JP2624497B2 - Planetary gear type transmission - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an improvement of a planetary gear type transmission.

(Prior Art) Conventionally, as a planetary gear type transmission, as shown in FIG. 4, a sun gear 2 is fixed to an input shaft 1, and a carrier 4 is spline-coupled to an output shaft 3 so as to be movable in the axial direction. A planetary gear 6 meshing with the sun gear 2 and the ring gear 5 is supported on the carrier 4, and the ring gear 5 is supported by the planetary gear 6, and the carrier 4, the planetary gear
6, a configuration in which a planetary gear unit U is constituted by the ring gear 5 has been proposed (see Japanese Patent Publication No. 62-7419).

Then, during direct drive (high-speed mode), the planetary gear unit U is moved rightward as shown to make the ring gear 5 free to prevent the planetary gear 6 from over-rotating, while at the reduction ratio drive (low-speed mode). 5), the planetary gear unit U is moved to the left to lock the ring gear 5 to the casing 7 as shown in FIG. 5, and the planetary gear 6 is caused to rotate in a planetary manner.

(Problems to be Solved by the Invention) However, since switching between the high-speed mode and the low-speed mode involves moving the entire planetary gear unit U, there is a problem that a large operation force is required and the structure is complicated. .

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problem, and has as its basic object to enable smooth switching between a high-speed mode and a low-speed mode with a light operating force.

(Means for Solving the Problems) For this reason, the present invention provides a planetary gear unit comprising a planetary gear meshed with a sun gear, a ring gear and both gears and supported by a carrier between an input member and an output member. Switching means for switching between the input and output members so as to drive the planetary gear unit directly, bypassing the gear system of the planetary gear unit, and switching between the input and output members via the gear system of the planetary gear unit. In a planetary gear type transmission that switches so as to perform deceleration driving, the switching means selectively connects the carrier connected to the input member and the output member during direct driving, and selectively connects the input member and the sun gear during deceleration driving. At the same time, the ring gear and the casing are fixed to the switching means during deceleration driving, and the fixing between the ring gear and the casing is released during direct driving. A switching member to be removed.

The switching member has a configuration having an engagement portion that moves on an engagement portion provided on the ring gear and the casing, or the rotation member is restricted in the rotation direction with respect to the casing, and is integrally formed with the ring gear slidable in the axial direction. Any of the combined configurations can be employed.

According to the present invention, the input member and the sun gear and the input member and the carrier are selectively connected by the switching member, and when the carrier is selected (at the time of direct drive), the fixing between the ring gear and the casing is released. It is something to do.

Therefore, at the time of direct drive (high-speed mode), the ring gear is free, so that over rotation of the planetary gear can be effectively prevented.

Further, since the sun gear and the carrier are only selectively connected by the switching member, there is no need to move the entire planetary gear unit as in the related art, and the operation force can be smoothly and smoothly switched, and the structure can be simplified. .

Further, the switching member is separate from the planetary gear unit,
And since it is a small thing which has the engaging part which moves on the engaging part provided in the ring gear and the casing, the operation force is extremely light and the switching operation can be performed smoothly.

Furthermore, the switching member is configured such that the rotation direction is regulated with respect to the casing and is integrally connected to a ring gear slidable in the axial direction, so that the engagement portion is separately machined as in the above-described switching member type. There is no need to improve workability.

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

As shown in FIG. 1, in a transmission of a four-wheel drive vehicle, an input shaft 12 as an input member and an output shaft 10A for rear wheel drive are arranged on an upper part of a casing 11, and a front wheel drive is provided on a lower part of the casing 11. Output shaft 10B is arranged, the input shaft 12 and the output shaft 1
0A and 10B, a planetary gear type auxiliary transmission A and a planetary gear type differential B as an output member are basically interposed.

FIG. 2 shows a planetary gear type transmission in which the ring gear 20 does not move in the axial direction with respect to the casing 11.

The output shaft is connected to a bearing (not specifically shown) of the casing 11.
10A is rotatably supported, and an input shaft 12 is rotatably supported by a bearing 13 of a casing 11 coaxially with the output shaft 10A.

The tip of the output shaft 10A is rotatably supported by a needle bearing 14 interposed between the output shaft 10A and a shaft hole of the input shaft 12.

The sun gear 15 of the planetary gear type auxiliary transmission A is provided with a needle bearing near the input shaft 12 on the output shaft 10A.
It is rotatably fitted via 16.

A carrier 17 is fitted to the output shaft 10A in the vicinity of the sun gear 15, and a spline
17b is formed, and the spline 17b is spline-coupled to the ring gear 32 of the planetary gear type differential B.

In the differential device B, a planetary gear 33 is a compound type (double pinion type), and as shown in FIG. The gear 51 of the shaft 10B is connected with the chain 52,
The sun gear 35 is fixed to the rear output shaft 10A.

Therefore, when the carrier 17 rotates, the ring gear 3
2, front output shaft 10B via planetary gear 33, carrier 34, etc.
Is rotated, the ring gear 32, planetary gear 3
3. The rear output shaft 10A is rotated via the sun gear 35.

A plurality of planetary gears 18 meshing with the sun gear 15 and the ring gear 20 are supported on the carrier 17 by shafts 19, respectively.

The ring gear 20 is supported by a planetary gear 18.

A spline 12a is formed on the outer periphery of the input shaft 12,
The spline 12a is provided on the flange portion 15b of the sun gear 15.
Are formed, and a switching sleeve 21 having a spline 21a that always meshes with both splines 12a, 15a is provided.

A spline 21c is provided on the flange portion 21b of the switching sleeve 21.
The spline 21c is formed in a reduction ratio drive position where the sleeve 21 is engaged with the spline 17a of the carrier 17 in the illustrated direct drive position, and the sleeve 21 is axially moved rightward in the figure (see a two-dot chain line). In this case, the engagement with the spline 17a is released.

A shift fork 23 is engaged with the switching sleeve 21, and the shift fork 23 is connected to the input / output shafts 12, 10A, 10B.
The shift rod 22 is slidably supported by the casing 11 in parallel with the shift rod 22. The shift rod 22 is slidably switched by a shift fork 23 through a shift fork 23.
Is switched and moved between a direct drive position and a reduction ratio drive position.

A switching member 24 having a spline 24a formed on the outer periphery is engaged with the switching sleeve 21, and meshes with the spline 24a on the inner periphery of the ring gear 20 when the switching sleeve 21 moves to the reduction ratio drive position. A spline 20a is formed.

A casing fixing member (iron-based member) 25 is fixed to the casing (made of aluminum casting) 11 by a spline connection with a gap from the ring gear 20, and a spline 20a of the ring gear 20 is fixed to a flange portion 25b of the casing fixing member 25. An opposing spline 25a is formed, and the spline 24a of the switching member 24 always meshes with the spline 25a.

With the above configuration, the switching sleeve 21 is now in the direct drive position in the state of FIG.
The splines 21c of the 21 mesh with the splines 17a of the carrier 17, and the splines 24a of the switching member 24 and the splines 20a of the ring gear 20 are disengaged.

Therefore, the rotational force of the input shaft 12 is
→ Carrier 17 → Ring gear 32, etc. → Directly transmitted to output shafts 10A and 10B, and output shafts 10A and 10B rotate in high-speed mode.

At the time of this direct drive, the ring gear 20 is free with respect to the casing 11, so that excessive rotation of the planetary gear 18 is effectively prevented.

Next, when the switching sleeve 21 is axially moved rightward in the figure by the shift fork 23 to switch to the reduction ratio driving position, the spline 21c of the switching sleeve 21 and the spline 17a of the carrier 17 are disengaged, and the switching member 24 is disengaged. Of the ring gear 20 meshes with the spline 24a of the ring gear 20.

Therefore, the ring gear 20 has the spline 20a and the switching member
24 splines 24a, casing fixing member 25 splines
25a, the rotational force of the input shaft 12 is changed from the sun gear 15 → the planetary gear 18 → the carrier 17 → the ring gear 32, etc. → the output shafts 10A and 10A.
The output shafts 10A and 10B are rotated in the low speed mode.

Switching between the direct drive and the reduction ratio drive is simply performed by reciprocating the switching sleeve 21 with the shift fork 23, so that the switching operation can be performed smoothly with a small operating force.

FIG. 3 shows a planetary gear type transmission that employs a configuration in which the ring gear 20 moves in the axial direction with respect to the casing 11. Note that the same configuration and operation as those in FIG. 2 are assigned the same reference numerals, and detailed description is omitted.

In this embodiment, the ring gear 20 is extended to
4 'is integrally formed and the switching portion 24' is engaged with the switching sleeve 21. On the outer periphery of the ring gear 20, when the switching sleeve 21 moves to the reduction ratio driving position, the spline 25a of the casing fixing member 25 is moved. A spline 20c is formed to mesh with the spline 20c.

With the above configuration, the switching sleeve 21 is now in the direct drive position in the state of FIG.
Are engaged with the spline 17a of the carrier 17, and the spline 20c of the ring gear 20 is disengaged from the spline 25a of the casing fixing member 25.

Therefore, the rotational force of the input shaft 12 is
→ Carrier 17 → Ring gear 32, etc. → Directly transmitted to output shafts 10A and 10B, and output shafts 10A and 10B rotate in high-speed mode.
At the time of this direct drive, the ring gear 20 is free with respect to the casing 11, so that excessive rotation of the planetary gear 18 is effectively prevented.

Next, when the switching sleeve 21 is axially moved rightward in the drawing by the shift fork 23 to switch to the reduction ratio driving position,
The spline 21c of the switching sleeve 21 disengages from the spline 17a of the carrier 17, and the spline 20c of the ring gear 20 meshes with the spline 25a of the casing fixing member 25.

Therefore, since the ring gear 20 is fixed to the casing 11, the rotational force of the input shaft 12 is reduced and transmitted to the sun gear 15 → the planetary gear 18 → the carrier 17 → the ring gear 32, etc. → the output shafts 10A and 10B, The shafts 10A and 10B are rotated in the low speed mode.

Since the switching between the direct drive and the reduction ratio drive is only performed by reciprocating the switching sleeve 21 with the shift fork 23, the switching operation can be performed smoothly with a small operating force.

[Brief description of the drawings]

FIG. 1 is a cross-sectional side view of a main part of a planetary gear type transmission according to the present invention, FIG. 2 is an enlarged cross-sectional view of a main part of FIG. 1 of the first embodiment,
3 is an enlarged cross-sectional view of a main part of FIG. 1 of the second embodiment, FIG. 4 is a cross-sectional view of a conventional planetary gear type transmission when directly driven, and FIG. 3 is an enlarged sectional view of a main part of FIG. 10 output shaft, 11 casing, 12 input shaft (input member), 15 sun gear, 15a spline, 17 carrier, 17a spline, 18 planetary gear, 20 ring gear, 20a, 20c spline, 21 ... Switching sleeve, 2
1a, 21c: Spline, 24: Switching member, 24 ': Switching section, 24
a ... spline, 25 ... casing fixing member, 25a ... spline, 34 ... carrier, A ... planetary gear type transmission, B ... planetary gear type differential.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-203740 (JP, A) JP-A-60-151461 (JP, A) Fully open 58-177645 (JP, U) Really open 36748 (JP, U) U.S. Pat. A) US Patent 4,549,449 (US, A)

Claims (3)

(57) [Claims] 1. A sun gear between an input member and an output member.
A planetary gear unit comprising a planetary gear meshed with the ring gear and both gears and supported by the carrier is interposed, and the switching means directly drives the input and output members between the input and output members, bypassing the gear path of the planetary gear unit. A planetary gear type transmission that switches between the input and output members so as to reduce and drive the input and output members via a gear path of a planetary gear unit. And the carrier selectively connected between the input member and the sun gear at the time of deceleration driving, and the switching means is fixed to the ring gear and the casing at the time of deceleration driving, and the ring gear and the casing at the time of direct driving. A planetary gear type transmission having a switching member for releasing the fixation of the planetary gear. 2. The planetary gear type transmission according to claim 1, wherein the switching member has an engaging portion that moves on an engaging portion provided on the ring gear and the casing. 3. The switching device according to claim 1, wherein the switching member has a rotation direction restricted with respect to the casing and is integrally connected to a ring gear slidable in the axial direction. Planetary gear type transmission.