AU600780B2

AU600780B2 - Method for winding coils of single-phase induction electromotor

Info

Publication number: AU600780B2
Application number: AU83087/87A
Authority: AU
Inventors: In Suk Kim
Original assignee: Individual
Current assignee: Individual
Priority date: 1986-12-30
Filing date: 1987-12-29
Publication date: 1990-08-23
Anticipated expiration: 2007-12-29
Also published as: KR890003300B1; AU8308787A; KR880008491A; CA1291516C

Description

T

COMPLE

COMMONWEALTH OF AUST L f Patents Act 1952-196 0 7 8 0 TE SPECIFICATION

(ORIGINAL)

Form 0 FOR OFFICE USE: Class Int. Class Application Number Lodged Complete Application No, Specification Lodged Published Priority: Related art:

TO

IN SUK KIn BE COMPLETED BY APPLICANT Name of Applicant: Address of Applicant: Actual Inventor: t #10-615 Samig Apt., of 134-21, Cheong-dam-Dong, Kang-nam-Ku, Seoul, Korea IN SUK KIM k-J *7 Address for Service: COLLISON CO., Patent Attorneys, 117 King William Street, Adelaide, south Australia, 5000, Complete Specification for the invention entitled: "METHOD FOR WINDING COILS OF SINGLE-PHASE INDUCTION

ELECTROMOTOR"

The following statement Is a full descriptlon of this invention, Including the best method of performing it known to me; 2 METHOD FOR WINDING COILS OF SINGLE-PHASE INDUCTION

ELECTROMOTOR

FIELD OF THE INVENTION The present invention relates to a method of winding coils of a single-phase induction electromotor. There are two types of winding coils of a single phase induction electromotor, a starting and a main winding coil. The starting and the main winding coils comprise of wire wound about a former having teeth and slots.

The method for winding coils of single-phase induction electromotor promotes operation efficiency. Further the invention improves the starting torque of the electromotor because there are no unavaiiahle teeth between slots of starting winding coils, while keeping an electric angle between the magneto-motive force produced by the starting ing nng coils and the magneto-motive force produced by the main winding coils at ai electrical angle of substantially 900° S DESCRIPTION OF PRIOR ART In general, a single-phase induction electromotor will have between each pole of the induction eletromotor one tooth of the former not incorporated in any r"c pole. In the case of a single-phase four pole induction electromotor, there wli be four unavailable teeth which are not Included In any of the poles. During operation of the electromotor the unavailable teeth of the main winding coils do not produce a magnetic flux that rotate the rotor of the electromotor but exercise a damping action on the rotor due to a counter electromotive force.

m a In order to remove such unavailable teeth between adjacent poles of the main winding coils, pnor art teaches the making of a single-phase induction 30' electromotor such that adjacent poles and their outer coils are wound in the same slot by one-slot expansion of the coil pitch. That is, by expansion of each coil loop of each pole. That is, the windings about the pole center of the main winding coil remain symmetrical.

An example of such a main winding is illustrated in FIG. 1. In this case a single-phase induction electromotor of four poles end 36 slots is lilustrated, Each coil pitch of coil Cl, one of the main winding coils, spans the 1 t slot to the 10t h S, 3 slot, the 2 nd slot to the 9th slot, the 3 rd slot to the 8th slot and the 4th slot to the 7 t h slot, with the outer coil pitch of coil C2 which forms an adjacent pole span the 1 0 th slot to the 19 th slot. Consequently, the 10 th slot is jointly owned by the coil C1 and the outer coil pitch of coil C2. Thus the unavailable tooth between coil C1 and C2 is non-existent. This process is extended to coils C3 and C4 as illustrated in FIG. 1.

Although the manner of coil windings as illustrated in FIG. 1 is the best way in order to remove unavailable teeth in the main winding coils, the electric angle formed by the magneto-motive force created by the starting winding coils and the magneto-motive force created by the main winding coils cannot be maintained at in the case of a single-phase four pole induction motor. So previously there has been no way but to wind a coil of a starting winding so that unavailable teeth exist between respective adjacent coils of the starting winding coils.

Accordingly, the efficiency and starting torque of an induction electromotor will be lower than that of an induction electromotor which had means to ha\va no unavailable teeth and maintain an electric angle substantially of 900.

SUMMARY OF THE INVENTION 'i The invention may be said to reside in a method for winding coils of a singlephase induction electromotor comprising; Ittt 125 a stator and a rotor having formers consisting of a plurality of slots with teeth between the slots; main winding coils, which create a number of main poles; starting winding coils which create a number of starting poles where the outer winding of each of the starting winding coils are wound such that "30 there are no teeth not incorporated In a starting pole; and during operation of the electromotor the electric phase angle between the magneto-motive force created by the starting winding coils and the Smagneto-motive force created by the main winding colls is maintained at substantially 900, In preference the invention may be said to reside in a method for winding coils of a single-phase induction electromotor as in the last paragraph where for each starting pole the outer windings of the starting winding coil are wound such that 119/V, U T _'41 4 the center of a coil loop formed by the outer windings are not co-incident with the center of a coil loop formed by the inner windings of the starting winding coil.

Alternatively the invention may be said to reside in a method for winding stator coils of a single-phase 4-pole 36-slot induction electromotor comprising: winding a starting coil through slots of said electromotor for forming a starting winding; avoiding winding of said starting coil about selected slots, said selected slots being unused slots; moving an outer coil pitch to form coil overlapping slots adjacent to said selected unused slots for eliminating unused teeth between said unuksed slots and said coil overlapping slots; and winding a main coil through slots for forming a main winding whereby the starting coil overlaps the starting coil in the saik balected slots, a 900 15 electric angle being formed between said main winding and said starting winding, and four slots being unused by the starting winding for effectively increasing the starting torque and promoting the operation efficiency of the electromotor.

However, the present invention is designed in consideration of such prior defects as described hereinabove. It maintains an electric angle between the magneto-motive force created by the main winding coils and the starting winding coils of substantially 900 by one-slot expansion of only the outer coil pitch of the coil which forms each of the starting winding coils. That is, the windings of the I -,25 starting coil are non-symmetrical about the pole center of the coil. This produces no unavailable teeth between adjacent poles of the starting winding coils. It is designed not to weaken the starting torque because a magnetic flux produced from such unavailable teeth does not exercise a damping action on the rotation of the rotor.

BRIEF DESCRIPTION OF THE DRAWINGS i To aid in the understanding of this invention, the invention will now be described with reference to the attached diagrams.

1 r I I FIG. 1 is a schematic diagram of a single-phase 4-pole induction electromotor showing coils wound under a scheme which forms pan of the prior art; FIG. 2 is a schematic diagram showing a coil as wound under the present invention; FIG. 3 is a development diagram showing the stator slots of the present invention, and FIGS. 4 and 5 are diagrams showing a ;le comparison drawn between prior art and the present invention respeci' ely.

DESCRIPTION OF THE PREFERRED EMBODIMENT r r FIG. 2 is a diagram showing how the main winding coils and the starting 1 b winding coils are wound through slots as under the present invention, It shows that all coil pitches of each pole are expanded by one-slot so that the main windings do not have unavailable teeth between respective poles. These are Sshown as coils C1, 02, C3 and C4.

On the other hand, the starting winding is wound to maintain an electric angle between the magneto-motive force created by the starting winding coils and

S,,

t the magneto-motive force created by the main winding coils of 900. This is achieved without changing the center of each pole formed by coils T5, T6, T7 and T8. However the outer coil pitch slots, for example the 6 th slot, 15th slot, 24 th slot S: *25 and the 33rd slot are made to be owned jointly by the adjacent poles without unavailable teeth being created. That is, coils T5, T6, T7 and T8 are all one-slot expansion of the outer coil pitch. Accordingly the pole center of the inner colt pitch of each pole of the starting winding is coincident with the center pole of the starting winding coil made under prior art schemes but the pole center of the outer coll pitch is offset by 50 (in tLe. case of 36 slots). Note that for coil T1 there are no windings in the 1 th slot making the windings about the pole center nonsymmetrical. A comparison of this part of FIG. 2 with the corresponding part of FIG. 1 clearly illustrates the invention.

Such a single-phase Induction electromotor as designed undor the present invention removes unavailable teeth by one-slot expansion of only the ~aT" 6 outer coil pitch of each pole and improves the starting torque thereby promoting the entire efficiency of the electromotor.

Such a single-phase induction electromotor as described hereinabove has an advantage of improving the power factor and the efficiency of the electromotor.

te I C1*~ t t IF I k 4I I I I I I I 4*

Claims

1. A method for winding stator coils of a single phase 4-pole 36-slot induction electromotor comprising: winding a starting coil through slots of said electromotor for fornming a starting winding; avoiding winding of said starting coil about selected slots, said selected slots being unused slots; 1 0 moving an outer coil pitch to form coil overlapping slots adjacent to said selected unused slots for eliminating unused teeth between said unused slots and said coil overlapping slots; and winding a main coil through slots for forming a main winding whereby the starting coil overlaps the starting coil in the said selected slots, a 900 1 5 electric angle being formed between said main winding and said starting winding, and four slots being unused by the starting winding for effectively increasing the starting torque and promoting the operation efficiency of the electromotor.

2. A method of winding coils for a single-phase Induction electromotor substantially as described, with reference to FIGS. 2.

3 and 5, herein. DATED this 8th day of June 1990 IN SUK KM By his Patent Attorneys CQLLISON CO o.