JP2006077847A - Power transmission chain and power transmission device equipped with it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power transmission chain of improved transmission efficiency and durability, with reduced noise at chain driving and manufacturing cost. <P>SOLUTION: The chain comprises a plurality of links 2 aligned in a chain advancing direction X, and a plurality of pins 3. The links 2, corresponding to each other, are bendably connected each other using a single pin 3. The pin 3 is idle-fitted in a front through hole 6 of a corresponding one link 2 to allow rolling/sliding contact to a periphery 8 of the front through hole 6, and is press-fitted in a back through hole 7 of a corresponding the other link 2, so that relative movement (relative rotation) of the link 2 is regulated. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a power transmission chain and a power transmission device including the power transmission chain.

An endless power transmission chain used in a power transmission device such as a pulley-type continuously variable transmission (CVT) of an automobile has a plurality of links arranged in the chain traveling direction and links adjacent to each other in the chain traveling direction. Are connected to each other by a pin and an interpiece that can roll and move (see, for example, Patent Document 1).
In the chain of Patent Document 1, one of a pair of pins and interpieces is press-fitted and fixed into a through-hole of a corresponding link, and the other is fitted into the through-hole so as to be relatively movable. Of the pins and interpieces, only the pins contact the pulley and transmit power to and from the pulley.

With the above configuration, when the pin comes into contact with the surface of the pulley, the pin hardly rotates with respect to the surface of the pulley, and it is possible to reduce friction loss and ensure high transmission efficiency.
Japanese Patent Laid-Open No. 8-31725

  In a power transmission chain, there is a need to reduce noise when driving the chain, improve durability, and reduce manufacturing costs. The present invention aims to solve these problems.

  The inventor of the present application first tried to reduce the noise when driving the chain in the power transmission chain. Specifically, by reducing the thickness of the pin and interpiece, the pitch between adjacent pins is made shorter (shorter pitch), and more pins are provided. An attempt was made to increase the number of pins that contact the pulley. This is because the contact sound between the pin and the pulley can be brought close to a high frequency that is difficult for humans to recognize, and noise can be reduced.

However, the pin needs a certain thickness in order to secure a contact area with the pulley, and it is difficult to reduce the thickness. In addition, there is a limit to reducing the thickness of the interpiece while ensuring sufficient strength.
Therefore, the present invention provides a power transmission chain including a plurality of links arranged in the chain traveling direction, and each link includes a first through hole and a second through hole arranged in the chain traveling direction, and there is a link corresponding to each other. A single pin is used to be able to bend each other, and each of the pins is loosely fitted into the first through hole of one link so that it can make rolling and sliding contact with the periphery of the first through hole. And is fitted into the second through hole of the other link, and the relative movement with respect to the other link is restricted.

  According to the present invention, for example, when the pair of end faces of the pin contacts the sheave surface of the pulley to transmit power, the pin hardly rotates with respect to the sheave surface, and the friction loss is reduced and high. Transmission efficiency can be ensured. Further, since only a single pin is fitted in each through hole, the distance between adjacent pins can be shortened (short pitch), and more pins can be provided. This makes it possible to increase the number of pins that contact the pulley per unit time when driving the chain, making the contact sound between the pin and pulley closer to a high frequency that is difficult for humans to recognize, and dramatically reducing noise. can do. In addition, since the number of pins that contact the pulley at a time can be increased, the load per pin can be reduced and the durability can be significantly improved. Moreover, the interpiece provided in the conventional chain can be abolished, the number of parts can be reduced, and the manufacturing cost can be further reduced. Moreover, if the said link contains the communicating groove which connects the 1st and 2nd through-hole mutually, it will become possible to relieve | moderate the stress concentration of the peripheral part of a 1st and 2nd through-hole more. .

  In the present invention, the one link and the pin loosely fitted in the first through-hole of the one link are used as one set, and the periphery of the first through-hole of the one link and the pin are slid. There are cases where two or more sets with different contact point trajectories are provided, and these sets are arranged at random. In this case, for example, the contact sound when the pin contacts the pulley can be made different in each group to disperse the frequency band of the contact sound, and the driving sound of the chain can be further reduced.

In the present invention, the locus of the contact point of the rolling sliding contact between the peripheral edge of the first through hole of the one link and the pin may include an involute curve. In this case, for example, when the pins are sequentially engaged with the sheave surface of the pulley, it is possible to suppress the occurrence of string vibration motion in the power transmission chain. As a result, noise during driving of the chain can be further reduced.
In the present invention, two or more types of links having different pitches may be provided, and these links may be randomly arranged. In this case, for example, the contact sound when the pin comes into contact with the pulley can be prevented from resonating, and the chain drive sound can be extremely reduced.

  The present invention also includes first and second pulleys each having a pair of conical sheave surfaces facing each other, and the power transmission chain wound around these pulleys, and a pair of the pins. The present invention provides a power transmission device characterized in that a power transmission surface provided at each of the end portions engages with a sheave surface to transmit power. According to the present invention, it is possible to realize a power transmission device that is excellent in transmission efficiency, quietness, and durability, and that is inexpensive.

Preferred embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 schematically shows a main configuration of a chain-type continuously variable transmission (hereinafter also simply referred to as a continuously variable transmission) as a power transmission device including a power transmission chain according to an embodiment of the present invention. It is a perspective view. Referring to FIG. 1, a continuously variable transmission 100 is mounted on a vehicle such as an automobile, and includes a drive pulley 60 made of metal (such as structural steel) as a first pulley, and a second pulley. And a driven pulley 70 made of metal (such as structural steel) and an endless power transmission chain 1 (hereinafter also simply referred to as a chain) wound between the pulleys 60 and 70. . In addition, the chain 1 in FIG. 1 has shown a partial cross section for easy understanding.

  FIG. 2 is a partially enlarged sectional view of the drive pulley 60 (driven pulley 70) and the chain 1 of FIG. Referring to FIGS. 1 and 2, drive pulley 60 is attached to an input shaft 61 that is connected to a drive source of a vehicle so as to be able to transmit power, and includes a fixed sheave 62 and a movable sheave 63. The fixed sheave 62 and the movable sheave 63 have a pair of sheave surfaces 62a and 63a that face each other. The sheave surfaces 62a and 63a include conical inclined surfaces. A groove is defined between the sheave surfaces 62a and 63a, and the chain 1 is held with a strong pressure by the groove.

  Further, a hydraulic actuator (not shown) for changing the groove width is connected to the movable sheave 63, and the movable sheave 63 is moved in the axial direction of the input shaft 61 (left-right direction in FIG. 2) at the time of shifting. Thus, the groove width is changed, whereby the chain 1 is moved in the radial direction of the input shaft 61 (vertical direction in FIG. 2), and the winding radius (effective radius) of the chain 1 around the input shaft 61 is set to the minimum value R1. It can be changed between the maximum value R2 (see FIG. 3B) and the maximum value R2 (see FIG. 3A).

  On the other hand, as shown in FIGS. 1 and 2, the driven pulley 70 is attached to an output shaft 71 that is connected to a drive wheel (not shown) so as to be capable of transmitting power and is integrally rotatable. A fixed sheave 72 and a movable sheave 73 having a pair of opposed sheave surfaces 72a and 73a for forming a groove for sandwiching the chain 1 with high pressure are provided. A hydraulic actuator (not shown) is connected to the movable sheave 73 of the driven pulley 70 in the same manner as the movable sheave 63 of the drive pulley 60, and the groove width is changed by moving the movable sheave 73 during shifting. Thus, the chain 1 is moved, and the winding radius (effective radius) of the chain 1 around the output shaft 71 is between the maximum value R2 (see FIG. 3 (A)) and the minimum value R1 (see FIG. 3 (B)). Can be changed.

FIG. 4 is a perspective view schematically showing the configuration of the main part of the chain 1. FIG. 5 is a cross-sectional plan view of the main part of the chain shown in FIG. 6 is a partial cross-sectional view taken along the line II-II in FIG.
4 and 5, the chain 1 includes a plurality of links 2 arranged in the chain traveling direction X and a plurality of pins 3 that connect the corresponding links 2 to each other.

  Referring to FIGS. 5 and 6, each link 2 is formed in a plate shape, and includes a front end portion 4 and a rear end portion 5 as a pair of end portions arranged in front and rear in the chain traveling direction X. The front end portion 4 and the rear end portion 5 are respectively formed with a front through hole 6 as a first through hole and a rear through hole 7 as a second through hole. The peripheral edges 8 and 9 of the through-holes 6 and 7 have a smooth curve, and have a shape that hardly causes stress concentration even when a load is applied from the pin 3 or the like. Each link 2 is formed to a sufficient thickness (for example, 1.6 mm, which is about twice as thick as a conventional chain link using pins and interpieces).

  The first to third columns 51 to 53 are formed by using a plurality of links 2, respectively. Specifically, each of the first row 51, the second row 52, and the third row 53 includes a plurality of links 2 arranged in the chain width direction W. In each of the first to third rows 51 to 53, the links 2 in the same row are aligned so that the positions in the chain traveling direction X are the same. The first to third rows 51 to 53 are arranged along the chain traveling direction X.

Each of the links 2 in the first to third rows 51 to 53 can be bent with respect to the corresponding links 2 in the first to third rows 51 to 53 by using a single (one) pin 3. It is connected.
Specifically, the front through hole 6 of the link 2 in the first row 51 and the rear through hole 7 of the link 2 in the second row 52 correspond to each other along the chain width direction W. The links 2 in the first and second rows 51 and 52 are connected to each other so as to be bent in the chain traveling direction X by the pins 3 that pass through the through holes 6 and 7.

Similarly, the front through hole 6 of the link 2 in the second row 52 and the rear through hole 7 of the link 2 in the third row 53 correspond to each other along the chain width direction W. The links 2 in the second and third rows 52 and 53 are connected to each other so as to be able to bend in the chain traveling direction X by the pins 3 inserted through the through holes 6 and 7.
In FIG. 5, only one of the first to third columns 51 to 53 is shown, but the first to third columns 51 to 53 are arranged so as to repeat along the chain traveling direction X. Yes. The two rows of links 2 adjacent to each other in the chain traveling direction X are sequentially connected by corresponding single pins 3 to form an endless chain 1.

  The pin 3 is a rod-like body extending in the chain width direction W. A pair of end portions of the pins 3 protrude in the chain width direction W from the links 2 arranged at the pair of end portions in the chain width direction W, respectively. Power transmission surfaces 10 and 11 are provided on a pair of end surfaces of the pin 3, respectively. Referring to FIG. 2, power transmission surfaces 10 and 11 can contact (engage) corresponding sheave surfaces 62a, 63a, 72a and 73a of pulleys 60 and 70, respectively. Since the pin 3 directly contributes to power transmission by the power transmission surfaces 10 and 11, the pin 3 is formed of a high-strength wear-resistant material such as bearing steel (SUJ2), for example.

  The effective radius R (the winding radius of the chain 1) with respect to the pin 3 in each pulley 60, 70 is defined as follows. That is, the effective radius R related to the pin 3 in the pulley 60 (hereinafter referred to as “effective radius R in the pulley 60”) is a pulley between the contact point T1 between the pulley 60 and the pin 3 and the central axis C1 of the pulley 60. Defined as radial distance. The contact point T1 is a contact point between each sheave surface 62a, 63a of the pulley 60 and the corresponding power transmission surface 10, 11 of the pin 3.

  Similarly, the effective radius R related to the pin 3 in the pulley 70 (hereinafter, referred to as “effective radius R in the pulley 70”) is between the contact point T2 between the pulley 70 and the pin 3 and the central axis C2 of the pulley 70. It is defined as the distance in the pulley radial direction. The contact point T2 is a contact point between each sheave surface 72a, 73a of the pulley 70 and the corresponding power transmission surface 10, 11 of the pin 3.

  Referring to FIGS. 5 and 6 again, the feature of the present embodiment is that the pin 3 is loosely fitted into the front through hole 6 of one link 2 and rolls around the peripheral edge 8 of the front through hole 6. Sliding contact (relative movement) is possible, and the corresponding other link 2 is fitted into the rear through-hole 7 (press-fitted), and relative movement (relative rotation) with respect to the other link 2 is performed. It is in a regulated point. The rolling sliding contact means a contact including at least one of a rolling contact and a sliding contact.

Specifically, the peripheral edge 8 of the front through-hole 6 of the link 2 is formed in a shape larger than the cross-sectional shape of the pin 3, and the peripheral edge 9 of the rear through-hole 7 is a shape corresponding to the cross-sectional shape of the pin 3. Is formed.
The pin 3 is loosely fitted into the front through-hole 6 of the link 2 in the first row 51 so as to be relatively movable with respect to the link 2 in the first row 51, and the link 3 in the second row 52. The relative rotation of the second row 52 with respect to the link 2 is restricted by being press-fitted into the rear through-hole 7. Similarly, the pins 3 are loosely fitted into the front through holes 6 of the links 2 in the second row 52 and are press-fitted into the rear through holes 7 of the links 2 in the third row 53. Further, although not shown, the pin 3 is loosely fitted in the front through hole 6 of the third row 53. Further, the pin 3 is press-fitted into the rear through hole 7 of the first row 51.

With the above configuration, when the links 2 adjacent to each other in the chain traveling direction X bend each other (see FIG. 7), the pin 3 rolls and slides on the peripheral edge 8 of the front through hole 6 of the corresponding link 2.
In addition, the locus of the contact point L of the rolling sliding contact between the pin 3 and the peripheral edge 8 of the front through-hole 6 of the link 2 corresponding to the pin 3 is set to be an involute curve.
Specifically, in the straight portion of the chain 1 (the link 2 that is the rearmost in the chain traveling direction X among the three links 2 in FIG. 7), of the peripheral surface 12 (outer peripheral surface) of the pin 3, The cross-sectional shape of the portion facing the chain traveling direction X forms an involute curve, and the contact portion 13 is provided in this portion. As shown in FIG. 8, the involute curve is an involute curve having a radius Rb and a basic circle B having a center M.

Further, as shown in FIG. 7, of the peripheral edge 8 (inner peripheral surface) of the front through-hole 6 of the link 2, the front end portion in the chain traveling direction X is orthogonal to the chain traveling direction X and the width direction W. (Is formed in a cross-sectional linear shape). A contact portion 14 that can come into contact with the contact portion 13 of the corresponding pin 3 is provided in the flatly extending portion.
In the linear part of the chain 1, the contact point L between the pin 3 and the front through-hole 6 of the corresponding link 2 is the origin, the direction along the chain traveling direction X is the x axis, and the direction along the orthogonal direction V is the y axis, Further, when the angle between the tangential direction of the pin 3 at the contact point L between the pin 3 and the front through-hole 6 of the corresponding link 2 in the bent portion of the chain 1 and the y axis is γ, the locus of the contact point L Is an involute curve of a circle having a basic circle radius Rb that satisfies the following expressions (1) and (2).

x = Rb · (sin γ−γ · cos γ) (1)
y = Rb · (cos γ + γ · sin γ) −Rb (2)
For example, as shown in FIGS. 3A and 3B, the basic circle radius Rb is set to a minimum value R1 (Rb = R1) of the effective radius R in each of the pulleys 60 and 70.
That is, the cross-sectional shape of the contact portion 13 of the pin 3 is an involute curve of a circle having a basic circle radius Rb that satisfies the above formulas (1) and (2).

  With reference to FIGS. 1 and 2, in continuously variable transmission 100 configured as described above, for example, a continuously variable transmission can be performed as follows. That is, when the rotation of the output shaft 71 is decelerated, the groove width of the drive pulley 60 is increased by the movement of the movable sheave 63, and the power transmission surfaces 10 and 11 at both ends of the pin 3 of the chain 1 are conical. Sliding contact under the condition of boundary lubrication toward the inner side of 62a and 63a (downward direction in Fig. 2) (lubrication state where part of the contact surface is in direct contact with the microprojections and the rest is in contact with the lubricating oil film) Meanwhile, the winding radius of the chain 1 around the input shaft 61 is reduced.

On the other hand, in the driven pulley 70, the groove width is reduced by the movement of the movable sheave 73, and the power transmission surfaces 10 and 11 of the pin 3 of the chain 1 are moved outward from the conical sheave surfaces 72a and 73a (upward direction in FIG. 2). ) To increase the winding radius of the output shaft 71 of the chain 1 while making sliding contact under boundary lubrication conditions.
On the contrary, when the rotation of the output shaft 71 is increased, the groove width of the drive pulley 60 is reduced by the movement of the movable sheave 63 and the power transmission surfaces 10 and 11 of the pin 3 of the chain 1 are conical. The wrapping radius of the input shaft 61 of the chain 1 is increased while making sliding contact under the boundary lubrication condition toward the outer side of the surfaces 62a and 63a. On the other hand, in the driven pulley 70, the groove width is expanded by the movement of the movable sheave 73, and the power transmission surfaces 10, 11 of the pin 3 of the chain 1 are directed toward the inner side of the conical surface of the sheave surfaces 72a, 73a. The sliding radius on the output shaft 71 of the chain 1 is reduced while making sliding contact underneath.

  As described above, according to the present embodiment, when the power transmission surfaces 10 and 11 of the pin 3 are in contact with the corresponding sheave surfaces 62a, 63a, 72a and 73a of the pulleys 60 and 70, the power is transmitted. The link 2 rolls and comes into sliding contact with the loosely-fitted pin 3, whereby the links 2 can be bent. At this time, with respect to the link 2 and the pin 3 that are in rolling contact with each other, the rolling contact component is large and the sliding contact component is extremely small. As a result, the pin 3 has the sheave surfaces 62a, 63a, 72a, 73a. As a result, the frictional loss is reduced and high transmission efficiency can be secured.

  Further, since only a single pin 3 is fitted in each through-hole 6, 7 of the link 2, the distance between the pins 3 adjacent to each other in the chain traveling direction X is made shorter (short pitch). ), More pins 3 can be provided. As a result, when the chain 1 is driven, the number of pins 3 that contact the pulleys 60 and 70 per unit time is increased, and the person recognizes the contact sound between the pins 3 and the pulleys 60 and 70. It is possible to approach a difficult high frequency, and noise can be significantly reduced.

  Moreover, since the number of pins 3 that contact each pulley 60 and 70 at a time can be increased, the load per pin 3 can be reduced, and the durability and the allowable transmission load can be significantly improved. Furthermore, since the load per pin 3 is reduced, the impact when the pin 3 contacts the pulleys 60 and 70 can be further reduced, and noise can be further reduced. Moreover, the interpiece provided in the conventional chain can be abolished, the number of parts can be reduced, and the manufacturing cost can be further reduced. Moreover, the cross-sectional shape of the pin 3 can be made larger by eliminating the interpiece, and as a result, the bending strength of the pin 3 can be further increased.

  The locus of the contact point L between the contact portion 14 of the front through-hole 6 of the link 2 and the contact portion 13 of the pin 3 draws an involute curve. As a result, when the pin 3 is sequentially engaged with the sheave surfaces 62a, 63a, 72a, 73a of the pulleys 60, 70, the linear portion of the chain 1 is affected by the engagement and the string vibration is dynamic. It is possible to suppress the movement. As a result, noise during driving of the chain can be further reduced.

Furthermore, the chain 1 has a simple configuration in which the link 2 and the pin 3 are combined, and since there are few movable parts, it is easy to manage the dimensions during assembly, and the chain 1 with high accuracy can be easily manufactured.
In addition, since the link 2 has a sufficient thickness, the link 2 itself can have sufficient strength and can be in line contact with the contact portion 13 of the pin 3, and the surface pressure received from the pin 3 is low. It is possible to ensure sufficient durability. In addition, by providing the link 2 with sufficient strength, the number of links 2 used can be reduced, and the number of parts can be reduced to further reduce the manufacturing cost.

Therefore, the continuously variable transmission 100 that is excellent in transmission efficiency, quietness, and durability and that is inexpensive can be realized.
In the present embodiment, the third row 53 includes five links 2 as shown in FIG. 5. Of these, one link 2 in the center in the chain width direction W is abolished. You may do it. In this case, the number of links 2 in each column of the first to third columns 51 to 53 can be unified to four. As a result, the number of links 2 stacked in the chain width direction W can be unified to 12. As a result, the strength of each part of the chain 1 can be made more uniform and the number of parts can be further reduced. Can do.

Further, regarding the involute curve of the contact portion 13 of the pin 3, the involute curve is innumerable according to the basic circle radius Rb, and even if the basic circle radius Rb changes, the same noise reduction / damping effect can be maintained. Not only satisfying the above expressions (1) and (2), but also satisfying the following expressions (3) and (4).
x = k · R1 · (sin γ−γ · cos γ) (3)
y = k.R1. (cos.gamma. +. gamma..sin.gamma.)-k.R1 (4)
Note that Rb = k · R1 and k is a constant.

Here, it is preferable to set k to the following range, where r is the gear ratio of the continuously variable transmission 100.
0.25 ≦ k ≦ 2r
For example, if the gear ratio r = 1, the range of k is 0.25 ≦ k ≦ 2. At this time, if the minimum value R1 of the winding radius of the chain 1 is 50 mm, the range of k · R1 (that is, the basic circle radius Rb) is 12.5 ≦ k · R1 ≦ 100.

From the range of the above formulas (3), (4) and k · R1, the involute curve of the contact portion 13 of the pin 3 is a curve satisfying the following formulas (5), (6) (allowable lower limit curve) and the following formula ( It suffices to be within the range of the curve (allowable upper limit curve) that satisfies 7) and (8).
Allowable lower limit curve x = 12.5 (sin γ−γ · cos γ) (5)
y = 12.5 (cosγ + γ · sinγ) -12.5 (6)
Allowable upper limit curve x = 100 (sin γ−γ · cos γ) (7)
y = 100 (cosγ + γ · sinγ) −100 (8)
That is, as shown in FIG. 9, an arbitrary involute curve between an involute curve (allowable lower limit curve) when k = 0.25 and an involute curve (allowable upper limit curve) when k = 2 is obtained. The cross-sectional shape of the contact portion 13 may be used. Also in this case, it is possible to suppress the occurrence of string vibration motion in the chain, and noise can be sufficiently reduced.

The lower limit of k is more preferably 0.6 (0.6 ≦ k). When the lower limit of k is 0.6, the lower limit of k · R1 (the lower limit of the basic circle radius Rb) is 0.6 × 50 = 30. The upper limit of k is more preferably 1.6 (k ≧ 1.6). When the upper limit of k is 1.6, the upper limit of k · R1 (basic circle radius Rb) is 1.6 × 50 = 80.
FIG. 10 is a cross-sectional side view of the main part of another embodiment of the present invention. In the following, differences from the embodiment shown in FIG. 6 will be mainly described, and the same components will be denoted by the same reference numerals and description thereof will be omitted.

  Referring to FIG. 10, the feature of this embodiment is that one link 2 and pins 3 loosely fitted in the front through-hole 6 of this one link 2 are set as one set 15, and The link 2 and the pin 3A loosely fitted in the front through hole 6 of this one link 2 are used as another set 16, and two types of sets are provided, and the front through hole 6 of the link 2 in each of the sets 15 and 16 is provided. The contact points L and LA between the peripheral edge 8 and the corresponding pins 3 and 3A are made different from each other, and the sets 15 and 16 are arranged randomly (irregularly).

Specifically, the base circle radii Rb and RbA of the involute curves of the cross sections of the contact portions 13 and 13A of the pins 3 and 3A are different, and the radius RbA is smaller than the radius Rb (RbA <Rb). Is set.
Therefore, the cross-sectional shape of the pin 3A is smaller than the cross-sectional shape of the pin 3, and a gap is formed in a part between the pin 3A and the corresponding rear through-hole 7 of the link 2. The pin 3A Is fixed to the rear through-hole 7 as follows. That is, in the cross-sectional view of the pin 3A, substantially all of the portion of the peripheral surface 12A other than the contact portion 13A is pressed against the peripheral edge 9 of the corresponding rear through-hole 7 of the link 2, and the contact portion 13A is At least one point Q is in pressure contact with the peripheral edge 9 of the rear through-hole 7.

That is, the circumferential surface 12A of the pin 3A has three locations (three surfaces) of a pair of end portions in the orthogonal direction V and an end portion opposite to the contact portion 13A in the chain traveling direction X in the cross-sectional view. The contact part 13 </ b> A is in point contact with the peripheral edge 9.
In this way, the contact portion 13A of the pin 3A only needs to be in contact with the peripheral edge 9 of the rear through-hole 7 at at least one point, and even if the shapes of the contact portions 13 and 13A of the pins 3 and 3A are slightly different, There is no need to change the shape of the rear through-hole 7 corresponding to the shape of each pin 3, 3A, and the link 2 having the same shape of the rear through-hole 7 can be used. can do.

“Randomly arranged” means that the sets 15 and 16 are irregularly mixed and arranged in at least a part of the chain traveling direction X.
Further, as a condition for randomly arranging the sets 15 and 16 in the chain traveling direction X, it is preferable that the number of the same sets 15 and 16 that are continuously arranged is a prime number.
According to the present embodiment, the contact sound when each pin 3, 3 </ b> A contacts each pulley 60, 70 can be made different in each set 15, 16 to disperse the frequency band of the contact sound, The driving sound of the chain 1 can be further reduced.

In the present embodiment, the same number of the two types of sets 15 and 16 may be provided, or the number of one set may be larger than the number of the other set. Moreover, you may provide 3 or more types of pins (groups from which the locus | trajectory of the contact point of rolling sliding contact differs) from which the cross-sectional shape of a contact part differs.
11 (A) and 11 (B) are cross-sectional side views of the main part of still another embodiment of the present invention. Referring to FIGS. 11A and 11B, the feature of this embodiment is that two types of links 2 and 2A are provided, and the pitches P and PA of these links 2 and 2A are set. The links are different from each other, and the links 2 and 2A are randomly arranged.

  The pitch P of the link 2 refers to the distance in the chain traveling direction X between the adjacent pins 3 in the link 2 of the linear portion of the chain 1, and specifically, the contact portion 14 and the pin of the front through hole 6 of the link 2 3 between the contact point L with the contact part 13 and the contact point L2 of the contact part L between the peripheral edge 9 of the rear through-hole 7 and the contact part 13 of the pin 3 and the contact point L2 aligned in the chain traveling direction X. Is defined as Similarly to the pitch P of the link 2, the pitch PA of the link 2A is defined. The pitch P of the link 2 is set to 6 mm, for example, and the pitch PA of the link 2A is set to 7.5 mm, for example, and P <PA.

The links 2 and 2A are randomly arranged in the chain traveling direction X in the same manner as the “random arrangement” described in the embodiment shown in FIG.
According to the present embodiment, it is possible to prevent the contact sound from resonating by making the period when the pin 3 contacts the corresponding sheave surfaces 62a, 63a, 72a, 73a of the pulleys 60, 70 irregular, Chain drive noise can be made extremely small.

  In the present embodiment, the same number of the two types of links 2 and 2A may be provided, or the number of one link may be larger than the number of the other link. Two or more types of pins having different cross-sectional shapes of the contact portions (a plurality of sets having different orbits at the contact point of the rolling sliding contact) may be used. In this case, the basic circle radius of the contact portion of the pin may be increased or decreased according to the size of the pitch of the link into which the pin is inserted. More specifically, the basic circle radius of the pin fitted into the link 2A may be larger or smaller than the basic circle radius of the pin fitted into the link 2. Furthermore, the basic circle radius of the contact portion of the pin does not have to correspond to the size of the pitch of the link into which the pin is inserted. Three or more types of links having different pitches may be provided.

  The present invention is not limited to the above embodiments. For example, in each of the above embodiments, the cross-sectional shape of the contact portion of the pin may be a non-involute curve that falls within the allowable upper limit curve and the allowable lower limit curve shown in FIG. Further, as a combination of a plurality of types of pins, a combination in which the cross-sectional shape of the contact portion of the pin includes an involute curve and a non-involute curve may be combined.

  Moreover, you may interchange the shape of the contact part of a pin, and the shape of the contact part of the front through-hole of a corresponding link. Further, both the contact portion of the pin and the contact portion of the front through-hole of the link may be formed in a curved surface. Further, the arrangement of the front through hole 6 and the rear through hole 7 may be interchanged. Furthermore, you may use the power transmission block which provided the power transmission surface engaged with the sheave surface of a pulley in the both ends of a pin.

  Further, the front through-hole 6 and the rear through-hole 7 of each link may be communicated with each other as long as their functions are not impaired. Specifically, a communication groove that allows the through holes 6 and 7 to communicate with each other may be formed in a column portion disposed between the front through hole 6 and the rear through hole 7 of each link. Thereby, the stress concentration of the peripheral part of each said through-hole 6 and 7 can be relieve | moderated more. The present invention includes such a shape of the through hole.

Furthermore, the value of the speed ratio r may be smaller or larger than the above-illustrated value.
Further, the continuously variable transmission 100 is not limited to a mode in which the groove widths of both the drive pulley 60 and the driven pulley 70 are changed, and only one of the groove widths is changed, and the other is not fixed. It is also possible to adopt the mode described above. Furthermore, the groove widths of the pulleys 60 and 70 may be changed stepwise, or may be fixed (no speed change).

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view schematically showing a main configuration of a chain type continuously variable transmission as a power transmission device including a power transmission chain according to an embodiment of the present invention. It is a partial expanded sectional view of the drive pulley (driven pulley) and chain of FIG. It is a typical section side view of a continuously variable transmission, and (A) shows the state where the wrapping radius of the chain with respect to the input shaft is minimized and the wrapping radius of the chain with respect to the output shaft is maximized. (B) shows a state where the chain wrapping radius with respect to the input shaft is maximized and the chain wrapping radius with respect to the output shaft is minimized. It is a perspective view which shows typically the structure of the principal part of a chain. It is a cross-sectional top view of the principal part of the chain shown in FIG. FIG. 6 is a partial cross-sectional view taken along line II-II in FIG. 5. It is a partial cross section side view showing the state where a part of chain was bent. It is a figure for demonstrating the basic circle radius of the involute curve of a contact part. It is a graph which shows the range of the preferable shape of the contact part of a pin. It is a cross-sectional side view of the principal part of other embodiment of this invention. It is a sectional side view of the principal part of further another embodiment of the present invention, (A) shows a link with a relatively short pitch, and (B) shows a link with a relatively long pitch. Yes.

Explanation of symbols

1 Chain (Power transmission chain)
2,2A link 3,3A pin 6 front through hole (first through hole)
7 Rear through hole (second through hole)
8 Perimeter (of front through hole) 10, 11 Power transmission surface 15, 16 sets 60 Drive pulley (first pulley)
62a, 63a Sheave surface 70 Driven pulley (second pulley)
72a, 73a Sheave surface 100 continuously variable transmission (power transmission device)
L, LA Contact point of rolling / sliding contact P, PA Pitch X Chain travel direction

Claims (5)

In a power transmission chain having a plurality of links arranged in the chain traveling direction,
Each link includes a first through hole and a second through hole arranged in the chain traveling direction,
Links corresponding to each other are connected to each other so as to be bendable using a single pin,
Each of the pins is loosely fitted into the first through hole of one link so as to be able to make rolling and sliding contact with the peripheral edge of the first through hole, and is fitted into the second through hole of the other link. The power transmission chain is characterized in that relative movement with respect to other links is restricted.   The rolling sliding contact between the peripheral edge of the first through-hole of one link and the pin according to claim 1, wherein the one link and the pin loosely fitted into the first through-hole of the one link are made into one set. A power transmission chain, wherein two or more sets having different trajectories of contact points are provided, and these sets are randomly arranged. 3. The power transmission chain according to claim 1, wherein a locus of a contact point of rolling sliding contact between the peripheral edge of the first through hole of the one link and the pin includes an involute curve.   4. The power transmission chain according to claim 1, wherein two or more types of links having different pitches are provided, and these links are arranged at random.   The first and second pulleys each having a pair of conical sheave surfaces facing each other, and the power transmission chain according to claim 1, 2, 3 or 4 wound between these pulleys, A power transmission device in which a power transmission surface provided at each of a pair of end portions of the pin engages with a sheave surface to transmit power.

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