Propulsion system (2) for a helicopter (1) comprising a main engine (9), a main rotor (3), a main gearbox (4) including an output mechanically connected to the main rotor (3), a reduction gearbox (13) mechanically coupled between the main engine (9) and a first input of the main gearbox (4), and an assistance device (10).

The assistance device (10) comprises a first electric machine mechanically coupled to the reduction gearbox (13) and configured to operate as an electric generator to take off energy produced by the main engine (9), and a second electric machine mechanically coupled to a second input of the main gearbox (4), the second electric machine being supplied with electrical power by the first electric machine and configured to operate as an electric motor to deliver additional mechanical power to the main gearbox (4).

Provided are a hybrid engine system capable of protecting an engine from overspeeding when the load of a generator rapidly decreases, and a method of controlling the hybrid engine system.

The hybrid engine system includes: an engine; a generator driven by the engine to output electrical energy; a battery configured to store electrical energy produced by the generator or supply electrical energy together with the generator; and a controller configured to control the engine, wherein the controller includes a torque meter for measuring torque of an output shaft of the engine and a current meter for measuring output current of the generator, and is further configured to change a control mode of the engine when a reduction rate of at least one of the torque and the current is greater than a set value while the engine is operating in a fly mode.

A propulsion assembly includes a first torque source coupled with a first shaft and a second torque source coupled with a second shaft. A coupler selectively couples the first and second torque sources. When the first and second torque sources are coupled via the coupler, in response to a command to decouple the first torque source, an unloading operation is performed to decrease the torque output provided by the first torque source to a threshold, and when reached, the first shaft is decoupled from the coupler. When the first torque source is coupled with the coupler but the second torque source is not, in response to a command to couple the second torque source, a speed matching operation is performed to increase the speed of the second shaft to match a speed of the first shaft, and when the speeds are matched, the second shaft is coupled to the coupler.

A propulsion assembly includes a first torque source coupled with a first shaft and a second torque source coupled with a second shaft. A coupler selectively couples the first and second torque sources. When the first and second torque sources are coupled via the coupler, in response to a command to decouple the first torque source, an unloading operation is performed to decrease the torque output provided by the first torque source to a threshold, and when reached, the first shaft is decoupled from the coupler. When the first torque source is coupled with the coupler but the second torque source is not, in response to a command to couple the second torque source, a speed matching operation is performed to increase the speed of the second shaft to match a speed of the first shaft, and when the speeds are matched, the second shaft is coupled to the coupler.

An aircraft having a hybrid power source includes two horizontal drive units, four vertical drive units, a vertical drive unit comprising a power supply bus the output of which may be connected to a single horizontal drive unit which may be connected to at least two vertical drive units via a switch, two power generation sources connected, on the one hand, to each of the power supply buses by a respective input of the corresponding vertical drive unit and, on the other hand, to each horizontal drive unit via the respective output of each vertical drive unit, and a power supply command arranged to send a power command to the power generation sources according to the power requirements of the vertical drive units and/or horizontal drive units. The power generation sources are also suitable for recharging power sources of the vertical drive units.

A flotation system for an aircraft that includes a battery system providing power to the aircraft is presented. The flotation system can include a water propulsion system enables maneuvering of the aircraft, such as a seaplane, on the surface of water. The system can include waterjets located on floats of the aircraft that enable maneuvering of the aircraft in forward, backward, and lateral directions as well as rotational motion. The systems are quieter in operation than the main engine of the aircraft and provide precision maneuvering for docking or active stabilization of the aircraft's position.

A flotation system for an aircraft that includes a battery system providing power to the aircraft is presented. The flotation system can include a water propulsion system enables maneuvering of the aircraft, such as a seaplane, on the surface of water. The system can include waterjets located on floats of the aircraft that enable maneuvering of the aircraft in forward, backward, and lateral directions as well as rotational motion. The systems are quieter in operation than the main engine of the aircraft and provide precision maneuvering for docking or active stabilization of the aircraft's position.

A hybrid propulsion system with controllers and a drive shaft of a helicopter with a main rotor connected to a gearbox which can keep a flight attitude set by a pilot stable. It includes a pilot controller, a combustion engine and an electric motor, both of which act directly on the drive shaft. The VM is connected to a VM controller, and the EM is connected to an EM controller. One torque sensor and one tachometer are each arranged on the drive shaft, wherein during operation both the VM controller and the EM controller are able to receive values for the current speed and the current torque. Specified values for speed and torque, in which the VM can attain its optimum efficiency, are stored in memory and can be retrieved by the EM controller, wherein the first value can also be retrieved by the VM controller.

A propulsion assembly includes a first torque source coupled with a first shaft and a second torque source coupled with a second shaft. A coupler selectively couples the first and second torque sources. When the first and second torque sources are coupled via the coupler, in response to a command to decouple the first torque source, an unloading operation is performed to decrease the torque output provided by the first torque source to a threshold, and when reached, the first shaft is decoupled from the coupler. When the first torque source is coupled with the coupler but the second torque source is not, in response to a command to couple the second torque source, a speed matching operation is performed to increase the speed of the second shaft to match a speed of the first shaft, and when the speeds are matched, the second shaft is coupled to the coupler.

A propulsion assembly includes a first torque source coupled with a first shaft and a second torque source coupled with a second shaft. A coupler selectively couples the first and second torque sources. When the first and second torque sources are coupled via the coupler, in response to a command to decouple the first torque source, an unloading operation is performed to decrease the torque output provided by the first torque source to a threshold, and when reached, the first shaft is decoupled from the coupler. When the first torque source is coupled with the coupler but the second torque source is not, in response to a command to couple the second torque source, a speed matching operation is performed to increase the speed of the second shaft to match a speed of the first shaft, and when the speeds are matched, the second shaft is coupled to the coupler.