Abstract:
An advanced angled cylinder piston engine, pump, or compressor design. A method to determine optimum cylinder(s) orientation to achieve maximum torque. A method to determine proper cylinder(s) orientation achievable based on crankshaft and connecting rod dimensions. A cylinder, a cylinder insert sleeve, and a piston provide clearance for free operation of a connecting rod. A compensating piston provides proper cylinder volume to maintain desired compression ratio. An oil passage provides additional lubrication to cylinder wall. A crankshaft counterweight orientation provides proper crankshaft, connecting rod, and piston assembly balance.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of provisional patent applications filed by the present inventor: 
         [0000]    Application No. 61/217,858, filed 2009 Jun. 6, Confirmation No. 5343
 
Application No. 61/271,522, filed 2009 Jul. 22, Confirmation No. 3572
 
Application No. 61/271,523, filed 2009 Jul. 22, Confirmation No. 3755
 
Application No. 61/273,363, filed 2009 Aug. 3, Confirmation No. 7705
 
Application No. 61/340,083, filed 2010 Mar. 12, Confirmation No. 3185
 
     
    
     BACKGROUND 
     Prior Art 
       [0002]    The following is a tabulation of some prior art that presently appears relevant: 
         [0000]    
       
         
               
             
               
               
               
               
             
           
               
                   
               
               
                 U.S. Patents 
               
             
          
           
               
                   
                 Patent Number 
                 Issue Date 
                 Patentee 
               
               
                   
                   
               
               
                   
                 6,058,901 
                 2000 May 9 
                 Lee 
               
               
                   
                 6,745,746 B1 
                 2004 Jun. 8 
                 Ishii 
               
               
                   
                 4,664,077 
                 1987 May 12 
                 Kamimaru 
               
               
                   
                 5,816,201 
                 1998 Oct. 06 
                 Garvin 
               
               
                   
                 6,827,057 
                 2004 Dec. 07 
                 Dawson 
               
               
                   
                 5,076,220 
                 1991 Dec. 31 
                 Evans, et al 
               
               
                   
                 6,612,281 B1 
                 2003 Oct. 2 
                 Martin 
               
               
                   
                 4,708,096 
                 1987 Nov. 24 
                 Mroz 
               
               
                   
                 5,186,127 
                 1993 Feb. 16 
                 Custico 
               
               
                   
                 5,544,627 
                 1996 Aug. 13 
                 Terdev, et al. 
               
               
                   
                 4,702,151 
                 1987 Oct. 27 
                 Munro, et al. 
               
               
                   
                 7,543,556 B2 
                 2009 Jun. 9 
                 Hees, et al. 
               
               
                   
                   
               
             
          
         
       
     
       NONPATENT LITERATURE DOCUMENTS 
       [0000]    
       
         Dr. Taj Elssir Hassan, “Theoretical Performance Comparison between Inline, Offset and Twin Crankshaft Internal Combustion Engines” (July 2008) 
         www.speedtalk.com/forum/Offset Bore &amp; Crank Centerlines 
       
     
         [0005]    The angled-cylinder or offset-crankshaft technique of designing internal and external combustion piston engines, piston pumps, and gas compressors is a technology that has been met with limited success. Designers of such devices have little guidance when employing this design technique to achieve results that produce a piston device that yields maximum performance gains, while requiring a minimum amount of modifications to traditional or existing engine, pump, or compressor designs. 
         [0006]    Previous efforts to test and document the performance gains offered by the angled-cylinder or offset-crankshaft technology have employed tests that were conducted on internal combustion engines. Prototypes were constructed, and cylinder pressures, thermo-dynamics, and other characteristics of these engines were taken while in operation—for example discussion www.eng-tips.com/forum/thread7-201777, www.speedtalk.com/forum/offset bore &amp; crank centerlines and U.S. Pat. No. 6,058,901 to Lee (2000). These tests mainly focused on some specific offset-crankshaft configuration targeted at some specific point in the combustion stroke. Additionally, new prototypes needed to be constructed to test configuration variables. This limited method of testing has produced misleading results. 
         [0007]    Another method used to compare the performance between angled-cylinder or offset-crankshaft piston devices with conventionally configured piston devices focused on piston-to-sidewall frictions—for example “Reration between Crankshaft Offset and Piston Friction Loss. Amount of Offset and Engine Operating Condition”—Takiguchi Masaaki. Other efforts that have been employed are computer simulations and mathematical studies—for example www.camotruck.net/rollins/piston-offset, Theoretical Performance Comparison between Inline, Offset, and Twin Crankshaft Internal Combustion Engines—Taj Elssir Hasaan. These methods of determining performance gains have also produced misleading results. 
         [0008]    The orientation of the cylinder in such devices is extremely critical to performance. Some of the prior art related to the angled-cylinder or offset-crankshaft suggest values that are ineffective—for example U.S. Pat. No. 6,745,746 B1 to Ishii (2004) and U.S. Pat. No. 4,664,077 to Kamimaru (1987). Others specify designs that are too impractical to be viable—for example U.S. Pat. No. 5,816,201 to Garvin (1998) and U.S. Pat. No. 6,827,057 to Dawson (2004). Still other prior art and patents are very indeterminate in defining this relationship. Such terms as “approximately” and “about” are typically used—for example U.S. Pat. No. 6,612,281 B1 to Martin (2003) and U.S. Pat. No. 5,076,220 to Evans et al (1991). Additionally, if values are expressed in prior art at all, they fail to take into consideration other critical factors such as connecting rod-to-stroke ratios, which would render any expressed value effectively meaningless—for example U.S. Pat. No. 4,708,096 to Mroz (1987). 
         [0009]    Designers of piston devices wishing to employ the angled-cylinder or offset-crankshaft technology have also been confronted with mechanical interferences and clearance limitations between the cylinder, connecting rod, and piston. Prior art that has addressed this issue specify connecting rod designs that alter the connecting rod centerline, and therefore would be prone to early failure—for example U.S. Pat. No. 5,186,127 to Cuatico (1993) and US patent to Terzlev (1996). Manufacturers of piston devices would be reluctant to adopt such designs. Other prior art addressing this problem suggest integrating modifications to the block casting—for example U.S. Pat. No. 4,708,096 to Mroz. (1987). As the close proximity of the piston components with the bottom of the cylinder are critical in these devices, this approach would prove challenging in the manufacturing process. 
         [0010]    Other concerns encountered when designing a piston device employing the angled-cylinder or offset-crankshaft technology have no known directly related prior art. 
       ADVANTAGES 
       [0011]    Accordingly designs and methods for providing designers of angled-cylinder piston devices with the ability to produce a device that benefits from the mechanical advantage inherent in the technology, while requiring as few modifications to existing or traditional designs as possible, thus making the angled-cylinder or offset-crankshaft technology viable. 
       DETAILED DESCRIPTION 
     FIGS.  1  and  2 —First Embodiment 
       [0012]      FIGS. 1 and 2  share all the same components. A cylinder head  21  could contain valves, spark plugs or other components that are not necessary for this disclosure, and therefore are not included. The cylinder  22  can be a bore in a block casting, a sleeve inserted into a bore, or an independent structure. A piston  23  and a connecting rod  26  are pivotally joined at a piston pivot  24 . A piston pivot center axis  25 , and a piston pivot horizontal centerline  40  are included for reference purposes. A crankshaft main journal  33 , a throw  30 , and a crankpin  28  represent the moving components of a crankshaft, or crankshaft assembly, and positioned at top-dead-center (TDC). A crankshaft main axis of rotation  34 , and a crankpin center axis  32  are included for reference purposes. A stroke reference line  35  is included to show the travel of the crankpin center axis  29  as the crankshaft rotates 360° through an operating cycle. A length of connecting rod  27  and a length of throw  38  are included, as these dimensions are necessary for this disclosure. Both  FIGS. 1 and 2  are drawings of what could be a single cylinder device, or one cylinder of a multiple cylinder device. 
         [0013]      FIG. 1  is a drawing of an example of a piston device designed using the angled-cylinder technique. A piston engine employing this design technique basically begins with a traditional or existing design, and with the crankshaft  28 , 30 , 33  positioned to place the piston  23  at TDC (shown), a cylinder&#39;s centerline  37  orientation is rotated about the piston pivot center axis  25  location, thus orienting the cylinder&#39;s base in the direction of the crankpin  28  as the crankshaft&#39;s  28 , 30 , 33  operational rotation moves the crankpin  28  from TDC to bottom-dead-center (BDC). In the case of a compressor or pump, the cylinder&#39;s centerline  37  orientation is rotated about the piston pivot center axis  25  location to orient the cylinder&#39;s  22  base in the direction of the crankpin  28  as the crankshaft&#39;s  28 , 30 , 33  operational rotation moves from BDC to TDC. 
         [0014]      FIG. 2  is an example of a piston device designed using the offset-crankshaft or offset-cylinder technique. A piston engine employing this design technique also begins with a traditional or an existing design, and the crankshaft&#39;s main axis of rotation  34  is offset in a perpendicular direction away from the cylinder&#39;s centerline  37 , toward the direction of the crankpin  28  as the crankshaft&#39;s  28 , 30 , 33  operational rotation moves the crankpin  28  from BDC to TDC. In the case of a compressor or pump, the crankshaft&#39;s main axis of rotation  34  is offset in a perpendicular direction from the cylinder&#39;s centerline  37 , and toward the crankpin  28  as the crankshaft&#39;s  28 , 30 , 33  operational rotation moves the crankpin  28  from TDC to BDC. 
         [0015]    If corrected for TDC, the angled-cylinder and the-offset crankshaft design techniques both produce a piston device with identical piston  21 , cylinder  22 , connecting rod  26 , and throw  39  component relationships. The difference between these two design techniques involves which components of a traditional or existing design will be altered to achieve the desired result. Therefore, going forward, this design technique will be referred to as the angled-cylinder design, as when considering only the basic components involved, it is a more generic description. 
         [0016]    As previously disclosed, the angled-cylinder technique can be applied to engines, gas compressors and liquid pumps. In the case of an engine, either internal combustion such as a gasoline or diesel engine, or external combustion such as a steam engine, the direction of rotation of the crankshaft  28 , 30 , 33  in  FIGS. 1 and 2  would be clockwise. In the case of a gas compressor or liquid pump, the direction of rotation of the crankshaft  28 , 30 , 33  would be counter-clockwise. The throw  30 , and the crankpin  28  are represented in an alternate position of the operating cycle,  39  and  31 . In the case of an engine, this position would be 90° past TDC of a 360° clockwise crankshaft  28 , 30 , 33  rotation. In the case of a gas compressor or liquid pump, this position would be 270° past TDC of a 360° counter-clockwise crankshaft  28 , 30 , 33  rotation. 
       FIGS.  3  and  4 —First Embodiment 
       [0017]    The unique technique I used to measure the torque and performance gains offered by the angled-cylinder piston device employed the use of a hobby-grade steam engine. The reasons for choosing this device were as follows: 
         [0018]    1. Steam engines are typically built with open architecture lower ends. The crankshaft and connecting rod assemblies are not enclosed within a crankcase, and therefore they are exposed for easy experimentation. 
         [0019]    2. The cylinder and piston assemblies of the steam engine used are constructed as individual components, and then mounted to a plate. The plate is then mounted to the lower assembly by means of machined posts. Adding a system of shims to these posts was a simple procedure, thus creating an assembly that could easily produce variable cylinder angles. 
         [0020]    3. Steam engines are external combustion engines, and lend themselves to simple modifications that allow them to operate on controlled compressed air. This was critical, as my intention was to identify the performance gains offered by the angled-cylinder technique, without considerations of heat dissipation and accumulation, combustion gas expansion variations due to a multitude of factors, friction increases and decreases, and other variables related to combustion engines that could distort my observations. The modified steam engine allowed me to run tests that isolated the performance and torque gains inherent in the mechanical advantage of the angled-cylinder technique. 
         [0021]    The test engine was assembled with the above mentioned modifications. The output shaft was fitted with a cogged-belt pulley that allowed coupling to an electric generator, also fitted with a cogged pulley, and joined with a cogged belt. The engine&#39;s pulley was also marked to allow engine revolutions-per-minute (RPM) readings to be made with an optical tachometer. Extensive tests were conducted, and the results were consistent.  FIG. 3  is a chart of typical test results produced when voltage readings were taken at various cylinder angles.  FIG. 4  is a chart of typical test results produced when RPM readings were taken at various cylinder angles. 
         [0022]    Referring to this modification as cylinder angle became futile, as the small adjustments necessary became too difficult to gauge accurately when measured as cylinder angle. Therefore, I developed the more precise technique of measuring this configuration in terms of the cylinder&#39;s centerline with length of throw&#39;s centerline intersect. A traditional piston device would have its cylinder oriented in a manner such that its centerline would be drawn directly through the piston pivot center axis  25 , and the crankshaft main axis  34 . Using the throw  31  positioned at 90° of a clockwise crankshaft rotation  31 , and measuring from the crankshaft main center axis  34  to the crankpin center axis  32 , a cylinder oriented in such a manner as to have its centerline  37  intersect with throw&#39;s centerline  36  can have its orientation calibrated in terms of a percentage of the length of throw centerline  36 ,  38 . Going forward, this measurement will be referred to as throw centerline intersect  45 . This method of determining cylinder orientation can be effectively used when designing either an angled-cylinder, or an offset-crankshaft piston device. 
         [0023]    What these tests allowed me to conclude are as follows: 
         [0024]    1. The configuration of the cylinder&#39;s centerline  37  with the length of throw centerline  36 ,  38  is extremely critical. Very minute changes to the cylinder angle produces measurable changes in torque and performance. 
         [0025]    2. The performance and torque gains that can be gleaned from the angled cylinder technique are not linear. During testing, as the cylinder&#39;s centerlines  37  were oriented away from the crankshaft main axis  34  and towards the crankpin center axis position held at 90° of a clockwise rotation  32 , the gains were rather small until I approached a throw centerline intersect  45  of 30%. The gains then increased exponentially until reaching a throw centerline intersect  45  of 45%, and then began to decrease. Gains in performance rapidly decreased after reaching a throw centerline intersect  45  of 49% . It is within the range of a throw centerline intersect  45  of 30% to 49% that performance increases of 15% or more can be realized, and this range of cylinder  22  orientation is within the scope of the present embodiment. 
       FIGS.  1 ,  2  and  5 —Second Embodiment 
       [0026]    Piston devices designed to operate with a throw centerline intersect of 30% to 49% present certain challenges.  FIG. 5 , reference  48 , illustrates a limitation that would be presented when applying this technique to traditional or existing designs. The increased swing of the connecting rod  47  opposite the direction of cylinder angle or cylinder offset can cause an interference between the connecting rod  26  and the bottom of the piston  23 . This interference can also occur with the connecting rod  26 , and the bottom of the cylinder  22 . A solution to this problem provided by this embodiment, is to balance the amount of throw centerline intersect  45  with the degree of interference, which is in direct proportion to the devices connecting rod-to-stroke ratio. A piston device with a ratio of 1.5/1 respectively or less presents the greater amount of interference and therefore permits lower amount of throw centerline intersect  45 , and therefore a throw centerline intersect  45  of 33%, +/−3% of length of throw is determined. A piston device with a ratio of 1.9/1 respectively or greater presents the least amount of interference and therefore permits a greater amount of throw centerline intersect  45 , and a value of 46%, +/−3% of length of throw is determined. Piston devices with connecting rod-to-stroke ratios between 1.5/1 to 1.9/1 would have the throw centerline intersect  45  determined proportionally with respect to the above described limits, +/−3% of length of throw. The 3% tolerance is to allow for other device characteristics such as connecting rod  26  width, or piston  23  diameter. This method of determining cylinder centerline  37  orientation is within the scope of the present embodiment. 
       FIGS.  5  and  6 —Third Embodiment 
       [0027]    Another concern when designing an angled-cylinder piston device is the interference between the connecting rod  26  and the piston&#39;s  23  base as shown in  FIG. 5 , reference  48 . A solution to this issue provided by this embodiment is the recessed piston  46  as shown in  FIG. 6 . A cut out  51  formed at the base of the piston  46 , or in the piston skirt if so designed, and oriented in a manner to accommodate the swing of the connecting rod  26 , will provide clearance for the free operation of the connecting rod  26  throughout the crankshaft&#39;s  28 , 30 , 33   360 ° rotation cycle. This piston design is within the scope of the present embodiment. 
       FIGS.  5  and  7 —Fourth Embodiment 
       [0028]    Another concern when designing an angled-cylinder piston device is the interference between the connecting rod  26  and the cylinder&#39;s  22  base, as shown in  FIG. 5 , reference  48 . A solution to this issue provided by this embodiment is the recessed cylinder sleeve  53  as shown in  FIG. 7 . A sleeve inserted into a cylinder&#39;s bore  52 , and having a cut out  55  that is oriented in a manner to accommodate the swing of the connecting rod  26 , will provide clearance for the free operation of the connecting rod  26  throughout the crankshaft&#39;s 360° rotation cycle. This sleeve design is very effective, as piston devices designed using the angled-cylinder technique would require extremely accurate relationships between the piston rings  50 , and the cut out  55  in the sleeve. Therefore, providing such a cut out formed in a bored block would be challenging in the manufacturing process. A sleeve designed as described could be held in the bore  52  either mechanically or through some bonding means, but would require some mechanical means to keep it from rotating within the cylinder bore  52 . A misalignment between the connecting rod  26  and the cut out  51  would lead to failure. This sleeve design is within the scope of the present embodiment. 
       FIGS.  8  and  9 —Fifth Embodiment 
       [0029]    When designing an angled-cylinder piston device that is constructed as a separate cylinder  64  and crankcase  62  as shown in  FIG. 9 , the area of connection rod to cylinder interference is indicated at reference  53 . A relief cut out formed at the base of the cylinder  64 , and oriented in a manner such as to accommodate the swing of the connecting rod  26 , would allow for the free operation of the connecting rod  26  throughout the crankshafts 360° rotation cycle. This cylinder design is within the scope of the present embodiment. 
       FIGS.  10 ,  11  and  12 —Sixth Embodiment 
       [0030]    A designer of an angled-cylinder piston device wishing to avoid re-designing as many peripheral components as possible may take the approach of angling the cylinder  23  about the piston pivot  24  location at TDC in the original design. This design technique would avoid having to re-design the cylinder heads  21 , but would create a condition of excess cylinder volume  57  when the piston is positioned at TDC, as shown in  FIG. 10 . A solution to this problem is to design a piston  59  whose top is formed in such a manner as to compensate for this excess volume, as shown in  FIG. 12 . This solution may prevent the re-designing of many other internal and external components as well. This piston design is within the scope of the present embodiment. 
       FIGS.  5  and  13 —Seventh Embodiment 
       [0031]    Another concern when designing an angled-cylinder piston engine is the increase in friction between the piston  23  and the cylinder  22  wall as shown in  FIG. 5 , reference  49 . This increase in friction occurs as the piston travels from BDC to TDC. If the piston engine is centrally lubricated, an oil passage  67  formed in the connecting rod  26 , and oriented in such a manner as to apply additional oil to the affected area of the cylinder&#39;s  22  wall as shown in  FIG. 13 , would solve this issue. The movement of the connecting rod  26  as the crankpin  28  travels from BDC to TDC would provide excellent oil distribution. An oil passage properly formed in the crankshaft  28 , 30 , 33  would provide the same benefit. This method of design is within the scope of the present embodiment 
       FIGS.  14  and  15 —Eighth Embodiment 
       [0032]    Another concern when designing an angled-cylinder piston device is an imbalance of the crankshaft  28 , 30 , 33  created by directing the weight of the piston  23  and connecting rod  26  assembly away from BDC.  FIG. 14  shows prior art that illustrates the configuration of a traditional piston device with a crankshaft counterweight  69  oriented exactly opposite the piston pivot  24  when the crankshaft  28 , 30 , 33  is positioned at TDC. An imaginary centerline  70  can be drawn through the piston pivot  24 , the crankshaft main axis  33 , and the center of the counterweight  69 .  FIG. 15  shows a method of design that corrects this imbalance. By retarding the orientation of the counterweights center  71  away from the crankshaft&#39;s  28 , 30 , 33  operational rotation, the crankshaft&#39;s  28 , 30 , 22  balance of the angled-cylinder piston device can be corrected. This method of design is within the scope of this embodiment. 
         [0033]    Thus the scope of the embodiments should be determined by the appended claims, and their legal equivalents, rather than by the examples given. 
     
    
     
       DRAWINGS 
       Figures 
         [0034]      FIG. 1  shows a cross section of a cylinder, piston and crankshaft assembly which is an example of an angled-cylinder configuration with the crankshaft positioned at top dead center. Also, an alternate position of the crankpin with the crankshaft positioned at 90° past top dead center of a clockwise rotation is shown. 
           [0035]      FIG. 2  shows a cross section of a cylinder, piston and crankshaft assembly which is an example of an offset crankshaft, or offset cylinder configuration with the crankshaft positioned at top dead center. Also, an alternate position of the crankpin with the crankshaft positioned at 90° past top dead center of a clockwise rotation is shown. 
           [0036]      FIG. 3  shows test results expressed as voltage readings. 
           [0037]      FIG. 4  shows test results expressed as revolutions per minute. 
           [0038]      FIG. 5  shows an angled cylinder piston device with the crankpin located at 270° past top dead center of a clockwise crankshaft rotation. This figure shows the interference between the connecting rod with the bottom of the cylinder and/or piston bottom. 
           [0039]      FIG. 6  shows an example of a recessed piston with a relief cut out. 
           [0040]      FIG. 7  shows an example of a recessed cylinder insert sleeve with a relief cut out. 
           [0041]      FIG. 8  shows an example of an angled cylinder piston device constructed as a separate cylinder affixed to a crankcase. 
           [0042]      FIG. 9  shows an example of a separately constructed cylinder with a relief cut out. 
           [0043]      FIG. 10  shows an angled-cylinder piston device with the crankshaft positioned at top dead center. This figure shows the excess volume of the cylinder chamber at top dead center. 
           [0044]      FIG. 11  shows an example of a compensating piston. 
           [0045]      FIG. 12  shows an angled cylinder piston device with the crankshaft positioned at top dead center. This figure shows the excess volume of the cylinder chamber at top dead center corrected with a compensating piston. 
           [0046]      FIG. 13  shows an example of an angled cylinder piston device with an additional lubrication passage. 
           [0047]      FIG. 14  shows an example of prior art of a piston device with the crankshaft positioned at top dead center, and the crankshaft counterweight in a traditional configuration. 
           [0048]      FIG. 15  shows an example of an angled cylinder piston device with the crankshaft positioned at top dead center, and with the crankshaft counterweight centerline adjusted to re-balance the crankshaft, connecting rod, and piston assembly. 
       
    
    
     DRAWINGS 
     Reference Numerals 
       [0000]    
       
           21  cylinder head 
           22  cylinder 
           23  piston 
           24  piston pivot 
           25  piston pivot center axis 
           26  connecting rod 
           27  length of connecting rod 
           28  crankpin 
           37  centerline of cylinder 
           29  crankpin center axis 
           38  length of throw 
           30  throw 
           31  crankpin position at 90° past top dead center of a clockwise crankshaft rotation 
           32  crankpin center axis position at 90° past top dead center of a clockwise crankshaft rotation 
           33  crankshaft main journal 
           34  crankshaft main axis 
           35  stroke path of crankpin center axis 
           36  throw centerline location at 90° past top dead center of a clockwise crankshaft rotation 
           37  centerline of cylinder 
           38  length of throw 
           39  throw position at 90° past top dead center of a clockwise crankshaft rotation 
           40  piston pivot horizontal centerline 
           41  connecting rod centerline 
           42  stroke diameter 
           43  crankpin horizontal centerline 
           44  crankshaft main axis vertical centerline 
           45  cylinder centerline with length of throw centerline intersect 
           46  recessed piston 
           47  connecting rod swing 
           48  point of interference 
           49  point of increased friction 
           50  piston rings 
           51  piston bottom cut out 
           52  cylinder bore 
           53  recessed cylinder sleeve 
           54  location of cylinder bore bottom 
           55  cylinder sleeve cut out 
           57  area of excess cylinder volume 
           59  compensating piston 
           60  compensating piston top 
           62  crankcase 
           63  cylinder mounting flange 
           64  separately constructed cylinder 
           65  separately constructed cylinder cut out 
           67  oil passage 
           69  crankshaft counterweight 
           70  crankshaft counterweight centerline 
           71  crankshaft counterweight centerline adjusted orientation