Field of the invention
[0001] The invention relates to hydraulically driven machines, in particular for pumping
difficult-to-pump fluid materials, like minerals, ores, sludges, suspensions, slurries,
and gels. These pumping machines may be referred to herein simply as pumps or machines.
Background of the Invention
[0002] Conventional pumping machines that can be used for difficult-to-pump materials have
displacement organs such as pistons, plungers, peristaltic hoses etc. However such
displacement organs are subject to frictional wear and the drive of the machine is
not properly isolated from the pumped material.
[0003] WO 2005/119063 discloses a hydraulically driven multicylinder diaphragm pumping machine, in particular
for pumping difficult-to-pump materials. This pumping machine comprises a plurality
of pump cylinders each having one end with an inlet and outlet for fluid to be pumped
and another end with an inlet and outlet for hydraulic fluid. These inlets and outlets
can be a separate inlet and outlet (for the hydraulic fluid) or a combined inlet/outlet
(for the fluid material being pumped). The inlets and outlets are associated with
respective inlet and outlet valves.
[0004] In such machine, a separator is located inside and is movable to-and-fro along each
pump cylinder. The movable separator has one side facing the pumped-material end of
the cylinder and another side facing the hydraulic-fluid end of the cylinder. This
movable separator is connected to the inside of the pumped-material end of the cylinder
by a first flexible diaphragm in the form of a concertina-like bellows that is expandable
and contractable inside the cylinder along the length direction of the cylinder as
the movable separator moves to-and-fro along the cylinder. The movable separator delimits
a first chamber inside the first bellows-like flexible diaphragm for containing a
variable volume of pumped fluid in communication via the inlet and outlet with a pumped
fluid manifold and circuit. The movable separator is connected also to the inside
of the second end of the cylinder by a second flexible diaphragm in the form of a
concertina-like bellows that is contractable and expandable along the length direction
of the cylinder in correspondence with expansion and contraction of the first flexible
diaphragm. The second side of the movable separator delimits a second chamber inside
the second expandable and contractable diaphragm for containing a variable volume
of hydraulic fluid in communication with the second inlet and outlet. An annular space
is defined between the outside of the first and second diaphragms and the inner wall
of the pump cylinder which annular space in use contains a fluid that is the same
as said hydraulic fluid or has similar hydraulic characteristics.
[0005] This pumping machine is directly driven by a hydraulic pump drive, greatly simplifying
the machine and providing simple means of variation and control of the flow of the
pumped fluid delivered. Moreover, the double diaphragm arrangement provides a double
protection of the pumped fluid from the pumping fluid.
[0006] Supplemental research with such machines has demonstrated that various aspects such
as the reliability of the operation of the bellows-like diaphragm and the facilities
of the automatic switching arrangement for controlling the hydraulic drive could be
improved.
Summary of the Invention
[0007] This invention aims to improve a machine of the above-mentioned type or more generally
other hydraulically-operated machines.
[0008] One aspect of the invention relates to an improvement of the hydraulic machine as
set out above wherein the movable separator is in the form of a plunger that is slideably
mounted inside a middle part of the inside of the cylinder between the first and second
bellows-like diaphragms, one end of the plunger being connected to the first bellows-like
diaphragm and the other end of the plunger being connected to the second bellows-like
diaphragm to define respective first and second annular spaces, namely a first annular
space between the outside of the first bellows-like diaphragm and the inner wall of
the pump cylinder and a second annular space between the outside of the second bellows-like
diaphragm and the inner wall of the pump cylinder, wherein the first and second annular
spaces are independent of one another and the pressure of fluid in the first annular
space is independent of the pressure of fluid in the second annular space.
[0009] Preferably, the plunger is slidably mounted in a sealing element secured inside a
middle part of the inside of the cylinder. In this way, the first and the second annular
spaces are not coupled together, and the fluid pressure values in these two cavities
may be different and independent from each other. The outer diameter of the plunger
corresponds to the median working diameter of the first and second bellows-like diaphragms
and the volume of the first and second spaces remains essentially constant during
operation.
[0010] The above-described inventive arrangement results in eliminating or greatly reducing
radial deformation of the bellows-like diaphragms resulting in greater reliability
and enhanced life for the diaphragms.
[0011] Another aspect of the invention relates to a hydraulic machine for a machine as set
out above or generally any other hydraulic machine - comprising a hydraulic cylinder
having a part mounted for cyclic reciprocating linear motion along the hydraulic cylinder,
and means for commutating a valve to control the supply of hydraulic fluid to the
hydraulic cylinder at given moments of the machine's cycle, wherein the valve commutating
means comprises a hydromechanical switch comprising: a linkage for converting linear
motion of said machine part into rotary motion; a cam rotatably driven by said linkage;
and a spring arranged to be compressed to store energy by rotation of the cam during
a stroke of said machine part, and arranged to release its stored energy to commute
said valve for controlling the supply of hydraulic fluid to the hydraulic cylinder
of the machine when said part reaches it's given positions along the hydraulic cylinder.
[0012] The spring can be a compression spring mounted on an arm extending from the cam such
that, upon rotational drive of the cam by the linkage, the end of the spring adjacent
the cam is compressed until the spring reaches an unstable equilibrium point past
which the spring releases its stored energy to commute said valve. For example, when
the spring releases its stored energy it firstly abruptly drives the cam and after
the cam has turned through a given angle the cam rotates a part to commutate the valve.
The linkage can be arranged to turn the cam through an angle less than 180° for each
stroke of said machine part.
[0013] By the use of this hydromechanical switch, the hydraulic machine can be operated
without the need for electromagnetically actuated and electronically controlled directional
valves and as a result the machine is less complicated and more reliable.
[0014] This commutation device also relates to any hydraulic cyclical working machine having
a linear moving operating part and requiring to be automatically controlled via openings
commutation in order to achieve desired working cycle parameters e.g. pressure values,
cycle phases duration, etc.
[0015] Further aspects and advantages of the invention are set out in the detailed description
and particular features of the invention are set out in the claims.
Brief Description of the drawings
[0016] The accompanying schematic drawings, given by way of example, show embodiments of
the hydraulically driven pumping machine according to the invention. In the drawings:
Fig. 1 is a view of one embodiment of a pumping machine according to the invention
having four cylinders, for example;
Fig. 2 is a cross sectional view of one cylinder of a pumping machine according to
the invention;
Fig. 3 is a perspective view showing the inside of a hydromechnical switch according
to the invention;
Fig. 4 diagramatically shows part of a cylinder to which a hydromechanical switch
is fitted; and
Fig. 5 is a broken-away perspective view showing the connection of the spring to the
cam in the hydromechanical switch according to the invention.
Detailed Description
[0017] The principal improvement of the invention relates to a plunger device to provide
fluids separation in a hydraulically driven pumping machine.
[0018] The hydraulically driven pumping machine shown in Fig. 1 comprises one or several
cylinders 5, a switching control system 1 and a hydraulic drive unit 3. The machine
is normally a multicylinder machine and such basic hydraulic multicylinder machine
is described in detail in
PCT patent application WO 2005/119063.
[0019] To enhance the life of the bellows-like diaphragms, namely to eliminate their radial
deformation under pressure differentials arising between internal and external bellows
cavities, the basic machine described in
WO 2005/119063 was improved in the following way.
[0020] The pump's cylinder 5 contains two bellows 4 and 10 (see Fig. 2) mechanically connected
to each other via a plunger 6 which moves during the working cycle inside a ring-shaped
sealing element 7 mounted in the middle-height part of the cylinder 5. The plunger-sealing
assembly 6/7 replaces the separator employed in the previous design.
[0021] Two oil-filled "a" cavities are located externally of the bellows 4 and 10 inside
the cylinder 5. The plunger 6 is hydraulically obturated in the sealing element 7.
This allows keeping each of the "a" cavities volume independent from each other. The
plunger outside diameter is also equal to the average efficient diameter of the bellows.
This allows keeping each of the "a" cavities volume constant during the plunger working
movement. Therefore, the pressure values in each of the bellow's external "a"-cavities
is exactly piloted by pressure value in the corresponding bellow's internal cavity
"b" or "c".
[0022] The pressure in the internal bellows cavities "b" and "c" varies between the suction
and discharge cycles and it depends on the machine working mode. The "b" cavity is
located inside the bellows-like membrane 10 and the "c" cavity is located inside the
bellows-like membrane 4.
[0023] During each of the machine working cycle phases, the "b" and "c" cavities pressure
values are nearly equal, since the driving cavity pressure is transmitted to the driven
cavity through the plunger 6 cover. For instance, during the suction stroke the "c"
cavity is driving, the "b" - cavity is driven; and vice versa during the discharge
stroke. For this to happen, the hydraulic pressure must enter the machine under sufficient
pressure to overcome the mechanical and hydraulic resistances, as the machine does
not have any mechanical means to effect the suction stroke. However, a small part
of the driving cavity energy is always consumed by the above mentioned switching device
and by other hydraulic and mechanic resistances, therefore, a small pressure drop
arises between these "b" and "c" cavities.
[0024] In the previous design, having the single and common "a"-cavity, this pressure drop
provokes the "a" - cavity to act as equilibration unit, i.e., the "a" - cavity pressure
value is getting median between the "b" and "c" cavities pressure values. Accordingly,
the pressure values acting on the external and on the internal surface of each bellows
are not equal, and the bellows should suffer from some radial deformation, to which
it is not designated.
[0025] In the design according to the invention, the pressure drop between the "b" and "c"
cavities is not equilibrated via "a"-cavities, because the latter are not connected
together hydraulically. The pressure in the "b" and "c" cavities always acts on fluid
in the two independent "a" cavities via the bellows wall. The corresponding pressure
in the "a" cavities compensates this action precisely and independently balances the
pressure values acting on the inner and outer bellows surfaces. The achieved balance
eliminates radial deformation and greatly improves the bellows life.
[0026] During operation, the "a" cavities pressure increases to the minimal necessary value,
which is sufficient to avoid radial deformation of the bellows wall due to the fluid's
low compressibility. This pressure does not depend on the pressure differential between
the "b" and "c" cavities, which acts only on the upper and lower surfaces of plunger
6.
[0027] The arrangement according to the invention eliminates additional radial deformation
of the bellows, which would inevitably arise in the previous design that has a conjoint
"a" cavity.
[0028] Another advantage of the inventive solution is improved protection of the pumping
fluid from the pumped fluid and vice versa. The previous design could lead to the
fluids becoming mixed and corresponding machine malfunction in case of two cavities
becoming non-fluid-tight in series: namely cavity "b" and conjoint cavity "a". The
present solution has two independent "a" cavities and thus adds one more cavity in
this series. It presents, thereby, a triple fluid protection instead of double.
[0029] The described pump operates as follows (see Fig.2):
During the suction stroke the bellows 4 internal "c" cavity is fed by the pumped material
from intake manifold 8 through lower valves module 9. The material is pumped at a
small pressure (for example 3-8 bar) that moves the plunger 6 upwards. Correspondingly,
the bellows 4 is stretched and bellows 10 is compressed which leads to the pumping
hydraulic fluid being displaced from cavity "b" into the hydraulic driving system
suction manifold. The pressure of the pumped material acting in the 'c" cavity on
the bellows 4 internal surface is balanced by a corresponding increase in the fluid
pressure in cavity "a" which acts on the bellows 4 external surface. Similarly, the
pressure increase in cavity "b" is balanced by the increase in fluid pressure in the
bellows 10 external "a" cavity. As soon as the suction stroke is completed, the control
system 1 switches, and pumping hydraulic fluid supplied by hydraulic drive under high
pressure (for example 200 bar) is fed into the bellows 10 "b" cavity. This moves the
plunger 6 downward, which generates the discharge stroke. During the discharge stroke
the bellows 10 is stretched and bellows 4 is compressed. In a corresponding manner
to before, the pressure in cavities "b" and "c" (which is now increasing) is balanced
by means of the pressure (which increases) in the two independent cavities "a", which
prevents radial deformation of the bellows 4,10 during the whole discharge stroke.
The compressed pumped material is displaced from the "c" cavity through the valves
module 8 into the discharge manifold 11. At the end of the discharge stroke the control
system 1 switches again, and the machine working cycle starts from the beginning.
[0030] The above-described inventive arrangement results in eliminating or greatly reducing
radial deformation of the bellows-like diaphragms that occurred with the prior arrangement
as a result of pressure differentials, resulting in greater reliability and enhanced
load capacity for the diaphragms.
[0031] Electromagnetically driven and electronically controlled directional valves are conventionally
employed to control cyclic operations of hydraulic machines and mechanisms. These
multilevel, sophisticated control systems complicate the hydraulic machines and decrease
their reliability.
[0032] The invention can be used with a new device or "hydromechanical switch" to simplify
the control systems and increase the reliability of such class of machines. In this
hydromechanical switch, the hydraulic openings are commutated only by mechanical means,
without electronic or magnetic appliances. Use of the hydromechanical switch is capable
of broadening a controlled machine's area of application in severe environmental conditions,
and reduces and simplifies maintenance, staff training, etc.
[0033] The hydromechanical switch of Figs. 3 to 5 is applicable in general to any hydraulic
machine comprising a hydraulic cylinder 107 having a part namely a piston 106 mounted
for cyclic reciprocating linear motion along the hydraulic cylinder 107, and means
for commutating a valve 102 to control the supply of hydraulic fluid to the hydraulic
cylinder at given moments of the machine's cycle. The hydromechanical switch comprises
a linkage (screw nut 108, screw rod 109) for converting linear motion of the piston
106 into rotary motion; a cam 103 rotatably driven by said linkage; and a spring 115
arranged to be compressed to store energy by rotation of the cam 103 during a stroke
of the piston 106. Spring 115 has one end near the cam 103 and another free end that
bears against a flange 114. This spring 115 is moreover arranged to release its stored
energy to commute the valve 102 for controlling the supply of hydraulic fluid to the
hydraulic cylinder 107 of the machine when the piston 106 is at given positions along
the hydraulic cylinder 107.
[0034] The spring 115 is a compression spring mounted on an arm 150 (Fig. 2) extending from
the cam 103 such that, on rotational drive of the cam 103 by the linkage (108,109),
the end of the spring adjacent the cam is compressed until the spring reaches an unstable
equilibrium point "A" past which the spring releases its stored energy to commute
said valve 102. When the spring 115 releases its stored energy it firstly abruptly
drives the cam 103 through a given angle (say 45°) and then as the cam 103 continues
to rotate, it rotates a part to commutate the valve 102 by turning it through, say,
45°.
[0035] Said linkage (108,109) is arranged to turn the cam through an angle less than 180°
for each stroke of the piston 106. It comprises, for instance, the screw nut 108 and
the screw rod 109 forming the screw gear linkage.
[0036] The working principle of the hydromechanical switch is based on the consumption of
a part of the machine's linear movement energy. A small portion of this energy is
taken away via a screw gear and stored in the spring 115's elastic deformation energy.
This stored energy is then released to produce the necessary openings / commutations
at given moments of the machine's working cycle.
[0037] The hydromechanical switch may be designed in the form of a rotating cylindrical
valve (see Fig. 3), which comprises immobile housing 101, rotating valve body 102,
cam 103, driving spring 115 and screw-gear (108,109) for transforming linear motion
of piston 106 into rotational motion of the cam 103.
[0038] When the hydromechanical switch is incorporated in the pumping machine of Figs. 1
and 2, said part mounted for cyclic reciprocating movement along the cylinder is the
piston 106 or a plunger or other part fixed thereto.
[0039] The illustrated hydromechanical switch operates as follows.
[0040] Together with the piston 106's linear motion, nut 108 is also moving. This motion
causes rotation of the screw rod 109. The screw rod's axial motion is disabled via
bearing and sealing unit 111. Another purpose of the unit 111 is to hold the screw
109 fluid-tightly inside the cover 110. The screw shaft 112 rotates the cam 103 through
pin 113 and the finger 104. Compression of spring 115 occurs simultaneously with rotation
of the cam 103. The spring pivots also about its free end and reaches an unstable
equilibrium state point "A" at the end of the piston stroke. This unstable equilibrium
point corresponds to the maximum compression of the spring 115, when the lateral axis
of the spring 115 intersects the rotation axis of the cam 103, i.e. the spring elastic
force is at it's maximum value, but produces no torque to the cam geometrically having
no lever effect. The further small angle rotation of cam 103 causes a small lever
arm effect, and the spring 115 stored energy release starts. Fig 5 shows the spring
laterally offset from the equilibrium position, with the spring 115 in a less-compressed
state at the beginning of its compression stroke, ready to start turning.
[0041] Pivoting beyond the unstable equilibrium point "A", the spring 115 starts to release
the stored energy, and the switching process starts without any liaison to the piston
motion, i.e. automatically. Initially, the spring's expansion after point "A" abruptly
pivots only the cam 103 as its expansion energy overcomes only the cam's joint 113
friction forces and hydraulic resistance of the damper 116. The latter is designed
to stabilize the spring's motion velocity. After the cam's free rotation through about
45 degrees, its cog 117 starts to act on the valve's 112 stud 118 and brings the valve
102 into angular motion. Further rotation of the cam 103 produces simultaneous rotation
of the rotating valve 102 through an angle of about 45 degrees and corresponding necessary
commutation of fluid channels made in the bodies of valve 102 and of it's housing
101. The desired openings commutation for commanding the machine is thereby achieved
by rotation of this valve 102.
[0042] A ball-fastener 119 is designed to limit rotation of the valve in extreme positions.
The valve comes against the stop 120 and is fixed by the ball-fastener 119 at the
end of the turn..
[0043] The following features increase the hydromechanical switch's reliability.
[0044] The cog 117 is equipped with a rubber damper 121 to minimize shock upon contact of
the stud 118 and stop 120.
[0045] The rotating valve 102 is statically and dynamically hydraulically balanced to compensate
radial pressure components that otherwise would cause undue friction during the valve's
rotation..
[0046] The spring 115's compression occurs during the whole piston stroke to evenly consume
it's energy. For this purpose, the spring is soft and has corresponding low resistance
variation over the stroke.
[0047] The circular surface "B" of the pin 113 is sustained by balancing pressure directed
from the internal cylinder's cavity through a special channel, and the surface "B"
area is equal to the shaft's 112 sectional area to balance the pulling force, which
acts on the screw 109 by reason of the internal cylinder's pressure.
[0048] The hydromechanical switch is equipped with an indicator 122 to observe the valve
and the piston positions, motion direction, velocity and operation. Instead of a mechanical
indicator any angular sensors may be employed to monitor the machine operation electronically,
if required.
[0049] Involute splines 124 and 125 on the cam's shaft are designed to adjust the piston
stroke and the indicator pointer 123 position during the assembly process.
[0050] Bolts 126 are designed to produce a fine tune of the cam 103 rotation angle and the
whole hydromechanical switch operation.
[0051] A tunable junction 127 is designed to adjust the spring 115's performance.
[0052] After an initial fine tune, the hydromechanical switch operates automatically, i.e.
the working machine commands itself. For example, if the piston velocity changes,
the valve commutation still continues to happen at the right time, because the commutation
process depends only on the piston position, not on velocity nor on acceleration.
[0053] Such solution increases the machine's reliability and dispenses with the need for
any control system maintenance.
1. A hydraulically driven diaphragm pumping machine, in particular for pumping difficult-to-pump
materials, the pump comprising at least one pump cylinder (5) that has a first end
with a first inlet and outlet (11) for fluid to be pumped and a second end with a
second inlet and outlet (1) for hydraulic fluid, the inlets and outlets being associated
with respective valves, a separator (6) located inside and movable to-and-fro along
the pump cylinder, the movable separator (6) having a first side facing the first
end of the cylinder and a second side facing the second end of the cylinder, wherein:
- the movable separator (6) is connected to the inside of the first end of the cylinder
by a first flexible diaphragm (4) in the form of a concertina-like, bellows that is
expandable and contractable inside the cylinder (5) along the length direction of
the cylinder as the movable separator (6) moves to-and-fro along the cylinder, the
first side of the movable separator delimiting a first chamber (c) inside the expandable
and contractable flexible diaphragm (4) for containing a variable volume of pumped
fluid in communication with the first inlet and outlet;
- the movable separator (6) is connected to the inside of the second end of the cylinder
(5) by a second flexible diaphragm (10) in the form of a concertinalike bellows that
is contractable and expandable along the length direction of the cylinder (5) in correspondence
with expansion and contraction of the first flexible diaphragm (4), the second side
of the movable separator delimiting a second chamber (b) inside the second expandable
and contractable diaphragm (10) for containing a variable volume of hydraulic fluid
in communication with the second inlet and outlet; and
- an annular space (a) is defined between the outside of the first and second diaphragms
(4,10) and the inner wall of the pump cylinder (5), which annular space (a) in use
contains a fluid that is the same as said hydraulic fluid or has similar hydraulic
characteristics,
characterized in that:
the movable separator (6) is in the form of a plunger that is slidably mounted in
the middle part of the inside of the cylinder (5) between the first and second bellows-like
diaphragms (4,10), one end of the plunger (6) being connected to the first bellows-like
diaphragm (4) arid the other end of the plunger (6) being connected to the second
bellows-like diaphragm (10) to define respective first and second annular spaces (a),
namely a first annular space (a) between the outside of the first bellows-like diaphragm
(4) and the inner wall of the pump cylinder (5) and a second annular space (a) between
the outside of the second bellows-like diaphragm (10) and the inner wall of the pump
cylinder (5), wherein the first and second annular spaces (a) are independent of one
another and the pressure of fluid in the first annular space (a) is independent of
the pressure of fluid in the second annular space (a).
2. The machine of claim 1, wherein the plunger (6) is slidably mounted in a sealing element
(7) secured inside a middle part of the inside of the cylinder (5).
3. The machine of claim 1 or 2, wherein the outer diameter of the plunger (6) corresponds
to the median working diameter of the first and second bellows-like diaphragms (4,10).
4. The machine of claim 1, 2 or 3, wherein during operation the volume of the first and
second spaces (a) remains essentially constant.
5. The machine of any preceding claim, comprising means for automatic commutating of
a valve (102) to control the supply of hydraulic fluid to the hydraulic cylinder at
given moments of the machine's cycle, wherein said means for commuting the valve comprises
a hydromechanical switch comprising:
- a linkage (108,109) for converting linear motion of said machine part (106) into
rotary motion;
- a cam (103) rotatably driven by said linkage (105,109); and
- a spring (115) arranged to be compressed to store energy by rotation of the cam
(103) during a stroke of said machine part (106), and arranged to release its stored
energy to commute said valve (102) for controlling the supply of hydraulic fluid to
the hydraulic cylinder (107) of the machine when said part (106) is at given positions
along the hydraulic cylinder (107), i.e. for controlling the machine working cycle.
6. The machine of claim 5, wherein the spring (115) is a compression spring mounted on
an arm (150) extending from the cam (103) such than on rotational drive of the cam
(103) by the linkage (108,109) the end of the spring adjacent the cam is compressed
until the spring reaches an unstable equilibrium point "A" past which the spring releases
its stored energy to commute said valve (102).
7. The machine of claim 6 or 7, wherein when the spring releases its stored energy it
firstly abruptly drives the cam (103) and after the cam has turned through a given
angle the cam (103) rotates a part to commutate the valve (102).
8. The machine of claim 5, 6 or 7, wherein said linkage (109) is arranged to turn the
cam through an angle less than 180° for each stroke of said machine part (106).
9. The machine according to any one of claims 5 to 8, wherein the linkage (108,109) is
a screw gear linkage comprising a nut (108) and a screw rod (109).
1. Eine hydraulisch angetriebene Membranpumpen-Vorrichtung, insbesondere zum Pumpen schwer-zu-pumpender
Materialien, wobei die Pumpe mindestens einen Pumpenzylinder (5) enthält, der ein
erstes Ende hat mit einem ersten Ein- und Auslass (11) für die zu pumpende Flüssigkeit
und ein zweites Ende mit einem zweiten Ein- und Auslass (1) für Hydraulikflüssigkeit,
wobei die Ein- und Auslässe mit entsprechenden Ventilen verbunden sind, einem Separator
(6), der sich innerhalb des Pumpenzylinders befindet und entlang dieses hin- und her-
beweglich ist, wobei der bewegliche Separator (6) eine erste Seite hat, die dem ersten
Zylinderende zugewandt ist und eine zweite Seite, die dem zweiten Zylinderende zugewandt
ist, wobei:
- der bewegliche Separator (6) mit der Innenseite des ersten Endes des Zylinders verbunden
ist durch eine erste elastische Membran (4) in Form eines Zieharmonika-artigen Balges
der im Zylinder (5) ausdehn- und zusammenziehbar ist in Längsrichtung des Zylinders
wenn sich der bewegliche Separator (6) im Zylinder hin- und herbewegt, wobei die erste
Seite des beweglichen Separators eine erste Kammer (c) innerhalb der ausdehn- und
zusammenziehbaren elastischen Membran (4) abtrennt um ein variables Volumen der gepumpten
Flüssigkeit in Kommunikation mit dem ersten Ein- und Auslass zu enthalten;
- der bewegliche Separator (6) mit der Innenseite des zweiten Endes des Zylinders
(5) verbunden ist durch eine zweite elastische Membran (10) in Form eines Zieharmonika-artigen
Balges der ausdehn- und zusammenziehbar ist in Längsrichtung des Zylinders (5) im
Zusammenspiel mit dem Ausdehnen und Zusammenziehen der ersten elastischen Membran
(4), wobei die zweite Seite des beweglichen Separators eine zweite Kammer (b) innerhalb
der zweiten ausdehn- und zusammenziehbare elastischen Membran (10) abtrennt um ein
variables Volumen der gepumpten Flüssigkeit in Kommunikation mit dem zweiten Ein-
und Auslass zu enthalten; und
- ein ringförmiger Raum (a) gebildet wird zwischen den Außenseiten der ersten und
zweiten Membranen (4,10) und der Innenwand des Pumpenzylinders (5), und selbiger ringförmiger
Raum (a) im Betriebszustand eine Flüssigkeit enthält die die gleiche Flüssigkeit wie
die erwähnte Hydraulikflüssigkeit ist oder ähnliche Eigenschaften wie diese aufweist,
dadurch gekennzeichnet dass:
der bewegliche Separator (6) in Form eines Kolbens vorliegt der verschiebbar im mittleren
Bereich der Innenseite des Zylinders (5) angebracht ist zwischen der ersten und zweiten
Balg-artigen Membran (4, 10), wobei ein Ende des Kolbens (6) an der ersten Balg-artigen
Membran (4) angebracht ist und das andere Ende des Kolbens (6) an der zweiten Balg-artigen
Membran (10) angebracht ist um entsprechend den ersten und zweiten ringartigen Raum
(a) zu bilden, nämlich einen ersten ringförmigen Raum (a) zwischen der Außenseite
der ersten Balg-artigen Membran (4) und der Innenwand des Pumpenzylinders (5) und
einen zweiten ringförmigen Raum (a) zwischen der Außenseite der zweiten Balg-artigen
Membran (10) und der Innenwand des Pumpenzylinders (5), wobei der erste und zweite
ringförmige Raum (a) unabhängig voneinander sind und der Druck der Flüssigkeit im
ersten ringförmigen Raum (a) unabhängig ist vom Druck der Flüssigkeit im zweiten ringförmigen
Raum (a).
2. Eine Vorrichtung nach Anspruch 1, wobei der Kolben (6) verschiebbar in einem Dichtungselement
(7) angebracht ist welches innerhalb des mittleren Teils der Innenseite des Zylinders
(5) befestigt ist.
3. Eine Vorrichtung nach Anspruch 1 oder 2, wobei der Außendurchmesser des Kolbens (6)
dem Medianwert des wirksamen Durchmessers der ersten und zweiten Balg-artigen Membran
(4, 10) entspricht.
4. Eine Vorrichtung nach Anspruch 1, 2 oder 3, wobei der während des Betriebs das Volumen
des ersten und zweiten Raumes (a) im Wesentlichen konstant bleibt.
5. Eine Vorrichtung nach einem der vorstehenden Ansprüche, welche Mittel für das automatische
Umstellen eines Ventils (102) enthält um die Zufuhr von Hydraulikflüssigkeit zum Hydraulikzylinder
zu gegebenen Zeitpunkten der Arbeitszyklen der Vorrichtung zu kontrollieren, wobei
besagte Mittel zur Umstellung des Ventils einen hydromechanischen Schalter enthalten,
welcher enthält:
- eine Kopplung (108,109) um die Linearbewegung des besagten Vorrichtungsteils (106)
in Rotationsbewegung zu konvertieren;
- eine Nocke (103) drehbar angetrieben durch besagte Kopplung (105, 109); und
- eine Feder (115) dergestalt angebracht dass sie zusammengedrückt werden kann um
Energie durch die Rotation der Nocke während eines Arbeitshubes des besagten Vorrichtungsteil
(106) zu speichern, und dergestalt angebracht um ihre gespeicherte Energie freizusetzen
um besagtes Ventil (102) umzustellen um die Zufuhr von Hydraulikflüssigkeit zum Hydraulikzylinder
(107) der Vorrichtung zu kontrollieren wenn besagtes Teil (106) sich zu gegebenen
Positionen entlang des Hydraulikzylinders (107) befindet, d.h. um den Arbeitszyklus
der Vorrichtung zu kontrollieren.
6. Die Vorrichtung nach Anspruch 5, wobei die Feder (115) eine Druckfeder ist die auf
einem Arm (150) angebracht istder von der Nocke (103) erstreckt in der Art dass bei
Rotationsbewegung der Nocke (103) durch die Verbindung (108, 109) das zur Nocke benachbarte
Ende der Feder zusammengedrückt wird bis die Feder einen instabilen Gleichgewichtspunkt
"A" erreich, ab dem die Feder ihre gespeicherte Energie freisetzt um besagtes Ventil
(102) umzustellen.
7. Die Vorrichtung nach Anspruch 6 oder 7, wobei, wenn die Feder ihre gespeicherte Energie
freisetzt, dies zuerst kurzzeitig die Nocke (103) antreibtund nachdem die Nocke einen
gegebenen Winkel durchlaufen hat, die Nocke (103) einen Teil zum Umstellen des Ventils
(102) dreht.
8. Die Vorrichtung nach Anspruch 5, 6, oder 7, wobei besagte Verbindung (109) angeordnet
ist um die Nocke um einen Winkel von weniger als 180° für jeden Arbeitshub des besagten
Vorrichtungsteils (106) zu drehen.
9. Die Vorrichtung gemäß einem der Ansprüche 5 bis 8, wobei die Verbindung (108, 109)
eine Schneckengetriebekopplung ist welche eine Mutter (108) und eine Gewindestange
(109) enthält.
1. Machine de pompage à diaphragme entraînée par voie hydraulique, en particulier pour
pomper des matériaux difficiles à pomper, la pompe comprenant au moins un cylindre
de pompe (5) qui a une première extrémité avec une première entrée et une première
sortie (11) pour du fluide à pomper, et une seconde extrémité avec une seconde entrée
et une seconde sortie (1) pour un fluide hydraulique, les entrées et les sorties étant
associées à des valves respectives, un séparateur (6) situé à l'intérieur et mobile
en va-et-vient le long du cylindre de pompe, le séparateur mobile (6) ayant un premier
côté en face de la première extrémité du cylindre et un second côté en face de la
seconde extrémité du cylindre, dans laquelle :
- le séparateur mobile (6) est connecté vers l'intérieur de la première extrémité
du cylindre par un premier diaphragme flexible (4) sous la forme d'un soufflet en
accordéon qui est capable de se dilater et de se contracter à l'intérieur du cylindre
(5) le long de la direction de la longueur du cylindre lorsque le séparateur mobile
(6) se déplace en va-et-vient le long du cylindre, le premier côté du séparateur mobile
délimitant une première chambre (c) à l'intérieur du diaphragme flexible capable de
se dilater et de se contracter (4) pour contenir un volume variable de fluide pompé
en communication avec la première entrée et la première sortie ;
- le séparateur mobile (6) est connecté vers l'intérieur de la seconde extrémité du
cylindre (5) par un second diaphragme flexible (10) sous la forme d'un soufflet en
accordéon qui est capable de se contracter et de se dilater le long de la direction
de la longueur du cylindre (5) en correspondance avec la dilatation et la contraction
du premier diaphragme flexible (4), le second côté du séparateur mobile délimitant
une seconde chambre (b) à l'intérieur du second diaphragme capable de se dilater et
de se contracter (10) pour contenir un volume variable de fluide hydraulique en communication
avec la seconde entrée et la seconde sortie ; et
- un espace annulaire (a) est défini entre l'extérieur du premier et du second diaphragme
(4, 10) et la paroi intérieure du cylindre de pompe (5), ledit espace annulaire (a)
contenant en utilisation un fluide qui est le même que ledit fluide hydraulique ou
qui a des caractéristiques hydrauliques similaires,
caractérisée en ce que :
le séparateur mobile (6) est sous la forme d'un plongeur qui est monté en coulissement
dans la partie médiane de l'intérieur du cylindre (5) entre le premier et le second
diaphragme (4, 10) en soufflet, une extrémité du plongeur (6) étant connectée au premier
diaphragme (4) en soufflet, et l'autre extrémité du plongeur (6) étant connectée au
second diaphragme (10) en soufflet pour définir un premier et un second espace annulaire
(a) respectif, à savoir un premier espace annulaire (a) entre l'extérieur du premier
diaphragme (4) en soufflet et la paroi intérieure du cylindre de pompe (5) et un second
espace annulaire (a) entre l'extérieur du second diaphragme (10) en soufflet et la
paroi intérieure du cylindre de pompe (5), dans laquelle le premier et le second espace
annulaire (a) sont indépendants l'un de l'autre et la pression du fluide dans le premier
espace annulaire (a) est indépendante de la pression du fluide dans le second espace
annulaire (a).
2. Machine selon la revendication 1, dans laquelle le plongeur (6) est monté en coulissement
dans un élément d'étanchement (7) fixé à l'intérieur d'une partie médiane de l'intérieur
du cylindre (5).
3. Machine selon la revendication 1 ou 2, dans laquelle le diamètre extérieur du plongeur
(6) correspond au diamètre moyen du premier et du second diaphragme (4, 10) en soufflet.
4. Machine selon la revendication 1, 2 ou 3, dans laquelle pendant le fonctionnement
le volume du premier et du second espace (a) reste essentiellement constant.
5. Machine selon l'une quelconque des revendications précédentes, comprenant des moyens
pour commuter automatiquement une valve (102) destinée à commander l'alimentation
de fluide hydraulique vers le cylindre hydraulique à des moments donnés du cycle de
la machine, dans laquelle lesdits moyens pour commuter la valve comprennent un commutateur
hydromécanique comprenant :
- une tringlerie (108, 109) pour convertir un mouvement linéaire de ladite pièce de
machine (106) en un mouvement rotatif ;
- une came (103) entraînée en rotation par ladite tringlerie (105, 109) ; et
- un ressort (115) agencé pour être comprimé et stocker de l'énergie par rotation
de la came (103) pendant une course de ladite pièce de machine (106), et agencé pour
dégager son énergie stockée et commuter ladite valve (102) pour commander l'alimentation
de fluide hydraulique vers le cylindre hydraulique (107) de la machine quand ladite
pièce (106) est située à des positions données le long du cylindre hydraulique (107),
c'est-à-dire pour commander le cycle de travail de la machine.
6. Machine selon la revendication 5, dans laquelle le ressort (115) est un ressort de
compression monté sur un bras (150) s'étendant depuis la came (103) de telle façon
que lors d'un entraînement en rotation de la came (103) par la tringlerie (108, 109)
l'extrémité du ressort adjacent à came est comprimée jusqu'à ce que le ressort atteigne
un point d'équilibre instable "A" au-delà duquel le ressort dégage son énergie stockée
pour commuter ladite valve (102).
7. Machine selon la revendication 5 ou 6, dans laquelle quand le ressort dégage son énergie
stockée, il entraîne en premier de manière abrupte la came (103) et, après que la
came ait tourné d'un angle donné, la came (103) fait tourner une pièce pour commuter
la valve (102).
8. Machine selon la revendication 5, 6 ou 7, dans laquelle ladite tringlerie (109) est
agencée pour faire tourner la came sur un angle plus petit que 180° pour chaque course
de ladite pièce de machine (106).
9. Machine selon l'une quelconque des revendications 5 à 8, dans laquelle la tringlerie
(108, 109) est une tringlerie à vis-et-écrou comprenant un écrou (108) et une tige
filetée (109).