Use of the hydraulically driven device in a series configuration with a minimally restrictive turbocharger is defined which will allow a very responsive and powerful boosting system to reach boost levels of 4-5 pressure ratio (PR) to support and enable OEM engine downsizing trends. An electric supercharger is also considered. A hydraulic drive assists to increase the acceleration rate of a turbocharger impeller/turbine shaft assembly and provide a secondary means of driving the compressor impeller at lower engine speeds where exhaust gases alone does not generate adequate shaft speeds to create significant induction boost. The hydraulic circuit includes a dual displacement motor, which provides high torque for acceleration yet converts to a single motor for high-speed operation. When the exhaust driven turbine function allows compressor speeds, beyond which the hydraulic system can contribute, a slip clutch allows disengagement of the hydraulic drive. In an alternative embodiment, the hydraulic drive provides means of forced induction air alone.

Use of the hydraulically driven device in a series configuration with a minimally restrictive turbocharger is defined which will allow a very responsive and powerful boosting system to reach boost levels of 4-5 pressure ratio (PR) to support and enable OEM engine downsizing trends. An electric supercharger is also considered. A hydraulic drive assists to increase the acceleration rate of a turbocharger impeller/turbine shaft assembly and provide a secondary means of driving the compressor impeller at lower engine speeds where exhaust gases alone does not generate adequate shaft speeds to create significant induction boost. The hydraulic circuit includes a dual displacement motor, which provides high torque for acceleration yet converts to a single motor for high-speed operation. When the exhaust driven turbine function allows compressor speeds, beyond which the hydraulic system can contribute, a slip clutch allows disengagement of the hydraulic drive. In an alternative embodiment, the hydraulic drive provides means of forced induction air alone.

A turbocharger includes a shaft, a compressor wheel, a turbine wheel, and a bearing assembly including an inner race, a first outer race spaced from the inner race, a second outer race spaced from the inner race, a first rolling element disposed between the first outer race and the inner race, and a second rolling element disposed between the second outer race and the inner race. The bearing assembly includes a first biasing member configured to bias the first outer race toward the second outer race and against the first rolling element, and preload the first rolling element with a preloading force, and a second biasing member configured to bias the second outer race toward the first outer race and against the second rolling element, and preload the second rolling element with a second preloading force. The first preloading force is different than the second preloading force.

A turbocharger includes a shaft, a compressor wheel, a turbine wheel, and a bearing assembly including an inner race, a first outer race spaced from the inner race, a second outer race spaced from the inner race, a first rolling element disposed between the first outer race and the inner race, and a second rolling element disposed between the second outer race and the inner race. The bearing assembly includes a first biasing member configured to bias the first outer race toward the second outer race and against the first rolling element, and preload the first rolling element with a preloading force, and a second biasing member configured to bias the second outer race toward the first outer race and against the second rolling element, and preload the second rolling element with a second preloading force. The first preloading force is different than the second preloading force.

An engine system includes an internal combustion engine, an electrical power system configured to provide electrical power in the engine system, and an electrified air system powered by the electrical power system to selectively increase a flow of intake air and exhaust gas to the engine. The electrified air system further includes an EGR pump operable to recirculate a portion of exhaust gas output from the engine and an electric turbocharger including a turbine, a compressor driven by the turbine via a shaft coupled therebetween, and an electrical machine coupled to the shaft. The electrical machine is configured to operate in a motoring mode to drive the shaft and cause the compressor to output boosted intake air to the engine and operate in a generating mode to transform rotational power from the shaft into electrical power that is provided back into the electrical power system.

New and/or alternative approaches to performance control in an engine system having a compressor configured to receive torque from each of a turbine placed in an exhaust output of an engine and an electric motor. A control unit for the electric motor, referred to as an ETurbo controller, is provided with each of a speed control signal and a torque control signal from an engine control unit. The ETurbo controller is configured to use the torque control signal and speed control signal to operate the electric motor without causing the compressor to exceed a speed boundary.

Methods and systems are proposed for controlling a temperature of exhaust gases generated by the engine by operating an E-Turbo of the vehicle. In one embodiment, a method is provided, comprising increasing a power generated by an electric machine mechanically coupled with an exhaust turbine of an E-Turbo of a vehicle or adjusting an engine power based on a speed of the exhaust turbine and an air-fuel ratio (AFR) of an engine of the vehicle of the engine responsive to the speed of the exhaust turbine increasing above a threshold turbine speed. By increasing or decreasing the power generated by the electric machine and/or adjusting the engine power, the temperature of the exhaust gas may be maintained within a threshold temperature range where an efficiency of an aftertreatment system may be maximized, thereby reducing an emissions of the vehicle.

Methods and systems are proposed for controlling a temperature of exhaust gases generated by the engine by operating an E-Turbo of the vehicle. In one embodiment, a method is provided, comprising increasing a power generated by an electric machine mechanically coupled with an exhaust turbine of an E-Turbo of a vehicle or adjusting an engine power based on a speed of the exhaust turbine and an air-fuel ratio (AFR) of an engine of the vehicle of the engine responsive to the speed of the exhaust turbine increasing above a threshold turbine speed. By increasing or decreasing the power generated by the electric machine and/or adjusting the engine power, the temperature of the exhaust gas may be maintained within a threshold temperature range where an efficiency of an aftertreatment system may be maximized, thereby reducing an emissions of the vehicle.

A hybrid vehicle with four drive wheels having: an internal combustion heat engine, which transmits the motion to a first pair of drive wheels and has at least one cylinder provided with at least one intake valve and with an exhaust valve; a turbine, which is designed to be rotated by the exhaust gases; a first electric machine, which is designed to be rotated by the turbine so as to generate electrical energy; a second electric machine, which transmits the motion to a second pair of drive wheels; and a control unit, which is configured to cyclically determine an electric power to be necessarily generated and an electric power generated by the first electric machine and to adjust an opening advance of the exhaust valve depending on the difference between the electric power generated by the first electric machine and the electric power to be necessarily generated.

It is determined whether chargeable and dischargeable electric power of a battery which is a power storage device are limited. When it is determined that the chargeable and dischargeable electric power of the battery is limited, an electric power balance target value of the battery during gear shifting control in a stepped gear shifting unit which is a mechanical gear shifting mechanism is calculated. A smaller value is calculated as a change rate limit value when the chargeable and dischargeable electric power is small than when the chargeable and dischargeable electric power is great, and the calculated change rate limit value is used to perform gear shifting control in the stepped gear shifting unit.