US 2091537 A
Description (OCR text may contain errors)
Aug. 3l, 1937. K..J. wAHLBoRG v VACUUI CLEANER Fnac: D ec( 4, '1934 Q N ww Patented Aug. 31, 1937 VACUUM CLEANER xm mm waarborg, stockholm, sweden, u- Ilgnor to Electrolux Corporation,V Dover,` Del.,
a corporation of Delaware ApplicationDecember 4, 1934, Serial No. 755,870 In Germany December 13, 1933 s claims. '(cl. '23o-117) My invention relates to vacuuml cleaners and particularly to means for arranging the electric driving motor in the casing of a vacuum cleaner so as to obtain the maximum amount of cooling of the motor by the air circulated.
In order to maintain the noise produced by the operation of the vacuum cleaner at a minimum, it is desirable to resiliently mount the electric motor in the cleaner casing. This type of mounting absorbs the vibrations produced by the operation of the motor to a great extent and thus reduces the noise which would otherwise result from these vibrations. In order to obtain the maximum cooling effect from the air circulated through the cleaner, it is desirable to cause all of this air topass through the electric motor, which is provided with air passages for this pur- However, in order to assure that all of the air does pass through the motor, it is necessary to provide a seal between the motor housing and the casingin order that none of the air shall pass around the outside of the motor. A'Ihe aforementioned resilient mounting of the motor necessarily permits some movement of the motor with respect to the cleaner casing. Therefore,
the seal between the motor and casing cannotl be a rigid one. One of the objects of my invention is to provide a seal which will be air-tight while still permitting relative movement between the motor and the cleaner casing. A
Another object/of my invention is to reduce turbulence of the air dischargedffrom the fan rotor before it enters the motor. Turbulence re- 35 suns 1n a loss and. hence it is desirable to enminate it in the interest of efficiency.
Further objects and advantages of my invention will be apparent from the following description considered in connection with the accom- 40 panying drawing of which:
Fig. 1 is a cross-sectional view of a preferred embodiment of my invention;
Fig. 2 is a view on an enlarged scale of part of the apparatm shown in Fig. l; and 45 Fig. 3 is a cross-sectional v iew ltalren on the line 3-3 of Fig. 2.
Referring to the drawing, reference character Il designatesla preferably cylindrical casing. A cap member lI I may be secured to one end of cas- 50 ing III by means of releasable fasteners I2. Cap member II is provided with a threaded central aperture I3 into which may be screwed a coupling member I4. Coupling I4 is likewise provided with a central aperture adapted to receive one c5 end of a flexible hose I5. Secured between cap member II and the end of casing. I3 is aanged member Il to which is secured the open end of a dust bag I'l. A perforated plate I3 may be secured within casing III in such a position as to support the closed endl of dust bag I1. 5
The other end of casing I 0 is provided with a ring Il formed with an inner inwardly extending annular portion 20. Secured to ring I3 is a motor supporting zing 2l which may be formed with a plurality of inwardly extending lugs 22. Lugs 22 10 carry bolts 23. Each bolt supports one end of the spiral springs 24, the other end of which is secured to the motor housing 25. 'I'his type of resilient motor support is not new per se and is shown more in detail in the co-pending appli- 15 cation of Erik O. H. Hansson, Serial No. 687,839, filed Sept. 1, 1933. f
- The motor, designated generally by reference character 26, includes housing 25 and bearing shields 2l and 28. 'Ihese shields are formed with 20 air passages 29 and 30, respectively. Air ducts 3| are formed through the stator of the motor and provide for the passage of air therethrough. The front bearing shield 28 may also be provided with radially extending guide vanes 32, shown 25 more particularly in Fig. 3. A transverse wall 23a is carried by bearing shield 2B and, with vanes 32, denes radial channels leading to openings 30.
Secured to the shaft 33 of the motor is a cen- 30 trifugal fan including one or more rotors 34. In the present instance two rotors are shown. An inner fan housing 35 encloses one of the rotors and includes a cylindrical portion 36 and an end wall 3'I. Carried by and spaced from end wall 35 31 is a transverse wall 31a. 'I'he open end of cylindrical portion 38 is formed with an outwardly extending flange 3l and the end wall 31 is formed with a central aperture 33. An outer fan housing 40 is formed with a cylindrical portion 4I and 40 an end wall 42 -having a central opening 42a. The open end of cylindrical portion 4I is formed with an outwardly extending flange 43. A packing ring 44 is located within ring I9 and between the shoulder 23 thereon and motor supporting 45 ring 2i. Flange 38 extends between packing ring 44 and ring 2'I. Flange 43 extends into an annular recess formed in the packing ring. Thus, when ring 2I is drawn toward shoulder 20 and ring I3, it securely clamps'the flanges on fan 50 housings 35 and 40 and thus holds the fan housings in place.
Forward bearing shield 2B of the motor is provided with an outwardly extending 'annular-flange 45 which is formed with a groove 43 therein. A 55 sealing ring'lil, preferably made of rubber or like iiexible material, is retained in groove d6. I'he outer diameter of ring 41 is greater than the inner diameter of the cylindrical portion 36 of inner fan housing 35 and therefore contacts this cylindrical portion. Preferably, the thickness of ring 41 at the outer periphery thereof is less than at its inner periphery, as is clearly shown in Fig. 2. y This tapering form of the ring increases its flexibility.
A cap member d8 is secured to motor supporting ring 2| in any suitable manner and encloses the rear end of the motor. Cap d8 is formed with a threaded aperture 49 which is adapted to receive coupling lil when the cleaner is used for blowing purposes. Inclined vanes 50 may be placed across aperture 49 in order to direct the air discharged therethrough in an upward direction away from the oor. A pair of runners l are provided for movably supporting the cleaner on a ioor or other surface.
`'I'he operation of the device is as follows:
When the fan rotors 34 are rotated by electric motor 26 they serve to draw air through hose i5, coupling i4 and the central opening in cap H into the dust bag I1. Entrained dust is separated from the air stream and is retained in the dust bag while the air passes therethrough and is drawn into central opening 42a in transverse Wall 42 of fan housingd. The forward rotor throws this air outwardly and it passes between stationary wall 31a and transverse wall 31 of fan housing 35. From here the air passes through opening 539 and is acted upon by the second fan rotor which throws it outwardly against the cylindrical portion 36 of inner fan housing 35. Due to the action of the fan rotors this air is travelling in a circular path and is forced to ow radially inwardly between the forward bearing shield 28 of the motor and stationary wall 28a. Radial guide vanes 32 tend to stop the circular motion-of this air and tend to constrain it to ow in a radial direction, thus reducing turbulence. Sealing member 41 prevents the passage of any of this air around the outside of the motor. Consequently all of the air passes through openings 30 in forward bearing shield 28, through passages 3| in the stator and through openings29 in the rear bearing shield 21. Of course, some of the air will pass .between the stator and therotor. 'Ihe air nally will be discharged through the opening 29 in cap 48. 'I'he air thus comes in intimate contact with the motor windings and serves to cool them -eicientlin .The rotation of the motor causes vibrations to be set up therein which are absorbed by the supporting springs 24. These springs permit vthe motor to move somewhat with respect to casing I0 and consequently with respect to the fan housings. However, resilient packing member'41 between the motor and the inner fan housing maintains-an air-tight seal therebetween -while permitting vsuch movement to take place. Obviously, if the fan housings terminate forward of bearing shield 28, sealing member 41 may be of suiiicient diameter'to contact the interior of casing I 0 and thus establish an air-tight seal between the motor and the casing. l
While I have described one more vor less specific embodiment of my invention this has been done `for purposes .of illustration only and the scope of myinvention is not to be limited thereby, but only by the appended claims viewed in the light of the prior art.
What I claim is:
1. In a vacuum cleaner, a motor having a housing and a shaft, a fan rotor carried by said shaft, a casing around said rotor, said casing and said motor housing being resiliently mounted with respect to each other, said motor being formed with air passages therethrough, and exible packing means between said motor and said vcasing for restraining all of the air circulated by said fan rotor to -ow through said air passages'said packing means being separate fromV the resilient mounting.
2. Ina -vacuum cleaner, a motor having a housing and a shaft, a fan rotor carried by said shaft, a casing around said rotor, said casing and said motor housing being resiliently mounted with respect to each other, said motor being formed with air passages therethrough, guide vanes disposed in substantially axial planes between said motor and said rotor and located adjacent to the inlet ends -of said passages, and
'flexible packing means between said motor and said casing for restraining all of the air circulated by said fan rotor to now through said air passages, said packing ,means being separate 'ing a shaft resiiienuy mounted in said casing, a
fan rotor carried by said shaft, a fan housing around said `fan and supported in said casing resiliently with respect to said motor, said motor being formed with air passages therethrough, axially and'radially extending guide vanes located in said fan housing between said fan rotor and said motor adjacent to the inlet ends of said passages, and flexible packing means between said motor and said fan housing for restraining all of the air circulatedby said fan rotor to flow through said air passages.
5. In a vacuum cleaner, a motor having a housing and a shaft, a fan rotor carried by said shaft, a casing around said rotensprings for resiliently mounting said motor housing with respect to said casing, said motor being formed with air passages therethrough, and an annular ilexible packing member carried by said motor housing and contacting said casing for restraining all of the air circulated by said fan rotor to ow through said airvpassages.
6. In a. vacuum cleaner, a motor having a housing and a shaft, a fan rotor carried by said shaft, a casing around said rotor, coil springs for resiliently mounting said'motor housing with respect to said casing, said motor being formed with air passages therethrough, guide vanes disposed in substantially axial planes carried by said motor between said motor and said fan rotor and located adjacent to the inlet ends'of said passages,v and exible packing means between said motor housing andv said casing for restraining all oi the air circulated by Said fan rotor to iiow through said air passages.'
7. In a vacuum cleaner, a casing, a motor having a shaft resiliently mounted in said casing, a fan rotor carried by said shaft, a -fan housing a,oa1,sa7 3 around said fan and supported in said casing resiliently with respect to said motor, said motor being formed with air passages therethrough, an outwardly extending radial ange carried by said l motor and located within said fan housing, and
siliently with respect saidlmotor,` said i motor being formed with air passages therethrough, and
a iiexible annular packing ring carried by said motor within said ian housing, the thickness of saidring being less at the outer periphery than at the inner periphery thereof and the outer diameter of said ring being greater than the inner diameter of said fan housing whereby said ring contacts said housing to restrain ali of the air Y circulated by said fan rotor to pass through said -10 4B11' passages.
KARL JOHN WAHLBORG.