WO2020143149A1

WO2020143149A1 - Industrial robot comprising operation shaft structure

Info

Publication number: WO2020143149A1
Application number: PCT/CN2019/086717
Authority: WO
Inventors: 何杰; 吕健; 耿羚彪; 王杰高
Original assignee: 南京埃斯顿机器人工程有限公司
Priority date: 2019-01-11
Filing date: 2019-05-13
Publication date: 2020-07-16
Also published as: CN109551467A

Abstract

An industrial robot comprising an operation shaft structure, comprising a base (1), a first arm part (2), a second arm part (3) and an operation shaft (41); the first arm part is driven by a first motor (M1) to rotate, and the second arm part is driven by a second motor (M2) to rotate, a helical thread and a splined groove are provided on the operation shaft, a nut sleeve (44) and a harmonic speed reducer (47) are provided on the second arm part, the nut sleeve is rotatable relative to the second arm part, an outer ring (47a) of the harmonic speed reducer is mounted on the second arm part, a sliding sleeve (43) is provided on an output end (47b) of the harmonic speed reducer, an internal spline corresponding to the splined groove is provided in the sliding sleeve in a vertical direction; the operation shaft passes through the nut sleeve, the harmonic speed reducer and the sliding sleeve in sequence from top to bottom, the operation shaft is in a threaded connection with the nut sleeve and fits the sliding sleeve, the nut sleeve is connected to a third motor (M3) provided on the second arm part, and the harmonic speed reducer is connected to a fourth motor (M4) provided on the second arm part.

Description

Industrial robot with motion axis structure

Technical field

The invention relates to an industrial robot including an action axis structure, and belongs to the technical field of industrial robots.

Background technique

Multi-axis manipulators are used to quickly operate parts along trajectories close to the plane. For example, it is the case of picking up a part on a running transmission belt and preventing the part from being placed in the holder.

SCARA (Select Compliance Assembly Robot Arm) type manipulator is a multi-axis manipulator suitable for working on a horizontal plane. Conventionally, the SCARA robot includes a base, and the base can be placed on a table, for example, the SCARA robot also includes a first arm, the first arm can move at least in a rotational manner relative to the base, and the front end of the first arm is also provided with a relative The second arm portion where the first arm rotates, and finally the robot is also equipped with an action axis that can receive a tool, such as a gripping pliers or a gripping tool.

The actuating shaft can rotate or move up and down relative to the second arm. The outer surface of the actuating shaft includes a spiral groove and a longitudinal groove. The sliding sleeve and the nut sleeve are mounted on the groove shaft by means of balls contained in the groove of the shaft Upper, the inner surface of the nut sleeve is provided with a spiral groove, and the sliding sleeve is provided with a longitudinal groove. These sleeves rotate individually and enable the slotted shaft, and therefore also the received tool, to move axially, rotate, or perform combined rotation and up and down movements.

The weight of the tool that can be lifted by the action shaft is basically the same from different manufacturers. However, due to the different shape and center of gravity of the tool of the same weight, the inertia will be different. Because the sliding sleeve currently has a motor that is decelerated by the planetary reducer or deceleration mechanism, it is synchronized. With timing pulley on the control sliding sleeve. Since the speed ratio of planetary reducers or other speed reduction mechanisms is currently limited, the current speed ratio will not be very large. And if the output capacity of the motor will be limited by the timing belt capacity, the SCARA robots of different manufacturers currently have a low inertia for the action axis to load the tool.

The rotating shaft of the YAMAHA robot in the industry is driven by a reducer, which can load a large inertia, but uses a hollow motor, the robot body has a large inertia, and the hollow motor has a high cost.

Summary of the invention

An object of the present invention is to provide an industrial robot including an action shaft structure, which solves the technical defect of the tool inertia that can be loaded on the action axis of the industrial robot in the prior art.

In order to solve the above problems, the technical solution adopted by the present invention is: an industrial robot including a motion axis structure, including a base, a first arm, a second arm, and a motion axis. The end of the motion axis is provided with An end effector that operates components and parts, one end of the first arm portion is driven to rotate around a vertical J1 axis by a first motor provided on the base, and one end of the second arm portion is installed at The end of the first arm away from the base is driven by a second motor mounted on the second arm to rotate around a vertical J2 axis. The action shaft is provided with helical threads and splined grooves. The second arm is provided with a nut sleeve and a harmonic reducer, the nut sleeve can rotate relative to the second arm, and the outer ring of the harmonic reducer of the harmonic reducer is installed on the second On the arm part, a sliding sleeve is provided on the output end of the harmonic reducer of the harmonic reducer, and an internal spline corresponding to the spline groove is provided in the vertical direction of the sliding sleeve , The action shaft passes through the nut sleeve, the harmonic reducer and the sliding sleeve in order from top to bottom, the action shaft is threadedly connected to the nut sleeve and cooperates with the slide sleeve, and the nut sleeve The barrel is connected to a third motor provided on the second arm, and the harmonic reducer is connected to a fourth motor provided on the second arm. The present invention uses a harmonic reducer, which has a high transmission speed ratio, and has a large inertia for tools that can be loaded on the action shaft, especially when the output capacity of the motor is limited, which can effectively improve the carrying capacity of the present invention. In the prior art, the hollow motor can be driven by a common motor, which can effectively reduce the overall cost.

As a further improvement of the present invention, an outer sleeve is sleeved on the nut sleeve, the outer sleeve is detachably mounted on the second arm portion, and the nut sleeve can rotate in the outer sleeve , A nut pulley is installed on the nut sleeve, and a first pulley is provided on the output shaft of the third motor, and the first pulley and the nut pulley are connected by a first synchronous belt. The input end of the harmonic reducer is provided with a harmonic reducer pulley, the output shaft of the fourth motor is provided with a second pulley, and the second pulley and the harmonic reducer pulley Connected by the second timing belt. The invention adopts belt transmission, with simple structure and stable transmission.

As a further improvement of the present invention, the width of one end of the second arm near the first arm is greater than the width of the other end, and the third motor and the fourth motor are installed at the end near the first arm and both Along the width of the second arm, the height of the first pulley is the height of the second pulley. The second motor and the fourth motor in the present invention are arranged along the width direction of the second arm and close to the second motor, and the three motors are arranged in a triangle, making the internal structure of the second arm compact, and further reducing the robot body Moment of inertia.

As a further improvement of the present invention, it further includes a second arm cover, the second arm cover is covered on the second arm portion, and the height of the end of the second arm cover near the first arm portion is greater than the distance The height of one end of the first arm portion, the action axis penetrates the second arm cover upward. The invention is provided with a second arm cover to cover the components in the second arm to ensure the protection grade and overall shape of the robot.

As a further improvement of the present invention, one side of the base is provided with a mid-through cable bracket, the top of the cable bracket and the top of the second arm cover are connected by a flexible tube, and the second The cables of the motor, the third motor, and the fourth motor pass through the cable support and the flexible tube from the base to enter the second arm housing, and are connected to the second motor, the third motor, and the fourth motor, respectively. The invention can effectively prevent the winding of the cable.

In summary, the beneficial effects of the present invention are: the load inertia of the present invention is large, the action speed and acceleration are fast, the cost is lower, and the robot body inertia is smaller.

BRIEF DESCRIPTION

FIG. 1 is a schematic structural view of the present invention.

Fig. 2 is a cross-sectional view taken along line A-A of Fig. 1.

Fig. 3 is a schematic diagram of the inside of the second arm portion reflecting the present invention.

Fig. 4 is a diagram showing the use state of the action shaft in the present invention.

detailed description

The specific implementation of the present invention will be further described below with reference to the drawings.

As shown in FIGS. 1-3, the industrial robot including an action axis structure includes a base 1, a first arm 2, a second arm 3, and an action axis 41. The end of the action axis 41 is provided with For the end effector that operates the parts, the action shaft 41 in the present invention can rotate around the J3 axis. The J3 axis in the present invention is the vertical line where the center line of the action axis is located, and the action axis 41 can also move along the action The centerline of the shaft 41 moves up and down. The base 1 is used to place the present invention as a whole on a table, etc., to provide support for the present invention when using the present invention. One end is driven by the first motor M1 to rotate around the vertical J1 axis. In the present invention, one end of the first arm 2 is rotatably connected to the upper surface of the base 1. The specific rotation connection method is prior art, not the invention The improvement point is that the first motor M1 in the present invention is installed in the base 1 and the output axis of the first motor M1 is arranged to be connected to the first arm 2. The first motor M1 works and the first motor M1 The rotating output shaft drives the first arm portion 2 to rotate around the J1 axis on the base 1, and the output shaft of the first motor M1 in the present invention is on the same vertical line as the J1 axis.

The end of the second arm 3 is mounted on the end of the first arm 2 away from the base 1 and driven by a second motor M2 mounted on the second arm 3 to rotate around a vertical J2 axis. The second arm part in the figure includes a lower base plate, an upper base plate and a connecting plate connecting the lower base plate and the upper base plate, the lower base plate is rotatably disposed on the upper surface of the first arm section 2, and the second motor M2 uses bolts Disassembled and installed on the bottom plate, the output shaft of the second motor M2 is vertically downward and connected with the first arm portion 2, the second motor M2 works, and the output shaft that rotates drives the second arm portion 3Turn on the first arm 1.

A spiral thread (not shown in the figure) and a splined groove (not shown in the figure) are provided on the actuating shaft 41, and the splined groove is opened along the length of the actuating shaft, and The thread intersects with the thread, that is, the part of the action shaft between adjacent spline grooves is provided with a thread. In the present invention, a plurality of grooves are provided along the circumferential direction of the screw rod to listen to the grooves along the length of the screw rod to make the action shaft 41. The second arm 3 is provided with a nut sleeve 44 and a harmonic reducer 47. The harmonic reducer 47 has a harmonic reducer output 47b and the harmonic reducer output 47b Rotatably fixed in the outer ring 47a of the harmonic reducer, the harmonic reducer 47 also has a harmonic reducer input end 47c, and the harmonic reducer input end 47c is rotatably fixed in the harmonic reducer outer ring 47a And harmonic reducer output 47b. The inner ring teeth of the output end 47b of the harmonic reducer mesh with the teeth of the outer ring of the flexible wheel extending from the outer ring 47a of the harmonic reducer. The rollable part of the input end 47c of the harmonic reducer is elliptical, and the outer ring of the harmonic reducer The inner ring of the 47a flexible wheel is in contact, and when the input end 47c of the harmonic reducer rotates, it will generate harmonic motion to the outer ring 47a of the harmonic reducer, thereby driving the output end 47b of the harmonic reducer to rotate at a certain reduction ratio.

The nut sleeve 44 can rotate relative to the second arm 3, the harmonic reducer outer ring 47a is installed on the second arm 3, and the harmonic reducer output end 47b is provided with a sliding sleeve Barrel 43, the sliding sleeve 43 is provided with an internal spline corresponding to the spline groove in the vertical direction, and the action shaft 41 passes through the nut sleeve 44 and the harmonics in order from top to bottom The reducer 47 and the sliding sleeve 43, the actuating shaft 41 is screwed to the nut sleeve 44 and cooperates with the sliding sleeve 43, the nut sleeve 44 and the third provided on the second arm 3 The motor M3 is connected, the third motor M3 drives the nut sleeve 44 to rotate, the harmonic reducer input 47c is connected to the fourth motor M4 provided on the second arm 3, and the fourth motor M4 is driven to work The harmonic reducer 47 works. In the present invention, the transmission speed ratio of the harmonic speed reducer 47 is greater than or equal to 30. The harmonic speed reducer 47 can increase the torque of the fourth motor and output it to the action shaft 41. Moreover, the material of the harmonic reducer 47 is made of a light metal alloy (for example, aluminum or magnesium alloy), and the body inertia of the end of the second arm portion 3 is increased less, which can provide the robot movement speed and acceleration.

The nut sleeve 44 described in this application is sleeved with an outer sleeve 42. The outer sleeve 42 in the present invention includes a cylindrical first sleeve unit and a second sleeve unit, the first sleeve The outer diameter of the barrel unit is larger than the outer diameter of the second sleeve unit, the bottom end of the second sleeve unit is fixedly connected to the top end of the first sleeve unit, the first sleeve unit and the second sleeve The inner diameters of the units are equal and the center lines of the two coincide. The preferred first sleeve unit and the second sleeve unit of this application are integrally formed. The nut sleeve 44 can be mounted on the first sleeve unit and the In the two sleeve units, the first sleeve unit is uniformly provided with a plurality of first fixed through holes along the circumferential direction, and the upper and lower base plates are respectively provided with upper mounting through holes and lower mounting through holes Hole, a first threaded hole is evenly formed on the outer side of the upper mounting through hole in the circumferential direction, and the first sleeve unit passes through the first fixed through hole and a first bolt threaded with the first threaded hole Removably mounted on the upper bottom plate, the bottom end of the nut sleeve 44 passes downward through the upper mounting through hole, and a second threaded hole is evenly provided on the end of the lower end of the nut sleeve 44 in the circumferential direction, A nut pulley 46 is detachably installed at the bottom end of the nut sleeve 44 through a second nut threaded with the second threaded hole, and the actuating shaft 41 passes through the nut pulley 46 at both ends.

In the present invention, a third bolt is detachably installed at the end of the top end of the input end 47c of the harmonic reducer, and the pulley 48 of the harmonic reducer is detachably installed, and the action shaft 41 passes through the upper and lower ends of the pulley 48 of the harmonic reducer In the present invention, the sliding sleeve 43 includes a cylindrical first sliding unit and a second sliding unit, the outer diameter of the first sliding unit is larger than the outer diameter of the second sliding unit, the second The top end of the sliding unit is fixed to the bottom end of the first sliding unit and the center lines of the two coincide, the inner diameters of the first sliding unit and the second sliding unit are equal, and the internal splines are provided on the first sliding unit and On the inner surface of the second sliding unit, a plurality of second fixing holes are opened on the first sliding unit in the circumferential direction. The first sliding unit passes through the second fixing holes and is connected to the harmonic reducer 47 The nut of the threaded output end 47b is detachably installed on the harmonic reducer 47, and the preferred first sliding unit and second sliding unit of the present invention are integrally formed.

In the present invention, the third motor M3 and the fourth motor M4 are detachably mounted on the upper base plate with bolts, and the output axes of the third motor M3 and the fourth motor M4 pass downward through the upper base plate, and the third motor M3 A first pulley 35 is provided on the output shaft of the motor, the first pulley 35 and the nut pulley 46 are connected by a first timing belt 33, and a second pulley 36 is provided on the output shaft of the fourth motor M4. The second pulley 36 and the harmonic reducer pulley 48 are connected by a second timing belt 34. In the present invention, the width of one end of the second arm 3 near the first arm 2 is greater than the width of the other end. The third motor M3 and the fourth motor M4 are installed near one end of the first arm portion 2 and the two are arranged along the width direction of the second arm portion 3, because the nut pulley 46 described in the present invention is located at the harmonic Wave reducer above the pulley 48, so the height of the first pulley 35 described in the present invention is greater than the height of the second pulley 36 to ensure that the first pulley 35 and the nut pulley are at the same height, the second The pulley 36 and the harmonic reducer pulley 48 are located at the same height.

In order to protect the motor, the present invention is provided with a second arm cover 32 which covers the second arm portion 3 and the second arm cover 32 is close to the end of the first arm portion 2 Is greater than the height away from the end of the first arm portion 2, the action shaft 41 penetrates upwardly through the second arm cover 32, and the second arm cover 32 in the present invention includes an upper cover unit and a lower cover Shell unit, the bottom end of the upper shell unit is connected to the top of the lower shell unit, the length and width of the top of the lower shell unit are greater than the length and width of the bottom of the upper shell unit, respectively, in the upper shell The connection between the bottom of the unit and the top of the lower housing unit forms a horizontal connection. The height of the end of the upper housing unit near the first arm is greater than the height of the end used to install the action shaft. When the cover 32 is covered on the second arm portion 3, the connecting portion of the second arm cover 32 is supported by the edge of the upper bottom plate, and in order to fix the second arm cover 32, the present invention may have threads on the upper bottom plate Hole, a connection through hole is formed in the connecting part, and the second arm cover 32 can be fixed on the second arm part 3 by using a bolt that passes through the connection through hole and is screwed with the screw hole on the upper base plate, which is preferred in the present invention The length and width of the top end of the lower cover unit are greater than the length and width of the bottom end, respectively, so that the entire lower cover unit has a structure with a small upper end and a large lower end, so as to conveniently cover the second arm cover 32 on the second arm portion 3.

In the present invention, it is preferred that a cable support 6 is provided on one side of the base 1. The top of the cable support 6 and the top of the second arm housing 32 are connected by a flexible tube 7. The cables of the second motor M2, the third motor M3, and the fourth motor M4 pass from the base 1 through the cable holder 6 and the flexible tube 7 into the second arm housing 32 and the second motor M2, the third motor respectively M3 is connected to the fourth motor M4. The cable support 6 described in the present invention is inverted L-shaped. The vertical portion of the cable support 6 is detachably mounted on the base 1 using bolts and the like. The horizontal portion on the top of the cable support 6 is connected to the software. The tube 7 is rotationally connected. In the present invention, a hard sleeve can be provided at the end of the spool tube 7, and the sleeve is rotatably connected to the water station portion of the cable support 6 using a bearing. The flexible tube described in the present invention 7 is also rotatably connected to the top of the second arm housing 32 in the same way as the flexible tube 7 and the cable bracket 7 are connected.

In the present invention, when the third motor M3 is working and the fourth motor M4 is not working, the sliding sleeve 43 prevents the action shaft 41 from rotating, and the third motor M3 drives the nut sleeve 44 to rotate, because the nut sleeve 44 and the action shaft 41 are threaded Cooperate, so the nut sleeve 44 drives the action shaft 41 to move up and down; when the third motor M3 does not work, and the fourth motor M4 works, the fourth motor M4 drives the sliding sleeve 43 to rotate, because the sliding sleeve 43 and the action shaft 41 Key connection, so the sliding sleeve drives the action shaft 41 to rotate, and the nut sleeve 44 does not rotate at this time, so the action shaft 41 also moves up and down while rotating; when the third motor M3 and the fourth motor M4 work simultaneously, and When the third motor M3 drives the nut sleeve 44 to rotate so that the rotation speed of the nut sleeve 44 is the same as the rotation speed of the action shaft 41 driven by the fourth motor M4, the action shaft 41 does not move up and down relative to the nut sleeve 44. The shaft 41 only rotates without moving up and down.

As shown in FIG. 4, an end flange 51 is connected to the end of the action shaft 41, and the end flange 51 can be connected to the tool 50. Through the above design, the center of mass of the tool 50 is offset by a distance (that is, between the center of mass of the tool 50 and the center line of the J3 axis) The distance L1 may be greater, and the inertia of the end connection tool 50 may be greater in summary.

The parts not specifically described in the above description are all existing technologies, or can be realized by the existing technologies. Moreover, the specific embodiments described in the present invention are only preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. That is, all equivalent changes and modifications made according to the content of the patent application scope of the present invention should be regarded as the technical scope of the present invention.

Claims

An industrial robot with an action axis structure, characterized in that it includes a base (1), a first arm (2), a second arm (3) and an action axis (41), the action axis (41) ) Is provided with an end effector for operating the parts, and one end of the first arm (2) is driven vertically by a first motor (M1) provided on the base (1) The J1 axis rotates, one end of the second arm (3) is mounted on the first arm (2) away from the base (1) and the second arm mounted on the second arm (3) The motor (M2) is driven to rotate around the vertical J2 axis, the action shaft (41) is provided with helical threads and spline grooves, and the second arm (3) is provided with a nut sleeve ( 44) and the harmonic reducer (47), the nut sleeve (44) can rotate relative to the second arm (3), and the outer ring (47a) of the harmonic reducer (47) ) Installed on the second arm (3), a sliding sleeve (43) is provided on the output end (47b) of the harmonic reducer (47), and the sliding sleeve (43) ) There is an internal spline corresponding to the spline groove in the vertical direction, and the action shaft (41) passes through the nut sleeve (44) and the harmonic reducer (47) in order from top to bottom And the sliding sleeve (43), the actuating shaft (41) is screwed to the nut sleeve (44) and cooperates with the sliding sleeve (43), and the nut sleeve (44) is arranged at the second The third motor (M3) on the arm (3) is connected, and the harmonic reducer (47) is connected to the fourth motor (M4) provided on the second arm (3).
The industrial robot including an action shaft structure according to claim 1, wherein an outer sleeve (42) is sleeved on the nut sleeve (44), and the outer sleeve (42) can Removably installed on the second arm (3), the nut sleeve (44) can be rotated in the outer sleeve (42), and the nut sleeve (44) is provided with a nut pulley (46) The output shaft of the third motor (M3) is provided with a first pulley (35), and the first pulley (35) and the nut pulley (46) are connected by a first timing belt (33) , A harmonic reducer pulley (48) is provided on the input end of the harmonic reducer (47), and a second pulley (36) is provided on the output shaft of the fourth motor (M4), The second pulley (36) and the harmonic reducer pulley (48) are connected by a second timing belt (34).
The industrial robot with a motion axis structure according to claim 2, wherein the width of one end of the second arm (3) near the first arm (2) is greater than the width of the other end, the The third motor (M3) and the fourth motor (M4) are installed near one end of the first arm portion (2) and both are arranged along the width direction of the second arm portion (3), the first pulley ( The height of 35) is greater than the height of the second pulley (36).
The industrial robot with an action axis structure according to claim 3, further comprising a second arm cover (32), the second arm cover (32) is covered on the second arm portion (3) And the height of the end of the second arm cover (32) near the first arm (2) is greater than the height of the end away from the first arm (2), the action shaft (41) penetrates upward Second arm cover (32).
The industrial robot including a motion axis structure according to claim 4, wherein a side of the base (1) is provided with a mid-through cable support (6), and the cable support ( 6) The top of the second arm cover (32) is connected by a flexible tube (7), and the cables of the second motor (M2), third motor (M3) and fourth motor (M4) are connected from The base (1) passes through the cable support (6) and the flexible tube (7) into the second arm housing (32) and the second motor (M2), third motor (M3) and fourth motor (M4) ) Connected.