CN114320820A

CN114320820A - Two-stage compression oilless air compressor

Info

Publication number: CN114320820A
Application number: CN202210110118.4A
Authority: CN
Inventors: 樊军铖; 林知鸿; 廖仁鑫; 庄志雄; 黄荣峰
Original assignee: Xiamen Wonderroad Technology Co ltd
Current assignee: Xiamen Wonderroad Technology Co ltd
Priority date: 2022-01-29
Filing date: 2022-01-29
Publication date: 2022-04-12

Abstract

A double-stage compression oilless air compressor comprises a motor shell, a motor shaft, a first-stage crankcase, a second-stage crankcase, a side cylinder cover, a cooler, a first-stage air cylinder assembly and a second-stage air cylinder assembly which are matched with each other; the motor shell, the first-stage crankcase and the second-stage crankcase are of an integrated structure, and a side cylinder cover is hermetically arranged on the outer side of the motor shell; an air inlet pipeline is integrally arranged on the motor shell, air enters the secondary crankcase from an air inlet of the secondary crankcase, is communicated with an air inlet pipeline on the motor shell through an air outlet, enters the primary crankcase from an air inlet on the primary crankcase, and is discharged into the primary air cylinder assembly from an air outlet; the compressed gas is discharged from the exhaust port of the second-stage compression air cylinder component after flowing out of the first-stage air cylinder component after being compressed and then entering the cooler through the connecting pipe to be cooled and then entering the second-stage air cylinder component to be compressed again.

Description

Two-stage compression oilless air compressor

Technical Field

The invention relates to the field of oil-free air compressors, in particular to a two-stage compression oil-free air compressor.

Background

An air compressor, i.e., an air compressor, is a device for compressing gas. Among them, the air compressor of the reciprocating piston type structure is the most common one; the principle of the reciprocating piston type air compressor is that a rotating shaft is driven by a motor to rotate so as to drive an eccentric wheel, a piston connecting rod assembly is arranged on the eccentric wheel, a driving piston reciprocates in a closed space to generate pressure intensity change, and the closed space consists of an air cylinder and a valve plate; the air enters from the piston and exits from the valve plate, and finally high-pressure air is generated.

The existing oilless air compressor has the following defects:

1. most of the existing air compressors are single-stage compression, so that the power consumption ratio is high, the utilization rate of the cylinder volume is low, and the exhaust temperature is also high.

2. The motor end cover and the crankcase of the existing oilless air compressor are connected in a split mode, so that the assembly accuracy requirement is high, the error is large, and the strength is low.

3. Most of the existing motor casings of oil-free air compressors adopt a die-casting forming process, the structure is complex, the porosity is high, and the cost is high.

4. Most of the existing oil-free air compressor cooling fans are positioned on the bottom plate, and the cooling effect on the cylinder and the top cylinder cover is not high;

5. the existing cooler fan for the air compressor does not directly radiate heat of the cooling air passage, so that the cooling efficiency of the cooling air passage is not high;

6. the existing eccentric wheel of the air compressor is inconvenient to disassemble and assemble, is not easy to replace due to the adoption of riveting, interference fit and other modes, and is high in maintenance cost.

7. The existing air compressor cylinder body has poor wear resistance and high temperature resistance, so that the cylinder and the piston are seriously abraded and need to be frequently replaced.

Disclosure of Invention

The invention aims to solve the problems in the prior art and provides a two-stage compression oil-free air compressor which is simple and compact in structure, attractive in appearance and low in cost.

In order to achieve the purpose, the technical scheme of the invention is as follows:

a double-stage compression oilless air compressor comprises a motor shell, a motor shaft, a first-stage crankcase, a second-stage crankcase, a side cylinder cover, a cooler, a first-stage air cylinder assembly and a second-stage air cylinder assembly which are matched with each other; the motor shell, the first-stage crankcase and the second-stage crankcase are of an integrated structure, the first-stage crankcase and the second-stage crankcase are directly and fixedly arranged on the left side and the right side of the motor shell, and side cylinder covers are arranged on the outer sides of the first-stage crankcase and the second-stage crankcase in a sealing mode; an air inlet pipeline is integrally arranged on the motor shell, an air inlet and an air outlet are arranged on the secondary crankcase, an air inlet and an air outlet are arranged on the primary crankcase, the air inlet pipeline is respectively communicated with the air outlet on the secondary crankcase and an air inlet on the primary crankcase, air enters the secondary crankcase from the air inlet of the secondary crankcase and is communicated with the air inlet on the motor shell through the air outlet, the air enters the primary crankcase from the air inlet on the primary crankcase, and the air is discharged into the primary cylinder assembly from the air outlet; the cooler is connected to the first-stage air cylinder assembly through the connecting pipe, the second-stage air cylinder assembly is connected to the cooler, the second-stage air cylinder assembly is matched with the second-stage crankcase, and compressed air is discharged from an air outlet of the second-stage compression air cylinder assembly after flowing out of the first-stage air cylinder assembly after being compressed and then entering the cooler through the connecting pipe to be cooled and compressed again.

Further, a first ring groove is additionally arranged around a matching air port of the first-stage crankcase, the second-stage crankcase and the motor shell, and an O-shaped ring is placed in the first ring groove to improve the sealing property; the first-stage crankcase, the second-stage crankcase and the side cylinder cover are matched with one another to form a second annular groove, and the O-shaped ring is placed in the second annular groove to improve gas tightness; bearing positions for mounting motor bearings are arranged at the matching positions of the first-stage crankcase and the second-stage crankcase and the motor shaft, and bearing sleeves are additionally arranged outside the motor bearings and used for connecting the crankcase and the motor bearings in a transition mode; a bottom plate mounting hole is formed in the first-stage crankcase and the second-stage crankcase and used for fixing a bottom plate bracket; the shock pad is fixed on the bottom plate support.

Further, a motor shaft is matched with the eccentric wheel assembly, the motor drives the eccentric wheel assemblies on the sides of the primary crank case and the secondary crank case to act through the motor shaft respectively, and the eccentric wheel assembly drives the piston connecting rod assembly to act in the primary air cylinder assembly and the secondary air cylinder assembly; the eccentric wheel assembly comprises an eccentric wheel and an eccentric wheel bearing which are matched with each other; the piston connecting rod component comprises a piston head, a piston ring, a connecting rod bearing and a connecting rod which are mutually matched; the eccentric wheel and the motor shaft are in clearance fit and fastened by bolts, the eccentric wheel is in a large-shaped structure, and the motor shaft is locked by the bolts in a clamping mode so as to improve the fastening performance and stability of the motor shaft; the eccentric wheel bearing and the connecting rod are in clearance fit, the big end of the connecting rod is cut to form a notch, a limiting hole is formed in the notch, a limiting column is arranged in the notch, and the notch is tightly clamped through a bolt to enable the eccentric wheel bearing and the connecting rod to be tightly matched and fixed.

Further, the first-stage air cylinder assembly and the second-stage air cylinder assembly respectively comprise a cylinder body, a valve plate, a top cylinder cover and a piston connecting rod assembly which are matched with each other, the inner diameter of the cylinder body adopts a micro-arc oxidation process, a ceramic layer is plated on the surface of the inner wall of the cylinder body, and heat dissipation ribs outside the cylinder body and the top cylinder cover are transversely distributed.

Further, the secondary cylinder assembly comprises a top cylinder cover, a valve plate, a first sealing element, a second sealing element, a cylinder body and a piston connecting rod assembly which are matched with each other; wherein, a hollow inner cavity is formed in the middle of the cylinder body, and the piston connecting rod assembly is arranged in the hollow inner cavity and reciprocates up and down along the hollow inner cavity; the valve plate is arranged above the cylinder body, a sealing piece is arranged at the matching position of the valve plate and the cylinder body and is in sealing fit with the cylinder body, a gas inlet hole group and a gas outlet hole group are respectively arranged at two sides of the valve plate, a gas inlet control assembly is arranged on the lower surface of the valve plate in a matching way in the gas inlet hole group, and a gas outlet control assembly is arranged on the upper surface of the valve plate in a matching way in the gas outlet hole group; the top cylinder cover is arranged above the valve plate, a sealing element is arranged at the matching position of the top cylinder cover and the valve plate in a sealing fit mode, an inner cavity of the top cylinder cover is separated by a partition plate to form an air inlet cavity and an air outlet cavity, the air inlet cavity is communicated with an air inlet hole of the valve plate when the air inlet hole is opened, the air outlet cavity is communicated with an air outlet hole of the valve plate when the air outlet hole is opened, air inlet ports communicated with the air inlet cavity and air outlet ports communicated with the air outlet cavity are arranged on two sides of the top cylinder cover respectively, and air is fed through the air inlet ports and the cooler.

Furthermore, the cooler is arranged at the top of the motor shell, namely the middle of the cylinder body of the primary cylinder assembly and the cylinder body of the secondary cylinder assembly, and comprises a cooler body, and the left side and the right side of the cooler body are respectively provided with a cooling fan; cooler body one side is equipped with the entry, and one side is equipped with the export, and the entry is connected with the connecting pipe and is admitted air, and the export is given vent to anger with second grade cylinder subassembly intercommunication, forms the ventiduct in the middle of the cooler body is inside, and the ventiduct both sides form left air flue and right air flue respectively, and the inlet chamber of controlling the air flue is linked together and receives the connecting tube internal gas with the entry intercommunication, and the outlet chamber of controlling the air flue is linked together and flows out through refrigerated gas to the second grade cylinder subassembly in with the export intercommunication.

Furthermore, in the secondary cylinder component, the bottom of the top cylinder cover is provided with a groove, and the valve plate is placed in the groove; o-shaped ring grooves I are arranged on the top surfaces of the grooves and the bottom surface of the partition plate, and the two O-shaped rings I are arranged in the O-shaped ring grooves to ensure the tightness of the air inlet cavity, the air outlet cavity and the valve plate; the air inlet hole group and the air outlet hole group on the valve plate are respectively formed by a group of semicircular round holes; the air outlet control assembly comprises a first bolt, a pressing plate and an air outlet valve plate which are matched with each other, one end of the pressing plate and one end of the air outlet valve plate are fixed on the valve plate by the first bolt, the other end of the pressing plate and the other end of the air outlet valve plate cover the air outlet hole group, and the direction of the first bolt is towards the side of the top cylinder cover; the air inlet control assembly comprises a bolt II and an air inlet valve plate which are matched with each other; one end of the air inlet valve plate is fixed on the valve plate by a second bolt, and the other end of the air inlet valve plate covers the air inlet hole group and is installed towards the side of the piston chamber; the air inlet valve plate and the air outlet valve plate are of fan-shaped structures; and a second O-shaped ring groove is formed in the position, matched with the valve plate, of the cylinder body, and the second O-shaped ring is arranged in the second O-shaped ring groove and used for sealing the cylinder body and the valve plate.

Furthermore, the cooling fan is detachably fixed on the left side and the right side of the cooler body by bolts; the left air passage is communicated with an air inlet chamber of the right air passage and is connected with the air inlet chamber of the right air passage by a first hinge bolt; the air outlet chambers of the left air passage and the right air passage are communicated and connected by a second hinge bolt; two sides of the air duct are provided with mesh enclosures.

By adopting the technical scheme, the invention has the following advantages:

1. the air inlet pipeline is integrally formed on the motor shell of the air compressor, so that the whole air compressor is simple and compact in structure, attractive in appearance and low in cost. With the air inlet pipeline integration on the motor casing, motor casing surface temperature can be taken away during the gas circulation, cools down the motor casing.

2. The air compressor motor shell is formed by a deep drawing process, so that the structural strength is optimized, air holes are reduced, and the cost is reduced. The motor end cover and the crankcase are of an integrated structure, the motor end cover is omitted, assembly errors are reduced, strength is improved, and cost is reduced.

3. The crankcase and the motor casing are integrally designed, so that the side end cover of the motor is integrated on the crankcase, the assembly error is reduced, the strength is high, the assembly procedures are reduced, the production efficiency is improved, the cost is reduced, and the vibration and the noise of the whole machine are optimized;

4. the sealing structure is sealed by the O-shaped ring, the sealing effect is good, the assembly is simple and convenient, and the noise is reduced.

5. The eccentric wheel and the motor shaft are matched in a clearance fit mode, and the bolt is fastened, so that the eccentric wheel is easy to replace, disassemble and assemble, and the maintenance cost is reduced.

6. The eccentric wheel and the connecting rod are locked by bolts, so that the assembly, disassembly and maintenance are easy.

7. The cylinder body adopts a micro-arc oxidation process, and a ceramic layer is plated on the surface of the cylinder body, so that the wear resistance of the cylinder body is improved, the high temperature type is realized, the faults are reduced, and the maintenance cost is reduced.

8. The cooler is arranged between the first-stage cylinder and the second-stage cylinder, namely at the top of the motor shell, the fan is arranged beside the cooling air passage, so that the fan can radiate the cooling air passage and the cylinder body at the same time, and the cooling efficiency is optimized.

9. And the secondary compression adopts a valve plate air inlet and outlet mode, namely, the air enters the piston from the valve plate assembly and is compressed and then flows out of the valve plate assembly, so that the air leakage can be reduced, and the efficiency is improved.

Drawings

FIG. 1 is a schematic exploded view of the present invention;

FIG. 2 is a schematic view of the motor mount of the present invention in cooperation with a crankcase;

FIG. 3 is a schematic view of the eccentric shaft of the present invention in combination with a piston-link assembly;

FIG. 4 is a schematic view of a two-stage cylinder assembly of the present invention;

FIG. 5 is a first schematic view of a valve plate structure of the two-stage cylinder assembly of the present invention;

FIG. 6 is a second schematic view of a valve plate structure of the two-stage cylinder assembly of the present invention;

FIG. 7 is a first schematic view of the construction of the cooler of the present invention;

fig. 8 is a schematic view of the structure of the cooler of the present invention.

Detailed Description

In order to further explain the technical solution of the present invention, the present invention is explained in detail by the following specific examples.

As shown in fig. 1-8, a two-stage compression oilless air compressor comprises a motor casing 1, a motor shaft 2, a first-stage crankcase 3, a second-stage crankcase 4, a side cylinder cover 5, a cooler 6, a first-stage cylinder assembly 7, a connecting pipe 8 and a second-stage cylinder assembly 9 which are matched with each other; the motor shell 1, the first-stage crankcase 3 and the second-stage crankcase 4 are of an integrated structure, the first-stage crankcase 3 and the second-stage crankcase 4 are directly and fixedly installed on the left side and the right side of the motor shell 1, and the outer sides of the first-stage crankcase 3 and the second-stage crankcase 4 are hermetically provided with side cylinder covers 5; an air inlet pipeline 1-1 is integrally arranged on the motor shell 1, an air inlet 41 and an air outlet 42 are arranged on the secondary crankcase 4, an air inlet 31 and an air outlet (not shown in the figure) are arranged on the primary crankcase 3, the air inlet pipeline 1-1 is respectively communicated with the air outlet 42 on the secondary crankcase 4 and the air inlet 31 on the primary crankcase 3, air enters the secondary crankcase 4 from the air inlet 41 of the secondary crankcase, is communicated with the air inlet pipeline 1-1 on the motor shell from the air inlet 31 on the primary crankcase 3 through the air outlet 42, enters the primary crankcase 3 from the air inlet 31 on the primary crankcase 3 and is exhausted into the primary cylinder assembly 7 through the air outlet; the first-level air cylinder assembly 7 is connected with the cooler 6 through the connecting pipe 8, the cooler 6 is connected with the second-level air cylinder assembly 9, the second-level air cylinder assembly 9 is matched with the second-level crankcase 4, and air flows out after being compressed by the first-level air cylinder assembly 7 and then enters the cooler 6 through the connecting pipe 8 to be cooled and then enters the second-level air cylinder assembly 9 to be compressed again, and then compressed air is discharged from the exhaust port 91 of the second-level compression air cylinder assembly.

Further, a first ring groove 32 is additionally arranged around a matching air port of the first-stage crankcase 3, the second-stage crankcase 4 and the motor shell 1, and an O-shaped ring 33 is placed in the first ring groove 32 to improve the sealing performance (the structure of the second-stage crankcase is the same as that of the first-stage crankcase); the first-stage crankcase 3, the second-stage crankcase 4 and the side cylinder cover are matched and arranged with a second ring groove, and an O-shaped ring second 34 is placed in the second ring groove to improve gas tightness (the structure of the second-stage crankcase is the same as that of the first-stage crankcase); bearing positions 35 for mounting motor bearings 21 are arranged at the positions, matched with the motor shaft 2, of the first-stage crankcase 3 and the second-stage crankcase 4, and bearing sleeves 22 for connecting the crankcase and the motor bearings in a transition mode are additionally arranged outside the motor bearings 21 (the structure of the second-stage crankcase is the same as that of the first-stage crankcase); the first-stage crankcase 3 and the second-stage crankcase 4 are provided with bottom plate mounting holes for fixing the bottom plate bracket 36; the cushion 37 is fixed to the floor bracket 36 (the second stage crankcase is identical in construction to the first stage crankcase).

Further, a motor shaft 2 is matched with an eccentric wheel assembly 10, the motor drives the eccentric wheel assemblies 10 on the sides of the first-stage crankcase 3 and the second-stage crankcase 4 to act through the motor shaft 2 respectively, and the eccentric wheel assemblies 10 drive a piston connecting rod assembly 11 to act in a first-stage air cylinder assembly 7 and a second-stage air cylinder assembly 9; the eccentric wheel assembly 10 comprises an eccentric wheel 101 and an eccentric wheel bearing 102 which are matched with each other; the piston connecting rod assembly 11 comprises a piston head 111, a piston ring 112, a connecting rod bearing 113 and a connecting rod 114 which are matched with each other; the eccentric wheel 101 is in clearance fit with the motor shaft 2 and is fastened by bolts, the eccentric wheel 101 is in a large-shaped structure, and the bolts are fastened by clamping to lock the motor shaft so as to improve the fastening performance and stability of the motor shaft; the eccentric wheel bearing 102 is in clearance fit with the connecting rod 114, the big end of the connecting rod 114 is cut to form a notch, a limiting hole is arranged in the notch to accommodate a limiting column 115, and the notch is clamped through a bolt 116 to enable the eccentric wheel bearing 102 and the connecting rod 114 to be tightly matched and fixed.

Further, the first-stage air cylinder assembly 7 and the second-stage air cylinder assembly 9 respectively comprise a cylinder body, a valve plate, a top cylinder cover and a piston connecting rod assembly which are matched with each other, the inner diameter of the cylinder body adopts a micro-arc oxidation process, a ceramic layer is plated on the surface of the inner wall of the cylinder body, and heat dissipation ribs outside the cylinder body and the top cylinder cover are transversely distributed.

Further, the secondary cylinder assembly 9 comprises a top cylinder cover 91, a valve plate 92, a first sealing element 93, a second sealing element 94, a cylinder body 95 and a piston connecting rod assembly 11 which are matched with each other; wherein, a hollow cavity 951 is formed in the middle of the cylinder body 95, and the piston connecting rod assembly 11 is arranged in the hollow cavity and reciprocates up and down along the hollow cavity; the valve plate 92 is arranged above the cylinder body 95, a sealing piece 93 is arranged at the matching position of the valve plate 92 and the cylinder body 95 and is in sealing fit (the sealing piece is an O-shaped ring), an air inlet hole group 921 and an air outlet hole group 922 are respectively arranged on two sides of the valve plate 92, an air inlet control assembly 923 is arranged on the lower surface of the valve plate 92 in the air inlet hole group 921 in a matching manner, and an air outlet control assembly 924 is arranged on the upper surface of the valve plate in the air outlet hole group 922 in a matching manner; the bottom of the top cylinder cover 91 is provided with a groove 916, the valve plate 92 is placed in the groove 916, the matching position of the top cylinder cover 91 and the valve plate 92 is provided with a sealing element two 94 in sealing fit (the sealing element is an O-shaped ring), the inner cavity of the top cylinder cover 91 is separated by a partition board 911 to form an air inlet cavity 912 and an air outlet cavity 913, the air inlet cavity 912 is communicated with the air inlet hole of the valve plate 92 when the air inlet hole is opened, the air outlet cavity 913 is communicated with the air outlet hole of the valve plate 92 when the air outlet hole is opened, the two sides of the top cylinder cover 91 are respectively provided with an air inlet port 914 communicated with the air inlet cavity and an air outlet port 915 communicated with the air outlet cavity, and the air inlet port 914 is communicated with the cooler 6.

The air outlet control component 924 comprises a first bolt 9241, a pressure plate 9242 and an air outlet valve sheet 9243 which are matched with each other, one end of the pressure plate 9242 and one end of the air outlet valve sheet 9243 are fixed on the valve plate 92 by the first bolt 9241, the other end of the air outlet valve sheet 9243 covers the air outlet hole group 922, and the direction of the air outlet control component is towards the side of the top cylinder cover; the air inlet control assembly 923 comprises a second bolt 9231 and an air inlet valve plate 9232 which are matched with each other; one end of the air inlet valve plate 9232 is fixed on the valve plate 92 by the second bolt 9231, and the other end covers the air inlet hole group 921 and is installed towards the piston chamber side; the inlet valve plate 9232 and the outlet valve plate 9243 are fan-shaped structures

Further, the cooler 6 is arranged at the top of the motor casing 1, namely in the middle of the cylinder bodies of the primary cylinder assembly 7 and the secondary cylinder assembly 9, and comprises a cooler body 61, and cooling fans 62 are respectively arranged at the left side and the right side of the cooler body 61; an inlet 611 is arranged at one side of the cooler body 61, an outlet (not shown) is arranged at one side of the cooler body 61, the inlet 611 is connected with the connecting pipe 8 for air inlet, the outlet is communicated with the secondary cylinder assembly 9 for air outlet, a ventilation channel 612 is formed in the middle of the inside of the cooler body 61, a left air channel 613 and a right air channel 614 are respectively formed at two sides of the ventilation channel 612, an air inlet chamber 615 of the left air channel and an air inlet chamber 615 of the right air channel are communicated with each other and are communicated with the inlet 611 for receiving air in the connecting pipe 8, and air outlet chambers 616 of the left air channel and the right air channel are communicated with the outlet for flowing cooled air into the secondary cylinder assembly 9.

Cooling fans 62 are detachably fixed to the left and right sides of the cooler body 61 by bolts; the left air passage is communicated with an air inlet chamber of the right air passage by a hinge bolt I617 for connection; the air outlet chambers of the left air passage and the right air passage are communicated and connected by adopting a second hinge bolt 618; mesh enclosure 619 is provided on both sides of the air duct.

When the gas compressor works, the gas secondary crankcase enters the primary crankcase through the gas inlet pipeline on the motor shell, is subjected to primary compression through the primary cylinder assembly, then enters the cooler from the primary top cylinder cover for cooling, then flows into the secondary top cylinder cover, enters the secondary cylinder assembly for secondary compression, and finally is used for outputting compressed gas from the top cylinder cover of the secondary cylinder assembly.

The air inlet pipeline is integrally formed on the motor shell of the air compressor, so that the whole air compressor is simple and compact in structure, attractive in appearance and low in cost. With the air inlet pipeline integration on the motor casing, motor casing surface temperature can be taken away during the gas circulation, cools down the motor casing.

The air compressor motor shell is formed by a deep drawing process, so that the structural strength is optimized, air holes are reduced, and the cost is reduced. The motor end cover and the crankcase are of an integrated structure, the motor end cover is omitted, assembly errors are reduced, strength is improved, and cost is reduced.

The crankcase and the motor casing are integrally designed, so that the side end cover of the motor is integrated on the crankcase, the assembly error is reduced, the strength is high, the assembly procedures are reduced, the production efficiency is improved, the cost is reduced, and the vibration and the noise of the whole machine are optimized; the sealing structure is sealed by the O-shaped ring, the sealing effect is good, the assembly is simple and convenient, and the noise is reduced.

The eccentric wheel and the motor shaft are matched in a clearance fit mode, and the bolt is fastened, so that the eccentric wheel is easy to replace, disassemble and assemble, and the maintenance cost is reduced. The eccentric wheel and the connecting rod are locked by bolts, so that the assembly, disassembly and maintenance are easy. The cylinder body adopts a micro-arc oxidation process, and a ceramic layer is plated on the surface of the cylinder body, so that the wear resistance of the cylinder body is improved, the high temperature type is realized, the faults are reduced, and the maintenance cost is reduced.

The cooler is arranged between the first-stage cylinder and the second-stage cylinder, namely at the top of the motor shell, the fan is arranged beside the cooling air passage, so that the fan can radiate the cooling air passage and the cylinder body at the same time, and the cooling efficiency is optimized. And the secondary compression adopts a valve plate air inlet and outlet mode, namely, the air enters the piston from the valve plate assembly and is compressed and then flows out of the valve plate assembly, so that the air leakage can be reduced, and the efficiency is improved.

While the foregoing description shows and describes the preferred embodiments of the present invention, it is to be understood that the invention is not limited to the forms disclosed herein, but is not to be construed as excluding other embodiments and is capable of use in various other combinations, modifications, and environments and is capable of changes within the scope of the inventive concept as described herein, commensurate with the above teachings, or the skill or knowledge of the relevant art. And that modifications and variations may be effected by those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A two-stage compression oilless air compressor is characterized by comprising a motor shell, a motor shaft, a first-stage crankcase, a second-stage crankcase, a side cylinder cover, a cooler, a first-stage air cylinder assembly and a second-stage air cylinder assembly which are matched with each other; the motor shell, the first-stage crankcase and the second-stage crankcase are of an integrated structure, the first-stage crankcase and the second-stage crankcase are directly and fixedly arranged on the left side and the right side of the motor shell, and side cylinder covers are arranged on the outer sides of the first-stage crankcase and the second-stage crankcase in a sealing mode; an air inlet pipeline is integrally arranged on the motor shell, an air inlet and an air outlet are arranged on the secondary crankcase, an air inlet and an air outlet are arranged on the primary crankcase, the air inlet pipeline is respectively communicated with the air outlet on the secondary crankcase and an air inlet on the primary crankcase, air enters the secondary crankcase from the air inlet of the secondary crankcase and is communicated with the air inlet on the motor shell through the air outlet, the air enters the primary crankcase from the air inlet on the primary crankcase, and the air is discharged into the primary cylinder assembly from the air outlet; the cooler is connected to the first-stage air cylinder assembly through the connecting pipe, the second-stage air cylinder assembly is connected to the cooler, the second-stage air cylinder assembly is matched with the second-stage crankcase, and compressed air is discharged from an air outlet of the second-stage compression air cylinder assembly after flowing out of the first-stage air cylinder assembly after being compressed and then entering the cooler through the connecting pipe to be cooled and compressed again.

2. An oil-free air compressor with two-stage compression as claimed in claim 1, wherein: a first ring groove is additionally formed around a matching air port of the first-stage crankcase, the second-stage crankcase and the motor shell, and an O-shaped ring is placed in the first ring groove to improve the sealing property; the first-stage crankcase, the second-stage crankcase and the side cylinder cover are matched with one another to form a second annular groove, and the O-shaped ring is placed in the second annular groove to improve gas tightness; bearing positions for mounting motor bearings are arranged at the matching positions of the first-stage crankcase and the second-stage crankcase and the motor shaft, and bearing sleeves are additionally arranged outside the motor bearings and used for connecting the crankcase and the motor bearings in a transition mode; a bottom plate mounting hole is formed in the first-stage crankcase and the second-stage crankcase and used for fixing a bottom plate bracket; the shock pad is fixed on the bottom plate support.

3. A two-stage compression oil-free air compressor as claimed in claim 1 or 2, wherein: the motor shaft is matched with the eccentric wheel assembly, the motor drives the eccentric wheel assemblies on the sides of the first-stage crankcase and the second-stage crankcase to act through the motor shaft respectively, and the eccentric wheel assembly drives the piston connecting rod assembly to act in the first-stage air cylinder assembly and the second-stage air cylinder assembly; the eccentric wheel assembly comprises an eccentric wheel and an eccentric wheel bearing which are matched with each other; the piston connecting rod component comprises a piston head, a piston ring, a connecting rod bearing and a connecting rod which are mutually matched; the eccentric wheel and the motor shaft are in clearance fit and fastened by bolts, the eccentric wheel is in a large-shaped structure, and the motor shaft is locked by the bolts in a clamping mode so as to improve the fastening performance and stability of the motor shaft; the eccentric wheel bearing and the connecting rod are in clearance fit, the big end of the connecting rod is cut to form a notch, a limiting hole is formed in the notch, a limiting column is arranged in the notch, and the notch is tightly clamped through a bolt to enable the eccentric wheel bearing and the connecting rod to be tightly matched and fixed.

4. A two-stage compression oil-free air compressor as claimed in claim 1 or 2, wherein: the first-stage air cylinder assembly and the second-stage air cylinder assembly respectively comprise a cylinder body, a valve plate, a top cylinder cover and a piston connecting rod assembly which are matched with each other, the inner diameter of the cylinder body adopts a micro-arc oxidation process, a ceramic layer is plated on the surface of the inner wall of the cylinder body, and heat dissipation ribs outside the cylinder body and the top cylinder cover are transversely distributed.

5. An oil-free air compressor with two-stage compression as claimed in claim 4, wherein: the secondary air cylinder assembly comprises a top cylinder cover, a valve plate, a first sealing piece, a second sealing piece, a cylinder body and a piston connecting rod assembly which are matched with each other; wherein, a hollow inner cavity is formed in the middle of the cylinder body, and the piston connecting rod assembly is arranged in the hollow inner cavity and reciprocates up and down along the hollow inner cavity; the valve plate is arranged above the cylinder body, a sealing piece is arranged at the matching position of the valve plate and the cylinder body and is in sealing fit with the cylinder body, a gas inlet hole group and a gas outlet hole group are respectively arranged at two sides of the valve plate, a gas inlet control assembly is arranged on the lower surface of the valve plate in a matching way in the gas inlet hole group, and a gas outlet control assembly is arranged on the upper surface of the valve plate in a matching way in the gas outlet hole group; the top cylinder cover is arranged above the valve plate, a sealing element is arranged at the matching position of the top cylinder cover and the valve plate in a sealing fit mode, an inner cavity of the top cylinder cover is separated by a partition plate to form an air inlet cavity and an air outlet cavity, the air inlet cavity is communicated with an air inlet hole of the valve plate when the air inlet hole is opened, the air outlet cavity is communicated with an air outlet hole of the valve plate when the air outlet hole is opened, air inlet ports communicated with the air inlet cavity and air outlet ports communicated with the air outlet cavity are arranged on two sides of the top cylinder cover respectively, and air is fed through the air inlet ports and the cooler.

6. A two-stage compression oil-free air compressor as claimed in claim 1 or 2, wherein: the cooler is arranged at the top of the motor shell, namely the middle of the cylinder bodies of the first-stage air cylinder assembly and the second-stage air cylinder assembly and comprises a cooler body, and cooling fans are respectively arranged at the left side and the right side of the cooler body; cooler body one side is equipped with the entry, and one side is equipped with the export, and the entry is connected with the connecting pipe and is admitted air, and the export is given vent to anger with second grade cylinder subassembly intercommunication, forms the ventiduct in the middle of the cooler body is inside, and the ventiduct both sides form left air flue and right air flue respectively, and the inlet chamber of controlling the air flue is linked together and receives the connecting tube internal gas with the entry intercommunication, and the outlet chamber of controlling the air flue is linked together and flows out through refrigerated gas to the second grade cylinder subassembly in with the export intercommunication.

7. An oil-free air compressor with two-stage compression as claimed in claim 5, wherein: in the second-stage cylinder assembly, a groove is formed in the bottom of the top cylinder cover, and the valve plate is placed in the groove; o-shaped ring grooves I are arranged on the top surfaces of the grooves and the bottom surface of the partition plate, and the two O-shaped rings I are arranged in the O-shaped ring grooves to ensure the tightness of the air inlet cavity, the air outlet cavity and the valve plate; the air inlet hole group and the air outlet hole group on the valve plate are respectively formed by a group of semicircular round holes; the air outlet control assembly comprises a first bolt, a pressing plate and an air outlet valve plate which are matched with each other, one end of the pressing plate and one end of the air outlet valve plate are fixed on the valve plate by the first bolt, the other end of the pressing plate and the other end of the air outlet valve plate cover the air outlet hole group, and the direction of the first bolt is towards the side of the top cylinder cover; the air inlet control assembly comprises a bolt II and an air inlet valve plate which are matched with each other; one end of the air inlet valve plate is fixed on the valve plate by a second bolt, and the other end of the air inlet valve plate covers the air inlet hole group and is installed towards the side of the piston chamber; the air inlet valve plate and the air outlet valve plate are of fan-shaped structures; and a second O-shaped ring groove is formed in the position, matched with the valve plate, of the cylinder body, and the second O-shaped ring is arranged in the second O-shaped ring groove and used for sealing the cylinder body and the valve plate.

8. An oil-free air compressor with two-stage compression as claimed in claim 6, wherein: the cooling fan is detachably fixed on the left side and the right side of the cooler body by bolts; the left air passage is communicated with an air inlet chamber of the right air passage and is connected with the air inlet chamber of the right air passage by a first hinge bolt; the air outlet chambers of the left air passage and the right air passage are communicated and connected by a second hinge bolt; two sides of the air duct are provided with mesh enclosures.