The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 07, 1990
Filed:
Oct. 21, 1988
William J Watkins, Troy, OH (US);
Randal A Oyster, Troy, OH (US);
A.O. Smith Corporation, Milwaukee, WI (US);
Abstract
A three phase two-pole induction motor includes a three phase winding wound as a two-pole winding with an effective full pitch wound winding connected in a double delta connection. Each pole group includes a plurality of coils wound as a concentric winding or as a short pitch lap wound equivalent winding. A 36 slot stator is illustrated and includes each phase winding wound with 2 coil units each having 2 coil groups. Each coil group has 3 concentric coils and in the illustrated concentric winding the one phase winding has one group with coil sides in slots 1-3 and 16-18 and the second group in slots 19-21 and 34-36. The next phase winding has similar coils in slots 4-6 and 25-27 and in slots 7-9 and 22-24. The third phase winding has similar coils in slots 10-12 and 31-33 and in slots 13-15 and 29-30. The coil sides of each of the two groups are connected to form a full pitch winding. Thus, coil sides in slots 1-19, in 7-25 and in 13-31 are connected to form an effective coil spanning a full pitch of 18 slots. The coil groups of different phase windings are connected in the double delta circuit connection including a series circuit connection for starting, and a parallel circuit connection for running. The simplified full pitch winding for the double delta motor winding connection allows the motor to accelerate to operating speed in the start winding connection and also reduces the starting current while minimizing side pull effects and the rate of temperature rise.