WO2019109330A1

WO2019109330A1 - Robot of scara type and method for manufacturing the robot

Info

Publication number: WO2019109330A1
Application number: PCT/CN2017/115197
Authority: WO
Inventors: Luoluo Wang; Xiaodong Cao; Hui Yu; Zhu Zhu
Original assignee: Abb Schweiz Ag
Priority date: 2017-12-08
Filing date: 2017-12-08
Publication date: 2019-06-13

Abstract

A robot (100) of SCARA type comprises: a base (101); a first arm (102) coupled to the base (101), the first arm (102) being rotatable about a first axis (X1) relative to the base (101) when driven by a first motor (201) arranged in the base (101) via a first transmission mechanism (221); a second arm (103) coupled to the first arm (102), the second arm (103) being rotatable about a second axis (X2) relative to the first arm (102) when driven by a second motor (202) via a second transmission mechanism (222), wherein the second motor (202) is arranged in the base (101) or the first arm (102), and the second axis (X2) is substantially parallel to the first axis (X1); and an operating unit (104) arranged in the second arm (103) and including an operating shaft (801), wherein the operating shaft (801) is movable along a third axis (X3) relative to the second arm (103) when driven by a third motor (203) arranged in the base (101) or the first arm (102) via a third transmission mechanism (223), wherein the third axis (X3) is substantially parallel to the first and second axes (X1, X2), and wherein the operating shaft (801) is rotatable about the third axis (X3) relative to the second arm (103) when driven by a fourth motor (204) arranged in the base (101) or the first arm (102) via a fourth transmission mechanism (224). The load of the robot (100) around the first and second axes (X1, X2) may be reduced, and the heat generated by the motors can be dissipated into the floor or working table quickly.

Description

ROBOT OF SCARA TYPE AND METHOD FOR MANUFACTURING THE ROBOT

FIELD

Embodiments of present disclosure generally relate to the field of industrial robots, and more particularly, to a robot of selective compliance assembly robot arm (SCARA) type and a method for manufacturing the robot.

BACKGROUND

Robots of SCARA type, also referred to as SCARA robots, are widely used in Electronics Manufacturing Services (EMS) applications, such as assembling objects such as integrated circuit boards, automobile parts, or the like. A conventional SCARA robot typically includes a base, a rear arm, a forearm and a shaft. The base is usually mounted on a floor or a work table. The rear arm is connected to the base and rotatable about an axis ( “axis A” ) relative to the base when driven by a motor ( “motor A” ) . The forearm is connected to the rear arm and rotatable about an axis ( “axis B” ) parallel to the axis A relative to the rear arm when driven by a motor ( “motor B” ) . The shaft is connected to the forearm and movable along an axis ( “axis C” ) parallel to the first and second axes relative to the second arm when driven by a motor ( “motor C” ) and rotatable about the axis C relative to the second arm when driven by a motor ( “motor D” ) .

In a conventional SCARA robot, the motors B, C and D are usually arranged in the forearm. Such an arrangement may lead to several disadvantages for the SCARA robot. First, the load of the SCARA robot around the first and second axes may be relatively high because the forearm is big and heavy. In order to achieve desired dynamic performance and speed of the SCARA robot, more power would be needed for driving the SCARA robot. In addition, stronger connecting structures may be needed for supporting the rear arm and the forearm firmly. Second, when the SCARA robot operates, a large amount of heat may be generated by the motors. Since the motors B, C and D are positioned far away from the base, it is difficult for the heat generated by these motors to be transferred from the forearm to the base and dissipated into the floor or the work table. As a result, the SCARA robot is prone to malfunction due to overheating of the motors and thus may have a reduced lifetime.

SUMMARY

In an aspect of the present disclosure, a robot of SCARA type is provided. The robot comprises a base; a first arm coupled to the base, the first arm being rotatable about a first axis relative to the base when driven by a first motor arranged in the base via a first transmission mechanism; a second arm coupled to the first arm, the second arm being rotatable about a second axis relative to the first arm when driven by a second motor via a second transmission mechanism, wherein the second motor is arranged in the base or the first arm, and the second axis is substantially parallel to the first axis; and an operating unit arranged in the second arm and including an operating shaft, wherein the operating shaft is movable along a third axis relative to the second arm when driven by a third motor arranged in the base or the first arm via a third transmission mechanism, wherein the third axis is substantially parallel to the first and second axes, and wherein the operating shaft is rotatable about the third axis relative to the second arm when driven by a fourth motor arranged in the base or the first arm via a fourth transmission mechanism.

In some embodiments, the first arm comprises a first U-shaped part including a first branch and a second branch each coupled to the second arm.

In some embodiments, the first arm further comprises a main part coupled to the base.

In some embodiments, the first transmission mechanism comprises a first pulley arranged on a first output shaft of the first motor; a second pulley arranged in the base around the first axis and coupled to the first pulley via a first transmission belt; and a first reducer coupled between the second pulley and the main part of the first arm around the first axis.

In some embodiments, the second motor is arranged in the base, and the second transmission mechanism comprises a third pulley arranged on a second output shaft of the second motor; a fourth pulley arranged in the base around the first axis and coupled to the third pulley via a second transmission belt; a fifth pulley arranged in the main part of the first arm around the first axis and coupled to the fourth pulley via a first transmission shaft, the first transmission shaft extending through the first reducer and the second pulley; a sixth pulley arranged in the first branch of the first U-shaped part around the second axis and coupled to the fifth pulley via a third transmission belt; and a second reducer coupled between the sixth pulley and the second arm around the second axis.

In some embodiments, the third motor is arranged in the main part of the first arm, and the third transmission mechanism comprises a seventh pulley coupled to the operating unit; an eighth pulley arranged in the second arm around the second axis and coupled to the seventh pulley via a fourth transmission belt; a ninth pulley arranged in the second branch of the first U-shaped part around the second axis and coupled to the eighth pulley via a second transmission shaft; and a tenth pulley arranged on a third output shaft of the third motor and coupled to the ninth pulley via a fifth transmission belt.

In some embodiments, the fourth motor is arranged in the main part of the first arm, and the fourth transmission mechanism comprises an eleventh pulley coupled to the operating unit; a twelfth pulley arranged in the second arm around the second axis and coupled to the eleventh pulley via a sixth transmission belt; a thirteenth pulley arranged in the second branch of the first U-shaped part around the second axis and coupled to the twelfth pulley via a third transmission shaft coaxial to the second transmission shaft; and a fourteenth pulley arranged on a fourth output shaft of the fourth motor and coupled to the thirteenth pulley via a seventh transmission belt.

In some embodiments, the second, third and fourth motors are arranged in the main part of the base.

In some embodiments, the first arm further comprises a second U-shaped part including a third branch and a fourth branch each coupled to the base; and a connection part between the first and second U-shaped parts.

In some embodiments, the base comprises a first portion containing the first motor; and a second portion protruding from the first portion in a direction orthogonal to the first axis and coupled to the second U-shaped part of the first ann.

In some embodiments, the first transmission mechanism comprises a first pulley arranged on a first output shaft of the first motor; a second pulley arranged in the second portion of the base around the first axis and coupled to the first pulley via a first transmission belt; and a first reducer coupled between the second pulley and the third branch of the second U-shaped part around the first axis.

In some embodiments, the second motor is arranged in the first portion of the base and the second transmission mechanism comprises a third pulley arranged on a second output shaft of the second motor; a fourth pulley arranged in the second portion of the base around the first axis and coupled to the third pulley via a second transmission belt; a fifth pulley arranged in the third branch of the second U-shaped part around the first axis and coupled to the fourth pulley via a first transmission shaft, the first transmission shaft extending through the first reducer and the second pulley; a sixth pulley arranged in the first branch of the first U-shaped part around the second axis and coupled to the fifth pulley via a third transmission belt; and a second reducer coupled between the sixth pulley and the second arm around the second axis.

In some embodiments, the first transmission shaft is hollow.

In some embodiments, the third motor is arranged in the first portion of the base and the third transmission mechanism comprises a seventh pulley coupled to the operating unit; an eighth pulley arranged in the second arm around the second axis and coupled to the seventh pulley via a fourth transmission belt; a ninth pulley arranged in the second branch of the first U-shaped part around the second axis and coupled to the eighth pulley via a second transmission shaft; a tenth pulley arranged in the fourth branch of the second U-shaped part and coupled to the ninth pulley via a fifth transmission belt; a fifteenth pulley arranged in the second portion of the base around the first axis and coupled to the tenth pulley via a fourth transmission shaft; and a sixteenth pulley arranged on a third output shaft of the third motor and coupled to the fifteenth pulley via an eighth transmission belt.

In some embodiments, the fourth motor is arranged in the connection part of the first arm and the fourth transmission mechanism comprises an eleventh pulley coupled to the operating unit; a twelfth pulley arranged in the second arm around the second axis and coupled to the eleventh pulley via a sixth transmission belt; a thirteenth pulley arranged in the second branch of the first U-shaped part around the second axis and coupled to the twelfth pulley via a third transmission shaft coaxial to the second transmission shaft; and a fourteenth pulley arranged on a fourth output shaft of the fourth motor and coupled to the thirteenth pulley via a seventh transmission belt.

In some embodiments, the fourth motor is arranged in the first portion of the base and the fourth transmission mechanism comprises an eleventh pulley coupled to the operating unit; a twelfth pulley arranged in the second arm around the second axis and coupled to the eleventh pulley via a sixth transmission belt; a thirteenth pulley arranged in the second branch of the first U-shaped part around the second axis and coupled to the twelfth pulley via a third transmission shaft coaxial to the second transmission shaft; a fourteenth pulley arranged in the fourth branch of the second U-shaped part and coupled to the thirteenth pulley via a seventh transmission belt; a seventeenth pulley arranged in the second portion of the base around the first axis and coupled to the fourteenth pulley via a fifth transmission shaft coaxial to the fourth transmission shaft; and an eighteenth pulley arranged on a fourth output shaft of the fourth motor and coupled to the seventeenth pulley via an ninth transmission belt.

In some embodiments, the fourth motor is arranged in the first portion of the base and the third motor is arranged in the connection part of the first arm.

In some embodiments, the base is provided with a first electrical interface, the second arm is provided with a second electrical interface electrically connected to the first electrical interface via a wire running inside the base, the first arm, and the second arm.

In some embodiments, the operating unit comprises a ball screw including a screw shaft and a screw nut, the third transmission mechanism being coupled to the screw shaft; a ball spline including a spline shaft used as the operating shaft and a spline nut, the fourth transmission mechanism be coupled to the spline nut; and a coupling member coupled between the screw nut and the spline shaft.

In some embodiments, the operating unit comprises a ball screw spline including a ball screw spline shaft used as the operating shaft, a screw nut and a spline nut, the third transmission mechanism is coupled to the screw shaft, and the fourth transmission mechanism is coupled to the spline nut.

In another aspect of the present disclosure, a method is provided for manufacturing the robot according to any of the previous embodiments.

According to various embodiments of the present disclosure, each of the second, third, and fourth motors is arranged in the base or the first arm, instead of the second arm, rendering the second arm slim and light. In this way, the load of the SCARA robot around the first and second axes may be reduced, and less power would be needed for driving the robot so as to achieve desired dynamic performance and speed. Moreover, since these motors are arranged in or near to the base, heat transfer paths between these motors and the floor or working table are short. As such, the heat generated by these motors can be dissipated into the floor or working table quickly.

DESCRIPTION OF DRAWINGS

Through the following detailed descriptions with reference to the accompanying drawings, the above and other objectives, features and advantages of the example embodiments disclosed herein will become more comprehensible. In the drawings, several example embodiments disclosed herein will be illustrated in an example and in a non-limiting manner, wherein:

Fig. 1 schematically illustrates a SCARA robot according to some example embodiments of the present disclosure;

Fig. 2 schematically illustrates example connection between the first and second arms of the SCARA robot of Fig. 1;

Fig. 3 schematically illustrates example wire arrangement in the SCARA robot of Fig. 1;

Fig. 4 schematically illustrates example work range of the SCARA robot of Fig. 1;

Fig. 5 schematically illustrates a SCARA robot according to another example embodiment; and

Fig. 6 schematically illustrates a SCARA robot according to a further example embodiment.

Throughout the drawings, the same or similar reference symbols are used to indicate the same or similar elements.

DETAILED DESCRIPTION OF EMBODIEMTNS

Principles of the present disclosure will now be described with reference to several example embodiments shown in the drawings. Though example embodiments of the present disclosure are illustrated in the drawings, it is to be understood that the embodiments are described only to facilitate those skilled in the art in better understanding and thereby achieving the present disclosure, rather than to limit the scope of the disclosure in any manner.

As discussed above, the motors B, C and D are usually arranged in the forearm for the conventional SCARA robot. Such an arrangement may render the forearm big and heavy and the heat generated by these motors is difficult to be dissipated into the floor or the work table. According to embodiments of the present disclosure, the motors are arranged in the base or the rear arm and may drive corresponding components of the SCARA robot via corresponding transmission mechanisms.

The above idea may be implemented in various manners, as will be described in detail in the following paragraphs. Fig. 1 is an example manner for implementing the principles of the present disclosure. Figs. 2-4 illustrate additional improvements for the manner of Fig. 1. Fig. 5 illustrates another example manner for implementing the principles of the present disclosure. Fig. 6 illustrates a further example manner for implementing the principles of the present disclosure. Hereinafter, the principles of the present disclosure will be described in detail with reference to Figs. 1-6.

Fig. 1 schematically illustrates a SCARA robot 100 according to some example embodiments of the present disclosure. As shown, the robot 100 includes a base 101, a first arm 102, a second arm 103 and an operating unit 104. The base 101 may be mounted on a floor or a working table (not shown) . The first arm 102 is coupled to the base 101 and rotatable about a first axis X1 relative to the base 101 when driven by a first motor 201. The second arm 103 is coupled to the first arm 102 and rotatable about a second axis X2 relative to the first arm 102 when driven by a second motor 202. The second axis X2 is substantially parallel to the first axis X1. The operating unit 104 is arranged in the second arm 103 and includes an operating shaft 801. The operating shaft 801 is movable along a third axis X3 relative to the second arm 103 when driven by a third motor 203 and rotatable about the third axis X3 relative to the second arm 103 when driven by a fourth motor 204. The third axis X3 is substantially parallel to the first and second axes X1, X2.

In an embodiment, the first arm 102 may be coupled to the base 101 through one or more bearings, such as a ball bearing. Similarly, the second arm 103 may be coupled to the first arm 102 through one or more bearings. Hereinafter, example connection between the first and

second arms

102, 103 will be described in detail with reference to Fig. 2.

In the embodiment as depicted in Fig. 1, the first and

second motors

201, 202 are arranged in the base 101, and the third and

fourth motors

203, 204 are arranged in the first arm 102. The first motor 201 may drive the first arm 102 to rotate about the first axis X1 relative to the base 101 via a first transmission mechanism 221. The first transmission mechanism 221 is coupled between a first output shaft 211 of the first motor 201 and the first arm 102. The second motor 202 may drive the second arm 103 to rotate about the second axis X2 relative to the first arm 102 via a second transmission mechanism 222. The second transmission mechanism 222 is coupled between a second output shaft 212 of the second motor 202 and the second arm 103. Through such an arrangement, the load of the robot 100 around the first and second axes X1, X2 may be reduced, and the heat generated by the second, third and

fourth motors

202, 203, 204 can be dissipated into the floor or working table quickly.

The third motor 203 may drive the operating shaft 801 to move along the third axis X3 relative to the second arm 103 via a third transmission mechanism 223. The third transmission mechanism 223 is coupled between a third output shaft 213 of the third motor 203 and the operating unit 104. The fourth motor 204 may drive the operating shaft 801 to rotate about the third axis X3 relative to the second arm 103 via a fourth transmission mechanism 224. The fourth transmission mechanism 224 is coupled between a fourth output shaft 214 of the fourth motor 204 and the operating unit 104.

In an embodiment, in order to drive the first arm 102 to rotate relative to the base 101, the first transmission mechanism 221 may include a first pulley 301, a second pulley 302 and a first reducer 501. The first pulley 301 may be arranged on the first output shaft 211 of the first motor 201. The second pulley 302 may be arranged in the base 101 around the first axis X1 and coupled to the first pulley 301 via a first transmission belt 401. The first reducer 501 may be coupled between the second pulley 302 and the first arm 102 around the first axis X1 so as to provide a reduced speed and an increased torque. Through the first transmission mechanism 221, the first motor 201 may drive the first arm 102 to rotate about the first axis X1 relative to the base 101 reliably and precisely.

In operation, if the first output shaft 211 of the first motor 201 rotates, the first pulley 301 may rotate along with the first output shaft 211 and then drive the second pulley 302 to rotate via the first transmission belt 401. When driven by the second pulley 302, the first reducer 501 may drive the first arm 102 to rotate relative to the base 101 at a lower speed than that of the first output shaft 211 of the first motor 201.

In some embodiments, the first transmission mechanism 221 may include one or more additional pulleys and corresponding transmission belts for executing transmission between the first motor 201 and the first arm 102. In other embodiments, the first transmission mechanism 221 may include other transmission devices, such as gear-driving devices. The present disclosure does not intend to limit the specific implementation of the first transmission mechanism 221.

In some embodiments, as shown in Fig. 1, the first arm 102 may include a main part 122 and a first U-shaped part 112. The main part 122 may be coupled to the base 101. The first U-shaped part 112 may include a first branch 1121 and a second branch 1122 each coupled to the second arm 103. The third motor 203 and the fourth motor 204 may be arranged in the main part 122 of the first arm 102.

In an embodiment, in order to drive the second arm 103 to rotate relative to the first arm 102, the second transmission mechanism 222 may include a third pulley 303, a fourth pulley 304, a fifth pulley 305, a sixth pulley 306, and a second reducer 502. The third pulley 303 may be arranged on the second output shaft 212 of the second motor 202. The fourth pulley 304 may be arranged in the base 101 around the first axis X1 and coupled to the third pulley 303 via a second transmission belt 402. The fifth pulley 305 may be arranged in the main part 122 of the first arm 102 around the first axis X1 and coupled to the fourth pulley 304 via a first transmission shaft 601. The first transmission shaft 601 may extend through the first reducer 501 and the second pulley 302. The sixth pulley 306 may be arranged in the first branch 1121 of the first U-shaped part 112 around the second axis X2 and coupled to the fifth pulley 305 via a third transmission belt 403. The second reducer 502 may be coupled between the sixth pulley 306 and the second arm 103 around the second axis X2 so as to provide a reduced speed and an increased torque. As an example, the sixth pulley 306 may be fixedly connected to an input shaft 5021 of the second reducer 502. Through the second transmission mechanism 222, the second motor 202 may drive the second arm 103 to rotate about the second axis X2 relative to the first arm 102 reliably and precisely.

In operation, if the second output shaft 212 of the second motor 202 rotates, the third pulley 303 may rotate along with the second output shaft 212 and then drive the fourth pulley 304 to rotate via the second transmission belt 402. Through the first transmission shaft 601 and the third transmission belt 403, the fifth pulley 305 and the sixth pulley 306 may be driven to rotate. When driven by the sixth pulley 306, the second reducer 502 may drive the second arm 103 to rotate relative to the first arm 102 at a lower speed than that of the second output shaft 212 of the second motor 202.

In some embodiments, the second transmission mechanism 222 may include one or more additional pulleys and corresponding transmission belts for executing transmission between the second motor 202 and the second arm 103. In other embodiments, the second transmission mechanism 222 may include other transmission devices, such as gear-driving devices. The present disclosure does not intend to limit the specific implementation of the second transmission mechanism 222.

In some embodiments, the first transmission shaft 601 and the input shaft 5021 of the second reducer 502 may be solid. In other embodiments, the first transmission shaft 601 and the input shaft 5021 may be hollow. The

hollow shafts

601, 5021 may, on one hand, reduce the weight of the robot 100, and on the other hand, facilitate routing wires in the robot 100. Hereafter, example wire arrangement in the robot 100 will be described in detail with reference to Fig. 3.

In some embodiments, the operating unit 104 includes a ball screw 70, a ball spline 80, and a coupling member 90 coupled between the ball screw 70 and the ball spline 80. The ball screw 70 includes a screw shaft 701 and a screw nut 702 surrounding the screw shaft 701. The ball spline 80 includes a spline shaft used as the operating shaft 801 and a spline nut 802 surrounding the spline shaft. The coupling member 90 is coupled between the screw nut 702 of the ball screw 70 and the spline shaft of the ball spline 80. The spline shaft of the ball spline 80 may rotate about the third axis X3 relative to the coupling member 90 and move together with the coupling member 90 along the third axis X3. In operation, if the screw shaft 701 is rotated, the screw nut 702 may be driven to move along the screw shaft 701. In this way, the coupling member 90 and the spline shaft of the ball spline 80 may move along the third axis X3 relative to the second arm 103. If the spline nut 802 is rotated, the spline nut 802 may drive the spline shaft of the ball spline 80 to rotate about the third axis X3 relative to the second arm 103.

In an embodiment, in order to drive the operating shaft 801 to move relative to the second arm 103, the third transmission mechanism 223 may include a seventh pulley 307, an eighth pulley 308, a ninth pulley 309, and a tenth pulley 310. The seventh pulley 307 may be coupled to the operating unit 104. For example, as shown in Fig. 1, the seventh pulley 307 may be fixedly connected to the screw shaft 701 of the ball screw 70. The eighth pulley 308 may be arranged in the second arm 103 around the second axis X2 and coupled to the seventh pulley 307 via a fourth transmission belt 404. The ninth pulley 309 may be arranged in the second branch 1122 of the first U-shaped part 112 around the second axis X2 and coupled to the eighth pulley 308 via a second transmission shaft 602. The tenth pulley 310 may be arranged on the third output shaft 213 of the third motor 203 and coupled to the ninth pulley 309 via a fifth transmission belt 405. Through the third transmission mechanism 223, the third motor 203 may drive the operating shaft 801 to move along the third axis X3 relative to the second arm 103 reliably and precisely.

In operation, if the third output shaft 213 of the third motor 203 rotates, the tenth pulley 310 may rotate along with the third output shaft 213 and then drive the ninth pulley 309 to rotate via the fifth transmission belt 405. Through the second transmission shaft 602 and the fourth transmission belt 404, the eighth pulley 308 and the seventh pulley 307 may be driven to rotate. When the seventh pulley 307 rotates, the screw shaft 701 of the ball screw 70 may be driven to rotate and the screw nut 702 may be driven to move along the screw shaft 701. In this way, the coupling member 90 and the spline shaft of the ball spline 80 may move along the third axis X3 relative to the second arm 103.

In some embodiments, the third transmission mechanism 223 may include one or more additional pulleys and corresponding transmission belts for executing transmission between the third motor 203 and the operating unit 104. In other embodiments, the third transmission mechanism 223 may include other transmission devices, such as gear-driving devices. The present disclosure does not intend to limit the specific implementation of the third transmission mechanism 223.

In an embodiment, in order to drive the operating shaft 801 to rotate relative to the second arm 103, the fourth transmission mechanism 224 may include an eleventh pulley 311, a twelfth pulley 312, a thirteenth pulley 313, and a fourteenth pulley 314. The eleventh pulley 311 may be coupled to the operating unit 104. For example, as shown in Fig. 1, the eleventh pulley 311 may be fixedly connected to the spline nut 802 of the ball spline 80. The twelfth pulley 312 may be arranged in the second arm 103 around the second axis X2 and coupled to the eleventh pulley 311 via a sixth transmission belt 406. The thirteenth pulley 313 may be arranged in the second branch 1122 of the first U-shaped part 112 around the second axis X2 and coupled to the twelfth pulley 312 via a third transmission shaft 603 coaxial to the second transmission shaft 602. The fourteenth pulley 314 may be arranged on the fourth output shaft 214 of the fourth motor 204 and coupled to the thirteenth pulley 313 via a seventh transmission belt 407. Through the fourth transmission mechanism 224, the fourth motor 204 may drive the operating shaft 801 to rotate about the third axis X3 relative to the second arm 103 reliably and precisely.

In operation, if the fourth output shaft 214 of the fourth motor 204 rotates, the fourteenth pulley 314 may rotate along with the fourth output shaft 214 and then drive the thirteenth pulley 313 to rotate via the seventh transmission belt 407. Through the third transmission shaft 603 and the sixth transmission belt 406, the twelfth pulley 312 and the eleventh pulley 311 may be driven to rotate. When the eleventh pulley 311 rotates, the spline nut 802 of the ball spline 80 may be driven to rotate. In this way, the spline nut 802 may drive the spline shaft of the ball spline 80 to rotate about the third axis X3 relative to the second arm 103.

In some embodiments, the fourth transmission mechanism 224 may include one or more additional pulleys and corresponding transmission belts for executing transmission between the fourth motor 204 and the operating unit 104. In other embodiments, the fourth transmission mechanism 224 may include other transmission devices, such as gear-driving devices. The present disclosure does not intend to limit the specific implementation of the fourth transmission mechanism 224.

With the foregoing embodiments, the first, second, third and

fourth motors

201, 202, 203, 204 are arranged in the base 101 or the first arm 102, instead of the second arm 103, rendering the second arm 103 slim and light. In this way, the load of the robot 100 around the first and second axes X1, X2 may be reduced, and less power would be needed for driving the robot 100 so as to achieve desired dynamic performance and speed. Moreover, since the

motors

201, 202, 203, 204 are arranged in or near to the base 101, heat transfer paths between the

motors

201, 202, 203, 204 and the floor or working table are short. As such, the heat generated by the

motors

201, 202, 203, 204 can be dissipated into the floor or working table quickly.

In some embodiments, the second motor 202 may be shifted into the main part 122 of the base 101. In this event, the second, third and

fourth motors

202, 203, 204 may be all arranged in the main part 122 of the base 101. Similar to the arrangement of Fig. 1, the load of the robot 100 around the first and second axes X1, X2 may also be reduced, and the heat generated by the

motors

201, 202, 203, 204 can be dissipated into the floor or working table quickly.

Fig. 2 schematically illustrates example connection between the first and

second arms

102, 103 of the SCARA robot 100 of Fig. 1. As shown, in an embodiment, the first and second branches 1121 of the first U-shaped part 112 are coupled to second arm 103 through corresponding

angular contact bearings

231, 232. With the

angular contact bearings

231, 232, the second arm 103 may rotate about the second axis X2 relative to the first arm 102 with low friction. In addition, since the second arm 103 is supported by the first U-shaped part 112 on two sides, the robot 100 may support more tilting moments and achieve more stiffness. In this way, the dynamic performance of the robot 100 may be improved.

In some embodiments, the

angular contact bearings

231, 232 may be replaced by other types of bearings, such as tapered roller bearings. The present disclosure does not intend to limit the type of the bearings between the first and

second arms

102, 103.

Fig. 3 schematically illustrates example wire arrangement in the SCARA robot 100 of Fig. 1. As shown, the base 101 may be provided with a first electrical interface 701 for providing power supply to the first, second, third and

fourth motors

201, 202, 203, 204 through

corresponding wires

704, 705, 706, 707. As described above with reference to Fig. 1, the first transmission shaft 601 and the input shaft 5021 of the second reducer 502 may be hollow. As such, the

wires

706 and 707 may run through the first transmission shaft 601 and connect to the first electrical interface 701. In addition, the second arm 103 may be provided with a second electrical interface 702 for providing power supply to an end effector (not shown) to be connected on the operating shaft 801. The second electrical interface 702 may be electrically connected to the first electrical interface 701 via a wire 703 running inside the base 101, the first arm 102, and the second arm 103 through the input shaft 5021 and the first transmission shaft 601. In this way, all the wires run inside the robot 100, and there is no need to set a dress package outside of the robot 100.

Since all the wires run inside the robot 100, the robot 100 may provide a bigger work range, as shown in Fig. 4. The maximum rotation angle of the first arm 102 relative to the base 101 may range from -180°to + 180°.

Fig. 5 schematically illustrates a SCARA robot 100 according to another example embodiment. The robot 100 as shown in Fig. 5 is similar to the robot 100 as shown in Fig. 1. Hereinafter, only the difference between the robots 100 of Figs. 5 and 1 will be described in detail, and the description regarding the same portions will be omitted.

In the embodiment as depicted in Fig. 5, the first arm 102 includes a first U-shaped part 112, a second U-shaped part 132 and a connection part 142 between the first and second

U-shaped parts

112, 132. The first U-shaped part 112 includes a first branch 1121 and a second branch 1122 each coupled to the second arm 103. The second U-shaped part 132 includes a third branch 1321 and a fourth branch 1322 each coupled to the base 101. The base 101 includes a first portion 1011 and a second portion 1012. The second portion 1012 of the base 101 protrudes from the first portion 1011 in a direction orthogonal to the first axis X1 and is coupled to the second U-shaped part 132 of the first arm 102. The first, second and

third motors

201, 202, 203 are arranged in the first portion 1011 of the base 101. The fourth motor 204 is arranged in the connection part 142 of the first arm 102.

In an embodiment, in order to drive the first arm 102 to rotate relative to the base 101, the first transmission mechanism 221 may include a first pulley 301, a second pulley 302 and a first reducer 501. The first pulley 301 may be arranged on the first output shaft 211 of the first motor 201. The second pulley 302 may be arranged in the second portion 1012 of the base 101 around the first axis X1 and coupled to the first pulley 301 via a first transmission belt 401. The first reducer 501 may be coupled between the second pulley 302 and the third branch 1321 of the second U-shaped part 132 around the first axis X1 so as to provide a reduced speed and an increased torque.

In an embodiment, in order to drive the second arm 103 to rotate relative to the first arm 102, the second transmission mechanism 222 may include a third pulley 303, a fourth pulley 304, a fifth pulley 305, a sixth pulley 306, and a second reducer 502. The third pulley 303 may be arranged on the second output shaft 212 of the second motor 202. The fourth pulley 304 may be arranged in the second portion 1012 of the base 101 around the first axis X1 and coupled to the third pulley 303 via a second transmission belt 402. The fifth pulley 305 may be arranged in the third branch 1321 of the second U-shaped part 132 around the first axis X1 and coupled to the fourth pulley 304 via a first transmission shaft 601. The first transmission shaft 601 may extend through the first reducer 501 and the second pulley 302. The sixth pulley 306 may be arranged in the first branch 1121 of the first U-shaped part 112 around the second axis X2 and coupled to the fifth pulley 305 via a third transmission belt 403. The second reducer 502 may be coupled between the sixth pulley 306 and the second arm 103 around the second axis X2 so as to provide a reduced speed and an increased torque.

In an embodiment, in order to drive the operating shaft 801 to move relative to the second arm 103, the third transmission mechanism 223 may include a seventh pulley 307, an eighth pulley 308, a ninth pulley 309, a tenth pulley 310, a fifteenth pulley 315, and a sixteenth pulley 316. The seventh pulley 307 may be coupled to the operating unit 104. For example, as shown in Fig. 5, the seventh pulley 307 may be fixedly connected to the screw shaft 701 of the ball screw 70. The eighth pulley 308 may be arranged in the second arm 103 around the second axis X2 and coupled to the seventh pulley 307 via a fourth transmission belt 404. The ninth pulley 309 may be arranged in the second branch 1122 of the first U-shaped part 112 around the second axis X2 and coupled to the eighth pulley 308 via a second transmission shaft 602. The tenth pulley 310 may be arranged in the fourth branch 1322 of the second U-shaped part 132 and coupled to the ninth pulley 309 via a fifth transmission belt 405. The fifteenth pulley 315 may be arranged in the second portion 1012 of the base 101 around the first axis X1 and coupled to the tenth pulley 310 via a fourth transmission shaft 604. The sixteenth pulley 316 may be arranged on the third output shaft 213 of the third motor 203 and coupled to the fifteenth pulley 315 via an eighth transmission belt 408.

In operation, if the third output shaft 213 of the third motor 203 rotates, the sixteenth pulley 316 may rotate along with the third output shaft 213 and then drive the fifteenth pulley 315 to rotate via the eighth transmission belt 408. Through the fourth transmission shaft 604, the fifth transmission belt 405, the second transmission shaft 602 and the fourth transmission belt 404, the tenth pulley 310, the ninth pulley, 309, the eighth pulley 308 and the seventh pulley 307 may be driven to rotate. When the seventh pulley 307 rotates, the screw shaft 701 of the ball screw 70 may be driven to rotate and the screw nut 702 may be driven to move along the screw shaft 701. In this way, the coupling member 90 and the spline shaft of the ball spline 80 may move along the third axis X3 relative to the second arm 103.

In an embodiment, in order to drive the operating shaft 801 to rotate relative to the second arm 103, the fourth transmission mechanism 224 may include an eleventh pulley 311, a twelfth pulley 312, a thirteenth pulley 313, and a fourteenth pulley 314. The eleventh pulley 311 may be coupled to the operating unit 104. For example, as shown in Fig. 5, the eleventh pulley 311 may be fixedly connected to the spline nut 802 of the ball spline 80. The twelfth pulley 312 may be arranged in the second arm 103 around the second axis X2 and coupled to the eleventh pulley 311 via a sixth transmission belt 406. The thirteenth pulley 313 may be arranged in the second branch 1122 of the first U-shaped part 112 around the second axis X2 and coupled to the twelfth pulley 312 via a third transmission shaft 603 coaxial to the second transmission shaft 602. The fourteenth pulley 314 may be arranged on the fourth output shaft 214 of the fourth motor 204 and coupled to the thirteenth pulley 313 via a seventh transmission belt 407.

Similar to the robot 100 of Fig. 1, the load of the robot 100 as shown in Fig. 5 around the first and second axes X1, X2 may also be reduced, and the heat generated by the

motors

201, 202, 203, 204 can be dissipated into the floor or working table quickly.

Fig. 6 schematically illustrates a SCARA robot 100 according to a further example embodiment. The robot 100 as shown in Fig. 6 is similar to the robot 100 as shown in Fig. 5. Hereinafter, only the difference between the robots 100 of Figs. 6 and 5 will be described in detail, and the description regarding the same portions will be omitted.

In the embodiment as depicted in Fig. 6, the first, second, third and

fourth motors

201, 202, 203, 204 are all arranged in the first portion 1011 of the base 101. The first, second and

third transmission mechanisms

221, 222, 223 as shown in Figs. 5 and 6 may have the similar arrangement. The fourth transmission mechanisms 224 may include an eleventh pulley 311, a twelfth pulley 312, a thirteenth pulley 313, a fourteenth pulley 314, a seventeenth pulley 317 and an eighteenth pulley 318. The eleventh pulley 311 may be coupled to the operating unit 104. For example, as shown in Fig. 6, the eleventh pulley 311 may be fixedly connected to the spline nut 802 of the ball spline 80. The twelfth pulley 312 may be arranged in the second arm 103 around the second axis X2 and coupled to the eleventh pulley 311 via a sixth transmission belt 406. The thirteenth pulley 313 may be arranged in the second branch 1122 of the first U-shaped part 112 around the second axis X2 and coupled to the twelfth pulley 312 via a third transmission shaft 603 coaxial to the second transmission shaft 602. The fourteenth pulley 314 may be arranged in the fourth branch 1322 of the second U-shaped part 132 and coupled to the thirteenth pulley 313 via a seventh transmission belt 407. The seventeenth pulley 317 may be arranged in the second portion 1012 of the base 101 around the first axis X1 and coupled to the fourteenth pulley 314 via a fifth transmission shaft 605 coaxial to the fourth transmission shaft 604. The eighteenth pulley 318 may be arranged on the fourth output shaft 214 of the fourth motor 204 and coupled to the seventeenth pulley 317 via an ninth transmission belt 409.

In operation, if the fourth output shaft 214 of the fourth motor 204 rotates, the eighteenth pulley 318 may rotate along with the fourth output shaft 214 and then drive the seventeenth pulley 317 to rotate via the ninth transmission belt 409. Through the fifth transmission shaft 605, the seventh transmission belt 407, the third transmission shaft 603 and the sixth transmission belt 406, the fourteenth pulley 314, the thirteenth pulley 313, the twelfth pulley 312 and the eleventh pulley 311 may be driven to rotate. When the eleventh pulley 311 rotates, the spline nut 802 of the ball spline 80 may be driven to rotate. In this way, the spline nut 802 may drive the spline shaft of the ball spline 80 to rotate about the third axis X3 relative to the second arm 103.

Similar to the robots 100 of Figs. 1 and 5, the load of the robot 100 as shown in Fig. 6 around the first and second axes X1, X2 may also be reduced, and the heat generated by the

motors

201, 202, 203, 204 can be dissipated into the floor or working table quickly.

In some embodiments, the third motor 203 as shown in Fig. 6 may be shifted in to the connection part 142 of the first arm 102. In this event, the first, second and

fourth motors

201, 202, 204 are arranged in the first portion 1011 of the base 101, and the third motor 203 is arranged in the first arm 102.

In some embodiments, the operating unit 104 as shown in Figs. 1, 5 and 6 may be replaced by a ball screw spline. The ball screw spline may include a ball screw spline shaft used as the operating shaft 801, a screw nut and a spline nut. The screw nut and the spline nut surround the operating shaft 801. In order to drive the operating shaft 801 to move relative to the second arm 103, the third transmission mechanism 223 may be coupled to the screw shaft of the ball screw spline. For example, the seventh pulley 307 as shown in Figs. 1, 5 and 6 may be fixedly connected to the screw nut of the ball screw spline. In order to drive the operating shaft 801 to rotate relative to the second arm 103, the fourth transmission mechanism 224 is coupled to the spline nut of the ball screw spline. For example, the eleventh pulley 311 as shown in Figs. 1, 5 and 6 may be fixedly connected to the spline nut of the ball screw spline.

It should be appreciated that the above detailed embodiments of the present disclosure are only to exemplify or explain principles of the present disclosure and not to limit the present disclosure. Therefore, any modifications, equivalent alternatives and improvement, etc. without departing from the spirit and scope of the present disclosure shall be included in the scope of protection of the present disclosure. Meanwhile, appended claims of the present disclosure aim to cover all the variations and modifications falling under the scope and boundary of the claims or equivalents of the scope and boundary.

Claims

A robot (100) of selective compliance assembly robot arm (SCARA) type, comprising:

a base (101) ;

a first arm (102) coupled to the base (101) , the first arm (102) being rotatable about a first axis (X1) relative to the base (101) when driven by a first motor (201) arranged in the base (101) via a first transmission mechanism (221) ;

a second arm (103) coupled to the first arm (102) , the second arm (103) being rotatable about a second axis (X2) relative to the first arm (102) when driven by a second motor (202) via a second transmission mechanism (222) , wherein the second motor (202) is arranged in the base (101) or the first arm (102) , and the second axis (X2) is substantially parallel to the first axis (X1) ; and

an operating unit (104) arranged in the second arm (103) and including an operating shaft (801) ,

wherein the operating shaft (801) is movable along a third axis (X3) relative to the second arm (103) when driven by a third motor (203) arranged in the base (101) or the first arm (102) via a third transmission mechanism (223) , wherein the third axis (X3) is substantially parallel to the first and second axes (X1, X2) , and

wherein the operating shaft (801) is rotatable about the third axis (X3) relative to the second arm (103) when driven by a fourth motor (204) arranged in the base (101) or the first arm (102) via a fourth transmission mechanism (224) .
The robot (100) according to claim 1, wherein the first arm (102) comprises a first U-shaped part (112) including a first branch (1121) and a second branch (1122) each coupled to the second arm (103) .
The robot (100) according to claim 2, wherein the first arm (102) further comprises a main part (122) coupled to the base (101) .
The robot (100) according to claim 3, wherein the first transmission mechanism (221) comprises:

a first pulley (301) arranged on a first output shaft (211) of the first motor (201 ) ;

a second pulley (302) arranged in the base (101) around the first axis (Xl) and coupled to the first pulley (301) via a first transmission belt (401) ; and

a first reducer (501) coupled between the second pulley (302) and the main part (122) of the first arm (102) around the first axis (X1) .
The robot (100) according to claim 4, wherein the second motor (202) is arranged in the base (101) , and the second transmission mechanism (222) comprises:

a third pulley (303) arranged on a second output shaft (212) of the second motor (202) ;

a fourth pulley (304) arranged in the base (101) around the first axis (X1) and coupled to the third pulley (303) via a second transmission belt (402) ;

a fifth pulley (305) arranged in the main part (122) of the first arm (102) around the first axis (X1) and coupled to the fourth pulley (304) via a first transmission shaft (601) , the first transmission shaft (601) extending through the first reducer (501) and the second pulley (302) ;

a sixth pulley (306) arranged in the first branch (1121) of the first U-shaped part (112) around the second axis (X2) and coupled to the fifth pulley (305) via a third transmission belt (403) ; and

a second reducer (502) coupled between the sixth pulley (306) and the second arm (103) around the second axis (X2) .
The robot (100) according to claim 5, wherein the third motor (203) is arranged in the main part (122) of the first arm (102) , and the third transmission mechanism (223) comprises:

a seventh pulley (307) coupled to the operating unit (104) ;

an eighth pulley (308) arranged in the second arm (103) around the second axis (X2) and coupled to the seventh pulley (307) via a fourth transmission belt (404) ;

a ninth pulley (309) arranged in the second branch (1122) of the first U-shaped part (112) around the second axis (X2) and coupled to the eighth pulley (308) via a second transmission shaft (602) ; and

a tenth pulley (310) arranged on a third output shaft (213) of the third motor (203) and coupled to the ninth pulley (309) via a fifth transmission belt (405) .
The robot (100) according to claim 6, wherein the fourth motor (204) is arranged in the main part (122) of the first arm (102) , and the fourth transmission mechanism (224) comprises:

an eleventh pulley (311) coupled to the operating unit (104) ;

a twelfth pulley (312) arranged in the second arm (103) around the second axis (X2) and coupled to the eleventh pulley (311) via a sixth transmission belt (406) ;

a thirteenth pulley (313) arranged in the second branch (1122) of the first U-shaped part (112) around the second axis (X2) and coupled to the twelfth pulley (312) via a third transmission shaft (603) coaxial to the second transmission shaft (602) ; and

a fourteenth pulley (314) arranged on a fourth output shaft (214) of the fourth motor (204) and coupled to the thirteenth pulley (313) via a seventh transmission belt (407) .
The robot (100) according to claim 3, wherein the second, third and fourth motors (202, 203, 204) are arranged in the main part (122) of the base (101) .
The robot (100) according to claim 2, wherein the first arm (102) further comprises:

a second U-shaped part (132) including a third branch (1321) and a fourth branch (1322) each coupled to the base (101) ; and

a connection part (142) between the first and second U-shaped parts (112, 132) .
The robot (100) according to claim 9, wherein the base (101) comprises:

a first portion (1011) containing the first motor (201) ; and

a second portion (1012) protruding from the first portion (1011) in a direction orthogonal to the first axis (X1) and coupled to the second U-shaped part (132) of the first arm (102) .
The robot (100) according to claim 10, wherein the first transmission mechanism (221) comprises:

a first pulley (301) arranged on a first output shaft (211) of the first motor (201) ;

a second pulley (302) arranged in the second portion (1012) of the base (101) around the first axis (X1) and coupled to the first pulley (301) via a first transmission belt (401) ; and

a first reducer (501) coupled between the second pulley (302) and the third branch (1321) of the second U-shaped part (132) around the first axis (X1) .
The robot (100) according to claim 11, wherein the second motor (202) is arranged in the first portion (1011) of the base (101) and the second transmission mechanism (222) comprises:

a third pulley (303) arranged on a second output shaft (212) of the second motor (202) ;

a fourth pulley (304) arranged in the second portion (1012) of the base (101) around the first axis (X1) and coupled to the third pulley (303) via a second transmission belt (402) ;

a fifth pulley (305) arranged in the third branch (1321) of the second U-shaped part (132) around the first axis (X1) and coupled to the fourth pulley (304) via a first transmission shaft (601) , the first transmission shaft (601) extending through the first reducer (501) and the second pulley (302) ;

a sixth pulley (306) arranged in the first branch (1121) of the first U-shaped part (112) around the second axis (X2) and coupled to the fifth pulley (305) via a third transmission belt (403) ; and

a second reducer (502) coupled between the sixth pulley (306) and the second arm (103) around the second axis (X2) .
The robot (100) according to claim 5 or 12, wherein the first transmission shaft (601) is hollow.
The robot (100) according to claim 12, wherein the third motor (203) is arranged in the first portion (1011) of the base (101) and the third transmission mechanism (223) comprises:

a seventh pulley (307) coupled to the operating unit (104) ;

an eighth pulley (308) arranged in the second arm (103) around the second axis (X2) and coupled to the seventh pulley (307) via a fourth transmission belt (404) ;

a ninth pulley (309) arranged in the second branch (1122) of the first U-shaped part (112) around the second axis (X2) and coupled to the eighth pulley (308) via a second transmission shaft (602) ;

a tenth pulley (310) arranged in the fourth branch (1322) of the second U-shaped part (132) and coupled to the ninth pulley (309) via a fifth transmission belt (405) ;

a fifteenth pulley (315) arranged in the second portion (1012) of the base (101) around the first axis (X1) and coupled to the tenth pulley (310) via a fourth transmission shaft (604) ; and

a sixteenth pulley (316) arranged on a third output shaft (213) of the third motor (203) and coupled to the fifteenth pulley (315) via an eighth transmission belt (408) .
The robot (100) according to claim 14, wherein the fourth motor (204) is arranged in the connection part (142) of the first arm (102) and the fourth transmission mechanism (224) comprises:

an eleventh pulley (311) coupled to the operating unit (104) ;

a twelfth pulley (312) arranged in the second arm (103) around the second axis (X2) and coupled to the eleventh pulley (311) via a sixth transmission belt (406) ;

a thirteenth pulley (313) arranged in the second branch (1122) of the first U-shaped part (112) around the second axis (X2) and coupled to the twelfth pulley (312) via a third transmission shaft (603) coaxial to the second transmission shaft (602) ; and

a fourteenth pulley (314) arranged on a fourth output shaft (214) of the fourth motor (204) and coupled to the thirteenth pulley (313) via a seventh transmission belt (407) .
The robot (100) according to claim 14, wherein the fourth motor (204) is arranged in the first portion (1011) of the base (101) and the fourth transmission mechanism (224) comprises:

an eleventh pulley (311) coupled to the operating unit (104) ;

a twelfth pulley (312) arranged in the second arm (103) around the second axis (X2) and coupled to the eleventh pulley (311) via a sixth transmission belt (406) ;

a thirteenth pulley (313) arranged in the second branch (1122) of the first U-shaped part (112) around the second axis (X2) and coupled to the twelfth pulley (312) via a third transmission shaft (603) coaxial to the second transmission shaft (602) ;

a fourteenth pulley (314) arranged in the fourth branch (1322) of the second U-shaped part (132) and coupled to the thirteenth pulley (313) via a seventh transmission belt (407) ;

a seventeenth pulley (317) arranged in the second portion (1012) of the base (101) around the first axis (X1) and coupled to the fourteenth pulley (314) via a fifth transmission shaft (605) coaxial to the fourth transmission shaft (604) ; and

an eighteenth pulley (318) arranged on a fourth output shaft (214) of the fourth motor (204) and coupled to the seventeenth pulley (317) via an ninth transmission belt (409) .
The robot (100) according to claim 10, wherein the fourth motor (204) is arranged in the first portion (1011) of the base (101) and the third motor (203) is arranged in the connection part (142) of the first arm (102) .
The robot (100) according to claim 1, wherein the base (101) is provided with a first electrical interface (701) , the second arm (103) is provided with a second electrical interface (702) electrically connected to the first electrical interface (701) via a wire (703) running inside the base (101) , the first arm (102) , and the second arm (103) .
The robot (100) according to claim 1, wherein the operating unit (104) comprises:

a ball screw (70) including a screw shaft (701) and a screw nut (702) , the third transmission mechanism (223) being coupled to the screw shaft (701) ;

a ball spline (80) including a spline shaft used as the operating shaft (801) and a spline nut (802) , the fourth transmission mechanism (224) be coupled to the spline nut (802) ; and

a coupling member (90) coupled between the screw nut (702) and the spline shaft.
The robot (100) according to claim 1, wherein the operating unit (104) comprises a ball screw spline including a ball screw spline shaft used as the operating shaft (801) , a screw nut and a spline nut, the third transmission mechanism (223) is coupled to the screw shaft, and the fourth transmission mechanism (224) is coupled to the spline nut.
A method for manufacturing the robot (100) according to any of claims 1-20.