Method and Apparatus for Mounting a Machine Element onto a Shaft

A device for coaxially mounting a machine element having a bore upon a shaft comprising:

• a one-piece inner sleeve for encircling the shaft, having a forward and rearward end, wherein the inner sleeve comprises:
• a frustoconical external surface having a major diameter adjacent the threaded portion and a minor diameter spaced from the major diameter toward the forward end of the inner sleeve;
• an internal bore configured to cooperate with the shaft;
• an interlock at a first end;
• a recess extending around the inner sleeve at a second end remote from the interlock;
• a nut comprising:
• a threaded portion;
• a second interlock configured to cooperate with the first interlock to substantially permanently connect the inner sleeve with the nut to allow rotation of the inner sleeve relative to the nut while substantially impeding axial movement of the inner sleeve relative to the nut;
• an enlarged head;
• an outer sleeve engaging the machine element comprising:
• a frustoconical internal surface corresponding in angle of taper to the tapered external surface of the inner sleeve, and having a major diameter adjacent the rearward end and a minor diameter adjacent the forward end;
• an external surface corresponding to the bore of the machine element;
• and
• wherein rotation of the nut displaces the outer sleeve in one direction relative to the nut thereby displacing the minor diameter of the outer sleeve external surface toward the major diameter of the inner sleeve internal surface, thereby causing the internal bore of the inner sleeve to contract against the shaft and the external surface of the outer sleeve to expand against the bore of the machine element.

A method for mounting a machine element onto a shaft, comprising the steps of:

• providing an inner sleeve having forward and rearward ends, comprising:
• a tapered external surface;
• and
• a bore that is cooperable with the shaft;
• providing an outer sleeve comprising:
• an internal bore that is tapered to cooperate with the external surface of the inner sleeve;
• a threaded portion;
• and
• an external surface cooperable with the bore of the machine element;
• providing a nut having an enlarged head and a threaded portion that is cooperable with the threaded portion of the outer sleeve;
• connecting the inner sleeve to the nut to impede substantial axial displacement of the inner sleeve relative to the nut while allowing rotation of the nut relative to the inner sleeve;
• positioning a positioning sleeve over a portion of the outer sleeve;
• positioning the inner sleeve and the outer sleeve between the shaft and the bore of the machine element so that a rearward edge of the positioning sleeve abuts the enlarged head of the nut and a forward edge of the positioning sleeve abuts a sidewall of the machine element without extending into the bore of the machine element;
• rotating the nut in a forward direction to drive the outer sleeve axially relative to the nut and the inner sleeve so that the tapered surface of the inner sleeve wedges apart the outer sleeve to connect the outer sleeve to the machine element and the inner sleeve to the shaft;
• wherein rotating the nut in a reverse direction drives the outer sleeve relative to the nut and inner sleeve to release the outer sleeve from the machine element and the inner sleeve from the shaft.