U.S. patent application number 14/450321 was filed with the patent office on 2015-02-19 for hydraulic machine, in particular hydraulic pressure exchanger.
The applicant listed for this patent is Danfoss A/S. Invention is credited to Haraldur Sigurdsson.
Application Number | 20150050163 14/450321 |
Document ID | / |
Family ID | 48985636 |
Filed Date | 2015-02-19 |
United States Patent
Application |
20150050163 |
Kind Code |
A1 |
Sigurdsson; Haraldur |
February 19, 2015 |
HYDRAULIC MACHINE, IN PARTICULAR HYDRAULIC PRESSURE EXCHANGER
Abstract
A hydraulic machine, in particular hydraulic pressure exchanger,
is provided comprising a drum rotatable about a rotational axis, a
first front plate arrangement at a first front face of said drum, a
second front plate arrangement at a second front face of said drum,
said drum comprising a plurality of cylinders, said first front
plate arrangement comprising a first front plate and a pressure
shoe (8), said first front plate comprising at least a high
pressure supply port. Such a pressure exchanger should have a
simple construction. To this end the pressure shoe (8) comprises at
least a pressure cylinder (14), said pressure cylinder (14) opening
to said first front plate, a piston (17) being arranged in said
pressure cylinder (14), said pressure cylinder (14) being in fluid
contact with said high pressure supply port.
Inventors: |
Sigurdsson; Haraldur; (Arhus
V, DK) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Danfoss A/S |
Nordborg |
|
DK |
|
|
Family ID: |
48985636 |
Appl. No.: |
14/450321 |
Filed: |
August 4, 2014 |
Current U.S.
Class: |
417/64 |
Current CPC
Class: |
F04B 1/20 20130101; F01B
3/0041 20130101; F04B 9/117 20130101; F04B 7/0023 20130101; F04B
1/24 20130101; F04B 9/1176 20130101; F04F 13/00 20130101; F04B
9/109 20130101 |
Class at
Publication: |
417/64 |
International
Class: |
F04B 7/00 20060101
F04B007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 15, 2013 |
EP |
13180511.1 |
Claims
1. A hydraulic machine, in particular hydraulic pressure exchanger
comprising a drum rotatable about a rotational axis, a first front
plate arrangement at a first front face of said drum, a second
front plate arrangement at a second front face of said drum, said
drum comprising a plurality of working cylinders, said first front
plate arrangement comprising a first front plate and a pressure
shoe, said first front plate comprising at least a port, wherein
the pressure shoe comprises at least a pressure cylinder, said
pressure cylinder opening to said first front plate, a piston being
arranged in said pressure cylinder, said pressure cylinder being in
fluid contact with said port.
2. The hydraulic machine according to claim 1, wherein said
pressure cylinder is arranged in an area which is closer to said
rotational axis than to a circumference of said drum.
3. The hydraulic machine according to claim 1, wherein at least two
pressure cylinders are arranged in said pressure shoe.
4. The hydraulic machine according to claim 3, wherein said
pressure cylinders have the same cross section area.
5. The hydraulic machine according to claim 1, wherein said
pressure shoe comprises two ports on a side facing said first front
plate, said ports having a minimum distance along a straight line,
said pressure cylinder being offset to said straight line by a
predetermined displacement.
6. The hydraulic machine according to claim 5, wherein said
pressure cylinder is arranged between said ports.
7. The hydraulic machine according to claim 1, wherein said
pressure shoe comprises at least a high pressure channel connected
to said port and an outer pressure area loaded by a pressure in
said port in a direction towards said drum, said outer pressure
area being larger than an inner pressure area on a side of said
pressure shoe facing said drum.
8. The hydraulic machine according to claim 7, wherein said outer
pressure area is arranged within said channel.
9. The hydraulic machine according to claim 1, wherein said
pressure shoe rests against said drum in a contact area, two
different materials contacting each other in said contact area, one
material being steel and the other material being a plastic
material sliding with slow friction on steel, in particular a
high-resistant thermoplastic plastic material on the basis of
polyaryl etherketones, particularly polyetheretherketones (PEEK),
polyamides, polyacetals, polyarylethers, polyethylene
terephthalates, polyphenylene sulfides, polysulphones, polyether
sulphones, polyether imides, polyamide imides, polyacrylates,
phenol resins, like novolacquer resins or the like, preferably
provided with a filling of glass, graphite, polytetraflourethylene
or carbon, the fillings being particularly useful as fibres.
10. The hydraulic machine according to claim 2, at least two
pressure cylinders are arranged in said pressure shoe.
11. The hydraulic machine according to claim 2, wherein said
pressure shoe comprises two ports on a side facing said first front
plate, said ports having a minimum distance along a straight line,
said pressure cylinder being offset to said straight line by a
predetermined displacement.
12. The hydraulic machine according to claim 3, wherein said
pressure shoe comprises two ports on a side facing said first front
plate, said ports having a minimum distance along a straight line,
said pressure cylinder being offset to said straight line by a
predetermined displacement.
13. The hydraulic machine according to claim 4, wherein said
pressure shoe comprises two ports on a side facing said first front
plate, said ports having a minimum distance along a straight line,
said pressure cylinder being offset to said straight line by a
predetermined displacement.
14. The hydraulic machine according to claim 2, wherein said
pressure shoe comprises at least a high pressure channel connected
to said port and an outer pressure area loaded by a pressure in
said port in a direction towards said drum, said outer pressure
area being larger than an inner pressure area on a side of said
pressure shoe facing said drum.
15. The hydraulic machine according to claim 3, wherein said
pressure shoe comprises at least a high pressure channel connected
to said port and an outer pressure area loaded by a pressure in
said port in a direction towards said drum, said outer pressure
area being larger than an inner pressure area on a side of said
pressure shoe facing said drum.
16. The hydraulic machine according to claim 4, wherein said
pressure shoe comprises at least a high pressure channel connected
to said port and an outer pressure area loaded by a pressure in
said port in a direction towards said drum, said outer pressure
area being larger than an inner pressure area on a side of said
pressure shoe facing said drum.
17. The hydraulic machine according to claim 5, wherein said
pressure shoe comprises at least a high pressure channel connected
to said port and an outer pressure area loaded by a pressure in
said port in a direction towards said drum, said outer pressure
area being larger than an inner pressure area on a side of said
pressure shoe facing said drum.
18. The hydraulic machine according to claim 6, wherein said
pressure shoe comprises at least a high pressure channel connected
to said port and an outer pressure area loaded by a pressure in
said port in a direction towards said drum, said outer pressure
area being larger than an inner pressure area on a side of said
pressure shoe facing said drum.
19. The hydraulic machine according to claim 2, wherein said
pressure shoe rests against said drum in a contact area, two
different materials contacting each other in said contact area, one
material being steel and the other material being a plastic
material sliding with slow friction on steel, in particular a
high-resistant thermoplastic plastic material on the basis of
polyaryl etherketones, particularly polyetheretherketones (PEEK),
polyamides, polyacetals, polyarylethers, polyethylene
terephthalates, polyphenylene sulfides, polysulphones, polyether
sulphones, polyether imides, polyamide imides, polyacrylates,
phenol resins, like novolacquer resins or the like, preferably
provided with a filling of glass, graphite, polytetraflourethylene
or carbon, the fillings being particularly useful as fibres.
20. The hydraulic machine according to claim 3, wherein said
pressure shoe rests against said drum in a contact area, two
different materials contacting each other in said contact area, one
material being steel and the other material being a plastic
material sliding with slow friction on steel, in particular a
high-resistant thermoplastic plastic material on the basis of
polyaryl etherketones, particularly polyetheretherketones (PEEK),
polyamides, polyacetals, polyarylethers, polyethylene
terephthalates, polyphenylene sulfides, polysulphones, polyether
sulphones, polyether imides, polyamide imides, polyacrylates,
phenol resins, like novolacquer resins or the like, preferably
provided with a filling of glass, graphite, polytetraflourethylene
or carbon, the fillings being particularly useful as fibres.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] Applicant hereby claims foreign priority benefits under
U.S.C. .sctn.119 from European Patent Application No. EP13180511.1
filed on Aug. 15, 2013, the contents of which are incorporated by
reference herein.
TECHNICAL FIELD
[0002] The present invention relates to a hydraulic machine, in
particular hydraulic pressure exchanger, comprising a drum
rotatable about a rotational axis, a first front plate arrangement
at a first front face of said drum, a second front plate
arrangement at a second front face of said drum, said drum
comprising a plurality of working cylinders, said first front plate
arrangement comprising a first front plate and a pressure shoe,
said first front plate comprising at least a supply port.
BACKGROUND
[0003] Such a hydraulic pressure exchanger is known from EP 1 508
361 A1. A pressure exchanger of this kind can be used for example
in a reverse osmosis system in which a liquid is pumped through a
membrane under a rather high pressure. The liquid not passing the
membrane is supplied to the supply port of the pressure exchanger.
The high pressure of this liquid is transferred to a fluid being
supplied to the second front face of the drum. A piston in each
working cylinder is used to effect the pressure transfer. When a
working cylinder is in fluid connection with the supply port high
pressure fluid enters, shifting the piston to the other side
thereby transferring the high pressure to the liquid on the other
side. The drum rotates. After a predetermined rotational angle this
working cylinder comes in contact to a low pressure supply port in
which fresh liquid under a lower pressure fills the working
cylinder shifting the piston back to the first front face.
[0004] The path between the high pressure supply port (and all
other ports as well) and the working cylinder must be as tight as
possible to avoid leakage. In the known case each working cylinder
is provided with a bushing at each end. This bushing is pressed
axially outwardly to contact the pressure shoe with a force being
high enough to establish the necessary tightness. This force is
also used to press the pressure shoe at each front face axially
outwardly so that the pressure shoe rests against the front plates
at each front face of said drum.
SUMMARY
[0005] The object underlying the invention is to have a simple
construction of a hydraulic machine.
[0006] This object is solved in that the pressure shoe comprises at
least a pressure cylinder, said pressure cylinder opening to said
first front plate, a piston being arranged in said pressure
cylinder, said pressure cylinder being in fluid contact with said
high pressure supply port.
[0007] With this solution it is possible to keep the pressure shoe
unrotatable relative to the first front plate. The pressure shoe is
pressed against the front face of the drum. The force pressing the
pressure shoe against the front face of the drum is at least partly
generated by the piston in the pressure cylinder. This piston is
loaded by the pressure in the port which is preferably the highest
pressure in the pressure exchanger. In this case the port is a high
pressure supply port. This pressure presses the piston in the
pressure cylinder in a direction towards the first front plate.
This force creates a counter force pressing the pressure shoe
against the drum. The pressure pressing the pressure shoe against
the drum should be high enough to achieve the desired tightness.
However, it should be not too high in order to avoid excessive
wear. The resulting force can be determined rather exactly by the
dimension of the piston in the pressure cylinder. The term
"cylinder" is used to facilitate the explanation. Such a cylinder
can have a circular cross section although other forms are
possible. The working cylinders can simply be considered as
channels, such channels may be straight or curved.
[0008] Preferably said pressure cylinder is arranged in an area
which is closer to said rotational axis than to a circumference of
said drum. In this case, the force pressing the pressure shoe
towards the front face of the drum acts in a region near the center
of the pressure shoe and of the center of the drum. This allows a
rather equal distribution of forces over the entire area of the
pressure shoe.
[0009] Preferably at least two pressure cylinders are arranged in
said pressure shoe. In this case the force pressing the pressure
shoe against the front face of the drum can be doubled so that each
pressure cylinder can be kept small. Furthermore, such a
construction has the advantage that the forces act at different
positions on the pressure shoe.
[0010] In a preferred embodiment said pressure cylinders have the
same cross section area. In this way, the forces generated by the
pistons in each cylinder are equal since the pressure cylinders are
loaded with the same pressure. This makes it easier to distribute
the forces in the desired manner.
[0011] Preferably said pressure shoe comprises two ports on a side
facing said front plate, said ports having a minimum distance along
a straight line, said pressure cylinder being offset to said
straight line by a predetermined displacement. In many cases, the
pressure shoe comprises a first port connected to a high pressure
supply port and a second port connected to a low pressure return
port. When these two ports are arranged on a vertical line, the
pressure cylinder is offset to this vertical line in horizontal
direction. The same relation is true when the two ports are
arranged in another spatial direction. When the pressure cylinder
is offset to the straight line between the two ports, there is
sufficient space available so that the pressure cylinder can have a
sufficiently large diameter.
[0012] In a preferred embodiment said pressure cylinder is arranged
between said ports. Seen parallel to the above mentioned straight
line, said pressure cylinder and said ports overlap each other.
This makes it possible to position the pressure cylinder in an area
near the center of the pressure shoe.
[0013] Preferably said pressure shoe comprises at least a high
pressure channel connected to said port and an outer pressure area
loaded by a pressure in said port in a direction towards said drum,
said outer pressure area being larger than an inner pressure area
on a side of said pressure shoe facing such drum. In this way an
additional force is generated pressing the pressure shoe against
the front face of the drum. This additional force is based on the
difference between the outer pressure area and the inner pressure
area.
[0014] Preferably said outer pressure area is arranged within said
channel. No other areas are necessary. The liquid entering the
channel acts automatically on the outer pressure area.
[0015] In a preferred embodiment said pressure shoe rests against
said drum in a contact area, two different materials contacting
each other in said contact area, one material being steel and the
other material being a plastic material sliding with slow friction
on steel, in particular a high-resistant thermoplastic plastic
material on the basis of polyaryl etherketones, particularly
polyetheretherketones (PEEK), polyamides, polyacetals,
polyarylethers, polyethylene terephthalates, polyphenylene
sulfides, polysulphones, polyether sulphones, polyether imides,
polyamide imides, polyacrylates, phenol resins, like novolacquer
resins or the like, preferably provided with a filling of glass,
graphite, polytetraflourethylene or carbon, the fillings being
particularly useful as fibres. In this case, the pressure exchanger
and advantages be used as a water hydraulic device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] A preferred example of the invention will now be described
in more detail with reference to the drawing, wherein:
[0017] FIG. 1 is a schematic longitudinal section of a hydraulic
machine,
[0018] FIG. 2 is a view of a pressure shoe seen from a front plate
and
[0019] FIG. 3 is a section III-III of FIG. 2.
DETAILED DESCRIPTION
[0020] FIG. 1 shows a hydraulic machine in the form of a hydraulic
pressure exchanger 1 in a schematically longitudinal section.
[0021] The pressure exchanger 1 comprises a drum 2 rotatable about
an axis 3. The term "drum" is used to facilitate the explanation.
It is not necessary that this drum 2 is of cylindrical form. The
main purpose of the drum 2 is to form a basis for working cylinders
4. The drum 2 comprises a plurality of working cylinders 4, two
working cylinders 4 being shown in FIG. 1. The drum 2 can also be
termed as "cylinder carrier". The term "working cylinder" is used
to simplify the description. The working cylinder can be regarded
as channel. It is not necessary that the working cylinder has
circular cross section nor is it necessary that it is straight. It
can be curved as well.
[0022] A first front plate arrangement 5 is arranged at a first
axial end or front face of the drum 2. A second front plate
arrangement 6 is arranged at a second axial end or front face of
the drum 2 which is opposite of the first axial end of the drum
2.
[0023] The first front plate arrangement 5 comprises a first front
plate 7 and a pressure shoe 8. The pressure shoe 8 rests against
the drum 2. The pressure shoe 8 is loaded in a direction towards
the drum 2 by means explained below. A sleeve 9 is fixedly inserted
into the pressure shoe 8 and slidingly arranged in the first front
plate 7.
[0024] The first front plate 7 comprises a port 10 and a second
port 11. The sleeve 9 is inserted into an opening of the first
front plate 7 connected to the first port 10. The first port 10 can
be used to supply high pressure and the second port can be used to
return hydraulic liquid. However, this is just an example and other
pressure relations are possible in principle.
[0025] The first front plate 7 is connected to a housing 12. The
housing 12 is connected to a second front plate 13 which is
arranged on the opposite side of the housing 12 relative to the
first front plate 7. The second front plate 13 is part of the
second front plate arrangement 6.
[0026] Means for rotatably supporting and driving the drum 2 are
not shown in order to keep the illustration simple. However, the
drum 2 can be rotatable supported within the housing 12. A driving
shaft can be passed through the second front plate 13.
[0027] The pressure shoe 8 is supported unrotatably in the housing
12, so that it remains stationary in rotating direction relative to
the first front plate 7. However, a small movement in a direction
towards the drum 2 is possible.
[0028] As can be seen in FIGS. 2 and 3, the pressure shoe 8
comprises two pressure cylinders 14 which are connected to a high
pressure channel 15, said high pressure channel 15 being in fluid
connection with the first port 10. A short supply channel 16
establishes a connection between the cylinder 14 and the high
pressure channel 15. The pressure cylinder 14 has a circular cross
section although other forms are possible.
[0029] A piston 17 is arranged in each pressure cylinder 14. In
FIG. 3 it is shown that the piston 17 protrudes out of the pressure
shoe 8. The length of the piston 17 protruding out of the pressure
shoe 8 is larger than it is in reality in order to facilitate the
explanation. The piston 17 could have different diameters in order
to achieve an amplification.
[0030] The pressure shoe comprises two ports 18, 19, i.e. a first
port 18 which is connected to the high pressure channel 15 and
which overlaps the first port 10 in the first front plate 7, and a
second port 19 which is connected to a low pressure channel 20 in
the pressure shoe 8 and overlaps the second port 11 in the first
front plate 7.
[0031] The two ports 18, 19 have a minimum distance along a
straight line, said straight line running through the axis 3. The
two pressure cylinders 14 are offset to this minimum distance line,
i.e. offset to the axis 3 in radial direction.
[0032] Furthermore, the pressure cylinders 14 are nevertheless
arranged between said two ports 18, 19, i.e. seen in a direction
parallel to the above mentioned straight line the ports 18, 19 and
the pressure cylinders 14 overlap each other at least
partially.
[0033] During operation, the pressure cylinder 14 is loaded by the
pressure in the high pressure supply port 10. This pressure presses
the piston 17 against the first front plate 7 generating a counter
force pressing the pressure shoe against the drum 2. In this way, a
fluid tight or almost fluid tight connection can be established
between the first port 10 and the working cylinders 4.
[0034] The force with which the pressure shoe 8 is pressed against
the front face of the drum 2 should be sufficient to create a tight
fluid path between the first port 10 and the working cylinders 4.
However, it should not be too large in order to avoid wear and
abrasion. The force can be determined with high accuracy by
dimensioning the pressure cylinder 14 and the piston 17 in an
appropriate manner.
[0035] At the side facing the drum 2, the pressure shoe 8 comprises
two arc-shaped or kidney-shaped openings 21, 22. The area of the
first port 18 is larger than the area of the high pressure
kidney-shaped opening 21 and the area of the second port 19 is
larger than the area of the low pressure kidney-shaped opening 22.
In this way, additional forces are provided pressing the pressure
shoe 8 against the drum 2. According to this dimensioning, in the
high pressure channel 15 an outer pressure area is provided on
which the pressure in the high pressure supply port 18 can act.
This outer pressure area is larger than an inner pressure area on
which hydraulic pressure can act in the opposite direction.
[0036] When the hydraulic pressure exchanger 1 is used as a water
hydraulic machine, the pressure shoe 8 and the drum 2 rest against
each other in a contact area. In this contact area at least the
surfaces of the drum 2 and the pressure shoe 8, respectably, have
different materials, one material being steel and the other
material being a plastic material sliding with slow friction on
steel, in particular a high-resistant thermoplastic plastic
material on the basis of polyaryl etherketones, particularly
polyetheretherketones (PEEK), polyamides, polyacetals,
polyarylethers, polyethylene terephthalates, polyphenylene
sulfides, polysulphones, polyether sulphones, polyether imides,
polyamide imides, polyacrylates, phenol resins, like novolacquer
resins or the like, preferably provided with a filling of glass,
graphite, polytetraflourethylene or carbon, the fillings being
particularly useful as fibers. Such a combination of materials
guarantee a long lifetime duration even in the case water is used
as hydraulic fluid instead of an lubricating oil.
[0037] While the present invention has been illustrated and
described with respect to a particular embodiment thereof, it
should be appreciated by those of ordinary skill in the art that
various modifications to this invention may be made without
departing from the spirit and scope of the present.
* * * * *