U.S. patent application number 10/706182 was filed with the patent office on 2005-05-12 for apparatus and method for exchanging vehicular fluids.
Invention is credited to Heiliger, Jeff T., Monje, Michael A., Rounds, Todd M..
Application Number | 20050098226 10/706182 |
Document ID | / |
Family ID | 34552482 |
Filed Date | 2005-05-12 |
United States Patent
Application |
20050098226 |
Kind Code |
A1 |
Rounds, Todd M. ; et
al. |
May 12, 2005 |
Apparatus and method for exchanging vehicular fluids
Abstract
A method and apparatus for exchanging used fluid in a system
with new fluid. Used fluid is withdrawn from the system and stored
in a first chamber. In response to the used fluid in the first
chamber a first and a second pump are activated. The first pump
withdraws the used fluid from the first chamber into a waste tank.
The second pump draws new fluid from a new fluid tank for infusion
into the vehicle. In an alternative embodiment the second pump
draws new fluid from the new fluid tank into a second chamber. New
fluid in the second chamber activates a third pump for withdrawing
new fluid from the second chamber and infusing the new fluid into
the system.
Inventors: |
Rounds, Todd M.; (Gilbert,
AZ) ; Heiliger, Jeff T.; (Elkhart, IN) ;
Monje, Michael A.; (Arcadia, CA) |
Correspondence
Address: |
BEUSSE BROWNLEE WOLTER MORA & MAIRE, P. A.
390 NORTH ORANGE AVENUE
SUITE 2500
ORLANDO
FL
32801
US
|
Family ID: |
34552482 |
Appl. No.: |
10/706182 |
Filed: |
November 12, 2003 |
Current U.S.
Class: |
141/65 ;
184/1.5 |
Current CPC
Class: |
F01M 11/0458
20130101 |
Class at
Publication: |
141/065 ;
184/001.5 |
International
Class: |
B65B 031/04 |
Claims
1. A fluid exchange process for withdrawing a used fluid from a
system and supplying a new fluid into the system, comprising:
withdrawing the used fluid from the system into a first chamber;
supplying the new fluid into the system by activating a pump in
response to the used fluid in the first chamber; and removing the
used fluid from the first chamber.
2. The fluid exchange process of claim 1 wherein the step of
withdrawing the used fluid further comprises setting a switch to a
first state in response to the used fluid in the first chamber, and
wherein the step of supplying the new fluid further comprises
supplying the new fluid into the system in response to the first
state of the switch.
3. The fluid exchange process of claim 1 further comprising a step
of providing the new fluid from a second chamber wherein the step
of supplying the new fluid further comprises withdrawing the new
fluid from the second chamber and supplying the new fluid into the
system in response to the used fluid in the first chamber.
4. The fluid exchange process of claim 1 wherein the volume of the
used fluid withdrawn from the system is substantially equal to the
volume of the new fluid supplied to the system.
5. The fluid exchange process of claim 1 wherein the fluid
comprises automatic transmission fluid, and wherein the system
comprises a vehicular automatic transmission system.
6. The fluid exchange process of claim 1 wherein the used fluid is
withdrawn from the system at a first rate and the new fluid is
supplied to the system at a second rate.
7. The fluid exchange process of claim 6 wherein the first rate is
substantially equal to the second rate.
8. The fluid exchange process of claim 1 further comprising
terminating the supply of new fluid into the system in response to
an empty condition of the first chamber.
9. The fluid exchange process of claim 1 further comprising a step
of transferring heat from the used fluid to the new fluid.
10. The fluid exchange process of claim 9 wherein the step of
transferring heat comprises causing the used fluid to flow through
a heat exchanger surrounded by the new fluid for transferring heat
from the used fluid to the new fluid.
11. The fluid exchange process of claim 9 wherein the step of
transferring heat lowers a viscosity of the new fluid.
12. The fluid exchange process of claim 11 wherein the step of
transferring heat tends to equalize a viscosity the new fluid and
the viscosity of the used fluid.
13. The fluid exchange process of claim 1 further comprising in
response to the presence of used fluid in the first chamber,
activating a first pumping mechanism for removing the used fluid
from the first chamber.
14. The fluid exchange process of claim 13 wherein the step of
activating further comprises supplying power to the first pumping
mechanism in response to a position of a float switch disposed in
the first chamber, and wherein the position is responsive to a used
fluid level in the first chamber.
15. The fluid exchange process of claim 1 wherein the step of
removing further comprises transferring the used fluid into a used
fluid tank.
16. The fluid exchange process of claim 1 wherein the step of
supplying the new fluid further comprises activating a second
pumping mechanism for supplying the new fluid into the system.
17. The fluid exchange process of claim 1 wherein the step of
supplying the new fluid further comprises transferring the new
fluid from a new fluid tank into a second chamber, and wherein in
response to the new fluid in the second chamber and the used fluid
in the first chamber, the new fluid is supplied to the system.
18. The fluid exchange process of claim 1 wherein the system
comprises a closed loop system, the process further comprising
opening the closed loop system to form an outlet port and an inlet
port, and wherein the step of withdrawing the used fluid comprises
withdrawing the used fluid from the outlet port, and wherein the
step of supplying the new fluid comprises supplying the new fluid
into the inlet port.
19. The fluid exchange process of claim 18 further comprising:
connecting a first valve to one of the inlet port and the outlet
port; connecting a second valve to the other of the inlet port and
the outlet port; establishing a flow path through the first valve
and the second valve for withdrawing the used fluid from the outlet
port and for supplying the new fluid to the inlet port.
20. A fluid exchange process for withdrawing a used fluid from a
system and supplying a new fluid into the system, comprising:
causing the used fluid to flow into a first chamber; in response to
the used fluid in the first chamber, pumping the used fluid from
the first chamber into a waste chamber; and in response to the used
fluid in the first chamber as sensed by a fluid sensor, pumping the
new fluid into the system.
21. The fluid exchange process of claim 20 wherein the system is
pressurized, and wherein the step of causing the used fluid to flow
into the first chamber further comprises forming a used fluid flow
path from the system to the first chamber.
22. The fluid exchange process of claim 20 wherein the step of
pumping the new fluid further comprises: pumping the new fluid into
a second chamber; and in response to the new fluid in the second
chamber, pumping the new fluid from the second chamber into the
vehicle.
23. A process for infusing a new fluid into a system while a used
fluid is evacuating from the system, comprising: storing the new
fluid for infusing into the system in a tank; causing the used
fluid evacuating from the system to flow through a tube disposed in
the tank such that heat from the used fluid is transferred to the
new fluid; and supplying the new fluid into the system.
24. A fluid exchange process for withdrawing a used fluid from a
system and supplying a new fluid into the system, comprising:
withdrawing the used fluid from the system into a first chamber;
and in response to the used fluid in the first chamber as sensed by
a fluid sensing element, infusing the new fluid into the system by
operation of an electrically powered pumping mechanism.
25. A machine for exchanging a used fluid in a system with a new
fluid, comprising: a first fluid flow path for receiving the used
fluid from the system; a second fluid flow path for infusing the
new fluid into the system; a volume sensing element for determining
a volume of the used fluid received from the system; a first pump
responsive to the volume sensing element for supplying a
substantially equivalent volume of the new fluid into the system
through the second fluid flow path.
26. The machine of claim 25 wherein the system comprises a
vehicular transmission system, and wherein the new fluid and the
used fluid comprise new transmission system fluid and used
transmission system fluid, respectively.
27. The machine of claim 25 further comprising: a waste fluid tank;
a chamber for receiving the used fluid; and a second pump for
withdrawing the used fluid from the chamber and for supplying the
used fluid into the waste fluid tank, wherein the first pump is
responsive to the volume of the used fluid in the chamber for
supplying a substantially equivalent volume of the new fluid into
the system through the second fluid flow path.
28. The machine of claim 27 wherein the chamber comprises a float
switch responsive to the volume of the used fluid in the chamber
for energizing the first pump in response thereto.
29. The machine of claim 25 further comprising: a new fluid tank
containing the new fluid; a chamber; and a second pump responsive
to the new fluid in the new fluid tank for supplying the new fluid
into the chamber, and wherein the first pump is responsive to the
new fluid in the chamber for supplying the new fluid into the
system through the second fluid flow path.
30. The machine of claim 29 wherein the chamber comprises a float
switch responsive to the volume of the new fluid in the chamber for
energizing the second pump in response thereto.
31. The machine of claim 25 wherein the first fluid flow path and
the second fluid flow path are joined to form a closed fluid flow
path, and wherein a valve having selectable first and second fluid
flow paths therethrough is disposed within the path, and wherein
when the valve is disposed in the first position the used fluid is
withdrawn from the path into the chamber, and wherein in response
to the volume of the used fluid in the chamber the first pump
supplies a substantially equivalent volume of the new fluid into
the system through the second fluid flow path.
32. The machine of claim 31 further comprising: a waste fluid tank;
and a second pump for withdrawing the used from the chamber into
the waste fluid tank in response to a volume of the used fluid in
the chamber.
33. The machine of claim 31 wherein the valve comprises a solenoid
valve.
34. The machine of claim 25 further comprising: a chamber; a new
fluid tank for holding the new fluid; and a second pump responsive
to the new fluid in the new fluid tank, wherein the second pump
withdraws the new fluid from the new fluid tank into the chamber,
and wherein the first pump withdraws the new fluid from the chamber
for supplying the new fluid into the system through the second
fluid flow path.
35. The machine of claim 34 further comprising a float switch
disposed in the new fluid tank, wherein when a level of the new
fluid in the new fluid tank reaches the float switch the float
switch de-energizes the second pump.
37. The machine of claim 34 wherein the first and the second fluid
flow paths are joined to form a continuous fluid flow path, wherein
a segment of the continuous fluid flow path is disposed in the new
fluid tank such the heat retained by the used fluid flowing through
the continuous fluid flow path is transferred to the new fluid in
the new fluid tank.
38. The machine of claim 25 wherein the first fluid flow path and
the second fluid flow path are joined to form a continuous fluid
flow path, the machine further comprising a valve/spigot having an
opened and a closed position and disposed in the continuous fluid
path, and wherein fluid is discharged from the closed fluid path by
selectively placing the valve/spigot in the opened position.
39. The machine of claim 25 wherein one of the first and the second
fluid flow paths comprises a pressure gauge for determining a
pressure of the fluid flowing therethrough.
40. The machine of claim 25 wherein the system comprises a vehicle
transmission system, and wherein the used fluid comprises used
transmission fluid and the new fluid comprises new transmission
fluid.
41. The machine of claim 25 further comprising: a first valve
having first, second and third ports, wherein the first valve
further comprises first and second selectable positions, wherein in
the first position the first port is in fluid communication with
the second port and in the second position the first port is in
fluid communication with the third port; a second valve having
fourth, fifth and sixth ports, wherein the second valve further
comprises first and second selectable positions, wherein in the
first position the fourth port is in fluid communication with the
fifth port and in the second position the fourth port is in fluid
communication with the sixth port; wherein the third and the fifth
ports are connected in fluid communication at a junction and
wherein the junction further comprises a junction port in fluid
communications with the third and the fifth ports; wherein when the
first and the second valves are disposed in the first position, the
first fluid flow path for receiving the used fluid from the system
comprises the fourth and the fifth ports of the second valve and
the junction port, and wherein the second fluid flow path for
infusing the new fluid into the system comprises the second and the
first ports of the first valve; and wherein when the first and the
second valves are disposed in the second position, the first fluid
flow path for receiving the used fluid from the system comprises
the first and the third ports of the first valve and the junction
port, and wherein the second fluid flow path for infusing the new
fluid into the system comprises the sixth and the fourth ports of
the second valve.
42. A machine for exchanging a used fluid in a system with a new
fluid, comprising: a first fluid flow path for receiving the used
fluid from the system; a second fluid flow path for infusing the
new fluid into the system; a waste fluid tank; a first chamber for
receiving the used fluid from the first fluid flow path; a fluid
sensing switch in the first chamber; and first and second pumps
operative in response to the fluid sensing switch in the first
chamber, the first pump for withdrawing the used fluid from the
first chamber and for supplying the used fluid into the waste fluid
tank, the second pump for infusing the new fluid into the system
through the second fluid flow path.
43. The machine of claim 42 wherein the first and the second pumps
pump substantially the same volume of their respective fluids.
44. The machine of claim 42 further comprising: a third pump; a
second chamber; and a new fluid tank for holding the new fluid, the
third pump for pumping the new fluid from the new fluid tank into
the second chamber, wherein the second pump withdraws the new fluid
from the second chamber for infusing the new fluid into the system
through the second fluid flow path.
45. The machine of claim 44 wherein the second pump is operative in
response to the new fluid in the second chamber.
46. The machine of claim 45 wherein the second chamber comprises a
float switch having a first and a second position, and wherein the
position of the float switch is responsive to a level of the new
fluid in the second chamber such that the float switch is in the
second position when the level is above a predetermined value, and
wherein the second pump is operative in response to the second
position of the float switch.
47. The machine of claim 45 the second pump infuses substantially
all of the new fluid from the second chamber into the system
through the second fluid flow path, such that the volume of the new
fluid infused into the system is substantially equal to a volume of
the used fluid received from the system.
48. In a machine for exchanging a used fluid in a system with a new
fluid, an apparatus for withdrawing heat from the used fluid and
supplying heat to the new fluid, comprising: a tank holding the new
fluid; a coil having a fluid passageway therethrough disposed
within the tank and substantially surrounded by new fluid; a
component for passing used fluid through the coil, during which
heat flows from the used fluid to the new fluid held in the
tank.
49. The apparatus of claim 48 wherein the component comprises a
pump.
50. A fluid exchange process for withdrawing used fluid from a
system and supplying a new fluid into the system, comprising:
withdrawing the used fluid from the system into a first chamber;
creating a controlled new fluid volume in response to a volume of
the used fluid in the first chamber, wherein the new fluid volume
is substantially equal to the used fluid volume; and supplying the
new fluid into the system from the new fluid volume.
51. A fluid exchange process for withdrawing a used fluid from the
system and supplying a new fluid into the system, comprising:
storing the new fluid for infusing into the system in a tank;
causing the used fluid evacuating from the system to flow through a
tube disposed in the tank, such that heat from the used fluid is
transferred to the new fluid, wherein the used fluid flows into a
first chamber; and in response to the used fluid in the first
chamber, supplying the new fluid from the tank into the system.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to an apparatus and method for
exchanging vehicular fluids, and more specifically to an apparatus
and method for exchanging vehicular fluids according to fluid
volume.
BACKGROUND OF THE INVENTION
[0002] A vehicular transmission system transfers engine power to
the vehicle drive train, allowing the engine to operate in a narrow
speed range, while providing a wide range of output speeds and
torques to the drive train. This power transfer is accomplished
within the transmission, in which a plurality of gears
automatically select the proper gear ratio, in conjunction with the
position of the user operated transmission gear shift, based on the
vehicle's speed and torque demand.
[0003] Two other components associated with the transmission system
include the torque converter and the gear or fluid pump. The
converter is mounted to the engine flywheel (which is in turn
mounted on the engine drive shaft) to provide fluid coupling
between the engine and the transmission, allowing the engine to
spin somewhat independently of the transmission. Thus if the
vehicle is idling in a stopped condition, the amount of torque
transferred by the torque converter is small so restraining
vehicular motion requires only slight brake pressure. At higher
engine speeds, more fluid is pumped into the torque converter by
the fluid pump, causing more torque to be transferred from the
engine to the transmission and to the wheels.
[0004] The pump, typically affixed to the transmission cover, draws
fluid from a sump in the bottom of the transmission cover or pan
and feeds the fluid to the hydraulic system (for controlling and
actuating the transmission gear ratios), the torque converter and
the transmission fluid cooler. The transmission fluid cooler, a
cooling device within the radiator but separate from the main
engine cooling, comprises a heat exchanger where the fluid releases
heat energy to the cooler radiator coolant.
[0005] In the automatic transmission system described above the
transmission fluid is stored, delivered, and transferred through
various rigid enclosed passages, chambers, orifices, mechanisms, or
pumping/metering devices, all of which require regular cleaning to
ensure proper service and system life to remove fluid contaminants
and or by-products of the automatic power transmission process that
can foul and cause premature wear to system components or otherwise
impair system performance.
[0006] If contaminants, such as dirt, oil sludge, gum, varnish,
burned oil, deposits from worn parts, residues of transmission
fluid additives, etc., are not properly flushed from the automatic
transmission system, they can cause slow and hesitant acceleration,
rough or erratic shifting, incorrect shift points, excessive creep
and abnormal vibration when gears are shifted, gear position
slippage or lock up, premature transmission fluid burn-out causing
excessive fluid consumption and overheating, premature component
wear. If these problems are not resolved in a timely manner, an
expensive transmission overhaul may be required.
[0007] The simplest method for changing automatic transmission
fluid involves dropping or removing an automatic transmission pan
to allow the transmission fluid to drain (or draining the pan for
those transmissions equipped with a drain plug), followed by
refilling the transmission to the proper level with new fluid. It
is known, however, that when employing this method more than half
of the used and contaminated transmission fluid remains in the
transmission and the various related components operative
therewith, including the clutch actuators, control valves, pump(s),
transmission fluid cooler and connecting conduits, and the torque
converter.
[0008] Alternatively, the fluid can be withdrawn through a suction
tube inserted through a transmission fluid dipstick tube. Like the
drain and fill process, the suction tube process also results in
the retention of considerable used fluid within the transmission
system. Clearly, these processes merely dilute the used fluid with
new fluid while a proportion of the various contaminants remain
within the system.
[0009] To improve the fluid replacement process, there are known
machines for withdrawing the used fluid transmission fluid while
adding fresh or new fluid to replace the used fluid. To effectively
extract the used fluid from the transmission system components, the
vehicle engine is operated to allow the transmission fluid system
pressure to evacuate substantially all of the used fluid from the
various components. Operation of the vehicle engine activates the
transmission fluid pump, creating the transmission fluid pressure
that causes transmission fluid flow through the torque converter
and other transmission components to flush the used fluid from the
transmission system. According to these known machines, the
transmission system pressure also powers the machine components
that infuse the new fluid into the vehicle's transmission
system.
[0010] Advantageously, during the fluid exchange process the
vehicle is mounted on a chassis roller set to permit operation of
the drive wheels and cycling of the transmission through its
various gear ratios. Alternatively, the vehicle engine can be run
with the transmission in "neutral" or "park." The latter process is
less efficient than the former with respect to the quantity of used
fluid replaced with new fluid.
[0011] Most prior art fluid exchange (or flush) machines perform
the fluid exchange by connecting into the transmission fluid
cooling flow path at a location where the fluid enters or exits the
radiator (or other cooling component) referred to generally as the
cooler lines or coolant lines. These machines utilize the
pressure/flow of the used fluid in the cooler line to operate
functional components of the flush machine and perform the fluid
exchange. Such machines use pistons, bellows, gear drives, etc.
that are somehow displaced, moved, or turned by the incoming used
fluid from the vehicle. For example, one such machine comprises a
floating piston in a cylinder. The cylinder area above the piston
is filled within new fluid and the pressurized used fluid is
introduced into the bottom to the cylinder from the cooler line. As
the used fluid applies pressure to the underside of the piston, the
piston is driven upwardly to force the new fluid into the
transmission system. In another prior art technique, a flexible
bladder replaces the piston.
[0012] It is known that the time required to perform a transmission
fluid exchange is directly related to the speed at which the
vehicle can pump used fluid through the cooler line. Use of the
force/pressure of the vehicle's used fluid to infuse new fluid into
the transmission system can result in a slow exchange process, as
the exchange duration depends on the pressure of the used fluid as
it exits the vehicle and the mechanism by which the pressurized
fluid flow operates the flush mechanism. This pressure can range
from 5 psi (pounds per square inch) to 50 psi depending on vehicle
make and model. Thus the prior art techniques require a fluid
exchange machine that can accommodate all expected vehicle
pressures.
[0013] In an effort to accelerate the flush and exchange processes
for low pressure vehicles, it is known to use booster pumps or
mechanically assisted components to supplement the energy derived
from the fluid flow. Many vehicles, such as Toyota automobiles and
various Ford products, operate on a low flow/pressure transmission
system. The typical operating pressure is under 10 psi and can be
as low as 6 or 7 psi. A prior art gear-driven flush machine
requires almost 5 psi to operate the gear-drive mechanism, leaving
little pressure to accomplish the fluid exchange. Thus when
employing such a machine with a low-pressure vehicle, the fluid
exchange process may require 30 to 40 minutes. In addition to the
extended customer wait time, it is known that a longer duration
exchange allows more intermixing of the new and used fluids within
the transmission system, thus reducing the amount of fluid actually
exchanged. A faster exchange of used fluid for new fluid is
preferred to limit the intermixing.
[0014] In contrast to the low-pressure designs above, certain late
model vehicles are designed with high-pressure fluid transmission
systems. These pressures may be excessive for certain existing
fluid flow machines, and can damage machine components.
Additionally, the prior art machines may not be able to supply a
sufficiently high pressure to the new fluid as it is infused into
the vehicle.
[0015] Another disadvantage encountered in the prior art fluid
exchange machines is caused by the expected viscosity differential
between the new and the used fluids during the exchange process.
The viscosity of the old fluid is lower than the viscosity of the
new fluid (i.e., the new fluid is thicker). Machine inefficiencies
will arise as the incoming lower viscosity used fluid attempts to
force the higher viscosity new fluid into the vehicle, as the
pressure supplied by the old fluid to force the new fluid into the
vehicle may not be sufficient given the higher viscosity of the new
fluid.
[0016] Several different fluid exchange machines are known in the
art. One such flushing machine for an automotive automatic
transmission is known according to U.S. Pat. No. 5,337,708, issued
16 Aug. 1994 to We-Yu Chen. This patent is believed to teach a
transmission fluid exchange machine in which the transmission fluid
circulation loop is opened to serially connect the flushing machine
into the loop. In one mode of operation the used transmission
fluid, possibly including a transmission flushing solution, is
circulated through the machine for receiving old transmission fluid
and supplying fresh fluid to the transmission system at a selected
pressure or volume delivery rate. The Chen machine operates from
the vehicle's twelve-volt power supply for powering a pump to move
new transmission fluid from the fluid tank to the vehicle's
transmission. The operator visually inspects the fluid color as the
fluid travels through a sight tube, terminating the process when
the color indicates the presence of new fluid.
[0017] Another transmission fluid change apparatus is disclosed by
U.S. Pat. No. 5,318,080, issued 7 Jun. 1994 to James P. Viken. The
'080 patent is believed to disclose an apparatus in which supply of
the new transmission fluid is provided from a pressurized storage
container, which container is pressurized by the inflow of used
fluid pumped from the transmission by its gear or fluid pump. The
storage container has a chamber that is separated by a flexible
wall (i.e., a rolling-diaphragm piston) into two sub-chambers that
expand and contract in opposition. As one sub-chamber receives used
fluid, new fluid is displaced from the other sub-chamber into the
transmission. Another embodiment of this device uses two separate
containers, one receiving the old fluid and the other holding new
fluid. Air displaced from the one container as the old fluid enters
is routed into the other container to drive the new fluid into the
transmission. A pressurized air assist for the new fluid delivery
is provided. There is considerable uncertainty with these prior art
machines that the rate of new fluid delivery substantially matches
the rate of old fluid drainage from the transmission under service,
possibly creating a situation where the transmission may be
operating with insufficient fluid and damaging the system.
BRIEF SUMMARY OF THE INVENTION
[0018] A fluid exchange process according to the present invention
withdraws a used fluid from a system and supplies a new fluid into
the system. The process comprises withdrawing the used fluid from
the system into a first chamber and supplying the new fluid into
the system in response to the used fluid in the first chamber, and
removing the used fluid from the first chamber.
[0019] The present invention further comprises a machine for
exchanging a used fluid in a system with a new fluid. The machine
comprises a first fluid flow path for receiving the used fluid from
the system and a second fluid flow path for infusing the new fluid
into the system. A first pump is responsive to the volume of the
used fluid received from the system for supplying a substantially
equivalent volume of the new fluid into the system through the
second fluid flow path.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The features of the fluid replacement machine and a method
for replacing fluid constructed according to the teachings of the
present invention will be apparent from the following more
particular description of the invention, as illustrated in the
accompanying drawings, in which like reference characters refer to
the same parts throughout the different figures. The drawings are
not necessarily to scale, emphasis instead being placed upon
illustrating the principles of the invention.
[0021] FIG. 1 illustrates a schematic of a fluid exchange machine
according to the teachings of the present invention; and
[0022] FIG. 2 illustrates a four-way valve suitable for use with
the fluid exchange machine of FIG. 1. FIG. 3 illustrates the fluid
exchange machine of FIG. 1 connected to a vehicle.
DETAILED DESCRIPTION OF THE INVENTION
[0023] Before describing in detail the particular fluid replacement
machine and a method for replacing fluid according to the teachings
of the present invention, it should be observed that the present
invention resides primarily in a novel and non-obvious combination
of elements and method steps. Accordingly, the elements have been
represented by conventional elements in the drawings, showing only
those specific details that are pertinent to the present invention,
so as not to obscure the disclosure with structural details that
will be readily apparent to those skilled in the art having the
benefit of the description herein.
[0024] One advantage of a machine and process according to the
teachings of the present invention is use of the volume of used
fluid evacuated from the system to control the exchange process.
The use of pressure/force of the used fluid from the vehicle, as
disclosed by the prior art, is not employed. As stated above, the
exchange time is dictated by the speed at which a vehicle can pump
or push its fluid from the transmission system. According to the
present invention, the exchange machine provides the pumping action
to infuse the new fluid, based on the volume of old fluid that is
pumped from the vehicle. The inventors have found that the fluid
exchange time for the machine of the present invention is in most
cases twice as fast as the typical prior art machines.
[0025] FIG. 1 is a fluid circuit schematic for a fluid exchange
machine 10 constructed according to the teachings of the present
invention. The process of the present invention begins by inserting
the fluid exchange machine 10 in series with the transmission fluid
cooling path. As described above, the transmission system includes
a fluid line to a heat exchanger, such as the vehicle radiator,
where the fluid is cooled by heat transfer to the cooler cooling
fluid, then returned to the transmission system via a cooling
return line. Thus the two connections between the fluid lines and
the radiator (one connection serving as a fluid input to the
radiator and the other serving as a fluid output or return line
from the radiator) present easily accessible junctions for
connecting the fluid exchange machine 10 into the transmission
system. Typically, the radiator output (cooler) connection is
accessible near an upper end of the radiator and is thus an easier
connection junction for the machine 10. To effect the connection,
the return line carrying fluid from the radiator (or more
generally, the heat exchanger) to the transmission is disconnected
from the radiator. A mating adapter 12 connected to a fluid line 13
is attached to the radiator (not shown) or to the fluid return line
(not shown). A mating adapter 14 connected to a fluid line 15 is
attached to the other connection. The machine 10 is now serially
connected into the transmission fluid cooling path.
[0026] In a preferred embodiment electrical power to operate the
machine 10 is supplied from the vehicle's battery, thus permitting
the fluid exchange operation in an area where a fixed power source
is not available. In another embodiment an external power source is
used, which may comprise suitable voltage conditioning components
to produce electrical current compatible with the components of the
machine 10. The process thus continues by connecting machine power
cables (not shown) to the vehicular battery to power the machine
10.
[0027] At this point in the process, the machine main switch (not
shown) is in an OFF or closed loop mode position. Both manually
operated directional valves 18 and 20 are pointing in the same
direction, i.e., both to an A position or both to a B position.
Arrowheads within the valve body illustrated in FIG. 1 indicate the
fluid flow direction through the valve when the valve is in the
associated position, i.e., the A or the B position. The vehicle is
started and the fluid level and fluid condition are determined by
inspection of fluid residue on the dipstick.
[0028] The pressure created by the vehicle's transmission fluid
pump causes fluid to circulate into the machine 10 via one of the
mating adapters 12 and 14, and to return to the transmission via
the other one of the mating adapters 12 and 14. A machine operator
checks the flow indicator 22, including a ball 23, to determine the
direction of fluid flow. A correct direction is indicated when the
ball 23 is forced in the direction of an arrowhead depicted within
the flow indicator 22 in FIG. 1. If the flow direction is incorrect
the operator turns both directional valves 18 and 20 to the
alternative position. That is, if the valves 18 and 20 were in the
A position the operator moves both to the B position and vice
versa. By employing two valves in the machine 10, the operator can
easily remedy the problem of incorrect fluid flow direction without
having to disconnect and reverse the connections of the mating
adapters 12 and 14.
[0029] If the mating adapter 12 is connected to the radiator and
the mating adapter 14 is connected to the cooling return line,
while the vehicle is running the hot used fluid enters the machine
10 from the radiator through the mating adapter 12, the fluid line
13 and the B position of the valve 18. The used fluid flows through
a tee junction 26, the flow indicator 22, a heat coil 30, a
pressure gauge 32, a normally-opened path of a solenoid 36 (where
the normally-opened path is indicated by a solid arrowhead and an
energized path is indicated by a dashed arrowhead within the body
of the solenoid as depicted in FIG. 1). The fluid passes through a
fluid line 38 and a tee junction 40, returning to the vehicle's
return line through the valve 20 (in the B position), the fluid
line 15 and the mating adapter 14. Note that with the valve 20 in
the B position, fluid flow from tee junction 26 into the valve 20
is prevented. Also, a check valve 41 prevents flow into a fluid
line 42.
[0030] Alternatively, if the mating adapter 12 is connected to the
cooling return line and the mating adapter 14 is connected to the
radiator, the fluid path is altered. The used fluid enters the
machine 10 from the radiator through the mating adapter 14, the
fluid line 15 and the A position of the valve 20. The fluid then
flows through the tee junction 26 and the flow indicator 22,
continuing through the same components in the same direction as set
forth above. The fluid returns to the vehicle's cooling return line
through the A position of the valve 18, the fluid line 13 and the
mating adapter 12. Note that with the valve 18 in the A position,
fluid flow from tee junction 26 into the valve 18 is prevented.
[0031] Once the correct flow direction is established and
confirmed, the operator can check the transmission system fluid
pressure with the pressure gauge 32 and visually inspect the fluid
color and quality through a sight glass (not shown in FIG. 1). In
one embodiment, the flow indicator 22 also performs the sight glass
function. An excessively high or low pressure may indicate a system
problem and it may therefore be unadvisable to perform the flush
and replace process. However, according to the teachings of the
present invention, a transmission system exhibiting a low pressure
(as indicated by a pressure reading displayed on the pressure gauge
32) can be successfully flushed as the machine 10 does not rely on
the transmission system fluid pressure to perform the fluid
exchange, as described below.
[0032] If the system appears to be operating properly within an
expected pressure range, the operator may add a flush chemical
(i.e., a dispersive detergent) through the vehicle's transmission
dipstick tube. The operator fills a new fluid tank 24 with a volume
of transmission fluid equal to the capacity of the vehicle's
transmission system. The vehicle is operated for about five to ten
minutes to circulate the flush chemical and allow the transmission
fluid temperature to increase to a nominal operating temperature,
i.e., about 200.degree. F. As is known in the art, the use of a
flush chemical is not required, but may be beneficial to remove
harmful deposits from the transmission system components.
[0033] As the hot used fluid flows through the heat coil 30 (formed
from copper tubing in one embodiment), heat is transferred to the
"cold" new fluid in the new fluid tank 24, thus warming the new
fluid and cooling the used fluid. Hot used fluid can shorten the
useful life of machine components as the hot fluid circulates
through the machine 10; cooling the used fluid reduces the
likelihood of this potential problem. Also, as the temperature of
the new fluid increases toward the temperature of the used fluid
the viscosity of the new fluid approaches the viscosity of the used
fluid. That is, the viscosity of the new fluid (which can be
especially high in cold weather) is reduced as its temperature
rises. As the viscosity of the new fluid approaches the viscosity
of the old fluid, the machine 10 provides an increasingly more
accurate one-to-one volume ratio fluid exchange.
[0034] Further, as is known, the introduction of cold fluid into an
operating transmission system is sensed by temperature sensors and
thermostats that can trigger the closing and isolation of one or
more fluid flow paths. The used fluid can become trapped within
these closed paths, reducing the volume of fluid exchanged during
the process and retaining some used fluid in the vehicle. By
heating the used fluid as taught by the present invention, the
likelihood of creating the trapped flow paths can be reduced since
the heated new fluid is less likely to activate the temperature
sensors and thermostats.
[0035] To perform the fluid exchange, the operator applies power to
the machine 10, for example by turning the main power switch to an
ON position (not shown in FIG. 1). The application of power
energizes the solenoid 36, redirecting the flow through the dashed
line energized path of the solenoid 36 to a chamber 44 where a
float switch 50 senses the fluid and in response supplies power to
pumps 60 and 62. Preferably, contacts within the float switch 50
are normally open, switching to a closed position in response to
the rising fluid level in the chamber 44.
[0036] As the used fluid enters the chamber 44, the pump 60 empties
the used fluid into a waste fluid tank 63. The pump 62 pulls new
fluid from the new fluid tank 24 into a chamber 66. In one
embodiment the pump 60 empties the chamber 44 at the same rate as
the pump 62 fills the chamber 66.
[0037] When a float switch 54 senses fluid in the chamber 66, power
is supplied to the pump 64. New fluid is thus withdrawn from the
chamber 66 by the pump 64, supplying that fluid back to the vehicle
through the fluid line 42, the check valve 41, a tee junction 70,
the fluid line 38, the tee junction 40 and the valve 18 or the
valve 20, depending on whether the valves 18 and 20 are in the A or
the B position. Recall that the solenoid 32 is now in the energized
position and thus fluid passing through the tee junction 70 cannot
flow through the solenoid 36.
[0038] As the process continues, the pumps 60 and 62 continue to
exchange fluid simultaneously to-and-from the chambers 44 and 66 at
about a one-to-one rate. The pump 60 withdraws used fluid from the
chamber 44 while the pump 62 fills the chamber 66 with new fluid.
The pump 64 continues to independently fill the vehicle with fluid
received from the pump 62 via the chamber 66. This process ensures
that the volume of used fluid withdrawn from the vehicle is
replaced by the same volume of new fluid, since the flow of used
fluid from the vehicle controls the flow of new fluid to the
vehicle. Use of the pump 64 to supply new fluid to the transmission
system avoids the prior art difficulties associated with using the
transmission system pump to power the refill process. Further, the
pumps 60 and 62 operating in conjunction with the chambers 44 and
66, ensure about a one-to-one volume replacement of new fluid for
used fluid.
[0039] During the fluid exchange process the withdrawal of used
fluid from the vehicle may not be continuous nor always at a
constant flow rate. Thus the pumps 60 and 62 cycle on and off under
control of the position of the float switch 50 in response to the
used fluid level in the chamber 44. When the fluid in the new fluid
tank 24 nears a bottom surface 72 a float switch 74 is activated,
disconnecting power from the solenoid 36 and returning the solenoid
36 to the normally opened state. The fluid flow path thus returns
to the closed loop configuration in which the fluid flows from the
vehicle through one of the valves 18 and 20, through the fluid flow
indicator 22, the heat coil 30, the pressure gauge 32, the solenoid
36, the tee junction 70, the fluid line 38 and the tee junction 40.
The float switch 74 also activates an indicator on a machine
operator's console (not shown in FIG. 1) to indicate completion of
the fluid exchange process. The operator de-energizes the machine
at the completion of the process by positioning a main shut off
switch (not shown) in an off position, effectively removing power
from the machine components.
[0040] The new fluid volume in the new fluid tank 24, which was
filled to the vehicle's fluid capacity prior to beginning the
exchange process, meters the flow of new fluid into the vehicle to
achieve the volume controlled replacement taught by the present
invention. Use of the pump 64 to infuse new fluid into the vehicle
provides a faster fluid exchange than available with prior art
machines, reducing fluid intermixing and thus ensuring exchange of
a greater percentage of the used transmission fluid for new
transmission fluid.
[0041] During the fluid exchange process if the used fluid reaches
a predetermined upper limit in the chamber 44, the rising fluid
level is sensed by a float switch 52, which in turn de-energizes
the solenoid 36 and the pumps 60 and 62. The machine 10 then
returns to the closed loop mode where the transmission fluid pump
forces fluid through the closed loop circuit of the machine 10.
This feature reduces the possibility of overflowing the chamber 44
and running a vehicle's transmission system dry by continuing to
withdraw fluid from the vehicle.
[0042] If at any time during the fluid exchange process external
power is lost to the machine 10, the solenoid 36 and the pumps 60
and 62 are de-energized and the machine 10 returns to the closed
loop circuit configuration.
[0043] In one embodiment, after the fluid replacement service has
been completed, the machine 10 allows the operator to either lower
or top-off the vehicle's transmission fluid level. Lowering the
level is accomplished by operating the machine 10 in the closed
loop mode and opening a valve/spigot 79 to withdraw fluid from the
vehicle. The vehicle's transmission system pumps fluid from the
vehicle out the opened valve/spigot 79. Since the machine 10
operates on a volume replacement principle, if the vehicle
transmission system was in an over-filled condition prior to the
fluid exchange process, the system will be overfilled at the
conclusion of the replacement process. Thus it may be necessary to
lower the fluid level through the valve/spigot 79 as described.
Also, the flush chemical introduced prior to initiating the fluid
replacement process and any chemicals or fluids added to the system
after finishing the refill process can create an over-filled
condition.
[0044] If the volume of used fluid in the vehicle was low prior to
beginning the refill process the volume of new fluid in the vehicle
will also be low, as the machine 10 provides an approximately
one-to-one fluid volume replacement. The operator can detect a low
fluid volume by checking the dipstick level after completing the
flush and refill process. To fill the transmission system to the
correct volume, the pump 62 is manually activated by an override
switch on the operator's counsel (not shown in FIG. 1) to pump new
fluid from the new fluid tank 24 into the vehicle. Typically, about
a quart of new fluid will remain in the new fluid tank 24 after the
operator de-energizes the machine 10 as described above. Operator
activation of the override switch overrides the float switch 74 and
energizes the pump 62 to fill the chamber 66 with new fluid. The
float switch 54 in the chamber 66 energizes the pump 64 for pumping
new fluid into the vehicle. A check of the fluid level with the
dipstick will reveal when sufficient additional fluid has been
added.
[0045] The valve/spigot 79 can also be used to extract samples of
new or used fluid from the vehicle for inspection by the vehicle
owner or the machine operator. The used fluid is removed via the
valve/spigot 79 while the machine 10 is in closed loop operation
(that is, wherein the solenoid 36 is in the normally opened
position) before new fluid has been pumped into the vehicle. A new
fluid sample is removed via the valve/spigot 79 after the refill
process has been completed by operating the machine 10 in the
closed loop position and opening the valve/spigot 79.
[0046] The service operation of dropping the transmission pan and
replacing the transmission fluid filter can also benefit from use
of the machine 10. This operation typically results in fluid
spillage when the pan is removed from the transmission housing. To
avoid the spillage, after the transmission system is filled with
new fluid, the machine 10 can be run in the closed loop mode to
withdraw new fluid through the valve/spigot 79 (the new fluid is
retained in a container) until air bubbles are visible in the flow
indicator 23. The air bubbles indicate that the pan is empty
because the vehicle transmission pump draws fluid from the pan
sump. The pan is dropped without fluid spillage, the filter is
replaced, the pan is attached to the transmission housing and the
retained new fluid is poured back into the transmission through the
dip stick tube or by using the machine top off process as described
above.
[0047] The new fluid tank 24 can be drained by operating a switch
(not shown) to energize the pump 62. New fluid remaining in the new
fluid tank 24 is pumped into the chamber 66, the float switch 54
activates the pump 64 to pump the new fluid through the
valve/spigot 79 where it can be captured and retained for later
use. Since different fluids may be recommended for different
vehicles, this feature is especially beneficial when different
vehicles are serviced from the same machine 10 or anytime the
operator desires to completely empty the tank and switch to an
alternative transmission fluid.
[0048] In another embodiment of the machine 10, the pump 64 and the
chamber 66 are not present. In such an embodiment the pump 60 pumps
used fluid into the waste fluid tank 67 as described above. New
fluid is pumped to the vehicle by the pump 62 through the fluid
line 42 along the same fluid path as described in the embodiment
above. However, it was recognized by the inventors that if an
obstruction is present in the transmission fluid cooling system,
the pump 62 will encounter some back pressure that reduces the rate
at which new fluid is pumped into the vehicle, while the pump 60
encounters no restriction (open flow) as it pumps used fluid to the
waste fluid tank 67. This situation may cause an unbalanced
exchange rate of new fluid for old fluid, and the volume of new
fluid pumped into the vehicle may therefore be below the
recommended fluid capacity. An embodiment comprising the chamber 66
and the pump 64 is intended to overcome this disadvantage.
[0049] In lieu of using the two valves 18 and 20 as described
above, in another embodiment the machine 10 comprises a four-way
valve, such as a four-way valve 80 illustrated in FIG. 2. A
position of a handle 81 of the four-way valve 80 provides four
different flow paths therethrough. When the handle 81 is in a
position C, ports 83 and 84 (one of which provides fluid to the
vehicle and the other of which receives fluid from the vehicle)
supply fluid flow to ports 82 and 85, respectively. When the handle
81 is in a position D the ports 83 and 84 divert fluid into the
opposite ports, i.e., the port 83 provides fluid to the port 85 and
the port 84 provides fluid to the port 82, respectively. Thus the
single four-way valve 80 operates as a functional replacement for
the two two-way valves 18 and 20.
[0050] In another embodiment of the present invention, a bladder
tank, or a functional equivalent thereto, is inserted into the
fluid path between the pump 64 and the tee junction 70. The bladder
tank operates as a dampener to accept pressure from the pump 64
when a clog is present in the vehicle's transmission system. The
bladder relives the pressure over a time interval dependent on the
extent to which the obstruction causes a low flow rate from the
pump 64.
[0051] In another embodiment the heat coil 30 is replaced by a
fin-type heat exchanger, for example a radiator-like coil,
comprising a plurality of sinuous fluid path segments and cooling
fins extending outwardly therefrom to accelerate the heat transfer
from the hot used fluid to the new cold fluid.
[0052] In the embodiments described above the various float
switches were described as closing or opening to operate the
various pumps of the machine 10. In an alternative embodiment,
closure of the float switch contacts instead causes power to be
supplied to a coil of a relay (not shown in FIG. 1). The energized
coil closes associated relay contacts through which machine power
is supplied to the pump or pumps associated with the operative
float switch. Opening of the float switch contacts causes
de-energization of the relay coil and opening of the associated
relay contacts.
[0053] In yet another embodiment, a second float switch (not shown
in FIG. 1) is included in the chamber 66 for controlling the pump
62. The second float switch shuts down the pump 62 when the fluid
level in the chamber 66 reaches a high fluid limit. Use of the
second float switch in the chamber 64 avoids an overflow situation
where the chamber 66 fills with new fluid faster than the pump 64
can withdraw the fluid and pump the fluid into the vehicle. Such an
overflow of the chamber 66 can be caused, for example, if the pump
64 becomes inoperative or if the vehicle transmission system is
obstructed and preventing the pump 64 from pumping the new fluid
into the system at the desired rate.
[0054] Generally, the machine 10 operates in one of the following
modes: closed loop circulation (wherein the vehicle transmission
system pump pumps the fluid through a closed loop in the machine 10
without replacing old fluid with new fluid), flush, raise fluid
level/empty new fluid tank and lower fluid level.
[0055] The machine operator selects an operational mode by
appropriately positioning one or more switches of the machine 10
(in a preferred embodiment the switches are located on the
operator's console as described below). Operation of a first switch
allows the machine 10 to operate in the raise fluid level/empty
tank mode. In this mode the pump 62 and the solenoid 36 are
energized; the float switch 54 and the pump 64 are enabled. That
is, the float switch 54 is operative to energize the pump 64 in
response to the fluid level in the chamber 66. Further, in this
mode the pump 60 and the float switch 74 are disabled, i.e., the
pump 60 cannot be energized irrespective of the position of the
float switch 74, which in turn is responsive to the fluid level in
the new fluid tank 24. The vehicle fluid level is raised as the
pump 62 supplies new fluid from the new fluid tank 24 to the
chamber 66. The fluid level activates the float switch 54,
energizing the pump 64 to pump fluid into the vehicle. In this mode
the solenoid is in the closed state indicated by the dashed line
fluid flow path.
[0056] To empty the new fluid tank 24 in this mode of operation,
the valve/spigot 79 is opened while the pump 64 is pumping new
fluid. The new fluid is diverted through the valve/spigot 79 before
reaching the vehicle.
[0057] In a second embodiment a second switch (also preferably
located on the operator's console) can be used to lower the
vehicle's fluid level by supplying power to the solenoid 36,
disabling the pump 62 and enabling the float switch 50 to control
the pump 60. With the solenoid energized, fluid is withdrawn from
the vehicle into the chamber 44, activating the float switch 50 and
turning on the pump 60. The operator de-energizes the solenoid 36
to return operation to the closed loop circulation mode when the
vehicle's fluid level has fallen to the correct level.
[0058] A third switch (preferably located on the operator's
console) controls the machine 10 to operate in the flush mode,
during which the solenoid 36 is energized and the various float
switches and pumps in FIG. 1 are enabled, such that in response to
the chamber fluid levels the associated float switch energizes the
appropriate pump.
[0059] Those skilled in the art recognize that the functions of the
individual console switches can be combined such that a
multi-position switch, under operator control, can selectively
cause the machine 10 to operate in the preferred mode.
[0060] Although described herein with reference to the exchange of
transmission fluid in an automotive vehicle, those skilled in the
art recognize that the teachings of the present invention can also
be applied to the exchange of other fluids from a vehicle and
further to the exchange of fluids for other machines. Further,
although the machine 10 and the inventive features thereof have
been described with reference to various pumps, those skilled in
the art recognize that other devices capable of causing fluid flow
can be used in place of conventional pumps, and thus the pumps
described herein are intended to encompass such other devices.
[0061] FIG. 3 illustrates the machine 10 electrically connected to
a vehicle 100 via battery cables 102 and fluidly connected to a
transmission system of the vehicle 100 by the fluid lines 13 and
15. A console 106 of the machine 10 includes the various manually
operated switches and indicators described above.
[0062] A flush and fill process employing the machine 10 begins
when the operator fills the new fluid tank 24. Typically about two
to three quarts of fluid are required fill the various machine
fluid flow paths and the bottom volume of the new fluid tank 24,
that is, the volume below the float switch 74. The operator
continues to fill the new fluid tank 24 until a sight tube 120 on
the tank 24 (see FIG. 1) indicates a tank volume equal to the
vehicle transmission fluid capacity. The tank 24 thus contains the
correct amount of fluid to perform the one-to-one fluid volume
exchange.
[0063] For example, at the start of a typical service on a
twelve-quart capacity vehicle, a technician may add fourteen quarts
of transmission fluid to the machine 10, bringing the sight level
up to the twelve-quart level, with the additional two quarts
refilling the bottom volume of the new fluid tank 24 and any empty
fluid flow paths. During the one-to-one exchange process, twelve
quarts of fluid are pumped from the vehicle, and twelve quarts of
fluid are pumped into the waste fluid tank 67.
[0064] If the vehicle fluid was slightly low when the service
started, it will also be slightly low at the end of the service.
The technician utilizes the top-off feature described above to pump
a partial amount of the extra fluid remaining in the new fluid tank
24, back into the vehicle, thus raising the fluid level in the
vehicle to the proper level.
[0065] By way of illustration, if the technician filled the new
fluid tank 24 with twenty-four quarts of fluid, and then serviced a
twelve-quart vehicle, the vehicle will not be twelve quarts
overfilled. Since the operation according to the present invention
executes a one-to-one fluid exchange, the vehicle's fluid level
remains the same (twelve quarts). However, twelve wasted quarts of
fluid will have been passed through the vehicle, and back into the
waste fluid tank 67.
[0066] While the invention has been described with reference to
preferred embodiments, it will be understood by those skilled in
the art that various changes may be made and equivalent elements
may be substituted for elements thereof without departing from the
scope of the present invention. The scope of the present invention
further includes any combination of the elements from the various
embodiments set forth herein. In addition, modifications may be
made to adapt a particular situation to the teachings of the
present invention without departing from its essential scope
thereof. Therefore, it is intended that the invention not be
limited to the particular embodiment disclosed as the best mode
contemplated for carrying out this invention, but that the
invention will include all embodiments falling within the scope of
the appended claims.
* * * * *