JP6105764B2 - Belt drive - Google Patents

Description

  The present invention relates to a belt driving device having an endless toothed belt wound around a driving pulley and a driven pulley, and in particular, a belt driving suitable for use in a transport robot having a belt-driven linear movement mechanism. Relates to the device.

  As a workpiece transfer robot, a robot having a mechanism (linear movement mechanism) for moving a hand along a linear movement process is known (see, for example, Patent Document 1). A transfer robot having a linear movement mechanism is simpler and less expensive than a so-called articulated robot. For example, in a semiconductor device manufacturing process or a liquid crystal display panel manufacturing process, a wafer to each processing chamber is used. Or, it is widely used as a robot for carrying in or carrying out thin plate workpieces such as glass substrates.

  In the transfer robot described in Patent Document 1, a belt-driven drive device is employed as the linear movement mechanism. As shown in FIG. 11 and the like of this document, this belt driving device is endless with a plurality of pulleys including a driving pulley (335) and driven pulleys (336a, 336b) that are driven to rotate by a driving force from a driving source. The belt-shaped output belt (337) is wound around. The plurality of pulleys are rotatable about rotation axes that are substantially parallel to each other, and the output belt (337) is provided with a connecting member (42a) connected to the hand (4A). The hand (4A) is slidably supported by a linear guide rail, and the connecting member (42a) is moved linearly by reciprocating a moving section between the driven pulleys (336a, 336b). . Between the driving pulley (335) and the driven pulleys (336a, 336b), idler pulleys (336c, 336d) that abut against the outer surface of the output belt (337) and apply tension to the output belt (337) are provided. It has been.

  In recent years, for example, the panel size handled in the manufacture of a liquid crystal display panel tends to increase, and accordingly, the moving distance of a hand holding a workpiece is required to be increased. In addition, from the viewpoint of improving productivity, high-speed and high-precision workpiece conveyance is required. On the other hand, in the transfer robot using the belt driving device described above, it is relatively easy to increase the movement distance of the hand by lengthening the guide rail supporting the hand and the output belt. Can do. For handling high-speed conveyance, a timing belt (toothed belt) in which a driving pulley and a driven pulley are constituted by toothed pulleys, and concave and convex teeth meshing with the driving pulley and the driven pulley are formed on the inner surface as an output belt. Use. Thereby, the slip in the belt traveling direction between the output belt and the driving pulley or the driven pulley can be eliminated.

  In a belt drive device in which an output belt is wound around a plurality of pulleys, it is desired to improve the accuracy of parallelism between the rotation axes of these pulleys. However, in practice, it is difficult to sufficiently improve the accuracy of the parallelism between the rotation axes due to manufacturing errors of the plurality of pulleys, errors in assembling these pulleys, and the like. There are also variations in individual differences in the output belt. For this reason, when the output belt travels, the output belt is shifted to one side in the axial direction of the pulley, and the output belt is attached to the flange portion provided at the axial end of the pulley (drive pulley / driven pulley). The side edges may touch. In this case, the running state of the output belt becomes unstable, and there is a risk that the output belt will be damaged if the belt runs continuously. In addition, if the output belt is increased in length to increase the overall length of the output belt or to support high-speed workpiece conveyance, the amount of displacement in the width direction of the belt during traveling tends to increase, and the above disadvantages are further reduced. Become prominent.

JP 2008-272847 A

  The present invention has been conceived under such circumstances, and in a belt drive device in which an endless toothed belt is wound around a drive pulley and a driven pulley, It is an object of the present invention to provide a belt driving device suitable for suppressing the deviation.

  In order to solve the above problems, the present invention employs the following technical means.

  The belt driving device provided by the present invention includes a driving pulley and a driven pulley that are configured as toothed pulleys having concave and convex meshing teeth formed on the outer circumferences thereof in the rotational direction, and a concave and convex tooth whose inner surface meshes with the meshing teeth. And an endless toothed belt wound around the drive pulley and the driven pulley, and a belt running surface that contacts the outer surface of the toothed belt, and an intermediate portion in the width direction of the belt running surface is at both ends. And an idler pulley having a shape that bulges so as to have a larger diameter than the portion.

  In a preferred embodiment, the driven pulley includes first and second driven pulleys, and the toothed belt is hung between the first and second driven pulleys in the movement path of the toothed belt. The rotated section is set as a linear movement section, and the idler pulleys are arranged in pairs on both sides of the drive pulley in the moving direction of the toothed belt.

  In a preferred embodiment, in each of the pair of idler pulleys, a range in which the belt running surface and the outer surface of the toothed belt contact each other in the circumferential direction of the belt running surface with respect to the axis of the idler pulley. The wrapping angle, which is the angle formed by, is 50 ° or more.

  In a preferred embodiment, the toothed belt is provided with a carriage that is reciprocated in the linear movement section.

  In a preferred embodiment, an angle adjusting mechanism capable of adjusting an angle of the idler pulley in the axial direction relative to the axial direction of the drive pulley is further provided.

  In a preferred embodiment, there is further provided an auto tension mechanism that urges the outer surface of the toothed belt through the idler pulley by an urging member and applies tension to the toothed belt.

  In a preferred embodiment, the uneven teeth on the inner surface of the toothed belt are formed to be inclined with respect to the width direction of the toothed belt, and the meshing teeth of the driving pulley and the driven pulley are respectively It inclines with respect to each axial direction so as to correspond to the uneven teeth.

  Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the accompanying drawings.

It is a whole perspective view which shows an example of the conveyance robot provided with the belt drive device which concerns on this invention. It is a top view of the transfer robot shown in FIG. It is a side view of the conveyance robot shown in FIG. FIG. 4 is a partial cross-sectional view showing the belt drive device according to the embodiment of the present invention and taken along line IV-IV in FIG. 2. It is the elements on larger scale of the belt drive device shown in FIG. It is a partial expanded view of a toothed belt. It is sectional drawing which follows the VII-VII line of FIG. It is a VIII-VIII arrow line view of FIG. It is a figure similar to FIG. 8 which shows a driven pulley. It is the elements on larger scale of the belt drive device shown in FIG. It is sectional drawing which follows the XI-XI line of FIG. It is a figure for demonstrating an angle adjustment mechanism, and is the schematic seen from the direction perpendicular | vertical with respect to the axis line of an idler pulley. It is a figure for demonstrating an auto tension mechanism, and is the schematic which shows the state cut | disconnected along the direction perpendicular | vertical with respect to the axis line of an idler pulley. It is a schematic block diagram which shows the other example of a belt drive device. It is a schematic block diagram which shows the other example of a belt drive device. It is a schematic block diagram which shows the other example of a belt drive device.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

  1 to 3 show an example of a transport robot configured to include a belt driving device according to the present invention. The transfer robot A is for transferring a thin plate-like workpiece W such as a substrate for a liquid crystal display panel. The transfer robot A includes a fixed base 1, a turning base 2 supported by the fixed base 1, a guide body 3 supported by the turning base 2, and a belt driving device 4 ( 2) and two hands 5A and 5B supported separately by the guide body 3 respectively. The hands 5A and 5B are for holding the thin plate-like workpiece W in a horizontal posture.

  The swivel base 2 can be moved up and down with respect to the fixed base 1 and is supported so as to be rotatable around a vertical swivel axis Os. Inside the fixed base 1 are provided a lifting motor and a turning motor (not shown), and the turning base 2 is moved up and down or turned by driving these motors. The guide body 3 has a long rectangular box shape in plan view. Inside the guide body 3, guide rails (not shown) for supporting the hands 5A and 5B separately are provided. While the hands 5A and 5B are supported by the guide rails, the hands 5A and 5B can slide along the horizontal linear movement stroke GL without interfering with each other.

  As shown in FIGS. 1 to 4, the hands 5 </ b> A and 5 </ b> B are integrally formed with a plurality of hawk-shaped holding pieces 51 a and 51 b extending in the longitudinal direction of the guide body 3. The thin plate-like workpiece W is placed and held on 51b. 3 and 4, unlike FIGS. 1 and 2, both hands 5 </ b> A and 5 </ b> B are shown above the fixed base 1.

  The belt driving device 4 is for sliding the hands 5A and 5B on the guide rail, and is provided in pairs corresponding to the hands 5A and 5B (see FIG. 2). Inside the fixed base 1 are provided hand motors (not shown) for driving the hands 5A and 5B, respectively, so as to straddle the fixed base 1, the swivel base 2, and the guide body 3, A driving force transmission mechanism for transmitting the driving force of the hand motor to the belt driving device 4 is provided. Although detailed illustration and explanation of the support structure of the turning base 2, the support structure of the hands 5A and 5B, and the driving force transmission mechanism to the belt driving device 4 is omitted, for example, as disclosed in Japanese Patent Application Laid-Open No. 2008-272847. It can be realized by a structure similar to the structure.

  FIG. 4 shows a belt driving device according to an embodiment of the present invention. The belt drive device 4 of this embodiment includes a drive pulley 41, driven pulleys 42 and 42, idler pulleys 43 and 43, and an endless output belt 44 (toothed belt) wound around these pulleys. I have. The drive pulley 41, the driven pulleys 42 and 42, and the idler pulleys 43 and 43 are respectively supported by the guide body 3, and are rotatable about axes that are substantially parallel to each other. 4 and subsequent drawings show the belt driving device 4 corresponding to the hand 5A, the belt driving device corresponding to the hand 5B also has the same configuration as the belt driving device 4 shown in FIG.

  As shown in FIGS. 5 to 7, the output belt 44 is configured as a timing belt (toothed belt) in which concave and convex teeth 441 are formed on the inner surface. In the present embodiment, the output belt 44 is manufactured using, for example, an open end belt that can easily cope with an increase in length. The open end belt is a cylindrical belt material having an uneven strip extending along the axial direction, which is cut out in a spiral with a constant width, and by joining both ends of the open end belt by heat fusion, An endless output belt 44 having a desired length is formed. The uneven teeth 441 on the inner surface of the output belt 44 thus obtained are slightly inclined with respect to the width direction as shown in FIG.

  As the material of the output belt 44, for example, vinylidene fluoride-based fluororubber (FKM) that can be used in a high temperature environment (for example, about 160 ° C.) is preferably used. Further, as the output belt 44, a high-strength belt in which a glass core wire as a reinforcing material is embedded in the belt main body portion 442 along the traveling direction can be used. A belt including a glass core has a relatively small change rate in length with respect to a tensile load and a temperature change. As an example of the dimensions of the output belt 44, the overall length in the traveling direction is about 5 to 10 m, the width dimension L1 is about 60 mm, the thickness T1 of the belt main body portion 442 is about 2 mm, and the pitch P1 of the uneven teeth 441 is 8 mm. The inclination angle α of the concavo-convex teeth 441 with respect to the width direction is about 1 °.

  As shown in FIG. 4, the drive pulley 41 is disposed near the center in the longitudinal direction of the guide body 3, and receives an input shaft (not shown) that receives the driving force from the driving force transmission mechanism described above to rotate. ) And can be rotated together.

  As shown in FIG. 5 and FIG. 8, the drive pulley 41 is configured as a toothed pulley in which concave and convex meshing teeth 411 are formed on the outer peripheral portion in the rotation direction. At both ends in the axial direction of the drive pulley 41, annular flange portions 412 protruding in the radial direction are provided. The meshing teeth 411 are shaped so that the concave and convex teeth 441 of the output belt 44 mesh. In the present embodiment, the meshing teeth 411 are inclined with respect to the axial direction so as to correspond to the concave and convex teeth 441 of the output belt 44.

  As shown in FIG. 8, the output belt 44 is mounted in a state where both end portions in the width direction have a slight gap between both flange portions 442 of the drive pulley 41. As an example of the dimensions of the drive pulley 41, the radial dimension D1 of the outer peripheral portion where the meshing teeth 411 are formed is about 130 mm, and the dimension L2 between both flange portions 412 (the axial length of the meshing teeth 441) is 63 mm. It is said to be about. In FIG. 8, the output belt 44 is represented by a virtual line.

  As shown in FIG. 4, the driven pulleys 42 and 42 are disposed near both ends in the longitudinal direction of the guide body 3. The driven pulleys 42 and 42 are rotatably supported by support shafts (not shown). Each of the driven pulleys 42 and 42 has substantially the same configuration as the drive pulley 41 described above, and is provided on the concave and convex meshing teeth 421 and both ends in the axial direction as shown in FIG. And a collar portion 422.

  As shown in FIG. 4, the idler pulleys 43 and 43 are arranged in pairs on both sides of the drive pulley 41 in the moving direction of the output belt 44. The idler pulleys 43 and 43 are rotatably supported by support shafts (not shown). The idler pulleys 43, 43 abut against the outer surface 44 a of the output belt 44 and apply tension to the output belt 44. As shown in FIGS. 10 and 11, the idler pulley 43 has a belt running surface 43 a that rotates around the axis while contacting the outer surface 44 a of the output belt 44. The belt running surface 43a has a crown shape that bulges so that an intermediate portion in the width direction along the axis has a larger diameter than both ends. As an example of the dimensions of the idler pulley 43, the width direction dimension L3 is about 100 mm, the diameter D2 of the maximum outer diameter portion at the center in the width direction is about 100 mm, and the diameter D3 of the minimum outer diameter portion at the end in the width direction is about 98 mm. The maximum outer diameter portion bulges outward about 1 mm in the radial direction from the minimum outer diameter portion.

  In the present embodiment, the idler pulleys 43 and 43 are both disposed adjacent to the drive pulley 41. 4 and FIG. 10, in each idler pulley 43, the belt running surface 43a and the outer surface of the output belt 44 in the circumferential direction of the belt running surface 43a with respect to the axis of the idler pulley 43. The winding angle β, which is the angle formed by the range in contact with 44a, is, for example, 50 ° or more.

  The belt driving device 4 of the present embodiment further includes an angle adjustment mechanism 45 (see FIG. 12) and an auto tension mechanism 46 (see FIG. 13). The angle adjustment mechanism 45 adjusts the angle of the idler pulley 43 in the axial direction with respect to the axial direction of the drive pulley 41, and in this embodiment, the angle of one idler pulley 43 can be adjusted. For example, as shown in FIG. 12, the idler pulley 43 is supported by a support shaft 432 having a mounting flange 431 connected to the end thereof, and the mounting flange 431 is fixed to the guide body 3 (not shown). The support base 31 is attached. A plurality of through holes 431a and screw holes 431b are formed at appropriate portions of the mounting flange 431. A mounting bolt 311 implanted in the support base 31 is inserted into each through-hole 431a, and the mounting flange 431 is fastened to the support base 31 by tightening the nut 312 from the front end side of the mounting bolt 311. . An adjustment bolt 451 is screwed into each screw hole 431b. When any adjustment bolt 451 is tightened and the tip is pressed against the support base 31, the installation site of the adjustment bolt 451 in the mounting flange 431 is separated from the support base 31, and the axial direction of the idler pulley 43 changes accordingly. The axial direction of the idler pulley 43 can be adjusted by appropriately adjusting the distance between the installation site of each adjustment bolt 451 in the mounting flange 431 and the support base 31.

  The auto tension mechanism 46 urges the outer surface 44 a of the output belt 44 by an urging member to apply tension to the output belt 44. As shown in FIG. 13, the auto tension mechanism 46 includes a compression coil spring 461 as an urging member. The compression coil spring 461 is supported in a fixed posture by a support member 32 fixed to the guide body 3 (not shown), and the other idler pulley 43 (the above-described idler capable of adjusting the axial direction). The support shaft 433 (which is different from the pulley 43) is elastically pressed. The support shaft 433 is inserted into a long hole 32a formed in the support member 32, and the support shaft 433 (idler pulley 43) is slidable along the long hole 32a. With this configuration, an appropriate tension is applied to the output belt 44 by the elastic force of the compression coil spring 461.

  As shown in FIG. 4, in the movement path of the output belt 44 wound around the drive pulley 41 and the driven pulleys 42, 42, an area located above the driven pulleys 42, 42 is a linear movement section 47a. It has become. The output belt 44 can reciprocate in this linear movement section 47a. A carriage 48 is provided at a predetermined portion of the linear movement section 47a of the output belt 44, and the carriage 48 is connected to the hand 5A. Thereby, when the output belt 44 is reciprocated by the rotational drive of the drive pulley 41, the carriage 48 reciprocates in the linear movement section 47a together with the output belt 44. As the carriage 48 moves, the hand 5A slides horizontally along the moving stroke GL while being supported by the guide rail. The length dimension of the linear movement section 47a is set to a relatively long dimension to cope with an increase in the size of the workpiece W transferred by the hand 5A and an increase in the transfer distance, for example, about 4 m. When transporting the workpiece W using the transport robot A, high speed is required. The moving speed of the hands 5A and 5B (output belt 44) during workpiece conveyance is, for example, about 3 m / sec at the maximum.

  Next, the operation of the belt driving device 4 according to the above-described embodiment will be described.

  The output belt 44 having concave and convex teeth 441 on the inner surface is given tension from the outer surface side by idler pulleys 43 and 43. In the idler pulley 43, the belt running surface 43a that is in contact with the outer surface 44a of the output belt 44 has an intermediate portion bulging from both ends, and the tension acting on the output belt 44 in the middle portion of the belt running surface 43a Higher than site. Since the belt tends to be higher in tension during traveling, when the output belt 44 of the present embodiment reciprocates, as shown in FIG. 11, the output belt 44 is connected to the belt traveling surface 43a. Corrected to be located closer to the center. Therefore, it is possible to prevent the output belt 44 from being displaced in the pulley axial direction when the output belt 44 reciprocates. As a result, the contact of the output belt 44 with the driving pulley 41 and the flanges 412 and 422 of the driven pews 42 and 42 is suppressed, and the life of the output belt 44 can be extended.

  In the present embodiment, the drive pulley 41 and the driven pulleys 42 and 42 configured as toothed pulleys are not crowned, but the idler pulleys 43 and 43 that are in contact with the flat outer surface 44a of the output belt 44 are crowned. I have to. According to such a configuration, as compared with the case where the driven pulleys 42, 42 and the like are crown-shaped, complicated processing or the like is not required, and an increase in the manufacturing cost of the belt driving device 4 can be suppressed.

  The concave and convex teeth 441 on the inner surface of the output belt 44 are inclined with respect to the width direction of the output belt 44, and the meshing teeth 411 and 421 of the driving pulley 41 and the driven pulleys 42 and 42 correspond to the concave and convex teeth 441, respectively. It is inclined with respect to each axial direction. For this reason, when the output belt 44 travels, it tends to be shifted to one side in the width direction due to the inclination of the uneven teeth 441 described above. Further, when the output belt 44 is reciprocated in the linear movement section 47a, the output belt 44 is easily displaced in one direction in the width direction when traveling in one direction, and is displaced in the other direction in the width direction when traveling in the opposite direction. Cheap. Here, with respect to the correcting action of returning the output belt 44 toward the center in the width direction by the idler pulley 43, the idler pulley 43 is positioned on the downstream side relative to the driving pulley 41 on the upstream side in the belt traveling direction. If you do it is bigger. In the present embodiment, idler pulleys 43 and 43 are disposed on both sides of the drive pulley 41. This configuration is suitable for suppressing displacement of the output belt 44 on both sides in the width direction when the output belt 44 reciprocates.

The idler pulleys 43 and 43 are disposed adjacent to the drive pulley 41, and the winding angle β at which the outer surface 44a of the belt 44 contacts the belt running surface 43a of the idler pulley 43 is 50 ° or more. By securing a winding angle β of a certain level or more in this way, tension is appropriately applied to the output belt 44, and a correcting action for returning the output belt 44 toward the center in the width direction is appropriately exhibited.

  The belt driving device 4 of this embodiment includes an angle adjusting mechanism 45 for adjusting the angle of the idler pulley 43 in the axial direction with respect to the axial direction of the driving pulley 41. When the output belt 44 is long, the variation in individual differences of the output belt 44 becomes large, and the variation in the influence of the output belt 44 that is offset in the width direction is likely to occur. On the other hand, in the present embodiment, by adjusting the axial direction of the idler pulley 43, it is possible to suppress the influence due to variation in individual differences of the output belt 44. This is preferable for suppressing the displacement in the width direction when the output belt 44 travels.

  As described above with reference to FIG. 13, the belt driving device 4 of the present embodiment includes the auto tension mechanism 46. The transfer robot A configured with the belt driving device 4 of the present embodiment may be used in a high temperature environment. When the transfer robot A is used in a high temperature environment, the distance between the axes of the driven pulleys 42 and 42 may be extended and the output belt 44 may be pulled. Here, the idler pulley 43 moves in a direction in which the tension of the output belt 44 is relaxed while receiving the elastic force of the compression coil spring 461, and an appropriate tension is applied to the output belt 44.

  Although the embodiment of the present invention has been described above, the technical scope of the present invention is not limited to the above-described embodiment. Various modifications can be made to the specific configuration of each part of the belt driving device according to the present invention without departing from the spirit of the invention.

  In the above embodiment, the case where the idler pulleys 43 and 43 are arranged adjacent to the drive pulley 41 has been described with reference to FIG. 4. However, the arrangement of the crown-shaped idler pulley according to the present invention is as follows. It is not limited to this. For example, instead of the configuration shown in FIG. 4, the idler pulley according to the present invention may be arranged in the vicinity of the driven pulley 42 (first and second driven pulleys) that defines the linear movement section. FIG. 14 shows an example of the configuration (belt driving device 4 </ b> A) provided with such an idler pulley 43. When the idler pulley 43 is disposed in the vicinity of the driven pulley 42, an idler pulley 43 is disposed adjacent to the idler pulley 43 on the side opposite to the side where the driven pulley 42 is located. A sufficient winding angle of the output belt 44 on the traveling surface can be ensured. In the case shown in FIG. 14, ordinary cylindrical idler pulleys 49 are arranged on both sides of the drive pulley 41 in place of the idler pulley 43 in FIG. 4, and the winding angle of the output belt 44 in the drive pulley 41 is sufficient. To ensure. Further, in addition to the configuration shown in FIG. 4, the idler pulley according to the present invention may be additionally arranged in the vicinity of the driven pulley 42 (first and second driven pulleys) that defines the linear movement section. FIG. 15 shows an example of the configuration (belt driving device 4 </ b> B) provided with an additional idler pulley 53. When an idler pulley 53 is added in the vicinity of the driven pulley 42, an additional driven pulley 52 is disposed adjacent to the idler pulley 53 on the side opposite to the side where the driven pulley 42 is located. A sufficient winding angle of the output belt 44 on the traveling surface can be ensured.

  In the above embodiment, the case where the drive pulley 41 is disposed between the pair of driven pulleys 42 and 42 that are separated from each other is described with reference to FIG. 4. However, the arrangement of the drive pulley 41 is limited to this. Not. Instead of the configuration shown in FIG. 4, for example, a drive pulley may be arranged at one of the driven pulleys 42 and 42. FIG. 16 shows an example of a configuration (belt drive device 4C) provided with such a drive pulley 41, and a driven pulley 42 is arranged at a position where the drive pulley 41 was arranged in FIG.

  The belt driving device of the above embodiment is configured to move the carriage (movable object) according to the movement of the output belt by reciprocating the output belt, but is not limited thereto. The present invention can also be applied to, for example, a belt driving device configured to output the rotational driving force input to the driving pulley by the rotation of the driven pulley.

A Transfer robot 1 Fixed base 2 Rotating base 3 Guide body 31 Support base 311 Mounting bolt 312 Nut 32 Support member 32a Long hole 4, 4A, 4B, 4C Belt drive device 41 Drive pulley 411 Engagement tooth 412 Hook part 42 Driven pulley 421 Engagement Teeth 422 Gutter 43 Idler pulley 43a Belt running surface 431 Mounting flange 431a Through hole 431b Screw hole 432, 433 Support shaft 44 Output belt (toothed belt)
44a Outer surface 441 (toothed belt) Concavity and convexity 442 Belt main body 45 Angle adjustment mechanism 451 Adjustment bolt 46 Auto tension mechanism 461 Compression coil spring (biasing member)
47a Linear movement section 48 Carriage 53 Idler pulley

Claims (6)

Driving pulleys and driven pulleys that are configured as toothed pulleys in which concave and convex meshing teeth are formed in the rotation direction on each outer periphery,
An endless toothed belt having an inner surface that is an uneven tooth that meshes with the meshing teeth and an outer surface that is formed into a flat surface, and the inner surface is wound around so as to contact the driving pulley and the driven pulley.
It has a belt running surface that abuts on the outer surface of the toothed belt, has a shape that bulges so that an intermediate portion in the width direction of the belt running surface has a larger diameter than both ends, and the teeth An idler pulley that applies tension to the toothed belt from the outer surface side of the toothed belt, and a carriage provided on the toothed belt,
As the movement path of the toothed belt, it has a linear movement section that is sandwiched between the two driven pulleys and the carriage is reciprocated linearly, and a section other than the linear movement section,
In the sections other than the linear movement section, the idler pulley and the additional driven pulley different from the two driven pulleys are provided,
The concavo-convex teeth on the inner surface of the toothed belt are formed inclined with respect to the width direction of the toothed belt,
The belt driving device according to claim 1, wherein the meshing teeth of the driving pulley and the driven pulley are inclined with respect to the axial direction so as to correspond to the concave and convex teeth . 2. The belt driving device according to claim 1, wherein the idler pulley is disposed between one of the two driven pulleys defining the linear movement section and the additional driven pulley . 3. Driving pulleys and driven pulleys that are configured as toothed pulleys in which concave and convex meshing teeth are formed in the rotation direction on each outer periphery,
An endless toothed belt having an inner surface that is an uneven tooth that meshes with the meshing teeth and an outer surface that is formed into a flat surface, and the inner surface is wound around so as to contact the driving pulley and the driven pulley.
It has a belt running surface that abuts on the outer surface of the toothed belt, has a shape that bulges so that an intermediate portion in the width direction of the belt running surface has a larger diameter than both ends, and the teeth An idler pulley that applies tension to the toothed belt from the outer surface side of the toothed belt, and a carriage provided on the toothed belt,
As the movement path of the toothed belt, it has a linear movement section that is sandwiched between the driving pulley and the driven pulley and the carriage is reciprocated linearly, and a section other than the linear movement section,
The idler pulley is provided in a section other than the linear movement section,
The concavo-convex teeth on the inner surface of the toothed belt are formed inclined with respect to the width direction of the toothed belt,
The belt driving device according to claim 1, wherein the meshing teeth of the driving pulley and the driven pulley are inclined with respect to the axial direction so as to correspond to the concave and convex teeth . In each of the above SL idler pulley, the with respect to the axis of the idler pulley, the angle a is winding angle range of the outer surface of the belt running surface and the toothed belt is in contact in the circumferential direction of the belt running surface, The belt drive device according to claim 1 , wherein the belt drive device is at least 50 °. The belt drive device according to any one of claims 1 to 4 , further comprising an angle adjusting mechanism capable of adjusting an angle of the idler pulley in the axial direction with respect to the axial direction of the drive pulley. The belt according to any one of claims 1 to 5 , further comprising an auto tension mechanism that urges an outer surface of the toothed belt via the idler pulley by an urging member to apply tension to the toothed belt. Drive device.

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