JP2015230052A - Planetary gear mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a planetary gear mechanism which can suppress the deformation of a carrier when two gear parts of a stepped pinion gear are helical gears.SOLUTION: The moment acting on a stepped pinion gear 10 by a thrust load FT1 which is received by a first gear part 11 from a sun gear 3 and a thrust load FT2 which is received by a second gear part 12 from a ring gear 4 is set as the first moment M1, and the moment acting on the stepped pinion gear 10 by a radial load FR1 which is received by the first gear part 11 from the sun gear 3 and a radial load FR2 which is received by the second gear part 12 from the ring gear 4 is set as the second moment M2. In a state that a vehicle drive transmission mechanism transmits torque in a forward acceleration direction of a vehicle, torsional directions of teeth of the first gear part 11 and the second gear part 12 are set so that the first moment M1 and the second moment M2 are inverted in directions.

Description

  The present invention relates to a planetary gear mechanism used in a vehicle drive transmission mechanism.

  As a planetary gear mechanism used in a vehicle drive transmission mechanism, one described in JP2013-2527A (Patent Document 1) is known. Patent Document 1 describes a configuration in which a stepped pinion gear that integrally includes a large-diameter gear portion that meshes with a sun gear and a small-diameter gear portion that meshes with a ring gear is used as a pinion gear constituting the planetary gear mechanism. By adopting such a stepped pinion gear, for example, it is possible to secure a large reduction ratio when the driving force of the driving force source input to the sun gear is decelerated and transmitted to the wheels via the carrier. Become.

JP2013-2527A (paragraph 0018, FIG. 1 etc.)

  By the way, from the viewpoint of reducing noise generated at the meshing portion of the gears, it is conceivable that each of the two gear portions of the stepped pinion gear is a helical gear. In this case, if the moment acts on the stepped pinion gear due to the thrust load acting on the stepped pinion gear from the sun gear or ring gear, and the total moment acting on the stepped pinion gear is large, the stepped pinion gear is supported. The carrier may be deformed. If the shaft center of the stepped pinion gear is tilted with the deformation of the carrier, the tooth contact is not appropriate, and the durability of the stepped pinion gear is lowered. However, in Patent Document 1, no particular recognition has been made on this point.

  Therefore, when each of the two gear portions of the stepped pinion gear is a helical gear, it is desired to realize a planetary gear mechanism that can suppress the deformation of the carrier.

  A first characteristic configuration of the planetary gear mechanism used in the vehicle drive transmission mechanism according to the present invention is the stepped pinion gear in which the first gear portion and the second gear portion are arranged in the axial direction and have different diameters; A carrier that supports the stepped pinion gear, a sun gear that meshes with the first gear portion, and a ring gear that meshes with the second gear portion, both of the first gear portion and the second gear portion being helical. A first moment that is applied to the stepped pinion gear by the thrust load received by the first gear portion from the sun gear and the thrust load received by the second gear portion from the ring gear; The stepped pinion gear acts on the radial load that the gear portion receives from the sun gear and the radial load that the second gear portion receives from the ring gear. With the moment as the second moment, the first moment and the second moment are in opposite directions in a state where the vehicle drive transmission mechanism is transmitting torque in the forward acceleration direction of the vehicle. The twisting direction of each tooth of the gear portion and the second gear portion is set.

According to the first characteristic configuration described above, the thrust drive acts on the stepped pinion gear while the vehicle drive transmission mechanism is transmitting torque in the forward acceleration direction of the vehicle (hereinafter referred to as “first state”). The first moment to be applied can be in the opposite direction to the second moment acting on the stepped pinion gear by the radial load. Therefore, compared with the case where the first moment and the second moment are in the same direction, the total moment acting on the stepped pinion gear can be reduced, and as a result, deformation of the carrier supporting the stepped pinion gear is suppressed. be able to.
In this configuration, in a state where the vehicle drive transmission mechanism is transmitting torque in the direction opposite to the forward acceleration direction of the vehicle (hereinafter referred to as “second state”), the direction of the first moment is Since it is opposite to the first state, the first moment is in the same direction as the second moment. In this regard, in the first characteristic configuration described above, the first state in which the maximum value of the first moment that can act on the stepped pinion gear is likely to increase because the maximum value of the transmitted torque is larger than in the second state. In other words, in the first state where the influence on the deformation of the carrier can be large, the first moment and the second moment can be reversed. Thereby, a deformation | transformation of a carrier can be suppressed effectively.

  A second characteristic configuration of the planetary gear mechanism used for the vehicle drive transmission mechanism according to the present invention is the stepped pinion gear in which the first gear portion and the second gear portion are arranged in the axial direction and have different diameters, and A carrier that supports the stepped pinion gear, a sun gear that meshes with the first gear portion, and a ring gear that meshes with the second gear portion, both of the first gear portion and the second gear portion being helical. A direction of thrust load received by the first gear portion from the sun gear and the second gear portion from the ring gear in a state where the vehicle drive transmission mechanism is transmitting torque in the vehicle forward acceleration direction. The twisting directions of the teeth of the first gear portion and the second gear portion are set so that the direction of the thrust load received is opposite to each other.

  According to said 2nd characteristic structure, the twist direction of each tooth | gear of a 1st gear part and a 2nd gear part is set so that a 1st moment and a 2nd moment may become a reverse direction in said 1st state. be able to. Therefore, also in the second feature configuration, the operational effects according to the first feature configuration can be obtained similarly.

It is sectional drawing of the drive transmission mechanism for vehicles which concerns on embodiment of this invention. It is explanatory drawing of the moment which acts on the stepped pinion gear which concerns on embodiment of this invention.

  An embodiment of a planetary gear mechanism according to the present invention will be described with reference to the drawings. Here, the case where the planetary gear mechanism according to the present invention is applied to a speed reduction mechanism used in a vehicle drive transmission mechanism will be described as an example.

  In the following description, unless otherwise specified, “axial direction L”, “circumferential direction”, and “radial direction” are defined with reference to the axis A of the planetary gear mechanism 1 ( (See FIG. 1). “Axial first direction L1” represents a direction toward one side in the axial direction L, and “Axial second direction L2” represents a direction toward the other side in the axial direction L (a direction opposite to the axial first direction L1). Represents. In the present embodiment, as shown in FIG. 1, the first axial direction L <b> 1 is a direction along the axial direction L from the second gear portion 12 side toward the first gear portion 11 side. Moreover, in the following description, terms (eg, parallel, orthogonal, coaxial, etc.) relating to dimensions, arrangement direction, arrangement position, etc. for each member may have a difference due to an error (an error that is acceptable in manufacturing). It is used as a concept including.

  In this specification, the “rotary electric machine” is used as a concept including any of a motor (electric motor), a generator (generator), and a motor / generator functioning as both a motor and a generator as necessary. Further, in this specification, “driving connection” refers to a state where two rotating elements are connected so as to be able to transmit driving force, and the two rotating elements are connected so as to rotate integrally, or The two rotating elements are used as a concept including a state in which a driving force can be transmitted through one or more transmission members. Examples of such a transmission member include various members that transmit rotation at the same speed or a variable speed, and include, for example, a shaft, a gear mechanism, a belt, a chain, and the like. Further, as such a transmission member, an engagement device that selectively transmits rotation and driving force, for example, a friction engagement device or a meshing engagement device may be included.

1. Schematic Configuration of Vehicle Drive Transmission Mechanism In this embodiment, the vehicle drive transmission mechanism 100 using the planetary gear mechanism 1 is a drive for a vehicle (electric vehicle or hybrid vehicle) provided with a rotating electrical machine as a driving force source for wheels. It is a transmission mechanism. That is, as shown in FIG. 1, the vehicle drive transmission mechanism 100 according to this embodiment causes the vehicle to travel by transmitting the driving force of the rotating electrical machine 30 to the wheels. In the present embodiment, the vehicle drive transmission mechanism 100 is an in-wheel type drive transmission mechanism, and is disposed on the radially inner side of a wheel rim (not shown) of a drive wheel. Here, the wheel rim is a drum-like member to which a tire is attached, and is fixed to a radially outer side of a connecting portion 51 (see FIG. 1) fixed to the wheel hub 50. For example, the connecting portion 51 includes a plurality of spoke portions distributed in the circumferential direction. In this example, as shown in FIG. 1, the connecting portion 51 and the brake disc 52 are integrally fixed to the wheel hub 50 by joint fastening.

  The vehicle drive transmission mechanism 100 includes an input shaft 41 that is drivingly connected to a driving force source of wheels, an output shaft 40 that is drivingly connected to wheels (wheel hub 50 in this example), an input shaft 41, and an output shaft 40. And a planetary gear mechanism 1 provided in a power transmission path between the two. The planetary gear mechanism 1, the input shaft 41, and the output shaft 40 (a part of the output shaft 40 in this example) are accommodated in the case 20. The case 20 is suspended from the vehicle body via a suspension device (not shown). The input shaft 41 is drivingly connected to one or a plurality of driving force sources. In the present embodiment, the input shaft 41 is drivingly connected to a rotating electrical machine 30 serving as a wheel driving force source. The rotating electrical machine 30 includes a stator 31 that is fixed to the case 20 and a rotor 32 that is rotatably supported with respect to the stator 31. In the present embodiment, the input shaft 41 is drivingly connected so as to rotate integrally with the rotor 32. In the present embodiment, the rotating electrical machine 30 and the input shaft 41 are arranged coaxially with the planetary gear mechanism 1. In the present embodiment, the rotor 32 is disposed on the radially inner side of the stator 31.

  In the present embodiment, the output shaft 40 is drivingly connected so as to rotate integrally with the wheel hub 50. The wheel hub 50 is formed so as to extend radially outside the case 20 from a connecting portion (in this example, a spline connecting portion) with the output shaft 40. In the present embodiment, the output shaft 40 is disposed coaxially with the planetary gear mechanism 1 on the axial first direction L1 side of the input shaft 41. The output shaft 40 is supported so as to be rotatable with respect to the case 20 via the bearing 21.

2. Next, the configuration of the planetary gear mechanism 1 that is a main part of the present invention will be described. As shown in FIG. 1, the planetary gear mechanism 1 includes a carrier 2 that supports a stepped pinion gear 10, a sun gear 3, and a ring gear 4. The stepped pinion gear 10 is supported rotatably with respect to the carrier 2. Specifically, the stepped pinion gear 10 is supported by the carrier 2 so as to be rotatable around a pinion shaft 13 fixed to the carrier 2. A bearing (for example, a needle bearing or the like) is disposed between the stepped pinion gear 10 and the pinion shaft 13. Although illustration is omitted, a plurality of (for example, three or four) stepped pinion gears 10 are supported by the carrier 2 in a state of being distributed in the circumferential direction.

  The stepped pinion gear 10 includes a first gear portion 11 and a second gear portion 12 having different diameters. The first gear portion 11 and the second gear portion 12 are provided on the same axis and arranged in the axial direction L. The first gear portion 11 and the second gear portion 12 are provided integrally, and rotate around the pinion shaft 13 integrally. The sun gear 3 meshes with the first gear portion 11, and the ring gear 4 meshes with the second gear portion 12. In the present embodiment, the first gear portion 11 is configured to have a larger diameter than the second gear portion 12. In the present embodiment, the first gear portion 11 is configured to have a smaller tooth width than the second gear portion 12.

  In the present embodiment, the planetary gear mechanism 1 is a speed reduction mechanism. Specifically, the input shaft 41 is drivingly connected to the sun gear 3 and the output shaft 40 is drivingly connected to the carrier 2 without going through other rotating elements of the planetary gear mechanism 1. The ring gear 4 is fixed to the case 20. In this example, the sun gear 3 is drivingly connected to rotate integrally with the input shaft 41, and the carrier 2 is drivingly connected to rotate integrally with the output shaft 40. In the present embodiment, the carrier 2 is cantilevered in the radial direction on the first axial direction L1 side. Specifically, the carrier 2 is supported in the radial direction so as to be rotatable with respect to the case 20 via the bearing 21 on the axial first direction L1 side of the stepped pinion gear 10 and the pinion shaft 13.

  When the rotating electrical machine 30 is powered, in other words, when the planetary gear mechanism 1 transmits power from the input shaft 41 side to the output shaft 40 side, the rotational speed of the input shaft 41 (rotating electrical machine 30) is reduced. At the same time, the torque is amplified and transmitted to the output shaft 40 (wheel). On the other hand, during power generation (regeneration) of the rotating electrical machine 30, in other words, when the planetary gear mechanism 1 transmits power from the output shaft 40 side to the input shaft 41 side, the rotational speed of the output shaft 40 is reduced. The speed is increased and the torque is attenuated and transmitted to the input shaft 41.

  Both the first gear part 11 and the second gear part 12 are helical gears. Both the sun gear 3 that meshes with the first gear portion 11 and the ring gear 4 that meshes with the second gear portion 12 are also helical gears. Here, the helical gear is a cylindrical gear whose tooth line is a helical line (spiral). Therefore, in the state where the planetary gear mechanism 1 is transmitting power, the first thrust load FT1 and the first radial load FR1 are applied to the first gear portion 11, and the second thrust is applied to the second gear portion 12. The load FT2 and the second radial load FR2 act. Here, the first thrust load FT1 is a thrust load (load in the axial direction L) received by the first gear portion 11 from the sun gear 3, and the first radial load FR1 is a radial load received by the first gear portion 11 from the sun gear 3. Load (radial load). The second thrust load FT2 is a thrust load that the second gear portion 12 receives from the ring gear 4, and the second radial load FR2 is a radial load that the second gear portion 12 receives from the ring gear 4.

  The first thrust load FT1 is a load resulting from the twist of the teeth of the first gear portion 11, and the second thrust load FT2 is a load resulting from the twist of the teeth of the second gear portion 12. The magnitude of the thrust load is represented by the product of the tangential force and the tangent of the torsion angle. The direction of the thrust load differs depending on which of the tooth surfaces on both sides in the circumferential direction of the tooth is the tooth surface (working tooth surface) that contacts the meshing gear. That is, the direction of the thrust load is opposite to the case where the working tooth surface is the tooth surface on one side in the circumferential direction and the case where the working tooth surface is the tooth surface on the other side in the circumferential direction. In addition, the circumferential direction here is a circumferential direction on the basis of the stepped pinion gear 10.

  The first radial load FR1 is a load caused by the pressure angle of the teeth of the first gear portion 11, and the second radial load FR2 is a load caused by the pressure angle of the teeth of the second gear portion 12. The magnitude of the radial load is represented by the product of the tangential force and the tangent of the pressure angle. The direction of the radial load is always a direction toward the axial center of the stepped pinion gear 10 (a direction toward the inner side in the radial direction with reference to the stepped pinion gear 10).

  The meshing portion between the sun gear 3 and the first gear portion 11 and the meshing portion between the ring gear 4 and the second gear portion 12 are the axial direction L and the circumferential direction (a circumferential direction based on the stepped pinion gear 10, hereinafter in this paragraph). And the like) are formed at different positions. Specifically, the meshing portion between the sun gear 3 and the first gear portion 11 and the meshing portion between the ring gear 4 and the second gear portion 12 are formed at positions different from each other by 180 degrees (π radians) in the circumferential direction. Therefore, as shown in FIG. 2, when the first thrust load FT1 and the second thrust load FT2 are opposite to each other, a moment acts on the stepped pinion gear 10 by these thrust loads. Further, the first radial load FR1 and the second radial load FR2 are always in directions facing each other, and a moment acts on the stepped pinion gear 10 by these radial loads. Hereinafter, the moment acting on the stepped pinion gear 10 by the first thrust load FT1 and the second thrust load FT2 is referred to as a first moment M1, and the moment acting on the stepped pinion gear 10 by the first radial load FR1 and the second radial load FR2. Let the moment be the second moment M2. The first moment M1 and the second moment M2 are axes that pass through the central portion of the pinion shaft 13, and are orthogonal to a plane (both in FIG. 2) that includes both the axis A and the axis of the pinion shaft 13. This is the rotational moment about the virtual axis B.

  In the present embodiment, one of the sun gear 3 and the ring gear 4 (ring gear 4 in this example) that meshes with the stepped pinion gear 10 is fixed to the case 20, so that the first gear mechanism 1 transmits power in the first gear mechanism 1. The working tooth surface of the gear portion 11 and the working tooth surface of the second gear portion 12 are tooth surfaces opposite to each other in the circumferential direction with respect to the stepped pinion gear 10. Therefore, in the present embodiment, the tooth twist direction of the first gear portion 11 and the tooth twist direction of the second gear portion 12 are such that the first thrust load FT1 and the second thrust load FT2 are opposite to each other. Are set in the same direction.

  The direction of the second moment M2 is always the same direction. In the example shown in FIG. 2, the stepped pinion gear 10 is rotated clockwise in the drawing. On the other hand, the direction of the first moment M1 is a case where the first thrust load FT1 and the second thrust load FT2 are facing each other, and a case where the first thrust load FT1 and the second thrust load FT2 are away from each other. And in opposite directions. In view of this point, the torsional direction of the teeth of the first gear portion 11 and the second gear portion 12 is such that the vehicle drive transmission mechanism 100 is transmitting torque in the forward acceleration direction of the vehicle. The direction of the first thrust load FT1 and the direction of the second thrust load FT2 are set to face each other. As a result, as shown in FIG. 2, the first moment M1 and the second moment M2 are reversed in the state in which the vehicle drive transmission mechanism 100 is transmitting torque in the forward acceleration direction of the vehicle. That is, in a state where the vehicle drive transmission mechanism 100 is transmitting torque in the forward acceleration direction of the vehicle, the first gear portion 11 and the second gear portion 11 are arranged so that the first moment M1 and the second moment M2 are in opposite directions. The twist direction of each tooth of the gear part 12 is set. Accordingly, it is possible to suppress the rotational moment acting on the stepped pinion gear 10 in a state where the vehicle drive transmission mechanism 100 is transmitting torque in the forward acceleration direction of the vehicle.

  In FIG. 2, the rotation of the input shaft 41, the stepped pinion gear 10, and the output shaft 40 (carrier 2) in a state where the vehicle drive transmission mechanism 100 is transmitting torque in the forward acceleration direction of the vehicle. The direction is indicated by an arrow. In this case, each of the first gear portion 11 and the second gear portion 12 has a left-handed twist, as shown in FIG. Have teeth. Note that the twist angle of the teeth of the first gear portion 11 and the twist angle of the teeth of the second gear portion 12 may be the same angle or different angles. In the latter case, for example, the first gear load FT1 and the second thrust load FT2 have the same or similar magnitudes based on the diameters of the first gear portion 11 and the second gear portion 12 so that the first gear load FT1 and the second thrust load FT2 have the same magnitude. The torsion angle of each tooth of the part 11 and the second gear part 12 can be set.

  If the direction of the torque output by the rotating electrical machine 30 is “positive” in a state where the vehicle drive transmission mechanism 100 is transmitting torque in the forward acceleration direction of the vehicle, the rotating electrical machine 30 is outputting a positive torque. Regardless of the rotation direction of the rotor 32, the first moment M1 is opposite to the second moment M2. Therefore, in the present embodiment, the first moment M1 and the second moment M2 in a state where the rotating electrical machine 30 is generating power during the reverse travel of the vehicle, in addition to the state where the rotating electrical machine 30 is powering when the vehicle travels forward. And in the opposite direction. On the other hand, when the vehicle drive transmission mechanism 100 is transmitting torque in the direction opposite to the forward acceleration direction of the vehicle, in other words, when the rotating electrical machine 30 is outputting negative torque, the rotor 32 Regardless of the direction of rotation, the first moment M1 is in the same direction as the second moment M2. In other words, in the present embodiment, the first moment M1 and the second moment M2 are determined between the state where the rotating electrical machine 30 is generating power when the vehicle is traveling forward and the state where the rotating electrical machine 30 is powering when the vehicle is traveling backward. Are in the same direction.

3. Other Embodiments Finally, other embodiments of the planetary gear mechanism according to the present invention will be described. Note that the configurations disclosed in the following embodiments can be applied in combination with the configurations disclosed in other embodiments as long as no contradiction arises.

(1) In the above embodiment, the case where the first gear portion 11 has a larger diameter than the second gear portion 12 has been described as an example. However, the embodiment of the present invention is not limited to this, and the first gear portion 11 may be configured to have a smaller diameter than the second gear portion 12. In the above embodiment, the case where the first gear portion 11 is configured to have a smaller tooth width than the second gear portion 12 has been described as an example. However, the embodiment of the present invention is not limited to this, and the first gear portion 11 and the second gear portion 12 are configured to have the same tooth width, or the first gear portion 11 is more than the second gear portion 12. The tooth width may be large.

(2) In the above embodiment, the case where the planetary gear mechanism 1 is a speed reduction mechanism has been described as an example. However, the embodiment of the present invention is not limited to this. For example, the configuration is such that the output shaft 40 is drivingly connected to the sun gear 3 and the input shaft 41 is drivingly connected to the carrier 2 without passing through other rotating elements of the planetary gear mechanism 1, thereby increasing the planetary gear mechanism 1. You may comprise as a speed mechanism. In the above embodiment, the case where the ring gear 4 is fixed to the case 20 has been described as an example. However, the sun gear 3 may be fixed to the case 20 instead of the ring gear 4. In this case, the planetary gear mechanism 1 is configured as a reduction mechanism by drivingly connecting the output shaft 40 to the carrier 2 and drivingly connecting the input shaft 41 to the ring gear 4, or drivingly connecting the input shaft 41 to the carrier 2. The planetary gear mechanism 1 can be configured as a speed increasing mechanism by drivingly connecting the output shaft 40 to the ring gear 4.

(3) In the above embodiment, the case where one rotating element of the planetary gear mechanism 1 (the ring gear 4 in the above embodiment) is fixed to the case 20 has been described as an example. However, the embodiment of the present invention is not limited to this, and the planetary gear mechanism 1 can also be configured as a power distribution mechanism that distributes the torque transmitted to the carrier 2 to the sun gear 3 and the ring gear 4. In this case, the input shaft 41 is drivingly connected to the carrier 2, the output shaft 40 is drivingly connected to one of the sun gear 3 and the ring gear 4, and the other device (for example, a rotating electrical machine) is drivingly connected to the other. In such a configuration, when the planetary gear mechanism 1 functions as a power distribution mechanism, the working tooth surface of the first gear portion 11 and the working tooth surface of the second gear portion 12 are based on the stepped pinion gear 10. In the circumferential direction, the tooth surfaces are on the same side. Therefore, in this case, the first gear M1 and the second moment M2 are in the opposite directions while the vehicle drive transmission mechanism 100 is transmitting torque in the forward acceleration direction of the vehicle. By setting the twist direction of each tooth of the portion 11 and the second gear portion 12, the twist direction of the teeth of the first gear portion 11 and the twist direction of the teeth of the second gear portion 12 are opposite to each other.

(4) In the above embodiment, the configuration in which the carrier 2 is cantilevered in the radial direction on the first axial direction L1 side has been described as an example. However, the embodiment of the present invention is not limited to this, and the carrier 2 can be cantilevered in the radial direction on the second axial direction L2 side. For example, in the example shown in FIG. 1, when the positions of the first gear portion 11 and the second gear portion 12 in the axial direction L are switched (in this case, the right side in FIG. 1 is the first axial direction L1 side). The carrier 2 is cantilevered in the radial direction on the second axial direction L2 side.

(5) In the above embodiment, the case where the vehicle drive transmission mechanism 100 using the planetary gear mechanism 1 is an in-wheel type drive transmission mechanism for a vehicle has been described as an example. However, the embodiment of the present invention is not limited to this. That is, the vehicle drive transmission mechanism in which the planetary gear mechanism 1 is used can be a drive transmission mechanism other than the in-wheel type, such as a drive transmission mechanism mounted in front of or behind the vehicle compartment.

(6) In the above embodiment, the case where the vehicle drive transmission mechanism 100 in which the planetary gear mechanism 1 is used is a vehicle drive transmission mechanism including a rotating electrical machine as a wheel driving force source has been described as an example. However, the embodiment of the present invention is not limited to this. For example, the vehicle drive transmission mechanism in which the planetary gear mechanism 1 is used may be a vehicle drive transmission mechanism including an internal combustion engine or an external combustion engine as a driving force source for wheels. In this case, a rotating electrical machine may or may not be provided as a wheel driving force source.

(7) Regarding other configurations, it should be understood that the embodiments disclosed herein are illustrative in all respects and that the scope of the present invention is not limited thereby. Those skilled in the art will readily understand that modifications can be made as appropriate without departing from the spirit of the present invention. Accordingly, other embodiments modified without departing from the spirit of the present invention are naturally included in the scope of the present invention.

  The present invention can be used for a planetary gear mechanism used in a vehicle drive transmission mechanism.

1: Planetary gear mechanism 2: Carrier 3: Sun gear 4: Ring gear 10: Stepped pinion gear 11: First gear portion 12: Second gear portion 100: Vehicle drive transmission mechanism FR1: First radial load (radial load)
FR2: Second radial load (radial load)
FT1: First thrust load (thrust load)
FT2: Second thrust load (thrust load)
L: Axial direction M1: First moment M2: Second moment

Claims (2)

A planetary gear mechanism used in a vehicle drive transmission mechanism,
A stepped pinion gear in which the first gear portion and the second gear portion are arranged in the axial direction and have different diameters, a carrier that supports the stepped pinion gear, a sun gear that meshes with the first gear portion, and the second gear A ring gear meshing with the portion,
Both the first gear part and the second gear part are helical gears,
The first moment is a moment acting on the stepped pinion gear by the thrust load received by the sun gear from the sun gear and the thrust load received by the second gear portion from the ring gear.
The moment acting on the stepped pinion gear by the radial load received by the first gear portion from the sun gear and the radial load received by the second gear portion from the ring gear is defined as a second moment.
In a state where the vehicle drive transmission mechanism is transmitting torque in the forward acceleration direction of the vehicle, the first gear portion and the second gear are arranged such that the first moment and the second moment are in opposite directions. A planetary gear mechanism in which the twist direction of each tooth of the section is set. A planetary gear mechanism used in a vehicle drive transmission mechanism,
A stepped pinion gear in which the first gear portion and the second gear portion are arranged in the axial direction and have different diameters, a carrier that supports the stepped pinion gear, a sun gear that meshes with the first gear portion, and the second gear A ring gear meshing with the portion,
Both the first gear part and the second gear part are helical gears,
With the vehicle drive transmission mechanism transmitting torque in the vehicle forward acceleration direction, the direction of the thrust load received by the first gear portion from the sun gear and the thrust load received by the second gear portion from the ring gear A planetary gear mechanism in which the directions of twisting of the teeth of the first gear portion and the second gear portion are set so that the directions are opposite to each other.

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