JP5862793B2 - Power transmission device for vehicle - Google Patents

Description

  According to the present invention, a vehicle power transmission device that transmits rotation of an input shaft connected to a drive source to an output shaft connected to a drive wheel includes a plurality of transmission units that are axially juxtaposed inside a transmission case. About things.

  Crank type that converts the rotation of the input shaft connected to the engine into a reciprocating motion of the plurality of connecting rods having mutually different phases, and converts the reciprocating motion of the plurality of connecting rods into a rotating motion of the output shaft by a plurality of one-way clutches. A continuously variable transmission is known from Patent Document 1 below.

Japanese special table 2005-502543 gazette

  By the way, in the continuously variable transmission described in Patent Document 1, the eccentric disk provided on the input shaft rotates eccentrically, and the end of the connecting rod supported by the eccentric disk also rotates eccentrically. An outward eccentric load acts to cause vibration. In particular, among the casings of the continuously variable transmission, the peripheral wall portions that cover the upper and lower portions of the plurality of transmission units arranged side by side have a large area. In order to avoid this, it is only necessary to increase the rigidity by increasing the thickness of the peripheral wall portion of the transmission case, but there is a problem that the weight of the continuously variable transmission increases.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to suppress membrane vibration of a transmission case that houses a plurality of crank transmission units while minimizing an increase in weight.

  In order to achieve the above object, according to the present invention, a plurality of transmission units for transmitting rotation of an input shaft connected to a drive source to an output shaft are provided between the input shaft and the output shaft inside the mission case. In parallel with each other, each of the transmission units includes an input side fulcrum rotating eccentrically with the input shaft, a one-way clutch connected to the output shaft, an output-side fulcrum provided on an outer member of the one-way clutch, A power transmission device for a vehicle comprising a connecting rod that is connected to both ends of the input side fulcrum and the output side fulcrum and reciprocates, wherein the transmission case supports one end side of the input shaft and the output shaft. A first side wall, a second side wall that supports the other end of the input shaft and the output shaft, and a peripheral wall that connects the first side wall and the second side wall And a plurality of columnar portions that connect between the mutually facing inner surfaces of the peripheral wall portion, and the plurality of columnar portions are disposed between the connecting rods of the plurality of transmission units. A vehicle power transmission device is proposed.

  According to the present invention, in addition to the first feature, the transmission case includes a partition part that connects the inner surface of the peripheral wall part and the columnar part to partition the space for housing the transmission unit, A second feature is that the axial width of the eccentric disk constituting the input side fulcrum is larger than the axial width of the connecting rod, and a notch for avoiding interference with the eccentric disk is formed in the partition wall. A vehicle power transmission device is proposed.

  According to the present invention, in addition to the first or second feature, there is proposed a vehicle power transmission device having a third feature that the mission case includes a breather.

  The first notch 11g of the embodiment corresponds to the notch of the present invention, the eccentric disk 19 of the embodiment corresponds to the input side fulcrum of the present invention, and the pin 37 of the embodiment corresponds to the output of the present invention. Corresponding to the side fulcrum, the engine E of the embodiment corresponds to the drive source of the present invention.

  According to the first feature of the present invention, when the input shaft connected to the drive source rotates, the input side fulcrum of each transmission unit rotates eccentrically, and the connecting rod having one end connected to the input side fulcrum reciprocates. The output shaft rotates through a one-way clutch to which the other end of the connecting rod is connected. Since there are a plurality of columnar portions that connect the mutually facing inner surfaces of the peripheral wall portions that connect the first side wall portion and the second side wall portion of the transmission case, the rigidity of the peripheral wall portions is increased by the columnar portions, and membrane surface vibrations are generated. And noise can be reduced while minimizing the increase in weight. Moreover, since the plurality of columnar portions are disposed between the connecting rods of the plurality of transmission units, it is possible to avoid the columnar portions from interfering with the connecting rod.

  Further, according to the second feature of the present invention, the transmission case includes the partition wall portion that connects the inner surface of the peripheral wall portion and the columnar portion to partition the space for housing the transmission unit. Further increase makes it possible to more effectively reduce noise caused by membrane vibration. Further, since the volume of the internal space of the transmission case is reduced by the amount of the columnar portion and the partition wall, not only can the concentration of oil splash with respect to the volume of the internal space be increased to improve the lubrication performance, but also the columnar portion and the partition wall. In order to obtain the same lubricating performance as when no part is provided, the amount of oil can be reduced, so that the oil agitation resistance can be reduced. Furthermore, the oil mist scattered inside the mission case can be efficiently collected at the bottom of the mission case by adhering to the partition wall. Moreover, even if the axial width of the eccentric disk constituting the input side fulcrum is larger than the axial width of the connecting rod, a notch for avoiding interference with the eccentric disk is formed in the partition wall. Interfering with the part can be avoided.

  Further, according to the third feature of the present invention, the volume of the internal space of the transmission case is reduced by the amount of the columnar part and the partition part, so that when the thermal load increases rapidly, The amount of air discharged from the provided breather is reduced, and a situation in which the lubricating oil in the mission case blows out from the breather can be avoided.

FIG. 1 is an overall perspective view of a continuously variable transmission. (First embodiment) FIG. 2 is a partially broken perspective view of a main part of the continuously variable transmission. (First embodiment) 3 is a cross-sectional view taken along line 3-3 of FIG. (First embodiment) FIG. 4 is an enlarged view of part 4 of FIG. (First embodiment) 5 is a cross-sectional view taken along line 5-5 of FIG. (First embodiment) FIG. 6 is a diagram showing the shape of the eccentric disk. (First embodiment) FIG. 7 is a diagram showing the relationship between the amount of eccentricity of the eccentric disk and the gear ratio. (First embodiment) FIG. 8 is a diagram showing the state of the eccentric disk at the TD transmission ratio and the UD transmission ratio. (First embodiment) FIG. 9 is an exploded perspective view of the mission case. (First embodiment)

11 mission case 11a first side wall part 11b second side wall part 11c peripheral wall part 11d inner surface 11e columnar part 11f partition wall part 11g first notch (notch)
11i Breather 12 Input shaft 13 Output shaft 14 Transmission unit 19 Eccentric disc (input side fulcrum)
33 Connecting rod 36 One-way clutch 37 Pin (output fulcrum)
38 Outer member E Engine (drive source)

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

First embodiment

  As shown in FIGS. 1 to 5 and 9, the transmission case 11 of the continuously variable transmission T for an automobile is divided into an upper casing 11U and a lower casing 11L, and each of the upper casing 11U and the lower casing 11L is A first side wall portion 11a and a second side wall portion 11b which are arranged parallel to each other on both sides of the input shaft 12 in the axis L direction; and a peripheral wall portion 11c which connects the first and second side wall portions 11a and 11b in the axis L direction. Is provided. The input shaft 12 and the output shaft 13 are supported in parallel with each other on the first side wall portion 11a and the second side wall portion 11b of the transmission case 11, and the rotation of the input shaft 12 connected to the engine E is six transmission units. 14... Is transmitted to the drive wheel via the output shaft 13 and the differential gear D. A variable speed shaft 15 sharing an axis L with the input shaft 12 is fitted into the hollow formed input shaft 12 via seven needle bearings 16 so as to be relatively rotatable. Since the structure of the six transmission units 14 is substantially the same, the structure will be described below with one transmission unit 14 as a representative.

  The transmission unit 14 includes a pinion 17 provided on the outer peripheral surface of the transmission shaft 15, and the pinion 17 is exposed from an opening 12 a formed in the input shaft 12. A disc-shaped eccentric cam 18 divided into two in the direction of the axis L is splined to the outer periphery of the input shaft 12 so as to sandwich the pinion 17. The center O1 of the eccentric cam 18 is eccentric with respect to the axis L of the input shaft 12 by a distance d. In addition, the six eccentric cams 18 of the six transmission units 14 are offset in phase by 60 ° from each other.

  On the outer peripheral surface of the eccentric cam 18, a pair of eccentric recesses 19 a and 19 a formed on both end surfaces in the axis L direction of the disc-shaped eccentric disk 19 are rotatably supported via a pair of needle bearings 20 and 20. . The center O1 of the eccentric recesses 19a, 19a (that is, the center O1 of the eccentric cam 18) is shifted from the center O2 of the eccentric disk 19 by a distance d. That is, the distance d between the axis L of the input shaft 12 and the center O1 of the eccentric cam 18 and the distance d between the center O1 of the eccentric cam 18 and the center O2 of the eccentric disk 19 are the same.

  A pair of crescent-shaped guide portions 18a and 18a are provided on the split surface of the eccentric cam 18 divided into two in the direction of the axis L so as to be coaxial with the center O1 of the eccentric cam 18. The tooth tips of the ring gear 19b formed so as to communicate between the bottoms of the recesses 19a and 19a slidably contact the outer peripheral surfaces of the guide portions 18a and 18a of the eccentric cam 18. Then, the pinion 17 of the transmission shaft 15 meshes with the ring gear 19b of the eccentric disk 19 through the opening 12a of the input shaft 12.

  The right end side of the input shaft 12 is directly supported by the first side wall portion 11 a on the right side of the mission case 11 via a ball bearing 21. A cylindrical portion 18b provided integrally with one eccentric cam 18 positioned on the left end side of the input shaft 12 is supported by the second side wall portion 11b on the left side of the transmission case 11 via a ball bearing 22. The left end side of the input shaft 12 splined to the inner periphery of the eccentric cam 18 is indirectly supported by the mission case 11.

  The speed change actuator 23 that changes the speed ratio of the continuously variable transmission T by rotating the speed change shaft 15 relative to the input shaft 12 is supported by the transmission case 11 so that the motor shaft 24a is coaxial with the axis L. A motor 24 and a planetary gear mechanism 25 connected to the electric motor 24 are provided. The planetary gear mechanism 25 includes a carrier 27 that is rotatably supported by an electric motor 24 via a needle bearing 26, a sun gear 28 that is fixed to the motor shaft 24a, and a plurality of two stations that are rotatably supported by the carrier 27. A pinion 29, a first ring gear 30 splined to the shaft end of the hollow input shaft 12 (strictly speaking, the cylindrical portion 18b of the one eccentric cam 18), and a spline to the shaft end of the transmission shaft 15 And a second ring gear 31 coupled thereto. Each double pinion 29 includes a first pinion 29a having a large diameter and a second pinion 29b having a small diameter. The first pinion 29a meshes with the sun gear 28 and the first ring gear 30, and the second pinion 29b has a second ring gear. Mesh with 31.

  On the outer periphery of the eccentric disk 19, an annular portion 33 a on one end side of the connecting rod 33 is supported via a roller bearing 32 so as to be relatively rotatable.

  The output shaft 13 is supported on the first and second side wall portions 11a and 11b of the mission case 11 by a pair of ball bearings 34 and 35, and a one-way clutch 36 is provided on the outer periphery thereof. The one-way clutch 36 includes a ring-shaped outer member 38 pivotally supported at the tip of the rod portion 33b of the connecting rod 33 via a pin 37, and an inner member disposed inside the outer member 38 and fixed to the output shaft 13. 39 and a plurality of rollers 41 arranged in a wedge-shaped space formed between the inner circular arc surface of the outer member 38 and the outer peripheral plane of the inner member 39 and biased by a plurality of springs 40. … And.

  As shown in FIGS. 6 and 8, since the center O1 of the eccentric recesses 19a and 19a (that is, the center O1 of the eccentric cam 18) is shifted from the center O2 of the eccentric disk 19 by a distance d, the outer circumference of the eccentric disk 19 And the inner periphery of the eccentric recesses 19a, 19a are non-uniform in the circumferential direction, and crescent-shaped thinning recesses 19c, 19c are formed at portions where the interval is large.

  As shown in FIGS. 3 to 5 and FIG. 9, the inner surface 11d of the peripheral wall portion 11c of the upper casing 11U and the inner surface 11d of the peripheral wall portion 11c of the lower casing 11L are connected by five columnar portions 11e. The five columnar portions 11e extend into the space between the six connecting rods 33 in a direction perpendicular to the longitudinal direction of the connecting rods 33. The five columnar portions 11e and the inner surface 11d of the peripheral wall portion 11c are connected to the five plates disposed between the six connecting rods 33 through the partition wall portions 11f.

  A circular first notch 11g is formed in the front portion of the partition wall portion 11f, and the eccentric disk 19 is fitted into the first notch 11g. Since the thickness of the eccentric disks 19 in the direction of the axis L is larger than the thickness of the connecting rods 33 in the direction of the axis L, providing the first notches 11g in the partition walls 11f causes interference with the eccentric disks 19. Avoided. Further, circular second notches 11h are formed at the rear part of the partition walls 11f, and the one-way clutch 36 is fitted into the second notches 11h. Since the thickness of the one-way clutches 36 in the direction of the axis L is larger than the thickness of the connecting rods 33 in the direction of the axis L, providing the second notches 11h in the partition wall portions 11f causes interference with the one-way clutch 36. Avoided.

  In this way, the interior of the mission case 11 is partitioned into six spaces by the five partition walls 11f, and the transmission units 14 are arranged in each space. And the breather 11i which connects the internal space of the sealed mission case 11 to external space is provided in the upper casing 11U.

  Next, the operation of one transmission unit 14 of the continuously variable transmission T will be described.

  As is clear from FIGS. 5 and 7A to 7D, when the input shaft 12 is rotated by the engine E when the center O2 of the eccentric disk 19 is eccentric with respect to the axis L of the input shaft 12. As the annular portion 33a of the connecting rod 33 rotates eccentrically around the axis L, the rod portion 33b of the connecting rod 33 reciprocates.

  As a result, when the connecting rod 33 is pulled back and forth in the process of reciprocating movement, the rollers 41 urged by the springs 40 bite into the wedge-shaped space between the outer member 38 and the inner member 39, and the outer member 38 and the inner member 39 are coupled via the rollers 41... So that the one-way clutch 36 is engaged and the movement of the connecting rod 33 is transmitted to the output shaft 13. On the other hand, when the connecting rod 33 is reciprocated, the rollers 41 are pushed out of the wedge-shaped space between the outer member 38 and the inner member 39 while compressing the springs 40. As the inner members 39 slip each other, the one-way clutch 36 is disengaged and the movement of the connecting rod 33 is not transmitted to the output shaft 13.

  Thus, since the rotation of the input shaft 12 is transmitted to the output shaft 13 for a predetermined time while the input shaft 12 rotates once, the output shaft 13 rotates intermittently when the input shaft 12 rotates continuously. Since the eccentric discs 19 of the six transmission units 14 are out of phase with each other by 60 °, the six transmission units 14 alternately transmit the rotation of the input shaft 12 to the output shaft 13. Thus, the output shaft 13 rotates continuously.

  At this time, as the eccentric amount ε of the eccentric disk 19 increases, the reciprocating stroke of the connecting rod 33 increases, and the one-time rotation angle of the output shaft 13 increases, and the transmission ratio of the continuously variable transmission T decreases. Conversely, the smaller the eccentric amount ε of the eccentric disk 19, the smaller the reciprocating stroke of the connecting rod 33, the smaller the rotation angle of the output shaft 13, and the higher the gear ratio of the continuously variable transmission T. When the eccentric amount ε of the eccentric disk 19 becomes zero, the connecting rod 33 stops moving even when the input shaft 12 rotates, so the output shaft 13 does not rotate, and the gear ratio of the continuously variable transmission T is maximized ( Infinity).

  When the transmission shaft 15 does not rotate relative to the input shaft 12, that is, when the input shaft 12 and the transmission shaft 15 rotate at the same speed, the transmission ratio of the continuously variable transmission T is maintained constant. In order to rotate the input shaft 12 and the transmission shaft 15 at the same speed, the electric motor 24 may be rotationally driven at the same speed as the input shaft 12. The reason is that the first ring gear 30 of the planetary gear mechanism 25 is connected to the input shaft 12 and rotates at the same speed as the input shaft 12. When the electric motor 24 is driven at the same speed, the sun gear 28 and the first ring gear 30 are driven. Rotate at the same speed, the planetary gear mechanism 25 is locked and rotates as a whole. As a result, the input shaft 12 and the transmission shaft 15 connected to the first ring gear 30 and the second ring gear 31 that rotate integrally are integrated and rotate at the same speed without relative rotation.

  When the rotational speed of the electric motor 24 is increased or decreased with respect to the rotational speed of the input shaft 12, the first ring gear 30 coupled to the input shaft 12 and the sun gear 28 connected to the electric motor 24 rotate relative to each other. The carrier 27 rotates relative to the first ring gear 30. At this time, the gear ratio of the first ring gear 30 and the first pinion 29a meshing with each other is slightly different from the gear ratio of the second ring gear 31 and the second pinion 29b meshing with each other. And the transmission shaft 15 connected to the second ring gear 31 rotate relative to each other.

  When the transmission shaft 15 rotates relative to the input shaft 12 in this manner, the eccentric recesses 19 a and 19 a of the eccentric disk 19 in which the ring gear 19 b is engaged with the pinion 17 of each transmission unit 14 are integrated with the input shaft 12. The cam 18 rotates while being guided by the guide portions 18a, 18a, and the eccentric amount ε of the center O2 of the eccentric disk 19 with respect to the axis L of the input shaft 12 changes.

  FIG. 7A shows a state where the speed ratio is minimum (speed ratio: TD). At this time, the eccentric amount ε of the center O2 of the eccentric disk 19 with respect to the axis L of the input shaft 12 is the axis L of the input shaft 12. To a center O1 of the eccentric cam 18 and a maximum value equal to 2d, which is the sum of the distance d from the center O1 of the eccentric cam 18 to the center O2 of the eccentric disk 19. As shown in FIGS. 7B and 7C, when the transmission shaft 15 rotates relative to the input shaft 12, the eccentric disk 19 rotates relative to the eccentric cam 18 integral with the input shaft 12. Furthermore, the eccentric amount ε of the center O2 of the eccentric disk 19 with respect to the axis L of the input shaft 12 is gradually decreased from the maximum value 2d, and the transmission ratio is increased. When the transmission shaft 15 further rotates relative to the input shaft 12, the eccentric disk 19 further rotates relative to the eccentric cam 18 integral with the input shaft 12, and finally, as shown in FIG. The center O2 of the eccentric disk 19 overlaps the axis L of the input shaft 12, the eccentricity ε becomes zero, the transmission gear ratio is maximized (infinite) (transmission ratio: UD), and power is transmitted to the output shaft 13. Blocked.

  Now, the eccentric disks 19 of the transmission units 14 of the continuously variable transmission T rotate eccentrically, and the ends of the connecting rods 33 engaged with the eccentric disks 19 also rotate eccentrically. Thus, there is a problem that a membrane surface vibration is generated in the peripheral wall portion 11c of the casing 11 of the continuously variable transmission T and causes noise.

  However, according to the present embodiment, the upper and lower inner surfaces 11d of the peripheral wall portion 11c of the mission case 11 are connected by the five columnar portions 11e, so that the rigidity of the peripheral wall portion 11c is increased by these columnar portions 11e. Thus, it is possible to effectively reduce noise while suppressing the occurrence of membrane surface vibration and minimizing the increase in the weight of the casing 11. Moreover, in the transmission case 11, the inner surface 11d of the peripheral wall portion 11c and the columnar portion 11e are connected by the partition wall portion 11f, so that the rigidity of the transmission case 11 is further increased by the partition wall portion 11f to further reduce noise more effectively. be able to.

  At this time, since the columnar portions 11e are disposed between the adjacent connecting rods 33, the columnar portions 11e do not interfere with the connecting rods 33. Moreover, since the eccentric disk 19 and the one-way clutch 36 have a larger width in the axis L direction than the connecting rod 33 in the axis L direction, the eccentric disk 19 and the one-way clutch 36 may interfere with the partition wall 11f. However, since the first notch 11g and the second notch 11h are provided in the partition wall portion 11f, it is possible to prevent the eccentric disk 19 and the one-way clutch 36 from interfering with the partition wall portion 11f. .

  Further, since the volume of the internal space of the transmission case 11 is reduced by the amount of the columnar portions 11e and the partition wall portions 11f, the oil droplet concentration with respect to the volume of the internal space is increased to improve the lubricating performance of the continuously variable transmission T. In addition to increasing the amount of oil, the amount of oil can be reduced in order to obtain the same lubrication performance as when the columnar portions 11e and the partition walls 11f are not provided. Fuel consumption can be saved. Moreover, the oil mist scattered inside the mission case 11 can be efficiently collected at the bottom of the mission case 11 by adhering to the partition walls 11f.

  Further, since the volume of the internal space of the transmission case 11 is reduced by the amount of the columnar portions 11e and the partition wall portions 11f, the transmission case 11 is thermally expanded when the thermal load of the continuously variable transmission T increases rapidly. The amount of air exhausted from the breather 11i provided in the engine can be reduced, and a situation in which the lubricating oil in the mission case 11 blows out from the breather 11i together with the expanded air can be avoided.

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

  For example, in the embodiment, the casing 11 is divided into two parts, the upper casing 11U and the lower casing 11L. However, the way of dividing the casing 11 is arbitrary.

  The drive source of the present invention is not limited to the engine E of the embodiment, and may be another drive source such as an electric motor.

  Further, the transmission unit 14 of the present invention does not necessarily have a speed change function, and may be any as long as it has a driving force transmission function.

Claims (3)

A plurality of transmission units (14) for transmitting the rotation of the input shaft (12) connected to the drive source (E) to the output shaft (13) are connected to the input shaft (12) and the output inside the mission case (11). Juxtaposed axially between the shafts (13),
Each of the transmission units (14)
An input side fulcrum (19) rotating eccentrically with the input shaft (12);
A one-way clutch (36) connected to the output shaft (13);
An output fulcrum (37) provided on an outer member (38) of the one-way clutch (36);
A vehicular power transmission device comprising a connecting rod (33) connected to both ends of the input side fulcrum (19) and the output side fulcrum (37) and reciprocating;
The transmission case (11) includes a first side wall (11a) that supports one end side of the input shaft (12) and the output shaft (13), and the input shaft (12) and the output shaft (13). The second side wall (11b) supporting the other end, the peripheral wall (11c) connecting the first side wall (11a) and the second side wall (11b), and the peripheral wall (11c). And a plurality of columnar portions (11e) connecting the inner surfaces (11d) facing each other, and the plurality of columnar portions (11e) are disposed between the connecting rods (33) of the plurality of transmission units (14). A power transmission device for a vehicle.   The transmission case (11) includes a partition wall portion (11f) that connects the inner surface (11d) of the peripheral wall portion (11c) and the columnar portion (11e) to partition the space for storing the transmission unit (14). The axial width of the eccentric disk (19) constituting the input side fulcrum is larger than the axial width of the connecting rod (33), so that the partition wall (11f) avoids interference with the eccentric disk (19). The power transmission device for a vehicle according to claim 1, wherein a notch (11 g) is formed.   The power transmission device for vehicles according to claim 1 or 2, wherein said mission case (11) is provided with a breather (11i).

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