Systems, devices, and methods are disclosed that during cylinder deactivation, including skipfire, at low engines speeds and low engine loads maintain adequate oil pressure of valvetrain components or hardware required for CDA and/or skipfire operation.

Systems, devices, and methods are disclosed that during cylinder deactivation, including skipfire, at low engines speeds and low engine loads maintain adequate oil pressure of valvetrain components or hardware required for CDA and/or skipfire operation.

A piston engine may include a clearance gap between a piston assembly and a cylinder. The piston may be configured to translate in a bore of the cylinder. The clearance gap between the piston assembly and the bore may be actively or passively controlled. A control system may provide one or more adjustments based on, for example, a detected temperature, pressure, flow rate, work metric, and/or other indicator. The adjustments may include, for example, adjusting a cylinder liner, adjusting a flow through a bearing element, adjusting a coolant flow, adjusting a heat pipe property, and/or other adjustments. One or more auxiliary systems may be used to provide the adjustments.

A piston engine may include a clearance gap between a piston assembly and a cylinder. The piston may be configured to translate in a bore of the cylinder. The clearance gap between the piston assembly and the bore may be actively or passively controlled. A control system may provide one or more adjustments based on, for example, a detected temperature, pressure, flow rate, work metric, and/or other indicator. The adjustments may include, for example, adjusting a cylinder liner, adjusting a flow through a bearing element, adjusting a coolant flow, adjusting a heat pipe property, and/or other adjustments. One or more auxiliary systems may be used to provide the adjustments.

Systems and devices are disclosed for controlling fluid flow to piston cooling nozzles with a fluid flow control device configured to open when an internal combustion engine requires piston cooling at high speed but remains open for a period of time after the engine speed drops below a threshold to prevent heat soak damage to the pistons.

Systems and devices are disclosed for controlling fluid flow to piston cooling nozzles with a fluid flow control device configured to open when an internal combustion engine requires piston cooling at high speed but remains open for a period of time after the engine speed drops below a threshold to prevent heat soak damage to the pistons.

A piston of an internal combustion engine may include a piston shaft and a piston head. The piston head may be provided with a closed cooling channel with a cooling medium arranged therein. The piston shaft may have a spherically round cross-sectional shape, wherein a deviation from the roundness with respect to a piston diameter may be less than 0.5 per thousand.

A piston cooling jet is provided that may include a housing having an interior chamber that receives a fluid from an external source, and a conduit coupled with the housing and fluidly coupled with the interior chamber, the conduit having a bent shape to direct the fluid from the interior chamber of the housing toward an underside of an engine piston head. The piston cooling jet may also include a flow straightening nozzle coupled with the conduit and positioned to straighten flow of the fluid exiting from the conduit via the nozzle toward the underside of the engine piston head, the flow straightening nozzle having internal intersecting walls that intersect along a direction of the flow of the fluid in the conduit and out of the flow straightening nozzle.

A piston cooling jet is provided that may include a housing having an interior chamber that receives a fluid from an external source, and a conduit coupled with the housing and fluidly coupled with the interior chamber, the conduit having a bent shape to direct the fluid from the interior chamber of the housing toward an underside of an engine piston head. The piston cooling jet may also include a flow straightening nozzle coupled with the conduit and positioned to straighten flow of the fluid exiting from the conduit via the nozzle toward the underside of the engine piston head, the flow straightening nozzle having internal intersecting walls that intersect along a direction of the flow of the fluid in the conduit and out of the flow straightening nozzle.

The present invention refers to a method for controlling a piston cooling circuit of an internal combustion engine wherein said circuit comprises at least a circulation pump and means for emitting cooling oil connected to the delivery of the pump. According to the method, said pistons are cooled by a jet generated by said emitting means only during the upward stroke of said pistons from the bottom dead center to the top dead center.