Tri-coaxial four-arm transmission device, control method thereof, and wafer transfer robot

Abstract

The application provides a three-coaxial four-arm transmission device and a control method thereof and a wafer handling robot, wherein the device comprises a lower arm assembly, an upper arm assembly and a transmission assembly; the lower arm assembly comprises a lower finger unit, a first arm rod and a second arm rod; the upper arm assembly comprises an upper finger unit, a third arm rod and a fourth arm rod; the transmission assembly comprises an outer drive shaft, a middle drive shaft and an inner drive shaft arranged coaxially in sequence; the first arm rod is connected with the outer drive shaft, the second arm rod is connected with the middle drive shaft, the third arm rod is connected with the second arm rod in an overlapping mode, and the fourth arm rod is connected with the inner drive shaft; the first arm rod, the second arm rod, the third arm rod and the fourth arm rod are arranged in a stacked mode in sequence; the pair of lower finger units are arranged in a relative mode and are hingedly connected with the fourth arm rod and the third arm rod respectively and simultaneously; and the pair of upper finger units are arranged in a relative mode and are hingedly connected with the first arm rod and the second arm rod respectively and simultaneously.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mechanical arm transmission structure of semiconductor wafer transfer robot, in particular to a three-coaxial four-arm transmission device, a control method thereof and a wafer transfer robot. BACKGROUND

[0002] As the core automation equipment in the field of semiconductor manufacturing, the core function of wafer transfer robot is to realize high-precision and non-pollution automatic transmission and transfer of precision sensitive wafers (silicon chips) in a clean room environment. Specifically, its core role is reflected in three aspects: first, it completes the accurate transfer of wafers between key production processes such as lithography, etching and thin film deposition; second, it realizes the automatic loading and unloading operation of wafers in the cleaning and detection processes; third, it is responsible for the efficient circulation of wafers between equipment and warehouses in the storage and logistics link.

[0003] Currently, to meet the demand for high efficiency in semiconductor wafer manufacturing, the multi-arm transmission design of wafer transfer robot has become a key technical breakthrough. Through multi-arm collaborative design, the robot can realize multi-task parallel processing — for example, when one arm takes a wafer from the equipment, another arm can simultaneously place a wafer in the target position, thereby reducing the waiting time caused by single-arm reciprocating motion and greatly improving the wafer transfer quantity per unit time.

[0004] The existing vacuum type wafer transfer robot commonly has a structure of double-coaxial single-arm, or triple-coaxial double-arm, or quadruple-coaxial four-arm transmission form. From the efficiency point of view, the transfer capacity of double-arm structure is far inferior to that of four-arm structure; but the quadruple-coaxial four-arm structure has significant limitations: it must be equipped with four drive units to realize independent control of each arm, which will undoubtedly increase the equipment cost and occupy more equipment space.

[0005] Therefore, how to achieve precise control of more mechanical hands with fewer drive units in a more economical and reliable scheme has become a core issue that needs to be solved by technical personnel in the field. SUMMARY

[0006] Therefore, the main purpose of the present application is to provide a three-coaxial four-arm transmission device, a control method thereof and a wafer transfer robot, to realize four-arm transmission driven by a three-coaxial transmission assembly.

[0007] To achieve the above object, according to one aspect of the present application, a three coaxial four-arm transmission device is provided, which comprises a lower arm assembly, an upper arm assembly, and a transmission assembly, wherein the lower arm assembly comprises a lower finger unit, a first arm rod, and a second arm rod, the upper arm assembly comprises an upper finger unit, a third arm rod, and a fourth arm rod, and the transmission assembly comprises an outer drive shaft, a middle drive shaft, and an inner drive shaft arranged coaxially in sequence; the first arm rod is connected with the outer drive shaft, the second arm rod is connected with the middle drive shaft, the third arm rod is connected with the second arm rod in an overlapping manner, and the fourth arm rod is connected with the inner drive shaft; the first arm rod, the second arm rod, the third arm rod, and the fourth arm rod are arranged in sequence in a stacked manner; a pair of lower finger units are arranged in a facing manner and are hingedly connected with the fourth arm rod and the third arm rod respectively and simultaneously, and a pair of upper finger units are arranged in a facing manner and are hingedly connected with the first arm rod and the second arm rod respectively and simultaneously, so as to form a multi-layer double set reciprocating telescopic hinge mechanism.

[0008] In a possible preferred embodiment, the lower finger unit comprises a first connecting rod, a second connecting rod, and a first end finger, wherein the first end finger extends a pair of spaced connecting ends to define a clearance recess between the connecting ends, and one end of the first connecting rod and the second connecting rod is hingedly connected with the connecting ends of the first end finger, and the other end thereof is hingedly connected with the connecting ends of the first arm rod and the second arm rod respectively.

[0009] In a possible preferred embodiment, the first arm rod is provided with a leveling wall to at least raise the connecting ends thereof to be flush with the second arm rod, so that the first end fingers are arranged in a flush manner.

[0010] In a possible preferred embodiment, the first connecting rod and the second connecting rod are in a bent shape, and the bending angle thereof allows the pair of first end fingers to be retracted to a repositioning limit while being spaced from the outer drive shaft and the middle drive shaft.

[0011] In a possible preferred embodiment, the upper finger unit comprises a third connecting rod, a fourth connecting rod, and a second end finger, wherein one end of the third connecting rod and the fourth connecting rod is hingedly connected with the second end finger, and the other end thereof is hingedly connected with the connecting ends of the third arm rod and the fourth arm rod respectively.

[0012] In a possible preferred embodiment, the third arm rod is provided with a leveling wall to at least raise the connecting ends thereof to be flush with the fourth arm rod, so that the second end fingers are arranged in a flush manner.

[0013] In a possible preferred embodiment, the third connecting rod and the fourth connecting rod are in a bent shape, and the bending angle thereof allows the pair of second end fingers to be retracted to a repositioning limit while being relatively spaced.

[0014] In a possible preferred embodiment, the overlapping connection between the third arm rod and the second arm rod maintains an opening and closing angle of 30-120°.

[0015] To achieve the above object, according to another aspect of the present application, there is also provided a wafer transfer robot, comprising: a direct drive motor, a mechanical arm, wherein the mechanical arm is any of the above-mentioned three coaxial four-arm transmission devices, and the direct drive motor is drivingly connected with the outer drive shaft, the middle drive shaft and the inner drive shaft respectively.

[0016] To achieve the above object, according to another aspect of the present application, there is also provided a control method for any of the above-mentioned three coaxial four-arm transmission devices, wherein the single-finger stretching and retracting motion control step comprises any of the following steps:

[0017] driving the inner drive shaft and the middle drive shaft to rotate in opposite directions, driving the third arm rod and the fourth arm rod to open and close, while controlling the outer drive shaft and the middle drive shaft to rotate in the same direction by the same angle, maintaining the opening and closing angle of the first arm rod and the second arm rod, to separately control the relative stretching and retracting motion between the upper finger units; or

[0018] driving the outer drive shaft and the middle drive shaft to rotate in opposite directions, driving the first arm rod and the second arm rod to open and close, while controlling the inner drive shaft and the middle drive shaft to rotate in the same direction by the same angle, maintaining the opening and closing angle of the fourth arm rod and the third arm rod, to separately control the relative stretching and retracting motion between the lower finger units.

[0019] To achieve the above object, according to another aspect of the present application, there is also provided a control method for any of the above-mentioned three coaxial four-arm transmission devices, wherein the double-finger stretching and retracting motion control step comprises:

[0020] driving the inner drive shaft to rotate, driving the fourth arm rod and the third arm rod to open and close, and controlling the relative stretching and retracting motion between the upper finger units to be maintained;

[0021] driving the inner drive shaft and the middle drive shaft to rotate in the same direction by the same angle, maintaining the opening and closing angle of the fourth arm rod and the third arm rod;

[0022] driving the outer drive shaft and the inner drive shaft and the middle drive shaft to rotate in opposite directions, driving the first arm rod and the second arm rod to open and close, and controlling the relative stretching and retracting motion of the lower finger units.

[0023] To achieve the above object, according to another aspect of the present application, there is also provided a control method for any of the above-mentioned three coaxial four-arm transmission devices, wherein the single-finger arc stretching motion control step comprises any of the following steps:

[0024] driving the inner drive shaft to rotate, only driving the fourth arm rod to rotate, making the fourth arm rod and the third arm rod relatively open and close by a preset angle, to drive the second end finger to stretch out in an arc trajectory; or

[0025] In the driving process, the middle drive shaft rotates to drive the third arm rod to rotate, and the fourth arm rod is opened and closed relative to the third arm rod by a preset angle to drive the second end finger to stretch out in an arc trajectory; the outer drive shaft rotates simultaneously to keep the first arm rod and the second arm rod at a relative static distance; or

[0026] In the driving process, the outer drive shaft rotates to drive the first arm rod to rotate, and the first arm rod is opened and closed relative to the second arm rod by a preset angle to drive the first end finger to stretch out in an arc trajectory; or

[0027] In the driving process, the middle drive shaft rotates to drive the second arm rod to rotate, and the first arm rod is opened and closed relative to the second arm rod by a preset angle to drive the first end finger to stretch out in an arc trajectory; the inner drive shaft rotates simultaneously to keep the fourth arm rod and the third arm rod at a relative static distance.

[0028] The three coaxial four-arm transmission device and the wafer transfer robot provided by the application ingeniously designs the lower arm assembly and the upper arm assembly, which are matched with the transmission assembly arranged in three coaxial modes to construct a multilayer double-group reciprocating hinge mechanism. This innovative structure realizes the control of two groups of four finger units by three drive shafts, and accurately completes the stretching and rotating of single fingers and double fingers. In this way, the efficient demand of wafer transmission operation can be met, the number of drivers used can be effectively reduced, the production cost can be reduced, and the equipment occupied space can be significantly saved. BRIEF DESCRIPTION OF DRAWINGS

[0029] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application and are incorporated in and constitute a part of this application. The embodiments of the present application illustrated in the drawings and their descriptions are used to explain the present application and are not intended to limit the present application. In the drawings:

[0030] Figure 1 It is a schematic view of the overall structure of the three coaxial four-arm transmission device of the application from the shaft side;

[0031] Figure 2 It is a schematic view of the structure of the lower arm assembly in the three coaxial four-arm transmission device of the application;

[0032] Figure 3 It is a schematic view of the structure of the upper arm assembly in the three coaxial four-arm transmission device of the application;

[0033] Figure 4 It is a schematic view of the half-section structure of the three coaxial four-arm transmission device of the application;

[0034] Figure 5 It is a schematic view of the structure of the lower finger unit when it is stretched in the three coaxial four-arm transmission device of the application;

[0035] Figure 6 It is a schematic view of the three coaxial four-arm transmission device of the application from the top when it is at the origin position;

[0036] Figure 7 Figure 6 is a top view of the straight line extension of the first end finger of the lower layer on one side of the three coaxial four-arm transmission device of the present application;

[0037] Figure 8 Figure 7 is a top view of the arc line extension of the second end finger of the upper layer on one side of the three coaxial four-arm transmission device of the present application;

[0038] Figure 9 Figure 8 is a top view of the arc line extension of the second end finger of the upper layer on one side of the three coaxial four-arm transmission device of the present application;

[0039] Figure 10 Figure 9 is a top view of the arc line extension trajectory of the second end finger of the upper layer on one side of the three coaxial four-arm transmission device of the present application;

[0040] Figure 11 Figure 10 is a top view of the simultaneous extension of the first and second end fingers of the upper and lower layers on one side of the three coaxial four-arm transmission device of the present application.

[0041] BRIEF DESCRIPTION OF DRAWINGS

[0042] Lower arm assembly 1, upper arm assembly 2, transmission assembly 3, leveling wall 10, lower finger unit 11, first arm rod 12, second arm rod 13, upper finger unit 21, third arm rod 22, fourth arm rod 23, outer drive shaft 31, middle drive shaft 32, inner drive shaft 33, outer shaft connecting ring 34, outer shaft deep groove ball bearing 35, middle shaft connecting ring 36, middle shaft deep groove ball bearing 37, outer shaft tensioning sleeve 38, first connecting rod 111, second connecting rod 112, first end finger 113, avoidance recess 114, third connecting rod 211, fourth connecting rod 212, second end finger 213. DETAILED DESCRIPTION

[0043] In order for those skilled in the art to better understand the technical solutions of the present application, the specific technical solutions of the present application will be described below in conjunction with the embodiments to help those skilled in the art further understand the present application. Obviously, the embodiments described in the present application are only a part of the embodiments of the present application, not all the embodiments. It should be pointed out that, for those skilled in the art, the embodiments in the present application and the features in the embodiments can be combined with each other without departing from the concept of the present application and without being in conflict with each other. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the disclosure and protection scope of the present application.

[0044] Furthermore, the terms "first," "second," etc., used in the specification, claims, and drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such features can be interchanged where appropriate so that embodiments of the invention described herein can be implemented in orders other than those described herein. At the same time, the stages described in each step are not necessarily to be implemented in the same step; it should be understood that the implementation order of the contents of each step stage can be adjusted and interchanged without violating the inventive concept, so that embodiments of the invention described herein can be implemented in orders other than those described herein. Additionally, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. Unless otherwise expressly specified and limited, the terms "set," "arrange," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection through an intermediate medium; or a connection within two elements. Those skilled in the art can understand the specific meaning of the above terms in this case based on the specific circumstances and in conjunction with existing technology.

[0045] To achieve the drive of the four arms via the three coaxial transmission assembly 3, such as Figures 1 to 6 As shown, the present invention provides a three-coaxial four-arm transmission device, an example of which includes: a lower arm assembly 1, an upper arm assembly 2, and a transmission assembly 3, wherein the lower arm assembly 1 and the upper arm assembly 2 are respectively connected to the transmission assembly 3 to form a multi-layer double-set reciprocating telescopic hinge mechanism.

[0046] Specifically, such as Figures 1 to 4 As shown, the lower arm assembly 1 includes: a lower finger unit 11, a first arm 12, and a second arm 13; the upper arm assembly 2 includes: an upper finger unit 21, a third arm 22, and a fourth arm 23; and the transmission assembly 3 includes: an outer drive shaft 31, a middle drive shaft 32, and an inner drive shaft 33, wherein the outer drive shaft 31, the middle drive shaft 32, and the inner drive shaft 33 are arranged coaxially in sequence, and the middle drive shaft 32 extends outward to the outer drive shaft 31, and the inner drive shaft 33 extends outward to the middle drive shaft 32.

[0047] In addition, in a preferred embodiment, in order to drive each shaft in the transmission assembly 3 to rotate independently, the outer drive shaft 31, the middle drive shaft 32, and the inner drive shaft 33 can be respectively configured to be connected to a direct drive motor to support independent drive rotation. In addition, in other optional embodiments, they can also be independently connected to different drivers through existing pulleys or gears, thereby achieving the effect of three coaxial independent drive rotation. Since these solutions are prior art, they will not be described in detail here. Those skilled in the art can refer to the existing solutions for implementation.

[0048] In a general embodiment, the first arm 12 is connected to the outer drive shaft 31, the second arm 13 is connected to the middle drive shaft 32, the third arm 22 overlaps with the second arm 13 to form a preset opening angle, and the fourth arm 23 is connected to the inner drive shaft 33. In a preferred embodiment, to make the connection between each arm and the transmission assembly 3 more stable, the transmission assembly 3 may also include: an outer shaft connecting ring 34, an outer shaft deep groove ball bearing 35, a middle shaft connecting ring 36, a middle shaft deep groove ball bearing 37, and an outer shaft tensioning sleeve 38, wherein... Figure 4 As shown, the first arm 12 is driven by the outer shaft connecting ring 34 and the outer drive shaft 31, and the second arm 13 is driven by the middle drive shaft 32. At the same time, the outer shaft deep groove ball bearing 35 is disposed between the first arm 12 and the second arm 13 to support their stable relative rotational movement. The middle shaft connecting ring 36 is connected to the second arm 13 and sleeved on the outside of the inner drive shaft 33, and is arranged coaxially with the inner drive shaft 33. The third arm 22 is connected to the middle shaft connecting ring 36, is driven by the middle drive shaft 32, and overlaps and is fixed with the second arm 13 at a preset opening angle. In this example, the preset opening angle is preferably 30~120°. The fourth arm 23 is driven by the outer shaft tensioning sleeve 38 and the inner drive shaft 33. At the same time, the middle shaft deep groove ball bearing 37 is disposed between the fourth arm 23 and the third arm 22 to support their stable relative rotational movement. With this arrangement, the first arm 12, the second arm 13, the third arm 22, and the fourth arm 23 are stacked in sequence.

[0049] Furthermore, such as Figures 1 to 2 As shown, a pair of lower finger units 11 are respectively hinged to the fourth arm 23 and the third arm 22, so that the two lower finger units 11 are arranged opposite each other. Each of the lower finger units 11 includes: a first link 111, a second link 112, and a first terminal finger 113. The first terminal finger 113 has a pair of spaced-apart connecting ends extending from its tail to define a clearance recess 114 between the connecting ends. The clearance recess 114 keeps the finger at the extension / retraction limit position and spaced apart from the transmission assembly 3 to prevent collision interference. One end of the first link 111 and the second link 112 is hinged to the connecting end of the first terminal finger 113, and the other end is hinged to the connecting end of the first arm 12 and the second arm 13, respectively.

[0050] In order to arrange the first terminal fingers 113 evenly, in an optional embodiment, the first arm 12 is provided with a leveling wall 10 to at least raise its connecting end to be level with the second arm 13, so that the first terminal fingers 113 are arranged evenly.

[0051] To prevent the lower finger unit 11 from interfering with the transmission component 3 during extension / retraction movements, such as...Figure 2 As shown, in an optional embodiment, the first link 111 and the second link 112 may be configured in a bent shape, and their bending angle allows the pair of first end fingers 113 to maintain a distance from the outer drive shaft 31 and the middle drive shaft 32 when they retract to the reset limit. In addition, combined with the avoidance recess 114 at the tail of the first end finger 113, the extension / retraction stroke of the first end finger 113 can be further increased.

[0052] Furthermore, such as Figures 1 to 3 As shown, a pair of upper finger units 21 are hinged to the first arm 12 and the second arm 13, respectively, so that the two upper finger units 21 are arranged opposite each other. The upper finger unit 21 includes: a third link 211, a fourth link 212, and a second terminal finger 213. One end of the third link 211 and the fourth link 212 is hinged to the second terminal finger 213, and the other end is hinged to the connecting end of the third arm 22 and the fourth arm 23, respectively.

[0053] In an optional embodiment, in order to arrange the second terminal fingers 213 evenly, the third arm 22 is provided with a leveling wall 10 to at least raise its connecting end to be level with the fourth arm 23, so that the second terminal fingers 213 are arranged evenly.

[0054] To prevent the upper finger unit 21 from interfering with the transmission component 3 during extension / retraction movements, such as... Figure 1 , Figure 3 As shown, in an optional embodiment, the third link 211 and the fourth link 212 are bent, and their bending angle allows a pair of second end fingers 213 to maintain a relative distance when retracted to the reset limit.

[0055] To ensure efficient and accurate wafer transfer by robots, the industry generally requires robots to be able to control their end effectors to perform single-arm extension / retraction, double-arm extension / retraction, and multi-arm rotation. In the example above, when the fourth arm 23 and the third arm 22 rotate around the inner drive axis 33 or the middle drive axis 32, the pair of upper finger units 21 can extend, retract, or rotate around the axis depending on the opening angle of the fourth arm 23 and the third arm 22. Similarly, when the first arm 12 and the second arm 13 rotate around the outer drive axis 31 or the middle drive axis 32, the pair of lower finger units 11 can extend, retract, or rotate around the axis depending on the opening angle of the first arm 12 and the second arm 13.

[0056] Specifically, the following will describe how the first distal finger 113 on one side extends in a straight line. For example... Figure 4 , Figure 5 and Figure 7As shown, when the outer drive shaft 31 and the middle drive shaft 32 rotate relative to each other, the first distal finger 113 can reach... Figure 5 The position is shown. At this time, the lower first arm 12 and the second arm 13 together form a linkage motion. In an optional embodiment, the length of the first arm 12 and the equivalent length of the second arm 13 in the linkage motion can be set to a certain proportional relationship so that when the rotation angle of the outer drive shaft 31 and the middle drive shaft 32 moves in a specific proportional relationship, the extension direction of the first end finger 113 can be controlled. In this example, for example, the equivalent length relationship is set to be equal. At this time, the first arm 12 and the second arm 13 will move in a proportional relationship, and the first end finger 113 will extend in a straight line.

[0057] Meanwhile, since the central drive shaft 32 is fixedly connected to the second arm 13 and the upper third arm 22 through the central shaft connecting ring 36, the third arm 22 will rotate at the same angle as the lower second arm 13. At this time, in order to ensure that the pair of second end effectors on the upper layer do not extend, the fourth arm 23 will rotate at the same angle as the third arm 22 to maintain a relative stationary distance between them. At this time, the first end finger 113 on one side of the lower group extends in a straight line, and the first end finger 113 on the other side retracts in a straight line. Similarly, the first end fingers 113 in a group can alternately extend and retract, which will not be elaborated here. The second end fingers 213 in the upper group rotate around the axis and maintain a relative stationary distance from each other to complete the extension / retraction movement of the lower single arm.

[0058] Furthermore, the following describes how the upper second distal finger 213 extends in a straight line. For example... Figure 4 and Figure 8 As shown, when the inner drive shaft 33 and the middle drive shaft 32 rotate relative to each other, the second distal finger 213 can achieve the following: Figure 8 The position is shown. At this time, the upper fourth arm 23 and the third arm 22 together form a linkage motion. In an optional embodiment, the length of the fourth arm 23 and the equivalent length of the third arm 22 in the linkage motion can be set to a certain proportional relationship so that when the rotation angle of the inner drive shaft 33 and the middle drive shaft 32 moves in a specific proportional relationship, the extension direction of the second end finger 213 can be controlled. In this example, for example, the equivalent length relationship is set to be equal. At this time, the fourth arm 23 and the third arm 22 will move in a proportional relationship, and the first end finger 113 will extend along a straight line.

[0059] Meanwhile, since the middle driving shaft 32 is fixedly connected to the second arm rod 13 of the lower layer and the third arm rod 22 of the upper layer through the middle shaft connecting ring 36, the second arm rod 13 rotates at the same angle as the third arm rod 22. At this time, in order to ensure that the lower layer first end finger 113 does not stretch out, the first arm rod 12 of the lower layer rotates at the same angle as the second arm rod 13 to keep the relative static distance. At this time, one side of the upper layer second end finger 213 is stretched out in a straight line, and the other side of the second end finger 213 is retracted in a straight line. Similarly, the second end finger 213 of the group can be alternately stretched and retracted, and the first end finger 113 of the lower layer rotates around the shaft and keeps the relative static distance. To complete the upper layer single arm stretching / retracting movement.

[0060] On the other hand, it is worth mentioning that the device of the present scheme not only supports the straight line stretching / retracting movement of the finger unit, but also enables at least part of the finger unit to realize the unique arc stretching action, so as to flexibly adapt to the more complex wafer transfer scene of the target device station arrangement, and further expand the application range.

[0061] Specifically, the following introduces the completion mode of the arc stretching action of the upper layer second end finger 213. As shown in Figure 4 and Figure 9 When only the inner driving shaft 33 drives the upper layer fourth arm rod 23 to move, the connecting rod movement formed by the upper layer fourth arm rod 23 and the third arm rod 22 can drive the second end finger 213 to stretch out in an arc trajectory. The advantage of this stretching mode compared with the straight line stretching action is that only one outer driving shaft 31 rotates, and the demand for power and control is small. In the wafer transmission operation, the end point of the arc stretching can be used as the destination station to make the transmission more efficient. Especially in the vacuum processing process, the straight line space between the load lock and the wafer handling robot in the vacuum cavity is generally not smooth, and sometimes needs to avoid the intermediate structure through the inflection point. Therefore, the present scheme can avoid the structure through the special arc stretching movement, and improve the movement rhythm.

[0062] The arc movement trajectory is as shown in Figure 10As shown, the trajectory is a curve composed of radial straight lines whose endpoints are extended from the center of a circle and the rest of the points on the circle. The radius R of the base circle is related to the structure of the robot arm, and in this example, since the lengths of the first arm 12 and the second arm 13, and the third arm 22 and the fourth arm 23 are equal, R is the length of any of the fourth arm 23 / third arm 22. The equation of the radial straight line endpoint trajectory is related to the initial position angle θ of the robot arm, the lengths L1 and L2 of the arm links (i.e., the first link 111 of the lower finger unit 11 is L1, and the second link 112 is L2; the third link 211 of the upper finger unit 21 is L1, and the fourth link 212 is L2; when L1 is equal to L2, the trajectory is a circular arc), and θ determines the phase of the robot arm on the circular arc trajectory.

[0063] In addition, for the first end finger 113 of the lower layer, the movement principle of the upper and lower layers of the robot arm assembly is consistent, except that the shaft driving part is different, so this will not be described again, and reference can be made to the above example implementation.

[0064] The following describes the completion of the action of the upper second end finger 213 and the lower first end finger 113 extending at the same time, and the overall rotation of the lower arm assembly 1 and the upper arm assembly 2 at any time. Please refer to Figure 4 、 Figure 9 and Figure 11 As shown, on the basis of the action of the upper second end finger 213 extending in an arc, the inner drive shaft 33 and the middle drive shaft 32 further drive the upper fourth arm 23 and the third arm 22 to rotate clockwise at the same angle at the same time. Since the lower second arm 13 and the third arm 22 are fixedly connected, the lower second arm 13 will rotate clockwise at the same angle. If at this time, the inner drive shaft 33 drives the lower first arm 12 to move in the opposite direction of the other three arms, the lower first end finger 113 will extend along a straight line. Thus, the upper second end finger 213 and the lower first end finger 113 on one side extend at the same time.

[0065] If at this time, the inner drive shaft 33 drives the lower first arm 12 to move in the same direction as the other three arms, and the movement angle is consistent, then the four arms all rotate clockwise at the same angle at the same time, so that the robot arm assembly rotates as a whole. This action can be completed at any time to adjust the direction of the end finger.

[0066] In this way, each end finger can complete the single arm extension / contraction, double arm extension / contraction, and multi-arm overall rotation action, thereby realizing the control of two groups of four finger units with three drive shafts, and accurately completing the extension / contraction and rotation of single fingers and double fingers.

[0067] In another aspect, the present application also provides a control method for a three coaxial four-arm transmission device, which includes the following steps:

[0068] Controlling the extension and contraction of the upper finger unit 21: driving the inner drive shaft 33 and the middle drive shaft 32 to rotate in opposite directions, thereby driving the third arm 22 and the fourth arm 23 to open and close, while driving the outer drive shaft 31 and the middle drive shaft 32 to rotate in the same direction by the same angle, thereby maintaining the opening and closing angle of the first arm 12 and the second arm 13, so as to control the relative extension and contraction of the upper finger unit 21.

[0069] Controlling the extension and contraction of the lower finger unit 11: driving the outer drive shaft 31 and the middle drive shaft 32 to rotate in opposite directions, thereby driving the first arm 12 and the second arm 13 to open and close, while driving the inner drive shaft 33 and the middle drive shaft 32 to rotate in the same direction by the same angle, thereby maintaining the opening and closing angle of the fourth arm 23 and the third arm 22, so as to control the relative extension and contraction of the lower finger unit 11.

[0070] Further, the steps further include:

[0071] Controlling the extension and contraction of the upper finger unit 21 and the lower finger unit 11: setting the opening and closing angle of the third arm and the second arm to be 30-120°; driving the inner drive shaft 33 to rotate, thereby driving the fourth arm 23 and the third arm 22 to open and close, and controlling the relative extension and contraction of the upper finger unit 21; driving the inner drive shaft 33 and the middle drive shaft 32 to rotate in the same direction by the same angle, thereby maintaining the opening and closing angle of the fourth arm 23 and the third arm 22; while driving the outer drive shaft 31 and the inner drive shaft 33 and the middle drive shaft 32 to rotate in opposite directions, thereby driving the first arm 12 and the second arm 13 to open and close, and controlling the relative extension and contraction of the lower finger unit 11.

[0072] Further, the steps further include:

[0073] Controlling the rotation of the four arms as a whole: driving the inner drive shaft 33 to drive the first arm 12 and the second arm 13, the third arm 22, and the fourth arm 23 to rotate in the same direction, and the movement angle is consistent, so as to control the lower finger unit 11 and the upper finger unit 21 to rotate as a whole, thereby adjusting the direction of each end finger.

[0074] Further, the steps further include:

[0075] Controlling the arc extension movement of the second end finger 213: driving the inner drive shaft 33 to rotate, only rotating the fourth arm rod 23, making the fourth arm rod 23 and the third arm rod 22 open and close at a preset angle, so as to drive the second end finger 213 to extend in an arc trajectory. Similarly, the middle drive shaft 32 can also be driven to rotate, rotating the third arm rod 22, making the fourth arm rod 23 and the third arm rod 22 open and close at a preset angle, so as to drive the second end finger 213 to extend in an arc trajectory. At this time, if you want to keep the first end finger 113 from stretching, you can rotate the outer drive shaft 31 at the same time to ensure that the first arm rod 12 and the second arm rod 13 keep a relative static distance.

[0076] Controlling the arc extension movement of the first end finger 113: driving the outer drive shaft 31 to rotate, rotating the first arm rod 12, making the first arm rod 12 and the second arm rod 13 open and close at a preset angle, so as to drive the first end finger 113 to extend in an arc trajectory. Similarly, the middle drive shaft 32 can also be driven to rotate, rotating the second arm rod 13, making the first arm rod 12 and the second arm rod 13 open and close at a preset angle, so as to drive the first end finger 113 to extend in an arc trajectory. At this time, if you want to keep the second end finger 213 from stretching, you can rotate the inner drive shaft 33 at the same time to ensure that the fourth arm rod 23 and the third arm rod 22 keep a relative static distance.

[0077] On the other hand, corresponding to the above examples, the application also provides a wafer handling robot, which comprises a direct drive motor and a mechanical arm, wherein the mechanical arm is the three coaxial four-arm transmission device of any one of the above examples, and the direct drive motor is drivingly connected with the outer drive shaft 31, the middle drive shaft 32 and the inner drive shaft 33 respectively to drive them to rotate according to the steps of the above method examples, so as to control the lower arm assembly 1 and the upper arm assembly 2, and realize the control of the three coaxial driving four arms to complete the single finger, double finger extension / rotation and arc extension movement.

[0078] In summary, through the three coaxial four-arm transmission device, the control method thereof and the wafer handling robot provided by the application, the lower arm assembly 1 and the upper arm assembly 2 are ingeniously designed to adapt to the transmission assembly 3 arranged in three coaxial arrangement, so as to construct a multi-layer double set reciprocating hinge mechanism. This innovative structure realizes the control of two groups of four finger units by three drive shafts, and accurately completes the extension and rotation of single finger and double finger. In this way, the high efficiency demand of wafer transmission operation can be met, the number of drivers used can be effectively reduced, the production cost can be reduced, and the equipment occupied space can be significantly saved.

[0079] The preferred embodiments of the application disclosed above are only to facilitate the elucidation of the application. The preferred embodiments do not describe all of the details of the application, nor limit the application to the specific embodiments described. Obviously, many modifications and variations can be made in light of the above teachings. The above description is selected and described for the best illustrating the principles of the application and the best practice for its application to provide the best understanding of the application for the skilled in the art, so that they can best utilize the application. The application is limited only by the claims and their full scope and equivalents, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the application shall be included in the protection scope of the application.

[0080] Those skilled in the art can understand that, in addition to implementing the system, device, unit and each module thereof provided by the application in the form of pure computer readable program code, the same program can also be realized by logically programming the method steps to the form of logic gate, switch, application specific integrated circuit, programmable logic controller and embedded microcontroller, etc. Therefore, the system, device and each module thereof provided by the application can be considered as a hardware component, and the modules included therein for realizing various programs can also be considered as structures in the hardware component; the modules for realizing various functions can also be considered as both software programs for realizing methods and structures in the hardware component.

[0081] In addition, all or part of the steps of the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a program stored in a storage medium, including a plurality of instructions for causing a single-chip microcomputer, chip or processor to execute all or part of the steps of the method described in each embodiment of the application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), magnetic disk or optical disk and various program code storage media.

[0082] In addition, various different embodiments of the embodiments of the application can also be combined arbitrarily, as long as they do not deviate from the idea of the embodiments of the application, and they should also be considered as disclosed by the embodiments of the application.

Claims

1. A tri-coaxial four-arm transmission device comprising: The lower arm assembly, the upper arm assembly, the transmission assembly, wherein the lower arm assembly comprises a lower finger unit, a first arm rod, a second arm rod, the upper arm assembly comprises an upper finger unit, a third arm rod, a fourth arm rod, the transmission assembly comprises an outer drive shaft, a middle drive shaft, an inner drive shaft arranged coaxially in sequence; the first arm rod is in transmission connection with the outer drive shaft through an outer shaft connecting ring, the second arm rod is in transmission connection with the middle drive shaft, at the same time, the outer shaft deep groove ball bearing is arranged between the first arm rod and the second arm rod, the middle shaft connecting ring is connected with the second arm rod and is sleeved on the outer side of the inner drive shaft and arranged coaxially with the inner drive shaft, the third arm rod is connected with the middle shaft connecting ring and is driven by the middle drive shaft, and the third arm rod is overlapped with the second arm rod and fixed at a preset opening and closing angle, the fourth arm rod is in transmission connection with the inner drive shaft through an outer shaft tension sleeve, at the same time, the middle shaft deep groove ball bearing is arranged between the fourth arm rod and the third arm rod; the pair of lower finger units are arranged oppositely and are respectively and simultaneously hinged with the fourth arm rod and the third arm rod, the pair of upper finger units are arranged oppositely and are respectively and simultaneously hinged with the first arm rod and the second arm rod, so as to form a multi-layer double-group reciprocating telescopic hinge mechanism; wherein the lower finger unit comprises a first connecting rod, a second connecting rod and a first end finger, wherein the first end finger extends a pair of interval connecting ends at the tail part to define an avoiding concave between the connecting ends, one end of the first connecting rod and the second connecting rod is hinged with the connecting end of the first end finger, and the other end is respectively hinged with the connecting end of the first arm rod and the second arm rod; wherein the upper finger unit comprises a third connecting rod, a fourth connecting rod and a second end finger, wherein one end of the third connecting rod and the fourth connecting rod is hinged with the second end finger, and the other end is respectively hinged with the connecting end of the third arm rod and the fourth arm rod.

2. The three coaxial four-arm transmission device according to claim 1, wherein the first arm rod is provided with a leveling wall to at least pad the connecting end thereof to be flush with the second arm rod, so that the first end fingers are arranged flush.

3. The three coaxial four-arm transmission device according to claim 1, wherein the first connecting rod and the second connecting rod are bent, and the bending angle thereof allows the pair of first end fingers to be kept spaced from the outer drive shaft and the middle drive shaft when retracted to the reset limit.

4. The three coaxial four-arm transmission device according to claim 1, wherein the third arm rod is provided with a leveling wall to at least pad the connecting end thereof to be flush with the fourth arm rod, so that the second end fingers are arranged flush.

5. The three coaxial four-arm transmission device according to claim 1, wherein the third connecting rod and the fourth connecting rod are bent, and the bending angle thereof allows the pair of second end fingers to be kept spaced from each other when retracted to the reset limit.

6. The three coaxial four-arm transmission device according to any one of claims 1 to 5, wherein the third arm rod and the second arm rod are overlapped and connected to keep an opening and closing angle of 30-120°.

7. A wafer handling robot comprising: Direct drive motor, mechanical arm, wherein the mechanical arm is the three coaxial four-arm transmission device according to any one of claims 1 to 6, and the direct drive motor is in driving connection with the outer drive shaft, the middle drive shaft and the inner drive shaft respectively.

8. A control method for the three coaxial four-arm transmission device as claimed in any one of claims 1 to 6, wherein the single-finger stretching and retracting motion control step comprises any one of the following steps: driving the inner drive shaft and the middle drive shaft to rotate in opposite directions to drive the third arm and the fourth arm to open and close, while driving the outer drive shaft and the middle drive shaft to rotate in the same direction by the same angle to maintain the opening and closing angle of the first arm and the second arm, thereby controlling the relative stretching and retracting motion between the upper finger units; or driving the outer drive shaft and the middle drive shaft to rotate in opposite directions to drive the first arm and the second arm to open and close, while driving the inner drive shaft and the middle drive shaft to rotate in the same direction by the same angle to maintain the opening and closing angle of the fourth arm and the third arm, thereby controlling the relative stretching and retracting motion between the lower finger units.

9. A control method for the three coaxial four-arm transmission device as claimed in any one of claims 1 to 6, wherein the double-finger stretching and retracting motion control step comprises: driving the inner drive shaft to rotate to drive the fourth arm and the third arm to open and close, thereby maintaining the relative stretching and retracting motion between the upper finger units; driving the inner drive shaft and the middle drive shaft to rotate in the same direction by the same angle to maintain the opening and closing angle of the fourth arm and the third arm; driving the outer drive shaft and the inner drive shaft and the middle drive shaft to rotate in opposite directions to drive the first arm and the second arm to open and close, thereby controlling the relative stretching and retracting motion between the lower finger units.

10. A control method for the three coaxial four-arm transmission device as claimed in any one of claims 1 to 6, wherein the single-finger arc stretching motion control step comprises any one of the following steps: driving the inner drive shaft to rotate to drive only the fourth arm to rotate, thereby causing the fourth arm and the third arm to open and close by a preset angle to drive the second end finger to stretch out in an arc trajectory; or driving the middle drive shaft to rotate to drive the third arm to rotate, thereby causing the fourth arm and the third arm to open and close by a preset angle to drive the second end finger to stretch out in an arc trajectory; simultaneously driving the outer drive shaft to rotate to keep the first arm and the second arm at a relative static distance; or driving the outer drive shaft to rotate to drive the first arm to rotate, thereby causing the first arm and the second arm to open and close by a preset angle to drive the first end finger to stretch out in an arc trajectory; or driving the middle drive shaft to rotate to drive the second arm to rotate, thereby causing the first arm and the second arm to open and close by a preset angle to drive the first end finger to stretch out in an arc trajectory; simultaneously driving the inner drive shaft to rotate to keep the fourth arm and the third arm at a relative static distance.

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