U.S. patent application number 09/730720 was filed with the patent office on 2002-07-25 for watercraft hydraulic apparatus.
Invention is credited to Bland, Gerald Francis, Ferguson, Arthur R., Johnson, Stephen R..
Application Number | 20020098747 09/730720 |
Document ID | / |
Family ID | 24936550 |
Filed Date | 2002-07-25 |
United States Patent
Application |
20020098747 |
Kind Code |
A1 |
Bland, Gerald Francis ; et
al. |
July 25, 2002 |
WATERCRAFT HYDRAULIC APPARATUS
Abstract
A common fluid pressure supply apparatus (40) for a watercraft
(10). A fluid interconnection apparatus interconnects the hydraulic
fluid circuits operating the hydraulic transmission (18), power
steering (30), and tilt-trim function (34) for an inboard/outboard
stem drive (20) watercraft. A single fill vessel (104), oil cooler
(82), and filter (126) are utilized for the common fluid pressure
supply apparatus. The fluid interconnection apparatus may include
the transmission housing reservoir (42).
Inventors: |
Bland, Gerald Francis;
(Glenview, IL) ; Ferguson, Arthur R.; (Glenview,
IL) ; Johnson, Stephen R.; (Waukegan, IL) |
Correspondence
Address: |
COOK & FRANKE S.C. (OMC)
660 EAST MASON STREET
MILWAUKEE
WI
53202
US
|
Family ID: |
24936550 |
Appl. No.: |
09/730720 |
Filed: |
December 6, 2000 |
Current U.S.
Class: |
440/5 |
Current CPC
Class: |
B63H 20/10 20130101 |
Class at
Publication: |
440/5 |
International
Class: |
B63H 021/12 |
Claims
We claim as our invention:
1. A fluid pressure supply apparatus for a watercraft comprising: a
first reservoir for containing hydraulic fluid; a transmission pump
having an inlet in fluid communication with the first reservoir and
an outlet for providing pressurized hydraulic fluid to a hydraulic
transmission, and a fluid return path between the hydraulic
transmission and the first reservoir; a second reservoir having an
inlet in fluid communication with the first reservoir; a power
steering pump having an inlet in fluid communication with the
second reservoir and an outlet for providing pressurized hydraulic
fluid to a power steering apparatus, and a fluid return path
between the power steering apparatus and the first reservoir; a
third reservoir having an inlet in fluid communication with the
first reservoir; a trim pump having an inlet in fluid communication
with the third reservoir and an outlet for providing pressurized
hydraulic fluid to a trim apparatus, and a fluid return path
between the trim apparatus and one of the third reservoir and the
first reservoir.
2. The fluid pressure supply apparatus of claim 1, further
comprising a cooler in fluid communication with the power steering
pump outlet for removing heat from the hydraulic fluid.
3. The fluid pressure supply apparatus of claim 1, further
comprising a fill vessel having a low point outlet in fluid
communication with each of the second reservoir and the third
reservoir, and having a high point outlet in fluid communication
with each of the first reservoir, the second reservoir and the
third reservoir.
4. The fluid pressure supply apparatus of claim 3 further
comprising: a cooler in fluid communication with the power steering
pump outlet for removing heat from the hydraulic fluid; and the
fill vessel high point outlet being in fluid communication with the
cooler.
5. The fluid pressure supply apparatus of claim 3 further
comprising a level sensor adapted to provide a signal corresponding
to the level of hydraulic fluid contained in the fill vessel.
6. A watercraft comprising: a hull having a transom; an engine
disposed in the hull; a hydraulic transmission connected to the
engine; a stem drive apparatus connected to the transmission and
sealingly disposed through an opening formed in the transom; a
propeller connected to the stem drive apparatus; a steering
apparatus connected to the stern drive apparatus for moving the
propeller about a vertical axis for steering the watercraft; a trim
apparatus connected to the stern drive apparatus for pivoting the
propeller relative to the hull; the transmission further comprising
a first reservoir for containing hydraulic fluid, and a
transmission pump having an inlet in fluid communication with the
first reservoir and an outlet for providing pressurized hydraulic
fluid to a transmission valve, and a fluid return path between the
transmission valve and the transmission housing reservoir; a second
reservoir having an inlet in fluid communication with the first
reservoir; the power steering apparatus further comprising a power
steering pump having an inlet in fluid communication with the
second reservoir and an outlet for providing pressurized hydraulic
fluid to a power steering cylinder valve, and a fluid return path
between the power steering cylinder valve and the first reservoir;
a third reservoir having an inlet in fluid communication with the
first reservoir; a trim pump having an inlet in fluid communication
with the third reservoir and an outlet for providing pressurized
hydraulic fluid to a trim cylinder, and a fluid return path between
the trim cylinder and one of the third reservoir and the first
reservoir,
7. The watercraft of claim 6 wherein the power steering pump is
powered by a mechanical connection to the engine.
8. The watercraft of claim 6 wherein the power steering pump is
powered by an electric motor.
9. A marine power unit comprising: an engine; a hydraulic
transmission connected to the engine; a stern drive apparatus
connected to the transmission; a propeller connected to the stern
drive apparatus; a steering apparatus connected to the stern drive
apparatus for rotating the propeller about a vertical axis for
steering the watercraft; a trim apparatus connected to the stem
drive apparatus for raising and lowering the propeller about a
horizontal axis; the transmission further comprising a first
reservoir for containing hydraulic fluid, and a transmission pump
having an inlet in fluid communication with the first reservoir and
an outlet for providing pressurized hydraulic fluid to a
transmission valve, and a fluid return path between the
transmission valve and the first reservoir; a second reservoir
having an inlet in fluid communication with the first reservoir;
the steering apparatus further comprising a power steering pump
having an inlet in fluid communication with the second reservoir
and an outlet for providing pressurized hydraulic fluid to a power
steering cylinder valve, and a fluid return path between the power
steering cylinder valve and the first reservoir; a third reservoir
having an inlet in fluid communication with the first reservoir; a
trim pump having an inlet in fluid communication with the third
reservoir and an outlet for providing pressurized hydraulic fluid
to a trim cylinder, and a fluid return path between the trim
cylinder and one of the third reservoir and the first
reservoir.
10. A marine power unit comprising: an engine; a hydraulic
transmission connected to the engine; a stem drive apparatus
connected to the transmission; a propeller connected to the stern
drive apparatus; a steering apparatus connected to the stern drive
apparatus for rotating the propeller about a vertical axis for
steering the watercraft; a trim apparatus connected to the stern
drive apparatus for pivoting the propeller about a horizontal axis;
the transmission further comprising a first reservoir for
containing hydraulic fluid, and a transmission pump having an inlet
in fluid communication with the first reservoir and an outlet for
providing pressurized hydraulic fluid to a transmission valve, and
a fluid return path between the transmission valve and the first
reservoir; the steering apparatus further comprising a power
steering pump having an inlet in fluid communication with the first
reservoir and an outlet for providing pressurized hydraulic fluid
to a power steering cylinder valve, and a fluid return path between
the power steering cylinder valve and the first reservoir; a trim
pump having an inlet in fluid communication with the first
reservoir and an outlet for providing pressurized hydraulic fluid
to a trim cylinder, and a fluid return path between the trim
cylinder and the first reservoir.
11. In a water craft having a plurality of hydraulic circuits for
providing pressurized hydraulic fluid to a plurality of hydraulic
devices, a fluid interconnection apparatus in fluid communication
with each of the plurality of hydraulic circuits for providing an
exchange of hydraulic fluid among the plurality of hydraulic
circuits.
12. The apparatus of claim 11 wherein the fluid interconnection
apparatus comprises a transmission housing.
13. The apparatus of claim 11 further comprising a fluid
conditioning device for conditioning the hydraulic fluid exchanged
among the plurality of hydraulic circuits.
14. The apparatus of claim 13 wherein the fluid conditioning device
comprises a cooler.
15. The apparatus of claim 13 wherein the fluid conditioning device
comprises a filter.
16. The apparatus of claim 1 1 further comprising a common fill
vessel in fluid communication with each of the plurality of
hydraulic circuits.
17. The apparatus of claim 16 further comprising a sensor adapted
to provide a signal responsive to a level of hydraulic fluid in the
common fill vessel.
18. A hydraulic circuit comprising: a means for providing
pressurized hydraulic fluid to a tilt-trim device; a means for
providing pressurized hydraulic fluid to a power steering device;
and a common reservoir in fluid communication with both the means
for providing pressurized hydraulic fluid to a tilt-trim device and
the means for providing pressurized hydraulic fluid to a power
steering device for providing a volume of hydraulic fluid for use
in the tilt-trim device and the power steering device.
19. The hydraulic circuit of claim 18 further comprising a means
for providing pressurized hydraulic fluid to a transmission device
in fluid communication with the common reservoir.
20. The hydraulic circuit of claim 18 further comprising a fill
vessel disposed at a high point in the hydraulic circuit and in
fluid communication with the reservoir.
21. The hydraulic circuit of claim 18 further comprising a means
for cooling the hydraulic fluid in the reservoir.
22. The hydraulic circuit of claim 18 further comprising a means
for filtering the hydraulic fluid in the reservoir.
23. A pressurized fluid supply apparatus for a water craft
comprising: a reservoir for containing a volume of hydraulic fluid;
a first hydraulic circuit in fluid communication with the reservoir
for providing hydraulic fluid to a power steering device; and a
second hydraulic circuit in fluid communication with the reservoir
for providing hydraulic fluid to a tilt-trim device.
24. The pressurized fluid supply apparatus of claim 23 wherein at
least one of the first hydraulic circuit and the second hydraulic
circuit comprises a fluid conditioning device.
25. The pressurized fluid supply apparatus of claim 24 wherein the
conditioning device comprises a cooler.
26. The pressurized fluid supply apparatus of claim 24 wherein the
conditioning device comprises a filter.
27. The pressurized fluid supply apparatus of claim 23 further
comprising a third hydraulic circuit in fluid communication with
the reservoir for providing hydraulic fluid to a transmission
device.
28. The pressurized fluid supply apparatus of claim 27 wherein at
least one of the first hydraulic circuit, the second hydraulic
circuit and the third hydraulic circuit comprises a fluid
conditioning device.
29. The pressurized fluid supply apparatus of claim 28 wherein the
conditioning device comprises a cooler.
30. The pressurized fluid supply apparatus of claim 28 wherein the
conditioning device comprises a filter.
31. The pressurized fluid supply apparatus of claim 28 wherein the
reservoir comprises a portion of a transmission housing.
32. A method of conditioning hydraulic fluid for a plurality of
hydraulic circuits of a marine craft, the method comprising the
steps of: providing a common reservoir in fluid communication with
a plurality of hydraulic circuits of a water craft; providing a
conditioning device in at least one of the hydraulic circuits to
condition the hydraulic fluid passing through the at least one of
the hydraulic circuits; returning the conditioned hydraulic fluid
to the common reservoir for use in other of the plurality of
hydraulic circuits.
33. The method of claim 32 further comprising the step of providing
a cooler in the at least one of the hydraulic circuits to remove
heat from the hydraulic fluid passing through the at least one of
the hydraulic circuits.
34. The method of claim 32 further comprising the step of providing
a filter in the at least one of the hydraulic circuits to remove
particulate matter from the hydraulic fluid passing through the at
least one of the hydraulic circuits.
35. The method of claim 32 further comprising the steps of:
providing a fill vessel in fluid communication with the common
reservoir; and maintaining a predetermined level of hydraulic fluid
in the fill vessel to provide an adequate supply of hydraulic fluid
to the plurality of hydraulic circuits of the water craft.
36. A method of maintaining proper hydraulic fluid levels in a
plurality of hydraulic circuits of a water craft, the method
comprising the steps of: providing a common reservoir in fluid
communication with a plurality of hydraulic circuits of a water
craft; providing a common fill vessel in fluid communication with
the common reservoir; locating the fill vessel at a location on the
water craft accessible by an operator; maintaining a level of
hydraulic fluid in the fill vessel within a predetermined range of
levels to provide an adequate supply of hydraulic fluid to the
plurality of hydraulic circuits.
37. The method of claim 36 further comprising the step of providing
a means for cooling the hydraulic fluid in one of the plurality of
hydraulic circuits.
38. The method of claim 36 further comprising the step of providing
a means for cleaning the hydraulic fluid in one of the plurality of
hydraulic circuits.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates generally to the field of
recreational watercraft, and more particularly to the hydraulic
system for a watercraft, and specifically to a common hydraulic
system for providing pressurized fluid to a hydraulic transmission,
a power steering unit, and a trim unit of a watercraft.
[0002] Attention is directed to the following U.S. Patents which
describe the various hydraulic systems of a watercraft:
1 Borst 3,885,517 May 27, 1975 Lambrecht 3,929,089 Dec. 30, 1975
Borst 3,962,955 Jun. 15, 1976 Hall 4,064,824 Dec. 27, 1977
Blanchard 4,362,514 Dec. 07, 1982 Hall 4,431,422 Feb. 14, 1984 Hall
4,551,105 Nov. 05, 1985 Ferguson 4,605,375 Aug. 12, 1986 Hall
4,615,290 Oct. 07, 1986 Sullivan 4,642,058 Feb. 10, 1987 Bland
4,659,315 Apr. 21, 1987 Ferguson 4,698,035 Oct. 06, 1987
[0003] Recreational watercraft are generally propelled by an
internal combustion engine mounted either inboard to the watercraft
or supported outboard on the transom of the watercraft. An inboard
engine may be connected to the propeller via a stern drive unit
passing through the transom of the watercraft. It is known to
provide a power steering system for both inboard and outboard
watercraft. Such power steering systems typically include one or
more hydraulic cylinders selectively activated by being provided
with a pressurized hydraulic fluid via a power steering cylinder
valve that is responsive to the movement of a steering wheel. The
power steering hydraulic cylinder may be connected to a steering
arm which pivots the drive unit about a generally vertical axis,
thereby controlling the direction of thrust provided by the
propeller. The power steering cylinder valve controls the supply of
pressurized hydraulic fluid to the hydraulic cylinder. The operator
of the watercraft thus needs only to exert enough effort to operate
the power steering cylinder valve and not the total effort required
to actually rotate the steering arm. A cooler may be provided to
remove heat from the hydraulic fluid generated by the action of the
power steering pump.
[0004] It is also known to provide a power trim system for both
inboard and outboard drive units. A power trim system is used to
pivot the propeller about a generally horizontal axis to adjust the
vertical drive angle of the propeller with respect to the
watercraft. Such rotation of the propeller in the vertical
direction permits the angle of thrust to be optimized for both
on-plane and off-plane operation of the watercraft. To accomplish
the power trim function, pressurized hydraulic fluid may be
provided by a reversible pump to a lift cylinder to raise or lower
the bottom portion of the drive unit. The trim system may include
the capability to lift the propeller completely or nearly out of
the water for operation in shallow water and for removal of the
watercraft from the water. Such systems are referred to as
tilt-trim systems and often include separate hydraulic cylinders
for performing the tilt and the trim functions.
[0005] It is also known to utilize a hydraulic transmission with an
inboard/outboard watercraft. Such transmissions utilize pressurized
hydraulic fluid to actuate a shifting mechanism and also to provide
lubrication within the transmission. The flow of the hydraulic
fluid and the power to operate the shift mechanism is provided by a
transmission fluid pump through one or more transmission valves. A
cooler is usually provided to maintain the temperature of the
transmission fluid below an upper limit in order to protect the
transmission components and to prevent premature degradation of the
transmission fluid.
[0006] Typically, each of the hydraulic systems in a watercraft is
a self contained unit, including a reservoir for storing hydraulic
fluid, a pump connected to the reservoir for pressurizing the
hydraulic fluid, and appropriate valves and interconnecting typing.
Each system is provided with both fill and vent connections. The
hydraulic fluid in the power steering and hydraulic transmission
circuits may become heated due to the operation of the respective
pump, and individual coolers are normally provided to remove heat
from each of these fluid systems. The fluid level in each of the
hydraulic systems must be checked periodically to ensure that an
adequate supply of hydraulic fluid is available for operation of
the watercraft. Access to the various fluid fill locations and
associated dipstick level indicators is often restricted, causing
some watercraft operators to forego the appropriate schedule for
fluid fill verification. As a result, equipment damage and/or
unsafe operating conditions may result from the operation of the
watercraft with an inadequate hydraulic fluid supply in one or more
of the hydraulic systems.
BRIEF SUMMARY OF THE INVENTION
[0007] Thus there is a particular need for a watercraft having
hydraulic systems that are easy to inspect for proper fill level.
There is also a need for a simple and less expensive hydraulic
fluid supply apparatus for the various hydraulic systems on-board a
watercraft. Furthermore, there is a need for a watercraft that is
less susceptible to damage resulting from the operation of the
watercraft with an inadequate hydraulic fluid supply level in one
or more of its hydraulic systems.
[0008] Accordingly, a common fluid pressure supply apparatus is
described herein for a watercraft having a drive unit including a
hydraulic transmission, a hydraulically operated power steering
apparatus attached to the drive unit for steering the water craft,
and a hydraulically operated trim apparatus attached to the drive
unit for raising and lowering the drive unit with respect to the
watercraft. The watercraft includes a transmission housing
reservoir for containing hydraulic fluid; a transmission pump
having an inlet in fluid communication with the transmission
housing reservoir and an outlet for providing pressurized hydraulic
fluid to the hydraulic transmission, and a fluid return path
between the hydraulic transmission and the transmission housing
reservoir; a power steering pump reservoir having an inlet in fluid
communication with the transmission housing reservoir; a power
steering pump having an inlet in fluid communication with the power
steering pump reservoir and an outlet for providing pressurized
hydraulic fluid to the power steering apparatus, and a fluid return
path between the power steering apparatus and the transmission
housing reservoir; a trim pump reservoir having an inlet in fluid
communication with the transmission housing reservoir; a trim pump
having an inlet in fluid communication with the trim pump reservoir
and an outlet for providing pressurized hydraulic fluid to the trim
apparatus, and a fluid return path between the trim apparatus and
one of the trim reservoir and the transmission housing reservoir.
The fluid pressure supply apparatus may further include a fill
vessel having a low point outlet in fluid communication with each
of the power steering pump reservoir and the trim pump reservoir,
and having a high point outlet in fluid communication with each of
the transmission housing reservoir, the power steering pump
reservoir and the trim pump reservoir.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The features and advantages of the present invention will
become apparent from the following detailed description of the
invention when read with the accompanying drawings in which:
[0010] FIG. 1 is a partial side elevational view of a watercraft
employing the invention.
[0011] FIG. 2 is a schematic illustration of the hydraulic fluid
supply system of the watercraft of FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
[0012] FIG. 1 illustrates a watercraft 10 including a hull 12
having a transom 14. An internal combustion engine 16 is disposed
in the hull 12 and supported by one or more motor mounts 17. A
hydraulic transmission 18 is connected to the engine 16 for the
purpose of transmitting mechanical energy produced by the engine 16
through a drive shaft (not shown) having a plurality of gearing
ratios. Transmission 18 is also disposed within hull 12 and may be
supported by one or more transmission mounts 19. A stern drive
apparatus 20 is connected to the transmission 18 and is disposed
through an opening 22 formed in the transom 14. As is known in the
art, stern drive apparatus 20 is used to transmit the mechanical
energy from the engine 16 and transmission 18 to a propeller 26
located external to the hull 12 and below a waterline 28. Propeller
26 is rotatingly connected to the stern drive apparatus 20 at the
end of a drive shaft (not shown). A steering apparatus 30 is
connected to the stern drive apparatus 20 for rotating the
propeller 26 about a vertical axis 32 for steering the watercraft
10. As is known in the art, the steering apparatus 30 may include
one or more hydraulic actuators provided with pressurized hydraulic
fluid and responsive to steering inputs provided by an operator
through a steering wheel. A trim apparatus 34 is also connected to
the stem drive apparatus 20 for raising an lowering the propeller
26 about a horizontal axis 36 relative to hull 12. The trim
apparatus 34 is useful for adjusting the angle of thrust provided
by the propeller 26 in a vertical direction in order to optimize
the efficiency of the operation of the watercraft 10. The term trim
apparatus as used herein is meant to include a tilt-trim apparatus
for embodiments where the range of vertical motion of the propeller
26 is sufficient to lift propeller 26 and lower portion 38 of stem
drive apparatus 20 to a raised position near or above the water
line 28.
[0013] Each of the transmission 18, steering apparatus 30, and trim
apparatus 34 is a hydraulic system operable with pressurized
hydraulic fluid. These three pressurized hydraulic fluid circuits
are interconnected by a fluid interconnection apparatus to form a
common fluid pressure supply apparatus 40 as will be described more
fully with respect to FIG. 2. Such an apparatus simplifies the
tasks of maintaining proper conditioning of the hydraulic fluid and
maintaining a proper fluid level in each of the plurality of
hydraulic systems.
[0014] FIG. 2 is a schematic illustration of the common fluid
pressure supply apparatus 40 utilized in the watercraft 10 of FIG.
1. The common fluid pressure supply apparatus 40 includes a fluid
interconnection apparatus, which in the embodiment of FIG. 2
includes a transmission housing reservoir 42 that is formed to be
integral with the casing of transmission 18. The transmission
housing reservoir 42 contains a volume of hydraulic fluid 44 that
is exchanged among the plurality of hydraulic circuits of the water
craft. A vent connection 46 is provided into transmission housing
42 below a high point 48 of the reservoir 42 in order to provide
for a trapped air space 50 within the transmission 18. Such a
trapped air space 50 is known in the art to be necessary to
accommodate the foaming of the hydraulic fluid 44 during the
operation of hydraulic transmission 18. A transmission pump 52
having an inlet 54 in fluid communication with the transmission
housing reservoir 42 is operable to provide pressurized hydraulic
fluid through an outlet 56 to one or more transmission valves 58. A
filter 126 may be interposed between the transmission pump 52 and
transmission valves 58. A fluid return path 60 is provided between
the transmission valve 58 and a return inlet 62 formed in the
transmission housing reservoir 42. Fluid return path 60 may be a
conduit located outside the transmission casing or may be formed as
fluid passages within the transmission casing.
[0015] A power steering pump 64 having an inlet 66 in fluid
communication with a power steering pump reservoir 68 is operable
to provide pressurized hydraulic fluid through an outlet 70 to a
power steering cylinder valve 72. The power steering pump 64 is
operable to draw hydraulic fluid 44 from the transmission housing
reservoir 42, such as through an inlet 74 of power steering pump
reservoir 68. Power steering pump reservoir 68 is also provided
with a vent connection 76 located at a high point of power steering
pump reservoir 68. A fluid return path 78 is provided to return the
hydraulic fluid from power steering cylinder valve 72 to a return
inlet 80 of transmission housing reservoir 42. The interconnections
between the power steering pump 64 and power steering cylinder
valve 72 as well as the fluid return path 78 may be any form of
known hydraulic fluid line, such as stainless steel tubing or
flexible hydraulic line. Power steering pump 64 may be powered by a
mechanical connection to engine 16, such as by a belt drive, or it
may be driven by an electric motor. One may also appreciate that
return inlets 62, 80 may be formed as a single penetration through
transmission housing reservoir 42.
[0016] A trim pump reservoir 90 is in fluid communication with
transmission housing reservoir 42 through an inlet 92. A trim pump
94 having an inlet 96 in fluid communication with the trim pump
reservoir 90 has an outlet 98 for providing pressurized hydraulic
fluid to a trim cylinder 100. A fluid return path 102 is provided
to return the hydraulic 44 to the trim reservoir 90. In an
alternative embodiment, the fluid return path 102 may connect into
the transmission housing reservoir 42. The trim reservoir is
provided with both an inlet fill connection 112 and a vent
connection 116.
[0017] While the embodiment illustrated herein provides an
interconnection among three hydraulic fluid circuits, i.e. the
power steering, the tilt-trim and the hydraulic transmission, other
embodiments may include different combinations of hydraulic
circuits. For example, some water craft do not have hydraulic
transmissions. For such applications only the power steering and
tilt-trim hydraulic circuits may be interconnected.
[0018] Advantageously, a hydraulic fluid cooler 82 is provided as
part of the power steering apparatus 30. Cooler 82 is in fluid
communication with the outlet 70 of power steering pump 64 and is
operable to remove heat from the hydraulic fluid 44. Cooler 82 may
be of any design known in the art, and may include one or more
cooling coils 84 operable to transfer heat from the hydraulic fluid
located on a shell side to a cooling water supply such as lake
water 86 being pumped through a tube side of coils 84. As a result
of the intermixing of hydraulic fluid 44 from the transmission 18,
steering apparatus 30, and trim apparatus 34, one may appreciate
that a single cooler 82 is operable to provide cooling for all
three hydraulic systems. A filter may be disposed downstream of the
outlet 70 of the power steering pump 64 to supplement or to replace
filter 126, since in either location there is a continuous
recirculation of the hydraulic fluid 44 from transmission housing
reservoir 42. Accordingly, by providing a single cooler or filter
in just one of the hydraulic circuits, the hydraulic fluid for each
of the circuits may be cooled/filtered. Optionally, a vent
connection 88 may be provided on the shell side of cooler 82.
[0019] One may appreciate that the cooler 82 and filter 126 are
just two types of fluid conditioning devices that may be included
in the common fluid pressure supply apparatus 40. Other known types
of conditioning devices may be used alone or in combination with
cooler 82 and/or filter 126. Such conditioning devices may include
a device for controlling the level of additives in the hydraulic
fluid, for controlling the pH of the hydraulic fluid, for
conducting a nondestructive examination of the hydraulic fluid to
determine one or more quality parameters, etc. Advantageously, by
including one such device in any one or more of the plurality of
hydraulic circuits interconnected by the common transmission
housing reservoir 42, conditioning may be accomplished in the
entire volume of hydraulic fluid used in each hydraulic
circuit.
[0020] The fluid interconnection apparatus illustrated in FIG. 2
includes a common high point fill vessel 104. Fill vessel 104 may
be a translucent plastic bottle attached to hull 12. Fill vessel is
interconnected to each of the transmission 18, steering apparatus
30, and trim apparatus 34. A level 106 of hydraulic fluid 44 is
maintained within the fill vessel 104. Fill vessel 104 has a low
point outlet 108 in fluid communication with a fill inlet 110 of
the power steering pump reservoir 68, and with a fill inlet 112 of
the trim pump reservoir 90 for providing hydraulic fluid thereto
and to the transmission reservoir 42 through power steering pump
reservoir 68. Fill vessel 104 also contains a high point vent
outlet 114 in fluid communication with the vent connection 76 of
power steering pump reservoir 68, vent connection 116 of trim pump
reservoir 90, and vent connection 46 of transmission housing
reservoir 42. High point outlet 114 may also be connected with the
optional vent connection 88 of cooler 82. High point outlet 114 is
vented to the ambient atmosphere. A cap 118 having an attached
dipstick 120 may be utilized as an indicator of the level 106 of
hydraulic fluid in fill vessel 104. This single level indication of
hydraulic fluid 44 within fill vessel 104 provides assurance that
each of the three hydraulic systems contains an adequate supply of
hydraulic fluid 44. By locating a common fill vessel 104 at a
convenient location on the water craft that is accessible by the
water craft operator, the task of maintaining proper hydraulic
levels in each of the plurality of hydraulic circuits is greatly
simplified.
[0021] A sensor 122 may be adapted to provide a signal 124
corresponding to the level 106 of hydraulic fluid 44 contained in a
fill vessel 104. Sensor 122 may be any type known in the art for
providing signal 124. It may be appreciated that fill vessel 104
may be disposed at a convenient high point location within
watercraft 10 to allow for the operator to check the level 106 of
the hydraulic fluid and to add additional hydraulic fluid as
necessary. By providing a single fill vessel 104, the task of
maintaining a proper level of hydraulic fluid in each of the
transmission 18, steering apparatus 30, and trim apparatus 34, is
greatly simplified for the operator. Furthermore, by
interconnection the three hydraulic systems, a single cooler 82 and
a single filter 126 may be located within the common fluid pressure
supply apparatus 40 for regulating the temperature and cleanliness
of the hydraulic fluid 44 of all three systems. Furthermore, signal
124 may be utilized in a control system for avoiding undesirable
operating conditions, such as for limiting the speed of engine
operation when the hydraulic fluid level drops below a
predetermined level.
[0022] While the preferred embodiments of the present invention
have been shown and described herein, it will be obvious that such
embodiments are provided by way of example only. Numerous
variations, changes and substitutions will occur to those of skill
in the arts without departing from the invention herein.
Accordingly, it is intended that the invention be limited only by
the spirit and scope of the appendant claims.
* * * * *