JP2017082971A - Pulley device - Google Patents

Abstract

A pulley device capable of suppressing tilting of a movable sheave is provided. A pulley device (100) includes a fixed sheave (1), a fixed boss (2), a movable sheave (3), a movable boss (4), and a cam mechanism (7). A fixed boss 2 extends axially from the fixed sheave 1 . The movable boss 4 extends axially from the movable sheave 3 radially outwardly of the fixed boss 2 . The cam mechanism 7 converts relative rotation of the movable boss 4 with respect to the fixed boss 2 into axial thrust of the movable boss 4 . The cam mechanism 7 has a cam groove 71 and an engaging pin 72 . The cam groove 71 is formed on the outer peripheral surface of the fixed boss 2 . The engagement pin 72 protrudes radially inward from the inner peripheral surface of the movable boss 4 and engages with the cam groove 71 . [Selection drawing] Fig. 1

Description

  The present invention relates to a pulley apparatus.

  A scooter type motorcycle or the like employs a belt type continuously variable transmission. This continuously variable transmission includes a drive pulley device, a driven pulley device, and a belt. The belt is suspended between the drive pulley device and the driven pulley device.

  The driven pulley device holds the belt between the movable sheave and the fixed sheave. During sudden acceleration such as when starting, the belt may not be firmly clamped by the movable sheave and the fixed sheave. In order to prevent this, the pulley apparatus of Patent Document 1 includes a cam mechanism. This cam mechanism includes a cam portion provided on the movable boss and a cam receiving portion provided on the drive plate. When the movable sheave rotates relative to the fixed sheave, the cam mechanism converts the rotation into axial thrust and moves the movable sheave toward the fixed sheave. As a result, the belt is firmly held between the movable sheave and the fixed sheave.

Japanese Patent No. 3651628

  As described above, since the end of the movable boss on the drive plate side is a cam portion, the length of the movable boss in the axial direction of the portion that contacts the fixed boss is shortened. If the length in the axial direction of the contact portion between the movable boss and the fixed boss is shortened, the movable sheave collapses due to the load from the belt, and power transmission loss occurs.

  The subject of this invention is providing the pulley apparatus which can suppress the fall of a movable sheave.

  A pulley apparatus according to an aspect of the present invention includes a fixed sheave, a fixed boss, a movable sheave, a movable boss, and a cam mechanism. The fixed boss extends in the axial direction from the fixed sheave. The movable sheave is movable so as to approach and move away from the fixed sheave in the axial direction. The movable boss extends in the axial direction from the movable sheave on the radially outer side of the fixed boss. The cam mechanism converts the relative rotation of the movable boss with respect to the fixed boss into the axial thrust of the movable boss. The cam mechanism has a cam groove and an engagement pin. The cam groove is formed on the outer peripheral surface of the fixed boss. The engaging pin protrudes radially inward from the inner peripheral surface of the movable boss and engages with the cam groove.

  According to this configuration, the cam mechanism is configured by the cam groove formed on the outer peripheral surface of the fixed boss and the engagement pin protruding from the inner peripheral surface of the movable boss. That is, no cam portion is formed at the end of the movable boss on the drive plate side. For this reason, compared with a pulley apparatus in which the end of the movable boss is a cam part, the pulley apparatus according to the present invention can increase the axial length of the contact portion between the fixed boss and the movable boss. . As a result, the movable sheave can be prevented from falling.

  Preferably, the pulley device further includes a sliding member. The sliding member is attached to the inner peripheral surface of the movable boss. The sliding member has a lower coefficient of friction than the movable boss. According to this configuration, the movable boss can smoothly slide on the fixed boss via the sliding member. Further, since the engaging groove is formed not on the movable sheave but on the fixed sheave side, the sliding member can be elongated in the axial direction.

  Preferably, the pulley apparatus further includes a cover member attached to the outer peripheral surface of the movable boss. The movable boss has a mounting hole that penetrates in the radial direction and is covered by the cover member. The engagement pin is attached to the attachment hole. According to this configuration, after the movable boss is attached to the fixed boss, the engagement pin can be attached to the movable boss by inserting the engagement pin into the through hole. Further, by closing the through hole from the outside in the radial direction by the cover member, it is possible to prevent the engagement pin from coming out of the through hole due to centrifugal force.

  Preferably, an elastic body that urges the movable sheave toward the fixed sheave is further provided. The cover member has a cover main body portion and a contact portion. The cover main body extends along the outer peripheral surface of the movable boss. The contact portion contacts the end surface of the elastic body on the movable sheave side. According to this configuration, for example, when a spring is used as the elastic body, since the end surface of the spring is in contact with the contact portion, it is possible to prevent the end surface of the spring from damaging the movable sheave.

  The cam groove extends in the axial direction, and can be configured such that one end of the cam groove opens toward the side opposite to the movable sheave. According to this configuration, even when the engagement pin is attached to the movable boss, the movable boss can be attached to the fixed boss by inserting the engagement pin into the cam groove from the opening end of the cam groove. it can.

  According to the present invention, it is possible to suppress the falling of the movable sheave.

Side surface sectional drawing of a pulley apparatus. The side view of a fixed sheave and a fixed boss. Side surface sectional drawing of the pulley apparatus which concerns on a modification. The side view of the fixed sheave and the fixed boss which concerns on a modification.

  Hereinafter, embodiments of a pulley device according to the present invention will be described with reference to the drawings. The pulley apparatus 100 according to the present embodiment is a driven pulley apparatus. Torque is transmitted to the driven pulley apparatus 100 via a belt 110 from a driving pulley apparatus (not shown). The belt 110 is a member for transmitting torque.

  FIG. 1 is a side sectional view of the pulley device 100. In the following description, the rotation axis O means the rotation axis of the pulley device 100. The radial direction means the radial direction of a circle around the rotation axis O. The outer side in the radial direction means the side away from the rotation axis O in the radial direction, and the inner side in the radial direction means the side closer to the rotation axis O in the radial direction. The axial direction means a direction along the rotation axis O. The first side in the axial direction means the left side of FIG. 1, and the second side in the axial direction means the right side of FIG. The circumferential direction means the circumferential direction of a circle around the rotation axis O.

  As shown in FIG. 1, the pulley device 100 includes a fixed sheave 1, a fixed boss 2, a movable sheave 3, a movable boss 4, a cover member 5, a sliding member 6, a cam mechanism 7, a spring ( An example of an elastic body) 8, a spring seat 9, and a centrifugal clutch 10 are provided.

  As shown in FIGS. 1 and 2, the fixed sheave 1 is disposed so as to rotate about the rotation axis O. The central axis of the fixed sheave 1 is arranged substantially coaxially with the rotation axis O. The fixed sheave 1 is disposed on the second side of the movable sheave 3 in the axial direction. The fixed sheave 1 is fixed so as not to move in the axial direction.

  The fixed sheave 1 has a disk shape. The facing surface 11 of the fixed sheave 1 is inclined so as to move away from the movable sheave 3 as it goes outward in the radial direction. That is, the opposing surface 11 is inclined toward the second side in the axial direction toward the outer side in the radial direction. Note that the facing surface 11 of the fixed sheave 1 is a surface facing the movable sheave 3. That is, the facing surface 11 of the fixed sheave 1 faces the first side in the axial direction.

  The fixed boss 2 extends from the fixed sheave 1 to the first side in the axial direction. The fixed boss 2 rotates integrally with the fixed sheave 1. In the present embodiment, the fixed boss 2 and the fixed sheave 1 are formed of a single member. Note that the fixed boss 2 and the fixed sheave 1 are formed by separate members, and may be integrally rotated by being fixed to each other. The fixed boss 2 is cylindrical. The central axis of the fixed boss 2 is arranged substantially coaxially with the rotation axis O.

  A cam groove 71 is formed on the outer peripheral surface of the fixed boss 2. The cam groove 71 extends in the axial direction and is inclined in the circumferential direction. More specifically, the cam groove 71 is inclined toward the rotational direction side toward the second side in the axial direction. Note that the rotation direction is a direction in which the fixed boss 2 rotates when the vehicle moves forward. The cam mechanism 7 is configured by the cam groove 71 and an engagement pin 72 described later. Further, the cam groove 71 may penetrate in the axial direction.

  The centrifugal clutch 10 is attached to the first end 21 of the fixed boss 2. The fixed sheave 1 extends radially outward from the second end 22 of the fixed boss 2. The first end portion 21 is an end portion on the first side in the axial direction, and the second end portion 22 is an end portion on the second side in the axial direction. The first end portion 21 has an attachment surface extending in parallel with each other on the outer peripheral surface. Since the first end portion 21 has a smaller outer diameter than other portions, a shoulder portion 23 is formed.

  The output shaft (not shown) extends in the axial direction inside the fixed boss 2. The output shaft is a shaft for transmitting torque to the rear wheels, for example. The output shaft and the fixed boss 2 are relatively rotatable. Note that bearings 111 and 112 are disposed between the output shaft and the fixed boss 2.

  As shown in FIG. 1, the movable sheave 3 is arranged so as to rotate about the rotation axis O. The central axis of the movable sheave 3 is arranged substantially coaxially with the rotation axis O. The movable sheave 3 is arranged so as to move along the rotation axis O. That is, the movable sheave 3 is disposed so as to move in the axial direction. The movable sheave 3 moves toward and away from the fixed sheave 1 by moving in the axial direction. The movable sheave 3 is disposed on the first side of the fixed sheave 1 in the axial direction.

  The movable sheave 3 has a disk shape. The facing surface 31 of the movable sheave 3 is inclined so as to move away from the fixed sheave 1 as it goes outward in the radial direction. That is, the facing surface 31 is inclined toward the first side in the axial direction toward the outer side in the radial direction.

  The facing surface 31 of the movable sheave 3 is a surface facing the fixed sheave 1. That is, the facing surface 31 of the movable sheave 3 faces the second side in the axial direction. The facing surface 11 of the fixed sheave 1 and the facing surface 31 of the movable sheave 3 are opposed to each other with an interval. A V groove is formed by the facing surface 11 of the fixed sheave 1 and the facing surface 31 of the movable sheave 3. As the movable sheave 3 moves in the axial direction, the groove width of the V groove changes. A belt 110 is disposed in the V groove. The belt 110 is sandwiched between the facing surface 11 of the fixed sheave 1 and the facing surface 31 of the movable sheave 3.

  The movable sheave 3 has an annular support wall portion 32 protruding to the first side in the axial direction. The support wall portion 32 is disposed on the radially outer side of the movable boss 4. Between the support wall 32 and the movable boss 4, the end of the spring 8 is disposed.

  The movable boss 4 extends from the movable sheave 3 to the first side in the axial direction. That is, the movable boss 4 extends in a direction away from the fixed sheave 1. The movable boss 4 rotates integrally with the movable sheave 3. The movable boss 4 moves in the axial direction integrally with the movable sheave 3. In the present embodiment, the movable boss 4 and the movable sheave 3 are formed of a single member. Note that the movable boss 4 and the movable sheave 3 are formed by separate members, and may be integrally rotated and moved in the axial direction by being fixed to each other.

  The movable boss 4 has a cylindrical shape and is disposed on the radially outer side of the fixed boss 2. That is, the fixed boss 2 extends in the movable boss 4. The central axis of the movable boss 4 is arranged substantially coaxially with the rotation axis O.

  The movable boss 4 has a mounting hole 41 penetrating in the radial direction. An engagement pin 72 is fitted in the mounting hole 41. The engagement pin 72 protrudes radially inward from the inner peripheral surface of the movable boss 4. The engagement pin 72 rotates integrally with the movable boss 4 and moves in the axial direction integrally with the movable boss 4. The engagement pin 72 is engaged with the cam groove 71 and can slide in the cam groove 71. The engagement pin 72 and the cam groove 71 constitute the cam mechanism 7. That is, when the movable boss 4 rotates relative to the fixed boss 2, the cam groove 71 and the engagement pin 72 cause the relative rotation of the axial thrust for the movable boss 4 to move to the second side in the axial direction. Convert to Specifically, when the movable boss 4 rotates at a faster speed than the fixed boss 2, the cam mechanism 7 moves the movable boss 4 toward the fixed sheave 1.

  Note that at least one of the inner wall surface of the cam groove 71 and the outer peripheral surface of the engagement pin 72 is preferably covered with resin. As a result, the engagement pin 72 can slide smoothly in the cam groove 71. For example, at least one of the inner wall surface of the cam groove 71 and the outer peripheral surface of the engagement pin 72 is covered with at least one selected from the group consisting of nylon resin, fluorine resin, polyether ether ketone resin, and polyphenylene sulfide resin. ing. In this case, the engagement pin 72 can be formed of the same material as that of the movable boss 4 as described later, for example. Note that the engaging pin 72 itself may be formed of the resin as described above.

  The cover member 5 is attached to the outer peripheral surface of the movable boss 4. The cover member 5 covers the attachment hole 41 from the outside in the radial direction. For this reason, the engagement pin 72 attached to the attachment hole 41 can be prevented from coming off radially outward due to centrifugal force. The cover member 5 is formed of, for example, a steel plate.

  The cover member 5 has a cover main body 51 and a contact portion 52. The cover main body 51 is cylindrical and extends along the outer peripheral surface of the movable boss 4. The contact portion 52 is a flange portion that extends from the end portion on the second side in the axial direction of the cover main body portion 51 toward the outer side in the radial direction. The contact portion 52 is in contact with the end surface on the second axial side of the spring 8.

  The sliding member 6 is attached to the inner peripheral surface of the movable boss 4. In the present embodiment, the pulley device 100 includes a first sliding member 6 a and a second sliding member 6 b as the sliding member 6. The first sliding member 6 a is disposed on the first side in the axial direction from the engagement pin 72. The second sliding member 6b is disposed on the second side in the axial direction from the engagement pin 72.

  The first and second sliding members 6 a and 6 b are cylindrical and are attached to the inner peripheral surface of the movable boss 4. The first and second sliding members 6 a and 6 b have a lower coefficient of friction than the movable boss 4. For example, the first and second sliding members 6 a and 6 b are made of a material having a lower coefficient of friction than the movable boss 4. Specifically, the movable boss 4 is made of metal, and the first and second sliding members 6a are made of resin. More specifically, the movable boss 4 is made of steel or aluminum alloy. The movable boss 4 is formed of at least one selected from the group consisting of carbon steel and alloy steel. On the other hand, the first and second sliding members 6a and 6b are formed of at least one selected from the group consisting of nylon resin, fluororesin, polyether ether ketone resin, and polyphenylene sulfide resin. Thus, since the first and second sliding members 6 a and 6 b are interposed, the movable boss 4 can slide smoothly on the fixed boss 2. The movable boss 4 can slide on the fixed boss 2 without using grease.

  The spring 8 biases the movable sheave 3 toward the fixed sheave 1 in the axial direction. That is, the spring 8 urges the movable sheave 3 toward the second side in the axial direction. As a result, the fixed sheave 1 and the movable sheave 3 sandwich the belt 110. The spring 8 can be a coil spring, for example. The spring 8 is disposed outside the movable boss 4 in the radial direction so as to surround the movable boss 4.

  The spring seat 9 is configured to support the spring 8. The spring seat 9 has a cylindrical portion 91 and a flange portion 92. The spring seat 9 is made of resin, for example. Specifically, the spring seat 9 is at least one selected from the group consisting of a nylon resin, a fluororesin, a polyether ether ketone resin, and a polyphenylene sulfide resin. The cylindrical portion 91 and the flange portion 92 are integrally formed by one member.

  The cylindrical portion 91 is disposed on the radially outer side of the movable boss 4. The cylindrical portion 91 is disposed on the radially inner side of the spring 8. That is, the cylindrical portion 91 is disposed between the movable boss 4 and the spring 8 in the radial direction. The cylindrical portion 91 supports the spring 8 in the radial direction.

  The flange portion 92 extends radially outward from the cylindrical portion 91. Specifically, the flange portion 92 extends radially outward from the end portion on the first axial side of the cylindrical portion 91. The flange portion 92 is annular. The flange portion 92 supports the first end surface of the spring 8 in the axial direction. That is, the flange portion 92 supports the spring 8 in the axial direction.

  The centrifugal clutch 10 includes a drive plate 101, a plurality of clutch shoes 102, and a clutch housing 103. The centrifugal clutch 10 is configured to transmit or block the rotation of the fixed sheave 1 and the movable sheave 3 to the output shaft. Specifically, the centrifugal clutch 10 is configured to transmit or block the rotation of the fixed boss 2 to the output shaft.

  The drive plate 101 is attached to the first end 21 of the fixed boss 2. The drive plate 101 rotates integrally with the fixed boss 2. The drive plate 101 has a boss portion 104 and a disc portion 105.

  The boss 104 is cylindrical and extends in the axial direction. The boss portion 104 is attached to the fixed boss 2. Specifically, the boss 104 has a through hole 106 at the center. The through hole 106 is shaped to engage with the first end 21 of the fixed boss 2. Specifically, the outer peripheral edge of the through hole 106 has substantially the same shape as the outer peripheral edge of the fixed boss 2.

  The disc part 105 extends radially outward from the boss part 104. The disc part 105 has a flat plate shape. That is, the disc part 105 has substantially no step part. In addition, the disc part 105 may not be flat form, and may have a level | step difference part.

  The drive plate 101 is made of metal. Specifically, the drive plate 101 is made of steel or aluminum alloy. More specifically, the drive plate 101 is at least one selected from the group consisting of carbon steel and alloy steel. The drive plate 101 is restricted from moving toward the second side in the axial direction by contacting the shoulder 23 of the fixed boss 2. In addition, the drive plate 101 is restricted from moving in the axial direction to the first side by the retaining ring 113 attached to the first end portion 21.

  Each clutch shoe 102 has a circumferential end attached to the drive plate 101 so as to be swingable. Each clutch shoe 102 has a friction material (not shown) on its outer peripheral surface. A return spring (not shown) is attached to the other end of each clutch shoe 102 so as to urge each clutch shoe 102 inward in the radial direction.

  The clutch housing 103 is disposed so as to cover each clutch shoe 102 from the outside in the radial direction. The clutch housing 103 is rotatable relative to the fixed boss 2. Specifically, the clutch housing 103 has a boss portion 107. A spline hole 108 is formed in the boss portion 107. The output shaft can be spline engaged with the spline hole 108.

  When the centrifugal clutch 10 is in the transmission state, the friction material of each clutch shoe 102 is frictionally engaged with the inner peripheral surface of the clutch housing 103. Further, when the centrifugal clutch 10 is in the disconnected state, the friction material of each clutch shoe 102 is separated from the inner peripheral surface of the clutch housing 103. The transmission state of the centrifugal clutch 10 means a state in which the centrifugal clutch 10 transmits the rotation of the fixed sheave 1 and the movable sheave 3 to the output shaft. The disconnected state of the centrifugal clutch 10 means a state where the centrifugal clutch 10 does not transmit the rotation of the fixed sheave 1 and the movable sheave 3 to the output shaft.

  The pulley apparatus configured as described above operates as follows.

  In the driving pulley apparatus, when the width of the groove formed by the fixed sheave and the movable sheave is reduced, the winding diameter of the belt 110 is increased. That is, the belt 110 moves outward in the radial direction in the pulley apparatus on the driving side.

  In the driven pulley device 100, the width of the groove formed by the fixed sheave 1 and the movable sheave 3 operates in the opposite direction to the groove width in the driving pulley device. That is, when the belt 110 moves radially outward in the driving pulley apparatus, the belt 110 moves radially inward in the driven pulley apparatus 100.

  When the belt 110 moves inward in the radial direction, the movable sheave 3 moves away from the fixed sheave 1 against the biasing force of the spring 8. That is, the movable sheave 3 moves to the first side in the axial direction. As a result, the width of the groove between the fixed sheave 1 and the movable sheave 3 increases.

  Further, in the driving-side pulley device, when the width of the groove formed by the fixed sheave and the movable sheave increases, the winding diameter of the belt 110 decreases. That is, the belt 110 moves inward in the radial direction in the driving pulley apparatus.

  When the belt 110 moves radially inward in the driving pulley apparatus, the belt 110 moves radially outward in the driven pulley apparatus 100. Then, the movable sheave 3 moves in the direction approaching the fixed sheave 1 by the urging force of the spring 8. As a result, the width of the groove between the fixed sheave 1 and the movable sheave 3 is reduced.

  Next, the operation of the cam mechanism 7 will be described. When rapidly accelerating, such as when starting, the movable sheave 3 rotates at a faster speed than the fixed sheave 1. Then, the movable boss 4 rotates at a faster speed than the fixed boss 2. That is, the movable boss 4 rotates relative to the fixed boss 2 in the rotation direction (in the present embodiment, clockwise as viewed from the second side in the axial direction). Then, the cam mechanism 7 applies an axial thrust to the movable boss 4, and the movable boss 4 moves to the second side in the axial direction. As a result, the movable sheave 3 moves to the fixed sheave 1 side and firmly holds the belt 110.

  As described above, the pulley apparatus 100 according to the present embodiment has the following characteristics.

  The cam mechanism 7 includes a cam groove 71 formed on the outer peripheral surface of the fixed boss 2 and an engagement pin 72 protruding from the inner peripheral surface of the movable boss 4. That is, the cam portion is not formed at the end portion on the first axial side of the movable boss 4. For this reason, the pulley device 100 according to this embodiment has a longer axial length of the contact portion between the fixed boss 2 and the movable boss 4 than the pulley device in which the end of the movable boss is a cam portion. can do. As a result, the movable sheave can be prevented from falling.

[Modification]
As mentioned above, although embodiment of this invention was described, this invention is not limited to these, A various change is possible unless it deviates from the meaning of this invention.

Modification 1
In the above embodiment, the engaging pin 72 is a separate member from the movable boss 4, but the engaging pin 72 may be formed from the movable boss 4 and one member. For example, a convex portion protruding radially inward from the inner peripheral surface of the movable boss 4 can be used as the engagement pin.

Modification 2
In the above embodiment, only one cam groove 71 and one engagement pin 72 are shown, but the number of sets of cam grooves 71 and engagement pins 72 is not limited to one, but may be a plurality of sets.

Modification 3
In the above embodiment, the movable boss 4 slides on the fixed boss 2 without using grease, but may slide on the fixed boss 2 through grease.

Modification 4
As shown in FIGS. 3 and 4, the end portion on the first axial side of the cam groove 71 may open toward the first axial side. According to this configuration, even when the engagement pin 72 is attached to the movable boss 4, the movable boss 4 is moved by inserting the engagement pin 72 into the cam groove 71 from the open end of the cam groove 71. It can be attached to the fixed boss 2.

1: Fixed sheave 2: Fixed boss 3: Movable sheave 4: Movable boss 41: Mounting hole 5: Cover member 51: Cover main body 52: Abutting portion 6: Sliding member 7: Cam mechanism 71: Cam groove 72: Engagement Joint pin 8: Spring 100: Pulley device

Claims (5)

With fixed sheaves,
A fixed boss extending in the axial direction from the fixed sheave;
A movable sheave movable in an axial direction so as to approach and separate from the fixed sheave;
A movable boss extending in the axial direction from the movable sheave on the radially outer side of the fixed boss;
A cam mechanism for converting the relative rotation of the movable boss with respect to the fixed boss into the axial thrust of the movable boss;
With
The cam mechanism includes a cam groove formed on an outer peripheral surface of the fixed boss, and an engagement pin that protrudes radially inward from an inner peripheral surface of the movable boss and engages the cam groove.
Pulley device. A sliding member attached to the inner peripheral surface of the movable boss and further having a lower coefficient of friction than the movable boss;
The pulley apparatus according to claim 1. Further comprising a cover member attached to the outer peripheral surface of the movable boss,
The movable boss has a mounting hole that penetrates in the radial direction and is covered by the cover member,
The engagement pin is attached to the attachment hole.
The pulley apparatus according to claim 1 or 2. An elastic body for urging the movable sheave toward the fixed sheave;
The cover member includes a cover main body extending along the outer peripheral surface of the movable boss, and an abutting portion that abuts on an end surface of the elastic body on the movable sheave side.
The pulley apparatus according to claim 3. The cam groove extends in the axial direction,
One end of the cam groove opens toward the opposite side of the movable sheave,
The pulley apparatus in any one of Claim 1 to 4.

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