PROCESS FOR INSULATING PREFORMED COILS

PROCEDE D'ISOLATION DE BOBINAGES PREFERMES

English Abstract

A process for insulating preformed coils that are to be installed in an electric
machine. An automatic winding machine winds strips of insulating material around the
conductor bundles of the preformed coils. The process comprises the steps of increasing the
width between the sides of the coil legs and/or the angle of spread formed by the legs of the
coil to meet the minimum processing dimensions of the automatic machine, applying the
insulating material, and reshaping the coil width and angle of spread to dimensions required
for installation into the electric machine.

Claims

WHAT IS CLAIMED IS:
1. A process for insulating preformed coils prior to installation in an electric machine,
the coils comprising conductor bundles having a plurality of sides and legs, the legs defining
an angle of spread between the legs, the preformed coils being wound with strips of
insulating material by an automatic winding machine, the process comprising the steps of:
increasing the width between the sides of the preformed coil to conform to the
minimum processing dimensions required by the automatic winding machine, and
shaping the preformed coils to conform to the coil width and angle of spread required
for installation in the electric machine after applying the insulating material.
2. The process according to claim 1, wherein the process further comprises the step of
increasing the angle of spread.
3. The process according to claim 1, wherein the automatic machine is capable of
widening and reshaping the preformed coils.
4. The process according to claim 1, wherein the preformed coils are initially
manufactured with the dimensions required for installation in the electric machine.
5. The process according to claim 4, wherein the automatic winding machine is capable
of widening and reshaping the preformed coils.

6. A process for insulating preformed coils prior to installation in an electric machine,
the coils comprising conductor bundles having a plurality of sides and legs, the legs defining
an angle of spread between the legs, the preformed coils being wound with strips of
insulating material by an automatic winding machine, the process comprising the steps of:
increasing the angle of spread to conform to the minimum processing dimensions
required by the automatic winding machine, and
shaping the preformed coils to conform to the coil width and angle of spread required
for installation in the electric machine after applying the insulating material.
7. The process according to claim 6, wherein the process further comprises the step of
increasing the width between the sides of the preformed coil.
8. The process according to claim 6, wherein the automatic machine is capable of
widening and reshaping the preformed coils.
9. The process according to claim 6, wherein the preformed coils are initially
manufactured with the dimensions required for installation in the electric machine.
10. The process according to claim 9, wherein the automatic winding machine is capable
of widening and reshaping the preformed coils.

Description

PROCESS FOR INSULATING PREFORMED COILS
Field of the Invention
This invention relates to a process for insulating preformed coils, in which
an
automatic machine winds strips of insulating material around conductor bundles
of preformed
coils.
Background of the Invention
Automatic winding machines apply insulating tape to the conductor bundles of
preformed coils (typically made of copper). The machines that are presently
available can
wind the tape around the preformed coils only if the preformed coils meet
minimum
processing dimensions on the automatic machine. The minimum processing
dimensions at
issue are the width between the sides of the coil and the angle of spread
formed by the legs of
the coil. Regarding coil width, the minimum width required between the sides
of the coils is
150 to 170 mm. Regarding the angle of spread, the minimum angle required
between the legs
of the coils is at least 90°. However, after being wound with
insulating tape, the preformed

CA 02183132 2003-02-14
20365-3595
coils are installed in electric machines that often require
coil dimensions smaller than the minimum sizes required by
the automatic processing equipment.
Therefore, an objective of the invention is to
provide a process whereby preformed coils can be wound with
insulating material on automatic machines regardless of the
dimensions required for installation in an electric machine.
Summary of the Invention
The objective is achieved by enlarging the coil
width, the angle of spread or both to meet the processing
sizes required by the automatic machine. Once the
insulating material is applied, the coils are re-shaped so
that the coil width and angle of spread conform to the
dimensions required for installation in an electric machine.
Increasing coil width or angle of spread or both
make it possible to wind preformed coils with insulating
material completely on automatic machines. Subsequent
shaping imparts to the preformed coils the dimensions
required for installation in an electric machine.
In accordance with one aspect of this invention
there is provided a process for insulating preformed coils
prior to installation in an electric machine, the coils
comprising conductor bundles having a plurality of sides and
legs, the legs defining an angle of spread bet=ween the legs,
the preformed coils being wound with strips of insulating
material by an automatic winding machine, the process
comprising the steps of: increasing the width between the
sides of the preformed coil to conform to the minimum
processing dimensions required by the automatic winding
2

CA 02183132 2003-02-14
20365-3595
machine, and shaping the preformed coils to conform to the
coil width and angle of spread required for installation in
the electric machine after applying the insulating material.
In accordance with another aspect of this
invention there is provided a process for insulating
preformed coils prior to instal_Lation in an e=Lectric
machine, the coils comprising conductor bundles having a
plurality of sides and legs, the legs defining an angle of
spread between the legs, the preformed coils being wound
with strips of insulating material by an automatic winding
machine, the process comprising the steps of: increasing
the angle of spread to conform too the minimum processing
dimensions required by the automatic winding rnachine, and
shaping the preformed coils to ~:onform to the coil width and
angle of spread required for installation in the electric
machine after applying the insulating materia_L.
Brief Description of the Drawings
Figure 1 is a perspective view of a preformed coil
to be wound according to the principles of the invention.
Figure 2 is a schematic plan view of the preformed
coil.
Detailed Description of the Invention
As shown in Figure l, the conductor bundles of the
preformed coil 1 are wound with insulating material in the
form of insulating tape 4. Figure 2 shows that the
2a

preformed coil 1 is hexagonally shaped and comprises coil sides 2 and coil
legs 3. The coil
sides 2 are longer than coil legs 3. The angle between the coil legs 3 is the
angle of spread
and is denoted a. The coil width is the distance between the two coil sides 2.
Preformed coil 1 may be initially manufactured so that the coil width, the
S angle of spread a or both conform to the minimum processing dimensions
required for
automatic machines. After winding preformed coil 1 with insulating material 4,
the coil 1
may then be re-shaped to the dimensions required for installation in an
electric machine.
Preformed coil 1 may alternatively be manufactured with the dimensions
required for installation in an electric machine. The coil width or angle of
spread a may be
widened as needed to conform to the minimum processing size required by the
automatic
machine before applying the insulating material. Prefabricating coil 1 in its
final form is
especially advantageous when the angle of spread a and the coil width of the
final shape are
close to the minimum processing size required by the automatic machine. Prior
to winding,
coil 1 may be widened as needed due to its inherent elasticity without
resulting in permanent
1 S deformation. Then, after winding, preformed coil 1 practically reverts
back to its final shape
without requiring any significant reshaping.
The process described here makes it possible to wind preformed coil 1 with
insulating tape 4 completely on automatic machines regardless of coil width or
angle of
spread a. Increasing the angle of spread a creates sufficient room on the
preformed coil 1 for
engaging the component on the machine that performs the winding operation.
Increasing the
angle a also provides enough room at the crimping point at the end of the coil
so that the
component may also wind tape around this part of the preformed coil 1.
Likewise, increasing
the coil width allows winding of the sides 2 of preformed coil 1 that could
not otherwise be
wound on an automatic machine at all.

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In the preferred embodiment, equipment on the automatic winding machines
performs the widening and reshaping, which makes it unnecessary to transfer
the preformed
coils to separate equipment to perform the corresponding re-shaping of the
coils.
4

Representative Drawing