U.S. patent application number 10/958019 was filed with the patent office on 2005-02-24 for generator and fan.
This patent application is currently assigned to DELPHI TECHNOLOGIES, INC.. Invention is credited to Buening, Duane Joseph, Hull, Michael L..
Application Number | 20050040714 10/958019 |
Document ID | / |
Family ID | 32655556 |
Filed Date | 2005-02-24 |
United States Patent
Application |
20050040714 |
Kind Code |
A1 |
Buening, Duane Joseph ; et
al. |
February 24, 2005 |
Generator and fan
Abstract
An improved generator fan serves to draw air into the generator
through an inlet in the generator housing, pass the air through the
rotor and stator, and direct the air out openings in the generator
housing. The fan of the present invention includes a disc and at
least one multi-directional blade extending from the disc. The
multi-direction blade includes a leading segment extending from the
disc between a first radius measured from the axis of rotation and
a second radius, the leading segment including a leading edge
extending from the disc at an angle of about ninety degrees from
the disc, the leading segment extending from the disc with an
increasing angle along the length of the leading segment; and a
trailing segment extending from the disc between the second radius
and a third radius measured from the axis of rotation, the third
radius being greater than the second radius and the trailing
segment extending from the disc with an angle having a rate of
change different than the leading segment.
Inventors: |
Buening, Duane Joseph;
(Anderson, IN) ; Hull, Michael L.; (Anderson,
IN) |
Correspondence
Address: |
JIMMY L. FUNKE
DELPHI TECHNOLOGIES, INC.
Legal Staff, Mail-Code: 480-410-202
P.O. Box 5052
Troy
MI
48007-5052
US
|
Assignee: |
DELPHI TECHNOLOGIES, INC.
|
Family ID: |
32655556 |
Appl. No.: |
10/958019 |
Filed: |
October 4, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10958019 |
Oct 4, 2004 |
|
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10354634 |
Jan 29, 2003 |
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6800972 |
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Current U.S.
Class: |
310/62 ; 310/63;
417/423.1 |
Current CPC
Class: |
F04D 29/30 20130101;
F04D 29/281 20130101; H02K 9/06 20130101 |
Class at
Publication: |
310/062 ;
310/063; 417/423.1 |
International
Class: |
H02K 009/06; H02K
009/00 |
Claims
1. A generator fan, comprising: a disc adapted to be centrally
mounted perpendicular to an axis of rotation and at least two
multi-directional blades extending from the disc, the
multi-directional blades including: a leading segment extending
from the disc between a first radius measured from the axis of
rotation and a second radius measured from the axis of rotation,
the leading segment including a leading edge extending from the
disc at an angle of about ninety degrees from the disc, the leading
segment extending from the disc with a swept out shape starting at
the leading edge and extending from the disc with an increasing
angle along the length of the leading segment; and a trailing
segment extending from the disc between the second radius and a
third radius measured from the axis of rotation, the third radius
being greater than the second radius and the trailing segment
extending from the disc with an angle having a rate of change
different than the leading segment; wherein said multi-directional
blades further include an arced interface with said disc; and
wherein said multi-directional blades overlap one another so that
the leading segment begins proximal the second radius of an
adjacent multi-directional blade.
2. A generator comprising: a generator shaft defining an axis of
rotation; a fan including a disc mounted on the shaft and at least
one multi-directional blade extending from the disc, the
multi-directional blade including: a leading segment extending from
the disc between a first radius measured from the axis of rotation
and a second radius measured from the axis of rotation, the leading
segment including a leading edge extending from the disc at an
angle of about ninety degrees from the disc, the leading segment
extending from the disc with a swept out shape starting at the
leading edge and extending from the disc with an increasing angle
along the length of the leading segment; a trailing segment
extending from the disc between the second radius and a third
radius measured from the axis of rotation, the third radius being
greater than the second radius and the trailing segment extending
from the disc with an angle having a rate of change different than
the leading segment; at least one uniform blade having a uniform
angle from the disc; and a flow port between said multi-directional
blade and an adjacent blade.
Description
TECHNICAL FIELD
[0001] The present invention relates to an improved generator and
fan. More specifically, the invention provides a generator
utilizing an improved rotor fan.
BACKGROUND OF THE INVENTION
[0002] Without a generator, the electrical load of a vehicle would
quickly drain a fully charged battery. In a vehicle, a generator
producing alternating current (AC), known as an alternator, is
often mounted at the front of the engine and is linked to the
engine crankshaft pulley by a drive belt. When the engine turns the
drive belt, the drive belt turns a shaft in the alternator, and
current is generated. Current is produced in an alternator when a
wire intercepts a magnetic field. In an alternator, it is the wire,
in coiled form, that is held stationary and the magnetic field is
turned so that the magnetic field passes through the wire. Thus,
alternators include a stationary part, the stator, and a rotating
part, the rotor.
[0003] The stator may include stationary coils or slotted pins or
segments that surround a rotor. As the rotor is turned by the car
engine, the alternating magnetic field created by the rotor is
intercepted by the stationary coils, pins or segments, and current
flows through the stator first in one direction, then in the other,
resulting in alternating current. As the rotor is turned, air flow
within the assembly will produce noise in the audible range that
will emanate from the alternator assembly.
[0004] The rotor includes an electromagnet that is magnetized by
current from the battery. The electromagnet may include slip rings,
rotor windings, and north and south pole members surrounding the
rotor windings. Current from the battery flows through the slip
rings to the rotor windings. North and south pole members have pole
claws shaped like interlocking teeth surrounding the rotor
windings. The north and south pole members create an alternating
magnetic field as the rotor turns.
[0005] A housing surrounds the rotor and stator assembly. The
stator is fixed relative to the housing and the rotor shaft is
rotatably mounted relative to the housing. Because the battery and
electrical components in the car work on direct current (DC), the
AC output of the alternator must be converted to DC. This is done
with rectifiers which pass current in one direction only. The
components within the alternator produce heat and, in addition, the
alternator operates under high under hood temperatures. To reduce
the amount of heat in the alternator, a fan is included in the
alternator assembly as seen in reference to U.S. Pat. No. 4,549,103
to Shega, entitled Multi-Path Cooling in an AC Generator for a
Vehicle.
[0006] The fan may be placed inside or outside of the housing to
increase airflow between the rotor and stator and to increase
airflow through openings in the housing. The fan blades may face
inward toward the central portion of the alternator or outward away
from the central portion of the alternator. Rotation of the fan
helps increase airflow within the alternator and helps to reduce
heat within the alternator, but also increases the amount of
audible noise emanating from the alternator assembly, an
undesirable feature particularly from the point of view of the
operator of the vehicle in which the alternator is mounted.
[0007] The noise produced by an alternator depends, at least in
part, on the design of the alternator fan blades. Alternator fans
with straight fan blades having an inside angle of more than ninety
degrees from the base of the fan, tend to produce less noise, but
undesirably also provide less airflow. Alternator fans with
straight fan blades at ninety degrees from the base of the fan
produce more airflow, but undesirably more noise. To improve the
airflow resulting from a fan with swept out blades, the length of
the blade can be increased but this undesirably reduces the number
of blades that can be included on a single fan. Other designs have
incorporated alternating blades, some blades at ninety degrees and
other blades having an inside angle of more than ninety degrees.
However, the limitations associated with each type of blade are not
entirely overcome by known designs. The present invention overcomes
these problems to provide an alternator incorporating an improved
fan, resulting in an alternator with reduced noise, improved
tonality and improved radial and axial cooling airflow.
SUMMARY OF INVENTION
[0008] The present invention provides an improved generator with
improved sound quality and reduced noise level, and also provides
improved airflow through the generator, improving cooling of the
generator components. An improved generator fan serves to draw air
into the generator through an inlet in the generator housing, pass
the air through the rotor and stator, and direct the air out
openings in the generator housing. The fan of the present invention
includes a disc adapted to be centrally mounted on a shaft that
represents an axis about which the fan rotates. According to the
present invention, at least one multi-directional blade extends
from the disc. The multi-direction blade includes a leading segment
extending from the disc between a first radius measured from the
axis of rotation and a second radius measured from the axis of
rotation, the leading segment including a leading edge extending
from the disc at an angle of about ninety degrees from the disc,
the leading segment extending from the disc with a swept out shape
starting at the leading edge and extending from the disc with an
increasing angle along the length of the leading segment. A
trailing segment extends from the disc between the second radius
and a third radius measured from the axis of rotation, the third
radius being greater than the second radius and the trailing
segment extending from the disc with an angle having a rate of
change different than the leading segment.
[0009] An improved generator having the inventive fan exhibits
improved tonality and a reduced noise level. The resulting
generator also provides improved cooling. Other aspects of the
present invention are provided with reference to the figures and
detailed description of embodiments provided herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The present invention will now be described, by way of
example, with reference to the accompanying drawings, in which:
[0011] FIG. 1 is a cross-sectional view of an exemplary
generator;
[0012] FIG. 2 illustrates a front view of an embodiment of an
improved generator fan;
[0013] FIG. 3 illustrates a side view of an embodiment of an
improved generator fan;
[0014] FIG. 4 illustrates an isometric view of an embodiment of an
improved generator fan;
[0015] FIG. 5 illustrates a front view of an embodiment of an
improved generator fan;
[0016] FIG. 6 illustrates a side view of an embodiment of an
improved generator fan; and
[0017] FIG. 7 illustrates an isometric view of an embodiment of an
improved generator fan.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] The present invention provides a generator with improved
sound quality and reduced noise level, and also provides improved
airflow through the generator, improving cooling of the generator
components. An improved generator fan serves to draw air into the
generator through an inlet in the generator housing, pass the air
through the rotor and stator, and direct the air out openings in
the generator housing.
[0019] FIG. 1 illustrates an example of an exemplary generator 10
in which the improved fan of the present invention may be used. The
exemplary generator includes a stator assembly 15 surrounding a
rotor assembly 20. The rotor assembly 20 includes a shaft 21
supporting all rotating magnetic structures including conventional
pole-members 16A and 16B, a rotor core 17 and a field coil 18 wound
upon bobbin 12. Additionally, all other non-magnetic circuit
rotating structures are carried, including air circulation fans 19
and 27 located at axially opposite sides of the pole-members, and a
slip ring assembly 30 located at one extreme end of the shaft 21.
The fan 27 is formed from sheet metal stock and spot welded to the
pole-member 16B while fan 19 is formed from an appropriate
thermoplastic material and heat staked to tower extensions (not
shown) from the field coil bobbin 12. The shaft 21 is rotatably
supported within a housing 26 by a pair of bearings 23 and 22.
Bearing 23 is located between the slip ring assembly 30 and the fan
19. Coil leads 18A of field coil 18 are wrapped about respective
posts 12A of bobbin 12 and pass through holes 13 in fan 19. Slip
ring assembly 30 is made of a pair of copper rings 31 each having a
slip ring lead 32 joined such as by welding thereto. The copper
rings and wires are molded into a thermoset material to complete
the slip ring assembly 30. Slip ring assembly 30 is pressed onto
the end of rotor shaft 21 and the slip ring leads 32 are routed
into channels along the shaft 21 where they are joined, such as by
twisting and welding, to the coil leads 18A of field coil 18 via a
joint 24. The joint 24 is then bent to the surface of the fan 19
and received in a pyramid shaped tab structure 25. The joint 24 is
then secured to fan 19 by ultrasonic welding of the plastic
material of the tab 25. Bearing 23 is assembled to pass over the
slip ring assembly 30 to retain the lead wires 32 securely within
the shaft channels. Preferably, fan 27 of FIG. 1 is replaced by the
improved fan described with respect to FIGS. 2-7. Other
applications of the inventive fan are possible and remain within
the spirit and scope of the invention. Various embodiments of the
present invention are described herein.
[0020] FIG. 2 illustrates a front view of an embodiment of an
improved generator fan 110. The generator fan 110 of this
embodiment is suitable for use in an alternator such as would be
used in an automobile and may be replace either of fan 19 or fan
27, or both fan 19 and fan 27, in the exemplary generator of FIG.
1. The fan 110 of the present invention provides both axial and
radial airflow. The fan 110 includes a disc 120 adapted to be
mounted on a rotor shaft having an axis 130 of rotation that the
fan 110 rotates about. According to the present invention, at least
one multi-directional blade 170 extends from the disc 120. With
respect to a clockwise direction of rotation in this view, the
multi-direction blade includes a leading segment 180. The leading
segment 180 is defined as the portion of multi-directional blade
170 extending from the disc 120 between a first radius 140 measured
from the axis 130 of rotation and a second radius 150 measured from
the axis 130 of rotation, the second radius 150 being greater than
the first. The leading segment 180 extends from the disc 120 with a
swept out angle starting at a leading edge having an angle of
ninety degrees at the first radius and increasing along the length
of the leading segment 180. The trailing segment 190 is defined as
the portion of multi-directional blade 170 that extends from the
disc 120 between the second radius 150 and a third radius 160
measured from the axis 130 of rotation, the third radius 160 being
greater than the second radius 150. The trailing segment 190
differs from the leading segment 180 in that the trailing segment
extends from the disc 120 at an angle having a rate of change
different from the leading segment 180. According to one
embodiment, the trailing segment 190 extends from the disc 120 at a
fixed angle. The amount of radial and axial flow can be adjusted by
tailoring the rate of change of the angle of the trailing segment
190 to provide the desired amount of flow in each direction. Flow
directed radially will have greater interaction with the stator.
Flow directed axially will have greater interaction with the rotor.
The improved fan 110 provides increased flow rates at the same time
reducing noise and improving tonality. The improved fan 110 may be
formed from any of a variety of metals including without limitation
steel. The fan 110 of this embodiment can be formed by a punched
metal process in which the entire fan 110 is formed from a single
metal piece. In an alternative embodiment, the fan 110 may be of a
molded material including without limitation polymer materials. The
improved fan 110 provides increased flow rates at the same time
reducing noise and improving tonality.
[0021] FIG. 2 further illustrates an embodiment in which the base
portion 200 of the blade has an arced interface 220 with the disc
120. The fan 110 may additionally include flow apertures 260
between the multi-directional blade 170 and an adjacent blade. This
improves airflow on both sides of the fan 110 and helps to
eliminate flow blockage.
[0022] According to the embodiment shown in FIG. 2, the fan 110 may
include a plurality of overlapping multi-directional blades 170.
According to the invention, the first radius 140 is defined to be
less than the second radius 150 and the second radius 150 less than
the third radius 160, as a result, the plurality of
multi-directional blades 170 may overlap one another so that the
leading segment 180 of each multi-directional blade 170 begins
proximal the second radius 150 of an adjacent multi-directional
blade 170. This allows for an increased number of blades on the
disc 120 and allows for blades having increased length each
providing increased airflow. The first radius 140 and third radius
160 define a central blade angle A of about eighty degrees, and the
fan 110 includes eight overlapping multi-directional blades 170
distributed around the disc 120. According to one embodiment, the
multi-directional blades 170 are uniformly distributed about the
disc 120. According to one embodiment, the multi-directional blades
170 are non-uniformly distributed around the disc 120 to reduce the
level of noise created by the airflow. According to one embodiment,
angle A varies from multi-directional blade 170 to
multi-directional blade 170 on the same disc 120 to further
decrease the level of noise created by the airflow.
[0023] According to one embodiment, the upper portion 210 of the
multi-directional blade 170 terminates in an outer edge 230 defined
by the outermost portion of the leading segment 180 and trailing
segment 190, gradually increases in distance from the disc 120 as
the leading segment 180 extends from the first radius 140 to the
second radius 150 and gradually decreases in distance from the disc
120 as the trailing segment 190 extends from the second radius 150
to the third radius 160.
[0024] According to one embodiment, the leading section 180 sweeps
from the angle of about ninety degrees at the leading edge to an
angle of about one hundred twenty degrees where the leading segment
180 meets the trailing segment 190. This improves the flow rate in
both the axial and radial direction by increasing the mount of air
drawn in by the fan 110 while reducing noise level. According to
one embodiment, the trailing segment extends from the disc 120 at
an angle of about one hundred twenty degrees to provide the desired
ratio of radial flow and axial flow of air to cool the generator.
According to one embodiment, the trailing segment 190 extends from
the disc at an angle greater than about one hundred twenty degrees,
increasing the amount of axial airflow through the generator.
[0025] FIG. 3 is a side view of an embodiment of the improved
generator fan 110 showing the multi-directional blades 170
overlapping one another. As seen in this view, the trailing
segments 190 overlap the leading segments 180. The overlapping
multi-directional blades 170 provide better axial airflow than
known generator fans having only blades uniformly tilted inward.
The noise level is decreased in part due to less airflow
interaction with the stator. The overlapping multi-directional
blades 170 also provide smoother inlet and outlet airflow as the
air passes in and out of the generator. Flow apertures 260 between
the overlapping multi-directional blade 170 improve airflow on both
sides of the fan 110 and help to eliminate flow blockage.
[0026] FIG. 4 illustrates an isometric view of an embodiment of the
improved generator fan 110 utilizing a multi-directional blade 170
to provide both axial and radial airflow to a generator. The fan
110 includes a disc 120 adapted to be mounted on a generator shaft
or rotor shaft and at least one multi-directional blade 170
extending from the disc 120. In this embodiment, at least one port
270 is included in the disc 120 to dynamically balance the fan. In
this embodiment, the flow apertures between the multi-directional
blades are enlarged relative to the flow apertures shown in FIG. 2.
According to one embodiment, the leading section 180 sweeps from
the angle of about ninety degrees at the leading edge to an angle
of about one hundred twenty degrees where the leading segment 180
meets the trailing segment 190. This improves the flow rate in both
the axial and radial direction by increasing the mount of air drawn
in by the fan 110 while reducing noise level. According to one
embodiment, the trailing segment extends from the disc 120 at an
angle of about one hundred twenty degrees to provide the desired
ratio of radial flow and axial flow of air to cool the generator.
According to one embodiment, the trailing segment 190 extends from
the disc at an angle greater than about one hundred twenty degrees,
increasing the amount of axial airflow through the generator.
[0027] FIG. 5 illustrates a front view of an embodiment of the
improved generator fan 110'. The generator fan 110' of this
embodiment may be used in an alternator such as would be used in an
automobile and may be used in place of fan 19 or fan 27, or both
fan 19 and fan 27, in the exemplary generator of FIG. 1. The fan
110' of the present invention provides both axial and radial
airflow. The fan 110' includes a disc 120' adapted to be centrally
mounted on a rotor shaft which represents an axis 130' of rotation
that the fan 110' rotates about. According to the present
invention, at least one multi-directional blade 170' extends from
the disc 120'. The multi-direction blade includes a leading segment
180' extending from the disc 120' between a first radius 140'
measured from the axis 130' of rotation and a second radius 150'
measured from the axis 130' of rotation, the second radius 150'
being greater than the first. The leading segment 180' extends from
the disc 120' at an angle of about ninety degrees from the disc
120'. The trailing segment 190' extends from the disc 120' between
the second radius 150' and a third radius 160' measured from the
axis 130' of rotation, the third radius 160' being greater than the
second radius 150'. The trailing segment 190' extends from the disc
120' at an angle having a rate of change different than the leading
segment 180'. The amount of radial and axial flow can be adjusted
by tailoring the angle of the trailing segment 190' to provide the
desired amount of flow in each direction. Flow directed radially
will have greater interaction with the stator. Flow directed
axially will have greater interaction with the rotor. The improved
fan 110' provides increased flow rates at the same time reducing
noise levels and improving tonality.
[0028] In this embodiment, the multi-directional blade 170' is
combined with at least one straight blade 240' having a
substantially planar shape and a straight interface 250' with the
disc 120'. The straight blade 240' has a uniform angle from the
disc 120' along the entire length of the blade. Thus, the amount of
radial and axial flow can be further adjusted by tailoring the
angle of the straight blade 240' to provide the desired amount in
combination with the affect of the multi-directional blade 170'.
The straight blade 240' may be defined by a straight angle of
ninety degrees, less than ninety degrees, or more than ninety
degrees. Further, various combinations of straight and tilted
blades may be incorporated into the improved fan 110'.
[0029] According to one embodiment, at least one flow port 260' is
included in the fan 110' between the multi-directional blade 170'
and an adjacent blade. This improves airflow on both sides of the
fan 110'. According to one embodiment, the fan 110' includes six
multi-directional blades 170' and four uniform blades.
[0030] According to one embodiment, the leading section 180' sweeps
from the angle of about ninety degrees at the leading edge to an
angle of about one hundred twenty degrees where the leading segment
180' meets the trailing segment 190'. This improves the flow rate
in both the axial and radial direction by increasing the mount of
air drawn in by the fan 110' while reducing noise level. According
to one embodiment, the trailing segment extends from the disc 120'
at an angle of about one hundred twenty degrees to provide the
desired ratio of radial flow and axial flow of air to cool the
generator. According to one embodiment, the trailing segment 190'
extends from the disc at an angle greater than about one hundred
twenty degrees, increasing the amount of axial airflow through the
generator.
[0031] In the embodiment of FIG. 5, an outer edge 230', defined by
the outermost portion of the upper portion 210' of the leading
segment 180' and trailing segment 190' has a substantially constant
distance from the disc 120' providing a blade with a substantially
uniform height along the length of the blade. FIG. 6 is a side view
of the improved generator fan 110' of FIG. 5.
[0032] FIG. 7 illustrates an isometric view of an improved
generator fan 110' utilizing a multi-directional blade 170' to
provide both axial and radial airflow to a generator. The fan 110'
includes a disc 120' adapted to be mounted on a generator shaft and
at least one multi-directional blade 170' extending from the disc
120'. As seen in this view, the base of the multidirectional blade
may have an arced interface 220' with the disc 120'. According to
one embodiment of the invention, the angle between the second
radius 150' and third radius 160' is defined as a central blade
angle A' of about 8 degrees and the blades are distributed on the
disc 120' without overlapping an adjacent blade. According to one
embodiment, the fan 110' includes six multi-directional blades 170'
and four uniform blades distributed on the disc 120'.
[0033] The improved fan described herein can be mounted axially
inward of the housing with the blades extending outward. In an
alternative embodiment, the fan can be mounted axially outward of
the housing with the blades extending axially inward. More than one
fan 110 may be employed in a single generator.
[0034] The invention provided herein allows more flexibility to
tune a fan 110 design to provide airflow for a given application
according to the desired noise level, tonality, axial airflow and
radial airflow. While the present invention has been described with
reference to exemplary embodiments, a variety of embodiments may be
produced utilizing the apparatus and process described herein.
Modifications and variations in the invention will be apparent to
those skilled in the art in light of the foregoing description. It
is therefore contemplated that the appended claims and their
equivalents will embrace any such alternatives, modifications and
variations as falling within the scope of the present
invention.
* * * * *