JP2011094699A - Power transmission device, and inter-shaft beam and sprocket for use in the power transmission device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power transmission device and an inter-shaft beam and sprocket for use in the power transmission device, which suppress tooth skipping by preventing deformation and maintaining a shaft distance while reducing increases in the weight and manufacturing costs of rotary shafts and shaft holding members such as a case through structural simplification. <P>SOLUTION: The power transmission device 100 having at least two sprockets 120 on which a chain is entrained to transmit rotation includes the inter-shaft beams 110 for maintaining the shaft distance between the two sprockets 120. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a transmission device having at least two sprockets on which a chain is wound and rotation is transmitted, and an inter-axis beam and a sprocket used in the transmission device.

2. Description of the Related Art Conventionally, a transmission device is known in which a chain is wound around at least two sprockets having teeth engaged with a chain on the outer periphery and rotationally coupled to a rotating shaft to transmit a rotational driving force.
In a known transmission device, a plurality of rotating shafts having parallel axes are supported by a shaft holding member such as a case, and a chain is wound around a sprocket that is rotationally coupled to the plurality of rotating shafts. It is comprised so that rotational driving force may be transmitted between shafts (refer patent document 1 etc.).

Japanese Patent Laid-Open No. 2002-250406 (first page, FIG. 1)

  In these known transmission devices, when the rotational driving force increases or the load on the driven side increases, the tension of the chain increases, and the shaft holding member such as the rotating shaft and the case is deformed to reduce the distance between the shafts. There is a problem in that the tooth engagement between the chain and the sprocket becomes shallow, and the tooth jump tends to occur.

  In order to prevent deformation of the shaft holding member such as the rotating shaft and the case, it is necessary to increase the rigidity of the shaft holding member such as the rotating shaft and the case, and the weight of the shaft holding member such as the rotating shaft and the case is increased. There has been a problem that it has to be increased or expensive materials have to be used.

  The present invention solves the problems of the prior art as described above. That is, the object of the present invention is to increase the weight and manufacturing cost of a shaft holding member such as a rotating shaft and a case with a simple configuration. Another object of the present invention is to provide a transmission device that reduces, maintains deformation between shafts, and suppresses tooth skipping, an inter-axis beam and a sprocket used in the transmission device.

  The invention according to claim 1 is a transmission device having at least two sprockets in which a chain is wound and rotation is transmitted, and an inter-axis beam that maintains an inter-axis distance is provided between the two sprockets. Therefore, the above-described problem is solved.

  In the invention according to claim 2, in addition to the structure of the transmission device according to claim 1, the abutment portion having a cylindrical outer peripheral surface on the side of the sprocket and the outer peripheral surface of the corresponding contact portion are larger. An engagement boss comprising a flange portion having a diameter is provided, and the inter-axis beam is engaged with two engagement arm portions respectively engaged with the engagement boss, and a connection portion connecting the two engagement arm portions. The above-mentioned problem is further solved.

  According to a third aspect of the present invention, in addition to the structure of the transmission device according to the second aspect, the engagement arm portion of the inter-axis beam is a circle that contacts the outer peripheral surface of the contact portion of the engagement boss. It has an arcuate contact arc surface, and the radius of the contact arc surface is larger than the radius of the outer peripheral surface of the contact portion and smaller than the radius of the flange portion, thereby further solving the problem.

  According to the fourth aspect of the present invention, in addition to the configuration of the transmission device according to the third aspect, the shortest interval between the contact arc surfaces of the two engagement arm portions is the contact of each engagement boss. The problem is further solved by being smaller than the shortest interval of the outer peripheral surface of the portion when no load is applied.

  According to the fifth aspect of the present invention, in addition to the structure of the transmission device according to any one of the second to fourth aspects, the engagement boss is provided on both sides of the sprocket. The problem is further solved.

  According to a sixth aspect of the present invention, in addition to the structure of the transmission device according to any one of the second to fifth aspects, the engagement boss is formed integrally with the sprocket, thereby further solving the problem. To do.

  In the invention according to claim 7, in addition to the structure of the transmission device according to any one of claims 2 to 5, the engagement boss is formed on a rotary shaft that is rotationally connected to the sprocket. The problem is further solved.

  According to an eighth aspect of the present invention, in addition to the structure of the transmission device according to any one of the second to seventh aspects, the contact portion of the engagement boss is rolled by a rotary bearing with respect to the sprocket or the rotation shaft. By being comprised so that the said subject may be solved further.

  In the invention according to claim 9, in addition to the configuration of the transmission device according to any one of claims 2 to 8, the connecting portion of the inter-axis beam has a hollow hole in the center, The problem is further solved.

  The invention according to Claim 10 is an inter-axis beam used in the transmission device according to any one of Claims 1 to 9, wherein the two engagement arm portions engage with the engagement boss of the sprocket. And the connecting portion that connects the two engaging arm portions solves the above-described problem.

  The invention according to claim 11 is a sprocket used in the transmission device according to any one of claims 1 to 6, 8 and 9, and is cylindrical on one or both sides. The above-mentioned problem is solved by providing an engagement boss including a contact portion having an outer peripheral surface and a flange portion having a diameter larger than the outer peripheral surface of the corresponding contact portion.

  The transmission device according to the first aspect of the present invention is the transmission device having at least two sprockets in which the chain is wound and the rotation is transmitted, and an inter-axis beam that maintains an inter-axis distance is provided between the two sprockets. With this, even if the rotational driving force increases or the load on the driven side increases and the chain tension increases, the shaft holding member such as the rotating shaft or case can be secured simply by securing the rigidity of the beam between the axes. To reduce the distance between shafts due to deformation of the shaft, it is not necessary to increase the rigidity of the shaft holding member such as the rotating shaft and the case, and the weight and manufacturing cost of the shaft holding member such as the rotating shaft and the case are increased. Can be reduced to suppress tooth skipping.

  In addition to the effect of the transmission device according to claim 1, the transmission device according to the second aspect of the present invention includes a contact portion having a cylindrical outer peripheral surface on the side of the sprocket and an outer peripheral surface of the corresponding contact portion. An engagement boss composed of a large-diameter flange portion is provided, and an inter-axis beam is engaged with each of the engagement bosses, and two connection arm portions for connecting the two engagement arm portions. It is possible to hang and hold only the inter-axis beam on the side engagement bosses of the two sprockets. An increase in cost can be reduced.

  The transmission device according to the third aspect of the invention has an arc shape in which the engaging arm portion of the inter-axis beam comes into contact with the outer peripheral surface of the contact portion of the engaging boss in addition to the effect exhibited by the transmission device according to the second aspect. When the radius of the contact arc surface is larger than the radius of the outer peripheral surface of the contact portion and smaller than the radius of the flange portion, the engagement arm portion of the inter-axis beam is dropped by the flange portion. This is prevented and is securely held, and the contact arc surface of the engagement arm portion of the inter-axis beam and the outer peripheral surface of the contact portion of the engagement boss are not in an interference fit state, Therefore, it becomes possible to slide smoothly, and an increase in rotational resistance due to the beam between the axes can be suppressed.

  In the transmission device according to the fourth aspect of the invention, in addition to the effect produced by the transmission device according to the third aspect, the shortest distance between the contact arc surfaces of the two engagement arm portions is determined by the contact between the engagement bosses. Since the outer peripheral surface of the contact portion is smaller than the shortest interval when there is no load, the contact arc surface of the two engagement arm portions becomes the outer peripheral surface of the contact portion of any engagement boss at low load. Since it is not pressed evenly, the contact arc surface of the engagement arm portion of the interaxial beam and the outer peripheral surface of the engagement portion of the engagement boss are in contact with each other only by the weight of the interaxial beam. Can be further suppressed.

In addition to the effect of the transmission device according to any one of claims 2 to 4, the transmission device of the invention according to claim 5 is provided with engagement bosses on both sides of the sprocket,
Interaxial beams are provided on both sides of the sprocket to further improve the rigidity and prevent the sprocket from tilting with respect to the chain travel direction due to bending of the rotation axis, thereby further suppressing tooth skipping. .

  The transmission device according to the sixth aspect of the present invention is simple because the engagement boss is formed integrally with the sprocket in addition to the effect exhibited by the transmission device according to any one of the second to fifth aspects. It is possible to reduce the increase in weight and manufacturing cost of the entire transmission device.

  In addition to the effect of the transmission device according to any one of claims 2 to 5, the transmission device of the invention according to claim 7 is formed on the rotating shaft to which the engagement boss is rotationally connected to the sprocket. As a result, it is not necessary to change the sprocket simply by adding an engagement boss to the rotary shaft of the conventional transmission device, so that an increase in manufacturing cost can be reduced.

  According to the eighth aspect of the invention, in addition to the effect of the transmission device according to any one of the second to seventh aspects, the contact portion of the engaging boss is a rotary bearing with respect to the sprocket or the rotating shaft. Therefore, even if the contact arc surface of the engagement arm portion of the interaxial beam and the outer peripheral surface of the contact portion of the engagement boss strongly contact each other, sliding resistance is generated. Therefore, an increase in rotational resistance due to the interaxial beam can be suppressed.

  In the transmission device according to the ninth aspect of the invention, in addition to the effect exhibited by the transmission device according to any one of the second to eighth aspects, the connecting portion of the interaxial beam has a hollow hole in the center. Thus, even if another structure or the like exists between the two sprockets, the structure can be avoided while ensuring the rigidity of the beam between the axes.

  The interaxial beam according to the tenth aspect of the present invention is an interaxial beam used in the transmission device according to any one of the first to ninth aspects, wherein the two interaxial beams are engaged with the engagement bosses of the sprocket. By having an engagement arm part and a connecting part that connects the two engagement arm parts, it becomes possible to hang over and hold the engagement bosses on the sides of the two sprockets, Even if the rotational drive force in the transmission increases or the load on the driven side increases and the chain tension increases, the shaft holding member such as the rotating shaft and case is prevented from being deformed to reduce the distance between the shafts. Therefore, it is not necessary to increase the rigidity of the shaft holding member such as the rotating shaft and the case, and the increase in the weight and manufacturing cost of the transmission device can be reduced with a simple configuration, and tooth skipping can be suppressed.

  The inter-axis beam according to the eleventh aspect of the invention is a sprocket used in the transmission device according to any one of the first to sixth aspects, the eighth aspect, and the ninth aspect, and is either one or both sides. Is provided with an engagement boss comprising a contact portion having a cylindrical outer peripheral surface and a flange portion having a diameter larger than the outer peripheral surface of the corresponding contact portion. Even if the rotational driving force increases in the transmission, or the load on the driven side increases and the chain tension increases, the shaft holding member such as the rotating shaft or case deforms and In order to prevent the distance from becoming smaller, it is not necessary to increase the rigidity of the shaft holding member such as the rotating shaft or the case, and it is possible to reduce the increase in the weight and manufacturing cost of the transmission device with a simple configuration, thereby suppressing tooth skipping. be able to.

The partial perspective view of the use condition of the transmission which is one Example of this invention. 1 is a perspective view of an interaxial beam that is an embodiment of the present invention. FIG. The front view of the sprocket which is one Example of this invention. The side view of the sprocket which is one Example of this invention. Explanatory drawing of the contact state of the inter-axis beam and engagement boss | hub of the transmission which is one Example of this invention. The perspective view of the interaxial beam which is the other Example of this invention.

  The present invention provides a transmission device having at least two sprockets on which a chain is wound and rotation is transmitted, and includes an inter-axis beam that maintains an inter-axis distance between the two sprockets. As long as the rigidity of the shaft holding member does not need to be increased and the increase in the weight of the shaft holding member such as the rotating shaft or the case or the increase in manufacturing cost is suppressed to suppress tooth skipping, any specific embodiment is possible. It doesn't matter what it is.

  That is, the material of the inter-axis beam of the present invention may be a metal such as iron as long as it has rigidity capable of maintaining the inter-axis distance in cooperation with a shaft holding member such as a rotating shaft or a case. Any material such as resin or ceramic may be used.

Further, the engaging boss of the transmission of the present invention may be formed integrally with the sprocket, may be formed separately from the sprocket, and may be fitted to a rotating shaft to which the sprocket is fitted. May be formed on the rotating shaft itself.
Furthermore, the chain of the transmission device of the present invention may be any chain such as a roller chain or a silent chain, and may be a toothed belt instead of the chain.

Hereinafter, a transmission device, an interaxial beam, and a sprocket that are embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, a transmission 100 according to an embodiment of the present invention has a chain (not shown) wound around two sprockets 120 having parallel rotational axes having a predetermined inter-axis distance. Rotation is transmitted, and even if the chain tension is increased by the inter-axis beam 110 engaged with the engagement bosses 130 provided on both sides of each sprocket 120, the rotation shaft, the case, etc. The shaft holding member is prevented from being deformed to reduce the distance between the shafts, and the tooth skip is suppressed.

  As shown in FIG. 2, the inter-axis beam 110 includes an engaging arm portion 111 having an arcuate abutting arc surface 113 at both ends of a linear connecting portion 112, and the abutting arcuate surfaces 113 are arranged outside each other. It is arranged so as to face and is integrally formed.

  As shown in FIGS. 3 and 4, the sprocket 120 includes an engaging boss 130 including a contact portion 131 having a cylindrical outer peripheral surface on both side surfaces and a flange portion 132 having a larger diameter than the outer peripheral surface of the corresponding contact portion 131. Are integrally formed.

  As shown in FIG. 1, the interaxial beam 110 is configured such that the arc-shaped contact arc surfaces 113 of the engagement arm portions 111 at both ends engage with the contact portions 131 of the engagement boss 130, and the side surface of the sprocket 120 and the flange The parts 132 are prevented from falling off and are supported independently.

  The radius of the contact arc surface 113 of the engagement arm portion 111 of the interaxial beam 110 is formed to be larger than the radius of the outer peripheral surface of the contact portion 131 of the engagement boss 130. The shortest interval between the contact arc surfaces 113 of the combined arm portions 111 is formed to be smaller than the shortest interval when the outer peripheral surface of the contact portion 131 of each engagement boss 130 is unloaded.

  As a result, as shown in FIG. 5, when the load is low, the contact arc surface 113 of the engagement arm portion 111 of the interaxial beam 110 and the outer peripheral surface of the contact portion 131 of the engagement boss 130 are the upper part. Since the contact pressure at point A is generated only by the dead weight of the inter-axis beam 110, the contact arc surface 113 and the outer periphery of the contact portion 131 are contacted only at point A and not at points B and C. The sliding resistance with the surface is extremely small, and an increase in rotational resistance at a low load is suppressed.

  In addition, when the load is high, the distance between the axes of the two sprockets is reduced by a small gap at the point B due to deformation of the shaft holding member such as the rotating shaft and the case. Further reduction in the inter-axis distance is suppressed by the rigidity of the beam 110.

As shown in FIG. 6, an inter-axis beam 210 of a transmission device according to another embodiment of the present invention has a connecting portion 212 formed wide and a lightening hole 214 formed in the middle.
As a result, even if another structure or the like exists between the two sprockets on the structure of the mechanical device to which the transmission device is applied, the structure can be avoided while ensuring the rigidity of the inter-axis beam 210. it can.

  As described above, according to the present invention, even if the rotational driving force is increased or the load on the driven side is increased and the chain tension is increased, the rotation shaft or Since the shaft holding member such as the case can be prevented from being deformed to reduce the distance between the shafts, it is not necessary to increase the rigidity of the shaft holding member such as the rotating shaft or the case. The effect is enormous, such as reducing the weight of the holding member and the increase in manufacturing cost and suppressing tooth skipping.

  In the above embodiment, the engaging bosses 130 are integrally formed on both sides of the sprocket 120, and the inter-axis beam 110 is arranged on both sides so that the rotation axis is bent and the sprocket 120 is inclined with respect to the chain traveling direction. However, when the rotation shaft is slightly deformed, the structure may be further simplified by arranging the engaging boss 130 only on one side and using one inter-axis beam 110.

  Further, the engaging boss 130 may be formed separately from the sprocket 120 and may be fitted to the rotating shaft to which the sprocket 120 is fitted, and the engaging boss 130 may be attached to the rotating shaft itself to which the sprocket 120 is fitted. In this case, since conventional sprockets can be used as they are, special materials and surface treatments are required to cope with tooth wear and the like, which increases the manufacturing cost of sprockets, which are relatively expensive parts. Without increasing the manufacturing cost of the entire transmission device.

  Further, the outer peripheral surface of the contact portion 131 of the engagement boss 130 may be configured to be able to rotate independently of the sprocket 120 or the rotation shaft by interposing a rotation bearing such as a ball bearing or a roller bearing in the middle. In this case, even if the contact arc surface 113 and the outer peripheral surface of the contact portion 131 come into contact with each other, it does not slide, and only the resistance of the rotary bearing is smaller than the sliding resistance. Increase can be suppressed.

  In addition, when the number of sprockets around which the chain is wound in the entire transmission device is two or more, depending on the strength of the shaft holding member such as the rotating shaft and the case and the direction in which the load is applied, any two of the inter-axis beams are used. It may be provided between the sprockets, or an inter-axis beam may be provided at a plurality of positions for a plurality of sprocket sets.

DESCRIPTION OF SYMBOLS 100 ... Transmission apparatus 110, 210 ... Interaxial beam 111 ... Engagement arm part 112, 212 ... Connection part 113 ... Contacting arc surface 214 ... Meat removal hole 120 ... Sprocket 130 ... engaging boss 131 ... contact part 132 ... flange part

Claims (11)

In a transmission having at least two sprockets on which a chain is wound and rotation is transmitted,
A transmission device comprising an inter-axis beam that maintains an inter-axis distance between the two sprockets. On the side of the sprocket, there is provided an engagement boss comprising a contact portion having a cylindrical outer peripheral surface and a flange portion having a diameter larger than the outer peripheral surface of the corresponding contact portion,
2. The inter-axis beam includes two engaging arm portions that respectively engage with engaging bosses, and a connecting portion that connects the two engaging arm portions. The transmission device described in 1. The engagement arm portion of the inter-axis beam has an arcuate contact arc surface that contacts the outer peripheral surface of the contact portion of the engagement boss,
The transmission device according to claim 2, wherein the radius of the contact arc surface is larger than the radius of the outer peripheral surface of the contact portion and smaller than the radius of the flange portion.   The shortest interval between the contact arc surfaces of the two engagement arm portions is smaller than the shortest interval when no load is applied to the outer peripheral surface of the contact portion of each engagement boss. Transmission device.   The transmission device according to any one of claims 2 to 4, wherein the engagement bosses are provided on both sides of the sprocket.   The transmission device according to any one of claims 2 to 5, wherein the engagement boss is formed integrally with the sprocket.   The transmission device according to any one of claims 2 to 5, wherein the engagement boss is formed on a rotation shaft to which the sprocket is rotationally coupled.   The transmission device according to any one of claims 2 to 7, wherein the contact portion of the engagement boss is configured to roll with a rotary bearing with respect to a sprocket or a rotary shaft.   The transmission device according to any one of claims 2 to 8, wherein the connecting portion of the inter-axial beam has a lightening hole in the center. An inter-axis beam used in the transmission device according to any one of claims 1 to 9,
An inter-axis beam comprising two engagement arm portions that engage with an engagement boss of a sprocket and a connecting portion that connects the two engagement arm portions.   A sprocket used in the transmission device according to any one of claims 1 to 6, claim 8, and claim 9, corresponding to a contact portion having a cylindrical outer peripheral surface on one or both sides A sprocket comprising an engaging boss comprising a flange portion having a diameter larger than the outer peripheral surface of the contact portion.

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