JP2010121732A - Belt-type continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a belt-type continuously variable transmission capable of achieving an improvement in wear resistance and a reduction in frictional loss at the same time. <P>SOLUTION: In a belt-type continuously variable transmission in which a chain whose respective links are endlessly connected with each other by means of a pair of joint pins is wound around the truncated cone-shaped sheaves of an input-side pulley and an output-side pulley, the shape of the end surface of the pair of joint pins and the shape of the sheave are set so that one joint pin contacts with the sheave when the winding radius of the chain around the pulley is small or large and that both joint pins contact with the sheave when the winding radius is large or small. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technical field of a belt type continuously variable transmission.

In the belt-type continuously variable transmission described in Patent Document 1, both of a pair of joint pins that connect each link are in contact with the sheave. On the other hand, in the belt type continuously variable transmission described in Patent Document 2, only one of the pair of joint pins is in contact with the sheave.
JP 2005-513368 gazette Japanese Patent No. 3477545

  In the technique described in Patent Document 1, since two joint pins are always brought into contact with the sheave, the friction loss is large. On the other hand, in the technique described in Patent Document 2, since only one joint pin is always brought into contact with the sheave, the surface pressure of the end face of the joint pin is high, and the wear of the joint pin or the sheave is severe.

  An object of the present invention is to provide a belt type continuously variable transmission that achieves both improvement in wear resistance and reduction in friction loss.

  In the present invention, one joint pin is in contact with the sheave when the winding radius of the chain pulley is small or large, and both joint pins are in contact with the sheave when the winding radius is large or small. The end face shape and sheave shape of the pair of joint pins were set.

  In the present invention, the wrapping radius of the chain on the pulley, that is, the joint pin that contacts the sheave is changed to one or two according to the operating conditions, so that both wear resistance and friction loss can be reduced. Can be planned.

  Hereinafter, the best mode for carrying out the present invention will be described based on examples.

FIG. 1 is a configuration diagram of a belt-type continuously variable transmission according to a first embodiment.
The belt-type continuously variable transmission 1 according to the first embodiment is configured by winding an endless chain 4 around an input pulley 2 and an output pulley 3.
The input pulley 2 is connected to the input shaft 5, and the output pulley 3 is connected to the output shaft 6. The input shaft 5 is connected to an engine (not shown), and the output shaft 6 is connected to driving wheels (not shown) via reduction gears 7 and 8.

  Both pulleys 2 and 3 have fixed sheaves 2a and 3a and movable sheaves 2b and 3b. The fixed sheave 2 a of the input side pulley 2 is integrally fixed to the input shaft 5. The fixed sheave 3 a of the output pulley 3 is fixed integrally to the output shaft 6. The movable pulley 2 b of the input side pulley 2 is spline-fitted to the input shaft 5. The movable pulley 3 b of the output pulley 3 is spline-fitted to the output shaft 6. Therefore, the movable pulleys 2b and 3b can rotate integrally with the input shaft 5 and the output shaft 6 and can move in the axial direction. The fixed sheaves 2a and 3a and the movable sheaves 2b and 3b are each formed in a truncated cone shape.

In the input pulley 2, the fixed sheave 2a has a conical surface 2c, and the movable sheave 2b has a conical surface 2d. The conical surface 2c and the conical surface 2d constitute a V-shaped circumferential groove space.
In the output pulley 3, the fixed sheave 3a has a conical surface 3c, and the movable sheave 3b has a conical surface 3d. The conical surface 3c and the conical surface 3d constitute a V-shaped circumferential groove space.

  The belt-type continuously variable transmission 1 moves the movable sheaves 2b and 3b in the axial direction using an appropriate actuator (not shown) to change the groove width in the circumferential groove space of both pulleys 2 and 3. As a result, the wrapping radius of the chain 4 is changed steplessly to enable continuously variable transmission. For example, a hydraulic cylinder or a motor-driven ball screw mechanism can be used as the actuator.

FIG. 2A is a perspective view of the chain 4 of the first embodiment, and FIG. 2B is an enlarged view of a main part of FIG.
In the chain 4, a plurality of links 9 stacked in the width direction are overlapped with their positions shifted in the chain length direction, and openings 4a and 4b formed at the front end portion and the rear end portion of each link 9 are connected to the front and rear links 9 respectively. The first and second joint pins 10 and 11 are inserted into the openings 4a and 4b and endlessly connected to each other. Both joint pins 10 and 11 are set to be longer than the thickness (width direction length) of the laminated links 9, and project both ends of the laminated pins 9 outward in the width direction from the laminated links 9.

  During operation of the belt-type continuously variable transmission 1, at least the end surface 11a of the second joint pin 11 of the joint pins 10 and 11 is brought into contact with the conical surfaces 2c, 2d, 3c and 3d of the pulleys 2 and 3, Torque is transmitted from the input side pulley 2 to the output side pulley 3 via the chain 4.

  The opposing surfaces of both joint pins 10 and 11 are each formed, for example, in an arc shape so that when the link 9 bends at the position of both pulleys 2 and 3, the rolling surfaces relatively roll and contact. Here, rolling sliding contact refers to a contact state including at least one of rolling contact and sliding contact. When the links 9 adjacent to each other in the traveling direction of the chain 4 are alternately bent, wear of the links 9 can be suppressed by rolling and slidingly moving the joint pins 10 and 11.

Next, the characteristic part of the belt type continuously variable transmission 1 of the first embodiment will be described.
In the belt type continuously variable transmission 1 of the first embodiment, when the low speed stage is selected (reduction gear ratio), that is, the winding radius of the input pulley 2 is small, and the winding radius of the output pulley 3 is large. Then, both joint pins 10 and 11 are brought into contact with the conical surfaces 2c, 2d, 3c and 3d. Further, when the high speed stage is selected (speed-up gear ratio), that is, when the winding radius of the input pulley 2 is large and the winding radius of the output pulley 3 is small, the second joint pin 11 is conical. Contact with the surfaces 2c, 2d, 3c, 3d.

  In order to realize the above configuration, in the first embodiment, the shapes of the end faces 10a and 11a of the joint pins 10 and 11 are made different from each other, and the shapes of the conical surfaces 2c and 2d of the input pulley 2 and the output pulley 3 are The shapes of the conical surfaces 3c and 3d are made different.

3A is an enlarged view of a portion A in FIG. 1, and FIG. 3B is an enlarged view of a portion B in FIG.
The end surface 11a of the second joint pin 11 is, for example, a curved surface having a constant radius (for example, R100). On the other hand, the end face 10a of the first joint pin 10 has the same outer shape as the end face 11a of the second joint pin 11 on the outer peripheral side of the edge located on the outer side of the chain 4, and the inner peripheral side of the end edge located on the inner side of the chain 4. The curved surface has a smaller radius (for example, R100) than the end surface 11a.

  The conical surfaces 2c and 2d of the input side pulley 2 are curved surfaces (for example, R100) swelled inside the input side pulley 2. The conical surfaces 3c and 3d of the output pulley 3 are curved surfaces (for example, R100) that swell outward from the output pulley 3.

Next, the operation will be described.
In the belt-type continuously variable transmission 1 according to the first embodiment, the above-described configuration allows the input-side pulley 2 to have the joint pins 10 and 11 at the speed reduction gear ratio (hereinafter referred to as the speed reduction gear ratio pin position). Both end surfaces 10a and 11a are brought into contact with the conical surfaces 2c and 2d, and at the position of the joint pins 10 and 11 at the speed increase gear ratio (hereinafter referred to as speed increase gear ratio pin position), only one end surface 11a is conical surface 2c. , 2d.

  In the output pulley 3 as well, both end faces 10a and 11a are in contact with the conical surfaces 3c and 3d at the speed reduction gear ratio pin position, and only one end surface 11a is in contact with the conical surfaces 3c and 3d at the speed increasing gear ratio pin position. Can be made.

  Conventionally, in a chain in which a link is connected by a pair of joint pins, when the chain is wound around a pulley, the contact surface between the pair of joint pins has a relative angle, so that the chain can be bent. For this reason, the end surfaces of both joint pins rotate with respect to the sheave, and the friction loss between the joint pin end surfaces and the sheave increases, so the transmission efficiency decreases.

  On the other hand, in order to reduce friction loss, when one of the two joint pins is formed shorter than the other so that only one pin end surface is in contact with the sheave, the two pin end surfaces are defined as sheaves. Compared with the case of contact, since the surface pressure of the pin end surface is high, the wear of the pin or sheave becomes severe.

  On the other hand, in the belt-type continuously variable transmission 1 of the first embodiment, as shown in FIG. 4, the end surface 11a of one second joint pin 11 at the speed increasing gear ratio pin position of the input side pulley 2 is a sheave 2a, 2b, and the end faces 10a, 11a of both joint pins 10, 11 are in contact with the sheaves 2a, 2b at the reduction gear ratio pin position. Further, the end face 11a of one second joint pin 11 contacts the sheaves 3a, 3b at the speed increasing gear ratio pin position of the output side pulley 3, and the end faces 10a of both joint pins 10, 11 at the speed reducing gear ratio pin position. 11a contacts the sheaves 3a and 3b.

  That is, the number of joint pins in contact with the sheave is switched to one or two according to the operating condition (wrapping radius), so that the resistance between the end faces 10a, 11a and the sheaves 2a, 2b, 3a, 3b is increased. It is possible to achieve both improvement of wear and reduction of friction loss of the chain 4.

  Further, the two joint pins 10 and 11 are brought into contact with the sheaves 2a, 2b, 3a and 3b at the speed reduction gear ratio pin position, and the one second joint pin 11 is brought into the sheaves 2a, 2b, They are in contact with 3a and 3b. For this reason, in the case of operating conditions in which the reduction gear ratio is high torque and the acceleration gear ratio is low torque, the durability of the pins 10, 11 and the pulleys 2, 3 at high load is improved. Efficiency at low load can be improved.

Next, the effect will be described.
The belt type continuously variable transmission 1 of the first embodiment has the following effects.

  (1) The number of joint pins in contact with the sheaves 2a, 2b, 3a, 3b among the first and second joint pins 10, 11 differs depending on the wrapping radius of the chain 4 around the input pulleys 2, 3. The shape of the end faces 10a, 11a of the first and second joint pins 10, 11 and the shape of the sheaves 2a, 2b, 3a, 3b were set as follows (one or two). As a result, it is possible to improve both the wear resistance between the end faces 10a, 11a and the sheaves 2a, 2b, 3a, 3b and reduce the friction loss of the chain 4.

  (2) When the winding radius of the input pulley 2 is small and the winding radius of the output pulley 3 is large, the first and second joint pins 10 and 11 are connected to the sheaves 2a, 2b, 3a and 3b. The second joint pin 11 is brought into contact with the sheaves 2a, 2b, 3a, 3b when the winding radius of the input pulley 2 is large and the winding radius of the output pulley 3 is small. This improves the durability of the pins 10 and 11 and the pulleys 2 and 3 at the time of a high load in the case of operating conditions in which the reduction gear ratio is high torque and the acceleration gear ratio is low torque. Efficiency at low load can be improved.

  In the belt-type continuously variable transmission 1 of the second embodiment, the shapes of the end faces 10a, 11a of both joint pins 10, 11 are the same as those of the first embodiment, and the shapes of the conical surfaces 2c, 2d, 3c, 3d are the first embodiment. It is different from. Since other configurations are the same as those in the first embodiment, illustration and description thereof are omitted.

  In the second embodiment, as shown in FIG. 5, the conical surfaces 2 c and 2 d of the input side pulley 2 are curved surfaces (for example, R100) that swell outside the input side pulley 2. The conical surfaces 3 c and 3 d of the output pulley 3 are curved surfaces (for example, R100) that swell inside the output pulley 3.

Next, the operation will be described.
In the belt-type continuously variable transmission 1 according to the second embodiment, the end surface 11a of one second joint pin 11 is in contact with the sheaves 2a and 2b at the speed reduction gear ratio pin position of the input pulley 2, and at the speed increase gear ratio pin position. The end faces 10a, 11a of both joint pins 10, 11 are in contact with the sheaves 2a, 2b. Further, the end face 11a of one second joint pin 11 contacts the sheaves 3a, 3b at the speed reduction gear ratio pin position of the output pulley 3, and the end faces 10a of both joint pins 10, 11 at the speed increase gear ratio pin position. 11a contacts the sheaves 3a and 3b.

  That is, the two joint pins 10, 11 are brought into contact with the sheaves 2a, 2b, 3a, 3b at the speed increasing gear ratio pin position, and the one second joint pin 11 is brought into the sheaves 2a, 2b, at the speed reduction gear ratio pin position. They are in contact with 3a and 3b. For this reason, in the case of an operating condition in which the speed ratio on the speed increasing side is high torque and the speed ratio on the speed reducing side is low torque, the durability of the pins 10 and 11 and the pulleys 2 and 3 at high load is improved. Efficiency at low load can be improved.

Next, the effect will be described.
In addition to the effect (1) of the first embodiment, the belt type continuously variable transmission 1 of the second embodiment has the following effects.

  (3) When the winding radius of the input pulley 2 is large and the winding radius of the output pulley 3 is small, the first and second joint pins 10 and 11 are connected to the sheaves 2a, 2b, 3a and 3b. The second joint pin 11 is brought into contact with the sheaves 2a, 2b, 3a, and 3b when the winding radius of the input pulley 2 is small and the winding radius of the output pulley 3 is large. This improves the durability of the pins 10 and 11 and the pulleys 2 and 3 at the time of high load in the case of operating conditions in which the speed ratio on the acceleration side is high torque and the torque ratio on the deceleration side is low torque. Efficiency at low load can be improved.

  In the third embodiment, the shapes of the end faces 10a, 11a of both joint pins 10, 11 are the same as those of the first embodiment, and the shapes of the conical surfaces 2c, 2d, 3c, 3d are different from the first embodiment. Since other configurations are the same as those in the first embodiment, illustration and description thereof are omitted.

  In the third embodiment, as illustrated in FIG. 6, the conical surfaces 2 c and 2 d of the input side pulley 2 are curved surfaces (for example, R100) that swell outside the input side pulley 2. The conical surfaces 3c and 3d of the output pulley 3 are curved surfaces (for example, R100) that swell outward from the output pulley 3.

Next, the operation will be described.
In the belt type continuously variable transmission 1 according to the third embodiment, the end surface 11a of one second joint pin 11 contacts the sheaves 2a and 2b at the speed reduction gear ratio pin position of the input side pulley 2, and at the speed increase gear ratio pin position. The end faces 10a, 11a of both joint pins 10, 11 are in contact with the sheaves 2a, 2b. Further, the end faces 10a, 11a of both joint pins 10, 11 are in contact with the sheaves 3a, 3b at the speed reduction gear ratio pin position of the output side pulley 3, and the end face of one second joint pin 11 at the speed increasing speed ratio pin position. 11a contacts the sheaves 3a and 3b.

  That is, the wear resistance (due to hardness etc.) of the sheaves 2a, 2b, 3a, 3b varies depending on the position corresponding to the radius of the chain 4, and the sheave surface wear resistance on the large diameter side is lower than that on the small diameter side. In this case, the durability of the pulleys 2 and 3 when the chain 4 travels on the large diameter side can be improved, and the efficiency can be improved when the chain 4 travels on the small diameter side.

Next, the effect will be described.
In addition to the effect (1) of the first embodiment, the belt-type continuously variable transmission of the third embodiment has the following effects.

  (4) When the winding radius of the input pulley 2 is small and the winding radius of the output pulley 3 is large, the second joint pin 11 is on the small diameter side, and the first and second joint pins 10 are on the large diameter side. , 11 are brought into contact with the sheaves 2a, 2b, 3a, 3b, and when the winding radius to the input pulley 2 is large and the winding radius to the output pulley 3 is small, the second joint pin 11 is on the small diameter side. On the large diameter side, the first and second joint pins 10, 11 are brought into contact with the sheaves 2a, 2b, 3a, 3b. Thereby, when the wear resistance of the sheave surface on the large diameter side is lower than that on the small diameter side, the durability of the pulleys 2 and 3 when the chain 4 travels on the large diameter side is improved, and the chain 4 Efficiency can be improved when traveling.

  In the fourth embodiment, the shapes of the end faces 10a and 11a of the joint pins 10 and 11 are the same as those of the first embodiment, and the shapes of the conical surfaces 2c, 2d, 3c and 3d are different from those of the first embodiment. Since other configurations are the same as those in the first embodiment, illustration and description thereof are omitted.

  In the fourth embodiment, as illustrated in FIG. 7, the conical surfaces 2 c and 2 d of the input side pulley 2 are curved surfaces (for example, R100) that swell inside the input side pulley 2. The conical surfaces 3 c and 3 d of the output pulley 3 are curved surfaces (for example, R100) that swell inside the output pulley 3.

Next, the operation will be described.
In the belt-type continuously variable transmission 1 according to the fourth embodiment, the end faces 10a and 11a of both joint pins 10 and 11 are in contact with the sheaves 2a and 2b at the speed reduction gear ratio pin position of the input side pulley 2, and the speed increase gear ratio pin. At the position, the end surface 11a of one second joint pin 11 contacts the sheaves 2a and 2b. Further, the end face 11a of one joint pin 11 contacts the sheaves 3a, 3b at the speed reduction gear ratio pin position of the output pulley 3, and the end faces 10a, 11a of both joint pins 10, 11 at the speed increasing speed ratio pin position. It contacts the sheaves 3a and 3b.

  That is, the wear resistance (due to hardness etc.) of the sheaves 2a, 2b, 3a, 3b varies depending on the position corresponding to the radius of the chain 4, and the sheave surface wear resistance on the small diameter side is lower than that on the large diameter side. In this case, the durability of the pulleys 2 and 3 when the chain 4 travels on the small diameter side can be improved, and the efficiency can be improved when the chain 4 travels on the large diameter side.

Next, the effect will be described.
The belt type continuously variable transmission according to the fourth embodiment has the following effects in addition to the effect (1) of the first embodiment.

  (5) When the winding radius of the input pulley 2 is small and the winding radius of the output pulley 3 is large, the first and second joint pins 10 and 11 are on the small diameter side, and the second joint is on the large diameter side. When the pin 11 is in contact with the sheaves 2a, 2b, 3a, 3b, the winding radius of the input pulley 2 is large and the winding radius of the output pulley 3 is small, the first and second are on the small diameter side. The joint pins 10 and 11 are brought into contact with the sheaves 2a, 2b, 3a and 3b on the large diameter side. As a result, when the wear resistance of the sheave surface on the small diameter side is lower than that on the large diameter side, the durability of the pulleys 2 and 3 when the chain 4 travels on the small diameter side is improved. Efficiency can be improved when traveling.

  The best mode for carrying out the present invention has been described with reference to the embodiments based on the drawings. However, the specific configuration of the present invention is not limited to that shown in the embodiments, and the gist of the present invention. Even if there is a design change that does not change the value, it is included in the present invention.

1 is a configuration diagram of a belt-type continuously variable transmission according to Embodiment 1. FIG. It is the perspective view (a) and principal part enlarged view (b) of the chain 4 of Example 1. FIG. It is the A section enlarged view (a) and B section enlarged view (b) of FIG. FIG. 2 is an enlarged view of a part A and a part B in FIG. 1 showing a contact state between an end face of a joint pin and a sheave at a reduction gear ratio pin position and an acceleration gear ratio pin position according to the first embodiment. FIG. 3 is an enlarged view of a portion A and a portion B in FIG. 1 illustrating a contact state between an end surface of a joint pin and a sheave at a speed reduction gear ratio pin position and a speed increase gear ratio pin position according to a second embodiment. FIG. 6 is an enlarged view of a portion A and a portion B in FIG. 1 illustrating a contact state between an end surface of a joint pin and a sheave at a speed reduction gear ratio pin position and a speed increase gear ratio pin position according to a third embodiment. FIG. 6 is an enlarged view of part A and part B of FIG. 1 showing a contact state between an end face of a joint pin and a sheave at a speed reduction gear ratio pin position and a speed increase speed ratio pin position according to a fourth embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Belt type continuously variable transmission 2 Input side pulley 2a Fixed sheave 2b Movable sheave 2c, 2d Conical surface 3 Output side pulley 3a Fixed sheave 3b Movable sheave 3c, 3d Conical name 4 Chain 4a, 4b Opening 5 Input shaft 6 Output shaft 7, 8 Reduction gear 9 Link 10 First joint pin 10a End surface 11 Second joint pin 11a End surface

Claims (5)

In a belt-type continuously variable transmission in which a chain in which each link is connected endlessly with a pair of joint pins is wrapped around the frustoconical sheave of the input pulley and the output pulley,
One pair of joint pins are in contact with the sheave when the winding radius of the chain pulley is small or large, and both joint pins are in contact with the sheave when the winding radius is large or small. A belt type continuously variable transmission characterized in that the end face shape and sheave shape of the joint pin are set. The belt-type continuously variable transmission according to claim 1,
When the winding radius to the input pulley is small and the winding radius to the output pulley is large, both joint pins are brought into contact with the sheave,
A belt-type continuously variable transmission in which one joint pin is brought into contact with a sheave when a winding radius of the input pulley is large and a winding radius of the output pulley is small. The belt-type continuously variable transmission according to claim 1,
When the winding radius to the input pulley is small and the winding radius to the output pulley is large, one joint pin is brought into contact with the sheave,
A belt type continuously variable transmission characterized in that when the winding radius of the input pulley is large and the winding radius of the output pulley is small, both joint pins are brought into contact with the sheave. The belt-type continuously variable transmission according to claim 1,
When the winding radius to the input pulley is a small diameter and the winding radius to the output pulley is a large diameter, one joint pin on the small diameter side, both joint pins on the large diameter side are in contact with the sheave,
When the winding radius to the input pulley is large and the winding radius to the output pulley is small, one joint pin on the small diameter side and both joint pins on the large diameter side are in contact with the sheave. A belt-type continuously variable transmission. The belt-type continuously variable transmission according to claim 1,
When the winding radius to the input pulley is a small diameter and the winding radius to the output pulley is a large diameter, both joint pins on the small diameter side, one joint pin on the large diameter side is in contact with the sheave,
When the winding radius of the input pulley is large and the winding radius of the output pulley is small, both joint pins on the small diameter side and one joint pin on the large diameter side are in contact with the sheave. A belt-type continuously variable transmission.

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