Pitch change device of propeller

Abstract

To provide a pitch change device having an easier configuration.SOLUTION: A pitch change device includes a motor, a first pulley, a second pulley, a belt member, a guide member, and arm members. The motor has a drive shaft member which is parallel to a rotary shaft member. The first pulley is driven by the motor and rotates around the drive shaft member. Rotation of the first pulley is transmitted to the second pulley and the second pulley rotates around the rotary shaft member independently from the rotary shaft member. The guide member is connected to the second pulley through a screw mechanism and the screw mechanism guides the second pulley along a rotation axis direction in which the rotary shaft member extends when the second pulley rotates. The belt member is wound around the first pulley and the second pulley and transmits rotation of the first pulley to the second pulley. The arm members are connected to the second pulley and base parts of blades of a propeller, and are configured to change pitch angles of the blades in response to displacement of the second pulley in the rotation axis direction.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a propeller pitch change device. [Background technology]

[0002] Patent Document 1 discloses a coaxial counter-rotating helicopter. The coaxial counter-rotating helicopter of Patent Document 1 is equipped with a pitch change mechanism that changes the collective pitch or cyclic pitch of the rotor blades. This pitch change mechanism changes the pitch of the upper and lower rotor blades by raising or tilting upper and lower swash plates that control the upper and lower rotor blades. The upper and lower swash plates are each connected to a servo motor via a pitch link mechanism. The pitch link mechanism transmits the driving force of each servo motor to each swash plate so as to move each swash plate up and down or tilt it. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2002-316699 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the pitch change mechanism disclosed in Patent Document 1, the connection mechanism between the servo motor and the swash plate is configured using multiple rods and multiple ball joints that connect the rods together, which increases the number of parts required to configure the pitch change mechanism and tends to complicate the configuration.

[0005] An object of the present invention is to provide a pitch changer with a simpler configuration. [Means for solving the problem]

[0006] A pitch change device according to a first aspect of the present invention is a pitch change device for changing the pitch of a propeller rotating around a rotating shaft member, and includes a motor, a first pulley, a second pulley, a belt member, a guide member, and an arm member. The motor has a drive shaft member parallel to the rotating shaft member. The first pulley is driven by the motor and rotates around the drive shaft member. The second pulley receives the rotation of the first pulley and rotates around the rotating shaft member independently of the rotating shaft member. The guide member is connected to the second pulley via a screw mechanism, and when the second pulley rotates, the screw mechanism guides the second pulley along the rotation axis direction in which the rotating shaft member extends. The belt member is wound around the first pulley and the second pulley and transmits the rotation of the first pulley to the second pulley. The arm member is connected to the second pulley and a base of each blade of the propeller, and is configured to change the pitch angle of the blade in response to a displacement of the second pulley in the rotation axis direction.

[0007] A pitch change device according to a second aspect is the pitch change device according to the first aspect, in which the guide member has a passage through which the rotating shaft member is inserted and is a feed screw extending along the rotation axis direction, and the second pulley has a female thread structure that is combined with the feed screw. Alternatively, the guide member has a passage through which the rotating shaft member is inserted, and a female thread structure is formed on an inner wall surface that defines the passage, and the second pulley includes a screw portion having a screw thread that is combined with the female thread structure.

[0008] A pitch change device according to a third aspect is a pitch change device for changing the pitch of a propeller rotating around a rotating shaft member, and includes a motor, a first pulley, a second pulley, a belt member, a movable member, and an arm member. The motor has a drive shaft member parallel to the rotating shaft member. The first pulley is driven by the motor and rotates around the drive shaft member. The second pulley is transmitted the rotation of the first pulley and rotates around the rotating shaft member independently of the rotating shaft member. The belt member is wound around the first pulley and the second pulley and transmits the rotation of the first pulley to the second pulley. The movable member is connected to the second pulley via a screw mechanism and is restricted from rotating around the rotating shaft member, and when the second pulley rotates, the movable member moves along the rotation axis direction along which the rotating shaft member extends. The arm member is connected to the movable member and a base of each blade of the propeller and is configured to change the pitch angle of the blade in response to a displacement of the movable member in the rotation axis direction.

[0009] A variable pitch propeller device according to a fourth aspect includes a pitch change device according to any one of the first to third aspects, a rotating shaft member, a thrust motor that drives the rotating shaft member and rotates the rotating shaft member, and a propeller fixed to the rotating shaft member and rotating around the rotating shaft member, the propeller having a plurality of blades, each of the plurality of blades being connected to the rotating shaft member so as to change the pitch angle.

[0010] A thrust generating device according to a fifth aspect includes the controllable pitch propeller device according to the fourth aspect, and a control unit that controls the operation of the controllable pitch propeller device. Effect of the Invention

[0011] According to the present invention, a pitch changer with a simpler configuration is provided. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic diagram showing a configuration of a controllable pitch propeller device equipped with a pitch change device according to an embodiment. [Diagram 2] Top view of the propeller in Figure 1. [Diagram 3] 4A to 4C are diagrams illustrating the operation of the pitch changer. [Figure 4] 4A to 4C are diagrams illustrating the operation of the pitch changer. [Diagram 5] An example of the configuration of a thrust generating device. [Figure 6] FIG. 2 is a block diagram showing an example of an electrical configuration of a thrust generating device. [Figure 7] FIG. 13 is a schematic diagram showing the configuration of a pitch changer according to a modified example. [Figure 8] FIG. 13 is a schematic diagram showing the configuration of a pitch changer according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. However, the embodiment described below is merely an example of the present invention in every respect. It goes without saying that various improvements and modifications can be made without departing from the scope of the present invention. In other words, in carrying out the present invention, a specific configuration according to the embodiment may be appropriately adopted. In the following, for convenience of explanation, the explanation will be made based on the directions of the x-axis, y-axis, and z-axis defined in FIG. 1. The x-axis, y-axis, and z-axis are mutually perpendicular axes.

[0014] <1. Overview> Fig. 1 is a schematic diagram showing the configuration of a controllable pitch propeller device 3 according to this embodiment. For ease of explanation, Fig. 1 shows a part of the configuration in cross section. The controllable pitch propeller device 3 includes a pitch change device 1 and a propeller 2, and is applied to, for example, a thrust generating device 4 (see Fig. 5). The pitch change device 1 is a device for automatically changing the pitch of the propeller 2. Below, after explaining the propeller 2, the pitch change device 1, the controllable pitch propeller device 3, and the thrust generating device 4 will be explained in order.

[0015] <2. Propeller configuration> FIG. 2 is a top view of the propeller 2. The propeller 2 is a part that generates a thrust in the z-axis direction in the variable pitch propeller device 3, and is fixed to the tip of the rotating shaft member 30. The rotating shaft member 30 is a member that extends along the z-axis direction, and is configured to be driven by a thrust motor 37 described later and rotate around the rotating shaft A1. When the rotating shaft member 30 rotates, the propeller 2 rotates together with the rotating shaft member 30 around the rotating shaft member 30. The propeller 2 has blades 20 and a connecting member 21. The connecting member 21 is connected to an arm member 15 of the pitch change device 1 described later. The blades 20, the connecting member 21, and the arm member 15 are configured to rotate integrally around the rotating shaft member 30. The variable pitch propeller device 3 of this embodiment has three pairs of blades 20, connecting members 21, and arm members 15.

[0016] Each blade 20 extends in the radial direction with respect to the rotating shaft member 30. The shape of the blade 20 is not particularly limited and can be appropriately selected depending on the configuration of the controllable pitch propeller device 3. The base of the blade 20 is fixed to the connecting member 21 by bolts, nuts, etc. Each blade 20 is connected to the rotating shaft member 30 at the same position in the z-axis direction via the connecting member 21.

[0017] The connecting member 21 has a shaft portion 210 connected to the rotating shaft member 30. The shaft portion 210 extends along a direction perpendicular to the z-axis and can rotate relative to the rotating shaft member 30 around an axis extending in a direction perpendicular to the z-axis. The rotation of the shaft portion 210 relative to the rotating shaft member 30 changes the pitch angle of the blade 20. The pitch angle of the blade 20 is the inclination of the cross section of the blade 20, and in this embodiment, it coincides with the rotation angle of the shaft portion 210. By changing the pitch angle, it is possible to obtain any thrust in the forward / rearward direction while maintaining the rotation direction and rotation speed of the rotating shaft member 30 constant. Hereinafter, the state of FIG. 1 is defined as the reference state of the propeller 2, and the pitch angle of the blade 20 in this reference state is defined as 0 degrees. The connecting member 21 is connected to the arm member 15 at a portion spaced from the shaft portion 210.

[0018] The material constituting the blade 20 and the connecting member 21 is not particularly limited, but a material having a relatively high rigidity is preferable, such as synthetic resin or metal.

[0019] <3. Configuration of pitch change device> The pitch change device 1 includes a pitch angle control motor 10, a first pulley 11, a second pulley 12, a guide member 13, a belt member 14, and an arm member 15. The pitch angle control motor 10 and the guide member 13 are each fixed to a support member 31 of the variable pitch propeller device 3 with a gap therebetween. Each member will be described below.

[0020] The pitch angle control motor 10 is a drive device for changing the pitch of the blades 20, and is rotated by obtaining electric power from a power source. The power source can be mounted on the variable pitch propeller device 3 or the thrust generating device 4 (see FIG. 6). The pitch angle control motor 10 has a drive shaft member 100 which is an output shaft for rotation. The pitch angle control motor 10 is fixed to a support member 31 so that the drive shaft member 100 is parallel to the rotating shaft member 30.

[0021] A first pulley 11 is fixed to the drive shaft member 100. The first pulley 11 is driven by the pitch angle control motor 10 and rotates around the drive shaft member 100. A plurality of pairs of teeth and tooth roots (not shown) are formed on an outer circumferential surface 110 of the first pulley 11. In other words, the first pulley 11 is configured as a gear.

[0022] A ring-shaped belt member 14 is wound around the first pulley 11. The belt member 14 according to the present embodiment is a toothed belt, and a plurality of pairs of teeth and tooth bottoms are formed on its inner peripheral surface 140. The teeth and tooth bottoms of the inner peripheral surface 140 mesh with the teeth and tooth bottoms of the first pulley 11. As a result, the belt member 14 circulates in conjunction with the rotation of the first pulley 11. The belt member 14 is preferably a rubber belt made of rubber, but is not particularly limited thereto. The belt member 14 is also wound around the second pulley 12, and transmits the rotation of the first pulley 11 to the second pulley 12. As a result, the second pulley 12 rotates around the rotating shaft member 30. However, the second pulley 12 is connected to the rotating shaft member 30 via the guide member 13, and is configured to rotate independently of the rotating shaft member 30 due to the presence of the guide member 13.

[0023] The guide member 13 has one end fixed to the support member 31 of the variable pitch propeller device 3. The guide member 13 is assembled to the rotating shaft member 30 so as to surround the rotating shaft member 30 from the radially outer side. More specifically, the guide member 13 defines a passage 130 extending in the z-axis direction at its center, and the rotating shaft member 30 is inserted into this passage 130. The guide member 13 is a feed screw extending along the z-axis direction, and has a screw thread on its outer circumferential surface. The guide member 13 and the second pulley 12 are connected to each other via a screw mechanism. That is, the guide member 13 converts the rotational motion of the second pulley 12 around the rotation axis A1 into linear motion in the z-axis direction. The central axis of the guide member 13 in the z-axis direction coincides with the rotation axis A1.

[0024] More specifically, the second pulley 12 has a pulley portion 120, a transmission portion 121, and a bearing 122. The pulley portion 120 is a portion around which the belt member 14 is wound. Similar to the first pulley 11, an outer peripheral surface 1200 of the pulley portion 120 has teeth and tooth bottoms formed thereon that mesh with the teeth and tooth bottoms of the inner peripheral surface 140 of the belt member 14. The pulley portion 120 also has, at its center, a female screw structure 1201 that is combined with the threads of the guide member 13. The threads of the guide member 13 and the female screw structure 1201 of the pulley portion 120 mesh with each other to form the above-mentioned screw mechanism.

[0025] The transmission part 121 is formed on the propeller 2 side of the pulley part 120, and surrounds the rotating shaft member 30 from the radial outside. The transmission part 121 may be formed integrally with the pulley part 120, or may be formed as a separate body from the pulley part 120 and then fixed to the pulley part 120. The transmission part 121 has, in its center, a female screw structure 1210 that is combined with the thread of the guide member 13, just like the pulley part 120. This forms a female screw structure by combining the pulley part 120 and a part of the transmission part 121. The transmission part 121 supports a bearing 122 at a position on the propeller 2 side spaced from the female screw structure 1210 in the z-axis direction.

[0026] Although not limited thereto, the bearing 122 has an inner ring, an outer ring, and a plurality of rolling elements held between the inner ring and the outer ring. The inner ring is the innermost annular part of the bearing 122, and is connected to the rotating shaft member 30 so as to be movable along the z-axis direction on the outer circumferential surface of the rotating shaft member 30. Three arm members 15 are fixed to the surface of the inner ring on the propeller 2 side. The rolling elements are spheres in this embodiment. However, the rolling elements are not particularly limited as long as they can rotate between the inner ring and the outer ring. The outer ring is the outermost annular part of the bearing 122, and is fixed to the transmission unit 121. The rotation of the rotating shaft member 30 is transmitted to the inner ring of the bearing 122 via the arm member 15. That is, the inner ring of the bearing 122 can rotate around the rotating shaft member 30 following the rotation of the propeller 2. On the other hand, the outer ring of the bearing 122 is driven by the rotation of the first pulley 11 and can rotate around the rotating shaft member 30 together with the transmission part 121.

[0027] The arm member 15 is a member connected to the bearing 122 and the connecting member 21. The arm member 15 forms a link mechanism, and changes the pitch angle of the blade 20 by receiving linear motion in the z-axis direction from the second pulley 12. Note that the rotational motion of the second pulley 12 is not transmitted to the arm member 15. The arm member 15 has a first arm portion 150, a first shaft portion 151, a second arm portion 152, a second shaft portion 153, and a third arm portion 154.

[0028] One end of third arm portion 154 is fixed to the inner ring of bearing 122, and the other end extends radially outward away from the inner ring. The other end of third arm portion 154 is connected to second arm portion 152 by second shaft portion 153.

[0029] Second arm portion 152 extends from the bearing 122 side to the propeller 2 side. One end of second arm portion 152 is connected to third arm portion 154 by second shaft portion 153 so as to be rotatable relative to third arm portion 154. Furthermore, second arm portion 152 is connected to first arm portion 150 by first shaft portion 151 at the other end opposite to second shaft portion 153 so as to be rotatable relative to first arm portion 150.

[0030] One end of the first arm portion 150 is connected to the second arm portion 152 by a first shaft portion 151 so as to be rotatable relative to the second arm portion 152. Furthermore, the other end of the first arm portion 150 opposite the first shaft portion 151 is fixed to the connecting member 21. Note that the first arm portion 150 may be configured integrally with the connecting member 21. The first arm portions 150 of the present embodiment extend along a direction perpendicular to the shaft portion 210 of the connecting member 21 to which they are connected.

[0031] The materials constituting the first pulley 11, the second pulley 12, the guide member 13 and the arm member 15 are not particularly limited, but are preferably materials with relatively high rigidity, such as synthetic resins and metals. Note that the parts constituting the second pulley 12 and the arm member 15 may be made of the same material or different materials.

[0032] <4. Configuration of controllable pitch propeller device> The controllable pitch propeller device 3 can be applied to a thrust generating device 4 (see FIG. 5) described below. In addition to the pitch change device 1 and propeller 2 already described, the controllable pitch propeller device 3 includes a support member 31 and a bearing 32 that support the pitch change device 1. The controllable pitch propeller device 3 further includes a thrust motor 37, a rotating shaft member 30 driven by the thrust motor 37, a third pulley 33, a fourth pulley 34, and a belt member 35, as well as a support member 36 and a bearing 38 that support these members. Each member will be described below.

[0033] The support member 31 is a rod-shaped member extending in a direction perpendicular to the z-axis direction. The pitch angle control motor 10 and the guide member 13 are fixed to the support member 31 at an interval from each other along the longitudinal direction of the support member 31. In the thrust generating device 4, the pitch angle control motor 10 is disposed at or near the main body part 40 at the center by the support member 31, and the guide member 13 is disposed farther away from the main body part 40. A bearing 32 is further fixed to the support member 31.

[0034] The bearing 32 can have a configuration similar to that of the bearing 122, but is not limited thereto, and has an inner ring, an outer ring, and a plurality of rolling elements held between the inner ring and the outer ring. The bearing 32 is fixed to the support member 31 so that its central axis coincides with the central axis of the guide member 13. The outer ring of the bearing 32 is fixed to the support member 31, and the inner ring is fixed to the rotating shaft member 30.

[0035] The support member 36 is a rod-shaped member extending in a direction perpendicular to the z-axis direction. In the z-axis direction, the support member 36 is disposed farther from the propeller 2 than the support member 31. A thrust motor 37 and a bearing 38 are fixed to the support member 36 at an interval from each other along the longitudinal direction of the support member 36.

[0036] Bearing 38 can have a configuration similar to that of bearing 122, but is not limited to this, and has an inner ring, an outer ring, and a plurality of rolling elements held between the inner ring and the outer ring. Bearing 38 is fixed to support member 31 so that its central axis coincides with the central axis of rotating shaft member 30. The outer ring of bearing 38 is fixed to support member 36, and the inner ring is fixed to rotating shaft member 30.

[0037] The rotating shaft member 30 is driven by a thrust motor 37 and rotates about a rotation axis A1 parallel to the z-axis direction. The above-mentioned propeller 2 is fixed to one end of the rotating shaft member 30. The rotating shaft member 30 passes through, in order from the propeller 2 side, the second pulley 12, the guide member 13, a bearing 32, a fourth pulley 34, and a bearing 38. The fourth pulley 34 is fixed to the rotating shaft member 30. The fourth pulley 34 will be described later.

[0038] The thrust motor 37 is a drive device for rotating the rotating shaft member 30, and rotates by obtaining electric power from a power source. The power source can be mounted on the controllable pitch propeller device 3 or the thrust generating device 4. The thrust motor 37 has a drive shaft member 370 which is an output shaft for rotation. The thrust motor 37 is fixed to the support member 36 so that the drive shaft member 370 is parallel to the rotating shaft member 30.

[0039] A third pulley 33 is fixed to the drive shaft member 370. The third pulley 33 is driven by the thrust motor 37 and rotates around the drive shaft member 370. A plurality of pairs of teeth and tooth roots (not shown) are formed on an outer circumferential surface 330 of the third pulley 33. That is, the third pulley 33 is configured as a gear.

[0040] An annular belt member 35 is wound around the third pulley 33. An inner circumferential surface 350 of the belt member 35 has a plurality of pairs of teeth and tooth bottoms formed thereon. The teeth and tooth bottoms of the inner circumferential surface 350 mesh with the teeth and tooth bottoms of the third pulley 33. As a result, the belt member 35 circulates in conjunction with the rotation of the third pulley 33. The belt member 35 is preferably, but is not particularly limited to, a rubber belt made of rubber. The belt member 35 is also wound around the fourth pulley 34, and transmits the rotation of the third pulley 33 to the fourth pulley 34. As a result, the rotating shaft member 30 and the propeller 2 rotate together with the fourth pulley 34.

[0041] The fourth pulley 34 is configured as a gear, similar to the third pulley 33. That is, a plurality of pairs of teeth and tooth bottoms (not shown) are formed on an outer circumferential surface 340 of the fourth pulley 34. The teeth and tooth bottoms of the outer circumferential surface 340 mesh with the teeth and tooth bottoms of the belt member 35. This allows the rotation of the third pulley 33 to be transmitted to the fourth pulley 34 via the belt member 35, as described above.

[0042] The materials constituting the rotating shaft member 30, the support member 31, the bearing 32, the third pulley 33, the fourth pulley 34, the support member 36, and the bearing 38 are not particularly limited, but are preferably materials with relatively high rigidity, such as synthetic resins and metals. Note that the parts constituting the bearing 32 and the bearing 38 may be made of the same material or different materials.

[0043] <5. Operation of the pitch changer> 3 and 4 are diagrams for explaining the operation of the pitch change device 1 according to this embodiment. The pitch change device 1 operates when the rotating shaft member 30 and the propeller 2 are rotated in a constant direction and at a constant rotation speed by the thrust motor 37. The following description will be given on the assumption that the rotating shaft member 30 and the propeller 2 are rotating in a constant direction and at a constant rotation speed, and that the propeller 2 is in the reference state of FIG.

[0044] For example, consider a case where each blade 20 is tilted toward the arm member 15 as shown in FIG. 3. The pitch angle control motor 10 rotates the second pulley 12 so that the guide member 13 advances relatively to the female thread structure 1201 of the second pulley 12. That is, when the thread of the guide member 13 is a right-handed thread, the pitch angle control motor 10 outputs a clockwise rotation as viewed from the z-axis direction to the drive shaft member 100. As a result, the clockwise rotation is transmitted from the first pulley 11 to the second pulley 12 including the pulley portion 120 via the belt member 14. When the second pulley 12 rotates, the guide member 13 guides the second pulley 12 in a direction away from the propeller 2 along the rotation axis A1 direction. The arm member 15 deforms in response to the displacement of the second pulley 12 in the rotation axis A1 direction. In particular, when the first arm portion 150 is tilted from the reference state toward the second arm portion 152, the connecting member 21 rotates in conjunction with this, centering on the shaft portion 210. As a result, the pitch angle of each blade 20 is changed.

[0045] Also, consider a case where each blade 20 is tilted to the opposite side of the arm member 15 as shown in FIG. 4. The pitch angle control motor 10 rotates and drives the second pulley 12 so that the guide member 13 retreats relatively to the female thread structure 1201 of the second pulley 12. That is, when the thread of the guide member 13 is a right-handed thread, the pitch angle control motor 10 outputs a counterclockwise rotation as viewed from the z-axis direction to the drive shaft member 100. As a result, the counterclockwise rotation is transmitted from the first pulley 11 to the second pulley 12 including the pulley portion 120 via the belt member 14. When the second pulley 12 rotates, the guide member 13 guides the second pulley 12 in a direction approaching the propeller 2 along the direction of the rotation axis A1. The arm member 15 deforms in response to the displacement of the second pulley 12 in the direction of the rotation axis A1. In particular, when the first arm portion 150 is tilted from the reference state toward the opposite side to the second arm portion 152, the connecting member 21 rotates around the shaft portion 210 in conjunction with the first arm portion 150. As a result, the pitch angle of each blade 20 is changed.

[0046] When the propeller 2 is to be brought to the reference state from the state shown in Fig. 3, the pitch angle control motor 10 is rotated so that counterclockwise rotation as viewed from the z-axis direction is transmitted to the second pulley 12. Similarly, when the propeller 2 is to be brought to the reference state from the state shown in Fig. 4, the pitch angle control motor 10 is rotated so that clockwise rotation as viewed from the z-axis direction is transmitted to the second pulley 12. In this way, the pitch change device 1 can change the pitch angle continuously and reversibly.

[0047] The pitch angle can be derived based on the displacement of the second pulley 12 in the direction of the rotation axis A1 from a reference state. Moreover, the displacement in the direction of the rotation axis A1 is proportional to the number of rotations of the second pulley 12. Therefore, by calculating in advance the relationship between the pitch angle and the displacement of the second pulley 12 in the direction of the rotation axis A1 from a reference state, it is possible to realize a desired pitch angle by appropriately controlling the rotation direction of the pitch angle control motor 10 and the number of rotations in the same direction.

[0048] <6. Thrust generating device configuration> Fig. 5 is a diagram showing a configuration example of a thrust generating device 4 equipped with a controllable pitch propeller device 3. The thrust generating device 4 is, for example, a moving device that moves by itself using the thrust of the propeller 2. Examples of such moving devices include a multicopter (unmanned aerial vehicle), a helicopter, a ship, and a model ship. Fig. 5 shows a configuration example in which the thrust generating device 4 is configured as a multicopter.

[0049] 5, the thrust generating device 4 includes a plurality of controllable pitch propeller devices 3 and a main body 40. The main body 40 is a housing to which the plurality of controllable pitch propeller devices 3 are attached. Each controllable pitch propeller device 3 is attached to the main body 40 at the end of the support member 31 and the support member 36. Therefore, the pitch angle control motor 10, the first pulley 11, the thrust motor 37 and the third pulley 33 of the controllable pitch propeller device 3 are disposed inside the main body 40.

[0050] 6 is a block diagram showing the electrical configuration of the thrust generating device 4. The thrust generating device 4 further includes a power source 41, a control unit 42, a sensor unit 43, and a communication unit 44. The power source 41 supplies power to the control unit 42, the sensor unit 43, the communication unit 44, the pitch angle control motor 10, and the thrust motor 37. The power source 41 can be composed of a battery or the like.

[0051] The control unit 42 executes arithmetic processing for controlling the operation of the thrust generating device 4 according to a program. The control unit 42 has a processor such as a CPU (Central Processing Unit) and a GPU (Graphics Processing Unit). The control unit 42 also has a volatile memory such as a RAM (Random Access Memory) and a non-volatile memory such as a ROM (Read Only Memory) and an SD memory card. The volatile memory is used as appropriate for the calculations of the processor, and programs and the like are stored in advance in the non-volatile memory. The control unit 42 controls the operation of the thrust motor 37 and the operation of the pitch change device 1.

[0052] The sensor unit 43 has one or more sensors. Examples of the sensors include inertial sensors such as an acceleration sensor and a gyro sensor, a GPS (Global Positioning System) sensor, an altitude sensor, an air pressure sensor, a geomagnetic sensor, an ultrasonic sensor, and an image sensor (camera). The control unit 42 performs the above control based on an output signal from the sensor unit 43. That is, the control unit 42 controls the attitude, position, traveling direction, etc. of the thrust generating device 4.

[0053] The communication unit 44 is a communication module that enables data communication with an external device of the thrust generating device 4. The data communication may be wired or wireless. The communication unit 44 can, for example, transmit sensing data acquired by the sensor unit 43 to an external device and receive commands from a remote control device.

[0054] <7.Features> (1) In the pitch change device 1 according to the above embodiment, the output of the pitch angle control motor 10 is transmitted to the second pulley 12 as it is, and the rotation of the second pulley 12 is converted into linear motion in the direction of the rotation axis A1 by the guide member 13. The second pulley 12 and the guide member 13 are connected to each other by a screw structure. This allows the number of parts to be reduced and the configuration to be simplified compared to conventional pitch change mechanisms using rods and ball joints, etc. For this reason, the pitch change device 1 can be preferably applied to multicopters and helicopters, which are particularly required to be compact and lightweight. In addition, in the pitch change device 1, the rotation speed (rotation angle) of the pitch angle control motor 10 and the displacement of the second pulley 12 in the direction of the rotation axis A1 are in a linear relationship. This reduces energy loss compared to a mechanism that converts the output of a pitch change motor into linear motion using rods and ball joints, etc.

[0055] (2) In the pitch change device 1 according to the above embodiment, the member that transmits the displacement in the direction of the rotation axis A1 to the arm member 15 is composed of the second pulley 12 and the guide member 13, which are connected via a screw mechanism. This makes it possible to increase the rigidity of the portion that is likely to be subjected to a large force while the propeller 2 is rotating. For example, in a configuration in which the output from the pitch change motor is transmitted to the propeller arm using a rod and a ball joint or the like, there is a high possibility that the rod will buckle when it moves toward the propeller. This tendency is particularly noticeable when the thrust is large.

[0056] (3) In the pitch change device 1 according to the above embodiment, the rotation of the pitch angle control motor 10 is transmitted to the second pulley 12 using the first pulley 11 and the belt member 14. This increases the degree of freedom in the layout of the pitch angle control motor 10, and for example, the pitch angle control motor 10 can be arranged at a location radially away from the rotating shaft member 30. When the thrust generating device 4 is a multicopter, the moment of inertia of the thrust generating device 4 can be reduced by arranging the pitch angle control motor 10 and the first pulley 11 in the main body 40 of the thrust generating device 4 or in the vicinity of its center of mass. As a result, the attitude control of the thrust generating device 4 becomes easier. This effect can also be obtained by arranging the thrust motor 37 and the third pulley 33 in the main body 40 of the thrust generating device 4 or in the vicinity of its center of mass.

[0057] <8. Variations> Although the embodiment of the present invention has been described in detail above, the above description is merely an example of the present invention in every respect. It goes without saying that various improvements or modifications can be made without departing from the scope of the present invention. For example, the following modifications are possible. In the following, the same reference numerals are used for the same components as in the above embodiment, and the description of the same points as in the above embodiment is omitted as appropriate. The following modifications can be combined as appropriate.

[0058] (1) In the above embodiment, the second pulley 12 has the female screw structures 1201, 1210, and the guide member 13 has a screw thread (male screw structure). However, the second pulley 12 may have a screw thread, and the guide member 13 may have a female screw structure. For example, the pitch change device 1A shown in FIG. 7 includes a second pulley 12A and a guide member 13A that are connected via a screw mechanism. The second pulley 12A has a pulley portion 120A around which the belt member 14 is wound, and a screw portion 121A that is fixed to the pulley portion 120A so as to protrude from the pulley portion 120A in the z-axis direction and has a screw thread. The pulley portion 120A is connected to the arm member 15 via a bearing 122A so as to rotate independently of the rotation of the rotating shaft member 30 and the arm member 15. The guide member 13A has a passage through which the rotating shaft member 30 is inserted, and a female screw structure 130A is formed on an inner wall surface that defines the passage. When the second pulley 12A rotates, the threaded portion 121A advances or retreats relative to the guide member 13A, whereby the second pulley 12A is guided along the direction of the rotation axis A1.

[0059] 8 is an example of a pitch change device 1B having another configuration. The pitch change device 1B includes a pitch angle control motor 10B having a drive shaft member 100B, a first pulley 11B, a second pulley 12B, a belt member 14B, a movable member 13B, and an arm member 15B. The pitch angle control motor 10B and the movable member 13B are fixed to the support member 31 of the variable pitch propeller device 3 with a gap therebetween. The configurations of the pitch angle control motor 10B, the first pulley 11B, the belt member 14B, and the arm member 15B are the same as those of the pitch angle control motor 10, the first pulley 11, the belt member 14, and the arm member 15 of the pitch change device 1, so that the description thereof will be omitted. The arm member 15B is connected to the movable member 13B so as to be rotatable together with the rotating shaft member 30.

[0060] The second pulley 12B has a pulley portion 120B and a screw portion 121B fixed to the pulley portion 120B so as to protrude from the pulley portion 120B in the z-axis direction. A passage through which the rotating shaft member 30 is inserted is formed in the second pulley 12B, and the central axis of the second pulley 12B in the z-axis direction coincides with the rotating shaft A1. The second pulley 12B is connected to the support member 31 via a bearing 39 fixed to the pulley portion 120B, and is rotatable relative to the support member 31 around the rotating shaft A1. As a result, the second pulley 12B receives the rotation of the first pulley 11B via the belt member 14B, and rotates around the rotating shaft member 30 independently of the rotating shaft member 30. The screw portion 121B has a screw thread and is connected to the movable member 13B via a screw mechanism. The movable member 13B has a passage through which the rotating shaft member 30 is inserted, and a female screw structure 130B is formed on the inner wall surface that defines the passage. The movable member 13B is connected to a connected part 310 extending in the z-axis direction via a connecting part 131B. The connected part 310 is fixed to the support member 31. The movable member 13B is restricted from rotating around the rotating shaft member 30 by the connection between the connecting part 131B and the connected part 310, while it moves along the z-axis direction when the pulley part 120B rotates. In other words, the connecting part 131B and the connected part 310 function as a rotation stopper for the movable member 13B. The configuration of the rotation stopper is not particularly limited as long as it restricts the rotation of the movable member 13B and allows movement in the z-axis direction.

[0061] (2) The thrust motor 37 may be disposed so that the drive shaft member 370 is coaxial with the rotating shaft member 30. In addition, the third pulley 33 and the belt member 35 may be omitted.

[0062] (3) The number of blades 20 of the propeller 2 can be changed as appropriate. In addition, the bearings 32, 38, 122 are not limited to those in the above embodiment, and can be selected as appropriate, such as a thrust bearing or a combination of different types of bearings.

[0063] (4) The transmission of rotation from the pitch angle control motor 10 to the second pulley 12 does not have to be via the belt member 14, and a gear or the like may be used as appropriate. The same can be said for the transmission of rotation from the thrust motor 37 to the fourth pulley 34.

[0064] (5) The application of the pitch change device 1 is not limited to the above-described thrust generating device 4. For example, the pitch change device 1 can be applied to a control device that controls the attitude or vibration of a suspended load, a blower, an agitating and mixing device, and the like. [Explanation of symbols]

[0065] 1,1A,1B Pitch change device 2 Propellers 3. Controllable pitch propeller device 4 Thrust generating device 10 Pitch angle control motor (motor) 11 First pulley 12 No. 2 pulley 13 Guide member 14 Belt member 15 Arm parts 20 Blades 30 Rotating shaft member 33 3rd pulley 34 4th pulley 37 Thrust motor A1 Rotational Axis

Claims

1. A pitch change device for changing the pitch of a propeller rotating around a rotating shaft member, a motor having a drive shaft member parallel to the rotating shaft member; a first pulley driven by the motor and rotating about the drive shaft member; a second pulley that receives rotation of the first pulley and rotates around the rotating shaft member independently of the rotating shaft member; a belt member that is wound around the first pulley and the second pulley and transmits rotation of the first pulley to the second pulley; a guide member that is connected to the second pulley via a screw mechanism and that guides the second pulley along a rotation axis direction in which the rotating shaft member extends when the second pulley is rotated by the screw mechanism; an arm member connected to the second pulley and to a base of each blade of the propeller, and configured to change the pitch angle of the blade in response to a displacement of the second pulley in the rotation axis direction; Equipped with Pitch change device.

2. the guide member is a feed screw having a passage through which the rotating shaft member is inserted and extending along the rotation shaft direction, The second pulley has a female thread structure that can be combined with the feed screw, or The guide member has a passage through which the rotary shaft member is inserted, and an internal thread structure is formed on an inner wall surface that defines the passage, The second pulley includes a threaded portion having a thread that is coupled to the female thread structure.

2. The pitch alteration device according to claim 1.

3. A pitch change device for changing the pitch of a propeller rotating around a rotating shaft member, a motor having a drive shaft member parallel to the rotating shaft member; a first pulley driven by the motor and rotating about the drive shaft member; a second pulley that receives rotation of the first pulley and rotates around the rotating shaft member independently of the rotating shaft member; a belt member that is wound around the first pulley and the second pulley and transmits rotation of the first pulley to the second pulley; a movable member that is connected to the second pulley via a screw mechanism and whose rotation about the rotating shaft member is restricted, and that moves along a rotation axis direction in which the rotating shaft member extends when the second pulley rotates due to the screw mechanism; an arm member connected to the movable member and to a base of each blade of the propeller and configured to change the pitch angle of the blade in response to a displacement of the movable member in the direction of the rotation axis; Equipped with Pitch change device.

4. A pitch changer according to any one of claims 1 to 3; A rotating shaft member; a thrust motor that drives the rotating shaft member to rotate the rotating shaft member; A propeller fixed to the rotating shaft member and rotating around the rotating shaft member, the propeller having a plurality of blades, each of the plurality of blades being connected to the rotating shaft member so as to change a pitch angle. Equipped with Controllable pitch propeller device.

5. The controllable pitch propeller device according to claim 4, A control unit for controlling the operation of the controllable pitch propeller device; Equipped with Thrust generating device.

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