1951 results about "Vertical axis" patented technology

The invention discloses a deep ultraviolet spherical catadioptric detection objective lens, and relates to the technical field of optics, the deep ultraviolet spherical catadioptric detection objective lens comprises a first lens group, a second lens group and a diaphragm, one side of the first lens group is arranged to be an object plane, the first lens group is located between the second lens group and the object plane, the first lens group is used for converging light and correcting residual aberration of the second lens group, and the diaphragm is arranged between the second lens group and the object plane. The diaphragm is arranged in the middle of the second lens group, and the second lens group and the diaphragm are used for correcting vertical axis aberrations such as coma of the system. The objective lens adopts a spherical catadioptric structure, can realize deep ultraviolet band application, has a large numerical aperture, the numerical aperture can reach 0.8, the smaller wavelength and the larger numerical aperture have higher resolution, so that smaller defects can be detected, the working distance can be greater than 10mm, and the detection precision is improved on the basis of realizing the large NA design. The length of the system is reduced, the number of original parts is reduced, only five lenses are needed, the structure is simple, and installation and detection are convenient.

An accessory mount allows accessories to be removably and adjustably mounted to a surface. In an example, the surface may be that of a watercraft, and the accessory may be a fishing rod. The mount may be used with a track fixable to an environmental surface or mounted directed to the environmental surface. When used with a track, a post of the accessory mount releasably engages the track. Slidable engagement of the post allows lateral or horizontal adjustment of the accessory. An accessory engaging member is adjustable in relation to the post about a horizontal axis and a vertical axis, so that angular and azimuthal rotational adjustments of the accessory are enabled. A single lever is used to make angular and rotational adjustments, and to release the accessory engaging member from the post.

The invention relates to the technical field of aero-engine quality inspection, and discloses an aero-engine part machining quality detection method based on data management. The method comprises the following steps: collecting multi-source machining data of a part, wherein the multi-source machining data comprises dimensional tolerance, surface roughness and material hardness data; key quality features are extracted according to a design drawing, and the key quality features and the multi-source processing data are subjected to time sequence alignment according to process stages; a three-dimensional mass space model with the process stage as the horizontal axis, the key quality features as the longitudinal axis and the multi-source machining data as the depth axis is constructed, and a mass distribution thermodynamic diagram is generated; identifying an abnormal process region based on the thermodynamic diagram, extracting a corresponding data subset, inputting the data subset into the dynamic convolution kernel quality analysis network, and outputting a process abnormal probability value; when the probability value exceeds a threshold value, triggering cross-process correlation analysis, and fusing upstream and downstream process data to generate a composite quality feature vector; and an abnormal type is judged through a cascade classifier, and a compensation strategy library is called to generate a machining parameter adjustment instruction set.

A shading apparatus with panels, such as, for example solar panels, connected to a spindle assembly rotatable about a vertical axis. Two or more panels are arranged in a series and connected to the spindle assembly and each panel is rotatable on a horizontal-longitudinal axis and form an array configured to provide a shade canopy. Certain embodiments include a payload area, such as, for example, a seating platform which may be either affixed or releasably attachable to the spindle assembly and / or central pole and rotatable about the vertical axis as a carousel.

A transparent wideband microwave absorber unit cell, a transparent wideband microwave absorber and a method of forming a transparent wideband microwave absorber, include a metal substrate, a first layer of glass attached to the metal substrate and having a first pattern of indium tin oxide (ITO) configured as a square loop centered about a central vertical axis and a second pattern of ITO including four equidistant square patches, a second layer of glass attached to the first layer of glass and having a third pattern of ITO configured as a dipole having a cross shape with a center axis coaxial with the central vertical axis, and a third layer of glass attached to the second layer of glass and having a fourth pattern of ITO configured as five circular patches, with a first circular patch located coaxially with the central vertical axis and four equidistant circular patches.

The invention discloses an operation control method and device for a vertical axis wind turbine generator, and belongs to the technical field of wind power generation. The method comprises the steps that a pitch angle of a lower blade is driven to be gradually increased to a preset angle at a preset angular speed through a variable pitch controller; when the rotating speed of the wind wheel reaches the cut-in rotating speed, the optimal tip speed ratio is tracked until the rotating speed of the wind wheel rises to the rated rotating speed; when the rotating speed of the wind wheel reaches the rated rotating speed, the rotating speed of the wind wheel is stabilized at the rated rotating speed; when the driving torque under the action of the aerodynamic load continuously exceeds the rated torque of the generator and the rotating speed of the generator reaches an early-warning rotating speed threshold value, a shutdown control strategy is triggered; and under the shutdown control strategy, the connection between the generator and the power grid is cut off, and mechanical braking is applied, so that the wind wheel stops rotating. According to the technical scheme, smooth starting of the wind wheel, stable operation at the rated rotating speed and safe shutdown in the fault state are achieved, the starting and stopping capacity and power stability of the unit are effectively improved, the wind speed application range is expanded, and it is guaranteed that the whole-process operation of the unit is safe and reliable.

The present application relates to the technical field of warming machine, disclose a kind of embryo inserting device and warming machine.Warming machine includes embryo inserting device and rack, embryo inserting device includes rotating mechanism and several bottom supporting mechanisms, rotating mechanism can be rotated relative to rack around vertical axis, rotating mechanism is provided with several first matching parts along the circumference, and the first matching part is used to limit the upper end of bottle embryo;Several bottom supporting mechanisms are connected with rotating mechanism and are correspondingly arranged below several first matching parts, and bottom supporting mechanism can move upward along vertical direction at preset time, to lift and guide the lower end of bottle embryo located at corresponding first matching part.The warming machine of the present application can ensure that the bottle embryo clamping mechanism is accurately inserted and grasped by setting the above-mentioned embryo inserting device, and improve the yield of bottle embryo processing.

Present embodiments are directed to a gate system for an amusement park attraction. The gate system includes a loading platform configured to rotate about a central vertical axis of the loading platform, and a gate positioned on the loading platform. The gate is configured to transition between a closed position and an open position. A gate actuation system is coupled to the loading platform and is configured to actuate the gate between the closed position and the open position based on feedback indicative of a position of a ride vehicle relative to the gate.

The invention relates to the technical field of operation and maintenance management, and discloses a historical building operation and maintenance management method and system based on digital twinning, and the method comprises the steps: building a digital substrate based on historical data and point cloud, dividing a monitoring region according to a bearing structure, value elements and a function space, and associating an identifier. And mapping the operation data to a corresponding component storage space according to the area to which the operation data belongs, and forming a dynamic operation and maintenance file and a monitoring data stream. And performing visual coding on the data stream by taking the acquisition time as a horizontal axis and the spatial topology as a longitudinal axis to generate a spatial-temporal distribution map. And determining an abnormal area according to fluctuation form difference and trend deviation degree of real-time and historical data in the map, and binding identifiers and time periods to generate an abnormal list. Updating the file by taking the list as an index, and matching the disease record with a historical maintenance record to generate an operation and maintenance management scheme; the efficiency of historical building operation and maintenance management based on digital twinning can be improved.

The invention discloses an electro-hydraulic control underground adjustable angle device and an adjusting method thereof. A translation assembly and a rotating assembly in a shell assembly are sequentially arranged from outside to inside, a sliding sleeve of the translation assembly slides in the axial direction of a shell of the shell assembly, and a spiral rod of the rotating assembly is matched with the sliding sleeve through a spiral key to achieve rotating movement and axial movement of the spiral rod; the lower end of the rotating assembly is meshed with the rotating joint assembly through a spherical gear to realize rotation of a rotating joint; the lower end of the shell is connected with the rotary connector through a gear ring, and the included angle between the axis of the gear ring and the vertical axis of the shell is larger than 0 degree. The device has the advantages of being simple in structure, convenient to operate, reliable in performance and high in structure bending angle adjustment control precision; the bend angle is adjusted underground, the requirement for track control of a well with a complex structure is met, and the purpose of completing drilling track control of the well with the complex structure with low cost, high efficiency and high precision is achieved.

Apparatus and associated methods relate to evaluating impurity content in battery materials. In an illustrative example, a battery material impurity assessment system (BMIAS) may include a slurry mixing system and an impurity extraction system (IES). The slurry mixing system, for example, may include a motor configured to rotate a vertical axis of a slurry container. For example, the motor may pause a movement of the slurry container when the vertical axis is rotated at a predetermined angle. For example, the IES may include a translatable magnetic mass (TMM) enclosed within a sheath. For example, by operating a position of the TMM, the IES may release non-target impurity and retain target substances. In some implementations, the target substance may be ionized by an acid treatment solution rapidly without direct heating. In some implementations, the target substances may be dispersed on a conductive filter to be directly used in subsequent analysis. Various embodiments may advantageously rapid high precision and rapid impurity testing for battery manufacturing.

A system for attaching a front engine of an aircraft, having: a vertical median plane, an engine pylon with a nose having a main female clevis, and a cylindrical housing around a vertical axis, a main link fastened to a front casing of the engine by a secondary ball-joint connection about a secondary axis perpendicular to the median plane by a secondary shaft, a main shaft, perpendicular to the median plane and forming a main ball-joint connection of the main link in the main female clevis about a main axis, the main and secondary axes in the plane perpendicular to the median plane, and an outer cylinder, coaxial with the vertical axis and a first end of which fastened in the cylindrical housing and a second end of which mounted, via an annular linear connection, around the vertical axis with respect to the front casing.

The invention relates to the field of wind driven generators, and particularly discloses a floating type vertical axis wind turbine multi-partition variable pitch control strategy which comprises the steps that S1, basic parameters and operating condition parameters of a unit are obtained; s2, establishing an aerodynamic model based on a double-disk multi-flow management theory and a superposition wind speed method; s3, measuring parameters through a sensor, and calculating a theoretical attack angle of the blade; s4, establishing a multi-partition pitch angle change function based on the theoretical attack angle; s5, constructing an NSGA-II multi-target optimization model, and taking maximization of an average power coefficient and minimization of a blade thrust standard deviation as targets; s6, substituting a function to obtain an optimal variable pitch control factor and an optimal pitch angle; and S7, the optimal pitch angle is converted into a variable pitch actuator instruction. The problems that an existing strategy is limited in partition, the wind direction influence is ignored, and optimal parameters for working condition adaptation are lacked are solved, the wind energy capture efficiency is improved, the load fluctuation is reduced, and the variable pitch control accuracy is improved.

The invention discloses a gas chromatography sampling device and a gas chromatograph, and relates to the technical field of gas chromatographs. The gas chromatography sampling device comprises a supporting frame and further comprises a main lifting device which is fixedly installed on the supporting frame, the telescopic end of the main lifting device is fixedly connected with a supporting column, a rotating disc is rotatably installed on the outer wall of the supporting column, three sets of syringes which are distributed circumferentially are rotatably installed on the rotating disc, and the three sets of syringes are connected with the main lifting device. A switching part for driving the turntable to rotate is arranged on the supporting column; the sample disc is rotationally mounted on the supporting frame through a first vertical shaft, a disc is rotationally mounted on the supporting frame through a second vertical shaft, and a plurality of circular holes are circumferentially distributed in the disc; by means of the sample feeding device, alternate sample feeding work of a plurality of samples can be rapidly achieved, the sample feeding and detecting efficiency of the samples is remarkably improved, the rubber pads used each time in the detecting process can be replaced, and the detecting efficiency and accuracy of the samples are guaranteed.

The invention discloses a method for calculating aerodynamic characteristics of a vertical axis wind turbine. The method comprises the following steps: establishing a computational fluid mechanics model and a free vortex wake model and forming interaction, segmenting a blade and establishing a two-dimensional local area, and initializing flow field and vortex wake parameters; calculating an induced flow velocity sum of each vortex element in the center of a local area, and loading the induced flow velocity sum and a far-field incoming flow velocity to a boundary node; the airfoil action is equivalent to point vortex and dipole flow at the circle center, and induced velocities of the point vortex and the dipole flow at boundary nodes are loaded; carrying out fluid mechanics parameter calculation on the flow in each two-dimensional local area; integrating the airfoil surface pressure to obtain a lift force, and calculating a circular rector to update the point vortex intensity; the dipole flow intensity is calculated and updated through the flow velocities of the three specific observation points. The method for calculating the aerodynamic characteristics of the vertical axis wind turbine is high in calculation efficiency and reliable in precision, the aerodynamic characteristics of the vertical axis wind turbine are accurately obtained with small calculation amount, and powerful support is provided for structural design and optimization of the vertical axis wind turbine.

An automatic stacking apparatus and system. The automatic stacking apparatus comprises rails, a frame, a rotating mechanism, a lifting mechanism and a carrying mechanism, wherein the rails are arranged in a conveying direction; the frame is mounted on the rails, and can move along the rails to make a round-trip between a loading area and a unloading area; the rotating mechanism is in transmission connection with the lifting mechanism, one of the rotating mechanism and the lifting mechanism is mounted on the frame, and the other one of the rotating mechanism and the lifting mechanism is in transmission connection with the carrying mechanism; and the carrying mechanism is formed with a material transportation port, and materials can enter or be removed from the carrying mechanism through the material transportation port. After the frame moves to the unloading area along the rails, the lifting mechanism can drive the carrying mechanism to ascend and descend, and the rotating mechanism drives the carrying mechanism to rotate about a vertical axis, thereby adjusting the position of the material conveying port of the carrying mechanism, so as to accurately stack the materials at a suitable position without requiring manual re-adjustment, thus the degree of automation is higher, and the stacking efficiency is higher.

The present invention relates to a rotating device for integration in a substrate, preferably in a building floor element, more particularly in a screed floor, having at least three support units, which can be arranged individually in the circumference of the substrate within a circular area about an axis of rotation, a rotating plate which extends at least over the circular area and has a room side and a bearing side opposite the room side, a rotary bearing unit, and at least one drive apparatus, wherein the rotating plate is rotatably mounted in the axis of rotation and the at least three support units support the rotating plate in a rotationally movable manner in the orientation of the axis of rotation in a vertical axis on the bearing side, and wherein the drive apparatus is configured to set the rotating plate in rotation about the axis of rotation.

The invention relates to the technical field of film pasting agent preparation, and discloses a 3T film pasting agent preparation device for drilling fluid and a preparation method.The 3T film pasting agent preparation device comprises a drying box, a flow injection pipe is arranged on the upper portion of the drying box, an inner cylinder is arranged in the drying box, an atomization nozzle is arranged at the end, stretching into the inner cylinder, of the flow injection pipe, and a grinding assembly is arranged on the lower portion of the inner cylinder; a vibration assembly is arranged outside the grinding assembly, the upper portion of the base is rotationally connected with a hollow cylinder, shaft rods are distributed on the periphery of the hollow cylinder in an annular array mode, and grinding wheels are distributed on the outer surfaces of the shaft rods in a linear array mode in the vertical axis direction of the shaft rods. The rolling wheel on the outer surface of the shaft rod is used for rolling the granular 3T film pasting agent in the sliding process in the groove, and meanwhile, the shaft rod is matched with rotation, so that the rolling effect of the rolling wheel on the 3T film pasting agent is improved, the granular 3T film pasting agent is eliminated, it is guaranteed that the 3T film pasting agent becomes powder to be stored, and the situation that the interior of the 3T film pasting agent is not thoroughly dried due to the granular state is avoided.

A method of generating an interactive three dimensional (3D) game includes generating a manipulable volumetric 3D display object. The manipulable volumetric 3D display object includes a plurality of elements. Display data is generated to depict within the plurality of elements of the manipulable volumetric virtual 3D display object. The manipulable volumetric virtual 3D display object is rotated along a vertical axis, in response to a first user input, to view the display data from different angles. A view of the manipulable volumetric virtual 3D display object is changed, in response to a second user input.

To provide a spinneret for a multi-rotor coaxial spunbond and / or melt-blown plant.SOLUTION: A spinneret 1 includes: a plurality of acceleration ducts 2, each of which extends along its own supply axis 2a crossing the main plane 1b and each of which is adapted to supply a respective polymer filament along the supply axis; a plate 7 having first holes 70 accommodating the acceleration ducts, and second holes 71 that are spaced apart from the first holes and allow passage of air or gas; and a mask 8 that is adjacent to the plate along a vertical axis 1a, is centered on the first holes, is fluidly connected to the second holes, and accommodates a part of the acceleration ducts while having a plurality of third holes 80 through which air or gas passes, wherein the second holes are in a number greater than 4, are distributed around at least a part of the first holes, and have their centers located along a circumference 7a that develops around the first holes in parallel with the main plane without touching other first holes.SELECTED DRAWING: Figure 1a

An example implementation involves controlling robots with non-constant body pitch and height. The implementation involves obtaining a model of the robot that represents the robot as a first point mass rigidly coupled with a second point mass along a longitudinal axis. The implementation also involves determining a state of a first pair of legs, and determining a height of the first point mass based on the model and the state of the first pair of legs. The implementation further involves determining a first amount of vertical force for at least one leg of the first pair of legs to apply along a vertical axis against a surface while the at least one leg is in contact with the surface. Additionally, the implementation involves causing the at least one leg of the first pair of legs to begin applying the amount of vertical force against the surface.

The invention relates to a die bonding swing arm device which comprises a main shaft rotating motor which is fixed on a base below, and the output end of the bottom of the main shaft rotating motor is connected with a rotating main shaft which can rotate around a vertical axis; the two independent lifting modules are symmetrically and fixedly mounted on the left side and the right side of the rotating main shaft by taking the axis of the rotating main shaft as a symmetric center; and the two swing arm assemblies are installed on the swing arm fixing bases of the two lifting modules correspondingly, and a suction cup is installed at the tail end of each swing arm assembly. According to the double-swing-arm alternating parallel operation mode, crystal taking and crystal fixing actions are almost synchronously carried out, the theoretical carrying efficiency is nearly doubled compared with that of a single swing arm, and the equipment productivity is greatly improved.

A front engine attachment system for an engine having an engine pylon with a nose having a main female clevis and a cylindrical housing, a main rod fastened to the engine by a secondary ball joint connection about a secondary axis, a main shaft realizing a main ball joint connection of the main rod in the main female clevis about a main axis, wherein the main axis and the secondary axis are in the same vertical plane, a hollow outer cylinder with a vertical axis, of which a first end is fastened in the cylindrical housing and of which a second end is mounted so as to be able to move, via an annular linear connection, with respect to the front casing and an inner cylinder threaded and fastened in the outer cylinder.

The invention discloses an aircraft surface waviness measurement and analysis method and system, and the method comprises the steps: scanning the surface of an aircraft according to a planned path through employing a three-coordinate measuring machine and a scanning probe, obtaining scanning data, and obtaining the scanning data for evaluation through employing a segmented scanning and segment-to-segment direct splicing mode for a hole, a pin and other structural parts; fitting based on scanning data to obtain a point deviation data set, calculating corresponding point arc length data based on the point deviation data and the point coordinate data on this basis, and drawing a graph by taking a horizontal axis as the point arc length data and a longitudinal axis as the point deviation data; and determining the surface waviness of the airplane by combining the derivative at the intersection point of the point deviation data curve and the transverse axis and the distance between the wave crest and the wave trough, thereby realizing the efficient and accurate measurement of cavities, welding seams and other obstacle structures on the outer surface of a large-scale airplane part or the whole machine and the accurate calculation of the waviness.

The invention provides a curved surface engraving control method based on a laser engraving machine, which comprises the following steps of: in a to-be-processed area of a to-be-processed curved surface object, acquiring discrete point data by taking intersection points of plane rectangular grids in a plane coordinate system as acquisition points; performing parameterization calculation on discrete point data of each group of intersection points in the horizontal axis direction in the plane coordinate system to obtain a first virtual data sequence, and performing parameterization calculation on each group of discrete point data in the longitudinal axis direction in the plane coordinate system to obtain a second virtual data sequence; based on the first virtual data sequence and the second virtual data sequence, determining a curved surface fitting model of the to-be-processed area; a preset carving image is obtained, and a three-dimensional carving track is determined according to the preset carving image and the curved surface fitting model; and controlling a laser of the laser engraving machine to engrave in the to-be-processed area according to the three-dimensional engraving track so as to form a preset engraving image in the to-be-processed area. According to the invention, the irregular curved surface object can be automatically engraved.

The invention discloses a pressure cooker inner cylinder upper opening flanging circumference polishing device, and relates to the field of cooker inner container polishing machining.The pressure cooker inner cylinder upper opening flanging circumference polishing device comprises a machining table top and a positioning claw disc fixedly erected on the upper end face of the machining table top, the positioning claw disc is used for clamping and positioning a cooker inner container, and a rotary disc is further placed over the positioning claw disc; the center point of the rotary disc and the center point of the positioning claw disc are located on the same vertical axis, a lifting plate is arranged above the rotary disc, a second motor is fixedly erected on the upper end face of the lifting plate, and a lifting mechanism playing a role in lifting the lifting plate is further arranged on the upper end face of the machining table top. The pot inner container can be limited to the bottom of the rotary disc through the positioning claw disc, the positions of the polishing units are adjusted through the lifting mechanism and the distance adjusting unit, the two polishing units are made to make contact with a crack between the outer wall of the pot inner container and the outer ring of the turned edge at the same time, and then the polishing units are started; and the two grinding units are used for carrying out all-directional polishing and grinding treatment on the outer ring of the turned edge of the pot liner.

A multi-angle variable cross-section pipe section outer wall datum line assignment method comprises the steps that a vertical pipe section is supported through a supporting tool, the pipe section and the supporting tool are fixed through a chain type tensioner, the chain type tensioner is rotated, the vertical pipe section is pulled to rotate on a support bearing, the vertical pipe section is stopped when rotating to a 90-degree datum point and a 270-degree datum point are in a horizontal state, and the vertical pipe section is fixed to the supporting tool. 90-degree datum lines and 270-degree datum lines are surveyed through the datum points by utilizing the total station, then another two datum lines are surveyed through the total station, and an operator can adjust the pitch angle of the eyepiece, observe different positions, needing to be scribed, of the pipe wall of the pipe section and adjust the definition of the eyepiece under the conditions that the eyepiece passes through the eyepiece and the vertical shaft is locked. And guiding a lineation person to draw points at a position coinciding with a vertical standard wire in the eyepiece, and drawing 0-degree and 180-degree position lines at different positions by points at different positions in a chalk line popping manner. The scribing method for the pipe with the multi-angle section in the inner diameter has the advantages that the used scribing process is simple, the scribing precision is high, and an operator does not need to move an instrument many times.

A stroller handlebar actuator is provided. The handlebar actuator is provided at a handlebar of the stroller and includes cables that are attached to the handlebar actuator at one end and rear wheels of the stroller at another end. The handlebar actuator includes a protruding tab that a user to able to press using one or both thumbs without needing to remove their hands from the outer ends of the handlebar. By pressing the tab, a rotational force is exerted on the handlebar actuator, causing the handlebar actuator to rotate relative to the handlebar. This rotation causes the cables to pull inwards towards the handlebar actuator, thereby unlocking mechanisms provided at the rear wheels. The unlocking of the mechanisms causes the rear wheels to be able to freely rotate about a vertical axis. When the force is removed from the handlebar actuator, the handlebar actuator rotates back to its natural resting position and the cables return back to their original positions, locking the rear wheels.

The invention discloses a method and a system for improving the tracking performance of a photoelectric pod by using a fast reflector. Belongs to the technical field of photoelectric pod control. Comprising the following steps: constructing a dual-channel tracking control system, adding a fast reflector tracking channel, forming a decoupling dual-channel with an original servo frame channel, and cooperatively realizing dynamic tracking control of a target image; target miss distance information output by the image tracker is obtained, and visual axis deviation angles of the target in the horizontal X-axis direction and the vertical Y-axis direction are calculated respectively; dividing a visual axis deviation angle into a small-amplitude high-frequency signal or a large-amplitude low-frequency signal by taking the maximum swing angle capability of the fast reflector as a threshold value; when the visual axis deviation angle is a small-amplitude high-frequency signal, the fast reflecting mirror executes a tracking compensation function, and the servo frame mechanism performs follow-up compensation so as to expand the stroke of the fast reflecting mirror; and when the visual axis deviation angle is a large-amplitude low-frequency signal, the fast reflecting mirror is kept in the middle position, and target tracking control is independently completed by a servo frame channel.

The invention relates to a hydrofoil transport system comprising at least one hydrofoil craft extending in a longitudinal direction (X) and comprising two hulls connected by a central platform, propulsion means and a control house (4), wherein the hydrofoil craft further comprises, at its bow, a first underwater pylon (9) located along the longitudinal direction (X) and, at its stern, an underwater frame (12), wherein the first underwater pylon (9) comprises, at one end intended to be submerged, a first hydrofoil (8), and wherein the underwater frame (12) comprises, at one end intended to be submerged, a second hydrofoil (10), wherein the first hydrofoil and the second hydrofoil are intended to adopt at least two positions, a first position close to the hulls and a second position away from the hulls, and wherein the first pylon is mounted so as to be rotatable through the central platform about a vertical axis such that at least a first position can be assumed, in which the first hydrofoil is orthogonal to the longitudinal direction (X) and a second position can be assumed, in which the first hydrofoil has an orientation different from the orthogonal orientation, and in which the second hydrofoil has a fixed orientation orthogonal to the longitudinal direction.