Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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FIELD OF THE INVENTION
The present inventlon relates generally to cooling of
heat generating components, and typically cooling of
electric motors, compressors, inverters and the like.
PURPOSE AND BACKGROUND OF THE INVENTION
Some electric motors comprise an outer casing provided
with fins used as heat dissipators for the heat that is
produced by the motor and released in particular by pole
pieces of the motor.
In some motor designing, the motors have a smooth casing
and an inner cooling circuit, which makes possible to
reduce the weight of the motor. However, it has been
found that these motors could not easily be used for
example in compact conditioning units in which the motor
as well as the compressor, the inverter and the various
Z0 attachments associated thereto, are themselves arranged
in a housing. Moreover, cooling is made difficult for
seal-tight motors.
Such compact units are used in various applications, for
example in aeronautics, and it is necessary to provide a
cooling of the components of the motor by a circulation
of a fluid, for example air.
The purpose of the invention is to solve the above
mentioned problem by providing the motors, compressors
and other elements, with complementary means that make
possible to ensure with a great efficacity the cooling
thereof without substantially increasing their weight,
while occupying only a very small space in the housing,
box or container in which the relative machines are
arranged.
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SUMMARY OF THE INVENTION
According to the invention, the cooling arrangement for
electric motors, compressors, inverters and other
devices connected together and provided with means for
circulating a cooling gas, is characterized in that the
motor type device comprises a smooth casing at least in
an area that corresponds to heat releasing components,
in particular pole pieces, and in that this smooth
casing is covered by at least one segment of cooling
member comprising an external sheet for at least one
heat dissipator formed of a thin corrugated sheet, and a
connecting means such as a heat conducting glue that
connects the at least one segment of cooling member to
the casing by forming circulation channels for the
cooling gas which circulates therethrough.
Various other features of the invention are moreover
revealed from the detailed following disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention are shown as non-limitative
examples, in the accompanying drawings, wherein :
Fig. 1 is a diagrammatic cross-sectional elevation view
of an electric motor embodying the cooling arrangement
of the invention ;
Fig. 2 is a diagrammatic longitudinal cross-section of
the motor of Fig. 1 provided with the cooling
arrangement ;
Fig. 3 is a diagrammatic perspective view of a cooling
unit of an other shape.
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DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, Figs. 1 and 2 show a
motor type device made of an electric motor 1 that is
connected to a receiving machine 2 for driving the same,
which receiving machine 2 is for example a compressor of
an air conditioning unit that comprises an inverter
generally shown as a parallelepiped 3 in Fig. 3.
The electric motor 1 comprises pole pieces 4 formed by
packs of iron sheets that are maintained in a casing 5
of a cylindrical shape which is, or not, a part of the
static magnetic circuit of the motor 1. The casing 5 is
made of ferro-magnetic material in case it participates
to the magnetic circuit of the motor, or is made of
aluminum or the like material in case it does not
participate to the magnetic circuit of the motor.
In a general manner, the aluminum alloys that are used
in the latter case are moulded or manufactured from
rolled sheets.
The casing 5 is connected to front parts 6, 7 that are
preferably of a same material as the casing 5, and which
carry bearing members 8, 9 for a shaft 15 that supports
a rotor 11 for the motor 1.
As usual, the pole pieces 4 are provided with windings
12, and the rotor 11 with magnets 13.
The casing 5 of the motor 1 is surrounded, on all or
part of its surface, and at least on the part of its
surface that is opposed to the pole pieces 4, with a
cooling member 14.
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The cooling member 14 is formed with two sheets 15, 16
of copper, aluminum, nickel, or of an alloy thereof,
with heat dissipators 17 being fixed therebetween by
being brazed or fixed by another means such as a glue
which can advantageously be a heat conducting glue and
for example a glue loaded with a metal powder, in
particular a powder of aluminum, copper or any suitable
material.
Fig. 1 shows that the cooling member 14 can be formed by
a plurality of segments or sectors 141, 142, 143
which are connected to the surface of the casing 5 and
for example fixed by means of a suitable glue loaded
with a metal powder.
In case, and when the cooling member 14 is formed by a
plurality of segments or sectors, one or a plurality of
binder hoops 18 can be provided for preventing any risk
of separation of these segments or sectors.
The heat dissipators 17 are formed by thin corrugated
metal sheets as illustrated by Figs. 1 and 3.
In addition to the above description, there is provided
to position the cooling member 14 in a stream of air or
other cooling gas in circulation, which is provided, in
the illustrated example, by a hood 19 extending the
cooling member 14 and in which is arranged a fan or a
turbine 20 that is driven by the electric motor 1 or an
independent motor (not shown).
The receiving machine 2, for example a compressor, is
advantageously provided, at the periphery thereof, with
cooling members 14 similar to the one of the electric
motor 1 and which are similarly arranged.
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When the receiving machine 2 is at a distance from one
of the front parts 7 of the motor 1 as in the embodiment
of Fig. 2, the cooling member 14 will protrude beyound
the receiving machine 2 to be connected to the cooling
s member 14, so that the stream of air circulating in the
cooling member 14 of the motor will generate also a
stream of air within the heat dissipator covering the
receiving machine.
It is moreover advantageous to provide apertures or
punctures 22 in the sheet 16 that forms the external
casing of the cooling members 14, which apertures or
punctures 22 are arranged from place to place and
provided to aspirate cooler gases surrounding the sheets
16 that forms the casing of the cooling member.
Fig. 3 shows that a same type of cooling member 14 can
be positioned on an inverter or other member 3 to which
it is fixed as described above for example by means of
an advantageously heat conducting glue. Fixation members
23, for example screws, can supplementarily connect the
cooling member 14 to the inverter 3 to be used as safety
components.
In a variant of embodiment, the internal sheet 15 of the
cooling member 14 is no more used. In this case, the
heat dissipators 14 are directly fixed, by means of
their corrugations, onto the casing 5, inverter 3 or
other like device to be cooled.
The glues that can be used for fixing the segments of
the cooling members 14 are of various types. As an
example, bi-component glues manufactured by the company
CIBA have been used in the invention, in particular
those having the references HV 998 et AV 138 and
supporting a continuous temperature of 140~C and peaks
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of temperature of 200~C, as well as glues having the
reference AV 4415 and AV 4416 and supporting a
continuous temperature of 180~C. Other glues are
satisfactory, for example the glue sold under the
trademark 3M, reference AV 118 or 119 that supports a
continuous temperature of 140~C and peaks of temperature
of 200~C. Double-side adhesive films with a thickness of
5u sold also under the trademark 3M have permitted to
support a continuous temperature of 150~C and peaks of
temperature of 260~C during a time duration greater that
15 minutes.
The invention is not restricted to the embodiments shown
and described in detail and various modifications
1S thereof can be applied thereto without departing from
the scope of the invention as shown in the claims.
In particular, according to a variant of embodiment, the
segments of the cooling member are removably mounted and
maintained by a binding hoop or other suitable
maintaining member. In this case, a conducting grease is
preferably interposed between each of the segments of
the cooling member and the device carrying it.
