Screw compressor

Abstract

The application discloses a screw compressor, which comprises a shell, a pair of rotors, an exhaust passage and a silencing device. The silencing device is arranged in the exhaust passage and comprises at least one mounting sheet and a plurality of silencing units. The silencing device is configured so that the compressed gas entering the exhaust passage from the rotor cavity flows through the side wall of the mounting sheet and the silencing units and is then discharged from the exhaust port. The screw compressor of the application can be improved on the basis of the structure of the existing screw compressor, and the silencing device is additionally arranged in the exhaust shell or the exhaust shell including the silencing device is separately manufactured, so that the influence on the structure of the existing screw compressor is reduced, and the cost is low. In addition, the silencing device of the application can balance the gas pressure loss caused by the silencing device by increasing the flow area of the silencing passage, and the exhaust pressure of the screw compressor is not affected.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of compressors, in particular to a screw compressor. BACKGROUND

[0002] A pair of rotors are included in the screw compressor, the tooth space volume of the pair of rotors is engaged with each other, the change of the elementary volume composed of the tooth space volume completes the process of gas suction, compression and discharge. The screw compressor forms discontinuous interdental volume through the engagement of the rotors, which causes the periodic communication between the suction and discharge cavities and the working cavity, thereby causing the unstable flow of the gas, the pressure pulsation in the suction and discharge process, and further causing the vibration and noise of the compressor. SUMMARY

[0003] The present application provides a screw compressor, which comprises a housing, a pair of rotors, an exhaust passage and a sound attenuation device. The housing comprises a rotor housing and an exhaust housing, the rotor housing defines a rotor cavity, the exhaust housing defines an exhaust cavity, the rotor cavity and the exhaust cavity are in fluid communication, and the exhaust housing is provided with an exhaust port. The pair of rotors are arranged in the rotor cavity, the teeth of the pair of rotors and the housing can form a compression cavity, the rotor cavity has a suction end and a discharge end, and the pair of rotors are arranged to move the gas in the compression cavity from the suction end to the discharge end after being compressed. The exhaust passage is arranged in the exhaust housing, the exhaust passage is in fluid communication between the discharge end and the exhaust port, and the exhaust passage is configured to discharge the compressed gas in the rotor cavity from the exhaust port. The sound attenuation device is arranged in the exhaust passage, the sound attenuation device comprises at least one mounting sheet and a plurality of sound attenuation units, the mounting sheet has a side wall extending along the extension direction of the exhaust passage, and the plurality of sound attenuation units are arranged on the side wall of the at least one mounting sheet. The sound attenuation device is configured to make the compressed gas entering the exhaust passage from the rotor cavity flow through the side wall of the mounting sheet and the sound attenuation units, and then be discharged from the exhaust port.

[0004] According to the above, the exhaust passage comprises a sound attenuation passage, and the sound attenuation device is arranged in the sound attenuation passage. The number of the at least one mounting sheet and the flow area of the sound attenuation passage are arranged to make the compressed gas discharged from the exhaust port reach a predetermined gas pressure.

[0005] According to the above, the radial cross section of the sound attenuation passage is rectangular.

[0006] According to the above, the sound attenuation device is formed by a 3D printing process or a numerical control machining process.

[0007] According to the above, the muffling device comprises a limiting structure arranged on the cavity wall defining the muffling passage, and a limiting fitting structure arranged on the mounting sheet, the limiting structure and the limiting fitting structure being fitted to connect the mounting sheet to the cavity wall.

[0008] According to the above, the limiting structure comprises a slot arranged on the cavity wall, and the limiting fitting structure comprises a mounting portion arranged on the mounting sheet, the mounting portion being able to be insertedly fitted with the slot.

[0009] According to the above, the mounting sheet is integrally formed with the cavity wall defining the muffling passage.

[0010] According to the above, the plurality of muffling units comprises a plurality of resonance muffling units, each of which is configured to have a predetermined natural frequency to reduce noise by forming resonance with sound waves having the predetermined natural frequency in the noise in the exhaust passage.

[0011] According to the above, the resonance muffling units are acoustic superstructures, wherein at least a part of the resonance muffling units are configured to have different predetermined natural frequencies.

[0012] According to the above, the side wall of the mounting sheet has a wall, each of the resonance muffling units comprises a resonance cavity and a connecting pipe, the connecting pipe extends into the resonance cavity from the wall of the side wall and fluidly connects the resonance cavity and the exhaust passage.

[0013] According to the above, the inner surface of the wall is a partial spherical surface.

[0014] According to the above, each of the resonance muffling units further comprises a pressure balance passage extending through the wall to fluidly connect the resonance cavity and the exhaust passage.

[0015] According to the above, each of the resonance muffling units is configured to form the predetermined natural frequency by the volume of the resonance cavity and the length and inner diameter of the connecting pipe and the pressure balance passage.

[0016] According to the above, the screw compressor further comprises an additional muffling device arranged on a cavity wall defining the exhaust passage, the additional muffling device comprising a muffling unit as described above.

[0017] Other features, objects, and advantages of the application can be derived from the specific embodiments, drawings, and claims, which follow. Furthermore, it should be understood that the summary and the following detailed description are exemplary and intended to provide further explanation without limiting the scope of the application as claimed. The detailed description and specific examples are indicative, however, of the preferred embodiments of the application. Various changes and modifications within the spirit and scope of the application will become readily apparent to those skilled in the art from this detailed description. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1A is a perspective view of a screw compressor according to one embodiment of the application;

[0019] Figure 1B is a perspective view of the screw compressor shown in Figure 1A from another angle;

[0020] Figure 2 is a sectional view of the screw compressor shown in Figure 1A along the line A-A;

[0021] Figure 3 is a perspective view of one embodiment of the exhaust housing in Figure 1A ;

[0022] Figure 4A is a perspective view of an exhaust housing according to another embodiment of the application in a screw compressor;

[0023] Figure 4B is a perspective view of the exhaust housing shown in Figure 4A from another angle;

[0024] Figure 4C is a sectional view of the exhaust housing shown in Figure 4A along the line B-B;

[0025] Figure 4D is a sectional view of the exhaust housing shown in Figure 4A along the line C-C;

[0026] Figure 5A is a partial structural schematic view of one embodiment of a muffling device in Figure 3 ;

[0027] Figure 5B is a partial structural schematic view of another embodiment of a muffling device in Figure 3 ;

[0028] Figure 6A is a structural schematic view of a resonance muffling unit in Figure 5A ;

[0029] Figure 6B Fig. 1 is a perspective view showing a screw compressor according to an embodiment of the present application; Figure 6A Fig. 2 is an axial sectional view of the resonance muffling unit shown in Fig. 1;

[0030] Figure 7 Fig. 3 is a perspective view showing another embodiment of the resonance muffling unit; Figure 4A Fig. 4 is a perspective view showing still another embodiment of the resonance muffling unit;

[0031] Figure 8 Fig. 5 is a perspective view showing still another embodiment of the resonance muffling unit; Figure 4A Fig. 6 is a perspective view showing still another embodiment of the resonance muffling unit;

[0032] Figure 9 Fig. 7 is a perspective view showing still another embodiment of the resonance muffling unit; Figure 4A Fig. 8 is a perspective view showing still another embodiment of the resonance muffling unit;

[0033] Figure 10 Fig. 9 is a perspective view showing still another embodiment of the resonance muffling unit; Figure 4A Fig. 10 is a perspective view showing still another embodiment of the resonance muffling unit;

[0034] Figure 11A Fig. 11 is a perspective view showing an exhaust casing in a screw compressor according to still another embodiment of the present application;

[0035] Figure 11B Fig. 12 is a perspective view showing another angle of the exhaust casing shown in Fig. 11. Figure 11A DETAILED DESCRIPTION

[0036] The various embodiments of the present application will be described hereinafter with reference to the drawings, which are meant to illustrate and not to limit the application. Although terms indicating directions, such as "front", "rear", "upper", "lower", "left", "right", "top", "bottom", etc. are used to describe various example structural parts and elements of the present application, these terms are used herein only for the purpose of convenience of explanation, determined based on the example orientation shown in the drawings. Since the embodiments disclosed herein can be arranged in different directions, these terms indicating directions are used only as explanation and should not be considered as limiting.

[0037] Figure 1A Fig. 1 is a perspective view showing a screw compressor 100 according to an embodiment of the present application, for explaining the external structure of the screw compressor 100. In the drawings, Figure 1B Fig. 2 is a perspective view from the front, Fig. 3 is a perspective view from the rear, Fig. 4 is a perspective view from the front, Fig. 5 is a perspective view from the rear, Fig. 6 is a perspective view from the front, Fig. 7 is a perspective view from the rear, Fig. 8 is a perspective view from the front, Fig. 9 is a perspective view from the rear, Fig. 10 is a perspective view from the front, and Fig. 11 is a perspective view from the rear. Figure 1A Figure 1B Figure 1A Figure 1B ​​​​As shown, the screw compressor 100 includes a housing 101 which is substantially in the shape of a long cylinder, comprising a motor housing 102, a rotor housing 103 and an exhaust housing 104 connected in sequence in the length direction. The motor housing 102 has a suction port 105, and is mainly used to accommodate a motor 212 (see Figure 2 As shown, the rotor housing 103 has a rotor cavity 213 (see Figure 2 As shown, the rotor housing 103 has a rotor cavity 213 (see

[0038] Figure 2 A cross-sectional view of the screw compressor 100 along the line A-A is shown in Fig. 2, which is used to show the internal structure of the screw compressor 100. As shown in Fig. 2, the rotor cavity 213 accommodates a pair of rotors 221 which are substantially parallel and arranged side by side, and the pair of rotors 221 includes a male rotor and a female rotor. It is understood by those skilled in the art that only the male rotor is shown in the cross-sectional position as shown in the figure. The male rotor and the female rotor are engaged with each other, and the male rotor is connected with the motor 212, so that the pair of rotors 221 can be driven to rotate by the motor 212. The pair of rotors 221 has an axis which is parallel to each other, and the male rotor and the female rotor rotate around the respective axes. In this embodiment, the extension direction of the axis is the axial direction, and the pair of rotors 221 can rotate around the axial direction. Figure 1A Figure 2 The male rotor and the female rotor are each provided with a plurality of helical teeth, and the grooves are formed between adjacent teeth. The male rotor and the female rotor form an engaged structure through the respective teeth and the corresponding grooves, and together with the rotor housing 103 form a plurality of separated compression cavities 225. The rotor cavity 213 has a suction end 223 at the left end and an exhaust end 224 at the right end. The gas is sucked into the compression cavities 225 from the suction end 223, and with the rotation of the pair of rotors, the compression cavities 225 gradually move towards the exhaust end 224. At the same time, the volume of the compression cavities 225 also gradually decreases with the rotation of the pair of rotors, and the gas in the compression cavities 225 is gradually compressed. The compressed gas is discharged from the exhaust end 224.

[0039] The exhaust housing 104 defines an exhaust cavity 214, which includes an exhaust passage 218 for fluidly connecting the exhaust end 224 of the rotor cavity 213 and the exhaust port 106. The exhaust passage 218 can discharge the compressed gas discharged from the exhaust end 224 through the exhaust passage 218 and then from the exhaust port 106 of the screw compressor 100.

[0040] The exhaust housing 104 defines an exhaust cavity 214, which includes an exhaust passage 218 for fluidly connecting the exhaust end 224 of the rotor cavity 213 and the exhaust port 106. The exhaust passage 218 can discharge the compressed gas discharged from the exhaust end 224 through the exhaust passage 218 and then from the exhaust port 106 of the screw compressor 100. ​

[0041] When the screw compressor 100 is in operation, the engagement of the pair of rotors 221 forms discontinuous compression pockets 225, such that the compressed gas is intermittently discharged from the discharge end 224, then flows through the discharge passage 218 and is finally discharged from the discharge port 106, thereby generating a higher acoustic energy of the discharge pressure pulsation, which causes the vibration and noise of the screw compressor 100.

[0042] In order to reduce the noise effect caused by the discharge pressure pulsation, the screw compressor 100 further comprises a muffling device 220, which is arranged in the discharge passage 218. In the present embodiment, the muffling device 220 comprises at least one mounting piece 219 and a plurality of muffling units 210, which are arranged on the mounting piece 219. Thus, when the compressed gas in the screw compressor 100 generates the discharge pressure pulsation, the energy of the discharge pressure pulsation can be reduced during the flow through the discharge passage 218, thereby reducing the noise effect caused by the discharge pressure pulsation.

[0043] The discharge passage 218 comprises a muffling passage 217, which is defined by the pocket wall 216. The muffling device 220 is arranged in the muffling passage 217. The muffling device 220 arranged in the muffling passage 217 will cause the flow area of the muffling passage 217 for the flow of the gas to be reduced, and the pressure loss of the compressed gas when flowing through the muffling passage 217 will be increased. As an example, the flow area of the muffling passage 217 and the number of the at least one mounting piece 219 are arranged such that the pressure of the compressed gas discharged from the discharge port 106 reaches a predetermined gas pressure.

[0044] Figure 3 For Figure 1A the exploded view of the discharge housing 104 in FIG. 1. As Figure 3As shown, the exhaust casing 104 includes a mounting portion 381 and a seat portion 382. The mounting portion 381 is configured to be connected to the rotor casing 103, and the exhaust port 106 is provided on the seat portion 382, which is substantially cylindrical in shape. The exhaust cavity 214 includes a cavity 331 for accommodating other components such as the rotor end portion, and an exhaust passage 218, the cavity 331 being not in communication with the exhaust passage 218, and the exhaust end 224 of the rotor cavity 213 being capable of communicating with the exhaust passage 218 only. In this embodiment, the exhaust passage 218 extends substantially along the axial direction of the rotor, extending through the seat portion 382 from the mounting portion 381. The muffling passage 217 is a portion of the exhaust passage 218 in the extending direction (i.e. the length direction) thereof, and the cross-sectional shape of the muffling passage 217 is circular. Each mounting plate 219 of the muffling device 220 is substantially rectangular in shape, and extends along the extending direction of the exhaust passage 218. The range of the extending direction of each mounting plate 219 of the muffling device 220 substantially defines the muffling passage 217. In some embodiments, the mounting plate 219 of the muffling device 220 extends from the inlet to the outlet of the exhaust passage 218, and the exhaust passage 218 substantially forms the muffling passage 217 as a whole.

[0045] In this embodiment, the muffling device 220 includes three mounting plates 219, which are arranged in parallel and spaced apart from each other in the muffling passage 217, so that the mounting plates 219 do not directly block the gas flow, thereby reducing the pressure loss caused by the mounting plates 219 blocking the gas flow. In this embodiment, the mounting plates 219 can be integrally formed with the cavity wall 216 defining the muffling passage 217, for example, by 3D printing and numerical control machining.

[0046] Each mounting plate 219 has a pair of side walls 334 extending along the extending direction of the exhaust passage 218, and the muffling unit 210 is arranged on the side walls 334 of the mounting plate 219, so that when the gas flows in the exhaust passage 218, it needs to flow through the muffling unit 210 on the side walls 334, thereby enabling the muffling unit 210 to reduce the energy of the exhaust pressure pulsation in the gas flow, and further eliminating the noise.

[0047] Figures 4A-4D Another embodiment of the screw compressor according to the present application is shown, and the structure of the exhaust casing 404 is shown. In the embodiment as shown, the other parts of the screw compressor are the same as those in the screw compressor 100. Among them Figure 4A A perspective view of the exhaust casing 404 is shown from one angle, Figure 4B A perspective view of the exhaust casing 404 is shown from another angle, Figure 4C A perspective view of the exhaust casing 404 is shown from another angle, Figure 4A A perspective view of the exhaust casing 404 is shown from another angle, Figure 4DIt shows Figure 4A The exhaust housing 404 shown is a cross-sectional view along line CC, where the hollow arrows indicate the flow direction of the compressed gas.

[0048] like Figures 4A-4D As shown, the exhaust housing 404's exhaust cavity 414 also includes a cavity 431 and an exhaust passage 418. The cavity 431 accommodates components such as the rotor's end parts, and the exhaust passage 418 provides fluid communication between the rotor cavity and the exhaust port 406. The exhaust passage 418 includes a silencing passage 417, and a silencing device 420 is disposed within the silencing passage 417. Figure 3 Unlike the exhaust housing 104 shown, in this embodiment, the silencing channel 417 has a rectangular cross-section. The external dimensions of the mounting portion 481 of the exhaust housing 404 are approximately the same as those of the mounting portion 381, and the space occupied by the base 482 is approximately the same as that of the base 382. With the same wall thickness of the base 482, the silencing channel 417 of this application has a rectangular cross-sectional shape. Within the same spatial dimensions as a rectangle, the flow area of ​​the silencing channel 417 is larger than that of silencing channels with other cross-sectional shapes (e.g., circular). Therefore, even if a silencing device 420 is provided in the silencing channel 417, the pressure loss of the gas flow will not be significantly increased, allowing the compressed gas discharged from the exhaust port 406 to reach a predetermined pressure. In this embodiment, the base 482 includes a body 483 and an end cap 484, wherein the body 483 contains the silencing channel 417 with a rectangular cross-section, and the end cap 484 has a circular exhaust port 406 in its center. Therefore, even if the cross-section of the silencing channel 417 is rectangular, it will not affect the connection between the exhaust housing 404 and the external pipe through the exhaust port 406.

[0049] The silencing device 420 includes at least one mounting plate 419 and several silencing units, which are not shown in the figure. The silencing units are disposed on the sidewall 434 of the mounting plate 419 so that when compressed gas flows through the silencing channel 417, the energy of exhaust pressure pulsations can be reduced by the silencing units, thereby reducing noise. In this embodiment, at least one mounting plate 419 includes four mounting plates 419 arranged side-by-side. Each mounting plate 419 is generally rectangular and flat, spaced apart between the top and bottom of the cavity wall 416 of the exhaust housing 404, and extending along the extension direction of the exhaust channel 418, so that the mounting plates 419 do not directly obstruct gas flow, thereby reducing pressure loss caused by the mounting plates 419 obstructing gas flow.

[0050] In manufacturing the exhaust casing 404, the mounting piece 419 of the muffling device 420 is integrally formed with the muffling unit through a 3D printing process or a numerical control machining process, and then the muffling device 420 is connected to the cavity wall 416 to arrange the muffling devices 420 on the cavity wall 416. As an example, the muffling device 420 can be connected to the cavity wall 416 through interference fit, riveting, welding, gluing, etc. In the embodiment shown in Figures 4A-4D In the embodiment shown in

[0051] The muffling device 420 can be made of the same material as other parts of the exhaust casing 404, or can be made of different materials. In the embodiment, the muffling device 420 is made of an aluminum alloy material with certain expansion capability, and other parts of the exhaust casing 404 are made of cast steel or cast iron material with higher strength.

[0052] Since the cost of 3D printing and numerical control machining is high, the exhaust casing 404 in the embodiment separately manufactures the muffling device 420 and then connects the muffling device 420 to the cavity wall 416, which can save costs compared with the exhaust casing 104.

[0053] The muffling unit 210 of the present application includes a resonance muffling unit that reduces noise by resonating with certain sound waves in the noise. In other embodiments, the muffling unit 210 can also combine the resonance muffling unit with other types of muffling units, such as interference muffling units or quarter-wave tubes. Figure 5A and Figure 5B Two embodiments of the structure of the muffling device 220 are shown to illustrate the arrangement structure of the muffling unit 210 of the muffling device 220. Among them Figure 5A The muffling unit 210 of the muffling device 220 in Figure 5B The muffling unit 210 in includes a resonance muffling unit 540 and an interference muffling unit 550.

[0054] like Figure 5A As shown, the mounting plate 219 of the muffler 220 is provided with several resonant muffler units 540 arranged in sequence. These resonant muffler units 540 are acoustic superstructures. Each resonant muffler unit 540 has a predetermined natural frequency. These resonant muffler units 540 reduce the excitation energy of exhaust pressure pulsations by resonating with sound waves with the same predetermined natural frequency in the noise in the muffler channel 217, thereby reducing exhaust noise. When at least a portion of these resonant muffler units 540 have different predetermined natural frequencies, these resonant muffler units 540 can reduce exhaust noise over a wide frequency range.

[0055] As an example, these resonant silencing units 540 are evenly arranged on the mounting plate 219, for example, in rows, with the resonant silencing units 540 in each row spaced apart and the resonant silencing units 540 between adjacent rows staggered. Each resonant silencing unit 540 includes a resonant cavity 543, a connecting pipe 541, and a pressure balancing channel 542. The resonant cavity 543 is generally cylindrical and its axial direction is disposed within the mounting plate 219 along the thickness direction of the mounting plate 219. The connecting pipe 541 and the pressure balancing channel 542 form holes on the outer surface of the mounting plate 219 to fluidly communicate the resonant cavity 543 inside the mounting plate 219 and the silencing channel 217 outside the mounting plate 219. The specific structure of each resonant silencing unit 540 will be discussed in conjunction with... Figure 6A and Figure 6B Please provide a detailed explanation.

[0056] like Figure 5B As shown, the arrangement of the resonant noise reduction unit 540 is similar to... Figure 5A The embodiments shown are the same, except that in Figure 5BIn the illustrated embodiment, the muffling unit 210 includes a number of interference muffling units 550 in addition to the resonance muffling units 540. These interference muffling units 550 are disposed at intervals between adjacent resonance muffling units 540. As one example, an interference muffling unit 550 can also be disposed between a resonance muffling unit 540 and the edge of the mounting sheet 219. These interference muffling units 550 reduce exhaust noise by interfering with certain wavelengths of sound waves in the noise in the muffling passage 217. As one specific example, each interference muffling unit 550 includes an interference passage (not shown) that forms an interference passage inlet 539 and an interference passage outlet 549 at the outer surface of the mounting sheet 219 so that the muffling passage 217 outside the mounting sheet 219 is in fluid communication with the interference passage and the interference passage can act as a side branch of the muffling passage 217. By designing the length of the interference passage to be one-half wavelength plus an odd number of half-wavelengths different from the length of the muffling passage 217 between the interference passage inlet 539 and the interference passage outlet 549, the gas flowing out of the interference passage outlet 549 of the interference passage can interfere with the muffling passage 217 at the junction, thereby reducing the energy of the noise.

[0057] Those skilled in the art will appreciate that, in some other embodiments, the resonance muffling units can also be used in combination with quarter- wavelength tube muffling units.

[0058] In comparison with the illustrated embodiment, Figure 5A In comparison with the illustrated embodiment, Figure 5B The illustrated embodiment includes more muffling units, which can achieve better muffling effects. However, more muffling units will make the hollow part in the mounting sheet 219 larger, which can affect the strength of the mounting sheet 219. Those skilled in the art can set an appropriate number of muffling units according to the actual noise and the material, strength, etc. of the mounting sheet 219.

[0059] Figure 6A In comparison with the illustrated embodiment, Figure 6B A specific structure of one resonance muffling unit 540 is shown, in which Figure 6A is a structural schematic diagram of the resonance muffling unit 540, Figure 6B is a cross-sectional view of the resonance muffling unit 540. Figure 6A In order to more clearly show the specific structure of the resonance muffling unit 540, Figure 6A The resonance muffling unit 540 in the mounting sheet 219 is schematically shown as a cylindrical outer wall 644 around its resonance cavity 543, and the actual outer wall is formed by the mounting sheet 219 that is spaced between the resonance muffling units 540.

[0060] As Figure 6A In comparison with the illustrated embodiment, Figure 6BAs shown, the sidewall 334 of the mounting piece 219 has a wall 645 and a wall 646, and the resonance cavity 543 of the resonance muffling unit 540 is arranged between the wall 645 and the wall 646. The connecting pipe 541 extends from the wall 645 to the inside of the resonance cavity 543 for a certain length. The pressure balance channel 542 is arranged opposite to the connecting pipe 541, and the pressure balance channel 542 is below the connecting pipe 541 and penetrates the wall 645. The extending directions of the connecting pipe 541 and the pressure balance channel 542 are substantially parallel, and both are consistent with the axial direction of the resonance cavity 543. The connecting pipe 541 and the pressure balance channel 542 can fluidly connect the resonance cavity 543 and the muffling channel 217 outside the mounting piece 219. As an example, the pressure balance channel 542 is arranged at the bottom of the wall 645, and the connecting pipe 541 is arranged at the top of the wall 645.

[0061] In the present embodiment, the resonance cavity 543, the connecting pipe 541, and the pressure balance channel 542 together form the resonance muffling unit 540, and by setting the volume of the resonance cavity 543, the length of the connecting pipe 541, the pressure balance channel 542, and the inner diameter of the connecting pipe 541, each resonance muffling unit 540 can have a predetermined natural frequency, and several resonance muffling units 540 can have different predetermined natural frequencies.

[0062] The pressure balance channel 542 is used to balance the pressure inside and outside the resonance cavity 543. Specifically, the gas entering the exhaust channel 218 after compression has a high pressure and generates exhaust pressure pulsation. The pressure balance channel 542 can balance the pressure inside and outside the resonance cavity 543, and prevent the exhaust pressure pulsation from causing pressure impact on the resonance cavity 543. In addition, when the gas entering the exhaust channel 218 is mixed with liquid such as oil or water, the pressure balance channel 542 also helps to timely discharge the liquid in the resonance cavity 543 from the connecting pipe 541, so as to avoid the resonance muffling unit 540 being affected by the liquid in the resonance cavity 543 and failing to achieve the predetermined natural frequency as expected.

[0063] In order to further reduce the pressure impact of the exhaust pressure pulsation on the resonance cavity 543, the inner surface of the wall 645 is arranged in a partially spherical shape in the present embodiment. Those skilled in the art can understand that when the mounting part is made of a material with higher strength, the inner surface of the wall 645 can also be arranged in a planar shape or the like.

[0064] In some embodiments, the wall 546 can be formed by the sidewall of the mounting piece 219 on the other side opposite to the wall 645. In other embodiments, the resonance muffling unit can be arranged on both opposite sidewalls of the mounting piece 219, and the wall 546 can also be formed by the mounting piece 219 between the two opposite resonance muffling units.

[0065] The resonant silencing unit 540 of this application, by setting the shape of the pressure balance channel 542 and the wall 645, can effectively avoid the influence of exhaust pressure pulsation on the resonant silencing unit 540, and is suitable for operation in high pressure and liquid environments. Therefore, it is suitable for installation on the limiting wall of the compressor exhaust channel.

[0066] Figure 7 It shows Figure 4A A perspective view of another embodiment of the silencing device, in which the silencing unit is omitted. (See diagram below.) Figure 7 As shown, the muffler 720 includes several mounting plates 719, which are generally rectangular flat plates stacked and spaced apart in the longitudinal direction to allow compressed gas to flow through the spaces between them. Each mounting plate 719 extends along the direction of the exhaust passage 418, so the mounting plates 719 hardly obstruct the airflow, and the gas can reduce exhaust pressure pulsation as it flows through the mounting plates 719, thereby reducing noise. In this embodiment, limiting structures, such as grooves, are provided on the left and right sides of the cavity wall 416 defining the muffler passage 417, and the left and right ends of the mounting plates 719 form limiting fitting structures, such as mounting portions 735, for insertion into the grooves.

[0067] Figure 8 It shows Figure 4A A perspective view of another embodiment of the silencing device, in which the silencing unit is omitted. (See diagram below.) Figure 8 As shown, the muffler 820 includes several mounting plates 819, which are generally corrugated plates arranged side-by-side and spaced apart in the transverse direction, allowing compressed gas to flow through the spaces between the mounting plates 819. Each mounting plate 819 extends along the direction of the exhaust passage 418, so the mounting plates 819 hardly obstruct the airflow, and the gas can reduce exhaust pressure pulsation as it flows through the mounting plates 819, thereby reducing noise. In this embodiment, limiting structures, such as grooves, are provided on the front and rear sides of the cavity wall 416 defining the muffler passage 417, and the front and rear ends of the mounting plates 819 form limiting fitting structures for insertion into the grooves, such as mounting portions 835. In this embodiment, to facilitate the secure installation of the mounting plates 819 and the cavity wall 416, the mounting portions 835 are also provided with blocking strips 836, which extend in a direction different from the mounting portions 835, for example, extending in the left-right direction. Those skilled in the art will understand that, correspondingly, the cavity wall 416 is also provided with a slot that matches the shape and size of the blocking strip 836 at the corresponding position.

[0068] Figure 9 It shows Figure 4A A perspective view of another embodiment of the silencing device, in which the silencing unit is omitted. (See diagram below.) Figure 9As shown, the silencing device 920 includes several mounting plates 919, which are generally rectangular flat plates arranged in a cross pattern in the horizontal and vertical directions to allow compressed gas to flow through the spaces between the mounting plates 919. Each mounting plate 919 extends along the direction of the exhaust channel 418, so the mounting plates 919 hardly obstruct the airflow, and the gas can reduce the exhaust pressure pulsation as it flows through the mounting plates 919, thereby reducing noise. In this embodiment, the top, bottom, and left and right sides of the cavity wall 416 defining the silencing channel 417 are provided with limiting structures, such as grooves, and the top, bottom, and left and right ends of the mounting plates 919 form limiting fitting structures for insertion into the grooves, such as mounting portions 935.

[0069] Figure 10 It shows Figure 4A A perspective view of another embodiment of the silencing device, in which the silencing unit is omitted. (See diagram below.) Figure 10 As shown, the silencing device 1020 includes several mounting plates 1019. These mounting plates 1019 include several generally annular plates 1037 and several generally rectangular flat plates 1038. The plates 1037 are arranged sequentially around and spaced apart. The plates 1038 are arranged in a cross shape in the horizontal and vertical directions and connect the plates 1037 so that compressed gas can flow through the spaces between these mounting plates 1019. Each mounting plate 1019 extends along the direction of the exhaust channel 418, so the mounting plate 1019 hardly obstructs the airflow, and the gas can reduce the exhaust pressure pulsation ability when flowing through the mounting plate 1019, thereby reducing noise. In this embodiment, the top, bottom, and left and right sides of the cavity wall 416 defining the silencing channel 417 are provided with limiting structures, such as grooves. The top, bottom, and left and right ends of the plates 1038 of the mounting plate 1019 form limiting fitting structures for insertion into the grooves, such as mounting portions 1035.

[0070] Figure 11A and Figure 11B The structure of the exhaust housing 1104 is shown in another embodiment of the screw compressor according to this application. In the embodiment shown, the other parts of the screw compressor have the same structure as those in screw compressor 100. Figure 11A The diagram shows a three-dimensional view of the exhaust housing 1104 from one angle. Figure 11B A three-dimensional structural view of the exhaust housing 1104 from another angle is shown. (See diagram below.) Figure 11A and Figure 11BAs shown, in the present embodiment, the exhaust passage 1118 extends along the axial direction of the rotor first, and then bends about 90° to extend along the radial direction of the rotor. That is, the exhaust passage 1118 includes two substantially perpendicular portions, and the exhaust port 1106 is arranged at the side of the screw compressor, which is arranged at 90° to the suction port 105 arranged at the rear side of the screw compressor.

[0071] The exhaust passage 1118 includes a muffling passage 1117 extending along the radial direction of the rotor. A muffling device 1120 is arranged in the muffling passage 1117. In the present embodiment, the muffling device 1120 includes two cross-arranged mounting plates 1119 and a muffling unit 1110, one mounting plate is a wavy plate-shaped and connected to the front and rear sides of the cavity wall 1116 of the muffling passage 1117, and the other mounting plate is a longitudinal plate-shaped and connected between the top and bottom of the cavity wall 1116 of the muffling passage 1117. The compressed gas can flow through the space between the mounting plates 1119. The muffling unit 1110 is arranged on the side wall of the two mounting plates 1119. Each mounting plate 1119 extends along the extending direction of the muffling passage 1117, so the mounting plate 1119 hardly blocks the gas flow, and the gas can reduce the exhaust pressure pulsation ability when flowing through the mounting plate 1119, thereby reducing the noise.

[0072] In the present embodiment, the screw compressor further includes an additional muffling unit 1160 arranged on the cavity wall 1146 defining the exhaust passage 1118 to further reduce the noise of the compressed gas flowing in the exhaust passage 1118. The structure of the additional muffling unit 1160 can include the structure of the resonance muffling unit 540 as shown in Figure 5A or the structure of the interference muffling unit 550 as shown in Figure 5B .

[0073] In the present embodiment, the exhaust casing 1104 is integrally formed by a 3D printing or numerical control machining process, that is, the additional muffling unit 1160 and the cavity wall 1146, and the mounting plate 1119, the muffling unit 1110 and the cavity wall 1116 defining the muffling passage 1117 are integrally formed. Those skilled in the art can understand that in other embodiments, the muffling device 1140 can also be formed separately, and then connected to the cavity wall 1116 of the muffling passage 1117 through the limiting structure and the limiting fitting structure as described in the foregoing embodiments.

[0074] Those skilled in the art can understand that according to different embodiments of the screw compressor, the exhaust casing as shown in Figure 3 , as shown in Figures 4A-4D and as shown in Figures 11A-11B , and the muffling device as shown in Figure 7 , as shown in Figure 8 , as shown inFigure 9 and the muffling device as shown in Figure 10 may be used in combination or separately. It is only necessary to provide a muffling device in the muffling passage so that the compressed gas can be reduced in energy of the exhaust pressure pulsation by the muffling device after entering the muffling passage to reduce or eliminate noise.

[0075] In the existing screw compressor, the compressed gas flowing through the exhaust passage has a high acoustic energy of the exhaust pressure pulsation, causing vibration and noise of the screw compressor. During the process of being discharged from the exhaust port through the exhaust passage from the exhaust end of the rotor cavity, the compressed gas in the exhaust passage is usually high in temperature and pressure, and often has liquid such as oil or water mixed in the gas.

[0076] In the screw compressor of the present application, the muffling device is provided in the muffling passage of the exhaust passage, that is, in the flow path of the compressed gas discharged from the exhaust port through the exhaust passage, so that the noise can be eliminated. Moreover, the screw compressor of the present application can be improved on the basis of the structure of the existing screw compressor, and the muffling device can be additionally provided in the exhaust casing or a separate exhaust casing including the muffling device can be manufactured, which reduces the influence on the structure of the existing screw compressor and has a lower cost. In addition, the muffling device of the present application can balance the gas pressure loss caused by the muffling device by increasing the flow area of the muffling passage, without affecting the exhaust pressure of the screw compressor.

[0077] The resonance muffling unit of the present application has a pressure balancing passage and a partial spherical wall shape, which can increase the ability of the resonance muffling unit to withstand pressure, prevent the structure of the resonance muffling unit from being damaged by the exhaust pressure pulse, and at the same time can discharge the accumulated liquid in the muffling structure in real time, ensuring the stability of the noise elimination effect of the muffling device, so it can be provided in the exhaust passage with very high exhaust pressure pulsation energy.

[0078] Moreover, the resonance muffling unit of the present application has an acoustic superstructure, which reduces the energy of the exhaust pressure pulse by forming resonance with the acoustic waves of certain frequencies in the noise to achieve the purpose of reducing noise. Not only is the noise elimination effect of each resonance muffling unit good and the space occupied small, but also multiple resonance muffling units with different predetermined natural frequencies can eliminate noise in a wide frequency range in the exhaust passage.

[0079] In addition, the resonance muffling unit of the present application can also be used in combination with other types of muffling devices such as interference muffling units to achieve better noise elimination effect.

[0080] While the present disclosure has been described in connection with the illustrative examples described above, various alternative, modifications, variations, improvements, and / or substantial equivalents that are or can be presently unforeseeable can be made by persons skilled in the art with the benefit of the present disclosure. Therefore, the presently disclosed examples are intended to be illustrative only and not limiting. Various changes can be made without departing from the spirit or scope of the present disclosure. Accordingly, the presently disclosed examples are intended to be illustrative only and not limiting. The technical effects and technical problems described in this specification are exemplary and not limiting. It should be noted that the embodiments described in this specification can have other technical effects and can address other technical problems.

Claims

1. A screw compressor, characterized in that... Comprising: a housing including a rotor housing and an exhaust housing, the rotor housing defining a rotor cavity, the exhaust housing defining an exhaust cavity, the rotor cavity and the exhaust cavity being in fluid communication, the exhaust housing being provided with an exhaust port; a pair of rotors disposed in the rotor cavity, the pair of rotors being capable of forming a compression cavity with the housing, the rotor cavity having a suction end and an exhaust end, the pair of rotors being arranged to compress gas entering the compression cavity from the suction end to the exhaust end as the pair of rotors rotate; an exhaust passage disposed in the exhaust housing, the exhaust passage being in fluid communication with the exhaust end and the exhaust port, the exhaust passage being configured to discharge the compressed gas in the rotor cavity from the exhaust port; and a muffling device disposed in the exhaust passage, the muffling device including at least one mounting sheet having a side wall extending along an extension direction of the exhaust passage and a plurality of muffling units disposed on the side wall of the at least one mounting sheet; wherein the muffling device is configured such that the compressed gas entering the exhaust passage from the rotor cavity flows through the side wall of the mounting sheet and the muffling units before being discharged from the exhaust port.

2. The screw compressor according to claim 1, wherein: the exhaust passage includes a muffling passage, the muffling device being disposed in the muffling passage; wherein the number of the at least one mounting sheet and the flow area of the muffling passage are arranged such that the compressed gas discharged from the exhaust port reaches a predetermined gas pressure; and / or wherein the extension direction of the side wall of the at least one mounting sheet is parallel to the extension direction of the pair of rotors in the rotor cavity.

3. The screw compressor according to claim 2, wherein: a radial cross section of the muffling passage is rectangular.

4. The screw compressor according to claim 2, wherein: the muffling device is formed by a 3D printing process or a numerical control machining process.

5. The screw compressor according to claim 4, wherein: the muffling device includes a limiting structure disposed on a cavity wall defining the muffling passage and a limiting fitting structure disposed on the mounting sheet, the limiting structure and the limiting fitting structure being fitted to connect the mounting sheet to the cavity wall.

6. The screw compressor according to claim 5, wherein: the limiting structure includes a slot disposed on the cavity wall, and the limiting fitting structure includes a mounting portion disposed on the mounting sheet, the mounting portion being capable of being inserted and fitted with the slot.

7. The screw compressor according to claim 2, wherein: the mounting sheet is integrally formed with a cavity wall defining the muffling passage.

8. The screw compressor according to claim 2, wherein: The plurality of sound attenuation units includes a plurality of resonant sound attenuation units, each of the resonant sound attenuation units being configured to have a predetermined natural frequency to reduce noise in the exhaust passage by resonating with sound waves having the predetermined natural frequency in the noise.

9. The screw compressor of claim 8, wherein: The resonant sound attenuation units are acoustic superstructures, wherein at least a portion of the resonant sound attenuation units are configured to have different predetermined natural frequencies.

10. The screw compressor of claim 9, wherein: The side wall of the mounting plate has a wall, each of the resonant sound attenuation units includes a resonant cavity and a connecting tube, the connecting tube extending from the wall of the side wall into the resonant cavity and fluidly connecting the resonant cavity and the exhaust passage.

11. The screw compressor of claim 10, wherein: An inner surface of the wall is a partial sphere.

12. The screw compressor of claim 10, wherein: Each of the resonant sound attenuation units further includes a pressure equalization passage extending through the wall to fluidly connect the resonant cavity and the exhaust passage.

13. The screw compressor of claim 12, wherein: Each of the resonant sound attenuation units is configured to form the predetermined natural frequency by a volume of the resonant cavity and lengths and inner diameters of the connecting tube and the pressure equalization passage.

14. The screw compressor of any one of claims 1-13, wherein: The screw compressor further includes an additional sound attenuation device disposed on a cavity wall defining the exhaust passage, the additional sound attenuation device including a sound attenuation unit as in any one of claims 8-13.

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