The present invention relates generally to fluid seals for use with relatively rotatable members, such as shafts and the like.
Fluid seals assemblies of various types are used in numerous applications including and not limited to sealing vehicular engine crankshafts, transmission shafts, bearing lubrication systems, compressor shaft support assemblies, and the like. The fluid seal assembly is designed to retain and seal oil or grease in a predetermined location for lubricating the shaft and to prevent ingress of environmental contaminants.
Typical fluid seal assembly includes a casing unit, a flexible sealing member having a sealing lip adapted to engage against a sealing surface of a relatively rotatable member, such as the shaft. The flexible sealing member includes a body portion extending to an annular flex portion of reduced cross-sectional thickness bonded to the metal case member and located intermediate the seal lip and metal case. The purpose of this flex section is to allow the seal lip to stay in continuous, intimate contact with the shaft it is to seal despite any lack of concentricity between the relatively rotating members, e.g. the rotating shaft and the stationery engine block into which the annular metal case member is installed.
It is important to constantly retain and seal oil or grease in a predetermined location for lubrication of the shaft and to prevent ingress of environmental contaminants. There are numerous prior art seal assembly designs, which are effective to return oil or other lubricant to the sealed cavity upon rotation of the shaft. In either case, relative motion between the shaft and the seal assembly serves to “pump” the oil, grease, or other sealed fluid back into the sealed region defined between the shaft and the seal assembly.
The art is replete with various prior art references related to numerous seal designed adaptable to retain and seal oil or grease in a predetermined location for lubrication the shaft. These prior art references include and are not limited to U.S. Pat. No. 4,501,431 to Peisker et al., U.S. Pat. No. 4,667,968 to Nash et al., U.S. Pat. No. 4,969,653 to Breen, U.S. Pat. No. 6,213,476 to Chandler et al., U.S. Pat. No. 6,620,361 to Longtin et al., and U.S. Pat. No. 6,736,404 to Shuster.
The U.S. Pat. No. 4,501,431 to Peisker et al., teaches a seal assembly including a casing unit, a resinous sealing ring unit, which is secured to the portion of the casing unit by an annular elastomeric bonding and a locating collar. A seal ring includes an active surface and a reverse surface. A single spiral groove or multiple grooves are formed along the active surface of the inner diameter portion of the ring. These grooves are hydrodynamic pumping elements whose general nature of operation is known to those skilled in the oil seal art.
The seal assembly taught by the U.S. Pat. No. 4,501,431 to Peisker et al. has several problems. The hydrodynamic features, such as spirals, are formed into the wafer portion of the seal, which contacts with the countersurface, i.e. the rotatable shaft. The location of the spirals or grooves results in clogging of these spirals or grooves with carbonized oil thereby reducing the lifespan of the seal assembly. Another problem is static leakage of oil through these spirals or grooves.
The U.S. Pat. No. 4,969,653 to Breen teaches a seal unit including a casing unit and an annular seal body portion extending to a flexible neck portion nearest the anchored portion of the seal body. The remainder of the seal body includes a primary seal lip and a secondary seal lip. The seal body includes a series of hydrodynamic groove configurations in the form of a single spiral groove hydrodynamically formed in the seal body. These grooves function as hydrodynamic pumping elements.
Similar to the seal assembly taught by the U.S. Pat. No. 4,501,431 to Peisker et al., the seal assembly taught by the U.S. Pat. No. 4,969,653 to Breen presents the same problems. The hydrodynamic features, such as grooves, are formed into portion of the seal which contacts with the countersurface, i.e. the rotatable shaft, thereby resulting in clogging of these grooves with oil or other lubricant, which reduces of the lifespan of the seal assembly and results in static leakage of oil through these grooves.
Hence, there is a need for an improved fluid seals and methods to eliminate problems associated with prior art designs such as static leakage of oil, clogging up the seals with carbonized oil that negatively impact lifecycle of the fluid seals. The inventive concept as set forth further below improves the aforementioned prior art systems and methods.
A fluid seals assembly (the assembly) of the present invention has numerous applications including and not limited to sealing vehicular engine crankshafts, transmission shafts, bearing lubrication systems, compressor shaft support assemblies, and the like. The assembly is disposed between an outer surface, i.e. a housing or an engine block or any other part that requires application of the assembly and a rotatable member, such as, for example a shaft, wherein the assembly circumscribes the shaft and lubricated the shaft as the same rotates around the axis. The seal assembly includes a generally annular sealing member having a central portion and two axially-spaced apart side portions each extending generally radially from the central portion to define a generally annular groove. The seal assembly further includes first and second leg portions having a free end sealingly engageable with one of the shaft and the housing.
A generally annular support member is disposed within the annular groove and is configured to retain the central portion of the sealing member disposed generally against the other one of the shaft and the housing, formed with opposing inner and outer circumferential surfaces and a generally annular groove extending into one of the inner and outer circumferential surfaces, the sealing member central portion being disposed at least partially within the annular groove and the other one of the support member inner and outer surfaces being sealingly engaged with the other one of the shaft and the housing.
An advantage of the present invention is to provide an improved fluid seal assembly that eliminated problems associated with prior art designs such as static leakage of oil, clogging up the spirals with carbonized oil that negatively impact lifecycle of the fluid seals.
Another advantage of the present invention is to provide the fluid seal assembly that does not require molding.
Still another advantage of the present invention is to provide the fluid seal assembly that is cost effective in manufacturing and will lower cost of product.
Still another advantage of the present invention is to provide the fluid seal assembly design that allows more efficient process automation.
Still another advantage of the present invention is to provide the fluid seal assembly design that reduces waste of rubber materials.
Still another advantage of the present invention is to provide the fluid seal assembly design that does not require bond between structural member, i.e. support member and a rubber, i.e. a sealing member.
Still another advantage of the present invention is to provide the fluid seal assembly design that does not require any finishing procedures, other that assembly of the support member, the sealing member, disposed between the shaft and the housing.
Still another advantage of the present invention is to provide a new assembly seal, wherein a sealing lip is produced very inexpensively from a thin walled elastomeric tubing, which is cut to length and installed onto the outer diameter of the support member and then into an inner diameter of the housing.
Other advantages and meritorious features of this invention will be more fully understood from the following description of the preferred embodiment, the appended claims, and the drawings; a brief description of which follows.
The foregoing summary, as well as the detailed description of the preferred embodiments of the present invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings, which are diagrammatic, embodiments that are presently preferred. It should be understood, however, that the present invention is not limited to the precise arrangements and instrumentalities shown. In the drawings. Other advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:
Certain terminology is used in the following description for convenience only and is not limiting. The words “right”, left”, “lower”, “upper”, “upward”, “down” and “downward” designate directions in the drawings to which reference is made. The words “inner”, “inwardly” and “outer”, “outwardly” refer to directions toward and away from, respectively, a designated centerline or a geometric center of an element being described, the particular meaning being readily apparent from the context of the description. Further, as used herein, the word “connected” is intended to include direct connections between two members without any other members interposed therebetween and indirect connections between members in which one or more other members are interposed therebetween. The terminology includes the words specifically mentioned above, derivatives thereof, and words of similar import.
Referring now to the drawings in detail, wherein like numbers are used to indicate like elements throughout, a fluid seal assembly (the assembly) of the present invention is generally shown at 10 in
The assembly 10 is designed for sealing a space between the housing 14 and the rotary shaft 12 rotatable about the central axis A and disposed at least partially within the housing 14 and providing leakage protection. The assembly 10 includes a generally annular sealing member (the sealing member), generally indicated at 20 having a central portion 22 with opposing axial ends 24 and 26. The sealing member 20 includes first and second leg portions 28 and 30 each extending generally radially from the opposing axial ends 24 and 26 of the central portion 22 so as to define a generally annular groove, generally indicated at 32, between the first and second leg portions 28 and 30. Each of the first and second leg portions 28 and 30 presents an inner end 36, 38 extending generally parallel to the central axis A. Each inner end 36, 38 further presents a first sealing surface 40 and a second sealing surface 42 being axially spaced apart and sealingly engageable with an outer surface 44 of the rotary shaft 12. The generally annual sealing member 20 is formed of a generally flexible material, such as elastomer, a resin, and any other elastomeric material without limiting the scope of the present invention. The annular sealing member 20 has generally C-shaped axial cross-section, as best shown in
As best illustrated on
The assembly 10 further includes an annular support member, generally indicated at 60. The support member 60 is disposed within the generally annular groove 32 and is configured to retain the central portion 22 disposed generally about the rotary shaft 12 and engaged by the bore 18 with the first and second leg portions 28 and 30 and the central portion 22 engaging the annular support member 50 with the first sealing surface 40 and the second sealing surface 42 providing leakage protection as the rotary shaft 12 rotates around the central axis A and relative the housing 14.
The annular support member 60 is formed of a generally rigid material. The generally annular support member 60 includes inner and outer circumferential surfaces 62 and 64 and inclined side walls 68 and 70, as best shown in
Alluding to the above and without limiting the scope of the present invention, the annular support member 20 includes different embodiments. A first alternative embodiment is generally indicated at 100 in
Referring back to
An advantage of the present invention is to provide an improved fluid seal assembly 10 that eliminated problems associated with prior art designs such as static leakage of oil, clogging up the spirals with carbonized oil that negatively impact lifecycle of the fluid seals. The seal assembly 10 does not require molding and is cost effective in manufacturing thereby lowering cost of product. The manufacturing process of the seal assembly 10 reduces waste of rubber materials and does not require bond between structural member, i.e. support member and a rubber, i.e. a sealing member.
While the invention has been described with reference to an exemplary embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims