JPS6343049A - Gearing of automatic transmission - Google Patents

Abstract

PURPOSE:To obtain a gearing suitable for attaining a high power of an engine by adding a pair of planetary gears for increasing speed to a main gear train being made to be a forward four speed type by two pairs of planetary gears, so as to be changed to a forward five speed type by three pairs of planetary gears. CONSTITUTION:From the point of view that a large vehicle has a space capable of mounting an automatic transmission even if three pairs of planetary gears are provided, a planetary gear G3 for increasing speed is additionally provided in the rear stage of a main gear train 1 so as to be on the same axis. In the main gear train 1, four kinds of forward speed change stage can be selected by selectively operating various friction elements R/C, H/C, L/C, B/B, LR/B, L/OWC. Now, by keeping the gear G3 in such a transmission condition as the power from the main gear train 1 is output as it is, four kinds of forward speed change steps become just the forward first through fourth speeds. When the gear G3 is changed over to a speed-increasing condition in the maximum speed stage selection state of the main gear train 1, the power from the main gear train 1 is accelerated by the gear G3 to be output, enabling the forward fifth speed to be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a gear transmission used in a transmission train of an automatic transmission.

(Prior art) This type of gear transmission is normally configured with two sets of planetary gears to provide a three-speed forward speed type, and to create a four-speed forward type, it is usual to add one set of planetary gears. .

However, in this case, the automatic transmission is long and difficult to install in a small car. Therefore, the applicant of the present application first applied
Japanese Patent Publication No. 156753 has already proposed a technique for constructing a four-speed forward gear transmission using two sets of planetary gears.

(Problems to be Solved by the Invention) Nowadays, engines are becoming more and more powerful, and this trend is particularly noticeable in large vehicles. For this reason, large-sized vehicles are required to have even more multi-speed automatic transmissions, but the above technology is limited to four forward speeds.

(Means for Solving the Problems) The present invention provides two sets of planetary gears coaxially, from the viewpoint that there is space in large vehicles to mount an automatic transmission even with three sets of planetary gears. The power transmission path is determined by the selective operation of various friction elements, and the main transmission train is capable of selecting four types of forward gears. A speed-increasing planetary gear is provided that can be switched between a transmission state in which the main transmission train and the speed-increasing planetary gear are output, and five types of forward gears can be selected by the main transmission train and the speed-increasing planetary gear.

(Function) The main transmission train can select four types of forward gears by selectively operating various friction elements. Here, by maintaining the speed increasing planetary gear in a transmission state in which the power from the main transmission train is output as is, the four types of forward gears described above become the first to fourth forward speeds as they are.

When the speed-increasing planetary gear is switched to the speed-increasing transmission state in the state where the highest speed stage of the main transmission train is selected, the power from the main transmission train is increased in speed by the speed-increasing planetary gear and output, thereby obtaining the fifth forward speed. Can be done.

Therefore, it is possible to further increase the number of forward speeds to five, and provide a gear transmission that is compatible with today's high output engines.

(Example) Hereinafter, the present invention will be described in detail based on illustrated embodiments.

Fig. 1 shows an embodiment of the gear transmission of the present invention, in which E indicates the engine output shaft and 1 indicates the main transmission train. Input via converter T/C.

The main power transmission train 1 transmits power from the input shaft (2) to the intermediate shaft M at a variable speed, and is the same as that described in the aforementioned Japanese Patent Laid-Open No. 58-156753. That is, two sets of planetary gears G, , G are arranged coaxially with axes E, I, and M, and these are connected to sun gears S, , S, and ring gears R, respectively.
, R2, and carriers C, , C, which rotatably support pinions P+ and Pz. The sun gear SL can be fixed by a band brake B/B and can be connected to the input shaft I by a reverse clutch R/C. It can be fixed using reverse brake LR/H. Further, the carrier C5 can be rotated only in the same normal rotation direction as the engine by a row one-way clutch L10WC, and can be coupled to the ring gear R2 by a low clutch L/C. In addition, sun gear S2 is connected to input shaft ■, and carrier C
t is coupled to the ring gear R1 and the intermediate shaft M.

The main power transmission train 1 is set to the driver's desired range, that is, parking (
P) range, reverse drive (R) range, neutral (N) range, forward automatic shift (D) range, 2nd gear engine brake (n) range, 1st gear engine brake (I)
For each range, by supplying hydraulic pressure to the friction elements marked O in the table below to operate them (however, LloWC is mechanically self-actuated), four forward speeds and one reverse speed can be obtained. It is assumed that the band brake B/B operates when hydraulic pressure is supplied only to the engagement side, and is deactivated when hydraulic pressure is supplied to the disengagement side as well.

Table 1 Furthermore, a speed-increasing planetary gear G3 is additionally installed on the same axis after the main transmission train 1, and this planetary gear is also connected to the sun gear S3.
, a ring gear R3, and a carrier C3 that rotatably supports a pinion P3. Then, the carrier c3 is connected to the intermediate shaft M to serve as an input element, and can be connected to the sun gear S3 by a direct clutch D/C, and the sun gear S3 can be fixed by an overdrive brake 00/B. A direct one-way clutch D10WC is separately provided between the carrier C1 and the sun gear 33, and this one-way clutch is arranged in such a direction that the sun gear S3 is engaged with the carrier C3 when the sun gear S is about to rotate at a higher speed in the same direction as the carrier C3. do.

Ring gear R3 is used as an output element, and a counter gear C/G is meshed with the outer periphery of the ring gear R3, and an output shaft O of the transmission is connected to this counter gear.

Planetary gear G3 for speed increase is direct clutch D/C
In the interlock state due to the hydraulic operation, a direct transmission state is established in which the power from the main transmission train 1 to the carrier C1 is directly transmitted to the output shaft O via the ring gear R3 and the counter gear C/G. In this transmission state, the four forward and one reverse transmissions of the main transmission train 1 serve as the gears of the gear transmission of the present invention.

When the overdrive brake 00/B is hydraulically actuated to fix the sun gear S when the main transmission train 1 is in the fourth forward gear selection state, the pinion P is transferred around the sun gear 33, and as a result the speed-increasing planetary gear G , is a speed-up transmission state in which the power from the main transmission train 1 to the carrier C1 is increased to reach the output shaft 0 via the ring gear R3 and the counter gear C/G, and the fifth forward speed is faster than the fourth forward speed. can be obtained.

Note that during the shift between the first forward speed and the fourth forward speed obtained in the direct transmission state of the planetary gear G3 (during the shift of the main transmission train 1)
temporarily deactivates the direct clutch D/C. In this case, if the power is on when the intermediate shaft M drives the output shaft 0, the direct one-way clutch D1
Although the interlock state of planetary gear G3 is maintained by the operation (locking) of 0WC, if the engine brake running condition is such that the output shaft 0 drives the intermediate shaft M, the direct one-way clutch D10WC will be deactivated (idling).
The engine brake is not applied to prevent deceleration shock from occurring during the gear shift.

The above operations are summarized in the table below.

In this table, the ■ range indicates a range that prohibits the selection of 5th gear, and the △ mark indicates the direct one-way clutch D10WC, which is self-activated by disabling the direct clutch D/C during gear shifting as described above. .

FIG. 2 shows another example of the gear transmission of the present invention, and in this example, the direct one-way clutch D10WC is connected to the carrier C.
3 and ring gear R3. And in this one-way clutch D10WC, the ring gear R1 is the carrier C.
Place it in an orientation that allows it to rotate in the same direction as No. 3 at a higher speed. Thus, in this embodiment as well, when the direct clutch D/C is temporarily deactivated during shifting between the first forward speed and the fourth forward speed, the same effect as in the above embodiment can be obtained.

In addition, in this example, direct one-way clutch D10
Since the WC exists between the intermediate shaft M and the output shaft 0, it is also possible to obtain the effect of eliminating the influence of play due to backlash of the planetary gear G3 for increasing the number of stations at the first to fourth speeds.

(Effects of the Invention) Thus, as described above, the gear transmission of the present invention adds a speed-increasing planetary gear to the main transmission train, which has two sets of planetary gears for four forward speeds, and has a total of three sets of planetary gears for forward five speeds.
Because it is a high-speed type, it can be made into a compact gear transmission that matches the high output of today's engines.

[Brief explanation of the drawing]

FIG. 1 is a skeleton diagram showing one embodiment of the gear transmission device of the present invention, and FIG. 2 is a skeleton diagram similar to FIG. 1 showing another example of the present invention. 1... Main transmission train G3... Speed-increasing planetary gear G3... Carrier (input element) R3... Ring gear (output element) S3... Sun gear (remaining 1 element) D/C... Direct clutch DloWC... Direct one-way clutch (one-way clutch) 00/B... Overdrive brake C/G...
Counter gear 0... Output shaft patent applicant Nissan Motor Co., Ltd. agent patent attorney Hidetoshi Sugimura Akira Sugimura patent attorney

Claims (1)

[Scope of Claims] A main power transmission train comprising one or two sets of planetary gears coaxially, and capable of selecting four types of forward gears by determining the power transmission path through these planetary gears by selectively operating various friction elements. A gear transmission for an automatic transmission, comprising: a speed increasing planetary gear that can be switched between a transmission state in which the power from the main transmission train is output as is and a transmission state in which the power is increased and output. Device. 2. The speed-increasing planetary gear is switchable between a transmission state in which the input element is coupled to the output element or one remaining element, and a transmission state in which the remaining one element is fixed, and in the state in which the coupling is released. The gear transmission device for an automatic transmission according to claim 1, further comprising a one-way clutch that enables power transmission from the input element to the output element. 3. The gear transmission device for an automatic transmission according to claim 2, wherein the one-way clutch is interposed between input and output elements.