Combination to support and rotatably drive mass

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.

TECHNICAL FIELD

The present disclosure relates generally to a combination and, more particularly, to combination for use in supporting and rotatably driving a mass.

BACKGROUND

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.

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 '933 patent) to Hallewell, which was published on Mar. 24, 1954. The '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.

Although the crankshaft journal bearing may reduce bending movement of the crankshaft as taught in the '933 patent, the combination of the crankshaft journal bearing and the bolts connecting the crankshaft to the flywheel may limit the crankshaft'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 '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.

The disclosed combinations are directed to overcoming one or more of the problems set forth above and/or other problems in the art.

SUMMARY

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.

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.

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.

DETAILED DESCRIPTION

FIG. 1illustrates a generator set10having a crankshaft15connected to a mass17. For example, crankshaft15may be a crankshaft of a power source18, and mass17may be a rotor20of a generator25. Power source18and generator25may be coupled such that power source18rotatably drives rotor20via crankshaft15, and such that power source18supports rotor20. For example, power source18may support rotor20when generator25fails to adequately support rotor20. Generator25may fail to adequately support rotor20when, for example, generator25is a single bearing generator, which only supports one side of rotor20. Although the connection between crankshaft15and rotor20is described in more detail below, it should be noted that the components and features described herein are equally applicable to connections between crankshaft15and other masses17such as, for example, fan blades, propellers, or other masses that are rotatably driven by crankshafts15and supported by power sources18.

As illustrated inFIG. 1, power source18may include an engine block45, which may have cylinders50. Crankshaft15, which may be situated at least partially within power source18, may be rotatably driven by pistons (not shown) located within cylinders50. Alternatively, engine block45may not have cylinders50, and crankshaft15may be rotatably driven by other components of power source18such as, for example, rotors of a Wankel engine, rotors of an electric motor, or turbines of a jet engine.

Although crankshaft15may be directly connected to rotor20, it is contemplated that generator set10may include other components connected between crankshaft15and rotor20. These other components, which may receive support from a bearing52situated at least partially within power source18, may help support crankshaft15and/or rotor20, while allowing crankshaft15to transfer torque to and rotatably drive rotor20. For example, bearing52may be a journal bearing, a ball bearing, a magnetic bearing, or another type of bearing known in the art. Bearing52may support and at least partially house a flywheel55, which may be connected between crankshaft15and rotor20. Flywheel55may in turn support crankshaft15and a flexplate60, which may be connected between flywheel55and rotor20, and which may support rotor20. These chains of support may prevent orbiting and/or vibrating of a crankshaft end62of crankshaft15and a flywheel end63of flywheel55, thereby reducing bending movement of crankshaft15. However, the chains of support may also limit a diameter of flywheel end63if flywheel55is to be rotated at high speed. Specifically, bearing52, which may be damaged by excessive surface speeds of flywheel end63, may limit the diameter of flywheel end63. This is because the diameter of flywheel end63and the rotational speed of flywheel55may both be proportional to the surface speed of flywheel end63when the surface speed of flywheel end63is held constant. Therefore, the diameter of flywheel end63and the rotational speed of flywheel55may be inversely proportional to each other. In other words, bearing52may be damaged if flywheel end63has a large diameter and flywheel55is rotated at high speed.

The connection between crankshaft15and flywheel55, and more specifically, the connection between crankshaft end62and flywheel end63, may be configured such that the limit on the diameter of flywheel end63does not undesirably limit an amount of torque crankshaft15may transmit to rotor20via flywheel55. For example, threaded fasteners65may be used to connect crankshaft end62to flywheel end63. Threaded fasteners65may maintain in a meshed configuration teeth protruding from each of crankshaft end62and flywheel end63, allowing transmissions of torque via the teeth, as described in further detail below.

Threaded fasteners65may include heads67and threaded portions68. Crankshaft end62may include threaded bores80configured to receive threaded portions68of threaded fasteners65. And, flywheel55may include flywheel bores85alignable with threaded bores80and configured to allow passage though flywheel55of threaded portions68. Threaded bores80may be formed into crankshaft end62without passing through crankshaft15, while flywheel bores85may be free of threads and may extend through flywheel55. AlthoughFIG. 1illustrates generator set10as having multiple threaded fasteners65, threaded bores80, and flywheel bores85, it is contemplated that generator set10may, in some embodiments, include only one threaded fastener65, threaded bore80, and flywheel bore85. Regardless of how many threaded fasteners65, threaded bores80, and flywheel bores85generator set10includes, crankshaft end62may be connected to flywheel end63by aligning flywheel bores85with threaded bores80, and then screwing threaded fasteners65through flywheel bores85into threaded bores80until heads67of threaded fasteners65contact flywheel55either directly or indirectly. Threaded fasteners65may then maintain in a meshed configuration the teeth protruding from each of crankshaft end62and flywheel end63, as illustrated inFIG. 2.

The teeth protruding from each of crankshaft end62and flywheel end63may be, respectively, crankshaft teeth90and flywheel teeth95. Although crankshaft teeth90and flywheel teeth95may have varied shapes, it is contemplated that they may be configured to mesh with each other. For example, this meshing of crankshaft teeth90and flywheel teeth95may 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 crankshaft15to flywheel55and/or from flywheel55to crankshaft15. A hirth-type coupling may be formed when crankshaft teeth90and flywheel teeth95are triangularly shaped. For example, each of crankshaft teeth90may include a triangularly shaped protrusion of crankshaft end62, which may extend along a radius of crankshaft15(e.g., a crankshaft radius97, illustrated inFIG. 4), tapering toward a central axis of crankshaft15. In other words, a size of the triangularly shaped protrusion of crankshaft end62may vary along the radius of crankshaft15. Similarly, each of flywheel teeth95may include a triangularly shaped protrusion of flywheel end63, which may extend along a radius of flywheel55(e.g., a flywheel radius98, illustrated inFIG. 3), tapering toward a central axis of flywheel55. In other words, a size of the triangularly shaped protrusion of flywheel end63may vary along the radius of flywheel55. A curvic-type coupling may be formed when crankshaft teeth90and flywheel teeth95are convexly shaped. In other words, each of crankshaft teeth90may alternatively include a convexly shaped protrusion of crankshaft end62. For example, the convexly shaped protrusion of crankshaft end62may be a conically shaped protrusion, which may have an apex positioned on the central axis of crankshaft15. Similarly, each of flywheel teeth95may alternatively include a convexly shaped protrusion of flywheel end63. For example, the convexly shaped protrusion of flywheel end63may be a conically shaped protrusion, which may have an apex positioned on the central axis of flywheel55.

Regardless of the type of face gear coupling formed by the meshing of crankshaft teeth90and flywheel teeth95, flywheel teeth95may extend from an exterior edge of flywheel end63along radii of flywheel55(e.g., flywheel radius98) all the way to the central axis of flywheel55. Alternatively, flywheel teeth95may not extend all the way to the central axis of flywheel55. Instead, flywheel teeth95may form an annular portion100on flywheel end63, illustrated inFIG. 3. In other words, flywheel teeth95may extend from the exterior edge of flywheel end63along radii of flywheel55only part of the way to the central axis of flywheel55. In such an embodiment, flywheel bores85may be situated radially inward of annular portion100, and machining costs may be reduced. Similarly, crankshaft teeth90may extend from an exterior edge of crankshaft end62along radii of crankshaft15(e.g., crankshaft radius97) all the way to the central axis of crankshaft15. Alternatively, crankshaft teeth90may not extend all the way to the central axis of crankshaft15. Instead, crankshaft teeth90may form an annular portion105on crankshaft end62, illustrated inFIG. 4. In other words, crankshaft teeth90may extend from the exterior edge of crankshaft end62along radii of crankshaft15only part of the way to the central axis of crankshaft15. In such an embodiment, threaded bores80may be situated radially inward of annular portion105, and machining costs may be reduced.

Industrial Applicability

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.

During operation of generator set10(referring toFIG. 1), rotor20may orbit and/or vibrate as it rotates to produce electricity. Additionally, crankshaft15may orbit and/or vibrate as it rotates. It is contemplated that the orbiting and/or vibrating of rotor20and/or crankshaft15may cause crankshaft end62and/or flywheel end63to orbit and/or vibrate. But, bearing52may reduce or prevent the orbiting and/or vibrating of crankshaft end62, flywheel end63, and/or rotor20, thereby reducing bending movement of crankshaft15. Reducing this bending movement may prevent premature failure of crankshaft15, thus reducing maintenance costs associated with generator set10.

It is also contemplated that crankshaft15may transfer large amounts of torque to and rotatably drive rotor20at high speeds. The chain of connections between crankshaft15and rotor20, and more specifically, the connection between crankshaft15and flywheel55may be configured such that the large amounts of torque and high rotational speeds do not damage bearing52. In particular, the connection may be configured such that flywheel end63may have a diameter sufficiently small to prevent the high rotational speeds from generating excessive surface speeds of flywheel end63, which may damage bearing52. Specifically, the connection may allow crankshaft15to transfer large amounts of torque to rotor20via crankshaft teeth90and flywheel teeth95. These teeth may eliminate or reduce an amount of torque transferred via threaded fasteners65, and thereby alter a primary function of threaded fasteners65. Instead of directly transferring torque between crankshaft15and flywheel55, threaded fasteners65may indirectly transfer torque between crankshaft15and flywheel55by maintaining in a meshed configuration crankshaft teeth90and flywheel teeth95.