US20110303239A1 - Agitator with internal twin motor drive system - Google Patents

Abstract

A floor care apparatus includes a housing having a nozzle assembly and a canister assembly. Both a suction generator and a dirt collection vessel are carried on the housing. An agitator cavity is provided on the nozzle assembly. A rotary agitator is provided in the agitator cavity. The rotary agitator includes an internal space. An agitator drive system is provided in the internal space of the rotary agitator. The agitator drive system includes first and second drive motors that simultaneously drive the agitator.

Description

TECHNICAL FIELD AND INDUSTRIAL APPLICABILITY OF THE INVENTION
• The present invention relates generally to the floor care appliance field and, more particularly, to a vacuum cleaner incorporating an agitator with an internal twin motor drive system.
BACKGROUND OF THE INVENTION
• A vacuum cleaner, equipped with a rotary agitator having a single internal drive motor, is disclosed in U.S. Pat. No. 7,070,636. This patent is owned by the assignee of the present invention.
• By providing an agitator with an internal drive motor, one eliminates the need for a drive belt along with the inconvenient and troublesome maintenance required by such a feature. This represents a significant benefit. In addition, the overall design of the drive system is compact. Further, the internal drive system has proven to be a reliable performer characterized by a long service life.
• Despite these numerous benefits and advantages, further improvements are possible. The present invention relates to an agitator with an internal twin motor drive system. Such an arrangement provides a number of additional advantages over the state of the art agitator equipped with a single internal drive motor.
• Specifically, the internal twin motor drive system allows one to provide an agitator of reduced diameter with the same level or even more torque as provided by the state of the art single internal motor design. Thus, the vacuum cleaner equipped with the new internal twin motor drive system may be made with a lower profile. This allows for cleaning under lower bathroom and kitchen cabinet overhangs and furniture. Further, the twin motors may be positioned in the agitator to better balance the weight over the agitator and the overall vacuum cleaner. This functions to increase the cleaning performance and overall service life of the vacuum cleaner while providing the vacuum cleaner with neutral handling characteristics so that it is easier to steer.
SUMMARY OF THE INVENTION
• To achieve the foregoing and other objects, and in accordance with the purposes of the present invention as described herein, an improved floor care apparatus is provided. That floor care apparatus comprises a housing including a nozzle assembly and a canister assembly, a suction generator carried on the housing, and a dirt collection vessel carried on the housing. An agitator cavity is provided on the nozzle assembly. A rotary agitator is provided in the agitator cavity. The rotary agitator includes an internal space. An agitator drive system is provided in the internal space of the rotary agitator. That agitator drive system includes a first drive motor and a second drive motor.
• More specifically, the first and second drive motors are aligned within the internal space. The first drive motor is provided adjacent the first end of the rotary agitator while the second drive motor is provided adjacent a second end of the rotary agitator in order to provide weight balance. An air intake opening is provided at each end of the rotary agitator. An air exhaust outlet is provided between the first and second drive motors. Air filters are provided in the internal space between the intake openings and the drive motors and cooling air is drawn into these filters through the intake opening by the first and second drive motors. The cooling air flows through the first and second drive motors before being exhausted from the rotary agitator through the exhaust outlet.
• In accordance with an additional aspect of the present invention, a method is provided for driving a rotary agitator in a vacuum cleaner. The method comprises providing a first agitator drive motor, providing a second agitator drive motor and simultaneously driving the rotary agitator with the first and second agitator drive motors.
• More specifically, the method includes mounting both the first and second agitator drive motors in an internal space within the rotary agitator. Further, the method includes aligning the first and second agitator drive motors within the internal space while also orienting the first and second agitator drive motors in opposite directions. Thus, the method includes driving the first agitator drive motor in a clockwise direction while simultaneously driving the second agitator drive motor in a counter-clockwise direction.
• Still further, the method includes the step of reducing the overall diameter of the rotary agitator. This is done by using first and second agitator drive motors to drive the rotary agitator instead of a single drive motor where the single drive motor has a diameter D and power output P while each of the first and second agitator drive motors has a diameter less than D and a combined power output of at least P. Thus, the resulting agitator has a reduced diameter allowing the vacuum cleaner or floor care appliance to have a lower overall profile so as to better reach under cabinet overhangs, furniture and the like. At the same time, vacuum cleaner or floor care appliance performance is in no way compromised.
• In the following description there is shown and described several different embodiments of the invention, simply by way of illustration of some of the modes best suited to carry out the invention. As it will be realized, the invention is capable of other different embodiments and its several details are capable of modification in various, obvious aspects all without departing from the invention. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
• The accompanying drawings incorporated herein and forming a part of the specification, illustrate several aspects of the present invention and together with the description serve to explain certain principles of the invention. In the drawings:
• FIG. 1 is a perspective view of a vacuum cleaner constructed in accordance with the teachings of the present invention;
• FIG. 1ais a schematical diagram of the vacuum cleaner illustrated inFIG. 1;
• FIG. 2 is a cross-sectional view through the nozzle assembly of the vacuum cleaner showing the agitator and the agitator drive system;
• FIG. 2ais a detailed transverse cross-sectional view through the agitator illustrating the first power transmission assembly received in the internal space of the agitator;
• FIG. 2bis a detailed cross sectional view of the first end of the agitator including the first drive motor and first transmission assembly; and
• FIG. 3 is an exploded perspective view of the agitator and the agitator drive system.
• Reference will now be made in detail to the present preferred embodiment of the invention, an example of which is illustrated in the accompanying drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION
• Reference is now made toFIGS. 1 and 1ashowing thefloor care appliance10 of the present invention. It should be appreciated that while thefloor care appliance10 is illustrated as an upright vacuum cleaner, embodiments of the present invention also include canister vacuum cleaners, extractors and the like incorporating the rotary agitator and agitator drive system12 of the present invention as described in detail below.
• Theupright vacuum cleaner10 illustrated includes ahousing11 having anozzle assembly14 and acanister assembly16. Thecanister assembly16 further includes acontrol handle18 and ahand grip20. Thehand grip20 carries acontrol switch22 for turning thevacuum cleaner10 on and off. Of course, electrical power is supplied to thevacuum cleaner10 from a standard electrical wall outlet through a cord (not shown).
• At the lower portion of thecanister assembly16, rear wheels (not shown) are provided to support the weight of thevacuum cleaner10. A second set of wheels on the nozzle assembly14 (also not shown) allow the operator to raise and lower the nozzle assembly through selective manipulation of theheight adjustment switch24. Such a height adjustment mechanism is well known in the art. To allow for convenient storage of thevacuum cleaner10, afoot latch26 functions to lock thecanister assembly16 in an upright position as illustrated inFIG. 1. When thefoot latch26 is released, thecanister assembly16 may be pivoted relative to thenozzle assembly14 as thevacuum cleaner10 is manipulated to-and-fro to clean the floor.
• Thecanister assembly16 includes acavity28 adapted to receive and hold thedirt collection vessel30. In the illustrated embodiment, thecavity28 comprises a filter bag compartment that is accessed through aremovable door32. A dirt collection vessel in the form of areplaceable filter bag30 is received and held in that cavity. In alternative embodiments of the present invention thecavity28 receives a dirt cup. Substantially any design of dirt cup known in the art may be provided including those designed to provide cyclonic air flow. As also known in the art, such a dirt cup may or may not include a main filter assembly.
• In the illustrated embodiment, thehousing11 and, more particularly, thecanister assembly16 also carries asuction generator36. Such asuction generator36 comprises a suction fan and cooperating drive motor that function to generate a vacuum air stream for drawing dirt and debris from the surface to be cleaned. While thesuction generator36 is illustrated as being carried on thecanister housing16, it should be appreciated that it could likewise be carried on thenozzle assembly14 if desired.
• Thenozzle assembly14 includes anagitator cavity38 that houses arotary agitator40. As best illustrated inFIG. 2, therotary agitator40 incorporates an outercylindrical wall42 that holds a series ofbristle tufts44 that project outwardly. Thecylindrical wall42 also defines aninternal space44 that receives anagitator drive system46 that will be described in greater detail below. Thewall42 of theagitator40 may be made from, for example, metal, wood, ceramic, plastic and composite materials. More specifically, such materials include but are not limited to aluminum, steel, pressed wood and fiberglass reinforced plastics.
• During operation, the scrubbing action of thebristle tufts44 on theagitator40 and the negative air pressure created by thesuction generator36 cooperate to brush and beat dirt and debris from the nap of a carpet being cleaned and then draw dirt and debris laden air from the agitator cavity andsuction inlet38 into thedirt collection vessel30. Specifically, the dirt and dust-laden air passes serially through thesuction inlet38 and hose and/or integrally molded conduit in thenozzle assembly14 and/orcanister assembly16 as is known in the art. Next, it is delivered into the dirt collection vessel/filter bag30 which serves to trap the suspended dirt, dust and other particles inside while allowing the now clean air to pass freely through to thesuction generator36. A secondary filter (not shown) may be provided between the dirt collection vessel/filter bag30 and thesuction generator36 in order to further insure that no particulates are ingested by the motor of the suction generator. After the air stream passes over the motor of thesuction generator36 to provide cooling, it is forced through afinal filtration cartridge48 before being returned to the environment through anexhaust port34.
• As best illustrated inFIG. 2, the agitator drive system includes afirst drive motor52 and asecond drive motor54. The twodrive motors52,54 are aligned along the longitudinal axis A of theagitator40 within theinternal space46. The first and secondagitator drive motors52,54 are also oriented in opposite directions. Specifically, thefirst drive motor52 is received and held on afirst motor support56 while thesecond drive motor54 is received and held on asecond motor support58. Thefirst motor support56 includes a mountingblock60 keyed into aslot62 in one side of thenozzle assembly14 while thesecond motor support58 includes a mountingblock64 that is keyed into aslot66 at the opposite side of the nozzle assembly (see also detailed showing inFIG. 2b). Afirst bearing assembly68 is carried on thefirst motor support56 and provided between the first motor support and the first end of therotary agitator40. Similarly, asecond bearing assembly70 is provided on thesecond motor support58 and received between the second motor support and a second end of theagitator40. The twobearing assemblies68,70 support theagitator40 in theagitator cavity38 of thenozzle assembly14 while allowing the agitator to freely rotate relative to the nozzle assembly.
• As further illustrated inFIGS. 2 and 3, thefirst drive motor52 includes afirst drive shaft72 and withfirst gear teeth74 while thesecond drive motor54 includes asecond drive shaft76 withsecond gear teeth78. A first power transmission assembly, generally designated byreference numeral80 is received in theinternal space46 and transmits power from thefirst drive motor52 to therotary agitator40. Similarly, asecond transmission assembly82 is received in theinternal space46 and transmits power from thesecond drive motor54 to therotary agitator40.
• Reference is now made toFIGS. 2,2a,2band3 so as to allow detailed description of thefirst transmission assembly80. As illustrated, thefirst transmission80 includes a first planetary gear setcarrier84 carrying a first planetary gear set comprising threegears86, afirst drive ring88 and an associatedrubber drive boot90. Thefirst drive motor52 drives thefirst drive shaft72. Thedrive shaft72 extends through abearing92 held in thehub94 of the planetary gear setcarrier84. The planetary gear setcarrier84 includes threestub shafts96 that support each of the planetary gears86. Each of theplanetary gears86 include teeth that mesh with thegear teeth74 on thedrive shaft72. Additionally, theplanetary gears86 mesh with the teeth of anannular gear98 that is fixed to the housing of thefirst drive motor52 by pin or other means. Thus, it should be appreciated that as thedrive shaft72 is driven by thefirst drive motor52, theplanetary gears86 are driven around theannular gear98, thereby causing the planetary gear setcarrier84 to rotate.
• As noted above, planetary gear setcarrier84 also includes thedrive ring88 and the associatedrubber drive boot90. Thedrive ring88 andrubber drive boot90 both include a series of spacedchannels100 that receive and engageaxial ribs102 projecting inwardly radially from the inner surface of thecylindrical wall42 of therotary agitator40. Thus, the rotation of the planetary gear setcarrier84 is transmitted by thedrive ring88 and associateddrive boot90 directly to and causes like rotation of theagitator40. Therubber drive boot90 provides the necessary damping to ensure the smooth transmission of power to theagitator40.
• Thesecond transmission assembly82 that transmits power from thesecond drive motor54 to theagitator40 is substantially identical to thefirst transmission assembly80 and like reference numbers have been utilized to identify corresponding parts of the second transmission assembly in the drawing figures. Here it should be noted that thefirst drive motor52 andfirst transmission assembly80 are oriented in a first direction within theinternal space46 while thesecond drive motor54 andsecond transmission assembly82 are oriented in the opposite direction so that the two appear to be mirror images. Both drivemotors52,54 simultaneously drive therotary agitator40 through theirrespective transmission assemblies80,82. To achieve this end the firstagitator drive motor52 is operated in a counter-clockwise direction while the secondagitator drive motor54 is operated in a clockwise direction.
• It is important to provide proper cooling to the first andsecond drive motors52,54 confined within theinternal space46 in therotary agitator40. Toward this end, afirst intake opening110 is provided at a first end of theagitator40 and asecond intake opening112 is provided at a second end of the agitator. Afirst air filter114 is provided in theinternal space46 between thefirst intake opening110 and thefirst drive motor52. Similarly, asecond air filter116 is provided in theinternal space46 between thesecond intake opening112 and thesecond drive motor54.
• Athird filter118 is provided in theinternal space46 between the first andsecond drive motors52,54. Thethird filter118 covers a series ofair exhaust outlets120 provided in thewall42 of theagitator40. Typically thefilters114,116 and118 are made from open cell foam, woven filter media or non-woven filter media.
• Air is drawn into theair intake openings110,112 and then through the first andsecond air filters114,116 by operation of the first andsecond drive motors52,54. The air is then forced past bothtransmission assemblies80,82 and thethird filter118 before being exhausted from therotary agitator40 through the exhaust outlets120 (note action arrows B inFIGS. 2 and 2b).
• Advantageously, by using an agitator drive system12 incorporatingdual drive motors52,54, it is possible to reduce the overall diameter of theagitator40 as well as the overall height of thenozzle assembly14. The resulting “low profile”nozzle assembly14 is capable of more easily fitting under vacuum cleaning obstacles such as furniture and bathroom and kitchen cabinets that overhand the floor so as to allow more complete and convenient cleaning. Further, this is accomplished without any loss of power P. More specifically, the overall diameter of therotary agitator40 is reduced by using first and secondagitator drive motors52,54 to drive the rotary agitator instead of a single drive motor where the single drive motor has a diameter D and a power output (torque) P while each of the first and secondagitator drive motors52,54 has a diameter less than D and a combined power output of at least P. For example, a state of the art vacuum cleaner uses a single internal agitator drive motor to drive the rotary agitator. That single agitator drive motor has a diameter of 46 mm requiring an agitator with an outer diameter of 56 mm. In contrast, therotary agitator40 of the present invention equipped with the internal dual motor drive system12 has an overall diameter of 46 mm: that is 10 mm less than the old rotary agitator which is almost an 18% reduction in diameter. This is possible as thedual drive motors52,54 each have an outer diameter of only 39 mm. Specifically, since two drivemotors52,54 are used instead of one; the drive motors themselves may be smaller thereby allowing one to produce anozzle assembly14 with a lower overall profile. Advantageously, this is accomplished without any loss of power.
• The foregoing description of the preferred embodiments of the present invention have been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments were chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally and equitably entitled. The drawings and preferred embodiments do not and are not intended to limit the ordinary meaning of the claims in their fair and broad interpretation in any way.

Claims (20)

1. A floor care apparatus, comprising:

a housing including a nozzle assembly and a canister assembly;

a suction generator carried on said housing;

a dirt collection vessel carried on said housing;

an agitator cavity provided on said nozzle assembly;

a rotary agitator provided in said agitator cavity, said rotary agitator including an internal space; and

an agitator drive system provided in said internal space of said rotary agitator, said agitator drive system including a first drive motor and a second drive motor.

2. The apparatus ofclaim 1, wherein said first and second drive motors are aligned within said internal space.

3. The apparatus ofclaim 2, wherein said first drive motor is provided adjacent a first end of said rotary agitator and said second drive motor is provided adjacent a second end of said rotary agitator so as to provide weight balance.

4. The apparatus ofclaim 3, further including a first intake opening at a first end of said agitator, a second intake opening at a second end of said agitator and an exhaust outlet in a wall of said rotary agitator between said first drive motor and said second drive motor.

5. The apparatus ofclaim 4, further including a first air filter in said internal space between said first drive motor and said first intake opening, a second air filter in said internal space between said second drive motor and said second intake opening and a third air filter in said internal space between said first and second drive motors and covering said exhaust outlet;

cooling air being drawn into said filter through said first and second air intake openings by said first and second drive motors, said cooling air flowing through said first and second drive motors before being exhausted from said rotary agitator through said exhaust outlet.

6. The apparatus ofclaim 5, further including a first motor support engaging said first motor and mounting said first motor to said nozzle assembly and a second motor support engaging said second motor and mounting said second motor to said nozzle assembly.

7. The apparatus ofclaim 6, further including a first bearing assembly provided between said first motor support and said first end of said rotary agitator and a second bearing assembly provided between said second motor support and said second end of said rotary agitator.

8. The apparatus ofclaim 7, further including a first power transmission assembly received in said internal space and transmitting power from said first drive motor to said rotary agitator and a second power transmission assembly received in said internal space and transmitting power from said second drive motor to said rotary agitator.

9. The apparatus ofclaim 8, wherein said first drive motor includes a first drive shaft and said second drive motor includes a second drive shaft.

10. The apparatus ofclaim 9, wherein said first power transmission assembly includes a first planetary gear set carrier carrying a first planetary gear set as well as a first drive ring and associated rubber drive boot.

11. The apparatus ofclaim 10, wherein said second power transmission assembly includes a second planetary gear set carrier carrying a second planetary gear set as well as a second drive ring and associated rubber drive boot.

12. The apparatus ofclaim 11, wherein said first planetary gear set carrier holds a first bearing and said first drive shaft extends through said first bearing while said second planetary gear set carrier holds a second bearing and said second drive shaft extends through said second bearing.

13. The apparatus ofclaim 12, further including a first annular gear fixed to a first housing of said first drive motor and a second annular gear fixed to a second housing of said second drive motor, said first planetary gear set being driven around said first annular gear by said first drive motor while said second planetary gear set is being drive around said second annular gear by said second drive motor.

14. The apparatus ofclaim 13, further including a plurality of axial ribs projecting inwardly into said internal space from said wall of said rotary agitator.

15. The apparatus ofclaim 14, wherein said first and second drive ring and associated rubber drive boot include a plurality of spaced channels that receive and engage said plurality of axial ribs on said wall of said rotary agitator so that said rotary agitator is rotated with said first and second planetary gear set carriers.

16. A method of driving a rotary agitator in a vacuum cleaner comprising:

providing a first agitator drive motor;

providing a second agitator drive motor; and

simultaneously driving said rotary agitator with said first agitator drive motor and said second agitator drive motor.

17. The method ofclaim 16, including mounting both of said first and second agitator drive motors in an internal space within said rotary agitator.

18. The method ofclaim 17, including aligning said first and second agitator drive motors within said internal space in said rotary agitator while also orienting said first and second agitator drive motors in opposite directions.

19. The method ofclaim 18, including driving said first agitator drive motor in a counter-clockwise direction while simultaneously driving said second agitator drive motor in a clockwise direction.

20. The method ofclaim 19, including reducing the overall diameter of said rotary agitator by using said first and second agitator drive motors to drive said rotary agitator instead of a single drive motor where said single drive motor has a diameter D and a power output of P while each of said first and second agitator drive motors has a diameter less than D and a combined power output of at least P.

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