WO2015129937A1

WO2015129937A1 - Small-sized linear servo actuator

Info

Publication number: WO2015129937A1
Application number: PCT/KR2014/001599
Authority: WO
Inventors: 남형도; 김기덕; 이수준
Original assignee: 포테닛 주식회사
Priority date: 2014-02-25
Filing date: 2014-02-27
Publication date: 2015-09-03
Also published as: KR101513607B1

Abstract

A small-sized linear servo actuator is disclosed. The small-sized linear servo actuator, according to one embodiment of the present invention, comprises: a rod part having the overall shape of a rod and receiving driving force so as to carry out linear reciprocating motion; a servo motor having a rotating shaft for supplying driving force for driving the rod part; a power transmission member for converting rotational motion by the rotating shaft of the servo motor into the linear reciprocating motion of the rod part; an outer housing having a guide hole formed at one side thereof and penetrated by one end of the rod part, a hollow part formed therein along the central axis direction of the guide hole so as to accommodate the rod part, an accommodation space formed at the upper side of the hollow part so as to accommodate a potentiometer for measuring the movement distance of the rod part and a control board for controlling all of the operations, and an accommodation space formed at the lower side of the hollow part so as to accommodate the servo motor; and a pivot joint part provided with a joint main body, which has a plurality of cylindrical members having the same central axis but different diameters from each other and double-overlapped with each other, and a joint shaft, which vertically penetrates a side surface of the joint main body and is rotationally coupled to one end of the outer housing such that reciprocating rotational motion can be implemented for two shafts which are relatively perpendicular to each other, thereby obtaining two-degrees-of-freedom.

Description

Compact Linear Servo Actuator

The present invention relates to a small linear servo actuator, and more particularly, the present invention relates to a control board for controlling a rod part that linearly moves by driving a motor inside an external housing and a potentiometer for sensing a moving distance of the rod part. In order to construct a swivel joint with two degrees of freedom by implementing a reciprocating rotational movement about two axes which are relatively orthogonal, it is formed of a joint body having a simple structure to satisfy the miniaturization suitable for the endoskeletal structure of a biomimetic robot. The present invention relates to a small linear servo actuator which can be easily controlled and has a simple mechanical configuration.

Recently, various attempts have been made to produce biomimetic robots that mimic the skeleton structures of humans, insects, and animals with respect to industrial robot-related technologies that used rotary type driving devices.

As a result, various research institutes and universities publish biomimetic robots that can be used in industrial sites.In particular, various aids for the disabled, the elderly, and the rehabilitation include humanoid robots composed of human endoskeletal structures. Devices continue to be released.

Most of the humanoid robots or auxiliary devices implement a technology having a biomimetic structure using a linear driving device rather than a conventional rotary driving device.

Here, the linear drive device is generally used for the transfer of the factory automation, the transfer supply device and the assembly, the conveying line field, the industrial Cartesian robot, the conveying machine and the lift device, the automatic door and the conveying device of the CNC machine tool, the industrial automatic door field. It refers to a linear actuator that linearly moves an object in various industrial machinery such as packaging, welding, and linear motion devices of a painting machine.

In the case of a robot in which the linear actuator technology is implemented, since its size and weight are generally optimized, the internal space for installing the linear actuator for driving the robot has a very narrow structure.

However, in the case of the conventional linear actuator, it is difficult to miniaturize the external housing forming the linear actuator because the rotation axis of the drive motor and the movable body linearly moving in accordance with the rotation of the rotation shaft are coupled to each other in a single axis. In addition, since the control board for controlling the linear actuator is disposed outside the outer housing and only the connecting cable for the control and power supply is introduced inside, the mechanical configuration of the linear actuator is complicated and there is a limit in reducing the overall size. .

In addition, in the related art, a rotary joint formed at the rear end of the outer housing of the linear actuator generally has two shafts arranged adjacently so as to implement a two degree of freedom rotational movement by the endoskeletal structure of the biomimetic robot. Since it is formed by using a complicated mechanical configuration, the control efficiency is also lowered and there is a problem in that the miniaturization of the linear actuator.

Therefore, there is an urgent need for a practical and applicable technology for a small linear servo actuator that can satisfy the miniaturization suitable for the endoskeleton structure of the biomimetic robot and its simple mechanical configuration.

Prior literatures related to the present invention include Republic of Korea Patent No. 10-0472119 (Registration Date: February 04, 2005).

Accordingly, the present invention has been made in order to solve the above problems, the present invention is integrated into a control board for controlling the rod portion to move linearly by the drive of the motor inside the outer housing and a potentiometer for sensing the movement distance of the rod portion It is built with a joint body with a simple structure to implement a reciprocating rotational movement about two axes which are relatively orthogonal to each other, so that it can satisfy the miniaturization suitable for the endoskeletal structure of the biomimetic robot. It is an object of the present invention to provide a small linear servo actuator which can be easily controlled due to its simple mechanical configuration.

Small linear servo actuator according to an embodiment of the present invention, the rod portion is formed in a rod shape as a whole and receives a driving force to perform a linear reciprocating motion; A servo motor having a rotating shaft for supplying a driving force for driving the rod part; A power transmission member for converting the rotational motion by the rotational shaft of the servo motor into a linear reciprocating motion of the rod part; A guide hole through which one end of the rod portion penetrates is formed at one side, and a hollow portion for accommodating the rod portion is formed along the direction of the center axis of the guide hole, and a potentiometer for measuring a moving distance of the rod portion above the hollow portion. And an outer housing forming an accommodating space for accommodating a control board for controlling the overall operation and forming an accommodating space for embedding the servo motor under the hollow part. And a joint shaft having a plurality of cylindrical members having the same central axis and having different diameters overlapping each other, and a joint shaft vertically penetrating the side surfaces of the joint body and rotatably coupled with the other end of the outer housing. It can implement a reciprocating rotational motion about two axes that are relatively orthogonal; a rotary joint part having two degrees of freedom.

The rod part has a ball joint formed in a hemispherical shape at one end and a rotation formed to have a step around the other end so that the inner surface of the hollow part formed in the outer housing and the outer circumferential surface contact each other to allow a linear motion while preventing rotational motion. A prevention groove is provided.

The anti-rotation groove is formed with a straight groove for coupling the moving bar of the potentiometer disposed on the upper side of the hollow to measure the moving distance of the rod portion on the upper surface.

The outer housing is provided with a guide ring in which the outer circumferential surface of the rod part is retractably fitted so as to guide the rod part to slide in the hollow part.

The rotary joint part has a reciprocating rotational motion of the outer housing about a joint shaft to which the other end of the outer housing is coupled in a first direction, and is centered on the same central axis of the plurality of cylindrical members constituting the joint body. A reciprocating rotational motion generated between the plurality of cylindrical members is a second direction, and implements a reciprocating rotational motion having two degrees of freedom with respect to two axial directions of a first direction and a second direction that are relatively orthogonal.

The rotary joint part, and the joint shaft is coupled to the other end of the outer housing; A plurality of rotary joint bearing members coupled to both ends of the joint shaft to support a reciprocating rotational movement in the first direction of the outer housing; Is formed of a cylindrical member disposed inside in a relatively small size of the plurality of cylindrical members constituting the joint body to support the reciprocating rotational movement in the second direction, the side is provided with a through hole for the joint shaft is fitted An inner joint part having a first fixing screw groove to which a fixing screw for fixing the joint shaft to an upper surface is formed; And a second fixing screw groove having a same central axis as the inner joint part and having a cylindrical member having a shape surrounding the outer circumferential surface of the inner joint part, and fastening a fixing screw for fixing the body of the cylindrical member to the inner side of the lower surface. And an out joint part having an elliptical slot formed on the side of the inner joint part, the diameter of which is relatively large in length relative to the through hole diameter of the inner joint part, which is cut in the longitudinal direction and restricts the movement range of the joint shaft.

In this case, the range of the reciprocating rotational motion in the second direction of the inner joint portion may be adjusted by adjusting the length of the diameter cut in the longitudinal direction of the elliptical slot provided in the out joint portion.

The outer housing has a fork portion coupled to both ends of a joint shaft constituting the rotary joint portion at the other end, and the fork portion includes a bearing accommodation groove in the inner surface to accommodate the plurality of rotary joint bearing members.

The power transmission member includes: a motor sub-gear connected to one end of the rotating shaft of the servo motor in a receiving space formed under the hollow part of the outer housing to receive a rotational force; In the hollow part of the outer housing, one side is screwed into the screw groove part formed inside the other end of the rod part, and the rod part is linearly reciprocated in the hollow part while being drawn into or out of the rod part according to a driving direction. Screw to enable; And a screw gear that is axially coupled to the other end of the screw in the hollow portion of the outer housing and engaged with the motor sub-gear gear to transmit the rotational force of the servomotor to the screw.

Here, the screw bearing member formed to support the rotational movement to one side and the other side of the screw gear, and the spacer for maintaining a constant separation distance between the screw bearing member and the screw gear is preferably disposed.

As described above, the present invention, the internal skeleton of the bio-mimetic robot by integrally embedded in the outer housing a control board for controlling the rod to move linearly by the drive of the motor and a potentiometer for sensing the movement distance of the rod unit integrally It is effective to provide a compact linear servo actuator with high integration to satisfy the miniaturization suitable for the structure.

In addition, the present invention is to form a rotary joint portion consisting of a plurality of cylindrical members overlapping and coupled to the other end of the outer housing in a simple manner by implementing a mechanical configuration to reduce the size and easy to control the small linear servo actuator effect There is.

Furthermore, in order to be rotatably coupled to the two degree of freedom rotary joint coupled to the other end of the outer housing, a bearing coupled to both ends of the joint shaft of the two degree of freedom rotary joint is accommodated inside the fork portion formed at the other end of the outer housing. This reduces the number of parts, thereby reducing manufacturing costs.

In addition, instead of implementing the soccer tank of the power transmission member converting the rotational motion of the servo motor into a linear motion as a single axis, it is possible to reduce the size of the external housing by using a plurality of gears.

1 is a perspective view showing a small linear servo actuator according to an embodiment of the present invention.

2 is a cross-sectional view showing the internal structure of a small linear servo actuator according to an embodiment of the present invention.

3 is a perspective view of FIG. 2.

4 is a view illustrating the potentiometer and the control board shown in FIGS. 2 to 3.

5 is an exploded view of the rod viewed from different angles to show the rods shown in FIGS.

FIG. 5 is an exploded view illustrating the rotary joint part shown in FIGS. 2 and 3.

6 is a view for showing a rotary joint coupled to the outer housing shown in FIGS.

FIG. 7 is an exploded view of a two degree of freedom rotating joint viewed from different angles in order to explain the two degree of freedom rotating joint illustrated in FIG. 6.

8 is a view showing an operation of the rod constituting the small linear servo actuator according to an embodiment of the present invention.

9 is a view showing a universal joint implementing a two degree of freedom rotational motion in accordance with the prior art.

FIG. 10 is a view illustrating two axial directions having two degrees of freedom of a rotary joint part constituting a small linear servo actuator according to an exemplary embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

1 is a perspective view showing a small linear servo actuator according to an embodiment of the present invention, Figure 2 is a cross-sectional view showing the internal configuration of the small linear servo actuator according to an embodiment of the present invention, Figure 3 is a perspective view of Figure 2 to be.

As shown in the figure, the small linear servo actuator 10 according to the embodiment of the present invention, the rod portion 100, the servo motor 200, the power transmission member 300, the outer housing 400, and the rotation The joint part 500 is included.

In more detail, the rod part 100 is formed in a rod-like overall shape and is stretched in and out of the outer housing 400 by receiving the driving force of the servo motor 200 from the power transmission member 300. Perform a straight reciprocating motion.

In addition, the servo motor 200 has a rotary shaft 210 for rotating the rotation by the drive of the motor in order to drive the linear reciprocating motion of the rod unit 100 and supplying a rotational driving force to the rod unit 100 do.

Here, the rotating shaft 210 is one end is connected to the servo motor 200 and the other end is connected to the power transmission member 300.

In addition, the power transmission member 300, for converting the rotational movement by the rotation shaft 210 of the servo motor 200 to a linear reciprocating motion of the rod portion 100, shown in Figures 2 to 3 As shown in the figure, a motor subordinate gear 310, a screw 320, and a screw gear 330 are provided.

More specifically, the motor unit gear 310 is connected to one end of the rotating shaft 210 of the servo motor 200 in a receiving space formed below the hollow portion 410 of the outer housing 400 to be described later. Received.

In addition, the screw 320, one side of the hollow portion 410 of the outer housing 400 is screwed with the screw groove portion 121 formed inside the other end of the rod portion 100 and according to the driving direction The rod part 100 may be linearly reciprocated in the hollow part 410 while being drawn into or drawn out of the rod part 100.

In addition, the screw gear 330 is axially coupled to the other end of the screw 320 in the hollow portion 410 of the outer housing 400 and to transmit the rotational force of the servomotor 200 to the screw 320. In order to be engaged with the motor sub-gear 310.

At this time, as shown in the figure, a screw bearing member 340 formed to support the rotational movement to one side and the other side of the screw gear 330, and the screw bearing member 340 and the screw gear 330 It is preferable that a spacer 350 is disposed to maintain a constant separation distance therebetween.

As described above, the small linear servo actuator according to the embodiment of the present invention is configured by using a plurality of gear parts instead of implementing a soccer group of a power transmission member that converts the rotational motion of the servo motor into a linear motion as a single axis. There is an effect that can reduce the size of the housing.

On the other hand, the outer housing 400 constituting the small linear servo actuator according to an embodiment of the present invention, a guide hole 401 through which one end of the rod part 100 penetrates is formed on one side and the rod part 100 The hollow part 410 for accommodating the inside is formed along the central axis direction of the guide hole 401.

As shown in the figure, the outer housing 400, the potentiometer 600 for measuring the moving distance of the rod portion 100 to the upper side of the hollow portion 410 and a control board for controlling the overall operation ( A storage space for accommodating 700 is formed.

In addition, the outer housing 400 forms a storage space for embedding the motor sub-gear 310 constituting the servo motor 200 and the power transmission member 300 below the hollow portion 410. do.

In addition, the outer housing 400, the guide ring 420 is inserted into the outer circumferential surface of the rod portion 100 in order to guide the sliding movement of the rod portion 100 inside the hollow portion 410. ) Is provided inside the guide hole 401.

In addition, the outer housing 400, the fork portion 430 is coupled to both ends of the joint shaft 510 constituting the rotary joint portion 500 to be described later, the other end, the control board ( A connector hole 440 is formed to install a connector 800 for applying an electrical signal to the 700.

In addition, the rotary joint part 500 constituting the small linear servo actuator according to an embodiment of the present invention, the joint body and the joint body is formed by overlapping a plurality of cylindrical members having different diameters and having the same central axis double A joint shaft 510 penetrates the side surface of the main body vertically and the other end of the outer housing is rotatably coupled to implement a reciprocating rotational movement with respect to two orthogonal axes, which will be described later. do.

4 is a view illustrating the potentiometer and the control board shown in FIGS. 2 to 3, and FIG. 5 is an exploded view of the rod viewed from another angle to show the rod illustrated in FIGS. 2 to 3.

Referring to Figures 4 to 5 will be described in detail the components embedded in the outer housing of the small linear servo actuator according to an embodiment of the present invention.

In the small linear servo actuator according to the embodiment of the present invention, the potentiometer 600 and the control board 700 shown in FIG. 4 are embedded above the hollow part 410 formed in the outer housing 400.

In this case, the potentiometer 600 measures the moving distance of the rod unit 100 receiving the driving rotational force of the servo motor 200 and transmits the measurement result to the control board 700. As described above, the guide rail 601 is formed on the lower surface in the longitudinal direction and the moving bar 610 is coupled to the guide rail 601 to measure the distance reciprocating in a straight line of the rod part 100 in real time. can do.

On the other hand, the rod portion 100, as shown in the figure, the ball joint 110 is formed in a hemispherical shape at one end and the anti-rotation groove 120 is formed to have a step around the other end.

At this time, it is preferable that the screw thread 111 is formed at one end of the ball joint 110 extending in a straight line and corresponding to the screw thread 112 formed at one inner surface of the rod part 100. When applied to the robot, the ball portion coupled to the ball joint 110 can rotate freely, so that the expansion and contraction of the rod portion 100 can be absorbed by the action of the joint and the ball portion can be point contact Precise control is possible.

The anti-rotation groove 120 may contact the inner surface of the hollow portion 410 and the outer circumferential surface of the outer housing 400 to prevent rotational movement while allowing linear movement of the rod portion 100. In order to prevent the rotational movement of the rod part 100, it is preferable that the upper and lower surfaces have a horizontal surface rather than a circular circumference. Here, the inner upper and lower surfaces of the hollow part of the outer housing 400 are formed to correspond to the horizontal surfaces formed on the upper and lower surfaces of the rod part 100.

In addition, the rotation preventing groove 120, the moving bar 610 of the potentiometer 600 is disposed on the upper side of the hollow portion 410 to measure the moving distance of the rod portion 100 on the upper surface is coupled To be a straight groove 130 is formed.

In addition, a screw groove portion 121 is formed to couple the screw 320 to the inner side of the other end of the rod portion 100 in which the rotation preventing groove 120 is located.

As described above, the small linear servo actuator according to the embodiment of the present invention is integrated with a control board for controlling a rod part that linearly moves by driving of a motor inside the outer housing and a potentiometer for sensing a moving distance of the rod part. It can be built in high integration to satisfy the miniaturization suitable for the endoskeletal structure of the biomimetic robot.

FIG. 6 is a view illustrating a rotary joint part coupled to the external housing illustrated in FIGS. 2 to 3, and FIG. 7 is an exploded view of the rotary joint viewed from another angle to explain the two degree of freedom rotary joint illustrated in FIG. 6. to be.

6 to 7, the rotation joint constituting the small linear servo actuator according to the embodiment of the present invention will be described in detail as follows.

The rotary joint part 500 constituting the small linear servo actuator according to the embodiment of the present invention includes a joint body in which a plurality of cylindrical members having the same central axis and having different diameters are formed to overlap each other. A joint shaft 510 penetrates the side surface vertically and the other end of the outer housing is rotatably coupled to each other to implement a reciprocating rotational movement with respect to two relatively perpendicular axes.

As shown in the drawing, the rotary joint part 500 includes a joint shaft 510, a rotary joint bearing member 520, an inner joint part 530, and an out joint part 540.

In more detail, the joint shaft 510 is coupled to the fork part 430 formed at the other end of the outer housing 400 together with the inner joint part 530 and the out joint part 540. A plurality of bearing members 520 may be coupled to both ends of the joint shaft 510 to support a reciprocating rotational motion in the first direction of the outer housing 400. Here, the first direction refers to a reciprocating rotational direction of the outer housing 400 moving around the joint shaft 510 to which the other end of the outer housing 400 is coupled.

In addition, the inner joint part 530 is formed of a cylindrical member disposed inward with a relatively small size among the plurality of cylindrical members constituting the joint body to support the reciprocating rotational movement in the second direction, and The joint shaft 510 is provided with a through-hole 531 through which the body of the cylindrical member is fitted, and a first fixing screw (not shown) for fastening the joint shaft 510 to the upper surface inside is fastened. The screw groove 501 is formed. At this time, when the fixing screw is fastened through the first fixing screw groove 501 while the joint shaft 510 is fitted, the joint shaft 510 and the inner joint part 530 are firmly fixed to each other and the joint shaft is fixed. 510 is unable to rotate the rotation about the central axis.

Here, the reciprocating rotational motion in the second direction supported by the inner joint portion 530 is a reciprocating force generated between the plurality of cylindrical members about the same central axis of the plurality of cylindrical members constituting the joint body More detailed description will be described later to indicate the rotational motion.

In the embodiment of the present invention, the out joint part 540 has the same central axis as the inner joint part 530 and forms an outer circumferential surface of the inner joint part 530 in order to form a reciprocating rotational motion in the second direction. It is formed of a cylindrical member of a surrounding shape.

At this time, the out joint portion 540 is formed with a second fixing screw groove 502 to which a fixing screw for fixing the body of the cylindrical member forming the out joint portion 540 in the lower surface.

In addition, the out joint portion 540 is formed by cutting a diameter of a length larger than a diameter of the through-joint 531 of the inner joint portion 530 on the side surface of the joint shaft 510. It is provided with an oval slot 541 for limiting the movement range, and has a cylindrical accommodation space for accommodating the inner joint portion 530 therein.

In the embodiment of the present invention, by adjusting the length of the diameter cut in the longitudinal direction of the elliptical slot 541 provided in the out joint portion 540, the reciprocating rotation of the inner joint portion 530 in the second direction You can adjust the range of motion.

That is, when the inner joint part 530 reciprocates in the second direction while the out joint part 540 is fixed to a support (not shown) formed outside the rotary joint 500, the elliptical shape is elliptical. The range of the diameter of the slot 541 in the longitudinal direction is adjusted in a range of 1 ° to 180 ° based on the center axis of the joint shaft 510 to have a reciprocating rotational motion with respect to two axes perpendicular to each other. Can be implemented.

In this case, when the elliptical slot 541 is the same size as the through hole 531 of the inner joint portion 530 to which the joint shaft 510 is fitted, the inner joint portion 530 and the out joint portion 540. There is no reciprocating rotational motion in the second direction between the) and only one degree of freedom in the first direction of the outer housing 400 exists.

On the other hand, in the embodiment of the present invention, the fork part 430 is provided with a bearing accommodation groove 431 in which the plurality of rotation joint bearing members 520 are accommodated, and the bearing accommodation groove 431. ), A fixing hole 432 is formed at both ends of the joint shaft 510 passing through the bearing member 520 and then fixed.

As described above, the small linear servo actuator according to the embodiment of the present invention can reduce the size and facilitate the control by forming a rotary joint to simply implement a mechanical configuration, and a bearing coupled to both ends of the joint shaft of the rotary joint. To accommodate the inside of the fork portion formed on the other end of the outer housing to reduce the number of parts for the basic configuration that was required in the case of having a conventional bearing, thereby reducing the manufacturing cost.

8 is a view showing an operation process of the rod constituting the small linear servo actuator according to an embodiment of the present invention.

As shown in the figure, the small linear servo actuator according to the embodiment of the present invention, when an electric signal is applied to the control board, the drive rotational force of the servo motor 200 is the motor gear 310, screw gear 330, And the screw 320 in order to move the hollow part 410 formed inside the outer housing 200 to move in and out of the outer housing 200.

9 is a view showing a universal joint implementing a two degree of freedom rotary motion according to the prior art, Figure 10 is a two axial direction having two degrees of freedom of the rotary joint portion constituting a small linear servo actuator according to an embodiment of the present invention It is a figure which shows.

As shown in FIG. 9, the universal joint 1 according to the related art has a limitation in reducing the size because the joint body is formed by connecting two adjacent axes to implement two degrees of freedom, and is easy to control because the rotation range is narrow. Difficult to let

As shown in FIG. 10, the rotary joint part 500 constituting the small linear servo actuator according to the embodiment of the present invention has the center of the joint shaft 510 to which the other end of the outer housing 400 is coupled. A reciprocating rotation occurring between the plurality of cylindrical members about the same central axis of the plurality of cylindrical members constituting the main body of the rotary joint part 500 with the reciprocating rotational movement of the outer housing 400 as the first direction. The motion is taken as the second direction, and a reciprocating rotational motion having two degrees of freedom is realized with respect to two axial directions in a first direction and a second direction which are relatively orthogonal.

As described above, the present invention incorporates a control board for controlling the rod portion linearly moved by the driving of the motor in the outer housing and a potentiometer for sensing the movement distance of the rod portion integrally, and on two relatively perpendicular axes To realize the reciprocating rotational movement about the joint structure having a simple structure to form a rotary joint having two degrees of freedom, it can satisfy the miniaturization suitable for the endoskeletal structure of the biomimetic robot, and the mechanical configuration is simple and easy to control. It is effective to provide a small linear servo actuator.

The present invention has been described in detail so far, but the embodiments mentioned in the process are only illustrative and are not intended to be limiting, and the present invention is provided by the following claims and the technical spirit and field of the present invention. Within the scope not departing from the scope of the present invention, changes in the components that can be coped evenly will fall within the scope of the present invention.

The invention can be used in the manufacture of industrial robots, biomimetic robots (humanoids), and machinery.

Claims

A rod portion which is formed in a rod shape as a whole and receives a driving force to perform a linear reciprocating motion;

A servo motor having a rotating shaft for supplying a driving force for driving the rod part;

A power transmission member for converting the rotational motion by the rotational shaft of the servo motor into a linear reciprocating motion of the rod part;

A guide hole through which one end of the rod portion penetrates is formed at one side, and a hollow portion for accommodating the rod portion is formed along the direction of the center axis of the guide hole, and a potentiometer for measuring a moving distance of the rod portion above the hollow portion. And an outer housing forming an accommodating space for accommodating a control board for controlling the overall operation and forming an accommodating space for embedding the servo motor under the hollow part. And

A plurality of cylindrical members having the same central axis and having different diameters overlap each other, and a joint shaft which vertically penetrates the side surface of the joint body and is rotatably coupled to the other end of the outer housing. A small linear servo actuator comprising: a rotary joint having two degrees of freedom to implement a reciprocating rotational motion about two axes orthogonal to
The method of claim 1, wherein the rod portion,

A ball joint is formed in a hemispherical shape at one end and a rotation preventing groove which is formed to have a step around the other end to prevent the rotational movement while allowing linear movement by contacting the inner surface of the hollow portion and the outer circumferential surface formed inside the outer housing. Small linear servo actuator, characterized in that
According to claim 2, The anti-rotation groove,

Small linear servo actuator, characterized in that the linear groove for engaging the moving bar of the potentiometer disposed on the upper side to measure the moving distance of the rod portion on the upper surface is formed
The method of claim 1, wherein the outer housing,

Small linear servo actuator, characterized in that the guide ring is fitted into the guide hole so that the outer peripheral surface of the rod is retractable in order to guide the sliding movement of the rod inside the hollow portion
The method of claim 1, wherein the rotation joint portion,

The plurality of cylindrical members about the same central axis of the plurality of cylindrical members constituting the joint body in a first direction, with a reciprocating rotational movement of the outer housing about the joint shaft to which the other end of the outer housing is coupled; Small linear servo actuator characterized by realizing a reciprocating rotational motion having two degrees of freedom with respect to two axial directions in a first direction and a second direction that are relatively orthogonal, with the reciprocating rotational motion occurring between them as a second direction.
According to claim 1 or 5, The rotary joint portion,

A joint shaft to which the other end of the outer housing is coupled;

A plurality of rotary joint bearing members coupled to both ends of the joint shaft to support a reciprocating rotational movement in the first direction of the outer housing;

Is formed of a cylindrical member disposed inside in a relatively small size of the plurality of cylindrical members constituting the joint body to support the reciprocating rotational movement in the second direction, the side is provided with a through hole for the joint shaft is fitted An inner joint part having a first fixing screw groove to which a fixing screw for fixing the joint shaft to an upper surface is formed; And

A second fixing screw groove having a same central axis as the inner joint part and formed of a cylindrical member surrounding the outer circumferential surface of the inner joint part and fastened with a fixing screw for fixing the body of the cylindrical member to the inner side of the lower surface; And an out joint portion having an elliptical slot formed on the side of the inner joint portion, the diameter of the length of which is relatively larger than that of the through-hole portion in the longitudinal direction, and which limits the movement range of the joint shaft. Linear Servo Actuator
The method of claim 6,

Compact linear servo actuator, characterized in that for adjusting the length of the diameter cut in the longitudinal direction of the elliptical slot provided in the out joint portion can adjust the range of reciprocating rotation in the second direction of the inner joint portion
The method of claim 6, wherein the outer housing,

On the other end is formed a fork portion coupled to both ends of the joint shaft constituting the rotary joint portion,

The fork portion,

Small linear servo actuator, characterized in that provided on the inner surface bearing receiving groove for receiving the plurality of rotary joint bearing members
The method of claim 1, wherein the power transmission member,

A motor sub-gear connected to one end of the rotating shaft of the servomotor in a receiving space formed under the hollow part of the outer housing to receive a rotational force;

In the hollow part of the outer housing, one side is screwed into the screw groove part formed inside the other end of the rod part, and the rod part is linearly reciprocated in the hollow part while being drawn into or out of the rod part according to a driving direction. Screw to enable; And

A small linear servo actuator comprising: a screw gear that is axially coupled to the other end of the screw in the hollow portion of the outer housing and engaged with the motor sub-gear gear to transmit the rotational force of the servo motor to the screw.
The method of claim 9,

Small linear servo actuator, characterized in that the screw bearing member formed to support the rotational movement to one side and the other side of the screw gear, and a spacer for maintaining a constant separation distance between the screw bearing member and the screw gear is disposed.