Double-cylinder direct connection type oilless air compressor

Abstract

The invention provides a double-cylinder direct connection type oilless air compressor, and belongs to the technical field of air compressors. The problems that in the prior art, an air compressor is insufficient in working efficiency, large in connecting rod weight and insufficient in structural strength are solved. An upper cylinder hole and a lower cylinder hole are formed in the upper end and the lower end of the crankcase correspondingly, an upper cylinder seat and a lower cylinder seat are formed at the upper end of the upper cylinder hole and the lower end of the lower cylinder hole correspondingly, and a cylinder body is fixedly connected with the upper cylinder seat and the lower cylinder seat correspondingly. A bearing bush ring is connected outside the eccentric bearing bush seat and installed inside the connecting rod big end, an installation groove is formed in a seat body at the upper end of the connecting rod small end, a connecting hole is formed in the installation groove, a piston pin is connected in the dry type piston, the piston pin extends into the connecting hole and is connected with the connecting hole, and the dry type piston is installed in the installation groove. The connecting rod has the advantages of being large in gas displacement, high in working efficiency, light in weight and large in strength.

Description

Technical Field

[0001] This invention belongs to the field of air compressor technology and relates to a dual-cylinder direct-drive oil-free air compressor. Background Technology

[0002] The dual-cylinder direct-drive oil-free air compressor is an improved version of the oil-free air compressor that balances clean air supply and high-efficiency air production. It adopts a dual-cylinder piston structure to increase the exhaust volume and smooth pressure fluctuations. At the same time, the direct drive between the motor and the compressor cylinder replaces the belt drive, reducing transmission loss and maintenance requirements. It is suitable for medium and low flow continuous air use scenarios. However, the existing models still have shortcomings. The cylinder assembly and positioning are simple, which can easily lead to piston wear, weakening the long-term stability of oil-free air supply. It is difficult to meet the high reliability requirements of compact scenarios. Therefore, it is urgent to optimize its structure.

[0003] Chinese patent CN208950792U discloses a water-cooled oil-free air compressor, including a housing, two cylinders, and a motor installed inside the housing. The motor includes a rotating shaft, with a crank and a fan fixedly connected to both ends of the rotating shaft. The cylinders include cylinder liners and cylinder heads, with a piston slidingly installed inside the cylinder liners. The piston and the crank are connected by a connecting rod. An air supply pipe is provided between the two cylinder heads. The compressor also includes a water-cooling pipe and a water pump that drives the liquid in the water-cooling pipe to flow. The water-cooling pipe includes two heat dissipation parts located near the two fan end faces and two heat absorption parts attached to the two cylinder liners.

[0004] As can be seen from the specification and accompanying drawings provided in the patent, the water-cooled connecting rod and crankshaft structure design is relatively simple. The connecting rod has insufficient resistance to deformation and impact, the crankshaft has a high risk of axial movement, and the water-cooled water pump requires additional energy to operate, which affects exhaust performance and working efficiency. Summary of the Invention

[0005] The purpose of this invention is to address the aforementioned problems in the prior art by providing a dual-cylinder direct-drive oil-free air compressor.

[0006] The objective of this invention can be achieved through the following technical solution: A dual-cylinder direct-drive oil-free air compressor, comprising a crankcase, a long crankshaft, a connecting rod assembly, a dry piston, a cylinder assembly, and a drive motor. The crankcases are two in number and arranged in opposite directions. Connecting flanges extend from the inner ends of each crankcase and are fixedly fitted together. Upper and lower cylinder bores are respectively provided at the upper and lower ends of the crankcases. Upper and lower cylinder seats are respectively formed at the upper and lower ends of the upper and lower cylinder bores. An X-shaped shaft seal is formed inside the crankcase. The cylinder assembly comprises a cylinder body, a cylinder head, and a cylinder head cover. The cylinder body is fixedly connected to the upper and lower cylinder seats. The connecting rod assembly... The component includes several split connecting rods, each split connecting rod comprising a small end with a seat structure, a narrow rod body, and a large end with a split annular structure. Several eccentric bearing seats are sleeved and connected to the long crankshaft. Bearing rings are connected to the outside of each eccentric bearing seat and are installed inside the large end of the connecting rod. An installation groove is formed in the seat at the upper end of the small end of the connecting rod, and a connecting hole is formed in the installation groove. A piston pin is connected to the dry piston, extending into the connecting hole and connecting. The dry piston is installed in the installation groove. The cylinder assembly is installed on the upper end of the dry piston. A crankshaft sleeve is sleeved and connected to the outside of the long crankshaft inside the connecting rod assembly. A skeleton oil seal is sleeved and connected to the outside of the crankshaft sleeve near both sides, and the skeleton oil seal is installed inside the seal seat.

[0007] In the above-mentioned twin-cylinder direct-drive oil-free air compressor, a bushing mounting sleeve is formed near the upper end of the rod body, the connecting hole passes through the bushing mounting sleeve, and a pin bushing is sleeved and connected to the outside of the piston pin, with the pin bushing located in the bushing mounting sleeve.

[0008] In the aforementioned twin-cylinder direct-drive oil-free air compressor, a reinforcing seat is formed at the junction of the rod body and the small end of the connecting rod. A light-reducing groove is formed in the rod body, and a reinforcing protrusion is formed in the light-reducing groove of the rod body. A light-reducing hole is formed near the upper end of the reinforcing protrusion, and a reinforcing rib is formed on the outer side of the rod body to the large end of the connecting rod.

[0009] In the aforementioned twin-cylinder direct-drive oil-free air compressor, a motor end cover is fixedly installed on one side of the drive motor. One side of the motor end cover has an outwardly convex hemispherical structure. An inspection window is opened on one side of the hemispherical structure of the motor end cover. An inspection cover is fixedly connected to the outside of the inspection window. The drive motor has a motor shaft extending out. One end of the long crankshaft forms a connecting shaft extension. A coupling is externally connected to the connecting shaft extension. The motor shaft is connected to the other end of the coupling. The coupling is located inside the motor end cover.

[0010] In the aforementioned twin-cylinder direct-drive oil-free air compressor, a thrust washer is connected to the long crankshaft on the outer side of the split connecting rod, and a locking nut is connected to the long crankshaft on the outer side of the thrust washer. The locking nut presses the thrust washer against the side end face of the split connecting rod, and the thrust washer is firmly attached to the side end face of the split connecting rod.

[0011] In the aforementioned twin-cylinder direct-drive oil-free air compressor, protective baffles are formed on the crankcases outside the upper and lower cylinder seats, a side protrusion is formed on the side of the crankcase, a side window is provided in the side protrusion, and a side cover is installed on the outside of the side protrusion.

[0012] In the aforementioned twin-cylinder direct-drive oil-free air compressor, a protective end cover is fixedly connected to one side of the crankcase. A through hole is opened at the center of the protective end cover, and one end of the long crankshaft passes through the protective end cover. An inertial flywheel is connected to the long crankshaft outside the protective end cover, and a side end cover is fixedly connected to the outside of the protective end cover.

[0013] In the aforementioned twin-cylinder direct-drive oil-free air compressor, a support frame is formed on one side of the crankcase, and several fixed bases are installed in the support frame.

[0014] Compared with existing technologies, the dual-cylinder direct-drive oil-free air compressor provided by this invention has the following advantages: 1. The upper and lower cylinder bores and cylinder seats are respectively set at the upper and lower ends of the crankcase, which can be equipped with multiple sets of cylinder assemblies to achieve synchronous operation of multiple cylinders, significantly improving the exhaust volume and working efficiency, and is suitable for scenarios with high compressed air demand; 2. The split connecting rod is provided with a weight-reducing groove and weight-reducing hole, which can effectively reduce the overall weight of the connecting rod, reduce the inertial load and energy consumption during the operation of the air compressor, and at the same time, a reinforcing seat is set at the junction of the rod body and the small end of the connecting rod, a reinforcing rib is set on the outside of the rod body, and a reinforcing protrusion is set in the weight-reducing groove, which compensates for the potential strength loss caused by the lightweight design. To address the issue of insufficient strength, the connecting rod's impact and deformation resistance is enhanced. A pin bushing is integrated into the bushing mounting sleeve at the small end of the connecting rod, reducing friction loss and improving wear resistance when it mates with the piston pin, thus extending the overall machine's service life. 3. An eccentric bearing seat on the long crankshaft, paired with a bearing ring, connects to the connecting rod's big end. Combined with the crankshaft bushing and the sealing support structure of the skeleton oil seal, this ensures the coaxiality of the crankshaft rotation, reducing operating vibration and noise. The combination of thrust washer and lock nut axially presses and limits the split connecting rod, preventing axial movement during operation, ensuring the transmission accuracy between the crankshaft and connecting rod, and improving power transmission efficiency. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the internal structure of the present invention; Figure 3This is a schematic diagram of the exploded structure of the present invention; Figure 4 This is a schematic diagram of the connection structure at the link assembly; Figure 5 This is a schematic diagram of a split linkage structure; Figure 6 This is a schematic diagram of the crankcase structure; Figure 7 This is a schematic diagram of the motor end cover structure.

[0016] In the diagram: 1. Crankcase; 110. Connecting flange body; 120. Upper cylinder bore; 130. Lower cylinder bore; 140. Upper cylinder seat; 150. Lower cylinder seat; 160. Shaft seal seat; 170. Protective baffle; 180. Side protrusion; 181. Side window; 190. Support frame; 2. Long crankshaft; 21. Connecting shaft extension; 3. Dry piston; 31. Piston pin; 32. Pin bushing; 4. Cylinder assembly; 41. Cylinder body; 42. Cylinder head; 43. Cylinder head cover; 5. Drive motor; 51. Motor shaft; 6. Split connecting rod; 61. Connecting rod small end; 611. Mounting slot; 612. Connecting hole; 62. Rod body; 621. Bushing mounting sleeve; 622. Lightening slot; 623. Reinforcing protrusion; 624. Lightening hole; 63. Connecting rod big end; 64. Reinforcing seat; 65. Reinforcing rib; 7. Eccentric bearing seat; 8. Bearing ring; 9. Crankshaft bushing; 10. Skeleton oil seal; 11. Motor end cover; 111. Inspection window; 12. Inspection cover; 13. Coupling; 14. Thrust washer; 15. Lock nut; 16. Side cover; 17. Protective end cover; 18. Inertia flywheel; 19. Side end cover; 20. Fixed base. Detailed Implementation

[0017] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0018] like Figures 1 to 7 As shown, this embodiment includes a crankcase 1, a long crankshaft 2, a connecting rod assembly, a dry piston 3, a cylinder assembly 4, and a drive motor 5. There are two crankcases 1, which are symmetrically arranged in opposite directions. The inner end of the crankcase 1 extends integrally to form a connecting flange 110. The two connecting flanges 110 are attached together and fastened by a shaft pin to ensure the coaxiality of the overall structure. The upper and lower ends of the crankcase 1 are respectively provided with an upper cylinder hole 120 and a lower cylinder hole 130. The upper end of the upper cylinder hole 120 is integrally formed with an upper cylinder seat 140, and the lower end of the lower cylinder hole 130 is integrally formed with a lower cylinder seat 150. The crankcase 1 has an X-shaped shaft seal seat 160 inside, which optimizes the sealing installation space and improves the sealing reliability.

[0019] like Figures 1 to 5As shown, there are four sets of cylinder assemblies 4. Each set of cylinder assemblies 4 includes a cylinder body 41, a cylinder head 42, and a cylinder head cover 43. The cylinder body 41 is fixedly connected to the upper cylinder seat 140 and the lower cylinder seat 150 by bolts, which is convenient for disassembly and assembly and has a tight connection, effectively preventing gas leakage. The connecting rod assembly includes four split connecting rods 6. The split connecting rod 6 is integrally formed by a connecting rod small end 61 with a seat structure, a narrow rod body 62 with a split ring structure, and a connecting rod big end 63 with a split ring structure. Several eccentric bearing seats 7 are correspondingly sleeved and connected on the long crankshaft 2. Bearing rings 8 are interference-fitted to the outside of the eccentric bearing seats 7. The bearing rings 8 are precisely installed inside the connecting rod big end 63 to achieve the flexibility between the split connecting rods 6 and the long crankshaft 2. The connecting rod has a mounting groove 611 at the upper end of the connecting rod small end 61, and a connecting hole 612 is provided in the middle of the mounting groove 611. A piston pin 31 is fixed through the dry piston 3. The two ends of the piston pin 31 extend into the connecting hole 612 and form a rotational fit. The dry piston 3 is adapted to be installed in the mounting groove 611. The cylinder assembly 4 is installed on the upper end of the dry piston 3 to ensure the reciprocating motion accuracy of the dry piston 3 in the cylinder assembly 4. A crankshaft sleeve 9 is sleeved and connected to the outside of the long crankshaft 2 inside the connecting rod assembly. A skeleton oil seal 10 is sleeved and connected to the outside of the crankshaft sleeve 9 near both sides. The skeleton oil seal 10 is tightly installed inside the shaft seal seat 160 to achieve the sealing protection of the crankcase and prevent lubricating oil leakage.

[0020] like Figures 3 to 5 As shown, a bushing mounting sleeve 621 is integrally formed near the upper end of the rod body 62. A connecting hole 612 passes through the bushing mounting sleeve 621. A pin bushing 32 is sleeved and connected to the piston pin 31. The pin bushing 32 is interference-fitted into the bushing mounting sleeve 621 to reduce the friction coefficient between the piston pin 31 and the connecting rod assembly, thereby improving transmission efficiency and service life. A reinforcing seat 64 is integrally formed at the junction of the rod body 62 and the small end 61 of the connecting rod to enhance the structural strength of the connection and avoid stress concentration. A weight-reducing groove 622 is provided in the rod body 62 to reduce the weight of the connecting rod. A reinforcing protrusion 623 is integrally formed in the weight-reducing groove 622 of the rod body 62. A weight-reducing hole 624 is provided near the upper end of the reinforcing protrusion 623 to achieve a balance between lightweight and high strength. A reinforcing rib 65 is integrally formed on the outer side of the rod body 62 to the large end 63 of the connecting rod to further improve the overall rigidity of the connecting rod and adapt to high-pressure conditions.

[0021] To elaborate further, such as Figures 2 to 7As shown, a motor end cover 11 is fixedly installed on one side of the drive motor 5 by bolts. One side of the motor end cover 11 has an outwardly convex hemispherical structure to increase the internal installation space. An inspection window 111 is provided on one side of the hemispherical structure of the motor end cover 11. An inspection cover 12 is fixedly connected to the outside of the inspection window 111 by screws. A motor shaft 51 extends from the output end of the drive motor 5. A connecting shaft extension 21 is integrally formed at one end of the long crankshaft 2. A coupling 13 is connected to the outside of the connecting shaft extension 21 by a key. The other end of the motor shaft 51 and the coupling 13 are connected by a keyway. The coupling 13 is located inside the motor end cover 11 to realize direct drive between the motor and the crankshaft and reduce power loss.

[0022] To elaborate further, such as Figures 2 to 7 As shown, a thrust washer 14 is fitted on the long crankshaft 2 on the outer side of the split connecting rod 6. A lock nut 15 is threaded onto the long crankshaft 2 on the outer side of the thrust washer 14. The lock nut 15 presses and fixes the thrust washer 14 to the side end face of the split connecting rod 6. The thrust washer 14 fits tightly with the side end face of the split connecting rod 6, restricting the axial movement of the connecting rod assembly and ensuring transmission stability.

[0023] To elaborate further, such as Figures 1 to 7 As shown, a protective baffle 170 is integrally formed on the crankcase 1 outside the upper cylinder seat 140 and the lower cylinder seat 150 to protect the cylinder assembly and prevent damage from external impact. A side protrusion 180 is integrally formed on the side of the crankcase 1, and a side window 181 is provided in the side protrusion 180 to facilitate observation of the internal transmission. A side cover 16 is installed on the outside of the side protrusion 180 by screws to provide dust protection. A protective end cover 17 is fixedly connected to one side of the crankcase 1 by bolts. A through hole is provided in the center of the protective end cover 17, and one end of the long crankshaft 2 passes through the protective end cover 17. An inertia flywheel 18 is connected to the long crankshaft 2 outside the protective end cover 17 by a key. The inertia flywheel 18 can balance the crankshaft's rotational inertia and improve the stability of the equipment operation. A side end cover 19 is fixedly connected to the outside of the protective end cover 17 by bolts to protect the inertia flywheel 18.

[0024] To elaborate further, such as Figure 3 As shown, a support frame 190 is integrally formed on one side of the crankcase 1. Several fixed bases 20 are installed in the support frame 190 by bolts. The fixed bases 20 are used to fix the side of the whole of this embodiment to the external components, thereby improving the stability during use.

[0025] The working principle of this invention is as follows: After the drive motor 5 starts, the motor shaft 51 drives the long crankshaft 2 to rotate via the coupling 13. The eccentric bearing seat 7 on the long crankshaft 2 drives the split connecting rod 6 through the bearing ring 8, converting the circular motion into the linear reciprocating motion of the dry piston 3. The double crankcase 1 is fixed by the connecting flange body 110. The upper cylinder seat 140 and lower cylinder seat 150 at its upper and lower ends cooperate with the cylinder body 41 of the cylinder assembly 4, so that each cylinder alternately completes the intake and compression action, producing oil-free high-pressure gas. During operation, the thrust washer 14, crankshaft bushing 9 and skeleton oil seal 10 ensure stable transmission without leakage. The inertial flywheel 18 balances vibration. The protective baffle 170 and side cover 16 protect the internal components. The fixed base 20 stabilizes the whole machine. Optimized components such as pin bushing 32 and reinforcing rib 65 reduce wear. All numbered components work together to achieve continuous and efficient gas production.

[0026] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

[0027] Although this document uses a variety of terms, the possibility of using other terms is not excluded. These terms are used merely for the convenience of describing and explaining the essence of the invention; interpreting them as any additional limitation would contradict the spirit of the invention.

Claims

1. A twin-cylinder direct-drive oil-free air compressor, comprising a crankcase (1), a long crankshaft (2), a connecting rod assembly, a dry piston (3), a cylinder assembly (4), and a drive motor (5), characterized in that: The crankcases (1) are two in number and arranged in opposite directions. A connecting flange (110) extends from the inner end of each crankcase (1) and is fixedly fitted to each other. An upper cylinder bore (120) and a lower cylinder bore (130) are respectively provided at the upper and lower ends of the crankcases (1). An upper cylinder seat (140) and a lower cylinder seat (150) are respectively formed at the upper end of the upper cylinder bore (120) and the lower end of the lower cylinder bore (130). The crankcase (1) has an X-shaped shaft seal seat (160) inside. The cylinder assembly (4) consists of several cylinder bodies (41), cylinder heads (42) and cylinder head covers (43). The cylinder bodies (41) are fixedly connected to the upper cylinder seat (140) and the lower cylinder seat (150) respectively. The connecting rod assembly includes several split connecting rods (6). The split connecting rods (6) include connecting rod small ends (61) with a seat structure. The connecting rod consists of a narrow-structure rod body (62) and a split-ring structure connecting rod big end (63). Several eccentric bearing seats (7) are fitted onto the long crankshaft (2). Bearing rings (8) are connected to the outside of the eccentric bearing seats (7). The bearing rings (8) are installed inside the connecting rod big end (63). An installation groove (611) is provided in the seat at the upper end of the connecting rod small end (61). A connecting hole (612) is provided in the installation groove (611). A dry piston (3) is connected to... There is a piston pin (31), which extends into the connecting hole (612) and is connected. The dry piston (3) is installed in the mounting groove (611). The cylinder assembly (4) is installed on the upper end of the dry piston (3). The crankshaft (2) inside the connecting rod assembly is sleeved with a crankshaft bushing (9). The crankshaft bushing (9) is sleeved with a skeleton oil seal (10) near both sides. The skeleton oil seal (10) is installed inside the shaft seal seat (160).

2. The dual-cylinder direct-drive oil-free air compressor according to claim 1, characterized in that: The rod body (62) has a bushing mounting sleeve (621) near the upper end. The connecting hole (612) passes through the bushing mounting sleeve (621). The piston pin (31) is externally fitted with a pin bushing (32), which is located in the bushing mounting sleeve (621).

3. A twin-cylinder direct-drive oil-free air compressor according to claim 1, characterized in that: A reinforcing seat (64) is formed at the junction of the rod body (62) and the small end (61) of the connecting rod. A light-reducing groove (622) is formed in the rod body (62). A reinforcing protrusion (623) is formed in the light-reducing groove (622) of the rod body (62). A light-reducing hole (624) is formed near the upper end of the reinforcing protrusion (623). A reinforcing rib (65) is formed on the outer side of the rod body (62) to the large end (63) of the connecting rod.

4. A twin-cylinder direct-drive oil-free air compressor according to claim 1, characterized in that: A motor end cover (11) is fixedly installed on one side of the drive motor (5). One side of the motor end cover (11) has an outwardly convex hemispherical structure. An inspection window (111) is provided on one side of the hemispherical structure of the motor end cover (11). An inspection cover (12) is fixedly connected to the outside of the inspection window (111). The drive motor (5) has a motor shaft (51) extending out. One end of the long crankshaft (2) forms a connecting shaft extension (21). A coupling (13) is connected to the outside of the connecting shaft extension (21). The motor shaft (51) is connected to the other end of the coupling (13). The coupling (13) is located inside the motor end cover (11).

5. A twin-cylinder direct-drive oil-free air compressor according to claim 1, characterized in that: A thrust washer (14) is connected to the long crankshaft (2) on the outer side of the split connecting rod (6). A lock nut (15) is connected to the long crankshaft (2) on the outer side of the thrust washer (14). The lock nut (15) presses the thrust washer (14) against the side end face of the split connecting rod (6). The thrust washer (14) is tightly fitted against the side end face of the split connecting rod (6).

6. A twin-cylinder direct-drive oil-free air compressor according to claim 1, characterized in that: A protective baffle (170) is formed on the crankcase (1) outside the upper cylinder seat (140) and the lower cylinder seat (150). A side protrusion (180) is formed on the side of the crankcase (1). A side window (181) is provided in the side protrusion (180). A side cover (16) is installed on the outside of the side protrusion (180).

7. A twin-cylinder direct-drive oil-free air compressor according to claim 1, characterized in that: A protective end cap (17) is fixedly connected to one side of the crankcase (1). A through hole is opened in the center of the protective end cap (17) and one end of the long crankshaft (2) passes through the protective end cap (17). An inertial flywheel (18) is connected to the long crankshaft (2) outside the protective end cap (17). A side end cover (19) is fixedly connected to the outside of the protective end cap (17).

8. A twin-cylinder direct-drive oil-free air compressor according to claim 1, characterized in that: A support frame (190) is formed on one side of the crankcase (1), and a plurality of fixed bases (20) are installed in the support frame (190).

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