A conveyor system for Frieza, and Frieza

Abstract

To reduce malfunctions in the conveyor system used for Frieza. [Solution] A conveyor device for Frieza according to at least one embodiment of the present disclosure comprises an endless mesh belt, a drive device, a drive shaft body rotated by the drive device, and a plurality of sprockets attached to the drive shaft body so as to be aligned in the belt width direction and having a plurality of teeth that can penetrate the mesh of the mesh belt. The phase of the teeth of the first sprocket among the plurality of sprockets and the phase of the teeth of the second sprocket, which is positioned differently from the first sprocket in the belt width direction, are offset in the circumferential direction of the drive shaft body.

Description

Technical Field

[0001] The present disclosure relates to a conveyor device for a freezer and a freezer.

Background Art

[0002] As a freezer capable of cooling or freezing an object to be cooled, particularly food, a freezer capable of cooling or freezing an object to be cooled placed on the forward path portion of a conveyor belt for conveyance by cold air is known (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] It is desired that the conveyor belt advances without causing problems such as meandering, skewing, or only a part in the width direction leading. However, such problems may occur, and it is desired to prevent them from occurring.

[0005] In view of the above circumstances, at least one embodiment of the present disclosure aims to reduce problems occurring in a conveyor device for a freezer.

Means for Solving the Problems

[0006] (1) A conveyor device for a freezer according to at least one embodiment of the present disclosure includes an endless mesh belt, a drive device, a drive shaft body that is rotationally driven by the drive device, a plurality of sprockets attached to the drive shaft body so as to be arranged in the belt width direction and having a plurality of teeth that can penetrate into the meshes of the mesh belt, Equipped with, The phase of the teeth on the first sprocket among the plurality of sprockets and the phase of the teeth on the second sprocket, which has a different arrangement position in the belt width direction from the first sprocket, are offset in the circumferential direction of the drive shaft body.

[0007] (2) Frieza according to at least one embodiment of the present disclosure is A conveyor system for Frieza with the configuration described in (1) above, It is equipped with. [Effects of the Invention]

[0008] According to at least one embodiment of this disclosure, malfunctions occurring in the conveyor system for Frieza can be reduced. [Brief explanation of the drawing]

[0009] [Figure 1] This is an overall configuration diagram of Frieza as seen from the side according to one embodiment. [Figure 2] This figure shows an example of a conveyor belt for a belt conveyor according to one embodiment. [Figure 3] This diagram shows the drive shaft according to one embodiment, viewed from the downstream side in the conveying direction, illustrating the area near the center in the width direction of the conveyor belt. [Figure 4A] This is a side view of a drive shaft sprocket according to one embodiment. [Figure 4B] This is a side view of a drive shaft sprocket according to one embodiment. [Figure 4C] This is a side view of a drive shaft sprocket according to one embodiment. [Figure 5] This is a view along the VV arrow in Figure 3. [Figure 6] This is a perspective view of the support structure. [Figure 7] This is a schematic plan view illustrating the phase of the teeth of a sprocket in a drive shaft according to one embodiment. [Figure 8] This is a schematic plan view illustrating the phase of the sprocket teeth in a drive shaft according to another embodiment. [Figure 9] It is a schematic plan view for explaining the phase of the teeth of the sprocket on the drive shaft according to still another embodiment. [Figure 10] It is a schematic plan view for explaining the phase of the teeth of the sprocket on the drive shaft according to still another embodiment. [Figure 11] It is a schematic plan view for explaining the phase of the teeth of the sprocket on the drive shaft according to still another embodiment. [Figure 12] It is a schematic plan view for explaining the phase of the teeth of the sprocket on the drive shaft according to still another embodiment. [Figure 13] It is a diagram for explaining the dimensions of each part of the drive shaft main body and the sprocket. [Figure 14] It is a diagram for explaining the dimensions of each part of the drive shaft main body and the roller. [Figure 15] It is a diagram for explaining the relationship between the sprocket and the conveyor belt. [Figure 16] It is a diagram for explaining the relationship between the roller and the conveyor belt.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, some embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described as embodiments or shown in the drawings are not intended to limit the scope of the present disclosure thereto, but are merely illustrative examples. For example, expressions representing relative or absolute arrangements such as "in a certain direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric", or "coaxial" not only strictly represent such arrangements, but also represent states of relative displacement with tolerances or angles and distances that can obtain the same function. For example, expressions such as "identical," "equal," and "homogeneous" that describe things being in an equal state not only describe a state of being strictly equal, but also describe a state in which there is a tolerance or a difference that is sufficient to achieve the same function. For example, expressions describing shapes such as squares or cylinders shall not only represent geometrically precise shapes such as squares or cylinders, but also shapes that include protrusions, chamfers, etc., to the extent that the same effect can be achieved. On the other hand, expressions such as "to possess," "to be equipped with," "to have," "to include," or "to have" a single component are not exclusive expressions that exclude the existence of other components.

[0011] Figure 1 is an overall configuration diagram of Frieza 1 according to one embodiment, viewed from the side. One embodiment of the Freezer 1 is a freezer capable of cooling or freezing an object to be cooled, particularly food, and comprises a housing 3 that houses the main components of the Freezer 1, a belt conveyor 5 for transporting the object to be cooled (not shown), a heat exchanger (not shown) for cooling the air, and a fan (not shown) for circulating the cooled air (cold air) cooled by the heat exchanger within the Freezer 1.

[0012] In one embodiment of the Freeza 1, the housing 3 is configured to separate the inside and outside of the Freeza 1 and to retain cold air inside. In one embodiment, the Frieza 1 is configured to cool an object to be cooled (not shown) by blowing cold air from a fan (not shown) from either above or below the object to be cooled, which is placed on the forward portion 7a of the conveyor belt 7 of the belt conveyor 5. In the following description, the direction in which the conveyor belt 7 transports the object to be cooled (not shown) will be referred to as the transport direction of the conveyor belt 7, or simply the transport direction. Furthermore, in the following explanation, objects not shown will also be simply referred to as "cooled objects."

[0013] In one embodiment of the Freezer 1, a portion of the forward portion 7a of the conveyor belt 7, on the upstream side in the conveying direction, is exposed to the outside of the housing 3 in order to place the object to be cooled on the conveyor belt 7. In one embodiment of the Freezer 1, a portion of the forward portion 7a of the conveyor belt 7, on the downstream side in the conveying direction, is exposed to the outside of the housing 3 in order to send the object to be cooled on the conveyor belt 7 to the next process.

[0014] (Conveyor belt 5) In one embodiment of the Freeza 1, the belt conveyor 5 includes a conveyor belt 7 for transporting objects to be cooled, a drive device 6 for driving the conveyor belt 7, a drive shaft 9 for driving the conveyor belt 7 by the driving force of the drive device 6, and a direction changing shaft 11 for changing the direction of movement of the conveyor belt 7. The drive unit 6 includes a drive motor (not shown) and a transmission mechanism (not shown) for transmitting the driving force of the drive motor to the drive shaft 9. The direction change shaft 11 includes a driven shaft 13 positioned at the upstream end of the forward portion 7a of the conveyor belt 7, and at least one idler shaft 15 positioned to contact the conveyor belt 7 from the inside of the conveyor belt 7 (or from the outside of the conveyor belt 7, depending on the layout of the trajectory of the conveyor belt 7 due to the direction change of the conveyor belt 7) in the return portion 7b of the conveyor belt 7, which is wrapped around the drive shaft 9 and the driven shaft 13. In the freezer 1 shown in Figure 1, two idler shafts 15 are provided on the inside of the conveyor belt 7, spaced apart from each other in the conveying direction.

[0015] Figure 2 shows an example of a conveyor belt 7 of a belt conveyor 5 according to one embodiment. The conveyor belt 7 is, for example, an endless (endless strip) mesh belt made by weaving metal wires into a mesh shape, and can support objects to be cooled. For example, the conveyor belt 7 has several reinforcing ribs 71 which are wires extending in the width direction Drw of the conveyor belt 7 and spaced apart in a direction perpendicular to the width direction Drw, and helical portions 73 which are wires arranged to spirally wrap around two adjacent reinforcing ribs 71 from the outside in a direction perpendicular to the width direction Drw. Therefore, the helical portions 73 include a helical portion 73a located on the front side in Figure 2 relative to the reinforcing ribs 71 and a helical portion 73b located on the back side in Figure 2 relative to the reinforcing ribs 71, and the helical portions 73a located on the front side and the helical portions 73b located on the back side are arranged alternately along the width direction Drw. The ends of the reinforcing ribs 71 in the width direction Drw are connected to the ends of the helical portions 73 in the width direction Drw, for example, by welding. For the sake of explanation, Figure 2 is assumed to be a plan view of the forward portion 7a of the conveyor belt 7, with the outer side of the endless conveyor belt 7 being the foreground side of the paper in Figure 2 and the inner side of the endless conveyor belt 7 being the background side of the paper in Figure 2. Furthermore, the upper side of Figure 2 is assumed to be the downstream side in the conveying direction, and the lower side is assumed to be the upstream side in the conveying direction.

[0016] In one embodiment of the conveyor belt 7, the length of one link of the conveyor belt 7 is the arrangement pitch of two adjacent force ribs 71 in a direction perpendicular to the width direction Drw (conveying direction). In the following explanation, the width direction Drw of the conveyor belt 7 will also be simply referred to as the width direction Drw.

[0017] In one embodiment of the conveyor belt 7, in Figure 2, one mesh 75 of the conveyor belt 7, that is, the wire that constitutes the region in which the teeth 23t of the sprocket 23 (described later) enter from the inside of the endless belt-shaped conveyor belt 7, includes two adjacent force ribs 71 in the conveying direction, two adjacent helical portions 73b on the far side of the paper in the width direction Drw, and one helical portion 73a on the near side of the paper that connects the two helical portions 73b. For example, in Figure 2, hatching is applied to the region corresponding to one mesh 75 of the conveyor belt 7, and the direction of the hatching is different from that of the adjacent mesh 75 in the width direction Drw. Note that one mesh 75 of the conveyor belt 7 is included in one link of the conveyor belt 7.

[0018] The conveyor belt 7 is driven by a drive shaft 9, which is driven by a drive device 6, and is capable of transporting objects to be cooled placed on the forward path portion 7a of the conveyor belt 7 from the upstream side to the downstream side in the transport direction. Furthermore, the conveyor belt 7 of the belt conveyor 5 according to one embodiment is not limited to the structure shown in Figure 2, as long as it has a structure that allows cold air to pass through in the thickness direction of the conveyor belt 7 with relatively little pressure loss, and can wrap around the drive shaft 9 and the direction changing shaft 11 relatively easily, and has a structure that meshes with teeth provided on the sprocket 23, such as the teeth 23t of the sprocket 23 described later.

[0019] (Regarding drive shaft 9) Figure 3 shows a view of the drive shaft 9 from the downstream side in the conveying direction according to several embodiments, illustrating the area near the center of the width direction Drw of the conveyor belt 7. In some embodiments, the drive shaft 9 comprises a drive shaft body 21, at least one sprocket 23 that rotates in sync with the rotation of the drive shaft body 21, at least one roller 25 through which the drive shaft body 21 is inserted and which is rotatable relative to the drive shaft body 21, at least one cylindrical member 27 through which the drive shaft body 21 is inserted and which is rotatable relative to the drive shaft body 21, and a support portion 30.

[0020] In some embodiments of the drive shaft 9, the sprocket 23 and roller 25 are arranged side by side in the width direction Drw with a cylindrical member 27 in between. In some embodiments of the drive shaft 9, there are multiple sprockets 23, rollers 25, and cylindrical members 27, and the sprockets 23 and rollers 25 are arranged alternately in the width direction Drw, with the cylindrical member 27 positioned between adjacent sprockets 23 and rollers 25 in the width direction Drw. In some embodiments of the drive shaft 9, the sprocket 23, roller 25, and cylindrical member 27 are mounted on the drive shaft body 21 in such a manner that they can rotate relative to each other around the central axis AX of the drive shaft body 21. In some embodiments of the drive shaft 9, the sprocket 23 is positioned from near one end to near the other end in the width direction Drw of the conveyor belt 7. The sprocket 23, roller 25, and cylindrical member 27 are mounted on the drive shaft body 21 in such a manner that they can move relative to the drive shaft body 21 in the direction of extension of the drive shaft body 21 (width direction Drw).

[0021] (Drive shaft body 21) In some embodiments of the drive shaft 9, the drive shaft body 21 is an axial member extending in the width direction Drw of the conveyor belt 7, and is rotatably supported on a frame (not shown) of the housing 3 so as to be rotationally driven by the drive device 6 around a central axis AX. In the figures from Figure 5 onward described later, for the sake of explanation, the drive shaft body 21 is shown as a solid member, but the drive shaft body 21 may be a hollow member or a solid member. The drive shaft body 21 is formed of, for example, stainless steel, but it may be made of a metal other than stainless steel, or of resin, or of carbon fiber.

[0022] (Sprocket 23) Figure 4A is a side view of the sprocket 23 of the drive shaft 9 according to several embodiments. Figure 4B is a side view of the sprocket 23 of the drive shaft 9 according to several embodiments, showing that the phase of the teeth 23t is ahead in the rotational direction of the drive shaft body 21 compared to the sprocket 23 shown in Figure 4A. Figure 4C is a side view of the sprocket 23 of the drive shaft 9 according to several embodiments, showing a state in which the phase of the teeth 23t is delayed in the rotational direction of the drive shaft body 21 compared to the sprocket 23 shown in Figure 4A.

[0023] In some embodiments of the drive shaft 9, the sprocket 23 is a member having a plurality of teeth 23t that protrude radially outward from the tooth root surface 23a. Note that the sprocket 23 shown in Figure 3, and later in Figures 7 and 9, is depicted schematically. Note that in Figure 3, and later in Figures 7 and 9, the corresponding circle 23b that corresponds to the top of the teeth 23t of the sprocket 23 is represented by a dashed line, and the tooth root surface 23a is represented by a solid line. Sprocket 23 is made of, for example, resin.

[0024] The teeth 23t of the sprocket 23 are arranged in multiple rows with spacing between them in the direction of extension (width direction Drw) of the central axis AX of the drive shaft body 21. The teeth 23t of the sprocket 23 are formed to penetrate the mesh 75 of the conveyor belt 7, specifically the portion enclosed by two adjacent helical portions 73b in the width direction Drw and two adjacent force ribs 71 in the conveying direction, which form a single link inside the endless belt-shaped conveyor belt 7. By pressing the force ribs 71 with the sides of the teeth 23t, the conveyor belt 7 is driven. As described above, in Figure 2, the area corresponding to one mesh 75 of the conveyor belt 7 is hatched. Also in Figure 2, the four teeth 23t that penetrate each of, for example, four meshes 75 arranged in the width direction Drw are schematically shown by dashed lines.

[0025] The sprocket 23 is configured such that torque from the drive shaft body 21 is transmitted to the sprocket 23 by, for example, a key (not shown). Therefore, the sprocket 23 rotates in sync with the rotation of the drive shaft body 21. The sprocket 23 has a keyway 23g into which a key (not shown) is inserted. As described above, the sprocket 23 is mounted on the drive shaft body 21 in such a manner that it can move relative to the drive shaft body 21 in the direction of extension of the drive shaft body 21 (width direction Drw).

[0026] (Regarding the phase of the 23th tooth of sprocket 23) Here, the phase of the teeth 23t of the sprocket 23 is an indicator that shows the position of the teeth 23t of the sprocket 23 in the circumferential direction of the drive shaft body 21, for example, with reference to a certain position in the circumferential direction of the drive shaft body 21. It should be assumed that the circumferential position of the drive shaft body 21 with respect to the keyway (not shown) in the drive shaft body 21 into which the key (not shown) for attaching the sprocket 23 is inserted is the same for all of them. Therefore, in the following explanation, the phase of the teeth 23t of the sprocket 23 will be explained based on the circumferential position of the sprocket 23 (circumferential position 23pts) of the tooth 23ts, which is located at the circumferential position closest to the circumferential position of the sprocket 23 where the keyway 23g of the sprocket 23 exists (circumferential position 23pg). For the purposes of the following explanation, the sprocket 231 shown in Figure 4A, in which the circumferential position 23pg where the keyway 23g exists coincides with the circumferential position 23pts of the tooth 23ts located at the circumferential position closest to the circumferential position 23pg, will be used as the reference sprocket 23 for explaining the phase lead and lag of the tooth 23t.

[0027] For example, in the sprocket 232 shown in Figure 4B, the circumferential position 23pts of the tooth 23ts described above is located downstream in the rotational direction rs of the drive shaft body 21 compared to the circumferential position 23pts of the tooth 23ts described above in the sprocket 231 shown in Figure 4A. In this case, the phase of the tooth 23t in the sprocket 232 shown in Figure 4B is ahead in the rotational direction of the drive shaft body 21 compared to the phase of the tooth 23t in the sprocket 231 shown in Figure 4A.

[0028] For example, in the sprocket 231 shown in Figure 4A, the circumferential position 23pts of the tooth 23ts described above is located upstream of the drive shaft body 21 in the rotational direction rs compared to the circumferential position 23pts of the tooth 23ts described above in the sprocket 232 shown in Figure 4B. In this case, the phase of the tooth 23t in the sprocket 231 shown in Figure 4A lags behind the phase of the tooth 23t in the drive shaft body 21 in the rotational direction.

[0029] Furthermore, the teeth 23ts on the sprocket 232 shown in Figure 4B and the teeth 23ts on the sprocket 231 shown in Figure 4A intersect, for example, with the mesh 75 of the conveyor belt 7, which are aligned at the same position in the conveying direction and enclosed by the dashed line DL in Figure 2.

[0030] For example, in the sprocket 233 shown in Figure 4C, the circumferential position 23pts of the tooth 23ts described above is located upstream of the drive shaft body 21 in the rotational direction rs compared to the circumferential position 23pts of the tooth 23ts described above in the sprocket 231 shown in Figure 4A. In this case, the phase of the tooth 23t in the sprocket 233 shown in Figure 4C lags behind the phase of the tooth 23t in the drive shaft body 21 in the rotational direction.

[0031] For example, in the sprocket 231 shown in Figure 4A, the circumferential position 23pts of the tooth 23ts described above is located downstream in the rotational direction rs of the drive shaft body 21 compared to the circumferential position 23pts of the tooth 23ts described above in the sprocket 233 shown in Figure 4C. In this case, the phase of the tooth 23t in the sprocket 231 shown in Figure 4A is ahead of the phase of the tooth 23t in the rotational direction of the drive shaft body 21 compared to the phase of the tooth 23t in the sprocket 233 shown in Figure 4C.

[0032] Furthermore, the teeth 23ts on the sprocket 233 shown in Figure 4C and the teeth 23ts on the sprocket 231 shown in Figure 4A intersect, for example, with the mesh 75 of the conveyor belt 7, which are aligned at the same position in the conveying direction and enclosed by the dashed line DL in Figure 2.

[0033] The phase lead or lag of tooth 23t represents the relative circumferential positional relationship of the teeth 23t between two or more sprockets 23 whose phases are being compared.

[0034] (Laura 25) In some embodiments of the drive shaft 9, the roller 25 is a roller with no irregularities on its outer circumferential surface 25o, and is configured to support the conveyor belt 7 by contacting the inner surface of the conveyor belt 7 with its outer circumferential surface 25o on the surface opposite to the surface on which the object to be cooled is placed (outer surface) in the forward pass portion 7a. The roller 25 has a width dimension Drw that is the same as the width dimension Drw of the sprocket 23. The roller 25 is made of, for example, resin.

[0035] In some embodiments of the drive shaft 9, the inner circumferential surface 25i of the roller 25 is in contact with the outer circumferential surface 21o of the drive shaft body 21 in a manner that allows for separation and retraction. The inner diameter Dir of the roller 25 is larger than the outer diameter Dos of the drive shaft body 21, and the dimensional difference (Dir-Dos) between the inner diameter Dir of the roller 25 and the outer diameter Dos of the drive shaft body 21 is larger than, for example, the clearance fit in the JIS standard. In other words, in some embodiments of the drive shaft 9, the roller 25 is loosely fitted to the drive shaft body 21.

[0036] (Cylindrical member 27) In some embodiments of the drive shaft 9, the cylindrical member 27 is a cylindrical member having an outer diameter smaller than the tooth root surface 23a of the sprocket 23 and the outer circumferential surface 25o of the roller 25. The cylindrical member 27 has a widthwise Drw dimension that is smaller than the widthwise Drw dimension of the sprocket 23 and roller 25. For example, the widthwise Drw of the cylindrical member 27 is less than or equal to half the widthwise Drw of the sprocket 23 and roller 25. The cylindrical member 27 is made of, for example, resin.

[0037] In some embodiments of the drive shaft 9, the inner circumferential surface of the cylindrical member 27 is in contact with the outer circumferential surface 21o of the drive shaft body 21 in a manner that allows for separation and retraction. The inner diameter of the cylindrical member 27 is larger than the outer diameter Dos of the drive shaft body 21, and the dimensional difference between the inner diameter of the cylindrical member 27 and the outer diameter Dos of the drive shaft body 21 is larger than, for example, the clearance fit in the JIS standard.

[0038] (Support part 30) Figure 5 is a view along the VV arrow in Figure 3. Figure 6 is a perspective view of the support portion 30. In some embodiments of the drive shaft 9, the support portion 30 is configured to support at least one cylindrical member 27 from below in a rotatable state, and to restrict the range of movement of at least one sprocket 23 and at least one roller 25 in the extending direction (width direction Drw) of the drive shaft body 21. In one embodiment, the support portion 30 has a support plate portion 31 positioned between one sprocket 23 and one roller 25 adjacent to each other in the width direction Drw. The support plate portion 31 has a support recess 32 formed therein that can support the outer circumferential surface 27o of the cylindrical member 27 from below. The support recess 32 has an arc shape that extends in the circumferential direction of the cylindrical member 27 along the outer circumferential surface 27o of the cylindrical member 27. The thickness of the support plate portion 31, i.e., the widthwise Drw dimension, is smaller than the widthwise Drw dimension of the cylindrical member 27 supported by the support plate portion 31.

[0039] In some embodiments of the drive shaft 9, the support portion 30 has two support plate portions 31 that can support from below a single roller 25 located near the center of the conveyor belt 7 in the width direction Drw, and two cylindrical members 27 located on one side and the other side of the roller 25 in the width direction Drw. The two support plate portions 31 are connected to the connecting plate 33 at their upstream ends in the transport direction. In some embodiments of the drive shaft 9, the support portion 30 is fixed by a connecting plate 33 attached to a frame (not shown) of the housing 3.

[0040] In some embodiments of the drive shaft 9, in each of the two support plate portions 31, as shown in Figure 5, at least a portion of the support plate portion 31 is formed to overlap with at least a portion of the side surface of the roller 25 when viewed from the width direction Drw. Similarly, in each of the two support plate portions 31, at least a portion of the support plate portion 31 is formed to overlap with at least a portion of the side surface of the sprocket 23 when viewed from the width direction Drw. Therefore, the sprocket 23 and roller 25, which are positioned on either side of the support plate portion 31 in the width direction Drw, have their side surfaces in contact with the support plate portion 31, thereby restricting their movement toward the support plate portion 31 in the width direction Drw.

[0041] In some embodiments of the drive shaft 9, the support portion 30 is provided, which reduces the deflection of the drive shaft body 21 and reduces problems such as meandering or diagonal movement of the conveyor belt 7. Furthermore, according to some embodiments of the drive shaft 9, it is possible to limit the amount of movement of the sprocket 23 in the extending direction (widthwise Drw) of the drive shaft body 21 in response to small fluctuations in the position of the conveyor belt 7 in the widthwise Drw, while limiting the amount of movement.

[0042] In some embodiments of the drive shaft 9, there may be at least one support portion 30 having one support plate portion 31, or at least one support portion 30 having two or more support plate portions 31.

[0043] (Problems in the Belt Conveyor 5) Generally, in a belt conveyor, there is a risk that problems such as the conveyor belt meandering or skewing occur, or when the conveyor belt is a mesh belt, only a part of the conveyor belt in the width direction may lead. Therefore, it is desired to prevent such problems from occurring.

[0044] When the conveyor belt 7 contacts the tooth bottom surface 23a of the sprocket 23 with a certain surface pressure, the conveyor belt 7 is driven in the rotation direction of the sprocket 23 by the tooth bottom surface 23a due to the frictional force between the conveyor belt 7 and the tooth bottom surface 23a. In this case, since the radial positions of the teeth 23t and the tooth bottom surface 23a on the sprocket 23 are different, the moving speed V1 of the conveyor belt 7 determined by the relationship between the length of one link of the conveyor belt 7 and the number of teeth 23t fed per unit time according to the rotational speed of the drive shaft body 21, and the moving speed V2 of the conveyor belt 7 driven by the tooth bottom surface 23a will have a difference.

[0045] Since the tooth bottom surface 23a is located radially inside the teeth 23t, basically the moving speed V2 is smaller than the moving speed V1 (V2 < V1). However, for example, if the diameter of the tooth bottom surface 23a becomes undesirably large due to reasons such as temperature or manufacturing accuracy, or if the movement speed V2 becomes larger than the movement speed V1 due to inhibition of the bending of the link part due to freezing of the conveyor belt 7 or icing on the conveyor belt 7 resulting in an increase in the apparent thickness of the conveyor belt 7.

[0046] In addition, when the interval between the rib 71 and the spiral part 73 of the conveyor belt 7 becomes large due to the freezing of the water that has entered between them, and the length of one link of the conveyor belt 7 becomes short, the moving speed V1 of the conveyor belt 7 determined by the relationship between the length of one link of the conveyor belt 7 and the number of teeth 23t fed per unit time according to the rotational speed of the drive shaft body 21 becomes small. Due to these various factors, a difference arises between movement speed V1 and movement speed V2.

[0047] Therefore, when the drive shaft body 21 is rotated while the conveyor belt 7 is in contact with the tooth root surface 23a with a certain amount of surface pressure, the conveyor belt 7 may move at a speed V3 that is different from the conveyor belt 7's moving speed V1, which is determined by the relationship between the length of one link of the conveyor belt 7 and the number of teeth 23t fed per unit time due to the rotational speed of the drive shaft body 21, due to the difference in moving speed (V1-V2) mentioned above.

[0048] Furthermore, variations in the surface pressure at which the conveyor belt 7 contacts the tooth root surface 23a can cause fluctuations and positional variations in the conveyor belt 7's movement speed V2, which is driven by the tooth root surface 23a. Such fluctuations and variations can cause the conveyor belt 7 to meander or skewer.

[0049] In a belt conveyor 5 equipped with an endless mesh belt, the conveyor belt 7, being a mesh belt, is flexible. As a result, the position of the mesh 75 of the conveyor belt 7 may shift in the direction of transport depending on the width of the conveyor belt 7, or the dimensions of the mesh 75 in the transport direction may change. If such changes in the mesh 75 of the conveyor belt 7 are left unaddressed, it may lead to problems such as meandering, skewing, or only a portion of the conveyor belt 7 moving ahead in the width direction.

[0050] Therefore, in the drive shaft 9 according to several embodiments, the occurrence of problems related to the conveyor belt 7 is reduced by the following: Figure 7 is a schematic plan view illustrating the phase of the teeth 23t of the sprocket 23 in the drive shaft 9 according to one embodiment. Figure 8 is a schematic plan view illustrating the phase of the teeth 23t of the sprocket 23 in the drive shaft 9 according to another embodiment. Figure 9 is a schematic plan view illustrating the phase of the teeth 23t of the sprocket 23 in the drive shaft 9 according to yet another embodiment. Figure 10 is a schematic plan view illustrating the phase of the teeth 23t of the sprocket 23 in the drive shaft 9 according to yet another embodiment. Figure 11 is a schematic plan view illustrating the phase of the teeth 23t of the sprocket 23 in the drive shaft 9 according to yet another embodiment. Figure 12 is a schematic plan view illustrating the phase of the teeth 23t of the sprocket 23 in the drive shaft 9 according to yet another embodiment.

[0051] For the sake of clarity, the dimensions of the sprocket 23 in the transport direction in the plan view are exaggerated in Figures 7 to 12. In Figures 7 to 12, for example, the drive shaft 9 is provided with 12 sprockets 23 spaced apart in the width direction Drw, but the number of sprockets 23 provided on the drive shaft 9 is not limited to 12. In Figures 7 to 12, the sprockets are also referred to as the A sprocket 23A, B sprocket 23B, C sprocket 23C, D sprocket 23D, E sprocket 23E, and F sprocket 23F, starting from the sprocket 23 closest to the center Cw in the width direction Drw. In Figures 7 to 12, the hatched areas indicate the position of the tooth 23ts (circumferential position 23pts) located at the circumferential position closest to the circumferential position 23pg where the keyway 23g exists.

[0052] (Regarding the reduction of changes in mesh size 75: Part 1) After diligent investigation by the inventors, it was found that when the phase of the teeth 23t of all the sprockets 23 arranged in the width direction Drw is aligned and the conveyor belt 7 is rotated in the conveying direction, the tension of the conveyor belt 7 near the center of the width direction Drw tends to be lower than the tension of the conveyor belt 7 near both ends of the width direction Drw. When a force is applied to move the conveyor belt 7, a compressive force acts on the conveyor belt 7 in the width direction Drw. When a compressive force acts on the conveyor belt 7 in the width direction Drw, the wire members (reinforcement ribs 71) extending in the width direction Drw of the conveyor belt 7 tend to buckle. In this case, if the tension near the center of the width direction Drw of the conveyor belt 7 is low, the force resisting buckling is weak. This is because when there is a certain amount of tension on the conveyor belt 7, a force acts to maintain the shape of the link between the helical portion 73 of the conveyor belt 7 and the reinforcement ribs 71, but when the tension is weak, the link between the helical portion 73 and the reinforcement ribs 71 can move somewhat freely. Therefore, if the tension near the center of the widthwise Drw is low, buckling will occur more strongly when a compressive force acts on the conveyor belt 7 in the widthwise Drw, which can cause deformation in the area near the center of the widthwise Drw of the conveyor belt 7 to precede deformation downstream in the conveying direction compared to the areas near both ends of the widthwise Drw.

[0053] Therefore, in order to reduce such changes in the mesh 75, in the drive shaft 9 according to some embodiments, for example as shown in Figures 7, 8, and 9, the phase of the teeth 23t of a sprocket 23 (referred to as the first sprocket) located at a certain position in the width direction Drw is set to advance in the rotational direction rs of the drive shaft body 21 more than the phase of the teeth 23t of a sprocket 23 (referred to as the second sprocket) located at a position further from the center Cw in the width direction Drw than the first sprocket. In other words, in the drive shaft 9 according to some embodiments shown in Figures 7, 8, and 9, for example, the first sprocket is positioned closer to the center Cw in the width direction Drw than the second sprocket. The phase of the teeth 23t in the first sprocket is ahead of the phase of the teeth 23t in the second sprocket in the rotation direction rs of the drive shaft body 21.

[0054] For example, in the example shown in Figure 7, the phase of the teeth 23t of each sprocket 23 is set such that the phase of the teeth 23t gradually advances as it approaches the center Cw in the width direction Drw. In other words, in the example shown in Figure 7, if any one of the multiple sprockets 23 is designated as the first sprocket, then all sprockets 23 that are further from the center Cw in the width direction Drw than the designated first sprocket 23 become the second sprockets. In the example shown in Figure 7, the phases of the teeth 23t of two adjacent sprockets 23 in the width direction Drw are different, except when comparing two adjacent A sprockets 23A in the width direction Drw.

[0055] For example, as shown in Figure 8, in addition to comparing two adjacent A sprockets 23A in the width direction Drw, there may also be cases where the phase of the teeth 23t of two adjacent sprockets 23 in the width direction Drw is the same. For example, in the example shown in Figure 8, the phase of the teeth 23t of the B sprocket 23B and the C sprocket 23C is the same. For example, in the example shown in Figure 8, the phase of the teeth 23t of the D sprocket 23D, the E sprocket 23E and the F sprocket 23F is the same.

[0056] For example, in the example shown in Figure 8, if the A sprocket 23A is designated as the first sprocket, then all the other sprockets 23 become the second sprockets. For example, in the example shown in Figure 8, if the B sprocket 23B and C sprocket 23C are designated as the first sprockets, then the D sprocket 23D, E sprocket 23E, and F sprocket 23F become the second sprockets.

[0057] Furthermore, as shown in Figure 9, for example, the phase of the teeth 23t of the sprocket 23 located near the center Cw in the width direction Drw may be advanced, while the phases of the teeth 23t of the other sprockets 23 may all be the same. For example, in the example shown in Figure 9, the phase of the teeth 23t is the same from the B sprocket 23B to the F sprocket 23F, but the phase of the teeth 23t of the two A sprockets 23A is ahead of the phase of the teeth 23t of the other sprockets 23. In other words, in the example shown in Figure 9, if the A sprocket 23A is designated as the first sprocket, then all the other sprockets 23 become the second sprockets. Furthermore, a sprocket 23 whose tooth 23t is ahead in phase compared to other sprockets 23 is not limited to the A sprocket 23A; for example, the B sprocket 23B may also have the same tooth 23t phase as the A sprocket 23A.

[0058] For example, as shown in Figures 7, 8, and 9, if the phase of the teeth 23t of the first sprocket, which is positioned near the center Cw of the widthwise Drw, is set to advance the phase of the teeth 23t of the second sprocket, the tension of the conveyor belt 7 in the conveying direction near the center Cw of the widthwise Drw will not decrease easily. As a result, the influence of the force compressing the conveyor belt 7 in the widthwise Drw will be reduced, so the mesh 75 will not bend in the conveying direction near the center Cw of the widthwise Drw, and deformation such that the area near the center Cw of the widthwise Drw of the conveyor belt 7 leads the area near both ends of the widthwise Drw will not occur easily. Therefore, as shown in Figures 7, 8, and 9, for example, by configuring the phase of the teeth 23t in the first sprocket to advance in the rotational direction rs of the drive shaft body 21 compared to the phase of the teeth 23t in the second sprocket, the leading position of the conveyor belt 7 near the center Cw in the width direction Drw can be reduced.

[0059] (Regarding the reduction of changes in mesh size 75: Part 2) When a driving force (tension) is applied to the conveyor belt 7, as described above, the conveyor belt 7 receives a compressive force in the width direction Drw and attempts to buckle. At that time, by delaying the phase of the teeth 23t of the sprocket 23 in advance near the center Cw of the width direction Drw, the conveyor belt 7 is in a state where the area near the center Cw of the width direction Drw is slightly receding, and the direction of buckling can be limited to the upstream side in the conveying direction. In this state, even if the area near the center Cw of the width direction Drw tries to recede, it is stopped by hitting the teeth 23t of the sprocket 23, so it does not recede any further, and tension is also applied to the central part of the conveyor belt 7.

[0060] Therefore, in the drive shaft 9 according to some embodiments, as shown in Figures 10, 11, and 12, for example, with respect to a plurality of sprockets 23 arranged at intervals in the width direction Drw, the phase of the teeth 23t of a sprocket 23 (first sprocket) located at a certain position in the width direction Drw is made to lag behind the phase of the teeth 23t of a sprocket 23 (second sprocket) located at a position further from the center Cw in the width direction Drw than the first sprocket, in the rotation direction rs of the drive shaft body 21. In other words, in the drive shaft 9 according to several embodiments shown in Figures 10, 11, and 12, for example, the first sprocket is positioned closer to the center Cw in the width direction Drw than the second sprocket. The phase of the teeth 23t in the first sprocket lags behind the phase of the teeth 23t in the second sprocket in the rotation direction rs of the drive shaft body 21.

[0061] For example, in the example shown in Figure 10, the phase of the teeth 23t of each sprocket 23 is set such that the phase of the teeth 23t gradually lags as it approaches the center Cw in the width direction Drw. In other words, in the example shown in Figure 10, if any one of the multiple sprockets 23 is designated as the first sprocket, then all sprockets 23 that are further from the center Cw in the width direction Drw than the designated first sprocket 23 become the second sprockets. In the example shown in Figure 10, the phases of the teeth 23t of two adjacent sprockets 23 in the width direction Drw are different, except when comparing two adjacent A sprockets 23A in the width direction Drw.

[0062] For example, as shown in Figure 11, in addition to comparing two adjacent A sprockets 23A in the width direction Drw, there may also be cases where the phase of the teeth 23t of two adjacent sprockets 23 in the width direction Drw is the same. For example, in the example shown in Figure 11, the phase of the teeth 23t of the B sprocket 23B and the C sprocket 23C is the same. For example, in the example shown in Figure 11, the phase of the teeth 23t of the D sprocket 23D, the E sprocket 23E and the F sprocket 23F is the same.

[0063] For example, in the example shown in Figure 11, if the A sprocket 23A is designated as the first sprocket, then all the other sprockets 23 become the second sprockets. For example, in the example shown in Figure 11, if the B sprocket 23B and C sprocket 23C are designated as the first sprockets, then the D sprocket 23D, E sprocket 23E, and F sprocket 23F become the second sprockets.

[0064] Furthermore, as shown in Figure 12, for example, the phase of only the teeth 23t of the sprocket 23 located near the center Cw in the width direction Drw may be delayed, while the phases of the teeth 23t of all other sprockets 23 may be the same. For example, in the example shown in Figure 12, the phase of the teeth 23t is the same from the B sprocket 23B to the F sprocket 23F, but the phase of the teeth 23t of the two A sprockets 23A is delayed compared to the phase of the teeth 23t of the other sprockets 23. In other words, in the example shown in Figure 12, if the A sprocket 23A is considered the first sprocket, then all the other sprockets 23 become the second sprockets. Furthermore, for sprockets 23 whose tooth 23t is phase-delayed compared to other sprockets 23, not only the A sprocket 23A, but also, for example, the B sprocket 23B may have the same phase as the A sprocket 23A's tooth 23t.

[0065] For example, as shown in Figures 10, 11, and 12, if the phase of the teeth 23t of the first sprocket, which is positioned near the center Cw of the widthwise Drw, is delayed compared to the phase of the teeth 23t of the second sprocket, then, as described above, even if the area near the center Cw of the widthwise Drw tries to recede, it will be stopped by hitting the teeth 23t of the sprocket 23, preventing it from receding further, and tension will be applied to the central part of the conveyor belt 7. As a result, the effect of the force compressing the conveyor belt 7 in the widthwise Drw is reduced, making it less likely for the mesh 75 to bend in the conveying direction near the center Cw of the widthwise Drw, and making it less likely for deformation to occur in which the area near the center Cw of the widthwise Drw of the conveyor belt 7 leads the area near both ends of the widthwise Drw. Therefore, as shown in Figures 10, 11, and 12, for example, by configuring the phase of the teeth 23t in the first sprocket to lag behind the phase of the teeth 23t in the second sprocket in the rotational direction rs of the drive shaft body 21, the leading position of the conveyor belt 7 near the center Cw in the width direction Drw can be reduced.

[0066] Thus, as shown in Figures 7 to 12, for example, in the drive shaft 9 according to some embodiments, the phase of the teeth 23t of the first sprocket among the multiple sprockets 23 and the phase of the teeth 23t of the second sprocket, which has a different arrangement position in the width direction Drw from the first sprocket, are preferably offset in the circumferential direction of the drive shaft body 21. This makes it less likely for changes to occur in the mesh 75 of the conveyor belt 7, and reduces problems such as meandering, slanting, or only a portion of the width direction leading the conveyor belt 7.

[0067] (Other methods to reduce malfunctions) Furthermore, in some embodiments of the drive shaft 9, the occurrence of problems related to the conveyor belt 7 may be reduced by the following: Figure 13 is a diagram illustrating the dimensions of each part of the drive shaft body 21 and the sprocket 23, and corresponds to the view taken along the line XIII-XIII in Figure 3. Figure 14 is a diagram illustrating the dimensions of each part of the drive shaft body 21 and the roller 25, and corresponds to the view taken along the XIV-XIV arrow in Figure 3. Note that the conveyor belt 7 is not shown in Figures 13 and 14. Figure 15 is a view taken along the line XIII-XIII in Figure 3 to illustrate the relationship between the sprocket 23 and the conveyor belt 7. Figure 16 is a view taken along the line XIV-XIV in Figure 3 to illustrate the relationship between the roller 25 and the conveyor belt 7. In Figures 15 and 16, the position of the inner surface 7si of the endless conveyor belt 7 is indicated by a dashed line.

[0068] The outer diameter of the drive shaft body 21 is denoted as outer diameter Dos, the outer diameter of the tooth root surface 23a of the sprocket 23 is denoted as outer diameter Dosb, the inner diameter of the roller 25 is denoted as inner diameter Dir, and the outer diameter of the roller 25 is denoted as outer diameter Dor. Let the radius of the drive shaft body 21 be radius Ros, the radial thickness of the sprocket 23 from the inner circumferential surface 23i to the tooth root surface 23a be thickness ts, and the radial thickness of the roller 25 be thickness tr. In some embodiments of the drive shaft 9, the outer diameter Dos of the drive shaft body 21 is constant over the entire width direction Drw. Therefore, the radius Ros1 of the drive shaft body 21 in the portion where the sprocket 23 is attached is equal to the radius Ros2 of the drive shaft body 21 in the portion where the roller 25 is attached. However, the radius Ros1 of the drive shaft body 21 in the portion where the sprocket 23 is attached and the radius Ros2 of the drive shaft body 21 in the portion where the roller 25 is attached may be different.

[0069] (Regarding the desirable conditions that the dimensions of each part of the drive shaft 9 should meet: Part 1) In some embodiments of the drive shaft 9, the dimensions of each part of the drive shaft 9 are preferably such that they satisfy the following conditions. In other words, in some embodiments of the drive shaft 9, the sum of the radius Ros2 of the drive shaft body 21 in the portion where the roller 25 is attached and the radial thickness tr of the roller 25 (Ros2+tr) is greater than the sum of the radius Ros1 of the drive shaft body 21 in the portion where the sprocket 23 is attached and the radial thickness ts from the inner circumferential surface 23i to the tooth root surface 23a of the sprocket 23 (Ros1+ts) (Ros1+ts) <Ros2+tr)とよい。 For the sake of explanation, the above condition will also be referred to as condition 1.

[0070] As shown in Figures 15 and 16, the sprocket 23 and roller 25 are wrapped around the conveyor belt 7. Therefore, the sprocket 23 and roller 25 are biased downward and to the left in the figures by the tension of the conveyor belt 7. As described above, since the inner diameter Dir of the roller 25 is larger than the outer diameter Dos of the drive shaft body 21, exceeding the tolerance range in the JIS standard, the central axis AXr of the roller 25 is offset radially from the central axis AX of the drive shaft body 21, as shown in Figure 16. The inner circumferential surface 25i of the roller 25 and the outer circumferential surface 21o of the drive shaft body 21 come into contact at a contact position Ct on the straight line L connecting the central axis AXr of the roller 25 and the central axis AX of the drive shaft body 21.

[0071] In the first condition described above, the sum of the radius Ros1 of the drive shaft body 21 at the part where the sprocket 23 is attached and the radial thickness ts from the inner circumferential surface 23i to the tooth root surface 23a of the sprocket 23 (Ros1 + ts) is the distance from the central axis AX of the drive shaft body 21 to the tooth root surface 23a of the sprocket 23 (hereinafter referred to as distance Xs). Furthermore, in the first condition described above, the sum of the radius Ros2 of the drive shaft body 21 and the radial thickness tr of the roller 25 at the part where the roller 25 is attached (Ros2 + tr) is the distance from the central axis AX of the drive shaft body 21 on the straight line L passing through the contact position Ct to the outer circumferential surface 25o of the roller 25 (hereinafter referred to as distance Xr). Therefore, condition 1 described above means that the distance Xr is greater than the distance Xs. As a result, in some embodiments of the drive shaft 9, condition 1 described above is satisfied, so the inner surface 7si of the conveyor belt 7 contacts the outer circumferential surface 25o of the roller 25 and moves away from the tooth root surface 23a of the sprocket 23 radially outward from the sprocket 23.

[0072] Therefore, according to the drive shaft 9 of some embodiments, the sprocket 23 can transmit driving force to move the conveyor belt 7 in the conveying direction by teeth 23t that contact the conveyor belt 7, rather than by the tooth root surface 23a. As a result, the conveyor belt 7 can be moved in the conveying direction at a moving speed V1 determined by the relationship between the length of one link of the conveyor belt 7 and the number of teeth 23t that are fed per unit time due to the rotational speed of the drive shaft body 21. Therefore, problems such as meandering, slanting, or only a portion of the conveyor belt leading in the width direction can be reduced.

[0073] In some embodiments of the drive shaft 9, the inner diameter Dir of the roller 25 is larger than the outer diameter Dos of the drive shaft body 21. As mentioned above, the dimensional difference (Dir-Dos) between the inner diameter Dir of the roller 25 and the outer diameter Dos of the drive shaft body 21 is preferably larger than, for example, the clearance fit in the JIS standard.

[0074] In some embodiments of the drive shaft 9, when the above-described condition 1 is met, the conveyor belt 7 does not contact the tooth root surface 23a of the sprocket 23, as described above, but contacts the outer peripheral surface 25o of the roller 25. In some embodiments of the drive shaft 9, the sprocket 23 rotates once when the drive shaft body 21 rotates once. However, as described above, the inner diameter Dir of the roller 25 is larger than the outer diameter Dos of the drive shaft body 21. Therefore, assuming there is no slippage between the outer surface 21o of the drive shaft body 21 and the inner surface 25i of the roller 25, the rotation of the roller 25 is less than one full rotation. Consequently, the driving force that moves the conveyor belt 7 in the conveying direction is transmitted by the teeth 23t of the sprocket 23 pressing against the force ribs 71 of the conveyor belt 7. More precisely, even when the drive shaft body 21 rotates once, the rotation of the roller 25 is less than one full rotation. Therefore, unless the outer diameter Dor of the roller 25 is unnecessarily large, the roller 25 will rotate circumferentially at a speed slower than the moving speed V1 of the conveyor belt 7 driven by the teeth 23t of the sprocket 23. Then, the teeth 23t of the sprocket 23 forcibly press against the force ribs 71 of the conveyor belt 7 at a speed exceeding the rotational speed of the roller 25, thereby moving the conveyor belt 7 in the transport direction.

[0075] This allows the conveyor belt 7 to move in the transport direction at a speed V1 determined by the relationship between the length of one link of the conveyor belt 7 and the number of teeth 23t fed per unit time due to the rotational speed of the drive shaft body 21. As mentioned above, the rollers 25 rotate in the circumferential direction at a speed slower than the above transport speed V1, but in reality, slippage occurs between the drive shaft body 21 and the rollers 25, and between the rollers 25 and the conveyor belt 7, causing the conveyor belt 7 to move in the transport direction at the above transport speed V1.

[0076] Furthermore, according to some embodiments of the drive shaft 9, if the drive shaft 9 of the belt conveyor 5 is a drive shaft used in a low-temperature environment, such as the drive shaft 9 used in the freezer 1, the inner diameter Dir of the roller 25 is larger than the outer diameter Dos of the drive shaft body 21. This reduces the possibility of the roller 25 becoming stuck to the drive shaft body 21 due to contraction of the roller 25, or the possibility of the roller 25 becoming stuck to the drive shaft body 21 due to freezing between the inner circumferential surface 25i of the roller 25 and the outer circumferential surface 21o of the drive shaft body 21. This ensures that sliding between the drive shaft body 21 and the roller 25 can be maintained for a relatively long period of time.

[0077] (Regarding the desirable conditions that the dimensions of each part of the drive shaft 9 should meet: Part 2) In some embodiments of the drive shaft 9, the dimensions of each part of the drive shaft 9 are preferably such that they satisfy the following conditions. In other words, in the drive shaft 9 according to some embodiments, the product of the outer diameter Dor of the roller 25 and the value obtained by dividing the outer diameter Dos of the drive shaft body 21 by the inner diameter Dir of the roller 25 (Dos / Dir) (Dor × Dos / Dir) is preferably smaller than the outer diameter Dosb of the tooth root surface 23a of the sprocket 23. This can be expressed as equation (A) below. Dor×Dos / Dir <Dosb ···(A)

[0078] Equation (A) means that, assuming there is no slippage between the outer surface 21o of the drive shaft body 21 and the inner surface 25i of the roller 25, when the drive shaft body 21 rotates, the moving speed Vr of the outer surface 25o of the roller 25 is smaller than the moving speed Vsb of the tooth root surface 23a of the sprocket 23. This point will be explained below.

[0079] When the drive shaft body 21 rotates once, the outer surface 21o of the drive shaft body 21 moves by π × Dos. At this time, referring to Figure 14, the outer surface 25o of the roller 25 moves by {(π × Dor) / (π × Dir)} × π × Dos. Furthermore, referring to Figure 13, when the drive shaft body 21 rotates once, the tooth root surface 23a of the sprocket 23 advances by π × Dosb. If, when the drive shaft body 21 rotates, the speed Vr of the outer surface 25o of the roller 25 is less than the speed Vsb of the tooth root surface 23a of the sprocket 23, then the distance traveled by the outer surface 25o of the roller 25 when the drive shaft body 21 rotates once will be less than the distance traveled by the tooth root surface 23a of the sprocket 23 when the drive shaft body 21 rotates once. In other words, equation (B) below holds true. {(π×Dor) / (π×Dir)}×π×Dos<π×Dosb ···(B)

[0080] Rearranging equation (B) yields the following equation (C). {(π×Dor) / (π×Dir)}×π×Dos<π×Dosb {(π×Dor) / (π×Dir)}×Dos <Dosb {(Dor) / (Dir)}×Dos <Dosb Dor×Dos / Dir <Dosb ···(C) Equation (C) is the same as equation (A). Therefore, if equation (A) holds, when the drive shaft body 21 rotates, the moving speed Vr of the outer circumferential surface 25o of the roller 25 becomes smaller than the moving speed Vsb of the tooth root surface 23a of the sprocket 23.

[0081] Therefore, when equation (A) is true, the mesh 75 portion of the conveyor belt 7 that meshes with the teeth 23t of the sprocket 23 is pushed by the teeth 23t of the sprocket 23 from the upstream side to the downstream side in the conveying direction of the conveyor belt 7, and the driving force that moves the conveyor belt 7 in the conveying direction is transmitted by the teeth 23t of the sprocket 23 pressing against the mesh belt (conveyor belt 7). This allows the conveyor belt 7 to move in the transport direction at a speed V1 determined by the relationship between the length of one link of the conveyor belt 7 and the number of teeth 23t fed per unit time due to the rotational speed of the drive shaft body 21. As mentioned above, the outer surface 25o of the roller 25 moves in the circumferential direction at a speed even slower than the travel speed Vsb of the tooth root surface 23a, which is slower than the travel speed V1. However, in reality, slippage occurs between the drive shaft body 21 and the roller 25, and between the roller 25 and the conveyor belt 7, causing the conveyor belt 7 to move in the transport direction at the above travel speed V1. Therefore, problems such as meandering, slanting, or only a portion of the conveyor belt leading in the width direction can be reduced.

[0082] In some embodiments of the drive shaft 9, the sprocket 23 and the roller 25 are arranged alternately along the extending direction (width direction Drw) of the drive shaft body 21. As a result, even if the widthwise Drw dimension of the conveyor belt 7 is large, the driving force can be transmitted relatively uniformly regardless of the position of the widthwise Drw. This increases the reliability of the conveyor belt 7's drive and reduces problems such as diagonal movement, meandering, and only a portion of the widthwise direction leading.

[0083] In some embodiments of the drive shaft 9, the sprocket 23 is permitted to move relative to the drive shaft body 21 in the direction of extension of the drive shaft body 21 (width direction Drw). This allows the sprocket 23 to move in the extending direction (widthwise Drw) of the drive shaft body 21 in response to small fluctuations in the position of the conveyor belt 7 in the widthwise Drw due to expansion and contraction caused by temperature changes in the drive shaft body 21 and the conveyor belt 7. As a result, the possibility of the teeth 23t of the sprocket 23 unintentionally failing to engage with the conveyor belt 7 and causing tooth skipping or other problems is reduced.

[0084] If the sides of adjacent sprockets 23 and rollers 25 are in direct contact in the width direction (Drw), then if there is a difference in rotational speed between the sprockets 23 and rollers 25, rotational driving force will be transmitted between the adjacent sprockets 23 and rollers 25 in the width direction (Drw). As described above, since the sprocket 23 rotates in sync with the rotation of the drive shaft body 21, if rotational driving force is transmitted between adjacent sprockets 23 and rollers 25 in the width direction Drw, the rotational speed of the rollers 25 may change undesirably. In some embodiments of the drive shaft 9, the above-mentioned condition 1 is satisfied, so the inner surface 7si of the conveyor belt 7 is in contact with the outer surface 25o of the roller 25. Therefore, if the rotational speed of the roller 25 changes undesirably, problems such as diagonal movement, meandering, or only a portion in the width direction leading may occur. Therefore, in some embodiments of the drive shaft 9, a cylindrical member 27 is provided, which is positioned between the sprocket 23 and the roller 25, and whose outer diameter is smaller than the outer diameter Dosb of the tooth root surface 23a of the sprocket 23.

[0085] According to several embodiments of the drive shaft 9, the presence of the cylindrical member 27 prevents direct contact between the sides of adjacent sprockets 23 and rollers 25 in the width direction Drw. Therefore, even if there is a difference in rotational speed between adjacent sprockets 23 and rollers 25 in the width direction Drw, it becomes difficult to transmit rotational driving force between adjacent sprockets 23 and rollers 25 in the width direction Drw. This reduces problems such as diagonal movement, meandering, and only a portion of the width direction leading.

[0086] One embodiment of the belt conveyor 5 is a belt conveyor for transporting objects to be cooled inside the Freezer 1. This reduces problems such as meandering, slanting, or only a portion of the conveyor belt 7 leading in the width direction in the belt conveyor 5 used to transport objects to be cooled inside Frieza 1.

[0087] In one embodiment of the Freezer 1, the belt conveyor 5 is a belt conveyor for transporting objects to be cooled within the Freezer 1. The Freezer 1 in at least one embodiment of the present disclosure includes a drive shaft 9 for the belt conveyor 5 having the above-described configuration. This reduces problems such as meandering, slanting, or only a portion of the conveyor belt 7 leading in the width direction in the belt conveyor 5 used to transport objects to be cooled inside Frieza 1.

[0088] This disclosure is not limited to the embodiments described above, but also includes modified forms of the embodiments described above, as well as forms that combine these forms as appropriate.

[0089] The contents described in each of the above embodiments can be understood, for example, as follows: (1) A conveyor device (belt conveyor 5) for Frieza 1 according to at least one embodiment of the present disclosure comprises an endless mesh belt (conveyor belt 7), a drive device 6, a drive shaft body 21 that is rotationally driven by the drive device 6, and a plurality of sprockets 23 that are attached to the drive shaft body 21 so as to be aligned in the belt width direction (width direction Drw) and have a plurality of teeth 23t that can penetrate the mesh 75 of the mesh belt (conveyor belt 7). The phase of the teeth 23t of the first sprocket (for example, the A sprocket 23A in Figures 7 to 12) among the plurality of sprockets 23 and the phase of the teeth 23t of the second sprocket (for example, the F sprocket 23F in Figures 7 to 12) which has a different arrangement position in the belt width direction (width direction Drw) from the first sprocket (for example, the A sprocket 23A in Figures 7 to 12) are offset in the circumferential direction of the drive shaft body 21.

[0090] In a conveyor system (belt conveyor 5) equipped with an endless mesh belt (conveyor belt 7), because the mesh belt (conveyor belt 7) is flexible, the position of the mesh 75 of the mesh belt (conveyor belt 7) may shift in the direction of transport of the mesh belt (conveyor belt 7) depending on the position in the belt width direction (width direction Drw), or the dimensions of the mesh 75 in the transport direction may change. If such changes in the mesh 75 of the mesh belt (conveyor belt 7) are left unaddressed, it may lead to problems such as meandering or skewing of the mesh belt (conveyor belt 7), or only a portion of the width direction (width direction Drw) leading the way. According to the configuration described in (1) above, by adjusting the phase of the teeth 23t of the sprocket 23 depending on its position in the belt width direction (width direction Drw), it is possible to make changes in the mesh 75 as described above less likely to occur, and problems such as meandering, skewing, and only a part of the width direction leading the mesh belt (conveyor belt 7) can be reduced.

[0091] (2) In some embodiments, in the configuration of (1) above, the first sprocket (for example, the A sprocket 23A in Figures 7 to 9) is positioned closer to the center Cw in the belt width direction (width direction Drw) than the second sprocket (for example, the F sprocket 23F in Figures 7 to 9). The phase of the teeth 23t in the first sprocket (for example, the A sprocket 23A in Figures 7 to 9) may lead the phase of the teeth 23t in the second sprocket (for example, the F sprocket 23F in Figures 7 to 9) in the rotation direction rs of the drive shaft body 21.

[0092] According to the configuration in (2) above, the leading edge of the mesh belt near the center in the width direction can be reduced.

[0093] (3) In some embodiments, in the configuration of (1) above, the first sprocket (for example, the A sprocket 23A in Figures 10 to 12) is positioned closer to the center Cw in the belt width direction (width direction Drw) than the second sprocket (for example, the F sprocket 23F in Figures 10 to 12). The phase of the teeth 23t in the first sprocket (for example, the A sprocket 23A in Figures 10 to 12) may be delayed in the rotation direction rs of the drive shaft body 21 compared to the phase of the teeth 23t in the second sprocket (for example, the F sprocket 23F in Figures 10 to 12).

[0094] According to the configuration described in (3) above, the leading edge of the mesh belt near the center in the width direction can be reduced.

[0095] (4) In some embodiments, in any of the configurations (1) to (3) above, it is preferable to have a plurality of rollers 25 that are arranged between sprockets 23 aligned in the belt width direction (width direction Drw), through which the drive shaft body 21 is inserted and which are rotatable relative to the drive shaft body 21. The sum of the radius Ros2 of the drive shaft body 21 in the portion where the roller 25 is attached and the radial thickness tr of the roller 25 (Ros2+tr) is greater than the sum of the radius Ros1 of the drive shaft body 21 in the portion where the sprocket 23 is attached and the radial thickness ts from the inner circumferential surface 23i to the tooth root surface 23a of the sprocket 23 (Ros1+ts) <Ros2+tr)とよい。

[0096] According to the configuration in (4) above, the mesh belt (conveyor belt 7) does not come into contact with the tooth root surface 23a of the sprocket 23, but instead comes into contact with the outer circumferential surface 25o of the roller 25. As a result, the sprocket 23 can transmit the driving force to move the mesh belt (conveyor belt 7) in the conveying direction by the teeth 23t that come into contact with the mesh belt (conveyor belt 7) instead of the tooth root surface 23a. This allows the mesh belt (conveyor belt 7) to move in the conveying direction at a moving speed V1 determined by the relationship between the length of one link of the mesh belt (conveyor belt 7) and the length of one pitch of the teeth 23t. Therefore, according to the configuration of (4) above, by adjusting the phase of the teeth 23t of the sprocket 23 depending on the arrangement position in the belt width direction (width direction Drw), the effect of making it difficult for the changes in the mesh 75 as described above to occur is efficiently achieved.

[0097] (5) In some embodiments, in any of the configurations (1) to (4) above, it is preferable to have a plurality of rollers 25 that are arranged between sprockets 23 aligned in the belt width direction (width direction Drw), with the drive shaft body 21 loosely fitted to them, and which are rotatable relative to the drive shaft body 21. The product of the outer diameter Dor of the roller 25 and the value obtained by dividing the outer diameter Dos of the drive shaft body 21 by the inner diameter Dir of the roller 25 (Dos / Dir) (Dor × Dos / Dir) is preferable to be smaller than the outer diameter Dosb of the tooth root surface 23a of the sprocket 23.

[0098] According to the configuration in (5) above, assuming there is no slippage between the outer circumferential surface 21o of the drive shaft body 21 and the inner circumferential surface 25i of the roller 25, the distance traveled by the outer circumferential surface 25o of the roller 25 when the drive shaft body 21 rotates once is smaller than the distance traveled by the tooth root surface 23a. Therefore, the travel speed Vr of the outer circumferential surface 25o of the roller 25 is smaller than the travel speed Vsb of the tooth root surface 23a. Therefore, the mesh 75 portion of the mesh belt (conveyor belt 7) that meshes with the teeth 23t of the sprocket 23 is pushed by the teeth 23t of the sprocket 23 from the upstream side to the downstream side in the conveying direction of the mesh belt (conveyor belt 7), and the driving force that moves the mesh belt (conveyor belt 7) in the conveying direction is transmitted by the teeth 23t of the sprocket 23 pressing against the mesh belt (conveyor belt 7). This allows the mesh belt (conveyor belt 7) to move in the conveying direction at a speed V1 determined by the relationship between the length of one link of the mesh belt (conveyor belt 7) and the number of teeth 23t fed per unit time due to the rotational speed of the drive shaft body 21. As mentioned above, the outer surface 25o of the roller 25 moves in the circumferential direction at a speed even slower than the movement speed Vsb of the tooth root surface 23a, which is slower than the above-mentioned speed V1. However, in reality, slippage occurs between the drive shaft body 21 and the roller 25, and between the roller 25 and the mesh belt (conveyor belt 7), causing the mesh belt (conveyor belt 7) to move in the conveying direction at the above-mentioned speed V1. Therefore, problems such as meandering, slanting, or only a portion of the conveyor belt leading in the width direction can be reduced.

[0099] (6) A Frieza 1 according to at least one embodiment of the present disclosure includes a conveyor device (belt conveyor 5) for Frieza having any of the configurations described in (1) to (5) above.

[0100] According to the configuration described in (6) above, problems such as meandering, slanting, or only a portion of the mesh belt (conveyor belt 7) leading in the width direction can be reduced. [Explanation of symbols]

[0101] 1. Frieza 3 Housing 5 Belt conveyor 6. Drive unit 7 Conveyor belt 9 Drive shaft 21 Drive shaft body 21o Outer surface 23 sprocket 23a Tooth root surface 23t teeth 25 Laura 25o outer surface 25i Inner surface 75 mesh

Claims

1. An endless mesh belt, The drive unit and A drive shaft body that is rotationally driven by the aforementioned drive device, Multiple sprockets are attached to the drive shaft body so as to be aligned in the belt width direction, and each sprocket has multiple teeth that can penetrate the mesh of the mesh belt, Equipped with, The phase of the teeth on the first sprocket among the plurality of sprockets and the phase of the teeth on the second sprocket, which has a different arrangement position in the belt width direction from the first sprocket, are offset in the circumferential direction of the drive shaft body. A conveyor belt system for Frieza.

2. The first sprocket is positioned closer to the center in the belt width direction than the second sprocket. The phase of the teeth in the first sprocket is ahead of the phase of the teeth in the second sprocket in the rotational direction of the drive shaft body. The conveyor device for Frieza according to claim 1.

3. The first sprocket is positioned closer to the center in the belt width direction than the second sprocket. The phase of the teeth in the first sprocket lags behind the phase of the teeth in the second sprocket in the rotational direction of the drive shaft body. The conveyor device for Frieza according to claim 1.

4. A roller is positioned between the sprockets that are aligned in the belt width direction, through which the drive shaft body is inserted, and which is rotatable relative to the drive shaft body. Equipped with multiple, The sum of the radius of the drive shaft body and the radial thickness of the roller in the portion where the roller is attached is greater than the sum of the radius of the drive shaft body and the radial thickness of the sprocket from the inner circumferential surface to the tooth root surface in the portion where the sprocket is attached. A conveyor device for Frieza according to any one of claims 1 to 3.

5. A roller is positioned between the sprockets that are aligned in the belt width direction, into which the drive shaft body is loosely fitted, and which is rotatable relative to the drive shaft body. Equipped with multiple, The product of the outer diameter Dor of the roller and the value obtained by dividing the outer diameter Dos of the drive shaft body by the inner diameter Dir of the roller (Dor × Dos / Dir) is smaller than the outer diameter Dosb of the tooth root surface of the sprocket. A conveyor device for Frieza according to any one of claims 1 to 3.

6. A conveyor device for Frieza according to claims 1 to 3, Equipped with Frieza.

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