U.S. patent application number 09/867981 was filed with the patent office on 2002-05-23 for fluid mover.
Invention is credited to Cross, Paul C., Hansen, Craig N..
Application Number | 20020061256 09/867981 |
Document ID | / |
Family ID | 26731507 |
Filed Date | 2002-05-23 |
United States Patent
Application |
20020061256 |
Kind Code |
A1 |
Hansen, Craig N. ; et
al. |
May 23, 2002 |
Fluid mover
Abstract
A pump for moving a fluid has a housing with a internal chamber
accommodating a pair of rotating pistons. Each piston has
protrusions that register with pockets in the other piston in
non-contact relation as the pistons rotate.
Inventors: |
Hansen, Craig N.;
(Minnetonka, MN) ; Cross, Paul C.; (Minnetonka,
MN) |
Correspondence
Address: |
Southdale Office Centre
Suite 350
6750 France Avenue South
Edina
MN
55435-1905
US
|
Family ID: |
26731507 |
Appl. No.: |
09/867981 |
Filed: |
May 30, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09867981 |
May 30, 2001 |
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09504199 |
Feb 15, 2000 |
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6241498 |
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09504199 |
Feb 15, 2000 |
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09118625 |
Jul 17, 1998 |
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6138646 |
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60053148 |
Jul 18, 1997 |
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Current U.S.
Class: |
418/206.4 ;
418/206.5 |
Current CPC
Class: |
F02B 33/38 20130101;
F04C 18/126 20130101 |
Class at
Publication: |
418/206.4 ;
418/206.5 |
International
Class: |
F01C 001/18; F01C
001/24; F03C 002/00; F04C 018/00; F03C 004/00 |
Claims
1. A fluid mover comprising: a housing having a first chamber and a
second chamber open to the first chamber, each chamber having an
inside surface, said housing having a fluid intake passage and a
fluid exhaust passage open to the chambers, rotor means located in
the chambers to draw fluid through the intake passage, into the
chambers, and force fluid out of the chambers through the fluid
exhaust passage, shaft means rotatably mounted on the housing,
means to concurrently rotate the shaft means, said rotor means
having a pair of rotors mounted on the shaft means rotatably
support the rotors in the chambers, each rotor having a plurality
of pockets and protrusions, said protrusions having a non-contact
relation with the inside surfaces of the chambers and a non-contact
relation with the pockets of the adjacent rotor when the rotors are
rotated, the protrusions cooperating with the pockets of the
adjacent rotor to move fluid through the chambers when the rotors
are rotated, said shaft means comprising first and second shafts,
said pair of rotors having one rotor mounted on the first shaft and
the other rotor mounted on the second shaft, each rotor having
outer arcuate surface segments, the arcuate surface segments of the
rotors having the same arcuate lengths and diameters, said means to
concurrently rotate the shafts and rotors comprise a first spur
gear mounted on the first shaft and a second spur gear mounted on
the second shaft, said spur gears having engaging teeth whereby the
first and second spur gears concurrently rotate said shafts and
rotors, said first and second spur gears having pitch diameters
that are the same as the diameters of the arcuate surface segments
of the rotors.
2. The fluid mover of claim 1 wherein: each pocket has a generally
semi-circular cross section, each protrusion having a generally
semi-cylindrical shaped outer surface with a radius smaller than
the radius of the pocket.
3. The fluid mover of claim 1 wherein: each rotor has a body, and
said protrusions are integral portions of the body.
4. The fluid mover of claim 1 wherein: the fluid intake passage
includes a fluid inlet having two passages open to the chambers to
allow fluid to flow in general tangential directions into the
chambers.
5. The fluid mover of claim 1 wherein: the housing has first and
second side walls on opposite sides of the chamber, and means
operatively associated with the shaft means to maintain the rotors
in axial spaced relation relative to the first and second side
walls of the housing.
6. The fluid mover of claim 1 wherein: the housing has first and
second side walls on opposite sides of the chamber, each rotor has
opposite end walls, and means to maintain the end walls of each
rotor in axial spaced relation relative to the first and second
side walls of the housing.
7. The fluid mover of claim 6 wherein: the means to maintain the
end walls of the rotors in axial spaced relation relative to the
first and second side walls of the housing comprise bearing washers
adjacent opposite sides of the gears and biasing means engageable
with one bearing washer for each gear operable to maintain the end
walls of the rotors in axial spaced relation relative to the first
and second side walls of the housing.
8. The fluid mover of claim 1 wherein: each arcuate surface segment
has an arcuate length of about 50 degrees, each pocket having a
concave surface having an arcuate length of about 170 degrees, and
each protrusion having an outer convex surface having an arcuate
length of about 180 degrees.
9. A fluid mover comprising: a housing having a first chamber and a
second chamber open to the first chamber, each chamber having an
inside surface, said housing having a fluid intake passage, a fluid
exhaust passage open to the chambers, and side walls adjacent
opposite sides of the chambers, rotor means located in the chambers
to draw fluid through the intake passage, into the chambers, and
force fluid out of the chambers through the fluid exhaust passage,
a pair of parallel shafts rotatably mounted on the housing, said
rotor means having a pair of rotors mounted on the shafts rotatably
supported on the housing, means to concurrently rotate the shafts
and rotors, means operatively associated with the shafts to
maintain the rotors in axial spaced relation relative to the side
walls of the housing, each rotor having a plurality of pockets and
protrusions, said protrusions being integral portions of the rotors
and having a non-contact relation with the inside surfaces of the
chambers and non-contact relation with the pockets of the rotors
when the rotors are rotated, the protrusions cooperating with the
pockets of the adjacent rotor to move fluid through the chambers
when the rotors are rotated, each pocket having a concave surface
with a generally semi-circular cross section, each protrusion
having a generally semi-cylindrical shaped outer surface with a
radius smaller than the radius of the concave surface of the
pocket, each rotor having outer arcuate surface segments, the
arcuate surface segments of the rotors having the same arcuate
lengths and radii, said means to concurrently rotate the shafts and
rotors comprising a first gear mounted on one shaft and a second
gear mounted on the other shaft, said gears having engaging teeth
whereby the first and second gears concurrently rotate said shafts
and rotors in opposite directions, said first and second gears
having pitch diameters that are the same as the diameters of the
arcuate surface segments of the rotors.
10. The fluid mover of claim 9 wherein: the fluid intake passage
includes a fluid inlet having two passages open to the chambers to
allow fluid to flow in tangential directions into the chambers.
11. The fluid mover of claim 9 wherein: each rotor has opposite end
walls, said means to maintain the rotors in axial spaced relation
relative to the side walls of the housing being operative to
maintain the end walls of the rotors in spaced relation to the side
walls of the housing.
12. The fluid mover of claim 11 wherein: the means to maintain the
rotors in axial spaced relation to the side walls of the housing
comprise bearing washers adjacent opposite sides of the gears and
biasing means engageable with one bearing washer for each gear.
13. The fluid mover of claim 9 wherein: each arcuate surface
segment has an arcuate length of about 50 degrees, each pocket
having a concave surface having an arcuate length of about 170
degrees, and each protrusion having an outer convex surface having
an arcuate length of about 180 degrees.
14. The fluid mover of claim 9 wherein: each rotor has two pockets
open to opposite first portions of the rotor and two protrusions
extended outwardly from opposite second portions of the rotor, said
second portions of the rotor being located 90 degrees from the
first portions of the rotor.
15. A fluid mover comprising: a housing having a first chamber and
a second chamber open to the first chamber, each chamber having an
inside surface, said housing having a fluid intake passage, a fluid
exhaust passage open to the chambers, and side walls adjacent
opposite sides of the chambers, rotor means located in the chambers
to draw fluid through the intake passage, into the chambers, and
force fluid out of the chambers through the fluid exhaust passage,
a pair of parallel shafts rotatably mounted on the housing, said
rotor means having a pair of rotors mounted on the shafts rotatably
supported on the housing, means to concurrently rotate the shafts
and rotors, means operatively associated with the shafts to
maintain the rotors in axial spaced relation relative to the side
walls of the housing, each rotor having a plurality of pockets and
protrusions, said protrusions being integral portions of the rotors
and having a non-contact relation with the inside surfaces of the
chambers and non-contact relation with the pockets of the rotors
when the rotors are rotated, the protrusions cooperating with the
pockets of the adjacent rotor to move fluid through the chambers
when the rotors are rotated, each pocket having a concave surface
with a generally semi-circular cross section, each protrusion
having a generally semi-cylindrical shaped outer surface with a
radius smaller than the radius of the concave surface of the
pocket, each rotor having outer arcuate surface segments, the
arcuate surface segments of the rotors having the same arcuate
lengths and radii.
16. The fluid mover of claim 15 wherein: the fluid intake passage
includes a fluid inlet having two passages open to the chambers to
allow fluid to flow in tangential directions into the chambers.
17. The fluid mover of claim 15 wherein: each rotor has opposite
end walls, said means to maintain the rotors in axial spaced
relation relative to the side walls of the housing being operative
to maintain the end walls of the rotors in spaced relation to the
side walls of the housing.
18. The fluid mover of claim 15 wherein: the means to maintain the
rotors in axial spaced relation to the side walls of the housing
comprise bearing washers adjacent opposite sides of the gears and
biasing means engageable with one bearing washer for each gear.
19. The fluid mover of claim 15 wherein: each arcuate surface
segment has an arcuate length of about 50 degrees, each pocket
having a concave surface having an arcuate length of about 170
degrees, and each protrusion having an outer convex surface having
an arcuate length of about 180 degrees.
20. The fluid mover of claim 15 wherein: each rotor has two pockets
open to opposite first portions of the rotor and two protrusions
extended outwardly from opposite second portions of the rotor, said
second portions of the rotor being located 90 degrees from the
first portions of the rotor.
Description
FIELD OF THE INVENTION
[0001] The invention relates to fluid pumps, such as blowers and
superchargers for internal combustion engines, and other processes
requiring large volumes of fluid at relatively low pressure.
BACKGROUND OF THE INVENTION
[0002] In an internal combustion engine a boost in horsepower can
be accomplished by forcing a more dense air/fuel charge into the
cylinders with a supercharger. A supercharger can provide a
dependable and affordable method of increasing horsepower and
torque. A supercharger forces a more dense air/fuel mixture into an
internal combustion engine's cylinders than the engine can draw in
under normal conditions. This higher-energy mixture produces more
power. Supercharging increases the engine's volumetric flow without
increasing its displacement. Therefore, a supercharged small engine
can produce the horsepower and torque of a relatively larger
engine.
[0003] There are two basic blower systems used to force an air/fuel
mixture into an internal combustion engine. These blowers are
either a dynamic or a positive displacement equipment.
Turbocharging, which is a dynamic process, places a turbine wheel
in the exhaust flow of the engine. The turbine blades are directly
connected to a centrifugal blower. One major disadvantage of a
turbocharger is "turbo-lag." This is the delay that occurs after
calling for power with the throttle before the rotational speed of
the system spools up to deliver that power. An improperly sized or
designed turbo system can rapidly over-boost and damage a
spark-ignited internal combustion engine. The sizing of the
turbocharger to the engine and the matching of the turbine size and
design to impeller size and design are very critical. Additionally,
the exhaust turbine tends to cool the exhaust gases thereby
delaying the catalyst light-off of modern automotive emissions
systems.
[0004] Centrifugal impeller-type supercharging is a system having
an impeller rotated with a drive belt from the crankshaft. A
speed-increaser, either geared or gearless, is required to multiply
the speed of the impeller relative to that of the input shaft. The
delivery of a centrifugal impeller-type device varies dramatically
with its rotational speed, and is prone to under-boost at low speed
and over-boost at high speed. An example of a centrifugal impeller
supercharger is disclosed by M. Shirai in U.S. Pat. No.
5,158,427.
[0005] The most common positive displacement system is the "Roots
blower". In this system, a belt-driven shaft drives two
close-clearance rotors which are geared together. Each full
rotation sweeps out a specific fixed volume, unlike the fan-like
characteristics of a turbine device.
SUMMARY OF THE INVENTION
[0006] The invention is a fluid pump used as a supercharger to
provide an air/fuel mixture to an internal combustion engine in an
efficient and reliable manner for sharply increasing the torque and
corresponding horsepower of the engine across its entire operating
speed range. The supercharger has simple geometric shaped
structures which are easy to fabricate at a relatively low cost.
The supercharger employs a pair of cooperating rotors that do not
have complex curved surfaces which require relatively costly NC
profile milling or dedicated machine tool operations. Conventional
materials such as aluminum, cast iron or plastics and established
fabrication procedures are used to manufacture the
supercharger.
[0007] The supercharger rotors have clearances relative to their
cooperating or mating surfaces and housing surfaces that
accommodate deflection. The cylindrical shapes of the rotors and
inside surfaces of the housing allow for predictable and repeatable
clearances between non-contacting mating parts. This reduces
leakage which improves efficiency while maintaining low cost
manufacturing procedures. The cylindrical shapes of the
supercharger rotors and associated surfaces are inherently rigid
and not prone to flexing and twisting when subjected to pressures
and inertial loads.
[0008] The supercharger has a housing with two generally
cylindrical chambers open to each other and fluid inlet and outlet
ports. A rotor assembly located in the chambers operates to draw
fluid, such as an air/fuel mixture, into the chambers and discharge
the fluid out the outlet port and into the intake of an internal
combustion engine. The rotor assembly has a pair of rotors mounted
on shafts rotatably supported on the housing. Each rotor has
semi-cylindrical pockets and semi-cylindrical protrusions that
cooperate with the pockets of the adjacent rotor to move fluid
through the supercharger when the rotors are rotated. The
protrusions on each rotor do not contact the inside cylindrical
surfaces of the housing. Also, the protrusions on each rotor do not
contact the cooperating rotor as they move into and out of the
mating pockets. This allows for both high speed and oil free
operation. The protrusions are integral portions of the rotor. The
protrusions are located in the semi-cylindrical pockets of the
adjacent rotor generally half of the time during rotation of the
rotors. Therefore, the pressure fluctuations and associated noise
and heat are reduced. There is minimal trapped volume of fluid in
the pockets. This reduces one of the common sources of noise, heat,
and vibrations among prior devices. Additionally, the fluid inlet
has two passages. This improves volumetric efficiency and reduces
churning of the fluid and heating of the inlet region of the
rotor.
DESCRIPTION OF THE DRAWING
[0009] FIG. 15 is a diagrammatic view of an internal combustion
engine operatively connected to the supercharger of the
invention;
[0010] FIG. 16 is a perspective view of the supercharger of FIG.
15;
[0011] FIG. 17 is a top plan view of the supercharger of FIG.
16;
[0012] FIG. 18 is an end elevational view of the drive end of the
supercharger of FIG. 16;
[0013] FIG. 19 is an end elevational view of the left end of the
supercharger of FIG. 16;
[0014] FIG. 20 is a front elevational view of the supercharger of
FIG. 16;
[0015] FIG. 21 is a rear elevational view of the supercharger of
FIG. 16;
[0016] FIG. 22 is a bottom plan view of the supercharger of FIG.
16;
[0017] FIG. 23 is an enlarged sectional view taken along the line
23-23 of FIG. 17;
[0018] FIG. 24 is an enlarged sectional view taken along the line
24-24 of FIG. 17; and
[0019] FIG. 25 is an enlarged sectional view taken along the line
25-25 of FIG. 17.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] The supercharging system of the invention, shown in FIGS. 15
to 25, is used with an internal combustion engine 220 to increase
the engine's volumetric efficiency and output horsepower. As shown
in FIG. 15, engine 220 has a crank case 221 rotatably supporting a
power output shaft 222. A fuel intake pipe or manifold 224 directs
an air/fuel mixture to engine 220. An exhaust pipe 226 carries
exhaust gas away from engine 220. Engine 220 is a single cylinder
four cycle conventional air cooled internal combustion engine. An
example of engine 220 is a five horsepower, single cylinder, four
cycle internal combustion engine. Other types of internal
combustion engines including two cylinder models are adaptable to
the supercharging pump of the invention.
[0021] Engine 220 is supplied with an air/fuel mixture with a
supercharger or fluid pump 227. Supercharger 227 has a housing 228
rotatably supporting a drive shaft 229. A power transmission
comprising a first sprocket 231 on shaft 229, a second sprocket 232
on shaft 222, and an endless roller link chain 233 coupling
sprockets 231 and 232 provides a direct drive between engine 220
and supercharger 227. Sprockets 231 and 232 have the same diameters
whereby the RPM of engine 220 is the substantially the same as the
operating speed of supercharger 227. Sprockets 231 and 232 can have
a sprocket ratio to provide desired air flow to a specific engine
size. Supercharger 227 is a positive displacement fluid pump
operable to deliver a supply of air/fuel mixture to engine 220 to
increase its adiabatic efficiency and horsepower. The air/fuel
mixture flows through a pipe or tubular member 234 connected to
supercharger 227 and intake pipe 224 of engine 220.
[0022] An air/fuel mixing device 236, known as a carburetor,
mounted on housing 228 operates to introduce fuel, such as gasoline
and alcohol, into air flowing through device 236 to provide an
air/fuel mixture for engine 220. A fuel line 237 connected to
device 236 carries liquid fuel from a tank 235 to device 236.
[0023] An air/fuel mixture accumulator 238 is in fluid
communication with pipe 234 to hold a supply of an air/fuel mixture
between the engine intake strokes without excessive pressure rise.
For example, for a single cylinder engine the volume of accumulator
238 is about twelve times the engine displacement. Accumulator 238
has a funnel or cone shape which allows a vehicle driven with
engine 220 to accelerate and corner without pooling of fuel in
accumulator 238. Accumulator 238 has the same structure as
accumulator 38 shown in FIG. 9. The accumulator 238 is mounted on a
check valve assembly, as shown in FIGS. 9 and 10, which directs the
air/fuel mixture to the intake port of engine 220. Supercharger 227
may be employed in multi-cylinder engines of three cylinders or
greater without the need for accumulator 238.
[0024] Supercharger housing 228, shown in FIGS. 16 to 22, has a
central body 239 located between end members 241 and 242. A first
cover plate 243 is located adjacent to the outside of end member
241. A plurality of bolts 246 attach end member 241 and cover plate
243 to body 239. A second cover plate 244 closes the outside of end
member 242. A plurality of bolts 247 secure end member 242 and
cover plate 244 to body 239. As shown in FIGS. 18, 19 and 22, end
member 243 has a pair of downwardly directed legs 249. End members
244 has a pair of downwardly directed legs 250 laterally aligned
with legs 249. Each leg 249, 250 has a threaded bottom hole for
accommodating a bolt to secure housing 228 to a fixed support. Body
239 has a side passage 251 open to a pair of passages 252 and 253
to carry the air/fuel mixture from device 236 to the interior
chamber of body 239.
[0025] Body 239 has a first arcuate inside wall 254 surrounding a
first chamber 256 and a second arcuate inside wall 257 surrounding
chamber 258. Passage 252 is open to chamber 256 to allow the
air/fuel mixture to flow in a tangential direction into chamber
256. Passage 253 is open to chamber 258 so that the air/fuel
mixture flows in a tangential direction into chamber 258. Walls 254
and 257 have cylindrical surfaces which are machined with
conventional machine tools. Body 239 has a central portion 259
separating passages 252 and 253. Opposite portion 259 is an
air/fuel discharge port 260 for carrying the air/fuel mixture from
chambers 256 and 258 to pipe 234 leading to engine intake and
accumulator 238.
[0026] As shown in FIG. 24, a first rotor or rotating piston 261
mounted on shaft 229 is located in chamber 258. Rotor 261 has a
pair of semi cylindrical pockets or recesses 262 and 263 open to
opposite sections of its cylindrical outer surface 264. Body outer
surface 257 is concentric with arcuate rotor surface 264. Surface
264 concentric with shaft 229 comprise segments of a cylinder pitch
circle. Pockets 262 and 263 have semi-circular cross sections and
semi-cylindrical surfaces. Pockets 262 and 263 are located in
opposite sides of rotor 261. Rotor 261 has a pair of protrusions
268 and 269. As shown in FIG. 24, rotor surface 264 has four
arcuate surface segments extended between adjacent pockets 262, 263
and protrusions 268, 269. Each arcuate surface segment has a radius
extended from the axis of the shaft 229. The surface segments have
the same arcuate lengths. The arcuate length of each arcuate
surface is 50 degrees. The concave surfaces of rotor 261 forming
each pocket 262 and 263 has a cross sectional concave arcuate
length of less than 180 degrees. The concave arcuate length of each
concave surface is about 170 degrees. Each protrusions 268 and 269
has a semi-cylindrical shape with an outer convex surface having a
cross sectional circumferential length of 180 degrees. The radius
of curvature of the outer convex surface of each protrusion is less
than the radius of curvature of each concave surface of the pockets
262 and 263. The number and locations of pockets and protrusions
can vary to maintain dynamic balance of rotor 261. Each protrusion
268, 269 has a generally semi-cylindrical shape located 90 degrees
or normal to pockets 262 and 263. Protrusions 268 and 269 project
outwardly in opposite directions from surface 264 to dynamically
balance rotor 261. The outer apex portions of protrusions 268 and
269 are located in close non-contacting relationship with body
surface 257. There is a small space between protrusions 268 and 269
and surface 257 to prevent wear and friction between adjacent
surfaces of the protrusions and body 239 and generation of heat and
noise.
[0027] A second rotor or rotary piston 273 is mounted on a shaft
274. Rotor 273 has the same shape and structure as rotor 261.
Opposite ends of shaft 274 are rotatably mounted on end members 241
and 242 with bearings 276 and 277, as seen in FIG. 23. A sleeve 278
secured to shaft 274 with a bolt 279 supports shaft 274 on bearing
276. A second sleeve 281 surrounding the opposite end of shaft 274
is keyed to rotor body 282 with a tongue and groove coupling 283.
Sleeve 281 extends through bearing 277 whereby bearing 277 supports
shaft 274 on end member 241.
[0028] Shaft 229 extends through sleeves 284 and 286 located
adjacent opposite ends of body 261. Sleeve 284 extends through
bearing 271 to support shaft 229 on end member 242. Sleeve 286
extends through bearing 272 to support shaft 229 on end member 241.
A tongue and groove connection 287 drivably joins sleeve 286 to
body 261 so that body 261 rotates with shaft 229.
[0029] Returning to FIG. 24, rotor body 282 has a pair of
semi-cylindrical pockets 288 and 289 open to the outer cylindrical
surface 291. Surface 291 is concentric with body surface 259.
Surface 291 concentric with shaft 229 comprise segments of a
cylinder pitch circle. The adjacent portions of surfaces 264 and
291 move in contiguous relationship as there is a small clearance
between the adjacent surfaces. An example of this clearance is
0.005 to 0.007 inch. The rotor-to-rotor clearance reduces noise,
wear of the rotors, and reduces heat generation. Pockets 288 and
289 are on opposite portions of body 282 and ninety degrees from a
pair of protrusions 294 and 296. Each protrusion 294, 296 has a
semi-cylindrical outer surface having the shape and configuration
of pockets 262 and 263 of rotor 261. The outer apex portions of
protrusions 294 and 296 are in close non-contacting relation with
body surfaces 254. Protrusions 294 and 296 are integral portions of
the monolithic rotor body 282. The rotors 261 and 273 and their
protrusions 268, 269, 294 and 296 are one-piece structures. Rotors
261 and 273 are identical in size and shape. They can be made by an
extrusion process and externally broached or shaved to finished
size. Profile milling procedures can also be used to make the
one-piece rotors 261 and 273. Large rotors can be hollow to reduce
weight.
[0030] As shown in FIGS. 23 and 25, shafts 229 and 274 are drivably
connected with spur gears 316 and 317 located within end cover 243.
Gear 316 is fixed to shaft 229 with a key 318 and bolt 319. Gear
316 is located between thrust bearing washers 341 and 342. Washer
341 fits around an annular head 343 accommodating the head of bolt
219. Washer 342 surrounds sleeve 286. Washers 341 and 342 engage
opposite sides of gear 316. An annular spring 344, such as a
wave-type spring, located in a shallow recess in cover plate 243
engages washer 341 and biases the thrust bearing washers axially to
retain washer 342 against end member 242. This locates the axial
positions of the gear 316 and rotor 261. As shown in FIG. 23, the
flat ends of rotor 261 are spaced a small distance from adjacent
inside surfaces of end members 241 and 242. The small clearance
between rotor 261 and end members 241 and 242 reduces wear,
friction and heat generation during rotation of rotor 261. A bolt
321 secures gear 317 to shaft 274. A key 320 interconnects gear 317
with shaft 274 whereby gear 317 rotates shaft 274 and rotor 273.
Bolt 321 retains gear 317 between thrust bearing washers 346 and
347. Washer 346 fits on a head 348 accommodating bolt 321. Washer
347 surrounds sleeve 281. A spring 349, such as an annular
wave-like spring, located in a recess in cover plate 243 biases
washer 346 to retain washer 347 against end member 242 to maintain
the axial location of shaft 274, gear 317 and rotor 273. Rotor 273
has flat ends spaced a small distance from adjacent surfaces of end
plates 241 and 242. The small clearance, seen in FIG. 23, between
rotor body 282 and inside surfaces of end plates 241 and 242
reduces wear, friction and heat generation during rotation of rotor
273. Gears 316 and 317 have the same pitch diameters whereby shafts
229 and 274 rotate at the same speed. The pitch diameters of gears
316 and 317 are the same as the diameters of rotors 261 and 273.
Rotors 261 and 273 turn in opposite directions at the same speed so
that protrusions 268 and 269 register with pockets 288 and 289 in
non-contact relation and protrusions 294 and 296 register with
pockets 262 and 263 in non-contact relation during concurrent
rotation of rotors 261 and 273. This reduces wear of the
protrusions and rotor pockets and minimizes noise.
[0031] As shown in FIG. 23, cover plate 243 closes the open side of
end member 242 and bearings 271 and 276. A flat disk 322 located
between cover plate 243 and end member 241 is mounted on shaft 229.
Disk 322 on rotation of shaft 229 moves a lubricant, such as oil,
upward to lubricate bearings 271 and 276.
[0032] The present disclosure is preferred embodiments of the
supercharger for an internal combustion engine. It is understood
that the supercharger is not to be limited to the specific
constructions and arrangements shown and described. It is
understood that changes in parts, materials, arrangement and
locations of structures may be made without departing from the
invention.
* * * * *