US 3423619 A
Description (OCR text may contain errors)
Jan. 21, 1969 L. SVHAW 3,423,619
ROTORS FOR DYNAMOELECTRIC MACHINES WITH WINDING INSULATION Filed June 20, 1966 United States Patent 26,525/65 U.S. Cl. 310263 2 Claims Int. Cl. H02k 1/22 This invention relates to rotors for dynamoelectric machines, of the kind comprising a rotary shaft, a core piece on the shaft, a pair of pole pieces on the shaft at opposite ends of the core piece, a former surrounding the core piece, and a winding carried by the former, the former insulating the winding from the pole pieces and core pieces.
The invention resides in a rotor of the kind specific in which the former comprises a one-piece insulating member of generally rectangular form having an axial length equal at least to the circumference of the core piece, and a width equal to the length of the core piece, the member being bent to cylindrical form t surround the core piece and having integral outwardly extending arms which are bent so as to extend between the winding and the pole pieces.
One example of the invention is illustrated in the accompanying drawings wherein FIGURE 1 is a sectional view of a rotor, FIGURE 2 is a perspective view of the rotor shown in FIGURE 1 with the pole pieces removed for clarity, and FIGURE 3 is a plan view of a former before being incorporated in a rotor.
Referring first to FIGURE 1 there is provided a rotary shaft 11 having mounted thereon as an interference fit a hollow cylindrical core piece 12. Also secured as an interference fit to the shaft 11 are a pair of pole pieces 13 of generally annular form which are in contact with opposite ends of the core piece 12. The peripheries of .the pole pieces are provided with a plurality of oppositely directed teeth-like pole tips 14 respectively which are presented to the respective pole piece 13 so that the pole tips overlap in an axial direction relative to the shaft 11, and the pole tips 14 on the two pole pieces are alternately spaced in a circumferential direction.
Surrounding the core piece is a former 15 carrying a winding 17 the ends 18 of which pass through holes 19 in one of the pole pieces. The former serves to insulate the winding from the core piece and from the pole pieces 13.
The former 15 (FIGURE 3) is constituted by a onepiece insulating member 21 which is of generally rec- Patented Jan. 21, 1969 tangular form having an axial length equal to the circumferential of the core piece 12, and a width equal to the length of the core piece 12. Extending at right angles from opposite sides of the member 21 are integral arms 22 which are axially spaced from each other and from the arm of the opposite side of the member 21.
In order to form the rotor, the core 12 is placed in a jig and the insulating member 15 is wound around the core piece, its ends being interconnected by adhesive tape. In order to facilitate this operation, one end of the member 21 may be formed with a V-shaped integral projection, and the other end formed with a complementary recessed portion. A pair of end members (not shown) are then brought into contact with opposite ends of the core piece, these end members being provided with radially extending grooves in which the arms 22 on the insulating member 21 are located. A winding 17 is then wound on the former 15, whereafter the end members are removed. The arms are scored about lines 25, 26 positioned so that the arms 22 can be bent to overlie the winding 17 (FIGURE 2). Tape is then used to hold the assembly together. Finally the pole pieces 13 are placed in position, and the rotor is impregnated with an insulating varnish which flows into the channels defined between the arms 22 on the insulating member 21 and the pole pieces 13, and thence around the core piece 12. The varnish provides a mechanical connection between the parts of the rotor when it has set.
Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:
1. A rotor for a dynamoelectric machine of the kind specified in which the former comprises a 'one piece insulating member of generally rectangular form having an axial length equal at least to the circumference of the core piece, and a width equal to the length of the core piece, the member being bent to cylindrical form to surround the core piece and having integral outwardly extending arms which are bent so as to extend between the winding and the pole pieces.
2. A rotor as claimed in claim 1 wherein the assem bly is impregnated with insulating varnish which when it sets, forms a mechanical connection between the core piece, the pole pieces, the former and the windings of the rotor.
References Cited UNITED STATES PATENTS 2,795,715 6/1957 Gilchrist 310-261 WARREN E. RAY, Primary Examiner.
U.S. Cl. X.R. 310-194, 214