362 results about "Jet propulsion" patented technology

A watercraft includes an improved engine control system that enhances the responsiveness of the watercraft and eases watercraft operation. The watercraft includes a propulsion device, such as a jet propulsion unit, and an engine that powers the propulsion device. The engine control system is configured to maintain or increase engine speed under certain operating conditions.

A personal watercraft includes a hull and a jet propulsion unit that propels the hull. An engine powers the jet propulsion unit. The engine includes an air intake system to introduce air to a combustion chamber. The intake system includes a throttle valve to regulate an amount of the air. The throttle valve is moveable generally between a closed position and an open position. A fuel injection system is arranged to spray fuel for combustion in the combustion chamber. The engine also includes an intake pressure sensor, a throttle valve position sensor and an engine speed sensor. A control device is provided to control an amount of the fuel using either a D-j control mode or an alpha-N control mode. The D-j control mode is based upon a signal from the intake pressure sensor and a signal from the engine speed sensor. The alpha-N control mode is based upon a signal from a throttle valve position sensor and the signal from the engine speed sensor. The control device uses the D-j control mode either when the throttle valve is relatively in a low opening degree range or when an engine speed is relatively in a low speed range, and uses the alpha-N control mode either when the throttle valve is relatively in a high opening degree range or when the engine speed is relatively in a high speed range. Additionally, the control device is configured to detect the malfunction of the throttle valve position sensor and the pressure sensor. If the throttle valve position sensor malfunctions, the control device uses only the D-j control mode. If the pressure sensor malfunctions, the control device uses only the alpha-N control mode.

A watercraft has a jet pump and a venturi. A variable trim system (VTS) support and a reverse gate are rotationally mounted relative to the venturi. A steering nozzle is rotationally mounted to the VTS support. A rotary actuator has an output portion operatively connected to at least one of the VTS support and the reverse gate. Rotation of the output portion between a first angle and a second angle causes a rotation of the VTS support while the reverse gate remains in a stowed position relative to the steering nozzle. Rotation of the output portion between the second angle and a third angle causes a rotation of the reverse gate between the stowed position and a second position while the VTS support remains in a fixed position. A jet propulsion system and a method of operating a jet propulsion system are also disclosed.

An electronically assisted reverse gate system for a jet propulsion watercraft is provided. Control electronics are in communication with the operator interface of the watercraft to obtain commands from the operator, such as a selection between a forward, reverse or neutral mode, a braking command or a slow mode. The control electronics evaluates the target setting for these commands. This evaluation is made taking into consideration the operating conditions of the watercraft. Control signals are sent to an appropriate actuating device to adjust the gate orientation accordingly.

A method of operating a watercraft is disclosed. The watercraft includes an engine, a jet propulsion system operatively connected to the engine, the jet propulsion system includes a reverse gate, and a steering assembly for steering the watercraft. The method comprises: determining if the steering assembly is turned; sensing an operating parameter of the watercraft, the operating parameter being related to a thrust generated by the propulsion system; determining if the operating parameter of the watercraft is within a predetermined range; and moving the reverse gate to a lowered position when the steering assembly is turned and the operating parameter of the watercraft is within the predetermined range. A watercraft capable of performing the method is also disclosed.