Abstract: A rotor of an electric machine is disclosed that resists expansion of the rotor components even at high rotational speed. The rotor includes first and second pluralities of laminations having slots to accept rotor bars. A support disk, also having slots, is placed between the laminations. The support disk, into which the rotor bars are slid, restrains the rotor bars from bending outwardly at high rotational speeds of the rotor. The rotor bars are further restrained at the ends by end rings, which have apertures into which ends of the rotor bars are placed. In some embodiments, containment rings are placed over axial extension of the end rings to prevent outward bowing at high speeds. In some embodiments, the rotor includes a stiffener sleeve to provide additional resistance to expansion during high rotational speeds.

Abstract: A: piezoelectric fuel injector spring assembly and an assembly method for assembling such a piezoelectric fuel injector spring assembly. The assembly has a piezoelectric element (204}, a first spring {212), and a second spring (210). The first spring (212) biases the second spring (210) by expanding the second spring {210}, and the second spring {210} is further expanded when the piezoelectric element (204) expands. For the assembly, the first spring is compressed by an external compressing force prior to connecting a second end of the second spring to a second end of the piezoelectric element, and after connecting the external force is released allowing establishment of spring force equilibrium between the first and second spring.

Abstract: An electronically-controlled turbocharger (ECT) includes a rotor (of an electric motor) on the shaft of the turbomachine. There are a variety of embodiments for securing the rotor onto the shaft including, but not limited to: having a taper on both the shaft on the rotor and using a nut engaging with threads in the shaft to put the two tapers together; a press fit; splines and grooves also using a nut; and a shoulder on the shaft that the rotor abuts when a nut is engaged with threads on the shaft. To accommodate these retaining features, the diameter of the shaft is greater near the turbine end of the shaft. A first bearing installed on the shaft near the turbine end of the shaft has a larger inside diameter than a second bearing installed on the other side of the rotor.

Abstract: Master and slave pullrods are disclosed in which a master pullrod is coupled to a journal of a crankshaft. The slave pullrod indirectly couples to the crankshaft by coupling to the master pullrod. Such a configuration allows two connecting rods to be coupled to the journal of the crankshaft inline with each other.

Abstract: In a piston-ported engine, a sealing ring may be placed in a groove in the cylinder. As the groove is of greater diameter than the cylinder, the sealing ring overlaps into a helix allowing it to be enter the cylinder. However, such a helix does not fit into a groove without when in the helix. Alternatively, a shorter sealing ring is placed into the groove. However, the gap is too large. According to one embodiment, a groove of double the width of the ring is provided and the helical ring is installed and caused to unwind in the groove so that the ring sits in a plane. A spacer ring is placed in the groove to fill the extra space in the groove. An elastomeric material or a tension spring in an outer groove in the sealing ring can be used to cause the ring to press against the piston.

Abstract: Methods and systems for utilizing heated fuel to compensate for a low cetane number, cetane number variance and sub-optimal engine cold-start performance in internal combustion engines are disclosed herein. Systems comprise a heater, a sensor, and an engine control unit (“ECU”). Methods can comprise detecting variables that affect combustion, calculating conditions inside a combustion chamber, determining the difference between current ignition delay and a desired ignition delay, estimating a cetane number of a fuel, and using the data to determine a suitable temperature that will compensate for cetane number and improve the ignition delay. Other methods comprise sending a signal to a heater in communication with a fuel injection system such that said heater warms fuel within the fuel injection system prior to injecting the fuel into a combustion chamber.

Abstract: In some two-stroke engines, a stationary ring is disposed in a groove in the cylinder liner. However, it is a challenge to install such a stationary ring while maintaining a narrow gap to minimize gas flow through the gap. A ring system for an internal combustion engine is disclosed that includes an L-shaped, split ring with a reentrant angle and a nested, split ring with a convex quadrilateral cross section nested with the L-shaped ring proximate the reentrant angle. The two rings are affixed so that the two gaps of the split rings cannot align. Or, in other embodiments, the two are allowed to rotate relative to each other over a predetermined angle.

Abstract: A disclosed lubrication system for an internal combustion engine includes an inertia reactive oil injector in a piston that reacts to convey lubricating oil to the space between the piston and its adjacent cylinder wall immediately below the upper piston rings as the piston reaches top dead center. A first embodiment utilizes a passage and reservoir formed beneath the piston wall with inlet and outlet ports at each end. The oil injector carries the oil past the intake/exhaust ports of the cylinder until the piston decelerates while approaching its TDC position. During that deceleration, the oil carried by the injector reservoir is delivered through the outlet port into the space between the piston and the cylinder liner. A second embodiment utilizes a groove of predetermined length formed in the outer surface of the piston. A reservoir is formed in the groove and defines inlet and outlet ports at each end.

Abstract: A toroidal combustion chamber shape with side injectors is being developed for an opposed-piston engine. Favorable combustion characteristics of such configuration are transferred to a conventional engine, i.e., one with a combustion chamber delimited by a piston, a cylinder wall, and a cylinder head. At least one injector is disposed in the cylinder head at the periphery. The fuel is injected substantially along the plane of interface between the cylinder head and the cylinder block. The intake system is configured to provide a swirling flow in the combustion chamber. The fuel is injected in an angle that is displaced from the central axis of the cylinder and directed along the swirl. In some embodiments, a substantially torus-shaped volume is formed between the piston and the cylinder head when the piston is at top center. The injector or injectors spray fuel into the toroidally-shaped volume substantially tangent to the torus.

Abstract: Described herein are methods for controlling a piezoelectric element, for example, for use in a fuel injector, safely and efficiently at higher frequencies without causing damage to the fuel injector due to excessive heating. Methods incorporating features of the present invention can utilize waveform generation, waveform scaling and power amplification to drive a piezoelectric element. In some embodiments, various operating conditions are utilized to determine a scaling value which is compared to a target value to determine the level of scaling to be utilized with a generated waveform.

Abstract: An electronically-controlled turbocharger (ECT) includes an electric machine provided on the shaft of the turbomachine. It is desirable to mount the electric machine on the shaft in such a way that it can be removed for servicing. Disclosed herein is an ECT in which the rotor of the electric machine is retained on the shaft by a nut that is used to snug up the rotor against a shoulder on the shaft. Alternatively, the shaft and the rotor have a taper and the nut is used to cause the interior taper of the rotor is caused to engage with the exterior taper of the shaft. In yet another alternative, the rotor has fingers that engage with splines on the shaft. In some embodiments, to help prevent relative rotation of the shaft and the rotor, one or both of mating surfaces are roughened to increase the friction between the surfaces.

Abstract: In an electric machine, there may be lubrication and cooling needs, such as lubricating bearings and cooling coils of the electric machine. When lubricant is used for both, it is desirable to prioritize the lubrication to the bearings. By providing check valves between a pressurized oil manifold and the cooling coils, lubricant is diverted to the coils only when pressure in the system is sufficient to satisfy both lubrication and cooling. In some embodiments, an oil gallery is provided on an outside surface of a back iron of the stator of the electric machine and orifices are provided in the back iron so that oil drips onto the coils of the electric motor. In some embodiments, the current commanded to the electric motor is based on whether or not lubricant (or other coolant) is being provided to the coils.

Abstract: Returning engine oil to the primary oil sump from outboard locations in a flat engine can be a challenge. In the present disclosure, the pressure fluctuations occurring at the underside of the piston, due to reciprocation of the piston, are used to pump the oil from outboard locations to the primary oil sump. To prevent backflow of oil during periods of negative pressure difference, a check valve is placed in the oil drain passage. The check valve allows flow from the outboard location to the primary oil sump and no flow from the primary oil sump to the outboard location by opening and closing as driven by pressure fluctuations due to piston reciprocation. Such a check valve also prevents backflow of the oil to one of the outboard locations when the engine is tilted.

Abstract: In two-stroke engines, it is common to provide two compression rings on the piston and an additional oil ring. The oil ring can be on the piston, but yields a longer piston. Alternatively, the oil ring is placed in a circumferential groove in the cylinder liner. One problem with such a configuration is that the compression rings move with respect to the oil ring and the annular volume between the two is compressed during reciprocation of the piston, which can cause pumping of oil into the ports. According to embodiments of the present disclosure, axial slots are formed in the cylinder liner that extends from the circumferential groove toward the ports extending along the bridges and beyond the ports. This provides a vent for the annular volume to avoid pumping the oil into the ports.

Abstract: Reciprocating motion can be converted to rotary motion through a crankshaft and a connecting rod. In a connecting rod that is primarily in compression, two opposing connecting rods can be coupled to a single journal. Two bearing shell portions are placed over the journal with a pushrod placed over each bearing shell portion. The pushrods are normally in compression. To overcome the potentiality of the pushrods briefly being in tension, retainers can be coupled to the pushrods. Because both pushrods are coupled in-line, the width of the journal that can accommodate these pushrods is shorter than for a journal on which the two pushrods are side by side. The crankshaft can be shorter, stronger, and lighter weight.

Abstract: An opposed-piston, opposed-cylinder engine is disclosed that has the pistons symmetrically arranged in the opposed cylinders. In one embodiment, the inner pistons are exhaust pistons and the outer pistons are intake pistons. Alternatively, the inner pistons are intake pistons and the outer pistons are exhaust pistons. The pistons are coupled to the crankshaft that is situated between the opposed cylinders. Central axes of the two cylinders are offset by a predetermined distance. The connecting rods that couple between the crankshaft and the pistons are arranged adjacent to each other on journals of the crankshaft. The journal to which the pushrods couple is not a split-pin type. Instead, it is one that has a common central axis. Furthermore, the crankshaft is a one-piece or unitary structure.

Abstract: A piston coupled to a crankshaft via pullrods presents challenges for coupling the piston to the crankshaft because the connections are provided outside the piston. A bridge is coupled to a piston skirt at the end of the piston away from the piston crown. The bridge structure includes: a central support structure, a first projection extending outwardly from the central support structure in a first radial direction, and a second projection extending outwardly from the central support structure in a second radial direction. The central support structure is substantially hollow with a series of internal braces to yield a lightweight piston.

Abstract: A fuel injection method in an internal combustion engine and an internal combustion engine for performing the fuel injection method. The method includes heating fuel to a temperature between 300° F. and 840° F. (150 and 450° C.); pressurizing the fuel to a pressure exceeding 40 bar; pre-injecting at least 10% of the fuel charge as a pre-injected fuel during the intake stroke; injecting a fuel charge over at least part of the compression stroke into the cylinder; and injecting an ignition-injection of at least 10% of the fuel in a supercritical condition during the compression stroke at a rotational angle between 90° BTDCF and TDCF into the cylinder. The method and related combustion engine create a good mix of premix combustion and diffusion combustion increasing efficiency and consequently reducing emissions to the environment while also keeping noise and vibrations low.

Abstract: Master and slave pullrods are disclosed in which a master pullrod is coupled to a journal of a crankshaft. The slave pullrod indirectly couples to the crankshaft by coupling to the master pullrod. Such a configuration allows two connecting rods to be coupled to the journal of the crankshaft inline with each other.

Abstract: By providing an electrically-controlled turbocharger (ECT) on a compression-ignition (CI) engine, the engine can be provided a desired lambda and a desired EGR fraction over the range of operating conditions. When lambda in the exhaust is leaner than the desired lambda, electrical energy to the electric motor of the ECT is reduced to bring actual lambda to desired lambda. Analogously, when lambda in the exhaust is richer than the desired lambda, electrical energy to the ECT is increased.