Metal working – Method of mechanical manufacture – Electrical device making
Reexamination Certificate
2002-03-20
2003-03-25
Larson, Lowell A. (Department: 3725)
Metal working
Method of mechanical manufacture
Electrical device making
C029S732000
Reexamination Certificate
active
06536094
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to winding coils for lamination stacks of a stator. More particularly, the solutions of the invention are concerned with winding coils of alternator stators, and forming the relative end leads. The coils that become wound by the solutions of the invention have an undulated shape, like those that are formed by the apparatus and functioning principles described in U.S. Pat. No. 4,512,376 (herein referred to as “Barrera '376”) assigned to the same assignee of this application. (Barrera '376 is hereby incorporated by reference herein in its entirety.)
As shown in
FIG. 1
, which is a perspective view of a traditional undulated coil
10
formed according to the principles of Barrera '376, coil
10
has a central axis O, which is substantially perpendicular to the various wire turns
20
of the coil, each of the wire turns defining a plane P. (Those skilled in the art will appreciate that a reference to a “plane” in connection with a helical coil is an approximation used for convenience herein.) Initial lead
11
of the coil is contained in lowermost plane A of the planes P, while final lead
12
is contained in uppermost plane B of the planes P. Coil
10
becomes inserted in respective slots
13
of stator stack
14
as shown in FIG.
2
. This is done by means of an insertion operation requiring pushing of the coil in the longitudinal direction
15
, parallel to axis O with the stator stack in an overhead position, aligned with axis O. The coil is placed on an insertion tool (not shown) to accomplish such an operation. In pushing the coil into the stator stack, radial arms
16
of the coil become inserted in the slots
13
, while bridging sections
17
form the end portions of the coils, and are located outside the extreme faces of the stack. As shown in
FIG. 2
, leads
11
and
12
have been rotated to become practically parallel to axis O. In
FIG. 2
the stator stack has been turned upside down with respect to the position which it would have when pushing in direction
15
of
FIG. 1
during the insertion operation. The distances of leads
11
and
12
from axis O after the coil has been inserted in the stator stack are particularly pertinent to presentation of this invention. As shown in
FIG. 2
, initial lead
11
is nearer to axis O than final lead
12
.
Usually, at least three coils (often referred to as phase coils) like coil
10
are inserted in the stator stack to form the final product. These can be inserted into the stator stack simultaneously or separately. Each coil will be inserted in respective and different sets of slots. When inserted, the coils will be at different radial distances from center axis O of the stack, as shown by references R
1
, R
2
and R
3
in
FIG. 3
, corresponding to coils
8
,
9
, and
10
.
FIG. 3
is a partial view of the stator, as seen from direction
3
—
3
of
FIG. 2
, but with all three coils inserted, as would be required in the final product. For sake of clarity only one coil has been shown in FIG.
2
.
It is clear from
FIG. 3
that initial lead
11
of coil
10
(the nearest to axis O) can be very near to central opening
10
′ of the stack. This is also evident from
FIG. 3
a
, which is a view from direction
3
a
—
3
a
of FIG.
3
. (The location of axis O is not shown accurately in
FIG. 3
a
or
FIG. 11
to avoid unduly enlarging these FIGS.) Furthermore, initial lead
11
does not have bridge portions
17
between itself and central opening
10
′. This renders initial lead
11
more unstable to lateral displacements (in particular, in the radial direction with respect to the central axis) compared to the other leads. Because of this, small accidental displacements of initial lead
11
toward center axis O can cause it to enter central opening
10
′ of the stator stack. Such a situation can cause a physical interference of the initial lead
11
with the rotor that is destined to rotate in central opening
10
′. A frequent consequence of this is damage to the initial lead.
In view of the foregoing, it would be desirable to provide improved methods and apparatus for winding undulated coils for dynamo-electric machine stators. It would also be desirable to provide methods and apparatus for winding undulated coils for dynamo-electric machine stators that reduce the likelihood of damage to lead wires. It would further be desirable to provide an undulated coil whose wire leads are less susceptible to damage.
SUMMARY OF THE INVENTION
It is an object of this invention to provide improved methods and apparatus for winding undulated coils for dynamo-electric machine stators. It is also an object of this invention to provide methods and apparatus for winding undulated coils for dynamo-electric machine stators that reduce the likelihood of interference between lead wires and rotors of dynamo-electric machines. It is a further object of this invention to provide an undulated coil whose wire leads are less susceptible to damage.
These and other objects are accomplished by providing a wire coil winding head which includes, among other features, a gripper configured to hold an initial lead of the wire; a receiver structure configured to receive the wire extending from the gripper and to form a coil of the wire having successive turns that are substantially disposed in respective planes that are substantially perpendicular to a central longitudinal axis of the coil and laterally spaced from one another along that axis; a forming structure configured to produce undulations in the turns of wire in their respective planes while the turns are on the receiver structure, the undulations giving the turns portions that are substantially radial of the axis; and a gripper positioning structure configured to position the gripper relative to the receiver structure so that the initial and final leads can be placed substantially in the same plane as each other and each lead can also be substantially aligned with a respective portion of the coil that is substantially radially disposed with respect to the longitudinal axis. Accordingly, the invention permits both initial and final leads, as installed in a stator, to be disposed at a safe distance from the rotor destined to rotate within the stator.
REFERENCES:
patent: 3636990 (1972-01-01), Eminger et al.
patent: 4512376 (1985-04-01), Barrera
patent: 5076508 (1991-12-01), Arnold et al.
patent: 5881778 (1999-03-01), Barrera
patent: 0 818 874 (1998-01-01), None
Bonnacorsi Andrea
Stratico Gianfranco
Arons Edward M.
Axis USA Inc.
Fish & Neave
Larson Lowell A.
LandOfFree
Lead formation in undulated coils for dynamo-electric... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Lead formation in undulated coils for dynamo-electric..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Lead formation in undulated coils for dynamo-electric... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3051008