the back plate (14) and is fixedly connected to the diffuser plate (13); and the push rod (34) is arranged parallel to the sliding direction of the diffuser plate (13).

4. A compressor with adjustable diffuser width according to claim 2 or 3, characterized in that: The cylinder (31) comprises a cylinder body (311), a piston rod (312) and an elastic member (314); the cylinder body (311) is hinged on the fixing frame (11); the piston rod (312) is slidably connected in the cylinder body (311); and one end of the piston rod (312) away from the cylinder body (311) is hinged on the crank (32); A cavity (313) is provided between the cylinder body (311) and the piston rod (312), and the air pipe (123) is in communication with the cavity (313); The elastic member (314) is arranged on a side away from the cavity (313), and a first end of the elastic member (314) abuts against the cylinder body (311), and a second end of the elastic member (314) abuts against the piston rod (312).

5. The compressor with adjustable diffuser width according to claim 4, characterized in that: Two push rods (34) are arranged, and the two push rods (34) are symmetrically arranged along the axis of the impeller (2); two latch pins (331) are arranged on the shift fork (33); a first end of the shift fork (33) is connected to one of the push rods (34) through one of the latch pins (331); and a second end of the shift fork (33) is connected to the other push rod (34) through the other latch pin (331).

6. A compressor with adjustable diffuser width according to claim 2 or 3, characterized in that: The crank (32) comprises a driving arm (321), a driven arm (322) and a locking assembly (323); the driving arm (321) is telescopically arranged in the driven arm (322), or the driven arm (322) is telescopically arranged in the driving arm (321); and the locking assembly (323) is used to lock the driving arm (321) and the driven arm (322).

7. The compressor with adjustable diffuser width according to claim 6, characterized in that: The locking assembly (323) comprises a screw (3231), wherein the screw (3231) passes through the driven arm (322) and is rotationally connected to the driving arm (321), the screw (3231) is threadedly connected to the driven arm (322), and the screw (3231) is arranged along the telescopic direction of the driving arm (321).

8. The compressor with adjustable diffuser width according to claim 7, characterized in that: The locking assembly (323) further comprises a locking nut (3232), wherein the locking nut (3232) is threadedly connected to the screw (3231), and one side of the locking nut (3232) abuts against the driven arm (322).

9. A compressor with adjustable diffuser width according to any one of claims 1 to 3, characterized in that: The pressure diffuser plate (13) is provided with a sliding block (131), the back plate (14) is provided with a sliding groove, and the sliding block (131) is slidably connected in the sliding groove.

10. A compressor with adjustable diffuser width according to any one of claims 1 to 3, characterized in that: A guide surface (132) is provided at one end of the diffuser plate (13) close to the impeller (2), and the guide surface (132) is arranged toward the impeller (2).

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