WO2014112163A1

WO2014112163A1 - Multi-disk transmission

Info

Publication number: WO2014112163A1
Application number: PCT/JP2013/077524
Authority: WO
Inventors: 丹下　宏司
Original assignee: ジヤトコ株式会社
Priority date: 2013-01-21
Filing date: 2013-10-09
Publication date: 2014-07-24
Also published as: JP2016084822A

Abstract

Provided is a multi-disk transmission comprising a plurality of protrusions in the disk circumference direction thereof on a surface that forms the contact section of at least one of a primary disk and a secondary disk, said plurality of protrusions having a width in the disk radial direction that is narrower than the width of the contact section in the disk radial direction.

Description

Multi-disc transmission

The present invention relates to a multi-disc transmission.

In JP2010-53995A, a primary disk provided on the input shaft and a secondary disk provided on the output shaft are partially overlapped to provide a disk overlap area, and both disks are sandwiched between a pair of pressing rollers in this area. A multi-disc transmission that transmits the rotation of an input shaft to an output shaft by bringing them into contact is disclosed.

In multi-disc transmissions, shifting is realized by changing the position where a pair of pressing rollers sandwich both discs. That is, if the position between the two disks is close to the input shaft, the gear ratio changes to the low side (large gear ratio side), and if close to the output shaft, the gear ratio changes to the high side (low gear ratio side). .

In a multi-disc transmission, a contact portion that transmits torque is formed by slight elastic deformation of the disc, and therefore the contact portion becomes surface contact and spin loss occurs.

Spin loss is a drive loss that occurs when the disk is in sliding contact due to the difference in peripheral speed between the primary disk and the secondary disk at the contact portion. And since the peripheral speed difference of a primary disk and a secondary disk becomes large, so that the width | variety of a contact part is wide, there exists a problem that a spin loss becomes large and torque transmission efficiency falls (refer FIG. 6).

The present invention has been made in view of such technical problems, and aims to reduce spin loss.

According to an aspect of the present invention, an input shaft to which rotation from a power source is input, an output shaft arranged in parallel to the input shaft, a primary disk provided on the input shaft, and the output shaft A secondary disk having a disk overlapping area that overlaps the primary disk, a pair of pressing rollers disposed on both sides of the primary disk and the secondary disk in the disk overlapping area, and the pair of pressing rollers A transmission actuator that moves between the input shaft and the output shaft, and the pair of pressing rollers are pressed against the primary disk and the secondary disk, and a contact portion is provided between the primary disk and the secondary disk. A multi-disc transmission having a pressing mechanism to be formed; The surface of the contact portion of at least one of the primary disk and the secondary disk is provided with a plurality of protrusions in the disk circumferential direction whose width in the disk radial direction is narrower than the width in the disk radial direction of the contact part. A multi-disc transmission is provided.

FIG. 1 is an overall schematic view of a vehicle equipped with a multi-disc transmission. FIG. 2 is a view of the multi-disc transmission as viewed from the engine side. FIG. 3 is a bottom view of FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. 5 is a cross-sectional view taken along the line VV in FIG. FIG. 6 is a diagram illustrating a difference in peripheral speed between the primary disk and the secondary disk in the torque transmission contact portion. FIG. 7 is a diagram showing a disk overlap area. FIG. 8 is a top view of a center disk provided with a facing. FIG. 9 is a diagram showing a modification example of the facing. FIG. 10 is a diagram showing another modification of the facing. FIG. 11 is a diagram showing a modification of the center disk.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is an overall schematic diagram of a vehicle including a multi-disc transmission according to an embodiment of the present invention.

The vehicle 1 includes an engine 2 as a power source, a multi-disc transmission (hereinafter referred to as a transmission) 3, left and

right drive shafts

4 and 5, and left and

right drive wheels

6 and 7.

The transmission 3 includes a transmission case 9, an input shaft 10, a primary disk 11, a secondary disk 12, a pressing mechanism 13, an output shaft 14, a dry start clutch 15, a reverse gear 16, and a reverse idler gear. 17, an output gear 18, a synchronization mechanism 19, a final gear 20, and a differential gear unit 21.

The input shaft 10 and the output shaft 14 are arranged in parallel and are rotatably supported by the transmission case 9.

FIG. 2 is a view of the transmission 3 as viewed from the engine 2 side. FIG. 3 is a bottom view of FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. In addition, about drawing after FIG. 2, a part of member is abbreviate | omitted for description.

The primary disk 11 is configured by arranging two circular disks 11 a in the axial direction of the input shaft 10 and attaching them to the input shaft 10, and rotates integrally with the input shaft 10. A spacer 22 is provided between the two disks 11 a, and the two disks 11 a are arranged at a predetermined interval in the axial direction of the input shaft 10 by the spacer 22. The primary disk 11 is arranged so that the outer peripheral end of the disk 11 a is close to the output shaft 14. The primary disk 11 rotates with the input shaft 10 in the direction of the arrow in FIG.

The secondary disk 12 includes a center disk 12a and two side disks 12b provided facing both sides of the center disk 12a. The secondary disk 12 is configured by arranging a center disk 12 a and a side disk 12 b in the axial direction of the output shaft 14 and attaching to the output shaft 14, and rotates integrally with the output shaft 14. A spacer 23 is provided between the center disk 12a and the side disk 12b, and the center disk 12a and the side disk 12b are arranged with a predetermined distance in the axial direction of the output shaft 14 by the spacer 23. The secondary disk 12 is arranged so that the outer peripheral end of the center disk 12 a and the outer peripheral end of the side disk 12 b are close to the input shaft 10.

The center disk 12a is a circular disk, and is thicker in the axial direction of the output shaft 14 than the side disk 12b and the disk 11a of the primary disk 11. The center disk 12a includes facings 121 on both sides. The facing 121 will be described in detail later.

The disk 11a of the primary disk 11 is disposed between the center disk 12a and the side disk 12b of the secondary disk 12. The primary disk 11 and the secondary disk 12 form a disk overlap region where a part of the disk overlaps between the input shaft 10 and the output shaft 14.

In the disk overlap region, a gap is formed between the disk 11a of the primary disk 11 and the center disk 12a in a state where the pressing force by the pressing mechanism 13 described in detail below does not act.

On the other hand, in a situation where the pressing force by the pressing mechanism 13 is applied, the primary disk 11 and the secondary disk 12 are elastically deformed and contacted to form a torque transmission contact portion. In the transmission 3, the transmission of rotation from the input shaft 10 to the output shaft 14 is realized by forming a torque transmission contact portion between the primary disk 11 and the secondary disk 12. The axis connection line O is a line that connects the axis of the input shaft 10 and the axis of the output shaft 14 and is orthogonal to the input shaft 10 and the output shaft 14.

The pressing mechanism 13 includes a pair of pressing roller mechanisms 30, a pair of disk clamp mechanisms 31, a pressing force adjusting mechanism 32, and a first actuator 33.

The first actuator 33 moves the pressing roller mechanism 30 along the axial connection line O.

The first actuator 33 includes an electric motor 34, a ball screw mechanism 35, and a bracket 37.

The ball screw mechanism 35 has one end connected to the rotating shaft of the electric motor 34 and rotates in the forward or reverse direction depending on the rotating direction of the rotating shaft of the electric motor 34. The ball screw mechanism 35 is extended in the direction of the axis connection line O.

When the ball screw mechanism 35 rotates, the bracket 37 moves along the axial direction of the ball screw mechanism 35, that is, the direction of the axis connection line O according to the rotation of the ball screw mechanism 35. The bracket 37 is formed with a tapered surface 37a on the surface on the engine 2 side, the distance from the ball screw mechanism 35 becomes shorter toward the electric motor 34 side. When the bracket 37 is reciprocated by the electric motor 34, a push rod (not shown) that follows a tapered surface 37a like a so-called cam follower is reciprocated, and the release lever of the dry start clutch 15 is driven by the push rod. The clutch is engaged and released.

The bracket 37 is connected to the second support portion 44 and the roller follower support block 48 of the pressing roller mechanism 30 through a first shaft 38 extending in the direction of the axis connection line O. When the ball screw mechanism 35 is rotated by the electric motor 34, the bracket 37 moves back and forth along the direction of the axis connection line O according to the rotation direction of the ball screw mechanism 35, and the pressing roller mechanism 30 moves to the bracket 37 and the first. It is integrated with the shaft 38 and moves back and forth along the direction of the axis connection line O.

FIG. 5 is a VV cross-sectional view of FIG.

The pressing roller mechanism 30 includes a pressing roller 40, a holding portion 41, a pressing roller shaft 42, a first support portion 43, a second support portion 44, a support block 46, and a first roller follower 47.

The pair of pressing roller mechanisms 30 are disposed on both sides of the primary disk 11 and the secondary disk 12 and are attached to the guide block 49. The guide block 49 is slidably supported by two guide shafts 51 provided between the two guide shaft blocks 50 attached to the transmission case 9 and extending in the direction of the axis connection line O. In other words, the pressing roller mechanism 30 is slidably supported by the guide shaft 51 via the guide block 49, moves in the direction of the axis connection line O by the first actuator 33, and transmits torque to a position corresponding to the target gear ratio. A contact portion is formed.

The pressing roller shaft 42 extends in a direction intersecting with the direction of the axis connection line O, one end portion 42 a is supported by the first support portion 43, and the other end portion 42 b is supported by the second support portion 44. Is done. The pressing roller shaft 42 has a spherical end portion 42 b supported by the second support portion 44. A holding portion 41 that supports the pressing roller 40 is attached to the pressing roller shaft 42 between the first support portion 43 and the second support portion 44.

The first support portion 43 is rotatably supported by the guide block 49 via a rotation shaft 52 provided in parallel with the guide shaft 51. The first support portion 43 supports one end portion 42 a of the pressing roller shaft 42 via the needle bearing 53.

The second support portion 44 supports the other end portion 42 b of the pressing roller shaft 42 via the support block 46 and the needle bearing 54. A bush 55 having a spherical tip 55a is provided between the second support portion 44 and the support block 46 in the axial direction of the input shaft 10, and a gap is provided between the second support portion 44 and the support block 46. Is formed. The gap in the axial direction of the input shaft 10 is positioned closer to the primary disk 11 than the bush 55, and the tip 55 a of the bush 55 contacts the support block 46. The second support portion 44 is connected to the end portion of the second shaft 56 that extends in the direction of the axis connection line O and the direction orthogonal to the axial direction of the input shaft 10 and to which the first roller follower 47 is attached. The second support portion 44 moves in the axial direction of the input shaft 10 by a pressing force applied to the first roller follower 47. According to the movement of the second support portion 44 in the axial direction of the input shaft 10, the first support portion 43 and the holding portion 41 that supports the pressing roller 40 rotate about the rotation shaft 52.

The first support portion 43 is provided so as to form a gap between the needle bearing 53 and the pressing roller shaft 42 in the direction of the axis connection line O. The end portion 42 b of the pressing roller shaft 42 supported by the second support portion 44 has a spherical shape, and the end portion 42 b is in contact with the needle bearing 54. Accordingly, the pressing roller shaft 42 is supported by the first support portion 43 and the second support portion 44 so as to be rotatable and tiltable with respect to the direction of the axis connection line O.

The holding portion 41 is provided between the first support portion 43 and the second support portion 44 and is attached to the pressing roller shaft 42. The holding portion 41 rotates and tilts integrally with the pressing roller shaft 42.

The first shaft part 57 is fixed to the holding part 41. When the pressing roller shaft 42 is in a direction perpendicular to the axial center connection line O when viewed from the axial direction of the input shaft 10, the first shaft portion 57 coincides with the axial center connection line O. Further, the first shaft portion 57 is provided so that the first shaft portion 57 inclines with respect to the disk surface in FIG.

The pressing roller 40 is rotatably supported by the first shaft portion 57.

The pressing roller 40 abuts on the side disk 12b in the disk overlapping region and rotates around the first shaft portion 57. When the pressing force transmitted through the first roller follower 47 increases, the pressing roller 40 elastically deforms the

disks

11 and 12 to form a torque transmission contact portion.

The urging force of the springs 60 of the urging

portions

45 a and 45 b acts on the pressing roller 40 via the holding portion 41.

As shown in FIG. 5, in the first roller follower 47, a second shaft 56 connected to the second support portion 44 is inserted into the inner peripheral hole 47a, and the front clamp arm 67 and the rear clamp arm 68 on the side of the

disks

11, 12 are arranged. Rolls in contact with the side surfaces 67a and 68a.

The end portion of the second shaft 56 opposite to the end portion connected to the second support portion 44 is inserted into a hole 48 a formed in the roller follower support block 48. The hole 48 a is an oval-shaped hole formed along the axial direction of the input shaft 10. The roller follower support block 48 supports the second shaft 56 slidably in the axial direction of the input shaft 10 along the hole 48a. The roller follower support block 48 is connected to the bracket 37 via a first shaft 38 extending in the direction of the axis connection line O, and moves in the direction of the axis connection line O according to the movement of the bracket 37.

The disc clamp mechanism 31 includes an arm shaft 65, a front clamp arm 67, and a rear clamp arm 68.

The arm shaft 65 is a columnar member that extends in a direction perpendicular to the axial connection line O and the input shaft 10. The arm shaft 65 is provided so as to be orthogonal to the input shaft 10 and to overlap the center of the primary disk 11 in the axial direction of the input shaft 10 as shown in FIG.

The front clamp arm 67 is a plate-like member having a substantially L shape as shown in FIG. The front clamp arm 67 is rotatably supported on the arm shaft 65 on one end side. At the other end of the front clamp arm 67, an engaging portion 72 of a pressing force adjusting mechanism 32 described later is formed. As shown in FIG. 5, the front clamp arm 67 is in contact with the first roller follower 47 at the side surface 67 a (the surface forming the thickness of the plate member) on the side of the

disks

11 and 12.

The rear clamp arm 68 is a plate-like member having a substantially L shape as shown in FIG. The rear clamp arm 68 is rotatably supported on the arm shaft 65 on one end side. The other end of the rear clamp arm 68 is connected to a case 70 of a pressing force adjusting mechanism 32 described later. As shown in FIG. 5, the side surface 68 a (the surface forming the thickness of the plate-like member) of the rear clamp arm 68 contacts the first roller follower 47.

The front clamp arm 67 and the rear clamp arm 68 are rotated about the arm shaft 65 by the pressing force generated by the pressing force adjusting mechanism 32, and the pressing force is applied to the holding portion 41 by sandwiching the pair of pressing roller mechanisms 30. A pressing force is applied from the pressing roller 40 to the primary disk 11 and the secondary disk 12.

As shown in FIG. 3, the pressing force adjusting mechanism 32 includes a case 70, a second shaft portion 71, an engaging portion 72, a rotating portion 73, a compression spring 74, and a second actuator (not shown). Is provided.

The case 70 is connected to the end of the rear clamp arm 68. The case 70 accommodates a part of the rotating part 73, and the second shaft part 71 is attached thereto.

The second shaft portion 71 is a columnar member parallel to the arm shaft 65 and supports the rotating portion 73 in a rotatable manner.

The engaging portion 72 is formed at the end portion of the front clamp arm 67, and extends from the end portion toward the rear clamp arm 68, and the second shaft portion extends from the end portion of the connecting portion 75 on the rear clamp arm 68 side. And a curved surface portion 76 extending so as to surround 71. The curved surface portion 76 has an arc-shaped outer peripheral wall with the second shaft portion 71 as the center. The second roller follower 79 of the rotating portion 73 comes into contact with the outer peripheral wall of the curved surface portion 76 and rolls.

The rotating unit 73 includes a rotating body 77, a rotation transmitting block 78, and a second roller follower 79. The rotating body 77 includes a first body 80 and a second body 81.

The first body 80 is a substantially U-shaped member extending so as to sandwich the second shaft portion 71. The first body 80 abuts on the outer peripheral wall of the second shaft portion 71 and is supported by the second shaft portion 71 so as to be rotatable and slidable. The first body 80 includes a stopper 82 that supports one end of the compression spring 74 at the end on the open side.

The rotation transmission block 78 is supported by the second shaft portion 71 so as to be rotatable through the second shaft portion 71. The rotation transmission block 78 supports the end of the compression spring 74 opposite to the end supported by the stopper 82.

The first body 80 and the second body 81 are joined, and the second roller follower 79 is attached to the second body 81.

The rotating body 77 is always urged in the direction from the second shaft portion 71 toward the stopper 82 by the restoring force of the compression spring 74. However, the second body 81 located on the opposite side to the compression spring 74 with respect to the second shaft portion 71 abuts on the rotation transmission block 78, and the rotation body 77 moves from the second shaft portion 71 toward the compression spring 74. Is regulated.

The second roller follower 79 rolls in contact with the arc-shaped outer peripheral wall of the curved surface portion 76. The second roller follower 79 rotates the second shaft portion 71 integrally with the rotary body 77 by the second actuator, and is always biased toward the second shaft portion 71 by the compression spring 74.

The pressing force adjusting mechanism 32 rotates the second roller follower 79 about the second shaft portion 71, thereby causing the compression spring 74 to urge the second roller follower 79 toward the second shaft portion 71. Change direction. Thereby, the force which pushes the front clamp arm 67 to the rear clamp arm 68 side, ie, the pressing force which clamps a pair of pressing roller mechanism 30, is changed.

As described above, in the transmission 3, when the pressing force by the pressing mechanism 13 is applied, the primary disk 11 and the secondary disk 12 are elastically deformed to contact each other, and a torque transmission contact portion is formed to form the input shaft 10. Is transmitted to the output shaft 14.

In such a multi-disc transmission, since the torque transmission contact portion is formed by slight elastic deformation of the disc, the torque transmission contact portion is in surface contact. As the width of the torque transmission contact portion in the direction of the axis connection line O is wider, the spin loss (drive loss due to sliding contact) due to the peripheral speed difference of the disk at the torque transmission contact portion increases and the torque transmission efficiency decreases. Therefore, it is necessary to reduce the spin loss.

FIG. 6 is a diagram showing the peripheral speed difference between the primary disk 11 and the secondary disk 12 at the torque transmission contact portion.

The peripheral speed of the primary disk 11 and the peripheral speed of the secondary disk 12 are such that the primary disk 11 is a drive disk and the secondary disk 12 is a driven disk, so that the peripheral speed of the primary disk 11> the peripheral speed of the secondary disk 12. .

In an ideal driving state where no slip is generated at the torque transmission contact portion, the peripheral speed of the primary disk 11 and the peripheral speed of the secondary disk 12 are equal at the end of the torque transmission contact portion on the primary disk 11 side. The peripheral speed difference becomes maximum at the end on the secondary disk 12 side.

Thus, since the spin loss occurs in the portion where the peripheral speed difference between the primary disk 11 and the secondary disk 12 is generated, the torque transmission efficiency of the transmission 3 is lowered.

On the other hand, the center disk 12a according to the present embodiment includes facings 121 on both sides as shown in FIG. 7, and the facing 121 includes a plurality of circumferential grooves 122 as shown in FIG. And divided into a plurality of sections by a plurality of grooves 123 in the radial direction of the disk.

The positions of the plurality of circumferential grooves 122 in the disk are the radial width of the facing 121 divided by the circumferential grooves 122, that is, the radial width of the protrusion 124 in the circumferential direction of the disk. The width is set to be narrower than the width of the torque transmission contact portion formed when the circumferential groove 122 is not provided. For example, in the present embodiment, the pressing roller 40 is set to be narrower than the width in contact with the side disk 12b, so that the torque transmission contact portion of the facing 121 is not provided with the disk circumferential groove 122. The width can be narrowed.

Further, the width of the groove 122 in the circumferential direction of the disk is such that when the torque transmission contact portion is formed between the disk 11a and the center disk 12a, the disk 11a is other than the protrusion 124 that forms the torque transmission contact portion. It is set so as not to contact the protrusion 124.

In this way, the width in the disk radial direction of the protrusion 124 in the disk circumferential direction is set to be narrower than the width in which the pressing roller 40 comes into contact with the side disk 12b, so that the facing 121 has a groove 122 in the disk circumferential direction. The width of the torque contact transmission portion is narrower than when not provided. Accordingly, since the circumferential speed difference between the primary disk 11 and the secondary disk 12 at the torque transmission contact portion is smaller than when the facing 121 does not include the disk circumferential groove 122, the spin loss can be reduced.

Also, in the multi-disc transmission, torque is transmitted by the frictional force generated at the torque transmission contact portion. Therefore, when the pressing force is insufficient, there is a problem that slip occurs at the contact portion and the torque transmission efficiency is lowered.

On the other hand, in this embodiment, the width of the torque contact transmission portion becomes narrower and the surface pressure of the contact portion becomes higher than when the facing 121 does not include the disk circumferential groove 122. Therefore, the occurrence of slip can be suppressed without increasing the pressing force, and a reduction in the torque transmission efficiency of the transmission can be prevented.

In particular, as shown in FIG. 7, the protrusion 124 in the circumferential direction of the disk is formed so that the width of the torque transmission contact portion becomes narrower as it is closer to the input shaft 10, so that the gear ratio is on the low side (the gear ratio large side). Even when the input torque is large, the contact portion can be prevented from slipping without increasing the pressing force.

In addition, since the plurality of

disks

11 and 12 are pressed by the pressing roller 40, the pressing force is dispersed and transmitted to the inner disk, and the surface pressure of the torque transmission contact portion decreases, but the center disk 12a disposed on the innermost side. However, by providing the facing 121 having a high friction coefficient, a high frictional force can be secured and slip can be suppressed.

Further, as described above, the facing 121 includes a plurality of grooves 123 in the radial direction of the disk, so that the lubricating oil adhering to the surfaces of the center disk 12a and the disk 11a forming the torque transmission contact portion is grooved in the disk radial direction. 123 is discharged. Therefore, it is possible to prevent the lubricating oil from being caught in the torque transmission contact portion and to achieve fluid lubrication due to the wedge effect, and to suppress slip.

According to the above aspect, the width in the disk radial direction of the facing 121 divided by the plurality of grooves 122 in the circumferential direction of the disk, that is, the width in the disk radial direction of the protrusion 124 in the circumferential direction of the disk, the pressing roller 40 and the side disk 12b. Since the width is set to be narrower than the contact width, the width of the torque transmission contact portion is narrower than that in the case where the facing 121 does not include the groove 122 in the disk circumferential direction. Therefore, since the circumferential speed difference between the primary disk 11 and the secondary disk 12 at the torque transmission contact portion can be made smaller than when the facing 121 does not have the disk circumferential groove 122, the spin loss can be reduced and the torque transmission efficiency can be reduced. (Effects corresponding to claims 1 and 3).

Further, in the multi-disc transmission, torque is transmitted by the frictional force generated at the torque transmission contact portion. Therefore, when the pressing force is insufficient, slip occurs at the contact portion and the torque transmission efficiency decreases. , Since the width of the torque contact transmission portion is narrower than the case where the facing 121 does not include the disk circumferential groove 122 and the surface pressure of the contact portion increases, the occurrence of slip can be suppressed without increasing the pressing force, Reduction in torque transmission efficiency of the transmission can be prevented (effect corresponding to claims 1 and 3).

Further, by forming the protrusion 124 in the disk circumferential direction so that the width of the torque transmission contact portion becomes narrower as it is closer to the input shaft 10, even when the input gear ratio is large on the low gear ratio (large gear ratio ratio side), The slip of the contact portion can be suppressed without increasing the pressing force (effect corresponding to claim 5).

Further, since the facing 121 includes a plurality of disk radial grooves 123, the lubricating oil adhering to the surfaces of the center disk 12a and the disk 11a forming the torque transmission contact portion is discharged from the disk radial grooves 123, and torque Lubricating oil is caught in the transmission contact portion, and fluid lubrication can be prevented due to the wedge effect. Therefore, slip can be suppressed and a decrease in torque transmission efficiency can be suppressed (effect corresponding to claim 4).

The embodiment of the present invention has been described above, but the above embodiment is merely one example of application of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. is not.

For example, the facing 121 shown in FIG. 8 is divided into a plurality of sections by a plurality of circumferential grooves 122 and a plurality of disk radial grooves 123, and each section is completely separated. As shown in FIG. 9, the facing 121 may be continuous at the bottom of the groove 122 in the disk circumferential direction and the groove 123 (not shown) in the disk radial direction. Further, as shown in FIG. 10, the shape of the protrusion 124 in the circumferential direction of the disk may be formed in a mountain shape.

Since the

grooves

122 and 123 are formed in the facing 121, the design can be easily changed to various shapes.

In the above-described embodiment, the center disk 12a has the facing 121. However, the disk 11a and the side disk 12b may have the facing 121.

Further, in the above embodiment, the width of the torque contact transmission portion is narrowed by forming the protrusion 124 in the circumferential direction of the disk by the facing 121 provided in the center disk 12a. However, as shown in FIG. You may make it narrow the width | variety of a torque transmission contact part by using the center disk 12c which shape | molded the protrusion 125 of the circumferential direction.

Also in this case, as in the above embodiment, since the peripheral speed difference between the primary disk 11 and the secondary disk 12 at the torque transmission contact portion can be reduced, the spin loss can be reduced and the reduction in torque transmission efficiency can be suppressed. Corresponding effect).

Also, since the surface pressure of the torque transmission contact portion is increased, the occurrence of slip can be suppressed without increasing the pressing force, and the reduction in the torque transmission efficiency of the transmission can be prevented (effect corresponding to claim 2).

Further, by forming the disk circumferential direction projection 125 so that the width in the disk radial direction becomes narrower as it is closer to the input shaft 10, even when the input gear ratio is large on the low gear ratio side (high gear ratio side), The slip of the contact portion can be suppressed without increasing the force (effect corresponding to claim 5).

This application claims priority based on Japanese Patent Application No. 2013-008602 filed with the Japan Patent Office on January 21, 2013, the entire contents of which are incorporated herein by reference.

Claims

An input shaft to which rotation from a power source is input;
An output shaft disposed parallel to the input shaft;
A primary disk provided on the input shaft;
A secondary disk provided on the output shaft and having a disk overlap area overlapping the primary disk;
A pair of pressing rollers disposed on both sides of the primary disk and the secondary disk in the disk overlapping region;
A speed change actuator that moves the pair of pressing rollers between the input shaft and the output shaft;
In the multi-disc transmission comprising: a pressing mechanism that presses the pair of pressing rollers against the primary disk and the secondary disk to form a contact portion between the primary disk and the secondary disk;
A multi-protrusion having a plurality of protrusions in the circumferential direction of the disk in which the width in the disk radial direction is narrower than the width in the disk radial direction of the contact part on the surface forming the contact part of at least one of the primary disk and the secondary disk Disc transmission.
The multi-disc transmission according to claim 1,
The plurality of disk circumferential protrusions are formed by molding at least one of the primary disk and the secondary disk.
The multi-disc transmission according to claim 1,
The plurality of disk circumferential protrusions are multi-disk transmissions formed of a friction material provided on a surface forming the contact portion of at least one of the primary disk and the secondary disk.
The multi-disc transmission according to claim 3,
A multi-disc transmission in which a plurality of disc radial grooves are provided in the friction material.
The multi-disc transmission according to claim 1, wherein
A multi-disc transmission in which the disc radial width of the projection in the disc circumferential direction is narrower as it is closer to the input shaft.