KR20170068654A - Robot with improved bearing pre-load structure - Google Patents

Abstract

A robot having an improved bearing preload structure is disclosed. The robot according to the present invention combines the connecting shaft of the first power transmission module and the connecting member with the fastening bolt, which transmits the rotational force of the first motor to the supporting arm as one end of the arm. When the connecting shaft and the connecting member are coupled by the fastening bolt, the inner ring of the bearing supporting the rotation of the connecting shaft is pressed by one side of the connecting member. At this time, by adjusting the tightening degree of the fastening bolt, the degree of pressing of the inner ring of the bearing is adjusted, so that the preload of the bearing can be adjusted. That is, the connecting shaft and the connecting member can be coupled only by the fastening bolt, and the preload of the bearing can be adjusted, so that the cost can be reduced. In addition, if a shim is provided on one end surface of the bearing and the thickness of the shim is appropriately adjusted, the preload of the bearing can be adjusted more precisely by using the fastening degree of the fastening bolt. Since the coupling shaft of the first power transmission module, the coupling shaft of the bevel gear and the second power transmission module and the bevel gear are integrally formed, rigidity can be improved. Therefore, the durability of the product may be improved.

Description

[0001] ROBOT WITH IMPROVED BEARING PRE-LOAD STRUCTURE [0002]

The present invention relates to a robot having an improved bearing preload structure.

Robots are used widely in industrial fields such as painting, welding, pressing, transportation, automatic bonding / separation of workpieces, etc., by executing the programs necessary for the work through the control device, . In particular, robots are attracting a lot of attention as a means of replacing human labor force in the case of industries with bad work environments such as painting and welding, or where proficiency in work is required.

In general, the robot includes a base, a frame rotatably installed on the base, and an arm (not shown) formed of a multi-axis multi-joint in which one side of the frame is rotatably installed and the other end is provided with an end effector Arm.

And a support holder for supporting a cable for supplying power to the end effector is installed at the other end of the arm. At this time, the rotation of the other end of the arm coincides with the rotation of the support holder, so that the cable supported by the support holder is not twisted.

The other end of the arm and the support holder are rotated by the first motor and the second motor respectively and the rotational force of the first motor and the second motor is transmitted to the other end of the arm from the other end of the arm, A first power transmission module and a second power transmission module are provided.

The first power transmission module includes a cylindrical connecting shaft connected to a rotating shaft side of the first motor, and the connecting shaft is connected to the rotating shaft via a connecting member. That is, one end of the connecting member is coupled to one end surface of the connecting shaft, and the other end is coupled to the rotating shaft to connect the rotating shaft and the connecting shaft.

A bearing for supporting the rotation of the connection shaft is installed on the outer peripheral surface of the connection shaft. At this time, since the bearing has its own tolerance, the preload must be adjusted.

In the conventional robot, the nut is fastened to the outer circumferential surface of the connecting shaft to adjust the preload of the bearing. Therefore, a separate fastening member for coupling the connecting shaft and the connecting member is required, so that the number of parts increases, the number of assembling steps increases, and the cost increases.

A bevel gear is coupled to the connection shaft of the first power transmission module, and the connection shaft and the bevel gear are separately formed and joined by welding. The second power transmission module also includes a connection shaft and a bevel gear which are welded to each other. Since the rigidity of the welding portion of the connecting shaft and the bevel gear of the first power transmission module and the welding portion of the bevel gear of the second power transmission module and the bevel gear is relatively weak, .

It is an object of the present invention to provide a robot capable of solving all the problems of the prior art as described above.

Another object of the present invention is to provide a power transmission apparatus which can reduce the cost by combining the connection shaft of the first power transmission module of the power transmission unit with the connection member and adjusting the preload of the bearing supporting the rotation of the connection shaft, It may be to provide a robot.

It is still another object of the present invention to provide a robot capable of improving durability by integrally forming a connecting shaft of a first power transmission module of a power transmission unit, a connecting shaft of a bevel gear and a second power transmission module, Lt; / RTI >

According to an aspect of the present invention, there is provided a robot including: an arm; A support holder installed at one end of the arm and rotatable independently from one end of the arm as one end of the arm rotates and a cable connected to the end effector is supported; A first motor and a second motor for respectively rotating one end of the arm and the support holder; And a first power transmission module and a second power transmission module installed at one end of the arm and transmitting the rotational force of the first motor and the rotational force of the second motor to the one end of the arm and the support holder, Wherein the first power transmission module is formed in a hollow body and is installed inside the housing and has one end side connected to the rotation axis side of the first motor, shaft; A bevel gear formed on the other end side of the connecting shaft; A connection member connecting the connection shaft and the rotation shaft; A bearing installed between the outer circumferential surface of the connecting shaft and the inner circumferential surface of the housing and supporting the connecting shaft; And a fastening bolt for coupling the connecting shaft and the connecting member to each other and adjusting the preload of the bearing.

The robot according to the embodiment of the present invention combines the connecting shaft of the first power transmission module and the connecting member with the fastening bolt, which transmits the rotational force of the first motor to the supporting arm serving as one end of the arm. When the connecting shaft and the connecting member are coupled by the fastening bolt, the inner ring of the bearing supporting the rotation of the connecting shaft is pressed by one side of the connecting member. At this time, by adjusting the tightening degree of the fastening bolt, the degree of pressing of the inner ring of the bearing is adjusted, so that the preload of the bearing can be adjusted. That is, the connecting shaft and the connecting member can be coupled only by the fastening bolt, and the preload of the bearing can be adjusted, so that the cost can be reduced.

In addition, if a shim is provided on one end surface of the bearing and the thickness of the shim is appropriately adjusted, the preload of the bearing can be adjusted more precisely by using the fastening degree of the fastening bolt.

Since the coupling shaft of the first power transmission module, the coupling shaft of the bevel gear and the second power transmission module and the bevel gear are integrally formed, rigidity can be improved. Therefore, the durability of the product may be improved.

1 is a perspective view of a robot according to an embodiment of the present invention;
2 is a schematic cross-sectional view of the upper end side of the arm shown in Fig.
3 is an enlarged view of a portion "A" in FIG.

It should be noted that, in the specification of the present invention, the same reference numerals as in the drawings denote the same elements, but they are numbered as much as possible even if they are shown in different drawings.

Meanwhile, the meaning of the terms described in the present specification should be understood as follows.

The word " first, "" second," and the like, used to distinguish one element from another, are to be understood to include plural representations unless the context clearly dictates otherwise. The scope of the right should not be limited by these terms.

It should be understood that the terms "comprises" or "having" does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

It should be understood that the term "at least one" includes all possible combinations from one or more related items. For example, the meaning of "at least one of the first item, the second item and the third item" means not only the first item, the second item or the third item, but also the second item and the second item among the first item, Means any combination of items that can be presented from more than one.

It should be understood that the term "and / or" includes all possible combinations from one or more related items. For example, the meaning of "first item, second item and / or third item" may include not only the first item, the second item or the third item but also two of the first item, Means a combination of all items that can be presented from the above.

It is to be understood that when an element is referred to as being "connected or installed" to another element, it may be directly connected or installed with the other element, although other elements may be present in between. On the other hand, when an element is referred to as being "directly connected or installed" to another element, it should be understood that there are no other elements in between. On the other hand, other expressions that describe the relationship between components, such as "between" and "between" or "neighboring to" and "directly adjacent to" should be interpreted as well.

Hereinafter, a robot having an improved bearing preload structure according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

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

As shown, the robot 100 according to an embodiment of the present invention can be used in an industrial field such as painting, welding, pressing, conveying, automatic bonding or separation of workpieces, etc., and includes a base 110, (120) and a multiaxial articulated arm (130).

The base 110 may be placed on the floor of the workplace, or may be spaced from the floor of the workplace. When the base 110 is placed on the floor of the workplace, a plurality of rollers (not shown) may be rotatably installed on the bottom surface of the base 110. The rollers support the base 110 so that it can flow smoothly on the floor of the workplace.

The frame 120 may be rotatably mounted on the upper surface of the base 110.

The lower end of the arm 130 may be rotatably supported on one side of the frame 120. An end effector 50 may be provided on the upper end of the arm 130 according to the purpose of the work. And can be installed to be rotatable about mutually coupled parts.

The arm 130 includes a first connecting arm 131 corresponding to a lower portion, a second connecting arm 133 corresponding to an intermediate portion, and a supporting arm 135 corresponding to an upper portion of the arm 130. [ ).

The first connecting arm 131 may be rotatably mounted on one side of the frame 120 in a pendulum shape while the lower connecting end of the first connecting arm 131 is rotatably mounted on the upper end side of the first connecting arm 131 And the support arm 135 may be rotatably installed in the form of a pendulum by coupling the lower end of the second connection arm 133 to the upper end of the second connection arm 133. [ have. An end effector 50 may be coupled to the lower end of the support arm 135.

Since the position of the arm 130 can be adjusted by rotating the frame 120, the position of the support arm 135 can be easily adjusted according to the working position of the workpiece. Since the arm 130 is rotatably mounted in a pendulum shape on the basis of the mutually coupled portions, the height of the support arm 135 can be easily adjusted according to the work position of the workpiece, 135 and the workpiece can be easily adjusted.

A first motor 141, a third motor 145 and a fourth motor 147 for rotating respective parts of the arm 130 may be respectively installed at the respective parts of the arm 130, A fifth motor 149 for rotating the frame 120 may be installed. The first motor 141 and the third to fifth motors 145 to 147 and 149 can receive external power through the cable 150 installed from the base 110 to the lower end side of the support arm 135 have. A support holder 160, into which the cable 150 is inserted, may be installed on the lower end side of the support arm 135.

The support arm 135 rotates and the cable 150 supported by the support holder 160 is not twisted until the support holder 160 rotates in keeping with the rotation of the support arm 135. The rotational force of the second motor 143 for rotating the first motor 141 and the support holder 160 is transmitted to the support arm 135 and the support holder 160, A power transmission module for rotating the support arm 135 and the support holder 160 may be installed.

The power transmission module includes a housing 170 (see FIG. 2), a first power transmission module 180 (see FIG. 2) for transmitting the rotational force of the first motor 141 to the support arm 135, And a second power transmission module 190 (refer to FIG. 2) for transmitting the rotational force of the first power transmission member 143 to the support member 160.

The power transmission module will be described with reference to FIGS. 1 to 3. FIG. Fig. 2 is a schematic sectional view of the upper end side of the arm shown in Fig. 1, and Fig. 3 is an enlarged view of the "A"

As shown, the first power transmission module 180 may include a connecting shaft 181, a bevel gear 182, a connecting member 184, a bearing 186, and a fastening bolt 188.

The connection shaft 181 may be formed in a cylindrical shape as a hollow body and installed inside the housing 170. One end of the connecting shaft 181 may be connected to the rotating shaft side of the first motor 141 and a bevel gear 182 may be formed at the other end. The connecting member 184 may be formed in a cylindrical shape so as to connect one end side of the connecting shaft 181 to the rotating shaft of the first motor 141.

The bearing 186 is connected to the outer circumferential surface of one end side of the connecting shaft 181 connected to the connecting member 184 and the inner circumferential surface of the housing 170 and the outer circumferential surface of the other end of the connecting shaft 181 having the bevel gear 182, 170 to support the rotation of the connection shaft 181.

The bearing 186 having the balls disposed between the inner ring and the outer ring and between the inner ring and the outer ring has its own tolerance, which can lead to poor quality of design and mechanical vibration. To prevent this, the preload of the bearing 186 must be adjusted.

The robot according to the present embodiment can couple the connecting shaft 181 and the connecting member 184 with each other using the fastening bolts 188 and adjust the preload of the bearings 186.

A cylindrical support member 172 may be provided on the inner circumferential surface of the housing 170 so as to surround the connection shaft 181 and the one end side of the connection shaft 181 and the other end side of the support member 172 And a bearing 186 may be provided between the other end side of the connection shaft 181 and the other end side of the support member 172, respectively. Therefore, the inner ring and the outer ring of the bearing 186 can be contacted and supported on the outer circumferential surface of the connecting shaft 181 and the inner circumferential surface of the support member 172, respectively.

The inner ring of the bearing 186 provided at one end of the connecting shaft 181 may be pressed by a fastening bolt 188 coupling the connecting shaft 181 and the connecting member 184 to each other.

More specifically, the connecting member 184 may include a coupling tube 184a and a coupling frame 184b. The connection pipe 184a may be formed as a plurality of mutually coupled ones and one end side thereof may be connected to the rotation axis of the first motor 141. [ The coupling frame 184b may be formed at the other end of the coupling pipe 184a and may be coupled to the one end face of the coupling shaft 181 by the coupling bolt 188 and may be in contact with the inner ring of the bearing 186. [

That is, the fastening bolt 188 passes through the coupling frame 184b and the coupling shaft 181, thereby coupling the coupling frame 184b and the coupling shaft 181 to each other. At this time, when the degree of engagement of the fastening bolts 188 is adjusted, the pressing degree of the inner ring of the bearing 186 by the coupling frame 184b is adjusted, so that the preload of the bearing 186 can be adjusted.

The preload of the bearing 186 can be adjusted only when the bearing 186 provided between the connecting shaft 181 and the supporting member 172 does not flow along the longitudinal direction of the connecting shaft 181. To this end, a stepped surface 172a may be formed at one end of the support member 172 and the inner surface of the other end of the support member 172 to support the outer ring of the bearing 186.

The bearing 186 provided at the one end side and the other end side of the connection shaft 181 may not protrude outward of the connection shaft 181 due to the tolerance of the end surface 172a formed in the support member 172. [ Then, since the inner ring of the bearing 186 does not contact the engaging frame 184b, the preload of the bearing 186 can not be adjusted. A shim 189 may be disposed between the outer ring of the bearing 186 and the end face 172a of the support member 172. [ If the thickness of the padding 189 is appropriately adjusted, the preload of the bearing 186 can be more precisely adjusted by using the degree of engagement of the fastening bolts 188.

The connection shaft 181 and the bevel gear 182 of the first power transmission module 180 may be integrally formed and a plurality of integrally formed connection shafts 181 and bevel gears 182 are installed in a mutually engaged manner .

The second power transmission module 190 for transmitting the rotational force of the second motor 143 to the support holder 160 may include a connecting shaft 191 and a bevel gear 192 integrally formed with each other. A plurality of integrally formed connecting shafts 191 and bevel gears 192 may be provided in a mutually engaged manner.

The robot according to the present embodiment connects the connecting shaft 181 of the first power transmission module 180 with the connecting shaft 184 connecting the rotating shaft of the first motor 141 with the fastening bolt 188. When the coupling shaft 181 and the coupling frame 184b of the coupling member 184 are coupled by the coupling bolt 188, the inner ring of the bearing 186, which supports the rotation of the coupling shaft 181, 184, respectively. At this time, by adjusting the tightening degree of the fastening bolt 188, the degree of pressing of the inner ring of the bearing 186 is adjusted, so that the preload of the bearing 186 can be adjusted. That is, the connecting shaft 181 and the connecting member 184 can be coupled by using the fastening bolts 188, and the preload of the bearing 186 can be adjusted, so that the cost can be reduced.

Since the connection shaft 181 of the first power transmission module 180 and the connecting shaft 191 of the bevel gear 182 and the second power transmission module 190 and the bevel gear 192 are integrally formed, Can be improved.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Will be clear to those who have knowledge of. Therefore, the scope of the present invention is defined by the appended claims, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be interpreted as being included in the scope of the present invention.

170: Housing
172: support member
181, 191: connection axis
182, 192: Bevel gear
184:
186: Bearings
188: fastening bolt

Claims (6)

A multiaxial articulated arm having an end effector at one end; A support holder installed at one end of the arm and rotatable independently from one end of the arm as one end of the arm rotates and a cable connected to the end effector is supported; A first motor and a second motor for respectively rotating one end of the arm and the support holder; And a first power transmission module and a second power transmission module installed at one end of the arm and transmitting the rotational force of the first motor and the rotational force of the second motor to the one end of the arm and the support holder, As a result,
A housing is provided at one end side of the arm,
The first power transmission module includes:
A connection shaft formed in a hollow body and installed inside the housing and having one end side connected to a rotation axis side of the first motor;
A bevel gear formed on the other end side of the connecting shaft;
A connection member connecting the connection shaft and the rotation shaft;
A bearing installed between the outer circumferential surface of the connecting shaft and the inner circumferential surface of the housing and supporting the connecting shaft;
And a coupling bolt for coupling the connection shaft and the connection member and adjusting a preload of the bearing. The method according to claim 1,
Wherein a cylindrical support member is provided on the inner circumferential surface of the housing so as to surround the connection shaft,
The bearing is provided between one end of the connecting shaft and one end of the supporting member and between the other end of the connecting shaft and the other end of the supporting member,
The outer ring of the bearing is supported on the inner peripheral surface of the support member,
And the inner ring of the bearing provided at one end side of the connecting shaft is pressed by the fastening bolt. 3. The method of claim 2,
Wherein the connection member includes a cylindrical connection pipe having one side connected to the rotation shaft and a coupling surface formed on the other end of the connection pipe and coupled to one end surface of the connection shaft,
Wherein the coupling frame is in contact with the inner ring of the bearing,
And the fastening bolt is fastened through the coupling frame and the coupling shaft. 3. The method of claim 2,
Wherein a stepped surface is formed on the one end side and the other end side inner circumferential surface of the support member so as to contact and support the outer ring of the bearing. 5. The method of claim 4,
And a shim is disposed between the outer ring of the bearing and the stepped surface. The method according to claim 1,
The connection shaft of the first power transmission module and the bevel gear are integrally formed,
Wherein the second power transmission module includes a connecting shaft and a bevel gear integrally formed with each other.

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