Ball screw seal
AssigneeDana Corporation
InventorHubert E. Klinkenberg
Life of this patent
Estimating the term…
Abstract
A seal for use in a ball screw assembly sealingly engages portions of both the nut and the screw. The seal has a plurality of teeth at an outer peripheral surface, and further has a seal thread received in a thread on the screw. The seal is rotated relative to the nut and moves axially due to the screw thread until a seal face sealingly engages the nut. A set screw is then inserted through the nut, into a space formed between adjacent teeth on the seal, to prevent further relative rotation of the seal and the nut. A force from the nut on the seal urges the seal axially such that the seal thread is biased into the screw thread, providing sealing contact between the seal thread and the screw thread.
Claims21
A ball screw assembly comprising:
- a screw extending along an axis and having a screw thread at an outer peripheral surface;
- a nut extending along said axis and having two axial ends, said nut received on said screw and having a nut thread at an inner peripheral surface and extending between two nut thread axial ends;
- a seal bore extending axially inwardly from at least one axial end of said nut, a seal disposed in said seal bore and being free to move axially relative to said nut, said screw and said screw thread, means for urging said seal into sealing contact with an inner peripheral surface of said nut at a nut seal contact area which is spaced axially outwardly of said nut thread axial end, and said seal having a seal thread at an inner peripheral surface which is received in said screw thread, said means for urging also urging said seal thread into sealing contact with said screw thread at a screw seal contact area;
- and
- wherein said nut seal contact area is positioned axially outwardly of said thread seal contact area.
A seal for use in a ball screw assembly comprising:
- a seal body having an inner peripheral surface defining a central bore, said seal body extending along an axis between first and second axial ends, a seal thread formed on said inner peripheral surface;
- a seal face extending radially outwardly of the remainder of said seal body at said first axial end of said seal body;
- and
- a plurality of teeth spaced circumferentially about an outer peripheral surface of said seal body, and extending axially between said seal face and said second axial end, and spaces defined between adjacent teeth, and wherein centerlines of said spaces are circumferentially spaced by less than 20 degrees.
A ball screw assembly comprising:
- a screw extending along an axis and having a thread at an outer peripheral surface;
- a nut extending along said axis and having two axial ends, said nut received on said screw and having a thread at an inner peripheral surface;
- a seal bore extending axially inwardly from at least one axial end of said nut, a seal disposed in said seal bore and being free to move axially relative to said nut and said screw, and means to secure said seal at any one of a plurality of circumferential locations relative to said nut;
- said means to secure said seal include a plurality of teeth at an outer peripheral surface of said seal, spaces defined between said teeth, and a set screw extending from said nut into one of said spaces to prevent relative rotation of said seal and said nut, such that said seal may be turned relative to said nut to any one of a plurality of circumferential positions to adjust a force urging said seal into said nut, and then secured at a desired one of said circumferential locations by inserting said set screw into a selected one of said spaces.
A method of assemblying a ball screw assembly comprising the steps of:
- 1) placing a seal on a screw, the seal having a seal thread received in a screw thread on the screw, and inserting the seal into a seal bore in a nut;
- 2) rotating the seal relative to the nut such that the seal thread moves within the screw thread, and the seal moves axially relative to the nut until the seal reaches a desired axial position relative to the nut;
- 3) securing the seal against any further rotation relative to the nut;
- and
- 4) the rotation of step 2) is accomplished by inserting a tool into holes in an outer axial face of the seal and using the tool to rotate the seal relative to the nut.
Dependencies are inferred from the claim text.