KR20090093745A - Robot joint - Google Patents

Abstract

A robot joint is provided to feedback-control location and speed and guarantee simple structure and small size in case of multi degree of freedom. A robot joint supporting bending load comprises a first body(110), a bearing(120), a second body(130), and a first motor(140). The bearing comprises an outer ring fixed with the first body. The second body is fixed with an inner ring of the bearing. The first motor relatively rotates the second body to the first body.

Description

Robot joint

The present invention relates to a robotic joint.

Due to the development of the overall technology of the robot and the expansion of the market, many small household robots are being researched and developed out of the industrial field. Among them, robots in a form similar to human-like animals or humans occupy most of them.

The joints of an actual human or animal are centered around three different axes in one joint, such as the neck, shoulder, or wrist, rather than having one direction, ie one degree of freedom joint, such as the knee. Often there are multiple degrees of freedom. For this reason, it is desirable for a robot to have a multi-degree-of-freedom joint structure in order to express communication with a person, expression of emotions, and the like by movement of a body.

However, most robot joints up to now have a structure having a limited movement of one degree of freedom, and even with multiple degrees of freedom, there is a problem that the production cost increases due to the increase in overall size and complexity of the structure.

In addition, when the robot joint is configured in the form of a cantilever structure, such as a human arm, that is, one end is fixed (fixed end) and the other end is protruded from it (free end) and the load acts on it. However, there has been a problem that it is easily damaged by being vulnerable to shock.

The present invention provides a robot joint that maintains rigidity that is not damaged even by a large bending load or impact even with a simple structure.

According to one aspect of the invention, the robot joint (robot joint) for supporting the bending load, the first body (bearing), the outer ring is fixed to the first body (bearing), the second ring fixed to the inner ring of the bearing A robot joint is provided that includes a body and a first motor that rotates the second body relative to the first body.

The bearing may be tightly fitted and fixed with the first body.

The first body may further include a first cover coupled to the first body to compress the bearing toward the first body and fixing the first body and the bearing.

The bearing may be secured by being fitted with the second body.

The second body may further include a second cover coupled to the second body to compress the bearing toward the second body and fixing the second body and the bearing.

At least a part of the second body may be received inside the first body.

The apparatus may further include a rotation sensor configured to detect an angle at which the rotation shaft of the first motor rotates to generate an output signal corresponding to the rotation angle.

The second motor may further include a second motor disposed at an end of the first body or the second body at an angle different from that of the first motor.

The robot joint according to the embodiment of the present invention can maintain rigidity that does not break even under a large bending load or impact, and can be implemented in a small size and a simple structure even in the case of having multiple degrees of freedom. In addition, the position and velocity may be feedback controlled.

1 is an exploded perspective view showing a robot joint according to an embodiment of the present invention.

2 is a cross-sectional view showing a robot joint according to an embodiment of the present invention.

3 to 5 are cross-sectional views showing a process of fixing a bearing outer ring of the robot joint according to an embodiment of the present invention.

6 to 8 are cross-sectional views showing a process of fixing the bearing inner ring of the robot joint according to an embodiment of the present invention.

Figure 9 is a cross-sectional view showing a coupling state of the first body and the second body of the robot joint according to an embodiment of the present invention.

10 is an explanatory view showing a load and a supporting force acting on the robot joint according to an embodiment of the present invention.

11 to 13 are cross-sectional views showing a coupling process of the rotation axis of the motor and the first body of the robot joint according to an embodiment of the present invention.

Figure 14 is a side view showing a coupling state of the rotary shaft of the first motor of the robot joint according to an embodiment of the present invention.

15 is a side view showing a rotation detection sensor of the robot joint according to an embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

100: robot joint 110: first body

120: bearing 130: second body

140: first motor 142: rotating shaft

145: gear box 150: motor horn

152: tap 160: first cover

170: second cover 180: rotation detection sensor

190: second motor

An embodiment of a robot joint according to the present invention will be described in detail with reference to the accompanying drawings, in the following description with reference to the accompanying drawings, the same or corresponding components are given the same reference numerals and redundant description thereof will be omitted. Let's do it.

In addition, terms such as first and second used below are merely identification symbols for distinguishing the same or corresponding components, and the same or corresponding components are limited by terms such as the first and second components. no.

In addition, the combination is not only a case of physically direct contact between each component, but also a concept encompassing a case in which other components are interposed between each component and each component is in contact with the other component. To be used.

1 is an exploded perspective view showing a robot joint 100 according to an embodiment of the present invention. 2 is a cross-sectional view showing the robot joint 100 according to an embodiment of the present invention.

In the robot joint 100 according to the present embodiment, an outer race and an inner race of a bearing 120 are thoroughly formed with each of the first body 110 and the second body 130. By constraining, since the rigidity against bending load or impact is improved even with a simple structure, it can be applied to small robots requiring multiple degrees of freedom such as shoulders and wrists.

In addition, a rotation sensor 180 may be mounted therein to provide a feedback control on the position and speed of the rotation shaft 142 of the first motor 140, thereby implementing a simple servo system. Also, by modularizing it, it can be compatible with various robots.

The first body 110 may be coupled to the body of the robot to support the second body 130. In addition, a portion of the bearing 120 and the second body 130 is accommodated in the first body 110, and thus, the size of the entire robot joint 100 may be reduced.

The outer ring of the bearing 120 is fixed to the first body 110. That is, the outer ring of the bearing 120 accommodated in the first body 110 may be tightly fitted to the first body 110, thereby being fixed to the first body 110.

In addition, the first cover 160 is coupled to the first body 110 so that the bearing 120 is compressed toward the first body 110, thereby fixing the first body 110 and the bearing 120. You can. That is, the first cover 160 is coupled to the first body 110 to cover the outer ring of the bearing 120, by applying a compressive force to the outer ring of the bearing 120 toward the first body 110, the bearing 120 The outer ring of) can be completely restrained to the first body (110).

As such, the outer ring of the bearing 120 is forcibly fitted to the first body 110, and the first cover 160 is coupled to the first body 110 to apply a compressive force to the outer ring of the bearing 120. The outer ring of 120 is firmly fixed to the first body 110 so as not to flow.

3 to 5, the principle in which the outer ring of the bearing 120 is fixed to and constrained to the first body 110 will be described. 3 to 5 are cross-sectional views showing a process of fixing the outer ring of the bearing 120 of the robot joint 100 according to an embodiment of the present invention.

As shown in FIG. 3, a receiving groove having a size corresponding to the outer diameter of the bearing 120 is formed to insert the bearing 120 into the first body 110, and the depth A of the receiving groove is formed. May have a tolerance of, for example, -0.05 millimeters relative to the thickness of the bearing 120.

As shown in FIG. 4, the bearing 120 is inserted into the inside of the first body 110 by a force fitting, and as shown in FIG. 5, by combining the first cover 160, which is a hollow plate, by fastening the fastener. When fastened with a fastener, the outer ring of the bearing 120 may be compressed and firmly fixed to the first body 110 due to a tolerance between the thickness of the bearing 120 and the depth A of the receiving groove. . After being fastened with a fastener or the like, only the inner ring of the bearing 120 may be rotated.

As shown in FIGS. 1 and 2, a portion of the second body 130 is accommodated in the first body 110 and fixed to the inner ring of the bearing 120. That is, the inner ring of the bearing 120 is forcibly fitted with the second body 130, thereby being fixed to the second body 130.

Here, the second body 130 is configured to be separated into each of the parts (130a, 130b), but this is only for convenience of manufacturing, in addition to this may be configured in a variety of forms the second body 130. Of course.

In addition, the second cover 170 may be coupled to the second body 130 to compress the bearing 120 toward the second body 130, and may fix the second body 130 and the bearing 120. . That is, the second cover 170 is coupled to the second body 130 to cover the inner ring of the bearing 120, by applying a compressive force to the inner ring of the bearing 120 toward the second body 130, the bearing 120 It is possible to completely restrain the inner ring of the second body 130.

As such, the inner ring of the bearing 120 is forcibly fitted to the second body 130, and by coupling the second cover 170 to the second body 130 to apply a compressive force to the inner ring of the bearing 120, the bearing The inner ring of 120 is firmly fixed to the second body 130 and does not flow.

6 to 8, the principle in which the inner ring of the bearing 120 is fixed to and constrained to the second body 130 will be described. 6 to 8 are cross-sectional views showing a process of fixing the inner ring of the bearing 120 of the robot joint 100 according to an embodiment of the present invention.

As shown in FIG. 6, a protrusion having a diameter corresponding to the inner diameter of the bearing 120 is formed at the end of the second body 130, and the length B of the protrusion is larger than the thickness of the bearing 120. For example, it may have a tolerance of -0.05 millimeters.

As shown in FIG. 7, the inner diameter of the bearing 120 is inserted into the protrusion of the second body 130 by interference fit, and as shown in FIG. 8, the second cover 170 having a disc shape is coupled to each other. When fastened with a fastener or the like, the inner ring of the bearing 120 may receive a compressive force due to a tolerance between the thickness of the bearing 120 and the length B of the protrusion to be firmly fixed to the second body 130. After being fastened with a fastener or the like, only the outer ring of the bearing 120 may be rotated.

As described above, in the case of the present embodiment, by fixing the bearing 120 to the first body 110 and the second body 130, respectively, the rigidity against bending load or impact can be improved. That is, as shown in FIG. 9, the first body 110 independently constrains the outer ring of the bearing 120, and the second body 130 independently constrains the inner ring of the bearing 120. It is possible to improve the rigidity, and accordingly, even a simple structure can prevent sagging and breakage due to load or external force, which is a disadvantage of the cantilever structure.

Hereinafter, referring to FIG. 10, the rigidity of the robot joint 100 with respect to the bending load will be described through the distribution of the bearing force when the load W is applied to the end of the second body 130. 10 is an explanatory view showing a load and a supporting force acting on the robot joint 100 according to an embodiment of the present invention.

As shown in FIG. 10, when a load W is applied to an end portion of the second body 130 of the cantilever structure, support forces F1, F2, and F3 capable of supporting the load W are generated. That is, the second body 130 is struck and damaged by the load by the bearing force F1 generated as the outer ring of the bearing 120 is restrained and the bearing force F3 generated as the inner ring of the bearing 120 is restrained. Rigidity to can be improved.

In addition, at the same time, when the rotation shaft 142 of the first motor 140 is engaged with the motor horn 150, a bearing force F2 is generated, thereby reinforcing the bearing forces F1 and F3 by the bearing 120. .

As illustrated in FIGS. 1 and 2, the first motor 140 may rotate the second body 130 relative to the first body 110. That is, the body is coupled to any one of the first body 110 and the second body 130 and the rotation shaft 142 is coupled to the other, the driving force between the first body 110 and the second body 130 To convey.

In the present embodiment, as an example, the body of the first motor 140 is coupled to the second body 130, and the rotating shaft 142 of the first motor 140 is coupled to the first body 110 as an example. Although presented, in addition to the body of the first motor 140 is coupled to the first body 110 and the rotating shaft 142 of the first motor 140 is coupled to the second body 130 also the scope of the present invention Of course included.

Hereinafter, the coupling process between the first motor 140 and the first body 110 will be described with reference to FIGS. 11 to 13. 11 to 13 are cross-sectional views illustrating a process of coupling the first body 110 of the robot joint 100 and the rotating shaft 142 of the motor according to an embodiment of the present invention. 14 is a side view illustrating a coupling state of the rotation shaft 142 of the first motor 140 of the robot joint 100 according to an embodiment of the present invention.

As shown in FIG. 11, a hole for coupling a motor horn 150 is formed in the first body 110, and as shown in FIG. 12, for example, made of steel. The motor horn 150 is inserted into the hole of the first body 110 by fastening and fastened with a fastener or the like.

Thereafter, as shown in FIGS. 13 and 14, the rotation shaft 142 of the first motor 140 is disposed in a hole formed to correspond to the rotation shaft 142 of the first motor 140 in the center of the motor horn 150. By inserting the tab 152 on the side of the motor horn 150, the rotation shaft 142 of the first motor 140 is fixed. Therefore, according to the forward or reverse rotation of the first motor 140, the second body 130 relatively rotates forward or reverse with respect to the first body 110.

As shown in FIGS. 1 and 2, the second motor 190 is disposed at an end of the first body 110 or the second body 130 at an angle different from that of the first motor 140. That is, the second motor 190 may be coupled to the end of the second body 130 so as to be perpendicular to the first motor 140, and thus, to the first motor 140 and the second motor 190. By the robot joint 100 having two degrees of freedom can be implemented.

As such, the first body 110 and the second body 130 are fixed to the outer ring and the inner ring of the bearing 120, respectively, thereby improving the rigidity of the robot joint 100 against bending load and impact even with a simple structure. Therefore, even when the second body 190 is coupled to the second body 130 to implement two degrees of freedom, it is not necessary to take a complicated structure compared to the load or the impact, and as a result, the overall size of the robot joint 100 Can be miniaturized.

15 is a side view illustrating a rotation sensor 180 of the robot joint 100 according to an embodiment of the present invention. As shown in FIG. 15, the rotation sensor 180 may detect an angle at which the rotation shaft 142 of the first motor 140 rotates. That is, the rotation sensor 180 detects an angle at which the rotation shaft 142 of the first motor 140 rotates, generates an output signal corresponding to the rotation angle, and transmits the output signal to the control unit (not shown). do.

The control unit (not shown) receives the output signal to determine a corresponding rotation speed, rotation direction, or rotation amount, and generates an operation signal for operating the first motor 140 to generate the first motor 140. To pass on.

Hereinafter, the principle of driving the robot joint 100 according to an embodiment of the present invention.

The forward or reverse rotational driving force of the first motor 140 is decelerated through the gear box 145 and finally output through the rotation shaft 142 of the first motor 140, and the motor horn 150 The second body 130 is rotated by restraining the rotation shaft 142 of the first motor 140. Since the rotation angle of the rotation shaft 142 of the first motor 140 may be measured using the rotation detection sensor 180, the rotation angle and the speed of the rotation shaft 142 of the first motor 140 may be controlled using the rotation detection sensor 180. can do.

 That is, when the rotation shaft 142 of the first motor 140 is rotated by the driving force of the first motor 140, the rotation sensor 180 as shown in FIG. 15 causes the rotation shaft of the first motor 140 ( The position value of 142 is transmitted to the control unit (not shown) as an output signal.

After receiving the output signal from the control unit (not shown), the current position of the rotation shaft 142 of the first motor 140 is determined, the rotation direction and the speed are determined, and the corresponding operation signal is transmitted to the first motor 140. By transmitting the to rotate the rotating shaft 142 of the first motor 140 to the desired target position.

 In addition, even after reaching the target position, the current position is periodically fed back so that the rotation shaft 142 of the first motor 140 can stop at the target position.

In the case of the second motor 190, like the first motor 140, the rotation angle and the speed may be controlled by measuring the rotation angle by the rotation detection sensor, and a detailed description thereof will be omitted.

Many embodiments other than the above-described embodiments are within the scope of the claims of the present invention.

Claims (8)

A robot joint that supports bending loads A first body; A bearing in which an outer ring is fixed to the first body; A second body fixed to the inner ring of the bearing; And And a first motor that rotates the second body relative to the first body. The method of claim 1, The bearing is a robot joint, characterized in that the tight fit (tight fit) and the first body. The method of claim 1, And a first cover coupled to the first body to compress the bearing toward the first body, the first cover fixing the first body and the bearing. The method of claim 1, The bearing is a robot joint, characterized in that forcibly fitted with the second body. The method of claim 1, And a second cover coupled to the second body to compress the bearing toward the second body, the second cover fixing the second body and the bearing. The method of claim 1, The second body is a robot joint, characterized in that at least a portion is accommodated in the interior of the first body. The method of claim 1, And a rotation detection sensor configured to generate an output signal corresponding to the rotation angle by detecting an angle at which the rotation axis of the first motor rotates. The method of claim 1, And a second motor disposed at an end of the first body or the second body at an angle different from that of the first motor.