Seal and scraper assembly for ball bearing screws and the like

Claim 1

A ball screw and nut assembly comprising: a. an axially extending screw having an external helical thread and a ball receiving helical groove for the reception of a series of balls; b. a nut, having an internal helical groove, bounded by seal and scraper assembly receiving end surface portions, received on said screw; c. said helical grooves of the screw and nut forming a raceway; d. balls received in said raceway permitting relative rotation and translation of said nut and screw with relatively low frictional impedance; e. a non-rigid, resilient, annular seal ring housed by said nut in said receiving portion at each end of the nut and having an axially inboard section and an axially outboard section; f. said inboard section including a radially internal helical thread projection received by and mating with said screw groove; g. said inboard section further having a radially compressible lip integrated with its outer periphery and extending at an acute angle from said outer periphery in an axially outboard direction to engage and be radially compressed by said nut; h. a comparatively rigid, annular mount ring at each end of the nut, at least partly outboard of the seal ring, and having an axially inboard portion interfitting with said seal ring, the mount ring and seal ring having interfitting parts permitting relative axial movement of the seal ring and mount ring; i. the mount ring also having a radially internal thread received by and mating with said screw groove; and j. the mount ring and nut having parts preventing the mount ring in said receiving surface portions of the nut at each end of the nut from rotating relatively.

Claim 17

A method of sealing the threads of a ball screw and nut assembly having an axially extending screw with an external helical groove, and a nut with an internal helical groove bounded by a thread seal receiving end surface portion which is received on the screw, with the helical grooves of the screw and nut forming a raceway for balls permitting relative rotation and translation of the nut and screw, with relatively low frictional impedance, and wherein a resilient seal ring has an inboard section with a radially internal helical thread adapted to be received by the screw groove, and is provided with a rigid mount ring with a radially internal thread adapted also to be received by the screw groove, the mount ring and seal ring having interfitting parts capable of preventing their relative rotation while permitting relative axial movement of the rings, the steps of: a. axially relatively moving the seal ring and mount ring to interfit the interfitting parts thereof to form an assembly; b. relatively moving an interfitted seal ring and mount ring, and a nut, axially to position the seal ring and mount ring in said receiving end surface portion of the nut and restrain relative rotation of the nut and assembly; c. relatively rotating the nut and screw to thread the screw into the nut, and the seal ring and mount ring; and d. relatively axially moving the seal ring and mount ring to permit each to adjust independently to the helical configuration of the screw groove.

Claim 18

A method of sealing the threads of a ball screw and nut assembly having an axially extending screw with an external helical groove, and a nut with an internal helical groove bounded by a thread seal receiving end surface portion which is received on the screw, with the helical grooves of the screw and nut forming a raceway for balls permitting relative rotation and translation of the nut and screw, with relatively low frictional impedance, and wherein a resilient seal ring has an inboard section with a radially internal helical thread adapted to be received by the screw groove, and is provided with a rigid mount ring with a radially internal thread adapted also to be received by the screw groove, the mount ring and seal ring having interfitting parts capable of preventing their relative rotation while permitting relative axial movement of the rings, the steps of: a. axially relatively moving the seal ring and mount ring to interfit the interfitting parts thereof to form an assembly; b. relatively moving an interfitted seal ring and mount ring, and a nut, axially to position the seal ring and mount ring in said receiving end surface portion of the nut and restrain relative rotation of the nut and assembly; c. relatively rotating the nut and screw to thread the screw into the nut, and the seal ring and mount ring; and d. relatively axially moving the seal ring and mount ring to permit each to adjust independently to the helical configuration of the screw groove.