U.S. patent application number 10/908295 was filed with the patent office on 2005-08-25 for hydraulic system arranged between a first and a second marine propulsion device.
This patent application is currently assigned to AB VOLVO PENTA. Invention is credited to ASBERG, Mikael, HEDLUND, Benny.
Application Number | 20050186862 10/908295 |
Document ID | / |
Family ID | 34864978 |
Filed Date | 2005-08-25 |
United States Patent
Application |
20050186862 |
Kind Code |
A1 |
HEDLUND, Benny ; et
al. |
August 25, 2005 |
HYDRAULIC SYSTEM ARRANGED BETWEEN A FIRST AND A SECOND MARINE
PROPULSION DEVICE
Abstract
System and method for providing a hydraulic system (1) arranged
between a first marine propulsion device (2, 42) and a second
marine propulsion device (3, 43). Each propulsion device is
arranged to rotate about a respective axis (6, 7, 46, 47) at a
distance from one another. The system (1) includes a first
hydraulic piston-cylinder device (8, 50) and a second hydraulic
piston-cylinder device (13, 55) arranged between the second
propulsion device (2, 3, 42, 43) and an element (12, 17, 54, 59)
fixed in relation to the axis (6, 7, 46, 47). Connecting the
piston-cylinder devices (8, 13, 50, 55) to one another via a first
hydraulic circuit (18, 60) and a second hydraulic circuit (19, 61)
leads to rotation of one propulsion device (2, 3, 42, 43) resulting
in rotation of the other propulsion device (2, 3, 42, 43). The
method and arrangement afford a tie bar function.
Inventors: |
HEDLUND, Benny; (Hono,
SE) ; ASBERG, Mikael; (Torslanda, SE) |
Correspondence
Address: |
NOVAK DRUCE & QUIGG, LLP
1300 EYE STREET NW
SUITE 400 EAST
WASHINGTON
DC
20005
US
|
Assignee: |
AB VOLVO PENTA
S-405 08
Goteborg
SE
|
Family ID: |
34864978 |
Appl. No.: |
10/908295 |
Filed: |
May 5, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10908295 |
May 5, 2005 |
|
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PCT/SE03/01482 |
Sep 24, 2003 |
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10908295 |
May 5, 2005 |
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PCT/SE03/01205 |
Jul 14, 2003 |
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Current U.S.
Class: |
440/53 |
Current CPC
Class: |
B63H 20/08 20130101;
B63H 25/22 20130101; B63H 5/125 20130101 |
Class at
Publication: |
440/053 |
International
Class: |
B63H 020/08 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 6, 2002 |
SE |
0203280-3 |
Jul 19, 2002 |
SE |
0202268-9 |
Claims
What is claimed is:
1. A hydraulic system (1) arranged between a first marine
propulsion device (2, 42) and a second marine propulsion device (3,
43), each of which are arranged to rotate about spaced-apart,
respective axis (6,7, 46,47), said hydraulic system (1) comprising:
a first hydraulic piston-cylinder device (8,50) having a cylinder
chamber (9,10, 51,52) on each side of a piston (11, 53), said first
hydraulic piston-cylinder device (8,50) being arranged between the
first propulsion device (2, 42) and an element (12, 54) fixed in
relation to said axis (6,7, 46,47), and a second hydraulic
piston-cylinder device (13, 55) having a cylinder chamber (14,15,
56,57) on each side of said piston (16,58), said second hydraulic
piston-cylinder device (13, 55) being arranged between the second
propulsion device (3,43) and an element (17,59) fixed in relation
to said axis (6,7, 46,47); and a first hydraulic circuit (18,60)
and a second hydraulic circuit (19,61) configured to connect the
cylinder chambers (9,10, 51,52) in said first piston-cylinder
device (8,50) to the cylinder chambers (14,15, 56,57) in said
second piston-cylinder device (13,55) in order that rotation of one
propulsion device (2,3, 42,43) results in rotation of the other
propulsion device (2,3, 42,43).
2. The hydraulic system (1) as recited in claim 1, wherein said
first hydraulic circuit (18,60) and said second hydraulic circuit
(19,61) are connected to the cylinder chambers (9,10, 14,15, 51,52,
56,57) so that a pressure increase occurs in at least one of said
circuits (18,19, 60,61) when rotating the one propulsion device
(2,3, 42,43).
3. The hydraulic system (1) as recited in claim 1, wherein at least
one of said hydraulic circuits (18,19, 60,61) contains a hydraulic
accumulator (33,62) for achieving reloading in at least one of said
first and said second hydraulic piston-cylinder devices (8,13,
50,55).
4. The hydraulic system (1) as recited in claim 1, wherein a first
hydraulic pump (36,49) is connected to the first hydraulic circuit
(18, 60) and the second hydraulic circuit (19,61) in order to
permit rotation of one propulsion device (2,3, 42,43) relative to
the other propulsion device (2,3, 42,43).
5. The hydraulic system (1) as recited in claim 1, wherein said
first piston-cylinder device (8,50) and said second piston-cylinder
device (13,55) are arranged on opposite sides of each propulsion
device (2,3, 42,43) and hydraulically interconnected so that
rotation of one propulsion device (2,3, 42,43) in one direction
results in compression of the first piston-cylinder device (8,50)
and simultaneous expansion of the second piston cylinder device
(13,55) thereby rotating the other propulsion device (2,3, 42,43)
in the same direction.
6. The hydraulic system (1) as recited in claim 1, wherein at least
one additional piston-cylinder device (31,32) is arranged between
one propulsion device (2,3) and an element fixed in relation to
said axis (6,7), the piston-cylinder device (31,32) being connected
to a hydraulic pump (21) driven by a manual drive member (20) for
controlling the propulsion device (2,3).
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application is a continuation patent application
of International Application No. PCT/SE03/01205 filed 14 Jul. 2003
which was published in English pursuant to Article 21(2) of the
Patent Cooperation Treaty, and which claims priority to Swedish
Application No. 0202268-9 filed 19 Jul. 2002. Said applications are
expressly incorporated herein by reference in their entireties.
TECHNICAL FIELD
[0002] The present invention relates to a hydraulic system which is
arranged between a first and a second marine propulsion device, and
each of which are arranged so that they can rotate about a
respective axis at a distance from one another. A first hydraulic
piston-cylinder device is included that has a cylinder chamber on
each side of a piston and that is arranged between the first
propulsion device and an element fixed in relation to the axis of
rotation of that propulsion device. There is also a second
hydraulic piston-cylinder device having a cylinder chamber on each
side of a piston and which is arranged between the second
propulsion device and an element fixed in relation to the axis
about which it rotates.
BACKGROUND OF THE INVENTION
[0003] One example of marine propulsion devices of the
aforementioned type is a propeller rig in a boat propeller drive.
The boat propeller drive in this case includes a shield bolted to
the stern of the boat and in which the propeller rig is pivotally
suspended in order to allow the propeller rig to be rotated firstly
about a vertical axis for steering the boat and secondly about a
horizontal axis for trimming and tilting of the propeller rig. In
order to achieve such rotation, two hydraulic cylinders are usually
arranged between the shield and the propeller rig, more
specifically one on each side of the propeller rig.
[0004] Marine propulsion devices may also be designed with a
propeller rig that extends through the bottom of a boat, preferably
in the stern part of the boat, the propeller rig being suspended so
that it can rotate about a vertical axis for steering the boat.
[0005] In the case of twin marine propulsion devices as described
above, a tie bar is generally used between the propulsion devices
in order to ensure that the angle of the devices relative to one
another is kept within a desired interval under varying operating
conditions, such as running with a variously laden boat, running in
high seas or the like, but each of which gives rise to varying
hydrodynamic forces. Said tie bar is in this case arranged either
between the propulsion devices, outside the hull, or inside the
hull between lever arms connected to each propulsion device. One
disadvantage with the aforementioned solution is that the tie bar
does not allow for just one propeller rig to be raised, for example
after grounding in which the rig has been damaged, leaving the
other undamaged propeller rig in operation. A further disadvantage
with having a tie bar between the propeller rigs is that it is
relatively exposed to being damaged by external objects when, for
example, docking in a harbor. A further disadvantage of the latter
solution is that the tie bar with associated lever arms takes up
space in the boat's engine compartment where space is usually very
limited.
[0006] A further particular disadvantage that arises in boats of
the multiple hull type, such as catamarans, is that the tie bar is
relatively long and unprotected and therefore even more exposed to
being damaged by external objects. Moreover, the relative movements
between the hulls that usually occur on boats of this type results
in that the angle of the propulsion devices relative to one another
varies to an unacceptable degree.
[0007] U.S. Pat. No. 4,778,418 discloses a tie bar arrangement
between two boat propeller drives suspended from the stern of a
boat. The drives include a propeller rig which is pivotally
suspended in order to allow the propeller rig to be rotated firstly
about a vertical axis for steering the boat and secondly about a
horizontal axis for trimming and tilting of the propeller rig.
Trimming or tilting is achieved by means of two hydraulic cylinders
between the stern of the boat and the propeller rig; more
specifically, one on each side of the propeller rig. The tie bar
arrangement comprises (includes, but is not necessarily limited to)
a piston-cylinder device arranged between the propeller rigs and
designed to connect the propeller rigs rigidly together under
normal operating conditions and to be capable of extension when
tilting one of the propeller rigs in order thereby to allow the
boat to be powered by just one propeller rig/motor. For this
purpose the piston-cylinder device is designed, when rigid
connection is required, to assume a limit position by pneumatic or
hydraulic means or with the aid of a helical coil spring.
[0008] As with the aforementioned tie bar, one disadvantage with
the tie bar arrangement between the propeller rigs is that the
arrangement is relatively exposed to being damaged by external
objects when, for example, docking in a harbor. Another
disadvantage is that the arrangement is only capable of assuming a
predefined rigid position and a free position and thus does not
permit angular adjustment of the boat propeller drives relative to
one another while the boat is running.
SUMMARY OF THE INVENTION
[0009] An object of the present invention is to provide a hydraulic
system having a tie bar function between a first and a second
marine propulsion device, which are each arranged so that they can
rotate about a respective axis at a distance from one another,
which is both relatively unsusceptible to being damaged by external
objects and which takes up little, if any, space inside the hull of
a boat.
[0010] The invention relates to a hydraulic system arranged between
a first and a second marine propulsion device which are each
arranged so that they can rotate about a respective axis at a
distance from one another. The hydraulic system comprises a first
hydraulic piston-cylinder device having a cylinder chamber on each
side of said piston, arranged between said first propulsion device
and an element fixed in relation to said axis. A second hydraulic
piston-cylinder device is also included and which has a cylinder
chamber on each side of that piston, arranged between said second
propulsion device and an element fixed in rotation to said axis.
Connecting the cylinder chambers in the first piston-cylinder
device to the cylinder chambers in the second piston-cylinder
device via a first and a second hydraulic circuit leads to the
rotation of one propulsion device resulting in rotation of the
other propulsion device. This provides a tie bar function which
takes up little, if any space inside the hull of a boat, and at the
same time requires no external arrangement between the propulsion
devices which is relatively exposed to being damaged by external
objects, in order to obtain said function.
[0011] Connecting the cylinder chambers in the first
piston-cylinder device to the cylinder chambers in the second
piston-cylinder device so that an increase in pressure occurs in
one of said hydraulic circuits when rotating the one propulsion
device, causes the system to become rigid while avoiding the risk
of gas formation, due to a fall in pressure, in the hydraulic oil
enclosed in the system.
[0012] According to a preferred embodiment, at least one of said
hydraulic circuits is connected to a hydraulic accumulator in order
to permit reloading of the system. Depending on the selected
pressure level in the accumulator, a very rigid system with
simultaneous elimination of any risk of gas formation in the
hydraulic oil can be achieved, or alternatively a system with a
built in elasticity.
[0013] According to a further preferred embodiment, a hydraulic
pump is connected to the first and the second hydraulic circuit in
order to allow hydraulic oil to be pumped from one circuit to the
other. This allows one propulsion device to be rotated in relation
to the other, even while the boat is running, with a view not only
to adjusting their precise angular position relative to one
another, depending on for example the current speed of the boat,
but also in certain types of operation, to rotating one propulsion
device more than the other, for example when turning at high
speed.
[0014] According to an especially preferred embodiment, the first
and second piston-cylinder devices are arranged on opposite sides
of respective propulsion devices and so that rotating one
propulsion device in one direction results in compression of the
first piston-cylinder device and simultaneous expansion of the
other piston-cylinder device thereby rotating the other propulsion
device in the same direction.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The invention will be described below with reference to
preferred examples or embodiments and to the accompanying drawings
in which:
[0016] FIG. 1 shows a schematic representation of a hydraulic
system having a tie bar function on two boat propeller drives;
[0017] FIG. 2 shows a schematic view that is in partial phantom,
and which represents two boat propeller drives pivotally suspended
on the stern of a boat; and
[0018] FIG. 3 shows a schematic view that is in partial phantom,
and which represents the hydraulic system on two boat propeller
drives designed with a propeller rig that extends through the
bottom of a boat.
DETAILED DESCRIPTION
[0019] FIG. 1 shows a schematic representation of a hydraulic
system 1 arranged between a first marine propulsion device 2 and a
second marine propulsion device 3 of the propeller rig type in a
boat propeller drive. Each are arranged on the stern 5 of a boat 4
so that they can each rotate about a respective axis 6,7 at a
distance from one another. The hydraulic system 1 comprises a first
hydraulic piston-cylinder device 8, having a cylinder chamber 9,10
on each side of said piston 11, and which is arranged between the
first propulsion device 2 and an element 12 fixed in relation to
that axis 6 and stern 5. A second hydraulic piston-cylinder device
13 is also provided and which has a cylinder chamber 14,15 on each
side of said piston 16, arranged between said second propulsion
device 3 and an element 17 fixed in relation to said axis 7 and
stern 5. Connecting the cylinder chambers 9,10 in the first
piston-cylinder device 8 to the cylinder chambers 14,15 in the
second piston-cylinder device 13, via a first hydraulic circuit 18
and a second hydraulic circuit 19, leads to rotation of one
propulsion device 2 resulting in rotation of the other propulsion
device 3.
[0020] FIG. 1 further shows a steering wheel 20 connected to a
hydraulic pump 21, which is in turn connected to a hydraulic valve
22, a so-called control valve, which is in addition connected
firstly to a pressure pipe (not shown) from a servo pump driven by
a drive motor (not shown) and secondly to an oil reservoir (not
shown). The hydraulic valve 22 is further connected via hydraulic
pipes 23,24, 25,26 to the cylinder chambers 27,28, 29,30 in two
piston-cylinder devices 31,32, one on each propulsion device
2,3.
[0021] The function of the hydraulic control system described
above, including the tie bar function, is as follows: Turning the
steering wheel 20 to starboard causes the hydraulic pump 21 to pump
oil to the hydraulic valve 22 in which a slide (not shown) is
displaced for pumping oil to cylinder chambers 27,30 of the
piston-cylinder devices 31,32, which causes the piston-cylinder
device 31 to be expanded, thereby rotating the first propulsion
device 2 about the axis 6, to the right in FIG. 1, while the
piston-cylinder device 32 is compressed thereby rotating the second
propulsion device 3 about the axis 7, to the right in the same
Figure. If, due to longer hydraulic pipes, for example, the
pressure build-up in the piston-cylinder device 32 on the second
propulsion device 3 occurs somewhat after the pressure build-up in
the piston-cylinder device 31 on the first propulsion device 2, a
pressure build-up occurs in the cylinder chamber 9 in the
piston-cylinder device 8, which is transmitted via the second
hydraulic circuit 19 to the cylinder chamber 14 in the
piston-cylinder device 13 which ensures that both propulsion
devices 2,3 are rotated to the same extent.
[0022] In the embodiment shown in FIG. 1, a hydraulic accumulator
33 is also connected to the second hydraulic circuit 19 to achieve
reloading of the hydraulic system 1 which, depending on the
selected pressure level in the accumulator 33, provides a tie bar
function which is very rigid and in which there is, in principle,
no risk of any gas formation in the hydraulic oil, or
alternatively, a tie bar function with a built in elasticity.
[0023] In FIG. 1, the reference numeral 34 denotes a monitor device
which is arranged in proximity to the steering wheel 20 and is
electrically connected to an electronic control unit 35. The
control unit 35 is in turn electrically connected to the hydraulic
valve 22 and to a hydraulic pump 36 which is designed to pump oil
between the first hydraulic circuit 18 and the second hydraulic
circuit 19. The control unit 35 is at the same time designed to
control the hydraulic valve 22 and the hydraulic pump 36 as a
function of an input signal from the monitor device 34 so that the
propulsion devices 2,3 are turned independently of one another,
both for adjustment of the precise angle of the propulsion devices
relative to one another and for rotating just one propulsion device
when maneuvering for example in harbor or at high speed.
[0024] FIG. 2 shows, in more detail and partially in phantom, the
boat propeller drives shown in FIG. 1 fitted to the stern 5 of the
boat 4 with inboard engines 37,38. The boat propeller drives
comprise shields 39,40 which are bolted to the stern 5 and in which
the propeller rigs 2,3 are pivotally suspended in order to allow
the rigs 2,3 to be rotated firstly about vertical axes 6,7 for
steering the boat 4 and secondly about a horizontal axis 41 for
trimming and tilting of the propeller rigs 2,3. Also shown is the
one piston-cylinder device 31 for steering the boat 4 and the one
piston-cylinder device 13 which forms part of the tie bar function
of the hydraulic system 1, the other two piston-cylinder devices
8,32 being partially hidden behind the propeller rigs 2,3.
[0025] FIG. 3 shows an alternative embodiment of the marine
propulsion device designed with a propeller rig 42,43 which extends
through the bottom 44 of a boat 45, more specifically in the stern
part of the boat, the propeller rigs 42,43 being suspended so that
they can rotate about vertical axes 46,47 for steering the boat 45.
The propeller rigs 42,43 are rotated by means of electric motors
(not shown) which are controlled by an electrical control unit 48.
The control unit 48 is furthermore designed to control a hydraulic
pump 49, in a manner as described above, so that the propulsion
devices 42,43 can be turned independently of one another, both for
adjustment of the precise angle of the propulsion devices 42,43
relative to one another and for rotating just one propulsion device
when maneuvering for example in harbor or at high speed.
[0026] In a manner corresponding to that described above, a first
hydraulic piston-cylinder device 50, having a cylinder chamber
51,52 on each side of said piston 53, is arranged between the first
propulsion device 42 and an element 54 fixed in relation to said
axis, and a second hydraulic piston-cylinder device 55, having a
cylinder chamber 56,57 on each side of said piston 58, is arranged
between said second propulsion device 43 and an element 59 fixed in
relation to said axis 47. Connecting the cylinder chambers 51,52 in
the first piston-cylinder device 50 to the cylinder chambers 56,57
in the second piston-cylinder device 55 via a first hydraulic
circuit 60 and a second hydraulic circuit 61 leads to that rotating
of one propulsion device 42 results in rotation of the other
propulsion device 43.
[0027] In one embodiment shown in FIG. 3, a hydraulic accumulator
62 is connected to the second hydraulic circuit 61 in order to
provide reloading of the hydraulic system 1 which, depending on the
selected pressure level in the accumulator 62, provides a tie bar
function which is very rigid and in which there is, in principle,
no risk of any gas formation in the hydraulic oil, or alternatively
a tie bar function with a built in elasticity.
[0028] The invention is not limited to the exemplary embodiments
described above and shown in the figures, but lends itself to
variation within the scope of the patent claims. For example,
hydraulic accumulators may be connected to both of the hydraulic
circuits.
* * * * *