Cooling structure and two-stage oil-free piston air compressor

Abstract

The application provides a cooling structure and a two-stage oil-free piston air compressor, which comprises a cooler, a shell and a fan; the cooler is used for being connected between a first-stage compression cylinder and a second-stage compression cylinder of the air compressor, the cooler has a gas inlet communicated with a gas outlet end of the first-stage compression cylinder and a gas outlet communicated with a gas inlet end of the second-stage compression cylinder, and the cooler has a cooling gas channel curvedly extending from the gas inlet to the gas outlet; the shell is connected to a machine body of the air compressor and surrounds a ventilation cavity at the periphery of the first-stage compression cylinder, the periphery of the second-stage compression cylinder and the bottom of the cooler; and the fan is arranged in the shell and connected to a crankshaft of the air compressor, and is used for rotating under the driving of the crankshaft to form a continuous heat dissipation airflow in the ventilation cavity. The cooling structure and the two-stage oil-free piston air compressor can improve the air cooling heat dissipation efficiency of the second-stage compression cylinder and improve the stability of long-time operation of the whole machine.

Description

Technical Field

[0001] This invention belongs to the field of air compressor technology, specifically relating to a cooling structure and a two-stage oil-free piston air compressor. Background Technology

[0002] Automotive air compressors are primarily used to provide the necessary high-pressure air source for automotive braking systems, suspension systems, and other auxiliary air devices. Currently, common automotive air compressors include oil-free and oil-cooled compressors. Oil-free compressors have the advantages of clean compressed air and no risk of oil leakage, making them increasingly popular in the market. Common oil-free compressors are mainly cooled by either water or air.

[0003] Currently, air cooling can further leverage the cleanliness and leak-free advantages of oil-free compressors, while also offering better cost control and overall size compared to water-cooled compressors. However, its drawback lies in its relatively low cooling efficiency. For example, a two-stage air-cooled oil-free air compressor typically uses air-cooled fins on the periphery of the compressor cylinder, with a fan blowing air onto these fins for heat dissipation. For the first-stage compressor, the heat generated during air compression is relatively small, thus meeting the heat dissipation efficiency requirements. However, for the second-stage compressor, the heat generated during air compression is significant, making it difficult for this air-cooling method to maintain a low operating temperature for extended periods. This can affect the long-term stable operation of the second-stage compressor, necessitating the development of a superior air-cooling solution to address these issues. Summary of the Invention

[0004] This invention provides a cooling structure and a two-stage oil-free piston air compressor, aiming to improve the air cooling efficiency of the two-stage oil-free piston air compressor.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is: to provide a cooling structure, comprising:

[0006] A cooler is used to connect between the primary and secondary compression cylinders of an air compressor. The cooler has an air inlet that communicates with the outlet of the primary compression cylinder and an air outlet that communicates with the inlet of the secondary compression cylinder. The cooler has a cooling air passage that bends and extends from the air inlet to the air outlet inside.

[0007] The housing is connected to the body of the air compressor and forms a ventilation cavity around the periphery of the primary compression cylinder, the periphery of the secondary compression cylinder, and the bottom of the cooler;

[0008] The fan, located inside the housing and connected to the crankshaft of the air compressor, is used to rotate under the drive of the crankshaft to create a continuous flow of cooling air within the ventilation cavity.

[0009] In one possible implementation, the cooler includes:

[0010] The cooling body is horizontally connected between the primary compression cylinder and the secondary compression cylinder and is spaced apart from the peripheral wall of the machine body. Multiple through holes are distributed sequentially and spaced apart inside the cooling body. A barrier wall is formed between adjacent through holes. Each barrier wall has a break at one end to connect the through holes on both sides, and the breaks on adjacent barrier walls are located at the ends that are far apart from each other.

[0011] Two blocking plates are detachably connected to both ends of the cooling body and are used to block both ends of each through hole;

[0012] The end of the through hole near the first-stage compression cylinder forms an air inlet, and the end of the through hole near the second-stage compression cylinder forms an air outlet; each through hole forms a serpentine cooling air passage based on its respective break.

[0013] In some embodiments, a groove is provided at the bottom of each through hole, and an absorbent strip is embedded in each groove.

[0014] For example, the fan has a central hole, and a connecting sleeve is rotatably connected inside the central hole. The connecting sleeve is fixedly fitted onto the end of the crankshaft that extends out of the machine body. There is a coupling transmission component between the connecting sleeve and the central hole. The coupling transmission component has a coupled state that causes the connecting sleeve to drive the fan to rotate synchronously, and also has an interrupted state that causes the connecting sleeve to rotate independently.

[0015] For example, the intake end of the secondary compression cylinder is equipped with a normally closed switch valve that communicates with the outside air; the outlet is connected to a three-way valve, which has a first passage that connects the outlet to the intake end of the secondary compression cylinder, and a second passage that connects the outlet to the outside air; wherein, when the coupling transmission component is switched to the interrupted state, the normally closed switch valve is opened and the three-way valve is switched to the second passage.

[0016] In one possible implementation, the coupling transmission element includes:

[0017] Multiple first magnets are respectively embedded in the outer peripheral wall of the connecting sleeve and distributed at intervals along the circumference of the connecting sleeve, and there is an annular gap between each first magnet and the hole wall of the central hole;

[0018] Multiple second magnets are respectively embedded in the wall of the central hole and distributed at intervals along the circumference of the central hole. Each second magnet corresponds to each first magnet and forms a magnetic coupling force in the circumference of the central hole.

[0019] The telescopic drive component is fixedly connected to the housing and axially aligned with the center hole. The output end of the telescopic drive component is equipped with a magnetic shielding sleeve.

[0020] The interrupted state is formed when the magnetic shielding sleeve extends into the annular gap, and the coupled state is formed when the magnetic shielding sleeve extends out of the annular gap.

[0021] In some embodiments, the cooling structure further includes a dryer filter, the inlet of which is connected to the outlet, and the outlet of which is connected to the inlet of the secondary compression cylinder.

[0022] For example, the housing includes:

[0023] The end shell is connected to one end of the body and forms an air inlet cavity suitable for accommodating the fan. The part of the end shell that is aligned with the fan is provided with an air inlet grille.

[0024] The bottom shell is connected to the bottom of the body and to the end shell, and a ventilation gap is formed between the bottom shell and the peripheral wall of the body;

[0025] Two enclosures are respectively arranged around the primary compression cylinder and the secondary compression cylinder, and both are connected to the end shell and the bottom shell. One enclosure forms a first air-cooling cavity around the primary compression cylinder, and the other enclosure forms a second air-cooling cavity around the secondary compression cylinder. Both the first air-cooling cavity and the second air-cooling cavity are connected to the air inlet cavity and the ventilation side gap.

[0026] The cooler has two sides connected to two enclosures, and the bottom of the cooler forms an intermediate air-cooling cavity between the side walls of the two enclosures that are close to each other. One end of the intermediate air-cooling cavity is connected to the air inlet cavity, and the other end is connected to the outside.

[0027] For example, multiple heat dissipation fins are spaced apart on the bottom wall of the cooler, and heat dissipation air channels are formed between adjacent heat dissipation fins. All heat dissipation air channels together form an intermediate air-cooling cavity, and the lower ends of each heat dissipation fin are connected to a partition. The partition separates the first air-cooling cavity, the second air-cooling cavity, and the intermediate air-cooling cavity into their own independent cavities.

[0028] The beneficial effects of the cooling structure provided by this invention are as follows: Compared with the prior art, the cooling structure of this invention sets a cooler between the primary and secondary compression cylinders and uses the shell to form a ventilation cavity, so that the heat dissipation airflow generated by the fan rotating under the drive of the crankshaft is blown to the bottom of the primary and secondary compression cylinders and the cooler. On the one hand, it can improve the effective utilization rate of the heat dissipation airflow. On the other hand, it can cool the compressed air discharged from the primary compression cylinder before entering the secondary compression cylinder through the cooler, thereby reducing the air temperature entering the secondary compression cylinder. Since the temperature difference of the air before and after the work is done in the secondary compression cylinder is constant, reducing the intake temperature of the secondary compression cylinder can reduce the upper limit of the air temperature after the work is done in the secondary compression cylinder. This reduces the dependence of the secondary compression cylinder on the cooling airflow for heat dissipation, and allows both the secondary and primary compression cylinders to maintain the normal operating temperature range for a long time under the blowing of the heat dissipation airflow, thereby improving the stability of the whole machine during long-term operation.

[0029] This invention also provides a two-stage oil-free piston air compressor, including the above-mentioned cooling structure.

[0030] Compared with the prior art, the two-stage oil-free piston air compressor provided by this invention adopts the above-mentioned cooling structure, which can blow air into the ventilation housing through the crankshaft-driven fan, thereby simultaneously dissipating heat from the primary compression cylinder, the secondary compression cylinder, and the cooler. This allows the compressed gas discharged from the primary compression cylinder to be cooled in the cooler before entering the secondary compression cylinder, thereby reducing the dependence of the secondary compression cylinder on the cooling airflow. This allows both the primary and secondary compression cylinders to maintain normal operating temperature ranges for a long time under the blowing of the cooling airflow, thus improving the stability of the entire machine during long-term operation. Attached Figure Description

[0031] Figure 1 A three-dimensional structural diagram of the cooling structure provided in the embodiment of the present invention. Figure 1 ;

[0032] Figure 2 A three-dimensional structural diagram of the cooling structure provided in the embodiment of the present invention. Figure 2 ;

[0033] Figure 3 A three-dimensional structural diagram of the cooling structure (excluding the housing) provided in an embodiment of the present invention. Figure 3 ;

[0034] Figure 4 A front view schematic diagram of the cooling structure (end shell cut open) provided in an embodiment of the present invention;

[0035] Figure 5 for Figure 4 (Right view of the structure after removing the end shells)

[0036] Figure 6 This is a schematic diagram of the end face structure of the cooling body used in an embodiment of the present invention;

[0037] Figure 7 For along Figure 6 Schematic diagram of the cross-sectional structure along line AA;

[0038] Figure 8 for Figure 4 A magnified schematic diagram of the local structure at point B;

[0039] Figure 9 This is a schematic diagram of the distribution structure of the first magnet and the second magnet used in an embodiment of the present invention.

[0040] In the diagram: 10, primary compression cylinder; 20, secondary compression cylinder; 21, normally closed switch valve; 30, cooler; 300, cooling air duct; 301, air inlet; 302, air outlet; 3021, three-way valve; 303, through hole; 304, water suction strip; 305, break; 31, cooling body; 311, barrier wall; 312, heat dissipation fins; 3121, heat dissipation air duct; 313, partition plate; 32, blocking plate; 40, shell; 401 402. Air inlet cavity; 403. Ventilation side gap; 404. First air-cooled cavity; 405. Second air-cooled cavity; 406. Intermediate air-cooled cavity; 41. End shell; 417. Air inlet grille; 42. Bottom shell; 43. Enclosure; 50. Fan; 500. Annular gap; 51. Connecting sleeve; 52. Coupling transmission component; 521. First magnet; 522. Second magnet; 523. Telescopic drive component; 5231. Magnetic shielding sleeve; 60. Crankshaft; 70. Dryer filter. Detailed Implementation

[0041] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0042] It should be noted that when an element is referred to as being "set on" another element, it can be directly on or indirectly on the other element. It should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" or "several" means two or more, unless otherwise explicitly specified.

[0043] Please refer to the following: Figures 1 to 7The cooling structure provided by the present invention will now be described. The cooling structure includes a cooler 30, a housing 40, and a fan 50. The cooler 30 is used to connect between the primary compression cylinder 10 and the secondary compression cylinder 20 of the air compressor. The cooler 30 has an air inlet 301 communicating with the air outlet of the primary compression cylinder 10 and an air outlet 302 communicating with the air inlet of the secondary compression cylinder 20. The cooler 30 has a cooling air passage 300 extending from the air inlet 301 to the air outlet 302. The housing 40 is connected to the body of the air compressor and forms a ventilation cavity around the periphery of the primary compression cylinder 10, the periphery of the secondary compression cylinder 20, and the bottom of the cooler 30. The fan 50 is disposed inside the housing 40 and connected to the crankshaft 60 of the air compressor. It is used to rotate under the drive of the crankshaft 60 to form a continuous cooling airflow in the ventilation cavity.

[0044] It should be noted that in this embodiment, the cooler 30 achieves a cooling effect on the bottom of the cooler 30 by the blowing action of the cooling airflow formed by the fan 50 rotating in the ventilation cavity, and by utilizing the top area of ​​the radiator that is in contact with ambient air. It should be understood that, as an automotive air compressor, the top surface of the cooler 30 is in direct contact with ambient airflow during vehicle operation. Under normal circumstances, the faster the vehicle travels, the higher the heat dissipation efficiency of the top surface of the cooler 30. In fact, when the travel speed reaches a certain level, the heat dissipation efficiency of the top of the cooler 30 can even exceed the heat dissipation efficiency of the cooling airflow in the ventilation cavity on the bottom. Furthermore, heat dissipation fins 312 can be provided on both the top and bottom walls of the radiator to increase the heat dissipation area and improve the heat dissipation efficiency.

[0045] It should be explained that in this embodiment, the machine body mainly refers to the crankshaft 60 housing of the air compressor. The primary compression cylinder 10 and the secondary compression cylinder 20 can be distributed in a V-shape on the top of the crankshaft 60 housing, and there is no limit to the number of primary compression cylinders 10 and secondary compression cylinders 20. Both can be arranged in two side by side. In this embodiment, the housing 40 is used to fully cover the machine body, the primary compression cylinder 10 and the secondary compression cylinder 20, and the cooler 30 is used to shield the part between the primary compression cylinder 10 and the secondary compression cylinder 20, thereby forming a complete ventilation cavity.

[0046] In this embodiment, the fan 50 is directly connected to the crankshaft 60 to obtain rotational power. Since the crankshaft 60 is located at the center of the base, the fan 50 faces the base. Therefore, in order to improve the airflow efficiency of the ventilation cavity, the fan 50 can be a radial fan. During rotation, a negative pressure is formed in the central area of ​​the fan 50, which draws in ambient temperature air into the housing 40. Then, the ambient temperature air is thrown to the surroundings and enters the ventilation cavity formed around the base, thereby avoiding the outside air from directly colliding with the machine body when entering the ventilation cavity and affecting the airflow efficiency of the cooling air. Of course, it should be understood that the position of the housing 40 facing the fan 50 should have an air inlet such as an air inlet grille 411, and the positions of the housing 40, the primary compression cylinder 10, the secondary compression cylinder 20, and the radiator should have openings for ventilation to the outside, so as to realize that the outside air continuously enters the ventilation cavity and carries away the heat from the surface of the primary compression cylinder 10, the secondary compression cylinder 20, and the radiator.

[0047] Compared with the prior art, the cooling structure provided in this embodiment provides a cooler 30 between the primary compression cylinder 10 and the secondary compression cylinder 20, and uses the housing 40 to form a ventilation cavity. This allows the cooling airflow generated by the fan 50 rotating under the drive of the crankshaft 60 to be directed towards the bottom of the primary compression cylinder 10, the secondary compression cylinder 20, and the cooler 30. On the one hand, this improves the effective utilization rate of the cooling airflow. On the other hand, it allows the compressed air discharged from the primary compression cylinder 10 to be cooled by the cooler 30 before entering the secondary compression cylinder 20, thereby reducing the air temperature entering the secondary compression cylinder 20. Since the temperature difference of the air before and after the work is done in the secondary compression cylinder 20 is constant, reducing the intake temperature of the secondary compression cylinder 20 can reduce the upper limit of the air temperature after the work is done in the secondary compression cylinder 20. This reduces the dependence of the secondary compression cylinder 20 on the cooling airflow for heat dissipation, allowing both the secondary compression cylinder 20 and the primary compression cylinder 10 to maintain normal operating temperature range for a long time under the blowing of the cooling airflow, thereby improving the stability of the entire machine during long-term operation.

[0048] In some embodiments, see Figures 2 to 7The cooler 30 includes a cooling body 31 and two blocking plates 32. The cooling body 31 is horizontally connected between the primary compression cylinder 10 and the secondary compression cylinder 20, and is spaced apart from the peripheral wall of the machine body. Multiple through holes 303 are distributed sequentially and spaced apart inside the cooling body 31. A barrier wall 311 is formed between adjacent through holes 303. One end of each barrier wall 311 is provided with a break 305 for connecting the through holes 303 on both sides of it, and the breaks 305 on adjacent barrier walls 311 are located at the ends that are far apart from each other. The two blocking plates 32 are detachably connected to both ends of the cooling body 31 and are used to block both ends of each through hole 303. The end of the through hole 303 near the primary compression cylinder 10 forms an air inlet 301, and the end of the through hole 303 near the secondary compression cylinder 20 forms an air outlet 302. Each through hole 303 forms a serpentine cooling air passage 300 based on each break 305.

[0049] The structure of using a cooling body 31 and two blocking plates 32 reduces the difficulty of forming the cooling air passage 300. A serpentine cooling air passage 300 can be formed directly by using a row of through holes 303 and the cut 305 on the partition wall. This not only reduces the production and development cost of the cooler 30, but also increases the length of the compressed air flow path and the contact area between the compressed air and the cooling body 31 by using the serpentine cooling air passage 300. This improves the cooling effect on the compressed air discharged from the first-stage compression cylinder 10, allowing the compressed air to enter the second-stage compression cylinder 20 at a lower temperature. This reduces the temperature of the air after compression by the second-stage compression cylinder 20, preventing the temperature of the second-stage compression cylinder 20 from becoming too high. As a result, the second-stage compression cylinder 20 can be maintained in the normal operating range under the air cooling effect of the heat dissipation airflow, ensuring the stability of the second-stage compression cylinder 20 during long-term operation.

[0050] For some possible implementations, please refer to [link / reference]. Figure 6 and Figure 7Each through hole 303 has a groove at its bottom, and each groove is fitted with a water-absorbing strip 304. Because the compressed air entering the cooling air passage 300 is at a high temperature, it cools down during its passage, generating water mist and even accumulating water within the passage. This increases the humidity of the air entering the secondary compression cylinder 20, affecting the lifespan of the seals and accelerating wear. Over time, water may even accumulate in the cooling air passage 300, entering the secondary compression cylinder 20 with the compressed air and causing malfunctions. To avoid this, a water-absorbing strip 304 is installed in each through hole 303 to absorb condensed water mist and accumulated water, thereby reducing the humidity of the air passing through the cooling air passage 300 and preventing water from entering the secondary compression cylinder 20 with the compressed air. This ensures efficient cooling of the compressed air while reducing humidity, thus improving the operational stability and service life of the secondary compression cylinder 20.

[0051] In addition, the blocking plate 32 can be disassembled periodically, and the absorbent strip 304 can be pulled out of the groove for drying or replacement, thereby ensuring the washing effect of the absorbent strip 304.

[0052] Specifically, the aforementioned absorbent strip 304 includes a metal mesh sleeve and absorbent cotton inserted inside the metal mesh sleeve. The width of the groove opening is smaller than the width of the groove bottom. The cross-section of the metal mesh sleeve matches the groove, thereby ensuring the reliability of the connection of the metal mesh sleeve in the groove. At the same time, the metal mesh sleeve's barrier effect on the absorbent cotton can prevent the absorbent cotton from falling out of the groove under the airflow without affecting the washing effect, thus preventing blockage of the cooling air passage 300 and improving the overall machine's operational stability.

[0053] For one specific connection method of the aforementioned fan 50, please refer to [link / reference]. Figure 4 and Figure 8 The fan 50 has a central hole, and a connecting sleeve 51 is rotatably connected inside the central hole. The connecting sleeve 51 is fixedly fitted onto the end of the crankshaft 60 that extends out of the machine body. There is a coupling transmission component 52 between the connecting sleeve 51 and the central hole. The coupling transmission component 52 has a coupling state that causes the connecting sleeve 51 to drive the fan 50 to rotate synchronously, and also has an interrupted state that causes the connecting sleeve 51 to rotate independently.

[0054] Considering that the condensate in the cooling air passage 300 increases and water accumulation is likely to occur after the air compressor has been running for a long time, the coupling transmission component 52 can be switched to the interrupted state when the air compressor is started or stopped (such as when the vehicle is parked). At this time, the fan 50 no longer rotates with the crankshaft 60, so there is no cooling airflow in the ventilation cavity. At this time, the higher temperature of the compressed air entering the cold air passage can be used to dry the water suction strip 304. Then the coupling transmission component 52 is switched back to the coupling state, so that the fan 50 starts to rotate with the crankshaft 60 and forms a cooling airflow in the ventilation cavity to cool the first-stage compression cylinder 10, the second-stage compression cylinder 20 and the cooler 30. This can keep the cooling air passage 300 dry, avoid excessive humidity in the air entering the second-stage compression cylinder 20, which would affect the final compressed air quality and the normal operation stability of the second-stage compression cylinder 20. At the same time, it can also improve the service life of the water suction strip 304 and reduce the time spent on manual drying or replacing the water suction strip 304.

[0055] Specifically, the connecting sleeve 51 is connected to the central hole by a bearing to prevent wear caused by friction between the connecting sleeve 51 and the hole wall of the central hole when the coupling transmission component 52 is interrupted.

[0056] For some possible implementations, please refer to [link / reference]. Figure 2 The intake end of the secondary compression cylinder 20 is equipped with a normally closed switch valve 21 that communicates with the outside air; the outlet 302 is connected to a three-way valve 3021, which has a first passage connecting the outlet 302 to the intake end of the secondary compression cylinder 20, and a second passage connecting the outlet 302 to the outside air; wherein, when the coupling transmission component 52 is switched to the interrupted state, the normally closed switch valve 21 is opened and the three-way valve 3021 is switched to the second passage.

[0057] When the transmission of the coupling transmission component 52 is interrupted and the cooling air passage 300 is dried by the temperature of the compressed gas, the three-way valve 3021 connected to the outlet 302 is switched to the second passage that connects to the outside air, so that the humid air discharged from the outlet 302 can be discharged to the outside. At the same time, the normally closed switch valve 21 is opened to allow the secondary compression cylinder 20 to directly enter the outside air, thereby reducing the work and heat generation of the secondary compression cylinder 20 and preventing the secondary compression cylinder 20 from overheating due to lack of cooling during the drying process of the cooling air passage. Of course, the compressed air discharged from the secondary compression cylinder 20 at this time cannot reach the target pressure, so the compressed air discharged from the secondary compression cylinder 20 can be directly vented.

[0058] Specifically, both the three-way valve 3021 and the normally closed switch valve 21 can be solenoid valves and are controlled by the vehicle control system to automatically switch the passage or switch state. This can reduce manual operation and enable the linkage between the two and the coupling transmission component 52 through the vehicle control system, thereby improving the drying efficiency of the cooling air passage 300.

[0059] For example, see Figure 8 and Figure 9 The aforementioned coupling transmission component 52 includes a plurality of first magnets 521, a plurality of second magnets 522, and a telescopic drive component 523. The plurality of first magnets 521 are respectively embedded in the outer peripheral wall of the connecting sleeve 51 and are distributed at intervals along the circumference of the connecting sleeve 51, and there is an annular gap 500 between each first magnet 521 and the hole wall of the central hole. The plurality of second magnets 522 are respectively embedded in the hole wall of the central hole and are distributed at intervals along the circumference of the central hole, and each second magnet 522 corresponds one-to-one with each first magnet 521 and forms a magnetic coupling force in the circumference of the central hole. The telescopic drive component 523 is fixedly connected to the housing 40 and aligned axially with the central hole. The output end of the telescopic drive component 523 is provided with a magnetic shielding sleeve 5231. The magnetic shielding sleeve 5231 forms an interrupted state when it extends into the annular gap 500, and forms a coupled state when it extends out of the annular gap 500.

[0060] Both the first magnet 521 and the second magnet 522 can be radially or axially magnetized steel. They are coupled and driven by the attraction or repulsion between the magnetic poles of the first magnet 521 and the second magnet 522. The telescopic drive 523 can be an electric telescopic switch connected to the vehicle control system. When powered off, the output end of the telescopic drive 523 remains retracted, thus placing the magnetic isolation sleeve 5231 outside the annular gap 500 to ensure the magnetic coupling force between the first magnet 521 and the second magnet 522. This allows the fan 50 to rotate synchronously with the crankshaft 60. When the telescopic drive 523 is powered on, it outputs a thrust force, causing the magnetic isolation sleeve 5231 to move into the annular gap 500, thereby maintaining the magnetic coupling force between the first magnet 521 and the second magnet 522. The magnetic field is separated, and at this time, there will be no coupling force between the first magnet 521 and the second magnet 522 (the fan 50 loses power and stops rotating) or the coupling force is very small (the fan 50 can still rotate but at a very low speed). This interrupts the coupling transmission, and the cooling airflow in the ventilation cavity is no longer flowing. After the cooling air passage 300 dries, the telescopic drive 523 is de-energized, which can restore the magnetic isolation sleeve 5231 to its initial state, so that the fan 50 can rotate with the crankshaft 60 again. The magnetic coupling transmission method can not only easily interrupt the power of the fan 50, but also avoid wear and heat generation caused by the friction between the connecting sleeve 51 and the center hole due to the existence of the annular gap 500. Therefore, it is beneficial to improve the service life of the fan 50 and the connecting sleeve 51.

[0061] It should be noted that, see Figure 2In this embodiment, the cooling structure also includes a dryer filter 70. The inlet of the dryer filter 70 is connected to the air outlet 302, and the outlet of the dryer filter 70 is connected to the air inlet of the secondary compression cylinder 20. The dryer filter 70 can not only reduce the humidity of the air entering the secondary compression cylinder 20, but also filter impurities in the air, thereby improving the cleanliness of the final compressed air and thus improving the quality of the compressed air.

[0062] In some embodiments, combined with Figures 1 to 4 It is understood that the housing 40 includes an end shell 41, a bottom shell 42, and two enclosure shells 43; the end shell 41 is connected to one end of the body and forms an air inlet cavity 401 suitable for accommodating the fan 50, and an air inlet grille 411 is provided at the part of the end shell 41 that is aligned with the fan 50; the bottom shell 42 is connected to the bottom of the body and is connected to the end shell 41, and a ventilation side gap 402 is formed between the bottom shell 42 and the peripheral wall of the body; the two enclosure shells 43 are respectively arranged around the primary compression cylinder 10 and the secondary compression cylinder 20, and are both connected to the end shell 41 and the bottom shell 42, one enclosure shell 43 forms a first air-cooling cavity 403 on the periphery of the primary compression cylinder 10, and the other enclosure shell 43 forms a second air-cooling cavity 404 on the periphery of the secondary compression cylinder 20, and both the first air-cooling cavity 403 and the second air-cooling cavity 404 are connected to the air inlet cavity 401 and the ventilation side gap 402.

[0063] The cooler 30 has two side edges connected to two enclosures 43 respectively, and the bottom of the cooler 30 forms an intermediate air-cooling cavity 405 between the side walls of the two enclosures 43 that are close to each other. One end of the intermediate air-cooling cavity 405 is connected to the air inlet cavity 401, and the other end is connected to the outside.

[0064] The end shell 41 forms an air inlet cavity 401 that surrounds the fan 50. At the same time, the bottom shell 42 covers the lower half of the machine body (crankshaft 60 housing) and forms a ventilation side gap 402. The two casings 43 respectively cover the first-stage compressor cylinder 10 and the second-stage compressor cylinder 20 to form two cold air chambers. The rotation of the fan 50 causes the ambient temperature air entering through the air inlet grille 411 to diffuse evenly into the ventilation side gap 402, the first air-cooled chamber 403, the second air-cooled chamber 404, and the intermediate air-cooled chamber 405. This allows the crankshaft 60 housing, the first-stage compressor cylinder 10, the second-stage compressor cylinder 20, and the cooler 30 to come into contact with the ambient temperature heat dissipation airflow for heat exchange. Finally, the air with increased temperature after heat exchange is discharged to the outside through the outlets of each chamber. The heat dissipation airflow carries away the heat from the various heat-generating parts of the air compressor to achieve heat dissipation and cooling. The heat dissipation surface is large and the heat dissipation efficiency is high.

[0065] It is important to understand that, see Figure 5 and Figure 6In this embodiment, multiple heat dissipation fins 312 are spaced apart on the bottom wall of the cooler 30. A heat dissipation air duct 3121 is formed between adjacent heat dissipation fins 312. All heat dissipation air ducts 3121 together form an intermediate air-cooling cavity 405. The lower ends of each heat dissipation fin 312 are connected to a partition 313. The partition 313 separates the first air-cooling cavity 403, the second air-cooling cavity 404 and the intermediate air-cooling cavity 405 into their own independent cavities.

[0066] By utilizing the heat dissipation fins 312, the contact area between the bottom of the cooler 30 and the cooling airflow is increased, thereby improving the cooling effect of the cooling airflow on the cooler 30, and further improving the cooling efficiency of the cooler 30 on the primary compressed air. This minimizes the air temperature entering the secondary compression cylinder 20, ensuring that the air cooling of the secondary compression cylinder 20 meets the requirements and guarantees the long-term operational stability of the secondary compression cylinder 20.

[0067] In addition, the partition 313 surrounding the extended end of the heat dissipation fins 312 can separate the intermediate air-cooling cavity 405, the first air-cooling cavity 403 and the second air-cooling cavity 404 from each other, thereby avoiding crossflow between the three air-cooling cavities and mutual influence. At the same time, it is also conducive to the rapid flow of heat dissipation air into the three air-cooling cavities along their respective paths, thereby improving the air-cooling efficiency.

[0068] Based on the above, it should be noted that the peripheral walls of the primary compression cylinder 10 and the secondary compression cylinder 20 are also provided with heat dissipation fins 312. The casing 43 covers the periphery of the heat dissipation fins 312. The heat dissipation airflow enters the gap between the heat dissipation fins 312 and is discharged to the outside, thereby carrying away the heat of the primary compression cylinder 10 and the secondary compression cylinder 20, thereby improving the air cooling efficiency of the heat dissipation airflow on the primary compression cylinder 10 and the secondary compression cylinder 20.

[0069] Based on the above-described structure of the housing 40, the flow path of the heat dissipation airflow within the ventilation cavity includes:

[0070] First path: outside air → air inlet cavity 401 (central area of ​​fan 50 → surrounding area of ​​fan 50) → ventilation side gap 402 → first air-cooled cavity 403 / second air-cooled cavity 404 → outside;

[0071] Second path: outside air → air inlet cavity 401 (central area of ​​fan 50 → surrounding area of ​​fan 50) → first air-cooled cavity 403 / second air-cooled cavity 404 → outside;

[0072] Third path: outside air → air inlet cavity 401 (central area of ​​fan 50 → surrounding area of ​​fan 50) → intermediate air-cooling cavity 405 → outside.

[0073] Based on the same inventive concept, combined with Figures 1 to 9It is understood that this application also provides a two-stage oil-free piston air compressor, including the above-mentioned cooling structure.

[0074] Compared with the prior art, the two-stage oil-free piston air compressor provided in this embodiment adopts the above-mentioned cooling structure. It can blow air into the ventilation housing 40 through the fan 50 driven by the crankshaft 60, and at the same time dissipate heat from the primary compression cylinder 10, the secondary compression cylinder 20 and the cooler 30. This allows the compressed gas discharged from the primary compression cylinder 10 to be cooled in the cooler 30 before entering the secondary compression cylinder 20, thereby reducing the dependence of the secondary compression cylinder 20 on the cooling airflow. This allows both the secondary compression cylinder 20 and the primary compression cylinder 10 to maintain their normal operating temperature range for a long time under the blowing of the cooling airflow, thereby improving the stability of the whole machine during long-term operation.

[0075] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A cooling structure, characterized in that, include: A cooler is used to connect between the primary compression cylinder and the secondary compression cylinder of an air compressor. The cooler has an air inlet communicating with the air outlet of the primary compression cylinder and an air outlet communicating with the air inlet of the secondary compression cylinder. The cooler has a cooling air passage that bends and extends from the air inlet to the air outlet inside the cooler. The housing is connected to the body of the air compressor and forms a ventilation cavity around the periphery of the primary compression cylinder, the periphery of the secondary compression cylinder, and the bottom of the cooler; A fan, located inside the housing and connected to the crankshaft of the air compressor, is used to rotate under the drive of the crankshaft to form a continuous flow of heat dissipation airflow in the ventilation cavity; The cooler includes: The cooling body is horizontally connected between the primary compression cylinder and the secondary compression cylinder and spaced apart from the peripheral wall of the machine body. Multiple through holes are distributed sequentially and spaced apart in the cooling body. A barrier wall is formed between adjacent through holes. One end of each barrier wall is provided with a break for connecting the through holes on both sides, and the breaks on adjacent barrier walls are located at the ends that are far apart from each other. Two blocking plates are detachably connected to both ends of the cooling body and are used to block both ends of each of the through holes; The air inlet is formed at one end of the through hole near the first-stage compression cylinder, and the air outlet is formed at one end of the through hole near the second-stage compression cylinder; each through hole forms a serpentine cooling air passage based on each of the breaks; each through hole has a groove at its bottom, and each groove is fitted with a water-absorbing strip. The fan has a central hole, and a connecting sleeve is rotatably connected inside the central hole. The connecting sleeve is fixedly fitted onto the end of the crankshaft that extends out of the machine body. There is a coupling transmission component between the connecting sleeve and the central hole. The coupling transmission component has a coupled state that causes the connecting sleeve to drive the fan to rotate synchronously, and also has an interrupted state that causes the connecting sleeve to rotate independently. The intake end of the secondary compression cylinder is provided with a normally closed switch valve that communicates with the outside air; the outlet is connected to a three-way valve, which has a first passage that connects the outlet to the intake end of the secondary compression cylinder, and a second passage that connects the outlet to the outside air; wherein, when the coupling transmission component switches to the interrupted state, the normally closed switch valve opens and the three-way valve switches to the second passage.

2. The cooling structure as described in claim 1, characterized in that, The coupling transmission component includes: Multiple first magnets are respectively embedded in the outer peripheral wall of the connecting sleeve and distributed at intervals along the circumference of the connecting sleeve, and there is an annular gap between each first magnet and the hole wall of the central hole; Multiple second magnets are respectively embedded in the wall of the central hole and distributed at intervals along the circumference of the central hole. Each second magnet corresponds to each first magnet and forms a magnetic coupling force in the circumference of the central hole. A telescopic drive component is fixedly connected to the housing and axially aligned with the central hole; the output end of the telescopic drive component is provided with a magnetic shielding sleeve. The interrupted state is formed when the magnetic shielding sleeve extends into the annular gap, and the coupled state is formed when the magnetic shielding sleeve extends out of the annular gap.

3. The cooling structure as described in claim 1, characterized in that, The cooling structure also includes a drying filter, the inlet of which is connected to the outlet, and the outlet of which is connected to the inlet of the secondary compression cylinder.

4. The cooling structure according to any one of claims 1-3, characterized in that, The housing includes: An end shell is connected to one end of the body and forms an air inlet cavity suitable for accommodating the fan. An air inlet grille is provided at the part of the end shell that is aligned with the fan. A bottom shell is connected to the bottom of the body and to the end shell, and a ventilation gap is formed between the bottom shell and the peripheral wall of the body; Two enclosures are respectively arranged around the primary compression cylinder and the secondary compression cylinder, and both are connected to the end shell and the bottom shell. One of the enclosures forms a first air-cooling cavity around the primary compression cylinder, and the other enclosure forms a second air-cooling cavity around the secondary compression cylinder. Both the first air-cooling cavity and the second air-cooling cavity are connected to the air inlet cavity and the ventilation side gap. The cooler has two side edges connected to the two enclosures respectively, and the bottom of the cooler forms an intermediate air-cooling cavity between the side walls of the two enclosures that are close to each other. One end of the intermediate air-cooling cavity is connected to the air inlet cavity, and the other end is connected to the outside.

5. The cooling structure as described in claim 4, characterized in that, Multiple heat dissipation fins are spaced apart on the bottom wall of the cooler, and heat dissipation air channels are formed between adjacent heat dissipation fins. All heat dissipation air channels together form the intermediate air-cooling cavity, and the lower ends of each heat dissipation fin are connected to a partition plate. The partition plate separates the first air-cooling cavity, the second air-cooling cavity, and the intermediate air-cooling cavity into their own independent cavities.

6. A two-stage oil-free piston air compressor, characterized in that, Includes the cooling structure as described in any one of claims 1-5.

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