U.S. patent number RE33,687 [Application Number 07/327,036] was granted by the patent office on 1991-09-10 for auxiliary air conditioning, heating and engine warming system for trucks.
This patent grant is currently assigned to Pony Pack, Inc.. Invention is credited to J. Rex Greer.
United States Patent |
RE33,687 |
Greer |
September 10, 1991 |
Auxiliary air conditioning, heating and engine warming system for
trucks
Abstract
A small lightweight auxiliary power plant including an engine,
electrical alternator, water pump, air conditioning compressor and
a heat exchanger is mounted at a convenient location on the tractor
of a truck or other large vehicle. The main engine of the truck
operates the existing truck air conditioning and heating system in
a normal manner when the main engine is running. When the main
engine of the truck is not operating and the smaller engine of the
auxiliary power plant is operating, the truck air conditioning and
heating system is operated by the auxiliary power plant. The heat
exchanger of the auxiliary power plant then utilizes the heat of
exhaust gases generated by the auxiliary power plant engine to warm
the truck engine during the time it is not operating so that easy
starting of the truck engine is made possible even in very cold
regions. The electrical alternator of the auxiliary power plant
supplies electrical power for the truck electrical system when the
truck engine is not running. The truck storage batteries serve the
electrical systems of the truck and the auxiliary power plant. The
auxiliary power plant serves as an emeergency back-up system if the
truck alternator or compressor should fail. The arrangement reduces
air pollution caused by operation of the truck engine for long
periods of time while the truck is stopped. Provision can be made
for warming the fuel tanks and fuel lines to prevent fuel gelling
in cold climates.
Inventors: |
Greer; J. Rex (Fort Sumner,
NM) |
Assignee: |
Pony Pack, Inc. (Fort Sumner,
NM)
|
Family
ID: |
26985692 |
Appl.
No.: |
07/327,036 |
Filed: |
March 22, 1989 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
869607 |
Jun 2, 1986 |
04682649 |
Jul 28, 1987 |
|
|
Current U.S.
Class: |
165/43; 62/244;
180/69.6; 62/236; 123/142.5R; 180/89.1 |
Current CPC
Class: |
B60H
1/3226 (20130101); F25B 27/00 (20130101); F02N
19/10 (20130101); F01P 7/165 (20130101) |
Current International
Class: |
B60H
1/32 (20060101); F02N 17/06 (20060101); F02N
17/00 (20060101); F25B 27/00 (20060101); F01P
7/16 (20060101); F01P 7/14 (20060101); F02N
017/06 (); B60H 001/32 () |
Field of
Search: |
;180/69.6,89.1
;62/127,323,239,244,196.4,236 ;123/142.5R ;165/42,43 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Bertsch; Richard A.
Attorney, Agent or Firm: Birch, Stewart, Kolasch &
Birch
Claims
What is claimed is:
1. An air conditioning, heating and engine warming system for
trucks and like vehicles comprising:
an engine including a block connected to a radiator;
an engine and truck air conditioning and heating system including a
truck compressor, a condenser, refrigerant lines extending from the
truck compressor to at least one air conditioning unit and
extending from the air conditioning unit to the condenser and back
to the truck compressor, and heater conduits extending from the
engine block to at least one heating unit and extending back to the
engine block;
an auxiliary power plant on the truck including an auxiliary
engine, alternator, coolant system including a water pump and an
air conditioning compressor each driven by the auxiliary engine,
and a heat exchanger having a chamber located immediately adjacent
the auxiliary engine for receiving hot exhaust gases therefrom and
having a liquid heating coil within said chamber in heat transfer
relationship with the exhaust gases,
a first coolant conduit coupled from the engine block to one side
of the heating coil of the heat exchanger and a second coolant
conduit coupled directly back to the engine block, said second
coolant conduit being additionally coupled to the other side of
said heating coil,
a circulating pump connected in the first conduit between the
engine block and the heating coil;
the return of heated water to the engine block from said second
conduit acting to warm the engine block and thus aid starting of
the truck engine in cold weather when the auxiliary power plant is
operated;
additional refrigerant lines coupling the compressor of the
auxiliary power plant to refrigerant lines connecting said air
conditioning unit and said condenser whereby refrigerant can be
independently supplied to the truck air conditioning system from
the compressor of the auxiliary power plant when said auxiliary
power plant is operated; and
means in the refrigerant lines between the truck compressor and
said one air conditioning unit and between the compressor of the
auxiliary power plant and said one air conditioning unit for
restricting back flow of refrigerant between the two said
compressors.
2. In an air conditioning and heating system as defined in claim 1,
wherein said means for restricting back flow comprise automatic
pressure-actuated cut-off valves.
3. In an air conditioning and heating system as defined in claim 1,
and additionally including a third coolant conduit coupled from
said radiator to the coolant system of the auxiliary engine and
through the water pump thereof, and a fourth coolant conduit
coupled from said water pump directly back to the engine block, the
return of the heated water to the engine block from said fourth
conduit also acting to warm the engine block.
4. In an air conditioning and heating system as defined in claim 3,
and additionally including means connected in said first and second
cooling conduits on either side of the heating coil of said heat
exchanger for allowing the heat exchanger to boil dry when the
circulating pump is inactive and to prevent undesired back flow
through the heating coil from the water pump of said auxiliary
power plant.
5. In an air conditioning and heating system as defined by claim 3,
and wherein said second and fourth coolant circuits are commonly
connected.
6. In an air conditioning and heating system as defined by claim 3,
additionally including first and second valve means coupled to
opposite sides of said heating coil, said first valve means being
further coupled in said first coolant conduit between the
circulating pump and the heating coil, and said second valve means
being coupled between the heating coil and said second coolant
conduit, whereby undesired back flow through the heating coil from
said water pump is prevented and the heat exchanger is boiled dry
when the circulation pump is turned off.
7. In an air conditioning and heating system as defined in claim 6,
wherein said valve means comprise one-way check valves.
8. In an air conditioning and heating system as defined by claim 7,
wherein said connecting means comprise a pair of T connectors.
9. In an air conditioning and heating system as defined by claim 1,
and additionally including means commonly connecting the
refrigerant lines extending from and to the truck compressor and
the refrigerant lines extending from and to the compressor of the
auxiliary power to the refrigerant lines extending to and from said
at least one air conditioning unit and condenser.
10. In an air conditioning and heating system as defined by claim
1, and additionally including a temperature responsive switch in
thermal contact with the engine block and being electrically
connected to said circulating pump for controlling activation of
the pump to maintain the engine at a predetermined temperature when
the truck engine is not running.
11. In an air conditioning and heating system defined by claim 1,
and including a cab and a sleeping compartment and wherein said at
least one air conditioning and heating units are selectively
located in either said cab or said sleeping compartment.
12. In an air conditioning and heating system as defined by claim
11, and additionally including another air conditioning unit and
another heating unit located in the other said cab or said sleeping
compartment, and additionally including refrigerant lines coupling
both said air conditioning units in series, and heater conduits
coupling both said heating units in series.
13. In an air conditioning and heating system as defined by claim
12, and additionally including separate controls in said cab and
said sleeping compartment for independently controlling the heating
and air conditioning units at each location.
14. In an air conditioning and heating system as defined by claim
1, wherein said auxiliary engine comprises an internal combustion
engine.
15. In an air conditioning and heating system as defined by claim
14, wherein said internal combustion engine comprises a relatively
small diesel engine.
16. In an air conditioning, heating and engine warming system as
defined in claim 1, and further comprising a vehicle alternator, an
auxiliary power plant alternator, a vehicle storage battery, and
circuitry coupled to said battery, said circuitry including a
vehicle ignition switch and another switch independent of the
vehicle ignition switch, said another switch being operable to
start the auxiliary engine of the auxiliary power plant when the
vehicle ignition switch interrupts the vehicle ignition circuit,
said auxiliary power plant alternator being further connected to
and operable to charge said battery in place of said vehicle
alternator when the auxiliary power plant is operating.
17. In an air conditioning and heating system as defined by claim
1, and additionally including a water line passing through said
heat exchanger and being in thermal contact with selected fuel
lines of said truck engine and said auxiliary engine for warming
said fuel lines in cold weather. .Iadd.
18. In combination, a truck including a cab, a water cooled primary
engine, an air conditioning system including a first compressor
driven by said engine, air conditioning means and condenser means,
and a heating system operatively connected to the coolant of the
engine,
an auxiliary engine mounted on said truck and including a second
air conditioner compressor driven thereby, condenser means
operatively connected to said second compressor,
an alternator mounted on and driven by said auxiliary engine, said
alternator being operatively connected to the truck's electrical
system to supply electricity thereto when said primary engine is
not running,
means operatively connecting one side of said condenser means to
said air conditioning means,
means connecting the air conditioning means to said second air
conditioner compressor,
and control means for selectively supplying refrigerant from either
said second compressor or said first compressor to said air
conditioning means whereby the interior of said cab may be cooled
without operating the engine of said truck. .Iaddend. .Iadd.
19. The combination of claim 18 wherein said auxiliary engine is
water cooled and wherein means fluidly connects the coolant in said
auxiliary engine to said heating system whereby the hot coolant
water in said auxiliary engine may be supplied to said heating
system to provide heat to the interior of said cab without
operating the truck engine. .Iaddend. .Iadd.20. The combination of
claim 19 wherein means is provided for further heating the coolant
water by said auxiliary engine. .Iaddend. .Iadd.21. The combination
of claim 19 wherein the hot coolant water from the auxiliary engine
also heats the fuel in the truck fuel tank. .Iaddend.
.Iadd.22. A truck including a cab, comprising:
a water-cooled primary engine including a radiator for cooling
fluid moving through the water jacket of the engine,
a heating system for heating the interior of the cab including
heater unit means operatively connected to the hot fluid moving
through the water jacket,
an auxiliary water-cooled engine mounted on said truck,
an alternator mounted on and driven by said auxiliary engine, said
alternator being operatively connected to the truck electrical
system to supply electricity thereto when said primary engine is
not running,
means fluidly connecting the coolant water of said auxiliary engine
to said heater unit means to selectively supply hot coolant water
from said auxiliary engine to said heater unit means when said
primary engine is not running, whereby said auxiliary engine will
provide heat to the interior
of said cab without operating said primary engine. .Iaddend.
.Iadd.23. The apparatus of claim 22 wherein means is provided for
further heating the coolant water by said auxiliary engine.
.Iaddend.
Description
BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates to air conditioning and heating systems for
trucks or other large vehicles, and more particularly relates to an
auxiliary power plant which operates in conjunction with the
existing air conditioning and heating system of the vehicle and
also serves to warm the engine of the vehicle to enable easy
starting of the vehicle engine in cold weather.
2. Description of the Prior Art
Auxiliary systems are known in the prior art for heating a vehicle
engine and its fuel line while the engine is not operating.
Examples of such prior art are present in U.S. Pat. Nos. 3,877,639
and 4,192,457. U.S. Pat. No. 4,454,984 discloses an auxiliary
system for heating a truck cab in which the truck storage batteries
operate an auxiliary pump.
U.S. Pat. No. 4,531,379 discloses an auxiliary power system for a
vehicle air conditioner and heater. The system is designed for an
automobile or van. It utilizes a jack shaft assembly equipped with
an electromagnetic clutch to transfer power from an auxiliary
engine to an existing air compressor of the vehicle when the main
engine of the vehicle is not operating.
The objective of the present invention is to improve on the known
prior art through provision of an auxiliary power plant for trucks
or other large vehicles which is operatively connected with the
existing air conditioning and heating system of the vehicle in such
a way that the auxiliary power plant can efficiently operate the
air conditioning and heating system of the vehicle during such
times when the engine of the vehicle is not operating. To enable
this, the auxiliary power plant possesses its own engine,
alternator, air conditioning compressor, water pump and a heat
exchanger which includes heating coils connected in the water
cooling circuit of the vehicle main engine and being in heat
exchange relationship with the exhaust system of the engine of the
auxiliary plant.
A further important object of the invention is to provide in an
auxiliary power plant of the type mentioned means for warming the
main engine of the truck or other large vehicle when such main
engine is not operating, to thereby render easy the starting of the
main engine in cold weather after long periods of idleness.
Another important object of the invention is to provide an
auxiliary power plant whose dimensions do not exceed approximately
18".times.18".times.24" and whose weight including its frame does
not exceed approximately 200 pounds, thus enabling the power plant
to be installed conveniently at available locations on different
makes and models of trucks.
Other features and advantages of the invention will become apparent
to those skilled in the art during the course of the following
description.
As used herein, the word "truck" is not to be taken in a limiting
sense, and is intended to apply to any large vehicle, such as a
bus, road building equipment, or a mililary vehicle.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side elevation of a truck air conditioning
and heating system and an auxiliary power plant for such system
according to the present invention.
FIG. 2 is a side elevation of a truck tractor having the invention
applied thereto.
FIG. 3 is an enlarged vertical section taken on line 3--3 of FIG.
2.
FIG. 4 is a partial schematic view of the truck ignition system as
involved in the present system.
FIG. 5 is a schematic view showing terminals of a dash mounted
switch and associated elements.
DETAILED DESCRIPTION
Referring to the drawings in detail wherein like numerals designate
like parts, a conventional semi-trailer truck includes a tractor 10
having a compartment 11 for the truck engine 12, such as diesel
engine. The truck engine is equipped with a radiator 13, behind
which is located the usual fan 14 driven by a pulley means 15 on
the engine crank shaft 16. A truck alternator 17 is operated by a
drive belt and pulley 18 driven by the pulley means 15. Similarly,
a truck air conditioning compressor 19 is operated by a belt and
pulley 20 driven by the pulley means 15.
The truck cab is equipped with a dash-mounted conventional
ac/heater unit 21, and a separate ac/heater unit 22 is provided in
the sleeping compartment of the truck tractor. The truck air
conditioning condenser 23 may be grill or roof mounted, as found
desirable. When grill mounted, an electric temperature controlled
fan, not shown, is added to cool the condenser while the vehicle is
stationary, or the truck engine fan 14 can be replaced by a full
electric fan.
An auxiliary power plant 24 forming the principal subject matter of
the invention includes a suitable supporting and unitizing frame,
and may be mounted at any convenient location on the truck tractor,
such as behind the cab on the tractor main frame, or in the
location of the customary cab step.
The auxiliary power plant 24 comprises a small engine 26 such as a
Kubota diesel engine or an equivalent engine. The engine 26 drives
a crank shaft pulley 27, connected through a belt 28 with a pulley
29 of the power plant compressor 30. Another belt 31 driven by the
crank shaft pulley 27 drives a power plant alternator 32, and also
drives a power plant water pump 33.
A power plant heat exchanger 34 includes a chamber 35 receiving hot
exhaust gases from an exhaust port 36 of the power plant engine 26.
From the chamber 35, the spent exhaust gases pass to a muffler 37,
which, for added safety, is preferably connected into the customary
vertical exhaust stack 37' of the truck tractor 10, FIG. 2.
Within the chamber 35, the heat exchanger 34 includes heat
exchanger coils 38 preferably formed of copper and being of any
thermally efficient shape, such as wide, flat, thin coils.
A preferably insulated conduit 39 leads from the water jacket of
the truck engine 12 to the inlet end of the heat exchanger coil 38
and another insulated conduit 40 leads from the outlet end of the
heat exchanger coil back to the water jacket of truck engine 12. A
branch conduit 41 interconnects the power plant water pump 33 with
the water return conduit 40. Another preferably insulated conduit
42 leads from the truck radiator 13 to the water jacket of the
power pant engine 26.
A water circulating pump 43 is connected in the conduit 39 and
pulls water from one side of the truck engine 12, pumping it
through the power plant heat exchanger coil 38 and back through the
conduit 40 to the other side of the truck engine.
One-way check valves 44 are installed in the conduits 39 and 40
near the opposite ends of the heat exchanger coil 38. When the
circulating pump 43 is off, the check valves 44 allow the heat
exchanger 34 to boil dry, thereby stopping the heat transfer
process by preventing any back-flow of water through the lines 40
and 39.
Air conditioning pressure lines 45 and 46 lead from the truck
compressor 19 serially through the truck cab and sleeper
compartment ac units 47 and 48, each having their own controls, and
from these units back to the truck compressor 19. The return
refrigerant line 46 has the condenser 23 connected therein
immediately before the T-fitting 52 also connected with the return
refrigerant line 50.
Auxiliary air conditioning pressure lines 49 and 50 lead from and
to the power plant compressor 30 and are connected by T-fittings 51
and 52 with the truck air conditioning pressure lines 45 and 46,
respectively. Cut-off valves 53 are placed in the lines 45 and 49
leading from the two compressor 19 and 30. Automatic
pressure-actuated one-way cut-off valves are preferred, although
electric valves or even manual valves can be used to assure the
flow of freon in one direction only. The valves 53 are critical to
the operation of the system having the two compressors 19 and
30.
Existing truck heater hoses 54 and 55 extend to and from the truck
engine water cooling system and pass serially through the truck cab
dash-mounted and sleeper compartment heater units having their own
heater controls, as shown. A circulating pump 56 is connected in
the heater hose 54, with a control switch on the power plant panel,
not shown, which control panel can be located at any convenient
point on the truck. The power plant control panel is wired into the
truck electrical system so that the power plant alternator 32
charges the existing truck storage batteries 57, which are the only
batteries employed in the entire system. When the truck engine 12
is not operating, the power plant alternator 32 operates the total
electrical system embodied in the invention.
A cable 58 interconnects the truck storage batteries with the
starter 59 of power plant engine 26. The starter is conventional. A
temperature-responsive on-off switch 62 of the type commonly used
for fans is provided for the control of circulating pump 43 and is
connected therewith by a conductor 63. The switch 62 is in thermal
contact with the truck engine 12. In lieu of the thermal switch 62,
a manual on-off switch could be used to turn off the circulating
pump 43 when the desired temperature of the truck engine 12 is
reached while such engine is not running.
Operation
When the truck engine 12 is running, as when the truck is traveling
or stopped for a short time period only, the truck air conditioning
and heating systems operate in a conventional manner to supply
conditioned air or warm air to the truck cab and/or sleeping
compartment through the individually controllable units 21 and 22.
At this time, the auxiliary power plant including its small engine
26 is inactive and has no effect on the operation of the truck air
conditioning and heating systems or its electrical system.
When the truck stops for a lengthy period and its engine 12 is shut
off, the operation of the truck alternator 17 and compressor 19 of
course ceases. At this time, the auxiliary power plant 24 is
activated by starting its relatively small engine 26, which
activates the alternator 32, water pump 33 and the compressor 30
whenever air conditioning of the truck cab and/or sleeping
compartment is demanded. When it is demanded, the connections of
the pressurized freon lines 49 and 50 through the T-fittings 51 and
52 will supply air conditioning in the same manner that it would
ordinarily be supplied by the truck system including the compressor
19.
Simultaneously, the circulating pump 43 constantly draws water from
the truck engine water cooling system and pumps it through the coil
38 of the power plant heat exchanger 34 and back to the truck
engine, whereby proper heating of the cab and/or sleeping
compartment is made available on demand even though the truck
engine is not operating.
The heat of the exhaust gases from the power plant engine 26 is
utilized to heat the water flowing through the heat exchanger coil
38 in a continuous and efficient manner as long as the small engine
26 operates.
Additionally, the heated water flowing to and from the water jacket
of the truck engine 12 through the insulating conduits 40 and 39
maintains the truck engine warm so that it will start quickly even
in very cold weather. This added capability of the invention for
warming the truck engine while making availble cab and sleeping
compartment heating and air conditioning is a very important
feature not heretofore available in the prior art. The provision of
the additional circulating pump 56 in the existing truck heater
conduit system renders the operation of the invention even more
efficient. The cut-off valves 53 in the freon pressure lines 45 and
49 are essential to the proper operation of the air conditioning
system in accordance with the invention.
It may now be seen that the invention is characterized by
convenience and simplicity of construction and operation. Existing
components on the truck or other large vehicle are used in the
normal manner while the truck engine 12 is operating. When the
truck engine is not operating and the auxiliary power plant 24 is
in use, existing components of the truck heating and air
conditioning systems are still employed and therefore complete
duplication of system parts is avoided. Only such parts as are
essential to the proper functioning of the truck heating and air
conditioning system, and essential to maintaining the truck engine
warm while shut off for long periods, are included in the auxiliary
power plant 24. These essential components are the small engine 26,
alternator 32, compressor 30, heat exchanger 34 and the water pump
33. Throughout the system embodying the invention, conventional
commercial shelf components are used almost entirely. The heat
exchanger 34 is basically the only customized component of the
invention, and the heat exchanger is quite simplified in
construction.
As shown in FIG. 2, the auxiliary power plant 24, in many cases,
can be mounted on the main frame of the tractor 10 behind its fuel
tanks 64. The exact location of the power plant 24 will depend on
the style or configuration of the particular truck or other large
vehicle to which the invention is applied. Because of its lightness
and compactness, the auxiliary power plant 24 can easily be
installed on practically any large vehicle whether a truck, bus,
military vehicle or road building machine.
A desirable optional feature of the invention where use is
contemplated in extremely cold conditions consists of providing a
convenient and economical means of warming the fuel lines 65 and
65a extending from the fuel tank or tanks 64 to the truck engine 12
or auxiliary power plant engine 26. This means preferably comprises
the provision of a hot water line 66, FIG. 3, extending to or from
the heat exchanger 34, FIG. 2, and being placed in thermal contact
with the fuel lines 65 and 65a, both lines being jacketed with
insulation 67. This arrangement is fully effective in preventing
gelling of the diesel fuel even in extremely cold weather. All of
the necessary heat is provided by the exhaust of the small engine
26. This heat is more than adequate to warm the truck engine 12
while simultaneously warming the lines feeding fuel to both engines
12 and 26.
Since the fuel lines 65 and 65a are connected with the fuel tank 64
at or near its bottom, there is almost never a problem with gelling
of fuel in the tank. However, if desired, some external insulation
can be provided on the bottom of the tank 64.
Referring to FIG. 4, the truck storage battery means 57 and battery
cable 58 leading to the solenoid of the starter 59 for the power
plant engine 26 is indicated. Another cable 68 interconnects the
storage battery means 57 to the conventional electrical system of
the truck, which system need not be illustrated in detail. The
conventional truck ignition switch 69 has one terminal thereof
connected with a conductor 70 leading to the starter solenoid 59 of
power plant engine 26, the conductor 70 being the hot conductor.
Another terminal of the ignition switch 69 is connected with a
power plant engine starter wire 71. A third terminal of the switch
69 interconnects that switch with the power plant alternator 32
through a conventional ammeter 72.
A dash-mounted, preferably key operated, double pole double throw
(DPDT) switch 73, FIG. 5, separate from the truck ignition switch
69 is provided. Conductors 74 and 75 extend from terminals 76 and
77 of the switch 73, respectively, to the electric clutch of the
power plant air conditioning compressor 30 and to form a new hot
wire to supply power when the truck ignition key is turned off.
Terminals 78 and 79 of the switch 73 are connected through
conductors 80 and 81 to the electric clutch of truck compressor 19
and to the controls of the truck air conditioning units 47 and 48.
Terminals 82 and 83 of the switch 73 are connected, respectively,
to a conductor 84 leading to the clutch of truck compressor 19, and
to a conductor 85 which is the normal hot wire from the truck
ignition system to the switch 73.
It is to be understood that the form of the invention herewith
shown and described is to be taken as a preferred example of the
same, and that various changes in the shape, size and arrangement
of parts may be resorted to, without departing from the spirit of
the invention or scope of the subjoined claims.
* * * * *