The drive shaft of the conveyor belt, and Frieza

Abstract

To reduce malfunctions that occur in conveyor belts. [Solution] The drive shaft of a belt conveyor according to at least one embodiment of the present disclosure is a drive shaft of a belt conveyor using a mesh belt, and comprises a drive shaft body, at least one sprocket that rotates in synchronization with the rotation of the drive shaft body, and at least one roller through which the drive shaft body is inserted and which is rotatable relative to the drive shaft body. The sum of the radius of the drive shaft body and the radial thickness of the roller at the portion where the roller is attached is greater than the sum of the radius of the drive shaft body and the radial thickness from the inner circumferential surface to the tooth root surface of the sprocket at the portion where the sprocket is attached.

Description

Technical Field

[0001] The present disclosure relates to a drive shaft of a belt conveyor 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 transportation 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 travels 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 belt conveyor.

Means for Solving the Problems

[0006] (1) The drive shaft of the belt conveyor according to at least one embodiment of the present disclosure is a drive shaft of a belt conveyor using a mesh belt, a drive shaft main body, at least one sprocket that rotates in synchronization with the rotation of the drive shaft main body, at least one roller through which the drive shaft main body is inserted and which is rotatable with respect to the drive shaft main body, Equipped with, 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.

[0007] (2) Frieza according to at least one embodiment of the present disclosure is The aforementioned belt conveyor is a belt conveyor for transporting objects to be cooled inside Frieza. The drive shaft of the belt conveyor in 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 a belt conveyor 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 4] 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 diagram illustrates the dimensions of the drive shaft body and the various parts of the sprocket. [Figure 8] This diagram illustrates the dimensions of the drive shaft body and the various parts of the rollers. [Figure 9] This diagram illustrates the relationship between a sprocket and a conveyor belt. [Figure 10] This is a diagram for explaining the relationship between a roller and a 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, 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 representing that things such as "identical", "equal", and "homogeneous" are in an equal state not only strictly represent an equal state, but also represent states in which there are tolerances or differences that can obtain the same function. For example, expressions representing shapes such as a rectangular shape or a cylindrical shape not only represent shapes such as a rectangular shape or a cylindrical shape in a geometrically strict sense, but also represent shapes including concave and convex portions, chamfered portions, etc. within a range where the same effect can be obtained. On the other hand, the expressions "comprising", "having", "including", or "possessing" a component do not exclude the existence of other components.

[0011] FIG. 1 is an overall configuration diagram when the freezer 1 according to an embodiment is viewed from the side. The freezer 1 according to an embodiment is a freezer capable of cooling or freezing an object to be cooled, particularly food, and includes a housing 3 that houses the main constituent devices of the freezer 1 inside, a belt conveyor 5 for conveying the object to be cooled (not shown), a heat exchanger (not shown) for cooling air, and a fan (not shown) for circulating the cooled air (cold air) cooled by the heat exchanger inside the freezer 1.

[0012] In the freezer 1 according to one embodiment, the housing 3 separates the inside and outside of the freezer 1 and is configured to hold cold air inside. The freezer 1 according to one embodiment is configured to cool an object to be cooled (not shown) by blowing cold air from a fan (not shown) from at least one of above and below the object to be cooled (not shown) placed on the forward path portion 7a of the conveyor belt 7 of the belt conveyor 5. In the following description, the conveyance direction of the object to be cooled (not shown) by the conveyor belt 7 is also referred to as the conveyance direction of the conveyor belt 7 or simply the conveyance direction. Also, in the following description, the object to be cooled (not shown) is simply referred to as the object to be cooled.

[0013] In the freezer 1 according to one embodiment, a part of the upstream region in the conveyance direction within the forward path portion 7a of the conveyor belt 7 is exposed outside the housing 3 for placing the object to be cooled on the conveyor belt 7. In the freezer 1 according to one embodiment, a part of the downstream region in the conveyance direction within the forward path portion 7a of the conveyor belt 7 is exposed outside the housing 3 for sending the object to be cooled on the conveyor belt 7 to the next process.

[0014] (Belt conveyor 5) In the freezer 1 according to one embodiment, the belt conveyor 5 includes a conveyor belt 7 for conveying the object to be cooled, a drive motor (not shown) for driving the conveyor belt 7, a drive shaft 9 for driving the conveyor belt 7 by the driving force of the drive motor (not shown), and a direction conversion shaft 11 for converting the moving direction of the conveyor belt 7. The direction conversion shaft 11 includes a driven shaft 13 disposed at the upstream end of the forward path portion 7a of the conveyor belt 7, and at least one idler shaft 15 disposed so as to contact the conveyor belt 7 from the inside of the conveyor belt 7 looped around the drive shaft 9 and the driven shaft 13 in the return path portion 7b of the conveyor belt 7 (or, depending on the layout of the track of the conveyor belt 7 due to the direction conversion of the conveyor belt 7, from the outside of the conveyor belt 7). In the freezer 1 shown in FIG. 1, two idler shafts 15 are provided inside the conveyor belt 7 in a state of being spaced apart from each other in the conveyance 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 strip of mesh belt made by weaving metal wires into a mesh pattern, and can support objects to be cooled. For example, the conveyor belt 7 has a plurality of reinforcing ribs 71 that extend in the width direction Drw of the conveyor belt 7 and are spaced apart in a direction perpendicular to the width direction Drw, and a helical portion 73 that is 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 portion 73 includes a helical portion 73a located on the front side in Figure 2 with respect to the reinforcing ribs 71 and a helical portion 73b located on the rear side in Figure 2 with respect to the reinforcing ribs 71, and the helical portion 73a located on the front side and the helical portion 73b located on the rear 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 portion 73 in the width direction Drw, for example, by welding. For the sake of explanation, the outer side of the endless conveyor belt 7 is the foreground side of the page in Figure 2, and the inner side of the endless conveyor belt 7 is the background side of the page in Figure 2.

[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. 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] The conveyor belt 7 is driven by a drive shaft 9 driven by a drive motor (not shown), and is capable of transporting the object 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.

[0018] (Regarding drive shaft 9) Figure 3 is a view of the drive shaft 9 according to one embodiment, seen from the downstream side in the conveying direction, and shows the vicinity of the center of the width direction Drw of the conveyor belt 7. A drive shaft 9 according to one embodiment includes 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.

[0019] In one embodiment 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 them. In one embodiment 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 placed between adjacent sprockets 23 and rollers 25 in the width direction Drw. In one embodiment 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 one embodiment 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).

[0020] (Drive shaft body 21) In one embodiment 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 about a central axis AX by a drive motor (not shown). In the figures from Figure 5 onward, described later, the drive shaft body 21 is shown as a solid member for the sake of explanation, 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.

[0021] (Sprocket 23) Figure 4 is a side view of the sprocket 23 of the drive shaft 9 according to one embodiment. In one embodiment 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 of the sprocket 23. Note that the sprocket 23 shown in Figure 3, and in Figures 7 and 9 (described later) is depicted schematically. Note that in Figure 3, and in Figures 7 and 9 (described later), the corresponding circle 23b that corresponds to the top of the tooth 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.

[0022] 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 engage with the mesh 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 on the inside of the endless belt-shaped conveyor belt 7, and to drive the conveyor belt 7 by pressing the force ribs 71 with the sides of the teeth 23t.

[0023] 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. 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).

[0024] (Laura 25) In one embodiment 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.

[0025] In one embodiment 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 the drive shaft 9 according to one embodiment, the roller 25 is loosely fitted to the drive shaft body 21.

[0026] (Cylindrical member 27) In one embodiment 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.

[0027] In one embodiment 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.

[0028] (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 one embodiment 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.

[0029] In one embodiment 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 one embodiment of the drive shaft 9, the support portion 30 is fixed by attaching the connecting plate 33 to a frame (not shown) of the housing 3.

[0030] In the drive shaft 9 according to one embodiment, in each of the two support plate portions 31, as shown in Figure 5, at least a portion of the support plate portion 31 overlaps 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 overlaps 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.

[0031] In one embodiment, the drive shaft 9 is equipped with a support portion 30, 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 the drive shaft 9 of one embodiment, it is possible to move 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 such movement, thereby limiting the amount of movement of the conveyor belt 7 in the widthwise Drw.

[0032] In one embodiment, the drive shaft 9 may have at least one support portion 30 having one support plate portion 31, or it may have at least one support portion 30 having two or more support plate portions 31.

[0033] (Challenges in Belt Conveyor 5) In general, belt conveyors are prone to problems such as the conveyor belt meandering or becoming skewed, or, in the case of mesh belts, problems such as only a portion of the belt in the width direction leading the other. Therefore, it is desirable to prevent such problems from occurring.

[0034] 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, depending on 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 rotation speed of the drive shaft body 21, there is a difference between the moving speed V1 of the conveyor belt 7 and the moving speed V2 of the conveyor belt 7 caused by the conveyor belt 7 being driven by the tooth bottom surface 23a.

[0035] 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 bending of the link part is inhibited due to freezing of the conveyor belt 7 or icing on the conveyor belt 7 increases the apparent thickness of the conveyor belt 7, the moving speed V2 may become larger than the moving speed V1.

[0036] Also, 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 due to the rotation speed of the drive shaft body 21 becomes small. Due to such various factors, there is a difference between the moving speed V1 and the moving speed V2.

[0037] 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.

[0038] 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.

[0039] Therefore, in the drive shaft 9 according to one embodiment, the occurrence of problems related to the conveyor belt is reduced by the following: Figure 7 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 VII-VII arrow in Figure 3. Figure 8 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 arrow VIII-VIII in Figure 3. Note that the conveyor belt 7 is not shown in Figures 7 and 8. Figure 9 is a view taken along the line VII-VII in Figure 3 to illustrate the relationship between the sprocket 23 and the conveyor belt 7. Figure 10 is a view taken along the line VIII-VIII in Figure 3 to illustrate the relationship between the roller 25 and the conveyor belt 7. In Figures 9 and 10, the position of the inner surface 7si of the endless conveyor belt 7 is indicated by a dashed line.

[0040] 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 one embodiment 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.

[0041] (Conditions that the dimensions of each part of the drive shaft 9 must satisfy: Part 1) In the drive shaft 9 according to one embodiment, the dimensions of each part of the drive shaft 9 satisfy the following conditions. In other words, in the drive shaft 9 according to one embodiment, 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)。 For the sake of explanation, the above condition will also be referred to as condition 1.

[0042] As shown in Figures 9 and 10, 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 10. 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.

[0043] 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 the drive shaft 9 according to one embodiment, condition 1 described above is satisfied, so the inner surface 7si of the conveyor belt 7 is in contact with the outer circumferential surface 25o of the roller 25, and is away from the tooth root surface 23a of the sprocket 23 in the radially outward direction of the sprocket 23.

[0044] Therefore, according to the drive shaft 9 of one embodiment, 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.

[0045] In one embodiment 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 described 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 larger than, for example, the clearance fit in the JIS standard.

[0046] In one embodiment, the drive shaft 9 satisfies the above-described condition 1, so as described above, the conveyor belt 7 does not contact the tooth root surface 23a of the sprocket 23, but contacts the outer peripheral surface 25o of the roller 25. In one embodiment 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.

[0047] 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.

[0048] Furthermore, according to one embodiment 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.

[0049] (Conditions that the dimensions of each part of the drive shaft 9 must satisfy: Part 2) In the drive shaft 9 according to one embodiment, the dimensions of each part of the drive shaft 9 satisfy the following conditions. In other words, in the drive shaft 9 according to one embodiment, 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 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)

[0050] 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.

[0051] 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 8, the outer surface 25o of the roller 25 moves by {(π × Dor) / (π × Dir)} × π × Dos. Furthermore, referring to Figure 7, 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)

[0052] 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.

[0053] Therefore, when equation (A) holds true, the mesh 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.

[0054] In one embodiment 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.

[0055] In one embodiment 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.

[0056] 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 the drive shaft 9 according to one embodiment, 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 part of the width direction leading may occur. Therefore, in one embodiment 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.

[0057] According to the drive shaft 9 of one embodiment, 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.

[0058] Belt conveyor 5 according to one embodiment is a belt conveyor for transporting objects to be cooled inside Frieza 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.

[0059] In one embodiment of the Freeza 1, the belt conveyor 5 is a belt conveyor for transporting objects to be cooled within the Freeza 1. The Freeza 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.

[0060] 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.

[0061] The contents described in each of the above embodiments can be understood, for example, as follows: (1) The drive shaft 9 of the belt conveyor 5 according to at least one embodiment of the present disclosure is the drive shaft of the belt conveyor 5 using a mesh belt, and comprises a drive shaft body 21, at least one sprocket 23 that rotates in synchronization with the rotation of the drive shaft body 21, and 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. The sum of the radius Ros2 of the drive shaft body 21 and the radial thickness tr of the roller 25 in the portion where the roller 25 is attached (Ros2+tr) is greater than the sum of the radius Ros1 of the drive shaft body 21 and the radial thickness ts from the inner circumferential surface 23i to the tooth root surface 23a of the sprocket 23 in the portion where the sprocket 23 is attached (Ros1+ts).

[0062] According to the configuration described in (1) 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 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 mesh belt (conveyor belt 7) leading in the width direction can be reduced.

[0063] (2) In some embodiments, in the configuration of (1) above, the inner diameter Dir of at least one roller 25 is larger than the outer diameter Dos of the drive shaft body 21.

[0064] Since the drive shaft 9 of the belt conveyor 5 in the configuration of (2) above has the configuration of (1) above, the mesh belt (conveyor belt 7) does not come into contact with the tooth root surface 23a of the sprocket 23, but comes into contact with the outer circumferential surface 25o of the roller 25. According to the configuration in (2) above, when the drive shaft body 21 rotates once, the sprocket 23 rotates once. However, since the inner diameter Dir of the roller 25 is larger than the outer diameter Dos of the drive shaft body 21, 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 will be less than one rotation. Therefore, 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). More precisely, even when the drive shaft body 21 rotates once, the rotation of the roller 25 will be less than one rotation. Therefore, unless the outer diameter Dor of the roller 25 is unnecessarily large, the roller 25 will rotate in the circumferential direction at a speed slower than the moving speed V1 of the mesh belt (conveyor belt 7) driven by the teeth 23t of the sprocket 23. Then, the teeth 23t of the sprocket 23 forcibly press against the mesh belt (conveyor belt 7) at a speed exceeding the rotational speed of the roller 25, thereby moving the mesh belt (conveyor belt 7) in the conveying direction.

[0065] 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 rollers 25 rotate in the circumferential direction at a speed slower than the above-mentioned speed V1, but in reality, slippage occurs between the drive shaft body 21 and the rollers 25, and between the rollers 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.

[0066] Furthermore, according to the configuration in (2) above, if the drive shaft 9 of the belt conveyor 5 is the same 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.

[0067] (3) In some embodiments, in the configuration of (1) or (2) above, at least one sprocket 23 may include a plurality of sprockets 23, and at least one roller 25 may include a plurality of rollers 25, and the sprockets 23 and rollers 25 may be arranged alternately along the extending direction (width direction Drw) of the drive shaft body 21.

[0068] According to the configuration described in (3) above, even if the widthwise Drw dimension of the mesh belt (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 driving the mesh belt (conveyor belt 7) and reduces problems such as diagonal movement, meandering, and only a portion of the widthwise direction leading.

[0069] (4) In some embodiments, in any of the configurations (1) to (3) above, at least one sprocket 23 may be permitted to move relative to the drive shaft body 21 in the direction of extension of the drive shaft body 21 (width direction Drw).

[0070] According to the configuration in (4) above, the sprocket 23 can move in the extending direction (widthwise Drw) of the drive shaft body 21 in response to small fluctuations in the position of the mesh belt (conveyor belt 7) in the widthwise Drw due to expansion and contraction caused by temperature changes of the drive shaft body 21 and the mesh belt (conveyor belt 7). This reduces the possibility that the teeth 23t of the sprocket 23 may not engage with the mesh belt (conveyor belt 7) unintentionally, causing tooth skipping or other problems.

[0071] (5) In some embodiments, the configuration of (1) to (4) above may include at least one cylindrical member 27 positioned between at least one sprocket 23 and at least one roller 25, the outer diameter of which is smaller than the outer diameter Dosb of the tooth root surface 23a of the sprocket 23.

[0072] According to the configuration in (5) above, the presence of the cylindrical member 27 prevents the sides of adjacent sprockets 23 and rollers 25 in the width direction Drw from directly contacting each other. 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 for rotational driving force to be transmitted 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.

[0073] (6) In some embodiments, in the configuration of (5) above, at least one sprocket 23 and at least one roller 25 may be permitted to move relative to the drive shaft body 21 in the extending direction (width direction Drw) of the drive shaft body 21. In some embodiments, in the configuration of (5) above, at least one support portion 30 may be provided that supports at least one cylindrical member 27 from below in a rotatable manner and restricts 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.

[0074] According to the configuration of (6) above, the deflection of the drive shaft body 21 can be reduced, and problems such as meandering and slanting of the mesh belt (conveyor belt 7) can be reduced. Furthermore, according to the configuration of (6) above, the 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 mesh belt (conveyor belt 7) in the widthwise Drw can be limited, thereby limiting the amount of movement of the mesh belt (conveyor belt 7) in the widthwise Drw.

[0075] (7) In some embodiments, in any of the configurations (1) to (6) above, the belt conveyor 5 may be a belt conveyor for transporting objects to be cooled within the freezer 1.

[0076] According to the configuration described in (7) 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 in the belt conveyor 5 for transporting objects to be cooled inside Frieza 1.

[0077] (8) In the Freezer 1 according to at least one embodiment of the present disclosure, the belt conveyor 5 is a belt conveyor for transporting objects to be cooled within the Freezer 1. The Freezer 1 according to at least one embodiment of the present disclosure includes a drive shaft 9 for the belt conveyor 5 having any of the configurations (1) to (6) above.

[0078] According to the above configuration (8), problems such as meandering, slanting, or only a portion of the mesh belt (conveyor belt 7) leading in the width direction can be reduced in the belt conveyor 5 for transporting objects to be cooled inside Frieza 1. [Explanation of symbols]

[0079] 1. Frieza 3 Housing 5 Belt conveyor 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 27 Cylindrical member 30 Support part

Claims

1. A drive shaft for a belt conveyor using a mesh belt, The drive shaft body and At least one sprocket that rotates in sync with the rotation of the drive shaft body, The drive shaft body is inserted through at least one roller that is rotatable relative to the drive shaft body, Equipped with, 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. The drive shaft of a belt conveyor.

2. The inner diameter of at least one of the rollers is larger than the outer diameter of the drive shaft body. The drive shaft of the belt conveyor according to claim 1.

3. The at least one sprocket includes a plurality of sprockets, The aforementioned at least one roller includes a plurality of rollers, The sprocket and the roller are arranged alternately along the extending direction of the drive shaft body. The drive shaft for the belt conveyor according to claim 1 or 2.

4. The at least one sprocket is permitted to move relative to the drive shaft body in the direction of extension of the drive shaft body. The drive shaft for the belt conveyor according to claim 1 or 2.

5. The system comprises at least one cylindrical member disposed between the at least one sprocket and the at least one roller, the cylindrical member having an outer diameter smaller than the outer diameter of the tooth root surface of the sprocket. The drive shaft for the belt conveyor according to claim 1 or 2.

6. The at least one sprocket and the at least one roller are permitted to move relative to the drive shaft body in the direction of extension of the drive shaft body. The at least one cylindrical member is supported from below in a rotatable state, and at least one support portion restricts the range of movement of the at least one sprocket and the at least one roller in the extending direction of the drive shaft body. Equipped with The drive shaft of the belt conveyor according to claim 5.

7. The aforementioned belt conveyor is a belt conveyor for transporting objects to be cooled inside Frieza. The drive shaft for the belt conveyor according to claim 1 or 2.

8. The aforementioned belt conveyor is a belt conveyor for transporting objects to be cooled inside Frieza. The drive shaft of the belt conveyor according to claim 1 or 2, Equipped with Frieza.

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