Note: Descriptions are shown in the official language in which they were submitted.
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The present invention relates generally to a
multi-purpose electromechanical device which provides
a pumping function such as might be required in an air
conditioning system as well as an electrical energy
generating function to obviate the need for, for example,
a separately driven vehicle alternator.
This is a division of copending Canadian Patent
Application Serial No. 305,616, filed June 16, 1978.
This application is also related to my United
States Patent No. 4,097,754, issued June 27, 1978, for
"Short Pitch Alternator", assigned to the assignee of the
present invention.
In the past, vehicles have included a prime mover,
such as an internal combustion engine, which in addition
to supplying energy to drive the vehicle, also provides
energy to a number of other devices -through a maze of
V-belts, pulleys and the like. Specifically, such an
engine drives an electrical generator or alternator, a
water pump, a power steering pump, an air conditioner
pump or compressor, various anti-pollution devices and
perhaps other devices.
The typical alternator will be engine-driven
by way of a V-belt and a relatively small diameter pulley,
~or example, of the order of 2-1/2 inches in diameter.
The alternator typically therefor revolves at a relatively
high speed generating a relatively high frequency alternating
current voltage. With such a relatively high frequency
alternating current voltage, stator core losses are relatively
high and with such a small diameter pulley, belt slippage is
a substantial problem. From at least a size standpoint,
larger pulleys and lower frequencies have heretofore not
been practical.
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Compressors for vehicle air conditioning systems
are typically also belt-driven from the engine by way of a
pulley, which is selectively coupled to the compressor
shaft by an electromagnetic clutch arrangement. Much of
the time this electromagnetic clutch is not actuated
and the compressor pulley and V-belt are "free wheeling",
contributing nothing to the system except frictional
losses. As compared to an alternator, the current compressor
design is of a lesser number of revolutions per minute,
greater pulley diameter (a six inch diameter pulley would
not be uncommon) and a somewhat larger overall structure.
The larger pulley diameter and slower speed reduces belt
slippage and related problems
It is also known in the prior art, for example,
in United States Patent No. 2,660,~65 to provide a common
shaft for a pump and an electrical generator, however,
such prior art approaches amounted to little more than
placing the two machines end to end with the overall axial
length, weight and cost being substantially the sum of
those traits for the respective individual components.
Among the several objects of the present invention
may be noted the provision of a single electromechanical
device; the provision of a space, weight and cost saving
arrangement; the provision of an alternator function of
reduced frictional and eddy current losses as compared to
the above-mentioned alternator systems; and the provision
of an electromechanical device which provides an alternator
function while lessening the noise associated with prior
art alternators due to belt slippage and high speed of operation
or rapid acceleration.
According to the present invention there is
provided a unified compressor-generato.r assembly for a
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ehicle engine, the assembly including compressor means for
compressing refrigerant in an automobile air conditioning
system including a housing having an end face and a rotatable
driving shaft extending from the end face, and a hub member
rotatably supported on the shaft and adapted to be driven
by the engine to rotate about the shaft. A flywheel is
connected to a hub member and is rotatable therewith, the
flywheel having an annular flange portion at the periphery
thereof adjacent the housing end face, the flange portion
having a support surface concentric with the shaft.
Generator rotor elements are supported on the support
surface of the flywheel flange portion and a generator
stator assembly is suppoxted on the housing end face
concentrically within the rotor elements and surrounding
the shaft. A selectively actuable clutch means is provided
for drivingly coupling the hub member to the shaft, the
clutch means including a portion fixedly secured to the shaft
and rotatable therewith, a clutch plate adapted drivingly
to engage the hub member and a coil concentrically surrounding
the hub member and adapted when energized to urge the clutch
plate into driving engagement with the hub member.
The exact nature of the present invention will
become more clearly-apparent upon reference to the
following detailed specification taken in connection with
the accompanying drawings in which:
Fig. 1 is a perspective view of an electromechanical
device which embodies the present invention in one preferred
form;
Fig. 2 is an exploded view of the electromechanical
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~evice of ~ig. l;
Fig. 3 is a side view paxtiall~ in cross-section of the
elec~romechanical device of Fig. l;
~ ig. 4 is an electrical schema~ic diagram partially in
block form illus~ra~ing one electrical arrangement for ~he al-
terna~or o~ the present invention; and
~ ig~ 5 is a side view par~ially in cross-section of
another electromechanical device.
1~ Xn ~he several draw;ng views like reerenca n~merals
ident~fy like parts. The ollowing is illus~rative o~ ~he
invention in one fo~m and is not to be construed as limiting
in an~ manrler.
In a vehicle the prime mover, such as an in~ernal com-
bustion engine, has pulley 11 ~riven, for example, by ~he
engine cran~ sh~ft, and ~n ~ig. 1 tha~ pulley is coupled by
wa~ of V-~elt 13 to drive another pulley 15 whenever the
engine is running. Pulley 15 ~xives ~he altexnator o~ ~he
present invention whenever ~he engine is running, and when
clutch arrangement 17 is actwa~ed, also drives a~ aix con-
di~ioner co~pressor 19. T~ree leads 20, 22 and 24 extend
from Delta connected al~ernator phase windings and a clutch
energizing or c~ntrol lead 26 extends from a clutch act-.
ua~ing elec~romagnet to a thermosta~ ox control switch 32
for c1u~ch control. m e other ~lu~ch energiæing le~d may -
be grounded. Thus, ~ig. ~ illustra~s a un~ied pump~gener-
a~or structure and su~h a combined arrangement pxovides a
compressor unction fox a ~ehicle air conditioning sys~em
as well as a ge~erator ox alkernator ~unction for su~plying
~he vehicle electrical needs. ~he detailed construc~ion
ana operation of such a combined arrangement will be mos~
- easily understood b~ considering ~igs. 2 and 3 toge~her.
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The pump or compressor 19 has a housing 21 from which
there is axially extending a drivable compressor actuating
shaft 23, rotation of which actuates the compressor in a
conven~ional manner. ~Iousing 21 also has fixedly attached
thereto an annular senexator stator assembly 25 which com-
prises a slotted laminated ma~netic core 27 having windings
29 disposed in the core slots. Still fur~her housing 21
has a~fixed there~o annular coil 31 which when energized
creates a magnetic field to actua~e ~lutch 17. Shaft 23
may be thought o~ as rotating about imagina~y axis 33 and
th2 annular coil 31 as well as the generator stator assembly
25 are attached ~o housing 21 concentric to 0~2 another a~d
to axis 33. Si~ilarly, ~hese last two annular members are
concentric with compressor crank shaf~ 23.
- Shaft 23 is ~ixed, for example, by key 35 in ~eyway 37,
by threading, or bo~h, to membex 39. Such threaded attachm2nt ~:
may be facili~a~ed by nut 41 and ~hreads 43 on ~he compressor .
crank shaft. Still further, fixedly connected to member 39
and spaced therefrom is clutch support plate 4~O Clutch :;
suppor.~ plate 45 m~y be connec~ed to me~ber 39, for example,
by bolts or rivets 4 7 ~ and ~his bolt or xivet ~7 may also
a~ix one end o spring 4~ ~o the clu~ch suppor~ pla~e. ~s
illustrated three such springs 49 have their end~ remote from
~he bol~æ or rivets 47 connected to clut~h plate 51. If
shaft 23 is rotat~onally moti~nless so are member 39, clutch
support plate 45, lea~ springs 4~ and clutch plate 51
However, clutch plate Sl may move axially somewhat
due to the 1exing o~ springs 49 when the annular coil or
clutch actuating coil 31 is energized. E~ergizing coil 31
dxaws clutch plate Sl axially toward sid~ sur~ace 53 of pulley
15 frictionally ~o engage surface 53 ~hereby connecting rot-
atable member 55 ~ compressor crank shaft 23. When coil 31
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i5 deenergi~ed, fo~ example, by a manual or ~he;~os'ca'.,ic
contxol (not shown), clutch plate 51 ~der ~h2 in~luence
of springs 49 returns to its xes~ position and no longer
frictionally engages surace 53. In this rest position
compressor 19 is inacti~e, however, rota~a~le member 55
~ree wheels about the axi~ 33 on a bearing 57.
Rotatable member 55 includes not only pulley 15, but
also beari~g re~ainer spring 59, and generator rotor pox~ion
63, which includes flywheel 65 and a series of permanent
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magnets 67~ which toge~her form a mul~i-pole xotor fo~ the
alternator. Flywheel 65 may have ~he permanent magne~s 67
adhesively bonded to its in~xior rim. Flywheel 65 a~d its
permanen~ magnets 6 7 are again concentric within reasonable
limits with axis 33. Flywheel 65 may be prsvided with a
plurali~ of air passing apertures 69 for cooling the gen-
erator stator portion. A cooling f an may be mounted on
member 65 to force air through holes 69 ~or applications in
which.the ~ehicles main cooling fan is not favorably located
with respec~ to this alternator. The air passing apertures
have webs lying ~herebetween and these web p~r~ions may be
be~ ~o orm a fan type struc~ure.~
When ~he fixed annular coil 31 is not energized to
create a magnetic field, clutch 17 is motionless and ~he
comp~essor 19 is qu~escent, e~en ~hough ~he engin~ is oper-
ating and driving bel~ 13, ~o cause pulley 15, retainer 59,
fl~wheel 65~ ana its associated permanent magnets 67 to ro-
~ate about the stator 2S and induce a voltage in the windings
~herGo~. Energization of tha coil 31 causes clutch plate
51 to engage surface 53 o~ pulley 15 ~nd additionally, ~xic-
tionally to drive clutch 17 and ~ompressor crank shaft 23.
Axial space sav.ing is accomplished b~ the nesting ofgenerator and compressor poxtions which is most readily seen
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in Fig. 3. Thus generator elements, such as the permanentmagnets 67 ànd stator 25, including stator laminations 27
and windings 29, are nested with and overlap somewhat
magnetic clutch actuating coil 31 as well as bearing 57
and shaft engaging member 39. A substantial space saving and
weight saving over merely an end to end connection of a
generator and compressor is thereby achieved. It will be
understood that electromagnets energized through slip rings
on member 39 may be substituted for permanent magnets 67.
While many winding arrangements could be employed
in the annular stator assembly 25, typical known alternators
employ windings connected in a three-phase wye or star
configuration with an ungrounded center point of that wye.
Six diodes are employed to couple such a wye connection to, for
example, a vehicle storage battery with three of those
diodes conducting current fxom one terminal of the battery
to each of the three respective winding leads while three other -
diodes couple those same three respective winding leads to
the other side of the battery. Such a known winding
connection would be perfectly suitàble for use in the present
invention, however, Fig. 4 illus~rates another manner in
which the windings may be connected and which connection may
be preferred in some vehicle environments.
In Fig. 4 the three windings 29 are Delta connected
with each winding junction, such as 71 coupled by way of a diode
73 to the positive terminal of storage battery 75. Voltage
regulating circuit 77 may sense the voltage across the battery
and provlde appropriate gating signals to silicon controlled
rectifiers, such as 79, so as to pass or block charging current,
depending upon the state of charge of the battery 75.
Fig~re 5 illustrates an embodiment, which is also described and
is~claimed in above-identified paren-t Application Serial No. 305,616, and
includes a fan blade 80 supported on a shaft 82
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connec~ed to ~ pump 84 such as a vehicle ~ater pump having
an impeller 87. Frame 84 of the water p~mp supports stator
laminations 86 having windings 88 disposed ~herein. A
pulley 90 is engine dri~en and in tu~ drives a flywheel
92 supporting permanent magnets 94 to provide a generator
or alternator operating s~stantially as previously described.
Mounting the alternator directly behind the vehicle cooling
fan in this mannex allows excellent cooling of the alternator
windings, silicon controlled rectifiexs and diodes~ The
alterna~or rotor is common with ~he vehicle fan and water
pump sh~ft.
Thus, while the presen~ invention ha-~ been de~cribed
with respeck to a specific preferred embodiment, numerous
modifications will suggest themselves ~o ~h~se of ordinary
skil? in the art. ~or example, ~he illust~ated pxeferred
embodiment is of an alternator-compressor, however, pumps
- found in vehicles other than an air conditioner compressor
pum~ might equally well be integratea with an alternator,
or other ~ype genera~or advantageously according to ~he
pr~ciples of the present invention. Also a bracket may
upport the alternator when no compressor is presen~.
Accordin~ly, ~h~ scope o ~he present invenkion is to be
measured only by that o~ ~he appendad claims.
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