System for cooling exhaust valves of a reciprocating engine

Abstract

The present disclosure provides a system including an engine head mounted to an engine block of a reciprocating engine, and the engine head includes an intake flow passage, an exhaust flow passage, a coolant flow passage, and a first seal register and a second seal register disposed on opposite sides of the coolant flow passage. Further, the first and second seal registers are configured to receive a valve guide for supporting a valve stem of an exhaust valve. Further, the first seal register is disposed in a wall that separates the exhaust flow passage from the coolant flow passage. Further, a first wall portion of the wall extends between the first seal register and an exhaust valve seat configured to receive a valve head of the exhaust valve, and a second wall portion of the wall extends from the first seal register away from the first wall portion.

Description

Technical Field

[0001] The subject matter disclosed in this specification generally relates to reciprocating engines, and more specifically, to exhaust valves of reciprocating engines. Background Technology

[0002] Reciprocating engines (e.g., reciprocating internal combustion engines) use an oxidant (e.g., air) to burn fuel to produce hot combustion gases, which in turn drive a piston (e.g., a reciprocating piston) located within a cylinder in the cylinder head. Specifically, the hot combustion gases expand during the expansion stroke and exert pressure on the piston, causing it to move linearly from the top portion of the cylinder to the bottom portion. The piston converts the pressure exerted by the combustion gases and the linear movement of the piston into rotational motion (e.g., via connecting rods and crankshafts connected to the piston) that drives one or more loads (e.g., a generator). The cylinder head also includes intake and exhaust valves that open and close during operation of the reciprocating engine to control the intake of air and the exhaust of combustion gases. Unfortunately, the exhaust valves are subjected to a significant amount of heat from the combustion process, which can cause degradation and coking of the lubricant used in the exhaust valves. Therefore, improvements in the cooling and lubrication associated with the exhaust valves are needed. Summary of the Invention

[0003] The following outlines certain embodiments that conform to the scope of this disclosure as initially claimed. These embodiments are not intended to limit the scope of the claimed embodiments, but rather are intended only to provide a brief description of the possible forms of this disclosure. In practice, this disclosure may include various forms similar to or different from the embodiments described below.

[0004] In a first embodiment, a system includes an engine head mounted to an engine block of a reciprocating engine. The engine head includes an intake flow passage, an exhaust flow passage, a coolant flow passage, and a first sealing register and a second sealing register disposed on opposite sides of the coolant flow passage. The first sealing register is disposed in a wall separating the exhaust flow passage from the coolant flow passage. A first wall portion of the wall extends between the first sealing register and an exhaust valve seat, and a second wall portion extends away from the first sealing register. The engine head further includes a valve guide mounted in the engine head along the coolant flow passage, and the valve guide includes an annular guide body having a central axis. The annular guide body includes an annular cooling portion axially disposed between a first annular mounting portion and a second annular mounting portion, and the annular cooling portion is configured to extend into the coolant flow passage. Furthermore, the first and second annular mounting portions are configured to be mounted into corresponding first and second sealing registers located on opposite sides of the coolant flow passage. Additionally, the diameter of the annular cooling portion is smaller than the first and second diameters of the corresponding first and second annular mounting portions, and the wall thickness of the annular cooling portion is smaller than the first and second wall thicknesses of the corresponding first and second annular mounting portions. The valve guide also includes a valve bore extending along the central axis through the annular guide body, and the valve bore is configured to receive a valve stem of an exhaust valve having a valve head configured to open and close relative to the exhaust valve seat in the engine cylinder head.

[0005] In a second embodiment, a system includes a valve guide mounted in the cylinder head of a reciprocating engine along a coolant flow path, the valve guide comprising an annular guide body having a central axis. Furthermore, the annular guide body includes an annular cooling portion axially disposed between a first annular mounting portion and a second annular mounting portion. The annular cooling portion extends into the coolant flow path, and the first and second annular mounting portions are configured to be mounted into corresponding first and second sealing registers located on opposite sides of the coolant flow path. Furthermore, the diameter of the annular cooling portion is smaller than the first and second diameters of the corresponding first and second annular mounting portions, and the wall thickness of the annular cooling portion is smaller than the first and second wall thicknesses of the corresponding first and second annular mounting portions. The valve guide also includes a valve bore extending along the central axis through the annular guide body, wherein the valve bore is configured to receive a valve stem of an exhaust valve having a valve head configured to open and close relative to an exhaust valve seat in the engine cylinder head.

[0006] In a third embodiment, a system includes an engine cylinder head mounted to an engine block of a reciprocating engine, the engine cylinder head including an intake flow passage, an exhaust flow passage, a coolant flow passage, and a first sealing register and a second sealing register disposed on opposite sides of the coolant flow passage. Furthermore, the first and second sealing registers are configured to receive valve guides for supporting a valve stem of an exhaust valve. Additionally, the first sealing register is disposed in a wall separating the exhaust flow passage from the coolant flow passage. Furthermore, a first wall portion of the wall extends between the first sealing register and an exhaust valve seat configured to receive a valve head of the exhaust valve, and a second wall portion of the wall extends away from the first sealing register. Furthermore, the first wall portion includes a bump disposed along the coolant flow passage adjacent to the first sealing register. Furthermore, the second wall portion is angularly oriented relative to a central axis passing through the first and second sealing registers, and the angle is approximately 23 to 27 degrees.

[0007] In addition to the above embodiments, this disclosure also provides the following technical solutions: Technical Solution 1. A system comprising: An engine cylinder head configured to be mounted to an engine block of a reciprocating engine, wherein the engine cylinder head includes: Intake flow path; Exhaust flow path; Coolant flow path; and A first sealing register and a second sealing register are disposed on opposite sides of the coolant flow passage, wherein the first sealing register is disposed in a wall separating the exhaust flow passage and the coolant flow passage, a first wall portion of the wall extends between the first sealing register and the exhaust valve seat, and a second wall portion of the wall extends away from the first sealing register and away from the first wall portion; and A valve guide, configured to be mounted in the engine cylinder head along the coolant flow path, wherein the valve guide includes: An annular guide bearing body having a central axis, wherein the annular guide bearing body includes an annular cooling portion axially disposed between a first annular mounting portion and a second annular mounting portion, the annular cooling portion being configured to extend into the coolant flow passage, the first annular mounting portion and the second annular mounting portion being configured to be mounted in corresponding first and second sealing registers located on opposite sides of the coolant flow passage, the diameter of the annular cooling portion being smaller than the first diameter and second diameter of the corresponding first annular mounting portion and the second annular mounting portion, and the wall thickness of the annular cooling portion being smaller than the first wall thickness and the second wall thickness of the corresponding first annular mounting portion and the second annular mounting portion; and A valve bore extends along the central axis through the annular guide body, wherein the valve bore is configured to receive the valve stem of an exhaust valve having a valve head configured to open and close relative to the exhaust valve seat in the engine cylinder head.

[0008] Technical Solution 2. The system according to Technical Solution 1, wherein the second wall portion is oriented at an angle relative to the central axis passing through the first and second sealing registers, and the angle is approximately 23 to 27 degrees.

[0009] Technical Solution 3. The system according to Technical Solution 2, wherein the angle is substantially constant along at least 50% of the length between the first sealing register and the second sealing register.

[0010] Technical Solution 4. The system according to Technical Solution 1, wherein the first wall portion includes a protrusion disposed adjacent to the first sealing register along the coolant flow path.

[0011] Technical Solution 5. The system according to Technical Solution 1, wherein the ratio of the first diameter to the length of the first annular mounting portion is about 1.5 to 1.6.

[0012] Technical Solution 6. The system according to Technical Solution 1, wherein the annular cooling portion extends at least 30% of the length between the first sealing register and the second sealing register.

[0013] Technical Solution 7. A system comprising: A valve guide, configured to be mounted in the cylinder head of a reciprocating engine along a coolant flow path, wherein the valve guide includes: An annular guide bearing body having a central axis, wherein the annular guide bearing body includes an annular cooling portion axially disposed between a first annular mounting portion and a second annular mounting portion, the annular cooling portion being configured to extend into the coolant flow passage, the first annular mounting portion and the second annular mounting portion being configured to be mounted in corresponding first and second sealing registers located on opposite sides of the coolant flow passage, the diameter of the annular cooling portion being smaller than the first diameter and second diameter of the corresponding first annular mounting portion and the second annular mounting portion, and the wall thickness of the annular cooling portion being smaller than the first wall thickness and the second wall thickness of the corresponding first annular mounting portion and the second annular mounting portion; and A valve bore extends along the central axis through the annular guide body, wherein the valve bore is configured to receive the valve stem of an exhaust valve having a valve head configured to open and close relative to an exhaust valve seat in the engine cylinder head.

[0014] Technical Solution 8. The system according to Technical Solution 7, wherein the ratio of the first diameter to the length of the first annular mounting portion is about 1.5 to 1.6.

[0015] Technical Solution 9. The system according to Technical Solution 7 includes the exhaust valve having the valve stem disposed in the valve orifice of the valve guide.

[0016] Technical Solution 10. The system according to Technical Solution 9, comprising the engine cylinder head having the valve guide and the exhaust valve.

[0017] Technical Solution 11. The system according to Technical Solution 10, wherein the engine cylinder head includes: Exhaust flow path; Coolant flow path; The first and second sealing registers are disposed on opposite sides of the coolant flow passage, wherein the first and second annular mounting portions of the valve guide are mounted in the respective first and second sealing registers. The first sealing register is disposed in a wall separating the exhaust flow passage and the coolant flow passage, a first wall portion of the wall extending between the first sealing register and the exhaust valve seat, and a second wall portion of the wall extending away from the first sealing register from the first wall portion. The second wall portion is oriented at an angle relative to the central axis passing through the first and second sealing registers, and the angle is approximately 23 to 27 degrees.

[0018] Technical Solution 12. The system according to Technical Solution 11, wherein the first wall portion includes a protrusion disposed adjacent to the first sealing register along the coolant flow path.

[0019] Technical Solution 13. The system according to Technical Solution 9 includes the engine having the engine cylinder head, the valve guide and the exhaust valve.

[0020] Technical Solution 14. A system comprising: An engine cylinder head configured to be mounted to an engine block of a reciprocating engine, wherein the engine cylinder head includes: Intake flow path; Exhaust flow path; Coolant flow path; A first sealing register and a second sealing register are disposed on opposite sides of the coolant flow passage, wherein the first sealing register and the second sealing register are configured to receive a valve guide bearing supporting a valve stem of an exhaust valve, the first sealing register is disposed in a wall separating the exhaust flow passage and the coolant flow passage, a first wall portion of the wall extends between the first sealing register and an exhaust valve seat configured to receive a valve head of the exhaust valve, and a second wall portion of the wall extends away from the first sealing register from the first wall portion. The first wall portion includes a protrusion disposed adjacent to the first sealing register along the coolant flow path; and The second wall portion is oriented at an angle relative to the central axis passing through the first and second sealing registers, and the angle is approximately 23 to 27 degrees.

[0021] Technical Solution 15. The system according to Technical Solution 14, wherein the angle is substantially constant along at least 50% of the length between the first seal register and the second seal register.

[0022] Technical Solution 16. The system according to Technical Solution 14, wherein the ratio between the minimum cross-sectional area of ​​the exhaust flow passage and the exhaust outlet area is about 0.300 to 0.320.

[0023] Technical Solution 17. The system according to Technical Solution 14, wherein the thickness of the second wall portion is in ratio of the length between the first seal registration and the second seal registration to about 0.15 to 0.25.

[0024] Technical Solution 18. The system according to Technical Solution 14, wherein the engine cylinder head includes: The valve guide, configured to be mounted in the engine cylinder head along the coolant flow path, wherein the valve guide includes: An annular guide bearing body includes an annular cooling portion axially disposed between a first annular mounting portion and a second annular mounting portion, wherein the annular cooling portion is configured to extend into the coolant flow passage, the first annular mounting portion and the second annular mounting portion are configured to be mounted in corresponding first and second sealing registers located on opposite sides of the coolant flow passage, the diameter of the annular cooling portion is smaller than the first diameter and second diameter of the corresponding first annular mounting portion and the second annular mounting portion, and the wall thickness of the annular cooling portion is smaller than the first wall thickness and second wall thickness of the corresponding first annular mounting portion and the second annular mounting portion; and The valve hole extends through the annular guide body, wherein the valve hole is configured to receive the valve stem of the exhaust valve.

[0025] Technical Solution 19. The system according to Technical Solution 18, wherein the ratio of the first diameter to the length of the first annular mounting portion is about 1.5 to 1.6.

[0026] Technical Solution 20. The system according to Technical Solution 18, wherein the annular cooling portion extends at least 30% of the length between the first sealing register and the second sealing register. Attached Figure Description

[0027] These and other features, aspects, and advantages of this disclosure will be better understood by referring to the accompanying drawings, in which similar reference numerals denote similar parts, wherein: Figure 1 A block diagram illustrating an embodiment of an engine-driven power generation system; Figure 2 This is a cross-sectional side view of an embodiment of a reciprocating engine cylinder head, showing a piston, intake valve, and exhaust valve disposed in the cylinder; Figure 3 yes Figure 2 A partial cross-sectional side view of a portion of the engine cylinder head is shown, illustrating embodiments of the exhaust valve, exhaust valve guide, cooling flow passage, and exhaust flow passage. Figure 4 yes Figure 3 A cross-sectional side view of an embodiment of the exhaust valve guide shown; and Figure 5 yes Figure 2 and Figure 3 The image shows a cross-sectional side view of the engine cylinder head, in which the exhaust valve and exhaust valve guide are omitted for the purpose of discussing the details of the exhaust flow path and coolant flow path. Detailed Implementation

[0028] The following describes one or more specific embodiments of this disclosure. To provide a concise description of these embodiments, not all features of an actual implementation may be described in this specification. It should be understood that in developing any actual implementation in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developer's specific goals, such as complying with system-related and business-related constraints, which may vary from implementation to implementation. Furthermore, it should be understood that the development work may be complex and time-consuming, but will remain a routine task in design, manufacturing, and production for those skilled in the art to which this disclosure pertains.

[0029] In describing the elements in the various embodiments of this disclosure, the articles “a,” “an,” “the,” and “the” are intended to indicate the presence of one or more of the stated elements. The terms “comprising,” “including,” and “having” are intended to have an inclusive meaning and indicate that other elements may be present in addition to the listed elements.

[0030] The disclosed embodiments relate to a power cylinder system for a reciprocating engine (e.g., a reciprocating internal combustion engine). Each power cylinder system has a piston configured to move linearly within a cylinder (e.g., a liner) to convert the pressure exerted by the combustion gases and the linear movement of the piston into rotational motion, thereby powering one or more loads. For example, the reciprocating engine may include 1, 2, 4, 6, 8, 10, 12, or more power cylinder systems, which may be housed in a common engine cylinder head or individual engine cylinder heads. In operation, each power cylinder system delivers an exhaust flow (e.g., combustion gases) outside the cylinder through one or more exhaust flow passages (e.g., exhaust flow channels or exhaust ports). Each exhaust port includes an exhaust valve that selectively opens and closes the exhaust port during operation of the reciprocating engine. Furthermore, each exhaust valve may include an exhaust valve guide that axially guides the exhaust valve along its axis and provides lateral support. The exhaust gas leaving the cylinder still contains a significant amount of heat. In reciprocating engines operating with stoichiometric combustion, the exhaust gas may contain more heat. The disclosed embodiments provide engine cylinder heads, exhaust valves, and exhaust valve guides with improved cooling, reduced lubricant thermal degradation and coking, extended component life, and improved performance.

[0031] Figure 1A schematic diagram illustrating a portion of an embodiment of an engine-driven power generation system 8 is shown. This system may include various modifications to the engine cylinder head, exhaust valves, exhaust valve guides, and cooling features, as discussed in further detail below. The system 8 includes an engine 10 (e.g., a reciprocating internal combustion engine) having one or more combustion chambers 12 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 16, 18, 20, or more combustion chambers 12). An air supply 14 is configured to supply pressurized oxidant 16, such as air, oxygen, oxygen-enriched air, oxygen-reduced air, or any combination thereof, to each combustion chamber 12. The combustion chambers 12 are also configured to receive fuel 18 (e.g., liquid and / or gaseous fuel) from a fuel supply 19, and the fuel-air mixture is ignited and burned within each combustion chamber 12. The heated and pressurized combustion gases cause the piston 20 adjacent to each combustion chamber 12 to move linearly within the cylinder 26, and convert the pressure applied by the gases into rotational motion, thereby causing the shaft 22 (e.g., a crankshaft) to rotate. The engine 10 also includes an engine cylinder head 28, which can be used to supply oxidant 16 and fuel 18 to the cylinders 26. Furthermore, the engine cylinder head 28 may include passages allowing exhaust 30 to exit the engine 10. The engine cylinder head 28 may also include one or more engine cylinder heads. For example, the engine cylinder head 28 may include an engine cylinder head for each cylinder 26, or the engine cylinder head 28 may include a single engine cylinder head for multiple cylinders 26 (i.e., a single integral engine cylinder head) (e.g., each engine cylinder head has 2, 3, 4, 5, 6, or more cylinders). Additionally, the shaft 22 is connected to a load 24, which is powered by the rotation of the shaft 22. For example, the load 24 may be any suitable device for generating electricity through the rotational output of the system 10, such as a generator. Furthermore, although oxidant 16 in the following discussion refers to air, any suitable oxidant may be used in the disclosed embodiments. Similarly, fuel 18 may be any suitable gaseous fuel, such as natural gas, associated petroleum gas, propane, biogas, biogas, landfill gas, or coal mine gas.

[0032] The engine-driven power generation system 8 may also include a controller 32 (e.g., an electronic controller and / or a processor-based controller) to control the operation of the system 8. The controller 32 may independently control the operation of the system 8 by being electrically connected to the ignition system 34, the coolant system 36, the monitoring system 38, and / or the fuel injection system 40. The ignition system 34 may be used to control the ignition of the oxidizer 16 and fuel 18 mixture in the cylinder 26. For example, the ignition system 34 may include temperature sensors, pressure sensors, position sensors (e.g., sensors monitoring the position of the piston 20 or shaft 22), and ignition devices (e.g., spark plugs, hot-wire ignition plugs, etc.) for igniting the oxidizer 16 and fuel 18 mixture. The coolant system 36 may be used to dissipate heat from the engine 10 by allowing coolant (e.g., a liquid such as water) to flow through passages in the engine. For example, the coolant system 36 may include a coolant source and a coolant pump (e.g., an electric pump or a belt-driven pump) providing the coolant flow through the engine 10. The monitoring system 38 may be used to monitor various aspects of the engine 10. For example, the monitoring system 38 may include sensors located at various points in the engine that send data to the monitoring system 38 (e.g., air mass flow sensor, knock sensor, coolant temperature sensor, oil temperature sensor, oil level sensor, etc.). The monitoring system 38 can use the data provided by the sensors to determine the status of the engine 10, display data to the operator via a graphical user interface, etc. The fuel injection system 40 may be used to supply fuel 18 to the cylinder 26. For example, the fuel injection system 40 may include one or more fuel pumps (e.g., electric pumps or belt-driven pumps), fuel injectors, carburetors, etc., to supply fuel 18 to the cylinder 26.

[0033] The controller 32 may include a distributed control system (DCS) or any fully or partially automated computer-based workstation. For example, the controller 32 may include one or more processors 42 (e.g., one or more microprocessors) that can execute software programs to perform the disclosed techniques. Furthermore, the processor 42 may include multiple microprocessors, one or more "general-purpose" microprocessors, one or more application-specific microprocessors and / or one or more application-specific integrated circuits (ASICs), or specific combinations thereof. For example, the processor 42 may include one or more Reduced Instruction Set Computing (RISC) processors. The controller 32 may include a memory device 44 for storing instructions executable by the processor 42. Data stored on the memory device 44 may include, but is not limited to, the knock detection algorithm of system 8, coolant temperature parameters, oil temperature parameters, coolant flow rate parameters, oil flow rate parameters, fuel flow rate parameters, etc. The memory device 44 may include tangible non-transitory machine-readable media, such as volatile memory (e.g., random access memory (RAM)) and / or non-volatile memory (e.g., read-only memory (ROM), flash memory, hard disk drive, or any other suitable optical, magnetic, or solid-state storage medium, or combinations thereof). In addition, the controller 32 may include multiple controllers distributed throughout the system 8 (for example, each of the ignition system 34, coolant system 36, monitoring system 38 and fuel injection system 40 may include one or more controllers).

[0034] The system 8 disclosed in this specification can be adapted for use in stationary applications (e.g., industrial power generation engines) or mobile applications (e.g., automobiles, ships, locomotives, or aircraft). The engine 10 can be a two-stroke, three-stroke, four-stroke, five-stroke, or six-stroke engine. The engine 10 may also include any number of combustion chambers 12, pistons 20, and associated cylinders (e.g., 1 to 24). For example, in some embodiments, the system 8 may include a large industrial reciprocating engine having 4, 6, 8, 10, 16, 24, or more pistons 20 reciprocating in cylinders 26. In some of these cases, the diameter of the cylinders and / or pistons 20 may be between about 13.5 and 34 centimeters (cm). In some embodiments, the diameter of the cylinders and / or pistons 20 may be between about 10 cm and 40 cm, between 15 cm and 25 cm, or about 15 cm. The system 8 can generate electricity in the range of 10 kW to 10 MW. In some embodiments, engine 10 may operate at less than about 1800 revolutions per minute (RPM). In some embodiments, engine 10 may operate at less than about 2000 RPM, 1900 RPM, 1700 RPM, 1600 RPM, 1500 RPM, 1400 RPM, 1300 RPM, 1200 RPM, 1000 RPM, or 900 RPM. In some embodiments, engine 10 may operate between about 800 RPM and 2000 RPM, 900 RPM and 1800 RPM, or 1000 RPM and 1600 RPM. In some embodiments, engine 10 may operate at about 1800 RPM, 1500 RPM, 1200 RPM, 1000 RPM, or 900 RPM. Exemplary engine 10 may include, for example, a Jenbacher engine from General Electric (e.g., Jenbacher 2, 3, 4, 6 or J920FleXtra) or a Waukesha engine (e.g., Waukesha VGF, VHP, APG, 275GL).

[0035] Figure 2This is a cross-sectional side view of an embodiment of piston assembly 25, wherein the piston assembly has a piston 20 disposed within a cylinder 26 (e.g., an engine cylinder) of a reciprocating engine 10. The cylinder 26 has an inner annular wall 29 defining a cylindrical cavity 31. The piston 20 can be described with reference to an axial axis or axial direction 35, a radial axis or radial direction 37, and a circumferential axis or circumferential direction 39. As shown, the piston 20 is attached to a crankshaft 50 via a connecting rod 52 and a pin 54. The crankshaft 50 converts the reciprocating linear motion of the piston 24 into rotational motion. A fuel injector 56 supplies fuel 18 to a combustion chamber 12, and an intake valve 58 (e.g., an air intake valve) opens and closes to control the delivery of air 16 to the combustion chamber 12. The fuel 18 mixes with the air 16 in the combustion chamber 12 and burns to drive the piston 24 in linear motion within the cylinder 26. In operation, piston 20 moves reciprocally (e.g., back and forth) along axial direction 34 within cavity 30 of cylinder 26, thereby driving crankshaft 50 to rotate and providing load 24 (see...). Figure 1 The engine 10 provides power, as discussed above. Exhaust valves 60, supported along the axis of exhaust valve guides 62, open and close exhaust ports or passages 48 to control the emission of exhaust gas 30 (e.g., the heat products of combustion of fuel 18 with air 16) from the engine 10. In some embodiments, the combustion chamber 12 may include a plurality of exhaust ports 48 for exhaust gas 30, such as two, three, four, or more outlets. Therefore, the reciprocating engine 10 may include a plurality of exhaust valves 60 and exhaust valve guides 62, wherein each exhaust port 48 has a corresponding exhaust valve 60 and exhaust valve guide 62.

[0036] Combustion heat transfers a significant amount of heat to all components along the thermal path of the combustion gases or exhaust gas 30. In some embodiments, the engine 10 may be controlled by a controller 32 to operate using stoichiometric combustion, thus producing an exhaust gas 30 with higher temperatures and pressures than non-stoichiometric combustion. The exhaust valve 60, which bears a significant amount of heat from the exhaust gas 30, includes an exhaust valve guide 62 to help guide and cool the valve 60. In operation, the exhaust valve guide 62 helps guide the exhaust valve 60 linearly along its axis 61 between an open valve position and a closed valve position relative to the exhaust port or passage 48. In some embodiments, the exhaust valve guide 62 extends at least partially or completely around the outer periphery of the exhaust valve 60. For example, the exhaust valve guide 62 may be an annular exhaust valve guide 62 and / or include an annular support sleeve. The exhaust valve guide 62 provides lateral support to the exhaust valve 60 and thus prevents the exhaust valve 60 from moving laterally away from the axis 61. Furthermore, the exhaust valve guide 62 is configured to help improve the cooling and lubrication of the exhaust valve 60.

[0037] When exhaust gas 30 exits combustion chamber 12 through exhaust passage 48 under high temperature and pressure, it transfers a portion of the heat to exhaust valve 60 and exhaust valve guide 62. Therefore, coolant passage 64 is included in engine cylinder head 28 to provide coolant flow to exhaust valve guide 62, thereby helping to remove heat from exhaust valve 60 and exhaust valve guide 62 into the coolant flow. The disclosed embodiments are configured to increase heat transfer from valve 60 and guide 62 to the coolant flow, thereby increasing cooling, reducing lubricant thermal degradation and coking, extending the life of valve 60 and guide 62, and improving the overall performance of engine 10.

[0038] Figure 3 This is a cross-sectional side view of a portion of an embodiment of the engine cylinder head 28. Specifically, Figure 3 An embodiment of an exhaust passage 48, a coolant passage 64, an exhaust valve 60, and an exhaust valve guide 62 is shown. In the illustrated embodiment, the exhaust valve 60 includes a valve stem 86 and a valve head 88. The valve stem 86 has a nearly constant valve stem diameter 90 and extends axially 35 through a bore 85 (e.g., a cylindrical bore) in the exhaust valve guide 62. A lubricant (e.g., a liquid lubricant, a hydrocarbon-based lubricant, or an oil) is provided at the interface between the valve stem 86 and the inner surface (e.g., an annular inner surface) of the bore 85 in the exhaust valve guide 62 to reduce friction and allow for smoother movement of the valve stem 86 relative to the exhaust valve guide 62. In operation, the exhaust valve 60 is configured to selectively open and close the valve head 88 about the exhaust passage 48 relative to a valve seat 87 (e.g., a conical annular valve seat) by axially moving the valve stem 86 along the bore 85 within the valve guide 62. In this way, the valve head 88 enables the exhaust valve 60 to selectively fluidly communicate the combustion chamber 12 and the exhaust passage 48. Furthermore, the exhaust valve guide 62 is connected to the engine cylinder head 28 at a first sealing register 94 and a second sealing register 96. Each of the sealing registers 94 and 96 may be an annular sealing register that can be machined into the engine cylinder head 28. For example, sealing registers 94 and 96 may have an annular sealing surface 95 that receives a corresponding annular sealing surface 97 of the valve guide 62.

[0039] In this embodiment, the exhaust valve 60 is in the open position (e.g., lowered position) with the valve head 88 away from the valve seat 87, allowing exhaust gas 30 to flow from the combustion chamber 12 into the exhaust passage 48. As the exhaust gas 30 flows through the exhaust passage 48, heat from the exhaust gas 30 is transferred to the exhaust valve 60, the exhaust valve guide 62, the first exhaust wall 80, and the second exhaust wall 82. The cooling passage 64 provides a coolant flow 84 to absorb at least a portion of the heat transferred by the exhaust gas 30 and carry this heat away from the exhaust valve 60, the exhaust valve guide 62, the first exhaust wall 80, and the second exhaust wall 82. In the illustrated embodiment, the coolant 84 flows in a generally outward direction (e.g., upward axial 35) from the bottom portion 81 of the engine cylinder head 28 (e.g., closest to the combustion chamber 12) to the top portion 83 of the engine cylinder head 28 (e.g., further away from the combustion chamber 12). As the coolant 84 flows over the surface (e.g., the annular outer surface) of the exhaust valve guide 62, the coolant 84 absorbs at least a portion of the heat from the exhaust valve guide 62. The exhaust valve guide 62 includes an annular cooling portion 98 (e.g., an annular recess 89) configured to increase the heat absorbed by the coolant 84. In operation, heat is transferred from the exhaust 30 through the exhaust valve 60 to the exhaust valve guide 62, and then to the coolant 84. As heat is transferred from the exhaust valve 60 to the coolant 84, the annular cooling portion 98 (e.g., the annular recess 89) allows heat to travel through less material in the exhaust valve guide 62, thereby increasing the rate of heat transfer (e.g., conductive heat transfer) between the exhaust valve guide 62 and the coolant 84. The annular cooling portion 98 (e.g., the annular recess 89) also increases the cross-sectional flow area 91 of the cooling passage 64 around the valve guide 62, resulting in a greater flow rate of coolant 84 around the valve guide 62.

[0040] In the illustrated embodiment, the annular cooling portion 98 has an annular recess 89 extending axially along a distance or length 93 of the valve guide 62, the annular recess being positioned along a total distance or length 99 axially between the first sealing register 94 and the second sealing register 96. In some embodiments, the length 93 of the annular cooling portion 98 (e.g., the annular recess 89) may be at least equal to or greater than about 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, 97.5%, 99%, or 100% of the length 99. Furthermore, the valve guide 62 may have a cross-sectional area 63 at the first sealing register 94, a cross-sectional area 65 at the second sealing register 96, and a cross-sectional area 67 at the annular cooling portion 98 (e.g., the annular recess 89), wherein the cross-sectional area 67 is smaller than the cross-sectional areas 63 and 65. For example, in some embodiments, the cross-sectional area 67 may be less than or equal to about 20%, 30%, 40%, 50%, 60%, 70%, or 80% of the cross-sectional areas 63 and 65. The ratio of the cross-sectional area 67 to the cross-sectional areas 63 and 65 may be constant along the longitudinal direction of the length 93, or this ratio may vary along the length 93 (e.g., increase or decrease).

[0041] like Figure 3 As further shown, the structure in the engine cylinder head 28 surrounding the valve guide 62 and defining the coolant passage 64 includes additional thermal control features to improve the cooling of the exhaust valve 60 and the exhaust valve guide 62. For example, as discussed in further detail below, the first exhaust wall 80 includes a protrusion 124 near the edge 126 (e.g., the inner annular end) of the second sealing register 96. The protrusion 124 provides an increased thickness of the first exhaust wall 80 at the edge 126, thereby facilitating a more uniform heat transfer from the exhaust valve 60 and the exhaust valve guide 62 through the first exhaust wall 80 to the coolant 84 in the coolant passage 64. Otherwise, without the protrusion 124, the thickness of the first exhaust wall 80 at the edge 126 would be relatively small, potentially leading to increased thermal stress at the edge 126. Additionally, as discussed in detail below, the second exhaust wall 82 may have a thickness 123 and an angle 125 along the annular cooling portion 98 (e.g., the annular recess 89) (see [link to article]). Figure 5 The thickness 123 and angle 125 are selected to help increase the heat carried away from the exhaust valve 60 and the exhaust valve guide 62, while maintaining a sufficient flow area in the exhaust passage 48.

[0042] Figure 4This is a cross-sectional side view of an embodiment of an exhaust valve guide 62 having an annular channel 100 (e.g., a cylindrical valve bore) along a central axis 106, wherein the annular channel 100 is configured to support the valve stem 86 of an exhaust valve 60. The exhaust valve guide 62 also has an annular guide body 102 having a different thickness, diameter, and cross-sectional area along length 104. In the illustrated embodiment, the inner diameter 108 of the annular channel 100 remains substantially constant along length 104, allowing the valve stem 86, having a substantially constant diameter, to translate relative to the exhaust valve guide 62 along the central axis 106. In some embodiments, the inner diameter 108 may be about 0.4 to 0.7 inches, 0.45 to 0.65 inches, 0.5 to 0.6 inches, or 0.53 to 0.58 inches.

[0043] The outer diameter varies along the length 104 of the exhaust valve guide 62 to increase the rate of heat transfer between the coolant 84 and the exhaust valve guide 62. For example, the exhaust valve guide 62 has a first outer diameter 110 located near the distal end 112 and / or extending all or a portion of the sealing mounting region 113 of the exhaust valve guide 62 (e.g., the seal register length 114). The first outer diameter 110 (e.g., along the length 114) is sized to fit the exhaust valve guide 62 within a second seal register 96 and to fluidly isolate the exhaust passage 48 from the coolant passage 64. In some embodiments, the first outer diameter 110 may extend along the length of the exhaust valve guide 62 by about 1.001 to 1.0045 inches, 1.0015 to 1.004 inches, 1.002 to 1.0035 inches, or 1.0025 to 1.003 inches, which may correspond to all or a portion of the seal register length 114. In addition, the first outer diameter 110 can remain approximately constant across the sealing register length 114 of the exhaust valve guide 62.

[0044] The seal register length 114 (e.g., the length of seal register 96) can be a length capable of achieving a specific heat transfer rate between the exhaust valve guide 62 and the coolant 84. For example, if the seal register length 114 is too long, the heat transfer rate will be too low. Conversely, if the seal register length 114 is too short, the heat transfer rate will be too high, causing the coolant to vaporize. Therefore, the seal register length 114 can be any suitable length to achieve the desired heat transfer rate, including about 0.5 to 0.8 inches, 0.55 to 0.75 inches, 0.6 to 0.7 inches, or 0.62 to 0.68 inches.

[0045] The outer diameter 105 of the exhaust valve guide bearing 62 decreases from a first outer diameter 110 to a second outer diameter 116 along a tapered 118 (e.g., a conical annular surface or a conical surface) adjacent to the seal register length 114. The tapered 118 can be any suitable angle, including 5 degrees, 10 degrees, 15 degrees, 20 degrees, 25 degrees, 30 degrees, 35 degrees, 40 degrees, 45 degrees, or greater. Furthermore, the thickness 107 and cross-sectional area 109 of the annular guide bearing body 102 decrease along the tapered 118 from the seal register length 114 toward the annular cooling portion 98 (e.g., an annular recess 89) because the inner diameter 108 remains substantially constant as the outer diameter 105 decreases. Compared to an exhaust valve guide 62 without an annular cooling portion 98 (e.g., an annular recess 89), the smaller second outer diameter 116, smaller thickness 107, and smaller cross-sectional areas 67, 109 at the annular cooling portion 98 (e.g., an annular recess 89) are configured to provide a higher heat transfer rate between the exhaust valve guide 62 and the coolant 84. Therefore, the length 93 of the annular cooling portion 98 (e.g., the annular recess 89) having the second outer diameter 116 can be any suitable length, such as about 0.775 to 0.975 inches, 0.800 to 0.950 inches, 0.825 to 0.925 inches, or 0.850 to 0.900 inches. In this embodiment, the length 93 of the second outer diameter 116 across the annular cooling portion 98 (e.g., the annular recess 89) remains substantially constant. In some embodiments, the second outer diameter 116 can vary across the length 93 of the annular cooling portion 98 (e.g., the annular recess 89). Furthermore, in some embodiments, the length 93 of the annular cooling portion 98 may include a plurality of annular recesses 89 spaced apart from each other along the axial direction.

[0046] Following the annular cooling section 98, the outer diameter 105 of the exhaust valve guide 62 increases from a second outer diameter 116 to a third outer diameter 120 along a tapered section 122 (e.g., a conical annular surface or a conical surface). The tapered section 122 can be any suitable angle, including 5 degrees, 10 degrees, 15 degrees, 20 degrees, 25 degrees, 30 degrees, 35 degrees, 40 degrees, 45 degrees, or greater. The exhaust valve guide 62 has a third outer diameter 120 that extends in whole or in part along the sealing mounting area 111 of the exhaust valve guide 62 (e.g., the sealing register length 115). The third outer diameter 120 (e.g., along length 115) is sized to allow the exhaust valve guide 62 to fit within the first sealing register 94 and to isolate the coolant passage 64 from external (e.g., atmospheric) fluids surrounding the engine cylinder head 28. The length 115 of the third outer diameter 120 can be substantially equal to, less than, or greater than the length 114 of the first outer diameter 110. In some embodiments, the length 115 of the third outer diameter 120 can be any suitable length, including 1.001 to 1.0045 inches, 1.0015 to 1.004 inches, 1.002 to 1.0035 inches, 1.0025 to 1.003 inches, etc.

[0047] The lengths discussed above can correspond to engine cylinder heads with specific dimensions. Therefore, it may be beneficial to discuss these dimensions in the form of ratios relative to each other. For example, the ratio of the inner diameter 108 to the length 114 of the second seal register can be about 0.7 to 1, 0.75 to 0.95, 0.8 to 0.9, 0.83 to 0.88, etc. The ratio of the first outer diameter 110 to the length 114 of the second seal register can be about 1.35 to 1.75, 1.40 to 1.70, 1.45 to 1.65, 1.50 to 1.60, 1.52 to 1.58, etc. The ratio of the second outer diameter 116 to the length 114 of the second seal register can be about 1.10 to 1.60, 1.15 to 1.55, 1.20 to 1.50, 1.25 to 1.45, 1.30 to 1.40, 1.32 to 1.38, etc.

[0048] Furthermore, as discussed above, the annular cooling portion 98 (e.g., the annular recess 89) is configured to increase the cooling of the exhaust valve 60 and the exhaust valve guide 62 by at least one or more of the following: reducing the thickness 107 and cross-sectional areas 67, 109 between the valve stem 86 and the coolant 84; and increasing the cross-sectional flow area 91 of the coolant passage 64 surrounding the exhaust valve guide 62 (see...). Figure 3 Therefore, the lubricant (e.g., oil) between the valve stem 86 and the exhaust valve guide 62 is less likely to undergo thermal degradation and / or coking, and the life and performance of the exhaust valve 60 and the exhaust valve guide 62 can be significantly increased.

[0049] Figure 5 This is a cross-sectional side view of a portion of an embodiment of an engine cylinder head 28, wherein the engine cylinder head has an exhaust passage 48 and a coolant passage 64. As described above, the exhaust passage 48 is fluidly isolated from the coolant passage 64 by a first exhaust wall 80, a second exhaust wall 82, and a second sealing register 96. The structural characteristics of the first exhaust wall 80 and the second exhaust wall 82 allow exhaust gas 30 to flow through the exhaust passage 48 at a sufficient flow rate and heat transfer rate.

[0050] In the illustrated embodiment, the exhaust passage has a throat 129 (e.g., minimum cross-sectional flow area) and an exhaust outlet 130 (e.g., outlet cross-sectional flow area) that can be sized to provide a desired exhaust flow rate, pressure ratio, expansion rate of hot combustion gases in exhaust 30, etc. In some embodiments, angle 125 can be selected to increase cooling of exhaust valve 60 and exhaust valve guide 62 (e.g., by increasing the flow rate of coolant 84 around the annular recess 89) while ensuring that the cross-sectional areas of throat 129 and exhaust outlet 130 at least meet the minimum desired value or ratio. For example, angle 125 of the second exhaust wall 82 relative to the central axis 106 can maintain at least a minimum cross-sectional area of ​​throat 129, which is the minimum cross-sectional area along exhaust passage 48. Furthermore, angle 125 of the second exhaust wall 82 relative to the central axis 106 can maintain at least a minimum cross-sectional area at exhaust outlet 130. For example, in some embodiments, the ratio of the cross-sectional area of ​​the throat 129 to the cross-sectional area of ​​the exhaust outlet 130 may be about 0.210 to 0.410, 0.235 to 0.385, 0.260 to 0.360, 0.285 to 0.335, or 0.300 to 0.320. Therefore, in some embodiments, the angle 125 of the second exhaust wall 82 may be at least equal to or greater than about 20 degrees, 21 degrees, 22 degrees, 23 degrees, 24 degrees, 25 degrees, 26 degrees, 27 degrees, 28 degrees, 29 degrees, 30 degrees, or any other suitable angle relative to the central axis 106. For example, the angle 125 may be about 20 to 30 degrees, 22 to 28 degrees, or 24 to 26 degrees. Furthermore, the angle 125 of the second exhaust wall 82 may be substantially constant along any appropriate percentage of the length 99 between the sealing registers 94 and 96, for example, along a length that is at least equal to or greater than about 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100% of the length 99 (e.g., ±0%, 0.5%, 1%, 2%, 3%, 4%, or 5%).

[0051] Furthermore, the thickness 123 of the second exhaust wall 82 can achieve a sufficient heat transfer rate from the exhaust passage 48 through the second exhaust wall 82 to the coolant passage 64. For example, if the thickness 123 is too large, the heat transfer rate may be too low, while if the thickness 123 is too small, the heat transfer rate may be too high. Therefore, the thickness 123 can be about 0.300 to 0.500 inches, 0.320 to 0.460 inches, 0.340 to 0.420 inches, 0.350 to 0.400 inches, or 0.365 to 0.385 inches. Furthermore, the thickness 123 of the second exhaust wall 82 may be substantially constant along any suitable percentage of the length 99 between the sealing registers 94 and 96, for example, substantially constant along a length at least equal to or greater than about 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100% of the length 99 (e.g., ±0%, 0.5%, 1%, 2%, 3%, 4%, or 5%). Additionally, the thickness 123 may be expressed as a ratio between the thickness 123 and the length 99. For example, the ratio may be about 0.1 to 0.3, 0.15 to 0.25, 0.175 to 0.225, or 0.19 to 0.21. In some embodiments, the thickness 123 may not be substantially constant and may vary to include any thickness included within the aforementioned thicknesses.

[0052] The first exhaust wall 80 includes a protrusion 124 located near the edge 126 of the second sealing register 96. The protrusion 124 provides an increased thickness of the first exhaust wall 80 at the edge 126. At the protrusion 124, this increased thickness can reduce the rate of heat transfer between the first exhaust wall 80 and the coolant 84 in the coolant passage 64. For example, if the first exhaust wall 80 did not include the protrusion 124 and terminated at line 128 (i.e., consistent with the inner curvature or profile of the first exhaust wall 80), the thickness of the first exhaust wall 80 would gradually decrease and eventually reach a point at the edge 126, thus resulting in a higher rate of heat transfer between the first exhaust wall 80 and the coolant 84. Therefore, the protrusion 124 helps to make the thickness of the first exhaust wall 80 more uniform around the sealing register 96 and the exhaust valve guide 62, thereby contributing to a more uniform heat transfer along the sealing register 96, reducing thermal differentials, and reducing thermal stress.

[0053] The engine cylinder head 28 also includes a first coolant passage wall 136 and a second coolant passage wall 138, which are shaped to allow coolant 84 to flow around the exhaust valve guide 62. For example, the first coolant passage wall 136 includes a first surface 140 that extends generally parallel to the central axis 106 to increase the volume of the space around the exhaust valve guide 62 for coolant 84 to flow through.

[0054] The technical effects of the disclosed embodiments include providing a system that enhances the cooling of the exhaust valve guide 62. For example, a coolant passage 84 is provided around at least a portion of the exhaust valve guide 62 to increase the heat transfer rate between the coolant 84 and the exhaust valve guide 62. Furthermore, the exhaust valve guide 62 includes annular cooling portions 98, 89 having a reduced outer diameter and wall thickness, thereby further increasing the heat transfer rate between the exhaust valve guide 62 and the coolant 84. Additionally, the engine cylinder head 28 configured to receive the exhaust valve guide 62 includes a wall that fluidly isolates the coolant passage 64 from the exhaust passage 48. The wall of the engine cylinder head 28 can maintain a wall thickness that provides a sufficient heat transfer rate for adequate cooling but prevents the coolant 84 from receiving excessive heat. Furthermore, the angle of the wall maintains a specific minimum cross-sectional area in the exhaust passage 48 to provide a sufficient exhaust flow rate through the exhaust passage 48. Therefore, the cooling provided to the engine cylinder head 28 and the exhaust valve guide 62 is increased without reducing the performance of the exhaust flow.

[0055] This specification uses examples to disclose embodiments of the invention, including best practices, while also enabling any person skilled in the art to practice this disclosure, including making and using any apparatus or system and performing any included methods. The scope of patent protection for this disclosure is defined by the claims, but may include other examples that would occur to a person skilled in the art. Such examples are also intended to be within the scope of the claims if their structural components are identical to those in the claims, or if the equivalent structural components included in the examples are not substantially different from those in the claims.

Claims

1. A valve guide for receiving the valve stem of an exhaust valve in a cylinder head of a reciprocating engine, the cylinder head defining an exhaust flow passage and a first and second sealing register disposed on opposite sides of a coolant flow passage, the first sealing register being disposed adjacent to the exhaust flow passage, the valve guide comprising: An annular guide bearing body has a cooling portion disposed between a first mounting portion and a second mounting portion, wherein the first mounting portion and the second mounting portion are configured to be mounted in corresponding first and second sealing registers located on opposite sides of the coolant passage, and the cooling portion has a smaller wall thickness than the first mounting portion and the second mounting portion, and the annular guide bearing body includes a maximum diameter at a first distal portion including the first mounting portion; and A valve orifice extends along the central axis through the annular guide bearing body.

2. The valve guide according to claim 1, wherein, The cooling section has a smaller wall thickness than the first mounting section and the second mounting section.

3. The valve guide according to claim 1, wherein, The first mounting portion has a shorter length along the central axis than the second mounting portion, and the valve guide includes the maximum diameter at the first distal portion including the first mounting portion.

4. The valve guide according to claim 1, wherein, The first mounting portion is configured to seal with the first sealing register along a first axial length, the second mounting portion is configured to seal with the second sealing register along a second axial length, and the first axial length is shorter than the second axial length.

5. The valve guide according to claim 1, wherein, The first mounting portion is configured to directly contact the first seal register along the first axial length, and the second mounting portion is configured to directly contact the second seal register along the second axial length.

6. The valve guide according to claim 1, wherein, The first mounting portion has a first outer diameter that is constant along the first axial direction.

7. The valve guide according to claim 7, wherein, The second mounting portion has a second outer diameter that is constant along the second axial direction.

8. The valve guide according to claim 8, wherein, The first ratio of the first outer diameter to the first axial length is greater than the second ratio of the second outer diameter to the first axial length.

9. The valve guide according to claim 6, wherein, The first outer diameter extends in the first distal portion to the axial end of the valve guide.

10. The valve guide according to claim 6, wherein, The first outer diameter is the maximum diameter.

11. The valve guide according to claim 1, wherein, The valve guide is configured to be mounted in the engine cylinder head in an axial direction from the exhaust flow passage toward the cooling flow passage.

12. The valve guide according to claim 1, wherein, The first mounting portion has a first length and a first outer diameter, and the ratio of the first outer diameter to the first length is between 1.35 and 1.

75.

13. The valve guide according to claim 12, wherein, The first length is between 0.5 and 0.8 inches, and the second length is between 1.001 and 1.0045 inches.

14. The valve guide according to claim 12, wherein, The ratio of the first outer diameter to the first length is between 1.5 and 1.

6.

15. The valve guide according to claim 1, wherein, The first mounting portion has a first constant outer diameter along a first length configured to extend along a first entire interface with the first sealing register, and the second mounting portion has a second constant outer diameter along a second length configured to extend along a second entire interface with the second sealing register.

16. The valve guide according to claim 15, wherein, The first constant outer diameter is greater than the first length.

17. The valve guide according to claim 15, wherein, The ratio of the first constant outer diameter to the first length is between 1.5 and 1.

6.

18. The valve guide according to claim 15, wherein, The cooling portion of the annular guide bearing body has a third constant outer diameter along a third length, and the third constant outer diameter is smaller than the first constant outer diameter and the second constant outer diameter.

19. The valve guide according to claim 18, wherein, The annular guide bearing body decreases only in its outer diameter from the first constant outer diameter and the second constant outer diameter to the third constant outer diameter.

20. The valve guide according to claim 1, wherein, The valve guide has a maximum diameter at a first distal portion including the first mounting portion.

21. The valve guide according to claim 1, wherein, The valve guide is configured to be installed such that, before the first mounting portion is inserted into the first sealing register, the second mounting portion is inserted into and passes through the first sealing register.

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