CN113374571A

CN113374571A - External pressure type rotor engine

Info

Publication number: CN113374571A
Application number: CN202110663792.0A
Authority: CN
Inventors: 刘兴和
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-06-15
Filing date: 2021-06-15
Publication date: 2021-09-10
Anticipated expiration: 2041-06-15
Also published as: CN113374571B; WO2022262700A1

Abstract

The invention provides an external pressure type rotor engine, which relates to the technical field of engines, and comprises: the pneumatic power machine comprises a machine body, a main shaft, a working rotor, a pneumatic rotor, a plurality of working switch pieces and a plurality of pneumatic switch pieces; the machine body is provided with a working cavity and a compressing working cavity which are separated; the main shaft penetrates through the working cavity and the air compressing cavity, the main shaft is rotatably connected to the machine body, and the working rotor and the air compressing rotor are respectively arranged on the main shaft; the working switch pieces are arranged at intervals around the circumferential direction of the working rotor, and a combustion chamber is formed between at least one driving surface of the working rotor and the working switch pieces; the air compression switch pieces are arranged around the circumferential direction of the air compression rotor at intervals, an air compression chamber is formed between at least one air compression surface of the air compression rotor and the air compression switch pieces, and the air compression chamber is communicated with the combustion chamber in a fluid mode. The external pressure type rotor engine provided by the invention not only runs stably, but also improves the power performance.

Description

External pressure type rotor engine

Technical Field

The invention relates to the technical field of engines, in particular to an external pressure type rotor engine.

Background

The existing internal combustion engine mainly comprises a gasoline engine and a diesel engine, and a piston reciprocating type driving mechanism is generally adopted. However, the piston reciprocating type driving mechanism has poor running smoothness, and thus noise and balance are difficult to deal with. In the triangular rotor engine, although the technical problem of poor running stability is relieved, oil gas is discharged without being burnt out because work and exhaust are close to the same stroke, so that the oil consumption is increased, and the emission pollution is serious.

Disclosure of Invention

The invention aims to provide an external pressure type rotor engine to solve the technical problems of poor stability and low efficiency of the engine.

In a first aspect, the present invention provides an external pressure type rotary engine, comprising: the pneumatic power machine comprises a machine body, a main shaft, a working rotor, a pneumatic rotor, a plurality of working switch pieces and a plurality of pneumatic switch pieces;

the machine body is provided with a working cavity and an air compressing cavity, and the working cavity is separated from the air compressing cavity;

the main shaft penetrates through the working cavity and the air compression working cavity, is rotatably connected to the machine body, and is respectively arranged on the main shaft;

the working switch pieces are arranged around the working rotor at intervals in the circumferential direction, and a combustion chamber is formed between at least one driving surface of the working rotor and the working switch pieces;

the air compressing switch pieces are arranged around the circumferential direction of the air compressing rotor at intervals, an air compressing cavity is formed between at least one air compressing surface of the air compressing rotor and the air compressing switch pieces, and the air compressing cavity is communicated with the combustion chamber in a fluid mode.

With reference to the first aspect, the present disclosure provides a first possible implementation manner of the first aspect, wherein the working rotor is provided with a plurality of first cam portions, and the plurality of first cam portions are arranged at intervals along a circumference of the working rotor;

the driving surface is arranged on the first cam part, and a first thrust surface is arranged on one side of the first cam part, which is far away from the driving surface;

the first thrust surface is used for pushing the acting switch piece and enabling the acting switch piece to yield for the acting rotor.

With reference to the first possible implementation manner of the first aspect, the present disclosure provides a second possible implementation manner of the first aspect, wherein the first cam portion has a first circumferential surface;

the working rotor rotates, and the first circumferential surfaces sequentially block the first air inlets of the combustion chamber so as to enable the first air inlets to be periodically opened and closed.

With reference to the second possible implementation manner of the first aspect, the present invention provides a third possible implementation manner of the first aspect, wherein a plurality of exhaust ports are arranged on the machine body, and the exhaust ports are arranged at intervals along a circumferential direction of the working rotor;

the working rotor rotates, and the first circumferential surfaces sequentially block the exhaust ports so as to periodically open and close the exhaust ports.

In combination with the second possible implementation manner of the first aspect, the present invention provides a fourth possible implementation manner of the first aspect, wherein a valve is mounted on the body, the valve being mounted in an air port between the puffer chamber and the combustion chamber, the air port being in fluid communication with the first air inlet.

With reference to the second possible implementation manner of the first aspect, the present invention provides a fifth possible implementation manner of the first aspect, wherein the work switch includes: a first sector rotor and a first elastic device;

the first fan-shaped rotor is rotationally connected to the machine body and provided with a first station and a second station;

in the first station, the first sector rotor is inserted between two adjacent first cam portions;

at the second station, the first sector rotor is positioned outside the first circumferential surface;

the first elastic device is mounted on the machine body and has a tendency to switch the first fan-shaped rotor from the second station to the first station.

With reference to the fifth possible implementation manner of the first aspect, the present invention provides a sixth possible implementation manner of the first aspect, wherein a limiting portion is disposed on the first sector rotor, and the limiting portion abuts against the machine body in the first station.

With reference to the first aspect, the present invention provides a seventh possible implementation manner of the first aspect, wherein the displacer is provided with a plurality of second cam portions, and the plurality of second cam portions are arranged at intervals along a circumference of the displacer;

the gas pressure surface is provided on the second cam portion.

With reference to the seventh possible implementation manner of the first aspect, the present invention provides an eighth possible implementation manner of the first aspect, wherein the puffer switch piece includes: the second fan-shaped rotor, the electromagnetic locking piece and the second elastic device;

the second fan-shaped rotor is rotationally connected to the machine body and is provided with a first station and a second station;

in the first station, the second fan-shaped rotor is inserted between two adjacent second cam parts, and the air compression chamber is formed between the second fan-shaped rotor and the air compression surface;

at the second station, the second sector rotor abuts against a second circumferential surface of the second cam portion;

the electromagnetic locking piece and the second elastic device are respectively installed on the machine body, the electromagnetic locking piece is used for locking the second fan-shaped rotor at the first station, and the second elastic device has a tendency of enabling the second fan-shaped rotor to be switched from the second station to the first station.

With reference to the seventh possible implementation manner of the first aspect, the present invention provides a ninth possible implementation manner of the first aspect, wherein a plurality of second gas inlets are formed in the machine body, and the plurality of second gas inlets are spaced apart from each other in the circumferential direction of the puffer rotor;

as the compressor rotor rotates, the second circumferential surfaces of the plurality of second cam portions sequentially block the second intake ports, so that the second intake ports are periodically opened and closed.

The embodiment of the invention has the following beneficial effects: the machine body is provided with a working cavity and an air compressing cavity, the working cavity is separated from the air compressing cavity, a main shaft penetrates through the working cavity and the air compressing cavity, the main shaft is rotatably connected to the machine body, a working rotor and an air compressing rotor are respectively arranged on the main shaft, a plurality of working switch pieces are arranged around the working rotor at intervals in the circumferential direction, a combustion chamber is formed between at least one driving face of the working rotor and the working switch pieces, an oil-gas mixture is combusted in the combustion chamber to work, so that the working rotor, the main shaft and the air compressing rotor are driven to synchronously rotate, the air compressing switch pieces are arranged around the air compressing rotor at intervals in the circumferential direction, an air compressing chamber is formed between at least one air compressing face of the air compressing rotor and the air compressing switch pieces, the air compressing chamber is in fluid communication with the combustion chamber, the air in the air compressing chamber can be pressurized through the air compressing rotor, and the pressurized air is introduced into the working cavity. The combustion chambers with the number equal to that of the working switches can be generated in the process that the working rotor rotates for one circle, and then multiple combustion working is performed, so that the operation is stable, and the power performance is improved.

In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a sectional view of a working chamber of an external pressure type rotary engine according to an embodiment of the present invention;

fig. 2 is a sectional view of a compressed air working chamber of an external pressure type rotor engine provided by an embodiment of the invention;

fig. 3 is a first sectional view of the external pressure type rotary engine according to the embodiment of the present invention;

fig. 4 is a second sectional view of the external pressure type rotary engine according to the embodiment of the present invention.

Icon: 001-body; 002-main shaft; 003-working rotor; 301-a drive face; 302-a first thrust surface; 303-a first circumferential surface; 004-a gas compressor rotor; 401-air pressure surface; 402-a second circumferential surface; 005-a power switch; 501-a first sector rotor; 511-a limiting part; 502-a first elastic device; 006-pneumatic switch member; 601-a second sector rotor; 602-an electromagnetic latch; 007-combustion chamber; 701-a first air inlet; 702-an exhaust port; 008-a puffer chamber; 801-a second air inlet; 009-valve.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. The term "physical quantity" in the formula, unless otherwise noted, is understood to mean a basic quantity of a basic unit of international system of units, or a derived quantity derived from a basic quantity by a mathematical operation such as multiplication, division, differentiation, or integration.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Example one

As shown in fig. 1 and 2, an external pressure type rotary engine according to an embodiment of the present invention includes: the air compressor comprises a machine body 001, a main shaft 002, a work rotor 003, an air compressing rotor 004, a plurality of work applying switch pieces 005 and a plurality of air compressing switch pieces 006; the machine body 001 is provided with a work working cavity and an air compressing working cavity, and the work working cavity is separated from the air compressing working cavity; the main shaft 002 passes through the working cavity and the air compressing cavity, the main shaft 002 is rotatably connected to the machine body 001, and the working rotor 003 and the air compressing rotor 004 are respectively arranged on the main shaft 002; the plurality of working switches 005 are arranged at intervals around the working rotor 003 in the circumferential direction, and a combustion chamber 007 is formed between at least one driving surface 301 of the working rotor 003 and the working switches 005; a plurality of the air compression switch pieces 006 are arranged around the circumference of the air compression rotor 004 at intervals, an air compression chamber 008 is formed between at least one air compression surface 401 of the air compression rotor 004 and the air compression switch pieces 006, and the air compression chamber 008 is in fluid communication with the combustion chamber 007.

When a combustion chamber 007 is formed between the driving surface 301 and the working switch piece 005, an oil injector and an igniter in the combustion chamber 007 work in sequence, oil is injected into the combustion chamber 007 through the oil injector to form an oil-gas mixture, the oil-gas mixture is ignited through the igniter, high-temperature gas generated by oil-gas combustion pushes the driving surface 301 to further drive the working rotor 003 to rotate, and the main shaft 002 and the air compressing rotor 004 are driven to synchronously run through the working rotor 003. In addition, when diesel oil is used as fuel, an igniter can be omitted, and the oil-gas mixture in the combustion chamber 007 can be ignited in a compression ignition mode. In the process that the main shaft 002 rotates for one circle, the plurality of driving surfaces 301 of the working rotor 003 are sequentially opposite to the working switches 005, and the combustion chambers 007 with the same number as the working switches 005 are formed, and the plurality of combustion chambers 007 are sequentially ignited to work, so that multiple times of combustion work is performed, the operation is stable, and the dynamic performance is improved. In addition, the main shaft 002 drives the air compressing rotor 004 to rotate, the air compressing chamber 008 can be compressed through the air compressing rotor 004, so that the air in the air compressing chamber 008 is pressed into the working cavity, sufficient air is provided for the combustion chamber 007, and smooth combustion is ensured.

In the embodiment of the present invention, the working rotor 003 is provided with a plurality of first cam portions which are provided at intervals along the circumference of the working rotor 003;

the driving surface 301 is arranged on a first cam part, and a first thrust surface 302 is arranged on one side of the first cam part, which is far away from the driving surface 301;

the first thrust surface 302 is used for pushing the working switch piece 005 and making the working switch piece 005 give way for the working rotor 003.

When a combustion chamber 007 is formed between the driving surface 301 and the working switch piece 005, the igniter ignites the oil-gas mixture in the combustion chamber 007, and the oil-gas mixture burns to apply work, so that the working rotor 003 is driven to rotate. As the working rotor 003 rotates, the first thrust surface 302 of the other first cam portion abuts against the working switch 005, and the working switch 005 is driven to escape from the working rotor 003, thereby ensuring smooth rotation of the working rotor 003.

Further, the first cam portion has a first circumferential surface 303; as the working rotor 003 rotates, the plurality of first circumferential surfaces 303 sequentially close the first intake ports 701 of the combustion chambers 007 so that the first intake ports 701 are periodically opened and closed.

When a combustion chamber 007 is formed between the driving surface 301 and the working switch piece 005, the first air inlet 701 is communicated with an inner cavity of the combustion chamber 007; when the oil-gas mixture in the combustion chamber 007 is sufficiently combusted, the first cam portion behind the combustion chamber 007 is rotated to be in contact with the first intake ports 701, and the first intake ports 701 are closed by the first circumferential surface 303 of the first cam portion.

Further, a plurality of exhaust ports 702 are arranged on the machine body 001, and the exhaust ports 702 are arranged at intervals along the circumferential direction of the working rotor 003; as the working rotor 003 rotates, the plurality of first circumferential surfaces 303 close the exhaust ports 702 in sequence, so that the exhaust ports 702 are periodically opened and closed.

When the oil-gas mixture in the combustion chamber 007 is combusted, high-temperature gas generated by combustion of the oil-gas mixture drives the acting rotor 003 to rotate, and after the oil-gas mixture in the combustion chamber 007 is fully combusted, the first cam part in front of the combustion chamber 007 is moved away from the exhaust port 702, so that the inner cavity of the combustion chamber 007 is communicated with the exhaust port 702, and smoke generated by combustion in the combustion chamber 007 can be exhausted through the exhaust port 702. During the smoke evacuation, the first thrust surface 302 of the first cam portion located behind the combustion chamber 007 is continuously pushed toward the inside of the combustion chamber 007, thereby accelerating the discharge of smoke.

As shown in fig. 1, 2, 3 and 4, a gas gate 009 is mounted on the body 001, the gas gate 009 being mounted in a vent between the puffer chamber 008 and the combustion chamber 007, the vent being in fluid communication with the first gas inlet 701.

Specifically, the valves 009 may use springs to provide the closing force, by which the valves 009 have a tendency to remain closed. When the pressure in the puffer chamber 008 is greater than the pressure in the combustion chamber 007, the pressure difference drives the valve 009 to open, so that the gas in the puffer chamber 008 enters the combustion chamber 007.

As shown in fig. 2, the work switch 005 includes: a first sector rotor 501 and a first elastic means 502; the first sector rotor 501 is rotatably connected to the machine body 001 and has a first station and a second station.

In the first station, the first sector rotor 501 is inserted between adjacent two first cam portions. In the second station, the first sector rotor 501 is located outside the first circumferential face 303; the first elastic device 502 is installed on the body 001, and the first elastic device 502 has a tendency to switch the first sector rotor 501 from the second station to the first station.

When the first thrust surface 302 abuts against the first sector rotor 501, the first thrust surface 302 pushes the first sector rotor 501 along with the rotation of the working rotor 003, so that the first sector rotor 501 is switched from the first station to the second station. In this process, the first sector rotor 501 always abuts against the working rotor 003, thereby ensuring that the combustion chamber 007 is always in a sealed state.

Further, the first sector rotor 501 is provided with a limiting portion 511, and in the first station, the limiting portion 511 abuts against the machine body 001. The inner wall of the body 001 is provided with a sliding groove, and the limiting part 511 slides along the sliding groove. When the first sector rotor 501 rotates to the first station, the limiting portion 511 abuts against the end of the sliding groove, so that the first sector rotor 501 is limited.

As shown in fig. 1, the displacer 004 is provided with a plurality of second cam portions which are provided at intervals along the circumference of the displacer 004; the gas pressure surface 401 is provided on the second cam portion.

Specifically, the number of the second cam portions is one less than that of the air compression switch pieces 006, and when the air compression chamber 008 is formed between the air compression face 401 and the air compression switch pieces 006, the air compression switch pieces 006 should be switched to a locked state, and the air compression face 401 extrudes the air compression chamber 008 along with the rotation of the air compression rotor 004, so that the air pressure in the air compression chamber 008 rises.

Further, the puffer switch piece 006 includes: a second sector rotor 601, an electromagnetic locking member 602, and a second elastic member; the second fan-shaped rotor 601 is rotatably connected to the machine body 001, and the second fan-shaped rotor 601 is provided with a first station and a second station; in the first station, the second sector rotor 601 is inserted between two adjacent second cam portions, and an air compression chamber 008 is formed between the second sector rotor 601 and the air compression surface 401; in the second station, the second sector rotor 601 abuts against the second circumferential surface 402 of the second cam portion; electromagnetic locking piece 602 and second elastic device are installed respectively in organism 001, and electromagnetic locking piece 602 is used for locking second fan-shaped rotor 601 at first station, and the second elastic device has the trend that makes second fan-shaped rotor 601 switch over to first station from the second station.

Specifically, the inner wall of the machine body 001 is provided with a caulking groove, and the lock block of the electromagnetic locking piece 602 is contracted into the caulking groove in the lock releasing state, and the air pressing surface 401 abutting against the second fan-shaped rotor 601 can drive the second fan-shaped rotor 601 to rotate from the first station to the second station. When second fan-shaped rotor 601 is in first station, the locking piece of electromagnetism locking piece 602 can stretch out, and second fan-shaped rotor 601 butt is in the locking piece to make second fan-shaped rotor 601 by the locking at first station, along with the rotation of rotor 004 of calming the anger, the atmospheric pressure in the room 008 of calming the anger increases gradually, thereby impresses gas in the working chamber of doing work.

Further, a plurality of second air inlets 801 are arranged on the machine body 001, and the plurality of second air inlets 801 are arranged at intervals along the circumferential direction of the compressor rotor 004; as the compressor rotor 004 rotates, the second circumferential surfaces 402 of the plurality of second cam portions close the second intake ports 801 in sequence, and the second intake ports 801 are periodically opened and closed.

Specifically, the number of the second air inlets 801 is equal to the number of the compression switching pieces 006, and after the second circumferential surface 402 blocks the second air inlets 801, the compression chambers 008 are formed between the second sector rotor 601 and the compression surface 401. After the air compression is completed, the electromagnetic locking piece 602 is switched to the unlocking state, the air compression surface 401 pushes the second sector rotor 601 to rotate from the first station to the second station, and the second circumferential surface 402 of the second cam portion is dislocated with the second air inlet 801, so that the external air can enter the air compression working chamber from the second air inlet 801.

As shown in fig. 1 and 2, it should be noted that the first cam portion of the working rotor 003 and the second cam portion of the compressor rotor 004 both correspond to a large central angle, and at least three locking grooves for installing the sealing members may be provided. The sealing element is made of the same material as the piston ring and mainly plays a role in wear resistance and sealing. The central angles corresponding to the first cam part and the second cam part are 50-60 degrees, when the tail end of the first cam part is separated from the first fan-shaped rotor 501, the first fan-shaped rotor 501 rapidly rotates to a first station under the action of the first elastic device 502; when the tip of the second cam portion is separated from the second sector rotor 601, the second sector rotor 601 is rapidly rotated to the first station by the second elastic means. In addition, since the first and

second sector rotors

501 and 601 are respectively hit to swing, and thus a large impact is generated, the impact and wear of the power switch 005 and the compression switch 006 can be reduced by adding a counter weight. In addition, lubricating oil paths are respectively arranged on the main shaft 002, the working rotor 003 and the air compressing rotor 004, and lubricating oil can enter between the rotating piece and the machine body 001, so that the running resistance of the rotating piece is reduced, and the abrasion of the device is relieved.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An external pressure type rotary engine characterized by comprising: the air compressor comprises a machine body (001), a main shaft (002), a working rotor (003), an air compressing rotor (004), a plurality of working switch pieces (005) and a plurality of air compressing switch pieces (006);

the machine body (001) is provided with a work doing working cavity and an air compressing working cavity, and the work doing working cavity is separated from the air compressing working cavity;

the main shaft (002) penetrates through the working cavity and the air compressing working cavity, the main shaft (002) is rotatably connected to the machine body (001), and the working rotor (003) and the air compressing rotor (004) are respectively arranged on the main shaft (002);

the work doing switch pieces (005) are arranged at intervals around the circumferential direction of the work doing rotor (003), and a combustion chamber (007) is formed between at least one driving surface (301) of the work doing rotor (003) and the work doing switch pieces (005);

the air compression switch pieces (006) are arranged around the air compression rotor (004) at intervals in the circumferential direction, an air compression chamber (008) is formed between at least one air compression surface (401) of the air compression rotor (004) and the air compression switch pieces (006), and the air compression chamber (008) is communicated with the combustion chamber (007) in a fluid mode.

2. The external pressure type rotary engine according to claim 1 wherein the working rotor (003) is provided with a plurality of first cam portions arranged at intervals along the circumference of the working rotor (003);

the driving surface (301) is arranged on the first cam part, and a first thrust surface (302) is arranged on one side of the first cam part, which is far away from the driving surface (301);

the first thrust surface (302) is used for pushing the work switch piece (005) and enabling the work switch piece (005) to give way for the work rotor (003).

3. The external pressure type rotary engine according to claim 2 wherein the first cam portion has a first circumferential face (303);

the plurality of first circumferential surfaces (303) sequentially block the first air inlets (701) of the combustion chamber (007) as the working rotor (003) rotates, so that the first air inlets (701) are opened and closed periodically.

4. The external pressure type rotary engine according to claim 3 wherein a plurality of exhaust ports (702) are provided on the engine body (001), a plurality of exhaust ports (702) being provided at intervals in the circumferential direction of the working rotor (003);

the plurality of first circumferential surfaces (303) sequentially block the exhaust port (702) as the working rotor (003) rotates, so that the exhaust port (702) is periodically opened and closed.

5. External pressure rotary engine according to claim 3 characterized in that on the block (001) is mounted a gas valve (009), the gas valve (009) being mounted in a vent between the puffer chamber (008) and the combustion chamber (007), the vent being in fluid communication with the first gas inlet (701).

6. External pressure rotary engine according to claim 3 characterized in that said work switch member (005) comprises: a first sector rotor (501) and a first elastic means (502);

the first fan-shaped rotor (501) is rotatably connected to the machine body (001) and is provided with a first station and a second station;

in the first station, the first sector rotor (501) is inserted between two adjacent first cam portions;

in the second station, the first sector rotor (501) is located outside the first circumferential face (303);

the first elastic means (502) is mounted to the body (001) and the first elastic means (502) has a tendency to switch the first sector rotor (501) from the second station to the first station.

7. The external pressure type rotary engine according to claim 6 characterized in that the first sector rotor (501) is provided with a limiting part (511), and in the first station, the limiting part (511) abuts against the engine body (001).

8. External pressure rotary engine according to claim 1 characterized in that said displacer (004) is provided with a plurality of second cam portions, which are arranged at intervals along the circumference of said displacer (004);

the gas pressure surface (401) is provided on the second cam portion.

9. External pressure rotary engine according to claim 8 characterized in that said compression switching member (006) comprises: a second sector rotor (601), an electromagnetic locking piece (602) and a second elastic device;

the second fan-shaped rotor (601) is rotatably connected to the machine body (001), and the second fan-shaped rotor (601) is provided with a first station and a second station;

in the first station, the second fan-shaped rotor (601) is inserted between two adjacent second cam parts, and the air compression chamber (008) is formed between the second fan-shaped rotor (601) and the air compression surface (401);

in the second station, the second sector rotor (601) abuts against a second circumferential surface (402) of the second cam portion;

the electromagnetic locking piece (602) and the second elastic device are respectively mounted on the machine body (001), the electromagnetic locking piece (602) is used for locking the second fan-shaped rotor (601) at the first station, and the second elastic device has a tendency of enabling the second fan-shaped rotor (601) to be switched from the second station to the first station.

10. External pressure rotary engine according to claim 8 characterized in that a plurality of second inlet ports (801) are provided on the engine body (001), a plurality of second inlet ports (801) are provided at intervals along the circumferential direction of the compressor rotor (004);

as the compressor rotor (004) rotates, the second circumferential surfaces (402) of the plurality of second cam portions sequentially close the second intake ports (801) so that the second intake ports (801) are periodically opened and closed.