JP7427152B2 - chain sprocket wheel - Google Patents

Description

TECHNICAL FIELD The present invention relates to a chain sprocket wheel that longitudinally moves a chain stretched around its outer periphery.

In a typical chain mechanism, a plurality of chain sprocket wheels are arranged and a chain is wrapped around the outer periphery.At least one chain sprocket wheel is rotated by a drive device, and the rotational force is transmitted to the chain to extend the chain in the length direction. It is designed to be moved.
Since the chain is engaged with some of the teeth of the chain sprocket wheel, a large load is applied to these teeth, making them susceptible to breakage and wear. In particular, in chain conveyors that transport heavy objects and chain mechanisms in sludge scrapers, teeth are severely damaged, so chain sprocket wheels must be replaced more frequently. At this time, replacing the entire large chain sprocket wheel would not only require a great deal of labor and time, but would also be extremely costly.
The same applies to the driven chain sprocket wheel.

Therefore, Patent Document 1 discloses a chain sprocket wheel that is conventionally composed of a wheel body and a fixed plate for attaching and fixing the wheel body, and the wheel body is formed into a split type so that the wheel body can be replaced.
If the teeth of a split-type chain sprocket wheel become unusable due to partial loss or wear, you can remove part of the split piece of the wheel body while the chain is still running. It can be repaired by simply replacing it.

Japanese Patent Application Publication No. 2002-356217

However, in the chain sprocket wheel as described in Patent Document 1, the divided pieces of the wheel body and the fixed plate are attached and fixed only with bolts and nuts, so if a large force is applied to some of the teeth, the divided pieces There was a risk that the chain would shake against the fixed plate, and that force would not be transmitted sufficiently between it and the chain.
The problem to be solved by the present invention is to provide a chain sprocket wheel that allows only a part of the partial wheel to be replaced without removing the chain, and that prevents the partial wheel from shaking against the fixed platen. .

The invention according to claim 1 is a chain sprocket wheel that spans a chain around its outer periphery, and includes a wheel portion having a large number of teeth with which the chain engages, and a stationary plate, wherein the wheel portion has a plurality of teeth in the circumferential direction. each partial wheel is removably joined to the stationary platen by a fixing device, the partial wheel has an inner circumferential surface forming an outer shape in a front view, and the stationary platen has a A contact surface is formed that comes into contact with the inner circumferential surface of the partial wheel to restrict rotation of the partial wheel in the circumferential direction with respect to the fixed plate, and a gap is formed between the adjacent partial wheels. It is a chain sprocket wheel that is characterized by
In the invention according to claim 2, there is a plurality of fixing tools for removably attaching the partial wheel to the fixed plate, and the plurality of fixing tools include a first fixing tool and a second fixing tool that is attached to the first fixing tool. a second fixing device disposed at the rear in the rotational direction of the partial wheel, the distance from the rotation center of the wheel part where the first fixing device is arranged, and the wheel where the second fixing device is arranged; 2. The chain sprocket wheel according to claim 1, wherein the distances from the center of rotation of the chain sprocket wheels are different from each other.
The invention according to claim 3 is a chain sprocket wheel that spans a chain around the outer periphery, and includes a wheel portion having a large number of teeth with which the chain engages, and a fixed plate, wherein the wheel portion has a plurality of teeth in the circumferential direction. Each partial wheel is removably joined to the stationary platen by a fixing device, and the stationary platen is provided with a portion of the partial wheel that is in contact with the inner circumferential surface of the partial wheel and that is attached to the stationary platen. A contact surface for regulating rotation in the circumferential direction is formed, and there are a plurality of fixing tools that removably attach the partial wheel to the fixed plate, and the plurality of fixing tools include a first fixing tool and a first fixing tool. a second fastener disposed rearward in the rotational direction of the partial wheel than the first fastener, and a distance from the rotation center of the wheel portion where the first fastener is arranged; The chain sprocket wheel is characterized in that the distances from the center of rotation of the wheel portion where the tools are arranged are different.
The invention according to claim 4 is the chain sprocket wheel according to claim 3, wherein a gap is formed between the adjacent partial wheels.
In the invention according to claim 5, the chain sprocket wheel is a driving chain sprocket wheel, and the distance from the rotation center of the wheel portion where the first fastener is arranged is such that the second fastener is arranged. The chain sprocket wheel according to any one of claims 2 to 4, wherein the distance is longer than the distance from the center of rotation of the wheel portion.
In the invention according to claim 6, the chain sprocket wheel is a driven chain sprocket wheel, and the distance from the rotation center of the wheel portion where the first fastener is disposed is such that the second fastener is disposed. The chain sprocket wheel according to any one of claims 2 to 4, wherein the distance from the center of rotation of the wheel portion is shorter than the distance from the center of rotation of the wheel portion.
The invention according to claim 7 is characterized in that a convex portion is formed on one of the joint surfaces of the fixed platen and the partial wheel, and a concave portion is formed on the other, and the convex portion and the concave portion engage with each other. A chain sprocket wheel according to any one of claims 1 to 6.
The invention according to claim 8 is the chain sprocket according to any one of claims 1 to 7, characterized in that the wheel portion is divided in the circumferential direction through the troughs of the teeth. It's a wheel.
Moreover, the following may be used as another invention.
Means 1 is a chain sprocket wheel that spans a chain around its outer periphery, and includes a wheel portion having a large number of teeth with which the chain engages, and a stationary plate, and the wheel portion is connected to a plurality of partial wheels in the circumferential direction. Each partial wheel is removably joined to the fixed plate by a fixing device, and the fixed plate has a structure in which the partial wheel is in contact with the inner peripheral surface of the partial wheel in the circumferential direction with respect to the fixed plate. This is a chain sprocket wheel characterized by being formed with an abutment surface that restricts rotation.

Means 2 is characterized in that a convex portion is formed on one of the joint surfaces of the fixed platen and the partial wheel, and a concave portion is formed on the other, and the convex portion and the concave portion engage with each other. This is a chain sprocket wheel according to means 1 .

Means 3 includes a plurality of fixing devices for removably attaching the partial wheel to the stationary plate, and the plurality of fixing devices include a first fixing device and a rotation of the partial wheel relative to the first fixing device. a second fastener disposed rearward in the direction, the distance from the center of rotation of the wheel portion where the first fastener is disposed, and the center of rotation of the wheel portion where the second fastener is disposed; The chain sprocket wheel according to means 1 or 2, characterized in that the distances from the chain sprocket wheel are different from each other.

Means 4 is characterized in that the chain sprocket wheel is a driving chain sprocket wheel, and the distance from the center of rotation of the wheel portion where the first fastener is disposed is equal to the distance from the rotation center of the wheel portion where the second fastener is disposed. The chain sprocket wheel according to means 3 is characterized in that the distance from the center of rotation of the chain sprocket wheel is longer than the distance from the center of rotation of the chain sprocket wheel.

Means 5 is that the chain sprocket wheel is a driven chain sprocket wheel, and the distance from the center of rotation of the wheel portion where the first fastener is disposed is equal to the distance from the rotation center of the wheel portion where the second fastener is disposed. The chain sprocket wheel according to means 3 is characterized in that the distance from the center of rotation of the chain sprocket wheel is shorter than the distance from the center of rotation of the chain sprocket wheel.

Means 6 is a chain sprocket wheel according to any one of means 1 to 5, characterized in that a gap is formed between the adjacent partial wheels.

Means 7 is the chain sprocket wheel according to any one of means 1 to 6 , characterized in that the wheel portion is divided in the circumferential direction through the troughs of the teeth.

According to the present invention, if a malfunction occurs in any partial wheel, the partial wheel can be moved to a position where it does not engage with the chain, and only the worn or damaged partial wheel can be easily replaced without removing the chain. This makes it possible to significantly reduce the effort and cost required for replacement.
In addition, since the fixed plate is formed with a contact surface that comes into contact with the inner peripheral surface of the partial wheel and restricts rotation of the partial wheel in the circumferential direction, rotation of the partial wheel 5 in the circumferential direction with respect to the fixed plate 3 is restricted. Thus, the partial wheel 5 is stably fixed without wobbling.

In addition, by engaging the recesses and protrusions formed on the joint surfaces of the partial wheel and fixed plate that are joined by the fixing tool, the partial wheel remains fixed even when a large force is applied to some of the teeth. It is possible to prevent rattling against the board.

In addition, a plurality of fasteners for removably attaching the partial wheel to the stationary plate include at least a first fastener and a second fastener disposed rearward in the rotational direction of the partial wheel, and the first fastener is By making the distance from the rotation center of the wheel section where it is placed different from the distance from the rotation center of the wheel section where the second fastener is placed, a large force is applied to the teeth in the direction of movement of the chain. Also, it is possible to further prevent the partial wheels from rattling against the fixed platen.

In addition, when the chain sprocket wheel is a driving chain sprocket wheel, the distance from the rotation center of the wheel portion where the first fastener is arranged is determined by the distance from the rotation center of the wheel portion where the first fastener is arranged to the second fastener which is arranged rearward in the rotational direction of the wheel than the first fastener. By making the distance of the fastener longer than the distance from the center of rotation of the wheel portion, it is possible to increase the resistance against the rotational moment acting on the opposite side of the rotational direction of the partial wheel from the chain caused by the rotation of the drive chain sprocket wheel.

In addition, when the chain sprocket wheel is a driven chain sprocket wheel, the distance from the rotation center of the wheel portion where the first fastener is arranged is determined by the distance from the rotation center of the wheel portion where the first fastener is located to the second fastener located rearward in the rotational direction of the wheel. By making the distance shorter than the distance from the rotation center of the wheel portion of the fastener, it is possible to increase the resistance against the rotational moment from the chain acting in the rotational direction of the partial wheel caused by the movement of the chain.

In addition, by forming a gap between the adjacent partial wheels, it is possible to prevent the partial holes from competing with each other and to facilitate the attachment and detachment of the partial wheels.

In addition, since the wheel portion is divided in the circumferential direction through the troughs of the teeth, the contact surface is reduced compared to dividing between the crests, making attachment and detachment easier.

FIG. 1 is a front view of a chain sprocket wheel showing a first embodiment of the present invention. 1 is a sectional view of a chain sprocket wheel showing a first embodiment of the present invention. FIG. 1 is a front view of a fixed platen according to a first embodiment of the present invention. FIG. 2 is a rear view of the partial wheel according to the first embodiment of the present invention. FIG. 7 is a front view of a chain sprocket wheel showing a second embodiment of the present invention. FIG. 7 is a front view of a chain sprocket wheel showing a third embodiment of the present invention. FIG. 7 is a diagram illustrating the effects of the third embodiment of the present invention.

Embodiments of the present invention will be described below with reference to the drawings. Note that it goes without saying that the present invention is not limited to the embodiments.

[First embodiment]
A first embodiment of the present invention will be described below with reference to FIGS. 1 to 4.
FIG. 1 is a front view of a chain sprocket wheel according to the first embodiment, FIG. 2 is a sectional view of the chain sprocket wheel according to the first embodiment, and FIG. 3 is a fixed platen according to the first embodiment. FIG. 4 is a front view of the partial wheel according to the first embodiment, and FIG. 4 is a rear view of the partial wheel according to the first embodiment.

In the first embodiment, the chain sprocket wheel 1 is a driving chain sprocket wheel that moves a chain (not shown) extending around the outer periphery in the length direction.
As shown in FIGS. 1 and 2, the chain sprocket wheel 1 includes a wheel portion 2 and a disk-shaped fixed plate 3.
The wheel portion 2 has a large number of teeth 4 on its outer periphery that are engaged with the chain, and the teeth 4 include a peak portion 41 and a trough portion 42 . Further, the inner circumferential surface of the wheel portion 2 has a regular polygonal shape (regular octagonal shape in this embodiment).

The wheel portion 2 is divided into a plurality of (eight in this embodiment) partial wheels 5 at equal intervals in the circumferential direction. The number of divisions may be set so that there is at least one partial wheel 5 with which the chain does not engage even when the chain is stretched in a U-turn.
The wheel portion 2 is divided along a dividing line that extends in the radial direction through the peaks 41 of the teeth 4 and the vertices of a regular polygon formed on the inner periphery of the wheel portion 2, and all the partial wheels 5 are separated in the circumferential direction. By combining them, the whole is formed into a disk shape. Moreover, when all the partial wheels 5 are combined, a slight gap 7 is formed between adjacent partial wheels 5.

The partial wheel 5 is independently and removably joined to one side of the fixed platen 3 by bolts 8 inserted through bolt holes 9 (see FIG. 3) of the fixed platen 3 and bolt holes 10 (see FIG. 4) of the partial wheel 5. Ru.
Two bolts 8 are provided for one partial wheel 5, and these bolts include a first bolt 8a and a second bolt located rearward of the first bolt 8a in the rotational direction of the partial wheel 5. 8b. The bolt 8, the first bolt 8a, and the second bolt 8b correspond to a fastener, a first fastener, and a second fastener of the present invention, respectively.

The distance from the center of rotation of the wheel portion 2 where the first bolt 8a is disposed is different from the distance from the center of rotation of the wheel portion 2 where the second bolt 8b is disposed.
By arranging it in this way, even if a large force is applied to the teeth 4 in the direction of movement of the chain, it is possible to further prevent the partial wheels 5 from rattling with respect to the fixed platen 3.

Specifically, the distance from the rotation center of the wheel section 2 where the first bolt 8a is arranged is set to be longer than the distance from the rotation center of the wheel section 2 where the second bolt 8b is arranged. .
As a result, since this is a drive chain sprocket wheel, it is possible to increase the resistance against the rotational moment from the chain that acts on the opposite side of the rotational direction of the partial wheel 5 caused by the rotation of the chain sprocket wheel 1, and prevent rattling. Can be done.

As shown in FIGS. 2 and 3, the stationary platen 3 includes a cylindrical portion 30 through which a shaft (not shown) passes, and a wheel fixing portion 31 shaped like a circular brim to which the wheel portion 2 is attached.
A fixing flange 32 is formed along the inner peripheral edge on one surface of the wheel fixing portion 31 (the surface to which the wheel portion 2 is joined), and the inner circumferential surface of the fixing flange 32 is welded to the outer circumferential surface of the cylindrical portion 30. Fixed by
Further, the outer circumferential surface of the fixing flange 32 is a regular polygon (regular octagon in this embodiment) corresponding to the inner circumferential surface of the wheel portion 2, and has a plurality of shapes that contact the inner circumferential surface of each partial wheel 5. (Eight in this embodiment) contact surfaces 33 are formed.

As shown in FIGS. 2 and 3, a circular convex portion 11 is formed on one surface of the wheel fixing portion 31 along the entire outer periphery, and as shown in FIG. A recess 12 that engages with the protrusion 11 of the stationary platen 3 is formed along the circumferential direction on the surface to be joined.
When the inner peripheral surface of the partial wheel 5 is brought into contact with the contact surface 33 of the fixing flange 32, the partial wheel 5 and the fixed platen 3 are positioned in the radial direction, and the convex part 11 and the concave part 12 can be easily engaged. At the same time, the bolt holes 9 and 10 are also easily aligned. Further, since the inner circumferential surface of the partial wheel 5 and the contact surface 33 of the fixed platen 3 are flat, when they come into contact with each other, rotation of the partial wheel 5 in the circumferential direction with respect to the fixed platen 3 is restricted.

Since the circular convex portion 11 is formed along the entire outer peripheral edge of the wheel fixing portion 31, the convex portion 11 can be easily processed.
When rotating the chain sprocket wheel 1 to drive the chain, uneven force is applied to the teeth 4 of the partial wheel 5, and the partial wheel 5 tends to wobble against the fixed plate 3, but it extends in the circumferential direction. The convex part 11 of the fixed platen 3 and the concave part 12 of the partial wheel 5 engage with each other to suppress rattling.
In addition, since the inner peripheral surface of the partial wheel 5 and the contact surface of the fixed platen 3 are planes parallel to the tangent of the circle concentric with the wheel part 2, the inner peripheral surface of the partial wheel 5 is connected to the contact surface of the fixed platen 3. 33, movement of the partial wheel 5 in the circumferential direction with respect to the fixed platen 3 is restricted, and rattling of the partial wheel 5 can be further suppressed.

If any partial wheel 5 is worn or damaged, without removing the chain from the chain sprocket wheel 1, move the partial wheel 5 to a position where it does not engage with the chain, and then tighten the first bolt 8a and second bolt 8b. The partial wheel 5 that has been pulled out, worn or damaged is removed, and a new partial wheel 5 is installed.
At this time, a gap 7 is formed between the adjacent partial wheels 5. Since the gap 7 is thus formed, the partial wheel 5 can be easily removed without competition between the adjacent partial wheel 5 and the partial wheel 5 to be removed, and without being hindered by the adjacent partial wheel 5. Moreover, the installation work can be carried out without being obstructed by the adjacent partial wheels 5.

[Second embodiment]
A second embodiment according to the present invention will be described below with reference to FIG. 5. Note that descriptions of parts similar to those in the first embodiment will be omitted, and mainly different parts will be described.

The chain sprocket wheel 1 in the second embodiment is a driven chain sprocket wheel, and rotates as a chain (not shown) extending around the outer periphery moves.
The chain sprocket wheel 1 rotates in the direction of the arrow shown in FIG. 5 as the chain moves. Therefore, a rotational moment from the chain in the direction of rotation of the partial wheel, which is generated by the movement of the chain, acts on the partial wheel 5.

Correspondingly, the distance from the rotation center of the wheel part 2 where the first bolt 8a is arranged is set to the distance of the second bolt 8b which is arranged rearward in the rotational direction of the wheel part 2 than the first bolt 8a. The bolt 8 is arranged at a distance shorter than the distance from the center of rotation. By doing so, it is possible to increase the resistance against the rotational moment acting on the partial wheel 5 from the chain in the rotational direction caused by the movement of the chain.

[Third embodiment]
A third embodiment of the present invention will be described below with reference to FIGS. 6 and 7. Note that descriptions of parts similar to those in the first and second embodiments will be omitted, and mainly different parts will be described.

In the third embodiment, the wheel part 2 is divided into a plurality of partial wheels 5 along a dividing line extending radially through the troughs 42 of the teeth 4 .
When the wheel portion 2 is divided at the troughs 42 of the teeth 4 in this way, the strength is slightly lower than when the wheel portion 2 is divided at the ridges 41, and the spaces between the partial wheels 5 are easier to open. Since the portion that can come into contact with the partial wheels 5 arranged next to each other is reduced, the partial wheels 5 arranged next to each other do not get in the way, and attachment and detachment becomes easy. In addition, compared to a model divided at the peak 41, there are fewer parts that can come into contact with the adjacent partial wheel 5 during attachment and detachment, so there is less chance of fingers getting caught, allowing for safe attachment and detachment work. be able to.

The eight attached partial wheels 5 are installed so as to be flush with the joint surface of the wheel fixing part 31, but there is a difference in level between adjacent partial wheels 5 when attaching and removing them. may occur. Even in such a case, if the plurality of partial wheels 5 are divided along the dividing line extending radially through the troughs 42 of the teeth 4, the influence of the presence of the step on the movement of the chain will be reduced. It can be made smaller and contributes to smooth chain movement. This effect will be specifically explained with reference to FIG. 7.
FIG. 7 is a diagram for explaining this effect, and FIG. 7(A) is an enlarged plan view of a portion where the wheel portion 2 is divided by the peak portion 41 of the tooth 4 (a view seen from the direction A in FIG. 5). ), and FIG. 7(b) shows the third embodiment, and is an enlarged plan view of a portion where the wheel portion 2 is divided by the valley portion 42 of the tooth 4 (a view seen from direction B in FIG. 6). It is.

When a step Z occurs between adjacent partial wheels 5 and 5 disposed with a gap 7 in between, the distance of the divided peak portion 41 to the step Z is determined by the distance of the tooth 4 as shown in FIG. 7(A). In the case of division at the peak 41, the distance between the divided peaks 41 is L1 of the gap 7. On the other hand, in the case where the tooth 4 is divided by the valley part 42 as shown in FIG. In the case of division by 42, the distance over which the same step Z of the peak portion 41 occurs becomes longer.
From this, the influence of the step of the peak portion 41 on the chain is relatively smaller in the case where the chain is divided at the valley portion 42 in FIG. 7(b). Moreover, in the case where the chain is divided at the crest 41 in FIG. 7(a), a step Z occurs between the ridges 41 that engage one hole in the chain, but when the chain is divided at the trough 42 in FIG. 7(b), In this case, a step Z will occur between the peaks 41 that engage with the two holes of the chain, and the effect of the step on the chain will be reduced.

[Other variations]
The present invention is not limited to the above embodiments. Examples include the following:

In this embodiment, the wheel portion is divided into eight partial wheels, but the number of divisions can be changed as appropriate depending on the size of the chain sprocket wheel, the angle at which the chain engages, etc. Accordingly, a number of contact surfaces corresponding to the number of partial wheels are formed on the outer peripheral surface of the fixing flange of the fixed platen.

In this embodiment, the inner circumferential surface of the partial wheel and the contact surface of the fixed plate are flat, but any shape that restricts the movement of the partial wheel in the circumferential direction may be used, such as a curved surface or an uneven surface. You can also do that.

In the present embodiment, the contact surface 33 is formed on the outer circumferential surface of the fixing flange 32 of the wheel fixing part 31 fixed to the outer circumferential surface of the cylindrical part 30 of the fixed platen 3, but the present invention is not limited to this. If there is no fixing flange and the inner circumferential surface of the partial wheel directly contacts the outer circumferential surface of the cylindrical portion, a contact surface is formed on the outer circumferential surface of the cylindrical portion.

In this embodiment, the contact surface is a surface where the outer peripheral surface of the stationary platen and the inner peripheral surface of the partial wheel come into contact, but this contact is not limited to constant contact. For example, even if there is a slight gap when a partial wheel is joined to a fixed plate, force acts on the partial wheel and it moves slightly in the circumferential direction before coming into contact with the outer peripheral surface of the fixed plate. A case in which the movement is regulated is also included in the contact surface of the present invention.

In this embodiment, the convex portion is formed on the stationary plate and the concave portion is formed on the partial wheel, but of course, the concave portion may be formed on the stationary plate and the convex portion may be formed on the partial wheel.

In this embodiment, the circular convex portion 11 is formed along the entire length of the outer peripheral edge of the wheel fixing portion 31, but the present invention is not limited to this. It may be provided intermittently instead of along the entire outer periphery. Further, the convex portion may be formed not on the outer peripheral edge but on the inner joint surface. Moreover, in that case, it goes without saying that the engaging recesses are also formed at corresponding positions.

In this embodiment, each partial wheel is attached to the stationary platen with two bolts, the first bolt and the second bolt, but the present invention is not limited to this, and it may be attached to the stationary platen with one bolt.

In this embodiment, each partial wheel is attached to the fixed plate with two bolts, the first bolt and the second bolt, but depending on the size of the partial wheel, it may be attached with three or more bolts.

Although the present invention relates to the structure of a chain sprocket wheel, the technical idea described in this specification may be applied to the structure of a gear to create a gear invention. In this case, it is not the chain that engages with the large number of teeth, but the teeth of other gears.

Each technical matter in any embodiment may be applied to other embodiments to form an example.

1 Chain sprocket wheel 2 Wheel part 3 Fixed plate 4 Teeth 5 Partial wheel 7 Gap 8 Bolt 8a First bolt 8b Second bolt 9,10 Bolt hole 30 Cylindrical part 31 Wheel fixing part 32 Fixing flange 33 Contact surface

Claims (8)

A chain sprocket wheel that wraps the chain around its outer periphery,
comprising a wheel portion having a large number of teeth that the chain engages with, and a fixed plate;
The wheel portion is divided into a plurality of partial wheels in the circumferential direction, and each partial wheel is removably joined to the fixed plate by a fastener,
The partial wheel has an inner circumferential surface that forms an outer shape when viewed from the front,
The fixed plate is formed with a contact surface that comes into contact with the inner circumferential surface of the partial wheel to restrict rotation of the partial wheel in the circumferential direction with respect to the fixed plate,
A chain sprocket wheel characterized in that a gap is formed between the adjacent partial wheels. The plurality of fixing devices removably attach the partial wheel to the fixed platen,
The plurality of fixing devices include a first fixing device and a second fixing device arranged behind the first fixing device in the rotational direction of the partial wheel,
The distance from the rotation center of the wheel portion where the first fixing device is disposed is different from the distance from the rotation center of the wheel portion where the second fixing device is disposed. Chain sprocket wheel as described. A chain sprocket wheel that wraps the chain around its outer periphery,
comprising a wheel portion having a large number of teeth that the chain engages with, and a fixed plate;
The wheel portion is divided into a plurality of partial wheels in the circumferential direction, and each partial wheel is removably joined to the fixed plate by a fastener,
The fixed plate is formed with a contact surface that comes into contact with the inner circumferential surface of the partial wheel to restrict rotation of the partial wheel in the circumferential direction with respect to the fixed plate,
The plurality of fixing devices removably attach the partial wheel to the fixed platen,
The plurality of fixing devices include a first fixing device and a second fixing device arranged behind the first fixing device in the rotational direction of the partial wheel,
A chain sprocket wheel characterized in that a distance from the rotation center of the wheel portion where the first fixing device is disposed is different from a distance from the rotation center of the wheel portion where the second fixing device is disposed. The chain sprocket wheel according to claim 3, wherein a gap is formed between the adjacent partial wheels. The chain sprocket wheel is a driven chain sprocket wheel,
A distance from the rotation center of the wheel portion where the first fixing device is disposed is longer than a distance from the rotation center of the wheel portion where the second fixing device is disposed. The chain sprocket wheel according to any one of item 4. The chain sprocket wheel is a driven chain sprocket wheel,
A distance from the rotation center of the wheel portion where the first fixing device is disposed is shorter than a distance from the rotation center of the wheel portion where the second fixing device is disposed. The chain sprocket wheel according to any one of item 4. A convex portion is formed on one of the joint surfaces of the fixed platen and the partial wheel, and a concave portion is formed on the other, and the convex portion and the concave portion engage with each other. 6. The chain sprocket wheel according to any one of 6. The chain sprocket wheel according to any one of claims 1 to 7, wherein the wheel portion is divided in the circumferential direction through the tooth troughs.

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