Piston assembly, as well as related components and systems

Abstract

The piston assembly includes a piston head. The piston assembly further includes an upper connecting rod rotatably coupled to the piston head. The piston assembly further includes a shoe disposed between the upper connecting rod and the inner wall of the piston head.

Description

Technical Field

[0001] Priority Claim This application claims the benefit of U.S. Provisional Patent Application No. 63 / 368,183, filed Jul. 12, 2022, entitled "PISTON ASSEMBLY AND ASSOCIATED COMPONENTS, SYSTEMS, AND METHOD", the entire disclosure of which is incorporated herein by reference, under 35 U.S.C. § 119(e).

[0002] The present disclosure relates to internal combustion engines, and more particularly to piston assemblies for use within an engine and for connecting a piston head to a crankshaft of the engine.

Background Art

[0003] Conventional internal combustion engines of the type found in many current vehicles have a plurality of pistons movably disposed within a plurality of cylinders formed within an engine block. Each piston is connected to a piston rod at a first end of the piston rod, and the piston rod is coupled to a crankshaft at a second end of the piston rod. Further, when a spark plug within the engine block fires to ignite a fuel mixture, the piston is driven downward to rotate the crankshaft, ultimately driving the entire vehicle. In a typical engine, a single connecting rod is used, connected to a corresponding piston at each first end and to a corresponding portion of the crankshaft at each second end. The connection points between both ends of each connecting rod and the corresponding piston and corresponding crankshaft are located at the ends of the longitudinal central axis of each connecting rod.

Summary of the Invention

Means for Solving the Problems

[0004] Embodiments of the present disclosure include a piston assembly. The piston assembly includes a piston head. The piston assembly further includes an upper connecting rod rotatably coupled to the piston head. The piston assembly further includes a shoe disposed between the upper connecting rod and the inner wall of the piston head.

[0005] Another embodiment of the present disclosure includes an engine. The engine includes a cylinder, a crankshaft, and a piston assembly disposed within the cylinder. The piston assembly includes a piston head. The piston assembly further includes an upper connecting rod rotatably coupled to the piston head. The piston assembly further includes a lower connecting rod coupled between the upper connecting rod and the crankshaft. The piston assembly further includes a shoe slidably coupled between the upper connecting rod and the skirt of the piston head.

[0006] Another embodiment of the present disclosure includes an upper connecting rod of a piston assembly. The upper connecting rod includes a piston connection point. The upper connecting rod further includes a lower rod connection point. The upper connecting rod further includes a curved recess defined within the outer edge of the upper connecting rod. The curved recess is configured to receive an interface element between the upper connecting rod and the piston. The curved recess is disposed closer to the piston connection point than the lower rod connection point.

[0007] This specification concludes with claims that particularly and distinctly claim the embodiments of the present disclosure, but the advantages of the embodiments of the present disclosure may be more readily ascertained from the following description of the embodiments of the present disclosure when read in conjunction with the accompanying drawings.

Brief Description of the Drawings

[0008]

Figure 1

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DETAILED DESCRIPTION OF THE INVENTION

[0009] The figures presented in this specification are not actual figures of any internal combustion engine system, piston assembly, or any of its components, but rather are merely idealized figures employed to illustrate embodiments of the present disclosure.

[0010] As used in this specification, the singular forms following "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise.

[0011] The term "may" as used in this specification in connection with materials, structures, features, or acts of a method is intended to indicate that these materials, structures, features, or acts of the method are contemplated to be used in an implementation form of an embodiment of the present disclosure, and also to avoid any implication that other compatible materials, structures, features, and methods that may be used in combination with these materials, structures, features, or methods should or should not be excluded. It is preferably used rather than the more restrictive word "is".

[0012] As used herein, any relational terms such as "first", "second", "top", "bottom", "upper", "lower", etc. are used to clearly and conveniently understand the present disclosure and the accompanying drawings, and do not imply any specific preference or order whatsoever, nor do they depend on any specific preference or order, except when the context clearly indicates other meanings. For example, these terms can mean the orientation of elements of a piston assembly or an engine in a conventional orientation. Further, these terms can mean the orientation of elements of the piston assembly or engine shown in the drawings.

[0013] As used herein, the term "substantially" means the degree when one of ordinary skill in the art understands that a given parameter, characteristic, or condition undergoes a slight change within a range such as acceptable manufacturing tolerances, and also includes that degree. For example, depending on a particular parameter, characteristic, or condition that is substantially conforming, the parameter, characteristic, or condition may conform at least 90.0%, at least 95.0%, at least 99.0%, or at least 99.9%.

[0014] As used herein, the term "about" when used in reference to a given parameter includes the recited value and has a meaning determined by the context (e.g., including the error associated with the measurement of a given parameter).

[0015] FIG. 1 shows a schematic view showing a piston assembly 100 disposed within an engine 102. The piston assembly 100 can have a piston head 104, an upper rod 106, a gudgeon pin assembly 107 (e.g., two or more, a pin lock, a needle sleeve bearing, and a gudgeon pin (e.g., a wrist pin)), a lower rod 108, and a connector pin assembly 109. The engine 102 can have a cylinder 112, one or more valves 114 and exhaust ports 116 (e.g., an intake valve and an intake port, and an exhaust valve and an exhaust port), and a fuel injection device 118. One or more valves 114 and exhaust ports 116 of the engine 102 can be oriented in a conventional manner.

[0016] The piston head 104 of the piston assembly 100 can be disposed within the cylinder 112 of the engine 102 and can be configured to reciprocate back and forth (e.g., up and down as depicted in FIG. 1) during use. The upper rod 106 can be coupled to the piston head 104 via the gudgeon pin assembly 107 at a first longitudinal end of the upper rod 106 and can be coupled to the lower rod 108 at a second opposite longitudinal end of the upper rod 106. In some embodiments, the upper rod 106 can be coupled to the piston head 104 near or at its center of mass. In one or more embodiments, the upper rod 106 can be coupled to the piston head 104 at a point located at the center between the upper and lower surfaces of the piston head 104 and intersecting the longitudinal central axis 122 of the piston head 104. In one or more embodiments, the longitudinal axis 120 of the gudgeon pin assembly 107 can extend in a direction perpendicular to the longitudinal axis 122 of the piston head 104 and can intersect the longitudinal axis 122 of the piston head 104. The upper rod 106 can be configured not to rotate and / or translate relative to the piston head 104 during use.

[0017] The upper rod 106 may extend axially (e.g., in a direction parallel to the longitudinal axis 122 of the piston head 104) from the piston head 104 to a region below the piston head 104 (e.g., below the piston head 104 depicted in FIG. 1). For example, the longitudinal length of the upper rod 106 may be greater than the distance from the point at which the upper rod 106 is coupled to the piston head 104 to the lowermost surface of the piston head 104. Further, the longitudinal axis of the upper rod 106 may be parallel to the longitudinal axis 122 of the piston head 104. In view of the above, when the upper rod 106 is coupled to the piston head 104, the lower longitudinal end of the upper rod 106 may be directed below the piston head 104.

[0018] As described above, the upper rod 106 may be coupled to the lower rod 108 at the longitudinal end opposite the piston head 104 (i.e., the lower longitudinal end of the upper rod 106). In some embodiments, the upper rod 106 may be coupled to the lower rod 108 via a connector pin assembly 109. In one or more embodiments, the connector pin assembly 109 may have any gudgeon pins and / or wrist pins and associated assemblies known in the art.

[0019] The lower rod 108 may be rotatable about the upper rod 106. For example, the lower rod 108 may be configured to pivot about the connector pin assembly 109 and the upper rod 106. For example, the connector pin assembly 109 may provide a bearing about which the lower rod 108 can pivot as the piston assembly 100 repeats a plurality of strokes (described later).

[0020] The lower rod 108 can be coupled to the crankshaft 126 at the longitudinal end of the lower rod 108 on the opposite side of the upper rod 106. The crankshaft 126 can include a conventional crankshaft. For example, the crankshaft 126 can convert the reciprocating motion of the piston head 104 into a rotational motion. As is known in the art, a crankshaft has a plurality of "crank throws" or "crank pins", and a plurality of bearing surfaces (e.g., rod journals, connecting rod journals, etc.) having axes offset from the longitudinal central axis 128 of the crankshaft 126. The lower rod 108 can be coupled to each bearing surface of the crankshaft 126. Additionally, the lower rod 108 can be coupled to the crankshaft 126 via any conventional bearing. Further, as will be appreciated by those skilled in the art, the rotational axis 128 (i.e., the longitudinal central axis) of the crankshaft 126 can be parallel to the longitudinal axis 124 of the connector pin assembly 109.

[0021] To describe the operation of the piston assembly 100, the normal clock face time positions are herein referenced as the positions of the lower longitudinal end of the lower rod 108 about the rotational axis 128 of the crankshaft 126 (e.g., 12 o'clock, 3 o'clock, etc.). For example, the above positions can mean the center point of the lower longitudinal end of the lower rod 108 and its position with reference to the rotational axis 128 of the crankshaft 126 as depicted in FIG. 1, where the piston head 104 associated with the lower rod 108 is at top dead center at the 12 o'clock position and bottom dead center at the 6 o'clock position, regardless of the orientation of the associated engine and / or cylinder.

[0022] In some embodiments, the engine 102 and the piston assembly 100 can include a four-stroke engine. For example, in use, the piston assembly 100 can complete four separate strokes while rotating the crankshaft 126. In other words, the engine 102 and the piston assembly 100 can repeatedly perform a typical four-stroke cycle.

[0023] The piston assembly 100 can initiate a four-stroke cycle during the intake stroke (e.g., induction stroke or suction stroke). As is known in the art, the intake stroke starts with the piston head 104 positioned at top dead center and ends with the piston head 104 positioned at bottom dead center. During the intake stroke, the intake valve (e.g., valve 114) opens (by the breaker cam lobe of the breaker cam, as is known in the art), and as the piston head 104 moves downward within the cylinder 112, the piston head 104 draws an air mixture into the cylinder 112 by generating a vacuum pressure within the cylinder 112 through its downward movement. Additionally, the fuel injection device 118 injects fuel into the air to form an air-fuel mixture. As described above, the piston assembly 100 of the present disclosure can reduce the force required to move the piston head 104 from the 12 o'clock position to the 6 o'clock position, and as a result, a portion of the energy required to perform the intake stroke can be saved (e.g., energy from other piston assemblies that rotate the crankshaft 126 during their power stroke (i.e., combustion stroke)). As will be appreciated by those skilled in the art, reducing the amount of energy required to perform the intake stroke will increase the energy available for other operations of the engine 102 (e.g., when operating a vehicle using the engine 102). Therefore, the piston assembly 100 of the present disclosure can provide a more efficient engine compared to conventional piston assemblies.

[0024] After the intake stroke, the piston assembly 100 begins the compression stroke. The compression stroke begins at the piston head 104 disposed at the bottom dead center and ends at the piston head 104 disposed at the top dead center. During the compression stroke, the piston head 104 compresses the air-fuel mixture in preparation for ignition during the power stroke (described later). Further, during the compression stroke, the intake valve and the exhaust valve (e.g., valve 114) are closed. As described above, the piston assembly 100 of the present disclosure reduces the force required to move the piston head 104 from the 6 o'clock position to the 12 o'clock position, and as a result, a part of the energy required during the compression stroke can be saved. As will be appreciated by those skilled in the art, reducing the amount of energy required to perform the compression stroke increases the energy available for other operations of the engine 102.

[0025] When the air-fuel mixture is compressed and reaches the top dead center, the piston assembly 100 can initiate the power stroke (i.e., the combustion stroke or the ignition stroke). When the piston head 104 is near the top dead center, the air-fuel mixture is ignited by an initiator (e.g., a spark plug, a glow plug, etc.) or by the heat generated by high compression (e.g., a diesel engine). Igniting the air-fuel mixture causes an explosion, and this explosion forcibly returns the piston head 104 to the bottom dead center. As is known in the art, the power stroke creates a mechanical action from the engine 102 for rotating the crankshaft 126. For example, the power stroke can create a mechanical action through a conventional method that involves the piston assembly and the crankshaft.

[0026] As described above, the piston assembly 100 of the present disclosure reduces the force required to move the piston head 104 from the 6 o'clock position or from the 12 o'clock position. As a result, the piston assembly of the present disclosure enables the air-fuel mixture to be ignited closer to or at the 12 o'clock position as compared to a conventional piston assembly. For example, a conventional piston assembly typically has an ignition position between the 10 o'clock position and the 12 o'clock position, thereby providing the force required to rotate through the 12 o'clock position. Further, as will be understood by those skilled in the art, by igniting the air-fuel mixture closer to or at the 12 o'clock position (and not at a significantly early timing), it is possible to increase the pressure generated by ignition acting on the piston assembly to move the piston assembly downward during the power stroke.

[0027] When bottom dead center is reached, the piston assembly 100 begins an exhaust stroke. During the exhaust stroke, the piston head 104 of the piston assembly 100 returns from bottom dead center to top dead center again, where the exhaust valve (e.g., valve 114) is open. The action of the piston head 104 moving from bottom dead center to top dead center discharges the used air-fuel mixture through the exhaust port 116 in a form that passes through the exhaust valve 114. Further, when top dead center is reached, the piston assembly 100 can repeat the four strokes described above.

[0028] During various strokes, the forces transmitted through the upper rod 106 and the lower rod 108 can introduce longitudinal forces in a direction along the longitudinal central axis 122 and lateral forces perpendicular to the longitudinal central axis 122. The longitudinal force can act to move the piston head 104 within the cylinder 112 along the longitudinal central axis 122. The lateral force can generate a moment on the piston head 104 by a moment arm created by the upper rod 106. The piston head 104 can include a skirt 130 configured to substantially prevent the piston head 104 from tilting or rocking within the cylinder 112. However, the skirt 130 can contact the wall of the cylinder 112 and create additional friction. Therefore, additional structures configured to counter the lateral force and / or reduce the moment arm created by the upper rod 106 can reduce the frictional force and improve the efficiency of the associated engine 102.

[0029] Figures 2-4 show various views of the piston head 104 including the shoe 202 coupled between the upper rod 106 and the skirt 130 of the piston head 104. The shoe 202 can be configured to vary the moment arm of the upper rod 106 with respect to the piston head 104, and can reduce the lateral force transmitted to the piston head 104 by the upper rod 106. For example, the shoe 202 can include a skirt interface 204 and a rod interface 302. Each of the skirt interface 204 and the rod interface 302 can be a sliding connection, such that the shoe 202 can move relative to the skirt 130 and the upper rod 106. The sliding connection can facilitate slight rotation of the upper rod 106 relative to the piston head 104. For example, the rod interface 302 can form a fulcrum point about which the upper rod 106 can rotate slightly. The lateral force within the upper rod 106 can be transmitted to the skirt 130 through the shoe 202. The fulcrum created by the rod interface 302 between the shoe 202 and the upper rod 106 can apply a second opposing force to the piston connection point 304. The lateral forces at the piston connection point 304 and within the shoe 202 can each be applied to the piston head 104 at various locations on the same side of the piston head 104, with respect to the axis of rotation of the piston head 104. Accordingly, opposing lateral forces can create opposing moments on the piston head 104, and can significantly reduce the moment received by the piston head 104.

[0030] FIG. 5 shows an embodiment of the shoe 202. As shown, the skirt interface 204 can have a greater width than the rod interface 302. The greater width of the rod interface 302 can increase the surface area of the skirt interface 204 compared to the rod interface 302. The relatively large surface area of the skirt interface 204 can reduce the pressure generated by lateral forces, thereby reducing the pressure generated on the skirt 130 (FIGS. 2-4) by the skirt interface 204. Reducing the pressure on the skirt 130 (FIGS. 2-4) can facilitate forming the skirt 130 from a thinner material, thereby reducing the weight of the piston head 104.

[0031] The skirt interface 204 can have a radius that substantially conforms to the radius of the inner surface of the associated skirt 130 (FIGS. 2-4). This radius can facilitate a substantially even distribution of lateral forces on the associated skirt 130 (FIGS. 2-4) by the shoe 202. By distributing the forces, the local pressure applied to the inner surface of the skirt 130 (FIGS. 2-4) can be reduced, thereby facilitating forming the skirt 130 from a thinner material, similar to the increased surface area of the skirt interface 204.

[0032] Figure 6 shows a side view of the upper rod 106. The upper rod 106 includes a piston connection point 304 and a lower rod connection point 604. The upper rod 106 can further include a recess 602 configured to interface connect to a rod interface 302 of an associated shoe 202. The recess 602 can have a curved surface that is complementary to the rod interface 302 of the associated shoe 202. The curved surface of the recess 602 can define an arc having an angle greater than about 60 degrees, such as an angle greater than about 90 degrees or greater than about 100 degrees. In some embodiments, the recess 602 can include a bearing material or bearing insert configured to reduce friction between the rod interface 302 of the shoe 202 and the recess 602. The recess 602 can be disposed closer to the piston connection point 304 than the lower rod connection point 604. By disposing the recess 602 near the piston connection point 304, the moments and forces within the components and regions near the recess 602 and the piston connection point 304 can be equalized, thereby substantially preventing the piston head 104 (Figs. 1-4) from tilting or vibrating within the cylinder 112 (Fig. 1).

[0033] The non-limiting exemplary embodiments of the present disclosure further include the following embodiments:

[0034] Embodiment 1: A piston assembly, the piston assembly comprising: a piston head; an upper connecting rod rotatably coupled to the piston head; and a shoe disposed between the upper connecting rod and an inner wall of the piston head.

[0035] Embodiment 2: The piston assembly of Embodiment 1, wherein the shoe comprises a piston interface surface that slidably contacts an inner wall of the piston head.

[0036] Embodiment 3: The piston assembly of Embodiment 1 or Embodiment 2, wherein the inner wall of the piston head comprises an inner wall of a piston skirt.

[0037] Embodiment 4: The piston assembly of Embodiment 3, wherein the shoe is configured to disperse lateral forces across the inner wall of the piston skirt.

[0038] Embodiment 5: The piston assembly of any one of Embodiments 1 to 4, wherein the shoe includes a rod interface surface that slidably contacts the upper connecting rod.

[0039] Embodiment 6: The piston assembly of Embodiment 5, wherein the upper connecting rod has a complementary recess that slidably contacts the rod interface surface of the shoe.

[0040] Embodiment 7: The piston assembly of Embodiment 6, wherein the complementary recess has a curved surface.

[0041] Embodiment 8: The piston assembly of any one of Embodiments 1 to 7, wherein the shoe has a first width near the upper connecting rod and a second width near the inner wall of the piston head, and the second width is greater than the first width.

[0042] Embodiment 9: An engine, the engine comprising: a cylinder; a crankshaft; a piston assembly disposed within the cylinder, the piston assembly comprising: a piston head; an upper connecting rod rotatably coupled to the piston head; a lower connecting rod coupled between the upper connecting rod and the crankshaft; and a shoe slidably coupled between the upper connecting rod and the skirt of the piston head.

[0043] Embodiment 10: The engine of Embodiment 9, wherein the shoe has a skirt interface surface slidably connected to the skirt of the piston head.

[0044] Embodiment 11: The engine of Embodiment 10, wherein the skirt interface surface has a radius that substantially conforms to the radius of the inner surface of the skirt of the piston head.

[0045] Embodiment 12: The engine of any one of Embodiments 9 to 11, wherein the upper connecting rod includes a recess slidably coupled to the shoe.

[0046] Embodiment 13: The engine of Embodiment 12, wherein the recess includes a curved surface that is complementary to the rod interface surface of the shoe.

[0047] Embodiment 14: The engine of Embodiment 12 or Embodiment 13, wherein the recess further includes a bearing material.

[0048] Embodiment 15: The engine of any one of Embodiments 12 to 14, wherein the recess is disposed closer to the piston connection portion between the upper connecting rod and the piston head as compared to the lower rod connection portion between the upper connecting rod and the lower connecting rod.

[0049] Embodiment 16: An upper connecting rod of a piston assembly, the upper connecting rod comprising: a piston connection point; a lower rod connection point; and a curved recess defined within an outer edge of the upper connecting rod, the curved recess being configured to receive an interface element between the upper connecting rod and the piston, the curved recess being disposed closer to the piston connection point as compared to the lower rod connection point.

[0050] Embodiment 17: The upper connecting rod of Embodiment 16, wherein the piston connection point includes a gudgeon pin assembly.

[0051] Embodiment 18: The upper connecting rod of Embodiment 17, wherein the lower rod connection point includes a connector pin assembly.

[0052] Embodiment 19: The upper connecting rod of any one of Embodiments 16 to 18, wherein the curved concave portion has an arc of at least 60 degrees.

[0053] Embodiment 20: The upper connecting rod of any one of Embodiments 16 to 19, wherein the curved concave portion has an arc of at least 90 degrees.

[0054] Embodiments of the present disclosure can substantially prevent or significantly reduce the tilting or vibration of the piston head within the cylinder of the engine. By reducing or preventing the tilting or vibration of the piston head, the contact and associated friction between the piston head and the cylinder wall can be significantly reduced. By reducing the contact between the piston head and the cylinder wall, the efficiency of the engine can be improved and the wear of the piston head and the cylinder wall can be reduced. The embodiments of the present disclosure described above and shown in the figures of the accompanying drawings do not limit the scope of the present invention, because these embodiments are merely examples of embodiments of the present invention defined by the scope of the appended claims and their legal equivalents. Any equivalent embodiments are intended to be within the scope of the present disclosure. In fact, various modifications of the present disclosure, such as alternative useful combinations of the elements described, will be apparent to those skilled in the art from this description in addition to the embodiments shown and described herein. Such modifications and embodiments are also intended to be within the scope of the appended claims and their legal equivalents.

Claims

1. A piston head, an upper connecting rod rotatably coupled to the piston head, and a shoe disposed between the upper connecting rod and an inner wall of the piston head, the piston assembly comprising the same.

2. The piston assembly according to claim 1, wherein the shoe comprises a piston interface surface slidably contacting the inner wall of the piston head.

3. The piston assembly according to claim 1, wherein the inner wall of the piston head comprises an inner wall of a piston skirt.

4. The piston assembly according to claim 3, wherein the shoe is configured to disperse a lateral force across the inner wall of the piston skirt.

5. The piston assembly according to any one of claims 1 to 4, wherein the shoe includes a rod interface surface slidably contacting the upper connecting rod.

6. The piston assembly according to claim 5, wherein the upper connecting rod comprises a complementary recess slidably contacting the rod interface surface of the shoe.

7. The piston assembly according to claim 6, wherein the complementary recess comprises a curved surface.

8. The piston assembly according to any one of claims 1 to 4, wherein the shoe has a first width near the upper connecting rod and a second width near the inner wall of the piston head, and the second width is greater than the first width.

9. A cylinder, a crankshaft, and a piston assembly disposed within the cylinder, the piston assembly comprising: a piston head, an upper connecting rod rotatably coupled to the piston head, a lower connecting rod coupled between the upper connecting rod and the crankshaft, and a shoe slidably coupled between the upper connecting rod and a skirt of the piston head, the engine comprising the piston assembly.

10. The engine according to claim 9, wherein the shoe comprises a skirt interface surface slidably connected to the skirt of the piston head.

11. The engine according to claim 10, wherein the skirt interface surface has a radius substantially conforming to a radius of an inner surface of the skirt of the piston head.

12. The engine according to any one of claims 9 to 11, wherein the upper connecting rod includes a recess slidably coupled to the shoe.

13. The engine according to claim 12, wherein the recess includes a curved surface that is complementary to the rod interface surface of the shoe.

14. The engine according to claim 12, wherein the recess further includes a bearing material.

15. The engine according to claim 12, wherein the recess is disposed closer to the piston connection portion between the upper connecting rod and the piston head as compared to the lower rod connection portion between the upper connecting rod and the lower connecting rod.

16. An upper connecting rod of a piston assembly, the upper connecting rod comprising: a piston connection point; a lower rod connection point; a curved recess defined within an outer edge portion of the upper connecting rod, the curved recess configured to receive an interface element between the upper connecting rod and the piston, the curved recess being disposed closer to the piston connection point as compared to the lower rod connection point.

17. The upper connecting rod according to claim 16, wherein the piston connection point includes a gudgeon pin assembly.

18. The upper connecting rod according to claim 17, wherein the lower rod connection point includes a connector pin assembly.

19. The upper connecting rod according to any one of claims 16 to 18, wherein the curved recess has an arc of at least 60 degrees.

20. The upper connecting rod according to any one of claims 16 to 18, wherein the curved recess has an arc of at least 90 degrees.

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