Servo motor device and moving mechanism

Abstract

To provide a servo motor device that has preferable fitting property.SOLUTION: A servo motor device includes: a body part including a motor; an output shaft projecting from the body part, held by the body part so as to be freely rotatable and outputting power of the motor; and a through-hole penetrating through the body part.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a servo motor device having a main body including a motor and an output shaft that protrudes from the main body, is rotatably held by the main body, and outputs the power of the motor, and to a movable mechanism having a servo motor device and a driven part that is driven based on the power of the motor in the servo motor device. [Background technology]

[0002] For example, as disclosed in the following Patent Documents 1 and 2, there is known a servo motor device that can be used as an actuator in the steering mechanism of a model car, the joints of a robot, etc. The servo motor device comprises a main body including a motor, and an output shaft that protrudes from the main body, is rotatably held by the main body, and outputs the power of the motor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-29669 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-43848 Summary of the Invention [Problem to be solved by the invention]

[0004] Servo motor devices can be applied to various types of moving mechanisms, such as the steering mechanism and joints of robots, etc. When considering application to moving mechanisms, it is desirable for the servo motor device to have good attachability, such as increased flexibility in attachment to other components.

[0005] The present invention has been made in view of the above circumstances, and has as its object to provide a servo motor device that is easy to install. [Means for solving the problem]

[0006] A servo motor device according to the present invention includes a main body including a motor, and an output shaft that protrudes from the main body, is rotatably held by the main body, and outputs power from the motor, and has a through hole that penetrates the main body while avoiding components arranged inside the main body. and a bearing is provided in the through hole. This is what we do. By providing the above-mentioned through hole, when the servo motor device is used as an actuator in various moving mechanisms such as the steering mechanism of a model car or the joint parts of a robot, it becomes possible to adopt an attachment method using the through hole as a method of attaching the servo motor device to other parts.

[0007] The movable mechanism according to the present invention includes a main body including a motor, and an output shaft that projects from the main body, is rotatably held by the main body, and outputs power from the motor. At the same time, A through hole is provided that passes through the main body while avoiding components disposed inside the main body. and a bearing is provided in the through hole. and a driven part that is driven by the power of the motor. Such a movable mechanism also provides the same effects as those described above for the servo motor device. [Effects of the Invention]

[0008] According to the present invention, a servo motor device with good mountability can be realized. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a block diagram for explaining an outline of the electrical configuration of a radio control system according to an embodiment of the present invention; [Figure 2] FIG. 10 is a diagram showing an example of the configuration of a steering mechanism using a link mechanism. [Figure 3] 4 is an explanatory diagram of the steering angle dependency of the amount of change in the rotation angle of the steered wheels. FIG. [Figure 4]1 is a perspective view of the exterior of a model car according to an embodiment, mainly showing the steering mechanism and its surroundings in the model car; [Figure 5] 1 is an explanatory diagram of an external configuration of a servo motor device according to an embodiment; [Figure 6] FIG. 2 is an explanatory diagram of an internal component arrangement of the servo motor device according to the embodiment. [Figure 7] 3A and 3B are explanatory diagrams of a mounting mechanism for a steering wheel in the embodiment. [Figure 8] FIG. 2 is a diagram showing the state in the vicinity of the left steering wheel when traveling straight. [Figure 9] FIG. 10 is a diagram showing the state in the vicinity of the left steered wheel when steering to the right. [Figure 10] FIG. 1 is an explanatory diagram illustrating the attachment of a steering wheel using a wheel hub portion. [Figure 11] FIG. 10 is an explanatory diagram of the effect obtained by shortening the scrub radius. [Figure 12] 3 is an explanatory diagram of an input damping mechanism provided in the model car of the embodiment. FIG. [Figure 13] FIG. 10 is an explanatory diagram of an input damping mechanism provided in the model car of the embodiment. [Figure 14] FIG. 10 is an explanatory diagram of a steering mechanism as a modified example. [Figure 15] FIG. 10 is a perspective view illustrating another example of the configuration of the main body portion. [Figure 16] 10 is an explanatory diagram of a state in which a mounting member is attached to a servo motor device as another configuration example. FIG. [Figure 17] FIG. 10 is a perspective view illustrating yet another example of the configuration of the main body portion. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described in the following order. <1. Overview of the radio control system configuration> <2. Movable mechanism as an embodiment> <3. Input attenuation mechanism> <4. Modifications> <5. Summary of embodiments> <6. Other examples of main body configuration>

[0011] In the following description, a steering mechanism of a model car is taken as an example of a movable mechanism according to the present invention, and a steering servomotor used as a drive source for driving the steering wheels in the steering angle direction in the steering mechanism of the model car is taken as an example of a servo motor device according to the present invention.

[0012] <1. Overview of the radio control system configuration> FIG. 1 is a block diagram for explaining the outline of the electrical configuration of a radio control system 100 according to an embodiment. The radio control system 100 includes at least a model car 1 as a controlled object, and a transmitter 2 that functions as a controller for controlling the model car 1 wirelessly.

[0013] Although not shown in the figures, in this example the model car 1 is configured as a four-wheeled vehicle with a pair of wheels, one at the front and one at the back, for a total of four wheels, with the pair of left and right wheels serving as front wheels being provided as steering wheels W for turning the model car 1, and the pair of left and right wheels serving as rear wheels being provided as drive wheels for running the model car 1. In the following, the left steering wheel W will be referred to as "steering wheel WL" and the right steering wheel W will be referred to as "steering wheel WR".

[0014] The model car 1 is provided with at least a receiver 10 that receives a control signal from the transmitter 2, a running servomotor 14 as a servomotor for accelerating, decelerating, and steering, and a steering servomotor 15. In the model automobile 1 of this example, the steering servo motors 15 include a steering servo motor 15 (hereinafter referred to as "steering servo motor 15L") for driving the left steering wheel WL to rotate in the steering angle direction, and a steering servo motor 15 (hereinafter referred to as "steering servo motor 15R") for driving the right steering wheel WR to rotate in the steering angle direction. The running servo motor 14 is a servo motor for adjusting the carburetor of an engine (not shown) mounted on the model automobile 1. In this example, the model automobile 1 is an engine vehicle, and the rear wheels are driven by the engine as a drive source. By controlling the rotation of this running servo motor 14, it is possible to control the acceleration (accelerator) and deceleration (brake) of the model automobile 1. It is also possible to configure the model car 1 so that the wheels are driven by a motor as a drive source. In this case, an ESC (speed controller) is provided to control the motor for running.

[0015] The receiver 10 in the model car 1 will be described in detail later.

[0016] The transmitter 2 modulates a control signal for wirelessly controlling the model car 1 and transmits it as radio waves. As shown in the figure, the transmitter 2 includes an interface unit 20, an encoder 25, a transmitting unit 26, and an antenna 27.

[0017] The interface unit 20 performs interface operations for the user, such as accepting operation inputs from the user as a pilot and presenting various information to the user. The interface unit 20 is provided with two operation levers 21, two trim switches 22, a display unit 23, and a setting operation unit 24.

[0018] The operating levers 21 include an operating lever 21X for controlling the steering of the model automobile 1 and an operating lever 21Y for controlling acceleration and deceleration. In the example of Figure 1, the direction of the steering wheel W can be controlled by operating the steering control lever 21X in the direction indicated by the arrow X (horizontal on the paper), and the acceleration and deceleration of the model car 1 can be controlled by operating the other control lever 21Y in the direction indicated by the arrow Y (vertical on the paper). The steering and acceleration / deceleration controls are not limited to the lever-shaped controls shown as examples, and controls in other shapes, such as wheel-shaped controls, can also be used.

[0019] In this example, the steering servo motors 15 of the model automobile 1 are provided for the left and right steering wheels W, respectively, as described above, and therefore, in response to the operation of the operating lever 21X, a signal for driving the left steering servo motor 15L and a signal for driving the right steering servo motor 15R are generated separately. In this example, the operating lever 21X is configured to change the resistance value of a variable resistor in accordance with the amount of operation (displacement) and output a control signal for each of the steering servo motors 15L and 15R. The operating lever 21Y is also configured to output a control signal for the traveling servomotor 14 by changing the resistance value of a variable resistor in accordance with the amount of operation.

[0020] By the operation levers 21X and 21Y as described above, the transmitter 2 generates control signals for a total of three channels, one for the steering servomotor 15L, one for the steering servomotor 15R, and one for the traveling servomotor 14. In the figure, the control signals of these channels generated based on the operation of the control lever 21X and the control lever 21Y are shown as signals CH1, CH2, and CH3. Here, the signal CH1 is the control signal for the traveling servomotor 14, and the signals CH2 and CH3 are the control signals for the steering servomotors 15L and 15R, respectively. As shown, these signals CH1, CH2, and CH3 are input to an encoder 25.

[0021] The above channel assignment is merely an example for the purpose of explanation, and the combination of channels and signals can be changed as appropriate, for example, CH1 can be used for steering signals (left and right) and CH2 can be used for driving signals.

[0022] The interface unit 20 is also provided with a trim switch 22 for adjusting the resistance value of the variable resistor (value of the control signal of the servo motor) relative to the neutral position when the control lever 21 is not being operated. In this example, this trim switch 22 is provided for each of the control levers 21X and 21Y (see 22X and 22Y in the drawing). The resistance value of the variable resistor for the neutral position can also be configured to be set by operation via the setting operation unit 24, which will be described later.

[0023] Furthermore, the interface unit 20 is provided with a display unit 23 configured, for example, by an LCD (Liquid Crystal Display) or an organic EL (Electro-Luminescence) display. The user can use various controls provided in a setting operation unit 24 to configure various settings related to the operation of the model automobile 1 through a setting screen displayed on the display unit 23. For example, the maximum turning angle of the steering wheel W can be set as a steering-related setting. Settings here also include whether or not to perform control to change the toe angles of the steering wheels WL and WR (control to improve straight-line stability) in response to brake or accelerator operation using the control lever 21Y. In this case, toe angle adjustment is achieved by superimposing a toe angle adjustment signal on the control signal for the steering servo motors 15L and 15R.

[0024] In the transmitter 2, the encoder 25 performs, for example, pulse width conversion on the signals CH1, CH2, CH3 of each channel input from the interface unit 20, and also time-division multiplexes and outputs these signals CH1, CH2, CH3 at a predetermined frame period. The time-division multiplexed signals CH1, CH2, and CH3 are input to the transmitter 26, which then performs AM modulation (amplitude modulation) or FM modulation (frequency modulation FM) on the time-division multiplexed signals CH1, CH2, and CH3, and transmits the modulated signals as control signals via radio waves from the antenna 27.

[0025] In the model car 1, the receiver 10 has an antenna 11, a receiving unit 12, and a decoder 13. The receiver 10 receives and demodulates the control signal transmitted by the transmitter 2 via the antenna 11 and outputs the demodulated received signal to the decoder 13 .

[0026] The decoder 13 separates the operation signal received by the receiver 10 into signals CH1, CH2, and CH3 for each channel, and outputs the separated signals CH1, CH2, and CH3 to the corresponding servomotors among the traveling servomotor 14 and the steering servomotors 15L and 15R. Specifically, in this example, the signal CH1 is output to the traveling servomotor 14, the signal CH2 to the steering servomotor 15L, and the signal CH3 to the steering servomotor 15R. As a result, the steering servomotors 15L and 15R are each driven and controlled in response to the operation of the control lever 21X, and the steering of the model automobile 1 is realized in response to the operation of the control lever 21X. Furthermore, the running servo motor 14 is driven and controlled in response to the operation of the control lever 21Y, and the model car 1 is accelerated or decelerated in response to the operation of the control lever 21Y.

[0027] <2. Movable mechanism as an embodiment> Here, with regard to the steering mechanism of the model car 1, it is conceivable to adopt a configuration in which the steering servo motor 15 is provided on the vehicle body (chassis) side, and the rotational driving force from the steering servo motor 15 is transmitted to the steering wheel side via a steering link mechanism, as in the aforementioned Patent Document 1. FIG. 2 illustrates the configuration disclosed in FIG. 6 of Patent Document 1 as an example of a steering mechanism using such a link mechanism. As can be understood by referring to FIG. 2, the link mechanism converts the rotational driving force of the steering servo motor 15 into translational motion in the left and right direction, thereby driving the left and right steering wheels W to rotate in the steering angle direction.

[0028] However, in the above-described link mechanism, a considerable amount of connection play occurs, and this connection play leads to a decrease in steering control accuracy. Furthermore, because the above-mentioned link mechanism converts the rotational motion of the steering servo motor 15 into translational motion in the left-right direction to drive the steering wheels W, the amount of change in the rotational angle of the steering wheels W relative to a change in the rotational angle of the output shaft of the steering servo motor 15 changes depending on the steering angle, which is also a factor that leads to a decrease in steering control accuracy.

[0029] FIG. 3 is an explanatory diagram of the steering angle dependency of the amount of change in the rotation angle of the steered wheels W. As can be seen from Figure 3, when the above-mentioned link mechanism is used, the amount of change in the rotation angle of the steered wheels W relative to the change in the rotation angle of the output shaft of the steering servo motor 15 is relatively large in the region where the steering angle is small, whereas the amount of change in the rotation angle of the steered wheels W relative to the change in the rotation angle of the output shaft of the steering servo motor 15 is relatively small in the region where the steering angle is large, and the amount of change in the rotation angle of the steered wheels W varies depending on the steering angle.

[0030] Therefore, in view of the above-mentioned problems, in this embodiment, the steering mechanism of the model car 1 is configured such that a steering servo motor 15 is placed between the steering wheel W and an arm portion from the vehicle body side, that is, a so-called in-wheel servo configuration is adopted.

[0031] The steering mechanism 50 provided in the model car 1 according to the embodiment will be described with reference to FIGS. Fig. 4 is an external perspective view of the model automobile 1, mainly showing the area around the steering mechanism 50 of the model automobile 1, Fig. 5 is an explanatory diagram of the external configuration of the steering servo motor 15, and Fig. 6 is an explanatory diagram of the internal component arrangement of the steering servo motor 15. Fig. 7 is an explanatory diagram of the mounting mechanism for the steering wheels, and Figs. 8 and 9 are diagrams showing the area around the left steering wheel WL when traveling straight and when steering to the right, respectively. In FIG. 4, the wiring for the steering servomotor 15, the receiver 10, and the traveling servomotor 14 are omitted from the illustration. 5A and 5B are a top view and a side view, respectively, of steering servo motor 15, and Fig. 6 is a side view of steering servo motor 15. Furthermore, in Fig. 7, Fig. 7A is a top view of the mounting mechanism, and Fig. 7B is an explanatory diagram of various members used in the mounting mechanism, and in Fig. 8, Fig. 8A and Fig. 8B are a top view and a rear view (viewed from the rear of the vehicle) of the vicinity of the left steered wheel WL, respectively.

[0032] The steering mechanism 50 is disposed near the front end of the chassis 1a of the model car 1 (see FIG. 4). In this example, the steering mechanism 50 has a bilaterally symmetrical configuration, and each of the left and right sides has at least an upper arm 51, a lower arm 52, a steering servo motor 15, a rotating shaft 71, and a steering wheel W. In the following description, when distinguishing between the left and right components of the steering mechanism 50, the left component will have the suffix "L" added to the end of its reference number, and the right component will have the suffix "R" added to the end of its reference number.

[0033] Here, in FIG. 4, shock absorbers 61 (61L and 61R) and shock towers 62 are shown as components related to the suspension of the model automobile 1, but these components will be explained again later.

[0034] Upper arm 51 and lower arm 52 function as arm sections for supporting steered wheel W from the chassis 1a side, and are arranged spaced apart in the vertical direction. Upper arm 51 and lower arm 52 have their bases attached to the chassis 1a side so as to extend toward the outside of the vehicle body, and the portions near their tips (the portions farthest from the chassis 1a side) are formed as tip section 51a and tip section 52a, respectively.

[0035] In this example, a steering servo motor 15 is arranged between the tip 51a of the upper arm 51 and the tip 52a of the lower arm 52, and the steering wheel W is connected to the steering servo motor 15 via a rotating shaft portion 71.

[0036] The steering servo motor 15 has a main body 15a and an output shaft 15b (see FIG. 5). The output shaft 15b protrudes from the main body 15a and outputs the power of the motor. In other words, it functions as an output shaft for the rotational driving force generated by the motor. The main body 15a has a motor (motor 156, described later) inside and is the part that rotatably holds the output shaft 15b. As shown in the figure, the main body 15a is formed in a plate shape in this example, and the output shaft 15b protrudes upward from the top surface of the main body 15a. The directions here are based on the directions when attached to the model car 1.

[0037] The output shaft 15b protrudes from any of four of the six faces of the plate-shaped main body 15a that are parallel to the thickness direction of the main body 15a. In the steering mechanism 50 of this example, the steering servo motor 15 is disposed so that the output shaft 15b protrudes upward. In other words, the steering servo motor 15 is disposed so that the two main faces that are perpendicular to the thickness direction of the main body 15a are parallel to the up-down direction.

[0038] Here, the steering servomotor 15 has a through hole 151 that penetrates the main body portion 15a, and has a bearing 70 inside this through hole 151 (see FIG. 5B). 6, the through-hole 151 is formed as a hole that penetrates through the thickness direction of the main body portion 15a at approximately the center of the main surface of the main body portion 15a. In this example, the through-hole 151 is formed as a hole that is approximately cylindrical.

[0039] As shown in FIG. 6, inside the main body 15a, there are provided a motor 156, a speed reduction mechanism 157 that transmits the rotational power of the motor 156 to the output shaft 15b and reduces the rotational speed of the output shaft 15b relative to the rotational speed of the motor 156, an angle detection unit 158 ​​such as a potentiometer (variable resistor) that detects the rotational angle of the output shaft 15b, and a circuit board 159 on which a drive circuit for the motor 156 and other electronic components are mounted. Through hole 151 is formed in approximately the center of the main surface of main body 15a, avoiding components arranged inside main body 15a such as motor 156, speed reduction mechanism 157, angle detection unit 158, and circuit board 159. In other words, components arranged inside main body 15a such as motor 156, speed reduction mechanism 157, angle detection unit 158, and circuit board 159 are arranged so as to avoid a position that is approximately the center of the main surface so that through hole 151 can be formed in approximately the center of the main surface of main body 15a.

[0040] The bearing 70 is configured as a bearing such as a rolling bearing or a sliding bearing, and is fitted into the through hole 151 in the main body 15a. An inner hole 70h as a substantially cylindrical through-hole is formed inside the inner ring of the bearing 70. This inner hole 70h functions as a rotation shaft insertion hole through which the rotation shaft 71 of the steered wheel W is inserted.

[0041] Here, when bearing 70 is fitted into through hole 151 as described above, through hole 151 cannot be seen with the naked eye. However, in the configuration in which bearing 70 is embedded in main body portion 15a as shown in Fig. 5B, it is clear that through hole 151 for arranging bearing 70 is formed in main body portion 15a. Therefore, in a configuration in which the bearing 70 is embedded in the main body portion 15a as illustrated in FIG. 5B, it can be considered that the main body portion 15a has a through-hole 151 formed therein for arranging the bearing 70.

[0042] With reference to FIG. 7, the mechanism for attaching the steering wheel W to the steering servo motor 15 will be described. In Figure 7, only the left mounting mechanism of the left and right steering wheels WL and WR will be explained as a representative. However, the right mounting mechanism is symmetrical to the left mounting mechanism, so an explanation using the illustration will be omitted. In addition, in FIG. 7A, only the wheel portion of the steering wheel W (WL) is shown, and the upper half is cut away as a cutaway model.

[0043] The rotary shaft 71 is a rotary shaft of the steering wheel W, and is formed in a rod shape (see FIG. 7B). Specifically, in this example, the rotary shaft 71 is formed as a substantially cylindrical member. The rotary shaft portion 71 is used as a member for connecting the main body portion 15a of the steering servomotor 15 and the steering wheel W.

[0044] In the rotary shaft portion 71, the end portion to which the steering wheel W is connected is referred to as a tip portion 71b, and the end portion to which the main body portion 15a is connected is referred to as a base portion 71c. A thread is formed on the tip end portion 71b for threading onto a nut 73 used to fasten the steering wheel W. The diameter of the tip end portion 71b on which the thread is formed is smaller than the diameter of the base portion of the tip end portion 71b in the rotating shaft portion 71. That is, in the rotating shaft portion 71, a step portion 71d is formed at the boundary between the tip end portion 71b and the portion closer to the base portion, due to the difference in diameter from the tip end portion 71.

[0045] Further, the rotary shaft portion 71 is formed with a flange portion 71a at a position closer to the tip side than the base portion 71c and closer to the base side than the tip portion 71b. The flange portion 71a functions as a position restricting portion for preventing the rotating shaft portion 71 from being displaced toward the chassis 1a of the model car when the root portion 71c of the rotating shaft portion 71 is inserted into the inner hole 70h of the bearing 70. The flange portion 71a is formed at a position offset from the root end of the rotating shaft portion 71 toward the tip end by an amount corresponding to the thickness of the main body portion 15a.

[0046] A hole 71h that protrudes from the base end of the rotating shaft 71 toward the tip end is formed in the base 71c of the rotating shaft 71. This hole 71h is used to fasten a bolt 72 that fixes the base 71c of the rotating shaft 71 to the main body 15a of the steering servo motor 15, and a thread groove is formed on the outer peripheral wall of this hole 71h.

[0047] The steering wheel W is attached to the main body 15a using the rotation shaft 71 configured as described above, the bolts 72 and the nuts 73. Specifically, with the tip end 71b of the rotating shaft 71 inserted into the center hole Wh of the steering wheel W, a nut 73 is screwed onto the tip end 71b to fix the steering wheel W at the tip end 71b. At this time, the diameter of the step 71d formed on the rotating shaft 71 is larger than the center hole Wh, so the step 71d comes into contact with the outer periphery of the center hole Wh of the wheel of the steering wheel W and functions as a flange portion to prevent the rotating shaft 71 (and the steering wheel W) from being displaced in a direction approaching the steering servo motor 15.

[0048] Furthermore, the base portion 71c of the rotating shaft portion 71 is inserted into the inner hole 70h of the bearing 70 in the main body portion 15a, and in this state, the bolt 72 is screwed into the hole 71h in the base portion 71c. At this time, the diameter of the head of the bolt 72 is larger than the diameter of the base portion 71c (and the inner hole 70h of the bearing 70). In other words, the bolt 72 has a portion with a larger diameter than the diameter of the base portion 71c (and the inner hole 70h of the bearing 70).

[0049] As described above, by threading the bolt 72 into the hole 71h of the base portion 71c, the base portion 71c of the rotating shaft 71 is fixed to the main body 15a. At this time, the base portion 71c is inserted into the inner hole 70h of the bearing 70, so that the rotating shaft 71 and the steering wheel W fixed to its tip end 71b are rotatably held by the main body 15a.

[0050] Furthermore, when the bolt 72 is threaded into the hole 71h of the base portion 71c as described above, the head of the bolt 72 has a larger diameter than the hole 71h of the base portion 71c and the inner hole 70h of the bearing 70, and therefore the head of the bolt 72 abuts on a portion of the main body 15a that is outer circumferential of the portion where the inner hole 70h is formed. Specifically, in this example, the head of the bolt 72 abuts on the inner ring of the bearing 70. This prevents the rotating shaft portion 71 and the steering wheel W fixed thereto from being displaced in a direction away from the steering servo motor 15, and prevents the steering wheel W from coming off the model car 1 together with the rotating shaft portion 71.

[0051] The bolt 72 is an example of the "cap portion" referred to in the claims. The method of locking the cap portion to the rotary shaft portion 71 is not limited to the locking method using the threads and screw grooves exemplified above, and other locking methods can also be adopted.

[0052] Furthermore, when the bolt 72 is threaded into the hole 71h of the base portion 71c as described above, the flange portion 71a of the rotating shaft portion 71 abuts against a portion of the main body portion 15a that is more outer than the portion where the inner hole 70h is formed, specifically, in this example, against the inner ring of the bearing 70. Such flange portion 71a restricts the position of the rotating shaft portion 71 in the axial direction so as to prevent the rotating shaft portion 71 and the steered wheel W fixed thereto from being displaced toward the chassis 1a.

[0053] In addition, by employing the above-described mounting mechanism, in this example, one steering servo motor 15 can be mounted on either the left or right steering wheel W.

[0054] Next, the manner of connection with the arm portion will be described. 5, a connection part 15c for connecting to the upper arm 51 is attached to the tip of the output shaft 15b. The connection part 15c has a plate-like part 152 arranged parallel to a plane perpendicular to the output shaft 15b, and a pole part 153 extending from the end of the plate-like part 152 in a direction parallel to the output shaft 15b (upward in this example). The plate-like portion 152 has a substantially rectangular shape when viewed from above, and the tip of the output shaft 15b is connected to the center portion in the longitudinal direction. The pole part 153 is located at one of both ends in the longitudinal direction of the plate-like part 152. The part of the pole part 153 near its tip is formed as a tip part 153a.

[0055] Furthermore, a pillow ball 154 is formed on the lower surface of the main body 15a. The pillow ball 154 is formed to protrude downward from the lower surface of the main body 15a, and the tip end portion in the protruding direction (i.e., the lower end portion) is formed in a substantially spherical shape.

[0056] 8 and 9, a specific connection between the upper arm 51 and the lower arm 52 and the steering servo motor 15 will be described. In the following explanation, the configuration of the left side of the steering mechanism 50 will be described as a representative, but the configuration of the right side will not be described with reference to the drawings because it is the same as the configuration of the left side except that it is symmetrical to the left side. 8 and 9 also show a wheel rotation axis Ar. The wheel rotation axis Ar refers to the axis of rotation about which the wheel rotates as the model automobile 1 travels. In other words, the wheel rotation axis Ar is an axis passing through the radial center of the wheel.

[0057] First, in this example, the main body 15a of the steering servo motor 15L and the plate-like portion 152 at the connection portion 15c are oriented in a direction substantially parallel to the front-rear direction when traveling straight as shown in Fig. 8. Specifically, when traveling straight, the left and right side surfaces of the main body 15a and the longitudinal direction of the plate-like portion 152 are both substantially parallel to the front-rear direction. In this example, when traveling straight, the orientation of the plate-like portion 152 is such that the pole portion 153 is positioned on the rear end side as shown in the figure.

[0058] In this example, the tip 153a of the pole part 153 at the connection part 15c is connected to the tip 51a of the upper arm 51L so as to prevent rotation of the pole part 153. As a result, the output shaft 15b of the steering servo motor 15L, which is connected to the pole part 153 via the plate-shaped part 152, is supported from the upper arm 51L side so as not to be able to rotate.

[0059] 8B, a ball bearing 154 provided on the lower surface of the main body 15a of the steering servo motor 15L is connected to the tip end 52a of the lower arm 52L. Specifically, a recess D is formed in the tip end 52a of the lower arm 52L to fit the spherical portion of the ball bearing 154 so that it can slide freely in a direction along the spherical surface, and the ball bearing 154 is connected to the lower arm 52L via this recess D. As a result, the main body 15a of the steering servomotor 15L is supported from the lower arm 52L side so as to be freely rotatable about an axis parallel to the steering rotation axis (axis parallel to the output shaft 15b).

[0060] Here, when a drive signal is given to the steering servo motor 15L, it generates a drive force that rotates the output shaft 15b, but since the output shaft 15b is non-rotatably supported by the upper arm 51L and the main body 15a is rotatably supported by the lower arm 52L as described above, in response to the generation of such a rotational drive force, the main body 15a rotates around an axis parallel to the steering rotation axis, as exemplified by the state during right steering in Fig. 9. Then, in response to such rotation of the main body 15a, the steered wheel WL connected to the side of the main body 15a via the wheel hub 53 also rotates around an axis parallel to the steering rotation axis.

[0061] As can be seen from FIGS. 8 and 9, the steering rotation axis in the steering mechanism 50 of this example is the axis indicated by "As" in FIG. 9A, that is, the rotation center axis of the output shaft 15b. Hereinafter, the steering rotation shaft will be denoted by the symbol "As".

[0062] In the above configuration, the ball connector 154 formed on the main body 15a is connected to the lower arm 52, and the pole portion 153 of the connecting portion 15c is connected to the upper arm 51. However, in order to realize a configuration in which the steering wheel W rotates in conjunction with the rotation of the main body 15a as described above, it is also possible to connect the ball connector 154 to the upper arm 51 and the pole portion 153 to the lower arm 52. In this case, a recess D for fitting the ball connector 154 is formed in the tip 51a of the upper arm 51, and the tip 153a is connected to the tip 52a of the lower arm 52 so as to prevent the pole portion 153 from rotating. In other words, inversely to the above configuration, the output shaft 15b is held non-rotatably from the lower arm 52 side, and the main body 15a is supported from the upper arm 51 side so as to be freely rotatable about the output shaft 15b as a central axis. As can be understood from this point, in order to realize the operation of rotating the steered wheels W in conjunction with the rotation of the main body 15a, the steering mechanism 50 only needs to be configured as follows: That is, the output shaft 15b is supported non-rotatably from either the upper arm 51 or the lower arm 52, and the main body 15a is supported from the other arm of either the upper arm 51 or the lower arm 52 so as to be freely rotatable about the output shaft 15b as a central axis.

[0063] As can be understood from the explanation of FIGS. 4 to 9, the steering mechanism 50 of this embodiment is configured as an in-wheel servo. By adopting an in-wheel servo configuration, it is possible to eliminate the steering link mechanism that was previously required when the steering servo motor was placed on the vehicle body side, and it is also possible to synchronize the rotation angle of the steering servo motor with the rotation angle of the steered wheels. By eliminating the need for a steering link mechanism, it is possible to suppress a decrease in steering control accuracy due to connection play in the link mechanism. Also, by eliminating the need for a link mechanism, it is possible to prevent the rotation angle of the steered wheels from changing depending on the steering angle. Therefore, in these respects, it is possible to improve steering control accuracy.

[0064] Furthermore, in the steering mechanism 50 of this embodiment, when an in-wheel servo configuration is adopted, a mounting method using the through-hole 151 of the main body 15a is adopted as a mounting method for the steered wheel W to the steering servo motor 15. Specifically, the mounting method is adopted in which the rotation shaft 71 of the steered wheel W is inserted into the inner hole 70h of the bearing 70 formed in the through-hole 151. By adopting a mounting method for the steering wheel W that utilizes the through hole 151, it is possible to shorten the scrub radius, which corresponds to the distance from the steering rotation axis As to the fastening position of the steering wheel W (in this example, the fastening position by the nut 73).

[0065] When an in-wheel servo configuration is adopted, the steered wheels W may be attached using a wheel hub 53 (53L in the figure), as shown in Fig. 10. The wheel hub 53 is a mechanism that holds the steered wheels W rotatably. When the steering wheel W is attached to the steering servo motor 15 using the wheel hub portion 53, the wheel hub portion 53 is attached to the lateral surface (main surface in this example) of the main body portion 15a, and the steering wheel W is further attached to the wheel hub portion 53 so as to be freely rotatable. Therefore, the distance from the steering servo motor 15 to the engagement position of the steered wheels W becomes relatively long in the axial direction of the wheel rotation axis Ar, which contributes to an increase in the scrub radius.

[0066] In contrast, in the case of the present embodiment, when the mounting method is such that the rotating shaft portion 71 is inserted into the bearing 70 provided in the through hole 151 of the main body portion 15a, it is not necessary to provide the wheel hub portion 53, and therefore it is possible to significantly shorten the distance from the steering servo motor 15 to the fastening position of the steering wheel W in the axial direction of the wheel rotation axis Ar. In other words, it is possible to shorten the scrub radius compared to when the wheel hub portion 53 is used.

[0067] FIG. 11 is an explanatory diagram of the effect obtained by shortening the scrub radius, and FIG. 11A schematically shows the rotational behavior of the steered wheels WL and WR when the scrub radius is large, and FIG. 11B schematically shows the rotational behavior of the steered wheels WL and WR when the scrub radius is small. As can be seen from a comparison between FIGS. 11A and 11B, by reducing the scrub radius, it is possible to reduce the amount of change in the position of the steering wheel W when the steering wheel W is turned. This allows the scrub radius to be shortened, thereby improving steering control accuracy and providing the operator of the model car 1 with a good steering feeling.

[0068] <3. Input attenuation mechanism> In this embodiment, in response to the configuration in which the steering servo motor 15 is arranged between the arm portion and the steering wheel W, the configuration of the input damping mechanism for damping the input from the road surface via the steering wheel W has been devised. The input damping mechanism provided in the model car 1 of the embodiment will be described with reference to FIGS.

[0069] 12A is a front view (viewed from the front side of the vehicle) of the vicinity of the left side portion of the steering mechanism 50. Note that the wheel hub portion 53L and the steered wheel WL are not shown. The model automobile 1 of this embodiment is provided with a shock absorber 61L and a shock tower 62 as a component for input attenuation. The shock absorber 61L is configured to have a cylinder portion filled with a buffer material such as a liquid inside and a spring wound around the outer periphery of the cylinder portion, and is configured to be able to absorb impacts applied to the spring by the drag force generated by the liquid or gas inside the cylinder portion. The shock tower 62 is a member for connecting the left and right shock absorbers 61 to the chassis 1a side.

[0070] First, as a premise, in the steering mechanism 50 of the embodiment, the vehicle body side end 51b (the aforementioned base portion), i.e., the end opposite to the tip end 51a, of the upper arm 51L is connected to the chassis 1a so as to enable the upper arm 51L to swing up and down around the vehicle body side end 51b as a fulcrum. Also, the tip end 51a of the upper arm 51L is connected to the tip end 153a of the pole portion 153 so as to enable the upper arm 51L to swing up and down around the tip end 51a as a fulcrum. In other words, the upper arm 51L is connected to the output shaft 15b.

[0071] 8B is a perspective view for explaining an example of a connection configuration between the tip 51a of the upper arm 51L and the tip 153a of the pole part 153. As shown in the figure, the tip 153a is formed with a substantially cylindrical hook part 160 that protrudes toward the front of the model automobile 1, and the tip 51a of the upper arm 51L is formed with a substantially circular hole H into which the hook part 160 is inserted. In this case, the tip 51a is clamped to the pole part 153 side by a clamping member such as a nut 161, with the hook part 160 inserted into the hole H. For example, with such a configuration, the upper arm 51L is connected to the tip 153a of the pole part 153 so as to be able to swing up and down with the tip 51a as a fulcrum.

[0072] The lower arm 52L has a vehicle body side end 52b, i.e., an end opposite to the tip end 52a, connected to the chassis 1a so as to enable the lower arm 52L to swing up and down around the vehicle body side end 52b as a fulcrum. The tip end 52a of the lower arm 52L is connected to a pillow ball 154 so as to enable the lower arm 52L to swing up and down around the tip end 52a as a fulcrum. In other words, the tip end 52a is connected to the main body 15a of the steering servomotor 15L. As mentioned above, the lower arm 52L is slidably fitted with the spherical portion of the pillow ball 154 in the recess D, and therefore the lower arm 52L is connected to the main body 15a of the steering servo motor 15L so as to be able to swing up and down with the tip end 52a as the fulcrum.

[0073] With the above-described configuration, the shock absorber 61L has a lower end 61a connected to the lower arm 52L so as to be able to swing up and down about the vehicle body side end 52b of the lower arm 52L as a fulcrum, and to be able to swing up and down about the tip end 52a of the lower arm 52L as a fulcrum. In other words, the lower end 61a of the shock absorber 61L is connected to the lower arm 52 so as to be able to swing up and down about the connection portion between the lower end 61a and the lower arm 52L as a fulcrum. The upper end 61b of the shock absorber 61L is connected to the shock tower 62 (that is, connected to the vehicle body side) without the upper arm 51L interposed therebetween.

[0074] The suspension structure described above is a so-called double wishbone type suspension structure. The double wishbone system uses a parallel link, so the camber angle does not change even if the steering wheel W moves up and down due to unevenness in the road surface. Figure 13 is an explanatory diagram showing the steering and input damping mechanism when the steered wheel WL passes over a bump (Figure 13A) and a depression (Figure 13B) on the road surface, as viewed from the front, similar to Figure 12A. Figures 13A and 13B show that the camber angle of the steered wheel WL does not change in response to road surface irregularities.

[0075] Furthermore, according to the double wishbone suspension structure described above, the upper end 61b of the shock absorber 61 is not connected to the upper arm 51L, so even if a configuration is adopted in which the steering servo motor 15 is inserted between the upper arm 51 and the lower arm 52, the input attenuation action from the road surface is not hindered.

[0076] As described above, it is also possible to employ a configuration in which the tip 51 a of the upper arm 51L is connected to the main body 15a via the pillow ball 154, and the tip 52 a of the lower arm 52L is connected to the output shaft 15b. In that case, in order to realize the double wishbone suspension structure described above, it is sufficient that the tip 51 a of the upper arm 51L is connected to the main body 15a so as to enable the upper arm 51L to swing in the up and down direction around the tip 51 a as a fulcrum, and it is sufficient that the tip 52 a of the lower arm 52L is connected to the output shaft 15b so as to enable the lower arm 52L to swing in the up and down direction around the tip 52 a as a fulcrum.

[0077] Regarding the input attenuation mechanism, the configuration on the right side is the same as the configuration on the left side described above except that it is symmetrical, so a description using illustrations will be omitted.

[0078] <4. Modifications> The present invention is not limited to the specific examples described above, and various modified configurations can be adopted. For example, in the above description, the output shaft 15b is connected to the upper arm 51 via the connecting portion 15c, but as in the modified example shown in Fig. 14, a configuration in which the tip of the output shaft 15b is directly connected to the tip 51a of the upper arm 51 can also be employed. Specifically, in this case, the tip of the output shaft 15b is connected to the tip 51a of the upper arm 51 so as to disable rotation of the output shaft 15b. This realizes a configuration in which the main body 15a and the steered wheels W move in conjunction with each other in response to steering, similar to the case in which the configuration described in Fig. 8 etc. is employed.

[0079] Furthermore, in the above example, the steering mechanism 50 has a bilaterally symmetrical configuration, but the steering mechanism according to the present invention may include an asymmetrical configuration in at least a portion of the left and right sides. Furthermore, although the above example shows the application of the present invention to the model automobile 1 as a four-wheeled vehicle, the present invention can be suitably applied to a model automobile having one or more steering wheels and two or more wheels.

[0080] Although the above example illustrates the application of the present invention to a steering mechanism of a model car, the servo motor device and movable mechanism according to the present invention are not limited to use in steering mechanisms. For example, they can be used in movable mechanisms as joints of robots, or as servo motor devices used as drive sources for specific components in the movable mechanisms. Even when applied to moving mechanisms other than the steering mechanism of a model car or servo motor devices other than steering servo motors, by providing a through hole in the main body of the servo motor device, it becomes possible to employ a method of attaching the servo motor device to other components using the through hole. Specifically, it becomes possible to employ not only a method of attaching other components via the outer surface of the servo motor device, but also a method of attaching other components via the through hole. Therefore, the degree of freedom in attaching the servo motor device and other components to the movable mechanism can be improved.

[0081] <5. Summary of embodiments> As described above, the servo motor device (steering servo motor 15) as an embodiment comprises a main body portion (15a) including a motor (156), an output shaft (15b) protruding from the main body portion, rotatably held by the main body portion, and outputting the power of the motor, and has a through hole (151) penetrating the main body portion. By providing the above-mentioned through hole, when the servo motor device is used as an actuator in various moving mechanisms such as the steering mechanism of a model car or the joint parts of a robot, it becomes possible to adopt an attachment method using the through hole as a method of attaching the servo motor device to other parts. Therefore, it is possible to improve the degree of freedom in attaching the servo motor device to other components in the movable mechanism, and it is possible to realize a servo motor device with good attachability.

[0082] In the servo motor device according to the embodiment, the main body is formed in a plate shape, and the through-hole penetrates the main body in the thickness direction (see FIGS. 5 and 6, etc.). This makes it possible to minimize the length of the through hole, i.e., the length of the through hole can be made shorter than when the through hole is formed in a direction perpendicular to the thickness direction of the main body. Therefore, it is possible to suppress a decrease in strength of the main body portion due to the formation of the through hole.

[0083] Furthermore, in the servo motor device according to the embodiment, a bearing (70) is provided in the through hole. The rotor can be rotatably attached to the main body of the servo motor device via the bearing. Therefore, the present invention is suitable for realizing a servo motor device that rotatably holds a predetermined rotating body, such as a servo motor device that rotatably holds a steering wheel in a steering mechanism of a model car.

[0084] Furthermore, in the servo motor device of the embodiment, the inner hole (70h), which is a hole formed on the inside of the inner ring of the bearing, is made into a rotating shaft insertion hole through which the rotating shaft portion (71) of the steering wheel of the model automobile is inserted. This makes it possible to realize a servo motor device that rotatably holds the steering wheels in the steering mechanism of a model car. Therefore, an in-wheel servo can be realized, and the steering link mechanism that was required when the steering servo motor was conventionally disposed on the vehicle body side can be eliminated. By eliminating the need for a steering link mechanism, it is possible to suppress a decrease in steering control accuracy caused by connection play of the link mechanism. Furthermore, by eliminating the need for a link mechanism, it is possible to prevent the rotation angle of the steered wheels from changing depending on the steering angle. Therefore, in these respects, it is possible to improve steering control accuracy. Furthermore, since the link mechanism is no longer necessary, the steering wheel can be rotated 180 degrees. Furthermore, the above configuration eliminates the need for a link mechanism and allows the left and right steered wheels to be steered independently, which allows the Ackermann ratio to be adjusted electrically by adjusting the rotation angle of the steering servo motor (i.e., adjustment can be made while the vehicle is running). Here, the Ackermann ratio refers to the difference in the turning angle between the left and right steering wheels. If the turning angles of the left and right steering wheels were the same for a certain amount of steering, the left and right steering wheels would describe circles of the same radius. In this case, there is a difference equivalent to the width of the vehicle between the center of the arc described by the outside steering wheel and the center of the arc described by the inside steering wheel, so the trajectory of the outside steering wheel and the trajectory of the inside steering wheel will intersect at some point, causing the trajectory of the outside steering wheel to turn more inward than the trajectory of the inside steering wheel. As can be seen from this, if the turning angles of the left and right steering wheels were the same, it would be difficult to turn a model car smoothly. Therefore, the Ackermann ratio is adjusted to adjust the turning angle of the left and right steering wheels to achieve the desired steering characteristics of the model car, such as making the model car turn smoothly. Furthermore, with the above configuration, the rotation angles of the left and right steered wheels can be adjusted independently, compared to a steering mechanism that rotates the left and right steered wheels using the output of a single servo motor, such as the configuration shown in Figure 6 of Patent Document 1. Furthermore, being able to adjust the rotation angles of the left and right steered wheels independently makes it possible to electrically adjust the toe angle even while driving. Furthermore, by being able to insert the rotating shaft portion into the inner hole of the bearing, the scrub radius can be shortened compared to, for example, a configuration in which the main body portion and the steering wheel are connected via a wheel hub portion that holds the steering wheel in a rotatable manner. By shortening the scrub radius, it is possible to improve the steering control accuracy. In addition, the scrub radius can be easily adjusted by using wheel spacers. Furthermore, since the servo motor device also functions as a wheel hub, a wheel hub is not required, reducing the number of parts and also reducing the unsprung weight, thereby improving the operability of the model car.

[0085] In addition, the movable mechanism (steering mechanism 50) as an embodiment comprises a servo motor device (steering servo motor 15) having a main body including a motor, an output shaft protruding from the main body, held rotatably by the main body and outputting the power of the motor, and having a through hole passing through the main body, and a driven part (steering wheel W, rotating shaft part 71) driven based on the power of the motor. Such a movable mechanism also provides the same effects as those described above for the servo motor device. Therefore, a movable mechanism that allows for easy attachment of a servo motor device can be realized.

[0086] In the movable mechanism according to the embodiment, the main body is formed in a plate shape, and the through-hole penetrates the main body in the thickness direction. This allows the length of the through hole to be minimized. Therefore, it is possible to suppress a decrease in strength of the main body portion due to the formation of the through hole.

[0087] Furthermore, the movable mechanism according to the embodiment has a bearing in the through hole. The above-mentioned bearings enable the rotor to be rotatably mounted on the main body of the servo motor device. Therefore, it is possible to realize a movable mechanism that rotatably holds a predetermined rotating body using a servo motor device, such as a steering mechanism of a model car that rotatably holds the steering wheel using a servo motor device for steering and driving the steering wheel.

[0088] Furthermore, the movable mechanism in one embodiment is configured as a steering mechanism in a model automobile, and the rotating shaft of the steering wheel in the model automobile is inserted into an inner hole, which is a hole formed on the inside of the inner ring of the bearing. This makes it possible to realize an in-wheel servo for the steering mechanism of the model car. Therefore, an in-wheel servo can be realized, and the steering link mechanism that was required when the steering servo motor was conventionally disposed on the vehicle body side can be eliminated. By eliminating the need for a steering link mechanism, it is possible to suppress a decrease in steering control accuracy caused by connection play of the link mechanism. Furthermore, by eliminating the need for a link mechanism, it is possible to prevent the rotation angle of the steered wheels from changing depending on the steering angle. Therefore, in these respects, it is possible to improve steering control accuracy. Furthermore, since the link mechanism is no longer necessary, the steering wheel can be rotated 180 degrees, and the Ackermann ratio can be adjusted electrically by adjusting the rotation angle of the steering servo motor (i.e., it can be adjusted while driving). Furthermore, with the above configuration, the rotation angles of the left and right steered wheels can be adjusted independently, compared to a steering mechanism that rotates the left and right steered wheels using the output of a single servo motor, such as the configuration shown in Figure 6 of Patent Document 1. Furthermore, being able to adjust the rotation angles of the left and right steered wheels independently makes it possible to electrically adjust the toe angle even while driving. Furthermore, since the rotating shaft portion is inserted into the inner hole of the bearing, the scrub radius can be shortened compared to, for example, a configuration in which the main body portion and the steering wheel are connected via a wheel hub portion that holds the steering wheel in a rotatable manner. By shortening the scrub radius, it is possible to improve the steering control accuracy. In addition, the scrub radius can be easily adjusted by using wheel spacers. Furthermore, since the servo motor device also functions as a wheel hub, a wheel hub is not required, reducing the number of parts and also reducing the unsprung weight, thereby improving the operability of the model car.

[0089] In addition, in an embodiment of the movable mechanism, the servo motor device is positioned between the steering wheel and an arm portion extending from the body side of the model automobile toward the steering wheel, and the arm portion comprises a first arm portion and a second arm portion spaced apart in the vertical direction, the output shaft is supported from either the first arm portion or the second arm portion so as not to be rotatable, and the main body portion is supported from the other arm portion of the first arm portion or the second arm portion so as to be freely rotatable around the output shaft as a central axis. As described above, the output shaft is supported non-rotatably from either the upper or lower arm, and the main body is supported from the other arm so as to be freely rotatable about the output shaft. In this case, in the movable mechanism, the main body rotates about the output shaft in response to steering. And, because the rotating shaft of the steering wheel is connected to the main body via a bearing, the steering wheel rotates in conjunction with the rotation of the main body in response to steering. Therefore, according to the above configuration, when a configuration is adopted in which the rotating shaft portion of the steering wheel is connected to a bearing formed in the through hole of the main body portion to shorten the scrub radius, the steering wheel can be appropriately rotated using a servo motor device as a driving source.

[0090] Furthermore, in the movable mechanism of the embodiment, a cap member (bolt 72) having a portion with a larger diameter than the root end, which is the end inserted into the inner hole of the bearing, is engaged with one of the two end portions of the rotating shaft portion. As described above, the cap member engaged with the base end of the rotating shaft makes it possible to prevent the steering wheel from being displaced away from the servo motor device due to road resistance acting on the steering wheel, etc. Therefore, it is possible to prevent the steering wheel and the rotary shaft from coming off the model car.

[0091] <6. Other examples of main body configuration> In the explanation so far, the main body 15a of the steering servo motor 15 has a through hole 151 for attaching the rotating shaft 71 of the steering wheel W, but it is not essential to form a through hole 151 in the main body for attaching a member (hereinafter referred to as "attaching member") for attaching other parts to the servo motor device, such as the rotating shaft 71.

[0092] For example, as shown in FIGS. 15 and 16, a steering servomotor 15A can be proposed that is formed with a mounting portion 160 for mounting a mounting member. In the following description, parts that are similar to parts that have already been described are given the same reference numerals and descriptions thereof will be omitted.

[0093] FIG. 15 is a perspective view of the steering servomotor 15A, and FIG. 16 is a diagram showing a state in which an attachment member (here, a rotating shaft portion 71A) is attached to the steering servomotor 15A. 15, the steering servomotor 15A has a main body 15aA having an attachment portion 160 formed on, for example, a side surface thereof. As shown in the figure, the attachment portion 160 is provided so as to protrude laterally from the main body 15aA. In this case, the through-hole 151 is not formed in the main body portion 15aA.

[0094] In this example, the mounting portion 160 is formed with a mounting opening 160a having a thread groove for screwing in the rotating shaft portion 71A as a mounting member.

[0095] The attachment portion 160 may be integral with the main body portion 15aA, or may be a separate member that is fixed to the main body portion 15aA by adhesive or other means.

[0096] Although not shown in the figure, the rotating shaft portion 71A has a screw thread formed on the end opposite to the end where the steering wheel W is attached, which makes it possible to attach the rotating shaft portion 71A to the main body portion 15aA by screwing it, as shown in Figures 16A and 16B.

[0097] When the rotating shaft 71A is attached via the attachment portion 160 as described above, a bearing is provided on the steering wheel W side. That is, a configuration is adopted in which the tip end of the rotating shaft 71A (the end opposite to the end attached to the attachment portion 160) is attached to the steering wheel W via a bearing. In this case, the rotating shaft 71A does not rotate even when the steering wheel W rotates. However, since the rotating shaft 71A is disposed at a position that becomes the rotation axis of the steering wheel W, the term "rotating shaft" is used here.

[0098] According to the above configuration, it is not necessary to form through-hole 151 in the main body of the servo motor device, and therefore it is not necessary to reserve space in the main body for providing through-hole 151, thereby enabling the servo motor device to be made more compact. Furthermore, it is possible to alleviate layout restrictions on the internal components of the servo motor device that would otherwise be imposed by providing through-hole 151, thereby improving the degree of freedom in designing the servo motor device.

[0099] The method of attaching the rotary shaft portion 71A to the main body portion 15aA is not limited to screwing, and other methods such as adhesive or attachment using screws can also be used, and the method is not limited to a specific one.

[0100] Here, an example of a configuration in which a through hole 151 for attaching an attachment member is not formed in the main body of the servo motor device is a steering servo motor 15B configuration in which the attachment member (in the figure, the rotating shaft portion 15aa) is integrally formed, as shown in Figure 17. As shown in the figure, a main body 15aB of the steering servomotor 15B is integrally formed with a rotary shaft 15aa that protrudes from, for example, a side surface. In this case, similarly to the configurations shown in FIGS. 15 and 16, the rotary shaft 15aa is attached to the steering wheel W via a bearing at the tip of the attachment member.

[0101] When the configuration shown in FIG. 17 is adopted, the mounting member (rotating shaft portion 15aa) can be integrally molded with the main body portion 15aB, which reduces the number of parts and thereby reduces costs.

[0102] 15 to 17 may also be applied to devices other than steering mechanisms for model cars. In this case, in the configurations shown in FIGS. 15 and 16, the position of the mounting portion 160 is not limited to the side surface of the main body portion 15aA, and may be located at any position that prevents interference between other components connected via the mounting member attached to the mounting portion 160 and the output shaft 15b or components driven by the output shaft 15b. Similarly, in the configuration shown in FIG. 17, the position of the mounting member exemplified as the rotating shaft portion 15aa is not limited to the side surface of the main body portion 15aB, and may be located at any position that prevents interference between other components connected via the mounting member and the output shaft 15b or components driven by the output shaft 15b.

[0103] Furthermore, when considering applications other than steering mechanisms, it is conceivable that the parts connected via the mounting members may have power, in which case it is also conceivable that the main body portion 15aA or the main body portion 15aB may rotate or turn.

[0104] When considering applications other than steering mechanisms, the shape of the mounting member can be varied, including, for example, a cylindrical or other columnar shape like the rotating shaft portion 71A or the rotating shaft portion 15aa, a cubic or rectangular parallelepiped shape, a spherical shape, or a shape that combines different shapes, such as a shape that is partly columnar and partly spherical. [Explanation of symbols]

[0105] 1 model car 15(15L, 15R), 15A, 15B Steering servo motor W(WL,WR) Steering wheels Wh Center Hall 50 Steering mechanism 51(51L,51R) Upper arm 52(52L,52R) Lower arm 51a,52a Tip 51b, 52b Vehicle body side end 53 (53L, 53R) Wheel hub 61 (61L, 61R) shock absorber 62 Shock Tower 61a Lower end 61b Upper end 70 bearings 70h inner hole 71(71L, 71R), 71A Rotating shaft 71a Flange 71b Tip 71c Base 71d Stepped section 71h Hole 72 volts 73 Nut 15a Main body 15aa Rotating shaft 15b Output shaft 15c Connection 15d Support part 151 Through hole 152 Plate-shaped part 153 Pole section 153a Tip 154 Pillow Ball 156 Motor 157 Reduction mechanism 158 Angle detection unit 159 Circuit Board 160 Mounting part 160a mounting port D recess Ar Wheel rotation axis As steering rotation axis

Claims

1. a main body including a motor; an output shaft that protrudes from the main body portion, is rotatably held by the main body portion, and outputs power from the motor; a through hole that passes through the main body while avoiding components disposed inside the main body; A bearing is provided in the through hole Servo motor device.

2. The main body is formed in a plate shape, The through hole penetrates the main body in the thickness direction.

2. The servo motor device according to claim 1.

3. The inner hole, which is a hole formed on the inside of the inner ring of the bearing, is a rotation shaft insertion hole through which a rotation shaft of a steering wheel of a model car is inserted.

3. The servo motor device according to claim 1 or 2.

4. a servo motor device having a main body including a motor, and an output shaft that protrudes from the main body, is rotatably held by the main body, and outputs power from the motor, the servo motor device having a through hole that passes through the main body while avoiding components disposed inside the main body, and a bearing inside the through hole; a driven part that is driven based on the power of the motor; Movable mechanism.

5. The main body is formed in a plate shape, The through hole penetrates the main body in the thickness direction. The movable mechanism according to claim 4.

6. It is configured as a steering mechanism for a model car, The rotation shaft of the steering wheel of the model car is inserted into an inner hole, which is a hole formed inside the inner ring of the bearing. The movable mechanism according to claim 4 or claim 5.

7. the servo motor device is positioned between the steering wheel and an arm portion extending from the body of the model automobile toward the steering wheel, The arm portion includes a first arm portion and a second arm portion spaced apart in the vertical direction, the output shaft is supported non-rotatably from one of the first arm portion and the second arm portion, The main body is supported from the other arm side of either the first arm or the second arm so as to be freely rotatable about the output shaft as a central axis. The movable mechanism according to claim 6.

8. A cap member having a portion with a larger diameter than the base end, which is the end inserted into the inner hole of the bearing, is engaged with the base end of the rotating shaft. The movable mechanism according to claim 6 or 7.

Images