Power plants – Pressure fluid source and motor – Coaxial impeller and turbine unit
Reexamination Certificate
2000-12-06
2002-10-08
Look, Edward K. (Department: 3745)
Power plants
Pressure fluid source and motor
Coaxial impeller and turbine unit
C060S365000
Reexamination Certificate
active
06460331
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a torque converter for transmitting the power of an engine to a transmission or gearbox by means of oil, and more particularly, to an arrangement of oil passageways through which oil is supplied into a torque converter, or removed from it.
BACKGROUND OF THE INVENTION
A known torque converter is shown in
FIG. 3
of the accompanying drawings. It has a pump impeller
201
, a turbine runner
202
and a stator
203
. The pump impeller
201
is connected with a converter cover
204
to the output shaft of an engine not shown, and the turbine runner
202
is connected to the input shaft
206
of a transmission or gearbox by a turbine runner hub
205
. The stator
203
is connected to a stator shaft
210
by a one-way clutch
207
. The stator shaft
210
has a shaft member
211
situated about the input shaft
206
and a flange member
212
having a boss portion
212
a
press fitted about the shaft member
211
and a flange portion
212
b
attached to a transmission casing C. A pump impeller boss member
201
a
, which is attached to the pump impeller
201
, is situated about the boss portion
212
a
, and is rotatably supported/by a bearing
208
located between the pump impeller boss member
201
a
and the shaft member
211
.
Oil is supplied into the torque converter through a path formed by an oil passageway
221
in the flange portion
212
b
, to an oil passageway
222
between the shaft member
211
of the stator shaft
210
and the boss portion
212
a
of the flange member
212
, to an opening
222
a
in the boss portion
212
a
, to a clearance around the bearing
208
, to a space
223
between the pump impeller boss member
201
a
and the shaft member
211
. The oil is discharged from the torque converter through a path formed by a space
224
between the turbine runner hub
205
and the one-way clutch
207
, to an oil passageway
225
between the input shaft
206
and the shaft member
211
, an oil passageway
226
in the shaft member
211
and an oil passageway
227
between the shaft member
211
and the boss portion
212
a
of the flange member
212
.
In a conventional oil passage of this type the bearing
208
, however, causes an increased resistance to the flow of oil. Moreover, the bearing
208
prevents the boss portion
212
a
of the flange member
212
from having its left end extended near the stator
203
, and as the oil passageway
227
formed between the shaft member
211
and the boss portion
212
a
extends only to a position slightly short of the bearing
208
, the oil passageway
225
between the input shaft
206
and the shaft member
211
must be extended to near the left end of the oil passageway
227
. The oil passageway
225
is formed by a portion of the input shaft
206
having a smaller radius than the remaining portion, and thereby lowers the input shaft's strength and rigidity.
Moreover, the oil passageway
223
between the shaft member
211
and the pump impeller boss member
201
a
has a reduced diameter in its portion where it is supported by the bearing
208
, the bearing
208
not having a smaller thickness to be less expensive. Its portion having a reduced diameter gives an increased resistance to the flow of oil, but there is no alternative but to use it as an oil passageway, since the boss portion
212
a
of the flange member
212
is not allowed to have its left end extended beyond the vicinity of the bearing
208
, as stated before. The boss portion
212
a
is so small in length that there is hardly any freedom of forming the opening
222
a
in any other position along the boss portion
212
a
. While it may be possible to have the boss portion
212
a
extend in the opposite direction away from the torque converter, the transmission becomes undesirably large in overall length.
SUMMARY OF THE INVENTION
Under these circumstances, it is an object of this invention to provide a structure defining an improved arrangement of oil passageways in a torque converter and enabling a transmission to have an input shaft of improved strength and rigidity.
This invention is an attempt to solve the above problems. Besides improving the flow of oil to and from the torque converter, it is our purpose to provide a torque converter oil passageway with a structure that improves the strength and rigidity of the input shaft.
This object is attained by a structure comprising a torque converter having a pump impeller, a turbine runner and a stator, a transmission having an input shaft connected to the turbine runner and supported rotatably by a transmission casing, having about the transmission input shaft connected to the stator an inner cylindrical portion connected to the stator and situated about the input shaft (such as a shaft member
41
) and an outer cylindrical portion press fitted about the inner cylindrical portion and connected to the transmission casing (such as boss portion
42
a
of flange member
42
), and having a plurality of oil passageways (such as an oil passageway
102
) formed between the outer periphery of its inner cylindrical portion and the inner periphery of its outer cylindrical portion and along the input shaft for supplying oil into the torque converter and removing it therefrom, and a pump impeller boss member connected to the pump impeller, situated about the outer cylindrical portion of the stator shaft and having an outer periphery supported rotatably by a bearing in the casing, the outer cylindrical portion of the stator shaft having an end situated closer to the stator than that portion of the pump impeller boss member which is supported by the bearing, and the oil passageways having at least one outlet opening (such as an opening
40
b
or
40
c
) situated closer to the stator than that portion of the pump impeller boss member which is supported by the bearing.
No bearing is required between the pump impeller boss member and the inner cylindrical portion of the stator shaft, since the former has its outer periphery supported by a bearing. As a result, the outer cylindrical portion of the stator shaft may have an end extended close to the stator and the oil passageways formed between the inner and outer cylindrical portions of the stator shaft may have at least one outlet opening situated close to the stator.
The torque converter has an improved arrangement of oil passageways enabling an efficient supply or removal of oil, since there is no bearing giving an increased resistance to the flow of oil. An oil passageway
111
formed between and along the transmission input shaft and the inner cylindrical portion of the stator shaft is smaller in length. As that passageway is formed by a portion of the input shaft having a reduced radius, its reduction in length improves the strength and rigidity of the input shaft. As the outer cylindrical portion of the stator shaft has its end situated close to the stator, there is a greater degree of freedom in determining the arrangement of oil passageways.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
REFERENCES:
patent: 4271939 (1981-06-01), Iwanaga et al.
patent: 5013287 (1991-05-01), Hayakawa et al.
Nakamura Takashi
Sakuma Shinji
Yamaoka Takaki
Armstrong Westerman & Hattori, LLP
Honda Giken Kogyo Kabushiki Kaisha
Lazo Thomas E.
Look Edward K.
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