U.S. patent application number 14/450397 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 | 20150050177 14/450397 |
Document ID | / |
Family ID | 48985633 |
Filed Date | 2015-02-19 |
United States Patent
Application |
20150050177 |
Kind Code |
A1 |
Sigurdsson; Haraldur |
February 19, 2015 |
HYDRAULIC MACHINE, IN PARTICULAR HYDRAULIC PRESSURE EXCHANGER
Abstract
A hydraulic machine (1) comprising a drum (2) rotatable around a
rotational axis (3), a motor connection for driving said drum (2),
a first front plate arrangement (5) at a first front face of said
drum (2), a second front plate arrangement (5) at a second front
face of said drum (2), said drum (2) comprising a plurality of
cylinders (4), said first front plate arrangement (5) comprising a
first front plate (7), a pressure shoe (8), and first sealing means
(9), said first front plate (7) comprising at least a high pressure
supply port (10). To this end, said pressure shoe (8) comprises at
least a high pressure channel (17) connected to said high pressure
supply port (10) and an outer pressure area (18) loaded by a
pressure in said high pressure supply port (10) in a direction
towards said drum (2), said outer pressure area (18) being larger
than an inner pressure area (19) on a side of said pressure shoe
(8) facing said drum (2).
Inventors: |
Sigurdsson; Haraldur; (Arhus
V, DK) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Danfoss A/S |
Nordborg |
|
DK |
|
|
Family ID: |
48985633 |
Appl. No.: |
14/450397 |
Filed: |
August 4, 2014 |
Current U.S.
Class: |
418/161 |
Current CPC
Class: |
F04F 13/00 20130101;
F04B 9/109 20130101; F04B 1/2007 20130101; F04B 1/20 20130101; F04B
1/24 20130101; F04B 17/03 20130101 |
Class at
Publication: |
418/161 |
International
Class: |
F01C 1/22 20060101
F01C001/22; F01C 21/10 20060101 F01C021/10 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 15, 2013 |
EP |
13180505.3 |
Claims
1. A hydraulic machine comprising a drum rotatable around a
rotational axis, a motor connection for driving said drum, 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, said first front plate comprising at least a port, wherein
said pressure shoe is movable relative to the drum in a direction
of said rotational axis and 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.
2. The pressure exchanger according to claim 1, wherein said
pressure shoe is held unrotatable.
3. The pressure exchanger according to claim 1, wherein said outer
pressure area is arranged within said channel.
4. The pressure exchanger according to claim 3, wherein said
channel comprises a section area decreasing in a direction towards
said drum.
5. The pressure exchanger according to claim 4, wherein said high
pressure channel comprises a circle-shaped inlet on a side facing
said first front plate and a kidney-shaped outlet on a side facing
said drum.
6. The pressure exchanger according to claim 1, wherein a sleeve is
inserted in said high pressure channel in said pressure shoe and in
said high pressure supply port in said first front plate.
7. The pressure exchanger according to claim 6, wherein said sleeve
is fixed in said pressure shoe and movable and sealed in said first
front plate.
8. The pressure exchanger according to claim 1, wherein said first
front plate comprises two ports the centers of which are arranged
on a first straight line and said second front plate arrangement
comprises a second front plate with two ports the centers of which
are arranged on a second straight line, said first straight line
and said second straight line being angularly offset to each
other.
9. The pressure exchanger according to claim 8, wherein at least
one of said front plates comprises a connecting geometry having at
least a first mounting surface in which one of the ports is
arranged, said first mounting surface being arranged under a
predetermined angle relative to the rotational axis of said drum,
said angle being in the range of 10.degree. to 80.degree., in
particular in the range of 30.degree. to 60.degree. and preferably
in the range of 40.degree. to 50.degree..
10. The pressure exchanger 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.
11. The pressure exchanger according to claim 2, wherein said outer
pressure area is arranged within said channel.
12. The pressure exchanger according to claim 2, a sleeve is
inserted in said high pressure channel in said pressure shoe and in
said high pressure supply port in said first front plate.
13. The pressure exchanger according to claim 3, a sleeve is
inserted in said high pressure channel in said pressure shoe and in
said high pressure supply port in said first front plate.
14. The pressure exchanger according to claim 4, a sleeve is
inserted in said high pressure channel in said pressure shoe and in
said high pressure supply port in said first front plate.
15. The pressure exchanger according to claim 5, a sleeve is
inserted in said high pressure channel in said pressure shoe and in
said high pressure supply port in said first front plate.
16. The pressure exchanger according to claim 2, wherein said first
front plate comprises two ports the centers of which are arranged
on a first straight line and said second front plate arrangement
comprises a second front plate with two ports the centers of which
are arranged on a second straight line, said first straight line
and said second straight line being angularly offset to each
other.
17. The pressure exchanger according to claim 3, wherein said first
front plate comprises two ports the centers of which are arranged
on a first straight line and said second front plate arrangement
comprises a second front plate with two ports the centers of which
are arranged on a second straight line, said first straight line
and said second straight line being angularly offset to each
other.
18. The pressure exchanger according to claim 4, wherein said first
front plate comprises two ports the centers of which are arranged
on a first straight line and said second front plate arrangement
comprises a second front plate with two ports the centers of which
are arranged on a second straight line, said first straight line
and said second straight line being angularly offset to each
other.
19. The pressure exchanger according to claim 5, wherein said first
front plate comprises two ports the centers of which are arranged
on a first straight line and said second front plate arrangement
comprises a second front plate with two ports the centers of which
are arranged on a second straight line, said first straight line
and said second straight line being angularly offset to each
other.
20. The pressure exchanger according to claim 6, wherein said first
front plate comprises two ports the centers of which are arranged
on a first straight line and said second front plate arrangement
comprises a second front plate with two ports the centers of which
are arranged on a second straight line, said first straight line
and said second straight line being angularly offset to each other.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] Applicant hereby claims foreign priority benefits under
U.S.C. .sctn.119 from European Patent Application No. EP13180505.3
filed on Aug. 15, 2013, the contents of which are incorporated by
reference herein.
TECHNICAL FIELD
[0002] The invention relates to a hydraulic machine comprising a
drum rotatable about a rotational axis, a motor connection for
driving said drum, a first front plate arrangement at a first front
face of said drum, a second front plate arrangement at a second
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, said first front plate comprising at least a
port.
BACKGROUND
[0003] Such a hydraulic machine in the form of a hydraulic pressure
exchanger is known from EP 1 508 361 A 1. A pressure exchanger of
this kind can be used for example in a reverse osmosis system in
which the liquid is pumped through a membrane under a rather high
pressure. The liquid not passing the membrane is supplied to the
high pressure supply port of the pressure exchanger. This high
pressure is transferred to a fluid being supplied to the second
front face of the drum. A piston in each cylinder is used to affect
the pressure transfer. When a cylinder is in fluid connection with
the high pressure supply port high pressure fluid enters this
cylinder and shifts the piston to the other side, thereby
transferring the high pressure to the liquid on the other side. The
drum rotates. After a predeterment rotational angle this cylinder
comes in contact to a low pressure supply port in which fresh
liquid under a lower pressure fills the cylinder shifting the
piston back again.
[0004] The path between the high pressure supply port (and all
other ports as well) and the cylinder must be as tight as possible
to avoid leakage. In the known case each 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 shoes 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 by a hydraulic machine as mentioned
above in that said pressure shoe is movable relative to the drum in
a direction of said rotational axis and 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.
[0007] The term "drum" is used for the purpose of explanation only.
It is not necessary that the "drum" is cylindrical body. The term
"drum" just means a carrier of the cylinders mentioned above which
is rotatable about the rotational axis. Furthermore, the cylinders
can have a cross section which may be circular or may have any
other form. Furthermore, the cylinders may be straight or curved in
longitudinal direction. The pressure shoe is pressed against the
front face of the drum by means of the pressure at the high
pressure supply port. A pressure shoe is necessary only on one
side. The other side of the drum rests against the second front
plate arrangement. In this way equal pressures on both front faces
of the drum can be realised. This leads automatically to an
equilibrium of forces over the drum (independent of pressure).
[0008] Preferably said pressure shoe is held unrotatable. In this
way the first front face of the drum rests against the pressure
shoe and friction is generated between this front face and the
pressure shoe only. This reduces wear. Since the pressure shoe is
not rotating, the number of bushings needed is dramatically
reduced. Only one bushing is necessary for the high pressure port
connecting said first front plate and said pressure shoe. A second
bushing may be necessary between the first front plate and the
pressure shoe in a region of another port. The pressure shoe can be
moved in the direction of the rotational axis only, wherein such
movement is very small.
[0009] 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.
[0010] Preferably said channel comprises a section area decreasing
in a direction towards said drum. The decreasing section area
automatically provides the outer pressure area on which the
pressure acts at the high pressure supply port.
[0011] In a preferred embodiment said high pressure channel
comprises a circle-shaped inlet on a side facing said first front
plate and a kidney-shaped outlet on a side facing said drum. The
circle-shaped inlet comprises an area which is larger than the
kidney-shaped outlet. The difference between the area of the
circle-shaped inlet and the kidney-shaped outlet is the area on
which the pressure at the high pressure supply port acts in a
direction towards the drum.
[0012] Preferably a sleeve is inserted in said high pressure
channel in said pressure shoe and in said port in said first front
plate. This sleeve makes a fluid tight path between the first front
plate and the pressure shoe. When a circle-shaped inlet is used it
is rather simple to use a cylindrical sleeve.
[0013] In a preferred embodiment said sleeve is fixed in said
pressure shoe and movable and sealed in said first front plate. The
movement is restricted to the axial direction and allows to
establish sufficient pressure contact between the pressure shoe and
the front face of the drum.
[0014] Preferably said first front plate comprises two ports the
centres of which are arranged on a first straight line and said
second front plate arrangement comprises a second front plate with
two ports the centres of which are arranged on a second straight
line, said first straight line and said second straight line being
angularly offset to each other. In this way it is possible to have
connecting lines on one side extending in a first direction and
connection lines at the other side extending in a second direction
which is angularly offset to the first direction. This gives a
greater freedom in the arrangement of connecting lines.
[0015] Preferably one of said front plates comprises a connecting
geometry having at least a first mounting surface in which one of
the ports is arranged, said first mounting surface being arranged
under a predetermined angle relative to the rotational axis of said
drum, said angle being in the range of 10.degree. to 80.degree., in
particular in the range of 30.degree. to 60.degree., and preferably
in the range of 40.degree. of 50.degree.. When the mounting surface
is arranged under an angle relative to the rotational axis and
relative to a plane which is perpendicular to the rotational axis
there is a larger area available for connecting a line to the
mounting surface.
[0016] 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 hydraulic machine
and advantages be used as a water hydraulic device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] A preferred example of the invention will now be described
in more detail with reference to the drawing, wherein
[0018] FIG. 1 is a schematic longitudinal section of a hydraulic
machine,
[0019] FIG. 2 is an enlarged detail II of FIG. 1,
[0020] FIG. 3 is a perspective view of the hydraulic machine,
[0021] FIG. 4 is a view of a pressure shoe seen from the
inside,
[0022] FIG. 5 is a section V-V according to FIG. 6,
[0023] FIG. 6 is a view of a pressure shoe seen from the outside
and
[0024] FIG. 7 is a perspective view of the pressure shoe.
[0025] FIG. 1 shows a hydraulic machine 1 in form of a hydraulic
pressure exchanger in a schematically longitudinal section.
However, hydraulic machine can also be, for example, a pump, a
motor, an energy converter, an amplifier etc.
[0026] The hydraulic machine 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 cylinders 4. The
cylinders 4 can be considered as channels. It is not necessary that
they are of circular cross section.
[0027] A first front plate arrangement 5 is arranged at a first
front face of the drum 2. A second front plate arrangement 6 is
arranged at a second front face of the drum 2 which is opposite of
the first front face of the drum 2. The first front plate
arrangement 5 comprises a first front plate 7 and a pressure shoe
8. Further more, sealing means 9 are provided at the first front
plate arrangement 5.
[0028] The first front plate 7 comprises a first port 10 and a
second port 11. The first port 10 may be a high pressure supply
port and the second port 11 may be a low pressure return port.
However, other pressures and other flow directions may be
possible.
[0029] 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.
[0030] 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 and be
connected to a motor (not shown).
[0031] 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. A bushing or sleeve 14 is inserted into an
inlet 15 (FIG. 2) of the pressure shoe 8. This inlet 15 has the
form of a circle, so that the sleeve 14 can be made as a hollow
cylinder. The sleeve 14 is inserted as well in the first port 10.
Here, the sealing means 19 are used to form a fluid tight
connection between the first port 10 and the inlet 15 of the
pressure shoe 8.
[0032] As can been seen in FIG. 4 the pressure shoe 8 shows at the
side opposite to the inlet 15 an outlet 16 having the form of a
kidney. The side of the pressure shoe 8 in which the kidney-shaped
outlet 16 is arranged faces the drum 2. The kidney-shaped outlet 16
is arranged on the same radius as the cylinders 4. Therefore, the
openings of the cylinders 4 come in overlapping relation with the
kidney-shaped outlet 16 during a rotation of the drum. As can be
seen in FIG. 4-6, the pressure shoe 8 comprises a high pressure
channel 17 between the first port 10 and the drum 2.
[0033] A pressure area 18, which is termed "outer pressure area",
is arranged in this channel 17. The outer pressure area is larger
than an inner pressure area 19 on a side of said pressure shoe 8
facing said drum 2.
[0034] Due to this construction the force on the pressure shoe 8
acting in a direction towards the drum 2 is larger than the force
acting in the opposite direction so that the pressure shoe 8 is
firmly pressed against the drum 2. The effect is that a pressure
tight connection is formed between the high pressure channel 17 and
the cylinders 4 overlapping the kidney-shaped outlet 16. The force
acting in direction towards the drum 2 is a product of the pressure
in the first port 10 and the outer pressure area 18. The force
acting in the opposite direction is the product of the same
pressure and the slightly smaller inner pressure area 19.
[0035] Due to this construction only one pressure shoe on the first
front face of the drum 2 is necessary. The force pressing the
pressure shoe 8 against the drum 2 also presses the drum 2 against
the second front plate 13 so that a liquid tight seal is formed
between the drum 2 and the second front plate 13 as well.
[0036] In this way an equilibrium of forces is formed over the drum
2 (independent of pressure). By adjusting the sizes of the outer
pressure area 18 and the inner pressure area 19 the forces acting
between the pressure shoe 8 and the drum 2 or the drum 2 and the
second front plate 13 can be adjusted very accurately.
[0037] Due to the sleeve 14, the pressure shoe 8 can be moved in
axial direction, i.e. parallel to the axis 3. Such a movement is
necessary only to press the pressure shoe 8 against the drum 2.
Therefore, such a movement can be kept very small.
[0038] As can been seen in FIG. 3, the first front plate 7
comprises two ports (only the second port 11 is visible). These
ports are arranged on a first straight line.
[0039] The second front plate 13 comprises two ports as well, i.e.
a first port 20 and a second port (not visible). The last two ports
are arranged on a straight line as well. As can be seen in FIG. 3,
these two straight lines are angularly offset to each other. In the
embodiment shown in FIG. 3, the first straight line is arranged
vertically and the second straight line is arranged on the angle of
45.degree. relative to the vertical direction.
[0040] As can be seen in FIGS. 1 and 3, the first front plate 7
comprises a connecting geometry having at least a mounting surface
21, 22. The mounting surfaces 21, 22 are arranged under a
predetermined angle relative to the rotational axis 3 of the drum
2. In the present case, this angle is approximately 45.degree..
However, it can be in the range of 10.degree. to 80.degree., and
particular in the range of 30.degree. to 60.degree. and preferably
in the range of 40.degree. to 50.degree..
[0041] When the hydraulic machine 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, respectively, have different
materials, one material is steel and the other material is a
plastic material, said plastic material having a low friction
coefficient on steel. This plastic material is 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. 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.
[0042] 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.
* * * * *