JP7735129B2 - Servo horn and servo device - Google Patents

Description

The present invention relates to the technical field of servo horns fixed to the output shaft of servo motors and servo devices equipped with servo motors and servo horns.

Radio control systems, which enable remote control via radio, are used for controlled objects such as model cars and airplanes, as well as industrial controlled objects.

In such radio control systems, a servo device is mounted on the controlled object, and the servo device includes a servo motor with an output shaft and a servo horn fixed to the output shaft (see, for example, Patent Documents 1 and 2).

In a servo motor, the driving force is reduced by a group of reduction gears and transmitted to the output shaft, to which the rotating shaft of a variable resistor is connected. The rotation angle, rotation speed, and rotation direction of the output shaft are controlled based on a signal generated according to the resistance value of the variable resistor and a signal transmitted from the transmitter.

Shaft-side serrations (outer serrations) are formed on the outer peripheral surface of the output shaft, and a servo horn is fixed to the output shaft. Various types of servo horns with different shapes and sizes are used, and the servo horn has horn-side serrations (inner serrations). Therefore, the horn's horn-side serrations engage with the shaft-side serrations to prevent it from rotating relative to the output shaft, and it is fixed to the output shaft with screws or the like.

The servo horn has mounting holes at predetermined positions, to which wires of the linkage mechanism are attached. The linkage mechanism is connected to the moving parts of the controlled object, such as a model car.

In such radio control systems, the driving force of the servo motor is transmitted to the movable part of the controlled object via the servo horn and linkage mechanism, causing the movable part to operate in accordance with the signal sent from the transmitter.

Japanese Patent Application Laid-Open No. 2004-243026 JP 2014-76120 A

As mentioned above, the servo horn's role is to transmit the driving force of the servo motor to the linkage mechanism connected to the moving part. Therefore, if the servo horn's fixed state relative to the output shaft is unstable, the appropriate driving force will not be transmitted to the moving part, making it impossible to ensure the correct operating state of the moving part.

In particular, as mentioned above, the horn-side serrations engage with the shaft-side serrations to prevent the servo horn from rotating relative to the output shaft. However, a slight gap (play) is required between the horn-side serrations and the shaft-side serrations to easily attach and detach the servo horn to the output shaft. This gap reduces the positional accuracy of the servo horn in the rotational direction relative to the output shaft. Therefore, it is desirable to ensure a high level of fixation of the servo horn to the output shaft in order to improve the positional accuracy of the servo horn in the rotational direction relative to the output shaft while ensuring ease of attachment and detachment of the servo horn to the output shaft.

The servo horn and servo device of the present invention therefore aim to ensure high fixing strength to the output shaft.

The servo horn of the present invention comprises a first member fixed to an output shaft of a servo motor having shaft-side serrations, and a second member fixed to the output shaft or the first member, wherein the first member has an insertion hole formed on the output shaft side into which the output shaft is inserted, and horn-side serrations formed on its inner surface to engage with the shaft-side serrations, the outer surface of the first member is formed as an inclined surface that approaches the center as it goes in the insertion direction of the output shaft into the insertion hole, the second member has a fitting hole formed in which at least a portion of the first member is fitted, and the inner surface of the second member is formed as a tapered surface that is pressed against the inclined surface to press the horn-side serrations against the shaft-side serrations , and the first member has a slot formed in communication with the insertion hole .

As a result, when at least a portion of the first member is fitted into the fitting hole of the second member, the tapered surface of the second member is pressed against the inclined surface of the first member, and the horn-side serrations are pressed against the shaft-side serrations.

The servo device of the present invention comprises a servo motor having an output shaft on which shaft-side serrations are formed, and a servo horn fixed to the output shaft, the servo horn comprising a first member fixed to the output shaft and a second member fixed to the output shaft or the first member, the first member having an insertion hole that opens toward the output shaft and into which the output shaft is inserted, and horn-side serrations that engage with the shaft-side serrations on its inner surface, the outer surface of the first member formed as an inclined surface that approaches the center as it extends in the direction of insertion of the output shaft into the insertion hole, the second member having a fitting hole into which at least a portion of the first member is fitted, the inner surface of the second member being pressed against the inclined surface and formed as a tapered surface that presses the horn-side serrations against the shaft-side serrations , and the first member having a slot that communicates with the insertion hole .

As a result, when at least a portion of the first member of the servo horn is fitted into the fitting hole of the second member, the tapered surface of the second member is pressed against the inclined surface of the first member, and the horn-side serrations are pressed against the shaft-side serrations.

According to the present invention, when at least a portion of the first member is fitted into the fitting hole of the second member, the tapered surface of the second member is pressed against the inclined surface of the first member, and the horn-side serrations are pressed against the shaft-side serrations, ensuring high fixing strength to the output shaft.

2 to 13 show an embodiment of the servo horn and servo device of the present invention, and this figure is a perspective view showing the servo device with the servo motor and servo horn separated. 3 shows the servo horn according to the first embodiment, and this figure is an exploded perspective view of the servo horn. FIG. 3 is a cross-sectional view of a servo horn. 5 shows a servo horn according to a second embodiment, and this figure is an exploded perspective view of the servo horn. FIG. 3 is a cross-sectional view of a servo horn. 7 and 8 show a servo horn according to a third embodiment, and this figure is an exploded perspective view of the servo horn. FIG. 3 is a cross-sectional view of a servo horn. FIG. 2 is a perspective view of a first member. 10 shows a servo horn according to a fourth embodiment, and this figure is an exploded perspective view of the servo horn. FIG. 3 is a cross-sectional view of a servo horn. 12 and 13 show a servo horn according to a fifth embodiment, and this figure is an exploded perspective view of the servo horn. FIG. 3 is a cross-sectional view of a servo horn. FIG. 2 is a perspective view of a first member.

The following describes embodiments of the servo horn and servo device of the present invention, with reference to the accompanying drawings.

The servo motor of the servo device has an output shaft, and when directions are indicated below, the axial direction of the output shaft is used as the up/down direction. However, the directions shown below are for convenience of explanation, and the implementation of this invention is not limited to these directions.

<Overall configuration of servo device>
First, the overall configuration of the servo device 100 will be described (see FIG. 1).

The servo device 100 includes a servo motor 50 and a servo horn 1. The servo motor 50 has a case body 51 made of a metal material or the like, necessary components (not shown) arranged inside the case body 51, and an output shaft 52 protruding upward from the case body 51.

A control circuit board, reduction gears, angle sensor, etc. are arranged inside the case body 51. The output shaft 52 is connected to the angle sensor, etc. inside the case body 51, and is rotated at a reduced speed by the reduction gears. Saw-tooth axial serrations 52a are formed on the outer periphery of the output shaft 52.

<Servo horn according to the first embodiment>
Next, the servo horn 1 according to the first embodiment will be described (see FIGS. 2 and 3).

The servo horn 1 is composed of a first member 2 and a second member 3.

The first member 2 is formed into a shape having a longitudinal direction and consists of a fixed portion 4 fixed to the output shaft 52, protruding portions 5, 5 protruding in the opposite direction from the fixed portion 4, and hole-forming portions 6, 6 protruding in the opposite direction from the protruding portions 5, 5.

The fixed part 4 has a disk-shaped flat part 7 facing up and down and a roughly cylindrical tubular part 8 that protrudes roughly downward from the outer periphery of the flat part 7. Therefore, a space that opens downward is formed in the fixed part 4, and this space is formed as the insertion hole 4a.

The cylindrical portion 8 has an inclined surface 8a that is inclined so that the diameter increases as the outer surface approaches the bottom. Therefore, the outer diameter of the cylindrical portion 8 is smallest at the top end and largest at the bottom end, and the inclined surface 8a approaches the center as it extends in the direction of insertion of the output shaft 52 into the insertion hole 4a. A threaded groove 8b is formed on the outer surface of the cylindrical portion 8.

Horn-side serrations 8c are formed on the inner peripheral surface of the cylindrical portion 8. The horn-side serrations 8c are formed in a sawtooth shape that corresponds to the shaft-side serrations 52a of the output shaft 52. The cylindrical portion 8 is formed with slots 9, 9, for example, at positions 180 degrees apart. The slots 9 penetrate the inside and outside of the cylindrical portion 8, communicate with the insertion hole 4a, and open downward. The positions and number of slots 9 formed on the cylindrical portion 8 are optional.

The protrusions 5, 5 each protrude from the lower end of the cylindrical portion 8.

Mounting holes 6a, 6a are formed in the hole forming section 6, penetrating vertically and spaced apart in the longitudinal direction. The number of mounting holes 6a formed in the hole forming section 6 and the positions at which the mounting holes 6a are formed in the hole forming section 6 can be set arbitrarily.

The second member 3 is formed, for example, in a ring shape with a hexagonal outer shape, and the internal space is formed as a fitting hole 3a. The inner surface of the second member 3 is formed as a tapered surface 3b that is inclined so that the diameter increases as it goes downward. Therefore, the inner diameter of the second member 3 is smallest at the upper end and largest at the lower end. A threaded portion 3c is formed on the inner surface of the second member 3.

The inclination angle of the tapered surface 3b of the second member 3 relative to the horizontal plane is slightly larger than the inclination angle of the inclined surface 8a of the first member 2 relative to the horizontal plane. The inclination angle of the tapered surface 3b of the second member 3 relative to the horizontal plane may be the same as the inclination angle of the inclined surface 8a of the first member 2 relative to the horizontal plane.

In the servo horn 1 configured as described above, the first member 2 is attached to the output shaft 52 by first inserting the output shaft 52 into the insertion hole 4a of the fixed portion 4. At this time, the horn-side serrations 8c engage with the shaft-side serrations 52a, and the first member 2 is attached to the output shaft 52 in a state where it is positioned circumferentially relative to the output shaft 52.

Next, the second member 3 is fixed to the first member 2. The second member 3 is fixed to the first member 2 by rotating the second member 3 relative to the cylindrical portion 8 and threading the threaded portion 3c into the threaded groove portion 8b. When the second member 3 is fixed to the first member 2, the cylindrical portion 8 of the first member 2 is fitted into the fitting hole 3a of the second member 3, and the tapered surface 3b of the second member 3 is pressed against the inclined surface 8a of the first member 2, deforming the cylindrical portion 8 toward the output shaft 52 and pressing the cylindrical portion 8 against the output shaft 52. Therefore, the first member 2 is fixed to the output shaft 52 by deforming the cylindrical portion 8 toward the output shaft 52 and pressing the horn-side serrations 8c against the shaft-side serrations 52a.

At this time, because the first member 2 has slots 9, 9 formed in the cylindrical portion 8, the cylindrical portion 8 is particularly susceptible to deformation toward the output shaft 52, and the cylindrical portion 8 is pressed against the output shaft 52 with a large force.

By fixing the second member 3 to the first member 2 and the first member 2 to the output shaft 52 as described above, the servo horn 1 is fixed to the output shaft 52 with high fixing strength. With the servo horn 1 fixed to the output shaft 52, a wire or the like of a linkage mechanism (not shown) is attached to the mounting hole 6a formed in the hole formation portion 6 of the first member 2. The linkage mechanism is connected to a movable part of the controlled object, such as a model automobile. Therefore, the driving force of the servo motor 50 is transmitted to the movable part of the controlled object via the servo horn 1 and the linkage mechanism, causing the movable part to operate in accordance with the signal transmitted from the transmitter.

In the servo horn 1, a hole forming portion 6 is provided in the first member 2, positioned outside the second member 3, and an attachment hole 6a is formed in the hole forming portion 6 to which the linkage mechanism is attached.

As a result, because the mounting holes 6a are formed in a portion of the first member 2 positioned outside the second member 3, it is possible to freely design the shape and size of the first member 2 and form the mounting holes 6a without compromising the functionality of the first member 2 and second member 3, thereby improving the design freedom regarding the position of the mounting holes 6a on the servo horn 1 and the number of mounting holes 6a formed.

Furthermore, because the first member 2 has a slot 9, it can deform within the width of the slot 9 so that the first member 2 is pressed against the output shaft 52 when the tapered surface 3b of the second member 3 is pressed against the inclined surface 8a. This ensures high fixing strength of the first member 2 to the output shaft 52 without applying excessive load from the first member 2 to the output shaft 52.

Furthermore, because multiple slots 9 are formed at equal intervals in the circumferential direction, when the tapered surface 3b is pressed against the inclined surface 8a, force is applied evenly to the output shaft 52 from each portion of the first member 2 between the slots 9. Therefore, the first member 2 can be fixed with an even force applied to the output shaft 52, and high fixing strength of the first member 2 to the output shaft 52 can be ensured. Furthermore, because multiple slots 9 are formed at equal intervals in the circumferential direction, the load applied from the first member 2 to the output shaft 52 can be evenly distributed. Note that multiple slots 9 may be formed at uneven intervals in the circumferential direction. In this case, force is applied to the output shaft 52 from each portion of the first member 2 between the slots 9, and high fixing strength of the first member 2 to the output shaft 52 can be ensured.

Furthermore, a threaded groove portion 8b is formed on the outer peripheral surface of the first member 2, and a threaded portion 3c that screws into the threaded groove portion 8b is formed on the inner peripheral surface of the second member 3.

As a result, the second member 3 is fixed to the first member 2 by rotating and screwing it into place, so the second member 3 can be fixed to the first member 2 without using any additional screw members, reducing the number of parts and simplifying the process of fixing the second member 3 to the first member 2.

<Servo horn according to the second embodiment>
Next, a servo horn 1A according to a second embodiment will be described (see FIGS. 4 and 5).

The servo horn 1A shown below differs from the servo horn 1 described above only in that the second member is fixed to the first member by a screw member. Therefore, only the parts that differ from the servo horn 1 will be described in detail, and other parts will be given the same reference numerals as those used for similar parts in the servo horn 1 and will not be described again.

The servo horn 1A is composed of a first member 2A and a second member 3A.

The first member 2A consists of a fixed portion 4, protruding portions 5A, 5A, and hole-forming portions 6, 6.

The cylindrical portion 8 of the fixed portion 4 does not have a threaded groove 8b.

The protrusions 5A, 5A each protrude from the lower end of the cylindrical portion 8. A screw hole 5a is formed in the protrusion 5A, penetrating it from top to bottom.

The second member 3A is formed in a shape having a longitudinal direction, with the internal space formed as a fitting hole 3a. No threaded portion 3c is formed on the inner peripheral surface of the second member 3A. Screw insertion holes 3d, 3d that penetrate vertically are formed at both ends of the second member 3A in the longitudinal direction.

In the servo horn 1A configured as described above, the first member 2A is attached to the output shaft 52 by first inserting the output shaft 52 into the insertion hole 4a of the fixed portion 4. At this time, the horn-side serrations 8c engage with the shaft-side serrations 52a, so that the first member 2A is attached to the output shaft 52 in a state where it is positioned circumferentially relative to the output shaft 52.

Next, the second member 3A is fixed to the first member 2A. The second member 3A is fixed to the first member 2A by inserting the screw members 60, 60 into the screw insertion holes 3d, 3d of the second member 3A and threading them into the threaded holes 5a, 5a. When the second member 3A is fixed to the first member 2A, the cylindrical portion 8 of the first member 2A is fitted into the fitting hole 3a of the second member 3A, and the tapered surface 3b of the second member 3A is pressed against the inclined surface 8a of the first member 2A, deforming the cylindrical portion 8 toward the output shaft 52 and pressing the cylindrical portion 8 against the output shaft 52. Therefore, the first member 2A is fixed to the output shaft 52 by deforming the cylindrical portion 8 toward the output shaft 52 and pressing the horn-side serrations 8c against the shaft-side serrations 52a.

At this time, because the first member 2A has slots 9, 9 formed in the cylindrical portion 8, the cylindrical portion 8 is particularly susceptible to deformation toward the output shaft 52, and the cylindrical portion 8 is pressed against the output shaft 52 with a large force.

As described above, by fixing the second member 3A to the first member 2A and fixing the first member 2A to the output shaft 52, the servo horn 1A is fixed to the output shaft 52 with high fixing strength.

In the servo horn 1A, a hole forming portion 6 is provided in the first member 2A, positioned outside the second member 3A, and a mounting hole 6a is formed in the hole forming portion 6 to which the linkage mechanism is attached.

As a result, because the mounting holes 6a are formed in a portion of the first member 2A positioned outside the second member 3A, it is possible to freely design the shape and size of the first member 2A and form the mounting holes 6a without compromising the functionality of the first member 2A and second member 3A, thereby improving the design freedom regarding the position of the mounting holes 6a on the servo horn 1A and the number of mounting holes 6a formed.

Furthermore, because the first member 2A has a slot 9, it can deform within the width of the slot 9 so that it is pressed against the output shaft 52 when the tapered surface 3b of the second member 3A is pressed against the inclined surface 8a. This ensures high fixing strength of the first member 2A to the output shaft 52 without applying excessive load from the first member 2A to the output shaft 52.

Furthermore, because multiple slots 9 are formed at equal intervals in the circumferential direction, when the tapered surface 3b is pressed against the inclined surface 8a, an equal force is applied to the output shaft 52 from each portion of the first member 2A between the slots 9. Therefore, the first member 2A can be fixed to the output shaft 52 with an equal force being applied to it, and high fixing strength of the first member 2A to the output shaft 52 can be ensured.

<Servo horn according to the third embodiment>
Next, a servo horn 1B according to a third embodiment will be described (see FIGS. 6 to 8).

The servo horn 1B shown below differs from the servo horn 1 described above only in that both the first and second members are fixed to the output shaft by screw members. Therefore, only the parts that differ from the servo horn 1 will be described in detail, and other parts will be given the same reference numerals as those used for similar parts in the servo horn 1 and will not be described again.

Servo horn 1B is composed of a first member 2B and a second member 3B.

The first member 2B consists of a fixed portion 4B, protruding portions 5, 5, and hole-forming portions 6, 6.

The fixed portion 4B has a disk-shaped flat portion 7B facing up and down and a cylindrical portion 8 that protrudes substantially downward from the outer periphery of the flat portion 7B.

The fixed portion 4B has a screw insertion hole 7a that penetrates vertically in the center of the flat portion 7B. No threaded groove 8b is formed in the cylindrical portion 8 of the fixed portion 4B.

The second member 3B has, for example, a circular outer shape, with an internal space formed as a fitting hole 3a. No threaded portion 3c is formed on the inner peripheral surface of the second member 3B. A screw insertion hole 3d that penetrates vertically is formed in the center of the second member 3B.

In the servo horn 1B configured as described above, the first member 2B is attached to the output shaft 52 by first inserting the output shaft 52 into the insertion hole 4a of the fixed portion 4B. At this time, the horn-side serrations 8c engage with the shaft-side serrations 52a, so that the first member 2B is attached to the output shaft 52 in a state where it is positioned circumferentially relative to the output shaft 52.

Next, the first member 2B and the second member 3B are fastened together to the output shaft 52. The first member 2B and the second member 3B are fastened to the output shaft 52 by inserting the screw member 60 sequentially through the screw insertion hole 3d of the second member 3B and the screw insertion hole 7a of the first member 2B, and then threading it into a threaded hole formed in the center of the output shaft 52. When the first member 2B and the second member 3B are fastened to the output shaft 52, the cylindrical portion 8 of the first member 2B is fitted into the fitting hole 3a of the second member 3B, and the tapered surface 3b of the second member 3B is pressed against the inclined surface 8a of the first member 2B, deforming the cylindrical portion 8 toward the output shaft 52 and forcing the cylindrical portion 8 against the output shaft 52. Therefore, the first member 2B is fixed to the output shaft 52 by deforming the cylindrical portion 8 toward the output shaft 52 and pressing the horn side serrations 8c against the shaft side serrations 52a.

At this time, because the first member 2B has slots 9, 9 formed in the cylindrical portion 8, the cylindrical portion 8 is particularly susceptible to deformation toward the output shaft 52, and the cylindrical portion 8 is pressed against the output shaft 52 with a large force.

By fixing the first member 2B and the second member 3B to the output shaft 52 as described above, the servo horn 1B is fixed to the output shaft 52 with high fixing strength.

In servo horn 1B, a hole forming portion 6 is provided in the first member 2B, positioned outside the second member 3B, and a mounting hole 6a is formed in the hole forming portion 6 to which the linkage mechanism is attached.

As a result, because the mounting holes 6a are formed in a portion of the first member 2B positioned outside the second member 3B, it is possible to freely design the shape and size of the first member 2B and form the mounting holes 6a without compromising the functionality of the first member 2B and second member 3B, thereby improving the design freedom regarding the position of the mounting holes 6a on the servo horn 1B and the number of mounting holes 6a formed.

Furthermore, because the first member 2B has a slot 9, it can deform within the width of the slot 9 so that the first member 2B is pressed against the output shaft 52 when the inner surface of the second member 3B is pressed against the inclined surface 8a. This ensures high fixing strength of the first member 2B to the output shaft 52 without applying excessive load from the first member 2B to the output shaft 52.

Furthermore, because multiple slots 9 are formed at equal intervals in the circumferential direction, when the tapered surface 3b of the second member 3B is pressed against the inclined surface 8a, an equal force is applied to the output shaft 52 from each portion between the slots 9, 9 in the first member 2B. Therefore, the first member 2B can be fixed with an equal force applied to the output shaft 52, and high fixing strength of the first member 2B to the output shaft 52 can be ensured.

Furthermore, in the servo horn 1B, the first member 2B and the second member 3B are fastened to the output shaft 52 by tightening them together, so the first member 2B and the second member 3B can be fastened together in one operation, improving the workability of the fastening operation.

<Servo horn according to the fourth embodiment>
Next, a servo horn 1C according to a fourth embodiment will be described (see FIGS. 9 and 10).

The servo horn 1C described below differs from the servo horn 1 described above in that the shapes of parts of the first and second members are different, the second member is fixed to the first member with a screw member, and mounting holes are formed in the second member. Therefore, only the parts that differ from the servo horn 1 will be described in detail, and other parts will be assigned the same reference numerals as those assigned to similar parts in the servo horn 1 and will not be described again.

The servo horn 1C is composed of a first member 2C and a second member 3C.

The first member 2C consists of the fixed portion 4 and the protruding portions 5C, 5C.

The cylindrical portion 8 of the fixed portion 4 does not have a threaded groove 8b.

The protrusions 5C, 5C each protrude from the lower end of the cylindrical portion 8. Threaded holes 5a, 5a are formed in the protrusions 5C, 5C, respectively, penetrating vertically.

The second member 3C consists of a cover portion 10 that covers the fixed portion 4, protrusions 11, 11 that protrude in opposite directions from the cover portion 10, and hole-forming portions 12, 12 that protrude in opposite directions from the protrusions 11, 11.

A space that opens downward is formed in the cover portion 10, and this space is formed as a fitting hole 10a. The cover portion 10 has an inner circumferential surface that is tapered 10b, with the diameter increasing as it goes downward.

The protrusions 11, 11 each have screw insertion holes 11a, 11a that penetrate vertically.

Mounting holes 12a, 12a that penetrate vertically are formed in the hole forming section 12, spaced apart in the longitudinal direction. The number of mounting holes 12a formed in the hole forming section 12 and the positions at which the mounting holes 12a are formed in the hole forming section 12 can be set as desired.

In the servo horn 1C configured as described above, the first member 2C is attached to the output shaft 52 by first inserting the output shaft 52 into the insertion hole 4a of the fixed portion 4. At this time, the horn-side serrations 8c engage with the shaft-side serrations 52a, so that the first member 2C is attached to the output shaft 52 in a state where it is positioned circumferentially relative to the output shaft 52.

Next, the second member 3C is fixed to the first member 2C. The second member 3C is fixed to the first member 2C by inserting screw members 60, 60 into the screw insertion holes 11a, 11a of the second member 3C and threading them into the threaded holes 5a, 5a. When the second member 3C is fixed to the first member 2C, the cylindrical portion 8 of the first member 2C is fitted into the fitting hole 10a of the second member 3C, and the tapered surface 10b of the second member 3C is pressed against the inclined surface 8a of the first member 2C, deforming the cylindrical portion 8 toward the output shaft 52 and pressing the cylindrical portion 8 against the output shaft 52. Therefore, the first member 2C is fixed to the output shaft 52 by deforming the cylindrical portion 8 toward the output shaft 52 and pressing the horn-side serrations 8c against the shaft-side serrations 52a.

At this time, because the first member 2C has slots 9, 9 formed in the cylindrical portion 8, the cylindrical portion 8 is particularly susceptible to deformation toward the output shaft 52, and the cylindrical portion 8 is pressed against the output shaft 52 with a large force.

As described above, by fixing the second member 3C to the first member 2C and fixing the first member 2C to the output shaft 52, the servo horn 1C is fixed to the output shaft 52 with high fixing strength.

In the servo horn 1C, a hole forming portion 12 is provided in the second member 3C, positioned outside the first member 2C, and an attachment hole 12a is formed in the hole forming portion 12 to which the linkage mechanism is attached.

As a result, because the mounting holes 12a are formed in a portion of the second member 3C positioned outside the first member 2C, it is possible to freely design the shape and size of the second member 3C and form the mounting holes 12a without compromising the functionality of the first member 2C and second member 3C, thereby improving the design freedom regarding the position of the mounting holes 12a on the servo horn 1C and the number of mounting holes 12a formed.

Furthermore, because the first member 2C has a slot 9, it can deform within the width of the slot 9 so that the first member 2C is pressed against the output shaft 52 when the inner surface of the second member 3C is pressed against the inclined surface 8a. This ensures high fixing strength of the first member 2C to the output shaft 52 without applying excessive load from the first member 2C to the output shaft 52.

Furthermore, because multiple slots 9 are formed at equal intervals in the circumferential direction, when the tapered surface 3b of the second member 3C is pressed against the inclined surface 8a, an equal force is applied to the output shaft 52 from each portion between the slots 9, 9 in the first member 2C. Therefore, the first member 2C can be fixed to the output shaft 52 with an equal force being applied to it, and high fixing strength of the first member 2C to the output shaft 52 can be ensured.

<Servo horn according to the fifth embodiment>
Next, a servo horn 1D according to a fifth embodiment will be described (see FIGS. 11 to 13).

The servo horn 1D described below differs from the servo horn 1 described above in that the shapes of parts of the first and second members are different, that both the first and second members are fixed to the output shaft with screw members, and that a mounting hole is formed in the second member. Therefore, only the parts that differ from the servo horn 1 will be described in detail, and other parts will be given the same reference numerals as those used for similar parts in the servo horn 1 and will not be described again.

The servo horn 1D is composed of a first member 2D and a second member 3D.

The first member 2D is composed of the fixed portion 4D.

The fixed portion 4D has a disk-shaped flat portion 7D facing up and down and a cylindrical portion 8D that protrudes substantially downward from the outer periphery of the flat portion 7D. The fixed portion 4D has a screw insertion hole 7a that penetrates vertically through the flat portion 7D. The cylindrical portion 8D of the fixed portion 4D does not have a threaded groove 8b. The cylindrical portion 8D has, for example, four slots 9, 9, ... formed at equal intervals in the circumferential direction.

The second member 3D consists of a cover portion 10D that covers the fixed portion 4D, protrusions 11D, 11D that protrude in the opposite direction from the cover portion 10D, and hole-forming portions 12, 12 that protrude in the opposite direction from the protrusions 11D, 11D.

A space that opens downward is formed in the cover portion 10D, and this space forms the fitting hole 10a. The cover portion 10D has an inner circumferential surface that forms a tapered surface 10b, with the diameter increasing as it goes downward. A screw insertion hole 10c that penetrates vertically is formed in the center of the cover portion 10D.

Mounting holes 12a, 12a that penetrate vertically are formed in the hole forming section 12, spaced apart in the longitudinal direction. The number of mounting holes 12a formed in the hole forming section 12 and the positions at which the mounting holes 12a are formed in the hole forming section 12 can be set as desired.

In the servo horn 1D configured as described above, the first member 2D is attached to the output shaft 52 by first inserting the output shaft 52 into the insertion hole 4a of the fixed portion 4D. At this time, the horn-side serrations 8c engage with the shaft-side serrations 52a, so that the first member 2D is attached to the output shaft 52 in a state where it is positioned circumferentially relative to the output shaft 52.

Next, the first member 2D and the second member 3D are fastened together to the output shaft 52. The first member 2D and the second member 3D are fastened to the output shaft 52 by inserting the screw member 60 sequentially through the screw insertion hole 10c of the second member 3D and the screw insertion hole 7a of the first member 2D, and then threading it into a threaded hole formed in the center of the output shaft 52. When the second member 3D is fastened to the output shaft 52, the cylindrical portion 8D of the first member 2D is fitted into the fitting hole 10a of the second member 3D, and the tapered surface 10b of the second member 3D is pressed against the inclined surface 8a of the first member 2D, deforming the cylindrical portion 8D toward the output shaft 52 and forcing the cylindrical portion 8D against the output shaft 52. Therefore, the first member 2D is fixed to the output shaft 52 by deforming the cylindrical portion 8D toward the output shaft 52 and pressing the horn side serrations 8c against the shaft side serrations 52a.

At this time, because the first member 2D has slots 9, 9, ... formed in the cylindrical portion 8D, the cylindrical portion 8D is particularly susceptible to deformation toward the output shaft 52, and the cylindrical portion 8D is pressed against the output shaft 52 with a large force.

By fixing the first member 2D and the second member 3D to the output shaft 52 as described above, the servo horn 1D is fixed to the output shaft 52 with high fixing strength.

In the servo horn 1D, a hole forming portion 12 is provided in the second member 3D, positioned outside the first member 2D, and an attachment hole 12a is formed in the hole forming portion 12 to which the linkage mechanism is attached.

As a result, because the mounting holes 12a are formed in a portion of the second member 3D that is positioned outside the first member 2D, it is possible to freely design the shape and size of the second member 3D and form the mounting holes 12a without compromising the functionality of the first member 2D and second member 3D, thereby improving the design freedom regarding the position of the mounting holes 12a on the servo horn 1D and the number of mounting holes 12a formed.

Furthermore, because the first member 2D has a slot 9 formed therein, the first member 2D can deform within the width of the slot 9 so that it is pressed against the output shaft 52 when the inner surface of the second member 3D is pressed against the inclined surface 8a. This ensures high fixing strength of the first member 2D to the output shaft 52 without applying excessive load from the first member 2D to the output shaft 52.

Furthermore, because multiple slots 9 are formed at equal intervals in the circumferential direction, when the tapered surface 10b of the second member 3D is pressed against the inclined surface 8a, a uniform force is applied to the output shaft 52 from each portion between the slots 9, 9, ... on the first member 2D. Therefore, the first member 2D can be fixed to the output shaft 52 with a uniform force being applied to it, and high fixing strength of the first member 2D to the output shaft 52 can be ensured.

Furthermore, in the servo horn 1D, the first member 2D and the second member 3D are fixed to the output shaft 52 by tightening them together, so the first member 2D and the second member 3D can be fixed in one go, improving the workability of the fixing work.

<Summary>
As described above, in the servo horns 1, 1A, 1B, 1C, 1D and the servo device 100, the outer peripheral surfaces of the first members 2, 2A, 2B, 2C, 2D are formed as inclined surfaces 8a that approach the center as they move in the insertion direction into the insertion hole 4a of the output shaft 52, and the second members 3, 3A, 3B, 3C, 3D are formed with mating holes 3a, 10a into which at least a portion of the first members 2, 2A, 2B, 2C, 2D are fitted, and the inner peripheral surfaces of the second members 3, 3A, 3B, 3C, 3D are pressed against the inclined surfaces 8a, forming tapered surfaces 3b, 10b that press the first members 2, 2A, 2B, 2C, 2D toward the output shaft 52.

Therefore, when at least a portion of the first member 2, 2A, 2B, 2C, 2D is fitted into the fitting holes 3a, 10a of the second member 3, 3A, 3B, 3C, 3D, the tapered surfaces 3b, 10b are pressed against the inclined surface 8a and the horn-side serrations 8c are pressed against the shaft-side serrations 52a, ensuring high fixing strength to the output shaft 52.

Furthermore, when the tapered surfaces 3b, 10b of the second members 3, 3A, 3B, 3C, 3D are pressed against the inclined surface 8a, a force is applied uniformly in the circumferential direction from the first members 2, 2A, 2B, 2C, 2D to the output shaft 52, so the first members 2, 2A, 2B, 2C, 2D can be fixed to the output shaft 52 with a uniform force being applied to them.

<Others>
The above shows an example in which the servo device 100 is equipped with a servo motor 50 and a servo horn 1, but if a servo horn 1A, a servo horn 1B, a servo horn 1C or a servo horn 1D is used instead of the servo horn 1, the servo device 100 is configured to be equipped with a servo motor 50 and a servo horn 1A, a servo horn 1B, a servo horn 1C or a servo horn 1D.

100 Servo device 50 Servo motor 52 Output shaft 52a Shaft side serration 1 Servo horn 2 First member 3 Second member 3a Fitting hole 3b Tapered surface 3c Threaded portion 4a Insertion hole 6 Hole forming portion 6a Mounting hole 8a Inclined surface 8b Threaded groove portion 8c Horn side serration 9 Slot 1A Servo horn 2A First member 3A Second member 1B Servo horn 2B First member 3B Second member 1C Servo horn 2C First member 3C Second member 10a Fitting hole 10b Tapered surface 12 Hole forming portion 12a Mounting hole 1D Servo horn 2D First member 3D Second member

Claims (7)

a first member fixed to an output shaft of a servo motor having shaft-side serrations;
a second member fixed to the output shaft or the first member,
an insertion hole that opens toward the output shaft and into which the output shaft is inserted is formed in the first member, and horn-side serrations that engage with the shaft-side serrations are formed on an inner peripheral surface of the first member;
the first member has an outer peripheral surface formed as an inclined surface that approaches a center side in an insertion direction of the output shaft into the insertion hole,
a fitting hole into which at least a part of the first member is fitted is formed in the second member;
the second member has an inner peripheral surface formed as a tapered surface that is pressed against the inclined surface and presses the horn-side serrations against the shaft-side serrations ,
The first member has a slot formed therein that communicates with the insertion hole.
Servo horn. the first member is provided with a hole forming portion positioned outside the second member,
The servo horn according to claim 1 , wherein the hole forming portion has a mounting hole formed therein for mounting a linkage mechanism. the second member is provided with a hole forming portion positioned outside the first member,
The servo horn according to claim 1 , wherein the hole forming portion has a mounting hole formed therein for mounting a linkage mechanism. The slots are formed in a plurality at intervals in the circumferential direction.
The servo horn of claim 1 . a first member fixed to an output shaft of a servo motor having shaft-side serrations;
a second member fixed to the output shaft or the first member,
an insertion hole that opens toward the output shaft and into which the output shaft is inserted is formed in the first member, and horn-side serrations that engage with the shaft-side serrations are formed on an inner peripheral surface of the first member;
the first member has an outer peripheral surface formed as an inclined surface that approaches a center side in an insertion direction of the output shaft into the insertion hole,
a fitting hole into which at least a part of the first member is fitted is formed in the second member;
the second member has an inner peripheral surface formed as a tapered surface that is pressed against the inclined surface and presses the horn-side serrations against the shaft-side serrations,
the first member is provided with a hole forming portion positioned outside the second member,
A mounting hole for mounting a linkage mechanism is formed in the hole forming portion.
Servo horn. a spiral groove portion is formed on the outer peripheral surface of the first member,
6. The servo horn according to claim 1, wherein a threaded portion that threadably engages with the threaded groove portion is formed on an inner peripheral surface of the second member. a servo motor having an output shaft on which shaft side serrations are formed;
a servo horn fixed to the output shaft,
The servo horn is
a first member fixed to the output shaft;
a second member fixed to the output shaft or the first member,
an insertion hole that opens toward the output shaft and into which the output shaft is inserted is formed in the first member, and horn-side serrations that engage with the shaft-side serrations are formed on an inner peripheral surface of the first member;
the first member has an outer peripheral surface formed as an inclined surface that approaches a center side in an insertion direction of the output shaft into the insertion hole,
a fitting hole into which at least a part of the first member is fitted is formed in the second member;
the second member has an inner peripheral surface formed as a tapered surface that is pressed against the inclined surface and presses the horn-side serrations against the shaft-side serrations ,
The first member has a slot formed therein that communicates with the insertion hole.
Servo device.