JP2009250373A - Power transmitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To satisfy both traction performance and endurance in a power transmission device. <P>SOLUTION: A transmission has a conical input cone 34 coupled to an input shaft and an output cone coupled to an output shaft arranged reversely and parallel to each other, and as the torque acting on the output shaft by a grasping force adjusting mechanism increases, both the force of the cones for grasping a ring increases. In the transmission, a groove is formed so as to revolve around a circumference on a lateral side of the input cone 34 and an R shape is formed in a protrusion formed by the groove. Further, a curvature radius of the R is formed so as to get smaller as coming closer to the protrusion formed in a position where the speed reducing ratio gets smaller. By the R in the protrusion, excessive stress concentration is prevented from occurring in the protrusion and besides even when the speed reducing ratio is small and the grasping force gets small which acts on the ring by the grasping force adjusting mechanism, the surface pressure needed between the input cone 34 and the ring can be ensured. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a power transmission device, and more specifically, has an input shaft and an output shaft arranged in parallel with the input shaft, and continuously shifts the power input to the input shaft to the output shaft. The present invention relates to a power transmission device including a continuously variable transmission for output.

Conventionally, in this type of power transmission device, a conical member connected to an input shaft and a conical member connected to an output shaft are arranged in parallel to each other in opposite directions, and a ring is inserted into the conical member. There has been proposed one including a continuously variable transmission constituted by two conical members with a narrow pressure (see, for example, Patent Document 1). In this apparatus, by moving the ring in the axial direction, the power input to the input shaft with a change in the gear ratio is output to the output shaft through the ring.
JP-T-2006-501425

  In the power transmission device described above, power is transmitted while the ring is narrowed by the two conical members. Therefore, it is necessary to ensure a sufficiently large surface pressure at the contact portion between the ring and the conical member. On the other hand, if the surface pressure at the contact portion between the ring and the conical member is too strong, the member may be damaged. Therefore, the surface pressure between the ring and the conical member is designed within the allowable surface pressure range allowed for the member. There is also a need.

  The main purpose of the power transmission device of the present invention is to ensure the surface pressure between the conical input / output member and the annular transmission member to further improve the traction performance.

  The power transmission device of the present invention employs the following means in order to achieve the main object described above.

The power transmission device of the present invention is
A power transmission device having an input shaft and an output shaft arranged in parallel to the input shaft, and comprising a continuously variable transmission that continuously shifts the power input to the input shaft and outputs the power to the output shaft. There,
A conical input member connected to the input shaft;
An output member having substantially the same conical shape as the input member connected to the output shaft in a direction opposite to the input member;
An annular transmission member that is constricted by the input member and the output member and transmits power from the input member to the output member;
Slide means capable of changing a reduction ratio by sliding the transmission member;
Narrow pressure adjusting means for adjusting the narrow pressure acting on the annular member in a tendency to increase as the torque acting on the output shaft increases by a mechanical mechanism;
With
On at least one side surface of the input member and the output member, a convex portion is formed by a groove so that the contact area with the annular member tends to decrease as the annular member moves toward a position where the reduction ratio decreases. It is characterized by.

  In the power transmission device of the present invention, a conical input member connected to the input shaft, a conical output member substantially the same as the input member connected to the output shaft in the opposite direction to the input member, and the input member And the output member, the annular transmission member that transmits the power from the input member to the output member, the slide means that can change the reduction ratio by sliding the transmission member, and the mechanical mechanism to the output shaft A continuously variable transmission is constituted by a narrow pressure adjusting means for adjusting a narrow pressure acting on the annular member so that the larger the acting torque is, the annular member is arranged on at least one side surface of the input member and the output member. The convex portion is formed by the groove so that the contact area with the annular member tends to decrease as the distance decreases. As the annular member moves toward the portion where the reduction ratio becomes smaller, the torque acting on the output shaft becomes smaller and the narrow pressure of the ring adjusted by the narrow pressure adjusting means tends to become smaller. Since the area of the contact portion between the ring and the ring tends to be small, the surface pressure of the contact portion for securing traction can be made sufficiently large regardless of the reduction ratio. As a result, the traction performance can be further improved.

  In such a power transmission device of the present invention, the convex portion may be formed with a round (R). By so doing, it is possible to suppress the occurrence of excessive stress concentration at the contact portion between the annular member and the input member or output member. In the power transmission device of this aspect of the present invention, the convex portion may be formed such that the radius of curvature of the radius (R) tends to be smaller as the convex portion is formed at a portion where the reduction ratio is smaller. .

  In the power transmission device of the present invention, the convex portion may be formed such that the convex portion formed at a portion where the reduction ratio is small tends to have a narrower groove interval. If it carries out like this, it can adjust to the tendency for a contact area with an annular member to become small easily so that a cyclic | annular member goes to the site | part where a reduction ratio becomes small.

  Furthermore, the said convex part shall be designed so that it may become more than the surface pressure from which the maximum traction coefficient of the oil for traction is obtained within the range of the surface pressure permitted to a member. By doing so, it is possible to achieve both traction performance and durability.

  Next, the best mode for carrying out the present invention will be described using examples.

  FIG. 1 is a configuration diagram showing an outline of a configuration of a power transmission device 20 as an embodiment of the present invention. The power transmission device 20 of the embodiment is a transaxle device that can shift power transmitted from an engine (not shown) mounted on a vehicle via a starting device (for example, a torque converter) and transmit the power to left and right front wheels. As shown in the figure, a forward / reverse switching mechanism 24 that is connected to the output shaft 22 of the starting device and outputs power from the starting device with switching between forward rotation and reverse rotation, and a forward / reverse switching mechanism 24. A continuously variable transmission that has an input shaft 32 connected to the output shaft 38 and an output shaft 38 disposed in parallel to the input shaft 32 and continuously outputs the power input to the input shaft 32 to the output shaft 38. And the CVT 30 are connected to the output shaft 38 of the CVT 30 via the reduction gear 26 and to the left and right front wheels. And a differential gear 28, which are accommodated in a case 21 made of a transaxle housing 21a and the converter housing 21b and the rear case 21c. In addition, a partition plate 21d that partitions a space where the forward / reverse switching mechanism 24 and the differential gear 28 are disposed from a space where the CVT 30 is disposed is provided inside the case 21.

  The forward / reverse switching mechanism 24 includes a double-pinion planetary gear mechanism, a brake B1, and a clutch C1. The planetary gear mechanism of the double pinion includes an external gear sun gear 24a, an internal gear ring gear 24b arranged concentrically with the sun gear 24a, a plurality of first pinion gears meshed with the sun gear 24a, and the first pinion gear. A plurality of second pinion gears that mesh with each other and mesh with the ring gear 24b are coupled to each other and a carrier 24c that rotates and revolves freely. The sun gear 24a has an output shaft 22, and the carrier 24c has an input shaft 32 of the CVT 30. Each is connected. The ring gear 24b of the planetary gear mechanism is connected to the case 21 by a brake B1, and the ring gear 24b can be freely rotated or prohibited from rotating by turning on and off the brake B1. The sun gear 24a and the carrier 24c of the planetary gear mechanism are connected by a clutch C1, and the sun gear 24a and the carrier 24c are connected or disconnected by turning on and off the clutch C1. The forward / reverse switching mechanism 24 turns off the brake B1 and turns on the clutch C1 to transmit the rotation of the output shaft 22 to the input shaft 32 of the CVT 30 as it is to advance the vehicle or turn on the brake B1 and turn on the clutch C1. Is turned off, the rotation of the output shaft 22 is converted in the reverse direction and transmitted to the input shaft 32 of the CVT 30 to reverse the vehicle. Further, the output shaft 22 and the input shaft 32 of the CVT 30 can be disconnected by turning off the brake B1 and turning off the clutch C1. In the embodiment, the forward / reverse switching mechanism 24 is constituted by a double-pinion planetary gear mechanism, a brake B1, and a clutch C1, but it is constituted by a single-pinion planetary gear mechanism instead of the double-pinion planetary gear mechanism. It is good also as what is carried out and it is good also as what shall be set as another structure.

  The CVT 30 includes a conical input cone 34 integrally formed with an input shaft 32, and an output cone 36 that is substantially the same shape as the input cone 34 and is connected to the output shaft 38 so as to be opposite to the input cone 34. A ring 60 inserted into the input cone 34 and disposed between the input cone 34 and the output cone 36, and a sliding guide (not shown) capable of rotatably supporting the ring 60 and sliding the ring 60. And a narrow pressure adjusting mechanism 50 for adjusting a narrow pressure applied to the ring 60 between the input cone 34 and the output cone 36, and the ring 60 is slid by a sliding guide so that the power from the input shaft 32 is continuously stepped. To change the output And outputs it to the shaft 36. FIG. 2 shows how the CVT 30 shifts. As shown in the figure, the ring 60 is slid to the front side in the figure to change the power from the input cone 34 with a relatively small reduction ratio and transmit it to the output cone 36, and the ring 60 is slid to the back side in the figure. As a result, the power from the input cone 34 is shifted with a relatively large reduction ratio and transmitted to the output cone 36.

  The input cone 34 and the input shaft 32 are rotatable by a bearing 41 formed as a cylindrical roller bearing that is attached to the partition plate 21d at the right end in FIG. 1 and cannot receive a thrust force but can receive a relatively large radial force. And at the left end is rotatably supported by a bearing 42 formed as a tapered roller bearing attached to the transaxle housing 21a and capable of receiving a thrust force. On the other hand, the output cone 36 at the right end in FIG. 1 is rotatably supported by a bearing 45 attached to the partition plate 21d and formed as a cylindrical roller bearing, and at the left end attached to the transaxle housing 21a and formed as a cylindrical roller bearing. The bearing 46 is rotatably supported. Further, at the right end in FIG. 1 of the output shaft 38 connected to the output cone 36, it is rotatably supported by a bearing 49 which is attached to the converter housing 21b and formed as a tapered roller bearing.

  The oil seal 43 is attached to the partition plate 21d on the inner side (left side in FIG. 1) where the bearing 41 of the input cone 34 is disposed, and on the inner side of the position where the bearing 45 of the output cone 36 is disposed ( An oil seal 47 is attached to the left side in FIG. In addition, an oil seal 44 is attached to the transaxle housing 21a on the inner side (right side in FIG. 1) of the position where the bearing 42 of the input cone 34 is disposed, and at the position where the bearing 46 of the output cone 36 is disposed. An oil seal 48 is attached on the inner side (right side in FIG. 1). Thereby, the internal space of the case 21 is divided into a space (first space) formed by the transaxle housing 21a and the rear cover 21c, and a space (second space) formed by the transaxle housing 21a and the partition plate 21d. ), A space (third space) formed by the transaxle housing 21a, the converter housing 21b, and the partition plate 21d, and the first space and the third space include the first space. Are filled with lubricating oil for lubricating the mechanical parts such as the bearings 42, 46 arranged in the bearings 46, the bearings 41, 45, 49 arranged in the third space, the forward / reverse switching mechanism 24, the differential gear 28, etc. Traction oil for transmitting torque in the CVT 30 disposed in the space is filled. This traction oil is a mechanism in which the CVT 30 is a mechanism for transmitting power by the shear force of an oil film in an elastic fluid lubrication state formed between the input cone 34 and the output cone 36 and the ring 60. Thus, special oils having a high pressure viscosity coefficient are used.

  Although not shown, the sliding guide is configured to be slidable while rotatably supporting the ring 60 along a guide rail formed in the transaxle housing 21a. A slider slidably attached to the upper end portion along the guide rail and a pair of two rollers for rotatably holding the ring 60 are formed on the upper end portion and the lower end portion, respectively. Further, as a sliding mechanism, a rod inserted slidably into a through hole formed in parallel to the guide rail at the lower end of the sliding guide, and attached to the tip of the rod and fixed to the transaxle housing 21a at the center. A motor in which a rotating shaft is formed and a U-shaped U-shaped portion is formed at the other end, and a convex portion to be inserted into the U-shaped portion of the lever is attached at a position eccentric to the rotating shaft. The sliding guide is slid by tilting the rod up and down by rotating the motor. That is, when the motor is driven to rotate, the lever swings around the rotation axis due to the convex portion eccentric to the rotation axis of the motor, thereby tilting the rod connected to the lever in the vertical direction, The ring 60 is slid.

  The narrow pressure adjusting mechanism 50 is built in the output cone 36 and adjusts the narrow pressure acting on the ring 60 by the input cone 34 and the output cone 36 by a mechanical mechanism. FIG. 3 is a block diagram showing an outline of the configuration of the narrow pressure adjusting mechanism 50, and FIG. 4 is a partially enlarged view of the narrow pressure adjusting mechanism 50 partially enlarged. As shown in the figure, the narrow pressure adjusting mechanism 50 includes a fixing member 52 that is spline-fitted to a spline formed at the distal end portion of the output shaft 38 and fixed to the output shaft 38 so as not to move in the axial direction. A moving member 54 that is spline-fitted to a spline formed on the inner peripheral surface of the cone 36 and is movable in the axial direction together with the output cone 36 with respect to the output shaft 38, and a plurality of members formed on the fixed member 52. A plurality of balls 56 disposed between the hemispherical ball receiver 52 a and the plurality of hemispherical ball receivers 54 a formed on the moving member 54, and a fixing member provided between the fixing member 52 and the moving member 54. A spring 58 that biases the moving member 54 in the axial direction using the spring 52 as a spring receiver and an output cone 36 attached to the output cone 36 A support member 59 that supports the output cone 36 so as to be movable in the axial direction with respect to the output shaft 38, and converts the torque acting on the output shaft 38 into an axial force to act on the output cone 36. The narrow pressure of the ring 60 is adjusted. As shown in FIG. 4, when no torque is applied to the output shaft 38, the ball receiver 52 a of the fixing member 52 and the ball receiver 54 b of the moving member 54 are just opposite to each other. Although no force is received (see FIG. 4A), when a torque acts on the output shaft 38, a twist occurs between the ball receiver 52a of the fixing member 52 and the ball receiver 54a of the moving member 54, thereby fixing the member 52. A force for pushing the moving member 54 with the ball 56 is generated using the reaction force from (see FIG. 4B). As described above, since the output cone 36 is attached to the moving member 54, the output cone 36 is pushed out as the moving member 54 moves. At this time, the force that pushes out the output cone 36 increases as the torque acting on the output shaft 38 increases, whereby the narrow pressure of the ring 60 is adjusted. In the CVT 30, the torque acting on the output shaft 38 becomes smaller as the speed reduction ratio becomes smaller with respect to the torque input to the input shaft 32. Therefore, the narrow pressure of the ring 60 is adjusted to become smaller as the speed reduction ratio becomes smaller. become.

  A groove is formed on the side surface of the input cone 34 so as to circulate around the circumference of the cone by a laser or the like, so that the cross section thereof has a convex shape. FIG. 5 is a sectional view showing a section of the input cone 34. As shown in the figure, the grooves on the side surface of the input cone 34 are formed at equal intervals, and a radius (R) is formed at the corner of the convex portion formed by the groove, and the radius of curvature of the radius (R) is formed. Is formed such that the convex portion formed at a position where the reduction ratio in the input cone 34 becomes small, that is, a position where the diameter of the input cone 34 becomes large, becomes smaller. FIG. 6 shows an example of the relationship between the reduction ratio and the groove pitch, and FIG. 7 shows an example of the relationship between the reduction ratio and the radius of curvature of the convex portion (R). As a result, the contact area between the input cone 34 and the ring 60 becomes smaller as the ring 60 moves toward a position where the reduction ratio becomes smaller, so that the surface pressure at the contact portion can be increased. This is because, when the reduction gear ratio is relatively large, a large torque acts on the output shaft 38, so that a large narrow pressure acts on the ring 60 by the narrow pressure adjusting mechanism 50, and the gap between the input cone 34 and the ring 60. However, in the state where the reduction ratio is relatively small, only a small torque acts on the output shaft 38. Therefore, the narrow pressure adjusting mechanism 50 causes the ring 60 to have a small narrow pressure. However, it is based on the fact that the surface pressure for exerting the traction performance cannot be secured. Further, the contact area between the input cone 34 and the ring 60 is changed by setting a radius (R) to the convex portion formed on the side surface of the input cone 34 and adjusting the radius of curvature of the radius (R). In addition, excessive stress concentration does not occur in the convex portion. In the embodiment, the surface pressure between the input cone 34 and the ring 60 is a surface necessary for obtaining the maximum traction coefficient μmax of the traction oil used while setting the allowable surface pressure Plim allowed by the material of the input cone 34 as an upper limit. The pressure Ptr is designed to be within the range of the upper and lower limits with the lower limit. FIG. 8 shows the relationship between the surface pressure of the input cone 34 and the ring 60 and the reduction ratio, and FIG. 9 shows the relationship between the surface pressure of the input cone 34 and the ring 60 and the traction coefficient μ of the traction oil. The solid line in FIG. 8 shows an embodiment in which a groove is formed on the side surface of the input cone 34 and the radius of curvature of the round (R) of the convex portion is changed according to the reduction ratio, and the broken line is a groove formed on the side surface of the input cone. The comparative example which does not do is shown. As shown in the drawing, in the embodiment, the surface pressure between the input cone 34 and the ring 60 is changed to the allowable surface pressure Plim and the maximum traction coefficient μmax by changing the radius of curvature of the convex portion (R) according to the reduction ratio. In the comparative example, when the surface pressure between the input cone 34 and the ring 60 is designed to be within the allowable surface pressure Plim, the reduction ratio is It can be seen that the contact pressure is insufficient in a small case.

  A groove similar to the side surface of the input cone 34 is formed on the side surface of the output cone 36, but the radius of curvature of the convex portion (R) formed by the groove is small in the reduction ratio in the output cone 36. In other words, the convex portion formed at a position where the diameter of the output cone 36 becomes smaller is formed to be smaller. As a result, the contact area between the output cone 36 and the ring 60 becomes smaller as the ring 60 moves toward a position where the reduction ratio becomes smaller, so that the surface pressure at the contact portion can be increased.

  According to the power transmission device 20 of the embodiment described above, a groove is formed on the side surface of the input cone 34 (output cone 36) so as to circulate around the circumference, and a round (R ) And the radius of curvature of the radius (R) is formed such that the convex portion formed at a position where the reduction gear ratio becomes smaller becomes smaller. As a result, even when the reduction ratio is relatively small and the narrow pressure acting on the ring 60 is reduced by the narrow pressure adjusting mechanism 50, the necessary surface pressure between the input cone 34 (output cone 36) and the ring 60 is ensured. be able to. As a result, the traction performance can be further improved. In addition, since the round (R) is formed on the convex portion that is in contact with the ring 60, it is possible to suppress excessive stress concentration at the contact portion, and to achieve both traction performance and durability. Further, the surface pressure between the input cone 34 (output cone 36) and the ring 60 is required to obtain an upper limit of the allowable surface pressure Plim allowed by the material and to obtain the maximum traction coefficient μmax of the traction oil used. Since the surface pressure Ptr is designed to be within the range of the upper and lower limits with the surface pressure Ptr as the lower limit, the traction performance can be further improved.

  In the power transmission device 20 of the embodiment, the narrow pressure adjusting mechanism 50 is formed by a fixed member 52 attached to the output shaft 38, a moving member 54 attached to the output cone 36, and the fixed member 52. The plurality of hemispherical ball receivers 52a and the plurality of hemispherical ball receivers 54a formed on the moving member 54 are constituted by a plurality of balls 56, which act on the output shaft 38. Any mechanism may be used as long as it can convert the torque to be applied to the output cone 36 by converting it into an axial force. In the power transmission device 20 according to the embodiment, the narrow pressure adjusting mechanism 50 is built in the output cone 36, but may be built in the input cone 34 instead of the output cone 36.

  In the power transmission device 20 of the embodiment, the input shaft 32 and the input cone 34 are integrally formed, but may be formed separately. In this case, if a narrow pressure adjusting mechanism is provided for the input cone 34 instead of the output cone 36, the output shaft 38 and the output cone 36 can be integrally formed.

  In the power transmission device 20 of the embodiment, grooves are formed at equal intervals on the side surfaces of the input cone 34 and the output cone 36 to form a cross section in a convex shape, and a round (R) is formed in the convex portion. In addition, the radius of curvature of the radius (R) is formed so as to be smaller as the convex portion is formed at a position where the reduction gear ratio is small, but is not limited to this, and is formed at a position where the reduction gear ratio is small. For example, if the convex portion is formed so that the contact area with the ring 60 becomes smaller as the convex portion becomes larger, for example, the radius of curvature of the radius (R) of the convex portion is made constant and the pitch of the groove forming the convex portion is set. It is good also as what forms so that it may become so narrow that the position where a reduction ratio becomes small, and it forms so that the curvature radius of the radius (R) of a convex part may become small, so that the pitch of a groove may become narrow as the position where a reduction ratio becomes small. It may be used to.

  In the power transmission device 20 according to the embodiment, the convex shape is formed on the side surface of the input cone 34 and the side surface of the output cone 36, but the convex shape may be formed only on one of the side surfaces. Good.

  The best mode for carrying out the present invention has been described with reference to the embodiments. However, the present invention is not limited to these embodiments, and various modifications can be made without departing from the gist of the present invention. Of course, it can be implemented in the form.

  The present invention is applicable to the automobile industry and the like.

It is a block diagram which shows the outline of a structure of the power transmission device 20 as one Example of this invention. It is explanatory drawing which shows the mode of the transmission of CVT30. 2 is a configuration diagram showing an outline of a configuration of a narrow pressure adjusting mechanism 50. FIG. It is the elements on larger scale which expanded the narrow pressure adjustment mechanism 50 partially. 3 is a cross-sectional view showing a cross section of an input cone 34. FIG. It is explanatory drawing which shows the relationship between a reduction ratio and a groove pitch. It is explanatory drawing which shows the relationship between a reduction ratio and the curvature radius of the round (R) of a convex part. It is explanatory drawing which shows the relationship between the surface pressure of the input cone 34 and the ring 60, and a reduction ratio. It is explanatory drawing which shows the relationship between the surface pressure of the input cone 34 and the ring 60, and the traction coefficient (micro | micron | mu) of traction oil.

Explanation of symbols

  20 power transmission device, 21 case, 21a transaxle housing, 21b converter housing, 21c rear case, 21d partition plate, 22 output shaft, 24 forward / reverse switching mechanism, 24a sun gear, 24b ring gear, 24c carrier, 26 reduction gear, 28 differential Gear, 30 CVT, 32 Input shaft, 34 Input cone, 36 Output cone, 38 Output shaft, 41, 42, 45, 46, 49 Bearing, 43, 44, 47, 48 Oil seal, 50 Narrow pressure adjustment mechanism, 52 Fixed member, 52a, 54a Ball receiver, 54 Moving member, 56 Ball, 58 Spring, 59 Support member, 60 Ring.

Claims (5)

A power transmission device having an input shaft and an output shaft arranged in parallel to the input shaft, and comprising a continuously variable transmission that continuously shifts the power input to the input shaft and outputs the power to the output shaft. There,
A conical input member connected to the input shaft;
An output member having substantially the same conical shape as the input member connected to the output shaft in a direction opposite to the input member;
An annular transmission member that is constricted by the input member and the output member and transmits power from the input member to the output member;
Slide means capable of changing a reduction ratio by sliding the transmission member;
Narrow pressure adjusting means for adjusting the narrow pressure acting on the annular member in a tendency to increase as the torque acting on the output shaft increases by a mechanical mechanism;
With
On at least one side surface of the input member and the output member, a convex portion is formed by a groove so that the contact area with the annular member tends to decrease as the annular member moves toward a position where the reduction ratio decreases. A power transmission device characterized by.   The power transmission device according to claim 1, wherein the convex portion is formed with a round (R).   The power transmission device according to claim 2, wherein the convex portion is formed such that the radius of curvature of the radius (R) tends to be smaller as the convex portion is formed at a portion where the reduction ratio is smaller.   The power transmission device according to any one of claims 1 to 3, wherein the convex portion is formed such that a convex portion formed at a portion where the reduction ratio is reduced tends to have a narrower groove interval.   5. The power transmission according to claim 1, wherein the convex portion is designed so as to be equal to or higher than a surface pressure at which a maximum traction coefficient of the traction oil is obtained within a range of a surface pressure allowed for the member. apparatus.

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