JP6296923B2 - Power split type continuously variable transmission - Google Patents

Description

  The present invention relates to a power split type continuously variable transmission.

  A vehicle such as an automobile is equipped with a transmission such as a manual transmission, an automatic transmission, or a continuously variable transmission (CVT) in order to shift engine power and transmit it to wheels.

  A large number of inclined gears are used in the transmission. The helical gear has the advantage that the meshing of the teeth is smooth and the noise and torque fluctuation due to the meshing of the teeth are small compared to the straight tooth spur gear. On the other hand, the inclined gear has a drawback that a thrust load (axial load) is generated during rotation. Therefore, a thrust bearing such as a thrust needle bearing is interposed between the bevel gear and a member adjacent thereto to receive a thrust load and differential rotation.

  As a transmission, for example, a continuously variable transmission mechanism that continuously changes engine power, a gear mechanism that transmits engine power without passing through a continuously variable transmission mechanism, and a power and gear mechanism from the continuously variable transmission mechanism The thing provided with the planetary gear mechanism for synthesize | combining the motive power from is proposed. In the transmission according to this proposal, a larger number of gears are used than a conventional continuously variable transmission or the like. Therefore, there are many parts that generate a thrust load and differential rotation, and a large number of thrust bearings are required.

Japanese Patent No. 4552376

  However, since thrust bearings are relatively expensive, a transmission that uses many thrust bearings is expensive.

  An object of the present invention is to provide a power split type continuously variable transmission capable of reducing the number of thrust bearings used.

  In order to achieve the above object, a power split continuously variable transmission according to the present invention includes a continuously variable transmission mechanism for steplessly shifting power input to a rotating shaft, and power input to the rotating shaft. A constant transmission mechanism for shifting at a constant transmission ratio; and a combining gear mechanism for combining the power from the continuously variable transmission mechanism and the power from the constant transmission mechanism. Switchable between a continuously variable transmission mode that is transmitted to the synthesizing gear mechanism and a power split mode in which power is transmitted to the synthesizing gear mechanism via the continuously variable transmission mechanism and the constant transmission mechanism. A split type continuously variable transmission, in which a constant speed change mechanism includes a carrier whose inner peripheral portion is supported relative to a rotating shaft so as not to rotate relative to the outer peripheral portion, and a pinion gear rotatably supported on the outer peripheral portion; 1st opposing part which opposes from one side of the axial direction of A sun gear that engages with the pinion gear and a second opposing portion that faces the inner peripheral portion of the carrier from the other side in the axial direction, and is provided so as to be relatively rotatable with the rotation shaft. A ring gear that meshes with the pinion gear and a split drive gear that is provided so as to be rotatable integrally with the sun gear and that transmits power to the synthesizing gear mechanism. The sun gear and the split drive gear have the same twist direction. The ring gear has bevel teeth whose torsion direction is opposite to the bevel teeth of the sun gear and split gear, and the torsion angle of each bevel tooth of the sun gear and split drive gear depends on the thrust load generated on the sun gear. It is set to be larger than the thrust load generated in the drive gear.

  According to this configuration, the inner peripheral portion of the carrier is supported so as not to rotate relative to the rotation shaft, the first opposing portion of the sun gear faces the inner peripheral portion of the carrier from one side in the axial direction, and the second opposing portion of the ring gear. The part is opposed from the other side in the axial direction. The sun gear and the ring gear mesh with a pinion gear that is rotatably supported by the carrier. The split drive gear is a gear for transmitting power to the synthesizing gear mechanism, and is provided so as to be rotatable integrally with the sun gear. The sun gear, ring gear, and split drive gear are bevel gears.

  In the power split mode, when the ring gear is braked, the power of the rotating shaft is transmitted to the sun gear via the pinion gear, and the power is transmitted from the sun gear to the synthesizing gear mechanism via the split drive gear.

  At this time, the sun gear becomes a driven gear to which power is input from the pinion gear, and the split drive gear becomes a drive gear for inputting power to the synthesizing gear mechanism. Since the inclined teeth of the sun gear and the split drive ring gear are inclined in the same torsional direction, thrust loads in directions opposite to each other are generated in the sun gear and the split drive gear. The torsion angles of the inclined teeth of the sun gear and the split drive gear are set so that the thrust load generated in the sun gear is larger than the thrust load generated in the split drive gear. Therefore, a part of the thrust load generated in the sun gear remains in one body formed by the sun gear and the split drive gear.

  On the other hand, the ring gear is a driven gear to which power is input from the pinion gear. Since the ring gear has inclined teeth whose torsional direction is opposite to the inclined teeth of the sun gear, a thrust load in the direction opposite to the thrust load generated in the sun gear is generated in the ring gear.

  Therefore, in the power split mode, a thrust load is generated in the sun gear in the direction in which the first facing portion of the sun gear is separated from the inner peripheral portion of the carrier, and the thrust in the direction in which the second facing portion of the ring gear is separated from the inner peripheral portion of the carrier. If the twist direction of the sun gear and the rotation direction of the rotary shaft are set so that the load is generated in the ring gear, no load is applied to the inner peripheral portion of the carrier. Therefore, it is possible to eliminate the need for the thrust bearing from between the inner peripheral portion of the carrier and the first facing portion and the second facing portion, and the number of thrust bearings to be used can be reduced.

  According to the present invention, it is possible to reduce the number of thrust bearings used, thereby reducing costs.

It is a skeleton figure which shows the structure of the power split type continuously variable transmission which concerns on one Embodiment of this invention. It is a figure which shows the state of the high brake, reverse brake, and low clutch in each power transmission mode. It is a collinear diagram which shows the relationship of the rotation speed of the sun gear of a synthetic | combination gear mechanism, a carrier, and a ring gear. It is sectional drawing which shows the mechanical structure of a constant speed change mechanism, and shows only one side with respect to the axis line (rotation centerline) of an input shaft. It is a figure which shows the direction of the thrust load which arises in a split drive gear, a sun gear, and a ring gear at the time of split mode and reverse drive.

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

  FIG. 1 is a skeleton diagram showing a configuration of a power split type continuously variable transmission 1 according to an embodiment of the present invention.

  The power split type continuously variable transmission 1 is mounted, for example, in an automobile using an engine as a power source in order to shift engine power and transmit it to a differential gear 2. The power split type continuously variable transmission 1 includes an input shaft 3, an output shaft 4, a continuously variable transmission mechanism 5, a constant transmission mechanism 6, and a synthesizing gear mechanism 7.

  Engine power is input to the input shaft 3.

  The output shaft 4 is provided in parallel with the input shaft 3.

  The continuously variable transmission mechanism 5 is a belt-type continuously variable transmission mechanism. The continuously variable transmission mechanism 5 includes a primary shaft 11 coupled to the input shaft 3, a secondary shaft 12 provided in parallel with the primary shaft 11, a primary pulley 13 supported by the primary shaft 11 so as not to rotate relative thereto, A secondary pulley 14 supported on the shaft 12 so as not to rotate relative to the shaft 12 and a belt 15 wound around the primary pulley 13 and the secondary pulley 14 are provided.

  The constant speed change mechanism 6 includes a planetary gear mechanism 21, a split drive gear 22, a high brake 23, and a reverse brake 24.

  The planetary gear mechanism 21 includes a carrier 25, a sun gear 26, and a ring gear 27. The carrier 25 is supported by the input shaft 3 so as not to be relatively rotatable. The carrier 25 supports a plurality of pinion gears 28 so as to be rotatable. The plurality of pinion gears 28 are arranged at equal angular intervals on the circumference. The sun gear 26 is externally fitted to the input shaft 3 so as to be relatively rotatable, and meshes with each pinion gear 28 from the inner side in the rotational radial direction of the input shaft 3. The ring gear 27 has an annular shape that surrounds the periphery of the carrier 25, and meshes with each pinion gear 28 from the outside in the rotational radial direction of the input shaft 3.

  The split drive gear 22 is provided so as to be rotatable integrally with the sun gear 26.

  The high brake 23 is switched between a braking state (on) in which the ring gear 27 is braked and a released state (off) in which the ring gear 27 is allowed to rotate.

  The reverse brake 24 is switched between a braking state (on) in which the split drive gear 22 (sun gear 26) is braked and a released state (off) in which the split drive gear 22 is allowed to rotate.

  The synthesizing gear mechanism 7 has a configuration of a planetary gear mechanism. That is, the synthesizing gear mechanism 7 includes a carrier 31, a sun gear 32, and a ring gear 33. The carrier 31 is provided to be rotatable relative to the secondary shaft 12 of the continuously variable transmission mechanism 5. The carrier 31 supports a plurality of pinion gears 34 in a rotatable manner. The plurality of pinion gears 34 are arranged at equal angular intervals on the circumference. The sun gear 32 is supported by the secondary shaft 12 so as not to be relatively rotatable, and meshes with each pinion gear 34 from the inner side in the rotational radial direction of the secondary shaft 12. The ring gear 33 has an annular shape surrounding the periphery of the carrier 31, and meshes with each pinion gear 34 from the outer side in the rotational radial direction of the secondary shaft 12. Further, the ring gear 33 is provided so as to be able to rotate integrally with the output shaft 4.

  The synthesizing gear mechanism 7 includes a low clutch 35. The low clutch 35 is switched between an engaged state (ON) in which the output shaft 4 and the secondary shaft 12 are directly connected and a released state (OFF) in which the direct connection is released.

  Further, the synthesizing gear mechanism 7 includes a split driven gear 36 provided so as to rotate integrally with the carrier 31, and an idle gear 37 that meshes with the split drive gear 22 and the split driven gear 36.

  Further, the power split type continuously variable transmission 1 includes an idle mechanism 8. The idle mechanism 8 includes an idle shaft 41 provided in parallel with the output shaft 4, and a first idle gear 42 and a second idle gear 43 that are supported by the idle shaft 41 so as not to rotate relative to each other. An output gear 44 is supported on the output shaft 4 so as not to be relatively rotatable. The output gear 44 and the first idle gear 42 are engaged with each other. The second idle gear 43 meshes with a ring gear 45 provided in the differential gear 2.

  FIG. 2 is a diagram illustrating states of the high brake 23, the reverse brake 24, and the low clutch 35 in each power transmission mode.

  The power split continuously variable transmission 1 has a CVT mode (continuously variable transmission mode) and a split mode (power split mode) as power transmission modes.

  In the CVT mode, the high brake 23 and the reverse brake 24 are released. Then, the low clutch 35 is engaged. Thereby, the output shaft 4 and the secondary shaft 12 are directly connected.

  The power input to the input shaft 3 is transmitted to the primary shaft 11 of the continuously variable transmission mechanism 5 to rotate the primary shaft 11 and the primary pulley 13. The rotation of the primary pulley 13 is transmitted to the secondary pulley 14 via the belt 15 to rotate the secondary pulley 14 and the secondary shaft 12. Since the low clutch 35 is engaged, the output shaft 4 rotates integrally with the secondary shaft 12. The rotation of the output shaft 4 is transmitted to the ring gear 45 of the differential gear 2 via the output gear 44, the first idle gear 42, the idle shaft 41 and the second idle gear 43. As a result, the drive shafts 51 and 52 of the vehicle rotate in the forward direction.

  The transmission ratio of the constant transmission mechanism 6 is set to the same transmission ratio as the minimum transmission ratio of the continuously variable transmission mechanism 5. When the gear ratio of the continuously variable transmission mechanism 5 is changed to the minimum gear ratio according to the vehicle speed, the power transmission mode is switched from the CVT mode to the split mode. In the split mode, the high brake 23 is brought into a braking state, and the reverse brake 24 and the low clutch 35 are brought into a released state. When the high brake 23 is brought into a braking state, the ring gear 27 of the constant speed change mechanism 6 is braked. Further, when the low clutch 35 is released, the direct connection between the output shaft 4 and the secondary shaft 12 is released.

  The power input to the input shaft 3 is transmitted to the primary shaft 11 of the continuously variable transmission mechanism 5 to rotate the primary shaft 11 and the primary pulley 13. The rotation of the primary pulley 13 is transmitted to the secondary pulley 14 via the belt 15 to rotate the secondary pulley 14 and the secondary shaft 12. As the secondary shaft 12 rotates, the sun gear 32 of the synthesizing gear mechanism 7 rotates.

  Since the ring gear 27 of the constant speed change mechanism 6 is braked, the power input to the input shaft 3 revolves the carrier 25 of the constant speed change mechanism 6 and rotates the pinion gear 28 held by the carrier 25. Let As the pinion gear 28 rotates, power is input from the pinion gear 28 to the sun gear 26. As a result, the pinion gear 28 and the split drive gear 22 rotate. The rotation of the split drive gear 22 is transmitted to the split driven gear 36 via the idle gear 37 of the synthesizing gear mechanism 7 to rotate the split driven gear 36 and the carrier 31.

  Since the transmission ratio of the constant transmission mechanism 6 is the same as the minimum transmission ratio of the continuously variable transmission mechanism 5, immediately after switching from the CVT mode to the split mode, the carrier 31, sun gear 32, and ring gear 33 of the synthesizing gear mechanism 7 Rotates at the same speed. Then, the output shaft 4 rotates integrally with the ring gear 33. The rotation of the output shaft 4 is transmitted to the ring gear 45 of the differential gear 2 via the output gear 44, the first idle gear 42, the idle shaft 41 and the second idle gear 43. As a result, the drive shafts 51 and 52 of the vehicle rotate in the forward direction.

  Since the speed ratio of the constant speed change mechanism 6 is fixed at the same speed ratio as the minimum speed ratio of the continuously variable speed change mechanism 5, the rotation of the carrier 31 of the synthesizing gear mechanism 7 is held at a constant speed in the split mode. Therefore, as shown in FIG. 3, when the speed ratio of the continuously variable transmission mechanism 5 is increased, the rotational speed of the sun gear 32 (secondary shaft 12) decreases, and accordingly, the rotational speed of the ring gear (output shaft 4). Goes up. Therefore, the power split type continuously variable transmission 1 can have a large gear ratio range.

  Further, during reverse travel, the high brake 23 and the low clutch 35 are released. Then, the reverse brake 24 is brought into a braking state. As a result, the split drive gear 22 (sun gear 26) is braked. Due to braking of the split drive gear 22, the idle gear 37 of the synthesizing gear mechanism 7 becomes non-rotatable, and the split driven gear 36 and the carrier 31 become non-rotatable.

  The power input to the input shaft 3 is transmitted to the primary shaft 11 of the continuously variable transmission mechanism 5 to rotate the primary shaft 11 and the primary pulley 13. The rotation of the primary pulley 13 is transmitted to the secondary pulley 14 via the belt 15 to rotate the secondary pulley 14 and the secondary shaft 12. As the secondary shaft 12 rotates, the sun gear 32 of the synthesizing gear mechanism 7 rotates. Since the carrier 31 cannot rotate, when the sun gear 32 rotates, the ring gear 33 rotates in the direction opposite to the sun gear 32. The rotation direction of the ring gear 33 is opposite to the rotation direction of the ring gear 33 in the CVT mode and the split mode. Then, the output shaft 4 rotates integrally with the ring gear 33. The rotation of the output shaft 4 is transmitted to the ring gear 45 of the differential gear 2 via the output gear 44, the first idle gear 42, the idle shaft 41 and the second idle gear 43. As a result, the drive shafts 51 and 52 of the vehicle rotate in the reverse direction.

  FIG. 4 is a cross-sectional view showing the mechanical configuration of the constant speed change mechanism 6 and shows only one side with respect to the axis (rotation center line) C of the input shaft 3.

  The carrier 25 of the constant speed change mechanism 6 is integrally provided with an inner peripheral portion 61 and a flange portion 62. The inner peripheral portion 61 is externally fitted to the input shaft 3 and is provided on the input shaft 3 so as not to be relatively rotatable. The flange portion 62 projects from the inner peripheral portion 61 to the outside in the rotational radial direction of the input shaft 3. A gear support shaft 63 extending in parallel with the rotation center line C is provided at the outer peripheral end of the flange portion 62, and the pinion gear 28 is rotatably supported by the gear support shaft 63.

  The sun gear 26 is integrally provided with a first facing portion 64 and a gear portion 65. The first facing portion 64 is fitted on the input shaft 3 so as to be relatively rotatable, and faces the inner peripheral portion 61 of the carrier 25 from the side opposite to the continuously variable transmission mechanism 5 side. For example, a resin washer 66 is interposed between the inner peripheral portion 61 of the carrier 25 and the first facing portion 64. The gear portion 65 protrudes toward the pinion gear 28 from the end portion of the first facing portion 64 on the continuously variable transmission mechanism 5 side. Gear teeth 68 that mesh with the gear teeth 67 of the pinion gear 28 are formed on the surface of the gear portion 65 that faces the pinion gear 28.

  In the following, the continuously variable transmission mechanism 5 side is defined as “right side”, and the opposite side is defined as “left side”, and “left and right” are used for explanation of directions and the like.

  The split drive gear 22 is fixed to the right end portion of the first facing portion 64 in an externally fitted state.

  The ring gear 27 includes a second facing portion 69, an extending portion 70, and a gear portion 71. The second facing portion 69 surrounds the input shaft 3 with a space therebetween, and faces the inner peripheral portion 61 of the carrier 25 from the left side. For example, a resin washer 72 is interposed between the inner peripheral portion 61 of the carrier 25 and the second facing portion 69. The extending part 70 extends from the second facing part 69 in the rotational radial direction of the input shaft 3. A space is provided between the flange portion 62 of the carrier 25 and the extending portion 70. The gear portion 71 extends rightward from the outer peripheral end portion of the extending portion 70 to a position facing the pinion gear 28 and the input shaft 3 in the rotational radial direction. Gear teeth 73 that mesh with the gear teeth 67 of the pinion gear 28 are formed on the surface of the gear portion 71 that faces the pinion gear 28.

  The gear teeth 68 of the sun gear 26, the gear teeth 73 of the ring gear 27, the gear teeth 67 of the pinion gear 28, and the gear teeth 74 of the split drive gear 22 are bevel teeth. Specifically, the gear teeth 68 of the sun gear 26 and the gear teeth 74 of the split drive gear 22 are inclined teeth having the same twisting direction, for example, right-twisting inclined teeth. The gear teeth 73 of the ring gear 27 and the gear teeth 67 of the pinion gear 28 are inclined teeth whose torsion direction is opposite to that of the gear teeth 68 of the sun gear 26, for example, left-toothed inclined teeth. The torsion angles of the gear teeth 68 of the sun gear 26 and the gear teeth 74 of the split drive gear 22 are set so that the thrust load generated in the sun gear 26 is larger than the thrust load generated in the split drive gear 22.

  FIG. 5 is a diagram showing the direction of the thrust load generated in the split drive gear 22, the sun gear 26, and the ring gear 27 in the split mode and in reverse.

  As described above, during drive travel in the split mode (running with power from the engine), the ring gear 27 of the constant speed change mechanism 6 is braked, so that power input to the input shaft 3 is supplied to the carrier 25 and the pinion gear 28. To the sun gear 26. Then, the pinion gear 28 and the split drive gear 22 rotate, and power is transmitted from the split drive gear 22 to the idle gear 37 of the synthesizing gear mechanism 7. Accordingly, the sun gear 26 is a driven gear to which power is input from the pinion gear 28, and the split drive gear 22 is a drive gear that inputs power to the idle gear 37. Since the gear teeth 68 of the sun gear 26 and the gear teeth 74 of the split drive gear 22 are inclined teeth having the same twist direction, for example, a rightward thrust load is generated in the sun gear 26, and the split drive gear 22 Causes a thrust load in the left direction, which is the reverse direction. Since the thrust load generated in the sun gear 26 is larger than the thrust load generated in the split drive gear 22, a part of the thrust load in the right direction generated in the sun gear 26 remains integrally with the sun gear 26 and the split drive gear 22. .

  On the other hand, the ring gear 27 is a driven gear to which power is input from the pinion gear 28. Since the twisting direction of the gear teeth 73 of the ring gear 27 is opposite to the twisting direction of the gear teeth 68 of the sun gear 26, a leftward thrust load that is opposite to the thrust load generated in the sun gear 26 is generated in the ring gear 27.

  Therefore, no load is applied to the inner peripheral portion 61 of the carrier 25 from the first facing portion 64 and the second facing portion 69. Therefore, a thrust bearing is not required between the inner peripheral portion 61 of the carrier 25 and the first opposing portion 64 and the second opposing portion 69, and the inner peripheral portion 61, the first opposing portion 64, and the second opposing portion 69 are not required. In order to suppress the occurrence of seizure due to friction, washers 66, 72 and the like are preferably interposed.

  Therefore, in the power split type continuously variable transmission 1, it is possible to reduce the number of thrust bearings used, and consequently to reduce the cost.

  Note that when coasting in the split mode, the direction of torque input is reversed from that during driving, so that a thrust load in the left direction is generated integrally with the sun gear 26 and the split drive gear 22, and the ring gear 27 has a rightward direction. Thrust load is generated. However, the frequency of coasting is low, and the thrust load generated on the sun gear 26 and the like during coasting is small, so that the resin washers 66 and 72 can sufficiently withstand the thrust load.

  Further, during reverse travel due to inertia, a leftward thrust load is generated in the split drive gear 22, but since the reverse travel frequency is low, the washer 66, 72 made of resin can sufficiently withstand the thrust load.

  As mentioned above, although one Embodiment of this invention was described, it is possible to give a various design change to the above-mentioned structure in the range of the matter described in the claim.

1 Power split type continuously variable transmission 3 Input shaft (rotary shaft)
DESCRIPTION OF SYMBOLS 5 Continuously variable transmission mechanism 6 Constant transmission mechanism 7 Composition gear mechanism 22 Split drive gear 25 Carrier 26 Sun gear 27 Ring gear 28 Pinion gear 61 Inner peripheral part 64 1st opposing part 68 Gear tooth 69 2nd opposing part 73 Gear tooth 74 Gear tooth

Claims (1)

From the continuously variable transmission mechanism for steplessly shifting the power input to the rotating shaft, the constant transmission mechanism for shifting the power input to the rotating shaft at a constant gear ratio, and the continuously variable transmission mechanism. A continuously variable transmission mode in which power is transmitted to the synthesizing gear mechanism only through the continuously variable transmission mechanism. A split type continuously variable transmission configured to be capable of switching to a power split mode in which power is transmitted to the combining gear mechanism via the continuously variable transmission mechanism and the constant transmission mechanism,
The constant speed change mechanism includes:
A carrier that supports an inner peripheral portion so as not to rotate relative to the rotating shaft, and supports a pinion gear rotatably on the outer peripheral portion;
A sun gear that has a first facing portion facing the inner peripheral portion of the carrier from one side in the axial direction of the rotating shaft, is provided so as to be relatively rotatable with the rotating shaft, and meshes with the pinion gear;
A ring gear that has a second facing portion that faces the inner peripheral portion of the carrier from the other side in the axial direction, is provided so as to be relatively rotatable with the rotating shaft, and meshes with the pinion gear;
A split drive gear provided to be rotatable integrally with the sun gear, and for transmitting power to the synthesizing gear mechanism;
The sun gear and the split drive gear each have inclined teeth having the same twist direction,
The ring gear has inclined teeth whose torsion direction is opposite to the inclined teeth of the sun gear and the split gear;
The split type continuously variable transmission, wherein a torsion angle of each inclined tooth of the sun gear and the split drive gear is set such that a thrust load generated in the sun gear is larger than a thrust load generated in the split drive gear.

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