Abstract:
A fabricated crankshaft for single and multi-throw crankshafts utilizes roller bearings for achieving energy savings and reducing the size of parts and components with the single throw crankshaft using two throws interconnected by one main bearing pin and one drive end unit connected to each throw and the multi-throw crankshaft including at least two pair of throws, one crank pin interconnecting each pair of throws, a main bearing pin interconnecting both pairs of throws, and a pair of drive end units, with the drive end units and the crank pins, the connecting pins, and main bearing pins being secured to the throws by configurations that include keys and keyways, splines, and left and right hand thread arrangements so that the fabricated crankshaft is adaptable to any number of cylinders required.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention pertains to crankshafts for pumps, compressors, and internal combustion engines, and more particularly pertains to a fabricated crankshaft that utilizes roller bearings. 
       BACKGROUND OF THE INVENTION 
       [0002]    Crankshaft designs for pumps, compressors, and engines (internal combustion engines) are usually of a one-piece design. A single cylinder model crankshaft generally requires five major components that normally require such machine operations as forging and crankshaft grinding. Crankshafts are further delineated by the number of throws or counterweights they include, and crankshafts can include a single throw, a double throw, or even three throws or counterweights. Crankshafts having two or more throws are referred to as multi throw crankshafts. In addition, typical crankshafts include sleeve bearings on many of their bearing surfaces. 
         [0003]    The following patents disclose various types and kinds of crankshaft design: the Dusevoir patent (U.S. Pat. No. 2,013,039), the Bailey patent (U.S. Pat. No. 1,420,905), the Taylor patent (U.S. Pat. No. 2,364,109), and the Burgess patent (U.S. Pat. No. 2,095,968). 
         [0004]    Nonetheless, despite the ingenuity of the above devices, there remains a need for a crankshaft design that utilizes roller bearings instead of sleeve bearings. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention comprehends a fabricated crankshaft for both single cylinder crankshafts and multi throw crankshafts. The fabricated crankshaft of the present invention allows the designer to utilize roller bearings where previously sleeve bearings had to be used; and by using such roller bearings the present fabricated crankshaft design up to 5 to 10 percent of the energy needed to drive the piece of equipment will be saved by the reduction of drag on the roller bearings. The fabricated crankshaft of the present invention utilizes both a splined arrangement and a keyway arrangement for fastening and holding the components of the crankshaft together. 
         [0006]    With regard to a single cylinder crankshaft, a drive end unit will include a key and a bearing area or surface and a spline with a snap ring groove formed back from the drive end unit. The offset leg or throw will include an internal spline on one end and a hole with a key way on the opposite end of the offset leg or throw. Areas or portions of the throws will be recessed so that when the snap ring is in place so that the opposite ends of the hole or aperture extending through the throws will be flush with the opposed sides of the throws. A connecting rod pin will be double ended with opposed keyways and a central bearing area in the middle of the connecting rod pin and snap rings will be placed on both ends of the connecting rod pin. For a single cylinder crankshaft the designer, fabricator, or manufacturer would use two drive end units, two offset legs or throws, and one connecting rod pin for attaching the throws to each other. 
         [0007]    It is an objective of the present invention to provide a fabricated crankshaft wherein the installation of the roller bearings occurs before the crankshaft is fully assembled. 
         [0008]    It is another objective of the present invention to provide a fabricated crankshaft in which various metals are used to provide for a stronger crankshaft. 
         [0009]    It is still yet another objective of the present invention to provide a fabricated crankshaft in which various parts of the crankshaft can be heat-treated to become the race for the roller bearings. 
         [0010]    It is still yet a further objective of the present invention to provide a fabricated crankshaft wherein utilization of the roller bearings results in an energy savings of at least 10 percent. 
         [0011]    Still another objective of the present invention is to provide a fabricated crankshaft that can be manufactured on a CNC machine with no grinding involved. 
         [0012]    Still yet another objective of the present invention is to provide a fabricated crankshaft wherein the use of roller bearings lessens the power drain and saves engine and vehicle energy. 
         [0013]    Still yet a further objective of the present invention is to provide a fabricated crankshaft wherein thrust bearings can be incorporated into the cover plates and tapered Timken bearings can be used for the end bearings of the crankshaft. 
         [0014]    These and other objects, features, and advantages will become apparent to those skilled in the art upon a perusal of the following detailed description read in conjunction with the accompanying drawing figures and appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1  is a perspective view of the fabricated crankshaft of the present invention illustrating the crankshaft in its single throw embodiment; 
           [0016]      FIG. 2  is a perspective view of the fabricated crankshaft of the present invention illustrating the crankshaft in its multi-throw embodiment; 
           [0017]      FIG. 3  is a side elevational view of the fabricated crankshaft of the present invention illustrating the crankshaft in the multi-throw embodiment; 
           [0018]      FIG. 4  is a side elevational view of the fabricated crankshaft of the present invention illustrating the drive end unit for the crankshaft of the single throw embodiment; 
           [0019]      FIG. 4   a  is a side elevational view of the fabricated crankshaft of the present invention illustrating an alternative embodiment for the drive end unit for the crankshaft; 
           [0020]      FIG. 5  is a side elevational view of the fabricated crankshaft of present invention illustrating a straight bore crank pin; 
           [0021]      FIG. 6  is a side elevational view of the fabricated crankshaft of the present invention illustrating a middle crank pin tapered on both sides; 
           [0022]      FIG. 7  is a front elevational view of the fabricated crankshaft of the present invention illustrating one throw for the tapered middle crank pin; 
           [0023]      FIG. 8  is a sectioned elevational view of the fabricated crankshaft of the present invention illustrating the throw shown in  FIG. 7  taken along sectional lines  8 - 8  of  FIG. 7 ; 
           [0024]      FIG. 9  is a side elevational view of fabricated crankshaft of the present invention illustrating a straight bore multi-throw crankshaft; 
           [0025]      FIG. 10  is side elevational view of the fabricated crankshaft of the present invention illustrating one drive end unit for the straight bore multi-throw crankshaft first shown in  FIG. 9 ; 
           [0026]      FIG. 11  is a side elevational view of the fabricated crankshaft of the present invention illustrating one crank pin for the straight bore multi-throw crankshaft first shown in  FIG. 9 ; 
           [0027]      FIG. 12  is a side elevational view of the fabricated crankshaft of the present invention illustrating one middle bearing pin for the straight bore multi-throw crankshaft first shown in  FIG. 9 ; 
           [0028]      FIG. 13  is a front elevational view of the fabricated crankshaft of the present invention illustrating one throw for the various pins shown in  FIGS. 9-12 ; 
           [0029]      FIG. 14  is a side elevational view of the fabricated crankshaft of the present invention illustrating the throw shown in  FIG. 13  that interconnects the various pins shown in  FIGS. 9-12 ; 
           [0030]      FIG. 15  is a front elevational view of the fabricated crankshaft of the present invention illustrating an alternative embodiment for one of the openings of the throw first shown in  FIG. 1 ; 
           [0031]      FIG. 16  is a side elevational view of the fabricated crankshaft of the present invention illustrating the openings for the crankshaft throw first shown in  FIG. 15 ; 
           [0032]      FIG. 17  is a side elevational view of the fabricated crankshaft of the present invention illustrating one drive end unit for the throws first shown in  FIG. 15  and  FIG. 16 ; 
           [0033]      FIG. 18  is a side elevational view of the fabricated crankshaft of the present illustrating one middle bearing pin for the throw of the crankshaft first shown in  FIGS. 15 and 16 ; 
           [0034]      FIG. 19  is a front elevational view of the fabricated crankshaft of the present invention illustrating an alternative embodiment for the throw that includes two splined openings; 
           [0035]      FIG. 20  is a side elevational view of the fabricated crankshaft of the present invention illustrating the alternative embodiment for the throw first shown in  FIG. 19 ; 
           [0036]      FIG. 21  is a side elevational view of the fabricated crankshaft of the present invention illustrating one middle crank pin for use with the throws first shown in  FIGS. 19 and 20 ; 
           [0037]      FIG. 22  is a side elevational view of the fabricated crankshaft of the present invention illustrating an alternative embodiment for a crankpin that includes oppositely disposed tapered bores; 
           [0038]      FIG. 23  is a front elevational view of the fabricated crankshaft of the present invention illustrating an alternative embodiment for the crankshaft first shown in  FIG. 1  that includes openings to accommodate the tapered bore crankpin of  FIG. 22 ; 
           [0039]      FIG. 24  is a side elevational view of the fabricated crankshaft of the present invention illustrating the use of a fastener and a spring expander in conjunction with the crankpin and throw first shown in  FIGS. 22 and 23 ; 
           [0040]      FIG. 25  is a side elevational view of the fabricated crankshaft of the present invention illustrating an alternative embodiment for the crankpin wherein the crankpin includes a straight bore; 
           [0041]      FIG. 26  is a front elevational view of the fabricated crankshaft of the present invention illustrating the openings of the throw that accommodate the straight bore crank pin first shown in  FIG. 25 ; 
           [0042]      FIG. 27  is a side elevational view of the fabricated crankshaft of the present invention illustrating the alignment of a fastener with one of the openings of the throw of the crankshaft first shown in  FIG. 26 ; 
           [0043]      FIG. 28  is a side elevational view of the fabricated crankshaft of the present invention illustrating an alternative embodiment for a crank pin that includes left and right hand threads; and 
           [0044]      FIG. 29  is a side elevational view of the fabricated crankshaft of the present invention illustrating the throw first shown in  FIG. 28  having a shorter crank pin being brought in alignment with threaded apertures of the throw. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0045]    Illustrated in  FIGS. 1-29  is a design for a fabricated crankshaft that utilizes roller bearings instead of sleeve bearings for both single cylinder crankshafts and multi-throw or multi-cylinder crankshafts with the interconnections of the various drive end units, crank pins, and main bearing pins to the throws being through keyed, splined, or left and right hand threaded configurations. The keyed or the splined configurations can be used depending on horsepower requirements, and roller bearings are used to lessen the power drain and save energy. 
         [0046]    The primary components of the single cylinder arrangement are a pair of throws (also referred to as offset legs or counterweights), a pair of drive end units with one drive end unit connected to each throw, and a main bearing pin. A multi-throw or multi-cylinder arrangement would include two pairs of throws with each pair of throws having opposed flat surfaces and being interconnected by a crank pin in various keyed, splined, or threaded configurations, one main bearing pin interconnecting both pair of throws, and a pair of drive end units with one drive end unit connected to each outside throw of each pair of throws. 
         [0047]    Thus,  FIG. 1  illustrates a single cylinder crankshaft  10  that includes a pair of throws or counterweights  12  interconnected by a main bearing pin  14 . The throws  12  are mirror images of each other and each has a drive end unit  16  attached thereto. Each drive end unit  16  includes a key  18 , a stub  20  and a cylindrical bearing portion  22 . Throws  12  include two apertures with one aperture for receiving the drive end units  16  and the other aperture for receiving the main bearing pin  14 . One aperture on each throw  12  includes a keyway  24  for receiving a key of main bearing pin  14  and a self locking nut  26  further secures main bearing pin  14  to the throws  12  with one self locking nut  26  used on either end of main bearing pin  14 . 
         [0048]      FIGS. 2-4  illustrate a multi-throw crankshaft  28  that includes the same components as shown in  FIG. 1  but in a different number and configuration. Multi-throw crankshaft  28  includes two pairs of throws  12  with each pair interconnected by a crank pin  30 . Crank pins  30  include tapered portions  32 , keys  34  and opposed axially aligned and threaded ends  36  for aligning and locking crank pins  30  within apertures  38  of throws  12 . Drive end units  16  also include an inner tapered portion  40  having a key  42  projecting laterally therefrom with inner tapered portion  40  terminating with an inner threaded end  44 . Tapered portions  32  for crank pins  30  and inner tapered portions  40  for drive end units  16  are threadably received within apertures  38  of throws  12  and maintained in position by self locking nuts  26  that are flush with opposed flat surfaces  46  of throws  12 . Main bearing pin  14  of  FIGS. 2 and 3  has no counterweight. In addition, roller bearings  48  are disposed about one crank pin  30  and middle bearing pin  14  of the multi-throw crankshaft  28  shown in  FIG. 3 . 
         [0049]      FIG. 5  illustrates an alternative embodiment for crank pins  30  of  FIGS. 1-4 . The crank pin  50  of  FIG. 5  is for straight bore throws or crankshafts and is used where space is an issue in various types of pumps, compressors, and engines.  FIG. 6  illustrates a middle crank pin  52  that includes a cylindrical main bearing portion  54 , tapered and opposed cylindrical members  56 , a key  58  for each cylindrical member  56 , and opposed threaded studs  60  projecting from each cylindrical member  56  and which are in axial alignment with each other. 
         [0050]      FIGS. 7 and 8  illustrate throws  12  for use with tapered drive end units  16 , crank pins  30  and  50  and main bearing pins  14  and  52  shown in  FIGS. 2 ,  3 ,  4  and  6 . Throws  12  of  FIGS. 7 and 8  include pairs of tapered openings  62  with the taper of each opening  62  for each pair of openings  62  of each throw  12  being opposite or the mirror image of each other, and each opening  62  also including an annular seating portion  64  and a keyway  66 . 
         [0051]      FIGS. 9-14  illustrate the multi-throw crankshaft  28  that includes an alternative embodiment of straight bore openings instead of tapered openings  62 . Thus, each throw  12  includes a pair of straight bore openings  68  and each opening  68  includes a keyway  70 .  FIG. 10  illustrates a straight bore drive end unit  72  having a flanged inner end portion  74  and  FIG. 11  illustrates a straight bore connecting rod pin  76  for connecting each pair of throws  12  shown in  FIG. 9 . Connecting rod pin  76  includes opposed keys  78  and terminates at each end with an annular flanged portion  80 .  FIG. 12  illustrates a middle bearing pin  82  having a central annular bearing surface  84 , opposed cylindrical portions  86  each of which includes a key  88 , and opposed cylindrical portions  90  terminating with annular flanged portions  92 .  FIGS. 13 and 14  illustrate the configuration of the pairs of openings  68  for each throw  12  that accommodates and receives pins  72 ,  76 , and  82 . Specifically, the straight bore lower opening  68  for each throw  12  receives drive end units  72  and upper openings  68  are configured to receive connecting rod pins  76  and middle bearing pin  82 . Snap rings  93  instead of self-locking nuts  26  are placed upon flanged inner end portions  74  of drive end units  72 , annular flanged portions  80  of connecting rod pins  76 , and annular flanged portions  92  of middle bearing pin  82  to further secure drive end units  72 , connecting rod pins  76  and middle bearing pin  82  in openings  68  of throws  12 . In addition, roller bearings  48  are shown as being disposed circumjacent one connecting rod pin  76  and middle bearing pin  82  in  FIG. 9 . 
         [0052]      FIGS. 15-21  illustrate an embodiment for both single cylinder and multi-cylinder crankshafts  10  and  28  that accommodates splined components and parts. Thus, the throws  12  shown in  FIGS. 15 and 16  include one straight bore opening  68  and one splined opening  94  with the splined opening  94  including a plurality of individual splines  96  circumjacently spaced about the opening  94  which for the throw  12  of  FIGS. 15 and 16  is the lower opening  94 .  FIG. 17  illustrates a drive end unit  98  having a middle portion  100 , a cylindrical portion  102  having a key  104  projecting therefrom, and an opposite cylindrical splined portion  106  having a series of splines  108  projecting therefrom. A flanged portion  110  extends from the cylindrical splined portion  106  and includes an inner annular recess  112  for receiving a snap ring such as snap ring  93 .  FIG. 18  illustrates a middle bearing pin  116  that includes a cylindrical central bearing portion  118 , opposed end portions  120  one of which includes a series of splines  122 , and flanged terminating portions  124  onto which the snap ring  93  can be placed for locking the pin  116  to the throws  12 . 
         [0053]      FIGS. 19 and 20  are a front elevational view of the throw  12  modified for accommodating and receiving the aforedescribed components and parts. The throw  12  has both the upper and lower openings  94  with each opening  94  including the plurality of splines  96  defining and circumjacent each respective opening  94 .  FIG. 21  illustrates a connecting rod pin  126  that is a smaller version of the middle bearing pin  116  shown in  FIG. 18 . The connecting rod pin  126  includes a central bearing portion  128 , opposed splined ends  130 , necks  132  projecting axially from each opposed splined end  130 , and a flange  134  extending from each neck  132  for receiving the snap ring  93  in a groove formed between the neck  132  and flange  134 . 
         [0054]      FIGS. 22-29  disclose embodiments for throw  12  and various connecting and bearing pins that include threaded engagements with, specifically, right and left hand threaded components, configurations and connections.  FIG. 22  illustrates a crank pin  136  having a taper bore that includes opposed tapered ends  138  with each tapered end  138  defining a bore  140  and each bore  140  having annular inner threads  142 .  FIG. 23  illustrates an embodiment for the throw  12  of  FIGS. 1-3  that includes openings  144  (upper and lower) with each opening  144  having a keyway  146  for receiving the key  148  on crank pin  136  of  FIG. 22 .  FIG. 24  is a side elevational view of the throw  12  modified to include a pair of tapered apertures  150  sized to receive the crank pin  136  with the taper bore of  FIG. 22 . To further secure the crank pin  136  to the throw  12  an expander  152  is disposed in an annular recess  154  formed on each opening  144  and then a fastener  156  such as a stud or bolt having a threaded stem  158  is threadably secured to the inner annular threads  142  of the crank pin  136  that has been seated in the tapered apertures  150  of the throw  12 . 
         [0055]      FIGS. 25-27  illustrate an alternative embodiment to the configuration of the apertures  38  of throws  12  and the pins  14 ,  30  and  50  shown in  FIGS. 1-5  which utilizes a straight bore crank pin  160 . Thus, straight bore crank pin  160  includes a cylindrical central portion  162  that can function as a bearing surface and opposed straight bore portions  164  each of which includes internal annular threads  166  that can be either left-handed or right-handed. Crank pin  160  is inserted into either opening  168  of throw  12  shown in  FIGS. 26 and 27 , and then further fixed in place by having a fastener  170  with an externally threaded shank  172  threadably engage internal annular threads  166  of straight bore crank pin  160  for assembling components of the crankshaft whether single  10  or multi-throw  28 . 
         [0056]      FIGS. 28 and 29  illustrate embodiments for a throw configuration and crank pin having either left-handed or right-handed threads. Thus, the throws  12  of  FIGS. 28 and 29  have their openings modified so that one opening  174  is configured as a cylinder and the other opening  176  includes annular internal threads  178 . An annular groove  180  is formed at the point where the opening  176  registers flush with one surface of the throw  12 .  FIG. 28  illustrates a long stem crank pin  182  having a key  184 , a central enlarged flanged portion  186  and a short threaded stub  188  with an annular ledge  190  formed at the base of the short threaded stub  188  adjacent the central enlarged flanged portion  186 . The threaded stub  188  can be either right-handed or left-hand threaded, as circumstances may warrant, and will correspondingly mate with the annular internal threads  178 —either right-handed or left-handed in correspondence therewith—for threadable engagement thereto.  FIG. 29  illustrates a shortened crank pin  192  having only a cylindrical body portion  194  and a threaded portion  196  with an annular ledge  198  formed at the area where the threaded portion  196  connects to the cylindrical body portion  194 . The threads of the crank pin  192  can be either right-handed or left-handed to correspondingly engage and mate with the annular internal threads  178 —that are also correspondingly right-handed or left-handed as the circumstance and situation warrants. 
         [0057]    While the roller bearings  48  are shown being used with the throws  12  of  FIGS. 3 and 9  for representative purposes, it should be understood that the roller bearings  48  can be used with all the various throw  12  and pin configurations—single and multi, straight and tapered—shown in  FIGS. 1 and 2  and  10 - 29 . 
         [0058]    Although the various aspects of the invention have been described with respect to specific exemplary embodiments, it will be understood that numerous modifications, alterations, and variations are practicable and possible to those skilled in the art, and that such modifications, alterations, and variations will come within the ambit of the appended claims and thus the invention, and all its contemplated variations and embodiments, are entitled to the full, complete, and extensive protection of the broad scope of the appended claims.