Fluid handling – Processes – Cleaning – repairing – or assembling
Reexamination Certificate
1999-12-22
2001-09-18
Fox, John (Department: 3753)
Fluid handling
Processes
Cleaning, repairing, or assembling
C264S068000
Reexamination Certificate
active
06289913
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
MICROFICHE APPENDIX
Not Applicable
BACKGROUND OF THE INVENTION
The present invention relates to servo motor operated valves and particularly electrically operated valves of the type having a single inlet and plural outlets wherein a rotary valve member is progressively moved from an initial position blocking flow to one of the outlets and diverting flow to the remaining outlets progressively through positions permitting increasing flow through the one outlet and decreasing flow through the remaining outlets until full flow is directed through the one outlet.
Valves of this type are typically employed in a fluid flow circuit wherein it is desired in certain modes of operation to divert or bypass a portion of the flow for control purposes to a working fluid circuit and to divert the remainder of the flow away from the working load circuit such as to a sump or pump return.
The aforesaid type of bypass or diverted flow is desired in controlling flow of hot water or engine coolant to a heat exchanger or heater core for a motor vehicle passenger compartment climate control system, typically for heating the passenger compartment. In such automotive passenger compartment heaters, it is desired to control flow of the hot water to the heater core by diverting or bypassing a portion of the flow to the heater and directing the remaining portion to return to the engine coolant circuit or engine water pump inlet. Such an arrangement provides for accurate control of the flow of hot water to the heater core and thus gives the desired resolution of temperature control of the passenger compartment.
Heretofore bypass water valves for motor vehicle passenger compartment heater cores have typically been of the butterfly or rotary vane type which, have been employed because of their simplicity and low manufacturing cost, but which have the disadvantage or drawback of providing full flow between the closed position and about one-fourth of the full open position of the butterfly. This high gain change of flow with respect to rotary valve movement has caused the butterfly member in the valve to require a very fine control of its rotary position.
Where it has been desired to provide an electronically controlled automatic temperature control system for the vehicle passenger compartment, utilization of a motorized actuator for the bypass water valve has required extremely fine resolution of the motor actuator output and thus has proven to be difficult and costly with respect to the overall cost of the valve and heater system.
Thus, it has been desired to provide a bypass water valve for motor vehicle passenger compartment heater systems which provides accurate control of the flow and fine resolution of the flow with respect to movement of the valving member. It has further been desired to provide a linear relationship between the rotary movement of the valving member and the change in the diverted flow through the valve to the working load circuit.
Known servo motor actuated rotary water valves have required separate fasteners to attach the motor drive unit to the valve body, utilizing a sealing gasket and has the disadvantage of being a source of leakage and being costly in high volume mass production. It has thus been desired to provide such a servo motor actuated rotary valve for heater bypass flow control which provides linearity of control, simplicity of design and ease of assembly, robustness as to fluid seal integrity and reduced manufacturing cost.
BRIEF SUMMARY OF THE INVENTION
The present invention provides a servo motor actuated bypass type rotary valve which has a simplified construction eliminating fasteners for the assembly of servo motor unit and valve body, has linearity of flow response and which is low in manufacturing cost and reliably sealed and thus robust in service. The servo motor actuated valve of the present invention employs a cylindrical valving chamber with a partially valving member having a partially cylindrically-shaped valving surface rotated over face seals provided at each of the valve outlets. The servo motor is operative to rotate the valving member from a position blocking one outlet to a position at least partially blocking the outlet and progressively to a position fully opening the one outlet and blocking the remaining outlet. The valve body has the valving member and face seals for each of the outlet ports assembled into the valving chamber as a subassembly and an annular seal ring is provided between the valving member and the housing. The servo motor housing is then attached to the body subassembly by spin welding the housing onto the valve body about the valving member. Subsequently the motor and gear train are assembled into the housing which is closed over the motor and gear drive by a cover welded to the housing.
The valve of the present invention thus provides a linearly responding diverter valve having a simplified assembly, low cost with seal integrity for the valve body and valving chamber which employs spin welding for attachment of the servo motor to the valve body.
REFERENCES:
patent: 4844112 (1989-07-01), Pick et al.
patent: 6029685 (2000-02-01), Carruth
Eaton Corporation
Fox John
Johnston Roger A.
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