Abstract: A cylinder assembly with a cylinder liner and a sleeve is provided that includes features that reduce coolant flow stagnation. The sleeve encloses a center section of the cylinder liner to form cooling channels that removes excess heat from the combustion area of the cylinder. The cylinder liner includes features for cooling between bridges in the cylinder's exhaust port.

Abstract: A cylinder assembly with a cylinder liner and a sleeve is provided that includes features that reduce coolant flow stagnation. The sleeve encloses a center section of the cylinder liner to form cooling channels that removes excess heat from the combustion area of the cylinder. The cylinder liner includes features for cooling between bridges in the cylinder's exhaust port.

Abstract: A device and techniques for fabricating the device are described for forming a wafer-level thermal sensor package using microelectromechanical system (MEMS) processes. In one or more implementations, a wafer level thermal sensor package includes a thermopile stack, which includes a substrate, a dielectric membrane, a first thermoelectric layer, a first interlayer dielectric, a second thermoelectric layer, a second interlayer dielectric, a metal connection assembly, a passivation layer, where the passivation layer includes at least one of a trench or a hole, and where the substrate includes a cavity adjacent to the at least one trench or hole, and a bond pad disposed on the passivation layer and electrically coupled to the metal connection assembly; and a cap wafer assembly coupled to the thermopile stack, the cap wafer assembly including a wafer having a cavity formed on a side of the wafer configured to be adjacent to the thermopile stack.

Abstract: In one embodiment, an exhaust waste heat recovery system includes a first exhaust waste heat recovery assembly including a central exhaust channel configured to allow passage of exhaust along an exhaust axis, and a first plurality of thermoelectric (TE) legs, each of the first plurality of TE legs including a hot end in thermal communication with the exhaust channel, and a cold end opposite to the hot end, and an electrical coupler in electrical communication with each of the first plurality of TE legs, the electrical coupler configured to receive electricity from the first plurality of TE legs.

Abstract: A barrier ring for a cylinder assembly for an opposed-piston engine fits into a groove fashioned into a portion of the cylinder liner that is adjacent to the top dead center location of the end surfaces of the pistons, in a volume of the cylinder liner that defines the combustion chamber. The barrier ring and groove are part of a barrier assembly that prevents heat generated during combustion from reaching the outer wall of the cylinder assembly, reducing the need for conventional cooling systems and increasing the amount of heat retained in the combustion chamber. The barrier assembly allows for increased engine efficiency because of the combustion heat retained in the combustion chamber, as well as a reduction in the overall size of the engine because of the reduction in engine cooling needed.

Abstract: A sensor package can have a reference thermopile sensor and a reference temperature sensor disposed therein to determine an ambient temperature. In one or more implementations, the sensor package includes a substrate having a substrate surface, a reference thermopile sensor disposed over the substrate surface, a reference temperature sensor disposed over the substrate surface, and a lid assembly disposed over the thermopile sensor and the reference thermopile sensor. The lid assembly includes a structure having a transparent portion that passes electromagnetic radiation occurring in a limited spectrum of wavelengths. The reference thermopile sensor generates a reference thermopile sensor signal representing a difference between a temperature of the substrate surface and a temperature of a lid assembly surface. An external ambient temperature can be determined based upon the reference thermopile sensor signal.

Abstract: A barrier ring for a cylinder assembly for an opposed-piston engine fits into a groove fashioned into a portion of the cylinder liner that is adjacent to the top dead center location of the end surfaces of the pistons, in a volume of the cylinder liner that defines the combustion chamber. The barrier ring and groove are part of a barrier assembly that prevents heat generated during combustion from reaching the outer wall of the cylinder assembly, reducing the need for conventional cooling systems and increasing the amount of heat retained in the combustion chamber. The barrier assembly allows for increased engine efficiency because of the combustion heat retained in the combustion chamber, as well as a reduction in the overall size of the engine because of the reduction in engine cooling needed.

Abstract: In one embodiment, an exhaust waste heat recovery system includes a first exhaust waste heat recovery assembly including a central exhaust channel configured to allow passage of exhaust along an exhaust axis, and a first plurality of thermoelectric (TE) legs, each of the first plurality of TE legs including a hot end in thermal communication with the exhaust channel, and a cold end opposite to the hot end, and an electrical coupler in electrical communication with each of the first plurality of TE legs, the electrical coupler configured to receive electricity from the first plurality of TE legs.

Abstract: The present disclosure is directed to a sensor package having a reference thermopile sensor, and a reference temperature sensor disposed therein to determine an ambient temperature. In one or more implementations, the sensor package includes a substrate having a substrate surface, a reference thermopile sensor disposed over the substrate surface, a reference temperature sensor disposed over the substrate surface, and a lid assembly disposed over the thermopile sensor and the reference thermopile sensor. The lid assembly includes a structure having a transparent portion that passes electromagnetic radiation occurring in a limited spectrum of wavelengths. The reference thermopile sensor generates a reference thermopile sensor signal representing a difference between a temperature of the substrate surface and a temperature of a lid assembly surface. An external ambient temperature can be determined based upon the reference thermopile sensor signal.

Abstract: A device and techniques for fabricating the device are described for forming a wafer-level thermal sensor package using microelectromechanical system (MEMS) processes. In one or more implementations, a wafer level thermal sensor package includes a thermopile stack, which includes a substrate, a dielectric membrane, a first thermoelectric layer, a first interlayer dielectric, a second thermoelectric layer, a second interlayer dielectric, a metal connection assembly, a passivation layer, where the passivation layer includes at least one of a trench or a hole, and where the substrate includes a cavity adjacent to the at least one trench or hole, and a bond pad disposed on the passivation layer and electrically coupled to the metal connection assembly; and a cap wafer assembly coupled to the thermopile stack, the cap wafer assembly including a wafer having a cavity formed on a side of the wafer configured to be adjacent to the thermopile stack.