JP2005233275A - Power transmitting chain and power transmission device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power transmitting chain 3 and power transmission device equipped with an increased torque transmitting capacity and a prolonged lifetime. <P>SOLUTION: The power transmitting chain 3 to be set round pulleys 1 and 2 is structured so that a plurality of links 10 are coupled together by pins 11 endlessly, wherein each link 10 is provided with through holes 10a and 10b penetrating in the chain width direction, and the pins 11 are fitted by pressure into the through holes 10a and 10b. The contacting pressure distribution on the contacting surfaces with the pins 11 of the wall surfaces to form the through holes 10a and 10b is made approximately uniform. This enhances the tensile strength of the chain 3. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a power transmission chain (hereinafter referred to as a chain) in which a plurality of links are connected endlessly with pins and a power transmission device using the same.

For example, a continuously variable transmission (CVT) used in a vehicle such as an automobile includes, for example, a drive pulley provided on the engine side, a driven pulley provided on the drive wheel side, and an endless bridge spanned between the two. There is a chain in which a plurality of links are connected to each other by pins and strips (see, for example, Patent Document 1). In this chain, a pin and a strip are inserted in parallel in through holes provided in the link, and are caused to roll with respect to each other, thereby suppressing chordal motion during chain operation.
JP-A-8-312725

  The present invention provides a contact surface between a through hole provided in a link and a pin inserted into the through hole, a contact surface between the through hole and a strip inserted into the through hole, or a contact surface between the pin and the strip. It is an object to improve the tensile strength of the chain by preventing the concentration of contact pressure (edge load) from occurring.

  In the present invention, the distance between the contact surfaces of the through hole and the pin in the longitudinal direction of the chain, the distance between the contact surfaces of the strip and the through hole in the longitudinal direction of the chain, the distance between the contact surfaces of the pin and the strip By making at least one of the changes in the chain width direction the same as the change in the distance between the Lundberg curve and the plane, the contact pressure distribution on both contact surfaces of the link through-holes and pins is made almost uniform, so that It is assumed that the occurrence of this can be suppressed or prevented.

  In any of the cases described above, the present invention improves the tensile strength of the chain. Therefore, in a power transmission device in which the chain is wound between two pulleys, the torque capacity transmitted between the pulleys is increased. It becomes possible.

  According to the present invention, a chain with improved tensile strength can be provided. Further, it is possible to contribute to an increase in transmission torque capacity and an improvement in life in a power transmission device using this chain.

  1 is a perspective view schematically showing a continuously variable transmission as a power transmission device, FIG. 2 is a perspective view showing a part of the chain of FIG. 1, and FIG. 3 is a plan view of the chain of FIG. 4 is a sectional view taken along the line (4)-(4) in FIG. 3, FIG. 5 is a side view showing a part of the chain in FIG. 2, and FIG. 6 is a perspective view showing the pin in FIG. 7 is a diagram schematically showing the distance between the Lundberg curve and the plane.

  The continuously variable transmission of the illustrated example has a configuration in which an endless chain 3 is wound around a drive pulley 1 and a driven pulley 2.

  The drive pulley 1 is attached to the input shaft 4 connected to the engine side, and the driven pulley 2 is attached to the output shaft 5 connected to the drive wheel side.

  Both pulleys 1 and 2 are composed of fixed sheaves 1a and 2a and movable sheaves 1b and 2b. The fixed sheave 1a of the drive pulley 1 is fixed to the input shaft 4, and the fixed sheave 2a of the driven pulley 2 is fixed to the output shaft 5. The movable sheave 1b of the drive pulley 1 is fixed to the input shaft 4 and driven. The movable sheave 2b of the pulley 2 is attached to the output shaft 5 so as to be integrally rotatable and movable in the axial direction.

  The fixed sheaves 1a and 2a and the movable sheaves 1b and 2b each have a conical surface, and a V-shaped circumferential groove is formed between the conical surfaces of the fixed sheaves 1a and 2a and the conical surfaces of the movable sheaves 1b and 2b. Has been. The movable sheaves 1b and 2b are moved steplessly in the axial direction by a driving means such as a hydraulic actuator (not shown), for example, so that the groove width in the circumferential grooves of both pulleys 1 and 2 is changed steplessly. Stage shifts are performed.

  The chain 3 is composed of a combination of three links 10A, 10B, and 10C in which one set is sequentially shifted by a predetermined distance in the longitudinal direction of the chain, and each set has links at the same shifted position (reference numerals 10A and 10B). , 10C) each having a first, second, and third link set. Each link 10A, 10B, 10C in each link set is provided with first and second through holes 10a, 10b. The first through hole 10a is on one end side of each link 10A, 10B, 10C on the opposite side to the chain traveling direction, and the second through hole 10b is on each link 10A, 10B, on the chain traveling direction side. It is formed on the other end side of each 10C. The links 10A, 10B, and 10C in each set are connected to each other by pins 11 and strips 12 inserted or press-fitted into the through holes 10a and 10b, respectively. These through-holes 10a and 10b can be combined with one hole.

  Each pin 11 is connected to each link 10A, 10B, 10C so as to be partially surrounded by the wall surface of the first through hole 10a of the link 10A, 10B, 10C, and each strip 12 is connected to the second link 10A, 10B, 10C. It is connected to each of the links 10A, 10B, and 10C so as to be partially surrounded by the peripheral surface of the through hole 10b. Each pin 11 and the strip 12 are connected to the links 10A, 10B, and 10C by press-fitting. The strip 12 is slightly shorter than the pin 11, so that only the outer end surface of the pin 11 can make frictional contact with the pulleys 1 and 2. The outer end surface of the pin 11 has a convex shape or a planar shape so that the pulling force of the chain can be transmitted to the pulleys 1 and 2.

  The shapes of the first and second through holes 10a and 10b are as shown in FIG. That is, the portion 10a1 of the wall surface of the first through hole 10a is where the pin 11 is press-fitted, and is very close to the outline of the pin 11 or only slightly smaller. The remaining portion 10 a 2 of the wall surface of the first through hole 10 a is configured such that the strip 12 that cooperates in contact with the pin 11 can move freely with respect to the pin 11. As a result, the strip 12 can roll on the pin 11 in the first through hole 10a.

  A portion 10b1 of the wall surface of the second through hole 10b is where the strip 12 is press-fitted, and is very close to the outline of the strip 12, or only slightly smaller. The remaining portion 10 b 2 of the wall surface of the second through hole 10 b is configured such that the pin 11 that cooperates in contact with the strip 12 can move freely with respect to the strip 12.

  Here, on the page of FIG. 5, in one link set, the front side is the first link 10A, the middle side is the second link 10B, and the back side is the third link 10C. The first through hole 10a of the first link 10A is the same as the second through hole 10b (indicated by a broken line) of the second link 10B in the chain width direction (in FIG. 5, the direction penetrating the paper surface of FIG. 5). Located on a straight line. The first through hole 10a of the second link 10B is located on the same straight line as the second through hole 10b (indicated by a broken line) of the third link 10C in the width direction of the chain. The links 10A, 10B, and 10C are connected to each other in the longitudinal direction of the chain by pins 11 and strips 12 that are passed through the through holes 10a and 10b.

  The chain having the above configuration changes in the position of the tangent line between the pin 11 and the strip 12 as it proceeds in the pulley direction (the right direction in FIG. 5). The tensile force K in the chain is transmitted from one link to another link at the position of the tangent, and is generated on the first link 10A where the couple F = K · X enters. Here, X is the distance between the couples F. When entering the chain, the pin 11 in the first through hole 10a coupled to the first link 10A is not yet in contact with the pulleys 1 and 2, so that the first link 10A is Freely around the tangent line between the strip 12 in the second through-hole 10b coupled to the first link 10A and the pin 11 of the upstream link (not shown) that is in contact with the pulleys 1 and 2 at this time. Can rotate. The couple F acting on the first link 10A that is approaching the entry rotates the first link 10A a little, thereby causing a pin in the second through hole 10b of the second link 10B. 11 is moved up.

  When the pin 11 in the second through-hole 10b of the second link 10B is sufficiently moved up, the string vibration movement of the chain is caused as described in the specification of JP-A-8-31725. It will be suppressed. Since further details of this inhibitory action are described in detail in the publication, description thereof will be omitted.

  In this way, the links 11 are connected to each other by press-fitting or inserting the pins 11 and the strips 12 into the through holes 10a and 10b, and both ends of the pins 11 and the strips 12 are connected to each other as described above. The pin 11 protrudes from the through holes 10a and 10b, and the pin 11 is formed longer than the strip 12, and the outer ends thereof are in contact with the conical surfaces of the drive pulley 1 and the driven pulley 2. . A strip 12 is disposed on the front side of the chain 3 in the traveling direction, and a pin 11 is disposed on the rear side.

  In such a contact between the pin 11 and the strip 12, the bus bar shape of the pin 11 along the thickness direction of the chain 3 is an involute curve, and the bus bar shape of the strip 12 is a straight line. This is because the pin 11 and the strip 12 are brought into rolling contact when the chain 3 is wound around both pulleys 1 and 2.

  In the above configuration, in the present invention, changes in the distance between the contact surfaces of the first and second through holes 10a, 10b of the links 10A, 10B, 10C (collectively referred to as the link 10) and the pin 11 in the longitudinal direction of the chain. And the change in the distance between the contact surfaces of the through holes 10a, 10b of the link 10 and the strip 12 in the longitudinal direction of the chain, and the change in the distance between the contact surfaces of the pins 11 and the strip 12 in the chain width direction. The distance between the Lundberg curve and the plane is set to be the same as the change in the longitudinal direction so that the occurrence of edge load on these contact surfaces can be suppressed or prevented.

  This setting will be described in the following (1) to (6).

  The Lundberg curve is shown in the title “Roller bearings under radial and eccentric loads” and the author name “PMJohns and R. Gohar” described on pages 131 to 136 of the book name “TRIBOROGY international June 1981”, for example. Generally, it is represented by the following formula.

なお、上記式において、
ｙ：接触面の長手方向の位置
Ｑ：接触面にかかる全体荷重
ν：ポアソン比
Ｅ：ヤング率
Ｌ：接触面の全長
ａ_０：接触面の接触楕円における長手方向での長さの半分
ｂ：接触面の接触楕円における短手方向での長さの半分
である。

In the above formula,
y: Position in the longitudinal direction of the contact surface Q: Total load applied to the contact surface ν: Poisson's ratio E: Young's modulus L: Total length of the contact surface a ₀ : Half of the length in the longitudinal direction of the contact ellipse b: It is half the length in the short direction of the contact ellipse of the contact surface.

  The distance between the Lundberg curve and the plane is exaggerated in FIG. In FIG. 7, the plane is represented as the y-axis at the origin O of xy orthogonal two-dimensional coordinates.

  (1) Of the contact surfaces of the through holes 10a, 10b (inner wall surface) and the pin 11 (outer wall surface), for example, the bus bar shape in the longitudinal direction of the chain of one of the contact surfaces is a linear shape, and the other The generatrix shape of the contact surface in the longitudinal direction of the chain is a crowning shape consisting of a Lundberg curve. In addition, the said contact surface here forms two short sides in the pin 11 whose end surface is vertically long in the chain thickness direction and through-holes 10a and 10b in contact with each other so as to be surrounded by an alternate long and short dash line in FIG. This corresponds to a part of the wall surface. In this case, the bus bar shape of one contact surface and the other contact surface is a shape in a natural state in which the pin 11 is not attached to the through holes 10a and 10b.

  (2) Of the contact surfaces of the through-holes 10a, 10b (inner wall surface) and the strip 12 (outer wall surface), for example, the bus bar shape in the chain longitudinal direction of one of the contact surfaces is a linear shape and the other contact surface The generatrix shape of the surface in the longitudinal direction of the chain is a crowning shape consisting of a Lundberg curve. In addition, the said contact surface here is the through-hole 10a, 10b which two short sides in the strip 12 whose end surface is vertically long in the chain thickness direction, and it contacts so that it may enclose with a dashed-two dotted line in FIG. This corresponds to a part of the wall surface to be formed. Also in this case, the bus bar shape of one contact surface and the other contact surface is a shape in a natural state in which the pin 11 is not attached to the through holes 10a and 10b.

  (3) Of both contact surfaces of the pin 11 (outer wall surface) and the strip 12 (outer wall surface), the busbar shape in the chain width direction of one of the contact surfaces is a linear shape along the chain width direction, and the other The bus bar shape in the chain width direction of the contact surface is a crowning shape formed of a Lundberg curve. Also in this case, the bus bar shape of one contact surface and the other contact surface is a shape in a natural state in which the pin 11 and the strip 12 are not pressed against each other.

  (4) Both contact surfaces of the through holes 10a and 10b and the pin 11 are crowned in a predetermined shape.

  (5) Both contact surfaces of the through holes 10a and 10b and the strip 12 are crowned in a predetermined shape.

  (6) Both the contact surfaces of the pins 11 and the strips 12 are crowned in a predetermined shape.

  The crowning shape of the above (4), (5), (6) is different from the Lundberg curve, and the change in the distance between both contact surfaces is the same as the change in the distance between the Lundberg curve and the plane as shown in FIG. It should be set so that.

  A configuration including any one of the above (1) to (6), a configuration including any two or more of the above (1), (2), and (3), or the above (4) , (5), (6), any two or more.

  In this embodiment, as shown in FIG. 5 and FIG. 6, first, the end surface of the pin 11 whose longitudinal direction is vertically long in the chain thickness direction is the crown shape formed by a Lundberg curve in the generatrix shape of the upper surface and the lower surface in the chain longitudinal direction. In addition, the portion of the wall surface forming the through holes 10a and 10b where the upper surface and the lower surface of the pin 11 are in contact with each other has a linear shape along the longitudinal direction of the chain. The bus bar shape in the longitudinal direction of the chain on the upper surface and the lower surface is a crowning shape made of a Lundberg curve, and the portion where the upper surface and the lower surface of the strip 12 are in contact with the wall surface forming the through holes 10a, 10b is a straight line along the longitudinal direction of the chain Third, the end face is a vertically elongated pin in the chain thickness direction. 11 is a crowning shape made up of a Lundberg curve on the one side surface of the chain 11 in the chain width direction, and the bus shape in the chain width direction of the one side surface where the one side surface of the pin 11 contacts the strip 12 is a linear shape. .

  Even the pin 11 and the strip 12 having such a shape can be relatively easily manufactured by, for example, pultrusion molding. Note that when the pins 11 and the strips 12 are press-fitted into the through holes 10a and 10b, their respective contact surfaces are elastically deformed, so that the shape of the crowning before elastic deformation does not appear in FIG.

  According to the chain 3 having such a configuration, the contact pressure distribution in the longitudinal direction of the chain on the contact surface between the wall surface forming the through holes 10 a and 10 b of the link 10 and the pin 11 in accordance with the operation of the chain 3, The contact pressure distribution in the chain longitudinal direction of the contact surface between the wall surface forming the holes 10a and 10b and the strip 12 and the contact pressure distribution in the chain width direction of the contact surface between the pin 11 and the strip 12 are substantially uniform, respectively. It is possible to suppress or prevent the occurrence of edge loading on each contact surface. Thereby, since the tensile strength of the chain 3 is improved, it is possible to contribute to an increase in transmission torque capacity and an improvement in life of the continuously variable transmission.

  By the way, the continuously variable transmission may have a fixed width so that only the groove width of one of the circumferential grooves of the drive pulley 1 and the driven pulley 2 can be changed, and the other cannot be changed. . The present invention can also be applied to a transmission that changes the groove width in the circumferential groove stepwise and a fixed (non-shifting) power transmission device.

  In the above description, a pin type in which both ends of the pin 11 are brought into contact with the conical surfaces of the drive pulley 1 and the driven pulley 2 as the chain 3 is taken as an example. For example, as shown in Japanese Patent Laid-Open No. 1-176832, The present invention can be applied to a block type chain in which a block attached to the pin 11 is brought into contact with each conical surface of the drive pulley 1 or the driven pulley 2.

The perspective view which shows typically the continuously variable transmission which concerns on one Embodiment of this invention. The perspective view which shows a part of chain of FIG. Plan view of the chain of FIG. Arrow view of section of line (4)-(4) in FIG. Side view showing part of the chain of FIG. The perspective view which shows the pin of FIG. Diagram showing the distance between the Lundberg curve and the plane

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Drive pulley, 2 ... Driven pulley, 3 ... Chain, 10 ... Link, 10a, 10b ... Through-hole, 11 ... Pin, 12 ... Strip

Claims (4)

A power transmission chain formed by connecting a plurality of links endlessly with pins press-fitted into through-holes in the chain width direction provided in them,
A power transmission chain characterized in that the change in the longitudinal direction of the distance between both contact surfaces of the through hole and the pin is the same as the change in the distance between the Lundberg curve and the plane. A power transmission chain in which a plurality of links are connected to each other in an endless manner by a strip press-fitted into a through-hole in the chain width direction provided in them and a pin inserted so as to be able to make rolling contact with the strip,
A power transmission chain characterized in that the change in the longitudinal direction of the distance between the contact surfaces of the strip and the through-hole is the same as the change in the distance between the Lundberg curve and the flat surface. A power transmission chain in which a plurality of links are connected to each other endlessly by pins and strips inserted parallel to each other in through-holes provided in the chain width direction, and the pins and strips are in rolling contact with each other. And
A power transmission chain characterized in that the change in the distance between the contact surfaces of the pin and the strip in the chain width direction is the same as the change in the distance between the Lundberg curve and the plane. A power transmission device comprising two pulleys each having a V-shaped circumferential groove, and an endless power transmission chain wound around both pulleys,
A power transmission device using the power transmission chain according to claim 1 as a power transmission chain.

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