Power plants – Pressure fluid source and motor – Coaxial impeller and turbine unit
Reexamination Certificate
1999-03-08
2001-04-24
Look, Edward K. (Department: 3745)
Power plants
Pressure fluid source and motor
Coaxial impeller and turbine unit
C060S365000, C416S19700C, C416S180000, C416S143000
Reexamination Certificate
active
06220025
ABSTRACT:
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates generally to torque converters, and more particularly to a stator that includes blades which fold open to multiply the torque in the torque converter and which fold inward out of the fluid flow when a sufficient speed ratio between the impeller and turbine is achieved.
BACKGROUND AND SUMMARY OF THE INVENTION
A torque converter contains three parts: an impeller turned by the engine flywheel; a turbine that turns the input shaft of the automatic transmission; and a stator which is disposed between the impeller and the turbine. The torque converter is filled with oil which is moved by the impeller blades. The vanes of the stator deflect this oil from the turbine blades back to the impeller. As the impeller rotates, the speed of the turbine increases to almost match the impeller speed. This provides a fluid coupling between the engine and gear box that smoothes out speed changes. The hydraulic torque converter is an automatically and continuously variable torque converter. The efficiency of a hydraulic torque converter depends intimately on the angles at which the fluid enters and leaves the blades of the impeller, turbine, and stator. Conventional hydraulic torque converters include a stator having an overrunning clutch which, when it is “locked”, deflects oil back to the impeller from the turbine, and torque multiplication is achieved. When a sufficient speed ratio between the turbine and impeller is achieved, the overrunning clutch of the stator assembly overruns, and torque multiplication is completed.
With conventional hydraulic torque converters, the impeller, turbine, and stator all require individual balancing since each member rotates at very high speeds. Furthermore, with the conventional stator design, the requirement for an overrunning clutch influences the thickness of the stator assembly. This minimum thickness is a design criteria which can impact the overall size and weight of the torque converter. Finally, the modification of the vane configuration of a conventional stator assembly requires a casting redesign which can be expensive.
The torque converter stator assembly of the present invention is designed to overcome these deficiencies. Specifically, the stator assembly of the present invention includes a body portion and a plurality of blades pivotally mounted to the body portion. The blades pivot between a first radially outwardly extending position for providing torque multiplication, to a retracted annularly extending position out of the fluid flow so that there is limited or no loss due to the blades interfering with the fluid flow. The stator does not include an overrunning clutch. Thus, there is no balancing required since the body of the stator assembly does not rotate. The plurality of blades can be designed with complex profiles in order to obtain various performances. A two-stage torque ratio curve can be obtained by providing two different sets of profiled blades wherein groups of blades can fold independently of others at different speed ratios. The blades of the stator assembly can also be modified very easily and less expensively relative to conventional stator designs.
REFERENCES:
patent: 3852955 (1974-12-01), Wonn et al.
patent: 4009571 (1977-03-01), Black et al.
patent: 4012908 (1977-03-01), Dundore
patent: 5263319 (1993-11-01), By et al.
patent: 5307629 (1994-05-01), By et al.
Mauti Renato
Raley Darrin C.
DaimlerChrysler Corporation
Lazo Thomas E.
Look Edward K.
MacLean Kenneth H.
LandOfFree
Stator for torque converter does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Stator for torque converter, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Stator for torque converter will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2494937