CN109312835B - Robot, motor unit, and coupling unit - Google Patents
Robot, motor unit, and coupling unit Download PDFInfo
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- CN109312835B CN109312835B CN201680086999.3A CN201680086999A CN109312835B CN 109312835 B CN109312835 B CN 109312835B CN 201680086999 A CN201680086999 A CN 201680086999A CN 109312835 B CN109312835 B CN 109312835B
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- shaft
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- F16D1/00—Couplings for rigidly connecting two coaxial shafts or other movable machine elements
- F16D1/02—Couplings for rigidly connecting two coaxial shafts or other movable machine elements for connecting two abutting shafts or the like
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16H—GEARING
- F16H25/00—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms
- F16H25/18—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms for conveying or interconverting oscillating or reciprocating motions
- F16H25/20—Screw mechanisms
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- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Transmission Devices (AREA)
- Manipulator (AREA)
Abstract
The robot of the present invention includes: a ball screw (3) having a rotatable screw shaft (31); a moving body (32) that is screwed to the screw shaft (31) and moves with the rotation of the screw shaft (31); a motor (2) that has a rotatable output shaft (21) and rotates the output shaft (21); a shaft body (41) in which: a first hole (421) that has a shape corresponding to the shape of the shaft end (31b) of the screw shaft (31) and that opens to one axial side; and a second hole (422) having a shape corresponding to the shape of the shaft end (31b) of the output shaft (21) and opening to the other side opposite to the one side in the axial direction, wherein the shaft body (41) positions the shaft end (31b) of the threaded shaft (31) fitted into the first hole (421) and the shaft end (31b) of the output shaft (21) fitted into the second hole (422) in the radial direction; a first fixing section (43) for fixing the threaded shaft (31) to the shaft body (41), the threaded shaft (31) having a shaft end (31b) fitted into the first hole (421); and a second fixing portion (45) for fixing the output shaft (21) having a shaft end fitted into the second hole (422) to the shaft body (41).
Description
Technical Field
The present invention relates to a technique for coupling a screw shaft of a ball screw to an output shaft of a motor.
Background
In an industrial robot such as a single-axis robot, a linear motion mechanism is generally used that moves a moving body screwed with a ball screw by driving the ball screw using a motor. For example, in the single-axis robot described in patent document 1, a tubular rotating portion is built in a motor, and a shaft end of a screw shaft of a ball screw fitted into a hollow portion of the rotating portion is fixed to the rotating portion. When the motor rotates the rotating portion, the screw shaft of the ball screw rotates with the rotating portion.
Documents of the prior art
Patent document
Patent document 1: japanese patent laid-open No. 2001-304370
Disclosure of Invention
Problems to be solved by the invention
However, depending on the motor, instead of the tubular rotating portion, an output shaft, which is a shaft-shaped rotating portion, may be rotated. In order to use such a motor, it is necessary to couple the screw shaft of the ball screw to the output shaft of the motor.
The present invention has been made in view of the above problems, and an object thereof is to provide a technique capable of coupling a screw shaft of a ball screw to an output shaft of a motor.
Means for solving the problems
The robot of the present invention includes: a ball screw having a rotatable screw shaft; a moving body that is screwed to the screw shaft and moves with the rotation of the screw shaft; a motor having a rotatable output shaft and rotating the output shaft; a shaft body having formed therein in an axial direction: a first hole having a shape corresponding to a shape of an end of the screw shaft and opening to one side in the axial direction; and a second hole having a shape corresponding to the shape of the shaft end of the output shaft and opening to the other side opposite to the one side in the axial direction, the shaft body positioning the shaft end of the screw shaft fitted into the first hole and the shaft end of the output shaft fitted into the second hole in the radial direction; a first fixing portion for fixing the screw shaft with the shaft end inserted into the first hole to the shaft body; and a second fixing portion for fixing the output shaft with the shaft end inserted into the second hole to the shaft body.
The motor unit of the present invention includes: a motor having a rotatable output shaft and rotating the output shaft; a shaft body having formed therein in an axial direction: a first hole having a shape corresponding to a shape of an axial end of a screw shaft of the ball screw and opening to one side in an axial direction; and a second hole having a shape corresponding to the shape of the shaft end of the output shaft and opening to the other side opposite to the one side in the axial direction, the shaft body positioning the shaft end of the screw shaft fitted into the first hole and the shaft end of the output shaft fitted into the second hole in the radial direction; a first fixing portion for fixing the screw shaft with the shaft end inserted into the first hole to the shaft body; and a second fixing portion for fixing the output shaft with the shaft end inserted into the second hole to the shaft body.
The coupling unit of the present invention includes: a shaft body having formed therein in an axial direction: a first hole having a shape corresponding to a shape of an axial end of a screw shaft of the ball screw and opening to one side in an axial direction; and a second hole having a shape corresponding to the shape of the shaft end of the output shaft of the motor and opening to the other side opposite to the one side in the axial direction, the shaft body positioning the shaft end of the screw shaft fitted into the first hole and the shaft end of the output shaft fitted into the second hole in the radial direction; a first fixing portion for fixing the screw shaft with the shaft end inserted into the first hole to the shaft body; and a second fixing portion for fixing the output shaft with the shaft end inserted into the second hole to the shaft body.
The present invention (robot, motor unit, coupling unit) configured as described above includes a shaft body provided with a first hole that opens to one side in the axial direction and a second hole that opens to the other side in the axial direction. The first hole has a shape corresponding to the shape of the shaft end of the screw shaft of the ball screw, and the second hole has a shape corresponding to the shape of the shaft end of the output shaft of the motor. Such a shaft body positions the shaft end of the screw shaft fitted into the first hole and the shaft end of the output shaft fitted into the second hole in the radial direction. Further, the shaft end of the screw shaft fitted into the first hole is fixed to the shaft body by the first fixing portion, and the shaft end of the output shaft fitted into the second hole is fixed to the shaft body by the second fixing portion, whereby the screw shaft of the ball screw and the output shaft of the motor can be coupled in a state of being positioned relative to each other in the radial direction. In this way, the screw shaft of the ball screw can be coupled to the output shaft of the motor.
Effects of the invention
In the present invention, the screw shaft of the ball screw can be coupled to the output shaft of the motor.
Drawings
Fig. 1 is a perspective view showing an external configuration of an example of a single-axis robot according to the present invention.
Fig. 2 is a partial sectional view showing an internal structure of the single-axis robot of fig. 1.
Fig. 3 is a partial sectional view showing the periphery of the coupling unit in an enlarged manner.
Fig. 4 is a partial sectional view showing the periphery of the coupling unit in an enlarged manner.
Fig. 5 is a front perspective view of the coupling unit.
Fig. 6 is a rear perspective view of the coupling unit.
Detailed Description
Fig. 1 is a perspective view showing an external configuration of an example of a single-axis robot according to the present invention. Fig. 2 is a partial sectional view showing an internal structure of the single-axis robot of fig. 1. The single-axis robot 1 includes a rectangular housing 11 elongated in the X direction and a slider 13 reciprocating in the X direction along the housing 11. The single-axis robot 1 includes a motor 2 attached to an end portion of the housing 11 in the X direction, and the motor 2 generates a driving force for moving the slider 13.
In other words, as shown in fig. 2, the single-axis robot 1 includes a ball screw 3 and a coupling unit 4 that couples the ball screw 3 and the motor 2 inside a housing 11. The ball screw 3 has a screw shaft 31 disposed parallel to the X direction and rotatable, and a nut 32 screwed with the screw shaft 31, and the slider 13 is attached to the nut 32. The motor 2 has a rotatable output shaft 21 disposed parallel to the X direction. The screw shaft 31 of the ball screw 3 is coupled to the output shaft 21 of the motor 2 via the coupling unit 4. Therefore, when the motor 2 rotates the output shaft 21, the screw shaft 31 of the ball screw 3 rotates along with the output shaft 21, and the nut 32 moves the slider 13 in the X direction.
Fig. 3 and 4 are partial cross-sectional views showing the periphery of the coupling unit in an enlarged manner. Fig. 5 is a front perspective view of the coupling unit, and fig. 6 is a rear perspective view of the coupling unit. Fig. 3 shows a state in which the output shaft 21 of the motor 2 and the screw shaft 31 of the ball screw 3 are coupled to each other by the coupling unit 4, and fig. 4 shows a state in which the structures of the motor 2, the ball screw 3, and the coupling unit 4 are disassembled in the X direction, that is, the axial direction T of the output shaft 21 and the screw shaft 31. In fig. 3 and 4, the internal structure of the motor 2 is shown by broken lines, and the housing 11 partially shown in fig. 3 is omitted in fig. 4.
The motor 2 has: two radial bearings 22 supporting the output shaft 21 from the radial direction R; and a housing 23 that houses an electric circuit (not shown) for rotating the output shaft 21, the radial bearing 22, and the like. The shaft end 21a (output shaft end 21a) of the output shaft 21 protrudes from the housing 22 toward one side Ta in the axial direction T (i.e., toward the screw shaft 31). The shaft end 21a of the output shaft 21 has a cylindrical shape, and the outer peripheral surface of the shaft end 21a of the output shaft 21 is formed smoothly in parallel with the axial direction T, and has no step. Further, the corners of the shaft ends 21a are chamfered.
The screw shaft 31 of the ball screw 3 includes: a screw portion 31a provided with a screw thread 310 to which a nut 32 is screwed; and a shaft end 31b (a screw shaft end 31b) provided adjacent to the threaded portion 31a, the shaft end 31b extending from the threaded portion 31a toward the other side Tb (i.e., the output shaft 21 side and the opposite side to the one side Ta) in the axial direction T. The shaft end 31b has a cylindrical shape, and the outer peripheral surface of the shaft end 31b of the screw shaft 31 is formed smoothly in parallel with the axial direction T, and has no step. Further, the corners of the shaft end 31b are chamfered.
The coupling unit 4 couples the shaft end 21a of the output shaft 21 and the shaft end 31b of the threaded shaft 31, which are aligned in the axial direction T and face each other. The coupling unit 4 includes a shaft body 41 extending in the axial direction T. The shaft body 41 is a rigid body made of metal or the like, and has a shape rotationally symmetrical with respect to a symmetry axis parallel to the axial direction T. The shaft body 41 has a flange 411 formed at an end portion of one side Ta in the axial direction T and a threaded portion 412 formed at an end portion of the other side Tb in the axial direction T. The shaft body 41 is formed with a hollow portion 42 penetrating in the axial direction T, and the hollow portion 42 has a first insertion hole 421 opening to one side Ta of the axial direction T and a second insertion hole 422 opening to the other side Tb of the axial direction T. The first insertion hole 421 and the second insertion hole 422 each have a concentric cylindrical shape extending in the axial direction T, and an annular protrusion 423 protruding inward from the inner wall of the hollow portion 42 of the shaft body 41 is formed between the first insertion hole 421 and the second insertion hole 422.
The first insertion hole 421 has a shape corresponding to the shape of the shaft end 31b (first shaft end) of the screw shaft 31, and in this example, the first insertion hole 421 has a cylindrical shape having a diameter equal to the diameter of the cylindrical shape of the shaft end 31b of the screw shaft 31. In other words, the inner diameter of the first insertion hole 421 is equal to the outer diameter of the shaft end 31b of the screw shaft 31. Therefore, the shaft end 31b of the screw shaft 31 can be fitted into the first fitting hole 421 of the shaft body 41 without play from the one side Ta in the axial direction T, and the shaft body 41 restrains the shaft end 31b of the screw shaft 31 fitted into the first fitting hole 421 in the radial direction R.
The second insertion hole 422 has a shape corresponding to the shape of the shaft end 21a (second shaft end) of the output shaft 21, and in this example, the second insertion hole 422 has a cylindrical shape having a diameter equal to the diameter of the cylindrical shape of the shaft end 21a of the output shaft 21. In other words, the inner diameter of the second insert hole 422 is equal to the outer diameter of the shaft end 21a of the output shaft 21. Therefore, the shaft end 21a of the output shaft 21 can be fitted into the second fitting hole 422 of the shaft body 41 from the other side Tb in the axial direction T without play, and the shaft body 41 restrains the shaft end 21a of the output shaft 21 fitted into the second fitting hole 422 in the radial direction R.
In other words, the screw shaft 31 having the shaft end 31b fitted into the first fitting hole 421 and the output shaft 21 having the shaft end 21a fitted into the second fitting hole 422 are both constrained in the radial direction R by the shaft body 41. Thus, the shaft body 41 positions the shaft end 31b of the screw shaft 31 and the shaft end 21a of the output shaft 21 relative to each other in the radial direction R in a state where their center lines coincide with each other.
The hollow portion 42 of the shaft body 41 has a tapered hole 424 extending from the first insertion hole 421 to one side Ta in the axial direction T. The tapered hole 424 has a truncated cone shape whose diameter increases toward the one side Ta in the axial direction T, and a gap 425 is formed between the shaft end 31b of the screw shaft 31 fitted into the first fitting hole 421 and an inner wall of the shaft body 41 defining the tapered hole 424.
The coupling unit 4 has a wedging ring 43 inserted into the gap 425. The wedging ring 43 has a shape rotationally symmetrical with respect to an axis of symmetry parallel to the axial direction T. A hollow portion 431 penetrating in the axial direction T is formed in the caulking ring 43. The hollow portion 431 has a cylindrical shape having a diameter equal to the diameter of the cylindrical shape of the shaft end 31b of the screw shaft 31, and the shaft end 31b of the screw shaft 31 is fitted into the hollow portion 431 of the caulking ring 43. On the other hand, the other end Tb of the caulking ring 43 has a truncated cone-shaped outer shape having a diameter decreasing toward the other side Tb in the axial direction T. In other words, the peripheral edge of the end portion on the other side Tb of the caulking ring 43 has a wedge shape, and functions as an insertion portion 432 (wedge) that can be inserted into and removed from the gap 425. The wedge ring 43 has a flange 433 at an end on one side Ta.
When the insertion portion 432 of the wedge ring 43 is inserted into the gap 425 between the threaded shaft 31 and the shaft body 41, it is pressed by the inner wall of the tapered hole 424 of the shaft body 41 and the outer periphery of the shaft end 31b of the threaded shaft 31. Thereby, the shaft end 31b of the screw shaft 31 fitted into the first fitting hole 421 is fastened to the shaft body 41. The flange 433 of the wedge ring 43 is fastened to the flange 411 of the shaft body 41 by a screw 434. In this way, the screw shaft 31 can be reliably fixed to the shaft body 41 by the wedge ring 43.
Incidentally, an O-ring 44 made of rubber is disposed inside the first insertion hole 421 of the shaft body 41, and the shaft end 31b of the threaded shaft 31 is in contact with the annular protrusion 423 of the shaft body 41 via the O-ring 44. Therefore, the shaft end 31b of the screw shaft 31 is introduced into the first fitting hole 421 with the insertion of the caulking ring 43, and accordingly the O-ring 44 is elastically deformed. By the O-ring 44, the movement of the shaft end 31b of the threaded shaft 31 is not obstructed, and the fastening strength between the shaft end 31b of the threaded shaft 31 and the shaft body 41 is improved.
The coupling unit 4 further includes a split fastening mechanism 45 provided on the other side Tb of the shaft body 41. The split fastening mechanism 45 is formed integrally with the shaft body 41, and is provided at an end portion of the other side Tb of the shaft body 41. As shown in fig. 5, the split fastening mechanism 45 includes: two semi-circular members 451; a screw 452 fastening the two semicircular parts 451 to each other; and a pin 453 for attaching the two semicircular members 451 to each other. The two semicircular members 451 are arranged to form a circle, and a hollow portion 454 is formed therebetween. The hollow portion 454 of the split fastening mechanism 45 has a substantially cylindrical shape penetrating in the axial direction T, and is aligned with the second insertion hole 422 of the shaft body 41 in the axial direction T. When the shaft end 21a of the output shaft 21 is screwed into the screw 452 while being fitted into the second fitting hole 422 through the hollow portion 454 of the split fastening mechanism 45, the inner periphery of each semicircular member 451 is pressed against the outer periphery of the shaft end 21a of the output shaft 21 (split fastening). The two semicircular members 451 thus sandwich the shaft end 21a of the output shaft 21, thereby fastening the shaft end 21a of the output shaft 21 to the shaft body 41. This enables the output shaft 21 to be reliably fixed to the shaft body 41 by the split fastening mechanism 45.
In this way, the screw shaft 31 of the ball screw 3 and the output shaft 21 of the motor 2, which are positioned in the radial direction R by the shaft body 41, are fixed to the shaft body 41 by the wedge ring 43 and the split fastening mechanism 45, respectively. Thereby, the screw shaft 31 of the ball screw 3 is coupled to the output shaft 21 of the motor 2.
The coupling unit 4 includes two thrust bearings 46 for supporting the shaft body 41 in the axial direction T, and a base 47 for supporting the thrust bearings 46. The thrust bearing 46 has a housing raceway plate 461 fixed to the base 47 and a shaft raceway plate 462 supporting the shaft body 41. The base 47 is fixed to the housing 11 of the single-axis robot 1 by screws 470, and functions to support the shaft body 41 with respect to the housing 11 via the thrust bearing 46.
Specifically, the base 47 is formed with a shaft hole 471 that penetrates in the axial direction T. The diameter of the shaft hole 471 is slightly larger than the diameter of the outer periphery 41a of the shaft body 41 (the outer periphery of the cylindrical portion 41b between the flange 411 and the threaded portion 412), and the shaft body 41 is fitted into the shaft hole 471 of the base 47. The outer periphery 41a of the cylindrical portion 41b of the shaft body 41 has a shape corresponding to the inner periphery of the shaft raceway plate 462 of each thrust bearing 46. That is, the outer periphery 41a of the cylindrical portion 41b of the wedge ring 43 is formed to have a diameter equal to the diameter of the inner periphery of the shaft raceway plate 462 of each thrust bearing 46, and the shaft body 41 is fitted inside each thrust bearing 46. The diameter of the housing raceway disk 461 of each thrust bearing 46 is equal to or slightly larger than the diameter of the outer periphery 41a of the cylindrical portion 41b of the wedge ring 43. The two thrust bearings 46 are disposed so as to sandwich the peripheral edge 472 of the shaft hole 471 of the base 47 from the axial direction T. Then, a washer 482 (a toothed seat) is interposed between the thrust bearing 46 on the other side Tb of the two thrust bearings 46, and the nut 481 is attached to the threaded portion 412 of the shaft body 41.
Thus, the washer 482, the thrust bearing 46 (the other side thrust bearing 46b), the peripheral edge 472 of the base 47, and the thrust bearing 46 (the one side thrust bearing 46a) arranged in the axial direction T are sandwiched by the flange 411 and the nut 481. Therefore, when the nut 481 is screwed into the screw portion 412 of the shaft body 41, the housing raceway plate 461 of each thrust bearing 46 is pressed against the peripheral edge 472 of the base 47, the shaft raceway plate 462 of the thrust bearing 46 on one side Ta is pressed against the flange 411 of the shaft body 41, and the shaft raceway plate 462 of the thrust bearing 46 on the other side Tb is pressed against the nut 481 screwed into the shaft body 41 via the washer 482. Thereby, the housing raceway plate 461 of each thrust bearing 46 is fixed to the base 47, and the shaft raceway plate 462 of the thrust bearing 46 is fixed to the shaft body 41.
In such a configuration, the support of the screw shaft 31 and the output shaft 21 coupled by the coupling unit 4 in the axial direction T is mainly achieved by the thrust bearing 46. The support of the screw shaft 31 and the output shaft 21 in the radial direction R is mainly achieved by the radial bearing 22 of the motor 2.
In the embodiment described above, the shaft body 41 is provided with the first insertion hole 421 that opens on one side Ta in the axial direction T and the second insertion hole 422 that opens on the other side Tb in the axial direction T. The first insertion hole 421 has a shape corresponding to the shape of the shaft end 31b of the screw shaft 31 of the ball screw 3, and the second insertion hole 422 has a shape corresponding to the shape of the shaft end 21a of the output shaft 21 of the motor 2. In the shaft body 41, the shaft end 31b of the screw shaft 31 fitted into the first fitting hole 421 and the shaft end 21a of the output shaft 21 fitted into the second fitting hole 422 are positioned in the radial direction R. Further, the shaft end 31b of the screw shaft 31 fitted into the first fitting hole 421 is fixed to the shaft body 41 by the caulking ring 43, and the shaft end 21a of the output shaft 21 fitted into the second fitting hole 422 is fixed to the shaft body 41 by the half fastening mechanism 45, whereby the screw shaft 31 of the ball screw 3 and the output shaft 21 of the motor 2 can be coupled in a state of being positioned relative to each other in the radial direction R. In this way, the screw shaft 31 of the ball screw 3 can be coupled to the output shaft 21 of the motor 2.
Further, since the screw shaft 31 and the output shaft 21 are directly coupled by the coupling unit 4 without interposing a plate spring coupling or the like, the single-axis robot 1 can be shortened in the axial direction T.
Further, a thrust bearing 46 to which a housing raceway disk 461 is fixed is provided on a base 47 fixed to the housing 11, and a shaft raceway disk 462 of the thrust bearing 46 fitted into the outer periphery of the shaft body 41 is fixed to the shaft body 41. By supporting the shaft body 41 with respect to the housing 11 by the thrust bearing 46 in this way, the shaft body 41 can be reliably supported in the axial direction T, and the shaft body 41 can be smoothly rotated.
The outer periphery 41a of the cylindrical portion 41b of the shaft body 41 that supports the shaft end 31b of the screw shaft 31 has a shape corresponding to the inner periphery of the shaft raceway plate 462 of each thrust bearing 46, and the shaft raceway plate 462 of the thrust bearing 46 is disposed on the outer periphery of the shaft body 41. Therefore, it is not necessary to perform shaft end processing for matching the shape of the shaft end 31b of the screw shaft 31 with the shape of the inner periphery of the shaft raceway plate 462 of the thrust bearing 46 in order to support the screw shaft 31 by the thrust bearing 46.
Specifically, the base 47 is provided with a shaft hole 471 penetrating in the axial direction T. The shaft body 41 is fitted into the shaft hole 471, and the two thrust bearings 46 are arranged in the axial direction T so as to sandwich the peripheral edge 472 of the shaft hole 471 of the base 47. The shaft body 41 has a flange 411 provided at an end of one side Ta and a screw portion 412 provided at an end of the other side Tb. Further, the housing raceway disks 461 of the two thrust bearings 46 are fixed to the base 47, and the shaft raceway disks 462 of the two thrust bearings 46 are fixed to the shaft body 41, by sandwiching the peripheral edge portions 472 of the two thrust bearings 46 and the base 47 by the nuts 481 screwed to the screw portions 412 and the flange 411. In such a configuration, the fixation of the housing rail plate 461 to the base 47 and the fixation of the shaft rail plate 462 to the shaft body 41 can be easily achieved by screwing the nut 481 to the screw portion 412 of the shaft body 41.
The shaft body 41 is provided with an annular projection 423 adjacent to the first insertion hole 421, and the shaft end 31b of the threaded shaft 31 inserted into the first insertion hole 421 abuts against the annular projection 423 via the O-ring 44. In such a configuration, even if the end surface of the shaft end 31b of the screw shaft 31 is slightly inclined, the inclination can be absorbed by the elastic deformation of the O-ring 44, and therefore the inclination of the screw shaft 31 in which the shaft end 31b is fitted into the first fitting hole 421 is suppressed.
In the above embodiment, the first insertion hole 421 having the same diameter as the shaft end 31b of the screw shaft 31 of the ball screw 3 and the second insertion hole 422 having the same diameter as the shaft end 21a of the output shaft 21 of the motor 2 are formed in the shaft body 41. Therefore, the worker who performs the work of coupling the screw shaft 31 of the ball screw 3 and the output shaft 21 of the motor 2 does not need to perform the shaft end machining of cutting the outer periphery of the shaft end 31b in particular in order to match the diameter of the shaft end 31b of the screw shaft 31 with the diameter of the first insertion hole 421, nor does the worker need to perform the shaft end machining of cutting the outer periphery of the shaft end 21a in particular in order to match the diameter of the shaft end 21a of the output shaft 21 with the diameter of the second insertion hole 422, and as the work required of the worker, the degree of the work of cutting the shaft end 31b and the shaft end 21a in order to adjust the lengths thereof becomes high. Therefore, it is possible to suppress the inclination of the screw shaft 31 of the ball screw 3 and the output shaft 21 of the motor 2 fitted into the shaft body 41 due to the accuracy of the shaft end processing by the operator. As a result, the center of the screw shaft 31 of the ball screw 3 and the output shaft 21 of the motor 2 can be accurately determined.
In other words, the shaft end 31b of the screw shaft 31 has a cylindrical shape, and the first insertion hole 421 of the shaft body 41 also has a cylindrical shape having the same diameter as the cylindrical shape. As described above, the shaft end 31b of the threaded shaft 31 has a shape (cylindrical shape) that can be formed with high accuracy by the manufacturer of the threaded shaft 31, and the first insertion hole 421 of the shaft body 41 also has the same shape as the shaft end 31b of the threaded shaft 31. Therefore, the operator may fit the shaft end 31b of the threaded shaft 31 having high shape accuracy into the first fitting hole 421 of the shaft body 41 without performing shaft end processing, and the inclination of the threaded shaft 31 fixed to the shaft body 41 can be suppressed more reliably.
Similarly, the shaft end 21a of the output shaft 21 has a cylindrical shape, and the second insertion hole 422 of the shaft body 41 also has a cylindrical shape having the same diameter as the cylindrical shape. In this way, the shaft end 21a of the output shaft 21 has a shape (cylindrical shape) that can be formed with high accuracy by the manufacturer of the output shaft 21, and the second insertion hole 422 of the shaft body 41 also has the same shape as the shaft end 21a of the output shaft 21. Therefore, the operator may fit the shaft end 21a of the output shaft 21 having high shape accuracy into the second fitting hole 422 of the shaft body 41 without performing shaft end processing, and the inclination of the output shaft 21 fixed to the shaft body 41 can be suppressed more reliably.
At this time, the coupling unit 4 may be configured such that the diameter of the first insertion hole 421 of the shaft body 41 is equal to the diameter of the shaft end 31b determined by the specification defining the structure of the threaded shaft 31. Alternatively, the coupling unit 4 may be configured such that the diameter of the second insertion hole 422 of the shaft body 41 is equal to the diameter of the shaft end 21a determined by the specification that defines the configuration of the output shaft 21.
In the above-described embodiment, the single-axis robot 1 corresponds to an example of the "robot" of the present invention, the motor unit MU including the coupling unit 4 and the motor 2 corresponds to an example of the "motor unit" of the present invention, the coupling unit 4 corresponds to an example of the "coupling unit" of the present invention, the ball screw 3 corresponds to an example of the "ball screw" of the present invention, the screw shaft 31 corresponds to an example of the "screw shaft" of the present invention, the shaft end 31b corresponds to an example of the "shaft end of the screw shaft" of the present invention, the screw portion 31a corresponds to an example of the "screw portion" of the screw shaft of the present invention, the nut 32 and the slider 13 cooperate to function as the "movable body" of the present invention, the motor 2 corresponds to an example of the "motor" of the present invention, and the output shaft 21 corresponds to an example of the "output shaft" of the present invention, the shaft end 21a corresponds to an example of the "shaft end of the output shaft" of the present invention, the shaft body 41 corresponds to an example of the "shaft body" of the present invention, the first insertion hole 421 corresponds to an example of the "first hole" of the present invention, the second insertion hole 422 corresponds to an example of the "second hole" of the present invention, the flange 411 corresponds to an example of the "flange" of the present invention, the threaded portion 412 corresponds to an example of the "threaded portion" of the shaft body of the present invention, the annular protrusion 423 corresponds to an example of the "abutting portion" of the present invention, the O-ring 44 corresponds to an example of the "elastic member" of the present invention, the caulking ring 43 corresponds to an example of the "first fixing portion" and the "caulking ring" of the present invention, the split fastening mechanism 45 corresponds to an example of the "second fixing portion" and the "split fastening mechanism" of the present invention, and the housing 11 corresponds to an example of the "housing" of the present invention, the base 47 corresponds to an example of the "base" of the present invention, the shaft hole 471 corresponds to an example of the "shaft hole" of the present invention, the peripheral edge 472 corresponds to an example of the "peripheral edge" of the present invention, the thrust bearing 46 corresponds to an example of the "thrust bearing" of the present invention, the thrust bearing 46a corresponds to an example of the "one-side thrust bearing" of the present invention, the thrust bearing 46b corresponds to an example of the "other-side thrust bearing" of the present invention, the housing rail plate 461 corresponds to an example of the "housing rail plate" of the present invention, the shaft rail plate 462 corresponds to an example of the "shaft rail plate" of the present invention, the nut 481 corresponds to an example of the "nut" of the present invention, the axial direction T corresponds to an example of the "axial direction" of the present invention, one side Ta corresponds to an example of the "one side" of the present invention, the other side Tb corresponds to an example of the "the other side" of the present invention, the radial direction R corresponds to an example of the "radial direction" of the present invention.
The present invention is not limited to the above-described embodiments, and various modifications other than the above-described embodiments can be made without departing from the spirit of the invention. For example, the above-described coupling unit 4 may be used to couple the screw shaft 31 of the ball screw 3 to the output shaft 21 of the motor 2 in a multi-axis robot other than the single-axis robot 1.
In addition, when the motor 2 can support the output shaft 21 and the screw shaft 31 in the axial direction, the thrust bearing 46 may be omitted.
The specific mechanism for fixing the screw shaft 31 to the shaft body 41 is not limited to the wedge ring 43, and may be another mechanism such as a split fastening mechanism.
The specific mechanism for fixing the output shaft 21 to the shaft body 41 is not limited to the half fastening mechanism 45, and may be another mechanism such as a wedge ring.
The elastic member provided between the shaft end 31b of the screw shaft 31 and the annular projection 423 is not limited to the O-ring 44, and may be any member that can elastically deform in response to a force from the shaft end 31b of the screw shaft 31. Alternatively, the O-ring 44 may be omitted.
The shaft end 31b of the screw shaft 31 and the shaft end 21a of the output shaft 21 have cylindrical shapes having no step on the outer peripheral surfaces thereof. However, the shapes of the shaft ends 31b and 21a are not limited to this, and may have a key groove, for example. In this case, a key may be appropriately provided in the first insertion hole 421 or the second insertion hole 422 of the shaft body 41.
As described above, the following modifications can be appropriately applied to the present invention.
In other words, the robot may further include: a housing accommodating the shaft body; a base fixed to the housing; and a thrust bearing having a housing track disk fixed to the base and a shaft track disk having a shape corresponding to an inner circumference of the shaft track disk, the shaft track disk being embedded in the outer circumference of the shaft body and fixed to the shaft body. By supporting the shaft body with respect to the housing by the thrust bearing in this manner, the shaft body can be reliably supported in the axial direction and can be smoothly rotated.
The robot may further include a nut, the base may be provided with an axial hole that penetrates in the axial direction, the shaft body may be fitted into the axial hole, the thrust bearing may include a first side thrust bearing and a second side thrust bearing, the first side thrust bearing and the second side thrust bearing may be arranged to hold a peripheral edge portion of the axial hole of the base in the axial direction, the shaft body may include a flange provided at an end portion of the first side and a screw portion provided at an end portion of the second side, and the first side thrust bearing, the peripheral edge portion of the base, and the second side thrust bearing may be held by the flange and the nut screwed into the screw portion, so that the housing raceway plates of the first side thrust bearing and the second side thrust bearing may be fixed to the base, and the shaft raceway plates of the first side thrust bearing and the second side thrust bearing may be fixed to the shaft body. In such a configuration, the fixation of the housing rail plate to the base and the fixation of the shaft rail plate to the shaft body can be easily achieved by screwing the nut into the screw portion of the shaft body.
The robot may be configured such that the first fixing portion includes a wedge ring that fixes the screw shaft to the shaft body by being inserted into a gap between the screw shaft and the shaft body, the gap having a shaft end fitted into the first hole of the shaft body. In such a configuration, the screw shaft can be reliably fixed to the shaft body by the caulking ring.
The robot may be configured such that the second fixing portion includes a split fastening mechanism that is integrally formed with the shaft body and fixes the output shaft having the shaft end fitted into the second hole of the shaft body to the shaft body by split fastening. In such a configuration, the output shaft can be reliably fixed to the shaft body by the split fastening mechanism.
The robot may be configured such that the first hole of the shaft body is provided with a contact portion, and the elastic member is disposed between the contact portion and the shaft end of the threaded shaft fitted into the first hole. In such a configuration, even if the end surface of the shaft end of the screw shaft is slightly inclined, the inclination can be absorbed by the deformation of the elastic member, and therefore, the inclination of the screw shaft in which the shaft end is fitted into the first hole can be suppressed.
In the present invention, a first hole having a shape corresponding to the shape of the shaft end of the screw shaft of the ball screw and a second hole having a shape corresponding to the shape of the shaft end of the output shaft of the motor are formed in the shaft body. Therefore, an operator performing the work of coupling the screw shaft of the ball screw and the output shaft of the motor does not need to perform, in particular, shaft end machining for matching the shaft end shape of the screw shaft of the ball screw with the shape of the first hole and shaft end machining for matching the shaft end shape of the output shaft of the motor with the shape of the second hole. Therefore, it is possible to suppress the inclination of the screw shaft of the ball screw and the output shaft of the motor that are fitted into the shaft body due to the accuracy of the shaft end processing by the operator. As a result, the center of the screw shaft of the ball screw and the output shaft of the motor can be accurately determined.
Here, the robot may be configured such that the shaft end of the screw shaft is provided adjacent to a range of the screw shaft in which the screw portion is formed, and the shaft end of the screw shaft is formed in a cylindrical shape and fitted into the first hole of the shaft body. In such a configuration, the shaft end of the screw shaft has a shape (cylindrical shape) that can be formed with high accuracy by a manufacturer of the screw shaft. Therefore, by fitting the shaft end of the threaded shaft having high shape accuracy into the first hole of the shaft body without performing shaft end processing, the inclination of the threaded shaft fixed to the shaft body can be suppressed more reliably.
The robot may be configured such that the shaft end of the output shaft is formed in a cylindrical shape and fitted into the second hole of the shaft body. In such a configuration, the shaft end of the output shaft has a shape (cylindrical shape) that can be formed with high accuracy by a manufacturer of the output shaft. Therefore, the shaft end of the output shaft having high shape accuracy is fitted into the second hole of the shaft body without performing shaft end processing, and thereby the inclination of the output shaft fixed to the shaft body can be more reliably suppressed.
Industrial applicability
The present invention can be applied to all techniques for coupling the screw shaft of the ball screw and the output shaft of the motor.
Description of the reference numerals
1 … single-axis robot (robot), 11 … housing, 13 … slider (mobile body), 2 … motor, 21 … output shaft, 21a … shaft end (shaft end of output shaft), 3 … ball screw, 31 … screw shaft, 31a … screw portion, 31b … shaft end (shaft end of screw shaft), 310 … screw thread, 32 … nut 32 (mobile body), 4 … coupling unit, 41 … shaft, 41a … (outer circumference of shaft), 41b … cylindrical portion, 411 … flange, 412 … screw portion, 421 … first insertion hole (first hole), 422 … second insertion hole (second hole), 423 … annular projection (abutting portion), 43 … wedge ring (first fixed portion), 44 … O-ring, 45 … split fastening mechanism (second fixed portion), 46 … thrust bearing, 46a … first side thrust bearing, 46b … other side thrust disc bearing, … housing track 462, … track disc, 47 … base, 471 … shaft hole, 472 … peripheral edge, 481 … nut, T … axial direction, Ta … side, Tb … side, R … radial direction, MU … motor unit.
Claims (8)
1. A robot includes:
a ball screw having a rotatable screw shaft;
a moving body that is screwed to the screw shaft and moves with rotation of the screw shaft;
a motor having a rotatable output shaft and rotating the output shaft;
a shaft body having formed therein in an axial direction: a first hole having a shape corresponding to a shape of an end of the screw shaft and opening to one side in an axial direction; and a second hole having a shape corresponding to a shape of a shaft end of the output shaft and opening to the other side opposite to the one side in the axial direction, the shaft body positioning the shaft end of the screw shaft fitted into the first hole and the shaft end of the output shaft fitted into the second hole in the radial direction;
a first fixing portion that fixes the screw shaft, the shaft end of which is fitted into the first hole, to the shaft body;
a second fixing portion that fixes the output shaft, the shaft end of which is fitted into the second hole, to the shaft body;
a housing that houses the shaft body;
a base fixed to the housing; and
a thrust bearing having a housing track disk and a shaft track disk, and the housing track disk is fixed to the base,
the outer circumference of the shaft body has a shape corresponding to the inner circumference of the shaft raceway disk,
the shaft rail plate embedded in the outer circumference of the shaft body is fixed to the shaft body,
the robot is also provided with a nut,
the base is provided with a shaft hole which is through in the axial direction,
the shaft body is embedded into the shaft hole,
the thrust bearing is composed of a first side thrust bearing and a second side thrust bearing, the first side thrust bearing and the second side thrust bearing are arranged so as to sandwich a peripheral edge portion of the shaft hole of the base in an axial direction,
the shaft body has a flange provided at an end portion of the one side and a screw portion provided at an end portion of the other side,
the flange and the nut screwed into the threaded portion clamp the first side thrust bearing, the peripheral edge portion of the base, and the second side thrust bearing, thereby fixing the housing rail plate of the first side thrust bearing and the second side thrust bearing to the base, and fixing the shaft rail plate of the first side thrust bearing and the second side thrust bearing to the shaft body.
2. The robot of claim 1,
the first fixing portion has a wedge ring that fixes the screw shaft to the shaft body by being inserted into a gap between the screw shaft and the shaft body, the gap having a shaft end fitted into the first hole of the shaft body.
3. The robot according to claim 1 or 2,
the second fixing portion has a split fastening mechanism that is integrally formed with the shaft body and fixes the output shaft, whose shaft end is fitted into the second hole of the shaft body, to the shaft body by split fastening.
4. The robot according to claim 1 or 2,
an abutting portion is provided in the first hole of the shaft body,
an elastic member is disposed between the abutting portion and an axial end of the screw shaft fitted into the first hole.
5. The robot according to claim 1 or 2,
an axial end of the screw shaft is provided adjacent to a range of the screw shaft where the screw portion is formed, and the axial end of the screw shaft is formed in a cylindrical shape and is fitted into the first hole of the shaft body.
6. The robot according to claim 1 or 2,
the shaft end of the output shaft is formed in a cylindrical shape and is fitted into the second hole of the shaft body.
7. A motor unit is provided with:
a motor having a rotatable output shaft and rotating the output shaft;
a shaft body having formed therein in an axial direction: a first hole having a shape corresponding to a shape of an axial end of a screw shaft of the ball screw and opening to one side in an axial direction; and a second hole having a shape corresponding to a shape of a shaft end of the output shaft and opening to the other side opposite to the one side in the axial direction, the shaft body positioning the shaft end of the screw shaft fitted into the first hole and the shaft end of the output shaft fitted into the second hole in the radial direction;
a first fixing portion that fixes the screw shaft, the shaft end of which is fitted into the first hole, to the shaft body;
a second fixing portion that fixes the output shaft, the shaft end of which is fitted into the second hole, to the shaft body;
a housing that houses the shaft body;
a base fixed to the housing; and
a thrust bearing having a housing track disk and a shaft track disk, and the housing track disk is fixed to the base,
the outer circumference of the shaft body has a shape corresponding to the inner circumference of the shaft raceway disk,
the shaft rail plate embedded in the outer circumference of the shaft body is fixed to the shaft body,
the motor unit is further provided with a nut,
the base is provided with a shaft hole which is through in the axial direction,
the shaft body is embedded into the shaft hole,
the thrust bearing is composed of a first side thrust bearing and a second side thrust bearing, the first side thrust bearing and the second side thrust bearing are arranged so as to sandwich a peripheral edge portion of the shaft hole of the base in an axial direction,
the shaft body has a flange provided at an end portion of the one side and a screw portion provided at an end portion of the other side,
the flange and the nut screwed into the threaded portion clamp the first side thrust bearing, the peripheral edge portion of the base, and the second side thrust bearing, thereby fixing the housing rail plate of the first side thrust bearing and the second side thrust bearing to the base, and fixing the shaft rail plate of the first side thrust bearing and the second side thrust bearing to the shaft body.
8. A coupling unit is provided with:
a shaft body having formed therein in an axial direction: a first hole having a shape corresponding to a shape of an axial end of a screw shaft of the ball screw and opening to one side in an axial direction; and a second hole having a shape corresponding to a shape of a shaft end of an output shaft of a motor and opening to the other side opposite to the one side in the axial direction, the shaft body positioning the shaft end of the screw shaft fitted into the first hole and the shaft end of the output shaft fitted into the second hole in the radial direction;
a first fixing portion that fixes the screw shaft, the shaft end of which is fitted into the first hole, to the shaft body; and
a second fixing portion that fixes the output shaft, the shaft end of which is fitted into the second hole, to the shaft body;
a housing that houses the shaft body;
a base fixed to the housing; and
a thrust bearing having a housing track disk and a shaft track disk, and the housing track disk is fixed to the base,
the outer circumference of the shaft body has a shape corresponding to the inner circumference of the shaft raceway disk,
the shaft rail plate embedded in the outer circumference of the shaft body is fixed to the shaft body,
the coupling unit is further provided with a nut,
the base is provided with a shaft hole which is through in the axial direction,
the shaft body is embedded into the shaft hole,
the thrust bearing is composed of a first side thrust bearing and a second side thrust bearing, the first side thrust bearing and the second side thrust bearing are arranged so as to sandwich a peripheral edge portion of the shaft hole of the base in an axial direction,
the shaft body has a flange provided at an end portion of the one side and a screw portion provided at an end portion of the other side,
the flange and the nut screwed into the threaded portion clamp the first side thrust bearing, the peripheral edge portion of the base, and the second side thrust bearing, thereby fixing the housing rail plate of the first side thrust bearing and the second side thrust bearing to the base, and fixing the shaft rail plate of the first side thrust bearing and the second side thrust bearing to the shaft body.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/JP2016/077773 WO2018055682A1 (en) | 2016-09-21 | 2016-09-21 | Robot, motor unit, and coupling unit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109312835A CN109312835A (en) | 2019-02-05 |
| CN109312835B true CN109312835B (en) | 2021-09-07 |
Family
ID=61689864
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201680086999.3A Active CN109312835B (en) | 2016-09-21 | 2016-09-21 | Robot, motor unit, and coupling unit |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JP6647414B2 (en) |
| CN (1) | CN109312835B (en) |
| WO (1) | WO2018055682A1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113043314B (en) * | 2021-03-30 | 2022-11-08 | 滨州学院 | Mechanical automation grabbing device |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5924558U (en) * | 1982-08-05 | 1984-02-15 | 赤井電機株式会社 | Screw feed linear movement device |
| JPS6139054U (en) * | 1984-08-13 | 1986-03-12 | 長年 川井 | Knife guide groove plate |
| JPH049470Y2 (en) * | 1985-08-28 | 1992-03-10 | ||
| JPH0763906B2 (en) * | 1988-01-28 | 1995-07-12 | 日産自動車株式会社 | Positioning device |
| CN2238937Y (en) * | 1995-08-18 | 1996-10-30 | 首钢总公司 | Coupling with axial displacement special function |
| JPH1078098A (en) * | 1996-09-04 | 1998-03-24 | Yamaha Motor Co Ltd | Shaft connecting structure in single axis robot |
| DE29700712U1 (en) * | 1997-01-16 | 1997-02-27 | RK Rose + Krieger GmbH & Co. KG Verbindungs- und Positioniersysteme, 32423 Minden | Spindle drive |
| JP2002054709A (en) * | 2000-08-08 | 2002-02-20 | Makishinkoo:Kk | Rodless rectilinear operating machine |
| WO2014083597A1 (en) * | 2012-11-30 | 2014-06-05 | 黒田精工株式会社 | Shaft end adaptor and ball screw assembly |
| CN204035027U (en) * | 2014-08-07 | 2014-12-24 | 四川省双源环保设备有限公司 | A kind of sand-stone separator promotes screw mechanism |
| CN108971364A (en) * | 2018-08-28 | 2018-12-11 | 航珍航空技术（上海）有限公司 | Flareless inward turning single lead screw ex truding briquetting machine and its expander |
-
2016
- 2016-09-21 WO PCT/JP2016/077773 patent/WO2018055682A1/en active Application Filing
- 2016-09-21 CN CN201680086999.3A patent/CN109312835B/en active Active
- 2016-09-21 JP JP2018540524A patent/JP6647414B2/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN109312835A (en) | 2019-02-05 |
| JPWO2018055682A1 (en) | 2019-03-07 |
| JP6647414B2 (en) | 2020-02-14 |
| WO2018055682A1 (en) | 2018-03-29 |
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