General Electric Company

William H Stark

Arthur C Keck

Lawrence L Lee

Peter J Klug

Robert V Zigler

Muhammad S Malik

Disclosed are methods of making dynamoelectric machines which include use of two sheet metal cup-shaped members to form a housing that completely surrounds and encloses the stator. The stator is assembled with a can in such a manner that the core of the stator is completely contained within the can. Thereafter, a cap is positioned at the exposed face of the stator and the cap and can are joined together by a sheet metal fastening technique which displaces material from one superposed sheet into a second sheet of material. The can and cap are precision formed so that they will have precision sized and located bearing receivers and core retention regions. Both the cap and the can are provided with multiple flange locations which are utilized for fastening the can and cap together during the assembly process. The cap is also provided with a notch which accommodates a lead protecting grommet that preferably is held in place by one or more bosses or pins that are fastened in openings in still another flange formed on the can.

Dynamoelectric machine and processes for making the same

A permanent magnet rotor for an electronically commutated motor (ECM) has a core, a plurality of magnetizable elements spaced around the core, and a thin-walled retaining shell which has been stretched around the core and magnetizable elements to hold the elements in position. The rotor is made by an inventive method which involves axially aligning the core and surrounding magnetizable elements with the retaining shell, and cold-pressing the retaining shell over the core and elements to sandwich the elements between the shell and core. The core and magnetizable elements serve as a mandrel about which the shell is reformed in a cold working operation. Other aspects of the invention include the fixturing apparatus used to align the core and magnetizable elements with the retaining shell, and apparatus which is used to evenly space the magnetizable elements around the core and hold the elements in position during at least a portion of the cold-pressing operation. Additional features of certain embodiments of the rotor of the present invention include end plates axially disposed adjacent the ends of the rotor core and magnetizable elements, and the use of adhesives between the core and magnetizable elements and/or the ends of the core and magnetizable elements and the end plates.

Apparatus for making permanent magnet rotor

Permanent magnet rotor

A permanent magnet rotor includes a rotor core having an axis of rotation and longitudinally extending radially projecting ribs. A plurality of arcuate magnetic elements are retained against an outer surface of the rotor by a cylindrical shell such that each magnet is disposed between a pair of the ribs. A hardenable adhesive is interposed between the outer surface of the core and the magnets and cooperates with the ribs and magnets to prevent rotational slippage of the magnets relative to the core during rotation of the rotor. Various embodiments utilize different techniques for retaining the components in assembled relation.

Method of making a permanent magnet rotor

Permanent magnet rotor having magnet positioning and retaining means

A permanent magnet rotor for an electronically commutated motor (ECM) has a core, a plurality of magnetizable elements spaced around the core, and a thin-walled retaining shell which has been stretched around the core and magnetizable elements to hold the elements in position. The rotor is amde by an inventive method which involves axially aligning the core and surrounding magnetizable elements with the retaining shell, and cold-pressing the retaining shell over the core and elements to sandwich the elements between the shell and core. The core and magnetizable elements serve as a mandrel about which the shell is reformed in a cold working operation. Other aspects of the invention include the fixturing apparatus used to align the core and magnetizable elements with the retaining shell, and apparatus which is used to evenly space the magnetizable elements around the core and hold the elements in position during at least a portion of the cold-pressing operation. Additional features of certain embodiments of the rotor of the present invention include end plates axially disposed adjacent the ends of the rotor core and magnetizable elements, and the use of adhesives between the core and magnetizable elements and/or the ends of the core and magnetizable elements and the end plates.

Apparatus for assembling a permanent magnet rotor

Method for making permanent magnet rotor

A shaft of selected material and of a given desired nominal diameter corresponding to nominal desired shaft extension diameter for a particular motor is cut and then treated with optional operations such as chamfering and washing; grinding; machining of flats; and phosphatizing to inhibit rust. A first accessory member is assembled in a predetermined position by heat shrinking on the shaft; and a rotor body is assembled with the shaft. A second accessory member is also assembled by heat shrinking. For ball bearing applications, concenntric journals are turned on accessory members for the inner races of bearings after the accessory members have been assembled with shaft. The inner races of ball bearings are lightly pressed onto the journals, and rotors, end frames, and stator are assembled. The concentric journals permit press fitting of ball bearings without substantially exceeding 0.0005 of an inch press fit and thus avoid damage to the bearings. Shaft portions are stressed and maintained in a stressed condition so as to increase the stiffness of the rotor system and thereby increase the rotor system resonant frequency. Aluminum collars that conform to the shaft surface are preferably used. These collars establish a more thorough and uniformly stressed condition of the shaft.

Dynamoelectric machine structures

Shaft material of a given desired nominal diameter corresponding to a nominal desired shaft extension diameter for a particular motor is selected; shaft blanks are cut; optional operations such as chamfering and washing, grinding, machining of at least one flat and phosphatizing to inhibit rust are performed; a first accessory member is assembled in a predetermined position by heat shrinking; a rotor body is assembled with shaft; and a second accessory member is assembled by heat shrinking. For ball bearing applications, a person practicing the invention in one form may finish turn concentric journals on accessory members for the inner races of bearings after accessory members have been assembled with a shaft so that inner races of ball bearings may be lightly pressed onto the journals, and the rotor is assembled with end frames and stator. The concentric journals permit a press fit of ball bearings without substantially exceeding .0005 of an inch press fit and thus damage of the bearings is avoided. One preferred method includes stressing shaft portions and maintaining the stressed condition to increase stiffness of a rotor system and thereby increase the rotor system resonant frequency. Apparatus disclosed herein includes means for maintaining a desired perpendicular relationship between a shaft and various parts assembled therewith. Such apparatus assists in establishing desired dimensional relationships. In one exemplification, it is preferred to use aluminum collars that conform to a shaft surface and thus establish a more thorough and uniformly stressed condition of the shaft.

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Fort Wayne, IN, United States of America

William H Stark