192 clutches and power-stop control – Elements – Supports
Reexamination Certificate
2000-10-18
2002-04-23
Bonck, Rodney H. (Department: 3681)
192 clutches and power-stop control
Elements
Supports
C192S085060
Reexamination Certificate
active
06374977
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates in general to automotive automatic transmissions, and more particularly to a drum supporting structure installed in the automatic transmission for rotatably supporting a drum on a drum support. More specifically, the present invention is concerned with drum supporting structures of a type which has a well-balanced construction throughout the entirety thereof to suppress undesired inclination thereof.
2. Description of the Prior
As is known, in an automotive automatic transmission, there is arranged a drum supporting structure that comprises a drum support on which a drum is rotatably supported. Within the drum, there is installed a hub, and between the drum and the hub, there is arranged a friction element. When the friction element is in ON (viz., engaged) condition, power transmission is carried out between the drum and the hub, while, when the friction element becomes OFF (viz., disengaged) condition, the power transmission is suppressed.
In order to clarify the task of the present invention, one conventional drum supporting structure will be described with reference to
FIG. 15
of the accompanying drawings. The structure of the drawing is described in Japanese Patent First Provisional Publication 61-38261.
In
FIG. 15
, there is shown a rear view of a circular wall portion of a drum support
50
used in the drum supporting structure of the publication. As shown, a plurality of hydraulic fluid passages
52
are provided at a lower part of the circular wall portion of the drum support
50
, which feed a hydraulic fluid to hydraulic fluid passages
54
provided at a central portion of the drum support. On an upper part of the circular wall portion of the drum support
50
, there are integrally provided radially extending ribs
56
for reinforcement of that upper part. At a piston supporting portion
58
, there is arranged a piston (not shown) of a friction element. Behind the piston, there is defined a fluid working chamber for the piston. Although not shown, a drum is coaxially and rotatably supported on a cylindrical hollow shaft portion of the drum support
50
. (The entire construction of the drum support
50
is easily understood when referring to
FIG. 14.
)
However, the drum support
50
disclosed by the publication fails to exhibit a well balanced construction therethroughout due to an imbalanced arrangement of the structures such as the hydraulic fluid passages
52
and ribs
56
provided on the circular wall portion of the drum support
50
. That is, in the drum support
50
, the rigidity of the lower part of the circular wall portion is extremely different from that of the upper part of the same. As is known, if such ill-balanced drum support
50
is practically used in the transmission, undesired inclination of the drum support
50
relative to the bolted lower part tends to occur. This phenomenon becomes much severe when the lower part of the circular wall portion of the drum support
50
is secured to the transmission case by bolts
60
, as shown.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a drum supporting structure for an automotive automatic transmission, which is free of the above-mentioned drawback.
According to a first aspect of the present invention, there is provided a drum supporting structure for use in an automatic transmission including a transmission case, a drum rotatably installed in the transmission case and a friction element incorporated with the drum. The drum supporting structure comprises a drum support immovably installed in the transmission case, the drum support including a cylindrical hollow shaft portion on which the drum is rotatably disposed and a circular wall portion which is concentrically and integrally formed on one end of the cylindrical hollow shaft portion; a first part of the circular wall portion, the first part being secured to the transmission case and having a plurality of hydraulic fluid passages defined therein; and a second part of the circular wall portion, the second part having a plurality of blind bores defined therein, the number of the blind bores being at least the same as that of the hydraulic fluid passages, the first and second parts being provided at diametrically opposed portions of the circular wall portion and the blind bores extending toward the extension of the hydraulic fluid passages.
According to a second aspect of the present invention, there is provided a drum supporting structure for use in an automatic transmission including a transmission case, an output shaft rotatably installed the transmission case, a drum rotatably disposed around the output shaft, a first friction element incorporated with the drum and a second friction element arranged behind the drum. The drum supporting structure comprises a drum support immovably installed in the transmission case and having a through bore through which the output shaft passes, the drum support including a cylindrical hollow shaft portion on which the drum is rotatably disposed and a circular wall portion which is concentrically and integrally formed on one end of the cylindrical hollow shaft portion, the circular wall portion having a rear surface that faces the second friction element; a first part of the circular wall portion, the first part being bolted to the transmission case and having a plurality of hydraulic fluid passages defined therein; and a second part of the circular wall portion, the second part having a plurality of blind bores defined therein, the number of the blind bores being at least the same as that of the hydraulic fluid passages, the first and second parts being provided at diametrically opposed portions of the circular wall portion and the blind bores extending the extension of the hydraulic fluid passages.
REFERENCES:
patent: 3896706 (1975-07-01), Newstead et al.
patent: 4125178 (1978-11-01), Monks
patent: 4693353 (1987-09-01), Kobayashi et al.
patent: 4982826 (1991-01-01), Holbrook
patent: 5483850 (1996-01-01), Yamauchi
patent: 74 00 787 (1974-07-01), None
patent: 36 44 875 (1987-09-01), None
patent: 44 05 823 (2001-06-01), None
patent: 57-184758 (1982-11-01), None
patent: 61-38261 (1986-02-01), None
Bonck Rodney H.
Foley & Lardner
Jatco Transtechnology Ltd.
LandOfFree
Drum supporting structure for automotive transmission does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Drum supporting structure for automotive transmission, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Drum supporting structure for automotive transmission will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2865309