CN114670182A

CN114670182A - Closed loop rope of low return gap of high rigidity drives automatically controlled integrative device of flexible arm drive

Info

Publication number: CN114670182A
Application number: CN202210195502.9A
Authority: CN
Inventors: 徐文福; 黄一帆; 李文朔; 袁晗; 梁斌
Original assignee: Shenzhen Graduate School Harbin Institute of Technology
Current assignee: Shenzhen Graduate School Harbin Institute of Technology
Priority date: 2022-03-02
Filing date: 2022-03-02
Publication date: 2022-06-28

Abstract

The invention discloses a closed loop rope drive flexible arm drive electric control integrated device with high rigidity and low backlash, which comprises: a base; the sliding block is arranged on the base and can lift relative to the base, a movable pulley with a groove is rotatably connected to the sliding block, and the movable pulley with the groove is wound by a driving rope; the tensioning device is arranged on the base, the first end of the driving rope is connected with the tensioning device, and the second end of the driving rope is connected with the rolling joint; the lifting driving device is arranged on the base and used for driving the sliding block to lift relative to the base; by applying the device, the control precision of the driving rope can be improved, and the service life of the device is prolonged.

Description

Closed loop rope of low return gap of high rigidity drives automatically controlled integrative device of flexible arm drive

Technical Field

The invention relates to the field of robots, in particular to a closed-loop rope-driven flexible arm driving and electric control integrated device with high rigidity and low backlash.

Background

With the development of the robot technology, the robot structure applying high speed, high precision and high load-weight ratio is concerned by the industry and the aerospace field, and the flexible effect of the joints and the connecting rods is increased in the motion process, so that the structure is deformed, the precision of task execution is reduced, and the flexible mechanical arm is concerned and researched more and more; the rope-driven flexible mechanical arm has the advantages of simple structure, flexible movement and the like, and has good application in the fields of space exploration, disaster rescue, nuclear power equipment maintenance and the like.

In the existing rope-driven flexible mechanical arm, a rope tensioning adjusting device drives a cam by a servo motor, the cam is abutted against a rope, and the position of the rope is adjusted by rotating an eccentric wheel, so that the purpose of controlling the rope-driven flexible arm is achieved; the mode not only has the defect that the adjusting process is not linear enough and is not beneficial to improving the adjusting precision, but also has larger abrasion between the cam and the rope, thereby weakening the service life of the whole device to a certain extent.

Disclosure of Invention

The present invention is directed to solving at least one of the problems of the prior art. Therefore, the invention provides the closed-loop rope-driving flexible arm driving and electric control integrated device with high rigidity and low backlash, which can improve the control precision of a driving rope and prolong the service life of the device.

The invention discloses a closed loop rope drive flexible arm drive electric control integrated device with high rigidity and low backlash, which comprises: a base; the sliding block is arranged on the base and can lift relative to the base, a movable pulley with a groove is rotatably connected to the sliding block, and the movable pulley with the groove is wound by a driving rope; the tensioning device is arranged on the base, the first end of the driving rope is connected with the tensioning device, and the second end of the driving rope is connected with the rolling joint; and the lifting driving device is arranged on the base and is used for driving the sliding block to lift relative to the base.

According to some embodiments of the invention, two movable pulleys with grooves are distributed on the sliding block along the up-down direction, the two movable pulleys with grooves are respectively wound by one driving rope, the upper end and the lower end of the base are respectively provided with a tensioning device, the first ends of the two driving ropes are respectively connected with the tensioning devices at the upper end and the lower end, and the second ends of the two driving ropes are connected with the rolling joints.

According to some embodiments of the invention, the high-rigidity low-backlash closed-loop rope-driven flexible arm-driven electronically-controlled integrated device further comprises a conversion pulley block arranged on the base, and the driving rope of the tensioning device with the first end connected to the lower end is connected with the rolling joint through the conversion pulley block.

According to some embodiments of the invention, the lift drive comprises: the servo motor is arranged on the base; the ball screw is rotationally connected to the base, extends along the up-down direction and is in driving connection with the servo motor; and the screw nut is in threaded fit with the ball screw and is connected with the sliding block.

According to some embodiments of the invention, a coupling is connected between the servo motor and the ball screw.

According to some embodiments of the invention, the lifting drive device further comprises a driver, the driver is arranged on the base and electrically connected with the servo motor, and the driver is arranged outside the servo motor.

According to some embodiments of the invention, the base is provided with a slide rail extending in an up-down direction, and the slider is slidably engaged with the slide rail.

According to some embodiments of the invention, the base is provided at an upper end thereof with a fixed pulley assembly, and the driving rope is connected to the rolling joint through the fixed pulley assembly.

According to some embodiments of the invention, the tensioning device comprises: the hollow bolt is arranged on the base; the spring is arranged on one side, far away from the base, of the hollow bolt; the drive rope passes hollow bolt and spring, and the first end of drive rope is provided with the button head, button head butt spring.

According to some embodiments of the invention, the tensioner further comprises an internally threaded cap connected between the spring and the hollow bolt, the internally threaded cap being in threaded connection with the hollow bolt, the drive rope passing through the hollow bolt, the internally threaded cap and the spring in sequence.

The closed-loop rope-driven flexible arm with high rigidity and low backlash is used for driving the electric control integrated device, in the operation process, the lifting driving device drives the sliding block to lift on the base, and the movable pulley with the groove on the sliding block moves and lifts along with the sliding block, so that the second end of the driving rope pulls the rolling joint to drive the rolling joint to deform; when the sliding block changes the movement direction, the tensioning device can tension the loose rope, so that the direction change backlash of the closed loop driving rope is obviously reduced, and the movement precision of the flexible arm is improved; meanwhile, the movement distance of the second end of the driving rope is linearly related to the lifting distance of the sliding block, the control difficulty of the lifting driving device can be effectively simplified, the control precision of the driving rope is improved, meanwhile, the sliding friction between the driving rope and the movable pulley is small, the abrasion degree of the rope is low after long-term operation, and the service life of the device is effectively prolonged.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is an isometric view of a closed loop rope drive flexible arm drive electronically controlled integrated device with high stiffness and low backlash according to an embodiment of the invention;

FIG. 2 is an isometric view of a ball rolling joint mechanical arm connected and driven by the integrated electric control driving device in the embodiment of the invention;

FIG. 3 is an isometric view of the servo drive assembly of FIG. 1;

FIG. 4 is an isometric view of a portion of the servo drive assembly of FIG. 1;

fig. 5 is a schematic view of a closed loop rope drive according to an embodiment of the present invention;

fig. 6 is an isometric view of a portion of the closed loop cable drive arrangement of fig. 5;

FIG. 7 is a schematic view of the sheave assembly of FIG. 1;

FIG. 8 is a schematic view of the tensioner of FIG. 1;

the above figures contain the following reference numerals.

Reference numerals	Name (R)	Reference numerals	Name (R)	Reference numerals	Name (R)
						101	Rope guiding device	1211	Angular contact ball bearing	131	Fixed pulley seat
102	Rolling joint	122	Feed screw nut	1321	Grooved fixed pulley
						11	Servo drive assembly	123	Sliding block	14	Tensioning device
111	Servo motor	1231	Sliding block seat	141	Hollow bolt
						112	Driver	1232	Movable pulley with groove	142	Internal thread cap
113	Coupling device	124	Sliding guide rail	143	Locking head
						114	Support connecting piece	1242	Guide rail fitting part	144	Spring
12	Closed loop rope drive	125	Drive rope	15	Base seat
						121	Ball screw	13	Fixed pulleyAssembly

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

In the description of the present invention, it should be understood that the orientation or positional relationship referred to in the description of the orientation, such as the upper, lower, front, rear, left, right, etc., is based on the orientation or positional relationship shown in the drawings, and is only for convenience of description and simplification of description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, the meaning of a plurality of means is one or more, the meaning of a plurality of means is two or more, and more than, less than, more than, etc. are understood as excluding the present number, and more than, less than, etc. are understood as including the present number. If the first and second are described for the purpose of distinguishing technical features, they are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.

In the description of the present invention, unless otherwise specifically limited, terms such as set, installation, connection and the like should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention by combining the specific contents of the technical solutions.

Referring to fig. 1, 3 to 8, the closed loop rope driven flexible arm driven and electrically controlled integrated device with high rigidity and low backlash of the present embodiment includes: a base 15; a slider 123 provided on the base 15, the slider 123 being capable of moving up and down with respect to the base 15, a movable pulley 1232 with a groove being rotatably connected to the slider 123, the movable pulley 1232 with a groove being wound by one driving rope 125; the tensioning device 14 is arranged on the base 15, a first end of the driving rope 125 is connected with the tensioning device 14, and a second end of the driving rope 125 is connected with the rolling joint 102; and the lifting driving device is arranged on the base 15 and is used for driving the sliding block 123 to lift relative to the base 15.

The closed loop rope drive flexible arm with high rigidity and low backlash is used for driving the electric control integrated device, in the operation process, the lifting driving device drives the sliding block 123 to lift on the base 15, and the movable pulley 1232 with the groove on the sliding block 123 moves and lifts along with the sliding block 123, so that the second end of the driving rope 125 pulls the rolling joint 102 to drive the rolling joint 102 to deform; when the slider 123 changes the direction of motion, the tensioning device 14 can tension the slack cable, significantly reducing the direction-changing backlash of the closed loop drive cable 125, improving the precision of the flexible arm motion; meanwhile, the movement distance of the second end of the driving rope 125 is linearly related to the lifting distance of the sliding block 123, so that the control difficulty of the lifting driving device can be effectively simplified, the control precision of the driving rope 125 is improved, meanwhile, the sliding friction between the driving rope 125 and the movable pulley is small, the abrasion degree of the rope is low after long-term operation, and the service life of the device is effectively prolonged.

The lifting driving device can drive the sliding block 123 to lift in various ways, for example, the sliding block 123 is directly driven to lift by a linear motor, or the sliding block 123 is driven to lift by the rack and pinion mechanism driven by the servo motor 111.

Specifically, two movable pulleys 1232 with grooves are distributed on the sliding block 123 along the up-down direction, the two movable pulleys 1232 with grooves are respectively wound by one driving rope 125, the upper end and the lower end of the base 15 are respectively provided with the tensioning devices 14, the first ends of the two driving ropes 125 are respectively connected with the tensioning devices 14 at the upper end and the lower end, and the second ends of the two driving ropes 125 are connected with the rolling joints 102.

As shown in fig. 2, which is an axonometric view of a mechanical arm of a ball rolling joint 102, the high-rigidity low-backlash closed-loop rope-driven flexible arm driving electric control integrated device of the present embodiment is used as a driving box, a rope guide device 101 is a two-degree-of-freedom rolling joint 102, a set of two closed-loop driving ropes 125 are provided, when a slider 123 ascends or descends, the two driving ropes 125 have equal motion magnitude and opposite directions, and the motion of the ball rolling joint 102 in the corresponding degree of freedom can be controlled; reference may be made to the applicant's prior application for other configurations of ball rolling joint 102 and robotic arms.

As shown in fig. 1 and 5, the high-rigidity low-backlash closed-loop rope-driven flexible arm-driven and electrically-controlled integrated device of the present embodiment further includes a switching pulley block disposed on the base 15, and the driving rope 125 of the tensioning device 14 with a first end connected to the lower end is connected to the rolling joint 102 through the switching pulley block; the first of the two driving ropes 125 passes through the grooved movable pulley 1232 and then is connected with the ball rolling joint 102, and the second of the two driving ropes 125 passes through the movable pulley and the conversion pulley group and then is connected with the ball rolling joint 102, so that the two driving ropes 125 connected with the same sliding block 123 can be respectively connected with two ends of the upper end surface of the ball rolling joint 102.

As shown in fig. 3 and 4, the elevation driving device includes: a servo motor 111 provided on the base 15; the ball screw 121 is rotationally connected to the base 15, the ball screw 121 extends in the vertical direction, and the ball screw 121 is in driving connection with the servo motor 111; the lead screw nut 122 is in threaded fit with the ball screw 121, and the lead screw nut 122 is connected with the sliding block 123; wherein, the servo motor 111 drives the ball screw 121 to rotate, so that the ball screw 121 drives the slider 123 to lift; specifically, two ends of the ball screw 121 are connected to the base 15 through the angular contact ball bearings 1211, and the screw nut 122 is connected with the slider 123 through the slider seat 1231 to drive the slider 123 to lift and lower together; the nominal diameter of the ball screw 121 is preferably 16mm, the precision grade is preferably 7 grade, and the stable operation of the flexible mechanical arm is ensured; the lead screw nut 122 is connected with the slider 123, so that the overturning moment caused by the driving rope 125 can be dispersed by using the ball screw 121, the corresponding bending deformation is reduced, and the control precision of the flexible mechanical arm is improved.

As shown in fig. 6, the base 15 is provided with a slide rail 124 extending in the up-down direction, and the slider 123 is slidably engaged with the slide rail 124; specifically, the slide rail 124 is provided with a rail engaging portion 1242 capable of sliding up and down, and the slider 123 is connected to the rail engaging portion 1242.

As shown in fig. 5 and fig. 6, the slider 123, as a key device in the driving box of this embodiment, can drive two driving ropes 125 in the same degree of freedom to move simultaneously, wherein the slider 123 is connected to a slider seat 1231, and the slider seat 1231 is connected to the lead screw nut 122 and the guide rail matching portion 1242 simultaneously; the through holes on the slider seat 1231 are connected with the outer cylindrical surface of the lead screw nut 122 through preferable transition fit, and meanwhile, the straight plates on the slider seat 1231 are connected with the guide rail matching part 1242 through four threaded holes.

The slider 123 is provided with two movable pulleys 1232 with grooves for realizing reverse winding of two ropes, the groove width and the effective radius of the movable pulleys 1232 with grooves should preferably be of appropriate size in consideration of the radius of the driving rope 125, the curvature radius of rope routing is reduced to the greatest extent in a limited space, stress concentration and elastic-plastic deformation of the rope caused by too small curvature are avoided, and the servo stiffness of the driving box is improved.

As shown in fig. 3 and 4, a coupling 113 is connected between the servo motor 111 and the ball screw 121; the lifting driving device further comprises a driver 112, the driver 112 is arranged on the base 15, the driver 112 is electrically connected with the servo motor 111, and the driver 112 is arranged outside the servo motor 111; the lifting driving device is composed of a servo motor 111, a driver 112, a coupler 113, a motor fixing disc and a supporting connecting piece 114; the rope driving power can be provided and the requirement of servo motion precision can be met as the power source of the whole driving box; the servo motor 111 is a direct current brush motor with an encoder and sufficient power, the motor output shaft is coaxial with the ball screw 121, the driver 112 is arranged on the outer side of the corresponding servo motor 111, connection and debugging are facilitated, the coupler 113 is an oldham's 123 type metal coupler 113 with good lubrication, rigid connection from the motor output shaft to the ball screw 121 can be guaranteed, meanwhile, assembly stress caused by coaxiality errors of the motor output shaft and the screw shaft is avoided, and servo precision is improved.

As shown in fig. 3, in order to meet the requirements of different degrees of freedom of the same rolling joint 102 and the driving requirements of a plurality of rolling joints 102, a plurality of sliding blocks 123 and tensioning devices 14 are circumferentially distributed on the base 15, each sliding block 123 corresponds to an independent lifting driving device, wherein the drivers 112 and the servo motors 111 are circumferentially distributed on the motor fixing disc.

As shown in fig. 7, a plurality of fixed pulley assemblies 13 are disposed on the top end of the base 15, each fixed pulley assembly 13 includes a fixed pulley seat 131 and a grooved fixed pulley 1321 rotatably disposed on the fixed pulley seat 131, and the plurality of fixed pulley assemblies 13 are circumferentially distributed on the top end of the base 15 for changing the direction of the driving rope 125 and forming a desired routing track of the driving rope 125; as shown in fig. 2, in the present embodiment, each rolling joint 102 requires two sets of 4 driving ropes 125, so that each ball rolling joint 102 is independently controlled by two sliders 123 with one degree of freedom.

As shown in fig. 8, the tensioner 14 includes: a hollow bolt 141 provided on the base 15; a spring 144 provided on a side of the hollow bolt 141 remote from the base 15; the driving rope 125 penetrates through the hollow bolt 141 and the spring 144, and a round head is arranged at the first end of the driving rope 125 and abuts against the spring 144; in order to adjust the tension, the tensioning device 14 further includes an internal threaded cap 142, the internal threaded cap 142 is connected between the spring 144 and the hollow bolt 141, the internal threaded cap 142 is in threaded connection with the hollow bolt 141, and the driving rope 125 sequentially passes through the hollow bolt 141, the internal threaded cap 142 and the spring 144.

Specifically, the tensioning device 14 includes a hollow bolt 141, an internal threaded cap 142, a locking head 143, and a spring 144, the hollow bolt 141 is connected to a corresponding threaded hole on the base 15 through a thread, the hollow bolt 141 forms a thread fit with an internal thread of the internal threaded cap 142 through an external thread provided thereon, the locking head 143 is fixed to the rope and is located inside the internal threaded cap 142, two ends of the spring 144 are respectively abutted to the internal threaded cap 142 and the round head, the driving rope 125 passes through the hollow bolt 141, the internal threaded cap 142, the locking head 143, and the spring 144 and is connected to a source provided at a rope end, and an initial tension of the driving rope 125 can be adjusted by rotating a position of the hollow bolt 141 relative to the base 15.

When the driving ropes 125 are in a tensioned state, the locking heads 143 can abut against the ends of the hollow bolts 141 to limit the positions of the ropes, so that the elasticity of the springs 144 does not affect the driving rigidity and response speed of the ropes, and when one group of driving ropes 125 change direction, the originally tensioned driving ropes 125 become a relaxed state, and because of the mechanical clearances of the parts of the driving box and the elastic deformation of the ropes, the relaxed driving ropes 125 have backlash to affect the control accuracy; in the embodiment, when the rope loosens due to turning, the locking head 143 is separated from the abutment with the hollow bolt 141, the spring 144 tensions and drives the round head to move, so that the whole rope tensions, and in the process, the elastic force of the spring 144 can be adjusted by adjusting the position of the internal thread cap 142 relative to the hollow bolt 141, and the backlash of the driving rope 125 during turning is obviously reduced.

The embodiments of the present invention have been described in detail with reference to the drawings, but the present invention is not limited to the embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the gist of the present invention.

Claims

1. The utility model provides a closed loop rope of low backlash of high rigidity drives automatically controlled integrative device of flexible arm drive which characterized in that includes:

a base (15);

a slider (123) disposed on the base (15), wherein the slider (123) can be lifted relative to the base (15), a movable pulley (1232) with a groove is rotatably connected to the slider (123), and the movable pulley (1232) with a groove is wound by a driving rope (125);

the tensioning device (14) is arranged on the base (15), a first end of the driving rope (125) is connected with the tensioning device (14), and a second end of the driving rope (125) is connected with the rolling joint (102);

the lifting driving device is arranged on the base (15) and is used for driving the sliding block (123) to lift relative to the base (15).

2. The high-rigidity low-backlash closed-loop rope-driving flexible arm driving and electric-control integrated device according to claim 1, wherein two movable pulleys (1232) with grooves are distributed on the sliding block (123) in the up-down direction, the two movable pulleys (1232) with grooves are respectively wound by one driving rope (125), the tensioning devices (14) are respectively arranged at the upper end and the lower end of the base (15), the first ends of the two driving ropes (125) are respectively connected with the tensioning devices (14) at the upper end and the lower end, and the second ends of the two driving ropes (125) are connected with the rolling joints (102).

3. The high stiffness low backlash closed loop rope drive flexible arm drive electronically controlled integrated device according to claim 2, further comprising a switching pulley block provided on the base (15), through which the drive rope (125) of the tensioning device (14) with a first end connected to a lower end is connected to the rolling joint (102).

4. The high stiffness low backlash closed loop rope drive flexible arm drive electronically controlled integrated device of claim 1, wherein the lift drive comprises:

a servo motor (111) provided on the base (15);

the ball screw (121) is rotatably connected to the base (15), the ball screw (121) extends in the vertical direction, and the ball screw (121) is in driving connection with the servo motor (111);

and the lead screw nut (122) is in threaded fit with the ball screw (121), and the lead screw nut (122) is connected with the sliding block (123).

5. The high-rigidity low-backlash closed-loop rope-driven flexible arm driving electric control integrated device according to claim 4, wherein a coupling (113) is connected between the servo motor (111) and the ball screw (121).

6. The high-rigidity low-backlash closed-loop rope-driven flexible arm driving electric control integrated device according to claim 4, wherein the lifting driving device further comprises a driver (112), the driver (112) is arranged on the base (15), the driver (112) is electrically connected with the servo motor (111), and the driver (112) is arranged outside the servo motor (111).

7. The high-rigidity low-backlash closed-loop rope-driven flexible arm-driven and electric-controlled integrated device according to claim 4, wherein a sliding guide rail (124) extending in the up-and-down direction is arranged on the base (15), and the slider (123) is in sliding fit with the sliding guide rail (124).

8. The high-rigidity low-backlash closed-loop rope-driven flexible arm-driven and electric-controlled integrated device according to claim 1, wherein a fixed pulley assembly (13) is arranged at the upper end of the base (15), and the driving rope (125) is connected with the rolling joint (102) through the fixed pulley assembly (13).

9. A high stiffness low backlash closed loop rope drive flexible arm drive electronically controlled integrated device according to claim 1, wherein the tensioner (14) comprises:

a hollow bolt (141) provided on the base (15);

a spring (144) disposed on a side of the hollow bolt (141) away from the base (15);

the driving rope (125) penetrates through the hollow bolt (141) and the spring (144), and a round head is arranged at the first end of the driving rope (125) and abuts against the spring (144).

10. The high stiffness low backlash closed loop rope drive flexible arm drive electronically controlled integrated device according to claim 9, wherein the tensioner (14) further comprises an internally threaded cap (142), the internally threaded cap (142) being connected between the spring (144) and the hollow bolt (141), the internally threaded cap (142) being in threaded connection with the hollow bolt (141), the drive rope (125) passing through the hollow bolt (141), the internally threaded cap (142) and the spring (144) in sequence.