Abstract:
Disclosed herein is a revised version of housing wheel engine with method of hypotrochoid that patented U.S. Pat. No. 7,730,869. It keeps the main functions and also provides not only cases Rr≧3 but also cases Rr2 and Rr1, which means it would be able to develop engines as well as four pistons and two pistons, which the previous version cannot do.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
       [0001]    This invention relates to a four-stroke cycle internal combustion Housing Wheel Engine, it has been issued Jun. 8, 2010, U.S. Pat. No. 7,730,869. 
       2. Discussion of the Technical Problems of U.S. Pat. No. 7,730,869 
       [0002]    2.1 The kinematics feature of the Hypotrochoid and its defects:
       A hypotrochoid system formed by a fixed bigger circle R and two sets of smaller rolling circles r (here R and r represent the circles and also represent their radius), and each of r has an eccentric point P with an offset d. See  FIG. 1   a.      In order to build a machine with hypotrochoid system, the prerequisites are: Take 2 sets, and each set has a number N of smaller rolling circles r. (here N is an integer and N=R/r), put them inside of a stationary circle R evenly at polar angle α i , and set each of eccentric points P in polar angle θ i . See  FIG. 1   a.      The expressions of prerequisites of above are:
           1) N=R/r and Nε{3, 4, . . . };   2) α i =(i−1)180°/N, and iε{1, 2, . . . 2N};   3) θ i =α i +i180°, and iε{1, 2, . . . 2N}.   
           For simplicity, using RrN as a description of equation of N=R/r and also to describe the scale of the machine. For example, Rr3 machine means it is a machine that has N=R/r=3, also means it is a six pistons engine.   With reference to  FIG. 1 a   , it can be seen: Based on above essential setup, any two of the neighborhoods P will locate at opposite sides of the circle c. When all rolling circles r roll inside of the R with the same direction and velocity, it will make any two of neighborhoods P move either approaching or apart each other. It demonstrates that this hypotrochoid system has such a kinematics feature of a compressor mechanism.   The kinematics feature of hypotrochoid system has been adopted in the invention of Housing Wheel Engine (U.S. Pat. No. 7,730,869 dated Jun. 8, 2010).     FIG. 1 b    shows how to form a housing wheel engine based on such hypotrochoid system.   When six (here  FIG. 1 b    shows the example of Rr3 engine) rolling gears G r  roll inside of an annular internal gear G b , the eccentric pin G p  (which joined inside of the spoke&#39;s slot S s ), drives 2 sets of spokes S p 1, S p 2 and pistons P s 1, P s 2 (which fixed on the top of the spokes), doing (1) reciprocating swing with respect to the center of rolling gear O r  and (2) rotation moving with respect to the center of annular internal gear O b . These two kinds of movements represent respectively of (1) compressing/expanding motions between any two of neighborhoods of pistons, and (2) four-stroke circulation around O b .   Unfortunately the Housing Wheel Engine with hypotrochoid provides only Rr≧3 cases, which means it cannot be developed as an engine that has less than 6 pistons. This is because of: (1) hypotrochoid doesn&#39;t even have Rr1 case, and (2) in the case Rr2 the sizes of the rolling gears extend to the center of the big fixed gear O b  so that occupied the space which should be located of main drive shift. So, the prerequisites for the number N=R/r on the machine could not be 1 and 2, and only will be the integer Nε{3, 4, . . . }.   Now let&#39;s take look the epitrochoid system, with reference to  FIG. 2 a   . It can be seen this system has exactly the same kinematics features if it take the same setup as hypotrochoid system, which are:
           1) N=R/r, and Nε{1, 2, . . . } (here the major difference between epitrochoid system and hypotrochoid system is N start from 1 or 3);   2) α i =(i−1)180°/N, and iε{1, 2, . . . 2N};   3) θ i =α i +i180°, and iε{1, 2, . . . 2N}.   
            And also it will provide not only cases Rr≧3 but also cases Rr2 and Rr1, which means it would be able to develop engines as well as four pistons and two pistons (see  FIG. 3 a    and  FIG. 3 c   ), which the hypotrochoid system cannot do.     FIG. 2 b    and  FIG. 3 b    both show how to form a housing wheel engine based on epitrochoid system.   Make an offset of a crankshaft C s  ¼ length of the stroke, and mount this crankshaft C s  on the center of outer rolling gear G r . When all rolling gears G r  roll outside of a outer fixed annular gear G b , the crankshaft C s  (which joined inside of the slot S s ) will drive pistons P s  moving total ½ length of stroke around the center of the rolling gear O r . Any two of the neighborhoods of rolling gears will drive the pistons either depart till to a whole length of a stroke (like BDC in reciprocating engine) or approaching till to a minimum space (like TDC in reciprocating engine) each other.   The same kinematics feature as hypotrochoid system, which are two movements in this system: (1) the reciprocating swing of a piston with respect to the center of rolling gear O r  and (2) the rotation moving of all pistons with respect to the center of annular outer gear O b . These two kinds of movements represent respectively of (1) compressing/expanding motions between any two of neighborhoods of pistons, and (2) four-stroke circulation around O b  (The mechanism of four-stroke circulation will not be discussed in this invention since it won&#39;t be changed).       
 
         [0022]    2.2 The issues of the Housing Wheel Seals:
       Conceptually, Housing Wheel Seals, which could be using in the machine based on the principle of hypotrochoid system, most look like thin, annular and the size as larger as housing wheel, located between two housing wheel halves (see  FIG. 4 ). They must endure some particular harsh working environment, such as high friction, high temperature, high pressure and high velocity, and meanwhile they have to maintain high gas tightness. The housing wheel seals move with circumferential direction, which doing like blade with cutting movement. It&#39;s a very tough touching to Housing Wheel Halves. Compare with regular piston rings, which move with axial direction, doing like blade with shaving movement. It&#39;s a kind of mild touching to the cylinder wall. It is obviously that the way of piston ring should be adopted.   The instant invention proposed a new method that employs an “integral housing wheel” to substitute “a pair of housing wheel halves”, in order to avoid housing wheel seal. Also discussed some derivative issues, which are (1) making pistons no longer mounted inside of housing wheel halves, and using piston-sets (see  FIG. 6 ) doing relative motion within integral housing wheel instead. (2) Separating intake and exhaust valves and relocated them outside of the pistons (see  FIG. 7 ). (3) Using anti centrifugal system (see  FIG. 9 ,  FIG. 10 ) to overcome centrifugal force on piston-set.   The benefits of above are (1) using piston-ring to replace housing wheel seal, (2) makes each of individual valve no longer to take both functions within exhausting and intake strokes, and preventing the risk of the same valve could be overheated within exhaust stroke and could untimely to igniting within intake stroke, and (3) conquered friction resistance between the piston-set and housing well that generated by the centrifuge force on the piston-set.   Another issue is particularly for Rr1 case, since other than Rr1 will have centrosymmetry automatically when in running. The two pistons machine will be non-centrosymmetry when it does compression in one side and expanding in another side. This behave make the machine shaking. The instant invention proposed a mechanism called vibration balance system to counterbalance the shake (see  FIG. 11 ).       
 
       SUMMARY OF THE INVENTION 
       [0027]    It is a feature of the invention to provide a four-stroke Housing Wheel Engine. 
         [0028]    It is another feature of the invention to provide a Housing Wheel Engine with the method of epitrochoid, which supports whole range of dimension in engine designing. 
         [0029]    It is another feature of the invention to provide a planetary gear sets formed therein by a fixed annular outer gear and plurality pair sets of rolling gears. Plurality pair sets of rolling gears evenly interlocked each other and located outside of a fixed annular gear evenly. 
         [0030]    It is another feature of the invention to provide an integral housing wheel formed therein by plurality of housing wheel segments, which connected together by crankshaft holders and intake-exhaust ports holders. 
         [0031]    It is another feature of the invention to provide plurality of crankshafts, which&#39;s offset is ¼ of a stroke. Each of crankshafts connects to a piston-set with a rolling gear. The assembly of planetary gear set and crankshaft provides the kinematics features of epitrochoid and timing features of four-stroke. 
         [0032]    It is another feature of the invention to provide an anti centrifugal system which formed therein by spherical thrust bearing, logarithmic spiral cam, and gravity blocks etc. to balance the centrifugal force of the piston-sets. 
         [0033]    It is another feature of the invention to provide a vibration balance system for only Rr1 system. It formed by offset pin on rolling gear, gravity slider and track to counterbalance the vibration, which caused by non-centrosymmetry of Rr1 system. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0034]      FIG. 1   a - b  are schematic views of hypotrochoid system. 
           [0035]      FIG. 2   a - b  are schematic views of epitrochoid system. 
           [0036]      FIG. 3   a - b - c  are schematic views of epitrochoid system Rr1 and Rr2. 
           [0037]      FIG. 4  is a schematic view of the seal of hypotrochiod system. 
           [0038]      FIG. 5  is an exploded perspective view of the Rr1 housing wheel engine. 
           [0039]      FIG. 6  is an exploded perspective view of the piston-set. 
           [0040]      FIG. 7  is an exploded perspective view of the I_X ports holder. 
           [0041]      FIG. 8  is an exploded perspective view of the Rr1&#39;s planetary gear sets. 
           [0042]      FIG. 9  is a schematic view of the anti centrifugal system. 
           [0043]      FIG. 10  is an exploded perspective view of the anti centrifugal system. 
           [0044]      FIG. 11  is an exploded perspective view of the vibration balance system. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0045]    Here in the detail discussing, Rr1 as the only case be used, other Rr&gt;1 cases will be easier inferred. 
         [0046]    With reference to  FIG. 5 , it can be seen that the housing wheel engine, which formed by an integral housing wheel  600 , two piston-sets  700 , an epitrochoid planetary gear set  200 , two of I_X ports  800  and a main shaft  100  therein. 
         [0047]    Continuing with reference to  FIG. 5 , it can be seen that an integral housing wheel  600  formed by four (its 4Rr in general) housing wheel segments  601 , and be connected together by two (its 2Rr in general) crankshaft holders  501  and two (its 2Rr in general) I_X ports holders  502 . Two of crankshaft holders  501  and two of I_X ports holders  502  are located interlaced evenly and binding the housing wheel segments  601  tightly as hoops. 
         [0048]    Still with reference to  FIG. 5 , also  FIG. 6  and  FIG. 8 , it can be seen that two (its 2Rr in general) piston-sets  700  and each one formed by a pair of pistons  703 , and be fixed on two ends of a slotted rod  702 . Two piston-sets located inside of integral housing wheel  600 , and both connected with two rolling gears  202  by crankshafts  301 , which&#39;s offset part  302  be joined into the slot  705  of the slotted rod  702 , respectively. 
         [0049]    And still with reference to  FIG. 5  and also  FIG. 7 , it can be seen that intake valve  804  and exhaust valve  805  located within intake port  802  and exhaust port  803  respectively, and two ports located at two sides of the I_X ports holder  502  (another I_X ports hold not showing in  FIG. 5  because of the exploded perspective view, but its showing in  FIG. 7 ). Both of intake port  804  and exhaust port  805  go through a rectangle hole  806  into housing wheel  600 , and the size of the narrow side of the rectangle hole limited by TDC. It also can be seen that there is a spark igniter  810  located between intake port  802  and exhaust port  803 , in order to do its function properly. 
         [0050]    And still with reference to  FIG. 5  and also  FIG. 8 , it can be seen that an epitrochoid planetary gear set  200  formed by two (its 2Rr in general) rolling outer gears  202  meshed with a fixed annular outer gear  201 , and each of rolling gear  202  has a crankshaft  301  mounted on the center. 
         [0051]    In order to ensure epitrochoid planetary gear set  200  carries out a proper work to the engine, its need to be having an initial assembling correctly. Based on the previous discussion, we already knew the preset up is necessary for sure epitrochoid can be an engine machine, the essential setup are: 
         [0000]      α i =( i− 1)180°/ Rr , and  iε{ 1,2, . . . 2 Rr};  
 
         [0000]      θ i =α i   +i 180°, and  iε{ 1,2, . . . 2 Rr}.  
 
         [0000]    Base on these setup, the initial assembling must be both of the offset part  302  of the crankshafts lined up with three centers of the gear set and in the same direction (see  FIG. 8 ) (the offset pin  402  and offset t in  FIG. 8  will be discuss later at paragraph of Vibration Balance System). 
         [0052]    Since the axle part  301  of the crankshafts located inside of crankshaft holder  501  and fixed on rolling gear  202 , also the offset part  302  of the crankshafts located inside of slotted rod  702  respectively. The rolling gears  202  roll around the fixed annular gear  201  will drive integral housing wheel  600  rotating around the center of the fixed gear  201 , and piston-sets  700  swing around the center of the rolling gears  202 . 
         [0053]    With reference to  FIG. 3 a    and  FIG. 3 b   , it can be seen that there are two orbits revolved by two parts of crankshafts, one is an epitrochoid curve E which revolved by the offset part O s  of the crankshaft, and another is a circle c which revolved by the axle part A x  of the crankshaft. And also it can be seen that there are two (its 2Rr in general) intersections I on both orbits c and E. When planetary gear set is running, the two offsets O s  will be run always on opposite sides of the c except when both O s  on intersections I simultaneously. It will drive the two pistons P s  either closer or apart each other and will be reached BDC and TDC when both O s  arrival to I. Then the space of TDC will be expanded till to BDC, and the space BDC will be shrunk till to TDC when both O s  arrival to next I again. This circle makes only two strokes happen, it needs planetary gear set run two circles to finish four strokes. 
         [0054]    Since the length of the space of BDC is a whole of stroke, which formed by two neighbored pistons depart each other to the end, so the maximum moving of each piston will be ½ strokes, and the offset O s  of the crank will be ¼ strokes. 
         [0055]    Still with reference to  FIG. 9 ,  FIG. 10  and also  FIG. 5 ,  FIG. 6 . It can be seen that there is an anti centrifugal system  900  located between a piston-set  700  and wall of combustion chamber  600  ( FIG. 5  and  FIG. 6 ). When engine is running, the centrifugal force will push piston-set  700  to the wall of combustion chamber  600 . It generated a resistance between piston-set  700  and wall  600 . The faster rotating of the engine, the greater resistance will be. In order to counteract this resistance the anti centrifugal system is necessary. 
         [0056]    There is a base of anti centrifugal system  909  located on the top of the slotted rod of piston-set  702  to hold the anti centrifugal system  900 , which comprised by a pair of spiral cam axle halves  908 , a spherical thrust bearing  905  therein. A spiral cam axle halves  908  further formed by a gravity block  901 , a gravity block level  902 , a spiral cam  903  that has curve of logarithmic spiral, and a axle halves  904  therein. The running engine generates a centrifugal force on the gravity block  901  that makes a certain torque to the spiral cam  903 . Since a spiral cam  903  fixed on the axle halves  904 , which fits inside of a spherical thrust bearing  905  that is against the wall of combustion chamber  600 . So the spiral cam  903  will push the slotted rod  702  down by going through a cam follower  907  to balance the centrifugal force of the piston-set  700 . Here the curve of the cam follower  907  could be the same logarithmic spiral as spiral cam  903  but its polar radius is greater than the one spiral cam  903  has. A core of axle  906  located in the central of two of axle halves  904  to make sure no any of up-down movement on both of cam axle halves. 
         [0057]    There is a small angle on up side of axle halves  904  (see β in  FIG. 9 ) to have enough space to avoid against each other between both of axle halves  904 . 
         [0058]    Still with reference to  FIG. 3 b   ,  FIG. 8  and  FIG. 11 , it can be seen that the center of gravity of the engine does not stay in the center of the engine, because two of piston-sets move to one side of the engine for compressing/expanding ( FIG. 3 b   ). This is the special case only exist in Rr1. In order to avoid the vibration caused by this case, the vibration balance system is necessary for Rr1 engine. A pair of vibration balance systems, and each formed by an offset pin  401 , a gravity slider  402  and a track  403  therein ( FIG. 11 ). The offset pin  401  located on a rolling gear  202  in reverse t distance with the offset part of the crankshafts  302  ( FIG. 8 ), and it will be fitted inside of a slot  404  in order to move the gravity slider  402  along the track  403 , which is fixed outside of the crankshaft holder  501 . Therefore the gravity slider  402  runs in opposite way with the piston-set  700 . If the t is the same as offset part of the crankshaft  302 , which is ¼ strokes, the moving angle of the gravity slider ψ will be the same as the angle of the piston-set φ, so the weight of gravity slider should be the same as the piston-set to ensure the center of gravity of the engine will stay in the middle of the machine, The longer t is, the less weight of gravity slider will be.