# US 2009/0260464 A1 · Electric actuator > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2009/0260464 A1 - Document ID: US20090260464A1 - Status: Published application - Kind: A1 - Application number: 12/424,780 - Filed: 2009-04-16 - Published: 2009-10-22 - Earliest claimed: 2008-04-18 - Assignees: Tol-O-Matic, Inc. - Inventors: Brett C. Holker; Jeff Karls; Jeremy R. Forbord - Web page: https://patentgrep.com/patent/US20090260464A1 ## CPC - F16H 57/0497: {Screw mechanisms} - F16H 25/20: Screw mechanisms (with automatic reversal F16H25/12) - F16H 2025/2075: {Coaxial drive motors} - Y10T 74/18576: including screw and nut - Y10T 74/18656: Carriage surrounded, guided, and primarily supported by member other than screw [e.g., linear guide, etc.] - Y10T 74/18744: Lubrication - F16H: GEARING - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract An electrically powered linear actuator having a thrust assembly, a motor with a hollow rotor surrounding at least a portion of the thrust assembly, and a lubricant passage for replenishing lubricant to the force transmitting components of the actuator. ## Claims ### Claim 1 An electrically powered actuator comprising: a housing; a motor within the housing comprising: an axially fixed, rotatable hollow rotor; an axially fixed, externally threaded elongated screw shaft operably coupled to the hollow rotor and capable of rotating therewith; a rotationally fixed, internally threaded nut coupled to the elongated screw shaft, such that rotation of the screw shaft causes the nut to move axially; a lubricant access point provided exterior to the housing; and a lubricant passage extending from the lubricant access point to the threaded nut. ### Claim 2 (depends on 1) The electrically powered actuator of claim 1, further comprising a thrust tube operably coupled to the nut. ### Claim 3 (depends on 2) The electrically powered actuator of claim 2, wherein the lubricant access point is provided at the distal end of the thrust tube. ### Claim 4 (depends on 3) The electrically powered actuator of claim 3, wherein the distal end of the thrust tube includes a work piece connection member and the lubricant access point is provided at the work piece connection member. ### Claim 5 (depends on 4) The electrically powered actuator of claim 4, wherein the lubricant passage comprises an internal lubricant passage of the work piece connection member. ### Claim 6 (depends on 4) The electrically powered actuator of claim 4, wherein the lubricant passage comprises an internal lubricant passage of the thrust tube. ### Claim 7 (depends on 6) The electrically powered actuator of claim 6, wherein the thrust tube comprises: an elongated, outer hollow tubular portion; and an elongated, inner hollow tubular portion; wherein the inner tubular portion has a diameter that is less than the diameter of the outer tubular portion, creating the internal lubricant passage of the thrust tube between the outer and inner tubular portions. ### Claim 8 (depends on 7) The electrically powered actuator of claim 7, further comprising sealing members to substantially retain lubricant within the lubricant passage. ### Claim 9 (depends on 7) The electrically powered actuator of claim 7, wherein the nut comprises a lubricant passage which provides access to the internal mechanisms of the nut. ### Claim 10 An electrically powered actuator comprising a housing, a hollow rotor within the housing and rotatable relative to the housing, a threaded lead screw axially located within the hollow rotor, a threaded nut operably coupled to the screw, and means for lubricating the threaded nut. ### Claim 11 (depends on 10) The electrically powered actuator of claim 10, wherein the means for lubricating the threaded nut comprises a lubricant passage extending from a lubricant access point external to the housing to the threaded nut. ### Claim 12 (depends on 11) The electrically powered actuator of claim 11, further comprising a thrust tube operably coupled to the threaded nut. ### Claim 13 (depends on 12) The electrically powered actuator of claim 12, wherein the lubricant passage comprises an internal lubricant passage of the thrust tube. ### Claim 14 (depends on 14) The electrically powered actuator of claim 14, wherein the thrust tube comprises: an elongated, outer hollow tubular portion; and an elongated, inner hollow tubular portion; wherein the inner tubular portion has a diameter that is less than the diameter of the outer tubular portion, creating the internal lubricant passage of the thrust tube between the outer and inner tubular portions. ### Claim 15 (depends on 14) The electrically powered actuator of claim 14, wherein the threaded nut comprises a lubricant passage which provides access to the internal mechanisms of the threaded nut. ### Claim 16 (depends on 10) The electrically powered actuator of claim 10, wherein the threaded lead screw is operably coupled to the hollow rotor and capable of rotating therewith. ### Claim 17 A method for lubricating an electrically powered actuator, comprising; attaching a lubrication tool to an external lubricant access point of the actuator, the actuator comprising: a housing; a motor within the housing comprising: an axially fixed, rotatable hollow rotor; an axially fixed, externally threaded elongated screw shaft operably coupled to the hollow rotor and capable of rotating therewith; and a rotationally fixed, internally threaded nut coupled to the elongated screw shaft, such that rotation of the screw shaft causes the nut to move axially; delivering a lubricant from the lubrication tool to the lubricant access point; and flowing the lubricant along a lubricant passage extending from the lubricant access point to the threaded nut, thereby lubricating the nut.