CN113374670A

CN113374670A - Air compressor

Info

Publication number: CN113374670A
Application number: CN202110747824.5A
Authority: CN
Inventors: 吴学瑞; 郭宗斌; 郭凯江; 王令军; 秦东宾; 涂贵军; 张振超; 黄士伟; 张庆金
Original assignee: Qingdao SRI Technology Co Ltd
Current assignee: Qingdao SRI Technology Co Ltd
Priority date: 2021-07-01
Filing date: 2021-07-01
Publication date: 2021-09-10

Abstract

The application discloses air compressor includes: a crankcase, inside which a crankshaft assembly is arranged; two high-pressure cylinder assemblies correspondingly arranged on two sides of the crank case and connected to the crank shaft assembly; two low-pressure cylinder assemblies correspondingly arranged on two sides of the crank case and connected to the crank shaft assembly; the motor, connect in the bent axle subassembly through elastic coupling, the motor starts to drive the rotatory back of bent axle subassembly through elastic coupling, carries out the one-level compression to inspiratory ambient air through low pressure cylinder subassembly, and ambient air gets into intercooler cooling after the one-level compression, and rethread high pressure cylinder subassembly carries out the second grade compression to the ambient air after one-level compression and cooling, and ambient air gets into aftercooler cooling after the second grade compression, final output compressed air. The buffering chamber is arranged in front of the crankcase, so that the air suction buffering volume is further increased, and the air suction noise is reduced.

Description

Air compressor

Technical Field

The invention belongs to the field of air compressors, and particularly relates to an air compressor.

Background

Compared with the traditional oil-containing air compressor, the oil-containing air compressor has the advantages of environmental protection, less maintenance parts, high compressed air quality, wide adaptation working condition and the like. In recent years, with the development of oil-free lubrication material technology, rail vehicles at home and abroad are gradually configured with oil-free air compressors, but the oil-free air compressors still belong to the 'neck' technology at home and abroad for China due to the late start of related technologies at home.

In recent years, some companies in China continuously develop research and development work of oil-free piston type air compressors for rail transit vehicles, but in the test process, a series of problems that the developed model machines have high noise, high vibration, easy abrasion of piston rings and the like are found, and the technical indexes of the rail vehicles cannot be met or the performance difference between the model machines and foreign similar products is large. The main reason for these problems is that the domestic oil-free piston type air compressor basically adopts the horizontally opposed three-cylinder compression (two low pressure cylinders and one high pressure cylinder) or the X-type arranged four-cylinder compression or the V-type arranged four-cylinder compression, and these three arrangements are influenced by the internal structure design, fail to balance the internal vibration well, and also cause the vibration noise of the unit. Meanwhile, the compression structure adopted by the oil-free piston type air compressor developed at home at present still refers to the structural form of the traditional oil lubrication piston, only the piston ring and the guide ring are replaced by products made of self-lubricating materials, and systematic design on the oil-free piston type air compressor is lacked, so that the performance of the oil-free air compressor developed at home is poor.

Disclosure of Invention

The embodiment of the application provides an air compressor to at least, solve current air compressor and lack the problem that carries out systematic design to oil-free lubrication air compressor.

The invention provides an air compressor, which comprises:

a crankcase, inside which a crankshaft assembly is arranged;

the two high-pressure cylinder assemblies are correspondingly arranged on two sides of the crankcase and are connected with the crankshaft assembly;

two low-pressure cylinder assemblies correspondingly arranged on two sides of the crankcase and connected to the crankshaft assembly;

the motor through elastic coupling connect in the bent axle subassembly, the motor starts to pass through elastic coupling drives the rotatory back of bent axle subassembly, through low pressure cylinder subassembly carries out the one-level compression to inspiratory ambient air, and ambient air gets into intercooler cooling behind the one-level compression, and the rethread high pressure cylinder subassembly carries out the second grade compression to the ambient air after one-level compression and cooling, and the ambient air gets into aftercooler cooling behind the second grade compression, finally exports compressed air.

The air compressor further includes:

the buffer chamber is communicated with the crankcase, the air suction guide pipe and the air filter, the air suction guide pipe is arranged on the air filter, the air filter is communicated with the buffer chamber, the ambient air sequentially passes through the air suction guide pipe, the air filter for filtering, the buffer chamber and the crankcase, enters the low-pressure cylinder assembly for primary compression and then is output to the intercooler, and the high-pressure cylinder assembly sucks the ambient air cooled by the intercooler for secondary compression and then is cooled and outputs compressed air.

The air compressor, wherein the crankshaft assembly comprises:

the crankshaft, the auxiliary balance block, the connecting rod big end bearing, the main balance block and the bearing retainer ring; the auxiliary balance block and the main balance block are firmly held on the crankshaft through bolts and rotate synchronously with the crankshaft, the large end bearing of the connecting rod is sleeved on the crankshaft, the axial freedom degree of the large end bearing of the connecting rod is restricted by the auxiliary balance block, the main balance block and the bearing retainer ring, and the large end bearing of the connecting rod is connected with the low-pressure cylinder assembly and the high-pressure cylinder assembly.

The above air compressor, wherein, high-pressure cylinder subassembly and low-pressure cylinder subassembly all include:

the valve plate is arranged in a gap between the cylinder barrel and the cylinder cover; the valve plate is fixedly provided with one air inlet valve plate and at least four air outlet valve plates; the exhaust valve plates are uniformly arranged along the circumference of the valve plate, the exhaust valve plates are fixed on the valve plate through bolts and limiting plates, the piston assembly is connected with the needle roller bearing, and the connecting rod is connected with the connecting rod big end bearing.

The air compressor as described above, wherein said piston assembly comprises:

the piston ring is sleeved in a groove at the head of the cladding piston, and two ends of the piston pin are fixed in the cladding piston groove through the function of the elastic retainer ring; the cladding piston and the connecting rod are connected together through the piston pin, the needle roller bearing is arranged between the connecting rod and the piston pin, the shaft seals are arranged at two ends of the needle roller bearing, a gap exists between the cladding piston and the cylinder barrel, so that the piston axially moves in the cylinder barrel, and in the movement process of the cladding piston, the piston ring is expanded between the cladding piston and the cylinder barrel by air pressure, and the sealing between the cladding piston and the cylinder barrel is realized.

The air compressor described above, wherein said clad piston comprises:

the piston comprises a piston base body and a cladding, wherein the cladding is adhered to the piston base body, and the piston base body and the connecting rod are connected together through the piston pin.

The air compressor, wherein the cooling fan is connected to the crankshaft assembly.

The air compressor described above, wherein the cooler includes: and a cooler for cooling the generated compressed air.

The air compressor described above, wherein the cooler includes: the system comprises an intercooler and an aftercooler, wherein the intercooler cools compressed air after primary compression, and the aftercooler cools compressed air after secondary compression.

In the air compressor, the crankcase and the buffer chamber are coated with sound-absorbing damping paint, and the sound-absorbing damping paint can absorb part of noise and reduce the noise transmission inside the compressor.

The invention has the beneficial effects that:

compared with the traditional piston using a guide ring, the clad piston reduces the clearance between the piston and a piston cylinder, enhances the stability of piston motion, further reduces the abrasion of the piston ring, prolongs the service life of the piston ring and reduces noise.

The buffering chamber is arranged in front of the crankcase, so that the air suction buffering volume is further increased, and the air suction noise is reduced.

The crankcase and the buffer chamber of the invention are both coated with sound-absorbing damping paint with the thickness of about 1mm, thus reducing the noise transmission from the interior of the compressor.

According to the invention, the number of the exhaust valve plates in each low-pressure cylinder assembly is more than or equal to 8, the number of the exhaust valve plates in each high-pressure cylinder is more than or equal to 4, and the noise generated in the vibration process of the exhaust valve plates can be reduced by designing not less than the number.

Compared with the traditional straight cutting type, inclined cutting type and stepped piston ring, the airtight piston ring has lower leakage amount and higher compression efficiency of the compressor.

According to the invention, the heat radiating fins are also arranged on the cylinder cover, so that the heat radiating efficiency of the cylinder cover is improved.

According to the invention, the efficiency of the air compressor is increased and the power consumption is reduced by a 2-stage compression intercooling mode.

The invention reduces the stress of the connecting rod, the piston, the bearing and the like by arranging 4 compression cylinders, and improves the service life of the piston.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application.

In the drawings:

FIG. 1 is a structural component of the FIG. 1 oil-free air compressor of the present invention;

FIG. 2 is a block diagram of a crankshaft assembly;

FIG. 3 is a block diagram of a high-pressure cylinder assembly;

FIG. 4 is a block diagram of the low pressure cylinder assembly of the present invention;

in the figure: the device comprises a motor 1, an elastic coupling 2, a crankshaft assembly 3, a high-pressure cylinder assembly 4, a low-pressure cylinder assembly 5, a cooling fan 6, a cooler 7, a crankshaft fixing bearing 8, a crankcase 9, a buffer chamber 10, an air suction duct 11, an air filter 12, a crankshaft 31, an auxiliary balance block 32, a connecting rod big end bearing 33, a main balance block 34, a bearing retainer ring 35, a cylinder barrel 41, an air inlet valve plate 42, a valve plate 43, an exhaust valve plate 44, a cylinder cover 45, a piston ring 46-1, a clad piston 46-2, a piston pin 46-3, an elastic retainer ring 46-4, a needle bearing 47, a shaft seal 48, a connecting rod 49, a cylinder barrel 51, an air inlet valve plate 52, a valve plate 53, an exhaust valve plate 54, a cylinder cover 55, a piston ring 56-1, a clad piston 56-2, a piston 56-3, an elastic retainer ring 56-4, a piston pin bearing 57, a shaft seal 58, a connecting rod 59, a cooler 71, An aftercooler 72.

The first embodiment is as follows:

in order to make the objects, technical solutions and advantages of the present application more apparent, the present application will be described and illustrated below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments provided in the present application without any inventive step are within the scope of protection of the present application.

It is obvious that the drawings in the following description are only examples or embodiments of the present application, and that it is also possible for a person skilled in the art to apply the present application to other similar contexts on the basis of these drawings without inventive effort. Moreover, it should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another.

Reference in the specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the specification. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of ordinary skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments without conflict.

Unless defined otherwise, technical or scientific terms referred to herein shall have the ordinary meaning as understood by those of ordinary skill in the art to which this application belongs. Reference to "a," "an," "the," and similar words throughout this application are not to be construed as limiting in number, and may refer to the singular or the plural. The present application is directed to the use of the terms "including," "comprising," "having," and any variations thereof, which are intended to cover non-exclusive inclusions; for example, a process, method, system, article, or apparatus that comprises a list of steps or modules (elements) is not limited to the listed steps or elements, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus. Reference to "connected," "coupled," and the like in this application is not intended to be limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The term "plurality" as referred to herein means two or more. "and/or" describes an association relationship of associated objects, meaning that three relationships may exist, for example, "A and/or B" may mean: a exists alone, A and B exist simultaneously, and B exists alone. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship. Reference herein to the terms "first," "second," "third," and the like, are merely to distinguish similar objects and do not denote a particular ordering for the objects.

The present invention is described in detail with reference to the embodiments shown in the drawings, but it should be understood that these embodiments are not intended to limit the present invention, and those skilled in the art should understand that functional, methodological, or structural equivalents or substitutions made by these embodiments are within the scope of the present invention.

Before describing in detail the various embodiments of the present invention, the core inventive concepts of the present invention are summarized and described in detail by the following several embodiments.

As shown in fig. 1, the oil-free air compressor according to the present invention mainly comprises a motor 1, an elastic coupling 2, a crankshaft assembly 3, a high-pressure cylinder assembly 4, a low-pressure cylinder assembly 5, a cooling fan 6, a cooler 7, a crankshaft fixed bearing 8, a crankcase 9, a buffer chamber 10, an air intake duct 11, an air cleaner 12, and the like. Wherein the coolers comprise an intercooler 71 and an aftercooler 72. The scheme is characterized in that the cylinder assembly comprises two low-pressure cylinder assemblies 5 and two high-pressure cylinder assemblies 4, the two low-pressure cylinder assemblies 5 and the two high-pressure cylinder assemblies 4 are arranged on two sides of a crank case 9 in a split mode and are horizontally arranged in an opposite mode, and the low-pressure cylinder assemblies 5 and the high-pressure cylinder assemblies 4 are arranged in a staggered mode in the axial direction of a crank shaft. The two low-pressure cylinder assemblies 5 are completely the same except for different arrangement positions, and the high-pressure cylinder assembly 4 has the same structure; the low pressure cylinder assembly 5 and the high pressure cylinder assembly 4 are horizontally opposed so that the unbalanced force during the reciprocating motion of the piston is mainly concentrated in the horizontal direction. Through the staggered arrangement of the high-pressure cylinder assemblies 4 and the low-pressure cylinder assemblies 5, the pistons in the two pairs of high-pressure cylinder assemblies 4 always move in opposite directions, so that the reciprocating forces of the two pistons in the horizontal direction are mutually counteracted, and the same is true for the pistons in the two pairs of low-pressure cylinder assemblies 5; the crankshaft is also provided with a main balance block and an auxiliary balance block, so that the unbalanced force in the rotation process of the crankshaft is further balanced. Through the design, the moving parts in the air compressor run stably, and noise generated by unbalanced movement is reduced. The motor 1 is connected with the crankshaft assembly 3 through the elastic coupling 2, and the other end of the crankshaft assembly 3 is connected with the cooling fan 6; the crankshaft fixing bearings 8 at two ends of the crankcase 9 provide support and fixation for the crankshaft assembly 3; the intake duct 11 is fixed to an air cleaner 12, and the air cleaner 12, the surge tank 10 and the crankcase 9 are connected in series by a pipe. In the scheme, the low-pressure cylinder compression air chamber sucks air into the crankcase 9 through a pipeline, and the crankcase 9 serves as an air suction buffering air chamber and blocks part of aerodynamic noise. A buffer chamber is added outside the crankcase 9, which again counteracts part of the aerodynamic noise by increasing the buffer volume. The inner wall of the crank case 9 and the inner wall of the buffer chamber are both coated with sound-absorbing damping paint with the thickness of about 1mm, the sound-absorbing damping paint can not only prevent the air which is in dynamic vibration from directly colliding with the machine body to cause the machine body to vibrate, but also contains a large number of micropores, and can absorb the noise with different frequencies; the air suction guide pipe is arranged in front of the air inlet of the air filter, the air inlet of the air suction guide pipe is small, air suction resistance is increased, air is stably sucked through the air inlet of the air suction guide pipe in the working process of the air compressor, air suction unbalance is reduced, and accordingly air suction noise of the air compressor is reduced.

As shown in fig. 2, the crankshaft assembly is composed of a crankshaft 31, an auxiliary balance weight 32, a connecting rod big end bearing 33, a main balance weight 34, a bearing retainer 35 and the like. Each of the auxiliary balance weight 32 and the main balance weight 34 is composed of two pieces, and the two pieces are firmly held on the crankshaft 31 by bolts and rotate synchronously with the crankshaft 31. The connecting rod big end bearing 33 is sleeved on the crankshaft 31 to be fixed in the radial direction, and the axial degree of freedom of the connecting rod big end bearing 33 is restrained by the auxiliary balance weight 32, the main balance weight 34 and the bearing retainer ring 35. The crankshaft 31 has two crank shapes, wherein 1 low-

pressure cylinder assembly

5 and 1 high-pressure cylinder assembly 4 share one crank shape, and the rest 1 low-

pressure cylinder assembly

5 and 1 high-pressure cylinder assembly 4 share the other crank shape. According to the working principle, the air suction of the piston type air compressor is related to the motion direction of the piston, namely, the mode of intermittent air suction; intermittent inhalation produces aerodynamic noise.

As shown in FIG. 3, the high-pressure cylinder assembly 4 mainly comprises a cylinder 41, an intake valve plate 42, a valve plate 43, an exhaust valve plate 44, a cylinder cover 45, a piston ring 46-1, a cladding piston 46-2, a piston pin 46-3, a circlip 46-4, a needle bearing 47, a shaft seal 48, a connecting rod 49 and the like. The cylinder barrel 41 and the cylinder cover 45 are connected together through bolts, and the valve plate 43 is placed in a gap between the cylinder barrel 41 and the cylinder cover 45 of the high-low pressure cylinder; the valve plate 43 is fixed with 1 air inlet valve plate 42 and a plurality of air outlet valve plates 44 (the number is more than or equal to 4), the air outlet valve plates 44 are uniformly arranged along the circumference of the valve plate 43, and each air outlet valve plate 44 is fixed on the valve plate 43 through a bolt and a limiting plate; the piston ring 46-1 is sleeved in a groove at the head part of the cladding piston 46-2, and two ends of the piston pin 46-3 are fixed in the piston groove through the action of the elastic retainer ring 46-4; the clad piston 46-2 and the connecting rod 49 are connected together through a piston pin 46-3, a needle bearing 47 is arranged between the connecting rod 49 and the piston pin 46-3, and shaft seals 48 are arranged at two ends of the needle bearing 47. This scheme adopts cladding piston 46-2, forms an holistic guiding layer after the cladding is pasted on the piston base member, compares with traditional guide ring mode, and cladding piston 46-2 guiding area is bigger, and stability is higher. Because the traditional guide ring and the piston are two relatively independent parts and are influenced by factors such as installation fit and the like, the dimensional tolerance of the guide layer is larger, and the guide layer of the cladding piston 46-2 is integrated with the piston after being pasted, the piston can be processed to achieve higher dimensional accuracy, namely the piston moves more stably in the cylinder barrel. The piston ring and the piston cladding in the scheme are both made of the same composite material with polytetrafluoroethylene as a base body, the composite material has a self-lubricating function, and lubricating oil is not needed to be used for lubrication between the piston and the cylinder barrel. The shaft seal 48 is used to prevent the grease (oil) in the needle bearing 47 from overflowing into the inner space, so that the grease can be kept well without adding any lubricating oil during the life cycle. A slight clearance exists between the clad piston 46-2 and the high and low pressure cylinder bores 41 to ensure that the piston 46-2 moves axially within the high and low pressure cylinder bores 41. In the movement process of the piston 46-2, the piston ring 46-1 is expanded between the piston 46-2 and the high-low pressure cylinder barrel 41 by air pressure, so that the sealing between the piston 46-2 and the high-low pressure cylinder barrel 41 is realized; the clad piston 46-2 is composed of a piston base body and a cladding, and the cladding is adhered to the piston base body. This scheme adopts cladding piston 46-2, and the direction function of piston is realized to the cladding of piston base member surface, compares with the independent guide ring of tradition, and cladding piston 46-2 size precision is higher, can make the clearance between piston and the cylinder littleer to make piston motion more steady, the noise is lower.

As shown in FIG. 4, the low-pressure cylinder assembly 5 mainly comprises a cylinder barrel 51, an air inlet valve plate 52, a valve plate 53, an air outlet valve plate 54, a cylinder cover 55, a piston ring 56-1, a cladding piston 56-2, a piston pin 56-3, a circlip 56-4, a needle bearing 57, a shaft seal 58, a connecting rod 59 and the like. The low-pressure cylinder assembly and the high-pressure cylinder assembly are similar in structure and composition, and the sizes of all parts can be the same or slightly different according to specific product design. The inner wall of the cylinder barrel is subjected to micro-arc oxidation, and then the required size and roughness are achieved through grinding, so that the cylinder barrel is more wear-resistant than the traditional hard anodic oxidation. The small-end bearings (needle bearing 47, needle bearing 57) of the connecting rod adopt needle bearings, and shaft seals (shaft seal 48, shaft seal 58) are arranged at the two ends of the bearings to seal the internal lubricating grease (oil) and prevent the lubricating grease (oil) from overflowing.

Through the mode, under the condition that all the pistons and the bearings are well lubricated, the compressed air is not contacted with lubricating grease (oil), and finally the compressed air does not contain oil and does not need to be additionally added with lubricating oil.

Example two:

an air compression method applying the air compressor comprises the following steps: after the motor is started, the motor drives the crankshaft assembly to rotate through the elastic coupling, two crank grooves are formed in the crankshaft, and the crank grooves drive the piston to reciprocate through the connecting rod in the eccentric motion process. When the piston in the low-pressure cylinder assembly moves towards the direction close to the center of the crankcase, the low-pressure cylinder compresses the air chamber to generate negative pressure, and the air inlet valve plate and the air outlet valve plate in the low-pressure cylinder assembly are opened and closed. After the air inlet valve plate is opened, the low-pressure cylinder compression air chamber is communicated with the crank case, the buffer chamber and the air filter, and under the action of atmospheric pressure, air in the environment is filtered by the air suction conduit → the air filter → the buffer chamber → the crank case → the pipeline → the air is sucked into the low-pressure cylinder compression air chamber. When the piston moves to the limit position and then starts to move in the direction far away from the center of the crankcase, the air inlet valve plate in the low-pressure cylinder assembly is closed, the volume in the low-pressure cylinder compression air chamber is reduced, air is compressed to cause pressure rise, and when the air pressure reaches a certain value, the air outlet valve plate is opened to discharge the compressed air in the low-pressure cylinder compression air chamber, so that the primary compression process is completed. And the compressed air after the first-stage compression is converged into an intercooler for cooling. A filter is usually disposed behind the intercooler to separate condensed water discharged from the intercooler, thereby preventing moisture from entering the high-pressure cylinder assembly and damaging the oil-free lubrication environment inside the high-pressure cylinder assembly.

As the crankshaft assembly rotates, the piston within the high pressure cylinder assembly also undergoes similar motion as the piston within the low pressure cylinder assembly described above. When the piston in the high-pressure cylinder assembly moves towards the direction close to the center of the crankcase, the high-pressure cylinder compresses the air chamber to generate negative pressure, and the air inlet valve plate and the air outlet valve plate in the high-pressure cylinder assembly are opened and closed. After the air inlet valve plate is opened, the compression air chamber in the high-pressure cylinder assembly is communicated with the intercooler, and compressed air in the intercooler is sucked into the compression air chamber of the high-pressure cylinder under the action of air pressure. When the piston in the high-pressure cylinder assembly moves to the limit position and then starts to move in the direction far away from the center of the crankcase, the air inlet valve plate in the high-pressure cylinder assembly is closed, the volume in the high-pressure cylinder compression air chamber is reduced, air is compressed to cause pressure rise, and when the pressure reaches a certain value, the air outlet valve plate is opened to discharge the compressed air in the high-pressure cylinder compression air chamber, so that the secondary compression process is completed. And the compressed air after the secondary compression is converged into an aftercooler for cooling, and the cooled compressed air is discharged into other equipment.

Claims

1. An air compressor, comprising:

a crankcase, inside which a crankshaft assembly is arranged;

2. The air compressor of claim 1, further comprising:

3. The air compressor as recited in claim 1, wherein said crankshaft assembly comprises:

4. The air compressor of claim 3, wherein the high-pressure cylinder assembly and the low-pressure cylinder assembly each comprise:

5. The air compressor as claimed in claim 4, wherein said piston assembly includes:

6. The air compressor as claimed in claim 5, wherein said clad piston comprises:

7. The air compressor of claim 1, including a cooling fan coupled to the crankshaft assembly.

8. The air compressor as set forth in, wherein said cooler includes: and a cooler for cooling the generated compressed air.

9. The air compressor as set forth in, wherein said cooler includes: the system comprises an intercooler and an aftercooler, wherein the intercooler cools compressed air after primary compression, and the aftercooler cools compressed air after secondary compression.

10. The air compressor of claim 2, wherein the crankcase and the buffer chamber are each coated with an acoustic damping coating that absorbs some of the noise and reduces noise transmission from the interior of the compressor.