Scratch seal for ball screw actuator

Abstract

A scratch seal assembly for sealing a ball screw actuator includes a sealing element. The inner peripheral surface includes a first helical extension having a first pitch configured to be disposed within the ball screw thread. The at least one wiping bead is a second helical extension having a second pitch, extending toward the longitudinal axis, disposed at least partially above the first helical extension. The at least one wiping bead is configured to be in threaded contact with the ball screw. A cylindrical ring is in contact with the sealing element and is disposed at least partially around the sealing element. The sealing element is at least partially bonded to the cylindrical ring. The sealing element has a first coefficient of thermal expansion and the cylindrical ring has a second, different coefficient of thermal expansion.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to provisional application 63 / 481,572, filed January 25, 2023, the entire contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] The present invention relates generally to seals and, more particularly, to ball screw seals for ball screw actuators used in aerospace and industrial applications. Background Art

[0004] Ball screw actuators require seals to contain grease within the actuator. Furthermore, these seals must be able to break up external ice formation while preventing external debris from intruding (i.e., entering) the actuator and other flight systems. Current solutions have been devised that are not entirely successful in applications with high temperature fluctuations and present drag issues. The present invention overcomes these shortcomings.

[0005] Prior art publications and patents include, but are not limited to, the following: EP3392526B1; EP3428481B1; US4,905,533; US10,612,633; KR101584435B1; US6976399B2; JP4923624B2; JP4923624B2; US20140352470A1; JP3647597B2; US8025128B2; US4905533A; and EP3428481B1. Summary of the Invention

[0006] One embodiment of the present invention is a wiper seal assembly 10 configured to seal a ball screw actuator 11. A sealing element 12 is arranged in an annular manner around a longitudinal axis 13. The sealing element defines a front side 14 and an opposite rear side 15, wherein the front side and the rear side are substantially perpendicular to the longitudinal axis. The sealing element defines an outer peripheral surface 16 and an opposite inner peripheral surface 17, wherein the outer peripheral surface and the inner peripheral surface are substantially parallel to the longitudinal axis. The inner peripheral surface includes a first helical extension 18 having a first pitch 50, which extends toward the longitudinal axis. The first helical extension is configured to be capable of being disposed within a ball screw thread 19 of a shaft 20 of a ball screw actuator. The shaft is configured to be aligned along the longitudinal axis. A gap 51 is configured between the first helical extension and the ball screw thread.

[0007] The inner peripheral surface further includes at least one wiper bead 52, which is a second helical extension 53 having a second pitch 54 and extending toward the longitudinal axis. The at least one wiper bead is at least partially disposed above the first helical extension. The at least one wiper bead is configured to contact the ball screw threads of the shaft of the ball screw actuator.

[0008] A cylindrical ring 55 is annularly disposed about the longitudinal axis and extends a distance 56 along the longitudinal axis. The cylindrical ring defines a front side 57 and an opposite rear side 58, wherein the front and rear sides are generally perpendicular to the longitudinal axis. The cylindrical ring defines an outer peripheral surface 59 and an opposite inner peripheral surface 60, wherein the outer and inner peripheral surfaces are generally parallel to the longitudinal axis. The cylindrical ring contacts the sealing element and is at least partially disposed around the sealing element. The sealing element is at least partially bonded to the cylindrical ring.

[0009] In another exemplary embodiment, the sealing element may have a first coefficient of thermal expansion 61 and the cylindrical ring may have a second coefficient of thermal expansion 62. The first coefficient of thermal expansion of the cylindrical ring may be greater than the second coefficient of thermal expansion of the cylindrical ring.

[0010] In another exemplary embodiment, the sealing element may be made of an elastomer. For example, the sealing element may be made of fluorosilicone rubber, fluorovinyl methylsiloxane rubber (FVMQ), nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), fluororubber (FKM), silicone rubber (VMQ), liquid silicone resin (LSR), thermoplastic elastomer (TPE), and / or any combination thereof. The sealing element may have a Shore A hardness range of 40 to 80.

[0011] In another exemplary embodiment, the cylindrical ring can be made of metal. Alternatively, the cylindrical ring can be made of stainless steel, steel, aluminum, plastic and / or any combination thereof.

[0012] In another exemplary embodiment, the first pitch of the first helical extension and the second pitch of the second helical extension can be different. Alternatively, the first pitch of the first helical extension and the second pitch of the second helical extension can be in similar helical directions 63. Alternatively, the first pitch of the first helical extension and the second pitch of the second helical extension can be in opposite helical directions 64. Alternatively, the first pitch of the first helical extension and the second pitch of the second helical extension can be the same.

[0013] In another exemplary embodiment, the ice-breaking element 23 may be arranged in an annular shape around the longitudinal axis, the ice-breaking element defining a front side 24 and an opposite rear side 25, the front and rear sides being substantially perpendicular to the longitudinal axis. The ice-breaking element defines an outer peripheral surface 26 and an opposite inner peripheral surface 27, the outer and inner peripheral surfaces being substantially parallel to the longitudinal axis. The inner peripheral surface includes a third helical extension 28 extending toward the longitudinal axis, wherein the third helical extension is configured to be disposed within the ball screw threads of the shaft of the ball screw actuator. The third helical extension extends to the front side of the ice-breaking element, forming an ice-breaking lip 29. When the ice-breaking element is included, the sealing element is disposed adjacent to the ice-breaking element, wherein the rear side of the sealing element is adjacent to the rear side of the ice-breaking element. It will be understood from this teaching that the first helical extension is helically aligned with the third helical extension, wherein both the first and third helical extensions are configured to be disposed within the ball screw threads of the shaft of the ball screw actuator. The edge 33 of the ice-breaking lip is configured to be 0.005 inches (0.13 mm) or less from the ball screw threads of the shaft of the ball screw actuator. The sealing element and the ice-breaking element can be different materials so that they are not the same material. In addition, the ice-breaking element can include aluminum bronze and / or stainless steel.

[0014] In another exemplary embodiment, an annular bead 65 may be disposed about the longitudinal axis and extend from the front side of the sealing element.

[0015] In another exemplary embodiment, when the wiper seal assembly is installed between the housing 41 and the shaft of the ball screw actuator, the front side of the seal element is configured to be disposed toward the grease side 42 and the rear side of the seal element is configured to be disposed toward the ambient side 43 .

[0016] In another exemplary embodiment, at least one locating feature 66 may extend radially from the outer peripheral surface of the cylindrical ring to the longitudinal axis. The at least one locating feature is configured to be disposed within at least one recess 47 formed in the housing 41 and mechanically lock the rotation of the cylindrical ring and the sealing element relative to the housing.

[0017] Likewise, in another exemplary embodiment, at least one second locating feature 46 may extend radially from the outer peripheral surface of the ice-breaking element to the longitudinal axis. The at least one second locating feature is configured to be disposed within at least one recess 47 formed in the housing 41 and mechanically lock the rotation of the ice-breaking element relative to the housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention is illustrated in the accompanying drawings. In these drawings:

[0019] Figure 1 is an isometric view of an embodiment of a wiper seal assembly of the present invention;

[0020] Figure 2 It is along Figure 1 a cross-sectional view of the structure taken along line 2-2;

[0021] Figure 3 It is along Figure 2 an enlarged cross-sectional view taken along line 3-3 of FIG, now illustrating the inner shaft of the ball screw actuator;

[0022] Figure 4 It is along Figure 2 An enlarged cross-sectional view taken along line 4-4 now illustrates the housing of the ball screw actuator;

[0023] Figure 5 yes Figure 1 an enlarged cross-sectional view of the structure now showing the inner shaft and housing of the ball screw actuator and the ice breaking element;

[0024] Figure 6 yes Figure 1 An enlarged cross-sectional view of the structure of FIG. 1 now shows another embodiment of the present invention having an inner shaft and housing of a ball screw actuator and an ice breaking element;

[0025] Figure 7A yes Figure 2 The theoretical plan view of the inner peripheral surface of the sealing element shown if the inner peripheral surface is cut and flattened;

[0026] Figure 7B is similar to Figure 7A Another theoretical plan view now shows that although the first and second helical extensions have different pitches, they can be in similar helical directions;

[0027] Figure 7C is similar to Figure 7A and 7B Another theoretical plan view now shows that the first pitch of the first helical extension and the second pitch of the second helical extension can be the same pitch. DETAILED DESCRIPTION

[0028] Reference is now made to provisional application 63 / 481,572 Figure 1-6 . Figure 1 is an isometric drawing of the invention. Figure 2 yes Figure 1 Cross-sectional view of the structure. The metal ring surrounds the seal. The metal ring helps support the seal during shrinkage during cold testing. The metal ring can be made with a stainless steel sleeve for temperature extremes and corrosion resistance. The metal ring can also be made of steel, aluminum, plastic, or any combination thereof.

[0029] Inside the metal ring is an elastomeric seal, such as fluorosilicone, fluorovinyl methylsiloxane (FVMQ), nitrile (NBR), hydrogenated nitrile (HNBR), fluoroelastomer (FKM), silicone (VMQ), liquid silicone (LSR), thermoplastic elastomer (TPE), or any elastomer suitable for the application. The hardness is likely in the 40-80 Shore A range. The interior of the seal has a main helical thread that is configured to mate with the threads of the ball screw actuator, with clearance between the elastomer and the ball screw shaft.

[0030] This seal is a bi-directional pumping seal with a slight contact along a small wiper bead to help reduce friction. This seal differs from prior art designs in that it is bi-directional and has a modular design that can be customized to include an ice breaker.

[0031] This seal of the invention is bidirectional because as the ball screw shaft rotates and extends, small reverse threads wipe grease off the shaft and push it back into the grease reservoir. When it retracts, the same reverse threads wipe dust and water off the shaft and push it back toward the outside of the ball screw nut.

[0032] Figure 3 yes Figure 2 An enlarged view of a portion of the cross section now better shows the small wiping bead, which has a different pitch than the main helical thread of the ball screw actuator.

[0033] The seal of this invention is modular in design. The axial length can be adjusted to suit the available space, and ice breakers can be stacked on the ends (not shown). The number of reverse threads can be adjusted to match the needs of the application. The thread pitch can be adjusted to match the needs of the application.

[0034] An ice breaker may be included. As described above, it is stacked in series with the seal (see Figure 5 ) to provide icebreaking capability. It can also be integrated into the metal sleeve to make it a "one-piece" component (see Figure 6 ).

[0035] This invention has several novel features. It provides an airtight seal around the ball screw shaft. Furthermore, it wipes grease off the shaft and pushes it back into the grease reservoir. Similarly, it wipes dust and water off the shaft and pushes them back outside the seal.

[0036] As you can understand, the inner diameter of the metal sleeve is bonded with an elastomer. In harsh cold environments, the elastomer will contract faster than a steel sleeve, reducing interference on the shaft and the torque required to turn the shaft. Because the elastomer is bonded to the metal sleeve, the outer diameter of the elastomer cannot move. The elastomer will contract toward the "fixed" surface of the metal sleeve's inner diameter. The coefficient of thermal expansion (CTE) of the elastomer is greater than that of the metal. Therefore, the inner diameter of the seal will increase, and as the temperature decreases, the torque will decrease.

[0037] There are differences between this invention and prior art ball screw seals, which: do not provide an air seal; do not effectively retain grease; do not effectively prevent the ingress of contaminants; and significantly increase torque in extreme cold conditions.

[0038] Figure 4 A small elastomeric bead on the axial face of the seal is shown. When axial force is applied to the seal to clamp it in place, the bead creates a static seal that prevents flow out or in around the outer diameter of the seal. The shape of the bead can vary depending on the manufacturing method.

[0039] Figure 1 and Figure 2 The locating mechanism is shown at the top of each figure. The seal assembly must contain a lug (tab) or notch to interact with the ball screw nut hardware. This lug or notch keeps the seal threads oriented "in sync" with the threads on the ball screw shaft and nut.

[0040] The shapes of wiping beads and static beads can be Figure 3 and Figure 4 The full radius shown in the figure varies to a sharp "V" shape, depending on the design requirements.

[0041] Reference is now made to the drawings of the present application, which are very similar to the drawings of the '572 provisional application. Figure 1-6 An embodiment of the present invention is shown which is a wiper seal assembly 10 configured for sealing a ball screw actuator 11 . Figure 1 is an isometric view of an embodiment of the wiper seal assembly of the present invention. Figure 2 It is along Figure 1 A cross-sectional view of the structure taken along line 2-2. Figure 3 It is along Figure 2 An enlarged cross-sectional view taken along line 3-3 now illustrates the internal shaft of the ball screw actuator. Figure 4 It is along Figure 2 An enlarged cross-sectional view taken along line 4-4 now shows the housing of the ball screw actuator. Figure 5 yes Figure 1 An enlarged cross-sectional view of the structure now shows the internal shaft and housing of the ball screw actuator and the ice breaking element. Figure 6 yes Figure 1 Another embodiment of the present invention is now shown with an enlarged cross-sectional view of the structure having an inner shaft and housing of a ball screw actuator and an ice breaking element.

[0042] The sealing element 12 is arranged in an annular shape around the longitudinal axis 13. The sealing element defines a front side 14 and an opposite rear side 15, wherein the front side and the rear side are substantially perpendicular to the longitudinal axis. The sealing element further defines an outer peripheral surface 16 and an opposite inner peripheral surface 17. The outer peripheral surface and the inner peripheral surface are substantially parallel to the longitudinal axis. The inner peripheral surface includes a first helical extension 18 having a first pitch 50, which extends toward the longitudinal axis. The first helical extension is configured to be capable of being disposed within a ball screw thread 19 of a shaft 20 of a ball screw actuator. The shaft is configured to be aligned along the longitudinal axis. A gap 51 is provided between the first helical extension and the ball screw thread.

[0043] The inner peripheral surface further comprises at least one wiping bead 52, which is a second helical extension 53 having a second pitch 54 and extending toward the longitudinal axis. The at least one wiping bead is at least partially disposed above the first helical extension. The at least one wiping bead is configured to be able to contact the ball screw thread of the shaft of the ball screw actuator, such as Figure 3 Best shown.

[0044] The cylindrical ring 55 is arranged in an annular shape around the longitudinal axis and extends a distance 56 along the longitudinal axis. The cylindrical ring defines a front side 57 and an opposite rear side 58, wherein the front side and the rear side are generally perpendicular to the longitudinal axis. The cylindrical ring defines an outer peripheral surface 59 and an opposite inner peripheral surface 60, wherein the outer peripheral surface and the inner peripheral surface are generally parallel to the longitudinal axis. The cylindrical ring contacts the sealing element and is at least partially arranged around the sealing element. The sealing element is at least partially bonded to the cylindrical ring along this contact. Bonding can be achieved using an adhesive and / or a bonding agent. Bonding can also be achieved using an overmolding operation, wherein the sealing element is molded with the cylindrical (metal) ring already placed in a mold.

[0045] In another exemplary embodiment, the sealing element may have a first coefficient of thermal expansion 61 and the cylindrical ring may have a second coefficient of thermal expansion 62. The first coefficient of thermal expansion of the cylindrical ring may be greater than the second coefficient of thermal expansion of the cylindrical ring.

[0046] In another exemplary embodiment, the sealing element may be made of an elastomer. For example, the sealing element may be made of fluorosilicone rubber, fluorovinyl methylsiloxane rubber (FVMQ), nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), fluororubber (FKM), silicone rubber (VMQ), liquid silicone resin (LSR), thermoplastic elastomer (TPE), and / or any combination thereof. The sealing element may have a Shore A hardness range of 40 to 80.

[0047] In another exemplary embodiment, the cylindrical ring can be made of metal. Alternatively, the cylindrical ring can be made of stainless steel, steel, aluminum, plastic and / or any combination thereof.

[0048] In another exemplary embodiment, the first pitch of the first helical extension and the second pitch of the second helical extension may be different. Figure 2 The first pitch of the first helical extension and the second pitch of the second helical extension may be in opposite helical directions 64, as shown in FIG. Figure 2 and Figure 7A As shown in .

[0049] Figure 7A yes Figure 2 A theoretical plan view of the inner peripheral surface of the sealing element is shown, if the inner peripheral surface is cut open and flattened. This allows us to better understand how the two helical structures overlap. The first helical extension 18 is shown with a first pitch, with a flat cylindrical portion 48 disposed therebetween. The at least one wiping bead 52 is a second helical extension 53 in the opposite helical direction 64.

[0050] Figure 7B is similar to Figure 7A Another theoretical plan view of the now shows that the first and second helical extensions may be in a similar helical direction 63 although they have different pitches.

[0051] Figure 7C is similar to Figure 7A and 7B Another theoretical plan view now shows that the first pitch of the first helical extension and the second pitch of the second helical extension can be the same pitch.

[0052] In such Figure 5 and Figure 6 In other exemplary embodiments shown, the ice-breaking element 23 can be annularly arranged about the longitudinal axis. The ice-breaking element defines a front side 24 and an opposite rear side 25, wherein the front side and the rear side are generally perpendicular to the longitudinal axis. The ice-breaking element further defines an outer peripheral surface 26 and an opposite inner peripheral surface 27, wherein the outer peripheral surface and the inner peripheral surface are generally parallel to the longitudinal axis.

[0053] The inner peripheral surface of the ice breaker comprises a third helical extension 28 extending towards the longitudinal axis, wherein the third helical extension is configured to be arranged in a ball screw thread of a shaft of a ball screw actuator. The third helical extension extends to the front side of the ice breaking element to form an ice breaking lip 29.

[0054] When an ice-breaking element is included, the sealing element is disposed adjacent to the ice-breaking element, wherein the rear side of the sealing element is adjacent to the rear side of the ice-breaking element. It will be understood from this teaching that the first helical extension is spirally aligned with the third helical extension, wherein both the first and third helical extensions are configured to be disposed within a ball screw thread of the shaft of the ball screw actuator. The edge 33 of the ice-breaking lip is configured to be 0.005 inches (0.13 mm) or less from the ball screw thread of the shaft of the ball screw actuator. The sealing element and the ice-breaking element may be different materials such that they are not the same material. Additionally, the ice-breaking element may comprise aluminum bronze and / or stainless steel.

[0055] like Figure 2 and Figure 4 As best shown in FIG, an annular bead 65 may be disposed about the longitudinal axis and extending from the front side of the sealing element. The annular bead seals against a vertical surface 67 of the housing as an annular channel 68 is formed in the housing to receive the wiper seal assembly 10.

[0056] When the wiper seal assembly is installed between the housing 41 and the shaft of the ball screw actuator, the front side of the seal element is configured to be positioned toward the grease side 42 (see FIG. Figure 4 ), and the rear side of the sealing element is configured to be disposed toward the ambient side 43 (see Figure 5-6 ).

[0057] At least one locating feature 66 may extend radially from the outer peripheral surface of the cylindrical ring to the longitudinal axis. The at least one locating feature is configured to be disposed within at least one recess 47 formed in the housing 41 and mechanically lock the rotation of the cylindrical ring and the sealing element relative to the housing.

[0058] Similarly, in another exemplary embodiment, at least one second locating feature 46 may extend radially from the outer peripheral surface of the ice-breaking element to the longitudinal axis. The at least one second locating feature is configured to be disposed within at least one recess 47 formed in the housing 41 and mechanically lock the ice-breaking element from rotating relative to the housing. Alternatively, the ice-breaking element may be non-rotatable relative to the scraper seal assembly, or vice versa. Furthermore, while only one locating feature is shown, one skilled in the art may utilize one, two, three, four, or any other number of locating features and corresponding recesses.

[0059] refer to Figure 4 , the embodiment shown shows how the cylindrical ring is disposed within an annular channel 69 formed in the sealing element. This then allows the outer peripheral surface 16 of the sealing element to be perfectly aligned with the outer peripheral surface 59 of the cylindrical ring. It will be understood by those skilled in the art that the annular channel 69 can be omitted so that the inner peripheral surface 60 of the cylindrical ring will adhere to the outer peripheral surface 16 of the sealing element. In addition, as Figure 2 and Figure 5As shown, the end 15 of the sealing element is aligned with the end 58 of the cylindrical ring. Again, it will be appreciated by those skilled in the art that this is not required, as each end may be extended or retracted as desired by the present invention.

[0060] Reference Signs List

[0061] 10 Scrape seal assembly

[0062] 11 Ball screw actuator

[0063] 12 Sealing elements

[0064] 13 Longitudinal axis

[0065] 14 front side

[0066] 15 rear side

[0067] 16 Peripheral surface

[0068] 17 inner peripheral surface

[0069] 18 first spiral extension

[0070] 19 ball screw thread

[0071] 20-axis

[0072] 23 ice breaking elements

[0073] 24 front side

[0074] 25 rear side

[0075] 26 Peripheral surface

[0076] 27 inner peripheral surface

[0077] 28 third spiral extension

[0078] 29 Ice Breaking Lip

[0079] 33 Edge

[0080] 41 shell

[0081] 42 Grease side

[0082] 43 Environmental side

[0083] 46 At least one second positioning feature, ice breaking element

[0084] 47At least one recess

[0085] 48 flat cylindrical portion

[0086] 50 first pitch, first helical extension

[0087] 51 gap

[0088] 52 At least one wiping bead

[0089] 53 second spiral extension

[0090] 54 second pitch

[0091] 55 cylindrical ring

[0092] 56 distance, cylindrical ring

[0093] 57 front side, cylindrical ring

[0094] 58 rear side, cylindrical ring

[0095] 59 outer surface, cylindrical ring

[0096] 60 inner surface, cylindrical ring

[0097] 61 First thermal expansion coefficient, sealing element

[0098] 62 Second thermal expansion coefficient, cylindrical ring

[0099] 63 similar spiral directions

[0100] 64 opposite spiral directions

[0101] 65 ring beads

[0102] 66 At least one locating feature, cylindrical ring

[0103] 67 vertical surface, shell

[0104] 68 annular channel, housing

[0105] 69 annular channel, sealing element

Claims

1. A wiper seal assembly configured to seal a ball screw actuator, comprising: a sealing element annularly disposed about the longitudinal axis; said sealing element defining a front side and an opposing rear side, said front side and said rear side being generally perpendicular to said longitudinal axis; the sealing element defining an outer peripheral surface and an opposing inner peripheral surface, the outer peripheral surface and the inner peripheral surface being generally parallel to the longitudinal axis; wherein the inner peripheral surface includes a first helical extension having a first pitch, the first helical extension extending toward the longitudinal axis, the first helical extension being configured to be disposed within a ball screw thread of a shaft of the ball screw actuator, the shaft being configured to be aligned along the longitudinal axis, and a gap being configured between the first helical extension and the ball screw thread; wherein the inner peripheral surface includes at least one wiping bead, the at least one wiping bead being a second helical extension having a second pitch, the second helical extension extending toward the longitudinal axis, the at least one wiping bead being at least partially disposed above the first helical extension, wherein the at least one wiping bead is configured to be capable of contacting a ball screw thread of a shaft of the ball screw actuator; a cylindrical ring annularly disposed about the longitudinal axis and extending a distance along the longitudinal axis; said cylindrical ring defining a front side and an opposing rear side, said front side and said rear side being generally perpendicular to said longitudinal axis; the cylindrical ring defining an outer peripheral surface and an opposing inner peripheral surface, the outer peripheral surface and the inner peripheral surface being generally parallel to the longitudinal axis; wherein the cylindrical ring is in contact with the sealing element and is at least partially disposed around the sealing element; and Therein, the sealing element is at least partially bonded to the cylindrical ring.

2. The wiper seal assembly according to claim 1, wherein: The sealing element has a first coefficient of thermal expansion and the cylindrical ring has a second coefficient of thermal expansion.

3. The wiper seal assembly according to claim 2, wherein: The first coefficient of thermal expansion of the cylindrical ring is greater than the second coefficient of thermal expansion of the cylindrical ring.

4. The wiper seal assembly according to claim 1, wherein: The sealing element is made of elastomer.

5. The wiper seal assembly according to claim 4, wherein: The sealing element is made of fluorosilicone rubber, fluorovinyl methylsiloxane rubber (FVMQ), nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), fluororubber (FKM), silicone rubber (VMQ), liquid silicone resin (LSR), thermoplastic elastomer (TPE) and / or any combination thereof.

6. The wiper seal assembly according to claim 4, wherein: The sealing element has a Shore A hardness range of 40 to 80.

7. The wiper seal assembly according to claim 4, wherein: The cylindrical ring is made of metal.

8. The wiper seal assembly according to claim 4, wherein: The cylindrical ring is made of stainless steel, steel, aluminum, plastic and / or any combination thereof.

9. The wiper seal assembly according to claim 1, wherein: A first pitch of the first helical extension and a second pitch of the second helical extension are different.

10. The wiper seal assembly according to claim 1, wherein: The first pitch of the first helical extension and the second pitch of the second helical extension are in similar helical directions.

11. The wiper seal assembly according to claim 1, wherein: The first pitch of the first helical extension and the second pitch of the second helical extension are in opposite helical directions.

12. The wiper seal assembly according to claim 1, wherein: The first pitch of the first helical extension and the second pitch of the second helical extension are the same.

13. The wiper seal assembly according to claim 1, wherein: The scraper seal assembly includes an ice-breaking element arranged in an annular manner around the longitudinal axis, the ice-breaking element defining a front side opposite to the rear side, the front side and the rear side being substantially perpendicular to the longitudinal axis, the ice-breaking element defining an outer peripheral surface opposite to the inner peripheral surface, the outer peripheral surface and the inner peripheral surface being substantially parallel to the longitudinal axis, wherein the inner peripheral surface includes a third helical extension extending toward the longitudinal axis, the third helical extension being configured to be capable of being arranged within a ball screw thread of a shaft of the ball screw actuator, the third helical extension extending to the front side of the ice-breaking element to form an ice-breaking lip, and the sealing element is arranged adjacent to the ice-breaking element, with the rear side of the sealing element adjacent to the rear side of the ice-breaking element.

14. The wiper seal assembly according to claim 13, wherein: The first helical extension is in helical alignment with the third helical extension, and the first and third helical extensions are each configured to be disposed within ball screw threads of a shaft of the ball screw actuator.

15. The wiper seal assembly according to claim 13, wherein: The edge of the ice breaking lip is configured to be 0.005 inches or less from the ball screw threads of the shaft of the ball screw actuator.

16. The wiper seal assembly according to claim 13, wherein: The sealing element and the ice-breaking element are not made of the same material. The ice-breaking element includes aluminum bronze and / or stainless steel.

17. The wiper seal assembly of claim 1, wherein: The wiper seal assembly includes an annular bead disposed about the longitudinal axis and extending from a front side of the sealing element.

18. The wiper seal assembly of claim 1, wherein: When the wiper seal assembly is installed between the housing and the shaft of the ball screw actuator, the front side of the sealing element is configured to be disposed toward the grease side, and the rear side of the sealing element is configured to be disposed toward the ambient side.

19. The wiper seal assembly of claim 1, wherein: The wiper seal assembly includes at least one locating feature extending radially from the outer peripheral surface of the cylindrical ring to the longitudinal axis, the at least one locating feature being configured to be disposed within at least one recess formed in the housing and mechanically lock rotation of the cylindrical ring and the sealing element relative to the housing.

20. The wiper seal assembly of claim 13, wherein: The wiper seal assembly includes at least one second locating feature extending radially from the outer peripheral surface of the ice-breaking element to the longitudinal axis, the at least one second locating feature being configured to be disposed within the at least one recess formed in the housing and mechanically lock rotation of the ice-breaking element relative to the housing.

21. A wiper seal assembly configured to seal a ball screw actuator, comprising: A sealing element is annularly arranged around the longitudinal axis, the sealing element comprising: a front side opposite the rear side, the front side and the rear side being generally perpendicular to the longitudinal axis; an outer peripheral surface opposite the inner peripheral surface, the outer peripheral surface and the inner peripheral surface being generally parallel to the longitudinal axis; wherein the inner peripheral surface includes a first helical extension having a first pitch, the first helical extension extending toward the longitudinal axis, the first helical extension being configured to be disposed within a ball screw thread of a shaft of the ball screw actuator, the shaft being configured to be aligned along the longitudinal axis, and a gap being configured between the first helical extension and the ball screw thread; wherein the inner peripheral surface includes at least one wiping bead, the wiping bead being a second helical extension having a second pitch, the second helical extension extending toward the longitudinal axis, the at least one wiping bead being at least partially disposed above the first helical extension, the at least one wiping bead being configured to be capable of contacting a ball screw thread of a shaft of the ball screw actuator; a cylindrical ring annularly arranged around the longitudinal axis and extending a certain distance along the longitudinal axis, the cylindrical ring comprising: a front side and an opposite rear side, said front side and said rear side being generally perpendicular to said longitudinal axis; an outer peripheral surface and an opposing inner peripheral surface, the outer peripheral surface and the inner peripheral surface being generally parallel to the longitudinal axis; and at least one locating feature extending radially from an outer peripheral surface of the cylindrical ring to the longitudinal axis, wherein the at least one locating feature is configured to be disposed within at least one recess formed in the housing and mechanically lock rotation of the cylindrical ring and the sealing element relative to the housing; wherein the cylindrical ring is in contact with and at least partially disposed around the sealing element, and the sealing element is at least partially bonded to the cylindrical ring; wherein the sealing element has a first coefficient of thermal expansion and the cylindrical ring has a second coefficient of thermal expansion, wherein the first coefficient of thermal expansion of the cylindrical ring is greater than the second coefficient of thermal expansion of the cylindrical ring; and The sealing element is made of an elastomer and has a Shore A hardness ranging from 40 to 80.

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