U.S. patent application number 13/637374 was filed with the patent office on 2013-04-25 for double diaphragm pump.
This patent application is currently assigned to Promera GmbH & Co, KG. The applicant listed for this patent is Thomas Schutze. Invention is credited to Thomas Schutze.
Application Number | 20130101445 13/637374 |
Document ID | / |
Family ID | 44510839 |
Filed Date | 2013-04-25 |
United States Patent
Application |
20130101445 |
Kind Code |
A1 |
Schutze; Thomas |
April 25, 2013 |
DOUBLE DIAPHRAGM PUMP
Abstract
A diaphragm pump, in which a fluid moves at least a first piston
of a first piston/cylinder system back and forth, the first piston
being mechanically connected to at least one other hydraulic piston
and the hydraulic piston driving at least one diaphragm by a
hydraulic medium.
Inventors: |
Schutze; Thomas;
(Schonungen, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Schutze; Thomas |
Schonungen |
|
DE |
|
|
Assignee: |
Promera GmbH & Co, KG
Sennfeld
DE
|
Family ID: |
44510839 |
Appl. No.: |
13/637374 |
Filed: |
March 18, 2011 |
PCT Filed: |
March 18, 2011 |
PCT NO: |
PCT/EP2011/001360 |
371 Date: |
December 4, 2012 |
Current U.S.
Class: |
417/395 |
Current CPC
Class: |
F04B 43/073 20130101;
F04B 43/026 20130101; F04B 43/06 20130101 |
Class at
Publication: |
417/395 |
International
Class: |
F04B 43/06 20060101
F04B043/06 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 26, 2010 |
DE |
10 2010 013 108.3 |
Claims
1.-29. (canceled)
30. A diaphragm pump, in which a fluid moves at least a first
piston of a first piston/cylinder system back and forth, the first
piston being mechanically connected to at least one other hydraulic
piston and the hydraulic piston driving at least one diaphragm of
the diaphragm pump by means of a hydraulic medium, wherein the
diaphragm pump is a dual-diaphragm pump having at least two
diaphragms, a hydraulic medium moving or driving the diaphragms, at
least one hydraulic piston moving the hydraulic medium, and in that
the at least two diaphragms are mechanically connected to each
other by a connection element.
31. A diaphragm pump, in which a fluid moves at least a first
hydraulic piston of a first piston/cylinder system back and forth,
the first hydraulic piston being mechanically connected to at least
one other hydraulic piston, and the hydraulic piston driving at
least one diaphragm by means of a hydraulic medium.
32. The diaphragm pump according to claim 31, wherein the diaphragm
pump is a dual-diaphragm pump having at least two diaphragms, a
hydraulic medium moving or driving the diaphragms, and the at least
one hydraulic piston moving the hydraulic medium.
33. The diaphragm pump according to claim 32, wherein the at least
two diaphragms are mechanically connected to each other by a
connection element.
34. The diaphragm pump according to claim 33, wherein the
connection element is connected to the diaphragms with each of the
ends of the connection element being either screwed or pressed to
one of the diaphragms.
35. The diaphragm pump according to claim 31, wherein at least one
of the diaphragms is arranged in a diaphragm space of a housing and
divides the diaphragm space into a conveying space and a hydraulic
space.
36. The diaphragm pump according to claim 35, wherein the hydraulic
space is connected to a first operating space of the
piston/cylinder system of the other hydraulic piston by a channel
or a line, and either forms an integral component of the operating
space or is the operating space itself.
37. The diaphragm pump according to claim 36, wherein compressed
air moves the first piston of the first piston/cylinder system back
and forth, and a main valve which is controlled by movement of the
first piston directs the compressed air alternately into the first
operating space or a second operating space of the first
piston/cylinder system.
38. The diaphragm pump according to claim 33, wherein the first
piston/cylinder system is arranged between two hydraulically acting
piston/cylinder systems, the first piston being connected to the
other hydraulic piston by at least one piston rod which engages(s)
through the first piston and/or which is/are secured thereto.
39. The diaphragm pump according to claim 38, wherein the
connection element is supported so as to be freely displaceable
with respect to the first piston and with respect to the other
hydraulic piston, and the connection element is displaceably
supported in the piston rod and engages through said other
hydraulic pistons of the piston/cylinder systems.
40. The diaphragm pump according to claim 39, wherein sealing
elements are arranged between the connection element and said other
hydraulic pistons and/or the piston rod in such a manner that no
hydraulic medium can travel along the connection element from one
hydraulic space into another hydraulic space.
41. The diaphragm pump according to claim 38, wherein the
hydraulically acting piston/cylinder systems each have a first and
a second operating space, and, in each case, the first operating
space is an integral component of a hydraulic space, forms the
hydraulic space, and is connected to the hydraulic space by means
of a channel, and the second operating spaces are connected to each
other by a connection line.
42. The diaphragm pump according to claim 41, wherein the second
operating spaces and the connection line are filled with a
hydraulic medium.
43. The diaphragm pump according to claim 41, wherein the diaphragm
pump has at least one device for monitoring a quantity of the
hydraulic medium in one and/or more operating space(s) of the
hydraulically acting piston/cylinder systems and/or in the
connection line.
44. The diaphragm pump according to claim 43, wherein the second
operating spaces and the connection line which connects the second
operating spaces to each other are connected by an additional
connection line to a storage container containing a hydraulic
medium, the monitoring device detecting a discharge and/or an
influx of hydraulic medium through the additional connecting
connection line.
45. The diaphragm pump according to claim 44, wherein at least the
hydraulic medium located in the hydraulic spaces is inert with
respect to the conveyed medium.
46. The diaphragm pump according to claim 35, wherein each
conveying space is connected, in each case, to a common supply line
by a supply channel and/or a common pressure line by an outlet
channel, the supply line and/or the pressure line being supported
in a floating manner on at least one connection region of a housing
of the pump.
47. The diaphragm pump according to claim 46, wherein a valve is
arranged in the supply channel and in the outlet channel,
respectively.
48. The diaphragm pump according to claim 47, wherein each valve is
a non-return valve.
49. The diaphragm pump according to claim 31, wherein a ratio of
the piston face of the first piston to the piston face of the other
hydraulic piston is from 1:1 to 1:40.
50. The diaphragm pump according to claim 38, wherein an exchange
of hydraulic medium from one operating space into the other
operating space of a hydraulically acting piston/cylinder system is
carried out by a valve when falling below or exceeding a specific
pressure difference between the operating spaces.
51. The diaphragm pump according to claim 31, wherein there is
arranged in the other hydraulic piston a reduced pressure valve or
an excess pressure valve which normally blocks a connection channel
which extends axially through the other hydraulic piston.
52. The diaphragm pump according to claim 31, wherein axial
cylinder walls of operating spaces of the first piston/cylinder
system are adapted to the shape of the axial walls of the first
piston and are constructed in a planar manner such that a remaining
operating space in dead centre points of the first piston is
minimal.
53. The diaphragm pump according to claim 52, wherein there is
arranged in the walls of the first piston/cylinder system that
delimit the operating spaces axially or at the end face a switching
valve which is mechanically actuated by the first piston before or
when the respective dead centre point or switching point is
reached, the switching valves controlling compressed air which
switches a main valve.
54. The diaphragm pump according to claim 53, wherein the first
piston mechanically actuates valve adjustment members of the
switching valves, the switching valves being constructed so as to
be able to be inserted from an outer side into a wall of the first
piston/cylinder system that delimits at the end face.
55. The diaphragm pump according to claim 54, wherein the main
valve is a 5/2 way valve or a 4/2 way valve which connects in the
switching phase the two operating spaces of the first
piston/cylinder system and consequently prefills a receiving
operating space with the compressed air from a transferring
operating space.
56. The diaphragm pump according to claim 53, wherein the main
valve has an inlet for uncontrolled compressed air from an external
compressed air source, the main valve itself having a pressure
control device for producing controlled compressed air of a
specific pressure.
57. The diaphragm pump according to claim 53, wherein the main
valve has a valve control member which is adjusted by the
compressed air controlled by the switching valves.
58. The diaphragm pump according to claim 57 wherein the valve
control member controls the compressed air controlled by the valve
control device and directs it into operating spaces of the first
piston/cylinder system in order to adjust the first piston.
59. The diaphragm pump according to claim 53, wherein the switching
valves have throttles.
60. The diaphragm pump according to claim 33, wherein the
connection element is a rod or a pipe.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is the U.S. National Phase Patent
Application of PCT International Application No. PCT/EP2011/001360,
filed Mar. 18, 2011, which claims priority to German Patent
Application No. 10 2010 013 108.3, filed Mar. 26, 2010, the
contents of such applications being incorporated by reference
herein.
FIELD OF THE INVENTION
[0002] The present invention relates to a diaphragm pump having at
least one diaphragm.
BACKGROUND OF THE INVENTION
[0003] In diaphragm pumps, the diaphragm delimits a conveying space
in which a supply line and a discharge line open. Generally,
non-return valves are arranged in the supply and discharge lines in
such a manner that, by the diaphragm being moved back and forth,
the conveying medium can first be drawn via the supply line into
the conveying space and can subsequently be pressed out of the
conveying space via the discharge line.
[0004] So that a continuous conveying action is possible, in most
cases two diaphragm pumps are connected in parallel, the first one
drawing in the conveying medium and the other at the same time
pressing the conveying medium out of the conveying space
thereof.
[0005] There are further known dual-diaphragm pumps, in which the
diaphragms, which in most cases are constructed as plate
diaphragms, are adjusted by means of a common piston/cylinder
system or by means of an electrical drive. In spaces in which
explosive gases may occur, no electrical pumps must be operated or
the strict provisions of Explosion Protection must be taken into
consideration. In this instance, pneumatic pumps are generally
used, in which a piston, which is mechanically connected to the
diaphragms, is moved back and forth in a cylinder by means of
compressed air. The compressed air in this instance is switched by
means of a main valve in such a manner that the two operating
spaces are alternately filled with compressed air. Such a pump is
known from U.S. Pat. No. 4,818,191. The spaces which are separated
from the conveying space by the diaphragms are connected to the
environment by means of channels so that, in the event of a
leakage, the conveying medium can be discharged from the pump and
does not impede the movement of the diaphragms. The disadvantage of
this pump is that the diaphragms, owing to the high pressure in the
conveying space and the ambient pressure behind the diaphragm, are
subjected to a high differential pressure load, which leads to
rapid wear in the diaphragms.
[0006] A further developed pneumatically driven dual-diaphragm pump
is known from WO 2009/024619. In this pump, the compressed air
which drives the piston is directed at the same time into the space
behind the diaphragm. At the same time, the diaphragm is supported
by means of a plate but the plate completely abuts the diaphragm in
a supporting manner only at a dead centre point. The disadvantage
of this pump is that, in the event of a defect of the diaphragm,
the conveying medium reaches the pneumatic system and disables the
valves and consequently the entire pump. The pump can subsequently
be restarted, if at all, only with great complexity.
[0007] A dual-chamber diaphragm pump without a driven piston is
known from DE 32 06 242. The disadvantage of this pump involves the
large spaces which must be filled with compressed air after the
dead centre point has been reached so that the diaphragms can be
moved in the other direction. A very large amount of compressed air
is thereby required, which increases the maintenance costs of the
pump. A similarly constructed pump with the same disadvantages is
known from CA 1172904, WO97/10902 and U.S. Pat. No. 5,368,452. With
the pump known from WO2009/024619, a disproportionately large
amount of compressed air is required for the operation of the pump.
These pumps are also not pressure-boosted so that the conveying
pressure is always below the feed pressure.
SUMMARY OF THE INVENTION
[0008] An object of the present invention is to provide a diaphragm
pump in which the diaphragms have a long service-life and are
subjected to low differential pressures and which has a good level
of efficiency.
[0009] This object is achieved according to the invention with a
diaphragm pump wherein a fluid moves at least a first piston of a
first piston/cylinder system back and forth, the first piston being
mechanically connected to at least one other hydraulic piston and
the hydraulic piston driving at least one diaphragm (M.sub.1,
M.sub.2) by means of a hydraulic medium, characterised in that the
diaphragm pump is a dual-diaphragm pump having at least two
diaphragms (M.sub.1, M.sub.2), a hydraulic medium moving or driving
the diaphragms (M.sub.1, M.sub.2), at least one hydraulic piston
moving the hydraulic medium, and in that two diaphragms (M.sub.1,
M.sub.2) are mechanically connected to each other by means of a
connection element, in particular a rod or a pipe,
respectively.
[0010] The notion of the invention is that the diaphragm pump has a
first piston/cylinder system whose piston drives at least one
hydraulic cylinder. The piston can be driven in this instance by
means of a fluid, for example, compressed air or a fluid medium,
that is to say, moved back and forth. The at least one hydraulic
piston is also thereby moved back and forth. The hydraulic piston
is itself arranged in a cylinder and divides it into two operating
spaces, a first and a second operating space. At least the first
operating space is filled in this instance with a hydraulic medium
which acts on the diaphragm of the diaphragm pump.
[0011] Advantageously, the diaphragm pump is constructed as a
dual-diaphragm pump so that each of the two diaphragms conveys
alternately. Advantageously, the first operating space is delimited
at the end face by the hydraulic piston and the diaphragm,
respectively. However, it is also possible for the operating space
to be connected via a connection line to the space separated from
the conveying space by the diaphragm and for the hydraulic medium
moved by the hydraulic piston thus to act on the diaphragm and
adjust it.
[0012] The first piston of the first piston/cylinder system is in
this instance advantageously driven by means of compressed air so
that the diaphragm pump can also be used in explosion-protected
spaces.
[0013] Owing to the freely selectable surfaces of the first piston
and hydraulic piston, any pressure boost between the driving
pneumatic pressure and the conveying pressure of the pump can be
adjusted.
[0014] Regardless of the conveying pressure of the diaphragm pump,
the diaphragms are subjected to a maximum differential pressure
load (maximum suction power) of one bar, whereby a long service
life of the diaphragms is advantageously obtained.
[0015] An inert fluid for the conveyed medium is advantageously
selected as a hydraulic medium so that, in the event of a defect of
the diaphragm, the conveying medium does not become contaminated.
Should conveying medium enter the first operating space in the
event of a malfunction, this does not influence the pump.
[0016] Advantageously, the second operating spaces of the
hydraulically acting piston/cylinder systems are connected to each
other so that they act as damping members by the medium which is
located in these operating spaces and which is advantageously the
same inert hydraulic medium as in the first operating spaces being
pumped back and forth.
[0017] If the pump is constructed as a dual-diaphragm pump, the
diaphragms are advantageously connected to each other by means of a
connection element which synchronises the movement of the
diaphragms. This connection element does not serve to drive the
diaphragms. Advantageously, the connection element has at each of
the ends thereof a thread by means of which it is screwed into the
diaphragms. The screwing can be carried out directly into the
material, in particular rubber, or into a threaded socket which is
enclosed in the diaphragm. Since the connection element does not
transmit any great forces, it is possible in most cases to dispense
with a threaded socket.
[0018] A small structural form is advantageously achieved when the
driving first piston/cylinder system is arranged between the
hydraulically acting piston/cylinder systems. In this instance, the
first piston is rigidly connected to the two hydraulic pistons by
means of piston rods, whereby they are synchronously adjusted
therewith. The connection element of the diaphragms may
advantageously extend through the tubular piston rods and is
displaceably supported therein. That is to say, the connection
element extends through the hydraulic pistons, correspondingly
arranged seals preventing hydraulic medium from one operating space
reaching the other through the piston rods.
[0019] Advantageously, the diaphragm pump has at least one device
for monitoring the quantity of the hydraulic medium in one and/or
more operating space(s) of the hydraulically acting piston/cylinder
systems and/or in the connection line thereof. If hydraulic medium
escapes and is drawn from a storage container, this is recognised
by the device and the pump is stopped and/or an error signal is
transmitted to a superordinate control system.
[0020] The fluid which moves the first piston of the first
piston/cylinder system back and forth, in particular compressed
air, is directed by a main valve, which is controlled in particular
by the movement of the first piston, alternately into the first and
second operating space of the first piston/cylinder system.
[0021] In the walls of the first piston/cylinder system that
delimit the operating spaces axially or at the end face, there are
arranged switching valves, in particular 3/2 way valves, which are
mechanically actuated by the first piston before or when the
respective dead centre point or switching point is reached. In this
instance, the switching valves control the compressed air which
switches the main valve. Advantageously, uncontrolled compressed
air is used in this instance, that is to say, compressed air which
is provided by an external compressed air source. This pressure is
generally higher than the pressure with which the diaphragm pumps
according to the prior art are operated. It is thereby ensured that
the diaphragm pump according to the invention switches in a
reliable manner. This is often not the case with diaphragm pumps
according to the prior art in which the main valve has only one
inlet for controlled air, since the controlled pressure at the
first piston/cylinder system is often very low.
[0022] The first piston actuates the valve adjustment members of
the switching valves mechanically, the switching valves being
constructed in particular as cartridge valves, that is to say, so
as to be able to be inserted, in particular screwed, from the outer
side into the wall of the first piston/cylinder system that
delimits at the end face in each case. A particularly favourable
construction is thereby achieved since the valves can be replaced
without opening the conveying spaces.
[0023] The main valve is also advantageously arranged on the
housing of the diaphragm pump at the outer side so that the main
valve can also be readily cleaned, repaired or replaced.
[0024] The main valve is advantageously constructed as a 4/2 way
valve or as a 5/2 way valve. That is to say, the valve control
element of the main valve moves alternately back and forth between
two end positions. It consequently has only two defined positions
in the form of the end positions. On the way from one end position
to the other end position, that is to say, during the movement, in
a central region between the end positions, the two operating
spaces of the first piston/cylinder system are connected to each
other by means of the valve control element of the main valve and
the receiving operating space is consequently prefilled with the
compressed air from the transferring operating space. Afterwards,
the operating space which has been prefilled is further filled with
controlled air. The other operating space is connected to the valve
outlet so that the remaining operating air from the operating space
can expand via silencers. A better degree of efficiency of the
diaphragm pump according to the invention is thereby achieved since
less compressed air is required for the operation of the pump.
[0025] Advantageously, the main valve has an inlet for uncontrolled
compressed air from an external compressed air source, the main
valve itself being able to have a pressure control device for
producing controlled compressed air of a specific pressure. By
means of a valve control element which is displaceably arranged in
the housing of the main valve and which is adjusted by the
compressed air which is controlled by the switching valves, in
particular the uncontrolled compressed air, the controlled
compressed air is directed alternately into the operating spaces of
the first piston/cylinder system.
[0026] So that the remaining operating space in the dead centre
points of the first piston is as small as possible, the axial
cylinder walls of the cylinder of the first piston/cylinder system
may advantageously be adapted to the shape of the axial walls of
the first piston. A planar construction of the walls is preferred
in this instance.
[0027] The switching valves may advantageously have throttles so
that the air which is pressed out of the respective operating space
is braked by the throttle and a slowed movement of the valve
control element of the main valve from the centre region is thereby
achieved, whereby the phase of the pressure compensation between
the pretensioned operating space and the operating space which is
to be emptied next and the operating space which is to be filled
next is as long as possible. The throttle does not yet act so
strongly at the beginning of the movement of the pneumatic piston
so that the valve control element of the main valve is adjusted
with high speed from the end position thereof in the direction of
the central region, in which the operating spaces of the pneumatic
cylinder are bypassed.
[0028] Each conveying space may advantageously be connected by
means of a supply channel to a common supply line, respectively,
and/or by means of an outlet channel to a common pressure line,
respectively, the supply line and/or the pressure line being
supported in a floating manner on at least one connection region of
the pump housing. It is thereby advantageously possible that no
alternately occurring loads occur at the connection locations
(appearances of mechanical fatigue). Valves, in particular
non-return valves, are arranged in the supply channels and in the
outlet channels, respectively.
[0029] It is of course possible, using the first piston/cylinder
system which is driven in particular pneumatically by means of
compressed air, for a plurality of hydraulic pistons which are
arranged parallel with respect to each other to be able to be
driven. It is thereby possible, using a pneumatic drive, to drive
or adjust more than two diaphragms, in particular a multiple of
two, for drawing and pressing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] One possible embodiment of the diaphragm pump which is
constructed as a dual-diaphragm pump is explained in greater detail
below with reference to drawings.
[0031] FIG. 1: is a perspective view of the diaphragm pump
according to the invention in the form of a dual-diaphragm
pump;
[0032] FIG. 2: is a sectioned illustration of the diaphragm pump
according to FIG. 1;
[0033] FIG. 3: is a sectioned illustration through the
dual-diaphragm pump according to FIGS. 1 and 2;
[0034] FIG. 4: is a partial cutout from FIG. 3;
[0035] FIG. 5: is a pneumatic diagram for a diaphragm pump
according to the invention having a 5/2 way valve as a main
valve;
[0036] FIG. 6: is a pneumatic diagram for a diaphragm pump
according to the invention having a 4/2 way valve as a main
valve.
DETAILED DESCRIPTION OF THE INVENTION
[0037] FIGS. 1 and 2 are perspective views of the diaphragm pump
according to the invention in the form of a dual-diaphragm pump.
The dual-diaphragm pump has a housing cover 19 and a housing
portion 11 which receives the cylinder 10 of the hydraulically
acting piston/cylinder system 9, 10. The housing portion 11, as
illustrated in FIG. 2, is secured by means of coaxial screws 11a to
the axial cylinder wall 3 of the first piston/cylinder system. The
diaphragm M is clamped at 22 by the housing cover 19 and the
housing portion 11 (see FIGS. 3 and 4). The housing cover 19 and
housing portion 11 are connected to each other by means of the
screws 19a and fix the diaphragm M in position. The housing cover
19 forms at the top and bottom a receiving member for a non-return
valve 24, respectively. The non-return valves 23, 24 are inserted
before the housing flanges 25, 27 are screwed to the housing cover
19 into the corresponding recesses of the housing cover 19.
Additional seals prevent conveying medium from being able to be
introduced around the housing of the non-return valves 23, 24. The
axial walls 3 of the first piston/cylinder system are retained with
spacing by means of spacer sleeves 7 and connected to each other by
means of the screws 6. The cylindrical wall sleeve 2 which forms
the cylinder is further arranged between the walls 3 in a
pressure-tight manner, additional seals ensuring the tightness. The
screws 6 have a screw head 6a and at the end thereof a thread 6b
with which they are screwed to the first axial wall 3.
[0038] In the cylinder 2, 3 of the first piston/cylinder system,
there is arranged the first piston 1 which is formed by two discs
1a, 1b and which separates the operating spaces A and B from each
other. The discs 1a, 1b are screwed together by means of the screws
4. The cylindrical wall 2 has, at the outer side thereof, ribs for
absorbing heat from the ambient air in order to prevent ice forming
on the diaphragm pump. The axial walls 3 also have recesses 3b
which also serve to better conduct heat and to provide rigidity and
save material. The piston 1 has a continuous seal 1c which abuts
the inner wall of the cylinder 2 in a sealing manner.
[0039] When the piston 1 is assembled, the piston rods 8a, 8b are
pushed beforehand through the holes 1d until the collars 8c rest in
the corresponding recesses 1e of the piston discs 1a, 1b. Owing to
the assembly of the piston discs 1a, 1b, the piston rods 8a, 8b are
secured to the piston 1 in a positive-locking manner.
[0040] The piston rods 8a, 8b extend through the holes 3a of the
axial walls 3, seals 56 ensuring that no compressed air from the
operating spaces A, B reaches the hydraulic spaces H.sub.2. With
the ends 8d thereof, the piston rods 8a, 8b are connected to the
hydraulic pistons in a sealing manner by means of screws 60. The
piston rods 8a, 8b are constructed as pipes in which the connection
element 5 rests in a displaceable manner in the form of a rod. The
connection element 5 is screwed with the ends 5a thereof having the
outer thread into the diaphragm plate 20. The diaphragm plate 20 is
formed in the diaphragm M.sub.1 in the centre 21 thereof.
[0041] The hydraulic pistons 9 each have a continuous seal 12 which
abuts the inner wall of the cylinder wall 10 in a sealing manner
and separates the two operating spaces H.sub.1, H.sub.2 from each
other. The two hydraulic spaces H.sub.2 of the two hydraulic
piston/cylinder systems are connected to each other by means of the
connection channels 16, 17 and 18. Differential pressure valves 13
are arranged in each case in the hydraulic pistons 9. If the
differential pressure between the operating spaces H.sub.1 and
H.sub.2 exceeds a specific value when the pump is operated, the
differential pressure valve 13 opens and the differential pressure
can be reduced to a predetermined value. The connection channel 16,
17, 18 can be connected by means of an additional connection line
(not illustrated) to a storage container and/or a sensor. If an
influx or discharge of hydraulic medium now occurs at the storage
container or the connection line, this may signify a breakage of
the diaphragm, whereupon an error signal can be sent to a
superordinate control system and/or the diaphragm pump is
automatically stopped. This can be carried out, for example, by the
forced closing of the line which supplies the pump with compressed
air.
[0042] The supply channels 28 are connected to each other by means
of the supply line 36, the supply line 36 forming with the one end
41 thereof the conveying medium inlet of the pump.
[0043] The other end of the supply line 36 which is constructed as
a pipe is closed by means of a screwed-in plug 34. The supply line
36 rests with the regions 36a thereof in a floating manner in the
housing flanges 27, seals 39 ensuring the necessary sealing. The
housing flanges 27 have an annular space 40 which surrounds the
regions 36a and which is formed by a continuous groove. In the
region 36a, the supply line 36 has window-like openings 38 through
which the conveying medium is introduced from the inner space 37 of
the supply line 36 into the annular space 40 and from there into
the supply channel 28.
[0044] The outlet channels 26 are connected to each other by means
of the pressure line 29, the pressure line 29 forming the conveying
medium outlet of the pump with the one end 33 thereof. The other
end of the pressure line 29 which is constructed as a pipe is
closed by means of a screwed-in plug 34. The pressure line 29 rests
with the regions 29a thereof in a floating manner in the housing
flanges 25, seals 39 ensuring the necessary fluid-tightness. The
housing flanges 25 have an annular space 32 which surrounds the
regions 29a and which is formed by a continuous groove. In the
regions 29a, the pressure line 29 has window-like openings 31,
through which the conveying medium can be introduced from the
annular space 32 into the inner space 30 of the pressure line
29.
[0045] In the axial walls 3, there are arranged switching valves 14
which extend with an extension 15 of the valve control members
thereof into the operating spaces A, B. If the piston 1 reaches its
dead centre point, the respective switching valve is actuated,
whereby compressed air is directed to the main valve 50 by means of
channels which are not illustrated, and the main valve is in turn
switched off.
[0046] The main valve 50 is arranged at the outer side on the pump
housing so that good heat exchange with the ambient air can take
place, whereby the risk of formation of ice is reduced.
[0047] In so far as the diaphragm plate 20 is adjusted by means of
the hydraulic piston 9 in such a manner that the conveying space
F.sub.1 is reduced, the conveying medium which is located in the
conveying space F.sub.1 is conveyed by the non-return valve 24 into
the outlet channel 26. The non-return valve 23 is closed during
this. If enlargement subsequently occurs in the conveying space
F.sub.1 by the diaphragm M.sub.1 being moved back, conveying medium
is drawn from the supply line 36 into the conveying space F.sub.1
via the non-return valve 23 which is open. During the suction
phase, the non-return valve 24 is closed.
[0048] FIG. 5 shows a pneumatic diagram of the diaphragm pump
according to FIGS. 1 to 4. The diaphragm pump which is operated
with compressed air has a compressed air inlet 43 which is
advantageously arranged on the main valve 50. In or on the main
valve 50 there may be arranged the pressure control device 45 which
is connected to the inlet 43 by means of the input line 44. The
pressure control device 45 may be a proportional valve which may
have an adjustment mechanism, for example, in the form of an
adjustment screw, by means of which a spring can be pretensioned
for pressure adjustment. If, by means of the external compressed
air source (not illustrated), uncontrolled pressure of 7 bar is
provided, controlled compressed air of, for example, 5.5 bar can be
supplied to the main valve 50 by means of the pressure control
device 45 via the connection line.
[0049] The inlet 43 is connected to the switching valves 14 by
means of connection lines 48, 49. The switching valves are
constructed as 3/2 way valves and are switched by means of the
extensions 15 of their valve control members extending into the
operating spaces A, B. A spring presses the valve control members
into the illustrated position, in which the control lines 52, 53
are not connected to the valve inlet or the connection line 48, 49.
As soon as the piston 1 adjusts the respective valve control member
15, the switching valve 14 is switched and the uncontrolled
compressed air of the external pressure source switches the main
valve 50.
[0050] The main valve 50 is constructed as a 5/2 way valve. In the
illustrated position, the controlled compressed air reaches the
operating space A via the connection line 57. The piston 1 is
consequently moved to the right together with the hydraulic pistons
9. Owing to the hydraulic medium which is located in the hydraulic
spaces H.sub.1, the non-illustrated right-hand diaphragm is moved
to the right, whereby the conveying space which is associated
therewith is reduced. The right-hand diaphragm consequently
conveys. At the same time, the left-hand diaphragm which is also
not illustrated in FIG. 5 draws conveying medium from the supply
line into the conveying space thereof. When the right-hand dead
centre point is reached, the right-hand switching valve 14 is
switched via the extension 15 so that the main valve 50 is also
switched. On the way to the left, the connection of the operating
space A to the connection line 47 is first interrupted. Afterwards,
the two operating spaces are bypassed with respect to each other so
that the pretensioned compressed air located in the operating space
B can expand into the operating space A. A specific time period is
available for this until the main valve 50 has ultimately
completely switched through and compressed air which is controlled
via the connection line 47 is directed into the operating space B,
whereby the piston 1 is moved to the left. The remaining compressed
air which has not yet been expanded in the pressure space B
subsequently expands via the valve outlets 51 via the silencers 35
into the environment.
[0051] FIG. 6 illustrates an alternative embodiment in which the
main valve 50 is constructed as a 4/2 way valve. The main valve 50
differs from the main valve illustrated in FIG. 5 simply in that
only one outlet 51 is provided.
LIST OF REFERENCE NUMERALS
[0052] A, B Operating space of the first piston/cylinder system
[0053] M.sub.1, M.sub.2 Diaphragm [0054] 1 First piston of the
first piston/cylinder system [0055] 1a, 1b Piston discs [0056] 1c
Seal [0057] 1d Hole [0058] 1e Recess for collar 8c [0059] 2
Cylinder of the first piston/cylinder system [0060] 2a Outer
cooling rib of the cylinder 2 [0061] 3 Axial cylinder wall of the
first piston/cylinder system [0062] 4 Screws [0063] 5 Connection
element [0064] 5a Thread of the connection element 5 [0065] 6
Connection screw [0066] 7 Spacing sleeve [0067] 8a, 8b Piston rod
[0068] 8c Collar [0069] 9 Hydraulic piston [0070] 10 Cylinder of
the hydraulically acting piston/cylinder system [0071] 11 Housing
portion [0072] 12 Seal [0073] 13 Differential pressure valve
(p.sub.H1>P.sub.H2) [0074] 14 Switching valve [0075] 15 Valve
control member [0076] 16, 17, 18 Channel/connection line [0077] 19
Housing cover [0078] 20 Diaphragm plate [0079] 21 Diaphragm region,
in which the diaphragm plate 20 is arranged
[0080] 22 Clamping region of the diaphragm M.sub.1 [0081] 23
Non-return valve in the supply channel (only illustrated in the
left chamber) [0082] 24 Non-return valve in the outlet channel
(only illustrated in the left chamber) [0083] 25 Housing flange
having an outlet channel 26 (outlet housing) [0084] 26 Outlet
channel [0085] 27 Housing flange with supply channel 28 (inlet
housing) [0086] 28 Supply channel [0087] 29 Pressure line [0088] 30
Inner space of the pressure line 29 [0089] 31 Through-opening in
the wall of the pressure line 29 [0090] 32 Annular space which
surrounds the pressure line 29 [0091] 33 Pump outlet for conveying
medium [0092] 34 Plug having a screw-in thread [0093] 35 Silencer
for discharging the expanding compressed air [0094] 36 Supply line
[0095] 37 Inner space of the supply line 36 [0096] 38
Through-opening in the wall of the supply line 36 [0097] 39 Sealing
rings [0098] 40 Annular space which surrounds the supply line 36
[0099] 41 Pump inlet for conveying medium [0100] 42 Base [0101] 43
Inlet for uncontrolled compressed air of an external compressed air
source [0102] 44 Connection line [0103] 45 Pressure control device
in the form of a proportional valve [0104] 46 Adjustment mechanism
for controlled outlet pressure of the pressure control device 46
[0105] 47 Connection line, guides controlled compressed air to the
main valve 50 [0106] 48, 49 Connection line for uncontrolled
compressed air [0107] 50 Main valve [0108] 51 Outlets of the main
valve, which are connected to the silencers 35 [0109] 52, 53
Control line of the switching valve 14 to the main valve 50 [0110]
54, 55 Outlet to the outer side [0111] 56 Seal [0112] 57 Connection
line to the operating space A [0113] 58 Connection line to the
operating space B [0114] 66 Throttle in the switching valve 14
* * * * *