Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63H—MARINE PROPULSION OR STEERING
  • B63H3/00—Propeller-blade pitch changing
  • B63H3/008—Propeller-blade pitch changing characterised by self-adjusting pitch, e.g. by means of springs, centrifugal forces, hydrodynamic forces
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63H—MARINE PROPULSION OR STEERING
  • B63H3/00—Propeller-blade pitch changing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63H—MARINE PROPULSION OR STEERING
  • B63H3/00—Propeller-blade pitch changing
  • B63H3/06—Propeller-blade pitch changing characterised by use of non-mechanical actuating means, e.g. electrical
  • B63H3/08—Propeller-blade pitch changing characterised by use of non-mechanical actuating means, e.g. electrical fluid
  • B63H3/081—Propeller-blade pitch changing characterised by use of non-mechanical actuating means, e.g. electrical fluid actuated by control element coaxial with the propeller shaft
  • B63H3/082—Propeller-blade pitch changing characterised by use of non-mechanical actuating means, e.g. electrical fluid actuated by control element coaxial with the propeller shaft the control element being axially reciprocatable
  • B63H2003/084—Propeller-blade pitch changing characterised by use of non-mechanical actuating means, e.g. electrical fluid actuated by control element coaxial with the propeller shaft the control element being axially reciprocatable with annular cylinder and piston

Definitions

• the present description relates generally to variable-pitch propellers and, more particularly, a device for controlling the pitch of a variable-pitch propeller.
• the present description applies in particular to propellers with a variable pitch propeller.
• Propeller thrusters are already widely used to set machines in motion, typically for navigating boats, for flying aircraft, etc.
• motorized propeller thrusters usually equip small boats capable of sailing over a wide range of speeds.
• these thrusters are often fitted with variable-pitch propellers, so that the propeller's pitch increases as the speed of the boat increases. This makes it possible to maintain a substantially constant engine speed whatever the speed of the boat. This improves the efficiency of the propellant.
• the modification of the pitch of the propeller of a variable-pitch propeller thruster is generally carried out automatically.
• the thruster then comprises a system for slaving the pitch of the propeller with respect, typically, to the speed of the boat and / or with respect to an engine torque applied to a propeller shaft.
• propeller pitch control systems we find in particular hydraulic, electrical, mechanical or hydrodynamic systems. These systems, which are often expensive and very sensitive to operate, are also complex to design and build. Their development raises, in particular, many sealing problems. In addition, they do not generally make it possible to obtain satisfactory control of the pitch of the propeller over the entire speed range of the boat.
• One embodiment overcomes all or part of the drawbacks of the pitch control devices of a known variable-pitch propeller.
• One embodiment provides for a device comprising a variable-pitch propeller and means adapted to modify the pitch of the propeller by the Venturi effect.
• an external flow of a fluid generates, by Venturi effect, a depression in a first compartment of a chamber comprising one or more first orifices not parallel to an axis of rotation of the propeller, a variation of this depression causing a displacement of a movable partition actuating a mechanism for modifying the pitch of the propeller.
• One embodiment provides a device comprising:
• a chamber comprising one or more first orifices not parallel to an axis of rotation of the propeller
• a movable partition delimiting, inside the chamber, a first compartment communicating with the outside through this or these first orifices;
• a variation of a vacuum, in the first compartment causes a modification of the pitch of the propeller.
• an increase in the depression causes an increase in the pitch of the propeller.
• a decrease in the vacuum causes a decrease in the pitch of the propeller.
• At least one additional part forms, relative to an external surface of the chamber, a constriction in the vicinity of this or these first orifices.
• the movable partition further defines, inside the chamber, a second compartment communicating with the outside through one or more second orifices parallel to the axis of rotation of the propeller.
• the movable partition is linked to a return spring to a position corresponding to an extreme value of the pitch of the propeller.
• the movable partition is a piston having an inclined surface, relative to the axis of rotation of the propeller, on which rests a cam adapted to actuate the pitch modification mechanism of the propeller.
• the movable partition is associated with a gear, consisting of a rack and a pinion, adapted to actuate the mechanism for modifying the pitch of the propeller.
• the mechanism for modifying the pitch of the propeller modifies a blade pitch angle over an angular range of less than 90 °, preferably of the order of 15 °.
• the propeller comprises at least two blades disposed radially and separated from the axis of rotation by a distance of approximately 35 mm, preferably equal to 35 mm, these blades having a length of about 240 mm, preferably equal to 240 mm.
• One embodiment provides a propellant device comprising a device as described.
• One embodiment provides for a human-powered craft comprising at least one propellant device as described.
• One embodiment provides an energy recovery device, comprising a device as described.
• Figure 1 illustrates schematically and partially, in a side view and in section, an embodiment of an automatic variable-pitch propeller thruster
• Figure 2 illustrates schematically and partially, in a side view and in section, another embodiment of an automatic variable-pitch propeller thruster
• Figure 3 illustrates schematically and partially, by side views (A) and (B) and in section, yet another embodiment of an automatic variable-pitch propeller thruster
• Figure 4 shows, by views (A) and (B) in perspective and cut away, yet another embodiment of an automatic variable-pitch propeller thruster
• FIG. 5 shows an example of a boat equipped with an automatic variable-pitch propeller thruster
• FIG. 6 partially shows an embodiment of a thruster propeller.
• the embodiments described take for example a propeller fitted to a thruster. However, these embodiments apply more generally to any variable-pitch propeller system in which similar problems arise, for example wind turbines or tidal turbines.
• FIG. 1 schematically and partially illustrates, in a side view and in section, an embodiment of a propeller 1 with an automatic variable-pitch propeller.
• the thruster 1 comprises a propeller 11 consisting of two blades 111 and 112.
• the blades 111 and 112 are arranged in opposition, perpendicularly to an axis 113 of rotation of the propeller 11.
• the axis 113 of rotation of the propeller 11 is, in Figure 1, parallel to the section plane.
• the blades 111 and 112 are mounted to pivot relative to a common axis 115, perpendicular to the axis 113 of rotation of the propeller 11.
• the axis 115, around which the blades 111 and 112 pivot. 'helix 11 is, in Figure 1, oriented perpendicular to the cutting plane
• a pivoting (or rotation) of the blades 111 and 112, around the axis 115, makes it possible to vary the pitch of the propeller 11 of the thruster 1.
• the pivoting, relative to the axis 115 , of the blade 111 of the propeller 11 modifies a pitch angle Q, or angle of attack, of the blade 111.
• the pivoting, with respect to the axis 115, of the blade 112 of the propeller 11 modifies a pitch angle, or angle of attack, of the blade 112.
• the thruster 1 is therefore provided with a propeller 11 with variable pitch.
• the thruster 1 is a variable pitch thruster.
• the angle Q corresponds, in this example, to an angle formed by a chord (straight line joining a leading edge to a trailing edge of a profile) of the blade 111 with respect to a normal to the axes 113 and 115.
• the angle corresponds, still in this example, to an angle formed by a chord of the blade 112 with respect to a normal to the axes 113 and 115.
• the pitch angle of the blade 112 has a value equal to that of the pitch angle Q of the blade 111. This makes it possible to balance the rotation of the propeller 11 around the axis 113, thus limiting the appearance of vibrations.
• a rotation of the propeller 11 in a clockwise direction causes a flow (arrow 116, FLOW) of a fluid towards the rear of the thruster 1 at a speed v.
• the speed v of this flow depends in particular on:
• the speed w of rotation of the propeller 11 is, for example, imposed by a motor driving a shaft connected to the propeller 11.
• a motor driving a shaft connected to the propeller 11. the more the angles of attack and Q increase , for a rotational speed w that is assumed to be constant, and the more the flow speed v increases.
• the thruster 1 comprises a body 13 in which is arranged a cavity (or recess) forming a chamber 15.
• the body 13 of the thruster 1 has one or more orifices 131 not parallel to the 'axis 113 of rotation of the propeller 11.
• two orifices 131 are made in a direction perpendicular to the axis 113 of rotation of the propeller 11. The orifices 131 thus form through holes which open out inside the chamber 15.
• the chamber 15 comprises a first compartment 151 separated from a second compartment 153 by a movable partition 17 or piston.
• the first compartment 151 communicates, via the two orifices 131, with the outside of the chamber 15.
• the second compartment 153 of the chamber 15 is, as for him, completely closed and therefore does not communicate with the outside of the room 15.
• the propellant 1 is immersed in a fluid, for example water, constituting an external environment where the chamber 15 and the propeller are placed in particular 11.
• the first compartment 151 of the chamber 15 is therefore, in Figure 1, filled with water. Water exchanges can thus occur freely, via the orifices 131 (or water intakes), between the interior and the exterior of the chamber 15.
• the second compartment 153 is, still in this example, preferably filled with a gas, for example air.
• the movable partition 17 provides, where appropriate, a dynamic seal between the first compartment 151 and the second compartment 153, so that the air contained in the second compartment 153 thus remains trapped therein whatever the position of the movable partition 17. .
• the pressure P3 is chosen or adjusted so that at rest, that is to say for a zero flow speed v, the pressure P3 is lower than the pressure PI.
• the movable partition 17 thus occupies, for a zero speed v, a stowed position located near the front of thruster 1 (left, in figure 1).
• the pressures P1 and P3 both tend to move the piston 17 in opposite directions.
• the piston 17 therefore comes to a standstill, at non-zero speed v, in a position resulting from a dynamic equilibrium being established between the pressures PI and P3.
• the movable partition 17 comprises a rack 171 arranged parallel to the axis 113 of rotation of the propeller 11. On this rack 171 a pinion 173 engages.
• the pinion 173 is, in FIG. 1, kept integral with the blade 111 of the propeller 11.
• the rack 171 is mounted such that a displacement of the movable partition 17 towards the rear of the thruster 1 (towards the right, in FIG. 1) causes an increase in the pitch angle Q of the blade 111.
• a similar mechanism (not shown), making it possible to modify the angle of the blade 112 of the propeller 11, is also implemented.
• an increase in the speed v leads, by the Venturi effect, to a decrease in the pressure PI in the first compartment 151. This thus causes a displacement of the movable partition 17 towards the rear of the thruster 1 ( to the right, in figure 1). This movement of the movable partition 17 tends, by means of the gear consisting of the rack 171 and the pinion 173, to increase the angle Q of attack of the blade 111.
• a decrease in the speed v leads, by Venturi effect, to an increase in the pressure PI in the first compartment 151. This thus causes a displacement of the movable partition 17 towards the front of the thruster 1 (towards the left, in FIG. 1).
• This movement of the movable partition 17 tends, via the rack 171 and the pinion 173, to reduce the angle Q of attack of the blade 111. Similar modifications take place, thanks to the movement of the movable partition 17, on the angle of attack of the blade 112.
• the displacement of the piston 17 in the chamber 15 between extreme positions thus leads to modifying the angles of attack Q and over an angular range of less than 90 °, preferably by around 15 °.
• the movable partition 17 allows, by moving, to control the pitch of the propeller 11 as a function of the speed v.
• the thruster 1 is therefore well equipped with an automatic variable-pitch propeller 11.
• the thruster 1 is an automatic variable pitch thruster.
• the medium in which the propellant 1 is placed is air.
• the first compartment 151 of the chamber 15 is, where appropriate, filled with air.
• a flow of air along the body 13 of the thruster 1 causes, by the Venturi effect, a depression in the first compartment 151. This depression tends, as explained above, to shift the piston 17 towards the rear of the thruster 1 (towards the right, in figure 1), therefore to increase the pitch of the propeller 11.
• FIG. 2 schematically and partially illustrates, in a side view and in section, another embodiment of a propeller 2 with an automatic variable-pitch propeller.
• the propellant 2 of FIG. 2 comprises elements common to the propellant 1 of FIG. 1. These common elements will not be detailed again below.
• the thruster 2 of Figure 2 differs from the thruster 1 of Figure 1 mainly in that the thruster 2 comprises at least one additional or additional part 135.
• This part 135 forms, relative to an external surface of the chamber 15, a constriction 137 narrowing in the vicinity of the orifices 131.
• the constriction 137 is, in FIG. 2, accentuated by a particular geometry (or curve, or shape) of the body 13 of the thruster 2 near the orifices 131.
• the part 135 is, for example, a ring surrounding the body 13 and fixed to the thruster 2 in several places (not shown in the sectional view).
• the constriction 137 is adapted to locally accelerate the flow of the fluid in the vicinity of the orifices 131.
• the fluid flows locally, near the orifices 131, at a speed greater than the speed v overall flow.
• This local acceleration of the flow makes it possible to accentuate the Venturi effect and thus increase the depression produced inside the first compartment 151 of the chamber 15.
• the pressure PI prevailing in the first compartment 151 of the thruster 2 will therefore, at an equal flow speed v, be less than the pressure PI prevailing in the first compartment 151 of the thruster 1 (FIG. 1).
• the thruster 2 also comprises, in addition to the two first orifices 131, one or more second orifices 133 parallel to the axis 113 of rotation of the propeller 11.
• two second orifices 133 are made in the thruster 2.
• the orifices 133 thus form through holes (or water intakes) which open into the interior of the chamber 15. When the thruster 2 is immersed, water exchanges can thus occur freely, through the orifices 131 and 133, between the interior and the exterior of the chamber 15.
• the first compartment 151 communicates, via the two first orifices 131, with the outside of the chamber 15; and the second compartment 153 communicates, via the two second orifices 133, with the outside of the chamber 15.
• the second compartment 153 is then, in FIG. 2, no longer filled with air as in FIG. 1, but with water.
• the second orifices 133 allow, when the flow speed v increases, to increase the pressure P3 prevailing inside the second compartment 153 of the chamber 15.
• the result is that an increase in the speed v not only causes a decrease, by Venturi effect, of the pressure PI, but also an increase of the pressure P3.
• the pressures PI and P3 therefore both tend to move the piston 17 in the same direction, here towards the rear of the propellant 2 (towards the right, in FIG. 2), unlike the example of Figure 1 where the pressures P1 and P3 tend to move the piston 17 in opposite directions.
• the propellant 2 of FIG. 2 is, moreover, provided with a return spring 19, for example, with non-contiguous turns.
• the return spring 19 is arranged along the axis 113 of rotation of the propeller 11. This spring 19 bears:
• the spring 19 thus tends, by a return force directed parallel to the axis 113, to push the movable partition 17 towards the front of the thruster 2 (towards the left, in FIG. 2), in other words towards a position corresponding to an extreme value of the pitch of the helix 11.
• the extreme value of the pitch of the propeller 11 is equivalent, in FIG. 2, to a minimum value of the pitch also called “small pitch”.
• the pressures PI and P3 are substantially equal.
• the position of the piston 17 is then located in front of the thruster 1 (on the left, in FIG. 2), that is to say in the position which corresponds to the small pitch of the propeller 11.
• the piston 17 compresses the spring 19 by moving to a position corresponding, in FIG. 2, to a maximum value of the pitch, also called “large pitch”, of the propeller 11.
• An advantage of the embodiment explained in relation to FIG. 2 lies in the fact that the pitch of the propeller 11 of the thruster 2 is regulated by a force of hydrodynamic origin, linked in a one-to-one manner to the speed of 1 'flow.
• FIG. 1 Another advantage of the embodiment of Figure 2 over that of Figure 1 is that it is freed from a constraint of maintaining a dynamic seal between the compartments 151 and 153 of the chamber 15
• the compartments 151 and 153 can, in fact, exchange small amounts of water, compared to the volumes of the compartments 151 and 153, without this however disturbing the operation of the mechanism for modifying the pitch of the. propeller 11. This makes it possible in particular to relax any precision constraints in the manufacture of the chamber 15 and of the piston 17.
• the thruster described in Figure 1 or 2 further comprises a mechanism for automatically modifying the pitch of the propeller 11 consisting of a small number of components.
• This thruster 2 is therefore overall simpler to design, to produce and to develop than the existing automatic variable-pitch thrusters.
• Figure 3 illustrates schematically and partially, by side views (A) and (B) and in section, yet another embodiment of a propeller 3 with automatic variable pitch propeller.
• the thruster 3 of Figure 3 comprises elements common with the thruster 2 of Figure 2. These common elements will not be detailed again below.
• the thruster 3 of Figure 3 differs from the thruster 2 of Figure 2 mainly in that it is devoid of the gear consisting of the rack 171 ( Figure 2) and the pinion 173 ( Figure 2).
• the piston 17 has an inclined surface 175, or inclined face, with respect to the axis 113 of rotation of the propeller.
• a cam 177 is adapted to bear (or roll, or slide) against the surface 175 to actuate the propeller pitch modification mechanism 11.
• the cam 177 is mounted at one end of the propeller. 'a lever 179.
• the other end of the lever 179 is held integral with the blade 111 of the propeller 11, or of the pivot pin 115.
• the gear consisting of the rack 171 ( Figure 2) and the pinion 173 ( Figure 2) is replaced, in Figure 3, by the inclined surface 175 of the piston 17, the cam 177 and the lever 179.
• Views A and B illustrate different pitch positions.
• the pitch angle of the blade 111 is always equal to the pitch angle of the blade 112.
• a thruster such as the thruster 3 is particularly suitable for equipping low-power craft, for example human-powered craft, where maximum efficiency of the propeller 11 is desired.
• the regulation of the pitch of the propeller 11 can then be easily adapted as a function of the physical capacities of a user of the boat, for example by installing a spring 19 having a different stiffness constant, or by modifying the shape of the cam. 177.
• FIG. 4 shows, through views A and B in perspective and in cutaway, yet another embodiment of a propeller 4 with an automatic variable-pitch propeller. Views A and B illustrate different pitch positions.
• the propellant 4 of FIG. 4 comprises elements in common with the propellant 3 of FIG. 3. These common elements will not be detailed again below.
• the propellant 4 of FIG. 4 differs from the propellant
• FIG. 3 of FIG. 3 mainly in that piston 17 drives a slide 47 in translation.
• This slide 47 actuates a lever 45 connected to the blade 111.
• Another lever 45 (not shown) is also connected to the blade 112.
• the body 13 of the propellant 4 is, in Figure 4, consisting of a hub 130 fitting into a cone 132. On the cone 132 is fixed the part 135 for accentuating the depression, caused by the Venturi effect, in the vicinity of the first orifices 131.
• the propeller 11 is fixed to a propeller shaft 43 passing through a part 41 for mounting to the system with which it is associated, for example a boat (not shown).
• the propellant 4 is, in view A, shown in a position where the spring 19 is relaxed. This position corresponds to the small pitch of propeller 11.
• the propellant 4 is, in view B, shown in a position where the spring 19 is completely compressed. This position corresponds to the large pitch of propeller 11.
• FIG. 5 represents an example of a boat equipped with an automatic variable-pitch propeller thruster.
• a boat 7 (for example, a human-powered boat or pedal boat) comprises at least one thruster 4 with automatic variable-pitch propeller, for example a single thruster 4.
• the thruster 4 for example, a boat 7 with automatic variable-pitch propeller, for example a single thruster 4.
• the boat 7 is fixed to a hull 71 of the boat 7.
• the boat 7 is provided with a transmission 73 adapted to modify the speed of rotation of the propeller 11 of the thruster 4.
• the boat 7 also has foils 77 or adjustable profiled wings by means of a control device 75 or feeler 75 making it possible to gauge a sinking of the boat 7 with respect to the surface of the water.
• the thruster 4 allows the boat 7 to sail on the water.
• the thruster 4 is placed in a flow of water, the overall speed v of which is equal to a speed of movement of the boat 7 on the water.
• the pitch of the propeller 11 of the thruster 4 is thus adapted or controlled as a function of the displacement speed of the boat 7. This allows, for example, a user of the boat 7, causing the propeller to rotate. 11 with the strength of his legs, to maintain a substantially constant pedaling rate whatever the speed of movement of the boat 7.
• FIG. 6 partially shows an embodiment of a propeller 11 of the thruster.
• the blade 111 of the propeller 11 has dimensions adapted according to the application.
• the blade 112, shown partially in FIG. 6, preferably has dimensions identical to those of the blade 111.
• the blade 111 has a length, denoted LP, of approximately 240 mm, preferably equal to 240 mm.
• the propeller 11 rotates, at an angular speed w, around an axis 113 of rotation, as explained previously in relation to Figures 1 to 5.
• a lower end 1111 of the blade 111 is arranged, relative to this axis of rotation 113, at a distance, denoted DA, of approximately 35 mm, preferably equal to 35 mm.
• a lower end 1121 of the blade 112 is arranged, relative to the axis of rotation 113, at a distance DA of approximately 35 mm, of preferably equal to 35 mm.
• the lower ends 1111 and 1121 of the blades 111 and 112, respectively, are approximately equidistant from the axis of rotation 113, preferably equidistant from the axis of rotation 113.
• the lower ends 1111 and 1121 are also called "blade feet".
• a quantity, called “geometric pitch”, is defined as being equal to a distance theoretically traveled by the propeller 11 when its blades 111 and 112 make a complete turn around the axis of rotation 113.
• the geometric pitches of propeller 11 are as follows:

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• Engineering & Computer Science (AREA)
• Aviation & Aerospace Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• Ocean & Marine Engineering (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Structures Of Non-Positive Displacement Pumps (AREA)
• Other Liquid Machine Or Engine Such As Wave Power Use (AREA)
• Working-Up Tar And Pitch (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=69572014

Family Applications (1)

Country Status (3)

Family Cites Families (4)

• 2019
  • 2019-05-29 FR FR1905753A patent/FR3096654B1/fr active Active
• 2020
  • 2020-05-20 EP EP20737261.6A patent/EP3976463B1/de active Active
  • 2020-05-20 WO PCT/FR2020/050845 patent/WO2020240119A1/fr unknown

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