Patent ID: 12220811

DETAILED DESCRIPTION

Hereinafter, example embodiments of the disclosure will be described in detail with reference to the accompanying drawings. The same reference numerals are used for the same components in the drawings, and redundant descriptions thereof will be omitted. The embodiments described herein are example embodiments, and thus, the disclosure is not limited thereto and may be realized in various other forms.

The embodiments described below are examples for promoting understanding of the disclosure, and it should be noted that the disclosure may be implemented while being modified in various forms, unlike the embodiments described herein. In explaining the disclosure below, in case it is determined that detailed explanation of related known functions or components may unnecessarily confuse the gist of the disclosure, the detailed explanation and detailed illustration will be omitted. Also, in the accompanying drawings, some components may not be illustrated according to their actual sizes, but they may be illustrated in exaggerated sizes, for promoting understanding of the disclosure.

As terms used in this specification and the claims, general terms were selected in consideration of the functions described in the disclosure. However, these terms may vary depending on the intention of those skilled in the art who work in the pertinent field, legal or technical interpretation, emergence of new technologies, etc. Further, there may be terms that were designated by the applicant on his own, and in such cases, the meaning of the terms may be interpreted as defined in this specification. Terms that are not specifically defined in the disclosure may be interpreted based on the overall content of this specification and common technical knowledge in the pertinent art.

In addition, in this specification, expressions such as “have,” “may have,” “include,” and “may include” denote the existence of such characteristics (e.g.: elements such as numbers, functions, operations, and components), and do not exclude the existence of additional characteristics.

As used herein, expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list. For example, the expression, “at least one of a, b, and c,” should be understood as including only a, only b, only c, both a and b, both a and c, both b and c, or all of a, b, and c.

Elements necessary for description of each embodiment of the disclosure were explained, and thus elements are not necessarily limited thereto. Accordingly, some elements may be modified or omitted, or other elements may be added. In addition, elements may be arranged while being dispersed to apparatuses independent from one another.

Further, while the embodiments of the disclosure will be described in detail with reference to the following accompanying drawings and the content described in the accompanying drawings, it is not intended that the disclosure is restricted or limited by the embodiments.

Hereinafter, the disclosure will be described in more detail with reference to the accompanying drawings.

FIG.1is a diagram of a robot arm structure including a joint apparatus for a robot according to an embodiment of the disclosure.FIG.2is a diagram of a joint apparatus for a robot according to an embodiment of the disclosure.

Referring toFIG.1andFIG.2, the arm apparatus for a robot1000according to an embodiment of the disclosure may include a plurality of joint apparatuses1and2. Specifically, the arm apparatus for a robot1000may be implemented as the plurality of joint apparatuses1and2having rotation axes in various directions according to the longitudinal direction are connected in series.

For example, the first joint apparatus1may have a rotation axis in a roll direction, and the second joint apparatus2may have a rotation axis in a pitch direction.

Specifically, four first joint apparatuses and three second joint apparatuses2may be alternatingly arranged one by one, and the arm apparatus for a robot1000may have seven degrees of rotational freedom.

The arrangement order and the numbers of the joint apparatuses1and2, are not limited thereto, and the joint structure of the arm for a robot may be implemented as the plurality joint apparatuses1and2having rotation axes in various directions are combined.

Also, on the end part of the arm apparatus for a robot1000, a robot hand that may grip an object may be arranged. Accordingly, the robot hand has a high degree of rotational freedom, and thus it may move to a desired location in a state of having various shapes, and perform a grip operation.

Hereinafter, the structure of the first joint apparatus1having a rotation axis in the roll direction will be described in detail.

The joint apparatus1may include housings100,200, a rotating member300, and a processor10.

The housings100,200may form the exterior of the joint apparatus1, and support the rotating member300rotating in the roll direction while being in a halted state without rotating.

The housings100,200may have a cylindrical shape with a hollow of which inside is empty. The housings100,200may house a plurality of components such as the rotating member300, the bearing400, the driving apparatus500(seeFIG.3), etc. on its inside.

The housings100,200may include a first housing100and a second housing200. The first housing100and second housing200may be fastened integrally after being manufactured separately, and form one internal space. The structures and the fastening method of the first housing100and second housing200will be described in detail later.

At least a part of the rotating member300may be arranged inside the housings100,200. The rotating member300may rotate in the roll direction based on the rotation axis X1.

The rotating member300may have a shape of a disk, and its rear surface may be exposed to the outside through an opening of the first housing100. To the rear surface of the rotating member300, another joint apparatus or a robot hand may be connected.

The joint apparatus1may include a processor10for controlling the operations of the joint apparatus1, and may include a sensor for recognizing the surrounding environment and a communication apparatus for communicating with other electronic apparatuses.

The processor10may control the overall operations of the joint apparatus1. For this, the processor10may include one or more of a central processing unit (CPU), an application processor (AP), or a communication processor (CP). Also, the processor10may be a micro controller (e.g., a micro control unit (MCU)).

The processor10may control hardware or software components connected to the processor10by driving an operating system or an application program, and perform various kinds of data processing and operations. Also, the processor10may load an instruction or data received from at least one of other components on a volatile memory and process them, and store various data in a non-volatile memory.

The processor10may be fixedly arranged on the front end of the second housing200, but the location is not limited thereto.

The processor10may control the driving apparatus500such that the rotating member300rotates as much as a specific angle. Also, the processor10may receive a signal regarding a rotation angle of the rotating member300detected by the sensor, and control the rotation angle of the rotating member300more precisely in accordance thereto.

FIG.3is a cross-sectional view of the joint apparatus inFIG.2according to an embodiment of the disclosure.FIG.4is a diagram of the joint apparatus inFIG.2according to an embodiment of the disclosure.

Referring toFIG.3andFIG.4, the joint apparatus1according to an embodiment of the disclosure may further include a bearing400, a driving apparatus500, a speed reducing apparatus600, and a hollow pipe700.

The outer ring410of the bearing400may contact the housings100,200, and the inner ring420may contact the rotating member300. That is, the bearing400may be arranged between the halted housings100,200and the rotating member300that is rotating, and rotatably support the rotating member300.

Specifically, the bearing400may receive loads in an axial direction, a radial direction, and a moment direction from the rotating member300. The housings100,200support and fixe the outer ring410of the bearing400, and thus the bearing400may not be detached from a designated location even if it receives the aforementioned loads.

The bearing400may include a plurality of rollers430arranged such that the central axes are alternatingly orthogonal between the outer ring410and the inner ring420. That is, the bearing400may be a cross roller bearing. Accordingly, compared to a general angular ball bearing, the bearing400may endure loads in each direction easily with one bearing, and may have improved rigidity.

The driving apparatus500may be arranged inside the housings100,200, and rotate the rotating member300. The driving apparatus500may include a motor510and a motor shaft520rotated by the motor510.

The motor510may include a rotor and a stator, and rotate the motor shaft520. The motor shaft520may have a cylindrical shape with a hollow, and may rotate based on the same axis as the rotation axis X1 of the rotating member300.

The joint apparatus1may further include a ball bearing30arranged between the motor shaft520and the second housing200. It is illustrated that the ball bearing30is implemented as two bearings, but the number is not limited thereto.

The motor shaft520may be rotatably supported by the ball bearing30. Accordingly, the motor shaft520may not be detached from a designated location, and stably rotate centered around the X1 axis.

The front end of the speed reducing apparatus600may be connected to the motor shaft520, and the rear end may be connected to the rotating member300. Accordingly, the speed reducing apparatus600may reduce the angular velocity of the motor shaft520rotating in high angular velocity, and thereby make the rotating member300rotate in low angular velocity and high torque.

Specifically, the speed reducing apparatus600may include a wave generator610, a flex spline620, and a circular spline630.

The wave generator610may be connected to the motor shaft520, and have an elliptical shape. The wave generator610may be formed integrally with the motor shaft520, and rotate at a high speed.

The flex spline620may contact the outer circumferential surface of the wave generator610and may be connected with the rotating member300, and a first tooth may be formed along the outer circumferential surface. The flex spline620may be formed of a flexible ductile material.

The circular spline630may have a cylindrical shape with a hollow, and on its inner circumferential surface, a second tooth engaging the first tooth of the flex spline620may be formed. The circular spline630may be fixedly arranged on the inner circumferential surface of the second housing200as a rigid body.

That is, the speed reducing apparatus600may be a harmonic drive, and may be small-sized and lightweight, and have a big speed reducing ratio. Also, as the capacity of the transmission torque is big and the backlash is small, it may have a precise speed reducing ratio.

The hollow pipe700may be arranged along the rotation axis X1 of the rotating member300, and may rotate integrally with the rotating member300. Also, the joint apparatus1may further include a plurality of cables arranged on the inner side of the hollow pipe700.

The plurality of cables may be connected with the robot hand arranged on the end part of the robot1000, and may transmit power and a signal to the robot hand. Also, the plurality of cables may be connected with another joint apparatus, and transmit power and a signal.

That is, the plurality of cables are housed inside the hollow pipe700, and thus interference with another rotating component may be minimized, and accordingly, a signal may be stably transmitted to each component.

The joint apparatus1may further include a braking device20. The braking device20may include a projecting area21projected forward, and the projecting area21may be arranged to selectively engage a groove formed on the motor shaft520.

Specifically, in case the power of the motor510is turned off or the motor shaft520is halted, the projecting area21of the braking device20may engage the groove formed on the motor shaft520, and prevent sagging of the motor shaft520in the direction of gravity.

FIG.5is a diagram of a fastening process of a first housing and a second housing according to an embodiment of the disclosure.FIG.6is a diagram of the A portion inFIG.3according to an embodiment of the disclosure.FIG.7is a diagram of a structure where the inner circumferential surface of the second housing covers the outer side surface of the outer ring according to an embodiment of the disclosure.

Referring toFIG.5, in order for the housings100,200to support the outer ring of the bearing400in all of the front direction, the rear direction, and the side direction, the inner diameters of the housings100,200may be smaller than the diameter of the bearing400.

Specifically, in order for the first housing100and second housing200to support both of the front surface411and the rear surface412of the outer ring410, one diameter D1of the first housing100and one diameter D2of the second housing200may be smaller than the diameter D3of the bearing400.

For the bearing400to be inserted into the housings having a smaller diameter, it may be necessary to fasten another housing to one housing in a state of supporting the bearing on the one housing.

That is, while the bearing400is being supported on one housing among the first housing100and second housing200, as another housing is fastened to the one housing, the front surface411and the rear surface412of the outer ring410may respectively be supported by the first housing100and second housing200.

InFIG.5toFIG.7, the first thread130is formed on the inner circumferential surface121of the first housing100, and the second thread230is formed on the outer circumferential surface222of the second housing200, and accordingly, while the rear surface412of the outer ring410is being supported on the second housing200, the first housing100may be fastened to the second housing200such that the first thread and second thread engage each other.

Referring toFIG.6andFIG.7, the first housing100may include a first support region110supporting the front surface411of the outer ring410, and a first fastening region120which extends rearward from the first support region110and where the first thread130is formed.

Also, the second housing200may include a second support region210supporting the rear surface412of the outer ring410, and a second fastening region220which extends forward from the second support region210and where the second thread230engaging the first thread130is formed.

The first support region110, the first fastening region120, the second support region210, and the second fastening region220may have a cylindrical shape with a hollow.

The first support region110and the first fastening region120may be orthogonal to each other, and the second support region210and the second fastening region220may be orthogonal to each other. Also, the first support region110and the second support region210may be arranged in parallel with each other, and respectively support the front surface411and the rear surface412of the outer ring410.

The first fastening region120and second fastening region220may be arranged in parallel with the outer side surface413of the outer ring410. That is, the first and fastening region120second fastening region220may be arranged to surround the outer side surface413of the outer ring410.

While any one of the first housing100and second housing200is fixed, if the other one is rotated, the first thread130and second thread230get to engage each other, and thus the first housing100and second housing200may be fastened.

Also, the first thread130may be formed on the inner circumferential surface121of the first fastening region120, and the second thread230may be formed on the outer circumferential surface222of the second fastening region220.

Specifically, referring toFIG.6, the first fastening region120may include a first inner circumferential surface121acontacting the outer side surface413of the outer ring410, and a second inner circumferential surface121bwhich is arranged to be distanced from the outer side surface413of the outer ring410and where the first thread130is formed. The inner circumferential surface221of the second fastening region220may contact the outer side surface413of the outer ring410.

Accordingly, the front surface411, the rear surface412, and the outer side surface413of the outer ring410are stably supported by the first housing100and second housing200, and thus the bearing400may rotatably support the rotating member300stably while enduring loads in various directions and not being detached from the designated location.

In particular, the first housing100and second housing200are fastened to each other stably by the frictional force between the first thread130and second thread230engaging each other, and thus the bearing400may endure the load in the moment direction easily.

Also, as the first housing100and second housing200are fastened such that the first and second threads130,230engage each other, the fastening process is simple, and a process of forming holes into which bolts will be inserted on the first housing100and second housing200will not be necessary. Further, spaces where bolts may be arranged may not be necessary on the first housing100and second housing200, and thus the first housing100and second housing200may have a slim exterior.

In addition, referring toFIG.7, the inner circumferential surface221of the second fastening region220may cover the outer side surface413of the outer ring410. That is, in some embodiments, the inner circumferential surface221of the second fastening region220may entirely or at least partially cover the outer side surface413of the outer ring410. That is, the second fastening region220may have a length corresponding to the thickness of the bearing400.

The inner surface of the first housing100inFIG.7has only one level difference, and accordingly, the first housing100has a simpler structure compared to the structure inFIG.6that has two level differences, and thus it may be manufactured easily.

FIG.8is a diagram illustrating a structure where a thread is formed on the inner circumferential surface of a second housing according to an embodiment of the disclosure. FIG.9is a diagram illustrating a structure where the inner circumferential surface of the first housing covers the outer side surface of the outer ring according to an embodiment of the disclosure.

Referring toFIG.8andFIG.9, the first thread130may be formed on the outer circumferential surface122of the first fastening region120, and the second thread230may be formed on the inner circumferential surface221of the second fastening region220.

InFIG.8andFIG.9, the first thread130is formed on the outer circumferential surface122of the first fastening region120, and the second thread230is formed on the inner circumferential surface221of the second fastening region220. Accordingly, while supporting the front surface411of the outer ring410on the first housing100, the second housing200may be fastened to the first housing100such that the first thread and second thread engage each other.

Specifically, referring toFIG.8, the second fastening region220may include a third inner circumferential surface221acontacting the outer side surface413of the outer ring410and a fourth inner circumferential surface221bwhich is arranged to be distanced from the outer side surface413of the outer ring410and where the second thread230is formed. The inner circumferential surface121of the first fastening region120may contact the outer side surface413of the outer ring410.

Accordingly, the front surface411, the rear surface412, and the outer side surface413of the outer ring410are stably supported by the first housing100and second housing200, and thus the bearing400may rotatably support the rotating member300stably while enduring loads in various directions and not being detached from the designated location.

Also, the fastening process of the first housing100and second housing200is simple, and a process of forming holes into which bolts will be inserted on the first housing100and second housing200may not be necessary. Further, spaces where bolts will be arranged may not be necessary on the first housing100and second housing200, and thus the first housing100and second housing200may have a slim exterior.

Referring toFIG.9, the inner circumferential surface121of the first fastening region120may cover (e.g., partially cover, entirely cover, etc.) the outer side surface413of the outer ring410. That is, the first fastening region120may have a length corresponding to the thickness of the bearing400.

The inner surface of the second housing200inFIG.9has only one level difference, and accordingly, the second housing200has a simpler structure compared to the structure inFIG.8that has two level differences, and thus it may be manufactured easily.

While embodiments of the disclosure have been shown and described, the disclosure is not limited to the aforementioned specific embodiments, and it is apparent that various modifications may be made by those having ordinary skill in the art to which the disclosure belongs, without departing from the gist of the disclosure as claimed by the appended claims, and such modifications are within the scope of the descriptions of the claims.