JP2014231896A - Sprocket for driving chain - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sprocket for driving a chain capable of reducing costs for replacing components of a buffer member to suppress noise by being kept into contact with the chain while easing mechanical impact shock, in driving the chain.SOLUTION: A sprocket 11 for driving a chain includes a rotating member 21 provided with a plurality of tooth portions 24a engageable with the chain 12 at equal intervals on an outer peripheral portion 28 in the circumferential direction, and a plurality of buffer members 31 mounted at least at one side in the tooth width direction of the tooth portions of the rotating member at intervals corresponding to circumferential pitches L of the tooth portions in the circumferential direction along a pitch cycle Q of the tooth portion in a state that they can be kept into contact with an inner plate 13 and an outer plate 14 of the chain. In removing and replacing the buffer members 31 from the rotating member, only the buffer member which is, for example, deteriorated and should be replaced among the plurality of mounted buffer members can be replaced.

Description

  The present invention relates to a sprocket for driving a chain that drives a chain by meshing and rotating a tooth portion provided on an outer peripheral portion with the chain.

  Conventionally, this type of chain driving sprocket has a problem in that when a chain is driven, if a roller or a bush included in the chain falls on and collides with the bottom of the sprocket tooth, there is a problem that noise is generated. Therefore, in order to suppress the generation of such noise, a cushion ring (buffer member) is provided on both sides of the sprocket teeth in the tooth width direction, and the cushion ring receives the edge of the link plate of the chain. There has been proposed a chain sprocket with a cushion ring so as not to collide with the tooth bottom (for example, Patent Document 1).

JP 2006-38031 A

  By the way, in the above-mentioned conventional sprocket, the cushion ring as a buffer member is formed in the annular | circular shaped integral thing over the whole circumferential direction of a sprocket. Therefore, if deterioration or damage is found in a part of the circumferential direction of the cushion ring, the entire cushion ring is integrated even if no deterioration or damage is found in other parts of the circumferential direction. There is a problem that it is necessary to replace parts as a product, and it is not possible to reduce costs related to the replacement.

  The present invention has been made in view of such a situation, and an object of the present invention is to provide a cushioning member that suppresses the generation of noise by relaxing mechanical contact with the chain when the chain is driven. An object of the present invention is to provide a chain-driven sprocket that can reduce the cost associated with component replacement.

Hereinafter, means for solving the above-described problems and the effects thereof will be described.
A sprocket for driving a chain that solves the above problems includes a rotating member in which a plurality of teeth that can mesh with the chain are provided on the outer peripheral portion at equal intervals in the circumferential direction, and a tooth width direction of the tooth portion of the rotating member. And a plurality of buffer members attached at intervals corresponding to the circumferential pitch of the teeth in the circumferential direction along the pitch circle of the teeth so as to be able to contact the link plate in the chain on at least one side.

  According to this configuration, since the buffer member is attached to the rotating member, the generation of noise can be suppressed by driving the chain so that the buffer member makes contact with the chain while reducing mechanical shock. When such a cushioning member is removed from the rotating member and replaced, a plurality of cushioning members attached at intervals corresponding to the circumferential pitch of the tooth portion in the circumferential direction along the pitch circle of the tooth portion. Of these, for example, it is only necessary to replace the buffer member that is recognized to be deteriorated and needs to be replaced. Therefore, unlike the case where the buffer member is an annular integral member extending over the entire circumferential direction of the rotating member, the cost associated with replacement of the buffer member as a component can be reduced.

  In the chain driving sprocket, the plurality of buffer members are attached at a distance equal to or twice the circumferential pitch of the tooth portion in a circumferential direction along the pitch circle of the tooth portion. Preferably it is.

  If a plurality of cushioning members are attached in the circumferential direction along the pitch circle of the tooth portion at a distance exceeding twice the circumferential pitch of the tooth portion, they are received by the buffer member when the chain is driven. Two or more link plates that cannot be formed continuously in the longitudinal direction of the chain. Therefore, in such a case, it is possible that a roller or the like located at a location where two or more continuous link plates are rotatably connected will drop into the tooth bottom of the tooth portion and collide with it, generating noise. There is sex. In this regard, according to the above configuration, when the chain is driven, two or more link plates that are not received by the buffer member are not continuously generated in the longitudinal direction of the chain. Therefore, the roller of the chain or the like does not fall and collide with the tooth bottom of the tooth portion on the outer peripheral portion of the rotating member. Therefore, it is possible to satisfactorily suppress the generation of noise due to such a collision.

  In the chain driving sprocket, the buffer member includes a mounting portion for the rotating member and a load receiving portion for receiving a load from the chain via the link plate, and the mounting portion has rigidity, The load receiving portion preferably has elasticity.

  According to this structure, since the attachment part with respect to a rotating member has rigidity, a buffer member can be attached to the rotating member in the stable state positioned. On the other hand, since the load receiving portion has elasticity, the mechanical impact applied from the chain side via the link plate can be relaxed, and the generation of noise can be suppressed.

  In the chain driving sprocket, the load receiving portion includes a contact portion that is a contact portion with the link plate, and an elastic portion interposed between the contact portion and the mounting portion, The material of the part preferably has a Young's modulus smaller than the material of the contact part.

  According to this configuration, durability can be ensured by selecting a material having a large Young's modulus for the contact portion that receives a load by contacting the link plate when the chain is driven, while the attachment portion side via the contact portion. Since the load applied to the elastic member can be absorbed by the elastic portion made of a material having a small Young's modulus, it is possible to satisfactorily reduce the impact and suppress the generation of noise.

  In the chain drive sprocket, a surface of the contact portion that is non-perpendicular to a radial direction of the rotating member in the rotation direction of the rotating member is an edge of the contact portion in the rotating direction. It is preferable that it is formed so as to be continuous with.

  According to this configuration, when a surface that is non-perpendicular to the radial direction of the rotating member, such as a tapered surface or a curved surface, is formed on the surface of the contact portion toward the edge in the rotating direction of the rotating member. Since the edge of the contact portion in the rotation direction of the rotating member can be made non-edge-shaped, it is possible to reduce the possibility of the contact portion being damaged by sliding with the link plate of the chain.

  ADVANTAGE OF THE INVENTION According to this invention, the cost regarding replacement | exchange of the buffer member which can suppress generation | occurrence | production of a noise by relieving a mechanical impact with respect to a chain at the time of driving of a chain can be reduced.

The perspective view which shows the chain drive state by the sprocket of 1st Embodiment. The perspective view of a rotation member. The perspective view of a buffer member. The disassembled perspective view of a buffer member. The front view which expands and shows the principal part of the chain drive state by a sprocket. The perspective view which shows the chain drive state by the sprocket of 2nd Embodiment. The perspective view which shows the chain drive state by the sprocket of 3rd Embodiment. The perspective view of the buffer member of the 1st modification. The perspective view of the buffer member of the 2nd modification.

(First embodiment)
Hereinafter, a first embodiment of a chain driving sprocket will be described with reference to the drawings.
As shown in FIG. 1, the sprocket 11 for driving a chain in this embodiment moves forward and backward along the longitudinal direction of the chain 12 by rotating based on transmission of driving force in a state where the chain 12 is engaged. To drive.

  That is, the chain 12 has an inner plate 13 as an example of a plurality of pairs of link plates opposed in the width direction and an outer plate 14 as an example of a plurality of pairs of link plates. The pair of inner plates 13 are held in opposed states separated from each other by being connected by a cylindrical bush (not shown). Then, outside the inner plate 13, the outer plate 14 is arranged in series so as to be alternately arranged with the inner plate 13, and the ends adjacent to each other in the series direction are inserted into the bush. The chain 12 is formed in a predetermined length by being rotatably connected by a pin 15.

  Further, a roller 16 is rotatably mounted on the outer peripheral side of the pin 15 between the plates 13 and 14 facing in the width direction of the chain 12, and a tooth portion provided on the outer peripheral portion of the sprocket 11 on which the roller 16 rotates. By engaging and pulling in the rotational direction of the sprocket 11, the chain 12 moves forward and backward along its longitudinal direction. At that time, the chain 12 brings the edges along the longitudinal direction of the inner plate 13 and the outer plate 14 into contact with the plurality of buffer members 31 provided at equal intervals in the circumferential direction on the outer peripheral portion of the sprocket 11.

  As shown in FIG. 2, the sprocket 11 includes a substantially disk-shaped rotating member 21 made of a metal material (for example, iron), a bolt 22 and a nut 23 made of a rigid metal material (for example, iron). A tooth body 24 made of a metal material (for example, iron or the like) that is fixed to the rotating member 21 is provided. A shaft hole 25 into which a driving shaft (not shown) for transmitting a driving force is inserted is formed at the center of the rotating member 21, and the rotating member 21 rotates along with the rotation of the driving shaft. Rotate around the center of rotation.

  The rotating member 21 has an inner peripheral portion 26 through which the shaft hole 25 is formed, and a radial direction (that is, radial direction) outside the inner peripheral portion 26, which is in an axial direction (that is, axial direction) than the inner peripheral portion 26. The intermediate portion 27 is continuous with a reduced thickness, and the outer peripheral portion 28 is connected to the outer side of the intermediate portion 27 in the radial direction with the thickness in the axial direction being thinner than that of the intermediate portion 27. The outer peripheral portion 28 has a thickness in the axial direction that is approximately half of the thickness in the axial direction of the intermediate portion 27 and is continuously formed on the outer peripheral side of the intermediate portion 27 through the entire circumferential direction via a step (not shown). It is an annular plate portion, and holes (not shown) through which the bolts 22 can be inserted are formed in a plurality of locations in the circumferential direction (20 locations in the present embodiment) in the thickness direction at equal intervals. Further, in the outer peripheral portion 28 of the rotating member 21, the shaft diameter is smaller than that of the bolt 22 at a plurality of locations (20 locations in the present embodiment) in the circumferential direction on the inner peripheral side of each hole through which the bolt 22 can be inserted. The holes 29 through which the bolts can be inserted are formed in the thickness direction at equal intervals.

  Further, the tooth body 24 is configured by a plurality (10 in this embodiment) of tooth bodies 24 that are fixed at a plurality of locations (10 in the present embodiment) in the circumferential direction at equal intervals. Each tooth body 24 is a plate piece formed so as to form an arc shape along the contour shape of the outer peripheral portion 28 having substantially the same thickness in the axial direction as the outer peripheral portion 28 of the rotating member 21. Is formed with two teeth 24a that can mesh with the roller 16 of the chain 12. Each tooth body 24 has an inner peripheral side portion made thinner through a step (not shown) so that its thickness is about half of the thickness of the outer peripheral side portion. Are fixed using bolts 22 or the like in a state of being overlapped in the axial direction.

  Further, as shown in FIG. 1, a plurality (40 in this embodiment) of buffer members 31 are fixed to the outer peripheral portion 28 of the rotating member 21 at equal intervals in the circumferential direction. That is, each buffer member 31 is rotated using a bolt 22 and a nut 23 for fixing the tooth body 24 to the rotating member 21 and a bolt 32 and a nut 33 inserted into the hole 29 of the outer peripheral portion 28 of the rotating member 21. It is fixed to the outer peripheral portion 28 of the member 21.

  As shown in FIGS. 3 and 4, the buffer member 31 has an attachment portion 34 attached in contact with the outer peripheral portion 28 of the rotating member 21 in the axial direction, and the inner plate 13 and the outer plate 14 when the chain 12 is driven. And a load receiving portion 35 for receiving a load from the chain 12 side. The attachment portion 34 is a bracket formed in a substantially L shape with a rigid metal material (for example, iron or the like), and is a fixed piece portion 38 that can contact the outer peripheral portion 28 of the rotating member 21 from the axial direction. And a support piece portion 39 bent and extended from the fixed piece portion 38, and the load receiving portion 35 is supported on the support piece portion 39.

  The load receiving portion 35 is interposed between a contact portion 36 that becomes a contact portion with the inner plate 13 and the outer plate 14 when the chain 12 is driven, and the support piece portion 39 of the contact portion 36 and the mounting portion 34. And an elastic portion 37. The abutting portion 36 is a plate member formed of a metal material having rigidity (for example, iron) so that the surface forms a uniform plane, as with the mounting portion 34, while the elastic portion 37 is in contact with the abutting portion 36. It is a plate member formed to have the same shape as the contact portion 36 with a metal material (for example, aluminum) having a smaller Young's modulus than the portion 36. Therefore, the load receiving portion 35 has elasticity by providing the elastic portion 37.

  As shown in FIG. 4, a hole 40 is formed through the support piece 39 of the mounting portion 34 of the buffer member 31 in the thickness direction. Further, the elastic portion 37 of the load receiving portion 35 in the buffer member 31 has the same position as the hole 40 of the support piece portion 39 in a state where the elastic portion 37 is superimposed on the support piece portion 39 of the attachment portion 34. A hole 41 is formed penetrating in the thickness direction. In addition, a similar hole 42 is formed in the thickness direction of the contact portion 36 overlapped with the elastic portion 37 at a position coincident with the hole 41 of the elastic portion 37 in a state where the contact portion 36 is overlapped on the elastic portion 37. Is formed through.

  Then, the elastic portion 37 and the abutting portion 36 are overlapped on the support piece portion 39 of the mounting portion 34 so that the holes 40, 41, and 42 coincide with each other so that the elastic portion 37 contacts the support piece portion 39. In the state, the nut 44 is fastened to the tip of the bolt 43 inserted from the hole 42 side to the hole 40 side, so that the load receiving portion 35 is integrated with the mounting portion 34 in the buffer member 31.

  As shown in FIGS. 1 and 5, the buffer member 31 has both sides in the tooth width direction of the tooth portion 24 a in each tooth body 24 fixed to the outer peripheral portion 28 of the rotating member 21 (direction orthogonal to the paper surface in FIG. 5). It is fixed to. That is, when the chain 12 is driven, the contact portion 36 can contact the inner plate 13 and the outer plate 14 of the chain 12 and corresponds to the circumferential pitch L of the tooth portion 24a in the circumferential direction along the pitch circle Q of the tooth portion 24a. The buffer members 31 are fixed to the outer peripheral portion 28 of the rotating member 21 at equal intervals with the same distance (the same distance as the circumferential pitch L in this embodiment).

Next, the operation of the chain drive sprocket 11 configured as described above will be described.
As shown in FIGS. 1 and 5, when the chain 12 wound around the outer periphery of the sprocket 11 is driven, the sprocket 11 causes the roller 16 of the chain 12 to mesh with the tooth portion 24a of the tooth body 24 on the outer peripheral side. Rotate. Then, when the roller 16 of the chain 12 meshes with the tooth portion 24a of the tooth body 24, the roller 16 falls into the tooth bottom between the tooth portion 24a and the tooth portion 24a of the tooth body 24 from the outside in the radial direction. When it collides with the tooth bottom, an impact force is applied to the rotating member 21 via the tooth body 24 and a large noise is generated. Therefore, it is desired to avoid a collision that generates such an impact force or a large noise.

  In this regard, in the present embodiment, as shown in FIGS. 1 and 5, when the sprocket 11 rotates to drive the chain 12 in a state where the chain 12 is wound around the outer periphery, the roller 16 rotates the teeth of the tooth body 24. The buffer member 31 contacts the longitudinal edges of the inner plate 13 and the outer plate 14 of the chain 12 before dropping into the tooth bottom between the portions 24a and colliding with the tooth bottom. Then, the movement of the roller 16 toward the tooth bottom of the tooth portion 24a after that time is restricted, and the roller 16 is prevented from colliding with the tooth bottom between the tooth portions 24a of the tooth body 24 when the chain 12 is driven. Is done.

  Further, since the buffer member 31 is also a portion where the inner plate 13 and the outer plate 14 are slidably contacted when the chain 12 is driven, the buffer member 31 may be deteriorated and replaced with age. Therefore, in such a case, when the buffer member 31 is removed from the rotating member 21 and replaced, the deterioration or the like is actually recognized among the plurality of buffer members 31 arranged dispersed in the circumferential direction of the rotating member 21. Only one or several buffer members 31 that need to be replaced are replaced.

  In addition, when attaching the buffer member 31 to at least one side in the tooth width direction of the tooth portion 24a on the outer periphery of the rotating member 21, the height of the corresponding tooth portion 24a and the insertion holes of the bolts 22 and 32 for attaching the buffer member 31 are provided. When there is an error in the processing accuracy such as the position, the following fine adjustment work is performed. That is, even when there is such an error, the buffer member 31 that can contact the inner plate 13 and the outer plate 14 of the chain 12 at an optimum height is prepared with different height dimensions of the load receiving portion 35. The buffer member 31 selected from the plurality of types of buffer members 31 is attached to the rotating member 21.

  Further, since each buffer member 31 is attached at equal intervals with the same distance as the circumferential pitch L of the tooth portion 24a in the circumferential direction along the pitch circle Q of the tooth portion 24a, the buffer member 31 is buffered when the chain 12 is driven. Two or more link plates (the inner plate 13 and the outer plate 14) that are not received by the member 31 do not continuously occur in the longitudinal direction of the chain 12. Therefore, the roller 16 mounted on the outer periphery of the pin 15 that rotatably connects the ends of the inner plate 13 and the outer plate 14 that are adjacent in the series direction includes the inner plate 13 and the outer Each of the plates 14 is received by contacting the buffer member 31. Therefore, the roller 16 is restricted from moving toward the tooth bottom of the tooth portion 24a after the contact time.

  Further, when the cushioning member 31 is attached to the rotating member 21, it is attached in a positioned and stable state via the attachment portion 34 having rigidity. On the other hand, since the load receiving portion 35 of the buffer member 31 has elasticity, when the inner plate 13 and the outer plate 14 of the chain 12 are received by the load receiving portion 35, the load receiving portion 35 is elastically deformed. By doing so, the mechanical impact applied from the chain 12 side via the inner plate 13 and the outer plate 14 is relieved.

  Further, in the load receiving portion 35 of the buffer member 31, the abutting portion 36 that is a contact portion between the inner plate 13 and the outer plate 14 of the chain 12 can be formed of a metal material having a Young's modulus larger than that of the elastic portion 37. Therefore, durability can be ensured by selecting a material having a large Young's modulus. On the other hand, as for the elastic portion 37, an optimum material is selected from a wide variety of materials having a Young's modulus smaller than that of the contact portion 36 according to the use environment.

According to the first embodiment, the following effects can be obtained.
(1) Since the buffer member 31 is attached to the rotating member 21, when the chain 12 is driven, the buffer member 31 can relieve the mechanical impact on the chain 12 and contact with the chain 12, thereby suppressing the generation of noise. . When such a cushioning member 31 is removed from the rotating member 21 and replaced, it is attached in the circumferential direction along the pitch circle Q of the tooth portion 24a with an interval corresponding to the circumferential pitch L of the tooth portion 24a. Of the plurality of buffer members 31, for example, only the buffer member 31 that has been recognized to be deteriorated and needs to be replaced may be replaced. Therefore, unlike the case where the buffer member 31 is a ring-shaped integral member extending over the entire circumferential direction of the rotating member 21, the cost associated with the replacement of the buffer member 31 as a component can be reduced.

  (2) Since the mounting part 34 with respect to the rotating member 21 has rigidity, the buffer member 31 can be attached to the rotating member 21 in a positioned and stable state. On the other hand, since the load receiving portion 35 has elasticity, the mechanical impact applied from the chain 12 side via the inner plate 13 and the outer plate 14 can be alleviated, and the generation of noise can be suppressed.

  (3) The durability can be ensured by selecting a material having a large Young's modulus for the contact portion 36 that receives a load by contacting the inner plate 13 and the outer plate 14 when the chain 12 is driven. On the other hand, since the load applied to the mounting portion 34 side via the contact portion 36 can be absorbed by the elastic portion 37 made of a material having a low Young's modulus, the impact can be satisfactorily reduced to suppress the generation of noise. Can do.

  (4) Each plate of the chain 12 on at least one side in the tooth width direction of the corresponding tooth portion 24a even when there are variations in processing accuracy in the plurality of tooth portions 24a and the like provided on the outer peripheral portion 28 of the rotating member 21 The buffer member 31 that can contact with the optimal height with respect to 13, 14 can be selected from a plurality of types of buffer members 31 and attached to the rotating member 21. That is, if this is done, the function of mitigating mechanical shock by the buffer member 31 can be finely adjusted.

(Second Embodiment)
Next, the sprocket of 2nd Embodiment is demonstrated, referring a figure. In addition, the sprocket of this 2nd Embodiment differs from the case of the 1st Embodiment in the attachment number of the buffer member with respect to a rotating member. And since it is substantially the same as 1st Embodiment in another point, the overlapping description is abbreviate | omitted by attaching | subjecting the same code | symbol about the same structure.

  Now, in the sprocket 11 of the first embodiment, in the outer peripheral portion 28 of the rotating member 21, the intervals between every other tooth portion on both sides in the tooth width direction of the tooth portion 24a, that is, in the circumferential direction along the pitch circle Q of the tooth portion 24a. A total of 40 buffer members 31 were attached at equal intervals with the same distance as the circumferential pitch L of the tooth portion 24a.

  On the other hand, as shown in FIG. 6, in the sprocket 51 of the present embodiment, the interval between every two tooth portions on the both sides in the tooth width direction of the tooth portion 24a in the outer peripheral portion 28 of the rotating member 21, that is, the tooth portion 24a. A total of 20 buffer members 31 are attached at equal intervals with a distance twice the circumferential pitch L of the tooth portion 24a in the circumferential direction along the pitch circle Q.

  Therefore, although a total of 20 tooth portions 24a are provided at equal intervals in the outer circumferential portion 28 of the rotating member 21, each of the tooth portions 24a has buffer members 31 attached to both sides in the tooth width direction. The tooth portions 24a that are provided and the tooth portions 24a that are not attached to the buffer member 31 are alternately located on both sides in the tooth width direction. Therefore, one of the pair of outer plates 14 (the outer plate 14 in FIG. 6) is received by the buffer member 31 when the chain 12 is driven, like the pair of inner plates 13 arranged in series in the chain 12. The other plate (inner plate 13 in FIG. 6) is not received by the buffer member 31 when the chain 12 is driven.

  Even in such a case, the link plate (in this case, the inner plate 13) that cannot be received by the buffer member 31 and other link plates adjacent in the series direction in which the ends are rotatably connected by the pins 15 (in this case) The outer plate 14) is received by the buffer member 31. Therefore, the roller 16 attached to the outer peripheral side of the pin 15 that rotatably connects the end portions of the plates 13 and 14 is received by the buffer member 31 on the link plate on one side in the series direction. It is controlled that the tooth part 24a falls toward the tooth bottom after the time point.

According to the said 2nd Embodiment, in addition to the effect of (1)-(4) in 1st Embodiment, the following effects can be acquired further.
(5) If a plurality of cushioning members 31 are attached in the circumferential direction along the pitch circle Q of the tooth portion 24a at intervals exceeding the circumferential pitch L of the tooth portion 24a, the chain Two or more link plates (inner plate 13 and outer plate 14) that are not received by the buffer member 31 during the drive of 12 are continuously generated in the longitudinal direction of the chain 12. For this reason, in such a case, the roller 16 or the like positioned at a position where the two or more continuous link plates (the inner plate 13 and the outer plate 14) are rotatably connected to the tooth bottom of the tooth portion 24a. May collide and generate noise. In this regard, according to the present embodiment, when the chain 12 is driven, two or more link plates (the inner plate 13 and the outer plate 14) that are not received by the buffer member 31 are continuously generated in the longitudinal direction of the chain 12. There is no. Therefore, the roller 16 or the like of the chain 12 does not fall and collide with the tooth bottom of the tooth portion 24a of the outer peripheral portion 28 of the rotating member 21. Therefore, it is possible to satisfactorily suppress the generation of noise due to such a collision.

  (6) Even when the number of the buffer members 31 attached to the outer peripheral portion 28 of the rotating member 21 is reduced, it is possible to restrict the roller 16 from colliding with the tooth bottom of the tooth portion 24a when the chain 12 is driven. The generation of noise can be suppressed while reducing the cost by the number of points.

  Next, the sprocket of 3rd Embodiment is demonstrated, referring a figure. The sprocket of the third embodiment is different from that of the first embodiment in the number of buffer members attached to the rotating member and the number of teeth formed. And since it is substantially the same as 1st Embodiment in another point, the overlapping description is abbreviate | omitted by attaching | subjecting the same code | symbol about the same structure.

  As shown in FIG. 7, in the sprocket 61 of the present embodiment, each tooth body 24 fixed to the outer peripheral side of the rotating member 21 by a bolt 22 has a tooth portion 24a that can mesh with the roller 16 of the chain 12 on its outer peripheral edge. One is formed. That is, the sprocket 11 of the first embodiment has two tooth portions 24 a on the tooth body 24, whereas the sprocket 61 of this embodiment has only one tooth portion 24 a on the tooth body 24. Therefore, when the chain 12 is driven, the sprocket 51 rotates in a state where the tooth portions 24a of the tooth bodies 24 are engaged with every other roller 16 among the rollers 16 positioned at a predetermined interval in the longitudinal direction of the chain 12. To do.

  On the other hand, with respect to the buffer member 31, the circumferential pitch of the tooth portions 24a in the circumferential direction along the pitch circle Q of the tooth portions 24a on both sides in the tooth width direction of the tooth portions 24a in the outer peripheral portion 28 of the rotating member 21 (first embodiment). In total, 20 buffer members 31 are attached at equal intervals with a distance of twice the circumferential pitch L in this case.

  Therefore, also in this embodiment, a link plate (inner plate 13 in FIG. 7) that cannot be received by the buffer member 31 when the chain 12 is driven and a link plate (outer plate 14 in FIG. 7) that are received are generated. However, even in this case, the link plate (in this case, the inner plate 13) that cannot be received by the buffer member 31 and other link plates adjacent in the series direction in which the ends are rotatably connected by the pins 15 (in this case) The outer plate 14) is received by the buffer member 31. Therefore, the roller 16 attached to the outer peripheral side of the pin 15 that rotatably connects the end portions of the plates 13 and 14 is received by the buffer member 31 on the link plate on one side in the series direction. It is controlled that the tooth part 24a falls toward the tooth bottom after the time point.

According to the said 3rd Embodiment, in addition to the effect of (1)-(4) in 1st Embodiment and (6) in 2nd Embodiment, the following effects can be acquired further.
(7) Since the sprocket 61 has only one tooth portion 24a of the tooth body 24, the weight of the sprocket can be reduced even if the tooth portion 24a has fewer tooth portions than the case of the sprocket 11 to which the two tooth bodies 24 are attached. Can be reduced in weight.

In addition, you may change the said embodiment as follows.
-As shown in FIG.8 and FIG.9, the buffer member may be the buffer members 71 and 81 whose surface of the contact part 36 of the load receiving part 35 is not a uniform plane. That is, the buffer member 71 is formed in the flat portion 72 in which an intermediate region in the rotation direction of the rotation member 21 when attached to the rotation member 21 is perpendicular to the radial direction of the rotation member 21. And the area | region which continues to the edge from the plane part 72 to the both sides of a rotation direction makes | forms the taper surface shape which makes an edge side a downward slope, The surface 73, 74 which becomes non-perpendicular with respect to the radial direction of the rotating member 21 Is formed. 9 is formed on a surface 82 in which the entire surface of the contact portion 36 is curved in the rotational direction of the rotating member 21 and is non-perpendicular to the radial direction of the rotating member 21. Yes.

  In such buffer members 71 and 81, the end edge in the rotation direction of the rotating member 21 can be made non-edge-shaped on the surface of the contact portion 36, so that the link plate (inner plate 13 and outer plate 14) of the chain 12 It is possible to reduce the possibility that the contact portion 36 is damaged by sliding.

  In each of the above embodiments, the material of the elastic portion 37 is not limited to aluminum but may be selected from various materials such as rubber and vibration-damping steel plate as long as the Young's modulus is smaller than that of the contact portion 36. It can be selected according to the usage environment.

  In each of the above embodiments, the material of the mounting portion 34 in the buffer member 31 may be a metal material other than iron, such as stainless steel, as long as the material is rigid, and further, a rigid ceramic material, etc. It may be a material.

  In each of the above embodiments, if the load receiving portion 35 of the buffer member 31 has elasticity, the load receiving portion 35 is replaced with an elastic portion 37 formed in a plate shape with a metal material having a small Young's modulus. A member (for example, a spring member) may be interposed between the contact portion 36 and the attachment portion 34.

  -In each above-mentioned embodiment, buffer member 31 should just be attached to at least one side of the tooth width direction of tooth part 24a in rotation member 21, and is not necessarily attached to both sides of the tooth width direction of tooth part 24a. May be.

  DESCRIPTION OF SYMBOLS 11, 51, 61 ... Sprocket, 12 ... Chain, 13 ... Inner plate (an example of link plate), 14 ... Outer plate (an example of link plate), 21 ... Rotating member, 24a ... Tooth part, 28 ... Outer peripheral part, 31 , 71, 81 ... buffer member, 34 ... mounting portion, 35 ... load receiving portion, 36 ... contact portion, 37 ... elastic portion, 73, 74, 82 ... surface, L ... circumferential pitch, P ... axis, Q ... Pitch circle.

Claims (5)

A rotating member in which a plurality of teeth that can mesh with the chain are provided on the outer periphery at equal intervals in the circumferential direction;
An interval corresponding to the circumferential pitch of the tooth portion is provided in the circumferential direction along the pitch circle of the tooth portion so as to be in contact with the link plate of the chain on at least one side of the tooth portion in the tooth width direction of the rotating member. And a plurality of shock-absorbing members attached thereto. The plurality of buffer members are attached to a circumferential direction along a pitch circle of the tooth portion at a distance equal to or twice the circumferential pitch of the tooth portion. 1. A sprocket for driving a chain according to 1. The buffer member includes a mounting portion for the rotating member and a load receiving portion that receives a load from the chain via the link plate, and the mounting portion has rigidity, while the load receiving portion has elasticity. The sprocket for driving a chain according to claim 1 or 2, wherein the sprocket is a chain drive. The load receiving portion includes a contact portion that is a contact portion with the link plate, and an elastic portion that is interposed between the contact portion and the mounting portion, and the material of the elastic portion is the contact portion. The sprocket for driving a chain according to claim 3, wherein Young's modulus is smaller than that of the material. A surface that is non-perpendicular to the radial direction of the rotating member in the rotating direction of the rotating member is formed on the surface of the contacting portion so as to be continuous with the edge of the rotating portion in the rotating direction. The sprocket for driving a chain according to claim 4.