RELATED APPLICATIONS

This application (Attorney's Ref. No. P219545pct) claims benefit of U.S.

Provisional Application Serial No. 62/571 , 181 filed October 1 1 , 2017, the contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to auxiliary power units (APUs) for use on vehicles and, in particular, APUs configured to consume fuel such as gasoline, diesel, or propane.

BACKGROUND

Vehicles such as cars, trucks, busses, and boats have a primary motor capable of moving the vehicle. The primary motor is also typically capable of generating power for secondary vehicle systems such as lighting, safety, security, communications, entertainment, navigation, heating, ventilating, and air conditioning. While the primary motor is operating to move the vehicle, the primary motor typically may efficiently be used to generate power for such secondary systems. When the primary motor is not moving the vehicle, operation of the primary motor to generate power for ancillary system may not be efficient. In the context of this application, the term "efficient" typically refers to efficient consumption of fuel and/or to the provision of energy in an

environmentally sensitive manner.

Vehicles are typically provided with what may be referred to as an auxiliary power unit (APU) capable of generating power for at least a portion of the secondary vehicle systems. For example, most vehicles include a battery that is charged by the primary motor when the primary motor is operating and which is capable of providing power to at least some of the secondary vehicle systems when the primary motor is not operating. Larger vehicles such as trucks, busses, and boats may be provided with APUs in the form of on-board generators.

Generators used as APUs are typically smaller and more efficient than the primary motor when used to supply power to secondary vehicle systems.

Accordingly, APUs are typically operated to supply power to secondary vehicle systems when the vehicle is stationary (e.g., primary motor not operating).

However, APUs may have utility when the primary motor is operating as well.

The present invention relates to APU systems and methods that are optimized for use on vehicles.

SUMMARY

The present invention may be embodied as an auxiliary power unit system for use on a vehicle comprising a load. The auxiliary power unit system comprises a housing assembly, a fuel tank assembly, and a generator assembly. The housing assembly comprises a first electrical connector operatively connected to the load of the vehicle and defines a first compartment portion and a second compartment portion, where the first electrical connector is within the second compartment. The fuel tank assembly comprises a fuel tank and a fuel hose and defines a fuel tank outlet. The generator assembly comprises a generator housing, a second electrical connector, and a generator fuel inlet. When the generator assembly is arranged in an engaged position within the second compartment portion, the second electrical connector engages the first electrical connector. The fuel hose extends between the fuel tank outlet and the generator fuel inlet to allow fuel to flow from the fuel tank to the generator assembly. The present invention may also be embodied as a method of supplying power to a load of a vehicle comprising the following steps. A housing assembly comprising a first electrical connector and defining a first compartment portion and a second compartment portion is provided. The first electrical connector is within the second compartment. The first electrical connector is operatively connected to the load of the vehicle. A fuel tank defining a fuel tank outlet is provided. The fuel tank is arranged within the first compartment portion. A generator assembly comprising a generator housing, a second electrical connector, and a generator fuel inlet is provided. The generator assembly is arranged in an engaged position within the second compartment portion in which the second electrical connector engages the first electrical connector. A fuel hose is operatively connected between the fuel tank outlet and the generator fuel inlet to allow fuel to flow from the fuel tank to the generator assembly. The generator assembly is operated to supply electrical power to the load of the vehicle.

The present invention may also be embodied as an auxiliary power unit system for use on a vehicle comprising a load and a main fuel tank. The auxiliary power unit system of the present invention comprises a housing assembly, an auxiliary fuel tank assembly, a main fuel hose, and a generator assembly. The housing assembly defines a first compartment portion and a second compartment portion and comprises a first rail set arranged within the first compartment portion, a second rail set arranged within the second compartment portion, and a first electrical connector operatively connected to the load of the vehicle and arranged within the second compartment. The auxiliary fuel tank assembly comprises an auxiliary fuel tank and an auxiliary fuel hose. The fuel tank assembly defines an auxiliary fuel tank outlet. The main fuel hose operatively is connected to the main fuel tank. The generator assembly comprises a generator housing, a second electrical connector, and a generator fuel inlet. The auxiliary fuel tank is supported by the first rail set within the first compartment portion. The generator assembly is supported by the second rail set within the second compartment portion. With the generator assembly in an engaged position within the second compartment portion, the second electrical connector engages the first electrical connector. The auxiliary fuel hose extends between the auxiliary fuel tank outlet and the generator fuel inlet to allow fuel to flow from the auxiliary fuel tank to the generator assembly. The main fuel hose extends between the main fuel tank and the generator fuel inlet to allow fuel to flow from the main fuel tank to the generator assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a side elevation view of a tractor used as part of a tractor-trailer type vehicle, where a first example APU of the present invention is supported by a frame of the tractor;

Figure 2 is a side view of the first example APU;

Figure 3 is a partial cutaway, top plan view of the first example APU taken along lines 3-3 in Figure 2, Figure 3 illustrating the first example APU in an engaged configuration;

Figure 4 is a partial cutaway, end elevation view of the first example APU in the engaged configuration taken along lines 4-4 in Figure 2, Figure 4 also illustrating a cover that may be used to protect the first example APU;

Figure 5 is a top plan view of the first example APU in a disengaged

configuration;

Figure 6 is a partial cutaway, end elevation view of the first example APU similar to Figure 4, Figure 6 illustrating the first example APU in the disengaged configuration and with the cover removed;

Figure 7 is a top plan view of a second example APU in an engaged

configuration;

Figure 8 is a top plan view of the second example APU in a disengaged configuration;

Figure 9 is a side elevation view of a third example APU in a locked

configuration;

Figure 10 is a partial cutaway, end elevation view of the third example APU in the locked configuration; and

Figure 1 1 is a partial cutaway, end elevation view of the third example APU in an unlocked configuration;

Figure 12 is a side elevation view of a tractor used as part of a tractor-trailer type vehicle, where a second example APU of the present invention is supported by a frame of the tractor; and

Figure 13 is a partial cutaway, top plan view of the second example APU illustrating the second example APU in an engaged configuration.

DETAILED DESCRIPTION

Referring initially to Figures 1 -6 of the drawing, depicted therein is a first example APU system 20 constructed in accordance with, and embodying, the principles of the present invention. The first example APU system 20 is mounted on a frame 22 of a vehicle 24 such as a tractor. The first example APU system 20 is mounted on a passenger side of the vehicle 24, but may be mounted on the driver side of the vehicle 24 or between frame members 26 forming the frame 22. The frame 22, vehicle 24, and frame members 26 are all well-known in the art and will be described herein only to that extent helpful for a complete

understanding of the present invention.

Figure 1 further illustrates that the example vehicle 24 comprises a load 28. The load 28 may be any electrical load supported by the vehicle 24, and the example load 28 may be formed by one or more secondary vehicle systems such as lighting, safety, security, communications, entertainment, navigation, heating, ventilating, and/or air conditioning systems. A cable assembly 28a allows electrical power to flow to the load 28.

The first example APU system 20 comprises a housing assembly 30, a fuel tank assembly 32, and a generator assembly 34. The generator assembly 34 generates electricity from fuel and may incorporate any generator capable of using the fuel in the fuel tank assembly 32 to generate electricity as appropriate for the load 28. One example generator suitable for use as part of the generator assembly 34 is a micro turbine generator comprising a compressor, combustor, turbine, and electric generator on a single shaft. Micro turbine generators are desirable because they are highly efficient, and example micro turbines suitable for use as part of the generator assembly 34 include micro turbine generators from MTT Micro Turbine Technology BV. The example housing assembly 30 comprises a housing 40, a tank rail set 42, a generator rail set 44, and a first electrical connector 46. The example housing 40 further defines an inner wall 48. In the example vehicle 24, the example first electrical connector 46 is operatively connected to the load 28 through the example cable assembly 28a.

The example housing assembly 30 further defines a housing compartment 50 and comprises a cover 52 adapted to selectively cover an access opening 54 that allows access to the housing compartment 50. The housing compartment 50 may be substantially enclosed when the cover 52 is detachably attached to the housing 40. The example inner wall 48 of the example housing 40 separates the housing compartment 50 into a first compartment portion 50a and a second compartment portion 50b.

The tank rail set 42 comprises a first tank rail 60 and a second tank rail 62. Each of the first tank rail 60 and second tank rail 62 defines a tank support portion 64 and a tank guide portion 66. The tank support portions 64 are substantially coplanar, and the tank guide portions 66 are substantially parallel. The tank support portions 64 are arranged between the tank guide portions 66.

The generator rail set 44 comprises a first generator rail 70 and a second generator rail 72. Each of the first generator rail 70 and second generator rail 72 defines a generator support portion 74 and a generator guide portion 76. The example generator support portions 74 are substantially coplanar, and the example generator guide portions 76 are substantially parallel. The generator support portions 74 are arranged between the generator guide portions 76. The example generator support portions 74 are substantially coplanar with the example tank support portions 64, and the example generator guide portions 76 are substantially parallel to the example tank guide portions 66. The example fuel tank assembly 32 comprises a fuel tank 80, a fuel tank outlet 82, and a fuel hose 84. The example fuel hose 84 defines a fuel hose first end assembly 86 and a fuel hose second end assembly 88. The fuel hose first end assembly 86 is configured to engage the fuel tank outlet 82 to allow flow of fuel from the fuel tank 80, through the fuel hose 84, and out of the fuel hose second end assembly 88.

The example generator assembly 34 comprises a generator housing 90, a second electrical connector 92, and a generator fuel inlet 94. The fuel hose second end assembly 88 is configured to engage the generator fuel inlet 94 to allow fuel flowing from the fuel hose second end assembly 88 to flow into the generator fuel inlet 94.

The example first and second tank rails 60 and 62 support the fuel tank 80 and hold the fuel tank 80 in a desired position within the housing compartment 50. The example first and second generator rails 70 and 72 support the generator assembly 34 and guide the generator assembly 34 between a disengaged position as shown in Figures 5 and 6 and an engaged position as shown in Figures 3 and 4. In the engaged position, the first and second electrical connectors 46 and 92 engage each other to allow electrical current to flow from generator assembly 34 and into the load 28 defined by the vehicle 24. The generator guide portions 76 engage the generator housing 90 such that the second electrical connector 92 engages the first electrical connector 46 as the generator assembly 34 is displaced from the disengaged position to the engaged position.

So arranged, fuel is supplied to the generator assembly 34 from the fuel tank 80 through tank fuel outlet 82, the fuel hose 84, and the generator fuel inlet 94. When operated to consume the fuel supplied from the fuel tank 80, the generator assembly 34 supplies electricity to the load 28 through the first and second electrical connectors 46 and 92 and the cable assembly 28a.

Referring now to Figures 7 and 8 of the drawings, depicted therein is a second example APU 120 which comprises a housing assembly 130, a fuel tank assembly 132, and a generator assembly 134. The second example APU 120 is configured to be supported by the frame 22 of the vehicle 24 in a manner similar to that of the first example APU system 20.

The example housing assembly 130 comprises a housing 140, a tank rail set 142, a generator rail set 144, and a first electrical connector 146. The example first electrical connector 146 is operatively connected to the load 28 supported by the vehicle 24.

The example housing assembly 130 further defines a housing compartment 150 and comprises a cover (not shown) adapted to selectively cover an access opening 152 that allows access to the housing compartment 150. The housing compartment 150 may be substantially enclosed when the cover is detachably attached to the housing 140.

The tank rail set 142 comprises a first tank rail 160 and a second tank rail 162. Each of the first tank rail 160 and second tank rail 162 defines a tank support portion 164 and a tank guide portion 166. The tank support portions 164 are substantially coplanar, and the tank guide portions 166 are substantially parallel. The tank support portions 164 are arranged between the tank guide portions 166.

The generator rail set 144 comprises a first generator rail 170 and a second generator rail 172. Each of the first generator rail 170 and second generator rail 172 defines a generator support portion 174 and a generator guide portion 176. The generator support portions 174 are substantially coplanar, and the generator guide portions 176 are substantially parallel. The generator support portions 174 are arranged between the generator guide portions 176. The example generator support portions 174 are substantially coplanar with the example tank support portions 164, and the example generator guide portions 176 are substantially parallel to the example tank guide portions 166.

The example fuel tank assembly 132 comprises a fuel tank 180, a fuel tank outlet 182, and a fuel hose 184. The example fuel hose 184 defines a fuel hose first end assembly 186 and a fuel hose second end assembly 188. The fuel hose first end assembly 186 is configured to engage the fuel tank outlet 182 to allow flow of fuel from the fuel tank 180, through the fuel hose 184, and out of the fuel hose second end assembly 188.

The example generator assembly 134 comprises a generator housing 190, a second electrical connector 192, and a generator fuel inlet 194. The fuel hose second end assembly 188 is configured to engage the generator fuel inlet 194 to allow fuel flowing from the fuel hose second end assembly 188 to flow into the generator fuel inlet 194. Further, the example fuel hose 184 is arranged such that the example fuel hose second end assembly 188 is supported by the housing 140.

The example first and second tank rails 160 and 162 support the fuel tank 180 and hold the fuel tank 180 in a desired position within the housing compartment 150. The example first and second generator rails 170 and 172 support the generator assembly 134 and guide the generator assembly 134 between a disengaged position as shown in Figure 8 and an engaged position as shown in Figure 7. In the engaged position, the first and second electrical connectors 146 and 192 engage each other to allow electrical current to flow from generator assembly 134 and into the load 28 defined by the vehicle 24. In the engaged position, the generator fuel inlet 194 engages the fuel hose second assembly 188. The generator guide portions 176 engage the generator housing 190 such that, as the generator assembly 134 is displaced from the disengaged position to the engaged position, the second electrical connector 192 engages the first electrical connector 146 and the generator fuel inlet 194 engages the fuel hose second assembly 188.

A third example APU 220 depicted in Figures 9-1 1 is similar to the first example APU system 20 described above but uses first and second lock systems 230 and 232 to secure the tank assembly 32 and generator assembly 34. The first and second lock systems 230 and 232 each comprises a hinge portion 340, a lock bar 342, a latch system 344, and a lock 346. The example latch system 344 comprises a latch projection 350 extending from the housing 40 and a latch slot 352 formed in the lock bar 342. A lock opening 354 is formed in the latch projection 350.

The hinge allows the lock bar 342 to be moved between a locked position

(Figures 9 and 10) and an unlocked position (Figure 1 1 ). In the locked position, the latch projection 350 extends through the latch slot 352. The lock 346 may be arranged through the lock opening 354 to present movement of the lock bar 342 out of the locked position. In the locked position, the lock bar 342 prevents unauthorized removal of either the tank assembly 32 or the generator assembly 34.

Turning now to Figures 12 and 13 of the drawings, depicted therein is a second example APU system 420 constructed in accordance with, and embodying, the principles of the present invention. The second example APU system 420 is mounted on a frame 422 of a vehicle 424 such as a tractor. The second example APU system 420 is mounted on a passenger side of the vehicle 424, but may be mounted on the driver side of the vehicle 424 or between frame members 426 forming the frame 422. The frame 422, vehicle 424, and frame members 426 are all well-known in the art and will be described herein only to that extent helpful for a complete understanding of the present invention.

Figure 12 further illustrates that the example vehicle 424 comprises a load 428. The load 428 may be any electrical load supported by the vehicle 424, and the example load 428 may be formed by one or more secondary vehicle systems such as lighting, safety, security, communications, entertainment, navigation, heating, ventilating, and/or air conditioning systems. A cable assembly 428a allows electrical power to flow to the load 428.

The second example APU system 420 comprises a housing assembly 430, a fuel tank assembly 432, and a generator assembly 434. The example housing assembly 430 defines a first electrical connector 436 and otherwise may be the same as or similar to the example housing assembly 30 described above and will not be described herein again in detail.

The example fuel tank assembly 432 comprises an auxiliary fuel tank 440, a fuel tank outlet 442, and an auxiliary fuel hose 444. The example auxiliary fuel hose 444 defines an auxiliary fuel hose first end assembly 446 and an auxiliary fuel hose second end assembly 448. The auxiliary fuel hose first end assembly 446 is configured to engage the fuel tank outlet 442 to allow flow of fuel from the fuel tank 440, through the auxiliary fuel hose 444, and out of the auxiliary fuel hose second end assembly 448.

The example generator assembly 434 comprises a generator housing 450, a second electrical connector 452, and a generator fuel inlet 454. The fuel hose second end assembly 488 is configured to engage the generator fuel inlet 454 to allow fuel flowing from the auxiliary fuel hose second end assembly 448 to flow into the generator fuel inlet 454. The example generator fuel inlet 454 comprises a valve assembly 456, the function of which will be described in further detail below. Figure 12 further illustrates that a main fuel hose assembly 460 is operatively connected to a main fuel tank 462 of the vehicle 424. The example main fuel hose assembly 460 defines a main fuel hose distal end 464 (Figure 12). The main fuel hose distal end assembly 464 is configured to engage the generator fuel inlet 454 to allow fuel to flow from the main fuel tank 462 and into the generator fuel inlet 454.

The example valve assembly 456 may be configured to allow the generator assembly 434 to operate using fuel from the auxiliary fuel tank 440 or fuel from the main fuel tank 462. The valve assembly 456 may be manually operated or automatically operated based on factors such as the fill level of one or both of the auxiliary fuel tank 440 and the main fuel tank 462.

Using the second example APU system 420, fuel may thus be supplied to the generator assembly 434 from the auxiliary fuel tank 440 or from the main fuel tank 462. When operated to consume the fuel supplied from one or both of the fuel tanks 440 or 462, the generator assembly 434 supplies electricity to the load 428 through the first and second electrical connectors 446 and 452 and the cable assembly 428a.