Metal working – Method of mechanical manufacture – Electrical device making
Reexamination Certificate
1999-08-03
2001-11-20
Young, Lee (Department: 3729)
Metal working
Method of mechanical manufacture
Electrical device making
C029S598000, C310S052000, C310S058000, C310S061000, C310S261100
Reexamination Certificate
active
06317963
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to dynamoelectric machines, and in particular to the housings for such machines and methods for manufacturing such housings.
BACKGROUND
It is known for dynamoelectric machines to utilize a multi-piece housing assembly including a cylindrical enclosure surrounding the stator and the rotor of the dynamoelectric machine, with bearing mounts fastened to each end of the enclosure to support the bearings for the shaft of the rotor. It is also known for the bearing mounts to include one or more cooling passages to allow a cooling flow over the stator and rotor of the dynamoelectric machine. In at least one known multi-piece housing assembly, the cylindrical stator/rotor enclosure is an extrusion including heat exchange fins on the outer surface of the enclosure to improve the heat dissipation from the stator and rotor of the dynamoelectric machine. In addition to a bearing mount, this multi-piece housing assembly also includes a sheet metal cover surrounding the stator/rotor enclosure to create cooling passages that direct a cooling flow over the fins. The sheet metal cover is fastened to a set of spokes on the extrusion that extend radially outward between the fins.
While there are known housing constructions that work well for their intended purpose, there is always room for improvement. For example, there is an continuing desire to reduce the cost and complexity of manufacturing the housings for dynamoelectric machines.
SUMMARY OF THE INVENTION
In accordance with the invention, a method is provided for manufacturing a dynamoelectric machine including a stator, a rotor, at least one bearing for rotatably supporting the rotor, and a one piece housing for the stator, the rotor and the at least one bearing. The method includes the step of forming a unitary metallic extrusion including a radially innermost cylindrical member, a radially outermost cylindrical member, a central cylindrical member spaced radially between the innermost and outermost members, a first set of spokes connecting the innermost and central cylindrical members together, a first set of arcuate cooling passages defined between the first set of spokes and the innermost and central cylindrical members, a second set of spokes connecting the outermost and central cylindrical members together, and a second set of arcuate cooling passages defined between the second set of spokes and the outermost and central cylindrical members, with the spokes, passages, and cylindrical members extending from a first end of the extrusion to a second end of the extrusion. The method further includes the steps of machining away sufficient lengths of the innermost cylindrical member and the first set of spokes to create a cavity in the central cylindrical member for receiving the stator and the rotor of the dynamoelectric machine, forming a bearing seat in a remaining length of the innermost member, and assembling the at least one bearing, the stator, and the rotor into the bearing seat and the central cylindrical member, respectively.
According to one form of the invention, a dynamoelectric machine is manufactured according to the method described above.
In accordance with one form of the invention, a method is provided for manufacturing a housing for a dynamoelectric machine including a stator, a rotor, and at least one bearing for rotatably supporting the rotor. The method includes the step of forming a unitary metallic extrusion including a radially innermost cylindrical member, a radially outermost cylindrical member, a central cylindrical member spaced radially between the innermost and outermost members, a first set of spokes connecting the innermost and central cylindrical members together, a first set of arcuate cooling passages defined between the first set of spokes and the innermost and central cylindrical members, a second set of spokes connecting the outermost and central cylindrical members together, and a second set of arcuate cooling passages defined between the second set of spokes and the outermost and central cylindrical members. The spokes, passages, and cylindrical members extend from a first end of the extrusion to a second end of the extrusion. The method further includes the step of machining away sufficient lengths of the innermost cylindrical member and the first set of spokes to create a cavity in the central cylindrical member for receiving the stator and the rotor of the dynamoelectric machine.
In one form of the invention, the method further includes the step of forming a bearing seat and a remaining length of the innermost member.
In accordance with one form of the invention, the step of forming a unitary metallic extrusion further comprises forming a plurality of fins surfaces extending from the central member into the second set of arcuate cooling passages.
According to one form of the invention, the step of forming a unitary metallic extrusion further includes forming the first set of spokes to be spaced at equal angular intervals from each other, and forming the second set of spokes to be spaced at equal angular intervals from each other and at equal angular intervals from each of the first set of spokes.
In accordance with one form of the invention, a method is provided for manufacturing a housing for a dynamoelectric machine including a stator, a rotor, and at least one bearing for rotatably supporting the rotor. The method includes the step of forming a unitary metallic extrusion including three nominally concentric cylindrical members connected to each other by spokes, and machining away sufficient lengths of a radially innermost one of the cylindrical members and its associated spokes to create a cavity in a radially central one of the cylindrical members for receiving the stator and the rotor of the dynamoelectric machine, while retaining a sufficient length of the radially innermost one of cylindrical members to receive the at least one bearing. Prior to the machining step, the spokes and the cylindrical members extend from a first end of the extrusion to a second end of the extrusion and define a first set of arcuate cooling passages between the radially innermost one of the cylindrical members and the radially central one of the cylindrical members, and a second set of arcuate cooling passages between a radially outermost one of the cylindrical members and the radially central one of the cylindrical members.
In one form of the invention, a housing for a dynamoelectric machine is manufactured according to the methods described in the paragraphs of this section above.
Other objects and advantages will be apparent from the following specification taken in connection with the accompanying drawings.
REFERENCES:
patent: 3844031 (1974-10-01), Stone
patent: 3874073 (1975-04-01), Dochterman
patent: 3932930 (1976-01-01), Dochterman
patent: 3990141 (1976-11-01), Stark
patent: 5796190 (1998-08-01), Takeda
patent: 5918360 (1999-07-01), Forbes
patent: 6161274 (2000-12-01), Stark
patent: 6181048 (2001-01-01), Smith
Campbell Kris Harold
Powers Theodore Clifton
Fairchild Jeffery N.
Hamilton Sundstrand Corporation
Kim Paul
Wood Phillips Van Santen Clark
Young Lee
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