CN113894834A

CN113894834A - Double-motor linkage structure for telescopic pitching of mechanical arm joint

Info

Publication number: CN113894834A
Application number: CN202010571384.8A
Authority: CN
Inventors: 陈柏希; 段绍全; 张伟军
Original assignee: Yunnan Power Grid Co Ltd
Current assignee: Yunnan Power Grid Co Ltd
Priority date: 2020-06-22
Filing date: 2020-06-22
Publication date: 2022-01-07
Anticipated expiration: 2040-06-22
Also published as: CN113894834B

Abstract

A dual-motor linkage structure for telescopic pitching of a mechanical arm joint comprises: the double-screw differential small arm mechanism is characterized by comprising a pair of large arm frames, encoders, motors and speed reducers which are arranged in the large arm frames, and double-screw differential small arm mechanisms which are connected with the speed reducers and provided with small arm frame square tubes, wherein the output shaft of a first motor is directly connected into an input shaft hole of the first speed reducer; the output shafts of the first speed reducer and the second speed reducer are respectively connected with the double-screw differential small arm mechanism through a first coupler and a second coupler, and the square tube of the small arm frame makes a compound motion of front-back translation, reverse rotation and same speed of the square tube of the small arm frame when the two motors rotate positively, and rotation and different speed of the square tube of the small arm frame when the two motors rotate reversely. The invention has compact mechanism, reduces the internal burden between the upper and lower shutdown stages, and improves the external output efficiency; the dynamic response is quicker, and the static rigidity of the joint is also improved.

Description

Double-motor linkage structure for telescopic pitching of mechanical arm joint

Technical Field

The invention relates to a technology in the field of robots, in particular to a double-motor linkage structure for stretching and pitching a mechanical arm joint.

Background

The mechanical arm joint generally adopts a series-connected transmission mechanism, namely a plurality of basic mechanisms with single degree of freedom are sequentially connected, so that the output motion of each preposed mechanism is used as the input motion of a subsequent mechanism, and one degree of freedom and one motor are used for controlling. The mechanical arm with the multiple joints has the outstanding characteristics that in the mechanical arm with the multiple joints, a transmission device such as a motor reducer of a previous-stage joint can become a load of a next-stage joint, internal consumption can be increased, power response is slow, and meanwhile, the utilization rate of the motor reducer is reduced.

Disclosure of Invention

Aiming at the defect that the stability and the rigidity of the prior art can not meet the requirements, the invention provides a double-motor linkage structure for stretching and pitching the joints of the mechanical arm, wherein the stretching and pitching joints of the mechanical arm are connected in parallel, the mechanism is compact, the internal load between the upper shutdown stage and the lower shutdown stage is reduced, and the external output efficiency is improved; meanwhile, the double motors work simultaneously, so that the dynamic response of the joint is quicker, and the static rigidity of the joint is improved.

The invention is realized by the following technical scheme:

the invention comprises the following steps: a pair of big cantilever crane that sets up relatively and set up encoder, motor and the reduction gear in big cantilever crane separately and the differential forearm mechanism of two lead screws that have little cantilever crane side pipe that links to each other with the reduction gear, wherein: the output shaft of the first motor is directly connected in the input shaft hole of the first speed reducer, the first encoder is connected behind the motor, the second motor and the second encoder are also directly connected and then directly connected with the second speed reducer, and the first speed reducer and the second speed reducer are sleeved with the large arm support through a motor speed reducer retainer; the output shafts of the first speed reducer and the second speed reducer are respectively connected with the double-screw differential small arm mechanism through a first coupler and a second coupler, and the square tube of the small arm frame makes a compound motion of front-back translation, reverse rotation and same speed of the square tube of the small arm frame when the two motors rotate positively, and rotation and different speed of the square tube of the small arm frame when the two motors rotate reversely.

The differential forearm mechanism of two lead screws include: flange and lead screw rear flange before little cantilever crane side pipe, first lead screw, second lead screw, bilateral rack nut, lead screw, wherein: the two ends of the first screw rod are supported by a first bearing and a fourth bearing, the two ends of the second screw rod are supported by a second bearing and a third bearing, the four bearings are respectively arranged in a front flange of the screw rod and a rear flange of the screw rod, the front flange of the screw rod and the rear flange of the screw rod are both fixed with a small arm support square tube, and a bilateral rack nut is respectively matched with the first screw rod and the second screw rod and integrally limited on the small arm support square tube.

The output shafts of the first speed reducer and the second speed reducer are respectively connected with the first screw rod and the second screw rod through the first coupling and the second coupling, and the speed reducer retainer is fixed with the rear flange of the screw rod.

And a first pinion and a second pinion which are coaxial, a first dry bearing and a second dry bearing which are used for eliminating axial gaps between the first pinion and the second pinion and two bilateral rack nuts and bearing certain radial force are arranged between the bilateral rack nuts, the first pinion is fixed with the first boom, and the second pinion is fixed with the second boom.

The large arm support and the front flange of the screw rod are used as a front connecting port and a rear connecting port, so that the whole double-motor parallel differential mechanism can be conveniently connected into the whole mechanical arm.

When two motors arranged in a pair of big arm frames rotate at the same speed and in the same direction, the nuts are driven to slide in the square tubes of the small arm frames theoretically, and the racks are static and do not move due to the reaction force because the left and the right of the middle of the rack nuts on the upper and the lower sides are respectively meshed with a pinion, so that the lead screw rotates and moves previously, and the small arm is stretched; when two motors are reversed, the two-sided rack nut can be driven to rotate around the pinion, so that the small arm is driven to rotate, and if the two motors are reversed at the same speed, the two motors rotate in a centering manner.

Technical effects

The invention integrally solves the problems of more internal consumption and slower power response when the existing series mechanism is used in a mechanical arm structure; compared with the prior art, the mechanical arm has the advantages that the pitching freedom degree and the stretching freedom degree in the mechanical arm are connected in parallel, the mechanical arm is simple in mechanism and neat in appearance, the motor efficiency is utilized to the maximum extent, and the dynamic response performance and the static rigidity of the system can be well improved through the double-motor drive.

Drawings

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

FIG. 2 is a top view of the present invention;

FIG. 3 is a schematic view of a differential mechanism connected in parallel inside a small arm square tube;

in the figure: the device comprises a first big arm support 1, a second big arm support 2, a first encoder 3, a second encoder 4, a first motor 5, a second motor 6, a first speed reducer 7, a second speed reducer 8, a motor speed reducer retainer 9, a first bolt 10, a first coupler 11, a second coupler 12, a screw rear flange 13, a first bearing 14, a second bearing 15, a first screw 16, a second screw 17, a first double-sided rack nut 18, a second double-sided rack nut 19, a first dry bearing 20, a second dry bearing 21, a first pinion 22, a second pinion 23, a third bearing 24, a fourth bearing 25, a screw rear flange 26, a pinion pin shaft 27 and a small arm support square tube 28.

Detailed Description

As shown in fig. 1, the present embodiment relates to a dual-motor linkage structure for extending and retracting and pitching a joint of a robot arm, including: big cantilever cranes 1, 2 and set up

encoders

3, 4,

motor

5, 6 and

reduction gear

7, 8 and the differential forearm mechanism of two lead screws that links to each other with the reduction gear in each big cantilever crane that set up relatively, wherein: an output shaft of a first motor 5 is directly connected in an input shaft hole of a first speed reducer 7, a first encoder 3 is connected behind the motor, a second motor 6 and a second encoder 4 are also directly connected and then directly connected with a second speed reducer 8, and the first speed reducer 7 and the second speed reducer 8 are sleeved with the large arm support 1 and the large arm support 2 through a motor speed reducer retainer 9; the output shafts of the first speed reducer 7 and the second speed reducer 8 are respectively connected with the double-screw differential small arm mechanism through a first coupler 11 and a second coupler 12, and the small arm support square tube 28 is connected with the screw rod front flange 13 and the screw rod rear flange 26 through screws.

The differential forearm mechanism of two lead screws include: the small arm support square tube 28, the first lead screw 16, the second lead screw 17, the

bilateral rack nuts

18, 19, the lead screw front flange 13 and the lead screw rear flange 26, wherein: two ends of the first screw rod 16 are supported by a first bearing 14 and a fourth bearing 25, two ends of the second screw rod 17 are supported by a second bearing 15 and a third bearing 24, the four bearings are respectively arranged in a screw rod front flange 13 and a screw rod rear flange 26, the screw rod front flange 13 and the screw rod rear flange 26 are both fixed with a small arm frame square pipe 28, and double-

side rack nuts

18 and 19 are respectively matched with the first screw rod 16 and the second screw rod 17 and are integrally limited on the small arm frame square pipe 28.

The output shafts of the first speed reducer 7 and the second speed reducer 8 are respectively connected with a first screw rod 16 and a second screw rod 17 through a first coupling 11 and a second coupling 12, and the speed reducer retainer 9 is fixed with a screw rod rear flange 13.

And relative to the small arm support square tube, the bilateral rack nut can only slide along the axial direction of the screw rod correspondingly matched with the bilateral rack nut.

A first pinion 22 and a second pinion 23 which are coaxial, a first dry bearing 20 and a second dry bearing 21 which are used for eliminating axial clearances between the first pinion 22 and the second pinion 23 and the two

bilateral rack nuts

18 and 19 and bearing certain radial force are arranged between the

bilateral rack nuts

18 and 19, the first pinion 22 and the first boom frame 1 are fixed, and the second pinion 23 and the second boom frame 2 are fixed.

The first pinion 22 and the second pinion 23 are coaxially arranged through a pinion pin 27, and the axes of the first pinion 22 and the second pinion 23 are perpendicular to the plane formed by the axes of the first screw rod 16 and the second screw rod 17.

The rotation of the first motor 5 and the second motor 6 is transmitted to the first screw rod 16 and the second screw rod 17 through the first speed reducer 7, the second speed reducer 8, the first coupling 11 and the second coupling 12, so that the first screw rod 16 and the second screw rod 17 are respectively proportional to the rotation speed of the first motor 5 and the second motor 6 and have the same rotation direction, when the first motor 5 and the second motor 6 rotate at the same speed and in the same direction, the first screw rod 16 and the second screw rod 17 rotate at the same speed and in the same direction to drive the first bilateral rack nut 18 and the second bilateral rack nut 19 to move forwards, and the first pinion 22 and the second pinion 23 which are meshed with the first bilateral rack nut 18 and the second bilateral rack nut 19 are fixed on the boom frames 1 and 2 and have a reaction force on the meshed bilateral rack nuts, so that the nuts are fixed and the screw rods rotate forwards or backwards for matching with the screw rods, the square tube 28 of the small arm frame fixedly connected with the square tube is driven to move forwards or backwards in a linear mode, when the rotating speeds of the first motor 5 and the second motor 6 are different, the speeds of the first screw rod 16 and the second screw rod 17 are also different, the moving speeds of the first bilateral rack nut 18 and the second bilateral rack nut 19 are also different, the first pinion 22 and the second pinion 23 between the bilateral rack nuts are driven to rotate theoretically, and due to the fact that the two pinions are fixed, the first bilateral rack nut 18 and the second bilateral rack nut 19 rotate around the axes of the two pinions relatively. Therefore, the telescopic and pitching motions of the whole small arm can be controlled by controlling the first motor 5 and the second motor 6, and meanwhile, the precise control of the angle and the linear motion of the small arm can be realized through the reading of the encoder.

The telescopic pitching of the square tube of the small arm frame is driven by the upper and lower lead screws to move in the same direction or in the opposite direction: the bottom end of the screw rod is supported by a bearing flange and is fixed with a motor reducer flange through bolts and then is fixed with the small arm frame, and the upper screw rod, the lower screw rod, the two bilateral rack nuts and the two gears form a differential mechanism. When the double motors move in the same speed and direction, the double motors are connected through the coupler, the two screw rods rotate in the same speed and direction, symmetrical teeth of the gear are simultaneously subjected to the same force of bilateral rack nuts of the screw rods, the nuts are fixed through reaction force, the screw rods move forward or backward in the same direction, and therefore the small arm support is driven to move forward or backward integrally; when the double motors are reversed, the upper rack and the lower rack rotate around the gear, if the speeds are the same, the centering rotation is performed, and if the speeds are different, the linear motion is performed while the rotation is performed. The invention can improve the static rigidity of the moving joint of the mechanical arm, has quick dynamic response, has the power of a single motor smaller than that of a single motor when two joints are separated, has the power of double motors working simultaneously larger than that of the single motor, and can improve the utilization rate of the motors to the maximum extent.

Through specific practical experiments, under the specific environment setting that the small arm double motors are DC servo 40W, the rotating speed is 5000 turns, the speed reduction ratio is 36, and the screw pitch P is 3: the small arm translates 0-104mm, the rotation angle is +/-55 degrees, and the composite motion of rotation and translation of the small arm can be realized. The load bearing is more than 10 KG.

Compared with the prior art, the device can realize the rotation and translation motion of the joint by using a low-power motor, and can realize the compound motion of rotation and translation.

The foregoing embodiments may be modified in many different ways by those skilled in the art without departing from the spirit and scope of the invention, which is defined by the appended claims and all changes that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims

1. The utility model provides a bi-motor linkage structure that is used for arm joint to stretch out and draw back every single move which characterized in that includes: a pair of big cantilever crane that sets up relatively and set up encoder, motor and the reduction gear in big cantilever crane separately and the differential forearm mechanism of two lead screws that have little cantilever crane side pipe that links to each other with the reduction gear, wherein: the output shaft of the first motor is directly connected in the input shaft hole of the first speed reducer, the first encoder is connected behind the motor, the second motor and the second encoder are also directly connected and then directly connected with the second speed reducer, and the first speed reducer and the second speed reducer are sleeved with the large arm support through a motor speed reducer retainer; the output shafts of the first speed reducer and the second speed reducer are respectively connected with the double-screw differential small arm mechanism through a first coupler and a second coupler, and the square tube of the small arm frame makes a compound motion of front-back translation, reverse rotation and same speed of the square tube of the small arm frame when the two motors rotate positively, and rotation and different speed of the square tube of the small arm frame when the two motors rotate reversely.

2. The dual-motor linkage structure of claim 1, wherein the dual-screw differential small arm mechanism comprises: flange and lead screw rear flange before little cantilever crane side pipe, first lead screw, second lead screw, bilateral rack nut, lead screw, wherein: the two ends of the first screw rod are supported by a first bearing and a fourth bearing, the two ends of the second screw rod are supported by a second bearing and a third bearing, the four bearings are respectively arranged in a front flange of the screw rod and a rear flange of the screw rod, the front flange of the screw rod and the rear flange of the screw rod are both fixed with a small arm support square tube, and a bilateral rack nut is respectively matched with the first screw rod and the second screw rod and integrally limited on the small arm support square tube.

3. The double-motor linkage structure of claim 2, wherein the output shafts of the first speed reducer and the second speed reducer are respectively connected with the first screw rod and the second screw rod through a first coupling and a second coupling, and a speed reducer retainer is fixed with a screw rod rear flange.

4. The dual-motor linkage structure of claim 2, wherein a first pinion and a second pinion which are coaxial and a first dry bearing and a second dry bearing which are used for eliminating axial gaps between the first pinion and the second pinion and between the two bilateral rack nuts and bearing certain radial force are arranged between the bilateral rack nuts, the first pinion is fixed with the first boom, and the second pinion is fixed with the second boom.

5. The dual-motor linkage structure of claim 1, wherein the large arm support and the front flange of the screw rod are used as a front connecting port and a rear connecting port, so that the whole dual-motor parallel differential mechanism can be conveniently connected to the whole mechanical arm.

6. The dual-motor linkage structure of claim 4, wherein the first pinion and the second pinion are coaxially arranged through a pinion pin shaft, and the axes of the first pinion and the second pinion are perpendicular to the plane formed by the axes of the first screw rod and the second screw rod.