JP6118104B2 - Propeller blade fixing mechanism - Google Patents

Description

  The present invention relates to a propeller blade fixing mechanism for fixing a base portion of a blade inserted into a propeller boss.

  Conventionally, propellers used in ships and the like ("propellers" in this specification and claims) include propellers used in liquids such as ships and land. It is often manufactured by integrally casting a plurality of blades (hereinafter also simply referred to as “boss”). However, for example, in the manufacture of a large propeller, it may be difficult to manufacture the boss and the plurality of blades integrally because of equipment limitations. Further, in the case of a propeller in which a boss and a wing are integrally manufactured, even if one wing reaches the replacement time, the entire propeller must be replaced, which requires a lot of cost and time.

  For this reason, some propellers have bosses and wings manufactured separately and assembled to form an integrated propeller. In such a propeller having a structure in which a plurality of blades are attached around the boss, there is one in which a spiral base is provided at the base of the blade and a spiral blade insertion groove for inserting the spiral base of the blade is provided at the boss. . And the propeller which united these by inserting the spiral base part of a wing | blade in the wing | blade insertion groove | channel of a boss | hub is known.

  For example, as a prior art of this type, with respect to a wing structure of a marine propeller, a fitting portion formed at the base of the wing is inserted into a plurality of spiral grooves formed around a boss (hub) and attached. (For example, refer to Patent Document 1).

JP 2009-286284 A

  By the way, when the boss and the wing are separately manufactured as described above, the spiral base of the wing inserted into the spiral groove must be integrated with the boss. As an integration method, for example, it is conceivable to manufacture and fit the spiral base portion of the blade with the blade insertion groove of the boss with a predetermined fit tolerance. However, for example, in the case of a marine propeller, if the pressing force of the fitting portion is small, a large force acts on the fitting portion when receiving fluid force from a liquid such as water during operation, start / stop, or reverse rotation. For this reason, deformation occurs in the fitting portion, and rattling occurs. And the generation | occurrence | production of the noise by wear, fatigue damage, contact sound, friction sound, etc. resulting from the repeated change of a contact condition arises. In order to prevent this, it is effective to increase the contact pressure of the fitting part.For example, if the fitting part is manufactured with a plus tolerance, the insertion work at the time of assembly becomes a very complicated work, and at the time of disassembly. The disengagement work becomes even more difficult. Further, in a large propeller such as a cargo carrier, the fluid force received by one wing increases, so that it is necessary to increase the plus tolerance, which makes assembly and disassembly more difficult.

  On the other hand, in this type of propeller used in a liquid, in order to further improve the propeller performance, it may be preferable to form the boss in a truncated cone shape having a diameter difference at both axial ends. . However, when the boss is formed in the shape of a truncated cone or the like, the arc of the spiral groove changes depending on the diameter change, so an accurate spiral blade insertion groove for inserting the spiral base of the blade as described above is formed. It becomes extremely difficult to do.

  Therefore, the cross-sectional shape of the blade insertion groove formed in the boss is formed with a large cross-sectional shape having a predetermined gap with respect to the cross-sectional shape of the spiral base portion of the blade, and the spiral base portion of the blade is inserted into the blade insertion groove of the boss. After that, it is conceivable to fix the spiral base of the wing to the wing insertion groove of the boss.

  However, the method of forming the blade insertion groove formed in the boss into a size having a predetermined gap with respect to the cross-sectional shape of the spiral base of the blade and integrating them without backlash is disclosed in Patent Document 1 described above. Is not described at all.

  Thus, in the prior art, there is no description about a mechanism in which the boss and the wing are configured separately and can be stably assembled / disassembled.

  Accordingly, an object of the present invention is to provide a propeller blade fixing mechanism capable of stably fixing a blade to a boss after inserting the blade base into a spiral blade insertion groove formed in the axial direction of the surface of the propeller boss. To do.

  In order to achieve the above object, the present invention provides a propeller blade fixing mechanism for a propeller that is integrated by inserting and fixing a base portion of a blade into a plurality of blade insertion grooves formed around a boss, The boss is provided with a spiral blade insertion groove formed at a predetermined depth from the boss surface side in the axial direction, and the blade is inserted into the blade insertion groove and engaged with the spiral blade insertion groove. The spiral base portion is pressed between the blade insertion groove of the boss and the spiral base portion of the blade with the spiral base portion inserted into the blade insertion groove radially outward from the center of the boss. A pressing member that presses the blade into the blade insertion groove is provided. The “spiral blade insertion groove formed at a predetermined depth” in the specification and claims refers to a groove having a depth into which the spiral base portion of the blade can be inserted.

  With this configuration, the spiral base is pressed into the blade insertion groove by inserting the spiral base of the blade into the blade insertion groove of the boss and pressing the spiral base radially outward with a pressing member from the center of the boss. Thus, the wing and the boss can be fixed integrally.

  The blade insertion groove is formed in a cross-sectional shape having a boss-side slope extending from the boss surface side toward the boss center direction in the axial direction of the outer surface, and the spiral base portion is inserted into the blade insertion groove and the boss You may form in the cross-sectional shape which has the blade side slope which spreads from a blade base end part so that it may engage with a side slope.

  If comprised in this way, the spiral base part of a wing | blade will be pressed by the blade | wing insertion groove of the cross-sectional shape extended toward the boss | hub center direction from the surface side of a boss | hub, and a wing | blade and a boss | hub can be fixed integrally.

  The boss-side slope of the blade insertion groove is formed symmetrically with respect to the center in the width direction of the blade insertion groove, and the blade-side slope of the spiral base is symmetrical with respect to the center in the width direction of the spiral base. It may be formed.

  With this configuration, by pressing the spiral base of the wing radially outward toward the boss insertion groove of the boss, both blade-side slopes with a substantially uniform force with respect to the center in the width direction of the spiral base. It can be pressed and fixed to the boss side slope of the blade insertion groove.

  The pressing member may be a bolt member disposed along the blade insertion groove so as to press the spiral base from the bottom surface of the blade insertion groove of the boss.

  If comprised in this way, the spiral base part can be adjusted and pressed to the force suitable for every place toward the wing | blade insertion groove of a boss | hub by the some bolt member arrange | positioned along a wing | blade insertion groove.

  Moreover, the said bolt member may be staggered arrangement | positioning shifted | deviated predetermined amount in the width direction of the said blade | wing insertion groove | channel.

  If comprised in this way, even if the spiral base part of a wing | blade is wide in the width direction, a spiral base part can be pressed with suitable force in the position shifted | deviated to the width direction of the wing | blade blade insertion groove | channel.

  The pressing member is a wedge member inserted between the blade insertion groove of the boss and the helical base, and the helical base has a concave groove that guides the wedge member in the longitudinal direction. It may be. The “wedge member” in the document of this specification and the claims is inserted between the blade insertion groove of the boss and the spiral base of the wing, so that the spiral base of the wing becomes the blade insertion groove of the boss. Any wedge-shaped member that can be pressed to fix the wing to the boss may be used.

  With this configuration, the wedge member is fitted between the boss blade insertion groove of the boss along the concave groove portion of the spiral base portion, thereby pressing and fixing the spiral base portion of the wing to the blade insertion groove of the boss. be able to.

  The spiral base may have concave groove portions at both ends of the spiral base so that the wedge member can be fitted from both ends of the spiral base.

  If comprised in this way, by inserting a wedge member in the concave groove part of a helical base, the helical base part of a wing | blade can be pressed to the wing | blade insertion groove of a boss | hub from both ends, and the stable fixation can be performed.

  According to the present invention, since the spiral base portion of the wing inserted into the spiral blade insertion groove provided in the axial direction of the boss can be stably fixed to the blade insertion groove of the boss, the boss and the blade are separated from each other. Assembling / disassembling property, propulsion performance, and low noise property of the propeller composed of the body can be improved.

It is a perspective view which shows the propeller which applies the propeller blade fixing mechanism which concerns on this invention. (a) is sectional drawing which concerns on 1st Embodiment of the blade insertion groove formed in the boss | hub shown in FIG. 1, (b) is sectional drawing which shows the modification of (a). It is a perspective view which shows the wing | blade of the propeller shown in FIG. It is a perspective view which expands and shows the spiral base part of the wing | blade shown in FIG. It is a perspective view which shows arrangement | positioning of the bolt member which is a press member provided in the blade | wing insertion groove | channel shown in FIG. It is a perspective view which shows arrangement | positioning of the bolt member of an example different from arrangement | positioning of the bolt member shown in FIG. It is a perspective view which shows the helical base part of the wing | blade which the bolt member shown in FIG. 4 contact | abutted. It is a perspective view which shows the spiral base part of the wing | blade which the bolt member shown in FIG. 5 contact | abutted. It is sectional drawing which concerns on 2nd Embodiment of the blade insertion groove formed in the boss | hub shown in FIG. It is the perspective view which expanded the spiral base part of the wing | blade inserted in the wing | blade insertion groove | channel shown in FIG. It is the perspective view which looked at the spiral base part of the wing | blade shown in FIG. 10 from the lower end side.

  Hereinafter, an embodiment (first embodiment) of the present invention will be described with reference to the drawings. In the following embodiment, there will be described an example in which there is a difference in diameter at both ends in the axial direction of the boss 10 and the helical base 21 of the blade 20 is inserted and fixed in the blade insertion groove 11 formed on the surface of the boss 10. . Moreover, the bolt member 30 and the wedge member 40 are demonstrated to an example as an example of a press member.

  As shown in FIG. 1, the boss 10 of the propeller 1 has an outer shape in a side view in which the front end side in the axial direction (right side in the drawing) has a large diameter and the rear end side (left side in the drawing) has a small diameter. It is formed in a part of a truncated cone shape formed by A plurality of spiral blade insertion grooves 11 are formed around the surface of the boss 10. These blade insertion grooves 11 are provided at equal intervals on the entire circumference of the boss 10. This figure shows a state where the spiral base 21 of the blade 20 is inserted partway into one of the plurality of blade insertion grooves 11. Details of the wing 20 will be described later. Further, the drive shaft 50 is inserted into the central portion of the boss 10.

  As shown in FIG. 2 (a), the cross-sectional shape (only one location is shown) of the blade insertion groove 11 formed in the boss 10 is a boss-side inclined surface 12 extending from the surface side of the boss 10 toward the boss center. It has become. The blade insertion groove 11 is formed at a predetermined depth from the surface of the boss 10. In the blade insertion groove 11 of this embodiment, the boss-side inclined surface 12 is formed symmetrically with respect to the center in the width direction. In the portion (bottom portion) closest to the boss center of the blade insertion groove 11, a bottom surface 13 is formed from a corner portion formed by a predetermined curved surface connected to the boss-side inclined surface 12. Further, a chamfered portion 14 is provided on the boss surface portion of the blade insertion groove 11 so as not to come into contact with a spiral base portion 21 of the blade 20 described later. The blade insertion groove 11 is formed in such a size that a gap S is formed between the blade base groove 21 and the spiral base portion 21 in a state where the spiral base portion 21 of the blade 20 is inserted.

  Moreover, the boss | hub surface of the opening part of the blade | wing insertion groove | channel 11 is provided with the recessed part 15 into which the collar part 24 provided in the helical base 21 of the wing | blade 20 mentioned later enters. When the flange 24 of the wing 20 enters the recess 15, the surface of the boss 10 becomes smooth.

  Furthermore, in this embodiment, as will be described later, a screw hole 16 for screwing a bolt member 30 which is a pressing member that presses and fixes the blade 20 to the boss 10 is provided from the bottom surface 13 toward the boss center. . The screw hole 16 is provided so as to penetrate from the hollow hole 17 provided at the center of the boss to the bottom surface 13. By screwing the bolt member 30 into the screw hole 16 from the hollow hole 17 side, the blade-side inclined surface 23 of the spiral base 21 can be pressed toward the boss-side inclined surface 12 of the boss 10. Thus, the wing 20 and the boss 10 can be integrally fixed by screwing the bolt member 30.

  In this embodiment, the blade-side inclined surface 23 of the spiral base 21 is pressed against the boss-side inclined surface 12 of the blade insertion groove 11 to integrally fix them, but as shown in FIG. The blade insertion groove 11 of the boss 10 may be a groove having a flat surface 60 parallel to the bottom surface 13, and the propeller blade fixing mechanism 7 may have a shape having a flat surface 61 that can be inserted into the blade insertion groove 11. . In this case, by pressing the spiral base portion 21 radially outward from the center of the boss 10 with the bolt member 30, the blade-side plane 61 of the spiral base portion 21 is pressed against the outer plane 60 of the blade insertion groove 11. And the boss 10 can be fixed integrally. The blade insertion groove 11 and the spiral base 21 may have other configurations as long as the spiral base 21 can be inserted into the blade insertion groove 11 and fixed integrally.

  On the other hand, as shown in FIGS. 3 and 4, the wing 20 has a wing portion 22 formed with a predetermined curved surface and the spiral base portion 21 provided at the base portion of the wing portion 22. The spiral base 21 is formed in a cross-sectional shape having a blade-side slope 23 extending from the blade base end so as to be inserted into the blade insertion groove 11 and engage with the boss-side slope 12. In this embodiment, the boss-side inclined surface 12 and the wing-side inclined surface 23 are formed in a substantially trapezoidal cross-sectional shape with an expanded bottom surface. In addition, the boss-side slope 12 and the wing-side slope 23 of this embodiment are formed in an isosceles trapezoidal cross section that is symmetric with respect to the center of the blade insertion groove 11 and the spiral base 21 in the width direction. And the wing | blade side inclined surface 23 is formed at the same angle (alpha) with respect to the perpendicular of a boss center (FIG. 2).

  In this embodiment, a flange 24 is provided between the wing 22 and the spiral base 21 to maintain the smoothness of the spiral base 21 and the surface of the boss 10. The flange 24 projects from the space between the spiral base portion 21 and the wing portion 22 in the width direction along the surface of the boss 10. The surface of the boss 10 is smoothed by the flange 24 entering the recess 15 (FIG. 2).

  Next, an arrangement example of the pressing member according to the first embodiment will be described with reference to FIGS. In these drawings, only the portion of one blade insertion groove 11 is illustrated and described. The pressing member of the first embodiment uses a bolt member 30. The example shown in FIG. 5 is an example in which the bolt member 30 is arranged at the center in the width direction along the blade insertion groove 11. In this example, the bolt member 30 is linearly arranged. Moreover, as shown in FIG. 6, the bolt members 30 may be arranged in a staggered manner in the width direction, or may be arranged in two straight lines. As described above, the bolt member 30 is provided by being screwed into the screw hole 16 of the boss 10.

  Then, if the bolt base 30 is screwed to press the spiral base 21 of the blade 20 in the radial direction of the boss 10, the blade-side inclined surface 23 of the spiral base 21 is changed to the boss-side inclined surface 12 as shown in FIG. Can be pressed toward. As a result, the blade-side inclined surface 23 comes into close contact with the boss-side inclined surface 12, and the spiral base portion 21 of the blade 20 can be fixed to the blade insertion groove 11 of the boss 10 by frictional force.

  As described above, when the bolt member 30 is used as the pressing member, the load is such that the axial force of the bolt member 30 always remains even if the propeller receives the force by the fluid force and a force that pushes back the pressing by the bolt member 30 is generated. By pressing at the setting, the bolt member 30 can be prevented from being loosened by twisting back (rotation).

  Furthermore, by adopting a general method such as a lock nut or an anaerobic adhesive as a detent for the bolt member 30, for example, more stable pressing and holding can be performed.

  5 and 6 show only the relationship between the blade insertion groove 11 of the boss 10 and the bolt member 30 in contact with the blade insertion groove 11. The number of bolt members 30 and the tightening force of each bolt member 30 may be set in accordance with the fluid force and the like. Further, by inserting a spacer (not shown) between the bolt member 30 and the spiral base portion 21 of the blade 20, the surface pressure can be adjusted while preventing the spiral base portion 21 from being damaged. .

  7 and 8 show a state in which the bolt member 30 in the first embodiment is in contact with the spiral base 21 of the blade 20. In the case of the arrangement of the bolt member 30 shown in FIG. 5, a plurality of bolt members come into contact with each other along the center in the width direction of the spiral base 21 as shown in FIG. 7. In the case of the arrangement of the bolt members 30 shown in FIG. 6, as shown in FIG. 8, a plurality of bolt members 30 come into contact with each other at a predetermined interval in the width direction of the spiral base portion 21.

  In these drawings, only the relationship between the spiral base portion 21 of the wing 20 and the bolt member 30 in contact with the spiral base portion 21 is shown. The number of bolt members 30 and the tightening force of each bolt member 30 may be set in accordance with the fluid force and the like.

  Further, as a method of tightening the bolt member 30, in this embodiment, the center of the boss 10 is the hollow hole 17 and is tightened radially outward from the hollow hole 17. A drive shaft 50 (FIG. 2) can be inserted. Therefore, the operation of fixing the boss 10 to the propeller drive shaft 50 (FIG. 2) can be easily performed. Moreover, if a stud bolt (head screw) is used for the bolt member 30 and a part of the bolt member 30 is protruded into the hollow portion of the boss 10, the rotation of the boss 10 is performed by pressing the protruding portion with the drive shaft 50. It can also be stopped.

  Thus, the propeller blade fixing mechanism 5 of the first embodiment presses and fixes the blade-side inclined surface 23 formed on the spiral base portion 21 of the blade 20 toward the boss-side inclined surface 12 of the boss 10 by the bolt member 30. It is a mechanism.

  Next, a second embodiment of the blade insertion groove formed in the boss 10 will be described with reference to FIG. The same components as those in the first embodiment shown in FIG. As a cross-sectional shape (only one location is shown) of the blade insertion groove 18 according to the second embodiment, a boss-side inclined surface 12 that spreads from the surface side of the boss 10 toward the boss center direction, and a perpendicular line from the predetermined depth to the boss center. And a parallel surface 19 extending substantially parallel to the boss center direction. Further, the blade insertion groove 18 of this embodiment has a boss center portion (bottom portion) at the most (same as above) boss center portion (bottom portion) of the parallel surface 19 extending from the lower end of the boss side inclined surface 12 to the boss center direction substantially parallel to the boss center perpendicular line. A bottom surface 13 is formed from a corner portion formed by a predetermined curved surface connected to the side inclined surface 12. The blade insertion groove 18 is formed at a predetermined depth from the surface of the boss 10. Also, in the blade insertion groove 18 of this embodiment, the boss-side inclined surface 12 and the parallel surface 19 are formed symmetrically with respect to the center in the width direction.

  Further, the spiral base portion 21 inserted into the blade insertion groove 18 has a blade-side inclined surface 23 formed at the same angle as the boss-side inclined surface 12 and a width dimension of the parallel surface 19 as shown by a two-dot chain line. And a parallel surface 26 having a small width dimension. The blade insertion groove 18 of this embodiment is also formed in such a size that a gap S is formed between the blade insertion groove 18 and the spiral base portion 25 in a state where the spiral base portion 25 of the blade 20 is inserted.

  Further, the boss surface portion of the blade insertion groove 18 is formed in the chamfered portion 14 so as not to contact the spiral base portion 25 of the blade 20. Furthermore, the boss | hub surface in the opening part of the blade | wing insertion groove | channel 18 is provided with the recessed part 15 into which the collar part 24 provided in the helical base 25 of the wing | blade 20 mentioned later enters. By inserting the flange 24 of the wing 20 into the recess 15, the surface of the boss 10 is made smooth.

  And in this embodiment, the concave groove parts 27 and 28 are provided in the helical base part 25 of the said wing | blade 20 so that the wedge member 40 which is a pressing member which fixes the wing | blade 20 to the boss | hub 10 can be inserted so that it may mention later. ing. By inserting the wedge member 40 into the concave grooves 27 and 28, the blade-side slope 23 of the spiral base 25 can be pressed toward the boss-side slope 12 of the boss 10.

  Next, based on FIG. 10, 11, the example of arrangement | positioning of the press member which concerns on 2nd Embodiment is demonstrated. As described above, the pressing member of the second embodiment uses the wedge member 40 that fits between the blade insertion groove 18 and the spiral base portion 25 that is inserted into the blade insertion groove 18.

  As shown in the drawing, the concave groove portions 27 and 28 provided at both end portions of the spiral base portion 25 are each provided with a length of about 2/5 from both longitudinal ends of the spiral base portion 25. The concave groove portions 27 and 28 are formed so that both end portions of the spiral base portion 21 are deepest and gradually become shallower toward the center in the longitudinal direction of the spiral base portion 21. The angle shallower in the longitudinal direction is the “wedge angle”. The wedge angle is set to, for example, 1 ° to 6 ° so that the wedge member 40 enters from both end portions of the spiral base portion 25 to the central portion in the longitudinal direction.

  Then, as described above, by inserting the wedge member 40 between the blade insertion groove 18 and the concave grooves 27 and 28 of the spiral base 25 (FIG. 9), the blade-side slope 23 of the spiral base 25 is inserted into the blade. The groove 18 can be pressed toward the boss-side inclined surface 12. As a result, the blade-side inclined surface 23 comes into close contact with the boss-side inclined surface 12, and the spiral base portion 25 of the blade 20 can be fixed to the blade insertion groove 11 of the boss 10 by frictional force.

  As described above, the propeller blade fixing mechanism 6 according to the second embodiment inserts the wedge member 40 into the concave grooves 27 and 28 provided in the spiral base portion 25 of the blade 20, and the wedge member 40 allows the The wing-side slope 23 is pressed and fixed toward the boss-side slope 12 of the boss 10.

  As described above, according to the propeller blade fixing mechanisms 5 and 6 (FIGS. 2 and 9), the spiral of the blade 20 is inserted into the blade insertion grooves 11 and 18 having a cross-sectional shape extending from the surface side of the boss 10 toward the center of the boss. After the bases 21 and 25 are inserted, the wing-side slopes of the spiral bases 21 and 25 are pressed by pressing the spiral bases 21 and 25 outwardly with a pressing member (bolt member 30 and wedge member 40) from the center of the boss. 23 is pressed against the boss-side inclined surface 12 of the blade insertion grooves 11 and 18, and the blade 20 can be fixed integrally with the boss 10 by frictional force.

  Moreover, in the said 1st Embodiment, since the boss | hub 10 is pressed and fixed toward the wing | blade insertion groove | channel 11 with the volt | bolt member 30 with the helical base 21 of the wing | blade 20, positioning of the wing | blade 20 can be performed easily.

  Furthermore, in the second embodiment, it is necessary to provide the concave groove portions 27 and 28 formed at a predetermined depth at both ends of the spiral base portion 25 of the wing 20 and the wedge member 40 must be inserted. The spiral base 25 can be fixed to the blade insertion groove 18 by force. In addition, the wedge member 40 has an advantage that it can be constructed even if the inner diameter (shaft insertion portion) of the boss 10 is narrow.

  Therefore, according to the propeller blade fixing mechanisms 5 and 6 as described above, when the boss 10 and the blade 20 are manufactured separately and integrated to form the propeller 1, the boss 10 and the blade 20 are small. It can be manufactured by equipment, and the propeller 1 can be easily assembled and disassembled. In addition, since the boss 10 and the blade 20 can be manufactured separately and the propeller 1 can be easily integrated, the assembly / disassembly property and propulsion performance of the propeller 1 including the boss 10 and the blade 20 as separate members can be manufactured. And it becomes possible to improve low noise property.

  In addition, the said embodiment is an example, The shape (diameter, the number of blades, blade shape, blade insertion angle, weight, fitting part shape), material (weight, friction coefficient), operating conditions (rotation speed, Since there are various combinations of speed and frequency of starting and stopping, the combination may be selected according to the structure, method, shape, and conditions for achieving the purpose.

  Further, the blade insertion grooves 11 and 18 of the boss 10 and the spiral base portions 21 and 25 of the blade 20 may have configurations other than the above embodiment, and are not limited to the above embodiment.

  Furthermore, the above-described embodiment shows an example, and various modifications can be made without departing from the gist of the present invention, and the present invention is not limited to the above-described embodiment.

  The propeller blade fixing mechanism according to the present invention can be used in a propeller having a structure in which the base of the propeller blade is inserted and fixed to the propeller boss.

DESCRIPTION OF SYMBOLS 1 Propeller 5,6,7 Propeller blade fixing mechanism 10 Boss 11 Blade insertion groove 12 Boss side slope 13 Bottom surface 14 Chamfer 15 Recess 16 Screw hole 17 Hollow hole 18 Blade insertion groove 19 Parallel surface 20 Blade 21 Spiral base 22 Blade 23 Wing-side slope 24 Hook 25 Spiral base 26 Parallel surface 27, 28 Concave groove 30 Bolt member 40 Wedge member 50 Drive shaft 60, 61 Plane
S clearance
α angle

Claims (4)

A propeller blade fixing mechanism of a propeller that is integrated by inserting and fixing the base portions of the blades into a plurality of blade insertion grooves formed around the boss,
The boss is provided with the spiral blade insertion groove formed in a predetermined depth from the boss surface side in the axial direction,
The blade includes a spiral base portion having a cross-sectional shape inserted into the blade insertion groove and engaged with the spiral blade insertion groove,
Between the blade insertion groove of the boss and the spiral base portion of the blade, the spiral base portion inserted into the blade insertion groove is pressed radially outward from the center of the boss so that the spiral base portion becomes the blade. Provide a pressing member to press the insertion groove,
The pressing member is a propeller blade fixing mechanism, characterized in that from the bottom of the blade insertion groove of the boss is a bolt member which is disposed along the wings insertion groove so as to press said helical base portion. The blade insertion groove is formed in the axial direction of the outer surface in a cross-sectional shape having a boss-side inclined surface extending from the boss surface side toward the boss center direction,
2. The propeller blade fixing according to claim 1, wherein the spiral base portion is formed in a cross-sectional shape having a blade side slope extending from a blade base end portion so as to be inserted into the blade insertion groove and engage with the boss side slope. mechanism. The boss side inclined surface of the blade insertion grooves are formed symmetrically with respect to the width direction center of the wings insertion groove, the blade-side inclined surface of the spiral base is formed symmetrically with respect to the width direction center of the spiral base The propeller blade fixing mechanism according to claim 2. The propeller blade fixing mechanism according to any one of claims 1 to 3, wherein the bolt member has a staggered arrangement that is shifted by a predetermined amount in the width direction of the blade insertion groove.

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