Patent ID: 12258968

Wherever possible, the same reference numbers will be used throughout the drawings to represent the same parts.

DETAILED DESCRIPTION OF THE INVENTION

Referencing thenFIGS.1-3, shown is the instant seal1aof the cartridge type, it being understood that the seal1aencircles the entire shaft30, formed as two halves which are set together and components for which would therefore be circumferential (FIG.3). Accordingly, “a” as used in the claims means one or more. When referenced, ‘x’ is the axis through shaft30, the view inFIG.1being in the z-y plane and the cross-sectional view inFIG.3being thus the x-y plane for instance.

Rotary subassembly21is the rotating component of seal1awith pump shaft30running against stationary subassembly20. Rotary subassembly21has a downshaft end22including end pin9and an upshaft end23relative to the location of the stuffing box or pump casing, i.e. traveling downshaft means past pump casing into pump. “Stuffing box” means the gland package but may also mean any general casing that would have a packing cavity or box to house the gland1, the gland1thus being within the casing. Therein, L-seat annular24is formed at downshaft end22to provide a seal at rotary face5thereof, which is the flat surface of the rotary subassembly21which runs against and thereby forms a seal or barrier between rotary subassembly21and stationary subassembly20. Rotary face5and stationary face6(below) are each preferably made of solid silicon carbide, tungsten carbide or carbon, thus the instant seal1ahas a monolithic design.

Rotary subassembly21includes a sleeve3packed against and underlying the L-seat annular24adapted to be in sealing disposition with the pump shaft30. An outer surface along sleeve3forms part of the boundary of inner seal cavity25. The sleeve3can be coated with a chrome oxide coating to inhibit premature failure. To aid in the seal, a primary o-ring16is inverted within the sleeve3as shown. “Inverted” means along the shaft-facing side of sleeve3such that the primary o-ring16is in sealing disposition between shaft30and rotary subassembly21. A secondary o-ring15slightly upshaft from primary o-ring16is seated within L-seat annular24at sealing face31. A spring17abuts stationary seal ring27, preferably at bottom portion of gland plate1, to thereby impart an axial load against the stationary seal face6in the absence of hydraulic pressure from the pump fluid. A thrust disk7towards the top of gland plate1helps support the fluid load, disposed between stationary seal ring27and bushing section26of gland plate1. Thrust disk7aids as an anti-rotation device for the stationary seal face6and the lug drive design reduces stress on faces during upset conditions and heavy torque loads. End pin9is the coupling member for the thrust disk2and bushing section26.

The stationary subassembly20is for attachment to the stuffing box or casing of the pump (not shown). Stationary subassembly20includes gland1, which has a front face1cand a back face1band a gland lip28extending from the back face1b. Stationary subassembly20defines inner seal cavity25sealed in part by tertiary o-ring14disposed between the front face1cof gland plate1and stationary seal ring27of gland plate1. Stationary seal ring27has stationary face6sealing against sleeve7as shown. Back up ring8is adjacent to tertiary o-ring14to aid in sealing off inner seal cavity25, especially upon wear of tertiary o-ring14. Upshaft, gland plate1is fastened to stuffing box (not shown) and can be preset using drive screws12. Setting clip10fixes the gland1upon locating. Setting clip10is placed over gland lip28which integrally extends axially from gland1as shown.

A lip seal19is formed under gland1adjacent to bushing section26. As shown, lip seal19is cup-shaped in cross-section forming an annular pocket34. Lip seal19is a close-fit tolerance seal preferably made of the flouro-rubber FKM. FKM lip seal19prevents lubricant from leaking out from the seal1a. Lip seal19also acts as a secondary lubricant contained in the seal1a. A circlip18is disposed behind lip seal19within gland1under gland lip28as shown (and thus below setting clip10). Circlip18prevents the lip seal19from coming unseated.

Drive collar2is at upshaft end23designed to fit around shaft30, set by flat head set screw11. Drive collar2maintains the sealing relationship of sealing face19aunder lip seal19by, in part, prohibiting axial movement, pressing against spring17to impart the axial load against stationary face6.

Now downshaft (downshaft end22), circumferentially disposed scroll4, also termed herein contra-flow scroll4, is a close-tolerance machined retainer crimped onto the downshaft end22of rotary subassembly21using set screw29. The distal end4aof scroll4overlaps L-seat annular24as shown. Outer surface4bof the scroll4is formed with intermittent peaks and valleys, i.e. notched, arranged in a spiraling fashion around the x-axis, thereby forming a spirally-arranged, ridged outer surface4b. The scroll4acts as a fluid retainer and changes the environment by creating a low-pressure area33upshaft therefrom around the respective seal faces. More particularly, the scroll4is crimped onto the sleeve3of the rotary subassembly21and has a notched (or ridged) outer surface4bspirally-arranged on its outer diameter (O.D.) to draw fluid away from the seal faces, thereby drawing a vacuum from the fluid thereon and creating a low pressure area33. Allowing for the operation at low differential pressures optimizes seal life.

A lubricant system (not shown) provides external lubrication through quench port32. Depending on the seal application, the lubricant is a clean external fluid selected from the group consisting of silicone oil, mineral oil, propylene glycol and isopropyl alcohol. The lubricant (not shown) in combination with the lip seal19maximizes lubrication supply.

While the invention has been described with reference to one or more embodiments, 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. In addition, all numerical values identified in the detailed description shall be interpreted as though the precise and approximate values are both expressly identified.