CN111075685A

CN111075685A - Compact air compressor

Info

Publication number: CN111075685A
Application number: CN201911398474.5A
Authority: CN
Inventors: 不公告发明人
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-12-30
Filing date: 2019-12-30
Publication date: 2020-04-28

Abstract

The invention belongs to the technical field of air compressors. The invention discloses a compact air compressor which comprises a shell, a main piston, a first piston and a main shaft, wherein a control chamber and a first air chamber which are independent of each other are arranged in the shell, the main piston is positioned in the control chamber, the first piston is positioned in the first air chamber, the main shaft is positioned in the shell and axially penetrates through the main piston, the main piston can drive the main shaft to axially and synchronously move, and when the main piston moves to the terminal position of the control chamber, the main shaft can axially move relative to the main piston so as to drive the main piston to rotate in the circumferential direction, so that two sides of the main piston are respectively and alternately communicated with high-pressure oil. The air compressor can perform air compression work under the driving of hydraulic pressure, has simple and compact structure, low manufacturing cost and high integration level, can omit the use of a reversing valve, does not need electric control, avoids unstable factors of electric appliances, can work for a long time and has long service life.

Description

Compact air compressor

Technical Field

The invention belongs to the technical field of air compressors, and particularly relates to a compact air compressor.

Background

With the large-scale application of large-scale mechanical equipment, the hydraulic driving technology is increasingly mature in the technical field of air compressor application. The traditional air compressor adopts a crank-link mechanism to realize reciprocating motion of a piston in a cylinder body so as to compress air, and the air compressor in the mode has large output pulse and is unstable and easy to block under severe working conditions.

In the existing hydraulic air compressor, the reciprocating motion of a piston is usually realized by means of a reversing valve, namely, the aim of controlling the reversing is achieved by means of the cooperation of an electromagnetic reversing valve and a displacement sensor. However, the proximity switch controls the sensor, so that the reversing is unstable and the reliability is poor, and the control circuit part of the reversing device adopts circuit board control, because the circuit board is a non-standard part, the manufacturing and processing are difficult, the repair after the damage is very difficult, and the maintenance cost is high. Meanwhile, if the existing reversing device is continuously electrified for a long time, small devices are easily damaged, the requirement of long-time electrification cannot be met, and the production efficiency is also influenced to a certain extent.

Disclosure of Invention

In order to solve the problems of the conventional air compressor, the invention provides a compact air compressor with a brand-new structure. The air compressor comprises a shell, a main piston, a first piston and a main shaft; the first piston is fixedly connected with the main piston and moves synchronously;

the shell is internally provided with a control chamber and a first air chamber which are mutually independent, and the shell is provided with a P port, a T port, a first air inlet and a first air outlet;

the main piston is positioned in the control chamber and divides the control chamber into a first control chamber and a second control chamber which are independent of each other; the P port and the T port are respectively communicated with the first control chamber and the second control chamber in an alternating mode, when the P port is communicated with the first control chamber, the T port is communicated with the second control chamber, and when the P port is communicated with the second control chamber, the T port is communicated with the first control chamber;

the first piston is located in the first air chamber and divides the first air chamber into a first working air chamber and a first auxiliary air chamber which are independent of each other; the first air inlet and the first air outlet are simultaneously communicated with the first working air chamber;

the main shaft is positioned in the shell and axially penetrates through the main piston, the main piston can drive the main shaft to axially and synchronously move, and meanwhile, the main shaft can also axially move relative to the main piston and drive the main piston to rotate in the circumferential direction in the relative axial movement process; the two ends of the main shaft are connected with the shell in a sliding mode along the axial direction; when the main piston drives the main shaft to axially move to a terminal position in the control chamber, the main shaft axially moves relative to the main piston, and then the main piston is driven to rotate along the circumferential direction to complete the communication relation switching of the P port and the T port with the first control chamber and the second control chamber.

Preferably, the outer surface of the main piston is provided with a first oil groove and a second oil groove which are axially formed, the first oil groove is axially communicated with the first control chamber, and the second oil groove is axially communicated with the second control chamber; the first oil groove and the second oil groove are respectively and adjacently arranged along the circumferential direction, when the first oil groove is communicated with the P port, the second oil groove is communicated with the T port, and when the first oil groove is communicated with the T port, the second oil groove is communicated with the P port; the main piston is internally provided with a spiral groove, the main shaft is provided with a convex column extending into the spiral groove, and when the main shaft moves axially relative to the main piston, the main piston is driven to rotate along the circumferential direction by the matching of the convex column and the spiral groove.

Preferably, a first auxiliary oil path, a second auxiliary oil path, a third auxiliary oil path and a fourth auxiliary oil path are arranged on the shell, a first communicating groove and a second communicating groove are arranged on the main shaft, a first reversing chamber and a second reversing chamber are respectively formed by two ends of the main shaft and the shell, the sectional area of the first reversing chamber is smaller than that of the first control chamber, and the sectional area of the second reversing chamber is smaller than that of the second control chamber;

one end of the first auxiliary oil way is communicated with the port P, and the other end of the first auxiliary oil way is selectively communicated with the first connecting groove; one end of the second auxiliary oil way is communicated with the port P, and the other end of the second auxiliary oil way is selectively communicated with the second communication groove; the third auxiliary oil way is provided with a damping hole and three ports, wherein one end of the third auxiliary oil way is communicated with the T port, the other end of the third auxiliary oil way is communicated with the first reversing chamber, and the other end of the third auxiliary oil way is selectively communicated with the first connecting groove; the fourth auxiliary oil way is provided with a damping hole and three ports, wherein one end of the fourth auxiliary oil way is communicated with the T port, the other end of the fourth auxiliary oil way is communicated with the second reversing chamber, and the other end of the fourth auxiliary oil way is selectively communicated with the second communicating groove;

in the process that the main shaft moves along with the main piston, the first auxiliary oil path and the third auxiliary oil path are kept disconnected from the first communicating groove, and the second auxiliary oil path and the fourth auxiliary oil path are kept disconnected from the second communicating groove; when the main shaft moves to the terminal of the first control chamber along with the main piston, the first auxiliary oil way and the third auxiliary oil way are simultaneously communicated with the first connecting groove, and a port P is communicated with the first reversing chamber; when the main shaft moves to the terminal of the second control chamber along with the main piston, the second auxiliary oil path and the fourth auxiliary oil path are simultaneously communicated with the second communicating groove to communicate the port P with the second reversing chamber.

Further preferably, the first communicating groove and the second communicating groove are annular grooves along the circumferential direction.

Preferably, the air compressor is also provided with a first rotation stopping rod; the first rotation stopping rod penetrates through the first piston along the axial direction and then is fixed in the first air chamber.

Further preferably, the compact air compressor further comprises a second piston, a second air chamber which is independent from the control chamber and the first air chamber is further arranged in the shell, and a second air inlet hole and a second air outlet hole are further formed in the shell; the second piston is fixedly connected with the main piston and moves synchronously;

the second piston is positioned in the second air chamber and divides the second air chamber into a second working air chamber and a second auxiliary air chamber which are independent of each other; the second air inlet hole and the second air outlet hole are simultaneously communicated with the second working air chamber.

Further preferably, the first piston and the second piston are located on both sides of the main piston, and the first air chamber and the second air chamber are located on both sides of the control chamber.

Further preferably, two ends of the main shaft are fixedly connected with the first piston and the second piston respectively.

Further preferably, the first auxiliary air chamber serves as a first reversing chamber, and the second auxiliary air chamber serves as a second reversing chamber.

Preferably, the shell adopts a split structure, a partition plate is arranged inside the shell, and the inside of the shell is divided into a control chamber and a first air chamber which are distributed along the axial direction.

Compared with the air compressor with the existing structure, the air compressor provided by the invention has the following beneficial technical effects:

1. in the invention, the shell is respectively provided with a P port connected with the hydraulic pump and a T port connected with the oil return tank, and the P port and the T port are alternately communicated with the control chambers on two sides of the main piston, so that the main piston is driven to axially reciprocate by hydraulic pressure, and the first piston and the second piston are driven to repeatedly compress air in the first air chamber and the second air chamber respectively to do work. Meanwhile, the spindle moving to the terminal position of the control chamber is axially moved relative to the main piston by the aid of high-pressure oil at the position of the P port, the main piston is driven to rotate to complete switching of hydraulic acting force alternately applied to two sides of the main piston by the high-pressure oil, the main piston is driven to axially reciprocate and alternately move, and the effect that the first piston and the second piston alternately compress air to do work under hydraulic driving is achieved. Therefore, the compressed air which takes hydraulic pressure as power to drive the first piston and the second piston does work, the auxiliary structures such as a motor, a crank-link mechanism and the like in the conventional air compressor are replaced, the structure is simplified, the compactness of the volume is improved, the problems of large and unstable output pulse of the conventional air compressor are solved, and the continuous and stable output of high-pressure air is realized.

2. In the invention, a plurality of oil ways and a plurality of annular grooves which are mutually associated are respectively arranged on the main piston and the main shaft, so that the switching of the alternative communication of the P port and the T port with the control chambers at the two sides of the main piston is completed in the relative movement process between the main shaft and the main piston. Furthermore, an auxiliary oil path and a communication groove which are mutually associated are respectively arranged on the shell and the main shaft, and the first auxiliary air chamber and the second auxiliary air chamber are used as reversing chambers, so that the main shaft is driven to axially move relative to the main piston by high-pressure oil at a P port, and the main piston is rotated. Like this, not only saved the use and the control requirement to the change valve among the current air compressor machine, reduced cost and control complexity, through set up a plurality of different functional structure on casing, main shaft and main piston respectively moreover to improve the rate of utilization to spare part, reduced the volume of whole air compressor machine, reduced the spare part use amount, realized the high integration of whole air compressor machine.

Drawings

Fig. 1 is a schematic structural diagram illustrating a main piston moving toward a second air chamber to a terminal end in the compact air compressor of this embodiment;

fig. 2 is a schematic structural diagram of the compact air compressor according to the embodiment after the main piston is located at the end of the second control chamber and the main shaft moves towards the second air chamber relative to the main piston;

fig. 3 is a schematic structural view illustrating the main piston moving toward the first air chamber to the terminal end in the compact air compressor of this embodiment;

fig. 4 is a schematic structural view of the compact air compressor according to the embodiment after the main piston is located at the end of the first control chamber and the main shaft moves toward the first air chamber relative to the main piston;

fig. 5 is a schematic cross-sectional view of the main piston in this embodiment.

Detailed Description

The technical solution of the present invention will be further described in detail with reference to the accompanying drawings and embodiments.

Referring to fig. 1, the compact air compressor of the present embodiment includes a housing 1, a main piston 2, a first piston 3, a second piston 4, and a main shaft 5. The main piston 2, the first piston 3 and the second piston 4 are coaxially and fixedly connected and can perform synchronous reciprocating linear motion in the axial direction.

The shell 1 is a hollow structure, a control chamber, a first air chamber 12 and a second air chamber 13 which are mutually independent are arranged in the shell 1, the first air chamber 12 and the second air chamber 13 are respectively positioned at two sides of the control chamber, and a P port, a T port, a first air inlet 14, a first exhaust hole 15, a second air inlet 16 and a second exhaust hole 17 are arranged on the shell 1. Wherein, corresponding ventilation one-way valves are respectively arranged in the first air inlet hole 14, the first exhaust hole 15, the second air inlet hole 16 and the second exhaust hole 17, so that corresponding one-way air inlet and one-way exhaust functions of the air holes are realized.

The master piston 2 is located in the control chamber and divides the control chamber into a first control chamber 111 and a second control chamber 112, which are independent of each other. Wherein the P port and the T port are alternately communicated with the first control chamber 111 and the second control chamber 112, respectively. When the port P communicates with the first control chamber 111, the port T communicates with the second control chamber 112, and the high-pressure oil enters the first control chamber 111 to drive the main piston 2 to move axially in the direction of the second control chamber 112. When the port P communicates with the second control chamber 112, the port T communicates with the first control chamber 111, and the high-pressure oil enters the second control chamber 112 to drive the main piston 2 to move axially in the direction of the first control chamber 111.

The first piston 3 is located in the first gas chamber 12, and divides the first gas chamber 12 into a first working gas chamber 121 and a first auxiliary gas chamber 122, which are independent of each other. Wherein the first air intake hole 14 and the first air exhaust hole 15 are simultaneously communicated with the first working air chamber 121.

The second piston 4 is located in the second air chamber 13, and divides the second air chamber 13 into a second working air chamber 131 and a second auxiliary air chamber 132 which are independent of each other. Wherein the second suction hole 16 and the second discharge hole 17 are simultaneously communicated with the second working air chamber 131.

The main shaft 5 is positioned inside the shell 1 and penetrates through the main piston 2 along the axial direction, and two ends of the main shaft 5 are connected with the shell 1 in a sliding mode along the axial direction. The main piston 2 can drive the main shaft 5 to axially move synchronously, and the main shaft 5 can axially slide relative to the main piston 2 and drive the main piston 2 to rotate along the circumferential direction in the relative axial movement process. When the main piston 2 carries the main shaft 5 to axially move to the terminal position of the first control chamber 111 or the second control chamber 112 under the driving action of the high-pressure oil introduced from the port P, the main shaft 5 continues to axially move relative to the main piston 2 to drive the main piston to rotate in the circumferential direction, so that the communication relation switching between the port P and the port T and the first control chamber 111 and the second control chamber 112 is completed, and the main piston 2 carries the main shaft 5 to axially move in the opposite direction under the driving action of the high-pressure oil introduced from the port P after switching.

As shown in fig. 1 and 5, in the present embodiment, the outer surface of the main piston 2 is provided with a first oil groove 21 and a second oil groove 22 which are opened in the axial direction, and the first oil groove 21 communicates with the first control chamber 111 in the axial direction, and the second oil groove 22 communicates with the second control chamber 112 in the axial direction; along the circumferential direction, the first oil groove 21 and the second oil groove 22 are respectively and adjacently arranged, when the first oil groove 21 is communicated with the port P, the second oil groove 22 is communicated with the port T, and when the first oil groove 21 is communicated with the port T, the second oil groove 22 is communicated with the port P; the main piston 2 is internally provided with a spiral groove 23, the main shaft 5 is provided with a convex column 53 extending into the spiral groove 23, when the main shaft 5 moves axially relative to the main piston 2, the convex column 53 is matched with the spiral groove 23 to drive the main piston 2 to rotate along the circumferential direction, and in order to prevent the convex column 53 from separating from the spiral groove 23, the right end of the main piston 2 is provided with a plug 6.

As shown in fig. 1, in this embodiment, the housing 1 is provided with a first auxiliary oil path 181, a second auxiliary oil path 182, a third auxiliary oil path 183, and a fourth auxiliary oil path 184, the main shaft 5 is provided with a first communicating groove 51 and a second communicating groove 52, and the cross-sectional area of the main piston 2 is larger than the cross-sectional areas of the first piston 3 and the second piston 4, that is, the acting force applied to the main piston is larger than the acting forces applied to the first piston and the second piston under the action of the same pressure oil.

One end of the first auxiliary oil path 181 is in communication with the port P, and the other end is selectively in communication with the first communication groove 51. One end of the second auxiliary oil passage 182 communicates with the port P, and the other end selectively communicates with the second communication groove 52. The third auxiliary oil path 183 is provided with a damping hole 1831 and three ports, one of which is in communication with the T port, the other of which is in communication with the first auxiliary air chamber 122, and the other of which is in selective communication with the first communicating groove 51. The fourth auxiliary oil passage 184 is provided with a orifice 1841 and has three ports, one of which is in communication with the T port, one of which is in communication with the second auxiliary air chamber 132, and the other of which is in selective communication with the second communication groove 52.

During the axial movement of the main shaft 5 with the main piston 2, the first auxiliary oil passage 181 and the third auxiliary oil passage 183 are kept in a disconnected state from the first communicating groove 51, the second auxiliary oil passage 182 and the fourth auxiliary oil passage 184 are kept in a disconnected state from the second communicating groove 52, and the first auxiliary air chamber 122 and the second auxiliary air chamber 132 are respectively kept in a communicated state with the T port through the third auxiliary oil passage 183 and the fourth auxiliary oil passage 184.

When the main shaft 5 moves to the end of the first control chamber 111 with the main piston 2, the first communicating groove 51 communicates with both the first auxiliary oil passage 181 and the third auxiliary oil passage 183, the P port communicates with the first auxiliary air chamber 122 via the orifice 1831, and the second auxiliary air chamber 132 communicates with the T port via the fourth auxiliary oil passage 184. At this time, the high-pressure oil at the P port forms a hydraulic acting force on the first piston 3, and the main shaft 5 is driven by the first piston 3 to move towards the first air chamber 12 relative to the main piston 2.

When the main shaft 5 moves to the end of the second control chamber 112 with the main piston 2, the second communication groove 52 communicates with both the second auxiliary oil passage 182 and the fourth auxiliary oil passage 184, the P port communicates with the second auxiliary air chamber 132 via the orifice 1841, and the first auxiliary air chamber 122 remains in communication with the T port via the third auxiliary oil passage 183. At this time, the high-pressure oil of the port P forms a hydraulic acting force on the second piston 4, and the main shaft 5 is driven by the second piston 4 to move in the direction of the second air chamber 13 relative to the main piston 2.

Preferably, in this embodiment, the main shaft has a cylindrical structure, and the first communicating groove and the second communicating groove are annular grooves formed along the circumferential direction. Therefore, when the main shaft moves axially relative to the shell, the main shaft can be prevented from rotating in the circumferential direction to influence the accurate switching of the communication relation among the first auxiliary oil way, the second auxiliary oil way, the third auxiliary oil way and the fourth auxiliary oil way, and the working stability and reliability of the whole air compressor are ensured.

In this embodiment, as shown in fig. 1, the air compressor is further provided with a first rotation stopping rod 8; the first rotation stopping rod 8 penetrates through the first piston 3 along the axial direction and then is fixed in the first air chamber, the first rotation stopping rod 8 is arranged to prevent the first piston 8 from rotating, and further prevent the main shaft 5 from rotating, so that when the main shaft 5 moves relative to the main piston 2 along the axial direction, the main piston 2 is driven to rotate relative to the main shaft 5 along the circumferential direction.

Similarly, in other embodiments, the main shaft may also be designed to be a polygonal structure or provided with an axial guiding structure to ensure accurate stability of the axial reciprocating movement of the main shaft relative to the housing, and at this time, the first communicating groove and the second communicating groove may also be designed to be radial holes to ensure accurate switching of the communication relationship among the first auxiliary oil path, the second auxiliary oil path, the third auxiliary oil path and the fourth auxiliary oil path.

In the embodiment, the communication control of the port P and the port T and the first auxiliary air chamber and the second auxiliary air chamber is realized by the auxiliary oil path on the housing and the communication groove on the main shaft, so that the axial movement of the main shaft relative to the main piston is realized by the driving control of the first piston and the second piston by the high-pressure oil liquid. Like this, not only can increase the stroke distance of first piston and second piston, improve the compression efficiency to the air, can increase first auxiliary air chamber and second auxiliary air chamber's utilization ratio moreover, improve the integrated level of whole air compressor machine.

Similarly, in other embodiments, according to the design, processing and use conditions, the main shaft may not be used to fixedly connect the main piston with the first piston and the second piston, but the main piston may be fixedly connected with the first piston and the second piston by means of an additional connecting rod, and a first direction changing chamber and a second direction changing chamber are further respectively disposed in the housing to replace the first auxiliary air chamber and the second auxiliary air chamber, so as to communicate with the port P and the port T and generate a driving force for the main shaft to axially reciprocate, thereby realizing the relative axial movement of the main shaft and the main piston, and at the same time, communicating the first auxiliary air chamber and the second auxiliary air chamber with the external environment to avoid the occurrence of air suction.

In addition, in this embodiment, the first piston and the second piston are respectively arranged on two sides of the main piston, and the first air chamber and the second air chamber are respectively arranged on two sides of the control chamber, so that the alternating compressed air of the first air chamber and the second air chamber is used for doing work in the reciprocating movement process of the main piston, and the efficiency of compressed air is improved. However, in other embodiments, the air compressor can be designed to have only the first piston and the first air chamber according to different working conditions, so that the volume of the whole air compressor is reduced, and a structural form of performing work by using one-way compressed air is formed. Even, the first piston and the second piston are sequentially arranged on the same side of the main piston, and the first air chamber and the second air chamber are arranged on the same side of the control chamber, so that a one-way compressed air work doing mode is formed, and the one-way compressed air work doing efficiency is improved.

In addition, as shown in fig. 1, in the present embodiment, the housing 1 is of a split structure, and is composed of three housings corresponding to the control chamber, the first air chamber 12 and the second air chamber 13, and the two partition plates 7 and the three housings are axially and fixedly connected by bolts. Therefore, the whole shell is convenient to process and manufacture, particularly relevant oil ways, so that the processing difficulty and cost are reduced, the disassembly is convenient, and the assembly efficiency and the maintenance convenience are improved.

Combine fig. 1 to fig. 4 to show, the air compressor machine of this embodiment carries out during operation, and P mouth and hydraulic pump connection, T mouth and oil return tank are connected, and concrete working process is as follows:

when the main piston 2 moves towards the direction of the second air chamber 13, the convex column 53 is located at the leftmost position of the spiral groove 23, so that the main piston 2 drives the main shaft 5 to move towards the direction of the second air chamber 13 together. At this time, the high-pressure oil outputted from the hydraulic pump flows to the first control chamber 111 through the port P and the first oil groove 21 in this order, and the oil in the second control chamber 112 flows to the oil return tank through the second oil groove 22. Thus, the main piston 2 moves towards the second air chamber 13 under the action of the high-pressure oil in the first control chamber 111, and simultaneously drives the second piston 4 to perform air compression work in the second air chamber 13 and output high-pressure air through the second exhaust hole 17, and the oil at the T-port flows into the second auxiliary working chamber 132 through the fourth auxiliary oil path 184 to perform oil supplementation, and simultaneously drives the first piston 3 to perform air suction operation in the first air chamber 12 and introduce air through the first air inlet hole 14, and the oil in the first auxiliary air chamber 122 is externally exhausted to the T-port through the third auxiliary oil path 183. At this time, since the oil in the first auxiliary air chamber 122 is discharged to the T port through the damping hole 183, a back pressure is generated in the first auxiliary air chamber 122, and the back pressure acts on the first piston 3 to generate a leftward thrust, so that the convex column 53 of the main shaft 5 is maintained at the left end position of the spiral groove 23.

When the main piston 2 moves to the terminal position of the second control chamber 112, the second communicating groove 52 communicates the second auxiliary oil path 182 and the fourth auxiliary oil path 184, so that the high-pressure oil of the port P is guided into the second auxiliary air chamber 132, an acting force toward the second working air chamber 131 direction by the second piston 4 is formed, the main shaft 5 is driven by the second piston 4 to move continuously toward the second air chamber 13 direction relative to the main piston 2, the main piston 2 rotates in the circumferential direction due to the matching of the convex column 53 and the spiral groove 23, the port P is switched to be communicated with the second control chamber 112, the port T is switched to be communicated with the first control chamber 111, and the reversing operation of the main piston 2 is completed.

When the main piston 2 moves towards the first air chamber 12, the convex column 53 is located at the rightmost end position of the spiral groove 23, so that the main piston 2 drives the main shaft 5 to move towards the first air chamber 12. At this time, the high-pressure oil outputted from the hydraulic pump flows to the second control chamber 112 through the port P and the second oil groove 22 in sequence, and the oil in the first control chamber 111 flows to the oil return tank through the first oil groove 21 and the port T. Thus, the main piston 2 moves towards the first air chamber 12 under the action of the high-pressure oil in the second control chamber 112, and simultaneously drives the first piston 3 to perform air compression work in the first air chamber 12 and output high-pressure air through the first exhaust hole 15, and the T-port oil flows to the first auxiliary air chamber 122 through the third auxiliary oil path 183 to perform oil supplementation, and simultaneously drives the second piston 4 to perform air suction operation in the second air chamber 13 and introduce air through the second intake hole 16, and the oil in the second auxiliary air chamber 132 is externally exhausted to the T-port through the fourth auxiliary oil path 184. At this time, since the oil in the second auxiliary air chamber 132 is discharged to the T port through the damping hole 1841, the back pressure is generated in the second auxiliary air chamber 132, and the back pressure acts on the first piston 3 to generate a rightward thrust to keep the convex column 53 of the main shaft 5 at the right end position of the spiral groove 23.

When the main piston 2 moves to the terminal position of the first control chamber 111, the first connecting groove 51 connects the first auxiliary oil path 181 and the third auxiliary oil path 183, so that the high-pressure oil at the P port is guided into the first auxiliary air chamber 122, an acting force to the first piston 3 in the direction of the first working air chamber 121 is formed, the main shaft 5 is driven by the first piston 3 to move continuously in the direction of the first air chamber 12 relative to the main piston 2, the main piston 2 rotates in the circumferential direction due to the matching of the convex column 53 and the spiral groove 23, the P port is switched to be connected with the first control chamber 111, the T port is switched to be connected with the second control chamber 112, and the reversing operation of the main piston 2 is completed.

And repeating the reciprocating action in sequence to finish the work of the reciprocating compressed air of the air compressor under the hydraulic drive.

Claims

1. A compact air compressor is characterized by comprising a shell, a main piston, a first piston and a main shaft; the first piston is fixedly connected with the main piston and moves synchronously;

2. The compact air compressor according to claim 1, wherein the outer surface of the main piston is provided with a first oil groove and a second oil groove which are opened in the axial direction, and the first oil groove is communicated with the first control chamber in the axial direction, and the second oil groove is communicated with the second control chamber in the axial direction; the first oil groove and the second oil groove are respectively and adjacently arranged along the circumferential direction, when the first oil groove is communicated with the P port, the second oil groove is communicated with the T port, and when the first oil groove is communicated with the T port, the second oil groove is communicated with the P port; the main piston is internally provided with a spiral groove, the main shaft is provided with a convex column extending into the spiral groove, and when the main shaft moves axially relative to the main piston, the main piston is driven to rotate along the circumferential direction by the matching of the convex column and the spiral groove.

3. The compact air compressor according to claim 1, wherein a first auxiliary oil path, a second auxiliary oil path, a third auxiliary oil path and a fourth auxiliary oil path are provided on the housing, a first communicating groove and a second communicating groove are provided on the main shaft, a first reversing chamber and a second reversing chamber are respectively formed at two ends of the main shaft and the housing, the sectional area of the first reversing chamber is smaller than that of the first control chamber, and the sectional area of the second reversing chamber is smaller than that of the second control chamber;

4. The compact air compressor according to claim 3, wherein the first communicating groove and the second communicating groove are annular grooves in a circumferential direction.

5. The compact air compressor as claimed in claim 1, wherein the air compressor is further provided with a first rotation stopping rod; the first rotation stopping rod penetrates through the first piston along the axial direction and then is fixed in the first air chamber.

6. The compact air compressor according to claim 3, further comprising a second piston, wherein a second air chamber independent from the control chamber and the first air chamber is further provided inside the housing, and a second air inlet hole and a second air outlet hole are further provided on the housing; the second piston is fixedly connected with the main piston and moves synchronously;

7. The compact air compressor as claimed in claim 5, wherein the first piston and the second piston are located on both sides of the main piston, and the first air chamber and the second air chamber are located on both sides of the control chamber.

8. The compact air compressor as claimed in claim 6, wherein both ends of the main shaft are fixedly connected with the first piston and the second piston, respectively.

9. The compact air compressor as claimed in claim 7, wherein the first auxiliary air chamber serves as a first reversing chamber and the second auxiliary air chamber serves as a second reversing chamber.

10. The compact air compressor according to any one of claims 1-9, wherein the housing is of a split structure, and the interior of the housing is provided with a partition dividing the interior of the housing into the control chamber and the first air chamber which are distributed along the axial direction.