JP2021146825A - 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; pitch angle changing motors that change pitch angles of the rotors; a first motion conversion part that converts rotation of the pitch angle changing motor into a linear motion of a linear motion shaft; and a second motion conversion part that changes the pitch angle of the rotor. The second motion conversion part comprises: a rotary hub; a plurality of grips that respectively supports the rotors; a second motion conversion mechanism that converts the linear motion of the linear motion shaft into rotational motion of the plurality of grips; and a plurality of double row angular contact ball bearings that rotatably supports the grips, respectively; and a plurality of thrust bearings inserted respectively with the grips. Each inner double row angular contact ball bearing is arranged in a large diameter hole in a hollow portion of the hub, and each outer thrust bearing is arranged in a small diameter hole in the hollow portion. When centrifugal force applied to the grip is applied to the thrust bearing, the thrust bearing is supported by an inner surface of an outer end wall of a case.SELECTED DRAWING: Figure 18

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 rotates a plurality of rotary blades to generate thrust, a pitch angle changing motor that changes the pitch angle of the rotating blades, and the pitch angle changing motor. It has a connected rotation transmission unit, a linear motion shaft, and a first motion conversion mechanism, and the first motion conversion mechanism can be connected to the rotation transmission unit and the linear motion shaft, and the rotation transmission unit. A first motion conversion unit that converts the rotation of the linear motion axis into a linear motion of the linear motion axis, and a second motion that converts the linear motion of the linear motion axis into a rotary motion to change the pitch angle of the rotary blade. It is equipped with a conversion unit. The second motion conversion unit includes a hub rotated by the thrust generating motor, a plurality of grips attached to the hub to support the rotary blades, and the plurality of grips for linear motion of the linear motion shaft. A second motion conversion mechanism that converts the rotational motion of the grip, and a plurality of duplexes that are arranged radially outside the hub from the second motion conversion mechanism and rotatably support the inner end portion of the grip. It includes a row angular ball bearing and a plurality of thrust bearings arranged on the radial outer side of the hub from the double row angular ball bearing and into which the inner end portion of the grip is inserted. When the rotary blade rotates, the centrifugal force applied to the grip is applied to the thrust bearing. The outer diameter of the outer ring of the double-row angular contact ball bearing is larger than the outer diameter of the thrust bearing. The hub has a case that accommodates the inner end of each grip, the second motion conversion mechanism, each double row angular contact ball bearing, and each thrust bearing. The case has an outer end wall and a plurality of hollow portions, each hollow portion has a small-diameter hole portion and a large-diameter hole portion which are coaxial circular holes, and the small-diameter hole portion is from the large-diameter hole portion. It has a small inner diameter, the double-row angular contact ball bearing is arranged in the large-diameter hole portion, and the thrust bearing is arranged in the small-diameter hole portion. When the centrifugal force applied to the grip is applied to the thrust bearing, the thrust bearing is supported on the inner surface of the outer end wall of the case.
In this embodiment, when the rotor is rotated, centrifugal force applied to the rotor and thus the grip is applied to the thrust bearing. When the centrifugal force applied to the grip is applied to the thrust bearing, the thrust bearing is supported by the inner surface of the outer end wall of the case. In each hollow portion of the case, a double-row angular contact ball bearing that rotatably supports the grip is arranged in the large-diameter hole portion, and a thrust bearing is arranged in the small-diameter hole portion. Therefore, the thrust generator can be downsized as compared with the case where the structure for individually supporting the double-row angular contact ball bearing and the thrust bearing is provided.

Preferably, the second motion conversion section further comprises a plurality of cylinders into which the inner ends of the grips are inserted and inserted into the double row angular contact ball bearings, respectively. The outer peripheral surface of the inner end portion of the grip has a portion having a diameter smaller toward the radial outer side of the hub. The cylinder has a sleeve and a flange arranged radially outside the hub, and the inner peripheral surface of the sleeve has a diameter smaller toward the radial outside of the hub. The sleeve is inserted into the inner ring of the double row angular contact ball bearing, and the flange is arranged in the small diameter hole portion. When the centrifugal force applied to the grip is applied to the sleeve of the cylinder, the flange of the cylinder transmits the centrifugal force to the thrust bearing.
In this case, the outer peripheral surface of the inner end of the grip fits the inner peripheral surface of the sleeve of the cylinder due to the centrifugal force applied to the rotor blade and the grip. When centrifugal force is applied to the cylinder, the flange of the cylinder transmits the centrifugal force to the thrust bearing, and the thrust bearing is supported by the inner surface of the outer end wall of the case. Functions as a stop. Further, when the centrifugal force increases to some extent, the outer peripheral surface of the inner end portion of the grip fits the inner peripheral surface of the sleeve of the cylinder, so that the longitudinal axis of the grip is adjusted to the ideal direction.

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. FIG. 16 is a bottom view of the hub case. FIG. 17 is a cross-sectional view taken along the line XVII-XVII of FIG. FIG. 18 is an enlarged cross-sectional view showing a part of the hub. FIG. 19 is a cross-sectional view of the grip of the thrust generator according to the embodiment and its vicinity. FIG. 20 is an exploded perspective view of the components shown in FIG. FIG. 21 is a front view of the combined components shown in FIG. FIG. 22 is a cross-sectional view of another type of grip of the thrust generator according to the embodiment and its vicinity. FIG. 23 is an exploded perspective view of the components shown in FIG.

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. Each rotation transmission unit has a rotating member that rotates with the rotation of the rotation 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 (first 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 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 a ball screw as the motion conversion mechanism of the rotary linear motion conversion unit 7, the drive torque can be reduced as compared with the case where the sliding screw is used, and the power saving of the pitch angle changing motor 5A can be reduced. 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 conversion unit 8 uses a rack pinion as a motion conversion mechanism (second motion conversion mechanism) to convert the linear motion of the linear motion transmission shaft 7D of the rotary linear motion converter 7 into a rotary motion. Convert.

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, thrust bearings, preferably 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. FIG. 16 is a bottom view of the case 21 of the hub 10. FIG. 17 is a cross-sectional view taken along the line XVII-XVII of FIG. 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.

Hereinafter, the structure in which the grips P1 to P3 supporting the rotary blades H1 to H3 are supported by the hub 10 will be described in more detail.

FIG. 18 is an enlarged cross-sectional view showing a part of the hub 10 that supports the grip P1. FIG. 19 is a cross-sectional view of the grip P1 and its vicinity. FIG. 20 is an exploded perspective view of the components shown in FIG. FIG. 21 is a front view of the combined components shown in FIG.

As shown in FIG. 18, in the case 21 of the hub 10, the linear motion transmission shaft 7D and the motion of the linear motion rotation conversion unit 8 that converts the linear motion of the linear motion transmission shaft 7D into the rotational motion of the plurality of grips P1 to P3. A conversion mechanism (particularly, a linear motion element 11, racks A1 to A3, pinions B1 to B3) is accommodated. The case 21 further accommodates the support shafts M1 to M3 and the bearings E1 to E3 that rotatably support the support shafts M1 to M3. The support shafts M1 to M3 can be regarded as the inner ends of the grips P1 to P3, respectively.

The hub 10 can be disassembled into a case 21, an outer lid 22 and an inner lid 23, but the case 21 itself is indivisible. The case 21 has a plurality of openings K1 to K3 into which support shafts M1 to M3, which are inner ends of the grips P1 to P3, can be inserted while the outer ends of the grips P1 to P3 are arranged outside the case 21. ..

In the following, the mechanism for supporting the grip P1 and the rotary blade H1 will be described in detail, but the mechanism for supporting the other grips P2 and P3 and the rotary blades H2 to H3 is the same (the grips P1 to P3 have the same shape). The same type of the same size).

As shown in FIGS. 18 to 21, a rubber ring 30, a thrust washer 31, a needle-shaped thrust bearing 32, a thrust washer 33, a shaft adapter D1, a bearing E1, a pinion B1, and a C-type retaining ring are around the support shaft M1. 34 and a fastening ring 35 are arranged.

The support shaft M1 is inserted into the rubber ring 30. As shown in FIG. 18, the rubber ring 30 is interposed between the outer surface of the outer end wall Q1a of the hollow portion Q1 of the case 21 and the outer end portion of the grip P1 to close the opening K1 and inside the case 21. Prevents the grease for bearings from scattering while suppressing the intrusion of dust into the area. The grip P1 including the support shaft M1 is rotatable with respect to the rubber ring 30.

The thrust washer 31 and the thrust washer 33 are brought into contact with both end faces of the needle-shaped thrust bearing 32. The thrust washer 31 and the thrust washer 33 are raceway rings or rings, and are brought into contact with a plurality of needles of the needle-shaped thrust bearing 32. The support shaft M1 is inserted into the thrust washer 31, the needle-shaped thrust bearing 32, and the thrust washer 33. The support shaft M1 does not come into contact with the inner peripheral surfaces of the thrust washer 31, the needle-shaped thrust bearing 32, and the thrust washer 33, and the grip P1 including the support shaft M1 is rotatable with respect to these.

The support shaft M1 is inserted into the shaft adapter (cylinder) D1, and the shaft adapter D1 is rotatably inserted into the bearing E1. The bearing E1 is, for example, a radial bearing, preferably a double row angular contact ball bearing. The shaft adapter D1 is divisible by a plane including the longitudinal axes of the grips P1 to P3 as a boundary, and has two segments D1a and D1b. The segments D1a and D1b are combined to form one stepped cylinder shaft adapter D1.

The shaft adapter D1 composed of the segments D1a and D1b has a sleeve 40 and a flange 41. The flange 41 is arranged radially outside the hub 10 from the sleeve 40. The sleeve 40 is inserted into the inner ring of the bearing E1. The end face of the bearing E1 is opposed to the flange 41.

A fastening ring 35 is wound around the flange 41 of the shaft adapter D1. The fastening ring 35 is an endd ring that restrains the flange 41 by an elastic restoring force and prevents the combined segments D1a and D1b from separating.

The end portion M1a of the support shaft M1 is formed in a substantially elliptical columnar shape, and is inserted into a substantially elliptical columnar central hole of the pinion B1. Therefore, the pinion B1 does not rotate with respect to the support shaft M1. A groove M1b is formed in the end portion M1a of the support shaft M1, and a C-shaped retaining ring 34 is fitted in the groove M1b. The C-shaped retaining ring 34 restricts the movement of the pinion B1 in the axial direction, and fixes the pinion B1 to the end portion M1a of the support shaft M1.

Inside the case 21, the bearings E1 to E3 are arranged radially outside the hub 10 from the linear moving body 11, the racks A1 to A3, and the pinions B1 to B3, and the needle-shaped thrust bearing 32 is the hub 10 from the bearings E1 to E3. It is arranged on the outer side in the radial direction of.

The outer end of the grip P1 is bifurcated and has two parallel flat plates. Although not shown, the base portion of the rotary blade H1 is sandwiched between these flat plate portions. A plurality of through holes are formed in these flat plate portions, and the bolts 36 penetrating the through holes and the bolts 36 bite into the flat plate portions. The base portion of the rotary blade H1 is fixed to the outer end portion of the grip P1 by the combined nut 37. Counterbore holes are formed around the through holes of the flat plate portion, and washers 38 are arranged in these counterbore holes. A bolt 36 is inserted in the washer 38.

As shown in FIGS. 17 and 18, the hollow portion Q1 of the case 21 has a small diameter hole portion Q1b and a large diameter hole portion Q1c. The small-diameter hole portion Q1b and the large-diameter hole portion Q1c are coaxial circular holes, and the small-diameter hole portion Q1b arranged on the radial outside of the hub 10 is from the large-diameter hole portion Q1c arranged on the radial inside of the hub 10. The inner diameter is small. A step wall Q1d is provided between the small-diameter hole portion Q1b and the large-diameter hole portion Q1c.

The thrust washer 31, the needle-shaped thrust bearing 32, and the thrust washer 33 are arranged in the small-diameter hole portion Q1b of the hollow portion Q1 of the case 21, and the thrust washer 31 is brought into contact with the inner surface of the outer end wall Q1a of the hollow portion Q1. The flange 41 of the shaft adapter D1 is brought into contact with the thrust washer 33 on the opposite side. The fastening ring 35 and the flange 41 are also arranged in the small diameter hole portion Q1b.

The outer diameter of the outer ring of the bearing E1 is larger than the outer diameter of the needle-shaped thrust bearing 32. The bearing E1 into which the sleeve 40 of the shaft adapter D1 is inserted is arranged in the large-diameter hole Q1c of the hollow portion Q1 of the case 21, and the end surface of the outer ring of the bearing E1 is brought into contact with the stepped wall Q1d of the hollow portion Q1. The other end surface of the inner ring of the bearing E1 is in contact with the end surface of the pinion B1 fixed to the end portion M1a of the support shaft M1.

Therefore, in the axial direction of the support shaft M1, the thrust washer 31, the needle-shaped thrust bearing 32, the thrust washer 33, and the shaft adapter D1 are placed between the pinion B1 and the inner surface of the outer end wall Q1a of the hollow portion Q1 of the case 21. It is sandwiched. Further, in the axial direction of the support shaft M1, the bearing E1 is sandwiched between the pinion B1 and the stepped wall Q1d of the hollow portion Q1 of the case 21.

In the shaft adapter D1, the inner peripheral surface of the sleeve 40 has a smaller diameter toward the outer side in the radial direction of the hub 10. On the other hand, on the outer peripheral surface of the support shaft M1, the portion M1c inserted into the shaft adapter D1 has a smaller diameter toward the outer side in the radial direction of the hub 10.

Therefore, when the grip P1 is pulled outward in the radial direction by the centrifugal force applied to the rotary blade H1, the outer peripheral surface portion M1c of the support shaft M1 fits on the inner peripheral surface of the sleeve 40 of the shaft adapter D1. In this way, when the centrifugal force is applied to the sleeve 40 of the shaft adapter D1, the flange 41 of the shaft adapter D1 transmits the centrifugal force to the needle-shaped thrust bearing 32 (as a thrust force to the needle-shaped thrust bearing 32). .. When centrifugal force is applied to the needle-shaped thrust bearing 32, the thrust washer 31 comes into contact with the inner surface of the outer end wall Q1a of the case 21, and the needle-shaped thrust bearing 32 comes into contact with the inner surface of the outer end wall Q1a of the case 21. Be supported. In this way, the centrifugal force applied to the grip P1 is applied to the needle-shaped thrust bearing 32 when the rotary blade H1 rotates.

When a centrifugal force is applied to the shaft adapter D1, the flange 41 of the shaft adapter D1 transmits the centrifugal force to the needle-shaped thrust bearing 32, and the needle-shaped thrust bearing 32 is supported by the inner surface of the outer end wall Q1a of the case 21. Therefore, the shaft adapter D1 functions as a stopper for the grips P1 to P3 to which centrifugal force is applied.

Further, when the centrifugal force increases to some extent, the portion M1c of the outer peripheral surface of the support shaft M1 fits the inner peripheral surface of the sleeve 40 of the shaft adapter D1, so that the longitudinal axis of the grip P1 is adjusted to an ideal direction.

In this embodiment, in each hollow portion Q1 of the case 21, double-row angular contact ball bearings E1 to E3 that rotatably support the grips P1 to P3 are arranged in the large-diameter hole portion Q1c, and a needle is arranged in the small-diameter hole portion Q1b. The shape thrust bearing 32 is arranged. Therefore, the thrust generator 1 can be downsized as compared with the case where the structure for individually supporting the double row angular contact ball bearings E1 to E3 and the needle-shaped thrust bearing 32 is provided.

In this embodiment, the grip including the support shaft can be changed according to the type of rotor blade. FIG. 22 is a cross-sectional view of another type of grip P4 different from the grips P1 to P3 and its vicinity. FIG. 23 is an exploded perspective view of the components shown in FIG.

The outer end of the grip P4 arranged on the outside of the case 21 is larger than the outer end of the grip P1 and suitable for supporting a rotor larger and heavier than the rotors H1 to H3 (not shown). Therefore, when an appropriate rotor is selected according to the weight of the projectile on which the thrust generator is mounted and, by extension, the thrust required for the thrust generator, a grip suitable for the rotor can be attached to the hub 10. It is possible.

The outer end of the grip P4 is bifurcated and has two parallel flat plates. Although not shown, the base portion of the rotary blade is sandwiched between these flat plate portions. A plurality of through holes are formed in these flat plate portions, and the bolts 36a penetrating the through holes and the bolts 36a mesh with each other. The base of the rotor is fixed to the outer end of the grip P4 by the nut 37a.

On the other hand, the support shaft M1 which is the inner end of the grip P4 has the same shape and size as the support shaft M1 of the grip P1. Therefore, the grip including the support shaft can be changed according to the type of the rotor while the linear moving body 11, the racks A1 to A3, the pinions B1 to B3, the bearings E1 to E3, and other components are left in the hub 10. Is. While the grips can be changed, the radial bearings E1 to E3 and the complex linear motion 11, racks A1 to A3, pinions B1 to B3, and other components can be used unchanged, increasing manufacturing costs. Can be minimized.

In this embodiment, the support shaft, which is the inner end of the grip, is inserted, and each shaft adapter inserted into the radial bearing can be divided with a plane including the longitudinal axis of the grip as a boundary. When incorporating the grip into the hub 10, the support shafts M1 to M3 are inserted through the openings K1 to K3 of the case 21 and arranged inside the case 21. Inside the case 21, bearings E1 to E3 are arranged around support shafts M1 to M3 so that the grips P1 to P3 can be rotatably supported. Specifically, the support shafts M1 to M3 are inserted into the shaft adapters D1 to D3, and the shaft adapters D1 to D3 are inserted into the bearings E1 to E3. Each of the shaft adapters D1 to D3 can be divided with a plane including the longitudinal axis of the grips P1 to P3 as a boundary, and can be easily arranged around the support shafts M1 to M3 and easily arranged in a combined state. It can be inserted into E3. Therefore, even if the case 21 is indivisible, the bearings E1 to E3 can be easily arranged around the support shafts M1 to M3 inside the case 21. Therefore, each grip P1 to P3 can be easily changed.

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 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 directly above the thrust generator 1. Arranged, the thrust generator 1 may be mounted on the upper part of the airframe of the projectile.

1 Thrust generator 2 Thrust generator R Propeller H1 to H3 Rotating blades P1 to P3 Grips M1 to M3 Support shaft 4 Rotor shaft 5A Pitch angle change motor 6 Motion transmission unit 6A Rotation transmission unit 7 Rotational linear motion conversion unit 7D Linear motion transmission Shaft 7E Linear guide 7F Ball screw Shaft 7G Ball screw nut 8 Linear rotation converter 10 Hub 11 Linear body A1 to A3 Rack B1 to B3 Pinion D1 to D3 Shaft adapter D1a Segment D1b Segment 40 Sleeve 41 Flange E1 to E3 Bearing 21 Case K1 to K3 Opening Q1 to Q3 Hollow part Q1a Outer end wall 32 Needle-shaped thrust bearing

Claims (2)

A thrust generator that rotates multiple rotors to generate thrust,
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
It has a linear motion shaft and a first motion conversion mechanism, and the first motion conversion mechanism can be connected to the rotation transmission unit and the linear motion shaft, and the rotation of the rotation transmission unit is transferred to the linear motion shaft. The first motion conversion unit that converts to linear motion,
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 second motion conversion unit is
The hub rotated by the thrust generation motor and
A plurality of grips attached to the hub and supporting the rotor blades, respectively.
A second motion conversion mechanism that converts the linear motion of the linear motion axis into the rotational motion of the plurality of grips, and
A plurality of double-row angular contact ball bearings, which are arranged radially outside the hub from the second motion conversion mechanism and rotatably support the inner ends of the grips, respectively.
It is provided with a plurality of thrust bearings which are arranged radially outside the hub from the double row angular contact ball bearings and into which the inner ends of the grips are inserted.
When the rotor blades rotate, the centrifugal force applied to the grip is applied to the thrust bearing.
The outer diameter of the outer ring of the double-row angular contact ball bearing is larger than the outer diameter of the thrust bearing.
The hub has a case that accommodates the inner end of each grip, the second motion conversion mechanism, each double row angular contact ball bearing, and each thrust bearing.
The case has an outer end wall and a plurality of hollow portions, each hollow portion has a small-diameter hole portion and a large-diameter hole portion which are coaxial circular holes, and the small-diameter hole portion is from the large-diameter hole portion. It has a small inner diameter, the double-row angular contact ball bearing is arranged in the large-diameter hole portion, and the thrust bearing is arranged in the small-diameter hole portion.
A thrust generator characterized in that when the centrifugal force applied to the grip is applied to the thrust bearing, the thrust bearing is supported by an inner surface of an outer end wall of the case. The second motion conversion unit further
A plurality of cylinders into which the inner ends of the grips are inserted and each inserted into the double row angular contact ball bearings are provided.
The outer peripheral surface of the inner end portion of the grip has a portion having a diameter smaller toward the radial outer side of the hub.
The cylinder has a sleeve and a flange arranged radially outside the hub, and the inner peripheral surface of the sleeve has a diameter smaller toward the radial outside of the hub.
The sleeve is inserted into the inner ring of the double row angular contact ball bearing, and the flange is arranged in the small diameter hole portion.
The thrust generator according to claim 1, wherein when the centrifugal force applied to the grip is applied to the sleeve of the cylinder, the flange of the cylinder transmits the centrifugal force to the thrust bearing.

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