A compression ratio control device includes a compression ratio controller configured to control a compression ratio of a combustion chamber so that the maximum combustion pressure approaches a combustion pressure upper limit value (cylinder-internal-pressure upper limit value) based on a detection signal of a detector at least when an engine load is equal to or less than a predetermined load (engine full load).

A compression ratio control device includes a compression ratio controller configured to control a compression ratio of a combustion chamber so that the maximum combustion pressure approaches a combustion pressure upper limit value (cylinder-internal-pressure upper limit value) based on a detection signal of a detector at least when an engine load is equal to or less than a predetermined load (engine full load).

A compression ratio control device includes a compression ratio controller configured to control a compression ratio of a combustion chamber so that the maximum combustion pressure approaches a combustion pressure upper limit value (cylinder-internal-pressure upper limit value) based on a detection signal of a detector at least when an engine load is equal to or less than a predetermined load (engine full load).

Disclosed herein is a bicycle rack for organizing a storage area and associated systems and methods of use thereof. The bicycle rack can be adapted to receive and hold bicycles having various diverse characteristics, and store the bicycles in a space-efficient manner. The bicycle rack can have a tire receiving zone for receiving and holding a tire of a bicycle for storage. The tire receiving zone can have an adjustable zone width, an adjustable zone depth, and an adjustable zone orientation.

A method of monitoring the health of an aircraft propeller whilst the propeller is in operation, the propeller having a plurality of blades extending radially outwardly from a central axis extending through the propeller and a propeller drive shaft, is provided. The method includes obtaining measurements representative of strain in the propeller drive shaft using multiple primary strain sensors, each primary strain sensor providing respective measurements representative of strain. The primary strain sensors are located around a circumference of the drive shaft of the propeller, and each strain sensor is located such that it crosses a plane defined by the radial direction of a blade and the central axis, the plane being bounded by the central axis. A corresponding propeller health monitoring system, an aircraft propeller comprising the system and an aircraft comprising the propeller are also provided.

A method controlling a thruster of a marine vehicle is provided. The marine vehicle is at least partially submerged in a liquid and includes a body and a thruster including two propellers. Each propeller includes blades intended to tum about a rotation axis of said propeller. The method includes a step of low-speed maneuver controlling, during which the thruster is controlled in such a way that each propeller generates a flow directed toward the flow generated by the other propeller and reaching the flow generated by the other propeller.

A variable pitch propeller is described, including an external central body and a plurality of rotatable blades, protruding from the central body, the central body housing, in its interior, a hub of a drive shaft which is placed coaxial to the hub, the central body housing in its interior a device to transform, in an automatic manner, the rotary motion of the hub or of the drive shaft into rotary motion of the at least one blade around its axis with respect to the body of the propeller, the device being coupled to at least one of the blades and to the hub or to the drive shaft. The device is a modified Scottish yoke kinematic system contained inside the central body.

A method for controlling a thruster of a marine vehicle includes a body and a thruster mounted on the body of the vehicle, the vehicle being at least partially immersed in a liquid and moving with respect to the liquid along an axis of displacement in a direction of displacement and rotating about at least one axis of rotation perpendicular to the axis of displacement with a rotational speed, the thruster including an upstream propeller and a downstream propeller along the axis of displacement in the direction of displacement. The method including a stabilization step, in which the thruster is controlled such that the main axis of the upstream flow generated by the upstream propeller at a given instant t is an estimated main axis on which a position of a center of the downstream propeller, situated substantially on the axis of rotation of the downstream propeller, is estimated to be situated at a later instant t+dt at which the flow generated by the upstream propeller at the given instant t reaches the downstream propeller, the estimated main axis depending on the rotational speed of the vehicle.

A hydraulic rotary feed-through with a neck which is accommodated in a housing via a bearing arrangement and through a pressurized fluid line extends to a pressure space with a seal arrangement provided axially between the pressure space and the bearing arrangement, the bearing arrangement and the seal arrangement are disposed in frames which are accommodated in the housing axially engaged with one another under pressure.

An aircraft can include a stacked propeller to generate lift during assent and descent. The stacked propeller includes a first propeller and a second propeller that co-rotate about an axis of rotation. In one embodiment, the blades are coupled to a rotor mast that contains an internal cavity. In one mode of operation, the first propeller and/or the second propeller can be stored in the internal cavity in order to reduce drag during flight. The aircraft can include one or more stacked propellers, such as a port propeller and a starboard propeller, which rotate in opposite directions during one or more modes of flight.