TWI880773B - Screw slide device and robot arm - Google Patents

Abstract

A screw slide device includes a guide rail seat, a linear transmission unit installed on the guide rail seat, a slide seat driven by the linear transmission unit, and a ball bearing unit. The guide rail seat includes a base wall, and a first side wall and a second side wall connected to the base wall and spaced apart from each other; the slide seat includes a seat body, the seat body has a mounting surface, a base surface at the opposite end of the mounting surface and adjacent to the base wall, and a first side surface and a second side surface adjacent to the first side wall and the second side wall; the ball unit includes a first ball chain installed between the slide seat and the base surface of the seat body and the base wall, a second ball chain installed between the slide seat and the first side surface of the seat body and the first side wall, and a third ball chain installed between the slide seat and the second side surface of the seat body and the second side wall. Thereby, the slide seat has high supporting force and can improve the moving accuracy and moving stability.

Description

Screw slide device and robot arm

The present invention relates to a transmission device, in particular to a screw slide device and a mechanical arm.

The screw slide device can be applied to various processing machines to achieve the effect of automated operation. There is a screw slide device having a long rail seat and a linear transmission unit mounted on the rail seat. The linear transmission unit has a screw rotatably mounted on the rail seat, a slide seat screwed to the screw, a motor for driving the screw to rotate, and two ball bearings symmetrically mounted between the slide seat and the rail seat. The slide seat is used to carry other components to move linearly along the screw.

The pair of ball rollers can provide the slide with supporting force to resist the torque generated by other components on the slide. When the screw slide device is placed horizontally, the supporting force provided by the pair of ball rollers to the slide is sufficient to resist the torque. However, when the screw slide device is placed upright, the supporting force provided by the pair of ball rollers to the slide is often insufficient to resist the torque, resulting in excessive displacement and deformation of the slide, ultimately resulting in excessive movement error, affecting the processing quality and failing to meet the high-precision use requirements of the processing machine.

Therefore, an object of the present invention is to provide a screw slide device that can solve the problems of the prior art.

Another object of the present invention is to provide a robot arm that can improve processing quality.

Therefore, the screw slide device of the present invention includes a guide rail seat, a linear transmission unit, a slide seat and a ball bearing unit. The guide rail seat extends along a long axis, and includes a base wall, and a first side wall and a second side wall connected to the base wall and spaced parallel to each other, and the base wall cooperates with the first side wall and the second side wall to define an accommodation space; the linear transmission unit is installed on the guide rail seat, and the linear transmission unit includes a screw extending along the long axis, and a power member for driving the screw to rotate; the slide seat is located in the accommodation space and is driven by the screw to move linearly along the long axis, and the slide seat includes a seat body, and the seat body has a mounting surface, a base surface at the opposite end of the mounting surface and adjacent to the base wall, a first side surface adjacent to the first side wall, and a The second side surface of the second side wall and two connecting surfaces connecting the mounting surface and the base surface and the first side surface and the second side surface, the seat body also includes a through hole extending along the long axis and connecting the two connecting surfaces for the screw to pass through; the ball unit is installed between the guide rail seat and the slide seat, and the ball unit includes a A first ball chain is installed between the base surface of the seat body and the base wall and can be cyclically rolled, at least one second ball chain is installed between the slide seat and the first side surface of the seat body and the first side wall and can be cyclically rolled, and at least one third ball chain is installed between the slide seat and the second side surface of the seat body and the second side wall and can be cyclically rolled.

The function of the screw slide device of the present invention is that the first ball chain, the second ball chain and the third ball chain of the ball unit can greatly increase the supporting force provided to the slide seat, thereby improving the moving accuracy and moving stability of the slide seat and meeting the high-precision use requirements of the processing machine.

The robot arm of the present invention comprises a feeding device, a screw slide device as described above, and a clamping device. The feeding device extends along a first direction, and comprises a guide rail seat, a linear transmission unit mounted on the guide rail seat, and a slide seat driven by the linear transmission unit to be linearly movable; the screw slide device is mounted on the slide seat of the feeding device and extends along a second direction intersecting the first direction; the clamping device is mounted on the slide seat of the screw slide device, and the clamping device comprises a chuck.

The function of the robot arm of the present invention is that the screw slide device enables the chuck to have good moving accuracy and moving stability, thereby improving the processing quality.

The present invention is described in detail below with reference to the accompanying drawings and embodiments.

1 and 2 , an embodiment of the screw slide device 1 of the present invention includes a guide rail seat 10 , a linear transmission unit 20 , a slide seat 30 and a ball bearing unit 40 .

Referring to Fig. 1, Fig. 2, and Fig. 4, the guide rail seat 10 is an elongated seat body and extends along a long axis direction X. The guide rail seat 10 includes a base wall 11, and a first side wall 12 and a second side wall 13 connected to the base wall 11 and spaced parallel to each other. The base wall 11 cooperates with the first side wall 12 and the second side wall 13 to define a receiving space 14. The base wall 11 has a base wall inner surface 111, and a first ball groove 112 disposed on the base wall inner surface 111 along the long axis direction X and connected to the receiving space 14. The first side wall 12 has a side wall inner surface 121, and two second ball grooves 122 disposed on the side wall inner surface 121 along the long axis direction X and connected to the receiving space 14. The second side wall 13 has a side wall inner surface 131 and two third ball rolling grooves 132 disposed on the side wall inner surface 131 along the long axis X and connected to the accommodating space 14 .

Referring to FIGS. 1, 2 and 5, the linear transmission unit 20 is mounted on the guide rail seat 10. The linear transmission unit 20 includes a first bearing seat 21 and a second bearing seat 22 fixed to two ends of the guide rail seat 10 and connected to the accommodating space 14, a screw 23 rotatably mounted between the first bearing seat 21 and the second bearing seat 22, a power member 24 mounted and fixed to the first bearing seat 21 for transmitting the screw 23, and a nut 25 which is sleeved on the screw 23 and can move along the long axis X.

The power member 24 can be a motor or a reduction motor.

The screw rod 23 and the nut 25 can be a general screw rod and nut structure or a ball screw structure.

Referring to FIG. 1 and FIG. 2 , the slide 30 is sleeved on the screw rod 23 and connected to the nut 25. In this embodiment, the slide 30 and the nut 25 are locked and connected by a plurality of screws, so that the slide 30 can be driven by the nut 25 and move along the long axis direction X in the accommodation space 14. It is worth noting that the nut 25 can also be directly fixed in the slide 30, or the nut 25 can be omitted, and a screw hole can be directly provided on the slide 30 to be screwed and connected to the screw rod 23. The above structure can also achieve the effect that the slide 30 is driven by the screw rod 23 and moves along the long axis direction X.

1, 2 and 3, the slide seat 30 includes a main body 31, the main body 31 having a mounting surface 311 exposed from the accommodating space 14, a base surface 312 located at the opposite end of the mounting surface 311 and adjacent to the base wall inner surface 111, a first side surface 313 adjacent to the side wall inner surface 121 of the first side wall 12, a second side surface 314 adjacent to the side wall inner surface 131 of the second side wall 13, and two connecting surfaces 315 and 316 connecting the mounting surface 311 and the base surface 312 and the first side surface 313 and the second side surface 314. 4 and 5, the seat body 31 further includes a through hole 32 extending along the long axis X and connecting the two connecting surfaces 315 and 316 for the nut 25 and the screw rod 23 to pass through, a first ball bearing hole 33 extending along the long axis X and connecting the two connecting surfaces 315 and 316 and close to the base surface 312, a second ball bearing hole 34 extending along the long axis X and connecting the two connecting surfaces 315 and 316 and close to the first side surface 313, and a second ball bearing hole 35 extending along the long axis X and connecting the two connecting surfaces 315 and 316 and close to the second side surface 314. The third ball rolling hole 35, a fourth ball rolling groove 36 corresponding to the first ball rolling groove 112, arranged on the base surface 312 and the connecting surfaces 315, 316 and connected to the first ball rolling hole 33, two fifth ball rolling grooves 37 corresponding to the second ball rolling grooves 122, arranged on the first side surface 313 and the connecting surfaces 315, 316 and connected to the second ball rolling holes 34, and two sixth ball rolling grooves 38 corresponding to the third ball rolling grooves 132, arranged on the second side surface 314 and the connecting surfaces 315, 316 and connected to the third ball rolling holes 35.

The ball unit 40 is installed between the guide rail seat 10 and the slide seat 30 . The ball unit 40 has a first ball chain 41 , two second ball chains 42 , two third ball chains 43 , two first cover plates 44 , two second cover plates 45 and two third cover plates 46 .

The first ball chain 41 is located between the first ball groove 112, the fourth ball groove 36 and the first ball hole 33 and can be cyclically rolled, the second ball chains 42 are located between the second ball grooves 122, the fifth ball grooves 37 and the second ball holes 34 and can be cyclically rolled, and the third ball chains 43 are located between the third ball grooves 132, the sixth ball grooves 38 and the third ball holes 35 and can be cyclically rolled. It is worth noting that the number of the first ball chain 41, the second ball chains 42 and the third ball chains 43 can be changed.

The first cover plates 44 are locked and fixed to the connection surfaces 315, 316 and cover the first ball hole 33, the fourth ball groove 36 and the first ball groove 112. Each first cover plate 44 has a first protrusion 441 embedded in the first ball groove 112, and a contact surface 443 provided with a first revolving groove 442. The first revolving groove 442 of the first cover plates 44 connects the first ball hole 33, the fourth ball groove 36 and the first ball groove 112, and cooperates to form a first circulation channel 47. The first ball chain 41 is located in the first circulation channel 47 and circulates stably.

The second cover plates 45 are locked and fixed to the connection surfaces 315, 316 and cover the second ball holes 34, the fifth ball grooves 37 and the second ball grooves 122. Each second cover plate 45 has two second protrusions 451 respectively embedded in the second ball grooves 122, and a contact surface 453 provided with two second rotary grooves 452. The second rotary grooves 452 of the second cover plates 45 are connected to the corresponding second ball holes 34, the fifth ball grooves 37 and the second ball grooves 122, and cooperate to form two second circulation channels 48. The second ball chains 42 are respectively located in the second circulation channels 48 to stably circulate and roll.

The third cover plates 46 are locked and fixed to the connection surfaces 315, 316 and cover the third ball holes 35, the sixth ball grooves 38 and the third ball grooves 132. Each third cover plate 46 has two third protrusions 461 respectively embedded in the third ball grooves 132, and a contact surface 463 provided with two third rotary grooves 462. The third rotary grooves 462 of the third cover plates 46 are connected to the corresponding third ball holes 35, the sixth ball grooves 38 and the third ball grooves 132, and cooperate to form two third circulation channels 49. The third ball chains 43 are respectively located in the third circulation channels 49 to stably circulate and roll.

The screw slide device 1 of the present invention has a first ball chain 41 of the ball unit 40 located between the base wall 11 of the guide rail seat 10 and the base surface 312 of the seat body 31 of the slide seat 30, and can be circularly rolled in the first circulation channel 47, the second ball chains 42 are located between the first side wall 12 of the guide rail seat 10 and the first side surface 313 of the seat body 31 of the slide seat 30, and can be circularly rolled in the second circulation channels 48, the third ball chains 43 are located between the second side wall 13 of the guide rail seat 10 and the base surface 312 of the seat body 31 of the slide seat 30, and can be circularly rolled in the second circulation channels 48. The slide 30 is located between the second side surfaces 314 of the seat body 31 and can circulate and roll in the third circulation channels 49. In this way, the supporting force provided to the slide 30 can be greatly increased, so that the slide 30 has a high supporting force sufficient to resist the torque generated by other components installed on the mounting surface 311 on the slide 30. When the screw slide device 1 is placed horizontally, the load-bearing effect of the slide 30 can be increased. When the screw slide device 1 is placed upright, the anti-torque effect of the slide 30 can be increased.

When in use, the driving member 24 drives the screw rod 23 to rotate around its axis, thereby driving the slide seat 30 to move stably and accurately along the long axis in the X-axis direction in the accommodating space 14.

6 , 7 and 9 , an embodiment of the robot arm of the present invention comprises a feeding device 5 , a first rotating device 6 , a screw slide device 1 , a second rotating device 7 and a clamping device 8 .

Referring to Figures 6, 7 and 8, the feeding device 5 extends along a first direction. The feeding device 5 can be the screw slide device 1 of the present invention or a general feeding slide device. When the feeding device 5 is the screw slide device 1, the feeding device 5 also includes a guide rail seat 51, a linear transmission unit 52, a slide seat 53 and a ball bearing unit 54.

The guide rail seat 51 also has a base wall 511 , a first side wall 512 , a second side wall 513 and an accommodating space 514 .

The linear transmission unit 52 also includes a first bearing seat 521, a second bearing seat 522, a screw 523 and a driving member 524. The screw 523 rotates around a first axis L1.

The slide 53 is also driven by the screw 523 and moves linearly along the first axis L1 in the accommodating space 514. The slide 53 also has a body 531, and the body 531 also has a mounting surface 5311, a base surface 5312, a first side surface 5313 and a second side surface 5314.

The ball unit 54 also has a first ball chain 541, two second ball chains 542, and two third ball chains 543. The first ball chain 541 can also cyclically roll between the slide seat 53 and the base wall 511 of the guide rail seat 51 and the base surface 5312 of the seat body 531. Similarly, the third ball chains 543 can cyclically roll between the slide seat 53, the first side wall 512 of the guide rail seat 51, and the first side surface 5313 of the seat body 531. Similarly, the third ball chains 543 can cyclically roll between the slide seat 53, the second side wall 513 of the guide rail seat 51, and the second side surface 5314 of the seat body 531.

It is worth noting that if the slide seat 53 does not require high supporting force, the first ball chain 541 can be omitted.

For the detailed structure of the feeding device 5 which is the screw slide device 1, reference can be made to the aforementioned description of the screw slide device 1, which will not be elaborated here.

When the feeding device 5 is a general slide device, the feeding device 5 includes a guide rail seat, a linear transmission unit mounted on the guide rail seat, and a slide seat driven by the linear transmission unit and capable of linear movement. The linear transmission unit can be a combination of a motor and a ball screw, a linear motor, a hydraulic cylinder, a pneumatic cylinder, or a gear and rack structure.

Referring to Fig. 6, Fig. 8, Fig. 9, and Fig. 10, the first rotating device 6 includes a first rotating motor 61 mounted and fixed on the mounting surface 5311 of the seat body 531 of the slide seat 53, a rotating disk 62 connected to a first rotating shaft 611 of the first rotating motor 61, and a first outer cover 63 disposed outside the first rotating motor 61. The first rotating shaft 611 rotates around a second axis L2, and the second axis L2 intersects with the first axis L1. The first rotating motor 61 can be a general motor or a reducer motor.

Referring to Fig. 9, Fig. 10, and Fig. 11, the screw slide device 1 extends along a second direction intersecting the first direction, and the second bearing seat 22 of the linear transmission unit 20 of the screw slide device 1 is mounted and connected to the turntable 62, so that the screw slide device 1 can be driven by the turntable 62 to rotate around the second axis L2. The screw 23 of the linear transmission unit 20 can rotate around a third axis L3, and the third axis L3 is parallel to the second axis L2, so that the slide seat 30 of the screw slide device 1 can move linearly along the third axis L3.

In this embodiment, the first direction is a horizontal direction, and the second direction is a vertical direction, but the present invention should not be limited to that the feeding device 5 must extend in a horizontal direction, and the screw slide device 1 must extend in a vertical direction.

Referring to Fig. 6, Fig. 9, Fig. 11, and Fig. 12, the second rotating device 7 includes a second rotating motor 71 mounted and fixed on the mounting surface 311 of the seat body 31 of the slide seat 30, a second rotating shaft 72 driven by the second rotating motor 71, a transmission belt 73 mounted between an output shaft of the second rotating motor 71 and the second rotating shaft 72, a rotating arm 74 connected to the second rotating shaft 72, and a second outer cover 75 covering the second rotating motor 71, the second rotating shaft 72, and the transmission belt 73. The second rotating shaft 72 rotates around a fourth axis L4, and the fourth axis L4 is parallel to the third axis L3 and the second axis L2. The second rotary motor 71 is started to drive the second shaft 72 to rotate around the fourth axis L4 through the transmission belt 73, and the second shaft 72 drives the rotary arm 74 to rotate synchronously. The second rotary motor 71 can be a general motor or a reducer motor.

Referring to Fig. 7, Fig. 9, Fig. 12, and Fig. 13, the clamping device 8 includes a third rotary motor 81 mounted and fixed to the rotary arm 74, and a chuck 82 connected to the third rotary motor 81 and driven by the third rotary motor 81. The chuck 82 rotates around a fifth axis L5, and the fifth axis L5 intersects with the fourth axis L4. The third rotary motor 81 can be a general motor or a reducer motor.

Referring to FIG. 9 , the robot arm of the present invention drives the first rotating device 6 to move linearly along the first axis L1 through the slide 53 of the feeding device 5, the screw slide device 1 is driven by the first rotating device 6 to rotate around the second axis L2, and the slide 30 of the screw slide device 1 drives the second rotating device 7 to move linearly along the third axis L3. The second rotating device 7 drives the clamping device 8 to rotate around the fourth axis L4, and the chuck 82 of the clamping device 8 rotates around the fifth axis L5, so that the chuck 82 has a five-axis motion function, which can not only meet the various usage requirements of the machine tool, but also is less restricted by the space of the installation site, and has excellent installation space design flexibility.

It is worth noting that the robot arm of the present invention can omit certain functions and components according to actual use requirements. For example, the function of the chuck 82 rotating around the fifth axis L5 can be omitted and the third rotary motor 81 can be omitted. The function of the chuck 82 rotating around the fourth axis L4 can be omitted and the second rotary device 7 can be omitted, so that the chuck 82 only needs to be installed and fixed on the mounting surface 311 of the slide seat 30 of the screw slide device 1. The function of the screw slide device 1 rotating around the second axis L2 can also be omitted and the first rotary device 6 can be omitted, so that the second bearing seat 22 of the screw slide device 1 only needs to be installed and fixed on the mounting surface 5311 of the slide seat 53 of the feed device 5.

The robot arm of the present invention only needs to include the feeding device 5, the screw slide device 1 and the clamping device 8, and the slide seat 30 of the screw slide device 1 can have a high supporting force, so that the robot arm of the present invention becomes a high-load type robot arm. In particular, when the screw slide device 1 is placed in a vertical direction, the excellent anti-torque effect of the slide seat 30 can be more prominent.

The screw slide device and the robot arm of the present invention have the following functions and advantages:

1. The screw slide device 1 of the present invention can greatly increase the supporting force provided to the slide 30 through the ball unit 40, so that the slide 30 has high supporting force and excellent movement accuracy and movement stability. When the screw slide device 1 is placed horizontally, the load-bearing effect of the slide 30 can be increased. When the screw slide device 1 is placed upright, the anti-torque effect of the slide 30 can be increased. It can not only meet the high-precision use requirements of the processing machine, but also improve the overall structural strength of the screw slide device 1.

2. The robot arm of the present invention includes the screw slide device 1, which can make the chuck 82 have excellent moving accuracy and moving stability, thereby improving the processing quality.

3. The chuck 82 of the present invention has the function of five-axis motion, which not only meets the various usage requirements of the machine tool, but also reduces the space constraints of the installation site and has a highly flexible design feature.

In summary, the screw slide device and the robot arm of the present invention can indeed achieve the purpose of the present invention.

However, the above is only an embodiment of the present invention and should not be used to limit the scope of implementation of the present invention. All simple equivalent changes and modifications made according to the scope of the patent application of the present invention and the content of the patent specification are still within the scope of the present patent.

1: Screw slide device 10: Guide rail seat 11: Base wall 111: Inner surface of base wall 112: First ball groove 12: First side wall 121: Inner surface of side wall 122: Second ball groove 13: Second side wall 131: Inner surface of side wall 132: Third ball groove 14: Accommodation space 20: Linear transmission unit 21: First bearing seat 22: Second bearing seat 23: Screw 24: Power piece 25: Nut 30: Slide seat 31: Seat body 311: Mounting surface 312: Base surface 313: First side surface 314: Second side surface 315: Connecting surface 316: Connecting surface 32: Perforation 33: First ball hole 34: Second ball hole 35: Third ball hole 36: Fourth ball groove 37: Fifth ball groove 38: Sixth ball groove 40: Ball unit 41: First ball chain 42: Second ball chain 43: Third ball chain 44: First cover plate 441: First protrusion 442: First rotating groove 443: Abutment surface 45: Second cover plate 451: Second protrusion 452: Second rotating groove 453: Abutment surface 46: Third cover plate 461: Third protrusion 462: Third rotating groove 463: Abutment surface 47: First circulation channel 48: Second circulation channel 49: Third circulation channel 5: Feeding device 51: Guide rail seat 511: Base wall 512: First side wall 513: Second side wall 514: Accommodation space 52: Linear transmission unit 521: First bearing seat 522: Second bearing seat 523: Screw 524: Power member 53: Sliding seat 531: Seat body 5311: Mounting surface 5312: Base surface 5313: First side surface 5314: Second side surface 54: Ball bearing unit 541: First ball chain 542: Second ball chain 543: Third ball chain 6: First rotating device 61: First rotating motor 611: First rotating shaft 62: Turntable 63: First outer cover 7: Second rotating device 71: Second rotating motor 72: Second rotating shaft 73: Drive belt 74: Rotating arm 75: Second outer cover 8: Clamping device 81: Third rotating motor 82: Clamping head X: Long axis L1: First axis L2: Second axis L3: Third axis L4: Fourth axis L5: Fifth axis

Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, wherein: FIG. 1 is a combined stereogram of an embodiment of the screw slide device of the present invention; FIG. 2 is a disassembled stereogram of the embodiment, showing that the embodiment includes a guide rail seat, a linear transmission unit, a slide seat and a ball roller unit; FIG. 3 is a disassembled stereogram of the slide seat and the ball roller unit of the embodiment; FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 1; FIG. 5 is a cross-sectional view taken along line V-V in FIG. 1; FIG. 6 is a combined stereogram of an embodiment of the robot arm of the present invention, showing that the embodiment includes a feeding device, a first rotating device, a screw slide device, a second rotating device and a clamping device; Figure 7 is another angled combined stereogram of the embodiment; Figure 8 is an exploded stereogram of the feeding device of the embodiment; Figure 9 is a view similar to Figure 6, in which a first outer cover of the first rotating device and a second outer cover of the second rotating device are omitted; Figure 10 is an incomplete bottom-up stereogram of the embodiment, showing the first rotating device and the screw slide device; Figure 11 is an incomplete top-down stereogram of the embodiment, showing the screw slide device and the first rotating device; Figure 12 is an incomplete combined stereogram of the embodiment, showing the screw slide device, the second rotating device and the clamping device; and Figure 13 is a partially exploded stereogram of the clamping device of the embodiment.

10: Guide rail seat

11: Base wall

111: Inner surface of base wall

112: First ball bearing groove

12: First side wall

121: Inner side wall

122: Second ball groove

13: Second side wall

131: Inner side wall

132: The third ball groove

14: Storage space

23: Screw

30: Sliding seat

31: Seat Body

311: Mounting surface

312: Base surface

313: First side

314: Second side

33: First ball hole

34: Second ball hole

35: The third bead hole

36: The fourth ball groove

37: The fifth ball groove

38: The sixth ball groove

41: The first ball chain

42: Second ball chain

43: The third bead chain

47: First Circulation Channel

48: Second Circulation Channel

49: The third circulation path

Claims (9)

A screw slide device comprises: A guide rail seat extending along a long axis, the guide rail seat comprising a base wall, and a first side wall and a second side wall connected to the base wall and spaced parallel to each other, the base wall cooperates with the first side wall and the second side wall to define a containing space; A linear transmission unit mounted on the guide rail seat, the linear transmission unit comprising a screw extending along the long axis, and a power member for driving the screw to rotate; A slide seat, located in the accommodating space and driven by the screw to move linearly along the long axis, the slide seat includes a seat body, the seat body has a mounting surface, a base surface at the opposite end of the mounting surface and adjacent to the base wall, a first side surface adjacent to the first side wall, a second side surface adjacent to the second side wall, and two connecting surfaces connecting the mounting surface with the base surface and the first side surface and the second side surface. The seat body also includes a through hole extending along the long axis and connecting the two connecting surfaces for the screw to pass through; and A ball unit is installed between the guide rail seat and the slide seat, and the ball unit includes a first ball chain installed between the slide seat and the base surface and the base wall of the seat body and can be cyclically rolled, at least one second ball chain installed between the slide seat and the first side surface and the first side wall of the seat body and can be cyclically rolled, and at least one third ball chain installed between the slide seat and the second side surface and the second side wall of the seat body and can be cyclically rolled. A screw slide device as described in claim 1, wherein the ball unit includes two second ball chains and two third ball chains. The screw slide device as described in claim 2, wherein the base wall of the guide rail seat has an inner surface of the base wall, and a first ball groove arranged on the inner surface of the base wall along the long axis and connected to the accommodating space, the first side wall has an inner surface of the side wall, and two second ball grooves arranged on the inner surface of the side wall along the long axis and connected to the accommodating space, the second side wall has an inner surface of the side wall , and two third ball rolling grooves arranged along the long axis on the inner surface of the side wall of the second side wall and connected to the accommodating space, the seat body of the sliding seat also has a first ball rolling hole extending along the long axis and connected to the two connecting surfaces and close to the base surface, two second ball rolling holes extending along the long axis and connected to the two connecting surfaces and close to the first side surface, and two second ball rolling holes extending along the long axis and connected to the two connecting surfaces. a third ball rolling hole disposed on the base surface and close to the second side surface, a fourth ball rolling groove disposed on the base surface and the connecting surfaces corresponding to the first ball rolling groove and connected to the first ball rolling hole, two fifth ball rolling grooves disposed on the first side surface and the connecting surfaces corresponding to the second ball rolling grooves and connected to the second ball rolling holes, and two fifth ball rolling grooves disposed on the second side surface and the connecting surfaces corresponding to the third ball rolling grooves and connected to the second ball rolling holes. The first ball chain is located between the first ball hole, the fourth ball groove and the first ball groove; the second ball chain is located between the second ball hole, the fifth ball groove and the second ball groove; the third ball chain is located between the third ball hole, the sixth ball groove and the third ball groove. The screw slide device as described in claim 3, wherein the ball unit further includes two first cover plates, two second cover plates and two third cover plates, The first cover plates are respectively locked and fixed to the connection surfaces and cover the first ball hole, the fourth ball groove and the first ball groove, each first cover plate has a first protrusion embedded in the first ball groove, and a contact surface provided with a first revolving groove, the first revolving groove of the first cover plates connects the first ball hole, the fourth ball groove and the first ball groove, and cooperates to form a first circulation channel, and the first ball chain is located in the first circulation channel and circulates and rolls; The second cover plates are respectively locked and fixed to the connection surfaces and cover the second ball holes, the fifth ball grooves and the second ball grooves. Each second cover plate has two second protrusions respectively embedded in the second ball grooves, and a contact surface with two second rotary grooves. The second rotary grooves of the second cover plates are connected to the corresponding second ball holes, the fifth ball grooves and the second ball grooves, and cooperate to form two second circulation channels. The second ball chains are respectively located in the second circulation channels and circulate and roll; The third cover plates are respectively locked and fixed to the connection surfaces and cover the third ball holes, the sixth ball grooves and the third ball grooves. Each third cover plate has two third protrusions respectively embedded in the third ball grooves, and a contact surface with two third rotating grooves. The third rotating grooves of the third cover plates are connected to the corresponding third ball holes, the sixth ball grooves and the third ball grooves, and cooperate to form two third circulation channels. The third ball chains are respectively located in the third circulation channels and circulate and roll. A robot arm comprises: a feeding device extending along a first direction, the feeding device comprising a guide rail seat, a linear transmission unit mounted on the guide rail seat, and a slide driven by the linear transmission unit and capable of linear movement; a screw slide device as claimed in any one of claims 1 to 4, the screw slide device being mounted on the slide of the feeding device and extending along a second direction intersecting the first direction; and a clamping device mounted on the slide of the screw slide device, the clamping device comprising a chuck. A robotic arm as described in claim 5, wherein the second direction is an upright direction. A robot arm, comprising: A feeding device, which is a screw slide device as in any one of claims 1 to 4, wherein the screw rotates around a first axis; A first rotating device, which is mounted on the slide of the feeding device and can move along the first axis, wherein the first rotating device includes a first rotating motor and a turntable connected to a first rotating shaft of the first rotating motor, wherein the first rotating shaft rotates around a second axis, wherein the second axis intersects the first axis; A screw slide device as in any one of claims 1 to 4, which is mounted on the turntable, wherein the screw rotates around a third axis, wherein the third axis is parallel to the second axis; A second rotating device, mounted on the slide seat of the screw slide device, the second rotating device includes a second rotating motor, a second rotating shaft driven by the second rotating motor, a transmission belt mounted between an output shaft of the second rotating motor and the second rotating shaft, and a rotating arm connected to the second rotating shaft, the second rotating shaft rotates around a fourth axis, the fourth axis is parallel to the third axis and the second axis; and A clamping device, including a clamp mounted on the rotating arm. A robot arm as described in claim 7, wherein the clamping device further includes a third rotary motor mounted and fixed on the rotary arm, the clamping head is connected to the third rotary motor and driven by the third rotary motor, and the clamping head rotates around a fifth axis, and the fifth axis intersects with the fourth axis. A robot arm as described in claim 7, wherein the feeding device extends along a first direction, and the screw slide device extends along a second direction intersecting with the first direction, and the second direction is a vertical direction.

Images