JP5275477B2 - Power transmission device - Google Patents

Description

  The present invention relates to a power transmission device, and more particularly to a power transmission device configured to transmit power between pulleys by a ball chain.

  A power transmission device that transmits power by winding an endless chain or the like between pulleys is generally used in, for example, a conveyor for transporting articles. In such a conveyor, a large number of roller bodies are arranged so that their axes are parallel to each other, and an article conveyance path extending in a direction orthogonal to the axes is formed on the roller body group. Further, each roller body is provided with two or more pulleys, and a chain is wound around pulleys of two roller bodies adjacent to each other in the article conveyance path direction and driven by a motor. By transmitting the rotational power of the roller body to the other roller body via the chain, the article moves on the article conveyance path. As the chain and the pulley, a roller chain or a bushless chain and a sprocket wheel, which can transmit relatively large power and are frequently used in bicycles, are used.

  However, in the combination of a roller chain or bushless chain and a sprocket wheel, there is a risk of injury due to fingers or clothes being caught between them, so measures such as attaching a safety device are taken, but the cost is correspondingly In addition, there is a case where an accident occurs during maintenance when the safety device is removed. Furthermore, there is a problem that maintenance is very troublesome.

  On the other hand, a ball chain formed by connecting a large number of ball members with link members is known. For example, Japanese Utility Model Laid-Open No. 63-34291 discloses a technique of using a ball chain for a blind opening / closing mechanism. . In order to transmit a large amount of power to such a ball chain, not only the ball member but also the link member are made of metal, and the power for driving the roller body group constituting the article transport path instead of the above-described roller chain or the like. It has been found that the use of the transmission device reduces the above-mentioned dangers and costs and facilitates maintenance, but has poor durability.

Japanese Utility Model Publication No. 63-34291

  Accordingly, it is an object of the present invention to provide a power transmission device using a metal ball chain with good durability.

  In order to solve the above problems, according to the present invention, the first pulley, the second pulley, and the first pulley and the second pulley for transmitting the rotational power of the first pulley to the second pulley. A ball chain wound around a pulley, and the ball chain includes a plurality of metal ball-shaped ball members and a metal link member that connects two adjacent ball members, The ball member has two connection holes for connecting to the link member on both sides in one diameter direction, and the link member is a linear bar-like link bar that can be inserted into and removed from the ball member through the connection hole, and the link A ball engaging portion that is provided at both ends of the bar and inside the ball member, and has a retaining end dimension that cannot pass through the connecting hole, and the first and second pulleys engage with the ball member. A plurality of grooves in the outer circumferential direction, the first and Power transmission device is set smaller than the pitch between two ball members adjacent the pitch between the two balls engaging grooves adjacent to each other in the circumferential direction of the second pulley in the ball chain is provided.

  In the present invention, the pitch between ball members refers to the distance between the centers of two adjacent ball members, and the pitch between ball engagement grooves refers to the distance between the centers of two adjacent ball engagement grooves. Say.

  In general, in a combination of a chain and a pulley, a large number of meshing portions that are continuously provided along the longitudinal direction of the chain and a meshed portion that is continuously provided on the outer periphery of the pulley and meshes with the meshing portion of the chain are mutually Therefore, the pitch between adjacent meshing portions is set to be equal to the pitch between adjacent meshing portions. However, it has been found that in the ball chain and the pulley, if the pitch between the ball members of the ball chain is equal to the pitch between the ball engaging grooves of the pulley, the following problem occurs. That is, when the ball member is bent from a straight shape into a curved shape by engaging a plurality of ball engaging grooves arranged along the outer periphery of the pulley, the two balls in which both ends of one link member are connected The distance between the connecting portion (connecting hole) with the link member in one of the ball members and the connecting portion (connecting hole) with the link member in the other ball member is slightly increased, and the link The members are pulled from both ball members, and thereby, the pulling force and the bending force are repeatedly applied to the link member, and the durability is impaired by causing metal fatigue.

  In the present invention, the pitch between the two ball engaging grooves adjacent to each other in the circumferential direction of the first and second pulleys is set smaller than the pitch between the two adjacent ball members in the ball chain. When the ball member engages with a plurality of ball engaging grooves arranged along the outer periphery of the pulley to form a curved shape, the link bar of one link member has two balls connected to the link member. By entering the inside of the member from the connecting hole, it is possible to deal with a pitch between the ball engaging grooves smaller than the pitch of the ball member, thereby preventing a tensile force and a bending force from acting on the link member. Since the pitch between the ball engaging grooves is smaller than the pitch between the ball members, the tolerance of variation in the pitch between the ball members is increased as compared to the case where both are made the same, and the tolerance of variation in the outer diameter of the ball member is also increased. And the ball chain can be manufactured easily.

  The degree to which the pitch between the ball engaging grooves is made smaller than the pitch between the ball members can be 1 to 20%, preferably only 1 to 5%, etc. Each of the two link members connected to one ball member is determined so that the retaining end portions in the ball member do not contact each other in the ball member. The pitch between the ball members, the pitch between the ball engagement grooves, and the extent to which the latter is made smaller than the former change depending on the diameter of the pulley and the number of the ball engagement grooves. There is a tendency that the degree of decreasing is increased, and even when the number of ball engaging grooves increases, the degree of decreasing the pitch between the ball engaging grooves tends to increase.

  In one embodiment of the present invention, one ball member in the ball chain transmitting the rotational power of the first pulley to the second pulley is one ball engagement of the first pulley or the second pulley. When the first ball member is first fully received in the groove, the one ball member is rotated forward with a front ball member engaged with a ball engaging groove adjacent to the one ball engaging groove forward in the rotation direction. The link member adjacent to the rear ball member at the rear in the direction and connecting between the one ball member and the front ball member has a link bar extending from the connection hole to the one ball member and / or the front ball. The stopper end is pulled away from the inner peripheral surface of the one ball member and / or the front ball member and pulled toward the center side of the one ball member and / or the front ball member. baud Link members for connecting the member and the rear of the ball member, the retaining end is in contact with the inner peripheral surface of one of the ball member and the rear of the ball member. Thereby, the ball member after being received in the ball engaging groove in the first and second pulleys is reduced without the link member being pulled between the ball members in the adjacent ball engaging grooves. It can correspond to the groove pitch.

  In the present invention, the pitch between the ball engaging grooves in the first and second pulleys around which the metal ball chain is wound is made smaller than the pitch between the ball members in the ball chain, so that The two ball members that engage with one ball engaging groove may correspond to the narrow pitch between the engaging grooves, because the link bar of the link member that connects between them enters the ball member through the connecting hole. The link member is not pulled from both ball members. Therefore, the durability of the power transmission device using the ball chain and the first and second pulleys can be improved, and it is safer and more cost-effective than the conventional power transmission device using a roller chain, a sprocket wheel or the like. Thus, a power transmission device that can be easily maintained can be realized.

FIG. 1 is a perspective view schematically showing a conveyor partially incorporating a power transmission device according to an embodiment of the present invention. FIG. 2 is an explanatory cross-sectional view schematically showing an engagement state between the ball chain and the pulley. FIG. 3 is an enlarged explanatory view of a part of FIG.

  Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view schematically showing a part of a conveyor 1 incorporating a power transmission device 10 according to an embodiment of the present invention. The conveyor 1 has a large number of cylindrical roller bodies 2a, 2b, 2c arranged so that their respective axes are parallel to each other (only three roller bodies in FIG. 1 are spaced apart from each other for convenience). Left and right side plates 4 that support both ends of the rotating shafts 3a, 3b, and 3c of the roller bodies 2a, 2b, and 2c via bearings (not shown) (only one side plate in FIG. 1). And a power transmission device 10 for transmitting the rotational power of the roller body 2a that is rotationally driven by a motor (not shown) to the roller bodies 2b and 2c. The roller bodies 2a, 2b, and 2c form an article conveyance path extending in a direction perpendicular to the axis on these roller body groups, and the articles (see FIG. (Not shown) moves in the direction of arrow B on the article conveyance path.

  The power transmission device 10 includes a first pulley 11a (driving side pulley) provided at one axial end of the roller body 2a and a second pulley (driven pulley) provided at one axial end of the roller body 2b. ) 11b and an annular first ball chain 20a wound around the first pulley 11a and the second pulley 11b as basic units. The power transmission device 10 has the same basic unit between the roller bodies 2b and 2c as the roller bodies 2a and 2b. That is, the roller body 2b has a third pulley (adjacent to the second pulley 11b). (Driving side pulley) 11c, the roller body 2c is provided with a fourth pulley (driven pulley) 11d, and the second ball chain 20b is wound around the third and fourth pulleys 11c, 11d. The roller body 2a is provided with a fifth pulley 11e, and the fifth pulley 11e is also a roller between the roller body 2a and a pulley of another roller body (not shown) adjacent downstream in the B direction. A chain is stretched over, and two pulleys and a roller chain are also added between the roller body 2c and another roller body (not shown) adjacent upstream in the B direction. In the conveyor 1, the rotation of the roller body 2a by a motor (not shown) is transmitted from the first pulley 11a to the second pulley 11b via the first ball chain 20a, and the roller body 2b rotates. The rotation of the body 2b is transmitted from the third pulley 11c to the fourth pulley 11d via the second ball chain 20b, and the roller body 2c rotates. Hereinafter, the first, second, third, and fourth pulleys 11a, 11b, 11c, and 11d are collectively referred to as the pulley 11, and the first and second ball chains 20a and 20b are collectively referred to as the ball chain 20.

  Referring to FIGS. 2 and 3, the ball chain 20 includes a number of metal hollow sphere-shaped ball members 21 and a metal link member 23 that connects two adjacent ball members 21. The ball member 21 has two connection holes 22 for connecting to the link member 23 on both sides in one diameter direction. The link member 23 includes a straight bar-shaped link bar 24 and retaining end portions 25 provided at both ends of the link bar. The diameter of the link bar 24 is smaller than the diameter of the connecting hole 22 of the ball member 21, so that the link bar 24 can enter and leave the connecting hole 22. The retaining end portion 25 is provided inside the ball member 21, and the diameter of the retaining end portion 25 is larger than the diameter of the connecting hole 22, so that the retaining end portion 25 cannot pass through the connecting hole 22.

  The pulley 11 has a number of ball engaging grooves 12 that receive the ball members 21 of the ball chain 20 at a predetermined pitch (hereinafter referred to as “groove pitch”) in the outer circumferential direction. The groove pitch is set slightly smaller than the pitch between two adjacent ball members 21 in the ball chain 20 (hereinafter referred to as “ball pitch”), for example, by about 2% or 3%. The ball engaging groove 12 includes an open end 13 having a diameter larger than the diameter of the ball member 21 and a groove bottom 14 that matches the bottom of the ball member 21, and the ball member 21 is completely received in the ball engaging groove 12. In this state, gaps 15 are formed on both sides of the ball member 21 in the ball engaging groove 12, and the top of the ball member 21 protrudes from the open end 13 to the outside of the groove. The adjacent ball engaging grooves 12 are connected by a link groove having a size larger than the diameter of the link bar 24 of the link member 23 and smaller than the ball engaging groove 12. With the ball members 21 engaged, the link bar 24 between the ball members 21 enters the link groove. The ball pitch of the ball chain 20 is defined as the dimension between the centers of the two adjacent ball members 21, and the retaining end portions 25 on both sides of the link member 23 between the two adjacent ball members 21 are respectively It can be defined as the sum of the dimension between the inner peripheral surfaces of the ball members 21 and twice the radius of the inner diameter of the ball member 21 in contact with the inner peripheral surfaces of the ball members 21, and the groove pitch is larger than this sum. Set small.

  In the power transmission device 10 configured as described above, the ball member 21 of the ball chain 20 is successively engaged with the ball engagement groove 12 of the pulley 11 rotating in the direction A during the operation of the conveyor 1. As the chain 20 turns, the rotation of the pulley 11 is transmitted to the adjacent pulley, that is, the roller body via the ball chain 20. At this time, the ball member 21 of the ball chain 20 is first completely in a ball engagement groove (hereinafter referred to as “vertex ball engagement groove”) 12t located at the top of the pulley 11 (position at 12 o'clock in FIG. 2). And then forward in the A direction (rotational direction). In the pulley (the pulley 11b in FIG. 1) adjacent to the pulley 11 (the pulley 11a in FIG. 1) via the ball chain 20, the ball engaging groove that completely receives the ball member 21 first is not the apex but the top. The lower point (6 o'clock position). 2 and 3, the two ball members 21 engaged with the two ball engaging grooves 12 adjacent to each other in the circumferential direction have a groove pitch smaller than the ball pitch. The link bar 24 of the link member 23 that connects the two members enters the inside of at least one of the ball members 21 on both sides from the connecting hole 22, and at least one of the retaining end portions 25 on both sides is separated from the inner peripheral surface of the ball member 21. 21 is drawn to the center side. Thereby, the link member 23 can respond to the reduced groove pitch without being pulled by the ball members 21 on both sides. The transmission of power from the pulley 11 to the ball chain 20 is substantially transmitted through the apex ball engaging groove 12t and the ball member (hereinafter referred to as “vertex ball member”) 21t engaged with the apex ball engaging groove 12t. To be done. The link member 23 that connects the apex ball member 21t and the ball member (hereinafter referred to as “front ball member”) 21t + 1 that engages with the apex ball engaging groove 12t and the ball engaging groove 12t + 1 adjacent to the apex ball engaging groove 12t in the front in the A direction, The link bar 24 enters the apex ball member 21t and / or the front ball member 21t + 1 from the connecting hole 22, and at least one of the retaining end portions 25 on both sides is separated from the inner peripheral surface of the apex ball member 21t and / or the front ball member 21t + 1. The top ball member 21t and / or the front ball member 21t + 1 is drawn into the center side. Further, a ball member (not completely received at this time) that is to be engaged with the apex ball member 21t and the ball engagement groove 12t-1 adjacent to the apex ball engaging groove 12t at the rear in the A direction (from now on). The link members 23 that connect 21t-1 (hereinafter referred to as “rear ball members”) have the retaining end portions 25 on both sides in contact with the inner peripheral surfaces of the apex ball member 21t and the rear ball member 21t-1.

DESCRIPTION OF SYMBOLS 1 Conveyor 2a, 2b, 2c Roller body 10 Power transmission device 11 Pulley 11a 1st pulley 11b 2nd pulley 12 Ball engagement groove 12t Vertex ball engagement groove 20 Ball chain 20a First ball chain 20b Second ball Chain 21 Ball member 21t Vertex ball member 21t + 1 Front ball member 21t-1 Back ball member 22 Connection hole 23 Link member 24 Link bar 25 Stop end

Claims (2)

The first pulley (11a), the second pulley (11b), and the first pulley (11a) and the second pulley (11a) for transmitting the rotational power of the first pulley (11a) to the second pulley (11b). A ball chain (20) wound around two pulleys (11b),
The ball chain (20) has a large number of ball members (21) made of metal and having a hollow sphere shape, and a metal link member (23) for connecting two adjacent ball members (21),
The ball member (21) has two connecting holes (22) for connecting to the link member (23) on both sides in one diameter direction, and the link member (23) passes through the connecting hole (22). A straight bar-like link bar (24) that can be inserted into and removed from the ball member (21), and provided at both ends of the link bar (24) and inside the ball member (21), and cannot pass through the connecting hole (22). A non-removable end (25)
The first and second pulleys (11a, 11b) have a large number of ball engaging grooves (12) that engage with the ball members (21) in the outer circumferential direction, and the first and second pulleys ( 11a, 11b) The power transmission device in which the pitch between the two ball engaging grooves (12) adjacent in the circumferential direction is set smaller than the pitch between the two adjacent ball members (21) in the ball chain (20). . One ball member (21t) in the ball chain (20) transmitting the rotational power of the first pulley (11a) to the second pulley (11b) is the first pulley (11a) or the second pulley. When it is first fully received in one ball engaging groove (12t) of the pulley (11b),
The one ball member (21t) rotates in front of the ball member (21t + 1) engaged with the ball engagement groove (12t + 1) adjacent to the one ball engagement groove (12t) in the forward direction of rotation. Next to the rear ball member (21t-1) in the rear direction,
The link member (23) for connecting the one ball member (21t) and the front ball member (21t + 1) has a link bar (24) extending from the connection hole (22) to the one ball member (21t). And / or the ball member (21t + 1) entering the front ball member (21t + 1), and the stopper end (25) being separated from the inner peripheral surface of the one ball member (21t) and / or the front ball member (21t + 1) (21t) and / or pulled toward the center of the front ball member (21t + 1),
The link member (23) connecting between the one ball member (21t) and the rear ball member (21t-1) has a retaining end portion (25) and the rear ball member (21t). The power transmission device according to claim 1, wherein the power transmission device is in contact with an inner peripheral surface of the ball member (21t-1).

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