Rotary expansible chamber devices – Working member has planetary or planetating movement – Plural working members or chambers
Utility Patent
1999-11-05
2001-01-02
Chin, Randall E. (Department: 1744)
Rotary expansible chamber devices
Working member has planetary or planetating movement
Plural working members or chambers
C418S122000, C418S129000, C015S327100
Utility Patent
active
06168405
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a vacuum cleaner, and more particularly, to a vacuum cleaner that creates substantially less noise by using a vacuum pump with a lobed chamber.
2. Description of Related Technology
Although vacuum cleaners have become virtually indispensable, the noise they create limits their utility because other nearby activities often must cease during vacuuming.
There have been many approaches to reducing the environmental noise from vacuum cleaners. One rather obvious one is to incorporate sound insulating material in the vacuum cleaner housing. While this approach will somewhat reduce the noise level around the vacuum cleaner, it does not actually attack at its source any of the noise generated by the vacuum cleaner. Another involves using muffler arrangements for the exhaust air flow. A more sophisticated approach to reducing exhaust noise uses a noise detector in the vacuum cleaner exhaust to provide a signal used to generate noise-canceling sound. A sampling of such approaches can be found in U.S. Pat. No. 4,418,443, No. 4,435,877, No. 4,512,713, No. 4,970,753, No. 5,502,869, No. 5,159,738, No. 5,499,423 and No. 5,513,417.
However, none of those approaches attacks two appreciable sources of noise in a vacuum cleaner. One of those sources is the high flow velocities that must be generated by existing vacuum cleaners to obtain a mass flow rate that will provide effective cleaning. The other is noise caused by the vacuum cleaner's rotating components.
According to well known principles, so-called “dipole noise,” N
db
, caused by rotating components satisfies the relationship:
N
db
∝&ohgr;
6
(1)
From equation (1) it can seen that dipole noise is proportional to the sixth power of the rotational speed &ohgr; of the flow-generating components of a vacuum cleaner. Therefore, very small increases or decreases in the rotational speed &ohgr; will have a great effect on the dipole noise.
The prior art approaches discussed above operate to mask the “jet noise” associated with the air stream exiting the vacuum cleaner housing. The approaches that use muffler arrangements generally seek to reduce the velocity of the air stream before allowing it to exit the vacuum cleaner. That approach results in meaningful jet noise reduction because jet noise scales to the eighth power of air flow velocity (that is, U
8
). Even further noise reductions would be possible if the velocity of the air flow exiting the vacuum cleaner impeller device were reduced.
The present invention uses a positive displacement vacuum pump to reduce noise, and there are no known vacuum cleaners that incorporate such a pump to create the pressure drop that produces the debris-entraining air flow in a vacuum cleaner. The reason for that lack in the prior art is quite likely due to the mechanical complexity of the most common types of positive displacement pumps. For example, a pump having a reciprocating piston would require complicated valving and parts manufactured to close tolerances. The cost of a vacuum cleaner incorporating such a pump would probably be much more than could be charged for a consumer product, and it would be far less reliable than existing vacuum cleaners that simply use a rotating impeller.
As a result, there are no known vacuum cleaners with a Wankel-type positive displacement pump. Wankel-type devices were simply a curiosity until solution of the problem of providing adequate sealing between the rotating “piston” and the walls of the stationary “cylinder.” While solutions to these problems are now well known, they would probably be considered exotic for a product such as a vacuum cleaner. In any event, they would certainly drive up the cost of a vacuum cleaner and would require frequent replacement because the compressor in a vacuum cleaner is subject to abrasion from the particulate matter entrained in the air flow.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a Wankel-type pump suitable for use in a vacuum cleaner.
It is another object of the present invention to provide a quiet vacuum cleaner by using a Wankel-type pump and thereby substantially reduce the dipole noise generated during operation of the vacuum cleaner and create a suitable pressure drop and mass flow rate at lower fluid flow velocities, thereby also reducing the jet noise associated with conventional vacuum cleaners.
It is still another object of the present invention to provide a vacuum cleaner capable of generating a reduced-pressure fluid flow in which matter can be entrained for transport from one location to another, comprising a compartment for collecting the entrained matter, and a vacuum pump having a chamber with a plurality of lobes and a generally polygonal rotor with a plurality of sides greater in number than the plurality of lobes, the rotor being mounted for eccentric rotation within the lobed chamber to generate a reduced pressure in the lobes as the rotor rotates relative to the chamber, wherein the chamber is operatively connected to the compartment to induce the fluid flow therethrough.
In one embodiment of such a vacuum cleaner, the fluid is air and the chamber has an epitrochoidal planform satisfying the equation
x
=(
a+b
)·cos(
t
)−
c
·cos((
a/b
+1)·
t
), and
y
=(
a+b
)·sin(
t
)−
c
·sin((
a/b
+1)·
t
),
x and y being plotted from a center of the chamber, wherein 0≦t≦2&pgr;, b/c=2, and a/b=2, thereby providing a chamber with two lobes, and the rotor is generally triangular (that is, a regular polygon having (a/b+1) sides) with curved sides.
In accordance with a preferred embodiment of the present invention, a vacuum cleaner capable of generating a reduced-pressure air flow in which matter can be entrained for transport from one location to another, comprises a compartment for collecting the entrained matter, the compartment having an inlet and an outlet for the air flow, a vacuum pump housing including a chamber with an epitrochoidal planform satisfying the equation
x
=(
a+b
)·cos(
t
)−
c
·cos((
a/b
+1)·
t
), and
y
=(
a+b
)·sin(
t
)−
c
·sin((
a/b
+1)·
t
),
x and y being plotted from a center of the chamber, wherein 0≦t≦2&pgr;, a/b is an integer defining the number of lobes of the chamber, and b/c=2, the chamber having plural outlet ports, at least one of the outlet ports being disposed in each of the lobes of the chamber, and plural inlet ports, at least one of the inlet ports being disposed in each of the lobes of the chamber, a stator gear in the chamber at the center thereof, the gear having (a/b)·n teeth (n being an integer), a generally polygonal, one-piece rotor with (a/b+1) curved sides, the rotor being disposed for eccentric rotation in the chamber, wherein at least one inlet and one outlet in each lobe of the chamber are in direct fluid communication during a portion of the rotation of the rotor, a rotor gear at a center of the rotor, the rotor gear having (a/b+1)·n teeth, a cover mounted to the housing to enclose the chamber, seals on opposing surfaces of the rotor facing the housing and the cover, a drive member including a disc fitting within a circular opening in the rotor and mounted eccentrically to a drive shaft for imparting rotational movement to the rotor to generate fluid flow from the inlet ports of the chamber to the outlet ports of the chamber, wherein the drive shaft passes through an opening in the cover coaxial with the stator gear, a drive motor operatively connected to the drive shaft for imparting rotational motion thereto, and a ducting system operatively connecting the inlet ports of the chamber to the outlet of the compartment for creating a pressure drop from the inlet to the outlet of the compartment.
In accordance with yet another aspect of the invention, a pump comprises a one-piece housing having a chamber therein with an epitrochoidal planform according to the equation
x
=(
a+b
)·cos(
t
)&m
Chin Randall E.
Quinlan David M.
SounDesign, L.L.C.
LandOfFree
Wankel type pump for transporting fluid with entrained... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Wankel type pump for transporting fluid with entrained..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Wankel type pump for transporting fluid with entrained... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2516242