Design method for cylinder for fluid transfer device Field of the Invention The invention relates to a design method for the fluid transfer device, especially to a design method for the cylinder for a fluid transer device. 5 Description of prior art The working prcess of the internal combustion engine is roughly such, the piston moves downward, the mixed combustible gas goes into the cylinder; the piston moves upward to compress 10 combustible gas, the spark plug ignites combustible gas to explode the gas, the exploded gas with high temperature and high pressure drives the piton moving downward, the linear movement of the piston is converted to the rotational movement of the crankshaft by the connecting rod; the crankshaft goes on rotating because of the 15 inertia, the rotational movement of the crankshaft is converted to the linear movement of the piston by the connecting rod, the piston moves upward to push exhaust gas out of the cylinder. In brief, inhale- compression -work- exhaust. 20 Whether we can make some reconstruction based on the structure of the cylinder of the current internal combustion engine, saving the process of " compression-work", keeping the precess of " inhale exhaust", such that the reconstructed device can be used in the field of pumping air, or compressing air, or drawing water or pumping 25 water. Summary of the present invention The object of the invention is to provide a design method for the cylinder for the fluid transfer device so as to solve the above 1/10 problem. In the following, the technical solution will be discribed. A design method for the cylinder for the fluid transfer device 5 comprises providing an input passage, an output passage and a receiving chamber; further providing a cylindrical valve chamber passing through the cylindre; 10 arranging for the receiving chamber to be cylindrical, and to be radial with respect of the valve chamber; providing the receiving chamber with a cylindrical portion and a trumpet-shaped constriction portion coaxial with the cylindrical portion; 15 arranging for the diameter of the of the head end of the constriction portion to be less than the interior diameter of the receiving chamber; arranging for the junction between the head end of the constriction portion and the tail end of the receiving chamber to 20 form a limiting surface configured to mate with the side surface of the cylinder casing, which surrounds the receiving chamber; communicating the tail end of the receiving chamber, the tail end of the input passage and the tail end of the output passage with the valve chamber; 25 arranging for the head end of the input passage and the head end of the output passage to extend to the exterior surface of the cylinder; communicating the cylindrical portion of the receiving chamber with the outside; 30 arranging for the width of the tail end of the constriction portion to be greater than the width of the swinging range of the first passage of the cartridge rotating in the valve chamber; arranging for the minimal distance between the tail end of the output passage and the tail end of the input passage to be greater 2/10 than the width of the second passage of the cartridge. Specifically, coaxially providing the valve chamber with two limiting grooves; the area between the two limiting grooves being for 5 loacating tail end of the receiving chamber, the tail end of the input passage and the tail end of the output passage. Preferably, arranging the valve chamber in the center of the cylinder; 10 uniformly arranging four receiving chambers in a ring array, the axis of the array is the axis of the valve chamber, arranging one input passage and one output passage between the two receiving chamber, the input and output passages are mirror-imaged. 15 Advantageously, arranging for the diameter of the head ends of the input and output passages to be greater than the diameter of the tail ends thereof, and providing the head ends thereof with thread for conncting with the outside; 20 arranging for the distance between the tail ends of the input and output passages to be less than the distance between the head ends thereof; arranging an aspirail between the input or output passage and the receiving chamber; 25 taking heat created from the cylinder away with the air flow passing through the aspirail which passes through the cylinder. Specifically, providing the cylinder with a head side surface and a tail side surface, two side surfaces thereof are parallel to the plane 30 which houses the axises of four receiving chambers, each of the two side surfaces has a blind hole; coaxially providing the bottom portion of the blind hole with a thread hole; uniformly arranging a pluralitiy of blind holes in a ring array, 3/10 the axis of the array is the axis of the valve chamber; removably matting the blind hole with the suppot pillar. Advantageously, arranging a pit for receiving the swinging arm to 5 each of the head side surface and the tail side surface; arranging the pit coaxial with the valve chamber; connecting the bottom portion of the pit with valve chamber through slope. 10 Advantageous Effects 1. Because the width of the tail end of the constriction portion is greater than the width of swinging range of the first passage of the cartridge rotating in the valve chamber, the receiving chamber communicates with the first passage of the cartridge as the 15 cartridge rotating. 2. Because the minimal distance between the tail ends of the output and input passages is greater than the width of the second passage, the input or output passages do not communicate with the second 20 passage of the cartridge at the same time, which guarantees that the fluid in the output passage do not flow to the input passage, so it is achieved that fluid flows in one direction. Design of arranging a blind hole and a thread hole to the side 25 surfaces of the cylinder can bring such advantages, a. the blind hole limits the axial and radial movements of the support pillar so as to avoid the shaking occured by the displacement of component; b. increasing the assemble convennience, the support pillar can be 30 quickly conveniently placed with the help of the blind hole of the cylinder; c. maximally enlarge the support effect of the support pillar, the support pillar and the blind hole support each other by the cylindrical surface inserted into the blind hole so as to avoid the 4/10 radial shearing force on the fastening screw, the screw only carries the axial force, it is reasonable. Brief description of the drawing 5 In the following, the invention will be described in greater detail by means of some embodiments with reference to the accompanying drawings, in which Fig.1 is a sectional front view of the transfer device; Fig.2 is a sectional view of a single receiving chamber of the 10 cylinder; Fig.3 is a drawing of the cylinder mounting to the fluid transfer device; Fig.4 is a 3d-drawing of the cylinder of the invention; Fig.5 is a sectional front view of the cylinder. 15 1. the receiving chamber; 2. the piston; 3. the cartridge; 4. the input passage; 5. the output passage; 6. the triggering wheel; 7. the first passage; 8. the second passage; 9. the swinging arm; 10.the constriction portion; 11. the limiting surface; 12. the cylindrical portion; 20 13. the aspirail; 14. the valve chamber; 15. the limiting groove; 16. the blind hole; 17. the thread hole; 18. the pit. Detailed description of the preferred embodiment In order to distinguish between the head and the end of the 25 component, the portion near the axis of the valve chamber 14 is called the end, and the portion away from the axis of the valve chamber 14 is called the head. Referring to Fig.1, it is the fluid transfer device of the invention, 30 inorder to increase the transferring efficiency of the device, the device includes four piston units 2, four piston units 2 are uniformly arranged in a ring array, the axis of the array is the axis of the valve chamber 14. Three of the four input passages 4 are sealed by plugs, 5 /10 and three of the four output passages 5 are sealed by plugs, the transfer device only keeps one input passage 4 and one output passage 5. 5 Under the effect of the outside power, the piston 2 with piston ring moves hermetically reciprocally in the cylinder casing in the receiving chamber 1, meanwhile, the triggering wheel also 6 rotates, the swinging arm 9 of the cartridge 3 interacts intermittently with the triggering wheel 6 so as to make the cartridge 3 swing in the 10 valve chamber 14 of the cylinder, that is the second passage 8 swings between the input passage 4 and the output passage 5, the swinging motion of the first passage 7 of the cartridge 3 achieves that the receiving chamber 1 communicates with the input passage 4 or the output passage 5. 15 Because the width of the tail end of the constriction portion 10 of the receiving chamber 1 is greater than the width of the swinging range of the first passage 7 of the cartridge 3 rotating in the valve chamber 14, the receiving chamber 1 always communicates with 20 the first passage 7 as the cartridge 3 rotating. When the piston 2 moves upward, the second passage 8 of the cartridge 3 communicates with the input passage 4, fluid passes sequentially through the input passage 4 of the cylinder, the second 25 passage 8 of the cartridge 3 and the first passage 7 under the outside pressure, finally fluid goes into the receiving chamber 1, the input of fluid is achieved. When the piston 2 moves downward, the second passage 8 of the 30 cartridge 3 communicates with the output passage 5 of the cylinder, fluid in the receiving chamber 1 sequentially passes through the first passage 7 of the cartridge 3 and the second passage 8 under the force from the piston 2, finally fluid is compressed out of the output passage 5 of the cylinder, the output of fluid is achieved. 6/10 Because the minimal distance between the tail end of the output passage 5 and the tail end of the input passage 4 is greater than the width of the second passage 8 of the cartridge 3, the input passage 5 4 or the output passage 5 do not communicate with the second passage 8 at the same time, which guarantees that fluid in the output passage 5 do not flow to the input passage 4. Referring to Fig.5, a valve chamber 14 for hermetically rotationally 10 matting with the cartridge 3 is situated in the center of the cylinder, four receiving chamber 1 are uniformly arranged in a ring array, the axis of the array is the axis of the valve chamber 14, one input passage 4 and one output passage 5 are situated between the two receiving chambers 1, the input and output passages 4, 5 are 15 mirror-imaged, the stability of the whole device is increased due to the uniform arrangement. The receiving chamber 1 is configured to be cylindrical and is radially arranged with respect of the valve chamber 14. The tail ends of the receiving chamber 1, the input passage 4 and the output passage 5 are configured to communicate 20 with the valve chamber 14, the head ends of the input and output passages 4, 5 are configured to extend to the exterior surface of the cylinder, the cylindrical portion of the receiving chamber 1 communicates with the outside. 25 The width of the head ends of the input and output passages 4, 5 is greater than the width of the tail ends thereof, and the head ends thereof have thread for connecting with the outside. The distance between the tail ends of the input and output passages 4, 5 is less than the distance between the heand ends thereof, such 30 arrangement increases the assemble convenience of connecting components. An aspirail 13 is situated between the input or output passage 4, 5 and the receiving chamber 1, the aspirail 13 passes through the cylinder, heat created from the cylinder is taken away by the air flow passing through the aspirail 13. 7/10 Referring to Fig.4, the cylindrical valve chamber 14 passing through the cylinder coaxially arranges two limiting grooves 15, the area between the two limiting grooves 15 is for loacating tail end of the 5 receiving chamber 1, the tail end of the input passage 4 and the tail end of the output passage 5. The cylinder comprises a head side surface and a tail side surface, two side surfaces thereof are parallel to the plane which houses the axises of four receiving chambers 1, each of the two side surfaces has a blind hole 16, the bottom 10 portion of the blind hole 16 coaxially has a thread hole 17, a pluralitiy of blind holes 16 are uniformly arranged in a ring array, the axis of the array is the axis of the valve chamber 14, the blind hole 16 removably mates with the suppot pillar. 15 The head side surface and the tail side surface each has a pit 18 for receiving the swinging arm 9, the pit 18 is coaxial with the valve chamber 14, the bottom portion of the pit 18 connects with valve chamber 14 through slope. 20 Referring to Fig.2, the receiving chamber 1 has a cylindrical portion 12 and a trumpet-shaped constriction portion 10 coaxial with the cylindrical portion 12, the diameter of the of the head end of the constriction portion 10 is less than the interior diameter of the receiving chamber 1, the junction between the head end of the 25 constriction portion 10 and the tail end of the receiving chamber 1 forms a limiting surface 11 configured to mate with the side surface of the cylinder casing, which surrounds the receiving chamber 1, the cylinder casing has an interference fitting with the cylinder. 30 Referring to Fig.3, the cartridge 3 hermetically rotates in the valve chamber 14 of the cylinder, the cartridge 3 is limited between the two limitting grooves by two retaining rings. The swinging arm 9 removably connected with the cartridge 3 swings in the pit 18 of the cylinder. 8/10 In the following, the application of the cylinder for the fluid transfer device will be discribed. 5 1. The inlet opening of the device connects to the water well through pipes, the outlet opening connects to the water tower. The piston 2 in the receiving chamber 1 moves upward to creat a negative pressure area in the receiving chamber 1, under the effect of the atmosphere, the air in the pipe connected with the inlet 10 opening goes into the second passage 8 through the input passage 4, then goes into the first passage 7 through the manifold chamber, finally the air is pressed into the receiving chamber 1. Due to the downward movement of the piston 2 in the receiving chamber 1, the air in the receiving chamber 1 is pressed into manifold chamber 15 through the first passage 7, then into the output passage 5 through the second passage 8, finally into the water tower along the pipe connected with the outlet opening. After the air in the pipe connected with the inlet opening is totally 20 pressed out, the piston 2 in the receiving chamber 1 moves upward to creat a negative pressure area in the receiving chamber 1, under the effect of the atmosphere, water in the well is compressed into the receiving chamber 1 through the second and first passages 7, 8. 25 The downward movement of the piston 2 within the receiving chamber 1 compresses water therein out of the output passage 5 opening through the first and second passages 7, 8, due to the near incompressibility of water, the output passage 5 can ouput water flow with equal pressure, the water flow at the outlet opening can 30 climb a certain height along the pipe with the help of the pressure into the water tower. So the device can transfer water in a well with a certain depth to a water tower with a certain height, even there is some air left in the pipe connected with the inlet opening, the device can still draw and pump water. 9/10 2. The inlet opening of the device connects with the atmosphere, the outlet opening connects with a gas tank through pipes. The piston 2 moves upward to creat a negative pressure area in the 5 receiving chamber 1, air near the inlet opening is compressed into the receiving chamber 1 through the second and first passages 8, 7 by the effect of the atmosphere. The downward movement of the piston 2 within the receiving chamber 1 compresses air therein out of the output passage 5 opening through the first and second 10 passages 7, 8, due to the compressibility of air, the output passage 5 can ouput air flow with a little pressure, which is collected in the gas tank little by little, such that air mass with a certain pressure is finally formed in the tank, so the device can be used as an air compressor. 15 3. The inlet opening of the device connects with a sealing container, while the outlet opening connects with the atmosphere, the piston 2 moves upward to creat a negative pressure area in the receiving chamber 1, the air in the sealing container is compressed into the 20 receiving chamber 1 through the second and first passage 8, 7 by the current air pressure in the container. The downward movement of the piston 2 within the receiving chamber 1 compresses air therein out of the output passage 5 opening through the first and second passages 7, 8, and then into the atmosphere, so the device 25 can draw air out of the sealing container to reduce air pressure in the container. So the device can be used as an air-extractor. 10/10