U.S. patent number RE28,831 [Application Number 05/514,790] was granted by the patent office on 1976-05-25 for electric motor winding.
This patent grant is currently assigned to Consolidated Foods Corporation. Invention is credited to Grayson Brown.
United States Patent |
RE28,831 |
Brown |
May 25, 1976 |
Electric motor winding
Abstract
In accordance with the present invention there is provided
improved winding retention means for the field coils in the stator
of a rotary electric machine, particularly for coils which are
wound in place on the field core by an automatic winding machine.
As is well known, winding guides are temporarily secured at each
axial end of the stator poles. The shuttles of the winding machine
wind successive turns of wire around the poles and in the space
between the latter and the winding guides. The retention means
includes insulated flat steel wire or strips which .[.are secured
to the core as by extending.]. .Iadd.extend .Iaddend.through
passages or slots formed in the core laminations. These strips
extend out from .[.opposite ends of.]. the core .[.and.]. .Iadd.in
both directions and are bent to form off-sets which bear against
opposite ends of the core to prevent longitudinal displacement of
the strips in the apertures. The end portions of the strips beyond
the off-sets extend .Iaddend.underneath the winding guides during
the winding operation so as to support the coils after the winding
guides have been removed and thereafter are bent around the coils
so as to securely anchor the latter to the core and retain them in
place.
Inventors: |
Brown; Grayson (Riverside,
CT) |
Assignee: |
Consolidated Foods Corporation
(Chicago, IL)
|
Family
ID: |
26983517 |
Appl.
No.: |
05/514,790 |
Filed: |
October 15, 1974 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
322607 |
Jan 11, 1973 |
03822391 |
Jul 2, 1974 |
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Current U.S.
Class: |
310/194;
310/260 |
Current CPC
Class: |
H02K
3/522 (20130101); H02K 15/095 (20130101) |
Current International
Class: |
H02K
15/095 (20060101); H02K 15/08 (20060101); H02K
3/52 (20060101); H02K 3/46 (20060101); H02K
003/00 () |
Field of
Search: |
;310/194,215,260,218,270,271,192,254,191,258,189,259,214,42
;29/596,598,605,205 ;242/1.1R,1.1E |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Skudy; R.
Attorney, Agent or Firm: Henry; William S.
Claims
What is claimed is:
1. In a rotary electric machine, a stator core having poles, a
field coil comprising a plurality of turns of conductive insulated
wire wound on each pole and extending axially on either side
thereof, said core being formed with an axially extending aperture
therethrough located at the circumferential center of each pole,
and a strip of .Iadd.electrically insulated .Iaddend.bendable metal
.[.secured to said core.]. extending through each aperture and
axially beyond said core in each direction, .Iadd.the extending
portion of each strip being bent to form off-sets which bear
against opposite ends of the core to prevent longitudinal
displacement of each strip with respect to the core, .Iaddend.the
extending portions of said turns being supported by the extending
portions of said strips .Iadd.beyond said off-sets, .Iaddend.said
extending portions of said strips being bent around said extending
portions of said turns for anchoring said turns in fixed position
on said core. .[.2. A device as defined in claim 1 in which said
metal strips are insulated..]. .[.3. A device as defined in claim 1
in which said strips are off-set at the ends of said apertures and
bear against the end surfaces of said
stator..]. 4. A device as defined in claim .[.2.]. .Iadd.1
.Iaddend.in which said axially extending apertures are slots formed
in the outer
circumferential surface of said stator. 5. A device as defined in
claim 4 in which the edges of said slots are upset against said
strips to secure the latter in the slots.
Description
BACKGROUND OF THE INVENTION
Heretofore, field coils have been retained in place .Iadd.in
various ways including .Iaddend.strips of metal.[., tape or cord
which are bent or tied around the turns at opposite ends of the
core and which bear against the outer surface of the core, but are
not secured to it in any manner and consequently do not securely
anchor the coils to the core..]. .Iadd.which are secured to the
core by rivets passing through holes formed in the core and strips.
These strips must be insulated and this has been done by either
placing a sleeve of insulating material around them before they are
riveted in place or by spraying them with an epoxy resin after
securing them to the core and at the same time that the rest of the
core is sprayed. Also, the rivet heads must be insulated as they
are contacted by the field coils and the rivets are in conductive
contact with the stack. If the strips are insulated by sleeves,
separate means must be employed to insulate the rivet heads. If the
core and strips are insulated by spraying epoxy resin, this would
also insulate the heads, but this type of insulation would be
damaged by the subsequent bending of the strips around the coils.
.Iaddend..[.Moreover, such retaining means have not been put in
place until after the coils have been wound and the winding guides
removed with the result that some of the turns may cascade, that is
fall out of place..].
SUMMARY OF THE INVENTION
During the winding of the field coils by the automatic winding
machine, the insulated strips extend out from the opposite ends of
the core and the extending ends .Iadd.beyond the off-sets
.Iaddend.are within or underneath removable wire guides. The guides
serve to guide the wire and form it into turns of the coil and to
temporarily support the coil. .[.and the insulated strips.]. Upon
the completion of the winding operation, when the guides are
removed the strips prevent raveling or cascading and then the
strips are bent around the coils to securely fix them to the
core.
DESCRIPTION OF THE FIGURES
FIG. 1 is a prospective view of a stator core in accordance with my
invention prior to the winding thereon of the field coils;
FIG. 2 is a prospective view of the core shown in FIG. 1 with the
wire guides of an automatic winding machine in place;
FIG. 3 is a view similar to FIG. 2, but showing the field coils
wound on the core;
FIG. 4 is a view similar to FIG. 3, but with the wire guides
removed;
FIG. 5 is a view similar to FIG. 4, but showing a finished stator
with the coil retention strips bent around the coils; and
FIG. 6 is a view similar to FIG. 1, but showing a slightly modified
embodiment of the invention.
Referring to FIG. 1, reference character 10 designates a stator
core, usually comprising a stack of laminations stamped from sheet
steel and secured together by rivets 11. Each lamination is formed
with pole pieces 12 and 14 having inner partial cylindrical
surfaces 16. Slots 18 extend through the core on opposite sides of
pole piece 12, while similar slots 20 are on opposite sides of pole
piece 14. A hole 22 extends completely through the core at the
circumferential center of each pole and electrically insulated flat
steel strips 24 extend therethrough. After being inserted, such
strip is bent to form off-sets 26 which bear against opposite ends
of the core to prevent longitudinal displacement of the strip in
the hole 22.
As shown in FIG. 2, preparatory to automatically winding field
coils in the pairs of slots 18 and 20 respectively, winding forms
or wire guides 28 are temporarily secured to the core in well known
manner, each guide being formed with a recess for receiving the
projecting end of the strip 24. As shown at 30, each guide is
spaced from the adjacent end of the core a distance sufficient to
accommodate the coil to be wound.
During the automatic winding operation, which per se forms no part
of this invention, a pair of wire feeding shuttles pass axially
back and forth through the central space between the surfaces 16
and move circumferentially at the end of each pass so as to lay
turns of insulated wire in the pairs of slots 18 and 20, and in the
spaces 30, to form the field coils 32 and 34 respectively, shown in
FIG. 3. When the winding is completed, the guides 28 are removed
and the portions of the coils extending across the ends of the core
are supported by the strips 24, as illustrated in FIG. 4, which
prevents any of the turns from cascading or slipping out of
place.
The final step is to bend the strips 24 tightly around the coils as
indicated at 36 in FIG. 5 to securely anchor the coils to the core
10 which prevents even slight movement which could wear insulation
off the wires of the coils thus creating shorts and grounds.
The embodiment shown in FIG. 6 is similar to that above described,
except that the strips 24 are received in slots 38 formed in the
outer circumferential surface of the core 10 and secured therein by
a staking operation which upsets the metal of the core at points
along the slots as shown at 40.
While I have shown two more or less specific embodiments of my
invention, it is to be understood that this has been done for the
purpose of illustration only, and that the scope of my invention is
not to be limited thereby, but is to be determined by the appended
claims.
* * * * *