CN108818616A

CN108818616A - A kind of robot arm gravity balance device

Info

Publication number: CN108818616A
Application number: CN201810627211.6A
Authority: CN
Inventors: 王玮
Original assignee: Baoji University of Arts and Sciences
Current assignee: Shaanxi Kunwei Zhida Intelligent Technology Co ltd; Baoji University of Arts and Sciences
Priority date: 2018-06-19
Filing date: 2018-06-19
Publication date: 2018-11-16
Anticipated expiration: 2038-06-19
Also published as: CN108818616B

Abstract

The invention discloses a robot arm gravity balance device, comprising a frame mechanism, the frame mechanism includes No. 1 board, No. 2 board and No. 3 board, and several The long screw is connected, and the long screw is plugged into the four corners of the third board, the long screw between the third board and the second board is provided with a No. 1 backing tube, and the second board is close to the No. 1 board A number of No. 1 nuts are provided on one side panel of the No. 1 nut, and the No. 1 nuts are threaded on the long screws. A slot is provided on the side of the No. 1 nut away from the No. 2 board, and a slot is inserted into the slot. No. 2 pad tube, the No. 2 pad tube is inserted on the long screw between the No. 1 nut and the No. 1 plate, and the No. 2 nut is arranged on the side panel of the No. 1 plate away from the No. 2 plate. The No. 2 nut is threaded with the long screw. The invention has the advantages of novel structure, simple principle and convenient use, and is a novel and practical robot arm gravity balance device.

Description

A kind of robot arm gravity balance device

Technical field

The invention belongs to robot equipment technology fields, fill in particular to a kind of robot arm gravitational equilibrium It sets.

Background technique

For robot arm when grabbing or promoting some weights, gravitational equilibrium will receive large effect, if not to it Carry out certain adjustment, then it is possible that robot arm bending or fracture the case where.In existing technology, gravitational equilibrium Monitoring and control system it is more perfect, and paired gravity balance device lacks that there are many drawbacks, such as when adjustment Vibration can be generated, the problems such as transmission mechanism is unstable, there are improvement and gaps in market, so the present invention provides a kind of robot arm Gravity balance device solves the above problems.

Summary of the invention

The object of the invention is that providing a kind of robot arm gravity balance device to solve the above-mentioned problems, solve It has determined problem of the existing technology.

To solve the above-mentioned problems, the present invention provides a kind of technical solutions：

A kind of robot arm gravity balance device, including frame mechanism, the frame mechanism include No.1 plate, No. two plates It with No. three plates, is connected between the No.1 plate, No. two plates and No. three plates by several long spiro nails, and the long spiro nail is plugged on three Four corners of number plate, the long spiro nail between No. three plates and No. two plates are equipped with No.1 pad pipe, and No. two plates are close to one The side panel of number plate is equipped with several No.1 nuts, and the No.1 nut thread is connected on long spiro nail, the No.1 nut One side far from No. two plates is equipped with slot, and No. two pad pipes are plugged in the slot, and No. two pads pipe is plugged on No.1 On long spiro nail between nut and No.1 plate, the No.1 plate is equipped with No. two nuts far from the side panel of No. two plates, described No. two nuts are threadedly coupled with long spiro nail, and the lower end of the No.1 plate, No. two plates and No. three plates is vertically connected on base plate, Motor fixing plate, the motor are connected with by several No.1 screws at the side face plate center of No. three plates far from No. two plates Fixed plate is fixedly connected with electric capstan on the side panel far from No. three plates, and the output end of the electric capstan is connected with connection Axis, the connecting shaft pass through two in the No.1 perforation and No. three plates being arranged on motor fixing plate far from one end of electric capstan Number perforation is connected with grafting block.

Preferably, the grafting block is arranged between No. two plates and No. three plates, and the grafting block passes through No. three screws It is connected with U-shaped connecting rod, the insertion end of No. three screws is threaded with No. three nuts, the interposition of the U-shaped connecting rod It sets and transmission shaft is connected with by welding block, the transmission shaft passes through No. two plate settings far from one end of welding block and perforates at No. three It is interior, and No. three perforation are arranged on No.1 plate, are fixedly connected on the transmission shaft there are two No.1 bearing, the No.1 axis It holds and is provided with groove on the corresponding No.1 plate side panel opposite with No. two plates, and the No.1 bearing is arranged in a one-to-one correspondence In groove, bearing connection ring is welded on the outside of the No.1 bearing, the bearing connection ring passes through several No. four screws point It is not connect with No.1 plate and No. two plates, the middle position of the transmission shaft between the No.1 plate and No. two plates is fixedly connected with turbine Worm screw pipe, the turbine and worm pipe are connected with transmission mechanism, and the top of turbine and worm pipe is arranged in the transmission mechanism.

Preferably, the transmission mechanism includes the No.1 gear being fitting to connection with turbine and worm pipe, the No.1 gear Fitting connection has No. two gears being arranged in above No.1 gear, and the No.1 gear is connected with No.1 by No. two bearings and connects Bar, No. two gears are connected with No. two connecting rods by No. two bearings, and the No.1 connecting rod is socketed with No. two connecting rods Have No.1 connection ring and No. two connection rings, between the No.1 connection ring and No. two bearings be equipped with fixed ring, the fixed ring with It is equipped with the pressure ring being welded in fixed ring between No. two bearings, No. three gasket rings are equipped between the fixed ring and No.1 connection ring, No. three gasket rings are equipped between the No.1 connection ring and No. two connection rings, the both ends of the No.1 connecting rod and No. two connecting rods are equal Equipped with internal screw thread, the internal screw thread one-to-one correspondence is threaded with No. five screws, between No. five screws and No. two connection rings Equipped with pressure ring, the pressure ring is welded on No. five screws, the No.1 connection ring in the No.1 connecting rod and No. two connection rings one One corresponds to and connect with the No.1 fixed arm of fixed link, and the No.1 connection ring in No. two connecting rods and No. two connection rings are one by one It corresponds to and is connect with No. two fixed arms of fixed link, the fixed link is welded on the both ends of welded plate, and the welded plate is far from solid The side panel of fixed pole is welded with No.1 plate and No. two plates respectively, and No. two gear upper ends are welded with mechanical arm connecting plate, institute It states and is equipped with several groups of springs between mechanical arm connecting plate and the upper panel of No.1 plate, the mechanical arm connecting plate and No. two plates Be equipped with several groups of springs between upper panel, the both ends of the groups of springs by spring coupling plate respectively with No.1 plate, No. two plates It is connected with mechanical arm connecting plate.

Preferably, the fixed ring is welded in No.1 connecting rod and No. two connecting rods.

Preferably, No. three gasket rings are socketed in No.1 connecting rod and No. two connecting rods.

Preferably, the length of the No.1 plate, width and height and length, width and the height of No. two plates correspond It is identical.

Preferably, No. two pads are equipped between the No.1 bearing and No.1 plate between No.1 bearing and No. two plates Ring.

Preferably, being equipped with No.1 gasket ring between side panel and long spiro nail of No. three plates far from No. two plates.

Compared with prior art, of the invention to have the following advantages that and marked improvement：

When needing to be adjusted mechanical arm, external gravity monitoring control system control electric capstan running, electric mincing Disk will drive the turbine and worm pipe being sequentially connected therewith and be rotated, and then turbine and worm pipe just will drive two in transmission mechanism A gear is rotated, and No. two gear upper ends are with mechanical arm due to being fixedly connected, so can be right when No. two gears rotate The tilt angle of mechanical arm is adjusted, and during which, No.1 bearing is to fixed conveyor axis, and No. two bearings are to fix two teeth Wheel, the present invention make transmission shaft and two gears not influence its fortune while spatial position is fixed using the connection type of bearing Make, principle is simple and practical, and good fixing effect；The No.1 pad pipe and No. two pad pipes that the present invention is arranged cooperate No.1 nut and two Number nut can clamp each plate, and then fix the spacing between three plates, and user can according to need choosing The pad pipe of suitable length is selected, the flexible design is changeable, and the fixed effect of spacing is good, is not susceptible to change；And electric mincing Disk then allows electric capstan easily from transmission system using the connection type that grafting block and U-shaped connecting rod combine It is detached from, the operation which is repaired or replaced it；And the groups of springs that the present invention is arranged then can be right Mechanical arm connecting plate carries out certain support, and alleviates the vibration generated when electric capstan running, and then carry out to mechanical arm Certain protection, structure of the invention is novel, and principle is simple, easy to use, is a kind of novel and practical robot arm gravity Balancing device.

Detailed description of the invention

Detailed description will be given by the following detailed implementation and drawings by the present invention for ease of explanation,.

Fig. 1 is the structural diagram of the present invention；

Fig. 2 is schematic diagram of transmission mechanism of the invention；

Fig. 3 is fixed ring structural schematic diagram of the invention；

Fig. 4 is fixed rod structure schematic diagram of the invention；

Fig. 5 is enlarged structure schematic diagram at A of the invention；

Fig. 6 is enlarged structure schematic diagram at B of the invention；

Fig. 7 is No. two plate structural schematic diagrams of the invention；

Fig. 8 is No.1 nut structure diagram of the invention.

In figure：1, frame mechanism；2, No.1 plate；3, No. two plates；4, No. three plates；5, long spiro nail；6, No.1 gasket ring；7, No.1 Pad pipe；8, No.1 nut；9, No. two pad pipes；10, slot；11, No. two nuts；12, base plate；13, No.1 screw；14, motor Fixed plate；15, electric capstan；16, connecting shaft；17, No.1 is perforated；18, No. two perforation；19, grafting block；20, No. three screws； 21, U-shaped connecting rod；22, No. three nuts；23, welding block；24, transmission shaft；25, No. three perforation；26, No.1 bearing；27, groove； 28, bearing connection ring；29, No. four screws；30, No. two gasket rings；31, turbine and worm pipe；32, transmission mechanism；33, No.1 gear； 34, No. two bearings；35, No.1 connecting rod；36, No.1 connection ring；37, No. two connection rings；38, fixed ring；39, pressure ring；40, three Number gasket ring；41, internal screw thread；42, No. five screws；43, No.1 fixed arm；44, No. two fixed arms；45, welded plate；46, fixed link； 47, No. two connecting rods；48, No. two gears；49, mechanical arm connecting plate；50, spring coupling plate；51, groups of springs.

Specific embodiment

As shown in figures 1-8, present embodiment uses following technical scheme：A kind of robot arm gravitational equilibrium dress It sets, including frame mechanism 1, the frame mechanism 1 includes 2, No. two plates 3 of No.1 plate and No. three plates 4,2, No. two plates of the No.1 plate It is connected between 3 and No. three plates 4 by several long spiro nails 5, and the long spiro nail 5 is plugged on four corners of No. three plates 4, described three Long spiro nail 5 number between plate 4 and No. two plates 3 is equipped with No.1 pad pipe 7, and No. two plates 3 are on the side panel of No.1 plate 2 Equipped with several No.1 nuts 8, the No.1 nut 8 is threaded on long spiro nail 5, and the No.1 nut 8 is far from No. two plates 3 One side is equipped with slot 10, is plugged with No. two pad pipes 9 in the slot 10, No. two pads pipe 9 be plugged on No.1 nut 8 and On long spiro nail 5 between No.1 plate 2, the No.1 plate 2 is equipped with No. two nuts 11 far from the side panel of No. two plates 3, described No. two nuts 11 are threadedly coupled with long spiro nail 5, and the lower end of 2, No. two plates 3 of No.1 plate and No. three plates 4 is vertically connected on bottom On seat board 12, motor is connected with by several No.1 screws 13 at the side face plate center of No. three plates 4 far from No. two plates 3 and is consolidated Fixed board 14, the motor fixing plate 14 are fixedly connected with electric capstan 15, the electric mincing on the side panel far from No. three plates 4 The output end of disk 15 is connected with connecting shaft 16, and the connecting shaft 16 is passed through to be arranged and be fixed in motor far from one end of electric capstan 15 No.1 perforation 17 on plate 14 and No. two perforation 18 on No. three plates 4 are connected with grafting block 19.

Wherein, the grafting block 19 is arranged between No. two plates 3 and No. three plates 4, and the grafting block 19 passes through No. three spiral shells Nail 20 is connected with U-shaped connecting rod 21, and the insertion end of No. three screws 20 is threaded with No. three nuts 22, the U-shaped connection The middle position of bar 21 is connected with transmission shaft 24 by welding block 23, and the transmission shaft 24 passes through two far from one end of welding block 23 The setting of number plate 3 is in No. three perforation 25, and No. three perforation 25 are arranged on No.1 plate 2, fixed on the transmission shaft 24 to connect It connects there are two No.1 bearing 26, is respectively provided on the corresponding No.1 plate 2 of the No.1 bearing 26 side panel opposite with No. two plates 3 Fluted 27, and the No.1 bearing 26 is arranged in a one-to-one correspondence in groove 27, the outside of the No.1 bearing 26 is welded with axis Connection ring 28 is held, the bearing connection ring 28 is connect with No.1 plate 2 and No. two plates 3 respectively by several No. four screws 29, described The middle position of transmission shaft 24 between No.1 plate 2 and No. two plates 3 is fixedly connected with turbine and worm pipe 31, the turbine and worm pipe 31 are connected with transmission mechanism 32, and the top of turbine and worm pipe 31 is arranged in the transmission mechanism 32.

Wherein, the transmission mechanism 32 includes the No.1 gear 33 being fitting to connection with turbine and worm pipe 31, the No.1 tooth Wheel 33, which is fitting to connection, No. two gears 48 that 33 top of No.1 gear is arranged in, and the No.1 gear 33 is connected by No. two bearings 34 It is connected to No.1 connecting rod 35, No. two gears 48 are connected with No. two connecting rods 47, the No.1 connection by No. two bearings 34 Bar 35 and No. two connecting rods 47 are socketed with No.1 connection ring 36 and No. two connection rings 37, the No.1 connection ring 36 and No. two axis It holds and is equipped with fixed ring 38 between 34, the pressure ring being welded in fixed ring 38 is equipped between the fixed ring 38 and No. two bearings 34 39, No. three gasket rings 40, the No.1 connection ring 36 and No. two connection rings are equipped between the fixed ring 38 and No.1 connection ring 36 No. three gasket rings 40 are equipped between 37, the both ends of the No.1 connecting rod 35 and No. two connecting rods 47 are equipped with internal screw thread 41, described The one-to-one correspondence of internal screw thread 41 is threaded with No. five screws 42, and pressure ring is equipped between No. five screws 42 and No. two connection rings 37 39, the pressure ring 39 is welded on No. five screws 42, No.1 connection ring 36 and No. two connection rings in the No.1 connecting rod 35 37 correspond and connect with the No.1 fixed arm 43 of fixed link 46, the No.1 connection ring 36 and two in No. two connecting rods 47 Number connection ring 37 is corresponded and is connect with No. two fixed arms 44 of fixed link 46, and the fixed link 46 is welded on welded plate 45 Both ends, side panel of the welded plate 45 far from fixed link 46 are welded with No.1 plate 2 and No. two plates 3 respectively, No. two teeth It takes turns 48 upper ends and is welded with mechanical arm connecting plate 49, if being equipped between the mechanical arm connecting plate 49 and the upper panel of No.1 plate 2 Dry groups of springs 51, is equipped with several groups of springs 51, the spring between the mechanical arm connecting plate 49 and the upper panel of No. two plates 3 The both ends of group 51 are connect with 2, No. two plates 3 of No.1 plate and mechanical arm connecting plate 49 respectively by spring coupling plate 50.

Wherein, the fixed ring 38 is welded in No.1 connecting rod 35 and No. two connecting rods 47, in order to fix No. two axis Hold 34.

Wherein, No. three gasket rings 40 are socketed in No.1 connecting rod 35 and No. two connecting rods 47, in order to fixed No.1 Connection ring 36 and No. two connection rings 37.

Wherein, the length of the No.1 plate 2, width and height and length, width and the height of No. two plates 3 correspond phase Together, in order to installing.

Wherein, No. two pads are equipped between the No.1 bearing 26 and No.1 plate 2 between No.1 bearing 26 and No. two plates 3 Ring 30, in order to fixation.

Wherein, No.1 gasket ring 6 is equipped between side panel and long spiro nail 5 of No. three plates 4 far from No. two plates 3, so as to In fixation.

Specifically：A kind of robot arm gravity balance device, in use, first by the No.1 plate of frame mechanism 12, two Number plate 3 and No. three plates 4 assemble as required, and then the lower end of three plates is welded on base plate 12 again, then again will be electronic The dependency structure and transmission mechanism 32 of capstan winch 15 assemble as required, and mechanical arm is finally mounted on mechanical arm connecting plate again 49, finally electric capstan 15, which is connected into gravity monitoring control circuit, again can be used the present invention, specifically, the present invention operates When, when needing to be adjusted mechanical arm, external gravity monitoring control system control electric capstan 15 is operated, electric capstan 15 It will drive the turbine and worm pipe 31 being sequentially connected therewith to be rotated, then turbine and worm pipe 31 just will drive in transmission mechanism 32 Two gears rotated, and No. two 48 upper ends of gear are with mechanical arm due to being fixedly connected, so rotating in No. two gears 48 When the tilt angle of mechanical arm can be adjusted, during which, No.1 bearing 26 to fixed conveyor axis 24, use by No. two bearings 34 To fix two gears, the present invention fixes transmission shaft 24 and two gears in spatial position using the connection type of bearing Its running is not influenced simultaneously, and principle is simple and practical, and good fixing effect；The No.1 pad pipe 7 that the present invention is arranged is matched with No. two pad pipes 9 Unification nut 8 and No. two nuts 11 can clamp each plate, and then fix the spacing between three plates, and make User can according to need the pad pipe for selecting to be suitble to length, and the flexible design is changeable, and the fixed effect of spacing is good, is not easy It changes；And electric capstan 15 then makes electric capstan 15 using the combined connection type of grafting block 19 and U-shaped connecting rod 21 It can be easily detached from from transmission system, the operation which is repaired or replaced it；And The groups of springs 51 that the present invention is arranged can then carry out certain support to mechanical arm connecting plate 49, and alleviate the fortune of electric capstan 15 As when the vibration that generates, and then certain protection is carried out to mechanical arm, structure of the invention is novel, and principle is simple, easy to use, is A kind of novel and practical robot arm gravity balance device.

The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention, the technology of the industry Personnel are it should be appreciated that the present invention is not limited to the above embodiments, and the above embodiments and description only describe this The principle of invention, without departing from the spirit and scope of the present invention, various changes and improvements may be made to the invention, these changes Change and improvement all fall within the protetion scope of the claimed invention, the claimed scope of the invention by appended claims and its Equivalent thereof.

Claims

1. A robot arm gravity balance device, comprising a frame mechanism (1), is characterized in that: said frame mechanism (1) comprises No. 1 plate (2), No. 2 plate (3) and No. 3 plate (4), The No. 1 board (2), No. 2 board (3) and No. 3 board (4) are connected by several long screws (5), and the long screws (5) are plugged into the No. 3 board (4) At the four corners of the No. 3 plate (4) and the No. 2 plate (3), the long screw (5) between the No. 3 plate (4) and the No. 2 plate (3) is provided with a No. 1 backing tube (7), and the No. The side panel of (2) is provided with some No. 1 nuts (8), and described No. 1 nuts (8) are threaded on the long screw (5), and described No. 1 nuts (8) are far away from No. 2 plate (3) ) is provided with a slot (10) on one side, the slot (10) is inserted with the No. 2 pad tube (9), and the No. 2 pad tube (9) is plugged into the No. 1 nut (8) On the long screw (5) between the No. 1 plate (2), the No. 1 plate (2) is provided with a No. 2 nut (11) on the side panel away from the No. 2 plate (3), and the No. 2 The nut (11) is threadedly connected with the long screw (5), and the lower ends of the No. 1 plate (2), the No. 2 plate (3) and the No. 3 plate (4) are all vertically connected on the base plate (12), and the No. 3 plate (4) is connected with motor fixing plate (14) by several No. 1 screws (13) at the center of the side panel away from No. 2 plate (3), and described motor fixing plate (14) is far away from No. 3 plate (4) ) is fixedly connected with an electric winch (15) on the side panel, the output end of the electric winch (15) is connected with a connection shaft (16), and the end of the connection shaft (16) away from the electric winch (15) passes through A plug-in block (19) is connected to the No. 1 perforation (17) on the motor fixing plate (14) and the No. 2 perforation (18) on the No. 3 plate (4).

2. The gravity balance device of a robot arm according to claim 1, characterized in that: the plug-in block (19) is arranged between the second plate (3) and the third plate (4), and the The socket block (19) is connected with a U-shaped connecting rod (21) by a No. 3 screw (20), and the insertion end of the No. 3 screw (20) is threadedly connected with a No. 3 nut (22), and the U-shaped connecting rod ( The middle position of 21) is connected with a transmission shaft (24) through the welding block (23), and the end of the transmission shaft (24) away from the welding block (23) passes through the second plate (3) and is arranged in the third perforation (25) inside, and the No. 3 perforation (25) is arranged on the No. 1 plate (2), and two No. 1 bearings (26) are fixedly connected to the transmission shaft (24), and the No. 1 bearings (26) correspond to Grooves (27) are provided on the opposite side panels of No. 1 plate (2) and No. 2 plate (3), and the No. 1 bearings (26) are arranged in the grooves (27) one by one, The outer side of the No. 1 bearing (26) is welded with a bearing connecting ring (28), and the bearing connecting ring (28) is respectively connected to the No. 1 plate (2) and the No. 2 plate (3) through several No. 4 screws (29). connection, the middle position of the transmission shaft (24) between the No. 1 plate (2) and the No. 2 plate (3) is fixedly connected with a worm tube (31), and the worm tube (31) is connected with a transmission mechanism (32), the transmission mechanism (32) is arranged above the worm tube (31).

3. The gravity balance device of a robot arm according to claim 2, characterized in that: the transmission mechanism (32) includes a No. 1 gear (33) fitted and connected to the worm tube (31), and the first The No. gear (33) is fitted and connected with the No. 2 gear (48) arranged on the No. 1 gear (33), and the No. 1 gear (33) is connected to No. 1 connecting rod (35) through the No. 2 bearing (34). The No. 2 gear (48) is connected with the No. 2 connecting rod (47) through the No. 2 bearing (34), and the No. 1 connecting rod (35) and the No. 2 connecting rod (47) are all sleeved with a No. 1 connecting ring ( 36) and No. 2 connecting ring (37), a fixed ring (38) is arranged between the described No. 1 connecting ring (36) and the No. 2 bearing (34), and the described fixed ring (38) and the No. ) is provided with a pressure ring (39) welded on the fixed ring (38), and a No. 3 backing ring (40) is provided between the fixed ring (38) and the No. 1 connecting ring (36), and the No. 1 No. 3 backing ring (40) is provided between connecting ring (36) and No. 2 connecting ring (37), and both ends of described No. 1 connecting rod (35) and No. 2 connecting rod (47) are provided with internal threads ( 41), the internal threads (41) are threaded one-to-one with No. 5 screws (42), and a pressure ring (39) is provided between the No. 5 screws (42) and the No. 2 connecting ring (37). The pressure ring (39) is welded on the No. 5 screw (42), and the No. 1 connecting ring (36) on the No. 1 connecting rod (35) is in one-to-one correspondence with the No. 2 connecting ring (37) and is connected with the fixed rod ( No. 1 fixed arm (43) of 46) is connected, and the No. 1 connecting ring (36) on the No. 2 connecting rod (47) corresponds to the No. 2 connecting ring (37) one-to-one and corresponds to the two No. fixed arm (44) is connected, and described fixed rod (46) is welded on the two ends of welded plate (45), and described welded plate (45) is away from the side panel of fixed rod (46) and No. 1 plate (2 ) is welded with the No. 2 plate (3), the upper end of the No. 2 gear (48) is welded with a mechanical arm connection plate (49), and the upper side panel of the No. 1 plate (2) is connected with the mechanical arm connection plate (49) There are several spring groups (51) between them, and some spring groups (51) are arranged between the connecting plate (49) of the mechanical arm and the upper side panel of the second plate (3). The two spring groups (51) The ends are respectively connected with the No. 1 plate (2), the No. 2 plate (3) and the mechanical arm link plate (49) through the spring link plate (50).

4. A robot arm gravity balance device according to claim 3, characterized in that: the fixing ring (38) is welded on the No. 1 connecting rod (35) and the No. 2 connecting rod (47).

5 . A robot arm gravity balance device according to claim 3 , characterized in that: the No. 3 backing ring ( 40 ) is sleeved on the No. 1 connecting rod ( 35 ) and the No. 2 connecting rod ( 47 ).

6. The gravity balance device for a robot arm according to claim 1, characterized in that: the length, width and height of the No. 1 board (2) and the length, width and height of the No. 2 board (3) are one by one. Corresponds to the same.

7. A kind of robot arm gravity balance device according to claim 2, is characterized in that: between said No. 1 bearing (26) and No. 1 plate (2) and between No. 1 bearing (26) and No. 2 plate ( 3) No. 2 backing rings (30) are arranged between them.

8. A robot arm gravity balance device according to claim 1, characterized in that: a side panel of the No. 3 plate (4) away from the No. 2 plate (3) and the long screw (5) is provided between backing ring (6).