Overhead vehicle system

Abstract

This overhead traveling vehicle system comprises: a track that is at least partially disposed in a grid pattern; a traveling unit that travels along the track; and an overhead traveling vehicle having a body unit that is disposed below the track and suspended from the traveling unit. The traveling unit includes a traveling wheel that rotates around a rotating shaft and rolls on the track; and a travel driving motor that drives the traveling wheel. The travel driving motor is installed on the rotating shaft of the traveling wheel.

Description

Technical Field

[0001] One aspect of the present invention relates to a ceiling traveling vehicle system.

Background Art

[0002] A ceiling traveling vehicle system including a lattice - shaped track, a traveling section that travels along the track, and a main body section that is disposed below the track and is suspended from the traveling section is known (see, for example, Patent Document 1). In such a ceiling traveling vehicle system, the traveling section includes traveling wheels that roll on the track with a rotation axis as a base axis, and a traveling drive motor that drives the traveling wheels. The traveling drive motor is provided below the track and transmits a driving force to the traveling wheels via a transmission mechanism including a belt or the like.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above - described ceiling traveling vehicle system, for example, the dimension in the height direction from the traveling drive motor to the traveling wheels may become relatively large, and downsizing of the traveling section is desired.

[0005] Therefore, one aspect of the present invention aims to provide a ceiling traveling vehicle system capable of downsizing the traveling section.

Means for Solving the Problems

[0006] (1) An overhead vehicle system according to one aspect of the present invention comprises a track that is at least partially arranged in a grid pattern, a running section that runs along the track, and an overhead vehicle having a main body that is positioned below the track and suspended from the running section, wherein the running section includes running wheels that roll on the track with a rotation axis as its axis, and a running drive motor that drives the running wheels, and the running drive motor is provided on the rotation axis of the running wheels.

[0007] This overhead vehicle system allows for the effective use of the space above the track to position the drive motor. This makes it possible to reduce the height dimension from the drive motor to the wheels, for example, and to make the running section more compact.

[0008] (2) In the overhead vehicle system described in (1) above, the track has a plurality of first rails extending along a first direction and a plurality of second rails extending along a second direction intersecting the first direction, and support walls are connected to the upper surfaces of each of the plurality of first rails and the plurality of second rails, and the support walls may be provided with notches that allow the passage of the drive motor when the overhead vehicle is running. In this case, the strength of the track is increased by the support walls, and interference of the drive motor with the support walls is avoided by the notches.

[0009] (3) In the overhead vehicle system described in (1) or (2) above, the running wheels are provided to be rotatable and are equipped with a steering drive unit for rotating the running wheels, and the steering drive unit may be provided below the track and below the running wheels. In this case, the steering drive unit can be placed in the dead space below the track and below the running wheels, for example, it is not necessary to place the steering drive unit between the top surface of the main body and the track, and the height dimension of the overhead vehicle can be reduced. As a result, the overhead vehicle can be made more compact.

[0010] (4) In the overhead vehicle system described in any one of the above items (1) to (3), the outer shape of the drive motor may be included in the outer shape of the drive wheel when viewed from the axial direction of the rotating shaft. In this case, the increase in size of the drive unit due to the drive motor can be suppressed.

[0011] (5) The overhead vehicle system described in (2) above comprises a support part that rotatably supports the running wheels, a connecting part connected to the lower part of the support part, and a cable electrically connected to a running drive motor, wherein the track includes a plurality of intersecting rails arranged with gaps between them to the ends of the first rail and the ends of the second rail, and the connecting part and the cable may extend from above to below the track through the gap. This makes it possible to increase the strength of the portion that extends from above to below the track through the gap (hereinafter also referred to as the "narrow portion") compared to the case in which a transmission mechanism such as a belt that transmits the driving force to the running wheels is included. [Effects of the Invention]

[0012] According to one aspect of the present invention, it is possible to provide an overhead-mounted vehicle system that allows for a more compact running section. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 is a perspective view showing an example of an overhead vehicle system according to an embodiment. [Figure 2] Figure 2 is an exploded perspective view showing the four rail units that make up the rail assembly in Figure 1 and the connecting members that connect them. [Figure 3] Figure 3 is a side view showing the overhead-mounted vehicle in Figure 1. [Figure 4] Figure 4 is a perspective view showing the overhead-mounted vehicle in Figure 1. [Figure 5] Figure 5 is a perspective view showing only the rail portion of the rail assembly. [Figure 6] Figure 6 is a cross-sectional view showing the connection points between multiple rail units. [Figure 7]Figure 7 is a side view showing the running gear, wheel turning mechanism, and track. [Figure 8] Figure 8 is a cross-sectional view showing the running section. [Figure 9] Figure 9 is a perspective view showing the running gear and wheel turning mechanism. [Figure 10] Figure 10 is a perspective view showing the inside of the gearbox in Figure 9 with the interior exposed. [Figure 11] Figure 11 is a cross-sectional perspective view showing the running gear and wheel turning mechanism in Figure 9. [Modes for carrying out the invention]

[0014] The embodiments will be described below with reference to the drawings. In the description of the drawings, the same elements will be denoted by the same reference numerals, and redundant explanations will be omitted. In the drawings, for the sake of clarity, each configuration of the embodiment will be shown with an appropriate change in scale. Some drawings will also show the XYZ Cartesian coordinate system. In the following description, this coordinate system will be referred to for ease of explanation. Hereafter, one direction along the horizontal plane will be referred to as the X direction (first direction), the direction perpendicular to the X direction and along the horizontal plane will be referred to as the Y direction (second direction), and the vertical direction will be referred to as the Z direction.

[0015] As shown in FIG. 1, the ceiling traveling vehicle system 1 according to the embodiment is a grid system (transport system) for transporting an article M by a ceiling traveling vehicle 2 in, for example, a clean room of a semiconductor manufacturing factory. The ceiling traveling vehicle system 1 includes, for example, a plurality of ceiling traveling vehicles 2 (hereinafter collectively referred to as "traveling vehicles 2"), a system controller 5 that controls the plurality of traveling vehicles 2, and a track R on which the plurality of traveling vehicles 2 travel. The traveling vehicle 2 moves along the track R of the ceiling traveling vehicle system 1. The traveling vehicle 2 travels along the track R and transports an article M such as a FOUP (Front Opening Unified Pod) that houses a semiconductor wafer or a reticle Pod that houses a reticle. The traveling vehicle 2 may be referred to as a carriage, a transport vehicle, a transport carriage, or a traveling carriage. With the plurality of traveling vehicles 2, high-density transport of the article M is possible, and the transport efficiency of the article M is improved. Note that the ceiling traveling vehicle system 1 may include only one traveling vehicle 2.

[0016] The track R is provided on the ceiling or near the ceiling of a building such as a clean room. The track R is provided adjacent to, for example, a processing apparatus, a stocker (automatic warehouse), or the like. The processing apparatus is, for example, an exposure apparatus, a coater developer, a film forming apparatus, an etching apparatus, or the like, and performs various processes on the semiconductor wafers in the article M transported by the traveling vehicle 2. The stocker stores the article M transported by the traveling vehicle 2.

[0017] The track R is arranged in a grid pattern in a plan view (see also FIG. 5). The track R extends along the horizontal direction. In the present embodiment, the track R is constructed by arranging a plurality of rail units 100 including a first rail R1, a second rail R2, and an intersection rail R3 in the X direction and the Y direction. The ceiling traveling vehicle system 1 includes a plurality of rail units 100 arranged in the X direction and the Y direction and a plurality of connecting members 140 that connect the plurality of rail units 100 to each other. The plurality of rail units 100 and the plurality of connecting members 140 form a rail assembly 200. The rail assembly 200 is suspended from a ceiling or the like (not shown) by a plurality of suspension members H at a portion where the rail units 100 are connected to each other by the connecting members 140.

[0018] FIG. 2 is an exploded perspective view showing four rail units 100 that constitute the rail assembly 200 in FIG. 1 and connecting members 140 that connect them. Each rail unit 100 is a rectangular parallelepiped (frame-shaped) member and has the same configuration. Each rail unit 100 includes two first rail members 110 arranged along the X direction, two second rail members 120 arranged along the Y direction, and four cross-rail members 130 arranged such that gaps are formed on the extension lines of the first rail members 110 and the second rail members 120 (i.e., at the positions of the intersections of the grids). When the rail unit 100 is viewed in plan, two parallel first rail members 110 and two parallel second rail members 120 are arranged in a square shape, and four cross-rail members 130 are arranged at the positions of the vertices of the square.

[0019] Each rail unit 100 is made of, for example, metal and is a unit in which each of the first rail member 110, the second rail member 120, and the cross-rail member 130 is formed and then integrated. Each first rail member 110 includes a first beam portion 111 arranged at the upper end position of the rail unit 100 and extending in the X direction, a first rail R1 arranged at the lower end position of the rail unit 100 and extending in the X direction, and a first support wall 113 arranged between the first beam portion 111 and the first rail R1 and joined to the first beam portion 111 and the first rail R1. Each second rail member 120 includes a second beam portion 121 arranged at the upper end position of the rail unit 100 and extending in the Y direction, a second rail R2 arranged at the lower end position of the rail unit 100 and extending in the Y direction, and a second support wall 123 arranged between the second beam portion 121 and the second rail R2 and joined to the second beam portion 121 and the second rail R2. A lattice-like structure extending along the XY plane is formed at the upper end position of the rail assembly 200 by the plurality of first beam portions 111 and the plurality of second beam portions 121. The first support wall 113 extends along the XZ plane. The second support wall 123 extends along the YZ plane.

[0020] The intersecting rail member 130 includes an intersecting support column 133 extending along the Z direction (vertical direction) at the position where the first beam section 111 and the second beam section 121 are joined at a right angle, and an intersecting rail R3 provided at the lower end of the intersecting support column 133.

[0021] As shown in Figures 1 and 5, multiple first rails R1 each extend along the X direction. Multiple second rails R2 each extend along the Y direction. The track R is formed in a grid pattern in plan view by the multiple first rails R1 and the multiple second rails R2. The track R forms multiple squares by the multiple first rails R1 and the multiple second rails R2. Intersecting rails R3 are positioned at the intersections of the first rails R1 and the second rails R2. Intersecting rails R3 are adjacent to the first rails R1 with a gap in the X direction and adjacent to the second rails R2 with a gap in the Y direction. Intersecting rails R3 are used when the vehicle 2 travels along the first rail R1, when the vehicle 2 travels along the second rail R2, and when the vehicle 2 travels from the first rail R1 to the second rail R2 or from the second rail R2 to the first rail R1.

[0022] Each rail unit 100 forms a square (or rectangular) track R inside it, corresponding to one grid cell. By arranging multiple rail units 100 in the X and Y directions, multiple first rails R1 extend in a continuous line in the X direction, and multiple second rails R2 extend in a continuous line in the Y direction. On the X-direction line, two intersecting rails R3 are placed at a distance between one first rail R1 and another first rail R1. On the Y-direction line, two intersecting rails R3 are placed at a distance between one second rail R2 and another second rail R2. The track R will be explained from another perspective. If we focus on four grid cells consisting of two grid cells aligned in the X direction and two grid cells aligned in the Y direction, then four intersecting rails R3 adjacent in the X and Y directions are placed at a distance (relative to the first rails R1) between two adjacent first rails R1 in the Y direction and two other adjacent first rails R1 in the Y direction. Furthermore, the same four intersecting rails R3 described above are positioned at intervals (relative to the second rails R2) between two adjacent second rails R2 in the X direction and two other adjacent second rails R2 in the X direction.

[0023] In the rail assembly 200, a plurality of first rails R1, a plurality of second rails R2, and a plurality of crossing rails R3 are arranged at predetermined intervals from each other, thereby constructing a track R. A gap G corresponding to the above interval is formed between each first rail R1 and each crossing rail R3. A gap G corresponding to the above interval is formed between each second rail R2 and each crossing rail R3. The gap G in the track R has a constant size. Each first rail R1 includes a first running surface R1a that is flat and horizontal on its upper surface, and the running wheels 31 of the vehicle 2 travel on the first running surface R1a in the X direction (first running direction D1). Each second rail R2 includes a second running surface R2a that is flat and horizontal on its upper surface, and the running wheels 31 of the vehicle 2 travel on the second running surface R2a in the Y direction (second running direction D2). The crossing rail R3 includes a crossing running surface R3a that is flat and horizontal on its upper surface. The heights of the first running surface R1a, the second running surface R2a, and the intersecting running surface R3a are equal throughout the entire track R. The first running surface R1a, the second running surface R2a, and the intersecting running surface R3a are located on the same or nearly identical horizontal plane.

[0024] For example, no gap of the size of gap G is formed between the four intersecting rails R3 described above. When the vehicle 2 passes through multiple rail units 100 in a straight line, the vehicle's wheels 31 travel on the intersecting running surface R3a. At that time, the wheels 31 pass over any two of the four intersecting rails R3 described above. Alternatively, when the vehicle 2 changes direction of travel between rail units 100 (changing direction by 90 degrees, i.e., turning), the vehicle's wheels 31 pass over the intersecting running surface R3a (while changing direction).

[0025] As described above, in the rail assembly 200, a grid-like track R is formed by the first rail member 110, the second rail member 120, and the intersecting rail member 130. The layout of the grid-like track R in the overhead vehicle system 1 can be adjusted or changed as appropriate by arranging the multiple rail units 100 in any arrangement (including adding or removing rail units 100).

[0026] Referring to Figures 2 and 6, the connection structure of the rail units 100 by the connecting members 140 will be described. As shown in Figures 2 and 6, each connecting member 140 includes an upper connecting member 141 and a lower connecting member 142. The upper connecting member 141, which is a horizontally extending plate-like or frame-like structure, is attached to the upper surface of one of the four corners of the multiple (typically four) rail units 100. The upper connecting member 141 abuts near the intersection of the first beam section 111 and the second beam section 121 in each rail unit 100. The lower connecting member 142, which is a horizontally extending plate-like or frame-like structure, supports the lower surface of one of the four corners of the multiple (typically four) rail units 100. The lower connecting member 142 abuts against the intersecting rail R3 in each rail unit 100.

[0027] A rod-shaped suspension member H extending vertically passes through the upper connecting member 141 and the lower connecting member 142. The upper connecting member 141 and / or the lower connecting member 142 are fixed to the rail unit 100 by fastening members (not shown), thereby connecting the rail units 100 to each other. A space 100e extending in the Z direction is formed between the rail units 100, and a space R3e extending in the Z direction is formed between four adjacent intersecting rails R3 in the X and Y directions (the central part in a plan view). The suspension member H is inserted through spaces 100e and R3e, and the upper connecting member 141 and / or the lower connecting member 142 are fixed to the suspension member H.

[0028] The overhead vehicle system 1 includes a communication system (not shown). The communication system is used for communication between the vehicle 2 and the system controller 5. The vehicle 2 and the system controller 5 are each connected to each other via the communication system so as to be able to communicate.

[0029] Next, the configuration of the vehicle 2 will be described with reference to Figures 1, 3, and 4. As shown in Figures 1 and 3, the vehicle 2 is provided to be able to travel along the track R. The vehicle 2 has a trolley 20 that travels on the track R, and a main body 10 that is attached to the lower part of the trolley 20 and is rotatable relative to the trolley 20. The trolley 20 includes, for example, a rectangular trolley unit 50 positioned below the track R, running sections 30 provided at the four corners of the trolley unit 50 in a plan view and protruding upward from the trolley unit 50, and four wheel swivel mechanisms 40 that swivel each of the four running wheels 31 on the running section 30 relative to the trolley unit 50. The running section 30 and the wheel swivel mechanisms 40 are integrated as a single unit. A trolley controller (control unit) 8 is provided inside the trolley unit 50.

[0030] The main body 10 is positioned below the track R and suspended from the running section 30. As shown in Figures 3 and 4, the main body 10 has a main body frame 12, for example, formed in a cylindrical shape. The main body frame 12 includes a disc-shaped top plate 12a and a cylindrical frame 12b hanging down from the periphery of the top plate 12a, and has an open bottom. The main body 10 is formed to fit within one grid cell (see Figure 1) of the track R in plan view. The running vehicle 2 can pass other running vehicles 2 traveling on adjacent first rail R1 or second rail R2. The main body 10 includes a transfer device 18 located inside the main body frame 12. The transfer device 18 is, for example, rectangular in plan view. The cylindrical frame 12b is open in part in the circumferential direction. The area in which the opening (notch) is formed is large enough to allow the passage of the transfer device 18. When the transfer device 18 moves horizontally, it passes through the opening of the cylindrical frame 12b.

[0031] The main body 10 is attached to the lower part of the trolley unit 50 and is rotatable around the rotation axis L10 in the Z direction relative to the trolley unit 50. The running wheels 31, located at the four corners of the trolley unit 50, rest on the track R (on the first running surface R1a, the second running surface R2a, or the intersecting running surface R3a). The trolley unit 50 is suspended from the track R via the four running wheels 31 and the four wheel swivel mechanisms 40. The four running wheels 31 allow the trolley unit 50 and the main body 10 to be stably suspended and the main body 10 to be stably driven. In other words, the vehicle 2 is suspended and supported by the running wheels 31 that travel along the track R and moves below the track R.

[0032] The transfer device 18 moves horizontally relative to the main body 10 to transfer the item M between it and the load port (mounting platform). The transfer device 18 is located below the top plate 12a of the main frame 12. The main body 10, including the transfer device 18, is rotatable around a rotation axis L10 by a rotation drive unit, such as an electric motor (not shown), provided on the top plate 12a. The transfer device 18 includes an item holding unit 13 that holds the item M below the track R, a lifting drive unit 14 that moves the item holding unit 13 vertically up and down, and a sliding mechanism 11 that slides the lifting drive unit 14 horizontally. The sliding mechanism 11 is held on the lower surface of the top plate 12a. Between the sliding mechanism 11 and the lifting drive unit 14, there is a rotation drive unit 16 that rotates the lifting drive unit 14 around the rotation axis L14 relative to the sliding mechanism 11. The rotary drive unit 16 is located below the sliding mechanism 11, and the lifting drive unit 14 is located below the rotary drive unit 16. The article holding unit 13 is located below the lifting drive unit 14 via a plurality of suspension members 13b. The load port is the transfer destination or source of the vehicle 2, and is the point where articles M are transferred between the vehicle 2 and the load port.

[0033] The article holding unit 13 suspends and holds the article M by gripping the flange portion Ma of the article M. The article holding unit 13 is, for example, a chuck having horizontally movable claw portion 13a. The article holding unit 13 holds the article M by inserting the claw portion 13a below the flange portion Ma of the article M and raising the article holding unit 13. The article holding unit 13 is connected to a suspension member 13b such as a wire or belt.

[0034] The lifting drive unit 14 is, for example, a hoist, which lowers the article holding unit 13 by extending the suspension member 13b and raises the article holding unit 13 by winding up the suspension member 13b. The lifting drive unit 14 is controlled by the trolley controller 8 and lowers or raises the article holding unit 13 at a predetermined speed. The lifting drive unit 14 is also controlled by the trolley controller 8 to hold the article holding unit 13 at a target height.

[0035] The slide mechanism 11 has multiple movable plates arranged in a stacked manner, for example, in the Z direction. By rotating the main body 10, the slide mechanism 11 moves the rotation drive unit 16, the lifting drive unit 14, and the article holding unit 13, which are attached to the lowest movable plate, in any direction in the horizontal plane. The rotation angle of the main body 10 relative to the trolley unit 50 determines the direction of movement of the movable plates in the slide mechanism 11. In the main body 10, the orientation of the transfer device 18 and the main body frame 12 is set so that the direction of movement of the movable plates coincides with the position of the opening of the cylindrical frame 12b.

[0036] The rotary drive unit 16 includes, for example, an electric motor, and rotates the lifting drive unit 14 (and the article holding unit 13) within a predetermined angular range around a rotation axis L14 extending in the vertical direction. The angle of rotation that the rotary drive unit 16 can rotate is, for example, any angle up to 180 degrees, but the upper limit is not limited to 180 degrees. The rotary drive unit 16 makes it possible to orient the laterally extended article holding unit 13 (or the article M held by the article holding unit 13) in a desired direction. The slide mechanism 11 and the rotary drive unit 16 are controlled by the trolley controller 8. Note that even when the movable plate of the slide mechanism 11 is not moved and is stored (shown by a solid line in Figure 3), the rotation of the lifting drive unit 14 by the rotary drive unit 16 is still possible. In that case, for example, the rotation axis L14 of the lifting drive unit 14 coincides with the rotation axis L10 of the main body 10.

[0037] The trolley unit 50 has a cylindrical support member (cylindrical member) 52 at its lower end. The top plate portion 12a of the main frame 12 is rotatably attached to the lower surface of the support member 52. For example, a rotational drive unit (not shown), such as an electric motor, is provided on the top plate portion 12a. The driving force of the rotational drive unit is transmitted to the support member 52, causing the main frame 12 to rotate around a rotation axis L10 that extends vertically with respect to the trolley unit 50. The angle in which the main frame 12 can rotate is, for example, any angle between 360 degrees and 540 degrees, but the upper limit is not limited to 540 degrees and the lower limit is not limited to 360 degrees. A slide mechanism 11 is attached to the lower surface of the top plate portion 12a, and the top plate portion 12a supports the slide mechanism 11. The main frame 12 and the transfer device 18 are integrated, and the main frame 12 and the transfer device 18 rotate together. The vehicle 2 can transfer goods M to and from the load port using the transfer device 18.

[0038] A cover (not shown) may be attached to the outer surface of the cylindrical frame 12b. In that case, the cover surrounds the transfer device 18 and the article M held by the transfer device 18. The cover is cylindrical with an open lower end and has a cutout for the portion (the open portion) from which the movable plate of the slide mechanism 11 protrudes.

[0039] The running section 30 has four running wheels 31. Each running wheel 31 is provided with two auxiliary wheels 32. As shown in Figure 4, the running wheels 31 are provided so as to protrude upward from the top cover 51 at the four corners of the bogie unit 50. Each running wheel 31 is rotatable around an axis of a horizontal or nearly horizontal axle along the XY plane. A running drive motor 33 is provided on the rotation axis L31 of each running wheel 31. Each running wheel 31 is rotationally driven by the driving force of the running drive motor 33. The running drive motor 33 is configured to be switchable between forward and reverse rotation, for example. Each running wheel 31 rolls on the track R around the rotation axis L31 (see Figures 7 and 8). Each running wheel 31 rolls on the running surfaces R1a, R2a, and R3a of the first rail R1, the second rail R2, and the crossing rail R3, causing the vehicle 2 to run. In other words, the running unit 30 travels along the track R. It should be noted that the configuration is not limited to all four running wheels 31 being rotationally driven by the driving force of the running drive motor 33; a configuration in which only some of the four running wheels 31 are rotationally driven is also possible.

[0040] Four wheel swivel mechanisms 40 (steering drive units) are fixed to a frame (not shown) within the bogie unit 50, and a base portion 34 is connected to each wheel swivel mechanism 40 via its pivot axis. On the base portion 34, a running wheel 31, two auxiliary wheels 32, and one running drive motor 33 are mounted via a connecting portion 35 and a support portion 36 (support member). For example, a square-shaped top cover 51 is provided on the top surface of the housing 53, and the base portion 34 is positioned in the notches formed at the four corners of the top cover 51. The connecting portion 35, running wheel 31, auxiliary wheels 32, and running drive motor 33 are positioned above the top cover 51.

[0041] As shown in Figures 3 and 4, the connecting section 35 connects the bogie unit 50 (specifically, the wheel swivel mechanism 40 fixed within the bogie unit 50) to the running wheels 31. This connecting structure positions the bogie unit 50 and the main body 10 below the track R, suspending them from the running section 30. The connecting section 35 is formed to a thickness that allows it to pass through the gaps G between the first rail R1 and the crossing rail R3, and between the second rail R2 and the crossing rail R3. The support section 36 is provided above the connecting section 35 and rotatably supports the rotation axis of the running wheels 31 and the rotation axis of the auxiliary wheels 32. The support section 36 maintains the relative position of the running wheels 31 and the auxiliary wheels 32.

[0042] As shown in Figure 4, the running wheels 31 are rotatably mounted around a vertically extending pivot axis L30. The four pivot axes L30 are positioned at the vertices of a square in plan view, and the rotation axis L10 is located at the center of the pivot axes L30. In other words, the four pivot axes L30 are positioned four times symmetrically with respect to the rotation axis L10 of the main body 10. In plan view, the positions of the running wheels 31 and the pivot axes L30 are different (shifted). The running wheels 31 rotate by the wheel rotation mechanism 40, and as a result, the direction of travel of the vehicle 2 can be changed.

[0043] The auxiliary wheels 32 are positioned one at the front and one at the rear in the direction of travel of the running wheels 31. Each of the auxiliary wheels 32 is rotatable around an axis of a horizontal or nearly horizontal axle along the XY plane. The lower end of the auxiliary wheels 32 is set to be higher than, for example, the lower end of the running wheels 31. Therefore, when the running wheels 31 are traveling on the running surfaces R1a, R2a, and R3a, the auxiliary wheels 32 do not come into contact with the running surfaces R1a, R2a, and R3a. Furthermore, when the running wheels 31 pass through the gaps G between the first rail R1 and the intersecting rail R3, and between the second rail R2 and the intersecting rail R3, the auxiliary wheels 32 come into contact with auxiliary members (not shown) provided on the first rail R1 and the second rail R2 to prevent the running wheels 31 from dropping. Furthermore, it is not limited to providing two auxiliary wheels 32 to one running wheel 31; for example, one auxiliary wheel 32 may be provided to one running wheel 31, or no auxiliary wheels 32 may be provided at all.

[0044] The wheel swivel mechanism 40 is a mechanism for swiveling the running wheels 31. The four wheel swivel mechanisms 40 are arranged, for example, one at each of the four corners within the housing 53 of the bogie unit 50. Each wheel swivel mechanism 40 has a steering motor 43 and a drive force transmission unit 42 provided between the steering motor 43 and the running wheels 31. The drive force transmission unit 42 is fixed to a frame (not shown) within the bogie unit 50. The drive force transmission unit 42 and the base unit 34 are connected via a swivel axis. Each wheel swivel mechanism 40 swivels the base unit 34, connecting unit 35, support unit 36, running wheels 31, auxiliary wheels 32, and running drive motor 33 as a single unit around the swivel axis L30. With the running vehicle 2 positioned at the center of each rail unit 100, each running wheel 31 is swiveled 90 degrees around each swivel axis L30. As a result, the running wheels 31 rotate on the intersecting rail R3. This allows the vehicle 2 to turn. Turning means switching from a first state in which the vehicle 2 travels in a first direction D1 to a second state in which it travels in a second direction D2, or from a second state in which the vehicle 2 travels in a second direction D2 to a first state in which it travels in a first direction D1. The turning of the vehicle 2 is performed, for example, when the vehicle 2 is stopped. The turning of the vehicle 2 may also be performed when the vehicle 2 is stopped but the item M is moving (for example, rotating). The drive of the wheel rotation mechanism 40 is controlled by the trolley controller 8.

[0045] The bogie controller 8 comprehensively controls the running vehicle 2. The bogie controller 8 is a computer consisting of a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), etc. The bogie controller 8 can be configured as software in which, for example, a program stored in ROM is loaded onto RAM and executed by the CPU. The bogie controller 8 may also be configured as hardware, such as electronic circuits. The bogie controller 8 may consist of one device or multiple devices. If it consists of multiple devices, these are connected via a communication network such as the Internet or an intranet to logically construct a single bogie controller 8. The bogie controller 8 is installed, for example, in the bogie unit 50.

[0046] The trolley controller 8 controls the movement of the trolley 2 based on the transport command. The trolley controller 8 controls the movement of the trolley 2 by controlling the travel drive motor 33 and the steering motor 43, etc. The trolley controller 8 controls, for example, the travel speed, stopping operations, and direction change operations. The trolley controller 8 controls the transfer operation of the trolley 2 based on the transport command. The trolley controller 8 controls the transfer direction of the transfer device 18 by controlling the rotation of the main body 10 (main body frame 12 and transfer device 18). The trolley controller 8 controls the transfer operation of the trolley 2 by controlling the transfer device 18, etc. The trolley controller 8 controls the load-grabbing operation to grasp the item M to be placed in a predetermined load port, and the load-unloading operation to lower the held item M to the predetermined load port.

[0047] The system controller 5 is a computer consisting of a CPU, ROM, RAM, etc. The system controller 5 can be configured as software, for example, where a program stored in ROM is loaded onto RAM and executed by the CPU. The system controller 5 may also be configured as hardware, such as electronic circuits. The system controller 5 may consist of a single device or multiple devices. If it consists of multiple devices, these are connected via a communication network such as the Internet or an intranet to logically construct a single system controller 5. At least some of the various controls of the system controller 5 may be performed by the trolley controller 8.

[0048] The system controller 5 selects one of several vehicles 2 capable of transporting the item M and assigns a transport command to the selected vehicle 2. The transport command includes a travel command to make the vehicle 2 travel to the load port, and a command to grab the item M placed at the load port or a command to unload the item M being held at the load port.

[0049] Next, the running section 30 will be described in detail with reference to Figures 7 and 8. Figures 7 and 8 show an example in which the running wheels 31 travel along the Y direction on the intersecting running surface R3a. Figure 8 shows a cross-section of the running section 30 along the XZ plane. As described above, the running section 30 includes running wheels 31, a running drive motor 33, a support section 36, and a connecting section 35. The running wheels 31 roll on the track R with the rotation axis L31 as its axis. The running wheels 31 pivot around the pivot axis L30. At this time, since the pivot axis L30 is located on the intersecting rail R3, the running wheels 31 can pivot on the intersecting rail R3. The running wheels 31 include an outer ring section 31a and a wheel section 31b.

[0050] The drive motor 33 is a drive source that generates driving force to rotate the drive wheels 31. The drive motor 33 drives the drive wheels 31. The drive motor 33 is positioned such that its output shaft 33a is coaxial with the rotation axis L31 of the drive wheels 31. The drive motor 33 is mounted on the rotation axis L31 of the drive wheels 31. Specifically, when viewed from a direction along the rotation axis L31, the drive motor 33 is positioned so that it overlaps with the rotation axis L31. The output shaft 33a of the drive motor 33 is connected to the wheel portion 31b of the drive wheel 31 via a connection portion 37. The connection portion 37 includes, for example, a reduction gear that reduces the rotational speed of the drive motor 33, and an axle that transmits the driving force of the drive motor 33 to the drive wheels 31.

[0051] The outer diameter of the drive motor 33 is smaller than the outer diameter of the running wheel 31. When viewed from the axial direction of the rotation axis L31, the outer shape of the drive motor 33 is included within the outer shape of the running wheel 31. Cable Ca is electrically connected to the drive motor 33. Cable Ca is electrically connected to the trolley controller 8, which will be described later. The drive motor 33 is driven based on instructions input from the trolley controller 8, causing the running wheel 31 to rotate.

[0052] The support portion 36 rotatably supports the running wheel 31 and the auxiliary wheel 32. In other words, the support portion 36 supports the axle of the running wheel 31 so that the running wheel 31 can rotate in the rotational direction around the rotation axis L31. The support portion 36 also supports the axle of the auxiliary wheel 32 so that the auxiliary wheel 32 can rotate in the rotational direction around the rotation axis of the auxiliary wheel 32. In the illustrated example, the support portion 36 extends in the vertical direction and rotatably supports the running wheel 31 via the connecting portion 37, and also rotatably supports the auxiliary wheel 32.

[0053] The connecting portion 35 is connected to the lower part of the support portion 36. In the illustrated example, the connecting portion 35 extends downward from the lower part of the support portion 36, curving inward (towards the running drive motor 33), then extends straight downward, and then curves outward (towards the running wheels 31). The cable Ca is arranged along the connecting portion 35. The connecting portion 35 and the cable Ca extend downward from above the track R, passing through the gap G, for example, when the running vehicle 2 travels on the first rail R1 and crosses the second rail R2, or when it travels on the second rail R2 and crosses the first rail R1 (see Figure 7). The base portion 34 is a roughly rectangular parallelepiped portion that is continuous with the lower part of the connecting portion 35 (see Figure 4). For example, the base portion 34 is fixed at its upper end to the swivel cylinder 48.

[0054] As shown in Figures 2 and 8, a first support wall (support wall) 113 is connected to the upper surface of a plurality of first rails R1, and a second support wall (support wall) 123 is connected to the upper surface of a plurality of second rails R2. A first notch K1 is formed in the first support wall 113 and the second support wall 123. The first notch K1 allows the running section 30 to pass through when the vehicle 2 is running. For example, the first notch K1 and the second notch K2 allow the running wheels 31 and the running drive motor 33 to pass through.

[0055] The first notch K1 of the first support wall 113 has a shape such that, when viewed from the Y direction, the end of the first support wall 113 in the X direction is notched so as to open outwards in the X direction. The first notch K1 of the second support wall 123 has a shape such that, when viewed from the X direction, the end of the second support wall 123 in the Y direction is notched so as to open outwards in the Y direction. The first notch K1 includes a first portion K11 and a second portion K12. The first portion K11 and the second portion K12 are continuous with each other. The first portion K11 allows passage of a portion of the travel drive motor 33 opposite to the travel wheel 31 side. The second portion K12 allows passage of the other portion of the travel drive motor 33, the connecting portion 37, the support portion 36, the travel wheel 31 and the auxiliary wheel 32.

[0056] A second notch K2 is formed on the side of the intersection support column 133. The second notch K2 allows the running wheels 31 and auxiliary wheels 32 to pass through. The second notch K2 has a shape that opens towards the first support wall 113 or the second support wall 123. The second notch K2 is formed to be continuous with the first notch K1. The second notch K2 is optional.

[0057] Next, the wheel swivel mechanism (steering drive unit) 40 will be described in detail with reference to Figures 7 and 9 to 11. As shown in Figure 7, the wheel swivel mechanism 40 is located below the track R and below the running wheels 31. As shown in Figures 9 to 11, the drive force transmission unit 42 of the wheel swivel mechanism 40 is a mechanism that transmits the driving force generated in the steering motor 43 to the running unit 30. The drive force transmission unit 42 includes a gearbox 44, a housing 45, and a swivel cylinder 48. The gearbox 44 is located below the base unit 34. The housing 45 is located below the gearbox 44. A fixing member 45a is provided on the side of the housing 45. The housing 45 is fixed to the frame 54 in the bogie unit 50 via the fixing member 45a (see Figure 7).

[0058] The slewing cylinder 48 is, for example, cylindrical in shape. The slewing cylinder 48 has its pivot axis L30 as its axial direction and passes through the gearbox 44 and the housing 45. The slewing cylinder 48 is rotatably mounted relative to the gearbox 44 and the housing 45 with the pivot axis L30 as its base axis. A base portion 34 is connected to the upper end of the slewing cylinder 48. The lower end of the slewing cylinder 48 protrudes downward from the housing 45. A retaining member 49 is provided at this lower end of the slewing cylinder 48. The outer diameter of the retaining member 49 is larger than the outer diameter of the through hole in the housing 45 through which the slewing cylinder 48 passes. This prevents the slewing cylinder 48 from coming out upward.

[0059] The steering motor 43 of the wheel turning mechanism 40 is a drive source that generates the driving force for turning. The steering motor 43 is located below the gearbox 44. The steering motor 43 is fixed to the housing 45. The output shaft 43b of the steering motor 43 is positioned parallel to the turning axis L30. The output shaft 43b is connected to the drive force transmission unit 42.

[0060] As shown in Figures 10 and 11, the gearbox 44 contains a first gear 46, a second gear 47, and a bearing 43c. The first gear 46 is, for example, a spur gear. The first gear 46 is positioned with the vertical direction as its axial direction. The first gear 46 is coaxially connected to the output shaft 43b of the steering motor 43. The second gear 47 is, for example, a sector gear. The second gear 47 is positioned with the pivot axis L30 as its axial direction. The second gear 47 meshes with the first gear 46. The second gear 47 is engaged with the outer circumferential surface of the slewing cylinder 48 in the rotational direction around the pivot axis L30. For example, a cylindrical body to which the inner circumferential surface of the second gear 47 is fixed is rotatable in the rotational direction around the pivot axis L30, and the inner circumferential surface of this cylindrical body and the outer circumferential surface of the slewing cylinder 48 are synchronously rotatable so as to become one unit in that rotational direction via a keyway. As a result, the second gear 47 is connected to the support portion 36 via the slewing cylinder 48, the base portion 34, and the connecting portion 35. The bearing 43c rotatably supports the output shaft 43b of the steering motor 43. The bearing 43c is located below the first gear 46.

[0061] In the wheel swivel mechanism 40 configured as described above, when the running wheels 31 are swiveled, first, a driving force is generated by the steering motor 43, and this driving force is transmitted to the first gear 46 via the output shaft 43b. As a result, the first gear 46 rotates, and the second gear 47, which meshes with the first gear 46, rotates around the swivel axis L30. Synchronized with the rotation of the second gear 47, the swivel cylinder 48 rotates, for example, 90 degrees around the swivel axis L30. As a result, the base portion 34, the connecting portion 35, and the support portion 36 rotate 90 degrees around the swivel axis L30, and the running wheels 31 swivel 90 degrees around the swivel axis L30.

[0062] Furthermore, guide rollers that contact the side surface of the intersecting rail R3 may be provided between the running wheels 31 and the wheel swivel mechanism 40 (for example, near the coupling portion 35). The guide rollers prevent misalignment of the running bogie 20 (running vehicle 2) relative to the track R.

[0063] In the overhead vehicle system 1 described above, a drive motor 33 for driving the wheels 31 is provided on the rotation axis L31 of the wheels 31 that roll on the track R. Therefore, in the overhead vehicle system 1, the drive motor 33 can be positioned by effectively utilizing the space above the track R. This makes it possible to reduce the height dimension from the drive motor 33 to the wheels 31, for example, and to make the running unit 30 more compact. This makes it possible to create a compact system.

[0064] In the overhead vehicle system 1, a first support wall 113 and a second support wall 123 are connected to the upper surfaces of each of the multiple first rails R1 and multiple second rails R2, respectively. The first support wall 113 and the second support wall 123 are provided with a first notch K1 that allows the vehicle 2 to pass through when it is moving. In this case, the strength of the track R is increased by the first support wall 113 and the second support wall 123, and interference of the vehicle 2 with the vehicle 33 by the first notch K1 can be avoided.

[0065] In the overhead vehicle system 1, the wheel swivel mechanism 40 is located below the track R and below the running wheels 31. In this case, the wheel swivel mechanism 40 can be placed in the dead space below the track R and below the running wheels 31. This eliminates the need to place the wheel swivel mechanism 40 between the upper cover 51 of the bogie unit 50 and the track R, allowing the height dimension of the vehicle 2 to be reduced. As a result, the vehicle 2 can be made more compact.

[0066] In the overhead vehicle system 1, the outer shape of the drive motor 33 is included in the outer shape of the drive wheel 31 when viewed from the axial direction of the rotating shaft L31. In this case, the diameter of the drive wheel 31 can be increased, and a well-balanced structure of the drive unit 30 can be realized in the vehicle 2. By increasing the size of the drive wheel 31, the movement of the vehicle 2 becomes more stable, and the overhead vehicle 2 can carry heavier loads (the load-bearing capacity of the vehicle 2 is improved). In addition, the drive wheel 31 can more reliably overcome gaps G. Furthermore, it is possible to suppress the increase in size of the drive unit 30 due to the drive motor 33.

[0067] In the overhead vehicle system 1, the connecting section 35 and the cable C pass through the gap G when, for example, the vehicle 2 travels on the first rail R1 and crosses the second rail R2, or travels on the second rail R2 and crosses the first rail R1. Since there is no need to provide a transmission mechanism such as a belt to transmit driving force to the wheels 31 in the connecting section 35, it is possible to increase the strength of the connecting section 35 and other components.

[0068] Furthermore, in the overhead vehicle system 1, since a transmission mechanism such as a belt is not required between the drive motor 33 and the driving wheels 31, the following effects are achieved: Backlash is reduced and rigidity is improved. Stopping position accuracy is improved. Guide roller size can be increased. Structure is simplified and productivity is improved.

[0069] In the overhead vehicle system 1 of this embodiment, the wheel swivel mechanism 40 can be unitized. As a result, the productivity of the wheel swivel mechanism 40 is improved, and the ease of replacement and inspection of the wheel swivel mechanism 40 is also improved.

[0070] In the overhead-running vehicle system 1 of this embodiment, the first gear 46 and the second gear 47 are located inside the gearbox 44, rather than on the top cover 51 of the bogie unit 50. Therefore, compared to a structure in which gears such as rack gears are directly mounted on the main body 10, friction between gears caused by vibrations during operation can be suppressed.

[0071] Although embodiments have been described above, one aspect of the present invention is not limited to the above embodiments, and various modifications are possible without departing from the spirit of the invention.

[0072] In the above embodiment, the drive motor 33 is positioned so that its output shaft 33a is coaxial with the rotation shaft L31, but the embodiment is not limited to this. As long as the drive motor 33 is positioned on the rotation shaft L31, the output shaft 33a may be offset from the rotation shaft L31.

[0073] In the above embodiment, the case where the vehicle is an overhead vehicle was described, but the vehicle may also be a tracked trolley that runs on a track provided on the ground. In the above embodiment, a grid system was adopted as the overhead vehicle system 1, but the overhead vehicle system 1 is not limited to a grid system. For example, an AGV (Automated Guided Vehicle) may be adopted as the overhead vehicle system, or various known systems that run on a grid-like track may be adopted.

[0074] The components in the above embodiments and modifications are not limited to the materials and shapes described above, and various materials and shapes can be applied. Each component in the above embodiments or modifications can be arbitrarily applied to each component in other embodiments or modifications. Parts of each component in the above embodiments or modifications can be omitted as appropriate without departing from the spirit of one aspect of the present invention. [Explanation of symbols]

[0075] 1...Overhead vehicle system, 2...Overhead vehicle, 10...Main body, 30...Running section, 31...Running wheels, 33...Running drive motor, 35...Coupling section, 36...Support section, 40...Wheel swivel mechanism (steering drive section), 113...First support wall (support wall), 123...Second support wall (support wall), C...Cable, G...Gap, K1...First notch (notch), R...Track, R1...First rail, R2...Second rail, R3...Intersection rail, L30...Swivel axis, L31...Rotation axis.

Claims

1. At least a portion of the orbits are arranged in a grid pattern, The vehicle comprises a running section that travels along the aforementioned track, and an overhead running vehicle having a main body that is positioned below the track and suspended from the running section, The aforementioned running unit is A running wheel that rolls on the aforementioned track with the axis of rotation as its base, Includes a drive motor that drives the aforementioned wheels, The aforementioned drive motor is mounted on the rotation shaft of the aforementioned drive wheel, The track comprises a plurality of first rails extending along a first direction and a plurality of second rails extending along a second direction intersecting the first direction. Support walls are connected to the upper surfaces of each of the multiple first rails and the multiple second rails. An overhead vehicle system, wherein the support wall is provided with a notch that allows the passage of the drive motor when the overhead vehicle is in motion.

2. The aforementioned running wheels are provided to be rotatable, It is equipped with a steering drive unit that rotates the aforementioned wheels, The overhead vehicle system according to claim 1, wherein the steering drive unit is provided below the track and below the wheels.

3. The overhead vehicle system according to claim 1 or 2, wherein, when viewed from the axial direction of the rotating shaft, the outer shape of the drive motor is included in the outer shape of the drive wheel.

4. A support part that pivotally supports the aforementioned running wheels so that they can rotate, A connecting part connected to the lower part of the support part, The vehicle includes a cable electrically connected to the aforementioned drive motor, The track includes a plurality of intersecting rails arranged with gaps between them and the ends of the first rail and the ends of the second rail, The overhead vehicle system according to claim 1, wherein the connecting portion and the cable extend from above to below the track through the gap.

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