A kind of compound piston type energy-saving vacuum pump, vacuum unit and vacuum system

Abstract

The utility model discloses a kind of double-acting piston type energy-saving vacuum pumps, vacuum unit and vacuum system, double-acting piston type energy-saving vacuum pump includes cylinder, and a piston is movably arranged inside cylinder. Reversing valve, reversing valve includes air inlet, air outlet, first air exchange port, second air exchange port, valve sleeve and valve core, first air exchange port is communicated with first chamber, second air exchange port is communicated with second chamber, valve sleeve is opened air inlet window and air outlet window, air inlet window is communicated with air inlet, air outlet window is communicated with air outlet, valve core is rotatably arranged in the inside of valve sleeve, and valve core is opened first groove and second groove. The movement of the piston once cycle cooperation reversing valve can realize twice air extraction and exhaust. Vacuum unit includes two reversing valves and two cylinders which cooperate with each other, so as to significantly improve efficiency. Vacuum system includes multiple vacuum units, each vacuum unit has a level of air exhaust passage, connects the air outlet of the current stage vacuum unit and the air outlet of the previous stage vacuum unit.

Description

Technical Field

[0001] This utility model relates to the field of vacuum pump technology, specifically to a reciprocating piston energy-saving vacuum pump, vacuum unit, and vacuum system. Background Technology

[0002] Vacuum technology is applied in many professional fields. Among the variable displacement vacuum pump types, the piston vacuum pump is simple in process, easy to manufacture, and has a low cost, so it is also widely used.

[0003] Existing piston vacuum pumps have a low limiting compression ratio and cannot achieve high vacuum. In vacuum systems, they are generally only used in low vacuum environments or as a pre-stage pump.

[0004] PECVD operates in a vacuum environment and is equipped with a high-vacuum system. One type uses a two-stage vacuum pump as the forestage and a molecular pump as the poststage. High vacuum is required to remove contaminants during the cleaning of the inner chamber. Because the reaction gas is continuously introduced during PECVD operation, the vacuum system needs to promptly exhaust the waste gas to maintain the dynamic stability of the vacuum in the deposition chamber. The pumping speed of the molecular pump varies depending on the gas. Using it for mixed gases can lead to changes in composition. Therefore, configuring a suitable vacuum system is a key aspect of PECVD equipment. Utility Model Content

[0005] To address the problems existing in the prior art, the purpose of this utility model is to provide a reciprocating piston energy-saving vacuum pump, vacuum unit, and vacuum system, which can improve the vacuum compression ratio.

[0006] To achieve the above objectives, the technical solution of this utility model is as follows:

[0007] A reciprocating piston energy-saving vacuum pump includes a cylinder, inside which a piston is movably disposed, dividing the cylinder interior into a first chamber and a second chamber. One side of the piston is connected to a piston rod, and one end of the piston rod extends out of the cylinder. A reversing valve includes an inlet, an outlet, a first exchange port, a second exchange port, a valve sleeve, and a valve core. The first exchange port communicates with the first chamber, and the second exchange port communicates with the second chamber. The valve sleeve has an inlet window and an outlet window; the inlet window communicates with the inlet port, and the outlet window communicates with the outlet port. The window is connected to the exhaust port, and the valve core is rotatably disposed inside the valve sleeve. The valve core has a first groove and a second groove. When the valve core is at a first angle, the first groove is connected to the first air exchange port, the air inlet window, and the air inlet, respectively, and the second groove is connected to the second air exchange port, the air outlet window, and the exhaust port, respectively. When the valve core is at a second angle, the first groove is connected to the first air exchange port, the air outlet window, and the exhaust port, respectively, and the second groove is connected to the second air exchange port, the air inlet window, and the air inlet, respectively.

[0008] Furthermore, it also includes a linkage drive mechanism, which drives the piston rod to move the piston back and forth inside the cylinder, and synchronously drives the valve core to rotate.

[0009] Furthermore, the linkage drive mechanism includes a bevel gear and a crank-connecting rod structure that cooperate with each other. The bevel gear is connected to the valve core, and the crank-connecting rod structure is connected to the piston rod.

[0010] Furthermore, the inner wall of the cylinder is provided with a friction-reducing coating.

[0011] Furthermore, the cylinder includes a cylinder body and an end cap, one end of the cylinder body is open, the end cap is disposed in the opening, and one end of the piston rod extends out of the end cap.

[0012] A vacuum unit comprising the aforementioned reciprocating piston energy-saving vacuum pump, wherein there are two reversing valves, namely a pre-stage reversing valve and a post-stage reversing valve, the air inlet of the pre-stage reversing valve being connected to the exhaust port of the post-stage reversing valve via an air passage; and there are two cylinders, namely a pre-stage cylinder and a post-stage cylinder, the first chamber and the second chamber of the pre-stage cylinder being respectively connected to the first air exchange port and the second air exchange port of the pre-stage reversing valve, and the first chamber and the second chamber of the post-stage cylinder being respectively connected to the first air exchange port and the second air exchange port of the post-stage reversing valve.

[0013] A vacuum system comprising the aforementioned vacuum units, wherein there are multiple vacuum units, and in each vacuum unit, a plurality of first sealing rings are spaced apart between the piston rod of the pre-stage cylinder and the inner wall of one end of the cylinder corresponding to the post-stage cylinder, and the gap between every two first sealing rings forms a first leak-proof cavity, and one first leak-proof cavity is connected to a first venting channel; each vacuum unit's pre-stage reversing valve and post-stage reversing valve are respectively provided with a plurality of second sealing rings, and the gap between every two second sealing rings forms a second leak-proof cavity, and one second leak-proof cavity is connected to a second venting channel; with the direction closest to the outside atmosphere as the positive direction, the plurality of first venting channels in the positive direction are divided into different levels, and the plurality of second venting channels in the positive direction are also divided into different levels; the plurality of vacuum units are divided into a pre-stage vacuum unit and a post-stage vacuum unit, and the first venting channels and second venting channels of the same level in the post-stage vacuum unit are merged and respectively connected to the exhaust port of the post-stage vacuum unit and the exhaust port of the pre-stage vacuum unit.

[0014] Furthermore, the pre-stage reversing valve and the post-stage reversing valve of each vacuum unit are isolated by a third sealing ring.

[0015] Furthermore, each pair of vacuum units is connected to a buffer chamber via an external pipeline.

[0016] The beneficial effects of this utility model are as follows:

[0017] First, both sides of the piston are under vacuum, resulting in a small pressure difference and low resistance to piston movement, thus saving energy. In conjunction with the reversing valve, one reciprocating motion of the piston can achieve two pumping and venting operations.

[0018] II. Due to the anti-friction coating, the reciprocating piston energy-saving vacuum pump does not require the addition of lubricating oil, thus making it a dry vacuum pump.

[0019] Third, by integrating two reversing valves and two cylinders into a single vacuum unit, efficiency and compression ratio can be significantly improved.

[0020] Fourth, the vacuum system has the characteristic of pressure gradient distribution, which intercepts leakage in stages. When the small amount of gas leaking through the piston rod moves through the leakage interception chamber, most of it is intercepted as it expands. In this way, the pressure ratio on both sides of the innermost sealing ring is small, and very little air leaks into the cylinder cavity. The vacuum pump can still work effectively in a high vacuum environment.

[0021] Fifth, the buffer chamber decouples the pre-stage vacuum unit and the post-stage vacuum unit, allowing multiple pre-stage vacuum units and post-stage vacuum units to be flexibly combined and matched, thus adapting to the PECVD system. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the reciprocating piston energy-saving vacuum pump in this utility model;

[0023] Figure 2 This is a schematic diagram of the structure of the reciprocating piston energy-saving vacuum pump in this utility model. Figure 1 ;

[0024] Figure 3 This is a schematic diagram of the structure of the reciprocating piston energy-saving vacuum pump in this utility model. Figure 2 ;

[0025] Figure 4 This is a schematic diagram of the reversing valve in this utility model. Figure 1 ;

[0026] Figure 5 This is a schematic diagram of the reversing valve in this utility model. Figure 2 ;

[0027] Figure 6 This is a schematic diagram of the reversing valve in this utility model. Figure 3 ;

[0028] Figure 7This is a schematic diagram of the vacuum unit in this utility model;

[0029] Figure 8 This is a schematic diagram of the vacuum unit in this utility model;

[0030] Figure 9 This is a schematic diagram of the structure of the front-stage reversing valve and the rear-stage reversing valve of the vacuum unit in this utility model;

[0031] Figure 10 This is a schematic diagram of the vacuum system in this utility model.

[0032] Figure Labels

[0033] 100. Reciprocating piston energy-saving vacuum pump; 200. Vacuum unit; 201. Pre-stage reversing valve; 202. Post-stage reversing valve; 203. Pre-stage cylinder; 204. Post-stage cylinder; 205. First air passage; 206. Second air passage; 300. Vacuum system; 301. First vacuum unit; 302. Second vacuum unit; 303. Third vacuum unit; 304. First connector; 305. Second connector; 306. Third connector;

[0034] 1. Cylinder; 11. Piston; 12. First chamber; 13. Second chamber; 14. Piston rod; 15. Cylinder body; 16. End cap; 17. First sealing ring; 18. First leakage chamber; 19. First venting passage; 1901. First stage venting passage of the first pre-stage cylinder; 1902. Second stage venting passage of the first pre-stage cylinder; 1903. Third stage venting passage of the first pre-stage cylinder; 1904. First stage venting passage of the first post-stage cylinder; 1905. First post-stage cylinder 1906. Second-stage exhaust port for cylinder; 1907. Third-stage exhaust port for first-stage rear-stage cylinder; 1908. First-stage exhaust port for second-stage front-stage cylinder; 1909. Second-stage exhaust port for second-stage front-stage cylinder; 1910. First-stage exhaust port for second-stage rear-stage cylinder; 1911. First-stage exhaust port for third-stage front-stage cylinder; 1912. First-stage exhaust port for third-stage rear-stage cylinder; 2. Reversing valve; 21. Inlet port; 22. Exhaust port; 23. 24. First air exchange port; 25. Second air exchange port; 26. Valve sleeve; 27. Inlet window; 28. Outlet window; 29. ​​Valve core; 20. First groove; 21. Second groove; 22. Second sealing ring; 23. Second leak-proof cavity; 24. Second venting passage; 25. First-stage venting passage of the first pre-stage reversing valve; 26.5. Second-stage venting passage of the first pre-stage reversing valve; 26.5. First-stage venting passage of the first post-stage reversing valve; 26.5. 1. Secondary venting duct of the first-stage reversing valve; 2655. Primary venting duct of the second-stage pre-stage reversing valve; 2656. Primary venting duct of the second-stage reversing valve; 2657. Primary venting duct of the third-stage pre-stage reversing valve; 2658. Primary venting duct of the third-stage reversing valve; 3. Vent plate; 31. Channel; 4. Third sealing ring; 51. First stage connection point; 52. Second stage connection point; 53. Third stage connection point; 6. Buffer chamber; 7. Linkage drive mechanism; 8. Anti-friction coating. Detailed Implementation

[0035] In the description of this utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", "top surface", "bottom surface", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the position or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0036] Furthermore, 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 technical features. Thus, the use of "first" and "second" to define a feature may explicitly or implicitly include one or more of that feature. In this description of the utility model, "a number" means two or more, unless otherwise explicitly specified.

[0037] In this utility model, unless otherwise explicitly specified and limited, the terms "assembly," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can also refer to a mechanical connection; they can refer to a direct connection or a connection through an intermediate medium; or they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0038] In this embodiment, "interface" refers to the boundary line or contact surface between two different materials or media.

[0039] The utility model will be further described below with reference to the accompanying drawings and specific embodiments. The following description is merely exemplary and does not limit the scope of protection of the utility model.

[0040] Please refer to Figures 1-6 This utility model discloses a reciprocating piston type energy-saving vacuum pump 100, including a cylinder 1. A piston 11 is movably disposed inside the cylinder 1, and the piston 11 divides the inside of the cylinder 1 into a first chamber 12 and a second chamber 13. One side of the piston 11 is connected to a piston rod 14, and one end of the piston rod 14 extends out of the cylinder 1. A reversing valve 2 is included, which includes an air inlet 21, an air outlet 22, a first air exchange port 23, a second air exchange port 24, a valve sleeve 25, and a valve core 26. The first air exchange port 23 communicates with the first chamber 12, and the second air exchange port 24 communicates with the second chamber 13. The valve sleeve 25 has an air inlet window 251 and an air outlet window 252. The air inlet window 251 communicates with the air inlet 21, and the air outlet window 252 communicates with the air outlet 22. The valve core 26 is rotatably disposed inside the valve sleeve 25, and the valve core 26 has a first groove 261 and a second groove 262.

[0041] When the valve core 26 is at the first angle, the first groove 261 is connected to the first air exchange port 23, the air inlet window 251 and the air inlet 21 respectively, and the second groove 262 is connected to the second air exchange port 24, the air outlet window 252 and the exhaust port 22 respectively.

[0042] When the valve core 26 is at the second angle, the first groove 261 is connected to the first air exchange port 23, the air outlet window 252 and the exhaust port 22 respectively, and the second groove 262 is connected to the second air exchange port 24, the air inlet window 251 and the air inlet 21 respectively.

[0043] Specifically, when the piston 11 moves toward the second chamber 13, the volume of the first chamber 12 gradually increases, and the valve core 26 rotates to the first angle at the same time, so that the first groove 261, the first air exchange port 23, the air inlet window 251, the air inlet 21 and the first chamber 12 are in a connected state, and the second groove 262, the second air exchange port 24, the air outlet window 252, the air outlet 22 and the second chamber 13 are in a connected state. This movement of the piston 11 simultaneously performs both suction and exhaust, which reduces the pressure difference on both sides of the piston 11, thereby reducing resistance and improving suction efficiency, thus achieving energy saving.

[0044] As piston 11 moves away from the second chamber 13, the volume of the second chamber 13 gradually increases. Simultaneously, valve core 26 rotates to a second angle, connecting the first groove 261, first air exchange port 23, air outlet window 252, exhaust port 22, and the first chamber 12. Similarly, the second groove 262, second air exchange port 24, air inlet window 251, air inlet 21, and second chamber 13 are connected. Likewise, this movement of piston 11 simultaneously performs both intake and exhaust, reducing the pressure difference across piston 11 and thus reducing resistance, while also improving intake efficiency, thereby achieving energy savings. Essentially, regardless of the direction of piston 11's movement, air inlet 21 is always connected to the chamber with the increased volume, while exhaust port 22 is always connected to the chamber with the decreased volume. Furthermore, one cycle of piston 11 (i.e., one reciprocating motion within cylinder 1) achieves two intake and exhaust cycles.

[0045] In this embodiment, the reciprocating piston energy-saving vacuum pump 100 also includes a linkage drive mechanism 7. The linkage drive mechanism 7 drives the piston rod 14 to move the piston 11 back and forth inside the cylinder 1, and synchronously drives the valve core 26 to rotate. Specifically, the linkage drive mechanism 7 includes a bevel gear and a crank-connecting rod structure that cooperate with each other. The bevel gear is connected to the valve core 26, and the crank-connecting rod structure is connected to the piston rod 14. The rotational motion of the crank in the crank-connecting rod structure is converted into the linear motion of the piston rod 14. The rotational motion of the bevel gear drives the valve core 26 to rotate at the same frequency and with a fixed phase as the piston rod 14, so as to ensure that the valve core 26 can rotate synchronously when the piston 11 moves, so that the piston 11 and the valve core 26 cooperate, and the air inlet 21 is always connected to the chamber with the increased volume.

[0046] In this embodiment, the inner wall of cylinder 1 is provided with a friction-reducing coating 8. Specifically, the friction-reducing coating 8 can be any one of polytetrafluoroethylene (PTFE) coating, molybdenum disulfide (MoD) coating, tungsten disulfide (TD) coating, or ceramic coating. As a preferred embodiment, this embodiment uses a PTFE coating as the friction-reducing coating 8. On the one hand, PTFE coating has one of the lowest coefficients of friction among almost all solid materials, and it possesses excellent self-lubricating properties. On the other hand, within the allowable processing and thermal expansion tolerances, PTFE coating can help fill the microscopic unevenness between cylinder 1 and piston 11, improving the sealing performance inside cylinder 1 to a certain extent and contributing to obtaining a good vacuum degree. In addition, PTFE coating also has excellent corrosion resistance and can handle various process gases, including corrosive gases. Based on the above reasons, this double-acting piston energy-saving vacuum pump 100 does not require the addition of lubricating oil, thus making it a dry vacuum pump.

[0047] In this embodiment, the cylinder 1 includes a cylinder body 15 and an end cap 16. One end of the cylinder body 15 is open, and the end cap 16 is disposed in this opening. One end of the piston rod 14 extends out of the end cap 16. Specifically, there are two end caps 16. The other end of the cylinder body 15 is also open, and the two end caps 16 are respectively disposed in the openings at both ends of the cylinder body 15.

[0048] More specifically, the reciprocating piston energy-saving vacuum pump 100 also includes an air duct plate 3, which is disposed between the cylinder body 15 and the reversing valve 2. Two channels 31 are provided through the interior of the air duct plate 3, and air holes are provided through the two end caps 16. The two ends of one channel 31 are connected to an air hole and a first air exchange port 23, respectively, while the two ends of the other channel 31 are connected to another air hole and a second air exchange port 24, respectively. This allows the first air exchange port 23 to connect to the first chamber 12, and the second air exchange port 24 to connect to the second chamber 13.

[0049] Please refer to Figures 7-9This utility model also discloses a vacuum unit 200, which includes the aforementioned reciprocating piston energy-saving vacuum pump 100. Specifically, there are two reversing valves 2, namely a pre-stage reversing valve 201 and a post-stage reversing valve 202. The air inlet 21 of the pre-stage reversing valve 201 is connected to the exhaust port 22 of the post-stage reversing valve 202 through an air passage (not shown in the figure). The exhaust port 22 of the pre-stage reversing valve 201 is connected to the outside atmosphere, and the air inlet 21 of the post-stage reversing valve 202 is connected to the outside atmosphere. The pre-stage reversing valve 201 and the post-stage reversing valve 202 are isolated by a third sealing ring 4. There are two cylinders 1, namely a front-stage cylinder 203 and a rear-stage cylinder 204. The first chamber 12 and the second chamber 13 of the front-stage cylinder 203 are respectively connected to the first air exchange port 23 and the second air exchange port 24 of the front-stage reversing valve 201. The first chamber 12 and the second chamber 13 of the rear-stage cylinder 204 are respectively connected to the first air exchange port 23 and the second air exchange port 24 of the rear-stage reversing valve 202.

[0050] Please refer to Figure 10 This utility model also discloses a vacuum system 300, which includes the aforementioned vacuum unit 200. Specifically, there are multiple vacuum units 200. In each vacuum unit 200, multiple first sealing rings 17 are provided at intervals between the piston rod 14 corresponding to the front cylinder 203 and the rear cylinder 204 and the inner wall of one end of the cylinder 1. The gap between every two first sealing rings 17 forms a first leakage interception cavity 18, and a first leakage interception cavity 18 is connected to a first venting air passage 19.

[0051] Furthermore, each vacuum unit 200 has a plurality of second sealing rings 263 provided for the pre-stage reversing valve 201 and the post-stage reversing valve 202. The gap between every two second sealing rings 263 forms a second leakage chamber 264, and each second leakage chamber 264 is connected to a second venting passage 265. Specifically, the second sealing rings 263 can be located at both ends of the valve cores 26 of the pre-stage reversing valve 201 and the post-stage reversing valve 202, or at both ends of the pre-stage reversing valve 201 and the post-stage reversing valve 202. That is to say, as long as there is gas flow, the second sealing rings 263 can be provided to form the second leakage chamber 264.

[0052] Taking the direction closest to the outside atmosphere as the positive direction, the corresponding first venting channels 19 of the multiple first-section leakage cavities 18 in this positive direction are divided into different levels, and the corresponding second venting channels 265 of the multiple second-section leakage cavities 264 in this positive direction are divided into different levels, wherein the first venting channels 19 and the second venting channels 265 far from the outside atmosphere are of the same level. For better description, this direction from far from the outside atmosphere to close to the outside atmosphere is hereinafter referred to as "from inside to outside".

[0053] Multiple vacuum units are divided into a pre-stage vacuum unit and a post-stage vacuum unit. The first vent 19 and the second vent 265 of the same level of the post-stage vacuum unit are merged and connected to the exhaust port 22 of the post-stage vacuum unit (i.e., the exhaust port 22 of the vacuum unit itself in this level) and the exhaust port 22 of the pre-stage vacuum unit, respectively.

[0054] It should be noted that the terms "pre-stage vacuum unit" and "post-stage vacuum unit" are used to refer to the first vacuum unit as the post-stage vacuum unit and the remaining vacuum units as pre-stage vacuum units. For example, if there are three vacuum units, with the first vacuum unit as the reference, the first vacuum unit is the post-stage vacuum unit, and the second and third vacuum units are the pre-stage vacuum units. With the second vacuum unit as the reference, the second vacuum unit is the post-stage vacuum unit, and the third vacuum unit is the pre-stage vacuum unit.

[0055] For details regarding vacuum system 300, please refer to [link / reference]. Figure 10 Taking this figure as an example for explanation: In one embodiment, there are three vacuum units 200, namely a first vacuum unit 301, a second vacuum unit 302, and a third vacuum unit 303. Of course, in other embodiments, the number of vacuum units 200 may be less than three or more than three, and this is not limited here.

[0056] In the first vacuum unit 301, the multiple first venting passages 19 of the pre-stage cylinder 203 are divided from the inside out into a first pre-stage cylinder primary venting passage 1901, a first pre-stage cylinder secondary venting passage 1902, and a first pre-stage cylinder tertiary venting passage 1903. Similarly, the multiple first venting passages 19 of the post-stage cylinder 204 are divided from the inside out into a first post-stage cylinder primary venting passage 1904, a first post-stage cylinder secondary venting passage 1905, and a first post-stage cylinder tertiary venting passage 1906. The second venting passage 265 of the pre-stage reversing valve 201 is divided from the inside out into a first pre-stage reversing valve primary venting passage 2651 and a first pre-stage reversing valve secondary venting passage 2652. The second vent 265 of the post-stage reversing valve 202 is divided into the first-stage vent 2653 and the second-stage vent 2654 of the first-stage reversing valve from the inside to the outside.

[0057] In addition, the first stage exhaust port 1901 of the first pre-stage cylinder, the first stage exhaust port 1904 of the first post-stage cylinder, the first stage exhaust port 2651 of the first pre-stage reversing valve, and the first stage exhaust port 2653 of the first post-stage reversing valve are at the same level, so they are merged and converged at the first connector 304, which is connected to the exhaust port 22 of the first vacuum unit 301.

[0058] In addition, the second-stage exhaust port 1902 of the first pre-stage cylinder, the second-stage exhaust port 1905 of the first post-stage cylinder, the second-stage exhaust port 2652 of the first pre-stage reversing valve, and the second-stage exhaust port 2654 of the first post-stage reversing valve are at the same level, so they are merged and converged at the second connector 305, which is connected to the exhaust port 22 of the second vacuum unit 302.

[0059] In addition, the first pre-stage cylinder third-stage exhaust port 1903 and the first post-stage cylinder third-stage exhaust port 1906 are at the same level, so they are merged and converged at the third connector 306, which is connected to the exhaust port 22 of the third vacuum unit 303.

[0060] In the second vacuum unit 302, the multiple first vent passages 19 of the pre-stage cylinder 203 are divided from the inside out into a second pre-stage cylinder primary vent passage 1907 and a second pre-stage cylinder secondary vent passage 1908. The multiple first vent passages 19 of the post-stage cylinder 204 are divided from the inside out into a second post-stage cylinder primary vent passage 1909 and a second post-stage cylinder secondary vent passage 1910. The second vent passage 265 of the pre-stage reversing valve 201 is the second pre-stage reversing valve primary vent passage 2655. The second vent passage 265 of the post-stage reversing valve 202 is the second post-stage reversing valve primary vent passage 2656.

[0061] In addition, the first-stage exhaust port 1907 of the second pre-stage cylinder, the first-stage exhaust port 1909 of the second post-stage cylinder, the first-stage exhaust port 2655 of the second pre-stage reversing valve, and the first-stage exhaust port 2656 of the second post-stage reversing valve are at the same level, so they are merged and converged at the second connector 305, which is connected to the exhaust port 22 of the second vacuum unit 302.

[0062] In addition, the second-stage exhaust port 1908 of the second pre-stage cylinder and the second-stage exhaust port 1910 of the second post-stage cylinder are at the same level, so they are merged and converged into the third connector 306, which is connected to the exhaust port 22 of the third vacuum unit 303.

[0063] In the third vacuum unit 303, the first exhaust port 19 of the pre-stage cylinder 203 is divided into a third pre-stage cylinder first-stage exhaust port 1911. The first exhaust port 19 of the post-stage cylinder 204 is divided into a third post-stage cylinder first-stage exhaust port 1912. The second exhaust port 265 of the pre-stage reversing valve 201 is the third pre-stage reversing valve first-stage exhaust port 2657. The second exhaust port 265 of the post-stage reversing valve 202 is the third post-stage reversing valve first-stage exhaust port 2658. The third pre-stage cylinder first-stage exhaust port 1911, the third post-stage cylinder first-stage exhaust port 1912, the third pre-stage reversing valve first-stage exhaust port 2657, and the third post-stage reversing valve first-stage exhaust port 2658 are at the same level, therefore they are merged and converge at the third connector 306, which is connected to the exhaust port 22 of the third vacuum unit 303.

[0064] More specifically, all of the aforementioned first vent ducts 19 and second vent ducts 265 are connected to the corresponding level exhaust ports 22 via pipes, and cascading points exist in these connected pipes, such as... Figure 10 In the vacuum system 300 shown, the cascade points are a first cascade point 51, a second cascade point 52, and a third cascade point 53. The first cascade point 51 is specifically located near the exhaust port 22 of the first vacuum unit 301, the second cascade point 52 is specifically located near the exhaust port 22 of the second vacuum unit 302, and the third cascade point 53 is specifically located near the exhaust port 22 of the third vacuum unit 303. The gas pressure at the first cascade point 51, the second cascade point 52, and the third cascade point 53 increases in a stepwise manner from the later stage to the earlier stage. Specifically, taking the first vacuum unit 301 as an example, the first-stage venting passage 1901 of the first pre-stage cylinder, the first-stage venting passage 1904 of the first post-stage cylinder, the first-stage venting passage 2651 of the first pre-stage reversing valve, and the first-stage venting passage 2653 of the first post-stage reversing valve are connected to the first-stage connection point 51. The second-stage venting passage 1902 of the first pre-stage cylinder, the second-stage venting passage 1905 of the first post-stage cylinder, the second-stage venting passage 2652 of the first pre-stage reversing valve, and the second-stage venting passage 2654 of the first post-stage reversing valve are connected to the second-stage connection point 52. The third-stage venting passage 1903 of the first pre-stage cylinder and the third-stage venting passage 1906 of the first post-stage cylinder are connected to the third-stage connection point 53. Therefore, the corresponding leakage chambers of different stages also form a corresponding stepped air pressure distribution. When outside air moves through piston rod 14, the leaking gas expands and is mostly blocked when it passes through the leak-stopping chamber. This results in a low pressure ratio on both sides of the innermost sealing ring, minimizing the leakage of outside air into cylinder 1. Similarly, outside air is also mostly blocked when passing through the leak-stopping chamber corresponding to reversing valve 2, thus reducing leakage of outside air into reversing valve 2.

[0065] In this embodiment, the first vacuum unit 301, the second vacuum unit 302, and the third vacuum unit 303 are connected in series to form a vacuum system 300. Each pair of vacuum units is connected to a buffer chamber 6 via an external pipe. Each buffer chamber 6 has a large volume, approximately ten times the volume of gas drawn in each time. During a vacuuming process, the pre-vacuum unit draws in gas, which enters the large buffer chamber 6. Ideally, pressure and volume are inversely proportional; by significantly increasing the volume of the buffer chamber 6, the pressure change during gas intake and exhaust is reduced. Normally, when the pre-vacuum unit and the subsequent vacuum unit are directly connected, the subsequent vacuum unit must exhaust gas while the pre-vacuum unit draws in gas; otherwise, operating efficiency will be affected. However, with the addition of the buffer chamber 6, the pre-vacuum unit and the subsequent vacuum unit can operate independently without affecting efficiency. That is, the buffer chamber 6 decouples the pre-vacuum unit and the subsequent vacuum unit, allowing for flexible combination and arrangement of multiple pre-vacuum units and subsequent vacuum units. Furthermore, when combined with a solenoid valve (not shown in the figure), it is possible to switch between parallel and series connection of the pre-vacuum unit and the post-vacuum unit.

[0066] The above description is a further detailed explanation of the present utility model in conjunction with specific preferred embodiments. It should not be considered that the specific implementation of the present utility model is limited to these descriptions. For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept of the present utility model, and all such deductions or substitutions should be considered to fall within the protection scope of the present utility model.

Claims

1. A reciprocating piston type energy-saving vacuum pump, characterized in that, include: A cylinder, wherein a piston is movably disposed inside the cylinder, and the piston divides the interior of the cylinder into a first chamber and a second chamber, one side of the piston is connected to a piston rod, and one end of the piston rod extends out of the cylinder; A reversing valve includes an air inlet, an air outlet, a first air exchange port, a second air exchange port, a valve sleeve, and a valve core. The first air exchange port communicates with a first chamber, and the second air exchange port communicates with a second chamber. The valve sleeve has an air inlet window and an air outlet window. The air inlet window communicates with the air inlet, and the air outlet window communicates with the air outlet. The valve core is rotatably disposed inside the valve sleeve, and the valve core has a first groove and a second groove. When the valve core is at a first angle, the first groove is connected to the first air exchange port, the air inlet window, and the air inlet, respectively, and the second groove is connected to the second air exchange port, the air outlet window, and the exhaust port, respectively. When the valve core is at a second angle, the first groove is connected to the first air exchange port, the air outlet window, and the exhaust port, respectively, and the second groove is connected to the second air exchange port, the air inlet window, and the air inlet, respectively.

2. The reciprocating piston energy-saving vacuum pump according to claim 1, characterized in that: It also includes a linkage drive mechanism, which drives the piston rod to move the piston back and forth inside the cylinder, and synchronously drives the valve core to rotate.

3. The reciprocating piston energy-saving vacuum pump according to claim 2, characterized in that: The linkage drive mechanism includes a bevel gear and a crank-connecting rod structure that cooperate with each other. The bevel gear is connected to the valve core, and the crank-connecting rod structure is connected to the piston rod.

4. The reciprocating piston energy-saving vacuum pump according to claim 1, characterized in that: The inner wall of the cylinder is provided with a friction-reducing coating.

5. The reciprocating piston energy-saving vacuum pump according to claim 1, characterized in that: The cylinder includes a cylinder body and an end cap. One end of the cylinder body is open, and the end cap covers the opening. One end of the piston rod extends out of the end cap.

6. A vacuum unit comprising the reciprocating piston energy-saving vacuum pump according to any one of claims 1-4, characterized in that: The number of reversing valves is two, namely a front-stage reversing valve and a rear-stage reversing valve. The air inlet of the front-stage reversing valve is connected to the exhaust port of the rear-stage reversing valve through an air passage. The cylinder is divided into two stages: a pre-stage cylinder and a post-stage cylinder. The first chamber and the second chamber of the pre-stage cylinder are respectively connected to the first air exchange port and the second air exchange port of the pre-stage reversing valve. The first chamber and the second chamber of the post-stage cylinder are respectively connected to the first air exchange port and the second air exchange port of the post-stage reversing valve.

7. A vacuum system comprising the vacuum unit of claim 6, characterized in that: The vacuum unit has multiple units. In each vacuum unit, multiple first sealing rings are provided between the piston rod corresponding to the front cylinder and the rear cylinder and the inner wall of one end of the cylinder. The gap between every two first sealing rings forms a first leak-proof cavity. Each first leak-proof cavity is connected to a first venting channel. Each vacuum unit has a plurality of second sealing rings provided for the front-stage reversing valve and the rear-stage reversing valve. The gap between every two second sealing rings forms a second leak-stopping chamber, and a second leak-stopping chamber is connected to a second venting channel. With the direction closest to the outside atmosphere as the positive direction, the multiple first venting channels in the positive direction are divided into different levels, and the multiple second venting channels in the positive direction are divided into different levels. The multiple vacuum units are divided into a pre-stage vacuum unit and a post-stage vacuum unit. The first and second venting channels of the same level of the post-stage vacuum unit are merged and connected to the exhaust port of the post-stage vacuum unit and the exhaust port of the pre-stage vacuum unit, respectively.

8. The vacuum system according to claim 7, characterized in that: The pre-stage reversing valve and the post-stage reversing valve of each vacuum unit are isolated by a third sealing ring.

9. The vacuum system according to claim 7, characterized in that: Each pair of vacuum units is connected to a buffer chamber via an external pipeline.

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