Patent Publication Number: US-2021180465-A1

Title: Rotary engine system with work done in multiple cavities

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of International Patent Application No. PCT/CN2019/085915 with a filing date of May 8, 2019, designating the United States, now pending, and further claims priority to Chinese Patent Application No. 201810994770.0 with a filing date of Aug. 29, 2018. The content of the aforementioned applications, including any intervening amendments thereto, are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure belongs to the technical field of engines, and in particular, to a rotary engine system with separate work done in two or more cavities. 
     BACKGROUND 
     In the long-term development process, a pressure gas engine has the thermal utilization efficiency increased from 5% to about 40%, which is already a great change, but still far below the maximum utilization efficiency. Therefore, it is desirable to design a novel engine to achieve efficient utilization and energy conservation. 
     SUMMARY 
     In view of the mentioned shortcoming of the prior art, an objective of the present disclosure is to provide a rotary engine system with work done in multiple cavities to solve the problem of low thermal efficiency of pressure gas utilization equipment in the prior art. 
     The present disclosure provides a rotary engine system with pressure gas ejected by pistons to do work twice includes a plane base. A left bearing seat, a middle bearing seat and a right bearing seat are disposed at the top of the plane base in sequence from left to right. Recesses are formed in the left bearing seat and the middle bearing seat, and a first-stage working unit and a second-stage working unit are disposed in the recesses in sequence from right to left. A swivel bearing A is disposed in the right bearing seat, while a plane thrust bearing is disposed in the middle bearing seat which can be chosen depending on pressure and system size. A swivel bearing B is disposed in the left bearing seat. A shaft is disposed through the centers of the swivel bearing A and the swivel bearing B. The shaft has a two-stepped shaft structure with a left small end designed as a solid shaft and a right big end, and a right portion of the big end is designed as a hollow shaft. A left cylindrical surface of the hollow shaft has a plurality of equally spaced gas delivery holes, and the first-stage working unit is disposed around the gas delivery holes. The first-stage working unit and the second-stage working unit are configured to complete two passes of work done simultaneously on the same concentric shaft. 
     The first-stage working unit includes a first-stage rotor and a stator around the first-stage rotor. The stator is composed of a front stator, a middle stator and a rear stator, and the front stator, the middle stator and the rear stator are disposed around the shaft in sequence from right to left. A plurality of groups of equally spaced gas delivery passages are axially formed within the first-stage rotor, and the gas delivery passages in each group are uniformly distributed. Pistons are disposed between the outer race of the first-stage rotor and the inner race of the stator. The pistons have a plurality of groups of equally spaced piston orifices that are formed axially, and the piston orifices in each group are uniformly distributed. Each gas delivery passage is communicated with the gas delivery hole of the hollow shaft and the piston orifice. 
     The first-stage working unit forms a cylinder. A chamber formed in the cylinder is communicated with the hollow shaft of the shaft by means of the piston orifices and the gas delivery passages. A plurality of uniformly distributed valves are circumferentially disposed at the inner race of the cylinder. The valves are opened and closed depending on the moving positions of the pistons, so that isolated cavities are formed in the chamber. 
     A plurality of uniformly distributed exhaust holes A (with the same number as that of pistons) are circumferentially formed in the first-stage rotor. The exhaust hole A has an inclined surface structure with an angular exhaust orifice. A tail end of the exhaust orifice is connected to an angular nozzle by means of a one-way valve, and the angular nozzle is capable of ejecting and releasing the pressure gas stored in the chamber. 
     A plurality of uniformly distributed diversion holes are circumferentially formed in the rear stator. The diversion hole has a waist-shaped hole structure. The angular nozzles are capable of releasing the pressure gas alternately through the diversion holes to do work due to the motion of mass and ejecting and releasing the residual pressure gas through exhaust inlets to exhaust holes B. 
     The second-stage working unit includes a moving blade and an additional moving blade on the first rotor. The second-stage working unit allows ejection from the angular nozzles of the first-stage working unit through the diversion holes in a cover plate of the rear stator to the second-stage moving blade and the exhaust inlets and ejection to the working piece additional moving blade of the second-stage working unit through the exhaust holes B. The pressure gas is delivered through deflecting guide holes of the first moving blade to a second moving blade and a follow-up moving blade and into the system of the second-stage working units of a third rotor and a fourth rotor to do work by the internal energy release mass motion of the total pressure gas. 
     A working method of the rotary engine system with pressure gas ejected by pistons to do work twice includes the following operation steps: 
     (1) Pressure Gas Delivery: 
     The pressure gas is delivered to the center of the first-stage rotor of the first-stage working unit through the gas delivery holes in the hollow shaft segment of the shaft. The pressure gas is delivered to the nozzles on the pistons through the gas delivery passages to enter the chamber. 
     (2) Formation of Isolated Cavities in the Chamber: 
     The pressure gas is delivered into the piston orifices of the pistons and the chamber of the cylinder in sequence through the gas delivery passages within the first-stage rotor, and the valves are caused to open and close depending on the moving positions of the pistons. A plurality of isolated cavities are formed in the chamber of the cylinder when the valves are closed. The chamber is divided into the isolated cavities for storing the pressure gas. 
     (3) First Work: 
     A pressure is applied by the pressure gas delivered into the chamber through the piston orifices on the pistons, causing the pistons to rotate along with the first-stage rotor under increased pressure. The moving of the pistons confirms the first work done by the pistons. The valves in the cylinder are closed automatically when the pistons move for a particular distance. The pressure gas delivered through the piston orifices is stored in the limited space of the chamber between two valves. The pressure of the gas in the chamber and the counter-acting force of ejection act on the pistons, causing the pistons to move to do mechanical work. Thus, the first-stage process of doing work is confirmed. 
     Since the pressure gas stored in the chamber needs to be released after doing work under pressure, the pressure gas is ejected into the second-stage working system through the exhaust holes A of the first-stage rotor and the angular nozzles to do work; and therefore, additional work is done on the first-stage rotor and added to the first-stage working unit, so that additional energy is obtained during the first-stage work and the efficiency of the first-stage work is increased. 
     4) Second Work: 
     The pressure gas stored in the chamber through the first work is released and the pressure in the chamber is relieved. The pressure gas is ejected to the first moving blade and the exhaust inlets in the second-stage working unit by means of the exhaust holes A and the angular nozzles through the diversion holes of the stator to do work and relieve the pressure. The ejected pressure gas is delivered to the moving blade and the additional moving blade of the second-stage working unit and then ejected by the moving blade to moving blades behind including the second moving blade and the follow-up moving blade into the system chamber of the second-stage working unit, thereby completing the second-stage work done with full energy from the mass motion of the pressure gas released by the turbine. The additional moving blade is an auxiliary blade mounted outside the moving blade to utilize exhaust gas to do work. 
     In the process of the second-stage work done with the stored gas, the residual gas in the chamber is vented at the end of the process, which is specifically delivered from the exhaust holes A via the orifices of the angular nozzles, through the exhaust inlets formed in the cover plate of the rear stator and the passages in the stator, to the exhaust holes B, and then ejected to the additional moving blade outside the moving blade to do work with the aid of the released energy. The space behind the additional moving blade is conventional atmospheric zero-pressure space. The second-stage work done by full release is thus completed. 
     In use of the rotary engine system with pressure gas ejected by pistons to do work twice, the first-stage working unit works based on the principle of continuously ejecting the pressure gas using concentrically rotating piston nozzles; switching valves are added in the cylinder camber in which unidirectional circular rotation of the pistons occurs to create a plurality of isolated cavities in the chamber, thereby forming independently closed cylinder cavities to isolate and store the pressure gas delivered by the pistons for ejection to the turbine to do work for the second time due to the mass motion of the gas; thus, the pressure gas is continuously utilized to do work with the turbine after the work done by the motion of the pistons under pressure during the delivery of the pressure gas, and separate utilization of the pressure of the pressure gas and the energy of the mass motion of the released gas to do work is realized. 
     Both intake and exhaust of the pressure gas are carried out on the assembly of the rotor with concentric pistons to complete the whole process of doing work. The pressure gas is delivered through the center of the shaft, and delivered to orifices in piston heads through the center and the internal gas delivery passages of the first-stage rotor for uninterrupted ejection. The pressure gas delivered by the pistons is isolated and stored after the first work done by the motion of the pistons under pressure, and the energy of the stored pressure gas is delivered through the exhaust orifices in the piston rotor to the second-stage system to do the second work with the turbine. The pressure gas delivered is actually utilized to do work twice consecutively, namely the work done by the rotating pistons under total pressure and the work done through the release of the total pressure gas with the turbine. 
     In an embodiment of the present disclosure, the number of the pistons may be dependent on the size of the circumferentially rotating rotor, that is, one or more piston heads may be mounted on the rotor. The piston head and the orifice body may be mounted on the body of the rotating rotor separately. The structure of the piston head and the orifice may be a flat rectangular structure to move in the piston chamber of the cylinder along with the rotor without limitation to distance. The exhaust holes A of the chamber and the angular nozzles, which are as many as the pistons, respectively, may be mounted on the body of the rotor at intervals to rotate synchronously with the piston rotor. The exhaust holes A and the angular nozzles may be configured to do work by ejection to increase the total work done on the first-stage rotor, and serve to turn the space with pressure behind the pistons into atmospheric or negative-pressure space. 
     The pressure gas is delivered by the pistons, causing the pistons to rotate under pressure to do work. The pressure gas stored in the isolated cavities of the cylinder chamber needs to be released by the turbine, and the stored pressure gas ejected through the orifices of the first-stage rotor is delivered to the conventional second-stage turbine to do work in another manner. The stored pressure gas is vented through two release cavities. That is, the exhaust inlets and the exhaust holes B are designed to relieve the pressure in the chamber, creating real zero-pressure space behind the pistons. 
     In an embodiment of the present disclosure, the switching valves may be added in the piston cylinder so that the chamber of the cylinder can be divided into isolated cavities for repeated motion of the pistons and the storage and output of energy. The valves may be mounted on the stator in the piston cylinder. The valves may be twice the piston heads to realize an alternate exhaust working mode without simultaneous impulsion. The valves mounted on the cylinder or the outer body of the stator are used to form isolated cavities, so that the motion of the pistons under pressure and the release of energy of ejection by the piston rotor are carried out in two independently isolated chamber areas. The switching valves mounted on the stator are opened and closed depending on the moving positions of the rotating pistons. 
     In an embodiment of the present disclosure, with the intake of the pressure gas controlled at the front end of the whole system, the rotating piston system may be designed to operate under overload, that is, the load may be above the maximum first-stage work output capacity. During the rotation of the rotating piston, a speed of rotation may depend on load output. The total energy of the pressure gas for subsequent utilization may be determined by the sectional area under pressure and the moving speed of the pistons under full load and certain working condition. 
     In an embodiment of the present disclosure, the whole system must be based on one or more balanced concentric foundation platforms and composed of the first-stage rotating piston structure configured to do work under pressure and the second-stage turbine configured to perform ejection and release. Two passes of work are done concentrically. 
     As described above, the rotary engine system with pressure gas ejected by pistons to do work twice provided in the present disclosure has the following advantages: the utilization of the pressure gas in the order of delivery, impulsion, release and turbine is changed, and hence a novel utilization structure is constructed, that is, the utilization in the order of delivery to the center, ejection, doing work with pressure, storage, ejection, impulsion and release to do work. Thus, full utilization of the internal energy of the pressure gas is achieved as defined. Two passes of work are achieved successively, so that the utilization efficiency of the energy of the pressure gas is improved, and the utilization process of twice collection in two cavities is realized. The piston type utilization structure is changed to enable uninterrupted continuous intake to the center to do work by rotation under pressure and through ejection. The utilization efficiency is the same as or higher than that of the turbine, and twice utilization of the total internal energy can be achieved with reduced noise and vibration. The mode of doing work in two cavities is adopted to complete two passes of work in different cavities, namely the work done under pressure and the work done with the mass released by the turbine, thereby realizing twice utilization of total energy. The pressure of the pressure gas and the energy from the mass motion are utilized in two cavities separately. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front view of a system structure according to an embodiment of the present disclosure. 
         FIG. 2  is a schematic diagram of an internal structure of a first-stage working unit according to an embodiment of the present disclosure. 
     
    
    
     What reference numerals in the drawings denote are:  1 , shaft;  2 , first-stage working unit;  3 , first-stage rotor;  4 , gas delivery passage;  5 , piston;  6 , piston orifice;  7 , chamber;  8 , cylinder;  9 , valve; 10 , exhaust hole A;  11 , exhaust orifice;  12 , angular nozzle;  13 , diversion hole;  15 , exhaust inlet;  16 , rear stator;  17 , moving blade;  18 , second moving blade;  19 , follow-up moving blade;  20 , exhaust hole B;  21 , second-stage working unit;  22 , additional moving blade;  25 , one-way valve;  31 , swivel bearing A;  32 , plane thrust bearing;  33 , swivel bearing B;  51 , plane base;  52 , front stator; and  53 , middle stator. 
     DETAILED DESCRIPTION 
     A particular embodiment of the present disclosure will be described below, and other advantages and effects of the present disclosure will become apparent for those skilled in the art from the disclosure of this specification. 
     See  FIG. 1  and  FIG. 2 . The structure, scale, size, and the like shown in the drawings of this specification are only used to match the content disclosed in the specification and for those skilled in the art to understand and read, which are not used to limit the limitations for implementing the present disclosure and thus are not technically substantial. Any structural modification, scaling relation change, or size adjustment made without affecting the effects and objectives that can be achieved by the present disclosure shall fall within the scope that can be encompassed by the technical content disclosed in the present disclosure. Moreover, as used herein, the terms such as “upper”, “lower,” “left” “right”, “middle” and “a/an” are merely employed for ease of description, and not intended to limit the scope of the present disclosure, and the change or adjustment of the relative relationships shall be deemed as falling within the scope of the present disclosure without substantial alteration of technical contents. 
     With reference to  FIG. 1 , a rotary engine system with pressure gas ejected by pistons to do work twice includes a plane base  51 . A left bearing seat, a middle bearing seat and a right bearing seat are disposed at the top of the plane base  51  in sequence from left to right. Recesses are formed in the left bearing seat and the middle bearing seat, and a first-stage working unit  2  and a second-stage working unit  21  are disposed in the recesses in sequence from right to left. A swivel bearing A  31  is disposed in the right bearing seat, while a plane thrust bearing  32  is disposed in the middle bearing seat and a swivel bearing B  33  is disposed in the left bearing seat. A shaft  1  is disposed through the centers of the swivel bearing A  31  and the swivel bearing B  33 . The shaft  1  has a two-stepped shaft structure with a left small end designed as a solid shaft and a right big end, and a right portion of the big end is designed as a hollow shaft. A left cylindrical surface of the hollow shaft has a plurality of equally spaced gas delivery holes, and the first-stage working unit  2  is disposed around the gas delivery holes. The first-stage working unit  2  and the second-stage working unit  21  are configured to complete two passes of work done simultaneously on the same concentric shaft. The design of two passes of work is based on the work of the pressure on the pistons and the work done by the turbine through the impulsion of the pressure gas and the expansion of the moving mass released by the turbine. 
     The first-stage working unit  2  includes a first-stage rotor  3  and a stator around the first-stage rotor  3 . The stator is composed of a front stator  52 , a middle stator  53  and a rear stator  16 , and the front stator  52 , the middle stator  53  and the rear stator  16  are disposed around the shaft  1  in sequence from right to left. A plurality of groups of equally spaced gas delivery passages  4  are axially formed within the first-stage rotor  3 , and the gas delivery passages  4  in each group are uniformly distributed. Pistons  5  are disposed between the outer race of the first-stage rotor  3  and the inner race of the stator. The pistons  5  have a plurality of groups of equally spaced piston orifices  6  that are formed axially, and the piston orifices  6  in each group are uniformly distributed. Each gas delivery passage  4  is communicated with the gas delivery hole of the hollow shaft and the piston orifice  6 . 
     With reference to  FIG. 2 , the first-stage working unit  2  forms a cylinder  8 . A chamber  7  formed in the cylinder  8  is communicated with the hollow shaft of the shaft  1  by means of the piston orifices  6  and the gas delivery passages  4 . A plurality of uniformly distributed valves  9  are circumferentially disposed at the inner race of the cylinder  8 . The valves  9  are opened and closed depending on the moving positions of the pistons  5 , so that isolated cavities are formed in the chamber  7 . 
     A plurality of uniformly distributed exhaust holes A  10  are circumferentially formed in the first-stage rotor  3 . The exhaust hole A  10  has an inclined surface structure with an angular exhaust orifice  11 . A tail end of the exhaust orifice  11  is connected to an angular nozzle  12  by means of a one-way valve  25 , and the angular nozzle  12  is capable of ejecting and releasing the pressure gas stored in the chamber  7 . 
     A plurality of uniformly distributed diversion holes  13  are circumferentially formed in the rear stator  16 . The diversion hole  13  has a waist-shaped hole structure. The angular nozzles  12  are capable of releasing the pressure gas alternately through the diversion holes  13  to do work due to the motion of mass and ejecting and releasing the residual pressure gas through exhaust inlets  15  to exhaust holes B  20 . 
     The second-stage working unit  21  includes a moving blade  17  and an additional moving blade  22  on the first rotor. The second-stage working unit  21  allows ejection from the angular nozzles  12  of the first-stage working unit through the diversion holes  13  in a cover plate of the rear stator  16  to the second-stage moving blade  17  and the exhaust inlets  15  and ejection to the working piece additional moving blade  22  of the second-stage working unit  21  through the exhaust holes B  20 . The pressure gas is delivered through deflecting guide holes of the first moving blade  17  to a second moving blade  18  and a follow-up moving blade  19  and into the system of the second-stage working units of a third rotor and a fourth rotor to do work by the internal energy release mass motion of the total pressure gas. Thus, the pressure gas can be utilized to do work twice. 
     The continuous motion of the piston  5  occurs at a low speed under overload. Energy loss caused during the motion of the piston  5  is equivalent to the resistance of a steam pipe and the temperature of the pipe. In consideration of the use and the switching speed of the valve  9  at present, the piston  5  is designed into flat rectangular structure. The moving speed of the piston  5  is determined to be a standard parameter of pressure gas delivery rate in pipe. 
     A working method of the rotary engine system with pressure gas ejected by pistons to do work twice includes the following operation steps: 
     (1) Pressure Gas Delivery: 
     The pressure gas is delivered to the center of the first-stage rotor  3  of the first-stage working unit  2  through the gas delivery holes in the hollow shaft segment of the shaft  1 . 
     (2) Formation of Isolated Cavities in the Chamber: 
     The pressure gas is delivered into the piston orifices  6  of the pistons  5  and the chamber  7  of the cylinder  8  in sequence through the gas delivery passages  4  within the first-stage rotor  3 , and the valves  9  are caused to open and close depending on the moving positions of the pistons  5 . A plurality of isolated cavities are formed in the chamber  7  of the cylinder  8  when the valves  9  are closed. The chamber  7  is divided into the isolated cavities for storing the pressure gas. 
     (3) First Work: 
     A counter-acting force is applied by the pressure gas delivered into the chamber  7  through the piston orifices  6  on the pistons  5 , causing the pistons  5  to rotate along with the first-stage rotor  3  under increased pressure. The moving of the pistons  5  confirms the first work done by the pistons  5 . The valves  9  in the cylinder  8  are closed automatically when the pistons  5  move for a particular distance. The pressure gas delivered through the piston orifices  6  is stored in the limited space of the chamber  7 . The pressure of the gas in the chamber  7  and the counter-acting force of ejection act on the pistons  5 , causing the pistons  5  to move to do mechanical work. Thus, the first-stage process of doing work under pressure is confirmed. The moving speed of the pistons  5  is restricted by selecting a gas delivery rate and choosing the valves  9  used. The continuous motion of the pistons  5  occurs at a low speed under overload. 
     Since the pressure gas stored in the chamber  7  needs to be released after doing work under pressure, the pressure gas is ejected into the second-stage working system  21  through the exhaust holes A  10  of the first-stage rotor  3  and the angular nozzles  12  to do work; and therefore, additional work is done on the first-stage rotor and added to the first-stage working unit, so that additional energy is obtained during the first-stage work and the efficiency of the first-stage work is increased. 
     (4) Second Work: 
     The pressure gas stored in the chamber  7  through the first work is released by the turbine and the pressure in the chamber  7  is relieved. The pressure gas is ejected to the first moving blade  17  and the exhaust inlets  15  in the second-stage working unit  21  by means of the exhaust holes A  10  and the angular nozzles  12  through the diversion holes  13  of the stator to do work and relieve the pressure. The ejected pressure gas is delivered to the moving blade  17  and the additional moving blade  22  of the second-stage working unit  21  and then ejected by the moving blade  17  to moving blades behind including the second moving blade  18  and the follow-up moving blade  19  into the system chamber of the second-stage working unit  21 , thereby completing the second-stage work done with full energy from the mass motion of the pressure gas released by the turbine. The additional moving blade  22  is an auxiliary blade mounted outside the moving blade  17  to utilize exhaust gas to do work. 
     In the process of the second-stage work done with the stored gas, the residual gas in the chamber  7  is vented at the end of the process, which is specifically delivered from the exhaust holes A  10  via the orifices of the angular nozzles  12 , through the exhaust inlets  15  formed in the cover plate of the rear stator  16  and the passages in the stator, to the exhaust holes B 20 , and then ejected to the additional moving blade  22  outside the moving blade  17  to do work with the aid of the released energy. The space behind the additional moving blade  22  is conventional atmospheric zero-pressure space. The second-stage work done by full release is thus completed. The structures related to the moving blade  17  of the second-stage working unit  21  are applied to large-scale high pressure systems. 
     In use of the rotary engine system with pressure gas ejected by pistons to do work twice, wherein the first-stage working unit  2  works based on the principle of continuously ejecting the pressure gas using concentrically rotating piston nozzles; switching valves  9  are added in the cylinder camber  7  in which unidirectional circular rotation of the pistons occurs to create a plurality of isolated cavities in the chamber, thereby forming independently closed cylinder cavities to isolate and store the pressure gas delivered by the pistons  5  for ejection to the turbine to do work for the second time due to the mass motion of the gas; thus, the pressure gas is continuously utilized to do work with the turbine after the work done by the motion of the pistons  5  under pressure during the delivery of the pressure gas, and full utilization of the pressure of the pressure gas and the energy of the mass motion of the released gas to do work is realized. 
     In such a working process, two passes of work have been done on the whole rotor, one by pressure and the other by ejection. Besides, the two passes of work are completed in two areas, that is, the work is done in two isolated cavities. Then, the pressure gas is continuously ejected and released to allow the first-stage rotor  3  to rotate continuously. The pressure gas delivered into the cylinder chamber is completely utilized to do work by such a process. The pressure gas is then utilized for the second-stage work done with the energy from the mass motion of the pressure gas released by the turbine. 
     Both intake and exhaust of the pressure gas are carried out on the assembly of the rotor with concentric pistons to complete the whole process of doing work. The pressure gas is delivered through the center of the shaft  1 , and delivered to orifices  6  in piston heads through the center and the internal gas delivery passages  4  of the first-stage rotor  3  for uninterrupted ejection. The pressure gas delivered by the pistons  5  is isolated and stored after the first work done by the motion of the pistons  5  under pressure, and the energy of the stored pressure gas is delivered through the exhaust orifices in the piston rotor to the second-stage system to do the second work with the turbine. The pressure gas delivered is actually utilized to do work twice consecutively, namely the work done by the rotating pistons under total pressure and the work done through the release of the total pressure gas with the turbine. 
     The number of the pistons is dependent on the size of the circumferentially rotating rotor, that is, one or more piston heads are mounted on the rotor; the piston head and the orifice body are mounted on the body of the rotating rotor separately. The structure of the piston head and the orifice is a flat rectangular structure to move in the piston chamber of the cylinder along with the rotor without limitation to distance. The exhaust holes A  10  of the chamber and the angular nozzles  12 , which are as many as the pistons, respectively, are mounted on the body of the rotor at intervals to rotate synchronously with the piston rotor. The exhaust holes A  10  and the angular nozzles  12  are configured to do work by ejection to increase the total work done on the first-stage rotor, and serve to turn the space with pressure behind the pistons into atmospheric or negative-pressure space. 
     The pressure gas is delivered by the pistons, causing the pistons to rotate under pressure to do work. The pressure gas stored in the isolated cavities of the cylinder chamber needs to be released by the turbine, and the stored pressure gas ejected through the orifices of the first-stage rotor is delivered to the conventional second-stage turbine and conventionally utilized to do work for the second time. The stored pressure gas is vented through two release cavities. That is, the exhaust inlets  15  and the exhaust holes B  20  are designed to relieve the pressure in the chamber  7 , creating real zero-pressure space behind the pistons. 
     The switching valves are added in the piston cylinder so that the chamber of the cylinder is divided into isolated cavities for repeated motion of the pistons and the storage and output of energy. The valves are mounted on the stator in the piston cylinder. The number of the valves is twice plus one of the number of the piston heads to realize an alternate exhaust working mode without simultaneous impulsion. The valves mounted on the cylinder or the outer body of the stator to form isolated cavities, so that the motion of the pistons under pressure and the release of energy of ejection by the piston rotor are carried out in two independently isolated chamber areas. The switching valves mounted on the stator are opened and closed depending on the moving positions of the rotating pistons. 
     With the intake of the pressure gas controlled at the front end of the whole system, the rotating piston system is designed to operate under overload, that is, the load is above the maximum first-stage work output capacity. During the rotation of the rotating piston, a speed of rotation depends on load output. The total energy of the pressure gas for subsequent utilization is determined by the sectional area under pressure and the moving speed of the pistons under full load and certain working condition. 
     The whole system is based on one or more balanced concentric foundation platforms and composed of the first-stage rotating piston structure configured to do work under pressure and the second-stage turbine configured to perform ejection and release. Two passes of work are done concentrically. 
     According to the present disclosure, such structural components as a foundation platform, a base, bearings, a thrust bearing, shaft  1 , a gas delivery pipe, stator, first-stage rotor  3 , pistons  5 , valves  9 , exhaust holes  10 , angular nozzles  12  and one-way valves  25  are used to form an independent rotary piston engine system, and the engine system with pistons is capable of completing two passes of work. The system is based on a horizontal concentric foundation platform and has the base, the bearings, the shaft  1  and the like. The stator is used as a housing to form an outer sealing portion of the cylinder, and the outside-diameter plane of the piston rotor is used as an inner sealing portion of the piston cylinder. Due to the use of the rotating pistons, connecting rods and crankshaft are omitted from the piston cylinder, and loss caused by reciprocating motion is avoided. Moreover, a continuous working mode is adopted, allowing for efficient operation of the pistons without vibration. The stator is configured to seal three sides of the cylinder. The rotor is located within the stator and the outer peripheral surface of the rotor forms a sealing surface for the cylinder chamber. The cylinder rotor is capable of rotating along with a pressure gas input shaft (pipe). A proper number of piston heads and exhaust holes including angular orifices may be mounted on the cylinder rotor. The pistons and the exhaust orifices are spaced apart at fixed intervals. The total pressure gas is delivered to the center of the rotor to complete the whole process of doing work. The switching speed is determined depending on the use of the rotating pistons. Also, the flat rectangular piston is used based on the characteristics of piston motion and valve use. Thus, the switching distance of the valve can be reduced with increased switching speed because the increase in the speed of rotation of the piston contributes to the improvement of efficiency. Likewise, the piston and the valve may be configured in other shapes. The switching valves are mounted within the stator, that is, on the inner wall of the stator sealed chamber of the cylinder, to form independent cylinder cavities more than twice the piston heads. Thus, the whole cylinder chamber can be divided into a plurality of independent cavities to receive the pressure gas delivered by the pistons and store the pressure gas released by the turbine to do work for the second time. Thus, the need of the whole system in doing work can be met. 
     The embodiment described above is merely illustrative of the principles and effects of the present disclosure, and not intended to limit the present disclosure. Any person skilled in the art can make modifications or alterations to the described embodiment without departing from the spirit and scope of the present disclosure. Hence, all equivalent modifications or alterations made by those of ordinary skill in the art without departing from the spirit and technical teachings disclosed in the present disclosure shall fall within the scope defined by appended claims to the present disclosure.