Modular electro-mechanical rotary valve with activated seal interface

[0001] Example aspects described herein relate to electro-mechanical rotary valves for use within fluid cooling systems of vehicular powertrains.

[0002] As fuel economy becomes paramount in the transportation industry, efforts have increased to achieve higher internal combustion (IC) engine efficiencies and to seek alternative powertrains. Coolant valves are well known and can be arranged to provide coolant flow control for temperature management of various powertrain components including internal combustion engines, transmissions and various components of hybrid electric and fuel cell vehicles.

[0003] A portion of coolant valves are electro-mechanical in design, incorporating an actuator assembly that interfaces with a mechanical rotary valve body to provide a controlled flow of coolant to a selected powertrain component or system. An electric motor, controlled by the engine control unit, is often employed within the actuator assembly of the electro-mechanical rotary valve (EMRV) to achieve any desired angular position of the rotary valve body. A transmission or gear train can be utilized between the electric motor and rotary valve body. An injection molded plastic outer housing is typically used for an EMRV that is often mounted directly on either a cylinder head or cylinder block of the IC engine. The use of plastic provides a light-weight solution to fulfill complex outer housing design specifications that are required for mounting and sealing the EMRV to the engine, providing connections for hoses, and guiding and sealing the internal rotary valve. The outer housing must be able to withstand the rigors of a vibrating IC engine, which include large temperature fluctuations and exposure to dust, water, and salt. Additionally, all of the fasteners for either mounting or sealing of the hoses must be accessible within a crowded IC engine compartment.

[0004] Due to these design requirements and rigorous environment, the outer housing is often one of the higher priced components of the EMRV and also contributes to many failure modes that could occur. Amongst all of the components of the EMRV, the outer housing typically requires the most time and effort to achieve a production-worthy design. A new design for an EMRV is needed that addresses these shortcomings while maintaining critical functions for current and future applications.

[0005] A modular electro-mechanical rotary valve (EMRV) is provided that eliminates a traditional outer housing and instead utilizes a mating cavity integrated within a powertrain component. “Modular” describes the scalability, flexibility, and simplicity of the modular EMRV that can easily be installed and removed as a unit within the mating cavity, which reduces packaging space and component cost while increasing robustness and serviceability.

[0006] The modular EMRV includes a valve enclosure, at least one rotary valve body with at least one fluid pathway, and an actuator assembly. The valve enclosure includes at least one inlet, at least one outlet, and a hollow center. At least one exterior seal interface is arranged on at least one of the at least one inlet or the at least one outlet to sealingly engage with at least one interior seal interface of the mating cavity. At least one seal may be present between the at least one exterior seal interface and the at least one interior seal interface. The at least one rotary valve body, disposed within the hollow center of the valve enclosure, includes at least one fluid pathway and an actuator interface. The actuator assembly can be located at a first end and the at least one outlet can be located at a second end of the valve enclosure. The at least one inlet can be radially arranged on the valve enclosure.

[0007] In one example embodiment of a modular EMRV, either or both of the at least one inlet and the at least one outlet can have a seal interface housing, configured with the at least one exterior seal interface, that moves longitudinally within a transverse through-bore arranged on the valve enclosure. Displacement of the seal interface housing within the transverse through-bore is accomplished by actuation of at least one cam follower arranged on the seal interface housing. The at least one cam follower is actuated by a cam groove arranged on at least one leg of a cam leg portion that extends from the actuator assembly. The at least one cam leg can be received and guided by at least one cam leg reception channel that extends longitudinally from a first end of the valve enclosure. The cam groove can include a retention portion that, when engaged with the cam follower, achieves a first transport position of the seal interface housing, defined by a first radial distance. The cam groove can also include a ramp portion that, when engaged with the cam follower, achieves a second installed position of the seal interface housing, defined by a second radial distance that is greater than the first radial distance.

[0008] The actuator assembly, engaged with the actuator interface of the at least one rotary valve body, includes an actuator that rotationally actuates the at least one rotary valve body to achieve any desired angular or rotational position. The actuator assembly may also include a gear train arranged between the actuator and rotary valve body, and a drive shaft arranged between the gear train and rotary valve body, with a first end of the drive shaft engaged with the gear train and a second end engaged with the rotary valve body. Continuously variable angular positions of the at least one rotary valve body are possible to manage the fluid flows and subsequent temperatures of a fluid-cooled system. For a modular EMRV with two inlets and a single rotary valve body having a single lobe configured with a first fluid pathway and a second fluid pathway, potential rotational positions could include: a first rotational position of the rotary valve body that allows fluid flow from the first and second inlets to the outlet; a second rotational position of the rotary valve body that prevents fluid flow from the first and second inlets to the outlet; and, a first intermediate position that allows fluid flow from one of the first or second inlet to the outlet, and prevents fluid flow from the other of the first or second inlet to the outlet.

[0009] The mating cavity for the modular EMRV can be configured within but not limited to a powertrain component such as a cylinder head or cylinder block of an internal combustion engine or a transmission housing of a vehicle drivetrain. The mating cavity can extend inwardly or protrude outwardly from an outer wall of the powertrain components or any receiving structure. The mating cavity serves as a fluid terminal for intersecting fluid flow paths that interface with the valve enclosure of the modular EMRV; the flow of fluid within each of these fluid flow paths is managed by the angular position of the at least one rotary valve body disposed within the valve enclosure. The mating cavity can be cylindrical in shape.

[0030] Identically labeled elements appearing in different figures refer to the same elements but may not be referenced in the description for all figures. The exemplification set out herein illustrates at least one embodiment, in at least one form, and such exemplification is not to be construed as limiting the scope of the claims in any manner. Certain terminology is used in the following description for convenience only and is not limiting. The words “inner,” “outer,” “inwardly,” and “outwardly” refer to directions towards and away from the parts referenced in the drawings. Axially refers to directions along a diametric central axis. Radially refers to directions that are perpendicular to the central axis. The words “left” and “right” designate directions in the drawings to which reference is made. The terminology includes the words specifically noted above, derivatives thereof, and words of similar import.

[0031] Referring to FIG. 14, a portion of a first prior art electro-mechanical rotary valve (EMRV) 500 is shown that includes an outer housing assembly 510 having a first inlet flange 514A, a second inlet flange 514B, a third inlet flange 514C, and an outlet flange 518, all radially arranged on a cylindrical outer housing 512. Separate first, second, and third inlet pipe components 516A-516C and an outlet pipe component 520A are attached to their respective flanges 514A-514C, 518. An additional outlet pipe component 520B is attached to an end of the outer housing 510. Hoses (not shown) extend from each of the inlet and outlet pipe components to various cooling system destinations to complete an engine cooling circuit.

[0032] Now referring to FIG. 15, a portion of a second prior art EMRV 600 is shown with an outer housing 610 configured with mounting features 612A-612G that attach the EMRV 600 to a mounting base of a powertrain component (for example, an IC engine, transmission or differential) or any other receiving structure. The outer housing 610 is also configured with an external sealing interface 614 to ensure that leakage does not occur between the EMRV 600 and the component or mounting surface upon which it is mounted. The outer housing 610 is typically injection-molded out of an expensive plastic material that can withstand extreme temperature fluctuations, and exposure to ethylene glycol or engine coolant in a vibrating and corrosive environment. The complexity of the outer housing 610 is significant, and therefore the design of the injection mold tooling is complex and requires significant development time and cost to incorporate many diverse exterior features while also providing interior features that require tight tolerances. Additionally, the packaging space required for the thermal management valve assembly 600 and its corresponding hoses is significant. A new design for an EMRV is needed that reduces the complexity and cost of the outer housing while lowering the packaging space.

[0033] FIGS. 1 through 5 and 11A through 13B show an example embodiment of a modular EMRV 10 that provides a simplified design that eliminates the use of a traditional outer housing. The modular EMRV 10 includes a valve enclosure 12, a rotary valve body 14, and an actuator assembly 16. The valve enclosure 12 includes a first inlet 20A, a second inlet 20B, a first transverse through-bore 27A, a second transverse through-bore 27B, an outlet 22, a central axis 18, and a hollow center 26. The first and second inlets 20A, 20B are radially arranged and the outlet 22 is located at a second end of the valve enclosure 12, however various positions of these elements on the valve enclosure 12 are possible. One skilled in the art of EMRVs would understand that it would be possible to switch the location of the outlet 22 with either one of the inlets 20A, 20B such that the outlet is radially arranged on the valve enclosure 12 and either the first or second inlet 20A, 20B is arranged on the second end 25 of the valve enclosure 12. Various shapes of the valve enclosure 12 are also possible to accommodate different applications having a wide array of packaging constraints.

[0034] The first inlet 20A includes a first inlet seal housing 46A disposed within the first transverse through-bore 27A, and the second inlet 20B includes a second inlet seal housing 46B disposed within the second transverse through-bore 27B. The shape of the first and second transverse through-bores 27A, 27B can be of any suitable form to support the first and second inlets 20A, 20B. The first inlet seal housing 46A is configured with a first exterior seal interface 28A, a first cam follower 48A, and a second cam follower 48B. The second inlet seal housing 46B is configured with a second exterior seal interface 28B, a third cam follower (not shown), and a fourth cam follower 48D. Optional first and second seals 29A, 29B can be arranged on the respective first and second inlet seal housings 46A, 46B, to engage first and second exterior seal interfaces 28A, 28B. Sealing interface designs other than what is shown are also possible that serve the purpose of sealing each of the first and second inlets 20A, 20B.

[0035] The rotary valve body 14, actuated by the actuator assembly 16, is disposed within the hollow center 26 of the valve enclosure 12. The rotary valve body 14 includes an actuator interface 24 and a lobe 17 configured with a first fluid pathway 36A and a second fluid pathway 36B. The actuator assembly 16, arranged at a first end 23 of the valve enclosure 12, includes an actuator in the form of an electric motor 34; other forms of actuators can also be utilized. Rotary motion of the electric motor 34 is transferred to the rotary valve body 14 by a gear train 32 and a drive shaft 30 engaged with the rotary valve body 14. A first end 31 of the drive shaft 30 engages the gear train 32, while a second end 33 of the drive shaft 30 engages the actuator interface 24 of the rotary valve body 14. Those skilled in the art of EMRVs are aware that other forms of actuator assemblies are possible such as those that eliminate use of the gear train 32 and/or the drive shaft 30.

[0036] The arrangement of the first and second exterior seal interfaces 28A, 28B on the respective first and second inlets 20A, 20B provides for a smaller packaging space for the modular EMRV 10. The first and second inlets 20A, 20B do not require axial spacing along the length of the valve enclosure 12, but only angular spacing at a given axial location; thus, the overall length of the valve enclosure 12 can be reduced. This inlet arrangement is further facilitated by the application of first and second fluid pathways 36A, 36B arranged within a single lobe 17 of the rotary valve body 14, as opposed to having two lobes, each configured with a single fluid pathway. Further variations of the modular EMRV 10 could include additional inlets, facilitated by a third fluid pathway applied to the lobe 17 of the rotary valve body 14 or multiple lobes arranged on the rotary valve body 14, each lobe configured with one or more fluid pathways.

[0037] FIGS. 7 through 10B show different structural applications of how a single or multiple modular EMRVs 10 can be applied to various applications. Two modular EMRVs 10 are shown in FIG. 8, each placed within a first and a second mating cavity 50A, 50B arranged on an engine block 100 of an internal combustion engine. FIGS. 9 and 10A show additional arrangements of modular EMRVs 10 within a cylinder head 200 of an internal combustion engine and a transmission housing 300 of a vehicle, respectively. The first mating cavity 50A, hereafter referred to as “the mating cavity 50A”, serves as a fluid terminal for at least two intersecting fluid flow paths, with the modular EMRV 10 regulating the amount of fluid flow. The mating cavity 50A can be formed on or within the engine block 100, cylinder head 200, or transmission housing 300 (or any powertrain component) by current state-of-the-art casting and machining methods. The arrangements shown in FIGS. 8 through 10B exemplify the versatility of the modular EMRV 10, having a capability to be placed in multiple locations in various orientations according to packaging and functional specifications of an application. With the modular EMRV 10, optimum locations can be selected to manage localized cooling zones, as opposed to selecting a single location that could require extra effort and cost to ensure that all controlled coolant passages are routed to that location. Additionally, the modular EMRV 10 and mating cavity 50A arrangement eliminates the need for hoses for external routing of coolant passages, as all coolant passages are internally routed to the mating cavity 50A.

[0038] FIG. 10A shows a third mating cavity 50C that extends inside of the transmission housing 300, as opposed to earlier described designs in FIGS. 8 and 9 where the mating cavity protrudes outwardly from an outer wall of the engine block 100 and cylinder head 200, respectively. A cross-sectional view shown in FIG. 10B provides further details of the third mating cavity 50C that includes a first inlet flow passage 54A′, a second inlet flow passage 54B′, and an outlet flow passage 56′.

[0039] For proper installation of the modular EMRV 10 within the mating cavity 50A, sealing isolation of the first and second inlets 20A, 20B is required to prevent cross-talk or communication of the two inlet flow passages 54A, 54B. Sealing isolation can be accomplished by the first exterior seal interface 28A sealingly engaging a third interior seal interface 58A of the mating cavity 50A and the second exterior seal interface 28B sealingly engaging a fourth interior seal interface 58B of the mating cavity 50A. Optional first and second seals 29A, 29B can be arranged between the first and second exterior seal interfaces 28A, 28B and the respective third and fourth interior seal interfaces 58A, 58B.

[0040] For the example embodiment of the modular EMRV 10 shown in FIGS. 1 through 5, engagement of the first and second exterior seal interfaces 28A, 28B with the third and fourth interior seal interfaces 58A, 58B of the mating cavity 50A is enabled by a cam groove and cam follower system. The actuator assembly 16 includes a cam leg portion 42 having a first, second, third, and fourth longitudinally extending cam legs 42A-42D. The four cam legs 42A-42D are received by respective first, second, third, and fourth reception channels 44A-44D that extend longitudinally from a first end 23 of the valve enclosure 12. Referring now to FIG. 12A that shows a cross-sectional view that cuts through the second and fourth legs 42B, 42D, each of the four legs 42A-42D is configured with a first (not shown), second 60B, third (not shown), and fourth 60D cam groove, respectively. The first and second 60B cam grooves engage and guide the respective first and second cam followers 48A, 48B arranged on the first inlet seal interface housing 46A; the third and fourth 60D cam grooves engage and guide the respective third (not shown) and fourth 48D cam followers. Given the angled form of the cam grooves, as the four cam legs 42A-42D penetrate deeper within their respective reception channels 44A-44D, the first and second seal interface housings 46A, 46B are displaced radially outward from the central axis 18 of the valve enclosure 12.

[0041] Referring specifically to the second cam groove 60B of FIGS. 12A and 13A, two portions are present to facilitate different radial positions of the first seal interface housing 46A within the first transverse through-bore 27A. A retention portion 62B holds the second cam follower 48B in a first transport position, as shown in FIG. 12A, such that the second cam leg 42B and the second cam follower 48B are locked together. This prevents the first inlet seal interface housing 46A from falling out of the first transverse bore 27A and the second cam leg 42B from sliding out of the second reception channel 44B of the valve enclosure 12. The first transport position is ideal for transporting the modular EMRV 10 to a manufacturing facility for assembly within the mating cavity 50A of any of the previously described powertrain components such as an IC engine or transmission—or any other receiving structure. FIG. 12B shows the first transport positions of the first and second inlet seal housings 46A, 46B relative to the central axis 18 of the valve enclosure 12, denoted by a first radial distance Rt. It should be noted that in the first transport position the first and second exterior seal interfaces 28A, 28B of the respective first and second inlet seal housings 46A, 46B are not sealingly engaged with the third and fourth interior seal interfaces 58A, 58B of the mating cavity 50A.

[0042] After insertion of the modular EMRV 10 within the mating cavity 50A while in the first transport position, the cam legs 42A-42D are displaced further within the respective reception channels 44A-44D, until an abutment surface 15 of the actuator assembly 16 engages a mounting surface 55 of the mating cavity 50A. With reference to FIGS. 13A and 13B, further insertion of the second cam leg 42B within the second reception channel 44B causes a ramp portion 62B of the second cam groove 60 to urge the second cam follower 48B upward, displacing the first inlet seal housing 46A to a second installed position. FIG. 13B shows the second installed positions of the first and second inlet seal housings 46A, 46B relative to the central axis 18 of the valve enclosure 12, denoted by a second radial distance Ri. It should be noted that the second radial distance Ri of the second installed position is greater than the first radial distance Rt of the first transport position.

[0043] To complete the installation, attachment apertures 13A-13D arranged on the actuator assembly 16 are aligned with reception apertures 53A-53D arranged on the mating cavity 50A to facilitate an appropriate rotational position and attachment of the modular EMRV 10 by fasteners (not shown); other means of attachment are also possible. In this rotational position, the first inlet flow passage 54A of the mating cavity 50A is aligned with the first inlet 20A of the valve enclosure 12, the second inlet flow passage 54B of the mating cavity 50A is aligned with the second inlet 20B, and the outlet flow passage 56 of the mating cavity 50A is aligned with the outlet 22 arranged on the second end 25 of the valve enclosure 12.

[0044] FIGS. 1 through 4 capture a cam groove and cam follower system that utilizes four cam legs 42A-42D, four cam grooves 60A-60D, and four cam followers 48A-48D; however, variations to this system are possible. For example, it may be possible to utilize only one cam groove (arranged on one cam leg) and one cam follower for each inlet or outlet seal housing. Additionally, the form of the cam groove and followers may be different than what is shown in the figures.

[0045] Referring to FIGS. 6A and 6B, an example embodiment of a modular EMRV 10′ is shown that does not use the cam groove and cam follower system previously described for the modular EMRV 10 of FIGS. 1 through 5. First and second inlets 20A′, 20B′ are arranged on the valve enclosure 12′ of the modular EMRV 10′. As in the previously described example embodiment, the first inlet 20A is configured with a first exterior seal interface 28A′ that sealingly engages the third interior seal interface 58A of the mating cavity 50A. Likewise, the second inlet 20B′ is arranged with a second exterior seal interface (not shown) that sealingly engages the fourth interior seal interface 58B of the mating cavity 50A. Optional first and second seals 29A′, 29B′ can be arranged between the respective exterior and interior seal interfaces. Given the stationary position of the first and second inlets 20A′, 20B′, proper sealing is achieved by simply inserting the valve enclosure 12′ within the mating cavity 50A until alignment between the respective seal interfaces occurs.

[0046] Referring to FIGS. 11A through 11C, three rotational positions of the rotary valve body 14 are shown for the previously described modular EMRVs 10, 10′ that result in different fluid flows from the first and second inlets 20A, 20B to the outlet 22. FIG. 11A shows a first rotational position of the rotary valve body 14 that allows fluid flow from both the first and second inlets 20A, 20B to the outlet 22. In the first rotational position, a portion of the first fluid pathway 36A of the rotary valve body 14 is in communication with the first inlet 20A, and a portion of the second fluid pathway 36B is in communication with the second inlet 20B to facilitate flow from the first and second inlets 20A, 20B to the outlet 22. FIG. 11B shows a second rotational position of the rotary valve body 14 that prevents fluid flow from the first and second inlets 20A, 20B to the outlet 22. In the second rotational position, no portions of the first and second fluid pathways 36A, 36B of the rotary valve body 14 are in communication with either the first or second inlets 20A, 20B, therefore, no fluid flow occurs. FIG. 11C shows a first intermediate rotational position of the rotary valve body 14 that allows fluid flow from the first inlet 20A to the outlet 22, but prevents fluid flow from the second inlet 20B to the outlet 22. In the first intermediate rotational position, the first fluid pathway 36A of the rotary valve body 14 is in communication with the first inlet 20A which allows fluid flow from the first inlet 20A to the outlet 22, and no portions of the first and second fluid pathways 36A, 36B are in communication with the second inlet 20B, therefore no flow from the second inlet 20B occurs. The previously described rotational positions are only a sampling of the positions and flow states that are possible. One that is skilled in the art of EMRVs would understand that additional fluid flow combinations are possible such as an alternative first rotational position that prevents fluid flow from the first inlet 20A to the outlet 22, but allows fluid flow from the second inlet 20B to the outlet 22.

[0047] The previously described modular EMRVs 10, 10′ provide a simplified, low-cost design that eliminates a traditional outer housing and the typical failure modes that often occur with plastic outer housings, such as cracking and leaking. The cumbersome packaging space typically associated with an EMRV is significantly reduced by the utilization of the mating cavity 50A that potentially eliminates all or most of the coolant hoses required for transport of engine coolant to various regions or parts of a powertrain system. The mating cavity 50A can be formed on or within a powertrain component or any other receiving structure by current state-of-the-art casting and machining methods. The unitized design of the modular EMRVs 10, 10′ facilitates improved serviceability and adaptability to a diverse array of fluid systems.

[0048] In the foregoing description, example embodiments are described. The specification and drawings are accordingly to be regarded in an illustrative rather than in a restrictive sense. It will, however, be evident that various modifications and changes may be made thereto, without departing from the broader spirit and scope of the present invention.

[0049] In addition, it should be understood that the figures illustrated in the attachments, which highlight the functionality and advantages of the example embodiments, are presented for example purposes only. The architecture or construction of example embodiments described herein is sufficiently flexible and configurable, such that it may be utilized (and navigated) in ways other than that shown in the accompanying figures.

[0050] Although example embodiments have been described herein, many additional modifications and variations would be apparent to those skilled in the art. It is therefore to be understood that this invention may be practiced otherwise than as specifically described. Thus, the present example embodiments should be considered in all respects as illustrative and not restrictive.