# US 5,347,880 A · Method and apparatus for servicing a gear assembly > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,347,880 A - Document ID: US5347880A - Status: Granted - Kind: A - Application number: 07/980,365 - Filed: 1992-11-23 - Granted: 1994-09-20 - Earliest claimed: 1992-11-23 - Assignees: Harnischfeger Corporation - Inventors: Harvey J. Kallenberger - Web page: https://patentgrep.com/patent/US5347880A ## CPC - F16H 55/12: with body or rim assembled out of detachable parts - Y10T 29/49462: Gear making - Y10T 29/4973: Replacing of defective part - Y10T 29/53683: Spreading parts apart or separating them from face to face engagement - Y10T 74/19926: Detachable - Y10T 74/1993: Segmental rim - F16H: GEARING - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract An aspect of the invention is an improved method for servicing a gear assembly having a gear segment and a spider for supporting the segment. The method includes the steps of providing a jack assembly with a jacking bolt mounted for radial outward movement, moving the jacking bolt radially outward, applying a separating force to the segment and disengaging the segment from the spider. Further steps involve providing a drawtight assembly with a coupler attached to the segment, applying a force to the coupler, moving the coupler radially inward and engaging the segment with the spider. Other aspects of the invention include the "jacking" apparatus for separating a segment from the spider (for service purposes) and the "drawtight" apparatus for re-attaching the segment to the spider. The invention is particularly useful in connection with large machinery, e.g., a walking dragline, involving heavy and/or unevenly-wearing gear parts and difficult field service conditions. ## Claims ### Claim 1 An improved method for servicing a gear assembly having a gear segment and a spider for supporting the segment, the method including the steps of: providing a jack assembly with jacking means mounted for radial movement; moving the jacking means radially outward to apply a separating force to the segment; and, disengaging the segment from the spider. ### Claim 2 (depends on 1) The method of claim 1 wherein the jack assembly includes a first force reaction member and the separating force is applied between the reaction member and the segment. ### Claim 3 (depends on 2) The method of claim 2 wherein the segment includes a push plate and the separating force is applied between the reaction member and the push plate. ### Claim 4 (depends on 1) The method of claim 1 wherein the segment has a first surface, the spider has a second surface and the disengaging step includes disengaging the surfaces from one another. ### Claim 5 (depends on 4) The method of claim 4 wherein the surfaces are disengaged from one another by sliding the first surface along the second surface. ### Claim 6 (depends on 1) The method of claim 1 wherein the jacking means includes a jacking bolt and the moving step includes rotating the bolt to move the bolt radially outward. ### Claim 7 (depends on 1) The method of claim 1 further including the steps of: providing a drawtight assembly with a coupler attached to the segment; applying a force to the coupler; moving the coupler radially inward; and, engaging the segment with the spider. ### Claim 8 (depends on 7) The method of claim 7 wherein the drawtight assembly includes a draw plate and the force is applied to urge the coupler toward the draw plate. ### Claim 9 (depends on 8) The method of claim 8 wherein the segment has a segment mounting member, the spider has a surface and the engaging step includes sliding the mounting member along the surface. ### Claim 10 (depends on 7) The method of claim 7 wherein the drawtight assembly includes a coupling bolt and the moving step includes rotating the coupling bolt to move the segment radially inward. ### Claim 11 (depends on 1) The method of claim 1 wherein: the segment is arc-shaped and has ends; the segment is attached to the spider by a plurality of fasteners spaced along the length of the segment, and the method includes, in either order with respect to the providing step, the step of: removing all but a single fastener from the segment, the single remaining fastener being adjacent to a segment end, and the disengaging step is preceded by the step of: pivoting the segment about the single remaining fastener. ### Claim 12 In a gear assembly having a gear segment and a spider for supporting the segment, the improvement comprising: a segment-attached mounting member; a spider-mounted jack assembly with jacking means mounted for radial movement to engage the mounting member and apply radial force thereto, whereby the segment may be disengaged from the spider. ### Claim 13 (depends on 12) The assembly of claim 12 wherein: the mounting member includes spaced support plates; the spider includes spaced webs, each web abutting a separate support plate; a push plate is attached to the support plates and engaged by the jacking means for disengaging the segment from the spider. ### Claim 14 In a gear assembly having a gear segment and a spider for supporting the segment, the improvement comprising: a segment-mounted coupler; a spider-mounted drawtight assembly including drawdown means to engage the coupler and apply radial force thereto, whereby the segment may be engaged with the spider. ### Claim 15 (depends on 14) The assembly of claim 14 wherein: the segment includes spaced support plates; the coupler is attached to the support plates; the spider includes spaced webs and each web abuts a separate support plate; the drawdown means includes a drawdown bolt rotated to move the segment radially inward.