Motor

Abstract

To provide a motor in which a gyro effect can be reduced.SOLUTION: A motor 100 includes a stator 30, a shaft 20 mounted on the stator 30 in a rotatable manner, a rotor 40 connected to the shaft 20 and disposed in a rotatable manner with respect to the stator 30, a weight 151, and a reverse rotation mechanism 200 that rotates the weight 151 in a direction opposite to the rotation direction of the rotor 40 with a rotation force generated by the rotor 40.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a motor. [Background technology]

[0002] Conventionally, motors such as that shown in Patent Document 1 have been used as power sources for model airplanes. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2000-134893 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, a problem with a motor such as that shown in Patent Document 1 is that the gyro effect caused by the rotation of the rotor causes the model airplane to behave in a way that is not intended by the pilot.

[0005] The present invention provides a motor capable of reducing the gyroscopic effect. [Means for solving the problem]

[0006] The motor according to the invention described in claim 1, which has been made to achieve the above object, comprises: A stator (30); A shaft (20) rotatably attached to the stator; a rotor coupled to the shaft and rotatably disposed relative to the stator; Weight (151) and and a reverse rotation mechanism (200) that rotates the weight in a direction opposite to the direction of rotation of the rotor by the rotational force generated by the rotor.

[0007] According to this, the weight is rotated in a rotational direction opposite to that of the rotor by the reverse rotation mechanism, so that the gyroscopic effect caused by the rotation of the rotor is reduced by the gyroscopic effect caused by the rotation of the weight which rotates in the opposite direction to that of the rotor.

[0008] The invention described in claim 2 is the invention described in claim 1, The weight is disposed coaxially with the rotor.

[0009] According to this, since the weight is arranged coaxially with the rotor, the gyroscopic effect of the rotor can be appropriately reduced compared to a motor in which the weight is not arranged coaxially with the rotor.

[0010] The invention described in claim 3 is the invention described in claim 2, The weight is rotatably attached to the shaft, The reverse rotation mechanism includes: A plate (153) that is plate-shaped, arranged opposite the weight, and non-rotatably attached to the shaft; an intermediate member (154) rotatably attached to the shaft between the weight and the plate; and an engagement member (155) rotatably attached to the intermediate member and engaging with the weight and the plate.

[0011] This ensures that the weight rotates in the opposite direction to the rotor, thereby ensuring a reduction in the gyroscopic effect of the rotor.

[0012] The invention described in claim 4 is the invention described in claim 3, The engaging member is a roller that contacts the weight and the plate.

[0013] This ensures that the weight rotates in the opposite direction to the rotor, and reduces noise generated when the engaging member rotates in engagement with the weight and the plate.

[0014] The invention described in claim 5 is the invention described in claim 4, The reverse rotation mechanism further includes a biasing member (159) that biases at least one of the weight and the plate so that the weight and the plate approach each other.

[0015] According to this, at least one of the weight and the plate is biased by the biasing member so that the weight and the plate approach each other, and the roller is pressed against the weight and the plate, which prevents the roller from slipping against the weight or the plate and ensures that the weight can be rotated in the opposite direction to the rotation direction of the rotor.

[0016] The invention described in claim 6 is the invention described in claim 3, The intermediate member is characterized in that a rotation preventing member (156) extending in a direction perpendicular to the shaft is attached to the intermediate member.

[0017] According to this, the rotation preventing member comes into contact with the object to which the motor is attached, preventing the rotation of the intermediate member, thereby enabling the weight to be reliably rotated in the direction opposite to the rotation direction of the rotor.

[0018] The invention described in claim 7 is the invention described in claim 6, A shock absorbing member (156b) made of a flexible material is attached to the outer surface of the rotation preventing member.

[0019] According to this, the impact absorbing member can suppress noise caused by vibrations when the rotor rotates and the rotation preventing member abuts against an object.

[0020] The invention described in claim 8 is the invention described in claim 3, The specific gravity of the plate is lighter than the specific gravity of the weight.

[0021] This reduces the rotational moment of the plate, which rotates in the same direction as the rotor, and the gyroscopic effect caused by the rotation of the plate, which not only reduces the weight of the plate itself but also the weight of the weight that cancels the gyroscopic effect of the rotor and plate, and ultimately reduces the weight of the motor.

[0022] The invention described in claim 9 is the invention described in claim 3, The weight is characterized by being composed of a disk-shaped portion (151a) and a ring-shaped portion (151b) protruding from the outer edge of the disk portion.

[0023] According to this, since the ring portion is formed to protrude from the outer edge of the disk portion, the moment of inertia of the weight can be made larger than that of the disk weight, so that even if the weight is made lighter, the same moment of inertia can be maintained, making it possible to reduce the weight of the weight, and therefore the weight of the motor.

[0024] The invention described in claim 10 is the invention described in claim 1, The rotor is disposed on the outer periphery of the stator.

[0025] According to this, since the rotor is disposed outside the stator, it is possible to generate a larger torque compared to a motor in which the rotor is disposed inside the stator. On the other hand, since the rotor is disposed outside the stator, the moment of inertia of the rotor becomes large, and the gyroscopic effect of the rotor becomes large, but the gyroscopic effect of the rotor can be reduced by using a weight.

[0026] The invention described in claim 11 is the invention described in claim 3, The engaging member is characterized by a first roller (171) that contacts the plate, and a second roller (172) that has a diameter larger than that of the first roller, rotates integrally with the first roller, and contacts the weight.

[0027] This allows the weight to reliably rotate in the opposite direction to the rotor. Also, since the diameter of the second roller is larger than that of the first roller, the rotation speed of the weight is faster than the rotation speed of the plate. This increases the gyro effect caused by the weight rotating in the opposite direction to the rotor, and the gyro effect caused by the rotor rotation is further reduced by the gyro effect caused by the weight rotating in the opposite direction to the rotor. Furthermore, it is possible to reduce noise when the engagement member engages with the weight and the plate and rotates.

[0028] The reference symbols in parentheses for each means described in this section and in the claims are examples showing the correspondence with the specific means described in the embodiments described later. [Brief description of the drawings]

[0029] [Figure 1] FIG. 1 is a top view of a model airplane equipped with a motor according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a top view of the front of a model airplane equipped with a motor according to the present embodiment, with the cover removed. [Diagram 3] FIG. 1 is a block diagram of a model airplane. [Figure 4] FIG. 2 is a top view of the motor according to the first embodiment. [Diagram 5] FIG. 11 is a top view of a motor according to a second embodiment. [Figure 6] FIG. 11 is a top view of a motor according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] (Structure of the model airplane and the motor of the first embodiment) A model airplane 500 equipped with a motor 100 according to a first embodiment of the present invention will be described below with reference to Figures 1 and 2. In this embodiment, the model airplane 500 is a so-called control line (U-control) model to which one or two control lines (not shown) are connected, and the pilot controls the attitude by operating the control lines.

[0031] The model airplane 500 has a fuselage 501, main wings 502, horizontal stabilizers 503, and vertical stabilizers 504, which are made of wood such as balsa wood, synthetic resin, carbon, metals such as aluminum alloys, and the like. The fuselage 501 is cylindrical in shape forward of its middle portion and extends in the front-to-rear direction. A cover 505 is detachably attached to a portion of the fuselage 501 forward of the main wings 502. The main wings 502 are plate-shaped and extend in the left-to-right direction from the middle portion of the fuselage 501. The horizontal stabilizers 503 are plate-shaped and extend in the left-to-right direction from the rear end of the fuselage 501. The vertical stabilizers 504 are plate-shaped and extend upward from the rear end of the fuselage 501.

[0032] As shown in Fig. 2, a mounting plate 506 extending in the width direction is attached to the front end of the body 501 so as to connect to the inner peripheral surface of the body 501. A shaft hole 506a is formed in the center of the mounting plate 506. The shaft 20 of the motor 100 passes through the shaft hole 506a, and the motor 100 is attached to the mounting plate 506. The structure in which the motor 100 is attached to the mounting plate 506 will be described in detail later. A propeller 551 is attached to the shaft 20 by a chuck member 550.

[0033] A block diagram of model airplane 500 will be described below with reference to Fig. 3. In addition to motor 100, model airplane 500 has control unit 250, battery 300, and switch 400. Control unit 250, battery 300, and switch 400 are housed and attached within fuselage 501. Operation unit 401 of switch 400 is attached to the outer surface of fuselage 501.

[0034] The motor 100 of the first embodiment is a three-phase AC brushless motor in this embodiment. The battery 300 is, for example, a secondary battery such as a lithium ion battery, and outputs a direct current. The switch 400 has an operation unit 401 such as a button or a lever, and the operation unit 401 is turned on or off by a user's operation. The switch 400 outputs an on signal or an off signal to the control unit 250 by the user's operation of the operation unit 401. In this embodiment, the switch 400 has a timer function. When the user turns the operation unit 401 on, the switch 400 outputs an off signal to the control unit 250 for a first specified time (e.g., several seconds), but outputs an on signal to the control unit 250 from the first specified time until a second specified time (e.g., several tens of seconds to several minutes) has passed, and outputs an off signal to the control unit 250 after the second specified time has passed. In this embodiment, the switch 400 also has an acceleration sensor 402, and outputs an acceleration signal to the control unit 250.

[0035] The control unit 250 controls the motor 100, and when an on signal is input from the switch 400, converts the DC current output from the battery 300 into a three-phase AC current and outputs it to the motor 100 to drive the motor 100. In this embodiment, the control unit 250 outputs a larger current to the motor 100 as the acceleration input from the acceleration sensor 402 of the switch 400 decreases.

[0036] The motor 100 of this embodiment will be described below with reference to Fig. 4. The motor 100 has a base member 10, a shaft 20, a stator 30, and a rotor 40. The motor 100 of this embodiment is an outer rotor type motor in which the rotor 40 is disposed on the outer periphery of the stator 30.

[0037] The base member 10 is a substantially disk-shaped member and is made of metal such as an aluminum alloy. A plurality of screw holes 10a are formed in the front surface of the base member. Here, the structure in which the motor 100 is attached to a mounting plate 506 will be described with reference to FIG. 2. A plurality of mounting holes 506b are formed in the mounting plate 506 and communicate with each other. Bolts 507 are inserted into the respective mounting holes 506b, and the bolts 507 are screwed into the screw holes 10a formed in the base member 10, thereby attaching the motor 100 to the mounting plate 506.

[0038] Returning to Fig. 4, the motor 100 will be described. A first motor bearing 51, such as a ball bearing, is attached to the center of the front surface of the base member 10. An intermediate portion of the shaft 20 is rotatably attached to the base member 10 by the first motor bearing 51. The shaft 20 protrudes forward from the front surface of the base member 10.

[0039] A stator 30 (fixed member) having a substantially cylindrical shape is attached to the rear surface of the base member 10. The stator 30 is composed of an iron core made of laminated electromagnetic steel and a coil made of enameled wire wound around the iron core. The stator 30 is electrically connected to the control unit 250, and generates a magnetic field when a three-phase AC current is supplied from the control unit 250. An insertion hole 30a is formed in the axis of the stator 30, and the shaft 20 is inserted into the insertion hole 30a. A second motor bearing 52 made of a ball bearing or the like is attached to the rear end of the insertion hole 30a of the stator 30. The rear part of the shaft 20 is rotatably attached to the axis of the rear end of the stator 30 by the second motor bearing 52. The shaft 20 protrudes rearward from the rear end of the stator 30.

[0040] The rotor 40 is composed of a casing 41, a plurality of permanent magnets 42, and a connecting member 43. The casing 41 is cylindrical, arranged on the outer periphery of the stator 30, and made of metal. The plurality of permanent magnets 42 are attached to the inner periphery of the casing 41 at regular intervals in the circumferential direction, and face the stator 30 in close proximity. The connecting member 43 is a member that connects the rear end of the casing 41 to the rear end of the shaft 20, and is made of a lightweight metal such as an aluminum alloy. With this configuration, the shaft 20 and the rotor 40 rotate together. The shaft 20 protrudes rearward from the rear end of the connecting member 43.

[0041] When a three-phase AC current is supplied from the control unit 250 to the stator 30, a magnetic field is generated from the stator 30, causing the rotor 40 and the shaft 20 to rotate. The motor 100 of this embodiment is an outer rotor type, and therefore can generate stronger torque than an inner rotor type motor. However, the gyro effect of the rotor 40 is larger than that of an inner rotor type motor. For this reason, if an outer rotor type motor is used in a model airplane, the strong gyro effect will cause the model airplane to behave in a way that is not intended by the pilot. In this embodiment, a gyro effect reduction mechanism 150 is installed in the motor 100 to reduce the gyro effect of the rotor 40.

[0042] The gyroscopic effect reduction mechanism 150 will be described below. The gyroscopic effect reduction mechanism 150 is composed of a substantially disk-shaped weight 151 that rotates in the opposite direction to the rotor 40, and a reverse rotation mechanism 200 that rotates the weight 151 in the opposite direction to the rotation direction of the rotor 40. Since the weight 151 rotates in the opposite direction to the rotor 40, the gyroscopic effect caused by the rotation of the rotor 40 is reduced. The reverse rotation mechanism 200 will be described in detail below.

[0043] The reverse rotation mechanism 200 includes an adapter 152 , a plate 153 , an intermediate member 154 , two rollers 155 , a rotation preventing member 156 , a nut 157 , two washers 158 , and a biasing member 159 .

[0044] A plurality of screw holes 43a are formed at the rear end of the connection member 43. The adapter 152 is composed of a chuck portion 152a and a shaft 152b. The chuck portion 152a is shaped like a truncated cone, and a cylindrically recessed insertion recess 152a1 is formed at the center of the front surface. The rear end of the shaft 20 is inserted and fitted into this insertion recess 152a1. A plurality of communication holes 152a2 are formed in the chuck portion 152a, which communicate in the axial direction of the chuck portion. A plurality of bolts 161 are inserted into these communication holes 152a2, and the tips of these bolts 161 are screwed into the screw holes 43a of the connection member 43, respectively, to attach the adapter 152 to the rear end of the connection member 43. The shaft 152b is shaped like a cylinder, and protrudes rearward from the center of the rear end surface of the chuck portion 152a. A screw portion 152b1 is formed at the rear end of the shaft 152b. The axis 152b and the shaft 20 are arranged coaxially.

[0045] The weight 151 is composed of a disk-shaped disk portion 151a and a ring-shaped ring portion 151b protruding forward from the outer edge of the disk portion 151a. The weight 151 is composed of a metal such as steel or stainless steel, which has a higher specific gravity than aluminum alloys. A bearing hole 151a1 is formed in the center of the disk portion 151a. A first bearing 162 such as a ball bearing is fitted into the bearing hole 151a1 and attached. The weight 151 is attached to the shaft 152b by the first bearing 162 so as to be rotatable and movable in the axial direction. The rear surface of the weight 151 is a contact surface 151c that is perpendicular to the axis of the shaft 20.

[0046] Two washers 158 are attached to the shaft 152b between the rear end surface of the chuck portion 152a and the front surface of the disk portion 151a. A biasing member 159 is attached to the shaft 152b between the two washers 158. In this embodiment, the biasing member 159 is a wave washer, but may be a coil spring. The biasing member 159 biases the weight 151 rearward. In other words, the biasing member 159 biases the weight 151 toward the plate 153 so that the weight 151 and the plate 153 approach each other.

[0047] The intermediate member 154 has a rectangular plate shape and is made of a lightweight metal such as an aluminum alloy. A bearing hole 154a is formed in the center of the intermediate member 154, and a second bearing 163 such as a ball bearing is fitted into the bearing hole 154a and attached. The intermediate member 154 is attached to the rear of the weight 151, facing the weight 151, by the second bearing 163 so as to be rotatable on the shaft 152b and movable in the axial direction of the shaft 152b.

[0048] A pair of rollers 155 are rotatably attached to both ends of intermediate member 154 in the width direction by screws 164 and rotation prevention members 156. Roller 155 is composed of a cylindrical rotating part 155a made of a bearing such as a ball bearing, and a ring-shaped friction member 155b made of a flexible member such as rubber or silicone attached to the outer circumferential surface of this rotating part 155a.

[0049] The rotation preventing member 156 is composed of a cylindrical base member 156a and a pipe-shaped shock absorbing member 156b attached to the outer circumferential surface of the base member 156a. A screw thread is formed on the base end of the base member 156a. The base end of the base member 156a is screwed into the end of the intermediate member 154, and the roller 155 on one side is attached to the intermediate member 154. The rotation preventing member 156 extends in a direction perpendicular to the shaft 20. The shock absorbing member 156b is composed of a flexible material such as silicone or rubber.

[0050] As shown in Fig. 2, a fixing member 509 made of balsa material, resin, or the like is attached to the inner peripheral surface of the body 501. A slit-shaped engagement portion 509a that opens to the motor 100 side is formed in the fixing member 509. The engagement portion 509a may be a hole. The rotation preventing member 156 is inserted into and engaged with the engagement portion 509a. With this configuration, the intermediate member 154 is prevented from rotating relative to the body 501.

[0051] The plate 153 is disk-shaped and made of a lightweight metal such as an aluminum alloy. The specific gravity of the plate 153 is lighter than that of the weight 151. A communication hole 153a is formed in the center of the plate 153. The plate 153 is disposed coaxially with the weight 151 so as to face the weight 151 behind the intermediate member 154. The rear end of the shaft 152b is inserted into the communication hole 153a, and a nut 157 is screwed into a threaded portion 152b1 formed in the rear end of the shaft 152b, so that the plate 153 is attached to the shaft 152b so as not to rotate. In other words, the plate 153 rotates integrally with the shaft 152b, the shaft 20, and the rotor 40.

[0052] The weight 151 is biased rearward, that is, toward the intermediate member 154 and the plate 153, by the biasing member 159, so that the rear surface of the weight 151 and the front surface of the plate 153 are pressed against and in contact with the rollers 155. With this structure, when the rotor 40 rotates, the plate 153 rotates in the same direction as the rotation direction of the rotor 40, but the pair of rollers 155 causes the weight 151 to rotate in the opposite direction to the rotation direction of the plate 153. In other words, the weight 151 rotates in the opposite direction to the rotation direction of the rotor 40.

[0053] (Effects of the motor according to this embodiment) The effects of the motor 100 of this embodiment will be described below. The motor 100 has a stator 30, a shaft 20 rotatably attached to the stator 30, a rotor 40 connected to the shaft 20 and arranged rotatably relative to the stator 30, a weight 151, and a reverse rotation mechanism 200 that rotates the weight 151 in a rotational direction opposite to that of the rotor 40 by the rotational force generated by the rotor 40.

[0054] According to this, the weight 151 is rotated in the opposite direction to the rotor 40 by the reverse rotation mechanism 200, so that the gyro effect caused by the rotation of the rotor 40 is reduced by the gyro effect caused by the rotation of the weight that rotates in the opposite direction to the rotor 40. As a result, the behavior of the model airplane 500 unintended by the pilot and periodic up and down movement during horizontal flight are reduced. In addition, the difficulty of turning the model airplane 500 at the start of turning during a stunt competition and the difficulty of turning when switching during the figure eight flight of the model airplane 500 are significantly improved. In addition, when the model airplane 500 is turned sharply (when a sharp turn close to the performance limit of the model airplane 500 is made), the yawing behavior during turning is significantly improved. Furthermore, when the model airplane 500 is turned sharply, the model airplane 500 does not immediately transition to straight flight after the sharp turn is completed, and the behavior of the model airplane 500 swaying in the yaw direction, pitching direction, and rolling direction is significantly improved.

[0055] Moreover, the weight 151 is disposed coaxially with the rotor 40 .

[0056] According to this, since the weight 151 is arranged coaxially with the rotor 40, the gyroscopic effect of the rotor 40 can be appropriately reduced compared to a motor in which the weight 151 is not arranged coaxially with the rotor 40.

[0057] Moreover, weight 151 is disc-shaped and rotatably attached to shaft 20. Reverse rotation mechanism 200 has a disc-shaped plate 153 disposed opposite weight 151 and non-rotatably attached to shaft 20, intermediate member 154 rotatably attached to shaft 20 between weight 151 and plate 153, and roller 155 rotatably attached to intermediate member 154 and serving as an engagement member that engages with weight 151 and plate 153.

[0058] According to this, it is possible to reliably rotate the weight 151 in the direction opposite to the direction of rotation of the rotor 40. Therefore, the gyroscopic effect of the rotor 40 can be reliably reduced.

[0059] The engagement member is a roller 155 that contacts the weight 151 and the plate 153 .

[0060] This allows weight 151 to reliably rotate in the opposite direction to rotor 40. Also, compared to a configuration in which the engaging member is a gear, it is possible to reduce noise generated when roller 155, which is the engaging member, engages with weight 151 and plate 153 and rotates.

[0061] Moreover, the reverse rotation mechanism 200 further includes a biasing member 159 that biases the weight 151 toward the plate 153 so that the weight 151 and the plate 153 approach each other.

[0062] According to this, the biasing member 159 biases the weight 151 toward the plate 153 so that the weight 151 and the plate 153 approach each other, and the roller 155 is pressed against the weight 151 and the plate 153. Therefore, the roller 155 is prevented from slipping against the weight 151 and the plate 153, and the weight 151 can be reliably rotated in the direction opposite to the rotation direction of the rotor 40.

[0063] Further, a rotation preventing member 156 extending in a direction perpendicular to the shaft 20 is attached to the intermediate member 154 .

[0064] According to this, since the rotation preventing member 156 is engaged with the engaging portion 509a attached to the body 501 to which the motor 100 is attached, the rotation of the intermediate member 154 is prevented. Therefore, the weight 151 can be reliably rotated in the direction opposite to the rotation direction of the rotor 40.

[0065] Additionally, a shock absorbing member 156b made of a flexible material is attached to the outer surface of the rotation preventing member 156.

[0066] According to this, the shock absorbing member 156b can suppress noise caused by vibrations when the rotor rotates and the rotation preventing member comes into contact with an object.

[0067] Moreover, the specific gravity of the plate 153 is lighter than the specific gravity of the weight 151 .

[0068] This makes it possible to reduce the rotational moment of plate 153, which rotates in the same direction as rotor 40, and to reduce the gyroscopic effect caused by the rotation of plate 153. As a result, not only can plate 153 itself be made lighter, but it is also possible to reduce the weight of weight 151, which cancels the gyroscopic effect of rotor 40 and plate 153, and ultimately the weight of motor 100.

[0069] Weight 151 is made up of a disk-shaped portion 151a and a ring-shaped portion 151b protruding from the outer edge of disk portion 151a.

[0070] According to this, because ring portion 151b is formed to protrude from the outer edge portion of disk portion 151a, the moment of inertia of weight 151 can be made larger than that of a disk weight. Therefore, even if weight 151 is made lighter, the same moment of inertia can be maintained, making it possible to reduce the weight of weight 151, and therefore the weight of motor 100.

[0071] The rotor 40 is disposed on the outer circumferential side of the stator 30 .

[0072] According to this, since the rotor 40 is disposed outside the stator 30, a larger torque can be generated compared to a motor in which the rotor is disposed inside the stator. On the other hand, since the rotor 40 is disposed outside the stator 30, the moment of inertia of the rotor 40 becomes large, and the gyroscopic effect of the rotor 40 becomes large, but the gyroscopic effect of the rotor 40 can be reduced by the weight 151.

[0073] (Motor of the second embodiment) The motor 600 of the second embodiment will be described below with reference to Fig. 5, focusing on the differences between the motor 600 of the second embodiment and the motor 100 of the first embodiment. In the motor 600 of the second embodiment, parts having the same structure as those in the motor 100 of the first embodiment are given the same reference numerals, and the description thereof will be omitted.

[0074] In the motor 600 of the second embodiment, the plate 153 is attached to the connecting member 43 by a plurality of bolts 167 with the shaft 20 inserted into the communication hole 153a. In the motor 600 of the second embodiment, the shaft 20 protrudes rearward significantly from the rear end surface of the connecting member 43. A threaded portion 20a is formed at the rear end of the shaft 20. In the second embodiment, the contact surface 151c of the weight 151 is formed on the front surface of the weight 151.

[0075] An intermediate member 154, to which a pair of rollers 155 and a rotation preventing member 156 are attached, is disposed behind the plate 153. The intermediate member 154 is rotatably supported on the shaft 20 by a second bearing 163 attached to the intermediate member 154. The weight 151 is disposed behind the intermediate member 154. The weight 151 is attached to the shaft 20 by a first bearing 162 attached to a bearing hole 151a1 formed in the weight 151 so as to be rotatable on the shaft 20 and movable in the axial direction of the shaft 20.

[0076] A stopper member 165 is attached to the threaded portion 20a formed at the rear end of the shaft 20. In this embodiment, the stopper member 165 is two nuts. A biasing member 166 is attached between the stopper member 165 and the weight 151. In this embodiment, the biasing member 166 is a coil spring arranged on the outer circumferential side of the rear end of the shaft 20. The biasing member 166 biases the weight 151 toward the plate 153 (front side), and the pair of rollers 155 is pressed against the rear surface of the plate 153 and the front surface of the weight 151.

[0077] With this structure, when the rotor 40 rotates, the plate 153 rotates in the same direction as the rotation direction of the rotor 40, but the pair of rollers 155 causes the weight 151 to rotate in the opposite direction to the rotation direction of the plate 153. In other words, the weight 151 rotates in the opposite direction to the rotation direction of the rotor 40.

[0078] (Motor of the third embodiment) The motor 700 of the third embodiment will be described below with reference to Fig. 6 with respect to the differences from the motor 600 of the second embodiment. In the motor 700 of the second embodiment, parts having the same structure as those in the motor 600 of the second embodiment are given the same reference numerals, and the description thereof will be omitted.

[0079] In the motor 700 of the third embodiment, a roller 170 is attached to the intermediate member 154 instead of the roller 155. The roller 170 is composed of a first roller 171 and a second roller 172. The first roller 171 and the second roller 172 are provided coaxially and adjacent to each other in the width direction. The diameter of the second roller 172 is larger than the diameter of the first roller 171. In this embodiment, the diameter of the second roller 172 is twice the diameter of the first roller 171.

[0080] The first roller 171 is composed of a cylindrical first rotating part 171a composed of a bearing such as a ball bearing, and a ring-shaped first friction member 171b composed of a flexible material such as rubber or silicon attached to the outer circumferential surface of the first rotating part 171a. The second roller 172 is composed of a disk-shaped second rotating part 172a having a bearing such as a ball bearing at its center, and a ring-shaped second friction member 172b composed of a flexible material such as rubber or silicon attached to the outer circumferential surface of the second rotating part 172a. Since the first rotating part 171a and the second rotating part 172a are connected, the first roller 171 and the second roller 172 rotate together.

[0081] The first roller 171 is in contact with the rear surface of the plate 153. The second roller 172 is in contact with a contact surface 151c on the rear surface of the weight 151.

[0082] With this structure, when the rotor 40 rotates, the plate 153 rotates in the same direction as the rotor 40, but the pair of rollers 170 rotate the weight 151 in the opposite direction to the rotation direction of the plate 153. That is, the weight 151 rotates in the opposite direction to the rotation direction of the rotor 40. In this embodiment, the diameter of the second roller 172 is larger than the diameter of the first roller 171, so the rotation speed of the weight 151 is faster than the rotation speed of the plate 153. The rotation speed of the weight 151 is approximately the number obtained by dividing the diameter of the second roller 172 by the diameter of the first roller 171 and multiplying it by the rotation speed of the plate 153. That is, in this embodiment, the rotation speed of the weight 151 is about twice the rotation speed of the plate 153.

[0083] In this manner, in motor 700 of the third embodiment, as described above, the diameter of second roller 172 is larger than the diameter of first roller 171, and therefore the rotation speed of weight 151 is faster than the rotation speed of plate 153. Therefore, the gyro effect caused by the rotation of weight 151 rotating in the opposite direction to rotor 40 becomes larger, and the gyro effect caused by the rotation of rotor 40 is further reduced by the gyro effect caused by the rotation of weight 151 rotating in the opposite direction to rotor 40.

[0084] (Other embodiments) The present invention has been described above in relation to the embodiment that is considered to be the most practical and preferable at this time. However, the present invention is not limited to the embodiment disclosed in the specification of this application, and may be modified as appropriate within the scope of the claims and the gist or concept of the invention that can be read from the specification as a whole. Motors 100, 600 with such modifications should also be understood to be included within the technical scope.

[0085] In the embodiment described above, the biasing member 159 biases the weight 151 toward the plate 153. An embodiment in which the biasing member 159 biases the plate 153 toward the weight 151 may also be used. Alternatively, an embodiment in which the biasing member 159 biases both the weight 151 and the plate 153 so that the weight 151 and the plate 153 approach each other may also be used.

[0086] In the embodiment described above, the engaging member that is rotatably attached to the intermediate member 154 and engages with the weight 151 and the plate 153 is a pair of rollers 155. An embodiment in which the engaging member is a gear that engages with the weight 151 and the plate 153 may be used. In this embodiment, a gear portion that engages with the gear rotatably attached to the intermediate member 154 is formed on the weight 151 and the plate 153.

[0087] In the embodiment described above, the weight 151 is composed of a disk-shaped disk portion 151a and a ring-shaped ring portion 151b protruding forward from the outer edge of the disk portion 151a. The weight 151 may be composed of a disk without the ring portion 151b.

[0088] The motors 100 and 600 of the embodiments described above are outer rotor type motors in which the rotor 40 is disposed on the outer periphery of the stator 30. The motors 100 and 600 may be inner rotor type motors in which the rotor 40 is disposed on the inner periphery of the stator 30.

[0089] In the above-described embodiment, the model airplane 500 on which the motor 100, 600 is mounted is a control line, but it may be a radio-controlled model airplane. Furthermore, the motor 100, 600 may be mounted not only on a model airplane, but also on other objects (for example, a model ship). [Explanation of symbols]

[0090] 30 Stator 100 Motor of the first embodiment (motor) 151 Weight 151a Disc section 151b Ring section 153 Plate 154 Intermediate parts 155 Roller (engagement member) 156 Rotation prevention member 156b Shock absorbing material 159 Pressing member 170 Roller (engagement member) 171 First Roller 172 Second Roller 200 Reverse rotation mechanism 600 Motor of the second embodiment (motor) 700 Motor of the third embodiment (motor)

Claims

1. A stator (30); A shaft (20) rotatably attached to the stator; a rotor coupled to the shaft and rotatably disposed relative to the stator; Weight (151) and and a reverse rotation mechanism (200) that rotates the weight in a direction opposite to the direction of rotation of the rotor by a rotational force generated by the rotor.

2. 2. The motor according to claim 1, wherein the weight is disposed coaxially with the rotor.

3. The weight is rotatably attached to the shaft, The reverse rotation mechanism includes: A plate (153) that is plate-shaped, arranged opposite the weight, and non-rotatably attached to the shaft; an intermediate member (154) rotatably attached to the shaft between the weight and the plate; 3. The motor according to claim 2, further comprising an engagement member (155) rotatably attached to said intermediate member and engaging with said weight and said plate.

4. 4. The motor according to claim 3, wherein the engagement member is a roller that contacts the weight and the plate.

5. 5. The motor according to claim 4, wherein the reverse rotation mechanism further comprises a biasing member (159) that biases at least one of the weight and the plate so that the weight and the plate approach each other.

6. 4. The motor according to claim 3, wherein the intermediate member is provided with a rotation preventing member (156) extending in a direction perpendicular to the shaft.

7. 7. The motor according to claim 6, wherein a shock absorbing member (156b) made of a flexible material is attached to an outer surface of the rotation preventing member.

8. 4. The motor according to claim 3, wherein the specific gravity of the plate is less than the specific gravity of the weight.

9. 4. The motor according to claim 3, wherein the weight is composed of a disk portion (151a) having a disk shape and a ring portion (151b) protruding from an outer edge of the disk portion.

10. 2. The motor according to claim 1, wherein the rotor is disposed on an outer periphery of the stator.

11. The motor according to claim 3, characterized in that the engagement members are a first roller (171) that contacts the plate, and a second roller (172) that has a diameter larger than that of the first roller, rotates integrally with the first roller, and contacts the weight.

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