JP2005256952A - Link operating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily realize elimination of looseness of a bearing and adjustment of preload, in regard to a fall stopper structure for a bearing provided in rotary pair of corners of a link mechanism. <P>SOLUTION: In this link operating device, end link members 1a-3a, 1c-3c are rotatably connected to input and output members 4 and 5 arranged in input and output sides, respectively, and each of the end link members 1a-3a, 1c-3c of the input side and the output side is rotatably connected to central link members 1b-3b to form three pairs or more of link mechanisms 1-3 formed of four rotary pairs of corners 6a-8a, 6b<SB>1</SB>, 6b<SB>2</SB>-8b<SB>1</SB>, 8b<SB>2</SB>, 6c-8c, and cross section in a central part of each of the link mechanisms 1-3 is formed geometrically same in the input side and the output side. Each of rotary corners 6a-8a, 6b<SB>1</SB>, 6b<SB>2</SB>-8b<SB>1</SB>, 8b<SB>2</SB>, 6c-8c of each of the link mechanisms 1-3 is formed into a bearing structure formed of two bearings, and a looseness eliminating means for regulating axial movement of the two bearings is provided in the rotary pairs of corners 6a-8a, 6b<SB>1</SB>, 6b<SB>2</SB>-8b<SB>1</SB>, 8b<SB>2</SB>, 6c-8c. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a link operating device, and for example, relates to a link operating device used for a link mechanism such as a robot joint that performs complicated processing and article handling in a three-dimensional space at high speed and with precision.

  For example, there is a working device equipped with a parallel link mechanism as a link actuating device that performs high-speed and precise operations such as complicated processing and article handling in a three-dimensional space (see, for example, Patent Document 1).

  This working apparatus includes a parallel link mechanism that changes the position and posture of the traveling plate with respect to the base plate by cooperatively expanding and contracting a plurality of links connecting the base plate and the traveling plate. By attaching a tool to the traveling plate of this parallel link mechanism and rotatably arranging a table to hold the workpiece, the position and posture of the tool with respect to the workpiece on the table can be freely changed. It enables complex processing and handling of articles in the space.

In the parallel link mechanism, the mass of the movable part can be reduced, and the positioning error of each link is averaged at the tip, and complicated work in three-dimensional space and handling of articles are performed. It has great features in executing at high speed and precision.
JP 2000-94245 A

  However, in the parallel link mechanism described above, since the operating angle of each link is small, if the operating range of the traveling plate is set to be large, the link length becomes long, which increases the overall size of the mechanism and increases the size of the device. There was a problem of inviting. There is also a problem that the rigidity of the entire mechanism is low and the weight of the tool mounted on the traveling plate, that is, the loadable weight of the traveling plate is limited to a small one.

  In order to solve this problem, the present applicant has previously proposed a link actuating device having a link mechanism having a compact structure, high rigidity, and a large transportable weight (Japanese Patent Application No. 2003-40086). .

  In this link actuating device, the end link members are rotatably connected to the link hubs provided on the input member and the output member, and the end link members on the input side and the output side are connected to the central link member. And three or more sets of link mechanisms that are rotatably connected to each other, and a configuration in which the input side and the output side are geometrically identical with respect to the cross section at the center of each link mechanism. Each link mechanism constitutes a three-bar chain composed of four rotating pairs.

  In this link actuating device, the bearing outer ring is included in the link hub and the bearing inner ring is coupled to the end link member so that the bearing structure is embedded in the link hub. And a drive mechanism such as an actuator that controls the attitude of the end link member via the rotation transmission part is provided, and the output is performed by fixing the input side link hub and driving the rotation transmission part. The side link hub is operated with two degrees of freedom.

  In this link actuating device, since the rotation pair of the link mechanism has a cantilever support structure, it cannot be said that the strength is excellent, and the rigidity of the link mechanism is lowered. Further, in the rotating pair portion of the link mechanism, a groove is formed in the link hub, and a retaining ring is fitted into the groove, thereby preventing the bearing from coming off.

  However, in the bearing retaining structure at the rotating mating part of the link mechanism using a retaining ring, there is an axial clearance between the retaining ring and the axial direction of the rotating mating part by this clearance. This appears as a backlash of the link mechanism. Also, in order to close the radial clearance, the outer ring of the bearing must be press-fitted into the link hub, so that it is difficult to disassemble once assembled. In addition, there are cases where caulking is used as a retaining structure other than the above-described retaining ring, but in this case, since it cannot be disassembled and cannot be regenerated, sufficient attention is required for assembly and maintenance is required. There was also a problem.

  Therefore, the present invention has been proposed in view of the above problems, and its object is to prevent backlash and preload adjustment of the bearing in the retaining structure of the bearing provided in the rotating pair of the link mechanism. It is an object of the present invention to provide a link actuator that can be easily realized.

  As a technical means for achieving the above-mentioned object, the present invention connects the end link members so as to be rotatable with respect to the input / output members respectively arranged on the input / output side. There are three or more sets of link mechanisms consisting of four rotating pairs that rotatably connect the end link members to the center link member, and the input and output sides of the cross section at the center of each link mechanism are geometrical. In the same link operating device, each rotating pair portion of the link mechanism has a bearing structure composed of two bearings, and backlashing means for restricting axial movement of the two bearings is provided in the rotating pair portion. It is characterized by that. In addition, the bearing structure which consists of two bearings also includes the bearing which has one double row structure like a double row angular contact ball bearing.

  Here, each of the three or more sets of link mechanisms provided between the input and output has the same geometric shape, and the reason why the link mechanisms are set to three or more sets is to provide a two-degree-of-freedom mechanism. is there. Here, “the input side and the output side are geometrically identical with respect to the cross section at the center of the link mechanism” means that the input side and the output side are separated on the symmetry plane of the central link member. It means that the geometric shape on the output side is the same.

  Each link mechanism forms a three-bar chain composed of four rotating pairs. The end link members on the input side and the output side have a spherical link structure, and the spherical link centers in the three or more sets of link mechanisms coincide with each other, and the distances from the centers are also the same. The rotation pair axis that becomes the connecting portion between the end link member and the central link member may have a certain crossing angle or may be parallel. However, the shape of the central link member in the three or more sets of link mechanisms is geometrically the same.

  In the present invention, each rotation pair of the link mechanism has a bearing structure composed of two bearings, and the backlash of the bearings at the rotation pair is reduced by providing a backlashing means for restricting the axial movement of the two bearings. It is possible to increase the rigidity of the link mechanism. The above-mentioned backlash means a state in which the bearing is not loose and no preload is applied, and the preload adjustment of the bearing not only eliminates the bearing play but also applies an appropriate preload to the bearing. means.

  As the aforementioned backlash filling means, a structure in which a spacer is interposed between two bearings and the thickness of the spacer is not more than twice the axial clearance of the bearing is desirable. In this way, since the backlash of the bearing can be reduced without applying a preload to the bearing, it is possible to use a miniature bearing that has generally been difficult to apply a preload conventionally. It is easy to reduce the size of the link mechanism. When a bearing other than a miniature bearing is used, it is possible to apply a preload to the bearing if the thickness of the spacer is larger than twice the axial clearance of the bearing.

  Further, as the aforementioned backlash filling means, a structure in which a pressing member for pressing the outer ring end portion of the bearing is attached to the rotating pair portion is desirable. In this way, even if the outer ring of the bearing is inserted into the rotating mating part with a clearance fit, the backlash of the bearing can be reduced by the pressing force by the pressing member, and the assemblability is improved.

  Further, as the aforementioned backlash filling means, a structure in which a locking portion for preload adjustment or positioning is formed on the shaft of the rotating pair is desirable. In addition, as this latching | locking part, the level | step difference formed in the outer peripheral surface of the axis | shaft of a rotation couple part, or the edge part of the axis | shaft of a rotation couple part, between two bearings, between a bearing and an end link member, or a bearing A step formed at least at one place is preferable between the rotation transmitting portion and the rotation transmitting portion. By utilizing this locking portion, it is possible to reduce the backlash of the bearing and to easily perform positioning and preload adjustment of the bearing, the end link member, etc., and to improve assemblability.

  In the above-described configuration, it is desirable to provide a bearing structure in which two bearings are housed in a common housing at each rotation pair of the link mechanism. The two bearings are preferably arranged so that the angular ball bearings are back-to-back. If it does in this way, unitization of the rotation pair which has a bearing structure will become easy to realize.

  Further, in the above-described configuration, two bearings are arranged on the rotating pair portion so as to support both ends of each rotating pair portion of the link mechanism, and the end link member or the central link member enters between the two bearings. Such a structure is desirable. In this way, the space between the two bearings can be used effectively, the space between the rotating pair can be saved, and the link mechanism can be easily made compact.

  Further, in the above-described configuration, a structure in which the rotation transmission portion and the fastening portion of the rotation pair portion and the fastening portion of the end link member and the rotation pair portion are formed in accordance with the phase of the end link member and the rotation transmission portion is desirable. The fastening portion preferably has a structure in which two flat portions formed on the axis of the rotating pair portion are shifted in phase. In this way, the relative positional relationship can be easily set.

  In addition, it is desirable that the structure for supporting both ends of the rotating pair portion of the link mechanism is configured by adding a reinforcing member to the shaft of the rotating pair portion provided in the input / output member. In this way, the backlash of the bearing and preloading can be easily performed, and a structure excellent in strength can be achieved.

  In addition, the rotating pair is preferably a bearing having a shaft-equipped inner ring that can be adjusted in preload or loosened, and the outer ring of the bearing having the shaft-equipped inner ring is preferably a structure having a flange. In this way, the backlash of the bearing and preloading can be easily performed.

  According to the present invention, each rotating pair portion of the link mechanism has a bearing structure including two bearings, and the backlash of the bearing at the rotating pair portion is provided by providing backlashing means for restricting axial movement of the two bearings. As a result, the rigidity of the link mechanism can be increased and the service life can be extended.

  The link actuating device of the embodiment shown in FIG. 1 and FIG. 2 is used for, for example, a link mechanism such as a robot joint that performs high-speed and precise operations such as complicated processing and article handling in a three-dimensional space. A set of link mechanisms 1 to 3 is provided. Each of these three sets of link mechanisms 1 to 3 has the same geometric shape.

As shown in FIGS. 1 and 2, each of the link mechanisms 1 to 3 is rotatably connected to the input side end link members 1 a to 3 a that are rotatably connected to the input member 4 and the output member 5. The output side end link members 1c to 3c and the both end link members 1a to 3a and 1c to 3c are rotatably connected to each other so as to connect the both end link members 1a to 3a and 1c to 3c to each other. is composed of a central link member 1b to 3b, form four rotating pair section _{6a~8a, 6b~8b, 6b 1, 6b} 2 ~8b 1, 8b 2, a three-section chain structure consisting 6C～8c.

The end link members 1a to 3a and 1c to 3c have a spherical link structure, and the spherical link centers in the three sets of link mechanisms 1 to 3 coincide with each other, and the distances from the centers are also the same. End links 1a to 3a, rotating pair section 6b~8b between 1c~3c and central link member 1b to 3b, the connecting shaft of _{6b 1, 6b 2 ~8b 1,} 8b 2 may be at a certain intersection angle , May be parallel. However, the shapes of the central link members 1b to 3b in the three sets of link mechanisms 1 to 3 are geometrically the same.

  In the link mechanisms 1 to 3, the geometric shapes of the end link members 1a to 3a and 1c to 3c are equal on the input side and the output side, and the shapes of the central link members 1b to 3b are also on the input side and the output side. When equal, the angular positional relationship between the central link members 1b to 3b and the end link members 1a to 3a and 1c to 3c connected to the input / output members 4 and 5 is input to the symmetry plane of the central link members 1b to 3b. If the side and the output side are the same, the input member 4 and the input side end link members 1a to 3a and the output member 5 and the output side end link members 1c to 3c move in the same manner due to geometric symmetry, The input side and the output side have the same rotation angle and rotate at a constant speed. The plane of symmetry of the central link members 1b to 3b when rotating at a constant speed is referred to as a uniform speed bisector.

  For this reason, by arranging a plurality of link mechanisms 1 to 3 having the same geometric shape sharing the input / output members 4 and 5 on the circumference, the central link member 1b is a position where the plurality of link mechanisms 1 to 3 can move without contradiction. -3b is limited to the movement only on the uniform speed bisector, so that constant speed rotation can be obtained even if the input side and the output side take any operating angle.

  In the link actuating device of this embodiment, an actuator such as a motor is connected to the rotation pair portions 6a to 8a of the input side end link members 1a to 3a, and the rotation angles of the end link members 1a to 3a are connected by the actuator. By controlling the position, the posture of a movable part such as a robot arm (not shown) attached to the output member 5 is controlled.

  The basic configuration of the link mechanisms 1 to 3 shown in FIG. 1 is the same as that disclosed in Japanese Patent Application No. 2003-40086 previously proposed by the present applicant, and the input / output members 4 and 5 have through holes in the central axis. Is a link hub having a donut shape with a spherical outer shape. Each rotation pair 6a-8a, 6b-8b, 6c-8c of this link mechanism 1-3 comprises the structure which supports end part link member 1a-3a, 1c-3c by cantilever.

On the other hand, the basic configuration of the link mechanisms 1 to 3 shown in FIG. 2 is the same as that disclosed in the Japanese Patent Application No. 2003-388307 previously proposed by the present applicant, and the input / output members 4 and 5 have a disk shape. . Each rotation pair section 6a~8a of the link mechanism _{1~3, 6b 1, 6b 2 ~8b} 1, 8b 2, 6c~8c may comprise a structure that both end supporting end links 1a to 3a, the 1c~3c To do.

  FIG. 3 shows rotating pair portions 6a to 8a which are connecting portions of the input member 4 and the input side end link members 1a to 3a in the embodiment shown in FIG. The input member 4 shown in the figure has a structure in which through holes are formed in the radial direction at equal intervals in the circumferential direction, and a shaft 10 is fitted into the through holes via two bearings 9a and 9b. Although not shown, the bearings 9a and 9b are rotatably inserted between a bearing outer ring fitted in the through hole of the input member 4, a bearing inner ring fitted on the shaft 10, and the bearing outer ring and the bearing inner ring. It consists of rolling elements such as balls. By adopting such a bearing structure, it is possible to reduce the rotational resistance by suppressing the frictional resistance at the connecting portion, and to ensure smooth power transmission and improve the durability.

  The outer peripheral surface of the periphery of the through hole of the input member 4 is formed in a flat shape, and a screw hole is provided in the portion. The bolt 11 is screwed into the screw hole so that the pressing member 12 is attached to the input member 4. doing. The pressing member 12 abuts against the outer ring of the bearing 9b interposed between the input member 4 and the shaft 10 and presses the end of the outer ring of the bearing 9b by tightening the bolt 11 to prevent the bearings 9a and 9b from coming off. Presents a structure.

  If the end surface of the bearing 9b is the same as or slightly protrudes from the outer peripheral surface of the input member 4, even if the outer rings of the bearings 9a and 9b are inserted into the input member 4 with a clearance fit, the backlash of the bearings 9a and 9b is suppressed. It can be reduced by pressing. Since this pressing member 12 has a structure fixed by bolting, the bearings 9a and 9b can be attached and detached, and the assemblability at the rotating pair portions 6a to 8a is also improved. Moreover, the outer diameter of the input member 4 can also be reduced, and the downsizing of the link mechanisms 1 to 3 is facilitated.

  As the aforementioned bearing structure, it is possible to use two radial ball bearings, angular ball bearings, roller bearings, slide bearings, or one double row angular ball bearing. The output member 5 has the same structure as the input member 4 of FIG. Although the circumferential positions of the shaft 10 do not have to be equally spaced, the input / output members 4 and 5 need to have the same circumferential positional relationship. The input / output members 4 and 5 are shared by the three sets of link mechanisms 1 to 3, and the end link members 1 a to 3 a and 1 c to 3 c are connected to the shafts 10. In addition, as a means for attaching the pressing member 12 to the input member 4, in the above-described case, tightening of the bolt 11 is used. However, as shown in FIG. It is also possible to adopt a structure in which the outer ring of the bearings 9a, 9b is pressed by screwing the screw-shaped pressing member 12 ′.

  In the rotating pair portions 6a to 8a shown in FIG. 3, two locking portions, for example, steps 13a and 13b are provided in the center portion of the shaft 10. The shaft 10 itself is positioned by the step 13a located inside, and the bearings 9a and 9b are fastened and fixed by the nut 14 at the end of the shaft 10. The end link members 1a to 3a are positioned by the step 13b located on the outside, and the end link members 1a to 3a are fastened and fixed with bolts 16 together with the rotation transmission member 15 mounted on the outside of the end link members 1a to 3a. To do. The aforementioned rotation transmission member 15 constitutes a part of a rotation transmission unit connected to an actuator that drives the end link members 1a to 3a.

  As the fastening means for the bearings 9a and 9b, the end link members 1a to 3a and the rotation transmission member 15, it is also possible to use caulking or the like in addition to the nuts and bolts described above. In that case, first, the bearings 9a and 9b are assembled to the shaft 10 using the step 13a located on the inner side, and then the bearings 9a and 9b are inserted into the input member 4, and then the bearings 9a and 9b are inserted into the input member 4 by the pressing member 12. After fixing 9b to the input member 4, the end link members 1a to 3a and the rotation transmission member 15 can be assembled. In this way, the assembly of the bearings 9a and 9b to the input member 4 is facilitated.

  In addition, a bevel gear, a worm, or the like is used as the rotation transmission member 15 and is connected to an actuator for driving the link mechanisms 1 to 3 (not shown). A set screw or a D-cut may be used to prevent the end link members 1a to 3a, 1c to 3c and the rotation transmission member 15 from rotating about the shaft 10.

  FIG. 5 shows a structure in which a spacer 17 is interposed between the two bearings 9a and 9b. If the thickness of the spacer 17 is set to be equal to or less than twice the axial clearance, the backlash of the bearings 9a and 9b can be reduced and the rigidity can be increased without applying a preload to the bearings 9a and 9b by tightening with the nut 14. it can. By adopting this structure, it is possible to use a miniature bearing that has conventionally been difficult to apply preload in general, and the link mechanisms 1 to 3 can be easily downsized.

  FIG. 6 shows a structure in which a step 18 is provided at the outer end of the shaft 10. In this structure, the rotation transmission member 15, the end link members 1 a to 3 a, the spacer 19, the pressing member 12, the bearings 9 a and 9 b and the spacer 17 are inserted into the shaft 10 and positioned at the step 18 to be integrated. The inner end portion is fastened and fixed by the nut 14. By tightening with the nut 14, the bearings 9a and 9b can be loosely packed.

  The spacer 19 positioned between the end link members 1a to 3a and the bearings 9a and 9b corresponds to the steps 13a and 13b formed at the center of the shaft 10 in the structure of FIG. Contrary to the structure described above, if the step is provided at the inner end portion of the shaft 10 and the outer end portion of the shaft 10 is fastened and fixed with a nut, the bearings 9a and 9b are assembled to the input member 4 by the pressing member 12. After that, the end link members 1 a to 3 a and the rotation transmission member 15 can be assembled to the shaft 10.

  In addition, it is effective to make the above-mentioned rotation transmission member 15 into a shape suitable for the movable range of the end link members 1a to 3a as shown in FIG. 7, and the end link members 1a to 3a and the rotation transmission member 15 are effective. It is necessary to assemble in consideration of the relative positional relationship. In that case, as described above, by providing the shaft 10 with the D cut or the like, not only the end link members 1a to 3a and the rotation transmitting member 15 are prevented from rotating, but also the end link member 1a to The relative positional relationship between 3a and the rotation transmitting member 15 can be set, and the assemblability is improved.

  In the above-described embodiment, the two bearings 9a and 9b are used as the bearing structure, and the spacer 17 is interposed between the two bearings 9a and 9b. Alternatively, one double-row angular contact ball bearing with a clearance in the inner ring may be used, and the backlash of the bearing portion may be filled up to the clearance of the inner ring.

  The rotary pair portions 6a to 8a of the above-described embodiment are cases where the end link members 1a to 3a are supported in a cantilever manner as in the link mechanisms 1 to 3 shown in FIG. 1, but the links shown in FIG. It is applicable also to the structure which supports the edge part link members 1a-3a like both ends like the mechanisms 1-3. The bearing rigidity can be improved by the both-end support structure in the rotating pairs 6a to 8a.

  As for the rotation pair parts 6a-8a of this both-ends support structure, a pair of support parts 21a-23a are installed in the upper surface of the input member 4 which makes | forms a disk shape about each link mechanism 1-3 (refer FIG. 2). For example, as shown in FIG. 8, a shaft 10 is rotatably supported by the pair of support portions 21 a to 23 a via two bearings 9 a and 9 b, and end link members 1 a to 3 a are connected to the shaft 10. The structure is provided. This structure can constitute a bearing unit by using the housings 21 to 23 in which the pair of support portions 21a to 23a are integrated. Through holes into which the shaft 10 is inserted are formed in both support portions 21 a to 23 a of the housings 21 to 23.

  That is, in the rotating pair portions 6a to 8a in FIG. 8, the two steps 24a and 24b are provided at positions shifted from the center portion of the shaft 10 to one end portion. The shaft 10 is inserted and disposed in the through holes of the housings 21 to 23, the bearing 9b is inserted into one of the support portions 21a to 23a, positioned at one step 24b, and then tightened with a nut 25 to fix the bearing 9b. To do. Further, the end link members 1a to 3a are positioned by the other step 24a, the spacer 26 is inserted between the end link members 1a to 3a and the bearing 9a, and the bearing 9a is inserted into the other support portions 21a to 23a. Then, the bearing 9 a is fixed by tightening with the nut 27.

  Here, even if the outer rings of the bearings 9a and 9b are inserted into the support portions 21a to 23a by clearance fitting, the backlash of the bearings 9a and 9b can be reduced by tightening with the nuts 25 and 27. Further, by adjusting the distance between the step 24a and the step 24b or the width of the spacer 26, the backlash of the bearing portion and the preload adjustment can be performed. If a spacer is used instead of providing the steps 24a and 24b on the shaft 10 as described above, the nut 25 attached to the end of the shaft 10 can also function as a step.

  Further, as shown in FIG. 9, steps 28a and 28b are provided at both ends of the shaft 10, the shaft 10 is inserted into the through holes of the housings 21 to 23, and the bearings 9a and 9b are inserted into the support portions 21a to 23a. Then, both the bearings 9a and 9b are fixed by positioning with the steps 28a and 28b and tightening with the nuts 25 and 27. As in the case described above, even if the outer rings of the bearings 9a and 9b are inserted into the support portions 21a to 23a by clearance fitting, the backlash of the bearings 9a and 9b can be reduced by tightening with the nuts 25 and 27. Further, by adjusting the gap between the step 28a and the step 28b, the bearing portion can be loosely packed or the preload can be adjusted. For positioning of the end link members 1a to 3a, a recess 30 having two steps 29a and 29b in the axial direction is formed in the central portion of the shaft 10, and the end link members 1a to 3a are fitted into the recess 30. Are connected by bolts 31.

  In addition, as a fastening means mentioned above, a volt | bolt and caulking other than the nuts 25 and 27 are also possible. Further, angular contact ball bearings can be arranged and used in the back-to-back direction for the bearings 9a and 9b. Further, a rotation transmission member can be disposed between the nuts 25 and 27 and the bearings 9a and 9b.

  10 to 12, bearings 9 a and 9 b are incorporated in the end link members 1 a to 3 a, and the shaft 10 ′ of the rotating mating portions 6 a to 8 a projecting sideways from the input member 4 is reinforced with another member. An embodiment is shown. In this embodiment, the input member 4 is coupled to a mounting member 32 for installing the input member 4 on its input side by a bolt 33, and the shaft 10 'of the rotating pair 6a to 8a protruding from the input member 4 to the side The end link members 1a to 3a in which the two bearings 9a and 9b are incorporated are connected. The lower end of the reinforcing member 34 is fixed to the attachment member 32 with the bolt 35, and the upper end of the reinforcing member 34 is fastened to the shaft 10 'of the rotating pair 6a to 8a with the bolt 36, thereby supporting the end link members 1a to 3a at both ends. It becomes the structure excellent in strength.

  In this structure, of the bearings 9a and 9b built in the end link members 1a to 3a, the bearing 9a located on the inner side is regulated by a step 37 formed at the base of the shaft 10 'of the rotating pair 6a to 8a. In addition, since the end face of the bearing 9b located on the outside protrudes from the end face of the shaft 10 'of the rotating pair 6a-8a, a spacer (not shown) is installed between the bearing 9a and the bearing 9b, Alternatively, by using a double row structure in which the bearings 9a and 9b are integrated, the bearing structure can be loosened and the bearing preload can be adjusted. If the end face of the bearing 9b located on the outer side is made the same as the end face of the shaft 10 'of the rotating mating parts 6a to 8a, only the backlash of the bearings 9a and 9b becomes possible.

  In the structure of FIG. 10, the reinforcing member 34 is fastened by a bolt 36. Instead of the bolt 36, as shown in FIG. 13, the shafts 10 'of the rotating pairs 6a to 8a are extended and a screw is attached to the tip thereof. Alternatively, the reinforcing member 34 may be inserted into the shaft 10 ′ of the rotating pair 6 a to 8 a and fixed with the nut 38. What is necessary is just to fasten the lower part of the reinforcement member 34 to the attachment member 32 with the volt | bolt 35 similarly to embodiment of FIG.

  FIG. 14 shows a structure that avoids interference by allowing the end link members 1a to 3a and the central link members 1b to 3b to enter the space between the bearings 9a and 9b. As the bearing structure, the unit structure in the above-described embodiment shown in FIGS. 8 and 9 may be used, and the housings 21 to 23 may be designed to increase the distance between the two bearings.

  Between the two bearings 9a and 9b, only the shaft 10 and the end link members 1a to 3a of the rotating pair portions 6a to 8a are present, so that an empty space is secured. Therefore, the adjacent end link members 1a to 3a and The central link members 1b to 3b can enter the space described above. Although the unit structure of the embodiment shown in FIGS. 8 and 9 is used for this bearing structure, both bearings 9a and 9b are attached separately if sufficient space can be secured. You may make it install in a member.

  15 and 16 show an embodiment using a double-row angular bearing 9 having an inner ring 41 with a shaft as another bearing structure. The bearing structure shown in FIG. 15 includes a shafted inner ring 41 in which an inner member 45 constituting a double row angular bearing is coupled by caulking, and a flanged outer ring 42 coupled to the input member 4 by caulking. . By coupling the inner member 45 with the inner ring 41 with shaft by caulking and providing a space between the inner member 45 and the inner ring 41 with shaft, the double row angular bearing 9 can be loosely packed or the preload can be adjusted. I have to.

  In addition to caulking, coupling with nuts or bolts is also possible. In the figure, there is a space between the inner member 45 and the shaft-equipped inner ring 41, but the bearing structure can become more rigid as the space is eliminated. Further, a step is provided at the end of the inner ring 41 with the shaft to position the end link members 1a to 3a, and the nut 44 is fastened and fixed. Although not shown, a rotation transmission member can be provided at the end of the inner ring 41 with the shaft. The bearing structure shown in FIG. 16 fixes the double-row angular bearing 9 by fastening the pressing member 43 to the input member 4 with a bolt (not shown) as in the embodiment of FIG. The backlash can be adjusted or the preload can be adjusted.

  In the above description, the rotation pair portions 6a to 8a between the input member 4 and the input side end link members 1a to 3a have been described. However, the connecting portion between the output member 5 and the output side end link members 1c to 3c. The rotating pair portions 6c to 8c are the same structure as the rotating pair portions 6a to 8a of the input member 4 and the end link members 1a to 3a on the input side, and a duplicate description is omitted.

The rotating pair section 6b ₁ ~8b ₁ and one end of the end link members 1a~3a and central link member 1b~3b the input side, and, on the output side end link member 1c~3c other The rotation pair 6b _{2 to} 8b ₂ , which is a connecting portion between the arm end and the other end of the central link members 1b to 3b, is also connected between the input member 4 and the input side end link members 1a to 3a. Since it is the same structure as the rotation pair 6a-8a, duplication description is abbreviate | omitted.

In the embodiment of the present invention, it is a perspective view showing a cantilever support type link actuating device provided with three sets of link mechanisms. In the embodiment of the present invention, it is a perspective view showing a link actuating device of a both end support type provided with three sets of link mechanisms. FIG. 2 is a cross-sectional view showing a rotating pair of an input member and an input side end link member in the link actuating device of FIG. 1. It is a principal part expanded sectional view which shows the other examples of the rotation pair part of FIG. It is a principal part expanded sectional view which shows the other example of the bearing structure in the rotation pair part of FIG. It is a principal part expanded sectional view which shows the other example of the rotation pair part of FIG. It is a front view for demonstrating the fastening method of the edge part link member of FIG. 5, and a rotation transmission part. FIG. 3 is a cross-sectional view showing a rotating pair of an input member and an input side end link member in the link actuating device of FIG. 2. It is sectional drawing which shows the other example of the rotation pair part of FIG. It is sectional drawing which shows the rotation pair part of both ends support using a reinforcement member. It is a front view which shows the rotation pair part of FIG. It is a plane which shows the state which has arrange | positioned three rotation pair parts of FIG. It is sectional drawing which shows the other example of the rotation pair part of FIG. It is a top view which shows the example which made the edge part link member and the center link member enter in the space between the bearings of a rotation pair part. It is sectional drawing which shows an example of the rotation pair part which has a bearing structure which has an inner ring | wheel with a shaft. It is sectional drawing which shows the other example of the rotation pair part which has a bearing structure which has an inner ring | wheel with a shaft.

Explanation of symbols

1-3 linkage 1a~3a, 1c~3c end link member 1b~3b intermediate link member 4 input member 5 output member 6a~8a rotation pair portion _{6b 1, 6b 2 ~8b 1,} 8b 2 rotating pair section 6c~ 8c Rotating pair 9a, 9b Bearing 12 Holding member 17 Spacer 34 Reinforcing member

Claims (14)

  Four end link members are rotatably connected to the input / output members respectively arranged on the input / output side, and each end link member on the input side and the output side is rotatably connected to the central link member. In a link actuating device having at least three sets of link mechanisms composed of two rotating pairs, and having the input side and the output side geometrically identical with respect to the cross section at the center of each link mechanism, A link actuating device characterized in that the portion has a bearing structure composed of two bearings, and backlashing means for restricting axial movement of the two bearings is provided in the rotating pair portion.   The link actuating device according to claim 1, wherein the backlashing means includes a spacer between two bearings, and the thickness of the spacer is equal to or less than twice the axial clearance of the bearing.   The link actuating device according to claim 1 or 2, wherein the backlashing means is provided with a pressing member that presses the outer ring end of the bearing attached to the rotating pair.   The link actuating device according to any one of claims 1 to 4, wherein the backlashing means is formed with a preload adjusting or positioning locking portion on the shaft of the rotating pair.   The link actuating device according to claim 4, wherein the locking portion is a step formed on the outer peripheral surface of the shaft of the rotating pair portion.   The locking portion is a step formed at least in one place between the end of the shaft of the rotating pair, between the two bearings, between the bearing and the end link member, or between the bearing and the rotation transmitting portion. Item 5. The link actuating device according to item 4.   The link actuating device according to any one of claims 1 to 6, wherein a bearing structure in which two bearings are housed in a common housing is provided in each rotating pair portion of the link mechanism.   The link actuator according to claim 7, wherein the two bearings are arranged so that the angular ball bearings are back-to-back.   2. The rotary pair portion is provided with two bearings so as to support both ends of each rotary pair portion of the link mechanism, and an end link member or an intermediate link member enters between the two bearings. The link actuating device according to any one of claims 8 to 9.   The fastening part of the rotation transmission part and the rotation pair part, and the fastening part of the end link member and the rotation pair part are formed according to the phase of the end link member and the rotation transmission part. The link actuating device according to item.   The link actuating device according to claim 10, wherein the fastening part is formed with two flat parts formed on the shaft of the rotating pair part at different phases.   The link according to any one of claims 1 to 11, wherein both ends of the rotating pair portion of the link mechanism are supported by adding a reinforcing member to a shaft of the rotating pair portion provided on the input member or the output member. Actuator.   The link actuating device according to claim 1, wherein the rotating pair portion is a bearing having a shaft-equipped inner ring capable of adjusting a preload or backlashing.   The link actuating device according to claim 13, wherein the outer ring of the bearing having the inner ring with a shaft has a flange.

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