(19) |
|
|
(11) |
EP 0 650 690 B1 |
(12) |
EUROPEAN PATENT SPECIFICATION |
(45) |
Mention of the grant of the patent: |
|
08.07.1998 Bulletin 1998/28 |
(22) |
Date of filing: 26.10.1994 |
|
(51) |
International Patent Classification (IPC)6: A47L 9/22 |
|
(54) |
Vacuum cleaner device
Staubsaugergerät
Aspirateur
|
(84) |
Designated Contracting States: |
|
DE DK ES FR GB IT NL SE |
(30) |
Priority: |
02.11.1993 SE 9303598
|
(43) |
Date of publication of application: |
|
03.05.1995 Bulletin 1995/18 |
(73) |
Proprietor: AKTIEBOLAGET ELECTROLUX |
|
105 45 Stockholm (SE) |
|
(72) |
Inventors: |
|
- Moren, Lars Gunnar
S-141 41 Huddinge (SE)
- Wiss, Christer Caleb Ingemar
S-181 31 Lidingö (SE)
- Lindmark, Magnus Carl Wilhelm
S-114 59 Stockholm (SE)
|
(74) |
Representative: Erixon, Bo et al |
|
c/o AB ELECTROLUX Corporate Patents & Trademarks 105 45 Stockholm 105 45 Stockholm (SE) |
(56) |
References cited: :
WO-A-94/15519 FR-A- 811 248 US-A- 2 531 342
|
DE-U- 7 442 752 US-A- 2 272 985
|
|
|
|
|
|
|
|
|
Note: Within nine months from the publication of the mention of the grant of the European
patent, any person may give notice to the European Patent Office of opposition to
the European patent
granted. Notice of opposition shall be filed in a written reasoned statement. It shall
not be deemed to
have been filed until the opposition fee has been paid. (Art. 99(1) European Patent
Convention).
|
[0001] This invention relates to a vacuum cleaner.
Vacuum cleaners having a fan unit driven by an electric motor and placed after the
dust bag as seen in the air flow direction, are previously known, see for instance
US-A-2272985. According to this arrangement the primary air flow created by the fan
unit is arranged to directly or indirectly leave the unit via an outlet to atmosphere.
There is also provided first means creating a secondary air flow which at least partly
cools the electric motor and which flows into the electric motor via one or several
inlets which are separated from the primary air flow.
[0002] Vacuum cleaners operating with high speed electric motors are described in WO-A-94/15518
and WO-A-94/15519 and mainly have the advantage that they because of the small dimensions
of the vacuum source (turbo fan unit), can be manufactured as small hand held appliances
which are easy to handle and to store at the same time, as the suction power is on
the same level as previously known traditional vacuum cleaners i.e. such having a
power demand of 500 - 1.500 W.
[0003] Normally, to cool electric motors in conventional vacuum cleaners, see for instance
US-A-2531342 or FR-A-811248, the air flow, which is created by the fan and which is
used for sucking up particles through the nozzle, is also used to cool the motor.
When the particles have been separated from the air in the dust bag and the air has
flown through the fan, the air or a part of the air passes outside and through the
electric motor before it is exhausted to atmosphere. This method for cooling the electric
motor is simple but can not be used in connection with the vacuum cleaners described
in the two WO-publications mentioned above since the air which reaches the motor despite
the separation of the particles is contaminated and can cause damages of the motor.
It is also desirable to use these fast running electric motors for so called wet and
dry suction cleaners i.e. such cleaners where the water or cleaning liquids are taken
up by the nozzle together with the contaminates, the moisty air flow, if beeing allowed
to pass through the motor, in a very short time would damage it. It is further a risk
that larger particles or details follow the air flow into the motor if for any reason
the dust bag would break and that these particles because of the small dimensions
of the motor and the narrow passages in the motor would damage it.
[0004] The purpose of this invention is to achieve a device which gives a reliable cooling
of the electric motor for a turbo fan unit described in said WO-publications at the
high speed wich is used in this connection. This is achieved with a device having
the caracteristics mentioned in independent claim 1.
[0005] Since the high speed motor because of its small dimensions and hence the concentrated
heat emission is sensitive for disturbances in the cooling air flow there is also
a risk that the motor is quickly damaged if the cooling air flow should be blocked
because the nozzle or air passages to the motor are clogged by dust or larger details.
According to the major part of the embodiments of the invention shown below a sufficient
cooling of the vacuum cleaner is achieved also if the air flow through the dust bag
should be disturbed.
[0006] Some embodiments of the invention will now be described with reference to the accompanying
drawings in which Fig. 1 in a schematic perspective view shows a vacuum cleaner according
to the invention, Fig. 2 is a longitudinal vertical section through the hand held
motor housing of the vacuum cleaner, Fig. 3 is a longitudinal vertical section through
the turbo fan unit in the motor housing, Fig. 4 shows in the same view as Fig. 3 an
alternative embodiment of the turbo fan unit and Fig. 5-7 in the same view show three
additional embodiments of the invention.
[0007] As appears from Fig. 1 and 2 the vacuum cleaner comprises a hand held motor housing
10 comprising a turbo fan arrangement 11 and a dust bag 12 the motor housing 10 via
a tube shaft 13 being connected to a nozzle 14. The motor housing is via a cable 15
connected to a stationary unit 16 which by means of a cable 17 and a plug 18 can be
connected to the electric supply system. The stationary unit comprises, with the exception
of a cable reel, and additional accessories for the vacuum cleaner also the electronic
equipment which is neccessary for running the electric motor. Speed control is made
by control means 19 placed on the motor housing.
[0008] The motor housing 10 comprises a plastic hood 20 having a handle 21 in which said
control means are inserted. The front end of the plastic hood is shaped as a lid 22
with a tube socket 23 to be fastened on the tube shaft 13. The tube socket 23 opens
into the dust bag 12 which is surrounded by a shell so that a tube shaped channel
24 is created. The channel continues in the direction towards the rear part of the
motor housing via a section 25 with gradually decreasing section area into an inlet
26 for a turbo fan unit 27 which is a part of the turbo fan arrangement 11. The turbo
fan unit 27 comprises a shell forming an inlet section 28 with gradually increasing
section area and a turbo fan impeller 29 having blades in close vicinity of the section
28. The turbo fan unit 27 also has an outlet 30.
[0009] The turbo fan impeller 29 which is a combined axial-radial impeller is fixed on a
shaft 31 of an associated electric motor 32 the same shaft also supporting the rotor
of the electric motor. The electric motor is driven at a speed which is above 50.000
rpm and which preferably is 70.000 - 120.000 rpm. The stator 34 of the electric motor
is surrounded by a motor shell 35 which together with an outer shell part 36 forms
an annular passage 37 in which the outlet 30 of the turbo fan unit opens. The rear
end of the motor shell 35 is shaped as a cut off tapered sleeve 38 one end of which
together with the shell part 36 forms a radial outlet 39 with a filter 40 through
which the air flow which the turbo fan unit 27 creates can leave to atmosphere.
[0010] The shaft 31 of the electric motor is at each side of the rotor 33 resting in a hub
part 41 of the motor shell 35 and the shell has several openings 42, 43 for cooling
air placed outside and near the hub part 41. Cooling air which is drawn from an inlet
44 at the outer part of the sleeve 38 is supplied to or withdrawn from the rotor and
stator windings of the electric motor by means of a fan 45. This fan for cooling air
is a centrifugal fan which is arranged at the rear side of the turbo fan impeller
29 so that the blades of the cooling fan are facing towards the electric motor. The
shell of the electric motor forms a fan housing in which the openings 42 are the inlets
for the cooling fan whereas the outlet 46 of the fan is placed in close vicinity to
the outlet 30 of the turbo fan unit. The cooling fan 45 can of course be a part which
is removable from the turbo fan impeller 29 or be integrated with it.
[0011] The device described in Fig. 1-3 operates in the following way. By activating the
control means 19 the electric motor 32 is started which means that the shaft 31 with
the turbo fan impeller 29 and the cooling fan 45 starts to rotate. The turbo fan impeller
creates a flow of air which is sucked through the nozzle 14 and which via the tube
shaft 13 enters into the dust bag 12 in which the dust particles are separated from
the air flow. The air then continues through the channel 24 and the section 25, through
the inlet 26 to the turbo fan unit 27 from which it escapes as a primary air flow
through the outlet 30 to the annular passage 37 surrounding the motor shell 32 and
cools the outside of the motor. At the same time air is sucked into the motor through
the inlet 44 in the sleeve 38 by means of the fan 45 in a counter flow with respect
to the air flowing through the annular passage. This cooling air, which is a secondary
air flow enters the motor shell via the openings 43 and flows over the the internal
parts of the motor thereby effectively cooling bearings, stator and rotor before leaving
to the cooling air fan 45 via the openings 42. The cooling air then flows through
the outlet 46 into the air flow which is leaving the turbo fan unit. The two air flows
are mixed with each other and then flow through the passage 37, the outlet 39 and
the filter 40 to atmosphere.
[0012] It has also proved to be possible to desist from the blades of the cooling air fan
and instead let the rear side of the turbo fan impeller be a mainly flat surface since
the friction which is present between the rotating surface and the molecules of the
air gases at these high speed is sufficient to throw the molecules towards the periphery
so that a cooling air flow is created through the motor.
[0013] The device shown in Fig.4 differs from the device which is shown in Fig. 3 only with
respect to the cooling air fan which is missing. Instead the passage 37 has a narrow
section 47 which together with through openings 48 in the motor shell 31 forms a venturi
which sucks cooling air from the inlet 44 via the openings 43 and through the motor.
However, this embodiment has the disadvantage that there is no cooling if the primary
air flow is blocked which could happen if something clogges the nozzle or the tube
shaft.
[0014] The embodiment shown in Fig. 5 has no separate cooling air fan. Instead the turbo
fan impeller 29 is used in order to suck the cooling air from the inlet 44 of the
cooling air through the electric motor via one or several channels 49 extending from
the inside 35 of the motor shell to a chamber 50 outside the shell part 36 the chamber
via one or several openings 51 communicating with the inlet 26 of the turbo fan unit.
[0015] In the embodiment shown in Fig. 6 a cooling air fan 52 is used which is placed at
the inlet 44 for the cooling air i.e. at the opposite side of the electric motor with
respect to the turbo fan impeller. The air is by means of the cooling air fan forced
through the electric motor and into the primary air flow through openings 53 in the
motor shell.
[0016] By means of the suggested arrangements which are illustrated in Figs. 2-3 and 5-6
an effective cooling of the motor is allways achieved at the high speed which is used
this cooling effect mainly being independent of the air flow through the nozzle.
[0017] Fig. 7 shows an arrangement which is similar to the arrangement shown in Fig. 3 but
in which there is a seperate annular deflector plate 54 surrounding the rear part
of the impeller 29. The plate 54 is placed at a distance from the motor shell 35 so
that a passage 55 is formed through which the cooling air flow from the fan 45 enters
into the primary flow in the passage 37 mainly in the same direction as the primary
flow. This arrangement has proved to give a considerable increase in the suction power.
1. Vacuum cleaner device wherein the device is provided with a suction nozzle (14) and
a dust bag connected to the nozzle for instance by means of a tube connection (13);
a turbo fan arrangement (11) comprising a turbo fan unit (27) driven by an electric
motor (32) and placed after the dust bag (12), seen in the air flow direction, the
primary air flow created by the turbo fan unit (27) being arranged to directly or
indirectly leave the unit via an outlet (39) to atmosphere; first means (45,47,29,52)
creating a secondary air flow which at least partly cools the electric motor (32)
and which flows into the electric motor (32) via one or several inlets (43) which
are separated from the primary air flow, the impeller (29) of the fan unit being driven
at a speed which is above 50.000 rpm; second means in the form of openings (46,48,51,53)
and/or a deflector plate (54) for directing at least a part of the secondary air flow
from the first means (45,47,29,52) into the primary air flow.
2. Device according to claim 1 wherein said first means comprises a fan (45) for cooling
air which is placed at the same side of the electric motor (32) as the turbo fan unit
(27), the fan preferably being of the radial type.
3. Device according to claim 2 wherein the fan (45) for cooling air and the turbo fan
impeller (29) are an integrated unit.
4. Device according to any of the preceding claims wherein the electric motor is provided
with hub parts (41) which support bearings for an electric motor shaft (31), the cooling
air inlets (43) to the electric motor being arranged close to one of said hub parts
whereas the cooling air outlets (42) from the electric motor are arranged close to
the other hub part.
5. Device according to claim 2 wherein the cooling air fan is formed by the mainly flat
rear side of the turbo fan impeller (29).
6. Device according to any of the preceding claims wherein it comprises a passage (37)
which is so arranged that the primary air flows around the shell (35) of the electric
motor (32) whereas the cooling air flow is arranged to counterflow within the motor
shell (35).
7. Device according to claim 1 wherein said first means is a venturi (47) in which the
primary air flow is the active medium of the venturi and in which the inlet (44) of
the secondary air flow communicates with the suction side (48) of the venturi.
8. Device according to claim 1 wherein said first means is the impeller (29) of the turbo
fan unit (27) the space within the shell of the electric motor communicating with
the inlet (26) of the turbo fan unit via a pipe connection or the like.
9. Device according to claim 1 wherein said first means comprises a fan (52) for cooling
air which is placed at the opposite side of the electric motor with regard to the
turbo fan impeller (29).
10. Device according to any of the preceding claims wherein said deflector plate (54)
directs the secondary air flow from the cooling air fan into the same direction as
the primary air flow.
1. Staubsaugergerät mit einer Saugdüse (14) und einem Staubbeutel, welcher mit der Saugdüse
beispielsweise über eine Rohrstange (13) verbunden ist, gekennzeichnet durch ein Turbogebläse (11), umfassend eine Turbogebläseeinheit (27), welche durch einen
Elektromotor (32) angetrieben wird und, in Strömungsrichtung der Luft gesehen, hinter
dem Staubbeutel (12) angeordnet ist, wobei der Primärluftstrom, der durch die Turbogebläseeinheit
(27) erzeugt wird, so geleitet wird, daß er aus der Einheit direkt oder indirekt über
einen Auslaß (39) in die Atmosphäre austritt; sowie durch eine erste Einrichtung (45,
47, 29, 52), die einen Sekundärluftstrom erzeugt, welcher zumindest teilweise den
Elektromotor (32) kühlt, und welcher über einen oder mehrere Einlässe (43), welche
vom Primärluftstrom getrennt sind, in den Elektromotor (32) einströmt, wobei das Gebläserad
(29) der Turbogebläseeinheit mit einer Geschwindigkeit angetrieben wird, die oberhalb
von 50.000 U/min liegt; und durch eine zweite Einrichtung in Form von Öffnungen (46,
48, 51, 53) und/oder einer Leitplatte (54), welche zumindest einen Teil des Sekundärluftstromes
von der ersten Einrichtung (45, 47, 29, 52) in den Primärluftstrom leitet.
2. Gerät nach Anspruch 1, dadurch gekennzeichnet, daß die erste Einrichtung ein Gebläse (45) für Kühlluft umfaßt, welche auf derselben
Seite des Elektromotors (32) angeordnet ist wie die Turbogebläseeinheit (27), wobei
das Gebläse vorzugsweise ein Radialgebläse ist.
3. Gerät nach Anspruch 2, dadurch gekennzeichnet, daß das Gebläse (45) für die Kühlluft und das Turbogebläserad (29) eine integrale Einheit
bilden.
4. Gerät nach einem oder mehreren der vorhergehenden Ansprüche, dadurch gekennzeichnet, daß der Elektromotor mit Nabenteilen (41) versehen ist, welche die Lager für die Welle
(31) des Elektromotors abstützen, und daß die Kühllufteinlässe (43) am Elektromotor
in der Nähe eines der Nabenteile angeordnet sind, während die Kühlluftauslässe (42)
aus dem Elektromotor in der Nähe des anderen Nabenteiles angeordnet sind.
5. Gerät nach Anspruch 2, dadurch gekennzeichnet, daß das Kühlluftgebläse durch die im wesentlichen flache Rückseite des Turbogebläserades
(29) gebildet wird.
6. Gerät nach einem oder mehreren der vorhergehenden Ansprüche, dadurch gekennzeichnet, daß dieses einen Durchlaß (37) aufweist, welcher so angeordnet ist, daß der Primärluftstrom
um das Gehäuse (35) des Elektromotors (32) fließt, wohingegen der Kühlluftstrom so
geleitet wird, daß er innerhalb des Motorgehäuses (35) entgegenfließt.
7. Gerät nach Anspruch 1, dadurch gekennzeichnet, daß die erste Einrichtung eine Venturidüse (47) ist, in welcher der Primärluftstrom das
aktive Medium ist, und in welcher der Einlaß (44) des Sekundärluftstromes Verbindung
zur Saugseite (48) der Venturidüse hat.
8. Gerät nach Anspruch 1, dadurch gekennzeichnet, daß die erste Einrichtung das Gebläserad (29) der Turbogebläseeinheit (27) ist, und der
Raum innerhalb des Gehäuses des Elektromotors Verbindung mit dem Einlaß (26) der Turbogebläseeinheit
über eine Rohrverbindung oder dergleichen besitzt.
9. Gerät nach Anspruch 1, dadurch gekennzeichnet, daß die erste Einrichtung ein Gebläse (52) für Kühlluft umfaßt, welches in bezug zum
Turbogebläserad (29) auf der gegenüberliegenden Seite des Elektromotors angeordnet
ist.
10. Gerät nach einem oder mehreren der vorhergehenden Ansprüche, dadurch gekennzeichnet, daß die Leitplatte (54) den Sekundärluftstrom vom Kühlluftgebläse in derselben Richtung
wie den Primärluftstrom leitet.
1. Dispositif formant aspirateur, dans lequel le dispositif est muni d'une buse d'aspiration
(14) et d'un sac à poussière relié à la buse, par exemple, par l'intermédiaire d'une
liaison par tuyau (13) ; un agencement de turboventilation (11) comportant une unité
de turboventilation (27) entraînée par un moteur électrique (32) et placée après le
sac à poussière (12), dans la direction d'écoulement de l'air, l'écoulement d'air
principal créé par l'unité de turboventilation (27) étant agencé pour quitter directement
ou indirectement l'unité via une sortie (39) vers l'atmosphère ; des premiers moyens
(45, 47, 29, 52) créant un écoulement d'air secondaire qui refroidit au moins partiellement
le moteur électrique (32) et qui s'écoule jusque dans le moteur électrique (32) via
une ou plusieurs entrées (43) qui sont séparées de l'écoulement d'air principal, la
roue (29) de l'unité de turboventilation étant entraînée à une vitesse qui est supérieure
à 50000 tours minute ; des seconds moyens ayant la forme d'ouvertures (46, 48, 51,
53) et/ou d'une plaque formant déflecteur (54) pour diriger au moins une partie de
l'écoulement d'air secondaire provenant des premiers moyens (45, 47, 29, 52) jusque
dans l'écoulement d'air principal.
2. Dispositif selon la revendication 1, dans lequel lesdits premiers moyens comportent
un ventilateur (45) pour l'air de refroidissement qui est placé au niveau du même
côté du moteur électrique (32) que l'unité de turboventilation (27), le ventilateur
étant de préférence du type radial.
3. Dispositif selon la revendication 2, dans lequel le ventilateur (45) pour l'air de
refroidissement et la roue de turboventilation (29) sont une unité formée en un seul
bloc.
4. Dispositif selon l'une quelconque des revendications précédentes, dans lequel le moteur
électrique est muni de parties de moyeu (41) qui supportent des paliers pour un arbre
de moteur électrique (31), les entrées d'air de refroidissement (43) vers le moteur
électrique étant agencées à proximité d'une desdites parties de moyeu alors que les
sorties d'air de refroidissement (42) depuis le moteur électrique sont agencées à
proximité de l'autre partie de moyeu.
5. Dispositif selon la revendication 2, dans lequel le ventilateur d'air de refroidissement
est formé par le côté arrière pratiquement plat de la roue de turboventilation (29).
6. Dispositif selon l'une quelconque des revendications précédentes, dans lequel il comporte
un passage (37) qui est agencé de sorte que l'air principal s'écoule autour de l'enveloppe
(35) du moteur électrique (32) alors que l'écoulement d'air de refroidissement est
agencé à contre-courant dans l'enveloppe de moteur (35).
7. Dispositif selon la revendication 1, dans lequel lesdits premiers moyens sont un venturi
(47) dans lequel l'écoulement d'air principal est le milieu actif du venturi et dans
lequel l'entrée (44) de l'écoulement d'air secondaire communique avec le côté d'aspiration
(48) du venturi.
8. Dispositif selon la revendication 1, dans lequel lesdits premiers moyens sont la roue
(29) de l'unité de turboventilation (27), l'espace situé dans l'enveloppe du moteur
électrique communiquant avec l'entrée (26) de l'unité de turboventilation via une
liaison par tuyau ou analogue.
9. Dispositif selon la revendication 1, dans lequel lesdits premiers moyens comportent
un ventilateur (52) pour l'air de refroidissement qui est placé au niveau du côté
opposé du moteur électrique par rapport à la roue de turboventilation (29).
10. Dispositif selon l'une quelconque des revendications précédentes, dans lequel ladite
plaque formant déflecteur (54) dirige l'écoulement d'air secondaire provenant du ventilateur
d'air de refroidissement dans la même direction que l'écoulement d'air principal.