Ball screw seal

A ball screw seal assembly which includes at least one energizer and a seal body, the ball screw seal assembly being configured for being positioned in a housing groove, the seal body including at least one outer diameter lip and two inner diameter lips, the at least one outer diameter lip being configured for contacting and sealing against the housing groove, the inner diameter lips being configured for wiping or scraping an outer surface of a threaded rod including a plurality of threads, the inner diameter lips being wipers or scrapers and being spaced apart from one another, the at least one energizer being configured for energizing and thereby biasing each of the inner diameter lips radially inwardly.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a non-provisional application based upon U.S. provisional patent application Ser. No. 61/749,741, entitled “BALL SCREW SEAL”, filed Jan. 7, 2013, which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to seals, and, more particularly, to ball screw seals.

2. Description of the Related Art

Ball screw assemblies are known. Ball screw assemblies are able to translate rotational motion into linear motion. Ball screw assemblies include a housing (which can be referred to as a nut) and a threaded rod (which can be referred to as a ball screw). Anti-friction elements, such as ball bearings, can be used between the nut and the ball screw. For instance, ball bearings can be positioned in the grooves between threads of the ball screw and can also be positioned in a raceway formed by the interior surface of the nut. The interior of the nut can include a lubricant such as grease. A screw seal can be used at the end of the nut, the screw seal being positioned between the nut and the ball screw and serving to wipe contaminants from the ball screw and to keep grease or other lubricants internal for smooth, long lasting operation.

What is needed in the art is redundant wiping or scraping in a short axial space.

SUMMARY OF THE INVENTION

The present invention provides redundant wiping or scraping in a short axial space and to provide low friction, long lasting service in a variety of application conditions.

The invention in one form is directed to a ball screw seal assembly which includes at least one energizer and a seal body, the ball screw seal assembly being configured for being positioned in a housing groove, the seal body including at least one outer diameter lip and two inner diameter lips, the at least one outer diameter lip being configured for contacting and optionally sealing against the housing groove, the inner diameter lips being configured for wiping or scraping an outer surface of a threaded rod including a plurality of threads, the inner diameter lips being wipers or scrapers and being spaced apart from one another, the at least one energizer being configured for energizing and thereby biasing each of the inner diameter lips radially inwardly.

The invention in another form is directed to a ball screw seal system which includes a housing, a threaded rod, and a ball screw seal assembly, the housing including a housing groove, the threaded rod including a plurality of threads, the ball screw seal assembly being positioned in the housing groove, the ball screw seal assembly including at least one energizer and a seal body, the seal body including at least one outer diameter lip and two inner diameter lips, the at least one outer diameter lip being configured for contacting and optionally sealing against the housing groove, the inner diameter lips being configured for wiping or scraping an outer surface of the threaded rod, the inner diameter lips being wipers or scrapers and being spaced apart from one another, the at least one energizer being configured for energizing and thereby biasing each of the inner diameter lips radially inwardly and onto the outer surface of the threaded rod.

The invention in yet another form is directed to a method of using a ball screw seal assembly, the method including the steps of: providing a ball screw seal system which includes a housing, a threaded rod, and a ball screw seal assembly, the housing including a housing groove, the threaded rod including a plurality of threads, the ball screw seal assembly being positioned in the housing groove, the ball screw seal assembly including at least one energizer and a seal body, the seal body including at least one outer diameter lip and two inner diameter lips, the inner diameter lips being wipers or scrapers and being spaced apart from one another; contacting and optionally sealing the at least one outer diameter lip relative to the housing groove; energizing and thereby biasing, using the at least one energizer, each of the inner diameter lips radially inwardly and onto the outer surface of the threaded rod; and wiping or scraping, using the inner diameter lips, an outer surface of the threaded rod.

An advantage of the present invention is that a one-piece seal body having two different exclusion lips can be assembled in a much smaller space, thereby providing redundant wiping/scraping in a relatively short axial space.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings, and more particularly toFIG. 1, there is shown a ball screw seal system10according to the present invention. The ball screw seal system10includes a housing12, a threaded shaft14, and a seal assembly16. In the various figures where a cross-sectional view is shown of a seal system, similar items have a multiple of 100 added to the two digit number used inFIG. 1. As in several of the drawings,FIG. 1shows a cross-section of the ball screw seal system10, more particularly, the top portion of the cross-section of the seal system10. A ball screw can be used to translate rotational motion into linear motion with little friction. As such, as threaded shaft14rotates, housing12or threaded shaft14can move linearly relative to the other.FIG. 1shows the outside of housing12, being to the right-side (where debris or other contaminants is present) and the inside of the housing12being to the left-side (where clean grease is present).

The housing12of the ball screw seal system10can be a ball assembly that acts as a nut relative to the threaded shaft14, which can act as a screw. Anti-friction elements, such as ball bearings for example, are not shown in the drawings, but it is understood that such anti-friction elements may be present in association with housing12and threaded shaft14. Housing12has an annular housing groove18. This housing groove18can be at one or both ends of housing12, each housing groove18receiving seal assembly16; the drawings show only one such end of housing12. Housing groove18receives and thereby houses seal assembly16. Housing groove18includes a profile which matches the profile of seal assembly16. Housing groove18can include one, two, or more tab recesses20to receive a tab22of seal assembly16, each tab22fitting in a corresponding tab recess20and thereby serving to prevent seal assembly16from moving (i.e., spinning, lateral movement) within housing groove18. In one example, housing groove18has only two such recesses, and seal assembly16has only two such corresponding mating tabs22. The material of housing12and thus housing groove18can be, for example, a mild steel or stainless steel; this is provided by way of example and not by way of limitation.

FIG. 1shows a portion of threaded shaft14(which can be referred to herein as a threaded rod14). It is understood that the threaded shaft14rotates about a longitudinal axis24which extends from left to right inFIG. 1. Threaded shaft14has a plurality of threads26and a plurality of grooves28. Each thread can have a flat plateau, which can be referred to as a land (the lands are provided by way of example and not by way of limitation). Each groove is between adjacent threads26. Threaded shaft14can be, for example, chrome coated (i.e., chromium plated) or carbide coated (below the coating can be, for example steel or any other suitable material); this is provided by way of example and not by way of limitation.

Seal assembly16(which can be referred to as a wiper assembly or a scraper assembly given that the primary function of the inner diameter lips42and44is wiping/scraping, as described below) has an annular ring configuration, but only a top portion of seal assembly16is shown.FIG. 1shows that seal assembly16includes a seal body30and two energizers32and34, which can also be referred to as springs30and32. Seal body30can be made of, for example, an elastomer, a plastic, a fluoroplastic, or polytretrafluoroethylene (PTFE); this is provided by way of example and not by way of limitation. Seal body30(which can also be referred to as the seal material30) can be formed by machining or molding. Seal body30includes a middle section36, two outer diameter lips38and40attached to middle section36, and two inner diameter lips42and44attached to middle section36. Each outer diameter lip38and40can optionally seal against housing groove18. Further, one outer diameter lip38(FIG. 1shows that this outer diameter lip38faces axially to the outside) can have one or more tabs22that extend radially outwardly. As indicated above, two such tabs22(by way of example and not by way of limitation) can be provided, each tab22fitting in a corresponding recess20extending radially outwardly along housing groove18. The outer diameter lips38and40can range from 0.5 mm to 0.75 mm in radial width (this dimension does not include tabs22). Inner diameter lips42and44can have a varying radial width about the circumference of seal assembly16and can range from 0.75 mm to greater than 2.0 mm (i.e., 4.0 mm). Further, the axial width of seal body30can be about 12.7 mm (0.5 inch). These dimensions are provided by way of example and not by way of limitation. Each inner lip42and44can have an inner radial surface that varies over the inner circumference to match the outer contour of threaded rod14, as indicated inFIG. 1. Thus, seal body30of the present invention advantageously provides a one-piece seal body30having two different exclusion lips (the inner diameter lips42and44which are wiper/scraper lips42and44) which can be easily assembled in a much smaller space. Seal body30can be made of all the same material. Further, axially extending through-holes through seal body30may or may not be included in seal body30; but, depending upon the design, such through-holes can defeat the purpose of keeping debris out of the interior of housing12.

Further, one or more axially extending grooves (not shown) can be formed on the outside diameter of seal body30, such grooves helping with the management of the lubricant (such as grease) in the interior of housing12. This groove may not extend all of the way from the interior of housing12to the exterior of housing12but may be formed on the interior face of the outside diameter of seal body30and extend axially only part of the way on seal body30toward the exterior of housing12. For instance, this groove may extend axially from the axial inner face (being open to the axial inner face of seal body30) toward the axial outer face (not all of the way to the axial outer face of seal body30) to a point just prior to the point that outer diameter lip38(the axial outer diameter lip) seals against the housing groove. This allows for pressure relief/backpumping. In other words, such a groove allows seal assembly16to vent something (for example, air, grease, lubricant, other pressurized media) from the inside of the nut to avoid seal assembly16from “blowing out” or “extruding” in some permanent deformation manner from the pressure. Such grooves are used to provide a channel where the pressure can act to energize a sealing lip (such as the axially inner outer diameter sealing lip) to momentarily lose contact with the housing groove wall to vent or “burp” the pressure. In another embodiment radial grooves (not shown) can be formed on the axial inner face of seal body30. Such radial grooves can be used for this pressure relief and backpumping (to prevent the aforementioned blowing out or extruding) and can be linked with, so as to communicate with, the described outside diameter grooves. The axial and/or radial grooves (which can also be referred to as radial slots or channels) help avoid “blow-by” and facilitate back pumping and pressure relieving capability. If housing groove18is configured such that housing groove18includes a radial wall on the axial outside of seal assembly16, then seal body30can include the outer diameter grooves extending from the axial outer face towards the axial inner face, as well as radial grooves on the axial outer face of seal body30; any such axial outer grooves, however, would not necessarily link up with the axial inner grooves extending from the axial inner face but may be interrupted by seal material that seals with housing groove18(however, when the “burping” occurs, the media that is burped can pass from one outer diameter groove to the other outer diameter groove in an axial direction). While these axial and/or radial grooves are described with reference toFIG. 1, it is understood that such grooves can be applied to any of the embodiments described herein.

FIG. 1shows that seal body30(which can also be referred to as a wiper body30or a scraper body30given the primary function of the inner diameter lips) thus forms two oppositely facing U-shaped recesses46and48(a U-shaped recess facing axially inwardly and a U-shaped recess facing axially outwardly). The outer diameter lip40facing axially inwardly, the inner diameter lip44facing axially inwardly, and middle section36of seal body30together form a U-shaped recess48facing axially inwardly. The outer diameter lip38facing axially outwardly, the inner diameter lip42facing axially outwardly, and the middle section36together form a U-shaped recess46facing axially outwardly. Each U-shaped recess46and48receives and holds therein a spring32and34, which can be a cantilever spring. The cantilever spring can be less expensive than a slant coil spring or another type of energizer32and34, but the same result can be achieved using a slant coil spring or another type of energizer. Springs32and34face axially opposite directions relative to one another. Stated another way, the two cantilever springs32and34are back-to-back to one another. Thus, the open portion of one spring faces axially inwardly, and the open portion of the other spring faces axially outwardly. The material of the cantilever springs can be, for example, stainless steel or Inconel® (which can be an austenitic nickel-chromium-based superalloy which can be used in high-temperature applications); this is provided by way of example and not by way of limitation. The cantilever spring can be inserted (by way of a manual process, or an automated process, or a semi-automated process) into the respective recess of the seal body30after machining the seal body30(alternatively, the spring can be overmolded by seal body30when forming seal body30by molding). Each spring32and34biases the corresponding outer diameter lip38and40radially outwardly and the corresponding inner diameter lip42and44radially inwardly. As shown inFIG. 1, the axially inner spring34uses the section of the seal body30below the heel area of the axially inner spring34to scrape threaded rod14, at scraping point52, which is in addition to the traditional (typical) scraping point50, below the front end of spring32(the focus here on what is traditional or typical is on the location of the scraping point relative to the position of the spring, not to the overall design of the spring assembly or to the number and position of springs and lips).FIG. 1points out that scraping point52is under the heel of spring34and the typical scraping point50is under the front end of spring32. Seal assembly16thus includes at least energizers32and34energize a plurality of wiper/scraper lips42and44. Positioning the axially-inner inner diameter lip44under the heel of the cantilever spring34(and the corresponding recess48), an axial length of seal assembly16which is relatively short can be achieved.

A single lip may divide into two downwardly extending subparts around the circumference of the seal body30(formed as a ring), but this lip is still a single lip because these subparts receive their configuration by being part of the same seal lip; these subparts thus do not have an independent configuration relative to one another. Thus, the wiper/scraper lips inFIG. 1are two separate lips because, while each inner diameter lip's individual configuration changes around the circumference of seal body30(formed as a ring), the two lips42and44have configurations which are independent of one another. Although the configurations of the two lips42and44are independent of one another, the configurations of the two lips42and44can be identical. The two inner diameter lips42and44face, and thus are oriented, in substantially the same direction relative to one another and thereby provide redundant wiping/scraping.

FIG. 1shows that the inner diameter lips42and44are spaced apart from one another by at least one thread. The inner diameter lips42and44can be spaced apart from one another and be positioned relative to one another such that each of the inner diameter lips42and44wipes/scrapes only a part of an adjacent groove of the ball screw and also wipes/scrape at least part of the adjacent lands of the ball screw (as shown inFIG. 1).

Seal assembly16can be installed into the housing groove18by hand-installation. Alternatively, seal assembly16can be installed in housing groove18by an automated process or by a semi-automated process (a semi-automated process can include starting the installation by hand (manually) and finishing the installation by an automated process). These alternative methods of installing seal assembly16in housing groove18are provided by way of example and not by way of limitation. During installation of seal assembly16in housing groove18, tabs22can be inserted in respective housing tab recesses20in housing12.

In use, threaded shaft14and housing12can be rotated relative to one another (for example, threaded shaft14may be rotated while housing12is fixed, or vice versa). Whether rotating or not, inner diameter lips42and44serve to wipe or scrape threaded shaft14(thus, the inside diameter lips (that is the inner diameter lips) can be referred to as wiper lips42and44or scraper lips42and44) and thereby to keep debris from the outside environment from entering the interior of housing12. That is, the primary function of seal assembly16and thus both inside diameter lips42and44serve a wiping/scraping function (to wipe and/or scrape the threaded shaft14) and thus to keep outside debris from entering into the interior of housing12. This wiping/scraping function is accomplished, at least in part, by the geometry of inside diameter lips42and44(for example, the sharp geometry, as shown in the drawings) and by arranging the majority of the forces to be on the axial outside (the air side, the exterior side) of seal assembly16, as opposed to the axial inside of seal assembly16. Secondarily, one or both of the inside diameter lips42and44, by virtue of wiping and/or scraping, can also be designed to provide a sealing function to keep grease or another lubricant (or at least much of the lubricant) from exiting the interior of housing12and departing to the outside of housing12. However, the primary function of the inner diameter lips42and44is wiping/scraping.

FIG. 2shows another embodiment of the ball screw seal system110of the present invention. The embodiment of the ball screw seal system10shown inFIG. 2is substantially similar to the ball screw seal system10shown inFIG. 1. The primary difference between the embodiment of the present invention shown inFIG. 1and the embodiment of the present invention shown inFIG. 2pertains to one of the energizers132and134. More specifically, the axially inner energizer134is a slant coil spring inFIG. 2, rather than a cantilever spring. The material of the slantcoil energizer134(which can be referred to as a slant coil spring134) can be, for example, stainless steel or Inconel® (which can be an austenitic nickel-chromium-based superalloy which can be used in high-temperature applications); this is provided by way of example and not by way of limitation. Slant coil spring134biases the corresponding outer and inner diameter lips140and144radially outwardly from slant coil spring134. Seal assembly116can be assembled, can be installed in the housing groove18, and can function similarly to the embodiment of seal assembly16described relative toFIG. 1.

FIG. 3shows yet another embodiment of the ball screw seal system210of the present invention. The embodiment of the ball screw seal system210shown inFIG. 3is substantially similar to the ball screw seal system10shown inFIG. 1. The primary difference between the embodiment of the present invention shown inFIG. 1and the embodiment of the present invention shown inFIG. 3pertains to one of the energizers232and234. More specifically, the axially inner energizer234is an O-ring inFIG. 3, rather than a cantilever spring. The material of the O-ring energizer234can be, for example, an elastomer, a plastic, a fluoroplastic, or polytretrafluoroethylene (PTFE); this is provided by way of example and not by way of limitation. O-ring234biases the corresponding outer and inner diameter lips240and244radially outwardly from O-ring234. This embodiment of seal assembly216can be assembled, can be installed in the housing groove18, and can function similar to the embodiment of seal assembly16described relative toFIG. 1.

FIG. 4shows yet another embodiment of the ball screw seal system310of the present invention. The embodiment of ball screw seal system310shown inFIG. 4is similar to the ball screw seal system10shown inFIG. 1; certain differences are highlighted herein. Ball screw seal system310includes housing12and a seal assembly316. Seal assembly316includes a seal body330with outer and inner diameter lips. Outer diameter lips338and340function similarly to the outer diameter lips38and40inFIG. 1. Inner diameter lips342and344also function similarly to the inner diameter lips42and44ofFIG. 1and can have substantially the same spacing between one another as shown inFIG. 1. Seal assembly316also includes an energizer332which can be a single flat band expander332, as shown inFIG. 5as a side profile, or a wave spring332, as shown inFIG. 6as a cross-sectional view, which is positioned in an outer radial recess of seal body330. This side profile ofFIG. 5shows that the flat band expander has a generally circular configuration and is broken at one point to allow the flat band expander to be compressed or to expand. The free ends of the flat band expander can be expanded to assemble the flat band expander into the recess of the seal body330(this assembly can be done manually or in an automated or semi-automated process). The flat band expander is an energizer332and functions to hold the inner diameter lips342and344on the threaded rod. This embodiment of seal assembly316can be installed in housing groove18similarly to the embodiment of the seal assembly16described relative toFIG. 1. The material of the flat band expander can be, for example, stainless steel, plain steel, or Inconel® (which can be an austenitic nickel-chromium-based superalloy which can be used in high-temperature applications); this is provided by way of example and not by way of limitation. Rather than having a split, the free ends of the flat band can alternatively be welded together (for example, the free ends can be welded together, and then the flat band can be installed in the outer diameter recess on the seal body330). As an alternative to what is shown inFIG. 4, seal body330can have one or more energizer recesses as shown inFIG. 1(recesses facing axially inwardly and/or outwardly), and an energizer32(as described above relative toFIGS. 1-3) can be installed in a respective such recess; thus, the seal assembly316ofFIG. 4can have the flat band expander, as well as additional energizers32and34, thereby forming a combination of what is shown inFIG. 4and what is shown inFIG. 1(orFIG. 2 or 3), for example.

FIG. 6, as mentioned above is a side profile view of energizer332in the form of wave spring332. This side profile shows that the wave spring has a wave configuration. Further, while not shown inFIG. 4 or 6, wave spring332can be pretensioned and thus be formed in a generally circular configuration with two free ends like the flat band expander ofFIG. 5and can be broken at one point to allow wave spring332to be compressed or to expand. The free ends of the wave spring can be expanded to assemble the wave spring into the recess of the seal body330(this assembly can be done manually or in an automated or semi-automated process). Wave spring332is an energizer332and functions to hold the inner diameter lips342and344on threaded rod14. This embodiment of the seal assembly316can be installed in the housing groove18similarly to the embodiment of the seal assembly16described relative toFIG. 1. The material of the wave spring can be, for example, stainless steel, plain steel, or Inconel® (which can be an austenitic nickel-chromium-based superalloy which can be used in high-temperature applications); this is provided by way of example and not by way of limitation. Rather than having a split, the free ends of the wave spring can alternatively be welded together (for example, the free ends can be welded together, and then the wave spring can be installed in the outer diameter recess on seal body330). As an alternative to what is shown inFIG. 4, seal body330can have one or more energizer recesses, as shown inFIG. 1(recesses facing axially inwardly and/or outwardly), and an energizer (as described above relative toFIGS. 1-3) can be installed in a respective such recess; thus, the seal assembly316ofFIG. 4can have wave spring332, as well as additional energizers32and34, thereby forming a combination of what is shown inFIG. 4and what is shown inFIG. 1(orFIG. 2 or 3), for example.

FIG. 7shows yet another embodiment of a ball screw seal system410of the present invention. The embodiment of ball screw seal system410shown inFIG. 7is similar to the ball screw seal system10shown inFIG. 1; certain differences are highlighted herein. Ball screw seal system410includes housing12and a seal assembly416. Seal assembly416includes a seal body430with outer and inner diameter lips. The outer diameter lips function similarly to the outer diameter lips38and40inFIG. 1. The inner diameter lips442and444also function similarly to the inner diameter lips42and44ofFIG. 1and can have substantially the same spacing between one another as shown inFIG. 1. The seal assembly416also includes a single chevron spring432which is positioned in an outer radial recess of seal body30. Chevron spring432has an angled configuration. Further, while not shown inFIG. 7, chevron spring432can be pretensioned and thus be formed in a generally circular configuration with two free ends like the flat band expander inFIG. 5and be broken at one point to allow chevron spring432to be compressed or to expand. The free ends of chevron spring432can be expanded to assemble chevron spring432into the recess of seal body430(this assembly can be done manually or in an automated or semi-automated process). Chevron spring432is an energizer432and functions to hold inner diameter lips442and444on threaded rod14. This embodiment of the seal assembly416can be installed in housing groove18similarly to the embodiment of the seal assembly16described relative toFIG. 1. The material of chevron spring432can be, for example, stainless steel, plain steel, or Inconel® (which can be an austenitic nickel-chromium-based superalloy which can be used in high-temperature applications); this is provided by way of example and not by way of limitation. Rather than having a split, the free ends of chevron spring432can alternatively be welded together (for example, the free ends can be welded together, and then the chevron spring can be installed in the outer diameter recess on the seal body430). As an alternative to what is shown inFIG. 7, seal body430can have one or more energizer recesses as shown inFIG. 1(recesses facing axially inwardly and/or outwardly), and an energizer (as described above relative toFIGS. 1-3) can be installed in a respective such recess; thus, the seal assembly416ofFIG. 7can have chevron spring432, as well as additional energizers32and34, thereby forming a combination of what is shown inFIG. 7and what is shown inFIG. 1(orFIG. 2 or 3), for example.

FIG. 8shows yet another embodiment of the ball screw seal system510of the present invention. The ball screw seal system510includes a housing12, a threaded rod14, and a seal assembly516. Seal assembly516fits in a housing groove18of housing12as described above. Seal assembly516includes a seal body530and two cantilever springs532and534. Seal body530includes two inner lips542and544which scrape and/or wipe the threaded rod (as described above) as a primary function. Seal assembly516can function and be assembled substantially similarly to the embodiment of seal assembly16shown inFIG. 1. Further, the materials of the seal assembly516can be substantially similar to what is described relative to the seal assembly16ofFIG. 1. Seal body530also forms two axially outwardly facing recesses. Each cantilever spring532and534is positioned within a corresponding recess546and548of seal body530. Each cantilever spring532and534has an open end that faces axially outwardly. The scraping action of this seal is intended to face the outside environment to keep out debris. Thus, each cantilever spring532and534faces axially to the outside. This design also provides redundant scraping/wiping (what can be described as “sealing” relative to contaminants from the outside), the two cantilever springs532and534being inline and facing the outside environment. A greater axial length is required in this embodiment since a hook tool can be required in between the two spring cavities for installation of the seal assembly16in the housing groove18and/or for removal of the seal assembly16from the housing groove18.FIG. 8shows that the inner diameter lips542and544are spaced apart by two screw threads26relative to threaded rod14.

FIG. 9shows yet another embodiment of a ball screw seal system610of the present invention. The ball screw seal system610includes a housing12, a threaded rod14, and a seal assembly616. Seal assembly616fits in a housing groove18of housing12as described above. Seal assembly616includes a seal body630and two cantilever springs632and634. Seal body630includes two inner lips642and644which scrape and/or wipe threaded rod14as a primary function at scraping points650and652. Seal assembly616can function and be assembled substantially similarly to the embodiment of seal assembly16shown inFIG. 1. Further, the materials of the seal assembly616can be substantially similar to what is described relative to the seal assembly16ofFIG. 1. Seal body630also forms two axially outwardly facing recesses646and648, which in this embodiment may be connected. Each cantilever spring632and634has an open end that faces axially outwardly. The item that sets in the mouth of spring634may be a flat band expander similar to that shown inFIG. 5. Recess648provides for added flexibility of seal assembly616. The scraping action of this seal is intended to face both direction to keep out debris from the outside environment and to scrape grease at scraping point652. Each cantilever spring632and634faces axially to the outside.

The invention in one form is directed to a ball screw seal assembly16which includes at least one energizer and a seal body30, the ball screw seal assembly16being configured for being positioned in a housing groove18, the seal body30including at least one outer diameter lip38and/or40and two inner diameter lips42and44, the at least one outer diameter lip38and/or40being configured for contacting and optionally sealing against the housing groove18, the inner diameter lips42and44being configured for wiping or scraping an outer surface of a threaded rod including a plurality of threads26, the inner diameter lips42and/or44being wipers or scrapers and being spaced apart from one another, with at least one energizer being configured for energizing and thereby biasing each of the inner diameter lips42and44radially inwardly.

The invention in another form is directed to a ball screw seal system10which includes a housing12, a threaded rod, and a ball screw seal assembly16, the housing12including a housing groove18, the threaded rod including a plurality of threads26, the ball screw seal assembly16being positioned in the housing groove18, the ball screw seal assembly16including at least one energizer and a seal body30, the seal body30including at least one outer diameter lip38and/or40and two inner diameter lips42and44, the at least one outer diameter lip38and/or40being configured for contacting and optionally sealing against the housing groove18, the inner diameter lips42and44being configured for wiping or scraping an outer surface of the threaded rod, the inner diameter lips being wipers or scrapers and being spaced apart from one another, the at least one energizer being configured for energizing and thereby biasing each of the inner diameter lips42and44radially inwardly and onto the outer surface of the threaded rod.

The invention in yet another form is directed to a method of using a ball screw seal assembly16, the method including the steps of: providing a ball screw seal system10which includes a housing12, a threaded rod, and a ball screw seal assembly16, the housing12including a housing groove18, the threaded rod including a plurality of threads26, the ball screw seal assembly16being positioned in the housing groove18, the ball screw seal assembly16including at least one energizer and a seal body30, the seal body30including at least one outer diameter lip38and/or40and two inner diameter lips42and44, the inner diameter lips42and44being wipers or scrapers and being spaced apart from one another; contacting and optionally sealing the at least one outer diameter lip relative to the housing groove18; energizing and thereby biasing, using the at least one energizer, each of the inner diameter lips42and44radially inwardly and onto the outer surface of the threaded rod; and wiping or scraping, using the inner diameter lips42and44, an outer surface of the threaded rod.