JP7422934B2 - transmission - Google Patents

Description

The present invention relates to a transmission that selectively couples a gear disposed on a shaft to the shaft.

In a transmission, a gear provided with a first tooth and a moving member provided with a second tooth are arranged on a shaft, and the moving member is moved in a first axial direction where the first tooth and the second tooth mesh. , a prior art is known in which a gear is selectively coupled to a shaft via a moving member by meshing first teeth and second teeth (Patent Document 1). In the prior art (see FIG. 9), the root of the drive torque acting surface of the second tooth has an inclination that generates a second axial thrust force that releases the mesh. The surface on which the coasting torque of the second tooth acts includes an engaging surface and a guide surface adjacent to the tooth tip side of the engaging surface, and when the coasting torque acts, a thrust force in the second axial direction is generated. .

A shift device that moves a moving member in an axial direction includes an engaging portion coupled to the moving member, a first cam that moves the engaging portion in a first axial direction by rotational movement, and a first cam that moves the engaging portion in a first axial direction by rotational movement. a second cam that moves in the two axial directions. A gap is provided between the first cam and the second cam in which the engaging portion can be moved in the second axial direction by the thrust force applied by the second tooth to the first tooth. At the time of upshifting, the drive torque moves the movable member in the second axial direction by the inclination of the tooth base in the lower gear shift stage where the first tooth and the second tooth engage, and at this time, the cam is rotated and the first After the engaging portion is in a state where it cannot move in the axial direction, the first tooth and the second tooth of the upper speed gear are engaged. In the lower gear shift state, which is in the coast state, the second tooth contacts the guide surface of the first tooth, and the first tooth and the second tooth disengage, and the upshift is completed.

JP2020-133827A

In the prior art, a drive torque acts between the second tooth and the first tooth that mesh with each other, and when the slope of the root of the second tooth and the first tooth are pressed, the gap between the first cam and the second cam is Since there is a gap in which the engaging part can move in the axial direction, the engaging part moves by the amount of the gap. Further, when coasting torque is applied between the second teeth and the first teeth that mesh with each other, the engaging portion moves by the amount of the gap between the first cam and the second cam until it hits the first cam. As a result of this movement, the second tooth comes into contact with the guide surface of the first tooth, and the first tooth and second tooth are disengaged from each other. If the angle between the plane containing the shaft and the guide surface is large, a large force will be applied to the moving member in the second axial direction in response to the coasting torque, so the machine that requires the members from the moving member to the engaging part There is a problem that the intensity of the target increases. If the angle between the plane containing the shaft and the guide surface is small, the kinetic energy of the moving member when it disengages is hardly reduced, so the mechanical strength required by the mechanism to stop the disengaged moving member is large. There is a problem that the moving member is stopped, and that an abnormal noise is generated when the moving member comes to a standstill. Further, when the direction of the torque acting between the second tooth and the first tooth changes, the engaging portion hits the first cam, causing a problem of impact and abnormal noise.

The present invention was made in order to solve these problems, and an object of the present invention is to provide a transmission that can reduce the required mechanical strength and reduce the impact and noise generated in the shift device. do.

In order to achieve this object, the transmission of the present invention is provided with a gear that is provided with a first tooth and is disposed on the shaft, and selectively couples to the shaft, and a gear that is provided with a second tooth that meshes with the first tooth. A shift in which the movable member is moved in a first axial direction in which the first tooth and the second tooth engage, and the movable member is moved in a second axial direction in which the first tooth and the second tooth are disengaged. A device. The first tooth includes a first surface facing one side in the circumferential direction and a second surface facing the other side in the circumferential direction. a third surface that faces at least a portion of the first surface when the teeth engage, and a third surface that faces at least a portion of the second surface when the moving member moves in the axial direction to engage the first and second teeth. A fourth side facing each other is provided. The first surface and the third surface include a first portion that transmits a torque in the direction of pressing the first surface and the third surface, and at least one of the first surface and the third surface is on the dedendum side of the first portion. The movable member includes an adjacent second portion that applies a thrust force in the second axial direction to the movable member in accordance with the torque in the direction of pressing the first surface and the third surface. The second surface and the fourth surface include a third portion that applies a thrust force in the second axial direction to the moving member in accordance with the torque in the direction of pressing the second surface and the fourth surface. The shift device includes an engaging part coupled to the moving member, a first cam that moves the engaging part in a first axial direction by rotational movement, and a first cam that moves the engaging part in a second axial direction by rotational movement. 2 cams, and a spring that generates elastic force as the engaging portion moves. The first cam stands still when the third part applies a second axial thrust to the moving member due to the spring in a state where the engaging part is in contact with the second cam, and applies the second axial thrust to the moving member. The second part rotates when acting.

According to the first aspect, the engaging portion is coupled to the moving member provided with the second teeth that mesh with the first teeth provided on the gear. The rotational movement of the first cam causes the engaging part to move in the first axial direction, and the rotational movement of the second cam causes the engaging part to move in the second axial direction, and as the engaging part moves, the spring becomes elastic. Force arises. With the engaging portion in contact, the first cam remains stationary when the third portion applies a second axial thrust due to coasting torque to the movable member due to the spring, and the second axial thrust due to the driving torque is applied to the first cam. The second part rotates when the second part applies a thrust in the direction to the moving member.

Since the engaging part is in contact with the first cam when the direction of the torque acting between the second tooth and the first tooth changes, the engaging part is moved between the first cam and the second cam in the axial direction. Compared to the case where there is a gap in which the moving member can move, the initial speed of the moving member when the first tooth and the second tooth are disengaged can be controlled. This makes it possible to control the kinetic energy of the member from the moving member to the engaging part, which reduces the mechanical strength required for the member from the moving member to the engaging part and the mechanism for stopping the disengaged moving member. The required mechanical strength can be reduced. Furthermore, it is possible to reduce shocks and abnormal noises generated in the shift device.

According to the second aspect, the pressure angle of the first cam and the pressure angle of the second cam are set to mutually independent values, and the first tooth and the second tooth of the second cam are set to be independent values. By making the pressure angle of the portion of the first cam that disengages from the teeth larger than the pressure angle of the portion of the first cam that engages the first tooth and the second tooth during downshifting from the upper gear to the lower gear, the first cam In addition to the effects of the above embodiments, the first teeth and the second teeth can be quickly disengaged and the first teeth and the second teeth can be engaged to prevent gear slippage.

According to the third aspect, the first cam has a pressure angle at a portion where the first tooth and the second tooth of the upper gear shift are engaged during an upshift from the lower gear shift to the upper gear shift, such that the pressure angle at a portion where the first tooth and the second tooth of the upper gear shift are engaged with each other during a downshift from the upper gear gear to the lower gear shift is larger than the pressure angle at the portion where the first tooth and the second tooth of the lower speed gear mesh. In addition to the effects of the first or second aspect, it is possible to quickly engage the first and second teeth of the upper gear shift and to mesh the first and second teeth of the lower gear to prevent gear slippage. can.

According to the fourth aspect, in downshifting from the upper gear to the lower gear, the shift device disengages the first tooth and the second tooth of the upper gear and disengages the first tooth and the second tooth of the lower gear. The engagement and are performed at the same time. In addition to the effects of any of the first to third aspects, seamless downshifting is possible.

It is a skeleton diagram of a transmission in a 1st embodiment. It is a schematic diagram of an idling gear and a moving member. (a) is a schematic diagram of a transmission that transmits coasting torque, and (b) is a schematic diagram of a transmission that transmits drive torque. FIG. 2 is a schematic diagram of a transmission that transmits coasting torque. FIG. 2 is a schematic diagram of a transmission in the middle of an upshift. FIG. 3 is a schematic diagram of the transmission at the end of a shift-up. FIG. 2 is a schematic diagram of a transmission in the middle of downshifting. FIG. 7 is a schematic diagram of the transmission at the start of downshifting in the second embodiment. FIG. 2 is a schematic diagram of a transmission in the middle of downshifting.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. First, a schematic configuration of a transmission 10 of the present invention will be described with reference to FIG. FIG. 1 is a skeleton diagram of a transmission 10 in the first embodiment. The transmission 10 includes a drive shaft 11 to which power is input, and a driven shaft 12 arranged parallel to the drive shaft 11, and an output gear 13 arranged on the driven shaft 12. The drive shaft 11 and the driven shaft 12 support a first gear 14, a second gear 17, a third gear 20, a fourth gear 23, a fifth gear 26, and a sixth gear 29, which are multiple gears. In this embodiment, the transmission 10 is mounted on an automobile (not shown).

The first speed gear 14 includes a fixed gear 15 fixed to the drive shaft 11 so as not to be relatively rotatable, and an idling gear 16 meshing with the fixed gear 15 and fixed to the driven shaft 12 so as to be relatively rotatable. The second gear 17 includes an idling gear 18 that is relatively rotatably fixed to the drive shaft 11 and a fixed gear 19 that meshes with the idling gear 18 and is fixed to the driven shaft 12 so that it is not relatively rotatable. . The third speed gear 20 includes a fixed gear 21 fixed to the drive shaft 11 so as not to be relatively rotatable, and an idling gear 22 meshed with the fixed gear 21 and fixed to the driven shaft 12 so as to be relatively rotatable.

The fourth gear 23 includes an idling gear 24 fixed to the drive shaft 11 so as to be relatively rotatable, and a fixed gear 25 meshing with the idling gear 24 and fixed to the driven shaft 12 so as not to be relatively rotatable. . The 5th gear 26 includes an idling gear 27 that is relatively rotatably fixed to the drive shaft 11 and a fixed gear 28 that meshes with the idling gear 27 and is fixed to the driven shaft 12 so that it is not relatively rotatable. . The 6th gear 29 includes an idling gear 30 fixed to the drive shaft 11 so as to be relatively rotatable, and a fixed gear 31 meshing with the idling gear 30 and fixed to the driven shaft 12 so as not to be relatively rotatable. .

First teeth 32 protruding in the axial direction are provided on the end surfaces of the idle gears 16, 18, 22, 24, 27, and 30, respectively. A hub 33 provided at a position adjacent to the first tooth 32 in the axial direction is coupled to the drive shaft 11 and the driven shaft 12. A moving member 34 is disposed around the outer periphery of the hub 33 so as to be non-rotatable with respect to the hub 33 and movable in the axial direction. A second tooth 35 that engages with the first tooth 32 in the circumferential direction is provided on an end surface of the moving member 34 . When the moving member 34 moves in the axial direction and the first teeth 32 provided on the idle gears 16, 18, 22, 24, 27, and 30 mesh with the second teeth 35 provided on the moving member 34, the movement begins. One of the idle gears 16, 18, 22, 24, 27, and 30 is selectively coupled to the drive shaft 11 and the driven shaft 12 via the member 34 and the hub 33.

A shift device 36 sets the axial position of the moving member 34. The shift device 36 includes shift forks 37, 38, and 39 that engage with the moving member 34, respectively, shift arms 40, 41, and 42 that are coupled to the shift forks 37, 38, and 39, respectively, and a cylindrical shift drum 43. It is equipped with The shift fork 37 engages with a moving member 34 disposed between the idling gear 18 and the idling gear 27. The shift fork 38 engages with a moving member 34 disposed between the idling gear 24 and the idling gear 30. The shift fork 39 engages with a moving member 34 disposed between the idling gear 16 and the idling gear 22.

The shift drum 43 is fixed to the case C and rotated around an axis by an actuator (not shown) such as a motor. Cam grooves 44, 45, and 46 are provided on the outer periphery of the shift drum 43. An engaging portion 47 coupled to the shift arm 40 engages with the cam groove 44 . An engaging portion 48 coupled to the shift arm 41 engages with the cam groove 45 . An engaging portion 49 coupled to the shift arm 42 engages with the cam groove 46 .

The shift drum 43 rotates based on an operation signal from a shift lever (not shown), or based on an accelerator opening degree and vehicle speed signal generated by operation of an accelerator pedal (not shown). When the shift drum 43 (cylindrical cam) rotates, the shift forks 37, 38, 39 move through the shift arms 40, 41, 42, which have engaging portions 47, 48, 49 guided by cam grooves 44, 45, 46, respectively. moves in the axial direction. As the shift forks 37, 38, and 39 move, the moving member 34 moves in the axial direction.

The shift device 36 includes a spring mechanism 50. In this embodiment, the spring mechanism 50 includes a plurality of recesses 51 provided on the outer periphery of each of the shift arms 40, 41, and 42, a ball 52 that engages with the recess 51, and presses the ball 52 against the recess 51 with elastic force. A spring 53 is provided. The recess 51 has a pair of inclined surfaces facing each other in the axial direction.

When the moving member 34 is in the neutral position and when the second teeth 35 and the first teeth 32 provided on the moving member 34 are most deeply engaged, the ball 52 is located at the bottom of the recess 51. When the ball 52 runs over or rides over the slope of the recess 51, the spring 53 applies an axial force to the shift arms 40, 41, and 42. The spring mechanism 50 uses the elastic force of the spring 53 to assist in positioning the moving member 34 in the axial direction and assist in disengaging the first tooth 32 and the second tooth 35 from engagement.

The spring mechanism 50 includes a plurality of recesses 51a provided on the outer periphery of the shift drum 43, a ball 52a that engages with the recess 51a, and a spring 53a that presses the ball 52a against the recess 51a with elastic force. The recess 51a has a pair of inclined surfaces facing each other in the rotational direction of the shift drum 43.

When the second tooth 35 provided on the moving member 34 and the first tooth 32 are most deeply engaged, the ball 52a is located at the bottom of the recess 51a. When the ball 52a runs over or rides over the slope of the recess 51a, the spring 53a applies a force in the rotational direction to the shift drum 43. The spring mechanism 50 assists in positioning the shift drum 43 in the rotational direction by the elastic force of the spring 53a.

The idling gear 24 and the moving member 34 will be explained with reference to FIG. 2. FIG. 2 is a schematic diagram of the free rotation gear 24 and the moving member 34 arranged on the drive shaft 11. FIG. 2 schematically shows the first teeth 32 and second teeth 35 when the free rotating gear 24 and the moving member 34 are viewed from the direction perpendicular to the axis. The idle gears 16, 18, 22, 24, 27, and 30 are provided with first teeth 32 like the idle gear 24, so the idle gear 24 will be explained, and the other idle gears 16, Descriptions of 18, 22, 27, and 30 will be omitted.

Teeth (not shown) that mesh with the fixed gear 25 are provided on the outer periphery of the idle gear 24. A first tooth 32 protruding in the axial direction is provided on one end surface of the idling gear 24. The first teeth 32 are arranged around the central axis of the idling gear 24 at intervals in the circumferential direction. The first tooth 32 includes a first surface 54 facing one circumferential direction and a second surface 57 facing the other circumferential direction.

Second teeth 35 protruding in the axial direction are provided on both end faces of the moving member 34 . The second teeth 35 are arranged around the central axis of the moving member 34 at intervals in the circumferential direction. The second tooth 35 includes a fourth surface 64 facing one circumferential direction, and a third surface 61 facing the other circumferential direction. The third surface 61 faces at least a portion of the first surface 54 when the moving member 34 moves in the axial direction and the first tooth 32 and the second tooth 35 engage with each other. The fourth surface 64 faces at least a portion of the second surface 57 when the moving member 34 moves in the axial direction and the first tooth 32 and the second tooth 35 engage with each other.

The first surface 54 includes a first portion 55 that transmits a torque in a direction that presses the first surface 54 and the third surface 61, and a second portion 56 adjacent to the root side of the first portion 55. The second portion 56 generates a thrust force that separates the free rotating gear 24 and the moving member 34 in the axial direction according to the torque in the direction of pressing the first surface 54 and the third surface 61. The first portion 55 is inclined so as to approach the second surface 57 as it goes toward the root of the tooth. The second portion 56 is inclined away from the second surface 57 toward the root of the tooth.

The third surface 61 includes a first portion 62 that transmits a torque in a direction that presses the first surface 54 and the third surface 61, and a second portion 63 adjacent to the dedendum side of the first portion 62. The second portion 63 generates a thrust force that separates the free rotating gear 24 and the moving member 34 in the axial direction according to the torque in the direction of pressing the first surface 54 and the third surface 61. The first portion 62 is inclined so as to approach the fourth surface 64 as it goes toward the root of the tooth. The second portion 63 is inclined away from the fourth surface 64 toward the root of the tooth. The first portions 55 and 62 transmit torque (drive torque) in the direction of pressing the first surface 54 and the third surface 61 together.

The second surface 57 includes a third portion 58 , a fourth portion 59 adjacent to the tip side of the third portion 58 , and a fifth portion 60 adjacent to the tip side of the fourth portion 59 . The third portion 58 and the fifth portion 60 are inclined so as to approach the first surface 54 toward the tooth tip. The fourth section 59 connects the third section 58 and the fifth section 60.

The fourth surface 64 includes a third portion 65 , a fourth portion 66 adjacent to the tip side of the third portion 65 , and a fifth portion 67 adjacent to the tip side of the fourth portion 66 . The third portion 65 and the fifth portion 67 are inclined so as to approach the third surface 61 toward the tooth tip. The fourth part 66 connects the third part 65 and the fifth part 67. The third parts 58, 65 and the fifth parts 60, 67 move the free rotating gear 24 and the moving member 34 in the axial direction according to the torque (coasting torque) in the direction of pressing the second surface 57 and the fourth surface 64. Generates a thrust to release the

In the first tooth 32, the angle θ1 between the third part 58 and the plane P including the drive shaft 11 (center axis of the free rotating gear 24), and the angle θ2 between the plane P and the fifth part 60 are the plane P is smaller than the angle θ3 between the fourth portion 59 and the fourth portion 59. The angle θ4 between the plane P and the second portion 56 is smaller than the angle θ3 between the plane P and the fourth portion 59. In this embodiment, the angle θ5 between the plane P and the first portion 55 satisfies θ5>0°. The axial length of the second portions 56 and 63 is equal to the axial length of the third portion 58 or shorter than the axial length of the third portion 58.

In the second tooth 35, an angle θ1 between a plane P including the drive shaft 11 (the central axis of the moving member 34) and the third part 65, and an angle θ2 between the plane P and the fifth part 67 are It is smaller than the angle θ3 formed with the fourth portion 66. The angle θ4 between the plane P and the second portion 63 is smaller than the angle θ3 between the plane P and the fourth portion 66. In this embodiment, the angle θ5 between the plane P and the first portion 62 satisfies θ5>0°.

In the first tooth 32 and the second tooth 35, the angle θ1 and the angle θ2 are preferably 20° or less, which is larger than the angle at which no locking occurs due to frictional force. θ1<θ3≦90°. The angle θ3 between the plane P and the fourth portion 59 may be the same as or different from the angle θ3 between the plane P and the fourth portion 66. Preferably, θ4>θ1 and θ4>θ2, and preferably 70°≦θ3≦90°.

The operation of the transmission 10 will be explained with reference to FIGS. 3 to 7. FIG. 3A is a schematic diagram of the transmission 10 that transmits coasting torque in the fourth gear 23. FIG. 3(b) is a schematic diagram of the transmission 10 that transmits drive torque in the fourth gear 23. In the figure, the rotational direction of the moving member 34 and the free rotating gear 24 is downward (in the direction of arrow R1) along the page (the same applies to FIGS. 4 to 9).

As shown in FIG. 3(a), the engaging portion 48 engages with the cam groove 45 of the shift drum 43 (see FIG. 1). When the shift drum 43 rotates, the axial positions of the engaging portion 48 and the shift arm 41 are set by the first cam 68 and the second cam 76 provided inside the cam groove 45 . The first cam 68 faces the second cam 76 in the axial direction. The first cam 68 moves the engaging portion 48 in the first axial direction so that the first tooth 32 and the second tooth 35 mesh with each other. The second cam 76 moves the engaging portion 48 in the second axial direction so that the first tooth 32 and the second tooth 35 are disengaged. The pressure angle of the first cam 68 (the angle between the axis of the shift drum 43 that coincides with the direction of movement of the engaging portion 48 and the normal line of the cam) and the pressure angle of the second cam 76 are equal to the pressure angle of the opposing partner. Takes an unbound independent value.

The first cam 68 is connected to a first plane 69, a first slope 70, a second slope 71, a third slope 72, a second plane 73, a fourth slope 74, a fifth slope 75, and a first plane 69 in this order. The first slope 70 , the second slope 71 , the third slope 72 , the second plane 73 , the fourth slope 74 , and the fifth slope 75 protrude in the axial direction with respect to the first plane 69 . The first slope 70 faces the opposite side of the rotation direction of the second slope 71, the third slope 72, the fourth slope 74, and the fifth slope 75.

The pressure angle of the first plane 69 and the second plane 73 is, for example, greater than or equal to the friction angle (equal to the tangent of the coefficient of static friction between the cam and the engaging portion 48). The pressure angles of the first plane 69 and the second plane 73 are smaller than the pressure angles of the first slope 70 , the second slope 71 , the third slope 72 , and the fourth slope 74 . The pressure angle of the first slope 70 is larger than the pressure angles of the second slope 71, the third slope 72, and the fourth slope 74. The pressure angle of the fifth slope 75 is larger than the pressure angles of the second slope 71, the third slope 72, and the fourth slope 74. The pressure angle of the second slope 71 is larger than the angle at which the engagement part 48 is not locked due to the frictional force of the engagement part 48 acting on the second slope 71, and the pressure angle of the second slope 71 is larger than the angle at which the engagement part 48 is not locked when coasting torque is applied. The angle is less than or equal to the angle at which the portion 48 comes to rest. The pressure angle of the second slope 71 is, for example, 8°-20°.

The second cam 76 is connected to a third plane 77, a sixth slope 78, a fourth plane 79, a seventh slope 80, a fifth plane 81, an eighth slope 82, and a third plane 77 in this order. The sixth slope 78 , the fourth plane 79 , the seventh slope 80 , the fifth plane 81 , and the eighth slope 82 are axially depressed with respect to the third plane 77 . The sixth slope 78 faces the opposite side of the rotation direction of the seventh slope 80 and the eighth slope 82. The pressure angles of the third plane 77, the fourth plane 79, and the fifth plane 81 are, for example, greater than or equal to the friction angle. The pressure angles of the third plane 77, the fourth plane 79, and the fifth plane 81 are smaller than the pressure angles of the sixth slope 78, the seventh slope 80, and the eighth slope 82. The pressure angles of the sixth slope 78 and the eighth slope 82 are larger than the pressure angle of the seventh slope 80. The pressure angles of the sixth slope 78 and the eighth slope 82 are larger than the pressure angles of the second slope 71, the third slope 72, and the fourth slope 74.

The first plane 69 and the third plane 77 set the position of the engaging portion 48 at a neutral position where the first tooth 32 and the second tooth 35 do not mesh with each other. The third plane 77 and the sixth slope 78 are located in the axial direction of the first plane 69. The fourth plane 79 is located in the axial direction of the first slope 70. The seventh slope 80 is located in the axial direction of the second slope 71. The fifth plane 81 is located in the axial direction of the third slope 72 , the second plane 73 , and the fourth slope 74 . The eighth slope 82 is located in the axial direction of the fifth slope 75 and the first plane 69.

As shown in FIG. 3(a), the first tooth 32 and the second tooth 35 mesh, and the fifth part 67 of the second tooth 35 is pressed against the third part 58 of the first tooth 32 and moved from the free rotating gear 24. When transmitting coasting torque to the member 34, the engaging portion 48 contacts the second slope 71. The third portion 58 of the first tooth 32 and the fifth portion 67 of the second tooth 35 pressed by the coasting torque generate a thrust force that separates the free rotation gear 24 and the moving member 34 in the axial direction. The axial thrust generated by the third portion 58 and the fifth portion 67 due to the coasting torque is normally smaller than the axial force exerted on the shift arm 41 by the spring mechanism 50 . Therefore, the shift arm 41 does not move in the axial direction, and the engagement between the first teeth 32 and the second teeth 35 is maintained with the engaging portion 48 coupled to the shift arm 41 in contact with the second slope 71.

The axial force acting on the shift arm 41 by the spring mechanism 50 includes the force of the spring 53 acting on the shift arm 41 to resist the thrust force that separates the free rotating gear 24 and the moving member 34 in the axial direction, and This refers to the force of the spring 53a that acts on the shift arm 41 to resist the force that rotates the shift drum 43 that is generated on the slope of the first cam 68 via the joint portion 48.

If θ4>θ1 and θ4>θ2, when the coasting torque that presses the second surface 57 and the fourth surface 64 is applied, the third portions 58, 65 and the fifth portions 60, 67 , the thrust force that separates the second surface 57 and the fourth surface 64 in the axial direction can be reduced. Therefore, coasting torque can be easily transmitted during times other than shifting.

As shown in FIG. 3(b), the third surface 61 of the second tooth 35 is pressed against the first surface 54 (see FIG. 2) of the first tooth 32, and drive torque is transmitted from the moving member 34 to the idling gear 24. . When the second tooth 35 contacts the second portion 56 of the first tooth 32 or the first tooth 32 contacts the second portion 63 of the second tooth 35, the free rotating gear 24 and the moving member 34 are moved in the axial direction. A thrust is generated to let go. When the axial thrust generated in the second portions 56, 63 by the drive torque is larger than the axial force E applied by the spring mechanism 50 to the shift arm 41, the moving member 34 and the shift arm 41 move in the axial direction.

When θ4>θ1 and θ4>θ2, the second portions 56 and 63 can generate a thrust force that separates the first surface 54 and the third surface 61 in the axial direction with a small drive torque. Therefore, in the lower gear of upshifting, the first tooth 32 and the second tooth 35 tend to disengage.

When the first portion 55 of the first tooth 32 and the first portion 62 of the second tooth 35 come into contact with each other, no thrust is generated to separate the free rotating gear 24 and the moving member 34 in the axial direction. An axial force E is applied to the moving member 34 by the spring mechanism 50 to maintain the engagement between the first tooth 32 and the second tooth 35 . The engagement between the first teeth 32 and the second teeth 35 is maintained by friction between the first portions 55 and 62, an axial force E by the spring mechanism 50, and the like.

As the moving member 34 and the shift arm 41 move in the axial direction due to the thrust force that separates the free rotating gear 24 and the moving member 34 in the axial direction, the engaging portion 48 coupled to the shift arm 41 moves toward the second slope of the first cam 68. Add force to 71. The pressure angle of the second slope 71 causes a rotational force to act on the shift drum 43 (see FIG. 1). The pressure angle of the second slope 71 is set to such an angle that the engaging part 48 does not come to rest due to this force, so the shift drum 43 rotates with the engaging part 48 in contact with the second slope 71, and the spring The shift drum 43 comes to rest at a position where the force in the rotational direction that the mechanism 50 applies to the shift drum 43 is balanced.

Both when coasting torque is transmitted between the first tooth 32 and the second tooth 35 and when drive torque is transmitted between the first tooth 32 and the second tooth 35, the spring mechanism 50 The engaging portion 48 is in contact with the first cam 68 due to the axial force acting on the shift arm 41 . Therefore, it is possible to reduce the impact caused by the engagement portion 48 hitting the first cam 68 and the second cam 76 when switching between the transmission of coasting torque and the transmission of drive torque.

Since the shift drum 43 is stationary when coasting torque is transmitted between the first tooth 32 and the second tooth 35, the engagement of the third portions 58 and 67 is maintained. If θ1<θ3, the thrust in the axial direction by the third portions 58 and 67 can be reduced.

FIG. 4 is a schematic diagram of the transmission 10 that transmits coasting torque. When the fifth part 67 of the second tooth 35 is pressed against the third part 58 of the first tooth 32 to transmit coasting torque from the free rotating gear 24 to the moving member 34 (see FIG. 3(a)), an excessive When coasting torque is applied, the meshing between the first tooth 32 and the second tooth 35 is caused by the thrust force generated by the third part 58 and the fifth part 67 that separates the free rotation gear 24 and the moving member 34 in the axial direction. There is a risk of it coming off. The first cam 68 is provided with a second plane 73 that sets the position of the engaging portion 48 in the axial direction when the fifth portion 60 of the first tooth 32 and the fifth portion 67 of the second tooth 35 are engaged. It is being The second plane 73 exists between a third slope 72 and a fourth slope 74 that slope downward in the axial direction toward the first plane 69.

When the pressure angle of the second plane 73 is approximately 0°, even if the engaging portion 48 coupled to the shift arm 41 applies an axial force to the second plane 73, the shift drum 43 (see FIG. 1) will not rotate. Almost no directional force acts. Even if the third part 58 of the first tooth 32 and the fifth part 67 of the second tooth 35 are disengaged, the second flat surface 73 of the first cam 68 allows the fifth part 60 of the first tooth 32 to Since the engagement with the fifth portion 67 of the teeth 35 can be maintained, excessive coasting torque can be transmitted.

When the pressure angle of the second plane 73 is equal to or greater than the friction angle, when the engaging portion 48 applies an axial force to the second plane 73, a rotational force is generated on the shift drum 43. However, as the axial distance between the free rotating gear 24 and the moving member 34 becomes longer, the axial force acting on the shift arm 41 by the spring mechanism 50 becomes larger. 35 can be maintained. Therefore, coasting torque can be transmitted.

The upshift operation of the transmission 10 will be described with reference to FIGS. 5 and 6. As an example, the operation of shifting up from the fourth gear 23 to the fifth gear 26 will be described. Shifting operations for other gears are similar to this, so explanations of upshifting operations for other gears will be omitted.

FIG. 5 is a schematic diagram of the transmission 10 in the middle of shifting up from the fourth gear 23 to the fifth gear 26. FIG. 6 is a schematic diagram of the transmission 10 when the shift up to the fifth gear 26 is completed. Arrow R2 in FIG. 5 indicates the rotation direction of the shift drum 43 (see FIG. 1) (the same applies to FIGS. 6 to 9). In the fifth speed gear 26, when the shift drum 43 rotates, the moving member 34 moves in the axial direction via the shift arm 40 whose engaging portion 47 is guided by the cam groove 44. Similar to the cam groove 45, the cam groove 44 is provided with a first cam 68 and a second cam 76.

As shown in FIG. 5, in the fourth gear 23, when the shift drum 43 rotates, the engagement portion 48 moves from the seventh slope 80 to the fifth plane 81, resisting the axial force E by the spring mechanism 50. , the moving member 34 is separated from the idle gear 24 in the axial direction. As a result, the first portion 55 of the first tooth 32 and the first portion 62 of the second tooth 35 come into contact with each other, and drive torque is transmitted. An axial force E is applied to the moving member 34 by the spring mechanism 50 to maintain the engagement between the first tooth 32 and the second tooth 35 .

In the fifth speed gear 26, when the shift drum 43 rotates from a neutral position where the first teeth 32 of the idling gear 27 and the second teeth 35 of the moving member 34 do not mesh, the engaging portion 47 that was in contact with the first plane 69 is pushed by the first slope 70 and moves in the axial direction. As the engaging portion 47 moves, the moving member 34 approaches the idle gear 27. Since the pressure angle of the first slope 70 is larger than the pressure angles of the second slope 71, the third slope 72, and the fourth slope 74 of the first cam 68, as the shift drum 43 rotates, the first tooth 32 and the The two teeth 35 can be engaged quickly.

When the first tooth 32 and second tooth 35 of the fourth gear 23 are engaged and the first tooth 32 and second tooth 35 of the fifth gear 26 are engaged, the fourth gear 23 is coasted depending on each gear ratio. state, the fifth gear 26 is in the drive state. In the fifth speed gear 26, the first portion 55 of the first tooth 32 and the first portion 62 of the second tooth 35 are in contact with each other, so that no thrust is generated that causes the idle gear 27 and the moving member 34 to separate in the axial direction. Therefore, when the shift drum 43 further rotates, the engaging portion 47 is pushed by the first slope 70 of the first cam 68, and the moving member 34 approaches the free rotating gear 27, causing the contact between the first tooth 32 and the second tooth 35. The engagement becomes faster and deeper.

When the direction of the torque between the first tooth 32 and the second tooth 35 of the fourth gear 23 changes from driving torque to coasting torque, the first portion 55 of the first tooth 32 and the first portion of the second tooth 35 change. 62 changes to meshing with the fourth portion 59 of the first tooth 32 and the second tooth 35, and a thrust force is generated that causes the idle gear 24 and the moving member 34 to move apart in the axial direction. Since θ3>θ1, the second portion 56 can reduce the kinetic energy of the members moving in the axial direction from the moving member 34 to the engaging portion 48. Therefore, impact and abnormal noise generated in the shift device 36 can be reduced.

In the fourth gear 23, when the shift drum 43 rotates, the engaging portion 48 is pushed by the eighth slope 82 of the second cam 76, the moving member 34 is separated from the free rotating gear 24 in the axial direction, and the first tooth 32 and The mesh with the second tooth 35 is disengaged. Since the pressure angle of the eighth slope 82 is larger than the pressure angles of the second slope 71, third slope 72, and fourth slope 74 of the first cam 68, as the shift drum 43 rotates, The two teeth 35 can be separated quickly.

As shown in FIG. 6, at the end of the upshift, the engaging portion 48 of the fourth gear 23 is in contact with the first plane 69 of the first cam 68, and the engaging portion 47 of the fifth gear 26 is in contact with the second slope 71 and the first plane 69 of the first cam 68. 7 slope 80.

In the fourth gear 23, when the first part 55 of the first tooth 32 and the first part 62 of the second tooth 35 are in contact with each other (see FIG. 5), the third part 58 of the first tooth and the second part 62 of the second tooth 35 are in contact with each other (see FIG. 5). A circumferential gap is created between the fifth portion 67 and the fifth portion 67 . The first tooth 32 and the second tooth 35 are disengaged from the state in which the first portion 55 of the first tooth 32 and the first portion 62 of the second tooth 35 are in contact with each other. The pressure angle of the eighth slope 82 is such that the moving member 34 is moved by the movement of the second cam 76 faster than the fourth surface 64 of the second tooth 35 hits the second surface 57 of the first tooth 32; , a circumferential distance S (see FIG. 2) between the first portion 55 and the fifth portion 60 of the adjacent first teeth 32 is set. When the first tooth 32 and the second tooth 35 disengage, the tip of the second tooth 35 can be prevented from coming into contact with the first tooth 32. This prevents wear and tear on the second surface 57 of the first tooth 32. Wear on the tips of the two teeth 35 can be reduced.

Furthermore, compared to the case where the second teeth 35 are disengaged by utilizing the thrust force generated on the second surface 57, the speed of the moving member 34 in the axial direction can be prevented from increasing due to the second surface 57. Since the kinetic energy of the members from the moving member 34 to the engaging portion 48 can be reduced, the mechanical strength required for the members from the moving member 34 to the engaging portion 48 and the mechanism for stopping the moving member 34 are reduced. The required mechanical strength can be reduced. Accordingly, abnormal noise generated when the moving member 34 stands still can be reduced.

In the fourth gear 23, when the first tooth 32 and the second tooth 35 disengage, the second tooth 35 does not touch the fourth part 59 and the fifth part 60 of the first tooth 32, and the first tooth The second tooth 35 separates from 32. This is due to the pressure angle of the second cam 76 that separates the second tooth 35 from the first tooth 32 in the axial direction, the rotational speed of the shift drum 43, the rotational speed of the first tooth 32, and the axial movement of the second tooth 35 from the first tooth 32. The circumferential length of the fourth portions 59 and 66 and the axial height of the first tooth 32 from the tooth root to the tooth tip are determined by considering the elastic force of the spring that acts on the moving member 34 to separate the moving member 34 in the direction. This can be realized by determining the length of the second tooth 35 from the first portion 62 to the fifth portion 67 in the circumferential direction. Since the first tooth 32 and the second tooth 35 have the fourth portions 59 and 66, the distance S can be secured and realized.

Note that when the first tooth 32 and the second tooth 35 disengage from each other in the lower gear position (4th gear 23) during upshifting and the teeth contact the fourth portions 59 and 66, the angle θ3 is 70°. It is preferable that the angle is greater than or equal to 90°. This is because the kinetic energy of the moving member 34 can be reduced, so that the speed of the moving member 34 in the axial direction when disengaged can be prevented from increasing.

In the fourth gear 23, the engaging portion 48 is in contact with the first cam 68 when the direction of the torque acting between the second tooth 35 and the first tooth 32 changes (Figs. 3(a) and 3). (b)), the first tooth 32 and the second tooth 35 It is possible to control the initial speed of the moving member 34 when it is disengaged. This makes it possible to control the kinetic energy of the members from the movable member 34 to the engaging portion 48, thereby reducing the mechanical strength required for the members from the movable member 34 to the engaging portion 48, and keeping the disengaged movable member 34 still. It is possible to reduce the mechanical strength required by the mechanism for making the structure.

The downshift operation of the transmission 10 will be described with reference to FIGS. 6 and 7. As an example, the operation of downshifting from the fifth gear 26 to the fourth gear 23 will be described. Shifting operations for other gears are similar to this, so explanations of downshifting operations for other gears will be omitted. FIG. 7 is a schematic diagram of the transmission 10 in the middle of downshifting from the fifth gear 26 to the fourth gear 23.

As shown in FIG. 6, in the fifth speed gear 26, the first tooth 32 and the second tooth 35 mesh with each other, and the first part 55 of the first tooth 32 and the first part 62 of the second tooth 35 are pressed by the drive torque. It is being As shown in FIG. 7, when the shift drum 43 rotates for downshifting to the fourth gear 23, the engaging portion 48 of the fourth gear 23, which was in contact with the first plane 69 in the neutral position, is moved to the fifth slope. 75 and the fourth slope 74 to move in the axial direction. As the engaging portion 48 moves in the axial direction, the moving member 34 approaches the idle gear 24. The fifth slope 75 having a larger pressure angle than the pressure angle of the fourth slope 74 allows the first tooth 32 and the second tooth 35 to be brought closer to each other quickly as the shift drum 43 rotates.

When the engaging portion 48 is pushed by the fourth slope 74 and the movable member 34 approaches the free rotating gear 24, in the fourth gear 23, the fifth portion 60 of the first tooth 32 is connected to the fifth portion 67 of the second tooth 35. The first tooth 32 and the second tooth 35 begin to mesh with each other as they touch each other. Since the angle θ2 between the plane P (see FIG. 2) and the fifth parts 60 and 67 is smaller than the angle θ3 between the plane P and the fourth parts 59 and 66, while the fourth parts 59 and 66 touch each other, Compared to the case where the first tooth 32 and the second tooth 35 start to mesh with each other, the thrust force that prevents the moving member 34 from approaching can be made smaller. Even if the output of the actuator (not shown) that rotates the shift drum 43 is small, the engaging portion 48 can be moved in the axial direction against the thrust force that prevents engagement, so the actuator can be made smaller.

The fourth slope 74 of the first cam 68, which has a pressure angle smaller than the pressure angle of the fifth slope 75, moves the engaging portion 48 in the axial direction as the shift drum 43 rotates, and the first tooth 32 of the fourth gear 23 Since the first cam 68 and the second tooth 35 are engaged with each other, the axial force applied by the first cam 68 to the engaging portion 48 can be increased compared to the case where the engaging portion 48 is moved in the axial direction by the fifth slope 75. As a result, the first tooth 32 and the second tooth 35 can be deeply engaged with each other against the thrust force that prevents the first tooth 32 and the second tooth 35 from engaging with each other.

In the fifth gear 26, the rotation of the shift drum 43 pushes the engagement portion 47 against the sixth slope 78 of the second cam 76, causing the shift arm 40 and the moving member 34 to move in the axial direction. As a result, the first tooth 32 and the second tooth 35 are disengaged. Since the pressure angle of the sixth slope 78 is larger than the pressure angle of the fourth slope 74, the first tooth 32 and the second tooth 35 can be disengaged quickly as the shift drum 43 rotates.

The first cam 68 and the second cam 76 are connected to the fourth gear 23 when the first teeth 32 and the second teeth 35 of the fifth gear 26 (upper gear) are disengaged as the shift drum 43 rotates. The first tooth 32 and the second tooth 35 (lower speed gear) are provided so as to mesh with each other. This allows seamless downshifts.

Since the pressure angle of the second plane 73 of the first cam 68 is smaller than the pressure angle of the third slope 72 and the fourth slope 74 of the first cam 68, the shift drum 43 rotates further and the angle is When the fourth portions 59 and 66 with large θ3 contact each other, the meshing between the first tooth 32 and the second tooth 35 can be deepened without reducing the transmission torque to zero. Therefore, it is possible to prevent torque loss at the lower gear shift stage.

In the fourth gear 23, when the shift drum 43 further rotates, the engaging portion 48 is pushed by the third slope 72, and the tip of the second tooth 35 reaches the axial position of the fourth portion 59 of the first tooth 32. do. When the shift drum 43 further rotates, the engaging portion 48 is pushed by the second slope 71, and the tip of the second tooth 35 reaches the axial position of the third portion 58 of the first tooth 32. This further deepens the meshing between the first teeth 32 and the second teeth 35.

A second embodiment will be described with reference to FIGS. 8 and 9. In the first embodiment, when the first tooth 32 and the second tooth 35 of the fifth speed gear 26 disengage as the shift drum 43 rotates, the first tooth 32 and the second tooth of the fourth speed gear 23 disengage. A case has been described in which the first cam 68 and the second cam 76 are provided so that the first cam 68 and the second cam 76 are engaged with each other. On the other hand, in the second embodiment, when the first tooth 32 and the second tooth 35 of the fourth speed gear 23 are engaged, the first tooth 32 and the second tooth 35 of the fifth speed gear 26 are disengaged. A case where the first cam 90 and the second cam 94 are provided will be described. The same parts as in the first embodiment are given the same reference numerals and the following explanation is omitted.

FIG. 8 is a schematic diagram of the transmission 10 at the time of starting a downshift in the second embodiment. FIG. 9 is a schematic diagram of the transmission 10 during a downshift. The first cam 90 and the second cam 94 are provided in the cam grooves 44 and 45 of the shift drum 43 (see FIG. 1), respectively.

As shown in FIG. 8, engaging portions 47 and 48 are engaged with cam grooves 44 and 45, respectively. When the shift drum 43 rotates, the axial positions of the engaging portions 47, 48 and the shift arms 40, 41 are set by a first cam 90 and a second cam 94 provided inside the cam grooves 44, 45, respectively. Ru. The first cam 90 faces the second cam 94 in the axial direction. The first cam 90 moves the engaging portions 47 and 48 in the axial direction so that the first tooth 32 and the second tooth 35 mesh with each other. The second cam 94 moves the engaging portions 47 and 48 in the axial direction so that the first tooth 32 and the second tooth 35 are disengaged.

The first cam 90 includes, in order, the first plane 69, the ninth slope 91, the sixth plane 92, the tenth slope 93, the second slope 71, the third slope 72, the second plane 73, the fourth slope 74, and the fifth slope. 75, connected to the first plane 69. The ninth slope 91, the sixth plane 92, the tenth slope 93, the second slope 71, the third slope 72, the second plane 73, the fourth slope 74, and the fifth slope 75 are arranged in the axial direction with respect to the first plane 69. sticking out. The ninth slope 91 and the tenth slope 93 face opposite to the rotation direction of the second slope 71 , third slope 72 , fourth slope 74 , and fifth slope 75 . The pressure angle of the sixth plane 92 is approximately 0°. The sixth plane 92 is provided at the same position in the axial direction as the portion of the second slope 71 that is closest to the first plane 69 . The pressure angle of the ninth slope 91 is larger than the pressure angle of the tenth slope 93. The pressure angle of the tenth slope 93 is larger than the pressure angles of the second slope 71, the third slope 72, and the fourth slope 74.

The second cam 94 is connected to the third plane 77, the eleventh slope 95, the fourth plane 79, the seventh slope 80, the fifth plane 81, the eighth slope 82, and the third plane 77 in this order. The eleventh slope 95, the fourth plane 79, the seventh slope 80, the fifth plane 81, and the eighth slope 82 are axially depressed with respect to the third plane 77. The eleventh slope 95 faces the opposite side of the rotation direction of the seventh slope 80 and the eighth slope 82. The pressure angles of the eleventh slope 95 and the eighth slope 82 are larger than the pressure angle of the seventh slope 80. The pressure angles of the eleventh slope 95 and the eighth slope 82 are larger than the pressure angles of the second slope 71, the third slope 72, and the fourth slope 74. The fourth plane 79 is located in the axial direction of the ninth slope 91, the sixth plane 92, and the tenth slope 93. A first plane 69 is located in the axial direction of the eleventh slope 95.

As the shift drum 43 rotates as shown in FIG. 90 until it touches the sixth plane 92. The engaging portion 48 of the fourth gear 23 is in contact with the first plane 69 of the first cam 90 . When coasting torque is transmitted from the free rotation gear 27 of the 5th gear 26 to the moving member 34, the fourth surface 64 of the second tooth 35 is pressed against the second surface 57 of the first tooth 32, and the thrust force generated causes free rotation. The moving member 34 moves away from the gear 27 in the axial direction, and the fifth portion 67 of the second tooth 35 contacts the fifth portion 60 of the first tooth 32 . Since the engaging portion 47 contacts the sixth plane 92 of the first cam 90, the movement of the moving member 34 in the axial direction is restricted, so the engagement between the first teeth 32 and the second teeth 35 is maintained, and the coasting Torque is transmitted.

As the shift drum 43 further rotates as shown in FIG. 9, the engaging portion 48 of the fourth gear 23 is pushed by the first cam 90 and moves in the axial direction. The engagement portion 47 of the fifth gear 26 is disengaged from the sixth plane 92. In the fourth gear 23, the second teeth 35 mesh with the first teeth 32 as the engaging portion 48 moves in the axial direction. Since the 5th gear 26 rotates faster than the 4th gear 23, when the first tooth 32 and the second tooth 35 of the 4th gear 23 mesh, the fifth part 60 of the first tooth 32 of the 5th gear 26 and the The first tooth 32 and the second tooth 35 are disengaged due to the thrust force generated when the fifth portion 67 of the two teeth 35 press against each other. This allows for seamless downshifts.

Although the present invention has been described above based on the embodiments, the present invention is not limited to these embodiments in any way, and it is easy to make various improvements and modifications without departing from the spirit of the present invention. This can be inferred. For example, the number of gear stages of the transmission 1, the shapes of the cam grooves 44 and 45 provided in the shift drum 43, the shapes of the first teeth 32 and the second teeth 35, etc. can be set as appropriate.

In the embodiment, a case has been described in which the transmission 10 is installed in a car, but the invention is not limited to this, and it is of course possible to install the transmission 10 in a construction machine, an industrial vehicle, an agricultural machine, or the like. In this case as well, the transmission 10 can eliminate torque loss during gear shifting. As a result, it is possible to ensure steering stability during downshifts during cornering, etc., and also to eliminate idle rotation of the drive shaft 11 and improve fuel efficiency.

In the embodiment, a case has been described in which the second portion 56 is provided on the first surface 54 of the first tooth 32 and the second portion 63 is provided on the third surface 61 of the second tooth 35, but this is not necessarily the case. It is not limited. It is of course possible to omit one of the second parts 56, 63.

In the embodiment, the spring mechanism 50 uses a spring 53 to press a ball 52 that engages with a recess 51 provided on the outer periphery of the shift arm 40, 41, 42, and applies an axial force to the shift arm 40, 41, 42. (hereinafter referred to as the "first mechanism"), and a mechanism (hereinafter referred to as Although a case has been described in which a "second mechanism" is provided, the present invention is not necessarily limited to this. For example, it is naturally possible to omit one of the first mechanism and the second mechanism.

In place of or in addition to the first mechanism, between the shift arm 40 and the shift fork 37, between the shift arm 41 and the shift fork 38, and between the shift arm 42 and the shift fork 39. Of course, it is possible to arrange a spring that applies an elastic force in the axial direction to the shift fork. In this case, as the shift arms 40, 41, 42 move in the axial direction, the spring applies an elastic force in the direction of disengaging the first tooth 32 and the second tooth 35 via the shift forks 37, 38, 39. Add.

It is of course possible to employ a spring-type brake motor as the actuator that rotationally drives the shift drum 43 instead of or in addition to the second mechanism. In this case as well, a force in the rotational direction is applied to the shift drum 43 by the spring of the actuator.

In the embodiment, the first portion 55 of the first tooth 32 is inclined so as to approach the second surface 57 as it goes toward the tooth root, and the first portion 62 of the second tooth 35 slopes closer to the second surface 57 as it goes toward the tooth root. A case has been described in which it is inclined so as to approach the fourth surface 64 (θ5>0°). However, it is not limited to this. Naturally, θ5 may be 0°. When the first parts 55, 62 contact each other and transmit torque, the axial component of the force due to the torque and the axial component of the friction force generated between the first parts 55, 62 It is sufficient that the resultant force of and does not act in a direction that separates the moving member 34 from the idle gears 24 and 27. As long as this relationship is satisfied, the first portions 55 and 62 may be inclined in opposite directions.

10 Transmission 11 Drive shaft (shaft)
24, 27 Idle gear (gear)
32 1st tooth 34 Moving member 35 2nd tooth 36 Shift device 47, 48 Engagement part 53, 53a Spring 54 1st surface 55 1st part 56 2nd part 57 2nd surface 58 3rd part 61 3rd surface 62 1st part 63 2nd part 64 4th surface 65 3rd part 68,90 1st cam 76,94 2nd cam

Claims (4)

A transmission selectively coupling a gear provided with a first tooth and disposed on a shaft to the shaft,
a moving member provided with second teeth that mesh with the first teeth;
The movable member is moved in a first axial direction in which the first tooth and the second tooth engage, and the movable member is moved in a second axial direction in which the first tooth and the second tooth are disengaged. and a shift device to
The first tooth includes a first surface facing one circumferential direction and a second surface facing the other circumferential direction,
The second tooth has a third surface that faces at least a portion of the first surface when the moving member moves in the axial direction and the first tooth and the second tooth engage with each other, and the moving member has a third surface that faces at least a portion of the first surface. a fourth surface that faces at least a portion of the second surface when the first tooth and the second tooth engage with each other by moving in the axial direction,
The first surface and the third surface include a first portion that transmits a torque in a direction that presses the first surface and the third surface,
At least one of the first surface and the third surface is adjacent to the dedendum side of the first part, and the movable member is provided with at least one of the first surface and the third surface in accordance with the torque in the direction of pressing the first surface and the third surface. a second part that applies a second axial thrust;
The second surface and the fourth surface include a third portion that applies a thrust force in the second axial direction to the movable member according to a torque in a direction that presses the second surface and the fourth surface,
The shift device includes an engaging portion coupled to the moving member;
a first cam that moves the engaging portion in the first axial direction by rotational movement;
a second cam that moves the engaging portion in the second axial direction by rotational movement;
a spring that generates an elastic force as the engaging portion moves;
The first cam remains stationary when the third portion applies a thrust in the second axial direction to the movable member due to the spring in a state in which the first cam is in contact with the second axial portion. A transmission that rotates when the second portion applies a thrust in a direction to the moving member. The pressure angle of the first cam and the pressure angle of the second cam are set to values that are independent of each other, and the first tooth and the second tooth of the lower gear shift are engaged with each other during upshifting from the lower gear gear to the upper gear gear. A pressure angle of the second cam that engages the first tooth and the second tooth of the lower gear during downshifting from the upper gear to the lower gear is greater than the pressure angle of the first cam that engages the first tooth and the second tooth of the lower gear. The transmission according to item 1. The first cam has a pressure angle at a portion where the first tooth and the second tooth of the upper gear shift are engaged in an upshift from a lower gear shift to an upper gear shift, and a pressure angle of a portion where the first tooth and the second tooth of the upper gear shift are engaged is equal to the pressure angle in a downshift from the upper gear gear to the lower gear gear. The transmission according to claim 1 or 2, wherein the pressure angle is larger than a pressure angle at a portion where the first teeth and the second teeth of the lower gear shift gear mesh. The shift device is configured to disengage the first tooth and the second tooth of the upper gear shift and to disengage the first tooth and the second tooth of the lower gear gear in downshifting from the upper gear gear to the lower gear gear. The transmission according to any one of claims 1 to 3, wherein the engaging and engaging operations are performed at the same time.

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