JP2011127734A - Planetary gear type auxiliary transmission for transfer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a planetary gear type auxiliary transmission for transfer improved in the torque transmitting efficiency. <P>SOLUTION: This planetary gear type auxiliary transmission for transfer includes: an input shaft 1; an input piece 1a integrally rotating with the input shaft; a sun gear 2a loosely fitted to the input shaft; a sun gear piece 2a integrally rotating with the sun gear; a planetary gear 2p engaged with the sun gear; a ring gear 2r engaged with the planetary gear; a carrier 2c supporting the planetary gear; a low gear piece 2b integrally rotating with the carrier; a sleeve 3 provided freely to shift; an output hub 4 provided freely to be spline-engaged with the sleeve; a high gear 3a loosely fitted to the sleeve and to be spline-engaged with the sun gear piece and the input piece by shifting to a low range side and to be spline-engaged with the input piece and the output hub by shifting to a high range side; and a low gear 3b connected to the sleeve and to be spline-engaged with the low gear piece and the output hub by shifting to a low range side. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a planetary gear subtransmission, and more particularly to a planetary gear subtransmission for transfer.

  Patent Document 1 discloses a transfer for distributing torque output from a transmission to a front wheel and a rear wheel in a four-wheel drive vehicle, particularly for a transfer that achieves a two-stage gear ratio between a high range and a low range by shifting a sleeve. A planetary gear type auxiliary transmission is disclosed.

  FIG. 4 is a gear train diagram of a planetary gear sub-transmission for transfer according to a conventional example as disclosed in Patent Document 1. Referring to FIG. 4, a planetary gear type transfer according to a conventional example includes an input shaft 11, a sun gear 12s rotating integrally with the input shaft 11, a sun gear piece 12a rotating integrally with the sun gear 12s, and a planetary gear 12p meshing with the sun gear 12s. The ring gear 12r meshing with the planetary gear 12p, the carrier 12c supporting the planetary gear 12p, the low gear piece 12b rotating integrally with the carrier 12c, the sleeve 13 that can be shifted along the axial direction of the input shaft 11, and the sleeve 13 are shifted. An output hub 14 that is freely spline-fitted, an output shaft 15 that rotates integrally with the output hub 14, and a sleeve 13, is always spline-fitted to the output hub 14, and the sleeve 13 is connected to the high range side. Shift, sun gear A high gear 13a spline-fitted to the over scan 12a, is coupled to the sleeve 13, the shift to the low range side of the sleeve 13 has a splined freely low gear 13b to Rogiyapisu 12b, and.

  According to the planetary gear sub-transmission for transfer shown in FIG. 4, the sun gear 12s and the sun gear piece 12a are coupled to the input shaft 11 so as to rotate together.

JP 2008-87607 A

  According to the planetary gear sub-transmission for transfer according to the conventional example shown in FIG. 4, the sun gear piece 12 a that rotates integrally with the input shaft 11 and the sun gear 12 s and the high gear 13 a that is coupled to the sleeve 13 in the high range. Is engaged, the planetary gear 12p meshed with the sun gear 12s is rotated even though it is not on the torque transmission flow. As a result, a decrease in torque transmission efficiency occurs.

  An object of the present invention is to provide a planetary gear type auxiliary transmission for transfer that can improve torque transmission efficiency.

  In a first aspect, the present invention provides an input shaft, an input piece that rotates integrally with the input shaft, a sun gear that is loosely fitted on the input shaft, a sun gear piece that rotates integrally with the sun gear, and the sun gear. A planetary gear that meshes, a ring gear that meshes with the planetary gear, a carrier that supports the planetary gear, a low gear piece that rotates integrally with the carrier, a sleeve that can be shifted along the axial direction of the input shaft, and a sleeve that shifts An output hub that is freely spline-fitted, an output shaft that rotates integrally with the output hub, and a sleeve that is loosely fitted, and the sun gear piece and the input piece that are spline-fitted by shifting the sleeve toward the low range side. When the sleeve is shifted to the high range side, And a high gear that is spline fitted to the sleeve and the output hub, and a low gear that is coupled to the sleeve and is spline fitted to the low gear piece and the output hub by shifting the sleeve to the low range side. A planetary gear type auxiliary transmission is provided.

  According to the present invention, the sun gear is provided separately from the input shaft and the input piece. Thus, when the sleeve is shifted to the high range side, torque input to the input shaft is transmitted to the output hub via the input piece and the high gear of the sleeve, but is separated from the input shaft and input piece. Torque is not transmitted to the sun gear. Therefore, the planetary gear meshing with the sun gear does not rotate completely. As a result, the friction loss or the meshing loss between the sun gear and the planetary gear is reduced, and the transmission efficiency of the drive torque is improved.

It is a gear train figure of the planetary gear type auxiliary transmission for transfer concerning one example of the present invention. FIG. 2 is a torque flow diagram in a high range of the transfer planetary gear sub-transmission shown in FIG. 1. FIG. 2 is a torque flow diagram in a low range of the planetary gear type auxiliary transmission for transfer shown in FIG. 1. It is a gear train figure of the planetary gear type auxiliary transmission for transfer concerning a prior art example.

  A planetary gear type auxiliary transmission for transfer according to a preferred embodiment of the present invention includes a bearing that is disposed between the input shaft and the sun gear in a radial direction and rotatably supports the sun gear with respect to the input shaft. . The sun gear is separated from the input shaft and the input piece by this bearing.

  A planetary gear type auxiliary transmission for transfer according to a preferred embodiment of the present invention has a high gear support mechanism that is provided on the sleeve and cuts off direct torque transmission between the high gear and the sleeve. This high gear support mechanism cuts off direct torque transmission from the high gear to the sleeve and the low gear coupled thereto, especially in the low range. In the high range, the high gear support mechanism may directly connect the high gear and the sleeve so as to be releasable.

  In a preferred embodiment of the present invention, on the sleeve, the high gear and the low gear are arranged along a shift direction, and an outer peripheral side of the low gear is formed so as to be able to be splined with the low gear piece. A peripheral side is formed so as to be spline-fit with the output hub, and an inner peripheral side of the high gear is formed so as to be spline-fitted with the input piece, and can be spline-fitted with the sun gear piece and the output hub. Formed.

  According to a preferred embodiment of the present invention, in order to distribute the torque output by the planetary gear sub-transmission for transfer according to the present invention, a sprocket, a belt suspended around the output shaft, a multi-plate clutch, etc. A synchronization device is provided.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. A planetary gear sub-transmission for transfer according to an embodiment of the present invention is incorporated in a transfer that distributes an input torque, and the input torque is shifted to a low range (Low) or a high range (High) and transmitted. Device. FIG. 1 is a gear train diagram of a planetary gear type auxiliary transmission for transfer according to an embodiment of the present invention.

  Referring to FIG. 1, a planetary gear sub-transmission for transfer according to an embodiment of the present invention includes an input shaft 1, an input piece 1 a that rotates integrally with the input shaft 1, and a sun gear that is loosely fitted on the input shaft 1. 2s, a sun gear piece 2a that rotates integrally with the sun gear 2s, a planetary gear 2p that meshes with the sun gear 2s, a ring gear 2r that meshes with the planetary gear 2p, a carrier 2c that supports the planetary gear 2p, and a low gear piece 2b that rotates integrally with the carrier 2c. And a sleeve 3 that can be shifted along the axial direction of the input shaft 1, an output hub 4 in which the sleeve 3 is spline-fitted so as to be shiftable, and a sleeve 3 that is loosely fitted so as to be freely coupled to the low range side of the sleeve 3 Shifts to the sun gear piece 2a and the input piece 1a by spline fitting, and the sleeve The high gear 3a that is spline-fitted with the input piece 1a and the output hub 4 is coupled to the sleeve 3 by the shift to the high range side, and the low gear piece 2b and the output hub 4 are coupled by the shift of the sleeve 3 to the low range side. And a low gear 3b for spline fitting.

  Furthermore, the planetary gear sub-transmission for transfer according to an embodiment of the present invention has a high gear support mechanism 6 that is provided on the sleeve 3 and cuts off direct torque transmission between the high gear 3a and the sleeve 3. The high gear support mechanism 6 can employ a bearing that rotatably supports the high gear 3a, or a clutch that can directly connect the high gear 3a to the sleeve.

  On the sleeve 3, a high gear 3a and a low gear 3b are arranged along the shift direction. The outer peripheral side of the low gear 3b is formed so as to be freely splined with the low gear piece 2b. The inner peripheral side of the low gear 3b is formed so as to be freely splined with the output hub 4. The inner peripheral side of the high gear 3a is formed so as to be spline-fitted with the input piece 1a, and is formed so as to be spline-fitted with the sun gear piece 2a and the output hub 4.

  A first bearing 7 that rotatably supports the input shaft 1 with respect to a housing (not shown) or the like is disposed on one side of the input shaft 1. Between the input shaft 1 and the sun gear 2s in the radial direction, a second bearing 8 that supports the sun gear 2s so as to be rotatable with respect to the input shaft 1 is disposed. A third bearing 9 that rotatably supports the output shaft 5 with respect to a housing or the like (not shown) is disposed on one side of the output shaft 5.

  The operation of the planetary gear type auxiliary transmission for transfer according to one embodiment of the present invention described above will be described.

[High range (High)]
FIG. 2 is a torque flow diagram in the high range of the planetary gear type auxiliary transmission for transfer shown in FIG.

  Referring to FIG. 2, when the sleeve 3 is shifted to the high range side (right side in FIG. 2), the high gear 3 a that is always spline-fitted with the input gear piece 1 a is further connected to the output hub 4. And spline mating. On the other hand, the spline fitting between the low gear 3b, the low gear piece 2b and the output hub 4 is released. Thus, the torque input to the input shaft 1 is transmitted to the output hub 4 and further to the output shaft 5 through the input piece 1a and the high gear 3a as shown by the thick line.

[Low range (Low)]
FIG. 3 is a torque flow diagram in the low range of the planetary gear type auxiliary transmission for transfer shown in FIG.

  Referring to FIG. 3, when the sleeve 3 is shifted to the low range (left side in FIG. 3), the high gear 3a is in a splined state only with the input gear piece 1a. On the other hand, the low gear 3b is in a spline-fit state with both the low gear piece 2b and the output hub 4. Thus, the torque input to the input shaft 1 is output via the input piece 1a, high gear 3a, sun gear piece 2a, sun gear 2s, planetary gear 2p, carrier 2c, low gear piece 2b and low gear 3b, as shown by the bold line. It is transmitted to the hub 4 and further to the output shaft 5.

  The effect of the planetary gear type auxiliary transmission for transfer according to one embodiment of the present invention described above will be described. During the high-range shift, torque is not transmitted to the sun gear 2a separated from the input shaft 1 and the input piece 1a. Therefore, the planetary gear 2p meshing with the sun gear 2a does not rotate completely. As a result, the friction loss or the meshing loss between the sun gear 2a and the planetary gear 2p is reduced, and the transmission efficiency of the drive torque in the planetary gear sub-transmission for transfer of this embodiment is improved.

  The planetary gear type auxiliary transmission of the present invention is suitably used for transfer of a four-wheel drive vehicle or the like.

1 Input shaft 1a Input piece 1a
2s sun gear 2a sun gear piece 2p planetary gear 2r ring gear 2c carrier 2b low gear piece 3 sleeve 3a high gear 3b low gear 4 output hub 5 output shaft 6 high gear support mechanism 7 first bearing 8 second bearing 9 third bearing

Claims (4)

An input shaft;
An input piece that rotates integrally with the input shaft;
A sun gear loosely fitted on the input shaft;
A sun gear piece that rotates integrally with the sun gear;
A planetary gear meshing with the sun gear;
A ring gear meshing with the planetary gear;
A carrier for supporting the planetary gear;
A low gear piece that rotates integrally with the carrier;
A sleeve that can be shifted along the axial direction of the input shaft;
An output hub in which the sleeve is splined so that it can be shifted; and
An output shaft that rotates integrally with the output hub;
The sleeve is loosely fitted, and the sun gear piece and the input piece are spline-fitted by shifting the sleeve to the low range side, and the input piece, the output hub and the spline are fitted by shifting the sleeve to the high range side. High gear to fit,
A low gear coupled to the sleeve and spline-fitted to the low gear piece and the output hub by shifting the sleeve to a low range side;
A planetary gear type auxiliary transmission for transfer, comprising:   2. The planetary gear sub-transmission for transfer according to claim 1, further comprising a bearing disposed between the input shaft and the sun gear in a radial direction so as to rotatably support the sun gear with respect to the input shaft. .   3. The planetary gear sub-transmission for transfer according to claim 1, further comprising a high gear support mechanism provided on the sleeve and configured to cut off direct torque transmission between the high gear and the sleeve. On the sleeve, the high gear and the low gear are arranged along the shift direction,
An outer peripheral side of the low gear is formed so as to be freely splined with the low gear piece,
The inner peripheral side of the low gear is formed so as to be able to be splined with the output hub,
The inner peripheral side of the high gear is formed so as to be spline fitted with the input piece, and is formed so as to be able to be spline fitted with the sun gear piece and the output hub.
The planetary gear type auxiliary transmission for transfer according to any one of claims 1 to 3.

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