# US 10,767,520 B1 · Valve seat insert for long life natural gas lean burn engines > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,767,520 B1 - Document ID: US10767520B1 - Status: Granted - Kind: B1 - Application number: 16/544,182 - Filed: 2019-08-19 - Granted: 2020-09-08 - Earliest claimed: 2019-08-19 - Assignees: Caterpillar Inc. - Applicants: Caterpillar Inc. - Inventors: Ashwin A. Hattiangadi; Paul David Smallidge; Rong Qu - Web page: https://patentgrep.com/patent/US10767520B1 ## CPC - F01L 3/20: Shapes or constructions of valve members, not provided for in preceding subgroups of this group - F01L 3/06: Valve members or valve-seats with means for guiding or deflecting the medium controlled thereby, e.g. producing a rotary motion of the drawn-in cylinder charge (for rotating lift-valves F01L1/32) - F01L 3/22: Valve-seats not provided for in preceding subgroups of this group; Fixing of valve-seats - F16K 1/42: Valve seats (for double-seat valves F16K1/44) - F16K 47/00: Means in valves for absorbing fluid energy (for pipes F16L55/00) - F16K 47/01: {Damping of valve members} - F01L 2303/00: Manufacturing of components used in valve arrangements - F01L 2820/01: Absolute values - Y02T 10/12: Improving ICE efficiencies - F01L: CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES - F16K: VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING {(devices for emptying and evacuating the excess liquid in valves or conduits F16L55/07)} - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A valve seat insert of an engine has a valve seating surface including an outer curved segment forming a first wear crown for contacting the valve at an early wear state, an inner curved segment forming a second wear crown for contacting the valve at a later wear state, and a linear segment extending between the outer and the inner curved segments. A top flow crown is set off radially inward from the engine head, and a sloping segment extending from the top flow crown is oriented at an acute angle relative to the valve seat center axis. ## Claims ### Claim 1 An engine head assembly for an internal combustion engine comprising: an engine head having a fluid conduit formed therein; a valve; a valve seat insert positioned at least partially within the engine head and defining a valve seat center axis extending between a first axial end surface structured to face a cylinder in the internal combustion engine, and a second axial end surface; the valve seat insert further having an inner peripheral surface forming a throat, an outer peripheral surface, and a valve seating surface; the valve seating surface including, in profile, an outer curved segment forming a first wear crown for contacting the valve at an early wear state, an inner curved segment forming a second wear crown for contacting the valve at a later wear state, and a linear segment extending between the outer curved segment and the inner curved segment; the inner peripheral surface including, in profile, an upper curved segment forming a top flow crown, and a sloping segment extending between the upper curved segment and the inner curved segment; and the upper curved segment transitioning with the second axial end surface and the top flow crown being set off radially inward from the engine head, and the sloping segment being oriented at an acute angle relative to the valve seat center axis, such that the inner peripheral surface either forms a venturi to accelerate an incoming flow of gases to the cylinder or a diffuser to decelerate an outgoing flow of gases from the cylinder. ### Claim 2 (depends on 1) The engine head assembly of claim 1 wherein the acute angle is from about 5° to about 20°. ### Claim 3 (depends on 2) The engine head assembly of claim 2 wherein the linear segment of the valve seating surface defines a break-in face contact width that is from about 1.5 millimeters to about 3.5 millimeters, and the sloping segment has a running length that is greater than the break-in face contact width. ### Claim 4 (depends on 3) The engine head assembly of claim 3 wherein the top flow crown is set off radially inward from the engine head a distance that is greater than a size of a radius forming the upper curved segment. ### Claim 5 (depends on 3) The engine head assembly of claim 3 wherein the size of the radius forming the upper curved segment is from about 0.2 millimeter to about 1.0 millimeter, a size of a radius forming the outer curved segment is from about 3 millimeters to about 6 millimeters, and a size of a radius forming the inner curved segment is from about 0.3 millimeters to about 0.6 millimeters. ### Claim 6 (depends on 3) The engine head assembly of claim 3 further comprising a vertical segment connecting the upper curved segment to the inner curved segment, and the throat is defined by the vertical segment. ### Claim 7 (depends on 3) The engine head assembly of claim 3 wherein the lower curved segment forms a second flow crown. ### Claim 8 (depends on 6) The engine head assembly of claim 6 wherein the vertical segment defines a height that ranges from about 1.0 millimeter to about 2.0 millimeters. ### Claim 9 (depends on 1) The engine head assembly of claim 1 further comprising a cylinder that is in fluid communication with the fluid conduit, a piston disposed in the cylinder that is configured to translate upwardly and downwardly in the cylinder, and the valve is disposed between the piston and the valve seat insert, the valve including an upwardly facing shut off surface that is configured to engage and disengage the valve seat insert. ### Claim 10 (depends on 9) The engine head assembly of claim 9 wherein the upwardly facing shut off surface is flat. ### Claim 11 A valve seat insert for an intake valve in an internal combustion engine comprising: an annular insert body defining a valve seat center axis extending between a first axial end surface structured for facing the cylinder in the internal combustion engine, and a second axial end surface; the annular insert body further having an inner peripheral surface defining a throat structured to fluidly connect the cylinder to an intake conduit in an engine head, an outer peripheral surface, and a valve seating surface for contacting an intake valve extending between the first axial end surface and the inner peripheral surface; the valve seating surface including, in profile, an outer curved segment forming a first wear crown for contacting the intake valve at an early wear state, an inner curved segment forming a second wear crown for contacting the intake valve at a later wear state, and a linear segment extending between the outer curved segment and the inner curved segment; the inner peripheral surface including, in profile, an upper curved segment forming a top flow crown, and a sloping segment extending between the upper curved segment and the inner curved segment; and the upper curved segment transitioning with the second axial end surface, and the sloping segment extending radially inward from the upper curved segment at an acute angle, of about 5° or greater, relative to the valve seat center axis, such that the inner peripheral surface forms a venturi to accelerate an incoming flow of gases to the cylinder. ### Claim 12 (depends on 11) The valve seat insert of claim 11 wherein the upper curved segment is formed by a radius larger than a radius forming the inner curved segment, and the outer curved segment is formed by a radius larger than the radius forming the upper curved segment. ### Claim 13 (depends on 11) The valve seat insert of claim 11 wherein the acute angle is from about 6° to about 8°. ### Claim 14 (depends on 11) The valve seat insert of claim 11 wherein: the linear segment of the valve seating surface defines a break-in face contact width that is from about 3 millimeters to about 4 millimeters; a size of a radius forming the upper curved segment is from about 0.8 millimeters to about 1.2 millimeters; a size of a radius forming the outer curved segment is from about 5.0 millimeters to about 6.0 millimeters; and a size of a radius forming the inner curved segment is from about 0.4 millimeter to about 0.6 millimeter. ### Claim 15 (depends on 14) The valve seat insert of claim 14 further comprising a vertical segment connecting the upper curved segment to the inner curved segment, and a throat is defined by the vertical segment. ### Claim 16 A valve seat insert for an exhaust valve in an internal combustion engine comprising: an annular insert body defining a valve seat center axis extending between a first axial end surface structured for facing the cylinder in the internal combustion engine, and a second axial end surface; the annular insert body further having an inner peripheral surface defining a throat structured to fluidly connect the cylinder to an exhaust conduit in an engine head, an outer peripheral surface, and a valve seating surface for contacting an exhaust valve extending between the first axial end surface and the inner peripheral surface; the valve seating surface including, in profile, an outer curved segment forming a first wear crown for contacting the exhaust valve at an early wear state, an inner curved segment forming a second wear crown for contacting the exhaust valve at a later wear state, and a linear segment extending between the outer curved segment and the inner curved segment; the inner peripheral surface including, in profile, an upper curved segment forming a top flow crown, and a sloping segment extending between the upper curved segment and the inner curved segment; and the upper curved segment transitioning with the second axial end surface, and the sloping segment extending radially inward from the upper curved segment at an acute angle, of about 9° or greater, relative to the valve seat center axis, such that the inner peripheral surface forms a diffuser to decelerate an outgoing flow of gases from the cylinder. ### Claim 17 (depends on 16) The valve seat insert of claim 16 wherein the upper curved segment is formed by a radius larger than a radius forming the inner curved segment, and the outer curved segment is formed by a radius larger than the radius forming the upper curved segment. ### Claim 18 (depends on 16) The valve seat insert of claim 16 wherein the acute angle is from about 10° to about 11°. ### Claim 19 (depends on 16) The valve seat insert of claim 16 wherein: the linear segment of the valve seating surface defines a break-in face contact width that is from about 2.75 millimeters to about 3.25 millimeters; a size of a radius forming the upper curved segment is from about 0.4 millimeter to about 0.6 millimeter; a size of a radius forming the outer curved segment is from about 3.0 millimeters to about 4.0 millimeters; and a size of a radius forming the inner curved segment is from about 0.3 millimeter to about 0.5 millimeter. ### Claim 20 (depends on 19) The valve seat insert of claim 19 further comprising a vertical segment connecting the upper curved segment to the inner curved segment, and the throat is defined by the vertical segment.