Abstract:
A combination for use in supporting and rotatably driving a mass is disclosed. The combination may have a power source. The combination may also have a flywheel, which may be configured to connect with and rotatably drive the mass. The flywheel may have a flywheel end, which may have a plurality of flywheel protrusions. Additionally, the combination may have a bearing, which may be situated at least partially within the power source. The bearing may be configured to support and at least partially house the flywheel. In addition, the combination may have a crankshaft, which may be shaped to connect with and rotatably drive the flywheel. The crankshaft may have a crankshaft end, which may have a plurality of crankshaft protrusions. The plurality of crankshaft protrusions may be shaped to mesh with the plurality of flywheel protrusions.

Description:
TECHNICAL FIELD 
       [0001]    The present disclosure relates generally to a combination and, more particularly, to combination for use in supporting and rotatably driving a mass. 
       BACKGROUND 
       [0002]    Engines are sometimes used to drive and support masses. For example, an engine can be used to drive a rotor of a single bearing generator. In such a setup, a first side of the rotor is supported by a bearing of the single bearing generator, while a second side of the rotor (opposite the first side of the rotor) is supported by the engine. Specifically, the second side of the rotor is supported by an end of a crankshaft of the engine. Unfortunately, when the crankshaft of the engine drives the rotor, movement of the crankshaft and the rotor causes the end of the crankshaft to orbit and/or vibrate. This orbiting and/or vibrating increases undesirable bending stresses within the crankshaft. 
         [0003]    One way to reduce the orbiting and/or vibrating of the end of the crankshaft is to support the end of the crankshaft with a bearing. An example of this strategy is described in G.B. Patent No. 705,933 (the &#39;933 patent) to Hallewell, which was published on Mar. 24, 1954. The &#39;933 patent describes a rotor carried on a bracket, which is bolted directly to a flywheel. The flywheel is bolted to a crankshaft of an engine. Bending movement of the crankshaft is reduced by providing a crankshaft journal bearing placed close up to the flywheel. 
         [0004]    Although the crankshaft journal bearing may reduce bending movement of the crankshaft as taught in the &#39;933 patent, the combination of the crankshaft journal bearing and the bolts connecting the crankshaft to the flywheel may limit the crankshaft&#39;s ability to transmit to the flywheel large amounts of torque at high rotational speeds. This is because a strength (an ability to transmit torque) of the connection between the crankshaft and the flywheel of the &#39;933 patent is proportional to the number of bolts of the connection. Although the number of bolts could be increased by increasing the diameter of the crankshaft (i.e., by increasing the connection area), the diameter of the crankshaft is limited by the rotational speed of the crankshaft. This is because the surface speed of the crankshaft is limited by the crankshaft journal bearing. Specifically, the surface speed of the crankshaft is limited by the crankshaft journal bearing because excessive surface speed can damage the crankshaft journal bearing. Since the diameter of the crankshaft and the rotational speed of the crankshaft are both proportional to the surface speed of the crankshaft, the diameter of the crankshaft and the rotational speed of the crankshaft are inversely proportional to each other when the surface speed of the crankshaft is held constant. Therefore, large diameters (capable of transmitting large amounts of torque) and high rotational speeds are mutually exclusive. In other words, the combination of the crankshaft journal bearing and the bolts connecting the crankshaft to the flywheel cannot, without damaging the crankshaft journal bearing, transmit to the flywheel some large amounts of torque at some high rotational speeds. 
         [0005]    The disclosed combinations are directed to overcoming one or more of the problems set forth above and/or other problems in the art. 
       SUMMARY 
       [0006]    In one aspect, the present disclosure is related to a combination for use in supporting and rotatably driving a mass. The combination may include a power source. The combination may also include a flywheel, which may be configured to connect with and rotatably drive the mass. The flywheel may include a flywheel end, which may include a plurality of flywheel protrusions. Additionally, the combination may include a bearing, which may be situated at least partially within the power source. The bearing may be configured to support and at least partially house the flywheel. In addition, the combination may include a crankshaft, which may be shaped to connect with and rotatably drive the flywheel. The crankshaft may include a crankshaft end, which may include a plurality of crankshaft protrusions. The plurality of crankshaft protrusions may be shaped to mesh with the plurality of flywheel protrusions. 
         [0007]    In another aspect, the present disclosure is related to a combination for use in supporting and rotatably driving a rotor of a single bearing generator. The combination may include a power source. The combination may also include a flywheel, which may be configured to connect with and rotatably drive the rotor. The flywheel may include a plurality of flywheel teeth. Additionally, the combination may include a bearing situated at least partially within the power source. The bearing may be configured to support and at least partially house the flywheel. In addition, the combination may include a crankshaft, which may be configured to connect with and rotatably drive the flywheel. The crankshaft may include a plurality of crankshaft teeth. The plurality of crankshaft teeth may be configured to mesh with the plurality of flywheel teeth. 
         [0008]    In yet another aspect, the present disclosure may be related to a generator set. The generator set may include a single bearing generator, which may include a rotor. The generator set may also include a power source. Additionally, the generator set may include a flywheel, which may be configured to connect with and rotatably drive the rotor. The flywheel may include a flywheel end. The flywheel may also include a plurality of flywheel teeth, which may protrude from the flywheel end. In addition, the generator set may include a bearing, which may be situated at least partially within the power source. The bearing may be configured to support and at least partially house the flywheel. The generator set may also include a crankshaft, which may be configured to connect with and rotatably drive the flywheel. The crankshaft may include a crankshaft end. Additionally, the crankshaft may include a plurality of crankshaft teeth, which may protrude from the crankshaft end. The plurality of flywheel teeth and the plurality of crankshaft teeth may both be configured such that a curvic-type coupling is formed by meshing the plurality of flywheel teeth with the plurality of crankshaft teeth. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a cross-sectional illustration of an exemplary disclosed generator set having an exemplary disclosed crankshaft connected to an exemplary disclosed mass; 
           [0010]      FIG. 2  is a pictorial illustration of an exemplary disclosed connection between the crankshaft of  FIG. 1  and an exemplary disclosed flywheel; 
           [0011]      FIG. 3  is a pictorial illustration of the flywheel of  FIG. 2  showing exemplary disclosed flywheel teeth; and 
           [0012]      FIG. 4  is a pictorial illustration of the crankshaft of  FIGS. 1-2  showing exemplary disclosed crankshaft teeth. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]      FIG. 1  illustrates a generator set  10  having a crankshaft  15  connected to a mass  17 . For example, crankshaft  15  may be a crankshaft of a power source  18 , and mass  17  may be a rotor  20  of a generator  25 . Power source  18  and generator  25  may be coupled such that power source  18  rotatably drives rotor  20  via crankshaft  15 , and such that power source  18  supports rotor  20 . For example, power source  18  may support rotor  20  when generator  25  fails to adequately support rotor  20 . Generator  25  may fail to adequately support rotor  20  when, for example, generator  25  is a single bearing generator, which only supports one side of rotor  20 . Although the connection between crankshaft  15  and rotor  20  is described in more detail below, it should be noted that the components and features described herein are equally applicable to connections between crankshaft  15  and other masses  17  such as, for example, fan blades, propellers, or other masses that are rotatably driven by crankshafts  15  and supported by power sources  18 . 
         [0014]    As illustrated in  FIG. 1 , power source  18  may include an engine block  45 , which may have cylinders  50 . Crankshaft  15 , which may be situated at least partially within power source  18 , may be rotatably driven by pistons (not shown) located within cylinders  50 . Alternatively, engine block  45  may not have cylinders  50 , and crankshaft  15  may be rotatably driven by other components of power source  18  such as, for example, rotors of a Wankel engine, rotors of an electric motor, or turbines of a jet engine. 
         [0015]    Although crankshaft  15  may be directly connected to rotor  20 , it is contemplated that generator set  10  may include other components connected between crankshaft  15  and rotor  20 . These other components, which may receive support from a bearing  52  situated at least partially within power source  18 , may help support crankshaft  15  and/or rotor  20 , while allowing crankshaft  15  to transfer torque to and rotatably drive rotor  20 . For example, bearing  52  may be a journal bearing, a ball bearing, a magnetic bearing, or another type of bearing known in the art. Bearing  52  may support and at least partially house a flywheel  55 , which may be connected between crankshaft  15  and rotor  20 . Flywheel  55  may in turn support crankshaft  15  and a flexplate  60 , which may be connected between flywheel  55  and rotor  20 , and which may support rotor  20 . These chains of support may prevent orbiting and/or vibrating of a crankshaft end  62  of crankshaft  15  and a flywheel end  63  of flywheel  55 , thereby reducing bending movement of crankshaft  15 . However, the chains of support may also limit a diameter of flywheel end  63  if flywheel  55  is to be rotated at high speed. Specifically, bearing  52 , which may be damaged by excessive surface speeds of flywheel end  63 , may limit the diameter of flywheel end  63 . This is because the diameter of flywheel end  63  and the rotational speed of flywheel  55  may both be proportional to the surface speed of flywheel end  63  when the surface speed of flywheel end  63  is held constant. Therefore, the diameter of flywheel end  63  and the rotational speed of flywheel  55  may be inversely proportional to each other. In other words, bearing  52  may be damaged if flywheel end  63  has a large diameter and flywheel  55  is rotated at high speed. 
         [0016]    The connection between crankshaft  15  and flywheel  55 , and more specifically, the connection between crankshaft end  62  and flywheel end  63 , may be configured such that the limit on the diameter of flywheel end  63  does not undesirably limit an amount of torque crankshaft  15  may transmit to rotor  20  via flywheel  55 . For example, threaded fasteners  65  may be used to connect crankshaft end  62  to flywheel end  63 . Threaded fasteners  65  may maintain in a meshed configuration teeth protruding from each of crankshaft end  62  and flywheel end  63 , allowing transmissions of torque via the teeth, as described in further detail below. 
         [0017]    Threaded fasteners  65  may include heads  67  and threaded portions  68 . Crankshaft end  62  may include threaded bores  80  configured to receive threaded portions  68  of threaded fasteners  65 . And, flywheel  55  may include flywheel bores  85  alignable with threaded bores  80  and configured to allow passage though flywheel  55  of threaded portions  68 . Threaded bores  80  may be formed into crankshaft end  62  without passing through crankshaft  15 , while flywheel bores  85  may be free of threads and may extend through flywheel  55 . Although  FIG. 1  illustrates generator set  10  as having multiple threaded fasteners  65 , threaded bores  80 , and flywheel bores  85 , it is contemplated that generator set  10  may, in some embodiments, include only one threaded fastener  65 , threaded bore  80 , and flywheel bore  85 . Regardless of how many threaded fasteners  65 , threaded bores  80 , and flywheel bores  85  generator set  10  includes, crankshaft end  62  may be connected to flywheel end  63  by aligning flywheel bores  85  with threaded bores  80 , and then screwing threaded fasteners  65  through flywheel bores  85  into threaded bores  80  until heads  67  of threaded fasteners  65  contact flywheel  55  either directly or indirectly. Threaded fasteners  65  may then maintain in a meshed configuration the teeth protruding from each of crankshaft end  62  and flywheel end  63 , as illustrated in  FIG. 2 . 
         [0018]    The teeth protruding from each of crankshaft end  62  and flywheel end  63  may be, respectively, crankshaft teeth  90  and flywheel teeth  95 . Although crankshaft teeth  90  and flywheel teeth  95  may have varied shapes, it is contemplated that they may be configured to mesh with each other. For example, this meshing of crankshaft teeth  90  and flywheel teeth  95  may form a hirth-type, a curvic-type, or another type of face gear coupling known in the art, which may allow transmissions of torque from crankshaft  15  to flywheel  55  and/or from flywheel  55  to crankshaft  15 . A hirth-type coupling may be formed when crankshaft teeth  90  and flywheel teeth  95  are triangularly shaped. For example, each of crankshaft teeth  90  may include a triangularly shaped protrusion of crankshaft end  62 , which may extend along a radius of crankshaft  15  (e.g., a crankshaft radius  97 , illustrated in  FIG. 4 ), tapering toward a central axis of crankshaft  15 . In other words, a size of the triangularly shaped protrusion of crankshaft end  62  may vary along the radius of crankshaft  15 . Similarly, each of flywheel teeth  95  may include a triangularly shaped protrusion of flywheel end  63 , which may extend along a radius of flywheel  55  (e.g., a flywheel radius  98 , illustrated in  FIG. 3 ), tapering toward a central axis of flywheel  55 . In other words, a size of the triangularly shaped protrusion of flywheel end  63  may vary along the radius of flywheel  55 . A curvic-type coupling may be formed when crankshaft teeth  90  and flywheel teeth  95  are convexly shaped. In other words, each of crankshaft teeth  90  may alternatively include a convexly shaped protrusion of crankshaft end  62 . For example, the convexly shaped protrusion of crankshaft end  62  may be a conically shaped protrusion, which may have an apex positioned on the central axis of crankshaft  15 . Similarly, each of flywheel teeth  95  may alternatively include a convexly shaped protrusion of flywheel end  63 . For example, the convexly shaped protrusion of flywheel end  63  may be a conically shaped protrusion, which may have an apex positioned on the central axis of flywheel  55 . 
         [0019]    Regardless of the type of face gear coupling formed by the meshing of crankshaft teeth  90  and flywheel teeth  95 , flywheel teeth  95  may extend from an exterior edge of flywheel end  63  along radii of flywheel  55  (e.g., flywheel radius  98 ) all the way to the central axis of flywheel  55 . Alternatively, flywheel teeth  95  may not extend all the way to the central axis of flywheel  55 . Instead, flywheel teeth  95  may form an annular portion  100  on flywheel end  63 , illustrated in  FIG. 3 . In other words, flywheel teeth  95  may extend from the exterior edge of flywheel end  63  along radii of flywheel  55  only part of the way to the central axis of flywheel  55 . In such an embodiment, flywheel bores  85  may be situated radially inward of annular portion  100 , and machining costs may be reduced. Similarly, crankshaft teeth  90  may extend from an exterior edge of crankshaft end  62  along radii of crankshaft  15  (e.g., crankshaft radius  97 ) all the way to the central axis of crankshaft  15 . Alternatively, crankshaft teeth  90  may not extend all the way to the central axis of crankshaft  15 . Instead, crankshaft teeth  90  may form an annular portion  105  on crankshaft end  62 , illustrated in  FIG. 4 . In other words, crankshaft teeth  90  may extend from the exterior edge of crankshaft end  62  along radii of crankshaft  15  only part of the way to the central axis of crankshaft  15 . In such an embodiment, threaded bores  80  may be situated radially inward of annular portion  105 , and machining costs may be reduced. 
       INDUSTRIAL APPLICABILITY 
       [0020]    The disclosed combinations may be applicable to masses. The combinations may be particularly beneficial when applied to rotatable masses, which are inadequately supported by other components. The combinations may support and rotatably drive the masses. For example, the combinations may support and rotatably drive rotors of single bearing generators. 
         [0021]    During operation of generator set  10  (referring to  FIG. 1 ), rotor  20  may orbit and/or vibrate as it rotates to produce electricity. Additionally, crankshaft  15  may orbit and/or vibrate as it rotates. It is contemplated that the orbiting and/or vibrating of rotor  20  and/or crankshaft  15  may cause crankshaft end  62  and/or flywheel end  63  to orbit and/or vibrate. But, bearing  52  may reduce or prevent the orbiting and/or vibrating of crankshaft end  62 , flywheel end  63 , and/or rotor  20 , thereby reducing bending movement of crankshaft  15 . Reducing this bending movement may prevent premature failure of crankshaft  15 , thus reducing maintenance costs associated with generator set  10 . 
         [0022]    It is also contemplated that crankshaft  15  may transfer large amounts of torque to and rotatably drive rotor  20  at high speeds. The chain of connections between crankshaft  15  and rotor  20 , and more specifically, the connection between crankshaft  15  and flywheel  55  may be configured such that the large amounts of torque and high rotational speeds do not damage bearing  52 . In particular, the connection may be configured such that flywheel end  63  may have a diameter sufficiently small to prevent the high rotational speeds from generating excessive surface speeds of flywheel end  63 , which may damage bearing  52 . Specifically, the connection may allow crankshaft  15  to transfer large amounts of torque to rotor  20  via crankshaft teeth  90  and flywheel teeth  95 . These teeth may eliminate or reduce an amount of torque transferred via threaded fasteners  65 , and thereby alter a primary function of threaded fasteners  65 . Instead of directly transferring torque between crankshaft  15  and flywheel  55 , threaded fasteners  65  may indirectly transfer torque between crankshaft  15  and flywheel  55  by maintaining in a meshed configuration crankshaft teeth  90  and flywheel teeth  95 . 
         [0023]    It will be apparent to those skilled in the art that various modifications and variations can be made to the combinations of the present disclosure. Other embodiments of the combinations will be apparent to those skilled in the art from consideration of the specification and practice of the combinations disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope of the disclosure being indicated by the following claims and their equivalents.