U.S. patent application number 10/111462 was filed with the patent office on 2002-10-24 for blower.
Invention is credited to Kehrer, Wolfgang.
Application Number | 20020154995 10/111462 |
Document ID | / |
Family ID | 7655533 |
Filed Date | 2002-10-24 |
United States Patent
Application |
20020154995 |
Kind Code |
A1 |
Kehrer, Wolfgang |
October 24, 2002 |
Blower
Abstract
The invention is based on a blower having a rotatable gas
delivery means (10). It is proposed that the gas delivery means
(10) comprise a mass distribution that generates a predefined
torque perpendicular to the axis of rotation (26) when the gas
delivery means (10) rotates.
Inventors: |
Kehrer, Wolfgang; (Freiburg,
DE) |
Correspondence
Address: |
Striker Striker Stenby
103 East Neck Road
Huntington
NY
11743
US
|
Family ID: |
7655533 |
Appl. No.: |
10/111462 |
Filed: |
April 23, 2002 |
PCT Filed: |
June 12, 2001 |
PCT NO: |
PCT/DE01/02177 |
Current U.S.
Class: |
415/220 |
Current CPC
Class: |
F04D 29/662
20130101 |
Class at
Publication: |
415/220 |
International
Class: |
F04D 003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 8, 2000 |
DE |
10044484.9 |
Claims
What is claimed is:
1. A blower having a rotatable gas delivery means (10), wherein the
gas delivery means (10) comprises a mass distribution that
generates a predefined torque perpendicular to the axis of rotation
(26) when the gas delivery (10) means rotates.
2. The blower according to claim 1, wherein a mass allocation on
the gas delivery means (10) projected onto a plane perpendicular to
the axis of rotation (26) is balanced within the tolerance range of
production-induced imbalance.
3. The blower according to claim 1 or 2, wherein the torque is
effected by at least two balancing masses (20, 22) situated offset
in the circumferential direction, one of which is located before
and the other of which is located after the center of gravity (24)
of the gas delivery means (10) in the axial direction.
4. The blower according to claim 3, wherein the balancing masses
(20, 22) are located offset by 180.degree. in relation to each
other.
5. The blower according to claim 3 or 4, wherein the balancing
masses (20, 22) are located on a central fixture of vanes (14) of
the gas delivery means (10).
6. The blower according to one of the claims 3 through 5, wherein
the balancing masses (20, 22) are moveable.
7. The blower according to one of the preceding claims, wherein the
mass distribution effecting the torque is integral with the gas
delivery means (10).
8. The blower according to claim 7, wherein the gas delivery means
(10) is an injection-molded part, and the mass distribution is
integrally extruded on the gas delivery means (10).
9. The blower according to one of the preceding claims, wherein the
gas delivery means (10) is a fan wheel.
Description
RELATED ART
[0001] The invention is based on a blower according to the preamble
of claim 1.
[0002] Numerous embodiments of blowers forming the generic class
are known and are used for cooling, heating, or ventilation.
Ventilators, fan wheels, or turbines are used as rotatable gas
delivery means. As a rule, fan wheels are used in engine radiator
blowers. Disturbing noises are produced by internal combustion
engine radiator blowers as a result of first-order excitation of
vibrations that are transmitted into a passenger compartment as
air-borne or structure-borne noise, and impair driving smoothness.
Presently, these noises are kept to a minimum by means of
single-plane balancing of the fully-assembled internal combustion
engine radiator blower, i.e., by balancing the static imbalance.
The static imbalance is thereby balanced manually using balancing
clamps. Although radial runout caused by imbalance and, therefore,
noise formation caused by untrue running can be prevented in fan
wheels balanced in this fashion, the fan wheel can move back and
forth between its two bearing end positions within the scope of its
bearing clearance.
ADVANTAGES OF THE INVENTION
[0003] The invention is based on a blower having a rotatable gas
delivery means.
[0004] It is proposed that the gas delivery means comprises a mass
distribution that generates a predefined torque perpendicular to
the axis of rotation when the gas delivery means rotates. If torque
in the center of gravity acts upon the gas delivery means
perpendicular to the axis of rotation, the gas delivery means is
tilted downward within the scope of its bearing clearance. This can
prevent the gas delivery means from moving freely within the
bearing clearance and thrashing back and forth between the end
positions of the bearing. A bracing of the gas delivery means can
be achieved, and noise emitted by the gas delivery means can be
reduced.
[0005] With the blower according to the invention, a mass
allocation on the gas delivery means projected onto a plane
perpendicular to the axis of rotation of the gas delivery means is
balanced within the tolerance range of production-induced
imbalance. This prevents runout caused by the selected mass
distribution or an outward and inward thrashing by the gas delivery
means in the radial direction and noise emitted as a result.
[0006] In an advantageous embodiment of the invention, torque is
effected by at least two balancing masses located in offset
positions in the circumferential direction, one of which is located
before and the other of which is located after a center of gravity
of the gas delivery means in the axial direction. Torque can be
achieved using a particularly simple design and in cost-effective
fashion.
[0007] Advantageously, two axially separated balancing masses are
situated offset by 180.degree. in relation to each other, which
allows the balancing masses to be designed the same. If balancing
masses are of equal size and their radial distance from the axis of
rotation is the same, the gas delivery means is balanced in the
plane perpendicular to its axis of rotation, with the exception of
imbalance resulting from production tolerances. The torque
components of the individual balancing masses not only add up
vectorially, but, with this geometry, according to their percentage
as well.
[0008] The balancing masses are preferably arranged on a central
fixture of vanes of the gas delivery means. With a long axial
design, the balancing masses can be separated by a wide axial
distance. Sufficiently high torque can be easily effected. The gas
delivery means is particularly stable on this central fixture of
vanes. Disturbing twisting of the gas delivery means resulting from
force acting on the balancing masses can be prevented. Moreover,
the attachment site on a central fixture of vanes is particularly
favorable in terms of aerodynamics.
[0009] In an advantageous embodiment of the invention, the
balancing masses are located on the gas delivery means in moveable
fashion, in the axial direction in particular. In principle, the
balancing masses could also be designed to be moveable in the
radial and/or circumferential direction. Using moveable balancing
masses, torque can be adjusting throughout the life of the blower.
Depending on its state of wear, the blower can always be adjusted
so that noise is minimized.
[0010] The mass distribution that effects torque can also be
advantageously integrated on the gas delivery means, however. A
separate working step, such as the attachment of balancing masses,
is eliminated. This is possible, preferably using production
engineering, when the gas delivery means is an injection-molded
part, and the mass distribution is integrally extruded on the gas
delivery means. Analogous to the attachment of individual balancing
masses, delimited areas can also be integrally extruded on the gas
delivery means as balancing masses.
[0011] In an advantageous embodiment of the invention, the gas
delivery means is designed as a fan wheel. Fan wheels are preferred
over ventilators because they produce a uniform air flow, and their
design is simple compared to that of turbines.
[0012] The means of attaining the solution according to the
invention can be used in numerous different blowers appearing
reasonable to one skilled in the art. The means of attaining the
solution is suited particularly advantageously for use with a
blower for an internal combustion engine radiator, which, as a
rule, produces a great deal of structure-borne noise.
BRIEF DESCRIPTION OF THE DRAWING
[0013] Further advantages result from the following description of
the drawing. An exemplary embodiment of the invention is presented
in the drawings. The drawing, the description, and the claims
contain numerous features in combination. One skilled in the art
will advantageously consider them individually as well and combine
them into reasonable further combinations.
[0014] FIG. 1 shows a front view of a fan wheel of an internal
combustion engine radiator blower having two balancing masses
located on the fan wheel hub,
[0015] FIG. 2 shows a view along the line II-II in FIG. 1, and
[0016] FIG. 3 shows a schematic diagram of the arrangement of
balancing masses in a plane containing the fan wheel axis.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENT
[0017] FIG. 1 shows a gas delivery means in the form of a fan wheel
10 of an internal combustion engine radiator blower. Seven vanes 14
are located on a central wheel hub 12. The vanes 14 are connected
by a ring 16 on their radially outer ends. Due to their shape, the
seven vanes 14 generate a uniform air flow through a radiator (not
shown) of an internal combustion engine of a motor vehicle.
[0018] Two balancing masses 20, 22 are located on a cylinder jacket
surface 18 of the wheel hub 12. Viewed in the axial direction, the
balancing masses 20, 22 are located diametrically opposed, or
offset 180.degree. in relation to each other in the circumferential
direction. As a result of this, the fan wheel 10 is balanced in a
plane perpendicular to its axis of rotation 26, with the exception
of imbalance due to production tolerances. That is, the center of
gravity 24 of the fan wheel 10 lies on its axis. This prevents the
fan wheel 10 from thrashing back and forth in the radial direction
during rotation. One balancing mass 20 is located before and one
balancing mass 22 is located after the center of gravity 24 of the
gas delivery means 10 in the axial direction (FIG. 2).
[0019] When the fan wheel 10 rotates, centrifugal forces {overscore
(F)}.sub.1 and {overscore (F)}.sub.2 act upon the balancing masses
20, 22. The vector product of the position vector {overscore
(s)}.sub.1 or {overscore (s)}.sub.2 of the distance of the
respective balancing mass 20, 22 from the center of gravity 24 and
this force {overscore (F)}.sub.1, {overscore (F)}.sub.2 yields a
torque {overscore (M)}.sub.1 or {overscore (M)}.sub.2 effected by
the respective balancing mass 20, 22. The total torque of both
balancing masses 20, 22 is therefore calculated as follows:
{overscore (M)}={overscore (M)}.sub.1+{overscore
(M)}.sub.2={overscore (s)}.sub.1.times.{overscore
(F)}.sub.1+{overscore (s)}.sub.2.times.{overs- core (F)}.sub.2
[0020] As illustrated in FIG. 3, the torque is situated
perpendicular to the axis of rotation 26 of the fan wheel 10. As a
result, the fan wheel 10 tilts downward slightly within its bearing
clearance. The bearing of the fan wheel 10 is therefore always
under preload during a rotational motion. Noise emitted from the
fan wheel 10 is reduced.
REFERENCE NUMERALS
[0021] 10 Fan wheel
[0022] 12 Wheel hub
[0023] 14 Vane
[0024] 16 Ring
[0025] 18 Cylinder jacket surface
[0026] 20 Balancing mass
[0027] 22 Balancing mass
[0028] 24 Center of gravity
[0029] 26 Axis of rotation
[0030] {overscore (F)}.sub.1 Centrifugal force
[0031] {overscore (F)}.sub.2 Centrifugal force
[0032] {overscore (s)}.sub.1 Position vector
[0033] {overscore (s)}.sub.2 Position vector
[0034] {overscore (M)}.sub.1 Torque
[0035] {overscore (M)}.sub.2 Torque
[0036] {overscore (M)} Torque
* * * * *