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EP-4435291-B1 - VEHICLE DRIVE DEVICE AND PRODUCTION METHOD FOR PLANETARY GEAR MECHANISM

EP4435291B1EP 4435291 B1EP4435291 B1EP 4435291B1EP-4435291-B1

Inventors

  • KATO MITSUHIKO
  • MATSUDA SHINTARO

Dates

Publication Date
20260506
Application Date
20230328

Claims (5)

  1. A vehicle drive device (1) comprising: an input member (25) drivingly connected to a driving source (2); and a speed reducer (3) that reduces a speed of rotation of the input member (25) and outputs resultant rotation to an output member (5) drivingly connected to a wheel (W), wherein the speed reducer (3) includes a planetary gear mechanism (30), the planetary gear mechanism (30) including 2N, where N represents an integer of 2 or more, planetary gears (33) each including a first gear portion (34) and a second gear portion (35) having a different number of teeth from the first gear portion (34), and a carrier (32) that rotatably supports each of the 2N planetary gears (33), the 2N planetary gears (33) are arranged at equal intervals in a circumferential direction, meshing phases of circumferentially adjacent ones of the planetary gears (33) are opposite to each other, the numbers of teeth of all gears that mesh with the first gear portion (34) and the second gear portion (35) in the planetary gear mechanism (30) are values whose remainder is N when divided by 2N, the 2N planetary gears (33) include N first type planetary gears (33X) and N second type planetary gears (33Y), the first type planetary gears (33X) and the second type planetary gears (33Y) are different from each other in phase of gear teeth (35a) of the second gear portion (35) with respect to gear teeth (34a) of the first gear portion (34), and the first type planetary gears (33X) and the second type planetary gears (33Y) are arranged alternately in the circumferential direction.
  2. The vehicle drive device (1) according to claim 1, wherein a phase difference (θ), that is a difference between the phase of the gear teeth (35a) of the second gear portion (35) with respect to the gear teeth (34a) of the first gear portion (34) of the first type planetary gear (33X) and the phase of the gear teeth (35a) of the second gear portion (35) with respect to the gear teeth (34a) of the first gear portion (34) of the second type planetary gear (33Y), is set to an angular difference on a planetary gear axis (X2) corresponding to a difference between an angle obtained by dividing 180° by the number of teeth of a ring gear that meshes with the first gear portion (34) and an angle obtained by dividing 180° by the number of teeth of the ring gear that meshes with the second gear portion (35), or an angular difference on the planetary gear axis (X2) corresponding to a difference between an angle obtained by dividing 180° by the number of teeth of a sun gear (31) that meshes with the first gear portion (34) and an angle obtained by dividing 180° by the number of teeth of the sun gear (31) that meshes with the second gear portion (35), the planetary gear axis (X2) being a rotation axis of each of the 2N planetary gears (33).
  3. The vehicle drive device (1) according to claim 1 or 2, wherein the driving source (2) is a rotating electrical machine (2) including a rotor (22) connected to the input member (25) so as to rotate with the input member (25), a pair of the output members (5) is provided, the vehicle drive device further includes a differential gear mechanism (4) that distributes rotation of the rotor (22) transmitted via the speed reducer (3) to the pair of output members (5), the speed reducer (3) further includes a sun gear (31) and a first ring gear (36) that mesh with the first gear portion (34), and a second ring gear (37) that meshes with the second gear portion (35), the sun gear (31) is connected to the rotor (22) so as to rotate with the rotor (22), the first ring gear (36) is fixed to a non-rotating member (7), and the second ring gear (37) is connected to an input element (41) of the differential gear mechanism (4) so as to rotate with the input element (41).
  4. The vehicle drive device (1) according to any one of claims 1 to 3, wherein the driving source (2) is a rotating electrical machine (2) including a rotor (22) connected to the input member (25) so as to rotate with the input member (25), and a pair of the output members (5) is provided, the vehicle drive device (1) further includes a differential gear mechanism (4) that distributes rotation of the rotor (22) transmitted via the speed reducer to the pair of output members (5), the rotor (22), the speed reducer (3), and the differential gear mechanism (4) are arranged coaxially, and the rotor (22), the speed reducer (3), and the differential gear mechanism (4) are arranged in this order from a first side (L1) in an axial direction to a second side (L2) in the axial direction, the axial direction (L) being a direction along a rotation axis of the rotor (22), the first side (L1) in the axial direction being one side in the axial direction (L), and the second side (L2) in the axial direction being the other side in the axial direction (L).
  5. A method for manufacturing a planetary gear mechanism (30) including 2N, where N represents an integer of 2 or more, planetary gears (33) each including a first gear portion (34) and a second gear portion (35) having a different number of teeth from the first gear portion (34), and a carrier (32) that rotatably supports each of the 2N planetary gears (33), the method comprising: setting the numbers of teeth of all gears that mesh with the first gear portion (34) and the second gear portion (35) to values whose remainder is N when divided by 2N; preparing N first type planetary gears (33X) and N second type planetary gears (33Y) as the 2N planetary gears (33) such that a phase of gear teeth (35a) of the second gear portion (35) with respect to gear teeth (34a) of the first gear portion (34) is different by a predetermined set phase difference (θ) between the first type planetary gears (33X) and the second type planetary gears (33Y); arranging the 2N planetary gears (33) at equal intervals in a circumferential direction and arranging the first type planetary gears (33X) and the second type planetary gears (33Y) alternately in the circumferential direction; and setting the set phase difference (θ) to an angular difference on a planetary gear axis (X2) corresponding to a difference between an angle obtained by dividing 180° by the number of teeth of a ring gear that meshes with the first gear portion (34) and an angle obtained by dividing 180° by the number of teeth of the ring gear that meshes with the second gear portion (35), or an angular difference on the planetary gear axis (X2) corresponding to a difference between an angle obtained by dividing 180° by the number of teeth of a sun gear (31) that meshes with the first gear portion (34) and an angle obtained by dividing 180° by the number of teeth of the sun gear (31) that meshes with the second gear portion (35), the planetary gear axis (X2) being a rotation axis of each of the 2N planetary gears (33).

Description

TECHNICAL FIELD The present invention relates to vehicle drive devices and methods for manufacturing a planetary gear mechanism. BACKGROUND ART A vehicle drive device has been used that includes: a rotating electrical machine; a pair of output members drivingly connected to wheels; a speed reducer that reduces the speed of rotation of a rotor; and a differential gear mechanism that distributes the rotation of the rotor transmitted via the speed reducer to the pair of output members. An example of such a vehicle drive device is disclosed in Japanese Unexamined Patent Application Publication No. 2002-104001 (JP 2002-104001 A) (Patent Document 1). The vehicle drive device (drive device for an electric vehicle) of Patent Document 1 includes, as a speed reducer (speed reduction device 3), a planetary gear mechanism including a carrier (carrier C) that rotatably supports planetary gears each including a first gear portion (first planetary gear P1) and a second gear portion (second planetary gear P2) having a different number of teeth from the first gear portion. The planetary gear mechanism that constitutes the speed reducer includes: a gear (sun gear S1) meshing with the first gear portions and connected to a rotor so as to rotate with the rotor; a gear (first ring gear R1) meshing with the first gear portions and fixed to a non-rotating member (housing 1); and a gear (second ring gear R2) meshing with the second gear portions and connected to an input element (ring gear DR) of a differential gear mechanism (differential 4) so as to rotate with the input element (ring gear DR). The vehicle drive device of Patent Document 1 achieves reduction in weight and cost by using the speed reducer having such a configuration. In the vehicle drive device of Patent Document 1, however, relatively loud gear noise may be generated due to meshing between the first gear portions and their corresponding gears and meshing between the second gear portions and their corresponding gear (i.e., radial vibration or torsional vibration may occur around the rotation axis of the carrier). Related Art Documents Patent Documents Patent Document 1: Japanese Unexamined Patent Application Publication No. 2002-104001 (JP 2002-104001 A) SUMMARY OF THE INVENTION Problem to be Solved by the Invention It is therefore desired to implement a vehicle drive device with reduced gear noise in a planetary gear mechanism that constitutes a speed reducer. Means for Solving the Problem A vehicle drive device according to the present invention is a vehicle drive device including: an input member drivingly connected to a driving source; and a speed reducer that reduces a speed of rotation of the input member and outputs resultant rotation to an output member drivingly connected to a wheel. The speed reducer includes a planetary gear mechanism, the planetary gear mechanism including 2N (where N represents an integer of 2 or more) planetary gears each including a first gear portion and a second gear portion having a different number of teeth from the first gear portion, and a carrier that rotatably supports each of the 2N planetary gears. The 2N planetary gears are arranged at equal intervals in a circumferential direction. Meshing phases of circumferentially adjacent ones of the planetary gears are opposite to each other. The numbers of teeth of all gears that mesh with the first gear portion and the second gear portion in the planetary gear mechanism are values whose remainder is N when divided by 2N. The 2N planetary gears include N first type planetary gears and N second type planetary gears. The first type planetary gears and the second type planetary gears are different from each other in phase of gear teeth of the second gear portion with respect to gear teeth of the first gear portion. The first type planetary gears and the second type planetary gears are arranged alternately in the circumferential direction. According to this configuration, radial forces generated by meshing of the gears can be cancelled out by the N first type planetary gears and the N second type planetary gears, so that the sum of the radial forces can be reduced to close to zero. In addition, tangential moments acting on meshing portions of the gears can be canceled out by the N first type planetary gears and the N second type planetary gears, so that the sum of the tangential motions can be reduced to close to zero. This can reduce radial vibration around the rotation axis of the carrier and can also reduce torsional vibration around the rotation axis of the carrier. Based on these, it is possible to implement the vehicle drive device with reduced gear noise. A method for manufacturing a planetary gear mechanism according to the present invention is a method for manufacturing a planetary gear mechanism including 2N (where N represents an integer of 2 or more) planetary gears each including a first gear portion and a second gear portion having a different number of teeth from the fir