Abstract: A method for assembling a double enveloping speed reducer assembly includes predetermining the thickness of the shims required to properly position a worm assembly and a worm gear assembly in the speed reducer such that the double enveloping worm spiral and the worm gear mesh at their centers of curvature. By predetermining the thickness of the shims, the speed reducer can be assembled without guesswork. The shim thicknesses are determined, in part, by determining the distance the center of curvature of both the worm spiral and the worm gear to preselected surfaces of the worm assembly and worm gear assembly. The method also includes placing the speed reducer housing and at least one of the bearing brackets for both the worm assembly and the worm gear assembly in gauges to determine various dimensions of the housing and brackets. The measured dimensions are then used to calculate the appropriate shim thicknesses, the shims are placed adjacent a surface of the brackets, and the speed reducer is assembled.

Abstract: A method of determining the distance L1 from the center of curvature of a worm gear to an axially outer surface of a worm gear assembly which includes the worm gear is provided. By determining this distance, the size of shims needed to assemble a speed reducer including the worm gear assembly and an associated worm can be calculated prior to assembly of the speed reducer. The distance L1 is measured by placing the worm in meshing contact with said worm gear in a gauge, moving the worm gear relative to said worm, determining the distance L1 between the axial outer surface when said worm is at a minimum vertical position, measuring the distance (L) between said axial outer surface and a corresponding second axial outer surface of said worm gear to obtain the distance L1.

Abstract: A gauge is provided for locating the center of curvature of a worm gear. The worm gear is part of a worm gear assembly which includes the worm gear, a shaft on which the worm gear is fixed, and two bearing assemblies. The gauge includes a base having a table and a worm gear bracket assembly on the table for removably receiving the worm gear assembly. The table is mounted on the base to be movable horizontally relative to the base. A vertical support extends above the base and includes a worm bracket which receives a worm. The worm bracket is mounted on the vertical support for vertical movement relative to the vertical support. The worm and worm gear are maintained in meshing contact with each other. A linear motion device is operably connected to the table to move the table, and hence the worm gear assembly, relative to the base and the worm. Thus, as the worm gear is moved horizontally relative to the worm, the worm will move vertically.

Abstract: A method of assembling a speed reducer assembly including a housing having a front wall or side defining a bearing shoulder having an inner surface, a back wall or side defining an opening and having an outer face; a bracket having an inner surface which rests against the back wall face to close the back wall opening and defining a second bearing shoulder having an inner surface, a worm and a worm gear held in meshing contact in the housing, and front and back shims which align the center of curvature of the worm gear with the axis of the worm. The method of aligning the worm and worm gear includes the steps of predetermining the width of the shims and then assembling the speed reducer assembly. To predetermine the width of the shims, the distance from the center of curvature of the worm gear to an axially outer surface of the worm gear assembly is determined. A gauge is provided to determine this distance.