WO2017199724A1 - Propeller and transport device propelled by same - Google Patents

Abstract

A propeller 16 includes: a hub 42; a plurality of blades 44 radially extending from the hub 42; and a guard 46 connected to the respective outer ends 58 of the plurality of blades 44. The guard 46 includes: a first member 60 consisting of the same material as the blades 44; and a second member 62 consisting of a different material from the blades 44. The first member 60 is formed in a ring-like shape and integrally formed with each of the plurality of blades 44. The second member 62 is formed in a ring-like shape on the inner peripheral surface of the first member 60. The second member 62 has higher bending elasticity than the first member 60. The friction coefficient of the outer peripheral surface of the first member 60 is smaller than the friction coefficient of the surface of the second member 62 which is in contact with the first member 60. The propeller 16 is used for a helicopter 10 and a boat 10a.

Description

Propeller and transportation equipment driven by it

The present invention relates to a propeller, and more particularly to a propeller having a guard and a transport device propelled thereby.

As an example of this type of prior art, Patent Document 1 discloses a propeller to which a safety ring is attached and a helicopter including the propeller. The propeller includes four blades extending outward from the center of the propeller and a safety ring having four pivots. Each of the four blades has a distal end distal to the center of the propeller. The safety ring is attached to the blade such that each of the four pivots receives the distal end of each of the four blades. Thus, by attaching the safety ring, it is possible to prevent the hand and eyes from being scratched at the distal end portion of the blade.

JP 2005-508236 A

However, in the propeller shown in Patent Document 1, when the propeller rotates, the safety ring is pulled outward by the centrifugal force generated with the rotation of the propeller. Therefore, a portion of the safety ring that is not attached to the distal end portion of the blade is deformed so as to bulge outward. As a result, when the rotation speed of the propeller is increased, air resistance increases, vibrations, and the like occur, making it difficult to rotate the propeller as it is.
Therefore, a main object of the present invention is to provide a propeller and a transport device propelled thereby that can suppress deformation of the guard when the propeller rotates.

According to one aspect of the present invention, a hub includes a hub, a plurality of blades extending radially from the hub, and a guard connected to each outer end of the plurality of blades, and the guard is made of the same material as the blade. And a second member made of a material different from that of the blade, the first member being formed integrally with each of the plurality of blades, and from the outer end of each of the plurality of blades to the adjacent blade. A propeller is provided that extends in an outwardly convex arcuate shape toward the outer end, and the second member is formed on the inner peripheral surface of the first member and has a higher bending elastic modulus than the first member.

In the present invention, since the first member is formed integrally with each of the plurality of blades (all blades), the first member is not separated from any blade. Therefore, even if a centrifugal force is applied to the guard when the propeller rotates, it is possible to suppress the displacement of the connection portion of the first member with each blade outward. In addition, since the guard includes the second member having a higher flexural modulus than that of the first member, the rigidity of the guard can be increased as compared with the case where the guard includes only the first member. Moreover, the second member is formed on the inner peripheral surface of the first member. Therefore, when the propeller rotates, the second member receives a force so as to be pressed outward, that is, against the first member, by the generated centrifugal force, thereby preventing the second member from being separated from the first member. It is possible to reliably maintain the high rigidity of the guard. As a result, when the propeller rotates, the guard can be reliably prevented from being deformed so as to bulge outward by centrifugal force. As described above, when the first member is integrally formed with each of the plurality of blades and the second member having a high bending elastic modulus is formed on the inner peripheral surface of the first member, the propeller is rotated. Thus, the deformation of the guard can be reliably suppressed, the increase in air resistance received by the propeller and the vibration of the propeller can be suppressed.

Here, “bending elastic modulus” refers to a physical property value indicating the difficulty of bending deformation.

Preferably, the first member is formed in a ring shape. In this case, since the outer ends of all the blades are connected to each other by the first member formed integrally with each of the plurality of blades, the outer ends of the blades oscillate to form a pitch angle (blade rotation axis). It is possible to suppress an increase or decrease in the angle of the blade with respect to a plane perpendicular to the. As a result, it is possible to prevent the control of the propulsive force or the air flow obtained by the rotation of the propeller from becoming complicated.

Also preferably, the second member is formed in a ring shape. In this case, the rigidity of the guard can be further increased with respect to the blade. Thereby, when a propeller rotates, it can further suppress that a guard deform | transforms with a centrifugal force.

More preferably, the first member includes a plurality of first member pieces formed integrally with each of the plurality of blades, and the plurality of first member pieces are formed discontinuously. In this case, the total length of the first member can be made smaller than when the first member is formed in a ring shape. Therefore, the propeller can be lightened and the rotational moment of inertia can be reduced. As a result, the centrifugal force generated when the propeller rotates can be reduced, and the deformation of the guard can be suppressed. Moreover, the usage-amount of a 1st member can be reduced and cost can be reduced.

Preferably, the second member includes a plurality of second member pieces formed discontinuously in the circumferential direction on the inner peripheral surface of the first member. In this case, the total length of the second member can be made smaller than when the second member is formed in a ring shape. Therefore, the propeller can be lightened and the rotational moment of inertia can be reduced. As a result, the centrifugal force generated when the propeller rotates can be reduced, and the deformation of the guard can be suppressed. Moreover, the usage-amount of a 2nd member can be reduced and cost can be reduced.

Preferably, the first member is also formed on the inner peripheral surface of the second member. In this case, since the inner peripheral surface and the outer peripheral surface of the second member are sandwiched by the first member, the second member is separated from the first member even when a force is applied from the outside of the guard. Can be prevented. Thereby, when the propeller rotates, the deformation of the guard can be suppressed more reliably.

More preferably, the second member is formed inside the first member. In this case, since the second member is not exposed to the outside, it is possible to prevent the second member from being separated from the first member no matter which direction the guard receives a force. Thereby, when the propeller rotates, the deformation of the guard can be suppressed more reliably.

Preferably, the friction coefficient of the outer peripheral surface of the first member outside the second member is smaller than the friction coefficient of the contact surface of the second member with the first member. In order to suppress a decrease in the rotation speed of the propeller when an object comes into contact with the outer peripheral surface (the outer peripheral surface of the guard) of the first member outside the second member during the rotation of the propeller, the outer periphery of the first member is suppressed. A smaller surface friction coefficient is preferred. Moreover, in order to suppress that a 2nd member isolate | separates from a 1st member, the one where the friction coefficient of the contact surface with a 1st member in a 2nd member is large is preferable. Therefore, the first coefficient outside the second member can be obtained by making the friction coefficient of the outer peripheral surface of the first member outside the second member smaller than the friction coefficient of the contact surface of the second member with the first member. Even if an object contacts the outer peripheral surface of the member (the outer peripheral surface of the guard), the propeller can be quickly returned to the original rotational speed.

Transport equipment such as helicopters and boats propelled by propellers gains propulsive power by rotating the propeller, but when the guard is attached to the propeller and the propeller is rotated at high speed, the guard is easily deformed. Therefore, the propeller according to the present invention can be suitably used for transportation equipment such as a helicopter and a boat propelled by the propeller.

According to this invention, deformation of the guard can be suppressed when the propeller rotates.

It is a side view which shows the helicopter provided with the propeller which concerns on one Embodiment of this invention. It is a perspective view which shows the propeller which concerns on one Embodiment of this invention. It is a top view which shows the propeller which concerns on one Embodiment of this invention. FIG. 4 is an end view taken along line AA in FIG. 3. FIG. 4 is a sectional view taken along line BB in FIG. 3. It is a perspective view which shows the propeller which concerns on other embodiment of this invention. It is a perspective view which shows the propeller which concerns on other embodiment of this invention. It is a perspective view which shows the propeller which concerns on other embodiment of this invention. It is sectional drawing which shows the other example of a guard. It is sectional drawing which shows the other example of a guard. It is sectional drawing which shows the further another example of a guard. It is sectional drawing which shows the other example of a guard. It is sectional drawing which shows the other example of a guard. It is a perspective view showing a boat provided with a propeller concerning one embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a case where a propeller 16 according to an embodiment of the present invention is used as a main rotor of an unmanned helicopter (hereinafter referred to as a helicopter) 10 which is an example of transportation equipment.

Referring to FIG. 1, helicopter 10 includes a main body 12, a mast 14, a propeller 16, a tail body 18, and a tail rotor 20.

The main body 12 includes a frame 22, a body cover 24, leg portions 26 and 28, a pair of skids 30 (only the left skid 30 is shown in FIG. 1), and an under cover 32.

The tail body 18 and the body cover 24 are supported by the frame 22.

The leg portions 26 and 28 are each formed in an inverted U shape when viewed from the front, and are supported by the frame 22.

The pair of skids 30 are attached to the legs 26 and 28 so as to be lined up on the left and right. Specifically, the skid 30 on one side (left side) is attached to the one side (left side) portion of the legs 26 and 28, and the skid 30 (not shown) on the other side (right side) is attached to the leg portion 26. , 28 on the other side (right side).

The under cover 32 is attached to the tail body 18 and the main frame 22.

The mast 14 is provided so as to protrude upward from the body cover 24 and to be rotatable. A propeller 16 is fixed to the upper end of the mast 14. Thereby, the mast 14 and the propeller 16 rotate integrally. The tail body 18 has a substantially cylindrical shape and extends rearward from the main body 12. The front end portion of the tail body 18 is supported by the rear end portion of the frame 22 in the body cover 24. The tail rotor 20 is rotatably provided at the rear end portion of the tail body 18.

The helicopter 10 further includes a drive source 34, a transmission 36, a drive shaft 38, and a control device 40. The drive source 34 and the transmission 36 are accommodated in the body cover 24.

The drive source 34 is supported on the front end of the frame 22 below the propeller 16. For example, an engine or a motor is used as the drive source 34.

The transmission 36 is supported by the frame 22 behind the drive source 34. The transmission 36 is connected to the drive source 34. A lower end portion of the mast 14 is connected to the transmission 36. The propeller 16 rotates based on the driving force transmitted from the driving source 34 via the transmission 36 and the mast 14. The helicopter 10 can be propelled by rotating the propeller 16.

A drive shaft 38 is provided so as to extend rearward from the transmission 36. The drive shaft 38 extends in the main body 12 and the tail body 18 in the front-rear direction. The tail rotor 20 is connected to the rear end portion of the drive shaft 38. The tail rotor 20 rotates based on the driving force transmitted from the driving source 34 via the transmission 36 and the drive shaft 38.

The control device 40 is provided on the frame 22 and controls various devices mounted on the helicopter 10.

Hereinafter, the propeller 16 will be described in detail.

2 and 3, the propeller 16 includes a disk-shaped hub 42, a plurality (in this embodiment, five) blades 44, and a guard 46.

The hub 42 is connected to the mast 14 that is a rotating shaft.

The plurality of blades 44 are arranged at equal intervals in the circumferential direction of the hub 42, and each blade 44 is formed in a substantially strip shape, extends from the outer surface of the hub 42 in the radial direction (radial) of the hub 42, and Connected. Each blade 44 is formed to have a positive pitch angle and rotates in a clockwise direction indicated by an arrow X.

Referring also to FIG. 4, each blade 44 includes a pressure surface 48 and a suction surface 50. As the blade 44 rotates, the positive pressure surface 48 receives positive pressure and the negative pressure surface 50 receives negative pressure. The positive pressure surface 48 is one main surface (the lower surface in FIGS. 2 and 3) of the blade 44, and the negative pressure surface 50 is the other main surface (the upper surface in FIGS. 2 and 3). The negative pressure surface 50 is curved in a convex shape from the front edge portion 52 on the front side in the rotation direction toward the rear edge portion 54 on the rear side in the rotation direction. Further, the suction surface 50 is curved so that a convex vertex is located closer to the front edge 52 than the center between the front edge 52 and the rear edge 54.

In each of the blades 44, the inner end 56 connected to the outer surface of the hub 42 and the outer end 58 on the guard 46 side both have a positive pitch angle (from the rear edge 54 to the front edge 52. The pitch angle on the inner end 56 side is larger than the pitch angle on the outer end 58 side. That is, each blade 44 has a twisted shape such that the inclination of the hub 42 with respect to the plane perpendicular to the axial direction is smaller at the outer end 58 than at the inner end 56 of the blade 44.

Referring to FIGS. 2, 3 and 5, guard 46 includes a first member 60 made of the same material as blade 44 and a second member 62 made of a material different from blade 44, and includes a plurality of blades. 44 is connected to the outer end 58 of each. The hub 42, the first member 60, and the second member 62 are formed concentrically. The outer peripheral surface of the second member 62 is in contact with the inner peripheral surface of the first member 60. The second member 62 has a higher flexural modulus than the first member 60, and therefore is less likely to bend and deform than the first member 60. Further, the friction coefficient of the outer peripheral surface of the first member 60 (that is, the outer peripheral surface of the guard 46) is smaller than the friction coefficient of the contact surface of the second member 62 with the first member 60. For example, the blade 44 and the first member 60 can be made of resin, and the second member 62 can be made of CFRP (carbon fiber reinforced plastic).

The first member 60 extends outwardly from the outer end 58 of each of the plurality of blades 44 toward the outer end 58 of the adjacent blade 44 in an outwardly convex arc shape (circumferential direction of the hub 42). It is formed in a ring shape and a longitudinal section strip shape. The outer end portions 58 of the plurality of blades 44 are provided on the inner peripheral surface of the first member 60, and the first member 60 is formed integrally with each of the plurality of blades 44 (all blades 44). At this time, the outer end portion 58 of each blade 44 is provided without protruding from the first member 60 in the axial direction of the first member 60.

The second member 62 is formed in a ring shape and a longitudinal cross-sectional strip shape, and is formed so as to contact the inner peripheral surface of the first member 60. In the axial direction of the second member 62, the height H <b> 2 of the second member 62 is smaller than the height H <b> 1 of the first member 60, and the distance C <b> 1 between one end of the second member 62 and one end of the first member 60. The distance C2 between the other end of the second member 62 and the other end of the first member 60 is substantially equal. Therefore, the second member 62 is formed without protruding from the first member 60 in the axial direction of the second member 62. Further, the second member 62 is not formed at a location connected to the outer end 58 of each blade 44 on the inner peripheral surface of the first member 60. The outer end 58 of each blade 44 is formed so as not to protrude from the second member 62 in the axial direction of the second member 62. That is, each blade 44 passes through the second member 62.

According to the helicopter 10 propelled by such a propeller 16, the first member 60 is formed integrally with each of the plurality of blades 44 (all blades 44). Not separated from. Therefore, even if a centrifugal force is applied to the guard 46 when the propeller 16 rotates, it is possible to suppress the displacement of the connection portion of the first member 60 with each blade 44 outward. Further, since the guard 46 includes the second member 62 having a higher bending elastic modulus than the first member 60, the rigidity of the guard 46 can be increased as compared with the case where the guard 46 includes only the first member 60. Moreover, the second member 62 is formed so as to contact the inner peripheral surface of the first member 60. Accordingly, when the propeller 16 rotates, the second member 62 receives a force so that the second member 62 is pressed outward, that is, against the first member 60 by the generated centrifugal force, so that the second member 62 is separated from the first member 60. And the high rigidity of the guard 46 can be reliably maintained. As a result, when the propeller 16 rotates, the guard 46 (the first member 60) can be reliably prevented from being deformed so as to expand outward due to the centrifugal force. As described above, the first member 60 is formed integrally with each of the plurality of blades 44, and the second member 62 having a high bending elastic modulus is formed on the inner peripheral surface of the first member 60. When the is rotated, the deformation of the guard 46 can be reliably suppressed, the increase of the air resistance received by the propeller 16 and the vibration of the propeller 16 can be suppressed.

Since the first member 60 formed integrally with each of the plurality of blades 44 connects the outer end portions 58 of all the blades 44, the outer end portions 58 of the blades 44 swing and the pitch angle increases or decreases. Can be suppressed. Thereby, it is possible to prevent the control of the propulsive force obtained by the rotation of the propeller 16 from becoming complicated.

Since the second member 62 is formed in a ring shape, the rigidity of the guard 46 can be further increased with respect to the blade 44. Thereby, when the propeller 16 rotates, it can further suppress that the guard 46 deform | transforms with a centrifugal force. In the guard 46, the first member 60 and the second member 62 are both formed in a ring shape (entire circumference), and the rigidity of the guard 46 can be greatly increased, so this effect becomes remarkable.

By making the friction coefficient of the outer peripheral surface of the first member 60 (the outer peripheral surface of the guard 46) outside the second member 62 smaller than the friction coefficient of the contact surface of the second member 62 with the first member 60, Even if an object comes into contact with the outer peripheral surface of the first member 60 (the outer peripheral surface of the guard 46) outside the second member 62, a decrease in the rotational speed of the propeller 16 can be suppressed, so the propeller 16 can be quickly brought back to the original rotational speed. Can be returned.

A helicopter propelled by a propeller obtains a propulsive force by rotating the propeller, but if the guard is attached to the propeller and the propeller is rotated at a high speed, the guard is easily deformed. Therefore, the propeller 16 according to the present invention can be suitably used for the helicopter 10 driven by the propeller.

Next, a propeller 16a according to another embodiment of the present invention will be described with reference to FIG.

The propeller 16a is different from the propeller 16 shown in FIG. 2 in that a guard 46a is used instead of the guard 46. The guard 46a is a second member having a divided structure instead of the second member 62 formed in a ring shape. It differs from the guard 46 in that 62a is used.

The second member 62a of the guard 46a is made of a material different from that of the blade 44, and includes a plurality of (in this embodiment, five) second member pieces 64a extending in the circumferential direction of the hub 42 between all adjacent blades 44. Including. Each of the second member pieces 64 a is formed in a thin strip shape, is curved in an arc shape except for the vicinity of the connection portion between the outer end portion 58 of each blade 44 and the first member 60, and the inner periphery of the first member 60. It is formed in contact with the surface. As described above, the plurality of second member pieces 64 a are formed discontinuously in the circumferential direction on the inner peripheral surface of the first member 60. That is, the second member 62 a is divided at a plurality of (in this embodiment, five) locations G in the vicinity of the connection locations between the outer end portions 58 of all the blades 44 and the first members 60. In other words, the second member 62 a corresponds to the second member 62 formed in a ring shape divided in the vicinity of the connection portion between the outer end portion 58 of each blade 44 and the first member 60. Since the other configuration of the propeller 16a is the same as that of the propeller 16, its overlapping description is omitted.

According to such a propeller 16a, the total length of the second member 62a can be made smaller than that of the second member 62. Therefore, the propeller 16a can be lighter than the propeller 16, and the rotational moment of inertia can be reduced. Thereby, the centrifugal force generated when the propeller 16a rotates is reduced, and deformation of the guard 46a can be suppressed. Moreover, the usage-amount of the 2nd member 62a can be reduced, and cost can be reduced.

The propeller 16a can be lighter and the cost can be further reduced by attaching the second member 62a only to the minimum part necessary for suppressing deformation of the guard 46a when the propeller 16a rotates.

The second member 62a may be formed integrally with the first member 60, or may be attached to the first member 60 by bonding or the like after the first member 60 is molded.

Next, a propeller 16b according to another embodiment of the present invention will be described with reference to FIG.

The propeller 16b is different from the propeller 16 shown in FIG. 2 in that a guard 46b having a divided structure is used instead of the guard 46 formed in a ring shape.

The guard 46b includes a first member 60b having a divided structure made of the same material as the blade 44 and a second member 62b having a divided structure made of a material different from the blade 44, and each outer end portion of the plurality of blades 44. 58.

A plurality of first members 60b extend outwardly from respective outer end portions 58 of the plurality of blades 44 toward the outer end portion 58 of the adjacent blade 44 (circular direction of the hub 42) (this embodiment). Then, five) first member pieces 66b are included. Each first member piece 66 b is formed in a thin strip shape, is curved in an arc shape, and is integrally formed with the corresponding blade 44. In this embodiment, the blades 44 corresponding to the first member pieces 66b are integrally formed so that the outer end portion 58 of the blade 44 is positioned on one end side of the first member piece 66b and substantially L-shaped. It is formed. There is a gap between the first member piece 66b and the adjacent first member piece 66b, the adjacent first member pieces 66b are not connected to each other, and the plurality of first member pieces 66b are formed discontinuously. Is done. That is, the first member 60b is divided at a plurality of (in this embodiment, five) locations G1 in the vicinity of the connection location between the outer end portions 58 of all the blades 44 and the first members 60b. In other words, the first member 60 b corresponds to the first member 60 formed in a ring shape divided in the vicinity of the connection portion between the outer end portion 58 of each blade 44 and the first member 60.

The second member 62b includes a plurality (five in this embodiment) of second member pieces 64b extending in the circumferential direction of the hub 42 between all adjacent blades 44. Each of the second member pieces 64b is formed in a thin strip shape, and is curved in an arc shape except for the vicinity of the connection portion between the corresponding first member piece 66b and the outer end portion 58 of the blade 44, and the corresponding first member. It is formed in contact with the inner peripheral surface of the piece 66b. As described above, the plurality of second member pieces 64b are discontinuously formed in the circumferential direction on the inner peripheral surface of the first member 60b. That is, the second member 62b is divided at a plurality of (in this embodiment, five) locations G2 in the vicinity of the connection location between the outer end portions 58 of all the blades 44 and the first member 60b. In other words, the second member 62 b corresponds to the ring-shaped second member 62 divided in the vicinity of the connection portion between the outer end portion 58 of each blade 44 and the first member 60.

Since the other configuration of the propeller 16b is the same as that of the propeller 16, its overlapping description is omitted.

According to such a propeller 16b, the first member 60b and the second member 62b can be made smaller in total length than the first member 60 and the second member 62, respectively. Accordingly, the propeller 16b can be made lighter than the propeller 16, and the rotational moment of inertia can be reduced. Thereby, the centrifugal force generated when the propeller 16b rotates is further reduced, and the deformation of the guard 46b can be suppressed. Moreover, the usage-amount of the 1st member 60b and the 2nd member 62b can be reduced, and cost can further be reduced.

It becomes possible to mold each unit including the blade 44, the first member piece 66b, and the second member piece 64b. A necessary number of units (five in this embodiment) are prepared and attached to the hub 42 so as to be openable and closable with respect to the axial direction of the hub 42 so that a folding structure can be obtained.

Next, a propeller 16c according to still another embodiment of the present invention will be described with reference to FIG.

The propeller 16c is different from the propeller 16 shown in FIG. 2 in that a guard 46c having a split structure is used instead of the guard 46 formed in a ring shape.

The guard 46 c includes a first member 60 c having a divided structure made of the same material as the blade 44 and a second member 62 c having a divided structure made of a material different from the blade 44, and each of the plurality of blades 44. Connected to the outer end 58.

A plurality of first members 60c extend outwardly from the outer end portions 58 of the plurality of blades 44 toward the outer end portions 58 of the adjacent blades 44 (in the circumferential direction of the hub 42) (this embodiment). Then, five) first member pieces 66c are included. Each first member piece 66 c is formed in a thin strip shape, curved in an arc shape, and formed integrally with the corresponding blade 44. In this embodiment, each first member piece 66c and the corresponding blade 44 are integrally formed so that the outer end portion 58 of the blade 44 is positioned at the center of the first member piece 66c and has a substantially T-shape. It is formed. There is a gap between the first member piece 66c and the adjacent first member piece 66c, the adjacent first member pieces 66c are not connected to each other, and the plurality of first member pieces 66c are formed discontinuously. Is done. That is, the first member 60c is divided at a plurality of (in this embodiment, five) locations G3 between all adjacent blades 44. In other words, the first member 60 c is equivalent to the first member 60 formed in a ring shape divided between all adjacent blades 44.

The second member 62c includes a plurality of (in this embodiment, five) second member pieces 64c extending in the circumferential direction of the hub 42. Each of the second member pieces 64c is formed in a thin strip shape, and is curved in an arc shape and corresponding to the first member piece except for a connection portion between the corresponding first member piece 66c and the outer end portion 58 of the blade 44. It is formed so as to contact the inner peripheral surface of 66c. In this way, the plurality of second member pieces 64c are formed discontinuously in the circumferential direction on the inner peripheral surface of the first member 60c. That is, the second member 62c is divided at a plurality of (in this embodiment, five) locations G3 between all adjacent blades 44. In other words, the second member 62 c corresponds to a member in which the second member 62 formed in a ring shape is divided between all adjacent blades 44.

Since the other configuration of the propeller 16c is the same as that of the propeller 16, its overlapping description is omitted.

According to such a propeller 16c, the total length of the first member 60c and the second member 62c can be made smaller than that of the first member 60 and the second member 62, respectively. Accordingly, the propeller 16c can be made lighter than the propeller 16, and the rotational moment of inertia can be reduced. Thereby, the centrifugal force generated when the propeller 16c rotates is further reduced, and deformation of the guard 46c can be suppressed. Moreover, the usage-amount of the 1st member 60c and the 2nd member 62c can be reduced, and cost can be reduced further.

It becomes possible to form each unit including the blade 44, the first member piece 66c, and the second member piece 64c. A necessary number of units (five in this embodiment) are prepared and attached to the hub 42 so as to be openable and closable with respect to the axial direction of the hub 42 so that a folding structure can be obtained.

In the above-described embodiment, the guard has a two-layer structure including the first member and the second member, but is not limited thereto.

In each of the embodiments described above, a guard 46d having a three-layer structure as shown in FIG. 9 may be used. FIG. 9 shows a cross section of the guard 46 d between the adjacent blades 44. In the guard 46d, the second member 62d is formed so as to be in contact with the inner peripheral surface of the first member 60d1, and further, the first member 60d2 is formed so as to be in contact with the inner peripheral surface of the second member 62d. That is, the first member 60d1 is formed to cover the outer peripheral surface of the second member 62d, and the first member 60d2 is formed to cover the inner peripheral surface of the second member 62d. Although not shown in FIG. 9, the first member 60d1 and the first member 60d2 are at least partially connected to each other. For example, in the vicinity of the connection portion between the first member 60d2 and the blade 44, the first member 60d1 and the first member 60d2 are connected to each other so as to penetrate the second member 62d.

According to the guard 46d, the first member 60d1 and 60d2 connected to each other sandwich the inner peripheral surface and the outer peripheral surface of the second member 62d. It is possible to prevent the two members 62d from being separated from the first members 60d1 and 60d2. Thereby, when the propeller rotates, the deformation of the guard 46d can be more reliably suppressed. In the guard 46d, in order to maintain a good rotational balance, it is preferable that the connection points between the first member 60d1 and the first member 60d2 are formed symmetrically in the circumferential direction, and there are two or more connection points. It is preferable.

Further, in each of the above-described embodiments, a three-layer guard 46e as shown in FIG. 10 may be used. FIG. 10 shows a cross section of the guard 46 e between the adjacent blades 44. In the guard 46e, the first member 60e is formed in contact with the outer peripheral surface, the inner peripheral surface, and the upper end portion of the second member 62e. That is, in the guard 46e, the first member 60e is formed so as to cover the outer peripheral surface, the inner peripheral surface, and the upper end portion of the second member 62e.

According to the guard 46e, it is possible to prevent the second member 62e from being separated from the first member 60e even when the guard 46e receives a force from the vertical direction.

Furthermore, in each of the above-described embodiments, a guard 46f having a three-layer structure as shown in FIG. 11 may be used. FIG. 11 shows a cross section of the guard 46 f between the adjacent blades 44. The guard 46f is formed such that the periphery of the second member 62f is in contact with the first member 60f. That is, in the guard 46f, the second member 62f is formed inside the first member 60f. For example, by forming a part of the first member 60f in advance, the second member 62f can be formed inside the first member 60f without being exposed to the outside.

According to the guard 46f, since the second member 62f is not exposed to the outside, the second member 62f can be prevented from being separated from the first member 60f no matter which direction the guard 46f receives force.

Further, in each of the above-described embodiments, a guard 46g as shown in FIG. 12 may be used. FIG. 12 shows a cross section of the guard 46 g between the adjacent blades 44. In the guard 46g, the fibrous second member 62g is formed so as to extend in the circumferential direction inside the first member 60g.

According to the guard 46g, since the second member 62g is not exposed to the outside, it is possible to prevent the second member 62g from being separated from the first member 60g no matter which direction the guard 46g receives a force. In this case, carbon fiber may be used as the second member 62g.

In each embodiment described above, a guard 46h as shown in FIG. 13 may be used. FIG. 13 shows a cross section of the guard 46 h between the adjacent blades 44. In the guard 46h, the first member 60h has protrusions 61a and 61b formed at the upper end and the lower end thereof, and the protrusions 61a and 61b cover the upper end surface and the lower end surface of the second member 62h. Formed. Further, in the guard 46h, the first member 60h is formed so as to contact the outer peripheral surface, the upper end portion, and the lower end portion of the second member 62h.

According to the guard 46h, since the upper end surface and the lower end surface of the second member 62h are sandwiched between the protrusions 61a and 61b of the first member 60h, the second member can be applied even if a force is applied from the outside of the guard 46h. It is possible to prevent 62h from being separated from the first member 60h. Thereby, when the propeller rotates, the deformation of the guard 46h can be suppressed more reliably.

Further, in each of the above-described embodiments, the blade and the guard may be formed by insert molding in which the second member formed in advance is loaded in a mold and the blade and the first member are integrally formed.

In the above-described embodiment, the case where the propeller according to the present invention is used as a main rotor of an unmanned helicopter has been described, but the present invention is not limited to this. The propeller according to the present invention may be used as a tail rotor of an unmanned helicopter, or may be used as a main rotor or a tail rotor of a manned helicopter. Furthermore, the propeller according to the present invention may be used as a rotor of a multicopter.

FIG. 14 shows the boat 10 a propelled by the propeller 16. A boat propelled by a propeller obtains a propulsive force by rotating the propeller. However, when the guard is attached to the propeller and the propeller is rotated at a high speed, the guard is easily deformed. Therefore, the propeller 16 according to the present invention can be suitably used for the boat 10a propelled by the propeller. The propellers 16a to 16c shown in FIGS. 6 to 8 and the guards 46d to 46h shown in FIGS. 9 to 13 may be applied to the boat 10a shown in FIG.

The propeller according to the present invention can be applied to any transport equipment propelled by a propeller, in addition to helicopters and boats.

In the above-described embodiment, a case has been described in which the blade is formed to have a positive pitch angle, and the propeller rotates in the clockwise direction indicated by the arrow X, but the present invention is not limited to this. The present invention can also be applied to the case where the blade is formed to have a negative pitch angle and the propeller rotates counterclockwise.

In the embodiment shown in FIG. 7, the adjacent first member pieces 66b are not connected to each other, and the plurality of first member pieces 66b are formed discontinuously. In the embodiment shown in FIG. 8, the adjacent first member pieces 66c. They are not connected to each other, and the plurality of first member pieces 66c are formed discontinuously, but are not limited thereto. In the present invention, one or a plurality of first member pieces may be formed so that there is at least one discontinuous portion (the first member is divided at at least one portion).

In the embodiment shown in FIG. 7, at least when the propeller 16b is rotated, the adjacent first member pieces 66b may be connected to form the first member 60b in a ring shape. The same applies to the embodiment shown in FIG.

Although the preferred embodiments of the present invention have been described above, it is apparent that various modifications can be made without departing from the scope and spirit of the present invention. The scope of the invention is limited only by the appended claims.

DESCRIPTION OF SYMBOLS 10 Unmanned helicopter 10a Boat 16, 16a, 16b, 16c Propeller 20 Tail rotor 42 Hub 44 Blade 46, 46a, 46b, 46c, 46d, 46e, 46f, 46g, 46h Guard 58 Outer end part 60, 60b, 60c of blade 60d1, 60d2, 60e, 60f, 60g, 60h First member 62, 62a, 62b, 62c, 62d, 62e, 62f, 62g, 62h Second member 64a, 64b, 64c Second member piece 66b, 66c First member piece

Claims (11)

A hub,
A plurality of blades extending radially from the hub;
A guard connected to each outer end of the plurality of blades,
The guard includes a first member made of the same material as the blade, and a second member made of a material different from the blade,
The first member is formed integrally with each of the plurality of blades, and extends outwardly from the outer end portion of each of the plurality of blades toward the outer end portion of the adjacent blade. ,
The second member is a propeller formed on an inner peripheral surface of the first member and having a higher flexural modulus than the first member. The propeller according to claim 1, wherein the first member is formed in a ring shape. The propeller according to claim 2, wherein the second member is formed in a ring shape. The propeller according to claim 1, wherein the first member includes a plurality of first member pieces formed integrally with each of the plurality of blades, and the plurality of first member pieces are formed discontinuously. 5. The propeller according to claim 1, wherein the second member includes a plurality of second member pieces formed discontinuously in the circumferential direction on the inner peripheral surface of the first member. The propeller according to any one of claims 1 to 5, wherein the first member is also formed on an inner peripheral surface of the second member. The propeller according to claim 6, wherein the second member is formed inside the first member. The friction coefficient of the outer peripheral surface of the first member outside the second member is smaller than the friction coefficient of the contact surface of the second member with the first member. propeller. Transportation equipment driven by the propeller according to any one of claims 1 to 8. A helicopter propelled by the propeller according to any one of claims 1 to 8. A boat propelled by the propeller according to any one of claims 1 to 8.

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