A smooth running compressor and assembly process

Abstract

The application relates to a smooth-running compressor and an assembling process, relates to the field of liquid variable volume type machines, and discloses a crankcase, a crankshaft, a connecting rod and a piston, the crankshaft comprises a crank and connecting rod shaft necks arranged on both sides of the crank, and further comprises a primary compression cylinder and a secondary compression cylinder arranged on the crankcase, the primary compression cylinder and the secondary compression cylinder are each provided with three groups and are oppositely arranged on both sides of the crankcase, the gas outlet of the primary compression cylinder is communicated with the gas inlet of the secondary compression cylinder, a shaft hole is arranged in the middle part of the crankcase, a supporting bearing is arranged in the shaft hole, the crank is a circular plate matched with the inner hole of the supporting bearing, and a limiting ring table for limiting the supporting bearing is arranged on one end of the shaft hole and on the hole wall. According to the application, the shaft hole is arranged in the middle part of the crankcase, the crank is rotationally fixed at the shaft hole through the supporting bearing, in working, the supporting bearing can bear most of the impact on the middle part of the crankshaft, the vibration of the crankshaft is reduced, and the overall service life is improved.

Description

Technical Field

[0001] This application relates to the field of fluid displacement machinery, and more particularly to a compressor with smooth operation and its assembly process. Background Technology

[0002] A gas compressor is a device that compresses gas. It is a pneumatic generator that produces compressed gas, utilizing the principle of gas compression to increase the pressure of the compressed gas to above atmospheric pressure. Gas compressors are widely used in various industries, from small-scale applications such as tire inflation, painting, vehicle braking, and door and window opening and closing, to large-scale applications such as defense industries, weapon systems, missile launches, torpedo launches, and submarine buoyancy control.

[0003] In related technologies, a horizontally opposed four-cylinder air compressor includes a crankcase, a crankshaft, cylinder blocks, connecting rods, and pistons. The crankshaft is installed within the crankcase and includes cranks and connecting rod journals. Two connecting rod journals are respectively fixed to both ends of the connecting rod journals and are symmetrically positioned around the center of the connecting rod journals. Four cylinder blocks are provided, arranged in pairs opposite each other at both ends of the crankcase in the horizontal direction. Four connecting rods are provided corresponding to the cylinder blocks, and pistons are installed on the small ends of the connecting rods. Two connecting rods are installed on the same connecting rod journal, and the pistons on the two connecting rods slide into the cylinder blocks on either side. When the crankshaft is driven to rotate, it can simultaneously drive four pistons to reciprocate within the cylinder blocks to compress the gas.

[0004] In some applications, a higher compressor output efficiency is required. Therefore, two additional cylinders are added to both sides of the existing four-cylinder compressor, creating a horizontally opposed six-cylinder compressor. To optimize the arrangement of connecting rods and cylinder positions and maintain balance of inertial forces on both sides of the crankshaft during rotation, one connecting rod is installed at the end of each connecting rod journal near the crank, and two connecting rods are installed at the ends of the two connecting rod journals furthest from each other.

[0005] In actual use, it was found that during normal operation, the connecting rods on both sides of the crank move in opposite directions. Although their inertial forces can cancel each other out, making the crankshaft rotation relatively balanced, when the two connecting rods drive the piston to the bottom dead center and top dead center positions, the inertia of the connecting rods and pistons will have a large impact on the crankshaft. After a period of use, the middle part of the crankshaft will bend, affecting the normal operation of the compressor. Summary of the Invention

[0006] In a first aspect, this application provides a compressor that operates smoothly, including a crankcase, a crankshaft, a connecting rod, and a piston. The crankshaft includes a crank and connecting rod journals disposed on both sides of the crank. It also includes a primary compression cylinder and a secondary compression cylinder disposed on the crankcase. Each of the primary and secondary compression cylinders has three sets and is disposed opposite to each other on both sides of the crankcase. The outlet of the primary compression cylinder is connected to the inlet of the secondary compression cylinder. A shaft hole is provided in the middle of the crankcase. A support bearing is disposed in the shaft hole. The crank is configured as a circular plate that mates with the inner hole of the support bearing. A limiting ring is provided on the hole wall at one end of the shaft hole for limiting the support bearing.

[0007] By adopting the above technical solution, a primary compression cylinder and a secondary compression cylinder are set on both sides of the crankcase. After being compressed by the primary compression cylinder, the gas enters the secondary compression cylinder, where it undergoes a second compression, resulting in higher pressure gas at the compressor output. Simultaneously, the crank is circular, and a shaft hole is formed inside the crankcase. The crank is rotatably fixed to the shaft hole via a support bearing. During operation, the support bearing supports the crank. When the connecting rods and pistons on both sides of the crank reciprocate, the support bearing can withstand most of the impact from the connecting rods and pistons, effectively reducing crankshaft vibration and bending, thus significantly improving crankshaft service life. A limiting ring is set on the wall of the shaft hole. During the installation of the support bearing, the limiting ring can position the support bearing and prevent displacement of the support bearing during operation.

[0008] Optionally, the end of the crank is provided with a positioning ring protrusion with a diameter larger than the crank diameter, and the positioning ring protrusion abuts against the end of the support bearing away from the limiting ring platform.

[0009] By adopting the above technical solution, a positioning ring protrusion is provided at one end of the crank. When the crank is installed into the support bearing, the positioning ring protrusion can position the crank in the installation position. At the same time, the positioning ring protrusion can also prevent the crank from shifting during operation.

[0010] Optionally, a connecting rod bearing is provided on the connecting rod journal corresponding to the installation position of the connecting rod, and a limiting sleeve is sleeved on the connecting rod journal between adjacent connecting rod bearings.

[0011] By adopting the above technical solution, a connecting rod bearing is installed on the connecting rod journal at the corresponding installation position of the connecting rod. The connecting rod bearing can effectively reduce the friction between the connecting rod and the crankshaft. A limiting sleeve is installed between adjacent connecting rod bearings. The limiting sleeve can position the installation position of the connecting rod bearing and prevent the connecting rod bearing from shifting during operation.

[0012] Optionally, a through groove is provided in the middle of the connecting rod journal.

[0013] By adopting the above technical solution, when installing the connecting rod bearing near the crank side, after the connecting rod bearing passes through the installation area at the end of the connecting rod journal, it can quickly slide from the through groove to the installation area near the crank of the connecting rod journal, which facilitates the installation of the connecting rod bearing near the crank side. If there is no through groove, the connecting rod bearing needs to be pressed from the end of the connecting rod journal all the way to the side near the crank. The connecting rod bearing and the connecting rod journal are always in a tight fit, which can easily damage the connecting rod journal and the connecting rod bearing.

[0014] Optionally, the crankshaft further includes a front shaft and a rear shaft. The front shaft and the rear shaft are detachably fixed to the ends of the two connecting rod journals that are far apart from each other. The front shaft and the rear shaft are coaxial with the crank. The crankcase is provided with a front cover and a rear cover at both ends corresponding to the front shaft and the rear shaft. The front shaft and the rear shaft are rotatably fixed on the front cover and the rear cover, respectively. The front shaft passes through the front cover, and a drive wheel is fixed on the front shaft.

[0015] By adopting the above technical solution, a detachable front and rear shaft is provided. After the crankshaft and connecting rod journals are assembled and installed into the crankcase, the front and rear shafts are then installed, which facilitates crankshaft assembly. The front and rear covers seal the crankcase, preventing dust from entering. At the same time, the front and rear covers can fix both ends of the crankshaft, improving the stability of crankshaft operation. A drive wheel is fixed on the front shaft, which drives the crankshaft to rotate. The structure is simple and easy to use.

[0016] Secondly, this application provides an assembly process for assembling the above-mentioned compressor, including the following steps:

[0017] S1. Insert the crank into the inner hole of the support bearing;

[0018] S2. Install the connecting rod bearing on the connecting rod journal;

[0019] S3. Insert the crankshaft with the support bearing and connecting rod bearing installed into the crankcase, and insert the support bearing into the shaft hole;

[0020] S4. Install the front shaft and the rear shaft at the ends of the two connecting rod journals that are far apart from each other;

[0021] S5. Install the front cover and rear cover at both ends of the crankcase;

[0022] S6. Install the drive wheels;

[0023] S7. Install connecting rods and pistons. After installing a set of connecting rods and pistons, install the corresponding primary or secondary compression cylinder.

[0024] By adopting the above technical solution, during assembly line operation, the support bearing and connecting rod bearing can be assembled onto the crankshaft and connecting rod journals at one station, and then the assembled whole can be put into the crankcase. Next, the front and rear shafts at both ends of the crankshaft can be assembled, which can improve the efficiency and accuracy of crankshaft assembly. Finally, the front and rear covers, as well as the connecting rod and compression cylinder, are assembled, which helps to improve assembly efficiency.

[0025] Optionally, before installing the support bearings and connecting rod bearings onto the crankshaft, apply lubricant to the corresponding mounting areas and wipe off the lubricant with absorbent paper after installation.

[0026] By adopting the above technical solution, applying lubricating oil during the installation of the support bearing and connecting rod bearing can lubricate the mating parts, facilitating the installation of the support bearing and connecting rod bearing; since the compressor needs to be used in food processing, the lubricating oil is wiped dry with oil-absorbing paper after installation to improve the cleanliness of the crankshaft.

[0027] Optionally, when installing connecting rod bearings, an upper limit sleeve is fitted on the connecting rod journal between adjacent connecting rod bearings.

[0028] By adopting the above technical solution, the connecting rod bearing is positioned using a limiting sleeve, thereby improving the installation accuracy of the connecting rod bearing.

[0029] Optionally, after installing the drive wheel, manually rotate the drive wheel to check if the crankshaft rotation is stuck.

[0030] By adopting the above technical solution, check whether the assembled crankshaft is stuck. If there is any sticking, troubleshoot the problem in time to prevent crankshaft sticking from affecting the overall operation.

[0031] Optionally, when installing a primary or secondary compression cylinder, after each primary or secondary compression cylinder is installed, the crankshaft needs to be rotated to check for any jamming.

[0032] By adopting the above technical solution, the connecting rod and piston can be prevented from getting stuck in the first-stage or second-stage compression cylinder, thus affecting the operation of the finished product.

[0033] In summary, this application includes at least one of the following beneficial technical effects:

[0034] 1. By setting a primary compression cylinder and a secondary compression cylinder on both sides of the crankcase, the gas is compressed by the primary compression cylinder and then enters the secondary compression cylinder for a second compression, thereby obtaining higher pressure gas at the output end of the compressor. At the same time, the crank is set to be circular, and a shaft hole is opened in the crankcase. The crank is rotated and fixed at the shaft hole by a support bearing. During operation, the support bearing can support the crank. When the connecting rod and piston on both sides of the crank reciprocate, the support bearing can withstand most of the impact from the connecting rod and piston, thereby effectively reducing the vibration and bending of the crankshaft and thus effectively improving the service life of the crankshaft. A limiting ring is set on the wall of the shaft hole. When installing the support bearing, the limiting ring can position the support bearing. At the same time, the limiting ring can also prevent the support bearing from shifting during operation.

[0035] 2. By creating a through groove in the middle of the connecting rod journal, when installing the connecting rod bearing near the crank, the connecting rod bearing can quickly slide from the through groove to the installation area near the crank after passing through the installation area at the end of the connecting rod journal, facilitating the installation of the connecting rod bearing near the crank. Without the through groove, the connecting rod bearing needs to be pressed from the end of the connecting rod journal all the way to the side near the crank, and the connecting rod bearing and the connecting rod journal are always in a tight fit, which can easily damage the connecting rod journal and the connecting rod bearing.

[0036] 3. By setting assembly steps, during assembly line operations, the support bearing and connecting rod bearing can be assembled onto the crankshaft and connecting rod journals at one station. Then, the assembled whole is put into the crankcase. Next, the front and rear shafts at both ends of the crankshaft are assembled, which can improve the efficiency and accuracy of crankshaft assembly. Finally, the front and rear covers, as well as the connecting rod and compression cylinder are assembled, which helps to improve assembly efficiency. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of this application;

[0038] Figure 2 This is a cross-sectional view of Embodiment 1 of this application;

[0039] Figure 3 This is a schematic diagram of the crankshaft structure in Embodiment 1 of this application;

[0040] Figure 4 yes Figure 2 A magnified view of area A in the middle;

[0041] Figure 5 yes Figure 2 A magnified view of area B in the middle;

[0042] Figure 6 This is a schematic diagram of the overall structure of Example 2.

[0043] Reference numerals: 1. Crankcase; 11. Support seat; 12. Shaft hole; 13. Limiting ring platform; 14. Support bearing; 15. Front cover; 16. Rear cover; 17. End cover bearing; 18. Operating port; 19. Cover plate; 191. Vent hole; 2. Crankshaft; 21. Crank; 211. Positioning ring protrusion; 212. Vent hole; 22. Connecting rod journal; 221. Through groove; 23. Front shaft; 231. Front connecting block; 232. Front mounting hole; 24. Rear shaft; 241. Rear connecting block; 242. Rear mounting hole; 25. Balance block; 26. Long limiting sleeve; 27. Short limiting sleeve; 3. Connecting rod; 31. Connecting rod bearing; 4. Piston; 5. First-stage compression cylinder; 6. Second-stage compression cylinder; 7. Drive wheel. Detailed Implementation

[0044] Example 1:

[0045] Firstly, this application discloses a compressor that operates smoothly, referring to... Figure 1 and Figure 2 The compressor includes a crankcase 1, a crankshaft 2, a connecting rod 3, and a piston 4. The crankcase 1 is a cubic housing. A primary compression cylinder 5 and a secondary compression cylinder 6 are mounted on opposite sides of the crankcase 1. There are three primary compression cylinders 5 and three secondary compression cylinders 6, horizontally opposite each other on both sides of the crankcase 1. The crankshaft 2 is installed inside the crankcase 1, the connecting rod 3 is mounted on the crankshaft 2, and the piston 4 is mounted on the small end of the connecting rod 3. When the crankshaft 2 rotates, it drives the connecting rod 3, which in turn drives the piston 4 to reciprocate within the primary compression cylinders 5 and 6, compressing the gas. The outlet of the primary compression cylinder 5 is connected to the inlet of the secondary compression cylinder 6. After compression in the primary compression cylinder 5, the gas enters the secondary compression cylinder 6 for secondary compression, effectively increasing the compressor's output pressure.

[0046] Reference Figure 3The crankshaft 2 includes a circular crank 21 and a connecting rod journal 22 integrally mounted on the crank 21. Two connecting rod journals 22 are located on opposite sides of the crank 21, symmetrically positioned around the crank 21. A front shaft 23 and a rear shaft 24 are respectively located at the ends of the two connecting rod journals 22 that are furthest from each other, and both are coaxial with the crank 21. A front connecting block 231 is integrally mounted on the end of the front shaft 23 closest to the connecting rod journal 22. A front mounting hole 232 is provided on the front connecting block 231, parallel to the axial direction of the front shaft 23. The end of the connecting rod journal 22 furthest from the crank 21 is inserted into the front mounting hole 232 and fixed with bolts. A balance block 25 is fixed to the side of the front shaft 23 furthest from the front connecting block 231 with bolts. A rear connecting block 241 is integrally provided at one end of the rear shaft 24 near the connecting rod journal 22. A rear mounting hole 242 is provided through the rear connecting block 241 in a direction parallel to the rear shaft 24. The end of the connecting rod journal 22 is inserted into the rear mounting hole 242 and fixed by bolts. A balance block 25 is fixed by bolts on the side of the rear shaft 24 away from the rear mounting block.

[0047] Reference Figure 2 and Figure 4 A support seat 11 is integrally formed in the middle of the crankcase 1, located between the primary compression cylinder 5 and the secondary compression cylinder 6 in the middle of the crankcase 1. A shaft hole 12 is formed on the support seat 11, and a limiting ring platform 13 with a diameter smaller than the shaft hole 12 is integrally formed at one end of the support seat 11. A support bearing 14 is installed in the shaft hole 12, with one end of the support bearing 14 abutting against the limiting ring platform 13. A crank 21 is coaxially inserted into the support bearing 14, and a positioning ring protrusion 211 with a diameter larger than the crank 21 is integrally formed at one end of the crank 21, abutting against the side of the support bearing 14 away from the limiting ring platform 13. Two vent holes 212 are formed through the crank 21, symmetrically positioned around the center of the crank 21.

[0048] Reference Figure 2 and Figure 5A connecting rod bearing 31 is fitted onto the connecting rod journal 22 at the mounting position corresponding to the connecting rod 3. A through groove 221 is coaxially formed in the middle of the connecting rod 3. When installing the connecting rod bearing 31 near the crank 21, the connecting rod bearing 31 can slide through the through groove 221 to the end of the connecting rod journal 22 near the crank 21, facilitating the installation of the connecting rod bearing 31. A limiting sleeve is fitted onto the connecting rod journal 22 between adjacent connecting rod bearings 31. The outer diameter of the limiting sleeve is less than or equal to the outer diameter of the inner ring of the connecting rod bearing 31. There are two types of limiting sleeves depending on the distance between adjacent connecting rod bearings 31. The limiting sleeve between two connecting rod bearings 31 at the end of the connecting rod journal 22 away from the crank 21 is a short limiting sleeve 27. The limiting sleeve between the middle connecting rod bearing 31 on the same connecting rod journal 22 and the connecting rod bearing 31 near the crank 21 is a long limiting sleeve 26.

[0049] A rear end cover 16 is bolted to the rear end of the crankcase 1, and an end cover bearing 17 is fixed to the rear end cover 16. The rear end shaft 24 is coaxially inserted into the end cover bearing 17. A front end cover 15 is fixed to the front end of the crankcase 1, and an end cover bearing 17 is also fixed to the front end cover 15. The front end shaft 23 is coaxially inserted into the end cover bearing 17, and the front end shaft 23 passes through the front end cover 15 and rotates with the front end cover 15. A drive wheel 7, which is a pulley, is bolted to the end of the front end shaft 23 that extends out of the front end cover 15.

[0050] Reference Figure 1 An operating port 18 is provided at the upper end of the crankcase 1 to facilitate assembly by workers. A cover plate 19 is fixed to the operating port 18 with bolts to prevent dust from entering the crankcase 1. A vent hole 191 for introducing air into the crankcase 1 is provided through the cover plate 19 on one side. When the compressor is running normally, filtered clean air is drawn into the compressor through the vent hole 191.

[0051] The implementation principle of a smoothly operating compressor disclosed in Embodiment 1 of this application is as follows: By setting a primary compression cylinder 5 and a secondary compression cylinder 6 on both sides of the crankcase 1, the gas enters the secondary compression cylinder 6 after being compressed by the primary compression cylinder 5, and is compressed a second time by the secondary compression cylinder 6, thereby obtaining gas with higher pressure at the output end of the compressor; at the same time, the crank 21 is set to be circular, and a shaft hole 12 is opened in the crankcase 1. The crank 21 is rotatably fixed at the shaft hole 12 by a support bearing 14. During operation, the support bearing 14 can support the crank 21. When the connecting rod 3 and piston 4 on both sides of the crank 21 reciprocate, the support bearing 14 can withstand most of the impact from the connecting rod 3 and piston 4, thereby effectively reducing the vibration of the crankshaft 2, thereby preventing the crankshaft 2 from bending and improving the service life of the crankshaft 2.

[0052] Secondly, Embodiment 1 of this application provides an assembly process for installing the above-mentioned compressor, including the following steps:

[0053] S1. Apply lubricating oil to the outside of crank 21, install crank 21 into support bearing 14, and wipe the lubricating oil off the surface of crank 21 with oil-absorbing paper after installation.

[0054] S2. Apply lubricating oil to one side of the connecting rod journal 22. First, install the connecting rod bearing 31 on the side closest to the crank 21. Then, wipe the lubricating oil through the groove 221 clean with oil-absorbing paper. Slide the long limiting sleeve 26 onto the connecting rod journal 22. Then, install a connecting rod bearing 31 at the end of the connecting rod journal 22 away from the crank 21, so that the inner ring of the connecting rod bearing 31 abuts against the long limiting sleeve 26. Next, slide the short limiting sleeve 27 onto the end of the connecting rod journal 22. Then, install the last connecting rod bearing 31. Finally, wipe the lubricating oil off the surface of the connecting rod journal 22 with oil-absorbing paper. The installation method for the other side of the connecting rod journal 22 is the same.

[0055] S3. Insert the crankshaft 2 with the support bearing 14 and connecting rod bearing 31 installed into the crankcase 1, and insert the support bearing 14 into the shaft hole 12. Gently tap the outer ring of the support bearing 14 with a copper or aluminum rod so that the support bearing 14 fits against the limiting ring platform 13.

[0056] S4. Install the front shaft 23 and the balance weight 25 on the connecting rod journal 22 near the front end of the crankcase 1, and install the rear shaft 24 and the balance weight 25 on the connecting rod journal 22 near the rear end of the crankcase 1.

[0057] S5. Install a front cover 15 at the front end of crankcase 1 and a rear cover 16 at the rear end of crankcase 1.

[0058] S6. Install the drive wheel 7 at the end of the front shaft 23 that protrudes from the front cover 15, and manually rotate the drive wheel 7 to check whether the crankshaft 2 is stuck during rotation. If there is any sticking, troubleshoot it in time.

[0059] S7. Insert connecting rod 3 into crankcase 1 from one side and fix it on the corresponding connecting rod bearing 31. Then install piston 4 at the small end of connecting rod 3. Finally, insert piston 4 into the corresponding first-stage compression cylinder 5 or second-stage compression cylinder 6. Fix the corresponding compression cylinder to crankcase 1 with bolts. Then rotate crankshaft 2 to check for jamming. Install other connecting rods 3, pistons 4, first-stage compression cylinder 5 and second-stage compression cylinder 6 in the same way. After installing each first-stage compression cylinder 5 or second-stage compression cylinder 6, drive wheel 7 must be manually rotated to check for jamming when crankshaft 2 rotates.

[0060] The implementation principle of the assembly process disclosed in Embodiment 1 of this application is as follows: By setting the above assembly steps, when assembling the compressor, multiple workstations can be set up for assembly line operation. First, the support bearing 14 and connecting rod bearing 31 are assembled onto the crank 21 and connecting rod journal 22 at the first workstation. Then, the crankshaft 2 with the support bearing 14 and connecting rod bearing 31 assembled is installed into the crankcase 1 at the second workstation. Next, the front end shaft 23 and rear end shaft 24 at both ends of the crankshaft 2 are assembled at the third workstation. At the fourth workstation, the front end cover 15, rear end cover 16 and drive wheel 7 are assembled. Finally, the connecting rod 3, piston 4, first-stage compression cylinder 5 and second-stage compression cylinder 6 are assembled at the fifth workstation, which can effectively improve the overall assembly efficiency.

[0061] Example 2:

[0062] The difference between Embodiment 1 and Embodiment 2 of this application is that, referring to... Figure 6 Vent hole 191 is located on cover plate 19 near the middle of crankcase 1; primary compression cylinder 5 and secondary compression cylinder 6 are arranged alternately, with one primary compression cylinder 5 placed between two secondary compression cylinders 6 and one secondary compression cylinder 6 placed at one end of two primary compression cylinders 5.

[0063] The implementation principle of Embodiment 2 of this application is as follows: by opening the vent 191 near the middle of the crankcase 1, air enters the crankcase 1 through the vent 191 during normal operation, and then the air enters the first-stage compression cylinders 5 on both sides from the crankcase 1. This can effectively balance the intake rate of the first-stage compression cylinders 5 on both sides, which helps to improve the overall working stability.

[0064] By adjusting the arrangement of the primary compression cylinder 5 and the secondary compression cylinder 6, the two secondary compression cylinders 6 at the end of the crankcase 1 furthest from the drive wheel 7 are positioned opposite each other, while the two primary compression cylinders 5 in the middle of the crankcase 1 are positioned opposite each other. During normal operation, the inertial forces of the opposing primary compression cylinders 5 and secondary compression cylinders 6 are well balanced, which helps improve the overall smoothness of operation. Simultaneously, the dynamic balance of the primary compression cylinders 5 and secondary compression cylinders 6 on both sides can be easily adjusted, thereby effectively reducing the complexity of the compressor manufacturing process and facilitating production. Furthermore, the adjusted positions of the primary compression cylinders 5 and secondary compression cylinders 6 facilitate the connection of their respective air pipes, contributing to improved production efficiency.

[0065] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A compressor with smooth operation, comprising a crankcase (1), a crankshaft (2), connecting rods (3), and a piston (4), wherein the crankshaft (2) includes a crank (21) and connecting rod journals (22) disposed on both sides of the crank (21), each side of the connecting rod journals (22) being provided with three connecting rods, and the six connecting rods being arranged alternately, characterized in that: It also includes a primary compression cylinder (5) and a secondary compression cylinder (6) disposed on the crankcase (1). The primary compression cylinder (5) and the secondary compression cylinder (6) are each provided in three sets and are disposed opposite to each other on both sides of the crankcase (1). The outlet of the primary compression cylinder (5) is connected to the inlet of the secondary compression cylinder (6). A shaft hole (12) is provided in the middle of the crankcase (1). A support bearing (14) is provided in the shaft hole (12). The crank (21) is configured as a circular plate that fits into the inner hole of the support bearing (14). A limiting ring platform (13) for limiting the support bearing (14) is provided on the hole wall at one end of the shaft hole (12). The end of the crank (21) is provided with a positioning ring protrusion (211) with a diameter larger than that of the crank (21), and the positioning ring protrusion (211) abuts against the end of the support bearing (14) away from the limiting ring platform (13); A connecting rod bearing (31) is provided on the connecting rod journal (22) at the installation position of the connecting rod (3). A limiting sleeve is provided on the connecting rod journal (22) between adjacent connecting rod bearings (31). A through groove (221) is provided in the middle of the connecting rod journal (22). The limiting sleeve is provided in two types according to the distance between adjacent connecting rod bearings (31). The limiting sleeve between the two connecting rod bearings (31) at the end of the connecting rod journal (22) away from the crank (21) is set as a short limiting sleeve (27). The limiting sleeve between the connecting rod bearing (31) located in the middle of the crankshaft (2) on the same connecting rod journal (22) and the connecting rod bearing (31) near the crank (21) is set as a long limiting sleeve (26).

2. The compressor with smooth operation according to claim 1, characterized in that: The crankshaft (2) also includes a front shaft (23) and a rear shaft (24). The front shaft (23) and the rear shaft (24) are detachably fixed to the ends of the two connecting rod journals (22) that are far apart from each other. The front shaft (23) and the rear shaft (24) are coaxial with the crank (21). The crankcase (1) is provided with a front cover (15) and a rear cover (16) at both ends corresponding to the front shaft (23) and the rear shaft (24). The front shaft (23) and the rear shaft (24) are rotatably fixed on the front cover (15) and the rear cover (16) respectively. The front shaft (23) passes through the front cover (15). A drive wheel (7) is fixed on the front shaft (23).

3. An assembly process for assembling the compressor of claim 2, characterized in that: Includes the following steps, S1. Insert the crank (21) into the inner hole of the support bearing (14); S2. Install the connecting rod bearing (31) on the connecting rod journal (22); S3. Insert the crankshaft (2) with the support bearing (14) and connecting rod bearing (31) installed into the crankcase (1), and insert the support bearing (14) into the shaft hole (12); S4. Install the front end shaft (23) and the rear end shaft (24) at the ends of the two connecting rod journals (22) that are far apart from each other. S5. Install the front cover (15) and the rear cover (16) at both ends of the crankcase (1). S6. Install the drive wheel (7); S7. Install connecting rod (3) and piston (4). After installing a set of connecting rods (3) and pistons (4), install the corresponding primary compression cylinder (5) or secondary compression cylinder (6).

4. The assembly process according to claim 3, characterized in that: Before installing the support bearing (14) and connecting rod bearing (31) onto the crankshaft (2), apply lubricating oil to the corresponding mounting parts. After installation, wipe the lubricating oil dry with absorbent paper.

5. The assembly process according to claim 3, characterized in that: When installing the connecting rod bearing (31), an upper limit sleeve is fitted on the connecting rod journal (22) between adjacent connecting rod bearings (31).

6. The assembly process according to claim 3, characterized in that: After installing the drive wheel (7), manually rotate the drive wheel (7) to check if the crankshaft (2) is stuck.

7. The assembly process according to claim 3, characterized in that: When installing a primary compression cylinder (5) or a secondary compression cylinder (6), after each primary compression cylinder (5) or secondary compression cylinder (6) is installed, the crankshaft (2) needs to be rotated to check for any jamming.

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