Oil-free air pump

Abstract

The utility model discloses an oil-free air pump which comprises a shell, an air inlet and an air outlet, the air inlet and the air outlet are formed in the shell, a piston cylinder allowing a piston to move up and down is arranged in the shell, an air outlet is correspondingly formed in the top of the piston cylinder, and the oil-free air pump further comprises a transmission structure located below the piston cylinder. The transmission structure comprises a rotating shaft and a base, the rotating shaft is rotatably connected with the shell, the base is fixedly arranged on the rotating shaft, the base comprises a curved surface which regularly fluctuates up and down in the circumferential direction of the rotating shaft, and a rolling piece which is in contact with the curved surface is rotatably arranged at the bottom of the piston. After the curved surface rotates along with the rotating shaft, the piston is limited by the piston cylinder, and the piston fluctuates up and down along with the curved surface and reciprocates up and down in the piston cylinder due to the combined action of the limiting structure, the base is driven by the motor to rotate, the vertical action of the piston can be transmitted, and the device can be suitable for an oil-free environment.

Description

Technical Field

[0001] The utility model belongs to the technical field of air pumps, and in particular relates to an oil-free air pump. Background Art

[0002] An air pump is a device used to compress or extract gas. It is mostly used in air compressors in cars. It mainly uses a piston pump to compress air and provide the required gas for the air compressor. When the engine is started, the electrical system provides electricity to the air pump to start working. The air pump generates air pressure through continuous reciprocating motion of the piston, compresses the air into high-pressure gas, and sends the gas into the air compressor.

[0003] Traditionally, air pumps mostly adopt piston, screw, scroll and vane designs. Each type serves different application scenarios with its unique mechanism. However, although these designs meet basic functional needs, they generally expose significant shortcomings in long-term operating stability and service life.

[0004] The internal components of air pumps currently used in the automotive field on the market (such as pistons, bearings, vanes, etc.) are facing severe tests of material durability. Long-term high-load operation leads to accelerated material fatigue and aging, significantly shortening the overall service life of the air pump; in particular, the reciprocating motion mechanism of piston-type air pumps relies on the precise coordination of the eccentric wheel, piston and connecting rod; however, when the eccentric wheel drives the piston to move in the piston cylinder, the friction on different parts of the surface of the eccentric wheel is different when it rotates, which is prone to uneven wear, causing the eccentric wheel to lose balance, increase vibration and noise, and usually require sufficient lubricating oil to reduce friction, which not only affects the operating efficiency of the equipment, but also increases the wear rate and increases maintenance costs.

[0005] To alleviate the above problems, existing solutions often rely on frequent maintenance and lubrication operations, which not only increases operating costs, but may also lead to the accumulation of oil-gas mixtures, further accelerating component aging and reducing service life. This problem is particularly prominent for piston air pumps that require regular refueling. Although the application of air pump technology in the field of air compressors is quite mature, its short service life, easy aging, high maintenance costs and other problems are still prominent, becoming a key factor restricting the further development of the industry. Summary of the Invention

[0006] The purpose of this utility model is to overcome the defects of the prior art, and to provide an oil-free air pump, which solves the problem that the transmission parts of the air pump are unevenly worn and need to use sufficient lubricating oil to reduce friction, but the service life is still short.

[0007] The technical solution of the utility model is: an oil-free air pump, comprising a shell and an air inlet and an air outlet arranged on the shell, a piston cylinder for the piston to move up and down is provided in the shell, the top of the piston cylinder is connected to the air outlet, and also includes a transmission structure in the shell, the transmission structure includes a rotating shaft rotatably connected to the shell and a base fixed or integrally arranged on the rotating shaft, the base includes a curved surface that regularly undulates up and down along the circumferential direction of the rotating shaft, a rolling element that contacts the curved surface is provided at the bottom of the piston for rotation, a limiting structure for controlling the contact between the rolling element and the curved surface is provided between the piston and the base, when the rotating shaft drives the base to rotate, the piston is acted upon by the curved surface and the limiting structure to perform an up and down reciprocating motion in the piston cylinder, an air vent is provided between the top and bottom of the piston, the piston includes a one-way valve 1 located at the top of the air vent, a one-way valve 1 is provided on the shell for connecting the piston cylinder and its corresponding air outlet, and the gas passes through the one-way valve 1 and the one-way valve 2 in sequence through the air inlet to the air outlet.

[0008] With the above technical solution, the piston is restricted by the piston cylinder and can only move up and down. When the piston is set on the up-and-down undulating curved surface, the curved surface rotates with the rotating shaft, and due to the limiting structure, the piston is acted upon by the curved surface and the limiting structure to perform an up-and-down reciprocating motion in the piston cylinder. When the piston moves downward, the volume between the one-way valve 1 and the one-way valve 2 increases, the air pressure decreases, and a pressure difference is formed between the one-way valve 1 and the one-way valve 2. The gas pushes open the one-way valve 1 and enters between the one-way valve 1 and the one-way valve 2; when the piston moves upward, the volume between the one-way valve 1 and the one-way valve 2 decreases, the air pressure increases, and the one-way valve 2 can be pushed open to flow to the outlet for discharge, thereby achieving the function of pumping the gas from the air inlet to the air outlet. The rotation of the base driven by the motor can be transmitted to the up-and-down motion of the piston. Compared with the prior art in which the piston realizes the reciprocating motion of the piston through the connecting rod and the eccentric wheel, the connecting rod structure is optimized to the base, which is fixedly arranged between the base and the rotating shaft, avoiding the need for a large amount of oil for lubrication between the connecting rod and the eccentric wheel, and can be applied to oil-free environments.

[0009] According to a further configuration of the present invention, the curved surface is uniformly undulating in the circumferential direction around the rotation axis, and at least two pistons are uniformly distributed on the curved surface in the circumferential direction, and each piston is correspondingly provided with a piston cylinder.

[0010] With the above further arrangement, the pistons are evenly distributed on the curved surface, so that the horizontal force on the rotating shaft is more balanced. If only a single piston is set or the pistons are unevenly set, the base will tilt to one side, causing uneven force on the rotating shaft and increasing the probability of damage.

[0011] A further arrangement of the present invention is that the base includes a disc portion and a cylindrical portion protruding upward from the center of the disc portion, the curved surface is the upper surface of the disc portion, the limiting structure includes a fixed shaft passing through the bottom of the piston, the fixed shaft is rotatably connected to a rotating part on the side close to the cylindrical portion, and a groove is provided on the outer circumference of the cylindrical portion for the rotating part to roll, and the top and bottom surfaces of the groove fluctuate up and down together with the curved surface.

[0012] The above-mentioned further setting is adopted to limit the base to a circular step-like structure, and a groove is provided on the circumference of the cylindrical part. The top and bottom surfaces of the groove both rise and fall together with the curved surface, so that the rotating part provided in the groove moves up and down with the groove and moves up and down together with the piston, and the width of the groove corresponds to the rotating part. The outer surface of the rotating part contacts the top or bottom surface of the groove. When the rotating part contacts the top surface of the groove, the piston moves downward due to the restriction of the top surface structure of the groove, so that the rotating part contacts the bottom of the groove and the rolling part contacts the curved surface. When the rotating part contacts the bottom surface of the groove, the piston moves upward due to the restriction of the bottom surface of the groove and the curved surface structure, thereby realizing the up and down reciprocating movement of the piston.

[0013] The present invention is further configured such that the bottom surface of the groove coincides with the curved surface or is located above the curved surface.

[0014] The above further arrangement facilitates placement of the rotating member into the groove during installation.

[0015] The present invention is further provided with a piston ring provided between the piston and the inner wall of the piston cylinder.

[0016] With the above-mentioned further arrangement, the one-way valve 1 moves up and down in the piston cylinder together with the piston, and the one-way valve 2 is fixed on the shell, so that the space between the one-way valve 1 and the one-way valve 2 can be changed, and by setting a piston ring, the piston cylinder is sealed and the air pressure in the piston cylinder can be changed. At the same time, the gas can only reach the outlet through the one-way valve 1 and the one-way valve 2, thereby avoiding leakage and ensuring the pumping efficiency.

[0017] A further configuration of the present invention is that the shell is split and includes a bottom shell, a piston body and a piston cover. The air inlet is arranged on the bottom shell, the piston body and the piston cover together constitute a piston cylinder, the air outlet is arranged on the piston cover, the rotating shaft is respectively rotatably connected to the bottom shell and the piston body, and the one-way valve 2 is fixedly arranged at the bottom of the piston cover.

[0018] With the above further arrangement, the shell is divided into three detachable parts, which makes it easy to install the transmission structure and the piston in the shell. It is also convenient to fix the one-way valve 1 and the one-way valve 2 on the piston and the piston cover and then assemble them together on the piston body to ensure their stable installation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the overall structure of a specific embodiment of the utility model;

[0020] Figure 2 This is a schematic diagram of the top view of a specific embodiment of the utility model;

[0021] Figure 3 yes Figure 2 Schematic cross-section of the middle AA;

[0022] Figure 4 This is a schematic diagram of the overall structure of the transmission structure in a specific embodiment of the present utility model;

[0023] Figure 5 This is a schematic diagram of the overall structure of the base in a specific embodiment of the present utility model;

[0024] Figure 6 This is a schematic diagram of the overall structure of the groove and the rotating member in a specific embodiment of the utility model;

[0025] Figure 7 This is a schematic diagram of the overall structure of the piston in a specific embodiment of the utility model;

[0026] Figure 8 This is a schematic diagram of the overall structure of the piston cover in a specific embodiment of the present utility model;

[0027] Figure 9 It is a schematic diagram of the overall structure of the piston body in a specific embodiment of the present utility model.

[0028] In the figure: 1. Shell; 11. Air inlet; 12. Air outlet; 13. Piston cylinder; 14. Bottom shell; 15. Piston body; 16. Piston cover; 2. Transmission structure; 21. Rotating shaft; 22. Piston; 221. Rolling element; 222. Air vent; 223. Fixed shaft; 224. Rotating element; 23. Base; 231. Disc; 232. Cylindrical portion; 233. Curved surface; 234. Groove; 3. One-way valve 1; 4. One-way valve 2; 5. Piston ring. DETAILED DESCRIPTION

[0029] The following will clearly and completely describe the technical solutions in this embodiment with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0030] It should be noted that in the description of the present invention, all directional indications (such as up, down, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0031] In addition, the terms "first," "second," and so on, used in this utility model are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the technical features being described. In the description of this utility model, "several" means at least two, such as two or three, unless otherwise specifically defined.

[0032] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that technical personnel in this field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by this utility model.

[0033] The utility model discloses an oil-free air pump, such as Figures 1 to 9 As shown, an oil-free air pump includes a housing 1 and an air inlet 11 and an air outlet 12 provided on the housing 1. The housing 1 is provided in a split body, including a bottom shell 14, a piston body 15 and a piston cover 16. The air inlet 11 is provided at the bottom of the bottom shell 14. The bottom shell 14 is hollow inside and can accommodate gas. The air outlet 12 is provided at the top of the piston cover 16.

[0034] The piston body 15 is provided with a through hole and together with the piston cover 16 constitutes a piston cylinder 13. The piston body 15 and the piston cover 16 constitute at least two piston cylinders 13. In this embodiment, four piston cylinders 13 are preferably constructed. The four piston cylinders 13 are evenly arranged in the circumferential direction, and each piston cylinder 13 corresponds to a piston 22.

[0035] A transmission structure 2 for driving a piston 22 to reciprocate up and down in the piston cylinder 13 is provided in the bottom shell 14. The transmission structure 2 includes a rotating shaft 21 rotatably connected to the housing 1, a base 23 fixedly provided on the rotating shaft 21, and four pistons 22 evenly distributed around the rotating shaft 21 in the circumferential direction. The pistons 22 correspond to the vertical positions of the piston cylinders 13. Each piston 22 reciprocates up and down in corresponding piston cylinders 13. The rotating shaft 21 is rotatably connected to the bottom shell 14 and the piston body 15 respectively through bearings.

[0036] In this embodiment, the rotating shaft 21 and the base 23 are separately provided; it should be noted that the rotating shaft 21 and the base 23 can also have the same technical effect if they are provided as one body.

[0037] The base 23 includes a curved surface 233 that regularly undulates up and down along the circumferential direction of the rotating shaft 21. The curved surface 233 includes peaks and valleys, and the peaks and valleys are smoothly transitioned. In this embodiment, the curved surface 233 is provided with two peaks and two valleys in the circumferential direction, and the peaks and valleys are arranged in sequence.

[0038] A fixed shaft 223 is provided at the bottom of the piston 22, and at least one rolling element 221 that can contact the curved surface 233 is rotatably provided on the fixed shaft 223. The rolling elements 221 are evenly distributed at the bottom of the piston 22. In this embodiment, two rolling elements 221 are preferably used. When the piston 22 and the curved surface 233 are relatively displaced, the rolling element 221 can roll on the curved surface 233. The rolling element 221 can be a roller.

[0039] The base 23 includes a disc portion 231 and a cylindrical portion 232 protruding upward from the center of the disc portion 231 . The curved surface 233 is the upper surface of the disc portion 231 .

[0040] A limiting structure is provided between the piston 22 and the base 23 for controlling the contact between the rolling member 221 at the bottom of the piston 22 and the curved surface 233. The limiting structure includes a groove 234 provided on the outer circumference of the cylindrical portion 232. The groove 234 is connected end to end around the cylindrical portion 232. A rotating member 224 is rotatably connected to one side of the fixed shaft 223 close to the cylindrical portion 232. The rotating member 224 can be a roller. The rotating member 224 rolls in the groove 234. The width of the groove 234 is greater than the diameter of the rotating member 224, and its top or bottom surface contacts the rotating member 224: when the piston 22 moves upward, the rotating member 224 contacts the bottom surface of the groove 234 and rolls over it; when the piston 22 moves downward, the rotating member 224 contacts the top surface of the groove 234 and rolls over it.

[0041] It should be noted that in actual use, the width of the groove 234 is slightly larger than the diameter of the rotating member 224, leaving sufficient clearance for the rotating member 224 to roll in the groove 234. This clearance is preferably no larger than 20 threads, ensuring that the rotating member 224 can roll in the groove 234 while preventing the rotating member 224 from generating loud noise when operating in the groove 234.

[0042] Since the rotating member 224 rolls in the groove 234, and the top and bottom surfaces of the groove 234 rise and fall together with the curved surface 233, when the piston 22 moves upward, the rolling member 211 is squeezed upward by the curved surface 233, and the rolling member 211 contacts the curved surface 233 and rolls on it.

[0043] A ventilation channel 222 is provided between the top and bottom of the piston 22. The piston 22 includes a one-way valve 3 located at the top of the ventilation channel 222. The piston cylinder 13 is a cylindrical structure. The one-way valve 3 and the piston 22 move up and down in the piston cylinder 13.

[0044] The rotation of the piston 22 is improved by the rotation of the piston 22, and the rotation of the piston 22 is improved.

[0045] The curved surface 233 can be set as the bottom surface of the groove 234 or a different surface. In this embodiment, the curved surface 233 is used as the bottom surface of the groove 234 to facilitate the processing and forming of the base 23 and avoid the situation where the bottom surface of the groove 234 and the curved surface 233 do not rise and fall together.

[0046] It should be noted that when the bottom surface of the groove 234 and the curved surface 233 are different surfaces, the bottom surface of the groove 234 can only be above the curved surface 233, and the rotating member 224 is rotatably arranged with the fixed shaft 223 and is coaxial with the rolling member 221. The diameter size of the rotating member 224 is sufficient to leave a fitting gap between the top surface and the bottom surface of the groove 234.

[0047] The bottom of the piston cover 16 includes four exhaust holes corresponding to the positions of the piston cylinders 13. The tops of the four exhaust holes are connected to the gas outlet 12 through pipes. A one-way valve 24 is fixedly installed in each exhaust hole at the bottom of the piston cover 16. After the piston cover 16 and the piston body 15 are fixed, piston rings are provided between the one-way valve 24 and the inner wall of the piston cylinder 13 and the exhaust holes for sealing. Gas can only pass through the one-way valve 24 to the gas outlet 12;

[0048] A piston ring 5 is also provided between the piston 22 and the inner wall of the piston cylinder 13 for sealing. The gas can reach the one-way valve 2 4 after passing through the one-way valve 1 3. Thus, after the gas enters the housing 1 from the air inlet 11, it passes through the one-way valve 1 3 and the one-way valve 2 4 in sequence, and is then pumped out from the air outlet 12, thus realizing the pumping function.

[0049] Furthermore, the one-way valve 1 3 and the one-way valve 2 4 ensure that the gas can only pass from the air inlet 11 through the one-way valve 1 3 and the one-way valve 2 4 to the air outlet 12 in sequence, and meet the air pressure control of the space between the one-way valve 1 3 and the one-way valve 2 4, preventing the gas from flowing back when the space is compressed or opened, affecting the pumping control and efficiency of the pumping.

[0050] Specifically, the gas enters the bottom shell 14 through the air inlet 11, and the rotating shaft 21 is driven by the motor to rotate, driving the base 23 to rotate. The peaks and valleys on the curved surface 233 pass through each piston 22 in turn, and the rolling member 221 rotatably connected to the bottom of the piston 22 rolls on the curved surface 233, and the rotating member 224 rotatably connected to the bottom of the piston 22 rolls in the groove 234, with only extremely small rolling friction, and no need to apply lubricating oil. The piston 22 rises and falls with the curved surface 233, realizing the up and down reciprocating movement of the piston 22 in the piston cylinder 13. When the piston 22 moves downward, the volume between the one-way valve 1 3 and the one-way valve 2 4 increases, the air pressure decreases, and a pressure difference is formed above and below the one-way valve 1 3. The gas pushes up the one-way valve 1 3 and then enters the space between the one-way valve 1 3 and the one-way valve 2 4; then when the piston 22 moves upward, the volume between the one-way valve 1 3 and the one-way valve 2 4 decreases, and the gas When the pressure increases, the one-way valve 24 is pushed open and the gas flows to the air outlet 12 for discharge, thereby realizing the function of pumping the gas from the air inlet 11 to the air outlet 12. At the same time, the four pistons 22 are evenly distributed on the curved surface 233 with two slope peaks and two slope valleys. When the two pistons 22 move upward, two pistons 22 move downward, and can always pump air to the air outlet 12. Therefore, the rotation of the base 23 driven by the motor can be transmitted to the up and down movement of the piston 22. Compared with the prior art in which the piston realizes the reciprocating movement of the piston through the connecting rod and the eccentric wheel, the connecting rod structure is optimized to the base 23, and the base 23 is fixedly arranged between the rotating shaft 21, which avoids the occurrence of large vibration and noise of the air pump due to uneven wear of the eccentric wheel, and does not require a large amount of oil for lubrication, thereby avoiding the evaporation of lubricating oil and the accumulation of oil-gas mixture in the vehicle, further accelerating the aging of components and reducing the service life.

[0051] The above are only further embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes based on the technical solution and concept of the present invention within the scope disclosed by the present invention, which falls within the protection scope of the present invention.

Claims

1. An oil-free air pump, comprising a housing (1), a piston (22), and an air inlet (11) and an air outlet (12) provided on the housing (1), wherein a piston cylinder (13) for the piston (22) to move up and down is provided in the housing (1), and the top of the piston cylinder (13) is communicated with the air outlet (12), characterized in that: The invention also includes a transmission structure (2) in the housing (1), the transmission structure (2) including a rotating shaft (21) rotatably connected to the housing (1) and a base (23) fixed or integrally arranged on the rotating shaft (21), the base (23) including a curved surface (233) that rises and falls regularly along the circumferential direction of the rotating shaft (21), a rolling element (221) for contacting the curved surface (233) is rotatably arranged at the bottom of the piston (22), and a limiting structure for controlling the contact between the rolling element (221) and the curved surface (233) is arranged between the piston (22) and the base (23). The rotating shaft (21) drives the base (23) to rotate, and the piston (22) is acted upon by the curved surface (233) and the limiting structure to perform an up-and-down reciprocating motion in the piston cylinder (13). A ventilation channel (222) is provided between the top and the bottom of the piston (22). The piston (22) includes a one-way valve (3) located at the top of the ventilation channel (222). A one-way valve (4) for connecting the piston cylinder (13) and its corresponding air outlet (12) is provided on the housing (1). The gas passes through the one-way valve (3) and the one-way valve (4) in sequence through the air inlet (11) to the air outlet (12).

2. The oil-free air pump according to claim 1, characterized in that: The curved surface (233) is uniformly undulating in a circumferential direction around the rotation axis (21), and at least two pistons (22) are uniformly distributed on the curved surface (233) in the circumferential direction.

3. An oil-free air pump according to claim 1 or 2, characterized in that: The base (23) comprises a disc portion (231) and a cylindrical portion (232) protruding upward from the center of the disc portion (231), and the curved surface (233) is the upper surface of the disc portion (231).

4. The oil-free air pump according to claim 3, characterized in that: The limiting structure includes a fixed shaft (223) passing through the bottom of the piston (22); a rotating member (224) is rotatably connected to a side of the fixed shaft (223) close to the cylindrical portion (232); a groove (234) is provided on the outer circumference of the cylindrical portion (232) for the rotating member (224) to roll; and the top and bottom surfaces of the groove (234) both rise and fall together with the curved surface (233).

5. The oil-free air pump according to claim 4, characterized in that: A matching gap is left between the groove (234) and the rotating member (224) in the linear direction of the movement of the piston (22). When the piston (22) moves up and down, the rotating member (224) contacts the top surface or bottom surface of the groove (234).

6. The oil-free air pump according to claim 4, characterized in that: The bottom surface of the groove (234) coincides with the curved surface (233) or is located above the curved surface (233).

7. The oil-free air pump according to claim 1, characterized in that: A piston ring (5) is provided between the piston (22) and the inner wall of the piston cylinder (13).

8. The oil-free air pump according to claim 1, characterized in that: The housing (1) is provided in a split manner, including a bottom shell (14), a piston body (15) and a piston cover (16); the air inlet (11) is provided on the bottom shell (14); the piston body (15) and the piston cover (16) together constitute a piston cylinder (13); the air outlet (12) is provided on the piston cover (16); the rotating shaft (21) is rotatably connected to the bottom shell (14) and the piston body (15) respectively; and the one-way valve (4) is fixedly provided at the bottom of the piston cover (16).

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