JP2021146822A - Thrust generator - Google Patents

Abstract

To provide a thrust generator that can realize miniaturization.SOLUTION: A thrust generator comprises: a thrust generating motor that rotates a plurality of rotors; a plurality of pitch angle changing motors that changes pitch angles of the rotors; and rotation transmission parts that are connected to the pitch angle changing motors; a first motion conversion part; and a second motion conversion part. The first motion conversion part converts rotation of the rotation transmission part into a linear motion of a linear motion shaft. The second motion conversion part converts the linear motion of the linear motion shaft into a rotary motion to change the pitch angle of the rotor. The first motion conversion part comprises: a feed screw shaft that is rotated by a rotation transmission part; a support member that supports the feed screw shaft; a nut that is meshed with the feed screw shaft to be fixed to the linear motion shaft; and a linear motion guide part that guides the nut to move linearly when the feed screw shaft rotates. The linear motion guide part has a pair of parallel guide flat surfaces supported by the support member. At least one of the nut and the linear motion shaft has a pair of parallel guided flat surfaces respectively facing the guide flat surfaces.SELECTED DRAWING: Figure 10

Description

The present invention relates to a thrust generator.

For example, Patent Document 1 discloses a technique for electrically changing the pitch of a propeller (rotor blade) without using a hydraulic pressure. In this technique, the rotary spindle is formed in a hollow shape, the operating rods are concentrically arranged in the rotary spindle so as to be movable only in the axial direction, and the arm fixed to the lower end of the operating rod is a link and a lever. It is connected to each support shaft of the blade via a mechanism. Then, by reciprocating the operating rod in the axial direction, the mounting angle of each blade is changed via the link and lever mechanism.

Japanese Unexamined Patent Publication No. 5-87037

In order to reduce the weight of a flyable projectile such as a multicopter, an airplane, a rotorcraft, and a flyable automobile, it is desirable that the thrust generator that gives thrust to the projectile is small and lightweight.

Therefore, an object of the present invention is to provide a thrust generator capable of realizing miniaturization and weight reduction.

The thrust generator according to an aspect of the present invention includes a thrust generating motor that generates thrust by rotating a propeller having a plurality of rotary blades, a pitch angle changing motor that changes the pitch angle of the rotary blades, and the pitch angle. It has a rotation transmission unit connected to a change motor, a linear motion shaft, and a motion conversion mechanism connected to the rotation transmission unit and the linear motion shaft to convert the rotation of the rotation transmission unit into a linear motion of the linear motion axis. It includes a first motion conversion unit and a second motion conversion unit that converts the linear motion of the linear motion axis into rotary motion to change the pitch angle of the rotary blade. The motion conversion mechanism of the first motion conversion unit is meshed with a feed screw shaft rotated by the rotation transmission unit, a support member that rotatably supports the feed screw shaft, and the feed screw shaft. It is provided with a nut fixed to the linear motion shaft and a linear motion guide portion that regulates the rotation of the nut and guides the nut to linearly move when the feed screw shaft rotates. The linear motion guide portion has a pair of parallel guide flat surfaces supported by the support member. At least one outer peripheral surface of the nut and the linear motion shaft has a pair of parallel guided flat surfaces facing the guide flat surface of the linear motion guide portion.
In this embodiment, the nut meshed with the feed screw shaft rotated by the rotation transmission portion and at least one outer peripheral surface of the linear motion shaft fixed to the nut have a pair of parallel guided flat surfaces. On the other hand, the linear motion guide portion has a pair of parallel guide flat surfaces. At least one of the nut and the linear motion shaft is sandwiched between the guide flat surfaces of the linear motion guide portion, and when the feed screw shaft rotates, it linearly moves along the feed screw shaft in a state where the rotation is restricted. The linear motion guide portion is supported by a support member that rotatably supports the feed screw shaft, and it is not necessary to increase the size of the first motion conversion unit and thus the thrust generator. Therefore, it is possible to reduce the size and weight of the thrust generator.

Preferably, the motion conversion mechanism of the first motion conversion unit further has a pair of resin sliding members arranged between the guide flat surface and the guided flat surface, and the sliding. The member is arranged in the guide flat surface or the recess formed in the guided flat surface.
In this case, a resin sliding member is arranged between the guide flat surface of the linear motion guide portion and the guided flat surface of at least one of the nut and the linear motion shaft. The resin sliding member can reduce the friction generated during the linear motion of the linear motion shaft. The sliding member is arranged between the guide flat surface of the linear motion guide portion and the guided flat surface of at least one of the nut and the linear motion shaft, and it is necessary to increase the size of the first motion conversion unit and thus the thrust generator. There is no.

Preferably, the linear motion shaft has a flange, the nut has a flange, and each of the flange of the linear motion shaft and the flange of the nut has a shape obtained by cutting a cylinder in two parallel planes. It has two arcuate protruding parts and two flat parts. The protruding portion of the flange of the linear motion shaft and the projecting portion of the flange of the nut are fixed by a fixing screw, and the flat surface portion of the flange of the linear motion shaft is a portion of the guided flat surface. The flat portion of the flange of the nut faces the guide flat surface without contacting the guide flat surface.
In this case, by providing a flat portion on the linear motion shaft and the flange of the nut, the size of the linear motion guide portion can be reduced, and the thrust generator can be further reduced in size and weight.

Alternatively, the linear motion shaft has a flange, the nut has a flange, and each of the flange of the linear motion shaft and the flange of the nut has a shape obtained by cutting a cylinder in two parallel planes. It may have one arcuate projecting portion and two planar portions. The protruding portion of the flange of the linear motion shaft and the projecting portion of the flange of the nut are fixed by a fixing screw, and the flat portion of the flange of the linear motion shaft does not come into contact with the guide flat surface. The flat portion of the flange of the nut facing the guide flat surface may be a portion of the guided flat surface.
Also in this case, by providing a flat portion on the linear motion shaft and the flange of the nut, the size of the linear motion guide portion can be reduced, and the thrust generator can be further reduced in size and weight.

FIG. 1 is a perspective view showing a thrust generator according to an embodiment to which a rotor blade is attached. FIG. 2 is a side view showing a thrust generator according to an embodiment to which a rotor blade is attached. FIG. 3 is a side view showing a thrust generator according to an embodiment to which a rotor blade is attached. FIG. 4 is an exploded perspective view of the thrust generator according to the embodiment. FIG. 5 is an exploded perspective view of the thrust generator according to the embodiment as viewed from another direction. FIG. 6 is a plan view of the thrust generator according to the embodiment. FIG. 7 is a cross-sectional view taken along the line VII-VII of FIG. FIG. 8 is a plan view of a rotation transmission unit and a rotation linear motion conversion unit of the thrust generator according to the embodiment. FIG. 9 is a cross-sectional view taken along the line IX-IX of FIG. FIG. 10 is a cross-sectional view taken along the line XX of FIG. FIG. 11 is a perspective view of a rotation transmission unit and a rotation linear motion conversion unit of the thrust generator according to the embodiment. FIG. 12 is a perspective view of the linear motion transmission shaft and the ball screw nut of the rotary linear motion conversion unit. FIG. 13 is a perspective view showing a linear moving body of the linear motion rotation conversion unit of the thrust generator according to the embodiment, and the position of the linear motion body corresponds to the pitch angle of the rotary blade of FIG. FIG. 14 is a perspective view showing a linear moving body, and the position of the linear moving body corresponds to the pitch angle of the rotary blade of FIG. FIG. 15 is an exploded perspective view of the hub of the thrust generator according to the embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments do not limit the invention, and not all combinations of features described in the embodiments are essential to the configuration of the invention. The configuration of the embodiment may be appropriately modified or changed depending on the specifications of the apparatus to which the present invention is applied and various conditions (use conditions, use environment, etc.). The technical scope of the present invention is defined by the claims and is not limited by the following individual embodiments. Drawing scales are not always accurate and some features may be exaggerated or omitted.

In the following description, the case where the number of rotor blades driven by the thrust generator is three is taken as an example, but the number of rotor blades driven by the thrust generator is not necessarily limited to three, and N (N is Any positive integer) may be used.

FIG. 1 is a perspective view showing a thrust generator according to an embodiment to which a rotor blade is attached. 2 and 3 are side views showing a thrust generator according to an embodiment to which a rotary blade is attached, and the pitch angles of the rotary blades are different.

As shown in FIGS. 1 to 3, the thrust generator 1 rotates a rotor or a propeller R having a plurality of rotor blades H1 to H3. The propeller R is arranged directly below the thrust generator 1. The propeller R has grips P1 to P3, and the grips P1 to P3 support the rotor blades H1 to H3 so as to extend horizontally radially from the thrust generator 1.

The thrust generator 1 is mounted on the airframe of the flying object via the upper mounting portion 1A. The flying object to which the thrust generator 1 is mounted is, for example, a flyable airframe or a vehicle body such as a multicopter flying by a motor, an airplane, a rotorcraft, and an automobile having a flight function. Although not shown, a plurality of thrust generators 1 to which a propeller R is attached may be mounted on the airframe of the flying object.

The thrust generator 1 includes a thrust generator 2, a pitch angle changing motor 5A, and a motion transmission unit 6. The thrust generation motor 2 rotates the propeller R to generate a thrust applied to the projectile. The pitch angle changing motor 5A changes the pitch angles θ1 to θ3 of the rotary blades H1 to H3. By changing the pitch angles θ1 to θ3 of the rotor blades H1 to H3, the thrust applied to the flying object can be changed. The motion transmission unit 6 transmits the rotational motion of the pitch angle changing motor 5A to the rotary blades H1 to H3.

4 and 5 are exploded perspective views of the thrust generator 1. FIG. 6 is a plan view of the thrust generator 1, and FIG. 7 is a cross-sectional view taken along the line VII-VII of FIG. As shown in FIGS. 4 to 7, the thrust generating motor 2 includes a stator 2A, a rotor 2B, and a frame 2C. The rotor 2B includes a rotor shaft 4 and hollow portions 3A and 3C on the inner side in the radial direction.

The stator 2A is composed of an electromagnetic steel plate and windings, and is located outside the rotor 2B. The stator 2A is fixed to the annulus portion of the frame 2C arranged outside the stator 2A. The mounting portion 1A of the thrust generator 1 can be provided in the center of the frame 2C. The mounting portion 1A includes an opening 1B, and the motion transmission unit 6 is inserted into the opening 1B. The mounting portion 1A is connected to the annulus portion via a plurality of spokes 1C extending radially. An inner cylindrical portion 1D is formed on the frame 2C, and the inner cylindrical portion 1D rotatably supports the rotor shaft 4 via the bearing U1. The frame 2C including the annulus portion, the mounting portion 1A, the spokes 1C and the inner cylindrical portion 1D can be formed by cutting an alloy such as duralumin.

The rotor 2B of the thrust generation motor 2 is connected to the rotor shaft 4 via a plurality of spokes 2D extending radially. The rotor 2B rotates together with the rotor shaft 4 about the central axis S0 (see FIGS. 2 and 3). The rotor 2B and the rotor shaft 4 are rotatably supported by the frame 2C via the bearing U1.

The hollow portion 3A is provided between the rotor 2B and the rotor shaft 4. A pitch angle changing motor 5A is arranged in the hollow portion 3A. The pitch angle changing motor 5A is fixed to the frame 2C.

The hollow portion 3C is a central hole of the rotor shaft 4 and extends along the axial direction of the rotor shaft 4. A part of the motion transmission unit 6 is inserted into the hollow portion 3C.

An extension 9 which is a hollow cylinder is fixed to the lower end surface of the rotor shaft 4 of the thrust generating motor 2, and the extension 9 is fixed to the hub 10 of the rotor R. Therefore, the hub 10 is supported by the frame 2C in a state of being rotatable around the central axis S0. Grips P1 to P3 that support rotary blades H1 to H3 are attached to the hub 10. In this way, the thrust generation motor 2 rotates the propeller R having the rotor blades H1 to H3. That is, when the thrust generating motor 2 operates and the rotor 2B rotates, the rotor shaft 4 rotates, and the rotor blades H1 to H3 rotate around the central axis S0. A thrust applied to the flying object is generated as the rotor blades H1 to H3 rotate.

The extension 9 is a spacer for maintaining a distance between the thrust generating motor 2 and the rotary blades H1 to H3 in the axial direction of the thrust generator 1, and the rotary blades H1 to H3 collide with the thrust generating motor 2. To prevent. The material of the extension 9 is, for example, duralumin.

The pitch angle changing motor 5A for changing the pitch angles of the rotary blades H1 to H3 is fixed to the frame 2C of the thrust generating motor 2, and is arranged inside the thrust generating motor 2, specifically, in the hollow portion 3A. There is. The rotation shaft of the pitch angle changing motor 5A extends in the vertical direction like the rotor shaft 4 of the thrust generating motor 2. That is, the rotation shaft of the pitch angle changing motor 5A and the rotor shaft 4 are parallel and different shafts.

Next, the motion transmission unit 6 for transmitting the rotational motion of the pitch angle changing motor 5A to the rotary blades H1 to H3 will be described. The motion transmission unit 6 includes a rotation transmission unit 6A, a rotation linear motion conversion unit 7, and a linear motion rotation conversion unit 8.

The rotation transmission unit 6A transmits the rotation of the rotation shaft of the pitch angle changing motor 5A to the ball screw shaft 7F of the rotation linear motion conversion unit 7. The ball screw shaft 7F extends in the vertical direction along the central axis S0 of the thrust generator 1 and is arranged in the hollow portion 3C which is the central hole of the rotor shaft 4. Therefore, the rotation transmission unit 6A transmits the rotational movement of the pitch angle changing motor 5A to the axis on the central axis S0. The rotation transmission unit has a rotating member that rotates with the rotation of the rotating shaft of the pitch angle changing motor. The rotation transmission unit 6A is fixed to the frame 2C.

The rotation linear motion conversion unit (first motion conversion unit) 7 transmits the rotation of the rotation transmission shaft (linear motion shaft) 7D extending in the vertical direction along the central axis S0 of the thrust generator 1 and the rotation transmission unit 6A. It has a motion conversion mechanism that converts the linear motion of the linear motion transmission shaft 7D into a linear motion. The motion conversion mechanism of the rotation linear motion conversion unit 7 is connected to the rotation transmission unit 6A and the linear motion transmission shaft 7D. This motion conversion mechanism has a ball screw shaft 7F coaxially arranged above the linear motion transmission shaft 7D. The upper part of the rotation linear motion conversion unit 7 is housed in the thrust generation motor 2, but the lower part of the rotation linear motion conversion unit 7 projects downward from the thrust generation motor 2. The rotation / linear motion conversion unit 7 is fixed to the frame 2C.

The linear motion rotation conversion unit (second motion conversion unit) 8 converts the linear motion of the linear motion transmission shaft 7D of the rotary linear motion conversion unit 7 into rotary motion, and changes the pitch angles of the rotary blades H1 to H3. .. The linear rotation conversion unit 8 is located below the thrust generating motor 2.

The pitch angle changing motor 5A, the rotation transmission unit 6A, and the rotation linear motion conversion unit 7 are fixed to the frame 2C of the thrust generating motor 2. Therefore, even if the rotor shaft 4 rotates, the pitch angle changing motor 5A, the rotation transmission unit 6A, and the rotation linear motion conversion unit 7 do not rotate around the rotor shaft 4. On the other hand, the linear rotation conversion unit 8 is supported by the rotor shaft 4. Therefore, the linear rotation conversion unit 8 rotates around the rotor shaft 4 as the rotor shaft 4 rotates.

As shown in FIGS. 8 to 11, a gear G1 is fixed to the upper end of the ball screw shaft 7F of the rotation linear motion conversion unit 7. The rotation transmission unit 6A has gears G2 and G3, the gear G3 is fixed to the rotation shaft of the pitch angle changing motor 5A, and the gear G2 is meshed with the gear G3 and the gear G1. Therefore, in the rotation transmission unit 6A, the gears G3 and G2 can transmit the rotational movement of the pitch angle changing motor 5A to the ball screw shaft 7F fixed to the gear G1. The material of the gears G1 to G3 is, for example, carbon steel.

The rotation linear motion conversion unit 7 is supported by the support member F1. As shown in FIGS. 4, 6 and 7, the support member F1 is arranged in the opening 1B of the mounting portion 1A of the frame 2C of the thrust generating motor 2. The support member F1 is supported by the frame 2C by, for example, four bolts J1 (see FIGS. 8 to 11). The bolts J1 can be arranged at the four corners of the support member F1, for example. Further, a support member F3 is arranged in the hollow portion 3A of the thrust generation motor 2. The support member F3 is also supported by the frame 2C by bolts J3 (see FIGS. 8, 9, and 11). A pitch angle changing motor 5A is fixed to the support member F3 in the hollow portion 3A by bolts J4 (see FIGS. 8 to 11).

As shown in FIGS. 8 to 11, the support member F2 is supported by the bolt J2 on the support member F1, and the support member F1 and the support member F2 rotatably support the gear G2 of the rotation transmission unit 6A. The material of the support members F1 to F3 is, for example, an aluminum alloy.

In this embodiment, in the rotation transmission unit 6A, the gear transmits the rotational motion of the pitch angle changing motor 5A to the ball screw shaft 7F of the rotation linear motion conversion unit 7. The rotation transmission unit may have a belt pulley mechanism or a chain sprocket. Specifically, the pulley may be fixed to the ball screw shaft 7F, and the belt may be wound around the pulley and the pulley fixed to the rotation shaft of the pitch angle changing motor 5A. A timing belt may be used as the belt. A sprocket may be fixed to the ball screw shaft 7F, and a chain may be wound around the sprocket and the sprocket fixed to the rotation shaft of the pitch angle changing motor 5A.

In this embodiment, the rotary linear motion conversion unit 7 uses a ball screw as a motion conversion mechanism to convert the rotary motion of the ball screw shaft 7F into a linear motion of the linear motion transmission shaft 7D. The motion conversion mechanism includes a support member F1, a ball screw shaft 7F, a ball screw nut 7G, and a pair of linear motion guide portions 7E. However, a sliding screw or other lead screw may be used instead of the ball screw. In this embodiment, by using the ball screw as the motion conversion mechanism of the rotary linear motion conversion unit 7, the drive torque required for changing the pitch angle can be reduced as compared with the case where the sliding screw is used, and the pitch angle can be changed. The power saving of the motor 5A can be achieved.

The ball screw shaft 7F extends in the vertical direction. As shown in FIG. 7, the ball screw shaft 7F is rotatably supported by a bearing U2 fixed to the tubular portion F1a of the support member F1, and the longitudinal axis of the ball screw shaft 7F is rotatably supported as the gear G1 rotates. Rotate around.

As shown in FIGS. 9 and 10, the ball screw nut 7G is meshed with the ball screw shaft 7F. The ball screw nut 7G also extends in the vertical direction, and is fixed to a linear motion transmission shaft 7D arranged below the ball screw nut 7G and extending in the vertical direction.

As shown in FIGS. 9 to 11, the ball screw nut 7G and the linear motion transmission shaft 7D are sandwiched between the linear motion guide portion 7E which is a pair of parallel long plate walls protruding from the cylindrical portion F1a of the support member F1. It is regulated by a pair of linear motion guides 7E so as not to rotate. As the ball screw shaft 7F rotates, the ball screw nut 7G and the linear motion transmission shaft 7D move linearly in the vertical direction along the axial direction of the ball screw shaft 7F. The linear motion guide portion 7E allows linear motion of the ball screw nut 7G and the linear motion transmission shaft 7D. In other words, the linear motion guide portion 7E guides the ball screw nut 7G and the linear motion transmission shaft 7D to move linearly. Therefore, when the ball screw shaft 7F rotates together with the gear G1, the ball screw nut 7G and the linear motion transmission shaft 7D move linearly in the vertical direction, guided by the linear motion guide portion 7E. The linear motion guide portion 7E can be provided integrally with the support member F1.

As shown in FIGS. 9 and 10, a cavity extending in the vertical direction is formed in the upper part of the linear motion transmission shaft 7D, and a ball screw nut 7G meshed with the ball screw shaft 7F is inserted into this cavity. Has been done.

As shown in FIGS. 10 and 11, two guided flat surfaces 7C are formed on the outer peripheral surface of the upper portion of the linear motion transmission shaft 7D. The two guided flat surfaces 7C are parallel to each other. On the other hand, the two linear motion guide portions 7E each have a guide flat surface 7E1, and these guide flat surfaces 7E1 are parallel to each other. The two guided flat surfaces 7C face each other of the guided flat surfaces 7E1 of the two linear motion guide portions 7E. However, the guided flat surface 7C does not come into contact with the guided flat surface 7E1, and a minute clearance is provided between the guided flat surface 7C and the guided flat surface 7E1.

As shown in FIGS. 10 and 12, recesses are formed in each of the guided flat surfaces 7C, and a sliding member 7H made of a low friction material, for example, a fluororesin is fitted in the recesses. A part of the sliding member 7H protrudes from the recess and slidably contacts the guide flat surface 7E1 of the linear motion guide portion 7E. Therefore, when the ball screw nut 7G and the linear motion transmission shaft 7D move linearly in the vertical direction, the sliding member 7H reduces the friction with the linear motion guide portion 7E. The sliding member 7H may be fixed to the recess with an adhesive or the like. In order to further reduce friction, the clearance between the guided flat surface 7C and the guided flat surface 7E1 may be coated with a lubricant such as grease.

As shown in FIGS. 9 to 12, a flange 7A is formed at the upper end of the ball screw nut 7G, and a flange 7B is also formed at the upper end of the linear motion transmission shaft 7D. The flanges 7A and 7B have a shape obtained by cutting a cylinder with two parallel planes. The flange 7A has two arcuate projecting portions 7A1 and two flat surface portions 7A2, and the flange 7B has two arcuate projecting portions. It has a portion 7B1 and two planar portions 7B2.

The arcuate protruding portions 7A1 and 7B1 of the flanges 7A and 7B are exposed from between the pair of linear motion guide portions 7E. The protruding portions 7A1 and 7B1 of the flanges 7A and 7B are fixed by bolts J5, and therefore the linear motion transmission shaft 7D is fixed to the ball screw nut 7G.

On the other hand, as shown in FIG. 10, the flat portions 7A2 and 7B2 of the flanges 7A and 7B face the guide flat surfaces 7E1 of the two linear motion guide portions 7E, respectively. The flat surface portion 7A2 of the flange 7A does not come into contact with the guide flat surface 7E1 of the linear motion guide portion 7E. The flat surface portion 7B2 of the flange 7B is a portion of the guided flat surface 7C, and the sliding member 7H is fitted in the recess formed therein. By providing the flat portions 7A2 and 7B2 on the flanges 7A and 7B in this way, the outer diameter of the pair of linear motion guide portions 7E can be reduced, and the rotation linearity can be suppressed while suppressing the increase in the diameter of the rotor shaft 4. The dynamic conversion unit 7 can be housed in the rotor shaft 4. Therefore, it is possible to further reduce the size and weight of the thrust generator 1.

As shown in FIG. 7, most of the rotary linear motion conversion unit 7 including the upper portion of the linear motion transmission shaft 7D is arranged inside the thrust generating motor 2, while the lower portion of the linear motion transmission shaft 7D is a hollow cylinder. It penetrates the internal space of a certain extension 9 and further reaches the inside of the hub 10 of the propeller R.

The lower portion of the linear motion transmission shaft 7D is connected to a linear motion rotation conversion unit 8 that converts the linear motion of the rotary linear motion conversion unit 7 into a rotary motion in order to change the pitch angles of the rotary blades H1 to H3. In this embodiment, the linear motion rotation conversion unit 8 uses a rack pinion as a motion conversion mechanism to convert the linear motion of the linear motion transmission shaft 7D of the rotary linear motion conversion unit 7 into a rotary motion.

As shown in FIGS. 4 and 5, the linear motion conversion unit 8 includes a linear motion element 11, racks A1 to A3, a case 21, support shafts M1 to M3, bearings E1 to E3, shaft adapters D1 to D3, and pinions B1 to. It is equipped with B3.

The linear moving body 11 has the shape of a regular triangular prism, and a cavity is formed in the center thereof. As shown in FIG. 7, the lower end of the linear motion transmission shaft 7D is fitted into the inner ring of the bearing U3, and the outer ring of the bearing U3 is fitted into the cavity of the linear motion body 11. Therefore, the linear motion body 11 can rotate around the linear motion transmission shaft 7D, and linearly moves in the vertical direction together with the linear motion transmission shaft 7D. As the bearing U3, for example, a double row angular contact ball bearing can be used.

The racks A1 to A3 are fixed to the three corners of the linear moving body 11, and move linearly together with the linear moving body 11. The racks A1 to A3 are meshed with the pinions B1 to B3, respectively, and the pinions B1 to B3 are simultaneously rotated along with the linear motion of the linear moving body 11 and the racks A1 to A3.

The support shafts M1 to M3 are arranged on the extension lines of the grips P1 to P3 that support the rotary blades H1 to H3 of the propeller R, respectively. That is, the support shafts M1 to M3 support the grips P1 to P3 so as to extend radially in the horizontal direction from the thrust generator 1. The grip P1 and the support shaft M1 can be provided integrally, the grip P2 and the support shaft M2 can be provided integrally, and the grip P3 and the support shaft M3 can be provided integrally. The material of the grips P1 to P3 and the support shafts M1 to M3 is, for example, duralumin. However, in order to increase the durability of the grips P1 to P3 and the support shafts M1 to M3, for example, titanium may be used as the material of the grips P1 to P3 and the support shafts M1 to M3.

The support shafts M1 to M3 are rotatably supported around the axes of the support shafts M1 to M3 by bearings E1 to E3 fixed to the case 21. As E1 to E3, for example, double-row angular contact ball bearings can be used.

The pinions B1 to B3 are fixed to the tips of the support shafts M1 to M3, respectively. Therefore, when the pinions B1 to B3 rotate with the linear motion of the linear motion body 11 and the racks A1 to A3, the support shafts M1 to M3 also rotate together with the grips P1 to P3. The material of the pinions B1 to B3 and the racks A1 to A3 is, for example, chrome molybdenum steel.

The case 21 is a part of the hub 10 of the propeller R. The case 21 accommodates a linear moving body 11, racks A1 to A3, support shafts M1 to M3, bearings E1 to E3, shaft adapters D1 to D3, and pinions B1 to B3. Therefore, the case 21 can be regarded as the case of the linear motion rotation conversion unit 8.

The upper portion of the case 21 is fixed to the lower end of the extension 9 which is a hollow cylinder, and the upper end of the extension 9 is fixed to the rotor shaft 4 of the thrust generating motor 2. Therefore, the case 21 rotates around the axis of the thrust generator 1 together with the rotor 2B and the rotor shaft 4.

The bearings E1 to E3 fixed to the case 21 can support the support shafts M1 to M3 against the centrifugal force applied to the rotary blades H1 to H3 when the thrust generator 1 rotates around the axis.

The shaft adapters D1 to D3 are arranged outside the support shafts M1 to M3 and inside the bearings E1 to E3, respectively, and are supported by the support shafts M1 to M3, respectively. The inner peripheral surfaces of the shaft adapters D1 to D3 are formed so as to fit the outer peripheral surfaces of the support shafts M1 to M3 whose diameters change, and the outer peripheral surfaces of the shaft adapters D1 to D3 are cylindrical bearings E1 to E3. It is formed to fit the inner peripheral surface of the. The shaft adapters D1 to D3 allow the bearings E1 to E3 to support the support shafts M1 to M3 while responding to changes in the diameters of the support shafts M1 to M3. The material of the case 21 and the shaft adapters D1 to D3 is, for example, duralumin.

The linear moving body 11, racks A1 to A3, support shafts M1 to M3, bearings E1 to E3, shaft adapters D1 to D3, and pinions B1 to B3 housed in the case 21 are provided around the axis of the thrust generator 1 together with the case 21. Rotate to. As described above, the linear motion body 11 is fixed to the outer ring of the bearing U3, and can rotate around the axis of the thrust generator 1 independently of the linear motion transmission shaft 7D fixed to the inner ring of the bearing U3. .. As shown in FIG. 7, the inner ring of the bearing U3 can be fixed to the lower end of the linear motion transmission shaft 7D by, for example, a nut 15, and the outer ring of the bearing U3 is, for example, a linear motion body 11 by a C-shaped retaining ring 16. Can be fixed to.

FIG. 13 shows the position of the linear moving body 11 corresponding to the pitch angle of the rotary blade of FIG. 2, and FIG. 14 shows the position of the linear moving body 11 corresponding to the pitch angle of the rotary blade of FIG. As shown in FIGS. 13 and 14, the linear rotation conversion unit 8 includes a base 13, lift guides T1 to T3, and nuts S1 to S3 in order to limit the movement range of the linear motion body 11 in the linear motion direction. The base 13 is an equilateral triangular plate whose contour is the same as the contour of the linear motion body 11, and a penetrating opening 14 through which the lower end of the linear motion transmission shaft 7D can pass is formed in the center of the base 13. The base 13 supports lift guides T1 to T3 parallel to each other, which are rods extending in the vertical direction. The lift guides T1 to T3 can be provided integrally with the base 13.

The linear moving body 11 having the shape of a regular triangular prism has three side surfaces Z1 to Z3. Racks A1 to A3 are fixed to the side surfaces Z1 to Z3, respectively. A cavity 12 is formed in the center of the linear motion body 11, and a bearing U3 (see FIG. 7) is arranged in the cavity 12.

Apertures V1 to V3 are formed at each of the three corners of the linear moving body 11. Lift guides T1 to T3 fixed to the base 13 are inserted into the openings V1 to V3, respectively. Nuts S1 to S3 are attached to the lower ends of the lift guides T1 to T3, respectively.

FIG. 15 is an exploded perspective view of the hub 10. The hub 10 includes a case 21, an outer lid 22, and an inner lid 23. The case 21 includes a housing portion 21A, an opening 21B, hollow portions Q1 to Q3, and openings K1 to K3 (see FIGS. 4 and 5).

The accommodating portion 21A is formed in the center of the case 21, and accommodates the linear moving body 11 to which the racks A1 to A3 are attached together with the base 13. The accommodating portion 21A is, for example, a hollow portion or a recess provided in the case 21. The planar shape of the accommodating portion 21A corresponds to the planar shape of the base 13, and can be made into an almost equilateral triangle. The opening 21B is formed to deploy the linear moving body 11 and the base 13 to which the racks A1 to A3 are attached to the accommodating portion 21A through the opening 21B.

The hollow portions Q1 to Q3 are arranged outside the accommodating portion 21A at an angular interval of 120 degrees and communicate with the accommodating portion 21A. The support shaft M1, the pinion B1, the bearing E1 and the shaft adapter D1 are arranged in the hollow portion Q1, and the support shaft M2, the pinion B2, the bearing E2 and the shaft adapter D2 are arranged in the hollow portion Q2. Is arranged with a support shaft M3, a pinion B3, a bearing E3, and a shaft adapter D3. Pinions B1 to B3, bearings E1 to E3, and shaft adapters D1 to D3 can be arranged in these hollow portions Q1 to Q3 through openings 21B and accommodating portions 21A.

The openings K1 to K3 are formed on the outer surface of the case 21 at an angular interval of 120 degrees, and communicate with the hollow portions Q1 to Q3, respectively. By inserting the support shafts M1 to M3 into the openings K1 to K3, respectively, the support shafts M1 to M3 can be deployed in the accommodating portion 21A.

The inner lid 23 is fixed to the case 21 by a plurality of bolts J7. Further, the outer lid 22 that covers the inner lid 23 is fixed to the inner lid 23. The material of the inner lid 23 is, for example, duralumin, and the material of the outer lid 22 is, for example, a resin.

A plurality of through holes 23A are formed in the inner lid 23. The lower ends of the lift guides T1 to T3 (see FIGS. 13 and 14) are inserted into the through holes 23A of the inner lid 23 and project to the outside of the inner lid 23, respectively. On the outside of the inner lid 23, nuts S1 to S3 are attached to the lower ends of the lift guides T1 to T3. As a result, the base 13 can be arranged in the accommodating portion 21A of the case 21.

Under the above configuration, when the pitch angle changing motor 5A rotates, the gears G3 and G2 transmit the rotational motion of the pitch angle changing motor 5A to the gears G1 in the rotation transmission unit 6A (see FIGS. 8 to 11). Since the gear G1 is fixed to the ball screw shaft 7F of the rotation linear motion conversion unit 7, the rotational motion of the pitch angle changing motor 5A is transmitted to the ball screw shaft 7F. When the ball screw shaft 7F rotates, the ball screw nut 7G and the linear motion transmission shaft 7D are guided by the linear motion guide portion 7E and linearly move in the vertical direction (see FIGS. 9 to 11).

The linear motion of the linear motion transmission shaft 7D is transmitted to the linear motion body 11. Along with the linear motion of the linear motion transmission shaft 7D, the racks A1 to A3 fixed to the linear motion body 11 together with the linear motion body 11 linearly move in the vertical direction. When the racks A1 to A3 move linearly together with the linear moving body 11, the lift guides T1 to T3 guide the linear moving body 11 (see FIGS. 13 and 14). The moving range of the linear moving body 11 is limited by the base 13 and the nuts S1 to S3. Pinions B1 to B3 are meshed with the racks A1 to A3, respectively, and when the racks A1 to A3 move linearly, the pinions B1 to B3 fixed to the support shafts M1 to M3 rotate at the same time (FIGS. 4 and 4). 5). Therefore, with the rotational movement of the pinions B1 to B3, the support shafts M1 to M3 rotate around their respective axes. Grips P1 to P3 that support the rotary blades H1 to H3 are attached to the support shafts M1 to M3, and the rotational movement of the support shafts M1 to M3 is transmitted to the rotary blades H1 to H3. Therefore, the pitch angles of the rotor blades H1 to H3 are changed at the same time. For example, when the linear moving body 11 is in the position of FIG. 13, the pitch angles of the rotary blades H1 to H3 are set as shown in FIG. 2, and when the linear moving body 11 is in the position of FIG. 14, the rotary blades H1 to H1 The pitch angle of H3 is set as shown in FIG.

The thrust generator 1 can change the thrust applied to the flying object by changing the rotation angle of the pitch angle changing motor 5A and thus the pitch angles of the rotary blades H1 to H3. By changing the thrust by changing the pitch angle, the response speed of the thrust change can be increased and the stability of the projectile can be improved as compared with the method of changing the thrust by changing the rotation speed of the thrust generating motor 2. Is possible. Further, since the thrust applied to the flying object can be changed by changing the pitch angles of the rotary blades H1 to H3, it is not necessary to increase the rotary blades H1 to H3, and the rotation speed of the thrust generating motor 2 is excessively increased. There is no need to let it. Since it is not necessary to increase the size of the rotor blades H1 to H3, it is possible to suppress the increase in size and weight of the flying object. Further, since the increase in the rotation speed of the thrust generating motor 2 is suppressed, the noise depending on the rotation speed can be suppressed.

Further, in the thrust generator 1, the pitch angles of the rotary blades H1 to H3 are electrically changed, so that it is not necessary to use the flood control. Therefore, it is not necessary to provide a complicated rotary seal mechanism for oil-sealing the hydraulic control unit for controlling the supply and discharge of oil and the rotating body, and it is possible to suppress the increase in size of the thrust generator 1. At the same time, maintenance and repair of the thrust generator 1 can be facilitated.

In this embodiment, by using a rack and pinion as the motion conversion mechanism of the linear motion rotation conversion unit 8, it is possible to align the longitudinal directions of the racks A1 to A3 with the linear motion direction of the linear motion body 11, and the pinion can be aligned with the linear motion direction of the linear motion body 11. It is possible to align each of B1 to B3 concentrically with the support shaft. Therefore, the arrangement of the three rack and pinions can be compactly integrated, and the linear rotation conversion unit 8 can be housed in the hub 10 while suppressing the increase in size of the hub 10.

In this embodiment, in the rotation linear motion conversion unit 7, the ball screw nut 7G and the linear motion transmission shaft 7D are sandwiched between the guide flat surfaces 7E1 of the linear motion guide unit 7E, and rotate when the ball screw shaft 7F rotates. Is linearly moved along the ball screw shaft 7F in a regulated state. The linear motion guide portion 7E is supported by a support member F1 that rotatably supports the ball screw shaft 7F, and it is not necessary to increase the size of the rotary linear motion conversion unit 7 and thus the thrust generator 1. Therefore, it is possible to reduce the size and weight of the thrust generator 1.

Further, a resin sliding member 7H is arranged between the guide flat surface 7E1 of the linear motion guide portion 7E and the guided flat surface 7C of the linear motion transmission shaft 7D. The resin sliding member 7H can reduce the friction generated during the linear motion of the linear motion transmission shaft 7D. The sliding member 7H is arranged between the guide flat surface 7E1 of the linear motion guide portion 7E and the guided flat surface 7C of the linear motion transmission shaft 7D, and the rotation linear motion conversion unit 7 and thus the thrust generator 1 are enlarged. You don't have to.

Further, by providing the flat portions 7A2 and 7B2 on the flanges 7A and 7B of the linear motion transmission shaft 7D and the ball screw nut 7G, the size of the linear motion guide portion 7E can be reduced, and the thrust generator 1 can be further miniaturized. And weight reduction can be realized.

Although the present invention has been illustrated and described above with reference to preferred embodiments of the present invention, those skilled in the art can change the form and details without departing from the scope of the invention described in the claims. It will be understood that there is. Such changes, modifications and modifications should be within the scope of the present invention.

For example, in the above embodiment, the sliding member is attached to the flat surface portion 7B2 of the flange 7B of the linear motion transmission shaft 7D, which is a part of the guided flat surface 7C formed on the outer peripheral surface of the upper portion of the linear motion transmission shaft 7D. 7H is fixed. However, the sliding member 7H may be fixed to another portion of the guided flat surface 7C.

Further, the flat surface portion 7A2 of the flange 7A of the ball screw nut 7G can also be regarded as a guided flat surface facing the guide flat surface 7E1 of the linear motion guide portion 7E. The sliding member 7H may be fixed to the flat surface portion 7A2 of the flange 7A. The sliding member may be fixed to the guided flat surface of both the ball screw nut 7G and the linear motion transmission shaft 7D.

Further, the sliding member may be fixed to the guide flat surface 7E1 of the linear motion guide portion 7E instead of the guided flat surface.

In the above embodiment, the propeller R is arranged directly below the thrust generator 1, the thrust generator 1 is mounted on the lower part of the airframe of the projectile, but the propeller R is arranged directly above the thrust generator 1. , The thrust generator 1 may be mounted on the upper part of the airframe of the flying object.

1 Thrust generator 2 Thrust generator 2A Stator 2B Rotor 2C Frame R Propeller H1 to H3 Rotating blades P1 to P3 Grip 4 Rotor shaft 5A Pitch angle change motor 6 Motion transmission unit 6A Rotation transmission unit 7 Rotational linear motion conversion unit 7A Flange 7A1 Protruding part 7A2 Flat part 7B Flange 7B1 Protruding part 7B2 Flat part 7C Guided flat surface 7D Linear transmission shaft 7E Linear guide 7E1 Guide flat surface 7F Ball screw shaft 7G Ball screw nut 7H Sliding member 8 Linear rotation converter 8 F1 support member

Claims (4)

A thrust generation motor that generates thrust by rotating a propeller with multiple rotor blades,
A pitch angle changing motor that changes the pitch angle of the rotor blades,
A rotation transmission unit connected to the pitch angle changing motor and
A linear motion shaft, a first motion conversion unit connected to the rotation transmission unit and the linear motion shaft, and having a motion conversion mechanism for converting the rotation of the rotation transmission unit into a linear motion of the linear motion axis.
It is provided with a second motion conversion unit that converts the linear motion of the linear motion axis into rotary motion and changes the pitch angle of the rotary blade.
The motion conversion mechanism of the first motion conversion unit is
The feed screw shaft rotated by the rotation transmission unit and
A support member that rotatably supports the feed screw shaft and
With a nut that is meshed with the feed screw shaft and fixed to the linear motion shaft,
It is provided with a linear motion guide portion that regulates the rotation of the nut and guides the nut to linearly move when the feed screw shaft rotates.
The linear motion guide portion has a pair of parallel guide flat surfaces supported by the support member.
A thrust generator characterized in that at least one outer peripheral surface of the nut and the linear motion shaft has a pair of parallel guided flat surfaces facing the guide flat surface of the linear motion guide portion. The motion conversion mechanism of the first motion conversion unit further includes a pair of resin-made sliding members arranged between the guide flat surface and the guided flat surface, and the sliding member is the sliding member. The thrust generator according to claim 1, wherein the thrust generator is arranged in a guide flat surface or a recess formed in the guided flat surface. The linear motion shaft has a flange and has a flange.
The nut has a flange
Each of the flange of the linear motion shaft and the flange of the nut has a shape in which a cylinder is cut out by two parallel planes, and has two arc-shaped protrusions and two flat surfaces.
The protruding portion of the flange of the linear motion shaft and the protruding portion of the flange of the nut are fixed by a fixing screw.
The flat surface portion of the flange of the linear motion shaft is a portion of the guided flat surface.
The thrust generator according to claim 1 or 2, wherein the flat portion of the flange of the nut faces the guide flat surface without contacting the guide flat surface. The linear motion shaft has a flange and has a flange.
The nut has a flange
Each of the flange of the linear motion shaft and the flange of the nut has a shape in which a cylinder is cut out by two parallel planes, and has two arc-shaped protrusions and two flat surfaces.
The protruding portion of the flange of the linear motion shaft and the protruding portion of the flange of the nut are fixed by a fixing screw.
The flat portion of the flange of the linear motion shaft faces the guide flat surface without contacting the guide flat surface.
The thrust generator according to claim 1 or 2, wherein the flat portion of the flange of the nut is a portion of the guided flat surface.

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