Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
40~35
REEL SPEED VALVE ASSEMBLY
I. Background of the Invention
A. Field of the Invention.
This invention it in the field of control valve
ambles for regulating the speed of harvester or
combine reels.
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Z35
B. Background Art.
Compensated valves for the control of farm
equipment machinery are well Known in the prior art. In
particular, proportional pressure compensated valves for
the control of combine reel speed are generally known.
Such valves are typically of either the open or closed
center type and are also typically manufactured for a
particular mounting configuration discreet, top of
stack, middle of stack, bottom of stack).
Further, such reel speed control valve
typically contain relief valves, manual control valves,
and/or pressure or load tense valve assemblies.
A valve for regulating hydraulic flow to a
combine reel motor is taught in U. S. Patent 3,474,908
to Anderson. This spool-type valve direct a priority
flow to the reel motors of a combine while providing
flow to a secondary load if possible. The priority flow
valve of this patent it usable in either an open-center
or closed-center system.
Yet another example of a hydraulic control valve
incorporating compensators is described in U. S. Patent
3,827,453 to Malta _ at. This valve comprises a
plurality of conventional spool-type valves and a con-
ventional compensator which regulates the pressure
I
differential across the spool valve metering orifice and
diverts excess flow to a reservoir when necessary. Also
illustrated it the use of a relief check valve for
diverting excessive pressures to the reservoir.
Il. Summer of the Invention
Y
A. Object of the Invention.
Notwithstanding the above background art, there
remains a need for an efficient, versatile, and compact
reel speed valve assembly.
It is therefore a primary objective of the
present invention to provide a reel speed valve
assembly adaptable to a maximal number of differing
configurations with minimum change in manufacturing
procedures.
Yet another object of the present invention it
to provide a reel speed valve assembly which is
controlled by a digital stepper motor or similar
proportional drive.
Still another object of the present invention
is to provide a reel speed valve assembly which is
capable of functioning in either an open or closed
center mode.
SLY
--4--
B. Brief Description.
The reel speed valve assembly of the prevent
invention incorporates within a single housing, a
double acting compensator valve, a manually adjustable
S controller valve, a proportional controller valve, a
relief check valve and a pressure or load tense valve.
The proportional control valve may be of the "spool
within a spool" servo-follower proportional valve type.
Manual control valves, relief check valve, and
pressure or load sense valves, are optional and may be
included within the unitary housing if desired.
In operation, the reel speed valve assembly of
the present invention provides proportional controller
flow which is compensated to allow constant flow volume
under varying conditions of pressure and flow.
III. Brief Description of the Figures
Fig. 1 shows a cros6-section of the reel speed
valve assembly of the present invention.
Fig. 2 is a cros~-section of the proportional
controller valve of the present invention.
Fig. pa owe an alternate linear actuator for
the proportional controller valve of toe present invent
lion.
- Fig. 2b shows another alternate linear actuator
for the proportional controller valve of the prevent
invention.
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Fig. 2c shows yet another linear actuator for
the proportional controller valve of the present invent
lion using a normally-open pilot valve.
Fig. 3 it a cross-section of the double acting
compensator valve of the present invention.
Fig. 4 is a cros~-section of the manual bypass
valve of the prevent invention.
Fig. 5 it a cross-section of the relief check
valve of the present invention.
Fig. 6 it a cros6-section of the pressure or
load sense valve of the present invention.
Figs. 7 through 14 are block schematic diagrams
of the operational mode of the reel speed valve
assembly of the present invention.
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Detailed Desert lion of toe Control Valve
P _ _
Referring now to Fig. 1 there is shown a reel
speed valve assembly comprising a compensator valve 600,
a control valve 700, a manual beep valve 800, a relief
valve 900, and an output pressure (load) sense ball
check valve 950. A source of hydraulic pressure such as
a pump (not shown) is connected to the reel speed valve
assembly at pressure inlet port 500. Low pressure
return flow to a tank (not shown) exits the valve
asfiembly at outlet port 400. Controlled flow exits the
valve assembly via outlet port 300, while beep 8 flow
exits via outlet port 200.
Focusing more closely on control valve 700,
shown in more detail in Fig. 2, there is shown a
~ervo-follower proportional control spool valve
generally described in parent application Serial No.
511,576, which comprises a housing 15 having a
cylindrical bore aye for receiving a main spool 12. The
main spool ha an open bore aye for slid ably receiving a
20 pilot spool 11. Valve 700 is coupled to a source of
hydraulic pressure (not shown) via inlet passage 32.
Main spool 12 has upper cylindrical land 100 and
lower cylindrical land 104 spaced axially with respect
to the longitudinal axis of main spool 12. A transverse
inlet metering orifice 42 extends between cylindrical
bore aye and bore aye id the main spool 12.
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Upper land 100 extends into a reduced diameter
cylindrical section 72 which defines the top end of
main spool 12 while lower land 104 extends into reduced
diameter cylindrical section 73 which define the
bottom end of main spool 12. Connecting passages 46
and 47 are formed transverse of the longitudinal axis
of main spool 12 and provide connecting passages
between bore aye and chambers formed by the outer
surface of section 46 and 47 respectively.
Land 100 and 104 on main spool 12 are laudably
but ~ealingly received in cylindrical bore aye. This
bore present a cylindrical land surface 31 disposed
between annular recesses aye and aye leading
respectively to inlet passage 32 and outlet passage 29.
Land 104 has metering V-groove aye formed thereon.
At it top end, bore lea forms an elongated end
recess 74 for receiving land 67 and a floating annular
spacer 50 which abuts an end wall of end cap 78.
Spacer 50 has its inner cylindrically-shaped bore
surface 50d ground to receive the outer surface of
section 72. A slot is formed on the outer surface of
spacer So to provide for an 0-ring Spa for sealing
engagement between the spacer and recess 74. It is in
this manner that spacer 50 it effective to "float"
within recess 74.
1~4023~
In a manner similar to the top end, a floating
ring 51 it duped about land 68 of pilot spool 11. It
will be understood that these lower end components are
substantially identical to analogous structure of the
upper end components and need not be described in
similar detail.
A previously described, pilot spool 11 it
received within bore aye of spool 12. Spool 11 has at
its center a V-groove piston 14 defined by a pair of
metering lands aye and 14b, where the V-groove 14c is
formed between the lands. In the null position of spool
11 with respect to spool 12 as shown in Fig. 1, V-
groove 14c is in communication with metering orifice 42.
Metering land aye and 14b each form a sharp metering
edge with a respective wall of orifice 42 and sealingly
engage bore aye 80 that there it no flow of fluid from
orifice 42 into the left or right side of bore aye.
Spool 11 also has two axially spaced cylindrical lands
tic and lid formed at the upper and lower ends of the
spool to sealingly engage the upper and lower ends of
open bore aye in all positions of spool 11. Metering
land aye and land tic are integrally interconnected by
stem portion ha which defines an elongated longitu-
finally directed annuls forming a longitudinal passage
which extends almost one-half of the length of spool 11.
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Similarly, stem portion fib interconnects a metering
land 14b and land lid with an elongated longitudinal
annuls forming a passage extending almost half the
length of spool 11. Passage ha leads through to
passage 46 and to bleed groove aye formed on the inner
surface of bore aye, while passage fib leads through to
bleed groove aye alto formed on the inner surface of
bore aye, and to passage 47. To provide axial movement
of pilot spool 11, there is provided an actuator 23
which it rigidly connected as shown through the center
of top portion tic to the top section of spool 11.
Actuator 23 extend through chamber 74 and through the
axis of end stop 78 in sealing relation thereto.
In operation, in the position Shown in Fig. 2,
spools 11 and 12 are in their center position within
bore aye and the spools are in their null position with
respect to each other. In this position, main spool 12
it at a neutral position in bore aye with land 104
sealingly engaging the radius of bore aye. Accordingly,
in this neutral position of main spool 12 in bore aye,
there is no flow of fluid from the inlet passage 32 to
outlet passage 29. With spool 11 and 12 at null there
is no flow of fluid from passage 32 through metering
orifice 42 to either of chambers 20 or 21.
Bleed grooves aye and aye, formed on the inner
surfaces of bore aye provide a path for fluid flow
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--10--
between passage 20 and 21 and tank. These bleed
groove are alternately opened and closed by motion of
inner spool end portion tic and lid.
When inner spool 11 moves from its illustrated
null position, the bleed groove on the end of spool 11
toward which movement occurs are exposed to ambient
pressure within bore aye. This action permits bleed of
this pressure to tank, thus permitting more rapid
frequency response of the valve assembly.
Detailed Ds6cription of the Compensator
As shown in detail in Fig. 3, compensator valve
600 is comprised of housing 15 having cylindrical bore
aye having four annular recesses 602, 604, 608 and 609.
Annular recesses 602, 604, 608 and 609 are in
communication with respective port 29, 610, 620 and
630. A source of hydraulic pressure such as a pump (not
one is connected to inlet port 500.
Located within cylindrical bore aye is
compensator spool 650 having at its upper end, metering
land aye and at its lower end, cylindrical stop 650b.
Spool 650 it biased into an upward position by biasing
spring 600b. Land aye has Groove 650n and 650m on
metering edges 650x and yo-yo respectively, for metering
flow against metering grooves 600c and 600d respective-
lye
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Cylindrical bore aye it further comprised of
metering groove 600c and 600d. Metering groove 600c
coats with metering edge 650x of cylindrical land aye
and U-groove 650n to meter fluid flow from inlet port
500 to bypass port 200. Metering groove 600d coquette
with metering edge yo-yo of cylindrical land aye and
U-groove 650m to meter flow from passage 29 to
controlled flow port 300.
In operation, pressure at inlet port 500 acts on
the top of spool 650 to compress biasing spring 600b.
Hydraulic fluid then flow out of compensator 600 via
outlet port 610. Controlled flow of hydraulic fluid
from control valve 700 enters compensator 600 at passage
29 and flows therefrom into annular recess 609.
Pressure in annular recess 608 and bore 600b acts
against metering edge yo-yo at the bottom of land aye to
urge spool 650 upward.
The above detailed opposed action of pressure
flow from port 500 and controlled flow in recess 608
serve to provide a constant volume controlled flow.
Variation in flow volume are metered by movement of
spool 650 Jo a to flow across U-groove 650n and exit
from the compensator via bypass port 200.
Detailed Desert lion of the Manual B ass
P YIP
Manual bypass valve 800 shown in Fig. 4, is
comprised of a housing 15 having a bore 801 with an
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--12--
inlet port 610, outlet port aye, and controlled flow
port 820. A source of hydraulic pressure connected to
compensator port 500 and exiting compensator 600 via
port 610 f owe through bore 801 and exits bore 801 via
line aye. Additionally, a portion of this flow may be
directed into line 820 by opening bypass valve 800.
Bypass valve 800 is comprified of valve seat 810
formed at the lower end of bore 801, valve body 860
mounted within bore 801 and protruding therefrom, lox
nut 870, valve stem 840, set screw 850, and valve plug 830.
Valve plug 830 is adapted to engage valve seat 810 in
sealing relationship. Valve 800 may be adjusted to
regulate fluid flow from bore 801 into line B20 by
adjustment of lead screw 850. Upward adjustment of lead
screw 850 cause concomitant upward motion of valve stem
840, and permits fluid flow into line 820.
It will be understood that the valve function of
bypass valve 800 may be accomplished by any suitable
known valve device.
Detailed Description of the Relief Valve
Relief valve 900 shown in Fig. 5, provides a
path for diverting excessive pressure to tank. The
relief valve is comprised of housing 15 having a bore
901. Bore 901 communicate at it upper end with
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channel 32b which in turn communicates at its upper end
with channel aye. Formed a the junction of channel 32b
and bore 901 is valve seat 904.
Relief valve 900 is preferably of the check
valve type. Situated within bore 901 are valve plug
910 having on its lower end plug stem 930, biasing
spring 920 for biasing valve plug 910 into sealing
relationship against valve seat 904, and adjustable
stop 934 having on its upper surface top stem 932.
biasing spring 920 is positioned in surrounding
relationship to plug stem 930 at its upper end and to
stop stem 932 at its lower end.
Adjustable top 934 it connected at its lower
surface to adjustment stem 945 which is slid ably
retained within collar 946 and sealed by O-ring 947.
Stem 945 is moved along its longitudinal axis by
adjustment of adjusting screw 940.
In operation, adjustment of adjusting screw 940
effects an essentially linear adjustment of the
pressure at which check valve 900 will open to permit
flow there through.
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Detailed Description of the Preseure/Load Sense
Pressure sense valve 950 shown in Fig. 6, is
comprised of housing 15 having bore 951 which
communicates at its upper end with channel 96~ which in
turn it in communication with channel aye. Located
within bore 951 are ball stop 990, biasing spring 980,
and ball 970. Valve seat 965 it formed at the junction
of bore 951 and channel 9600
Ball top 990 has at its upper end a reduced
10 diameter stem 992. Ball stop 990 further has at its
lower end, retaining plug 995.
In operation, biasing spring 980 biases ball 970
into sealing relationship with valve teat 965 to prevent
reverse flow into bore 960 from 953. Biasing spring
15 980 it situated in surrounding relationship to stem 992
and bears against thy upper surface of ball stop 990.
Bore 951 is in communication with channel 953 which
terminates at port aye which may be connected to
suitable prowar or flow monitoring means, or a load
sense pump.
Alternative embodiments of the valve assembly of
the present invention use a solid spool control valve
instead of the previously described servo follower con-
trot valve 700. In these embodiments, a spool having
Jo 25 the tame external configuration as previously described
and shown in Fife. 1 and 2 is controlled by linear
actuator other than a digital motor.
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I 35
-15-
A first alternative embodiment as shown in Fig.
pa, uses a manually adjustable lead-screw 100' to post-
lion the control valve spool 12' and thus set the con-
trolled flow rate. In this embodiment, spool 12' is
biased into an upward, valve-closed position by a coil
spring 101 located at the lower end of the spool.
Fig. 2b depict yet another linear actuator for
use within the valve assembly of the present invention.
Actuator 100" comprises a small cylinder and piston
assembly 105. This assembly may be actuated by a source
of fluid pressure applied to port 107.
Assembly 105 is comprised of bore lost within
which is mounted piston aye. The upper face of piston
aye is exposed within chamber 105b and is acted on by
fluid pressure therein. Chamber 105b is fed by orifice
aye which in turn communicates with port 107.
Yet another linear actuator which may be
employed for the purposes of the present invention is a
proportional solenoid or normally-open pilot a shown in
Fig 2c. When such an actuator is used, a feedback
transducer such as a linear variable displacement trays-
former or other transducer as, for instance, the Lion
Series 33 of Ceramic Magnetic, Inc. may also be used to
tense spool position and thus permit more precise
adjustment in flow rate.
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-16-
Desert lion of the Fluid Flow Path
P
The valve assembly of the present invention is
supplied a source of hydraulic flow by connection to a
pump (not shown) at pressure inlet port 500. The
primary fluid path through the valve assembly for
controlled flow, enters the assembly at port 500 and
exit the compensator assembly via line 610. Line 610
connect to inlet passage 32 of the controller valve
700 which allows flow through annular recess aye to
outlet passage 29. Outlet passage 29 traverses the
valve assembly and communicate with annular recess 609
of compensator 600. Annular recess 609 in turn
communicate with bore aye and in turn with annular
recess 608 and controlled flow port 300 which exits the
valve assembly. An alternative controlled flow path
diverge from the path just described at the junction
of bore 801 with passage 610. Flow enters bore 801
which further communicates with bore 820. Bore 820 is
also in communication with channel I which it in turn
in communication with annular recess 608 of compensator
600 and outlet port 300.
Bypass flows are metered by compensator spool
650 at it metering edge 650x and U-groove son and
allowed to flow across metering edge 600c to annular
Russ 604. Annular recess 604 is in communication
with bypass flow port 200 which exits the valve
assembly .
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-17-
Low pressure returns to tank which exits the
valve assembly at tank port 400 originate both at
controller bleed orifice 46 and 47, and at relief
check valve assembly 900.
Description of the Block Diagrams
Referring now to Figs. 7 -through 14, there are
shown block diagrams of the prevent invention which
describe the paths available for fluid flow and
positions of the flow controlling element.
lo Referring now to Fig. 7, the flow through the
valve assembly of the present invention is shown when
the controller spool 12 entirely prevents flow through
the controller valve 700. With the controller spool 650
closed, pressure is exerted on the compensator spool in
a downward direction permitting the entire flow to exit
the valve assembly via the bypass port 200.
Fig. 8 details the operation of the valve
assembly when the controller spool 62 allows fluid flow
across the metering V-groove control orifice on its
lower land. The metered control flow acts against the
lower metering edge of the compensator spool 650 forcing
it upward in opposition to the force exerted by the in-
coming flow from the pressure source 500. In this mode,
the compensator acts to maintain constant pressure
differential across the controller spool control
orifice
lZq~0235
-18-
An increase in pressure or in flow rate it
compensated by a recalibration of the spool position
within the compensator.
Referring now to Fig. 9, the controller 700 is
shown in it fully open position. Again, the
cornpeneator spool 650 attains an equilibrium position in
response to pressure and volume flow changes so as to
provide constant control flow volume by metering bypass
flow.
Fig. lo details the operation of the valve
assembly of the present invention when a manually
operated control valve it installed. The manually
operated control valve 800 provides a variable orifice
permitting fluid flow between the inlet of the
controller valve and the outlet passage of the
controller. When opened, the manual control valve
provides a constant flow rate proportional to its
orifice size through the controlled flow port 800. As
shown in Fig. 10, this flow it the only control flow due
to the controller spool 12 being in the closed
position.
Referring now to Fig. if, there is shown an
enhancement to the valve assembly of the present
to
--19--
invention comprising a pressure relief check valve 900.
As shown, the valve assembly is operated as an open
center valve. Pressure build-up which does not exceed
the pressure necefisary to open the relief check valve
flows via the compensator to bypass flow port 200.
Fig. 12 details the operation of the present
valve assembly when pressure within the valve exceeds
that required to actuate the relief check valve 900.
Flow within the valve is diverted across the check valve
orifice to tank 400.
Fig. 13 illustrates the operation of the valve
assembly of the present invention as a closed center
valve. It will be appreciated by those skilled in the
art that any of the foregoing modes of operation may be
analogously carried out as closed center operations by
the insertion of a plug or similar flow restriction in
the bypass port. When operated as a closed center valve
assembly, the compensator spool 650 continues to
regulate flow through the control flow port 300 by
attaining an equilibrium position to meter that flow.
Fig. I illustrates the operation of the valve
assembly of the present invention as a closed center
valve having a pressure or load ens valve. Load may
be sensed as a function of pressure of fluid in line 29
by a suitable ball check valve feeding a load sense
~2~0Z~5
-20-
port. Known load sense apparatus may be connecter to
the load sense port for operation in this mode.
Enhancements to the present valve as detailed
in Figs. 7 through 14, including manual control valves,
load sense valves, and relief check valves, may be
provided for operation in the closed center mode. In
particular, the relief check valve detailed in Figs. if
and 12 may be particularly desirable when operating
the present valve assembly in a closed center mode.
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