JP5528729B2 - Transmission power transmission shaft structure - Google Patents

Description

  The present invention relates to a power transmission shaft structure for transmitting rotational power included in a transmission.

  In a manual transmission (manual transmission) mounted on a vehicle, input rotation from a prime mover is transmitted to a transmission gear via a power transmission shaft. Here, the input torque to the power transmission shaft varies in accordance with the operating condition of the prime mover. However, when such fluctuations in the input torque are transmitted to the gears for transmission, noise and vibrations such as gear noise are generated. Therefore, as a conventional technique for reducing noise and vibration due to fluctuations in input torque, for example, as shown in Patent Document 1, a damping spring for damping fluctuations in input torque from a prime mover on a clutch disk (friction plate). A structure (torsion structure) is provided, or a dual mass flywheel (DMFW) structure is adopted.

  The damping spring structure of the clutch disk is obtained by interposing a coil spring (damper) that absorbs torque fluctuations at a position along the rotational direction of the clutch disk. In addition, the dual mass flywheel structure is a flywheel divided into two parts and connected by an elastic body such as a coil spring. By making the resonance speed of the drive system less than the idle speed of the prime mover, the input torque Noise / vibration due to fluctuations is reduced.

  In the damping spring structure of the clutch disc, the inertial mass of the clutch disc increases because the damping spring is installed at a location away from the rotation center of the clutch disc. As a result, there is a problem that the load when the power transmission shaft is synchronized (synchronized) increases and the load required for the shift operation (shift load) becomes heavy. In addition, since the damping spring is provided, the width dimension (thickness dimension) of the clutch in the axial direction is increased, and the dimension in the axial direction of the transmission is increased accordingly.

  In addition, in the dual mass flywheel structure, the damping spring structure for reducing noise and vibration due to torque fluctuation is provided on the flywheel side, not on the clutch disk side, so that the inertia mass of the clutch disk increases. However, since the flywheel is divided into two parts, the width dimension (thickness dimension) of the clutch in the axial direction is increased, and the axial dimension of the transmission is increased accordingly.

Japanese Patent Laid-Open No. 2003-14116

  The present invention has been made in view of the above points, and its purpose is to accompany fluctuations in input torque from the prime mover while ensuring miniaturization of the outer dimensions of the transmission and good operability with a simple structure. An object of the present invention is to provide a power transmission shaft structure for a transmission that can effectively reduce noise and vibration.

  The present invention for solving the above-mentioned problems is a power transmission shaft structure for transmitting rotational power provided in a transmission, and is provided with an inner input shaft (12) that rotates by receiving rotational power from a prime mover, and an inner input. The shaft (12) is coaxially disposed outside and has an engaging portion (14) that engages with the inner input shaft (12) so as not to rotate relative to the inner input shaft (12). An outer main shaft (13) provided, and rotational power input from one end (12d) of the inner input shaft (12) is received from the other end (12c) of the inner input shaft (12). ) To be transmitted to the outer main shaft (13) and the rotating part (55) for shifting.

  According to the power transmission shaft structure of the transmission according to the present invention, the power transmission shaft to which rotational power from the prime mover is input has a double structure of the inner input shaft and the outer main shaft, and the rotation input from one end of the inner input shaft. The power is transmitted from the other end to the outer main shaft via the engaging portion so that the speed change gear rotates. Therefore, the rotational power of the prime mover input to the power transmission shaft is transmitted from one end of the inner input shaft to the other end and then transmitted to the outer main shaft via the engaging portion. As a result, the transmission path of the rotational power in the axial direction of the power transmission shaft can be secured long (longer than the axial length of the inner input shaft), so that the power transmission shaft can be made compact while reducing the axial dimension of the power transmission shaft. Torsional rigidity can be kept low. Therefore, noise and vibration due to fluctuations in input torque from the prime mover can be effectively reduced.

  Further, when the power transmission shaft structure according to the present invention is applied to a manual transmission (manual transmission), the torsional rigidity of the power transmission shaft to which the rotational power of the prime mover is input can be kept low. It is possible to omit the damping spring structure provided in the clutch disk or to reduce the damping spring capacity. That is, since the power transmission shaft structure according to the present invention is provided on the power transmission shaft arranged at the center of rotation, an increase in the inertial mass of the rotating system can be minimized. Thereby, the inertial mass of the rotating system including the power transmission shaft and the clutch can be reduced. Therefore, the load during synchronization can be reduced and the shift load can be reduced. Moreover, since the damping spring capacity can be reduced, the thickness of the clutch can be reduced, so that the axial dimension of the transmission can be reduced.

  The power transmission shaft structure according to the present invention can be used in combination with a conventional damping spring structure of a clutch disk. If the power transmission shaft structure of the present invention and the damping spring structure of the clutch disk are used in combination, a structure for absorbing fluctuations in the input torque from the prime mover can be arranged in series along the axial direction of the power transmission shaft. The torsional rigidity of the system can be further reduced, and noise and vibration can be greatly reduced.

  In the power transmission shaft structure described above, when the input torque to the inner input shaft (12) exceeds a predetermined value, the twist that restricts relative rotation due to the twist of the inner input shaft (12) and the outer main shaft (13). A restricting portion (20) may be provided. The twist restricting portion (20) is, for example, a contact portion (21a, 22a) disposed with a predetermined gap in the rotation direction provided on the inner input shaft (12) and the outer main shaft (13). Can do. According to this, since the torsion of the inner input shaft is allowed until the input torque to the inner input shaft becomes equal to or higher than a predetermined value, the torsional rigidity of the power transmission shaft can be kept low. On the other hand, when the input torque to the inner input shaft exceeds a predetermined value, the twist of the inner input shaft is restricted by the twist restricting portion, so that excessive torque can be prevented from acting on the inner input shaft. Therefore, under normal conditions, it is possible to avoid insufficient rigidity when excessive torque is transmitted to the power transmission shaft due to sudden engagement of the clutch or the like while suppressing the torsional rigidity of the power transmission shaft.

  When the twist restricting portion (20) is a contact portion (21a, 22a) provided on the inner input shaft (12) and the outer main shaft (13), the contact portion (22a) of the outer main shaft (13) is The protrusion (22) protruding in the axial direction from the end (13d) of the outer main shaft (13) may be provided. At that time, at least a part of the protrusion (22) may be brought into contact with the inner periphery of the bearing (17) installed on the outer peripheral side of the outer main shaft (13). With this configuration, even when the load applied from the inner input shaft to the abutting portion of the outer main shaft becomes excessive due to the operation of the torsion restricting portion, the end portion of the outer main shaft and the protrusion provided on the end portion are in the radial direction. Can be prevented from being deformed outside.

  Further, in the power transmission shaft structure described above, the bending restricting portion (20) for restricting the bending of the inner input shaft (12) in the axial direction when the bending load applied to the inner input shaft (12) becomes a predetermined value or more is provided. Good. The bending restricting portion (20) includes, for example, a protruding portion (25) protruding from at least one of the outer periphery (12a) of the inner input shaft (12) and the inner periphery (13b) of the outer main shaft (13) toward the other. can do. According to this, when the bending in the axial direction of the inner input shaft becomes equal to or greater than a predetermined value, the protrusion can be in contact with the outer main shaft or the inner input shaft facing each other, and the bending can be restricted. Therefore, since the amount of bending when the bending load is applied to the inner input shaft can be controlled, it is possible to reduce the rigidity by reducing the diameter of the inner input shaft while ensuring the safety of the power transmission shaft. It becomes possible.

  In the power transmission shaft structure described above, the inner input shaft (12) and the outer main shaft (13) are twisted by the friction surface (35) slidingly contacted between the inner input shaft (12) and the outer main shaft (13). It is preferable to provide a friction mechanism (30) that generates a frictional force with respect to relative rotation due to. According to this, it is possible to obtain a damping force with respect to relative rotation caused by twisting of the inner input shaft and the outer main shaft. Therefore, it is possible to appropriately adjust the torsional rigidity of the power transmission shaft.

  Further, in this case, the friction surface (35) is an inclined surface that is inclined along the axial direction of the inner input shaft (12) and the outer main shaft (13), and the friction mechanism (30) includes the inner input shaft (12). The magnitude of the frictional force generated by moving the relative position of the inner input shaft (12) and the outer main shaft (13) in the axial direction on the friction surface (35) according to the direction of relative rotation of the outer main shaft (13). It is good to comprise so that it may change. According to this, since the characteristic of the frictional force generated according to the relative rotation direction of the inner input shaft and the outer main shaft can be made different, the frictional force generated at the time of acceleration and deceleration of the input rotation is made different. Thus, the torsional rigidity of the power transmission shaft can be changed. Therefore, it is possible to more effectively reduce noise and vibration caused by fluctuations in input torque from the prime mover.

  In the above power transmission shaft structure, the engaging portion (14) has a configuration in which spline teeth (27, 28) formed on the inner input shaft (12) and the outer main shaft (13) are spline-fitted, When the oil passage (26) penetrating in the radial direction from the center side of the inner input shaft (12) is provided, the oil passage (26) lacks a part of the spline teeth (27) in the engaging portion (14). It is good to make it open to a missing tooth part (27a).

In the above engaging portion, spline teeth are formed, the inner input shaft and the outer main shaft are spline-fitted, and the rigidity of the member is higher than other portions. Therefore, if the oil passage that penetrates in the radial direction from the center side of the inner input shaft is opened to the missing tooth portion that lacks a part of the spline teeth in the engaging portion, an excessive torsional torque is applied to the inner input shaft. Even when is applied, since the stress applied to the opening of the oil passage can be kept low, it is possible to effectively prevent cracks and the like from being generated around the opening.
In addition, the code | symbol in said parenthesis has shown the code | symbol of the corresponding component of embodiment mentioned later as an example of this invention.

  According to the power transmission shaft structure of the transmission according to the present invention, the noise and vibration associated with the fluctuation of the input torque from the prime mover can be ensured while ensuring the reduction of the outer dimension of the transmission and good operability with a simple configuration. Reduction can be achieved.

It is a longitudinal section showing a manual transmission (manual transmission) provided with a power transmission shaft structure concerning one embodiment of the present invention. It is the elements on larger scale which show the main shaft (input shaft) of a manual transmission. It is a figure which shows the stopper mechanism and friction mechanism which were provided in the main shaft, and is A partial enlarged view of FIG. It is the schematic sectional drawing which looked at the stopper mechanism from the axial direction of the main shaft. It is a figure for demonstrating the structure of a friction mechanism, and is a X arrow directional view of FIG. It is a figure which shows the component of a friction mechanism, (a) is a disassembled perspective view, (b) is a perspective view of the assembled state. (A) is a figure which shows an engaging part, and is the B section enlarged view of FIG. (B) is the elements on larger scale of the part corresponding to the engaging part of an inner side input shaft.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a longitudinal sectional view showing a manual transmission having a power transmission shaft structure according to an embodiment of the present invention. The manual transmission 1 shown in the figure includes a main shaft (input shaft) 10 and a counter shaft (output shaft) 70 that are rotatably supported by a case (transmission case) 1a, and a reverse shaft 72 that is fixedly supported at both ends. I have. The main shaft 10, the counter shaft 70, and the reverse shaft 72 are arranged in parallel to each other. The flywheel 3 of the clutch 2 is connected to a crankshaft 11 of an engine (not shown). The clutch cover 4 is fixed to the flywheel 3. A pressure plate 5 is attached to the clutch cover 4 so as to be movable in the axial direction. Further, a diaphragm spring 6 is attached to the clutch cover 4, and an outer peripheral end thereof is biased so as to press the pressure plate 5. A clutch disk 7 is sandwiched between the flywheel 3 and the pressure plate 5. The clutch disk 7 is provided with a coil spring 7a for absorbing fluctuations in input torque from the crankshaft 11. A release bearing 8 is attached to the diaphragm spring 6 so as to be slidable in the axial direction.

  In the illustrated clutch-on state, the pressure plate 5 is firmly pressed against the clutch disk 7 by the urging force of the diaphragm spring 6, and the rotation of the flywheel 3 is directly transmitted to the main shaft 10 via the clutch disk 7. On the other hand, when a clutch pedal (not shown) is depressed, the release fork 9 moves the release bearing 8 to the right in FIG. Thereby, the urging force of the diaphragm spring 6 is released, the clutch is turned off, and transmission of the rotational force to the main shaft 10 via the clutch 2 is interrupted.

  A first speed drive gear 40 and a second speed drive gear 41 are fixed to the main shaft 10, and a third speed drive gear 42, a fourth speed drive gear 43, a fifth speed drive gear 44 and a sixth speed drive gear 45 are relative to each other. It is supported rotatably. On the other hand, a first speed driven gear 46 and a second speed driven gear 47 that mesh with the first speed drive gear 40 and the second speed drive gear 41, respectively, are supported on the counter shaft 70 so as to be relatively rotatable, and the third speed drive gears 42, 4 A 3-speed driven gear 48, a 4-speed driven gear 49, a 5-speed driven gear 50, and a 6-speed driven gear 51 that mesh with the high-speed drive gear 43, the 5-speed drive gear 44, and the 6-speed drive gear 45 are fixed.

  In addition, synchromesh mechanisms 52, 53, and 54 for switching each transmission gear stage are provided. The first synchromesh mechanism 52 is provided on the counter shaft 70 between the first speed driven gear 46 and the second speed driven gear 47. The second synchromesh mechanism 53 is provided on the main shaft 10 between the third speed drive gear 42 and the fourth speed drive gear 43. The third synchromesh mechanism 54 is provided on the main shaft 10 between the fifth speed drive gear 44 and the sixth speed drive gear 45.

  Except at the time of a shift change, the power of the main shaft 10 is transmitted to the countershaft 70 through the selected transmission gear stage by the operation of the synchromesh mechanisms 52, 53 and 54. Then, after being decelerated by a final reduction mechanism composed of a final drive gear 60 and a final driven gear 61, it is transmitted to the differential device 62. As a result, the left and right axles 63 and 64 rotate in the forward direction.

  On the other hand, at the time of retreat, first, all the synchromesh mechanisms 52 to 54 are set to the neutral state. The reverse drive gear 66 fixedly attached to the main shaft 10 and the reverse driven gear 67 attached non-rotatably to the outer periphery of the synchromesh mechanism 52 are not directly meshed with each other, but are arranged in a line. . In this state, the reverse idler gear 68 that is rotatably and slidably mounted on the reverse shaft 72 slides axially on the reverse shaft 72 and meshes with both the reverse drive gear 66 and the reverse driven gear 67. Thereby, the power of the main shaft 10 is transmitted to the counter shaft 70 via the reverse drive gear 66, the reverse idler gear 68, and the reverse driven gear 67. Therefore, the rotation direction of the countershaft 70 is opposite to that at the time of forward movement, and the axles 63 and 64 rotate in the reverse direction.

  The power transmission shaft structure according to the present invention is applied to the main shaft 10 of the manual transmission 1 having the above-described configuration. FIG. 2 is a partially enlarged view showing the detailed structure of the main shaft 10. The main shaft 10 includes a substantially cylindrical rod-shaped inner input shaft 12 that is rotated by transmission of the rotational power of the crankshaft 11, and a hollow substantially cylindrical outer main shaft 13 that is coaxially disposed outside the inner input shaft 12. It has a heavy structure. The inner input shaft 12 and the outer main shaft 13 are spline-fitted with an engagement portion 14 provided between one end portion (end portion opposite to the clutch 2) 12c, 13c. The outer main shaft 13 is engaged with the engaging portion 14 so as not to be relatively rotatable. A 4-speed drive gear 43, a 5-speed drive gear 44, a 6-speed drive gear 45, and the like (hereinafter collectively referred to as “transmission gear 55”) are formed on the outer peripheral surface 13a of the outer main shaft 13. In addition, if the engaging part 14 engages the inner input shaft 12 and the outer main shaft 13 so as not to rotate relative to each other, the specific structure is not limited to the above spline fitting. Other configurations may be used.

  An input portion 15 to which rotational power is input is provided at the other end portion (end portion on the clutch 2 side) 12d of the inner input shaft 12. The input unit 15 is fixed to the center of the clutch disk 7. As a result, the rotational power from the crankshaft 11 is input to the main shaft 10 via the clutch disk 7. Therefore, in the main shaft 10, the rotational power input from the input portion 15 to the inner input shaft 12 is transmitted to the outer main shaft 13 via the engaging portion 14 so that the speed change gear 55 rotates.

  In the outer main shaft 13, the other end (end on the clutch 2 side) 13 d is arranged on the outer peripheral side at a position slightly closer to the clutch 2 side than the middle in the axial direction of the inner input shaft 12. Both end portions 13c and 13d of the outer main shaft 13 are rotatably supported by bearings 16 and 17, respectively.

  On the outer peripheral surface 12a of the inner input shaft 12 at an intermediate position between the engaging portion 14 and the end portion 13d of the outer main shaft 13, a protruding portion 25 that protrudes toward the inner peripheral surface 13b of the outer main shaft 13 is provided. The projecting portion 25 is a small protrusion having a substantially trapezoidal cross section formed on the outer peripheral surface 12a of the inner input shaft 12, and a slight gap with respect to the inner peripheral surface 13b of the outer main shaft 13 facing the outer peripheral surface. Are arranged close to each other. Therefore, when the deflection (axial deflection) of the inner input shaft 12 becomes equal to or greater than a predetermined value, the protrusion 25 can be brought into contact with the inner peripheral surface 13b of the outer main shaft 13 that faces the inner input shaft 12 to regulate the deflection. By providing such a deflection regulating portion, the amount of deflection when a bending load is applied to the inner input shaft 12 can be controlled. Therefore, the diameter of the inner input shaft 12 is reduced (thinned) to reduce the rigidity. It becomes possible.

  Further, between the end 13d of the outer main shaft 13 and the inner input shaft 12 opposed thereto, when the rotational power (torque) input to the inner input shaft 12 exceeds a predetermined value, the inner input shaft 12 and the outer input shaft 12 A stopper mechanism (torsion restricting portion) 20 for restricting relative rotation due to torsion with the main shaft 13 and a friction mechanism 30 for generating a frictional force with respect to relative rotation between the inner input shaft 12 and the outer main shaft 13 are provided. It has been. FIG. 3 is a partial enlarged view of a portion A in FIG. 2 and shows the stopper mechanism 20 and the friction mechanism 30. FIG. 4 is a schematic sectional view of the stopper mechanism 20 shown in FIG. 3 as viewed from the axial direction of the main shaft 10. FIG. 5 is a view taken in the direction of the arrow X in FIG. 3, and (a) and (b) respectively show operating states during acceleration and deceleration of the vehicle.

  As shown in FIG. 4, the stopper mechanism 20 includes a first protrusion 21 provided on the outer peripheral surface 12 a of the inner input shaft 12 and a second protrusion 22 provided on the end 13 d of the outer main shaft 13. Has been. The first protrusion 21 is formed as a protrusion having a substantially rectangular cross section that protrudes outward in the normal direction from the outer peripheral surface 12 a of the inner input shaft 12, and the second protrusion 22 is the end 13 d of the outer main shaft 13. Is formed as a protrusion having a substantially rectangular cross section protruding in the axial direction. Each of the first protrusions 21 and the second protrusions 22 is provided in plural (three in the figure) at equal intervals in the circumferential direction, and is arranged so that they are alternately overlapped on the same circumference. Yes. A gap C1 having a predetermined dimension is provided between one side surface (abutment portion) 21a in the rotation direction of each first projection portion 21 and the side surface (abutment portion) 22a of the second projection portion 22 opposed thereto. A gap C2 having a predetermined dimension is provided between the other side surface (abutment portion) 21a of each first projection 21 and the side surface (abutment portion) 22a of the second projection 22 opposite thereto. ing. The gap C1 and the gap C2 may have the same dimensions or different dimensions.

  Since the inner input shaft 12 and the outer main shaft 13 are spline-fitted at the engaging portion 14, when the torque input to the inner input shaft 12 is small, the inner input shaft 12 and the outer main shaft 13 are relatively rotated. (Relative rotation due to twisting) does not occur, or only slight relative rotation due to twisting occurs. However, when the torque input to the inner input shaft 12 increases when the vehicle is accelerated or decelerated, and the torsion of the inner input shaft 12 increases, the first protrusion 21 and the second protrusion 22 conflict with each other in the rotational direction. To move on. When the torque input to the inner input shaft 12 exceeds a predetermined value, the first protrusion 21 moves toward the second protrusion 22 by the amount of the clearance C1 (acceleration) or the clearance C2 (deceleration), The side surface 21a of the first protrusion 21 and the side surface 22a of the second protrusion 22 abut. Thereby, the relative rotation by the twist of the inner side input shaft 12 and the outer side main axis | shaft 13 is controlled by the position.

  Thus, the magnitude of the input torque when the relative rotation between the inner input shaft 12 and the outer main shaft 13 is restricted by the stopper mechanism 20 can be adjusted by setting the width dimension of the gap C1 or the gap C2. When excessive torque (skid torque) is transmitted to the main shaft 10 due to the sudden engagement of No. 2, the first protrusion 21 and the second protrusion 22 are in contact with each other, and the stopper mechanism 20 may be set to operate. .

  In addition, when the stopper mechanism 20 is operated, a load in the circumferential direction is applied to the first protrusion 21 and the second protrusion 22 due to contact. In this case, when the load applied from the first protrusion 21 to the second protrusion 22 becomes excessive, the end 13d of the outer main shaft 13 and the second protrusion 22 provided on the end 13d are directed outward in the radial direction. There is a risk of deformation as if drowning. In order to prevent this, in the present embodiment, as shown in FIG. 3, one end (left end in the figure) 20a of the stopper mechanism 20 is disposed at a position facing the inner ring 17a of the bearing 17 (inside the inner ring 17a). Thus, the end 13d of the outer main shaft 13 and the base portion of the second protrusion 22 are brought into contact with the inner peripheral surface of the inner ring 17a. With this configuration, the outer periphery of the second protrusion 22 is supported by the inner periphery of the bearing 17, so even if the load applied from the first protrusion 21 to the second protrusion 22 is excessive, the outer side It is possible to prevent the end 13d of the main shaft 13 and the second protrusion 22 from being deformed outward in the radial direction.

  On the other hand, the friction mechanism 30 provided between the inner input shaft 12 and the outer main shaft 13 is a position adjacent to the outer peripheral side of the stopper mechanism 20 and supports the outer periphery of the outer main shaft 13 as shown in FIG. It is provided between the bearing 17 and an oil seal 18 for sealing the outer periphery of the inner input shaft 12. 6A and 6B are diagrams showing components of the friction mechanism 30, where FIG. 6A is an exploded perspective view and FIG. 6B is a perspective view showing an assembled state. Hereinafter, the configuration of the friction mechanism 30 will be described with reference to FIG. 6 and FIGS. 3 and 5.

  As shown in FIG. 6, the friction mechanism 30 is fixed to the inner annular input cone 12 and a circular annular cone 31 fixed to the outer main shaft 13, a circular annular friction member 32 installed on the outer periphery of the cone 31. A circular annular case (positioning component) 33 covering the outer periphery and one side surface (side surface on the clutch 2 side) of the friction member 32 and a circular annular shape interposed between the friction member 32 and the case 33 in the axial direction are formed. A flat disc spring 34 is provided.

  The outer peripheral surface of the cone 31 and the inner peripheral surface of the friction member 32 opposed thereto are friction surfaces 35 that are in sliding contact with each other along the rotation direction. The friction surface 35 is formed in a circumferential shape over the entire circumference of the cone 31 and the friction member 32, and extends from the clutch 2 side to the opposite side along the axial direction of the inner input shaft 12 and the outer main shaft 13. It is formed in the shape of the inclined surface which inclines in the direction which leaves | separates gradually from a center (expanding diameter) toward it. The cone 31 and the friction member 32 and the friction surface 35 formed by them are made of a metal material such as ceramic.

  The friction member 32 and the case 33 are provided with a moving mechanism 36 that moves the relative position of the friction member 32 in the axial direction with respect to the cone 31 according to the relative rotation directions of the inner input shaft 12 and the outer main shaft 13. Yes. The moving mechanism 36 includes a protrusion 37 formed on the outer peripheral surface of the friction member 32 and a groove 38 that accommodates the protrusion 37 provided on the outer periphery of the case 33. The protrusions 37 are made of substantially rectangular parallelepiped small protrusions, and a plurality (three in FIG. 6) are formed at equal intervals along the circumferential direction of the friction member 32. On the other hand, the groove portion 38 is formed at a position facing the protrusion 37 on the outer periphery of the case 33, and one end side in the axial direction (end side opposite to the clutch 2) is formed in the notched opening 38a. It has become. In addition, one end side (hereinafter referred to as “first contact side”) 38 b of both end sides in the circumferential direction of the groove portion 38 is an inclined side that is inclined with respect to the circumferential direction. The first contact side 38b is inclined in a direction in which the width of the groove portion 38 gradually increases toward the opening 38a. The other end side (hereinafter referred to as “second contact side”) 38c is a side orthogonal to the circumferential direction. The friction member 32 moves relative to the case 33 in the rotational direction by a frictional force with the cone 31 generated on the friction surface 35. Thereby, the protrusion 37 slides in the groove portion 38 in the rotation direction, and comes into contact with the first contact side 38b or the second contact side 38c.

  The moving mechanism 36 changes the axial relative position of the friction member 32 with respect to the cone 31 in accordance with the direction of relative rotation between the inner input shaft 12 and the outer main shaft 13. That is, when the rotational acceleration input to the inner input shaft 12 is positive (during acceleration), the case 33 and the groove 38 fixed to the inner input shaft 12 are circular as shown in FIG. The friction member 32 that moves clockwise along the circumferential direction (upward in the same figure) and interlocks with the outer main shaft 13 by the frictional force between the cone 31 and the protrusion 37 are circumferential with respect to the case 33. And move counterclockwise (downward in the figure). Thereby, the protrusion 37 contacts the first contact side (inclined side) 38 b of the groove 38. Then, as shown by the arrow in the figure, the protrusion 37 is pushed out in the axial direction from the groove 38 by the first abutting side 38b, so that the friction member 32 moves in the axial direction toward the opposite side of the clutch 2. Here, the friction surface 35 provided between the friction member 32 and the cone 31 is an inclined surface that is inclined so as to increase in diameter as the distance from the clutch 2 increases. Therefore, the friction surface 35 is pressed with a stronger force by the movement of the friction member 32 in the axial direction. Thereby, the frictional force generated between the cone 31 and the friction member 32, that is, between the inner input shaft 12 and the outer main shaft 13 is increased.

  On the other hand, when the rotational acceleration input to the inner input shaft 12 is negative (during deceleration), the case 33 and its groove 38 are counterclockwise along the circumferential direction as shown in FIG. The friction member 32 and its protrusion 37 move clockwise (upward in the figure) along the circumferential direction with respect to the case 33. Thereby, the protrusion 37 contacts the second contact side 38 c of the groove 38. In this case, since the second contact side 38c is not inclined, the projecting portion 37 is not pushed out from the groove portion 38 in the axial direction. Therefore, since the friction member 32 does not move in the axial direction, the pressing force of the friction surface 35 is not increased, and the friction generated between the cone 31 and the friction member 32, that is, between the inner input shaft 12 and the outer main shaft 13. The force is smaller than when accelerating.

  As described above, in the friction mechanism 30, the characteristics of the frictional force generated according to the direction of relative rotation between the inner input shaft 12 and the outer main shaft 13 can be made different. The torsional rigidity of the shaft 10 can be varied. Thereby, the noise and vibration caused by the rotational fluctuation input from the crankshaft 11 can be more effectively reduced.

  As described above, in the power transmission shaft structure of the present embodiment, the main shaft 10 that is the power transmission shaft on the input side in the manual transmission 1 has a double structure of the inner input shaft 12 and the outer main shaft 13. The rotational power input to the inner input shaft 12 is transmitted to the outer main shaft 13 via the engaging portion 14 so that the speed change gear 55 rotates. Therefore, the rotational power input to the main shaft 10 is transmitted from the one end 12d of the inner input shaft 12 to the other end 12c and then transmitted to the outer main shaft 13 via the engaging portion 14. Thereby, since the transmission path of the rotational power in the axial direction of the main shaft 10 can be secured long, the torsional rigidity of the main shaft 10 can be kept low. Therefore, noise and vibration due to fluctuations in input torque from the crankshaft 11 can be effectively reduced.

  Further, according to the power transmission shaft structure of the present embodiment, the torsional rigidity of the main shaft 10 can be kept low, so that the coil spring 7a, which is a conventional damping spring structure provided on the clutch disk 7, is omitted. Alternatively, the capacity of the coil spring 7a can be reduced. Thereby, the inertial mass of the power transmission system including the main shaft 10 and the clutch 2 can be reduced. That is, since the power transmission shaft structure according to this embodiment is provided in the main shaft 10 disposed at the center of rotation, an increase in inertial mass can be minimized. Therefore, the load during synchronization can be reduced and the shift load can be reduced. Further, if the capacity of the coil spring 7a is reduced, the thickness dimension of the clutch 2 can be reduced, so that the axial dimension of the manual transmission 1 can be reduced.

  The power transmission shaft structure according to the present invention can be used together with the damping spring structure (coil spring 7a) of the clutch disk 7 as in the above embodiment. If the power transmission shaft structure of the present invention and the damping spring structure of the clutch disc 7 are used in combination, a mechanism for absorbing fluctuations in the input torque from the crankshaft 11 can be arranged in series along the axial direction of the main shaft 10. Further, the torsional rigidity of the power transmission system can be further reduced, and noise and vibration can be greatly reduced.

  In addition, the power transmission shaft structure of the present embodiment is provided with a stopper mechanism 20 that restricts relative rotation due to torsion between the inner input shaft 12 and the outer main shaft 13 when the input torque to the inner input shaft 12 exceeds a predetermined value. ing. Therefore, the torsional rigidity of the main shaft 10 can be kept low because the torsion of the inner input shaft 12 is not restricted until the input torque to the inner input shaft 12 becomes a predetermined value or more. On the other hand, when the input torque to the inner input shaft 12 exceeds a predetermined value, the stopper mechanism 20 restricts the torsion of the inner input shaft 12, so that excessive torque acts on the inner input shaft 12. Can be prevented. Therefore, at the normal time, it is possible to avoid insufficient rigidity of the main shaft 10 when excessive torque is transmitted to the main shaft 10 due to the sudden engagement of the clutch 2 or the like while keeping the torsional rigidity of the main shaft 10 low.

  In the power transmission shaft structure of the present embodiment, a protruding portion 25 that protrudes from the outer periphery of the inner input shaft 12 toward the inner periphery of the outer main shaft 13 is provided. Thereby, when the axial deflection of the inner input shaft 12 becomes equal to or greater than a predetermined value, the projecting portion 25 abuts against the inner peripheral surface 13b of the outer main shaft 13 that faces the inner input shaft 12, and the deflection can be restricted. Therefore, since the amount of bending when the bending load is applied to the inner input shaft 12 can be controlled, the rigidity of the main input shaft 12 is ensured and the rigidity of the inner input shaft 12 is reduced by reducing the diameter of the inner input shaft 12. It becomes possible.

  Further, in the power transmission shaft structure of the present embodiment, the frictional surface 35 provided between the inner input shaft 12 and the outer main shaft 13 generates a frictional force against relative rotation due to the torsion of the inner input shaft 12 and the outer main shaft 13. The friction mechanism 30 is provided. Thereby, the damping force with respect to the relative rotation by the twist of the inner side input shaft 12 and the outer side main shaft 13 can be obtained. Therefore, the torsional rigidity of the main shaft 10 can be adjusted appropriately.

  Further, in the friction mechanism 30, the friction surface 35 is an inclined surface that is inclined along the axial direction of the inner input shaft 12 and the outer main shaft 13, and the cone according to the direction of relative rotation between the inner input shaft 12 and the outer main shaft 13. By moving the relative position of the friction member 32 in the axial direction with respect to 31, the pressing force of the friction surface 35 is changed, and the magnitude of the generated frictional force is changed. As a result, the characteristics of the frictional force generated according to the direction of relative rotation between the inner input shaft 12 and the outer main shaft 13 can be made different, so that the torsional rigidity of the main shaft 10 can be reduced during deceleration and acceleration of the input rotation. Can be different. Therefore, noise and vibration caused by fluctuations in input torque can be reduced more effectively.

  Further, in the conventional manual transmission, in order to prevent the main shaft from swinging due to the reaction force from the transmission gear, a bearing that supports the end of the main shaft is necessary. In the main shaft 10 to which is applied, the vibration is reduced by the double structure of the inner input shaft 12 and the outer main shaft 13, so that the bearing that supports the end portion (end portion on the clutch 2 side) of the main shaft 10 is omitted. Is possible. Therefore, the number of parts of the manual transmission 1 can be reduced correspondingly, and the structure can be simplified.

  FIG. 7A is a partially enlarged view of a portion B in FIG. 2 and shows the engaging portion 14. FIG. 7B is a partially enlarged perspective view of a portion corresponding to the engaging portion 14 of the inner input shaft 12. In the power transmission shaft structure of the present embodiment, an opening 26 a of the oil passage 26 is provided in the engaging portion 14 provided at the end 12 c of the inner input shaft 12. That is, as shown in FIG. 7A, in the engaging portion 14 where the spline teeth 27 of the inner input shaft 12 and the spline teeth 28 of the outer main shaft 13 are spline-fitted as shown in FIG. In addition, a plurality of spline teeth 27 made of linear protrusions extending in the axial direction formed on the outer peripheral surface 12a of the inner input shaft 12 are formed at a predetermined interval, but some of them (in FIG. 7B) Every other two) spline teeth 27 have a cut-out portion (missed tooth portion) 27a cut by a predetermined length from the clutch 2 side, and are shorter than the other spline teeth 27. An opening 26 a of the oil passage 26 is disposed at a position corresponding to the cutout portion 27 a of the spline tooth 27. The oil passage 26 is a through hole penetrating in the radial direction from the center side of the inner input shaft 12 for flowing lubricating oil.

  The reason why the oil passage 26 of the inner input shaft 12 is provided in the engaging portion 14 is as follows. That is, when the oil passage 26 penetrating the inner input shaft 12 in the radial direction is provided, the oil passage 26 is assumed to be adjacent to the clutch 2 side of the engaging portion 14 in the inner input shaft 12 (a dotted line in FIG. 7B). When the excessive torsional torque due to the input rotation is applied to the inner input shaft 12, the stress is applied to the opening 26a of the oil passage 26 (including the opening on the axial center side). Concentration may cause a crack in the inner input shaft 12 around the opening 26a. In the worst case, the inner input shaft 12 may not be broken due to the crack.

  In this regard, in the power transmission shaft structure of the present embodiment, the engaging portion 14 of the inner input shaft 12 is a member due to the spline teeth 27 being formed or being splined to the outer main shaft 13. The rigidity is higher than other parts. Accordingly, if a part of the spline teeth 27 of the engaging portion 14 is cut out as described above and the opening 26a of the oil passage 26 is disposed in that portion, the oil can be removed even when excessive torsional torque acts on the inner input shaft 12. Since the stress applied to the opening 26a of the path 26 can be suppressed to a low level, it is possible to effectively prevent a crack from occurring around the opening 26a.

  In the present embodiment, the spline teeth 27 of the inner input shaft 12 are omitted and the opening 26a of the oil passage 26 is disposed in that portion, but in addition to this, two adjacent spline teeth 27 of the inner input shaft 12 are arranged. The flow of the lubricating oil may be ensured by disposing a part of the spline teeth 28 of the outer main shaft 13 facing the opening 26a by disposing the opening 26a of the oil passage 26 therebetween. Further, here, the case where the oil passage 26 provided in the inner input shaft 12 is opened in the engaging portion 14 has been described, but when the radial oil passage is provided in the outer main shaft 13, the oil passage is engaged. The opening may be provided in the portion 14.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea described in the claims and the specification and drawings. Is possible. It should be noted that any shape, structure, and material not directly described in the specification and drawings are within the scope of the technical idea of the present invention as long as the effects and advantages of the present invention are exhibited.

  For example, in the above-described embodiment, the case where the protruding portion 25 is provided on the outer peripheral surface 12a of the inner input shaft 12 as a structure for suppressing the axial deflection of the inner input shaft 12 is shown. The configuration is not limited to that shown in the above embodiment. Therefore, the protrusion for suppressing the bending of the inner input shaft may be provided so as to protrude from at least one of the outer periphery of the inner input shaft and the inner periphery of the outer main shaft toward the other.

  Further, in the main shaft 10 as an embodiment of the power transmission shaft structure according to the present invention, a stopper mechanism (twist restricting portion) 20 that restricts relative rotation due to torsion between the inner input shaft 12 and the outer main shaft 13; A case where all of the friction mechanism 30 that generates a frictional force with respect to the relative rotation between the inner input shaft 12 and the outer main shaft 13 and the protruding portion 25 (deflection restricting portion) are provided to prevent the inner input shaft 12 from bending. As described above, the power transmission shaft structure according to the present invention may be provided with only one or two of the above-described twist restricting portion, friction mechanism, and deflection suppressing portion.

1 Manual Transmission 2 Clutch 7 Clutch Disc 7a Coil Spring (Damping Spring Structure)
10 Main shaft (input shaft)
11 crankshaft 12 inner input shaft 12a outer peripheral surface 13 outer main shaft 13a outer peripheral surface 13b inner peripheral surface 14 engaging portion (spline fitting portion)
15 Input part 16 Bearing 17 Bearing 20 Stopper mechanism (torsion restricting part)
21 1st protrusion part 21a Side surface (contact part)
22 2nd protrusion part 22a Side surface (contact part)
25 Protruding part (deflection restricting part)
27 Spline teeth 27a Cut-out part (missing tooth part)
28 Spline Teeth 30 Friction Mechanism 31 Cone 32 Friction Member 33 Case 35 Friction Surface 36 Movement Mechanism 37 Projection 38 Groove 38a Opening 38b First Abutment Side 38c Second Abutment Side 55 Gear for Shifting (Rotating Parts for Shifting)
70 Counter shaft (output shaft)

Claims (4)

A power transmission shaft structure for transmitting rotational power included in the transmission,
An inner input shaft that rotates when the rotational power of the prime mover is input;
It is coaxially disposed outside the inner input shaft, and has an engaging portion that engages with the inner input shaft in a relatively non-rotatable manner at one end thereof , and a rotating component for shifting is provided on the outer periphery. An outer main shaft,
At least one of the outer periphery between the engaging portion and the opposite end portion of the inner input shaft and the inner periphery between the engaging portion and the opposite end portion of the outer main shaft to the other. A deflection restricting portion comprising a protruding portion protruding toward the
A torsion restricting portion that is provided in a case of the transmission and includes a contact portion that is disposed on the inner input shaft and the outer main shaft with a predetermined gap in a rotation direction;
A bearing installed on the outer peripheral side of the outer main shaft and rotatably supporting the outer main shaft ;
The contact portion of the twist restricting portion and the bearing are both arranged at the other end of the outer main shaft,
Rotational power input from one end of the inner input shaft is transmitted from the other end of the inner input shaft to the outer main shaft and the rotary component for shifting through the engagement portion,
When the bending load applied to the inner input shaft becomes equal to or greater than a predetermined value, the projecting portion of the deflection restricting portion comes into contact with the inner periphery of the outer main shaft or the outer periphery of the inner input shaft. Bending is regulated ,
When the input torque to the inner input shaft exceeds a predetermined value, the abutting portion of the torsion restricting portion abuts so that relative rotation due to torsion between the inner input shaft and the outer main shaft is restricted. A transmission power transmission shaft structure of a transmission, characterized in that A friction mechanism that generates a frictional force against relative rotation due to torsion between the inner input shaft and the outer main shaft by a friction surface that is in sliding contact between the inner input shaft and the outer main shaft;
The friction surface is an inclined surface that is inclined along the axial direction of the inner input shaft and the outer main shaft,
The friction mechanism has a frictional force generated by moving a relative position of the inner input shaft and the outer main shaft in the axial direction on the friction surface in accordance with a direction of relative rotation between the inner input shaft and the outer main shaft. The power transmission shaft structure according to claim 1, wherein the size is changed. The friction mechanism presses the friction surface with a stronger force when accelerating rotation input to the inner input shaft than when decelerating rotation input to the inner input shaft. The power transmission shaft structure according to claim 2, wherein a force is generated. The inner input shaft is formed with an oil passage penetrating in a radial direction from the center side of the inner input shaft.
The engagement portion is a configuration in which spline teeth formed on the inner input shaft and the outer main shaft are spline-fitted,
Wherein the oil passage of the inner input shaft, the power of any of claims 1 to 3, characterized in that it is open to the toothless portion consisting lacks a portion of the spline teeth in the engaging portion Transmission shaft structure.

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