Wiper seal for a ball screw actuator

A wiper seal assembly configured for sealing a ball screw actuator, wherein the ball screw actuator is configured to have an outer housing with a shaft disposed therein, wherein both the outer housing and the shaft are disposed about a longitudinal axis, and a plurality of roller balls are movably captured within a roller ball screw thread, the roller ball screw thread having an outer helical raceway divided by an outer helical crest which is formed in an inside surface of the outer housing and an inner helical raceway divided by an inner helical crest which are formed in the outer surface of the shaft, the wiper seal assembly comprising:

• an annularly shaped resilient seal element disposed about the longitudinal axis configured to separate a grease side from an environmental side;
• and
• an annularly shaped internal support disposed about the longitudinal axis and disposed at least partially within the seal element;
• wherein the seal element comprises:
• a first arcuately-edged surface comprising a first flat surface with a first arcuate edge, wherein the first arcuate edge is configured to be disposed in and adjacent the inner helical raceway of the shaft, and wherein the first flat surface is configured to be parallel with the longitudinal axis and exposed on the environmental side;
• a first arcuate lip extending from the first arcuate edge towards the environmental side and configured to make contact with the inner helical raceway of the shaft;
• a first tapered backside extending away from the first flat surface in an opposite direction of the first arcuate lip, the first tapered backside configured to draft away from the inner helical raceway as it moves further from the first flat surface;
• a second arcuately-edged surface comprising a second flat surface with a second arcuate edge, wherein the second arcuate edge is configured to be disposed in and adjacent the inner helical raceway of the shaft, and wherein the second flat surface is configured to be parallel with the longitudinal axis and exposed on the grease side;
• a second arcuate lip extending from the second flat surface towards the grease side and configured to make contact with the inner helical raceway of the shaft;
• a second tapered backside extending away from the second flat surface in an opposite direction of the second arcuate lip, the second tapered backside configured to draft away from the inner helical raceway as it moves further from the second flat surface;
• an ice scraper seal facing the environmental side and configured to make contact in at least 360 degrees around the longitudinal axis to or near the inner helical crest of the shaft;
• wherein the first arcuate surface, the second arcuate surface and the ice scraper are configured to seal the environmental side apart from the grease side when the wiper seal assembly is installed in the ball screw actuator.