Air conditioning system operating on vehicle waste energy

A waste energy-based vehicle air conditioning system includes efficient compression driving means coupled to refrigeration means. In one implementation, the compression driving means includes a controller (e.g., magnetic clutch) that couples mechanical waste energy from an engine fan axle, a vehicle drive shaft, or a transmission shaft to an axle of a refrigerant compressor. Alternatively, the controller can also include a battery that is charged from the mechanical waste energy. Upon detecting certain pressure values, the controller powers the refrigerant compressor with a rotating axle (e.g., during deceleration) or with battery power, as appropriate. In one implementation, the controller is configured to engage compression immediately upon detecting that the vehicle is decelerating. One or more kits can be used to retrofit existing vehicles to operate the respective air conditioning systems principally on waste energy.

BACKGROUND OF THE INVENTION

1. The Field of the Invention

Implementations of the present invention relate in part to air conditioning systems, such as used in automobiles.

2. Background and Relevant Art

For the past several decades, air conditioning systems have been used in automobiles and other motor vehicles during hot weather to provide more comfortable conditions for drivers and other vehicle occupants. Typically, an air conditioning system uses a refrigerant, which it compresses and expands at various points to cool warm air.

In general, vehicular air conditioning systems use energy from an active power source, such as an operating vehicle engine, to compress air conditioner refrigerant. One conventional air conditioner system, for example, might be configured with an air conditioner refrigerant compressor (“compressor”) that is selectively coupled to a vehicle engine. In particular, the compressor might be selectively coupled to an engine fan belt, via a magnetic clutch and engine fan pulley system. When an operator engages the air conditioner, therefore, the air conditioning system engages the magnetic clutch, which then couples the air conditioner compressor to the engine (i.e., through the engine fan and engine fan pulley), and translates engine power to the compressor. The compressor of the air conditioning system can then use this engine power to compress the refrigerant.

Once compressed, conventional air conditioning systems pass the refrigerant ultimately to an expansion valve (or orifice tube) in an air box heat exchanger/evaporator (“heat exchanger”) where the refrigerant may pass through a counter-current heat exchange with incoming air. Conventional air conditioning systems then pass the at least semi-condensed/compressed refrigerant from the heat exchanger back to the compressor for re-compression. Accordingly, the compressed refrigerant passes into the air box heat exchanger from the “high pressure side” of the air conditioning system, while the expanded refrigerant exits the heat exchanger into what is termed the “low pressure side” of the air conditioning system.

In general, and without use of the compressor, the exchange of differentially pressurized refrigerant volumes between the higher and lower pressure sides of the air conditioning system through the expansion valve will tend to equalize the overall refrigerant pressurization in the air conditioning system. That is, the pressure of refrigerant in the lower pressure side of the air conditioning system tends to increase with increased refrigerant volume, as well as with the addition of heat. Simultaneously, the pressure on the high pressure side of the air conditioning system tends to decrease as pressurized refrigerant passes into the heat exchanger. Ultimately, therefore, the air conditioning system will need to re-pressurize the refrigerant for it to be useful for cooling purposes.

Determining when to re-pressurize (i.e., “compress”) the refrigerant is typically done any number of ways. In one conventional example, an air conditioning system might use a high/low pressure switch to monitor the refrigerant pressurization on the high and/or low pressure sides. For example, if the air conditioning system detects that refrigerant pressurization on the low pressure side is above a desired threshold, the air conditioning system might thus deduce that pressure on the high pressure side of the air conditioning system is too low, and thus engage the magnetic clutch (i.e., and engage the compressor). The air conditioning system can then compress the lower-pressure refrigerant in the low pressure side, and pass the newly-compressed refrigerant to the high pressure side. Once the pressurization on the low and/or high side of the air conditioning system hits a particular threshold, the air conditioning system might then disengage the magnetic clutch, and stop the compressor.

Although the air conditioning system might only engage the compressor at select pressure thresholds, each engagement nevertheless applies a particular load on the active power source (i.e., the engine). Although this added load on the engine may appear to be comparatively low, each added load on the power source/engine results in a need to consume additional fuel. In some situations, for example, operation of the compressor can reduce overall vehicle fuel efficiency (e.g., mpg/kpl) by as much as 25 percent or more. This simply means that a vehicle will typically consume more fuel during warmer periods (e.g., when using the air conditioner), which of course adds financial costs of additional fuel purchases. This also means that operating an air conditioner can ultimately result in additional fossil fuel exhaust expelled into the environment.

Manufacturers of hybrid vehicles (i.e., engine and battery-powered hybrids) attempt to circumvent some of these engine load/fuel efficiency problems with vehicles that use large-capacity batteries together with regenerative brakes. Such hybrid vehicles couple charging of the large-capacity battery at least in part to waste kinetic energy generated only during braking actions (using dynamic brakes, which charge the battery). The additional costs associated with the larger battery, the complex mechanisms used by the hybrid vehicle to capture waste energy, and the extra weight added thereby, however, tend to make conventional hybrid vehicles fairly expensive. These complex mechanisms also tend to be expensive to maintain over time, and such costs could tend to offset some of the savings associated with the added fuel economy.

BRIEF SUMMARY OF THE INVENTION

Implementations of the present invention solve one or more problems in the art with systems, apparatus, and methods configured to mitigate fuel economy issues associated with using air conditioning systems in conventional vehicles. In particular, implementations of the present invention include readily-addable, low-cost components configured to coincide or constrain compressor (e.g., of air conditioning systems) operations principally with the presence of passive energy sources (i.e., vehicle waste mechanical kinetic energy—“waste energy”), and independent of braking actions. In one implementation, an air conditioning system can also be configured to use multiple sources of passive energy (i.e., “dual source” operations). As such, a vehicle air conditioning system can be easily and inexpensively configured to minimize loads on active energy sources (e.g., the engine) during air conditioner operation.

For example, a vehicle air conditioning system that is configured to compress refrigerant with mechanical waste energy in accordance with an implementation of the present invention can include refrigeration means. In general, the refrigeration means will include at least a compressor configured to pressurize refrigerant. In addition, the vehicle air conditioning system can include compression driving means configured to drive the refrigeration means at least in part upon detecting mechanical waste energy. In particular, the compression driving means will be configured so that compressor operation coincides with, and is operated by, the detected mechanical waste energy.

By contrast, a method in accordance with an implementation of the present invention of compressing refrigerant with minimal engine load by compressing the refrigerant primarily with vehicle waste energy can involve identifying that the vehicle's engine is decelerating. The method can also involve powering a refrigerant compressor and a self-charging motor with a rotating axle. In such a case, the refrigerant is compressed and a battery is charged with mechanical waste energy during times of vehicle deceleration. In addition, the method can involve compressing the refrigerant in a refrigerant compressor with the rotating axle, or with battery power, upon identifying that the refrigerant has reached a minimum pressure value.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Implementations of the present invention extend to systems, apparatus, and methods configured to mitigate fuel economy issues associated with using air conditioning systems in conventional vehicles. In particular, implementations of the present invention include readily-addable, low-cost components configured to coincide or constrain compressor (e.g., of air conditioning systems) operations principally with the presence of passive energy sources (i.e., vehicle waste mechanical kinetic energy—“waste energy”), and independent of braking actions. In one implementation, an air conditioning system can also be configured to use multiple sources of passive energy (i.e., “dual source” operations). As such, a vehicle air conditioning system can be easily and inexpensively configured to minimize loads on active energy sources (e.g., the engine) during air conditioner operation.

As will be appreciated more fully herein, the principles described herein can be performed with a number of relatively simple (and relatively low-cost) components, both mechanical and electrical. For example, implementations of the present invention include a number of mechanical components for coupling refrigerant compressor or air brake compressor (e.g., of a truck or bus) operations to moving components of a vehicle. In addition, implementations of the present invention include a number of electrical components for driving or operating the various mechanical components, including electrical detectors, electrical switches, microprocessors, motors, batteries (e.g., for dual source operations), and the like. Furthermore, implementations of the present invention provide after-market kits comprising these and other components that can be used to easily retrofit existing vehicle air conditioning systems for the use of waste energy when engaging compression/re-charging functions.

FIG. 1Aillustrates an overview schematic diagram in accordance with an implementation of the present invention of a “single mode” air conditioning system100aconfigured to primarily engage passive (e.g., “waste”) energy sources (e.g., a decelerating axle) in order to compress refrigerant. As shown, air conditioning system100agenerally comprises a refrigeration means105athat includes a number of components configured to exchange energy between warm air and cool, expanded refrigerant, and pass the ultimately cooled incoming air to passenger compartment103. For example,FIG. 1Ashows that refrigeration means105acomprises compressor110, which, in turn, is coupled to high pressure refrigerant reservoir115, and to low pressure refrigerant reservoir120.

As implied by their names, the refrigerant in refrigerant high pressure reservoir115will generally be in a state of greater compression than that in low pressure refrigerant reservoir120. The specific refrigerant pressure(s) in reservoirs115and120, however, can vary from one operating environment to the next. Furthermore, the specific type of refrigerant can also vary from one implementation to the next. For example, a manufacturer can select any refrigerant, such as one designed to cool when expanded, including such commonly known refrigerants as “FREON,” R-12, and/or R-134.

In any event,FIG. 1Aalso shows that refrigeration means105acomprises a condenser/heat exchanger125. Generally, refrigerant exits refrigerant reservoir115at a point123, and enters condenser/heat exchanger125. For example, air conditioning system100acan direct recently-compressed refrigerant from reservoir115to condenser/heat exchanger125via point123. Condenser/heat exchanger125, in turn, reduces the temperature of the compressed refrigerant.

FIG. 1Aalso shows that air conditioning system100adirects the refrigerant from condenser/heat exchanger125to air box heat exchanger135, such as at point127. Air box heat exchanger135, in turn, is generally configured with any number of components to exploit an effective temperature sink between incoming air133and refrigerant. For example, air box heat exchanger135comprises any number of components configured to facilitate countercurrent heat exchange between the relatively hot incoming air133and the relatively cool refrigerant. In at least one implementation, heat exchanger135includes, for example, a plurality of coils, tubing, or other known heat exchange components, and further includes refrigerant expansion valve130(or orifice tube).

In at least one implementation, expansion valve130is configured to cause the refrigerant to expand into a relaxed state. Specifically, the type of refrigerant chosen is such that the relaxed state is also a much cooler state than when the refrigerant is compressed. In particular, the temperature of the expanded refrigerant is significantly lower than the temperature of incoming air133, whether drawn from the external environment of the motor vehicle, and, in some cases, whether drawn from within passenger compartment103. This difference in temperature between incoming air133and the expanded refrigerant effectively creates a heat sink on the expanded refrigerant side. This heat sink on the expanded refrigerant side ultimately provides the cooling functionality of air conditioning system100a.

In particular, air box heat exchanger135provides a temperature gradient for both the incoming air and for the expanded refrigerant as each passes through in opposite directions. For example, as incoming air133enters heat exchanger135, the air first comes in contact with the expanded refrigerant that has been cooled since it first entered expansion valve130. As such, the incoming air experiences at least some heat transfer at its entry point, and further experiences additional heat transfers as it encounters cooler refrigerant along the remainder of heat exchanger135. As a result, the incoming air at point137is in a much cooler state than when it entered air box heat exchanger135. Similarly, the expanded refrigerant at point143is at a higher temperature state than when first exiting expansion valve130.

Upon exiting air box heat exchanger135, the air conditioning system100adirects refrigerant from point143to point147, and ultimately into low pressure reservoir120. In general, points143and147will be understood herein to represent the “low pressure side” of system100a(or of the refrigeration means), since the refrigerant compression/pressurization of the refrigerant at these points is generally lower than that at points123and127. The converse, of course, is that points123and127will be understood herein to represent the “high pressure side” of system100a(or of the refrigeration means).

Notwithstanding these generalized representations and/or designations, one will appreciate that the pressurization of the refrigerant within system100a(as well as100b,400, etc.) can cycle from high to low on any given low or high pressure side. For example, as the expanded refrigerant passes points143and147(i.e., the “lower pressure side” of system100a) and gathers in low pressure reservoir120, the pressure within low pressure reservoir120will increase. Similarly, as air conditioning system100adirects the compressed refrigerant out of high pressure reservoir115, its volume decreases in this reservoir, and ultimately so does its pressurization level.

Accordingly, air conditioning system100acan measure the low or high pressure sides to determine whether to turn on the compressor to compress the refrigerant. For example,FIG. 1Ashows an implementation in which air conditioning system100aincludes compression driving means107afor appropriately coupling energy sources to the refrigeration means105a. In particular,FIG. 1Ashows that driving means107aincludes a controller (e.g., magnetic clutch controller140), which, in turn, is coupled to pressure switch150.FIG. 1Aalso shows that pressure switch150is connected in this case to the low pressure side (143,147) of refrigeration means105. In one implementation, pressure switch150is configured to open or close a connection with magnetic clutch controller140based on pressure values (or pass pressure values thereto). The controller140(also referred to as “magnetic clutch controller140”), in turn, can engage refrigerant compression functions based in part on what is detected by pressure switch150.

For example, magnetic clutch controller140could identify from pressure switch150(e.g., via opening or closing of a switch) that pressure on the low pressure side of refrigeration means is too high, and thus that compressor110needs to be started. In one exemplary operation, this can involve magnetic clutch controller140opening a connection (or sending one or more electronic signals thereto) with magnetic clutch145, which thus engages magnetic clutch145. Of course, magnetic clutch controller140could also be configured with microprocessors and software designed to make these determinations based on a combination of data points received from pressure switch150(i.e., rather than the opening or closing of a specific switch).

In one implementation, therefore, compression driving means107a-ccan include “engagement means,” which comprise one or more “engagement components,” such as at least controller140and clutch145(or the like). In addition, the compression driving means107a-ccan also include a “pressurization system,” which comprises engagement means, and further comprises electronic means (e.g., switches, detectors, processors, electronic storage, circuitry, etc.) for engaging refrigerant pressurization through the engagement means.

In any event, when magnetic clutch145engages, magnetic clutch145harnesses pulley113b, which is rotating due to coupling with an engine fan (not shown) axle/shaft153of engine155via pulley113aand belt117(e.g., a notched belt). This engagement further causes axle157within compressor110to rotate. Rotation of axle157further provides compressor110energy, which compressor110can translate to compress the refrigerant from its pressurization value in the low pressure reservoir120to its pressurization value in the high pressure reservoir115. Conversely, and by reverse mechanisms, magnetic clutch controller140can also be configured to stop compression by, for example, disengaging magnetic clutch145. For example, magnetic clutch controller140might identify (e.g., via pressure switch150) that the refrigerant pressurization has reached a lower threshold value (or that the high pressure side has reached a maximum high pressure value).

As previously mentioned, air conditioning system100acan further be configured so that refrigerant compression functions occur during deceleration periods (as well, in some cases, in response to certain refrigerant pressure thresholds, discussed hereinafter). For example, air conditioning system100acan be configured to engage and translate power from engine155when determining that the vehicle is presently decelerating. Accordingly,FIG. 1Ashows at least one way of detecting deceleration using, for example, accelerator switch160. In particular,FIG. 1Ashows an implementation in which magnetic clutch controller140is coupled to accelerator switch160, which, in turn, is coupled to a vehicle gas pedal165.

In such an implementation, magnetic clutch controller140can be configured to determine deceleration by identifying information from accelerator switch160. For example, accelerator switch160identifies when there has been a release from gas pedal165, and sends this information in the form of electronic instructions to magnetic clutch controller140. Alternatively, this detection by accelerator switch160opens or closes an electronic switch in an electrical connection with magnetic clutch controller145. The reverse could be true when accelerator switch160detects added pressure to gas pedal165to stop compressor action. In one implementation, therefore, “deceleration” is defined herein as a state of reduction in fuel sent to the engine, a reduction of power output from the engine, or a state of no acceleration, based on fluctuations on gas pedal165.

In alternative or additional implementations, “deceleration” can also or alternatively be based on any number of other detected values or actions. For example, magnetic clutch controller140can be configured to identify deceleration when the vehicle drive shaft torque is in the opposite direction compared with its direction during acceleration (i.e., detecting “reverse torque.”) Magnetic clutch controller140can also be configured in some cases to determine deceleration periods when detecting application of vehicle brakes (e.g., via coupling of brakes with accelerator switch160or a brake switch—not shown). Magnetic clutch controller140can still further be configured to identify deceleration when engine155is no longer powering any vehicle movement at all, such as when the vehicle is moving downhill primarily in response to gravity and momentum. Magnetic clutch controller140can yet still further be configured to identify deceleration through the use of an axial accelerometer (not shown) that shows negative acceleration. In such a case, the vehicle could even be accelerating (e.g., downhill) even though the engine itself is actually decelerating, or providing no torque at all.

In one method of operation, therefore, a user begins to drive and fluctuate gas pedal165for various acceleration and driving speed requirements. When the user releases the gas pedal even momentarily, compression driving means107aof air conditioning system100adetects deceleration and immediately engages refrigeration means105to compress refrigerant. Specifically, magnetic clutch145immediately engages the engine fan axle (via pulleys113a-band belt117), which is still rotating albeit at a decelerating rate since no engine power is being applied (or decreasingly applied). This engagement, in turn, causes compressor110to engage axle157, which provides direct rotational energy that can be translated to compress refrigerant in reservoir120.

Since the air conditioning system100aimmediately (or almost immediately) begins compressing refrigerant in response to release from gas pedal165(or other appropriate deceleration determinations), refrigerant pressurization will generally remain above a useful operating threshold. This generally tends to be the case since the refrigerant pressure will have been recharged in bits and pieces in response to the driver's use of the gas pedal, such as during city driving. One will appreciate, nevertheless, that, with some vehicles, refrigerant pressure may still reach a sub-optimal value during extended periods of constant speed (where little if any deceleration is detected). For example, a driver may maintain fuel input to the engine at a relatively constant rate (e.g., hold the gas pedal at a constant pressure/level, maintain a “cruise control” speed value, etc.)

Accordingly, a “single-source” (i.e., single waste energy-source) air conditioning system100aoperating in accordance with implementations of the present invention can still compress refrigerant using engine155. In particular, air conditioning system100acan simply engage engine155power (as done conventionally) when detecting that refrigerant pressure is too low and/or when there is no detected waste energy. In one implementation, therefore, air conditioning system100acan ensure that refrigerant is always compressed to at least a minimum value for operating the vehicle air conditioning system effectively, even though primarily using waste energy to compress refrigerant.

By contrast, a “dual-source” air conditioning system100bin accordance with implementations of the present invention comprises two or more passive energy sources (or sources of mechanical waste energy) that can be used to compress refrigerant without directly harnessing active engine155power. For example,FIG. 1Billustrates an implementation in which compression driving means107bis configured to use waste mechanical energy not only to drive refrigeration means105b, but also to drive battery charging apparatus. In particular,FIG. 1Bshows that both compressor110and self-charging motor175can both be coupled to axle157. Thus, when magnetic clutch controller140engages magnetic clutch145(e.g., during deceleration), compressor110and self-charging motor175can both translate energy from rotating axle157(i.e., when the vehicle is in motion).

In addition to compressing refrigerant, this coupling with rotating axle157allows self-charging motor175to charge a battery (e.g.,180). One will appreciate that such coupling can provide the principal vehicle battery power (and/or additional sources for charging a battery) compared with what a conventional vehicle alternator might provide, without necessarily incurring added fuel costs to recharge the battery. While this can be especially the case where a separate battery is used, such a configuration can still provide fuel savings (equal in most cases) when using the same battery (e.g.,180) since only one of the two or more recharging sources (e.g., self-charging motor175and vehicle alternator185) relies on active engine155power (i.e., alternator185).

One will also appreciate that the charging of a battery (e.g.,180) can also be done in a “dual-mode” manner. For example, if compressor110operation depletes the charge of battery180to a critically low threshold value, magnetic clutch controller140can simply engage magnetic clutch145again, so that self-charging motor175recharges the battery using engine155power. Where the air conditioning system is not in operation, the vehicle may be configured to re-charge the battery with alternator185as needed. As a result, and as similarly described with respect to dual-mode air conditioning systems described herein, a vehicle can also be configured so that it charges its battery(ies) during air conditioner operation primarily with mechanical waste energy, and only resorts to engine155power within certain upper or lower battery charge thresholds.

In any event, one will appreciate that this additional, available battery power can Abe used for a wide variety of other functions. For example, if little deceleration has been detected (e.g., constant driving speeds, during vehicle stoppage, or if the engine has been turned off) and refrigerant pressure drops to too low of a value, self-charging motor175can simply reverse its electric field and operate compressor110on battery power. One will appreciate in at least some cases, therefore, that the vehicle air conditioning system can thus operate for longer periods of time at constant driving speeds (little or no deceleration detected) without using engine155to compress refrigerant. Furthermore, this also means that the vehicle can operate air conditioning system100bfor a much longer time than previously available without engaging engine155power when the vehicle is stopped, and/or the engine has been turned off.

In addition to the foregoing,FIG. 1Balso illustrates an implementation in which compression driving means107bcan be configured to harness waste energy only indirectly from engine155. This contrasts with other implementations in which compression driving means107bdirectly harness power from engine155, such as, for example, being directly coupled to the engine fan axle. For example,FIG. 1Bshows that pulley113bcan be alternatively coupled via belt117to different pulley113c, which, in turn, is connected to axle170. In general, axle170will include any type of vehicle axle that is directly connected to the vehicle driving wheels without passing through any torque converter, or other slippage devices, and continues to rotate after engine155has stopped providing force or torque. For example, a vehicle drive shaft or transmission shaft will continue to rotate during deceleration, or downhill travel, even though the rotation of the engine fan axle (e.g.,153) is decelerating, or is not rotating at all.

Accordingly, axle170can include a vehicle drive shaft, or can include a transmission shaft, such as one typically located between the vehicle drive shaft and a transmission fluid coupling or torque converter. This can also allow direct and efficient translation of vehicle waste kinetic energy through the vehicle's tires, which can be particularly helpful since such translation of waste energy can occur without any transmission slippage losses at all. Similar toFIG. 1A, therefore, magnetic clutch controller140can engage magnetic clutch145during deceleration. Rather than engaging engine155directly, however, magnetic clutch145immediately engages drive (or transmission) shaft170. During deceleration, the energy received from the still rotating drive shaft170(albeit decelerating) can be translated to power compressor110, and thus pressurize refrigerant.

FIGS. 2A and 2Billustrate exemplary electronic schematics of pressure switches (e.g.,150) and accelerator/decelerator switches that can be used to accomplish both the single and/or dual source functions described with respect toFIGS. 1A and 1B. In particular,FIG. 2Aillustrates a schematic diagram of an electronic circuit200a, which shows an electronic connection between magnetic clutch145and accelerator switch160. In one implementation, accelerator switch160(as well as any of the other switches described herein) can comprise a Single Pole, Double Throw (“SPDT”) switch, which provides alternating contact between two contacts, such as an accelerate contact and a decelerate contact.

For example, accelerator switch160can be configured to contact the accelerate contact when engine155is accelerating; while, when engine155is decelerating, accelerator switch160would contact the decelerate contact. As previously mentioned, this toggling between accelerate/decelerate contacts can occur in response to a wide range of detectable acceleration/deceleration events, including detections of changes in drive shaft torque, or the like.

In addition,FIG. 2Ashows that electronic circuit200acomprises an efficiency switch215that can only be traversed when accelerator switch160is toggled to an accelerate contact. Efficiency switch215, in turn, can be configured so that it only closes the electrical connection when refrigerant pressure (as determined from high or low pressure side calculations) in air conditioning system100ais outside of a preset or required, enveloped value (e.g., minimum high pressure side value, maximum low pressure side value). In the illustrated example, therefore, efficiency switch215is configured to close when the refrigerant pressurization is less than an exemplary pressure of about 200 psi. By contrast,FIG. 2Ashows that efficiency switch can open when the refrigerant pressure exceeds an exemplary pressure of about 250 psi, which, of course, does not allow for further compressor110engagement and resultant refrigerant pressurization. Thus, efficiency switch215can ensure that engine155power is used to operate compressor110only in relatively limited cases.

FIG. 2Aalso shows that electronic circuit200acan be configured with similar logic on the deceleration side, albeit configured to ensure that compressor engagement occurs at virtually any refrigerant pressure below a certain maximum value for system designs. As shown, for example, electronic circuit200aon the deceleration side includes pressure switch150, which is configured to close at pressures lower than an exemplary (and relatively high) threshold value of about 390 psi. Setting the switch to close at this high of a value virtually ensures that pressure switch150will remain closed in most cases, almost by default. In addition,FIG. 2Ashows that pressure switch150opens at pressures greater than the exemplary upper value of about 400 psi. Accordingly, despite being closed virtually by default, electrical circuit200acan still prevent magnetic clutch145from engaging and causing pressurization of refrigerant beyond system limits (e.g., about 400 psi in this exemplary case.)

In addition to the above-described efficiency switch215and pressure switch225,FIG. 2Aalso shows that electronic circuit200acan further include a thermal shut-off switch230. In general, thermal shut-off switch230ensures that there is no clutch145engagement when engine155(or other relevant motor vehicle component) is overheating, or approaching a high temperature design limit. In addition,FIG. 2Ashows that electrical circuit200acan comprise grounds220and235. In general, ground220connects with magnetic clutch145, and ground235connects with thermal switch230; and both grounds220,235are configured to maintain a safe electrical connection with system components.

FIG. 2Billustrates a schematic overview of alternate electronic circuit200b, such as may be used to modify a conventional air conditioning system to utilize vehicle waste energy to operate the compressor. In this example, pressure switch240and thermal shut-off switch230acan represent pre-existing components of a standard, vehicle air conditioning system. By contrast, secondary pressure switch150and accelerator switch160represent in this case after-market components that a user can add to the standard air conditioning system.

In the illustrated embodiment, conventional pressure switch240can be configured to actuate magnetic clutch145only when the refrigerant pressurization is less than an exemplary minimum threshold value of 200 psi. For example,FIG. 2Bshows that pressure switch240is configured to close (and engage magnetic clutch145) only when the refrigerant pressurization is detected to be at or below about 200 psi. By contrast, after-market secondary pressure switch150is configured to stay closed in almost all cases, except at relatively high upper threshold pressures of about 390 to about 400 psi. As such, after-market secondary pressure switch150can provide a bypass to the generally-open pressure switch240. Furthermore, both secondary switch150and standard switch240will be closed at pressures at or below the exemplary minimum threshold of about 200 psi.

Accordingly,FIG. 2Balso shows that electrical circuit200bcan further comprise after-market accelerator switch160.FIG. 2Bshows that accelerator switch160can be configured to close only when detecting deceleration (e.g., the driver's foot is not depressing gas pedal165). Furthermore, accelerator switch160is positioned so that it does not impede an electrical pass-through from pressure switch240. Thus, if pressure switch240is engaged at any time (e.g., a critically low refrigerant pressures), magnetic clutch145can be engaged regardless of acceleration or deceleration events. By contrast, accelerator switch160is configured to impede electrical pass-through from after-market pressure switch150, so that magnetic clutch145takes advantage of waste energy at pressures between about 200 psi and 390 psi (i.e., by engaging only during detected deceleration).

As with electrical circuit200a, electrical circuit200bis also configured to maximize the range for which magnetic clutch145uses waste energy to pressurize refrigerant, and further to minimize the range for which magnetic clutch145uses engine power to pressurize refrigerant. Accordingly, one will appreciate that the schematics ofFIGS. 1A through 2Billustrate a number of components and configurations (both general and specific) that can be used to incorporate waste energy from single waste energy-source (i.e., mechanical waste energy only) or dual waste energy-source (i.e., mechanical waste energy, or waste-energy-generated battery power) perspectives.

FIGS. 3A and 3Bdescribe sets of triggers and corresponding actions that can be taken in response thereto, as well as a pressurization plot graph of one example instance of operation. As shown inFIG. 3A, for example, a vehicle air conditioning system100a/b(e.g., via for magnetic clutch controller140configured with electronic circuitry, or microprocessor(s) and computer-executable instructions) can be set to an upper maximum pressure value “Z”340, such as a high pressure value on the high pressure side (e.g.,123,127) of refrigeration means105.

For example, air conditioning system100awill engage mechanical waste energy and/or battery power sources (in dual waste energy-source configuration—or “dual source” configuration) as much as possible (and as much as available). This can help to build up a sufficient reservoir of highly-pressurized refrigerant, and thus minimize the amount of engine155power that might ultimately be needed. Of course, a refrigerant compressor generally cannot pressurize refrigerant indefinitely. Accordingly, and as also illustrated inFIGS. 2A-2B, the high pressure value might be set high as to about 380-410 psi. Of course, this value can also be higher or lower in other implementations, depending on the operating environment. In particular, the pressures disclosed herein in the drawings and text are only example pressures and pressure ranges. The actual pressures and/or pressure ranges in a system can vary widely.

FIG. 3Aalso shows that air conditioning system100a/bcan be set with an intermediate pressure value/trigger “Y”320, which generally represents the maximum allowable amount of pressurization when using active energy sources (i.e., engine155power). As previously mentioned, this is referred to as “dual-mode” operation, where compressor110can be operated at least by one mode (i.e., an active energy source—engine155power) primarily within lower pressure ranges (e.g., between “X,” and “Y”) when insufficient passive energy is detected; and operated by a different, or second mode (i.e., a passive energy source—mechanical waste energy) at any pressure range (e.g., between “X,” and “Z”) any time passive energy is detected. Thus, “dual-mode” refers to the ability to use either engine power or waste energy, as available; while “dual-source” (or “dual waste energy-source”) configurations refer primarily the ability to use mechanical waste energy directly (e.g., translated from a rotating axle), or indirectly (e.g., previously translated electrically from a rotating axle and stored in a battery).

For example, air conditioning system100may have engaged active energy sources when mechanical waste energy and/or battery power sources are unavailable (e.g., during acceleration, or constant speed) and refrigerant pressurization is too low to effectively cool incoming air133. Nevertheless, in order to minimize the amount of active energy sources used to pressurize refrigerant, the intermediate pressure value “Y” can be set to a value sufficient to ensure the active engine155energy source is used sparingly. Accordingly, and as illustrated inFIGS. 2A-2B, this intermediate pressure value “Y” might be set as high (or low) as about 240-260 psi. Of course, this intermediate value can also be higher or lower in other implementations, depending on the operating environment.

In addition,FIG. 3Afurther shows that air conditioning system100acan be set with a critical, low pressure value/trigger “X”300, which generally represents the minimum allowable amount of refrigerant pressurization needed for effective operation of the air conditioning system. As described above, an extended period of air conditioner use coupled with a lack of deceleration (e.g., during freeway driving), may result in a need to engage whatever energy sources (e.g., engine155or possibly battery power) are available to ensure adequate refrigerant pressurization. Accordingly, and as illustrated inFIGS. 2A-2B, for example, this critical, low pressure value “X” might be set as high (or low) as about 190-210 psi. Of course, this low value can also be higher or lower in other implementations, depending on the operating environment.

Each of the values “X”300, “Y”320, “Z”340, therefore, correspond to a set of actions to be performed by air conditioning system100. For example, pressure value “X”300exemplifies reaching the minimum operating pressure, and results in action310of pressurizing refrigerant by engaging compression driving means (e.g., engaging magnetic clutch145, or engaging battery power, as available). In addition,FIG. 3Ashows that pressure value “Y”320represents an intermediate pressure value when using active engine155power to drive compression, and thus results in action330of stopping pressurization unless waste energy is now available. For example, engine155may be accelerating or at constant speed from the point at pressure value “X”300until reaching pressure value “Y”320. Nevertheless, at the point of reaching value “Y,” the vehicle may have begun decelerating, and, as such, waste energy would be available. If no waste energy is available, air conditioning system simply disengages magnetic clutch145at pressure value “Y”340.

FIG. 3Afurther shows that air conditioning system100a/bcan be set with a maximum pressure value “Z”340, which results in an action350(and/or350′) of stopping pressurization altogether. In accordance with at least one implementation of the present invention, such a maximum pressure value will only be reached when using mechanical waste energy (or battery power—e.g., dual mode) sources, due at least in part to the presence of intermediate value “Y”320and corresponding action330. Nevertheless, the maximum pressure value “Z”340can ensure that compressor110never pressurizes refrigerant beyond system design values (when appropriately configured), regardless of the manner in which the compressor is being driven. In one implementation, action350′ (i.e., disengaging battery power) can also be triggered alternatively at lower pressure values, such as at intermediate pressure value “Y”320, in order to save battery charge. For example, some smaller batteries may exhaust their charge relatively quickly if used to power compressor110for very long.

FIG. 3B, therefore, illustrates a graph of at least one exemplary operation source over time based on the values and actions set forth inFIG. 3A, and further based on the discussion of operations with respect toFIGS. 1A-2B. In particular,FIG. 3Billustrates a graph of refrigerant pressurization (e.g., on the high side) during vehicle operation using single and/or dual source functions. For example, when a user engages vehicle air conditioning system100at time t0, and waste energy is unavailable, refrigerant pressurization begins to decline somewhat. Upon hitting pressure value “X” at time t1, magnetic clutch controller140performs action310. In this case, if no battery power is available (e.g., “single source’ operations, or not charged), magnetic clutch controller140can engage magnetic clutch145so that engine155power powers compressor110.

With engine155power engaged, refrigerant pressure continues to increase until it ultimately reaches intermediate pressure value “Y” at time t2. This increase can be due to any engine155power or mechanical waste energy that is being produced by engine155, since magnetic clutch145will simply remain engaged. At this intermediate pressure value, magnetic clutch controller140(e.g., via electronic circuitry or through software instructions) could identify a deceleration event (e.g., mechanical waste energy), and thus keep magnetic clutch145engaged. Alternatively, if battery power is available, magnetic clutch controller140could still disengage magnetic clutch145and engage battery power. In the illustrated example, however, magnetic clutch controller140fails to identify waste energy, and thus performs action330of disengaging magnetic clutch145without any engagement of another power source. Accordingly,FIG. 1Bshows that refrigerant pressurization again begins to decrease.

In addition to the foregoing, magnetic clutch controller140can be configured to engage magnetic clutch145immediately at any time it detects available vehicle waste energy. As shown inFIG. 3B, for example, magnetic clutch controller140detects waste energy (e.g., a deceleration event) at time t3, and before hitting the critical minimum pressure “X”300. This results in corresponding action310of engaging magnetic clutch to pressurize refrigerant. In this particular example, there is sufficient deceleration occurring through time t4so that compressor110pressurizes the refrigerant to the maximum allowable pressure “Z”340. One will appreciate that, in dual mode, this deceleration can also drive self-charging motor175to also charge a battery during this time.

Upon reaching the maximum pressure value “Z,” magnetic clutch controller140performs action350of stopping pressurization, such as by disengaging magnetic clutch145. Refrigerant pressurization thus begins to fall. Again, one will appreciate that refrigerant pressure could immediately rise again shortly thereafter upon detecting a new deceleration event, and after the refrigerant pressure drops below a certain maximum value (e.g., about 390 psi), which allows the compressor to engage (e.g., switch150, FIGS.2A/2B). Nevertheless,FIG. 3Bshows that magnetic clutch controller140(or other controller mechanism) allows the refrigerant pressure to drop all the way to the minimum pressure value “X” at time t5.

In this particular example, magnetic clutch controller140identifies the presence of battery power when hitting the minimum pressure value “X” at time t5. As such, magnetic clutch controller140simply engages battery power, rather than engine155power, and compresses refrigerant until hitting a prescribed maximum pressure value at time t6, such as value “Y”320, or a maximum pressure value “Z”340, however configured. For example, a manufacturer may want to allow the battery to drive compressor110operation to pressure value “Z”340when using larger batteries in some vehicles.

As previously mentioned with smaller batteries, however, the manufacturer may want to limit battery power to pressure value “Y”320, similar to how engine155can be limited. Hence,FIG. 3Bshows a dotted line between times t5and t7, which indicates at least one alternate battery engagement/disengagement configuration. In any event, and depending on the maximum pressure prescribed for the battery usage, magnetic clutch controller140disengages the battery power when hitting the prescribed maximum. For example, magnetic clutch controller140can perform action350or350′ and stop compressing refrigerant with the battery.

In addition, since no mechanical waste energy (or sufficient battery power) is detected through time t7, magnetic clutch controller140allows the refrigerant pressurization to drop until it hits the minimum value “X”300. As at time t1, since only engine155power is the sufficient energy available at time t7, magnetic clutch controller140only keeps magnetic clutch145engaged until refrigerant pressure rises to intermediate pressure value “Y”320at time t8. This cycle can thus continue indefinitely. In particular the presence of battery power in this case can further minimize the use of engine155to power the air conditioning system. Accordingly,FIG. 3Billustrates how a dual-source air conditioning system in accordance with implementations of the present invention can operate for lengthy periods of time (i.e., at least from time t2through t7) without needing to engage engine155in an active state (i.e., accelerating or at constant speed).

As previously mentioned, one will appreciate that these principles described with respect toFIGS. 3A and 3Bcan also be applied to charge other components with waste energy in response to one or more values (e.g., battery/brake pressure, battery charge, or the like) values. For example, in addition to pressurizing refrigerant, one or more components can be set to drive air brake compression (e.g., in a truck) based primarily on waste energy. In particular, one or more components can be configured to engage compression of the air brakes any time waste energy (e.g., deceleration) is detected, and up to one or more maximum pressure values (e.g., system design limits). The one or more components can also be configured to pressurize the air brakes with engine power only when the air brake pressure drops to a prescribed minimum value. As such, this functionality for compressing air brakes with waste energy can mirror, in at least some implementations, what is already described herein for operating compressor110and/or re-charging a vehicle battery (e.g.,180) with waste energy.

FIG. 4illustrates a schematic diagram of air conditioning system400, which includes a number of components to retrofit an existing vehicle air conditioning system to primarily utilize waste energy, as discussed herein. As shown, air conditioning system400includes refrigeration means105c, which comprises compressor110, refrigerant reservoir410, and secondary reservoirs405aand405b. In one implementation, refrigerant reservoir410comprises the primary refrigerant reservoir of a standard air conditioning system, and can further include both a low pressure side reservoir and a high pressure side reservoir (or only a high pressure side reservoir). By contrast, either or both of secondary reservoirs405a/b(see alsoFIG. 5B) can be retrofit onto existing system components to provide additional refrigerant volume and to allow for desired operability of air conditioning system400. For example, existing reservoir410can be used as a high pressure reservoir, while reservoir405bcan be used as a low pressure reservoir. Similarly, reservoir405acan be configured as a high pressure reservoir, while reservoir410is used to accept and store low pressure refrigerant.

In any event, secondary reservoirs405aand/or405bcan be configured to serve at least one function of adding the to the total volume of refrigerant in the system. To this end, reservoirs405aand/or405bcan be further configured with a Schrader valve fitting (e.g., nipple/stem), compression hose, or other system components for easily hooking up to (and/or disconnecting from) current air conditioning systems (e.g., without system evacuation) and also for receiving additional refrigerant. One will appreciate that the added refrigerant volume can increase the amount of time air conditioning system400(or100a/b) can use to pressurize refrigerant with only waste energy (e.g., increase the value of t7-t3,FIG. 3B). Similarly, the added refrigerant volume can increase the amount of time air conditioning system400(or100a/b) can operate without engine155power (e.g. increase the value of t7-t2,FIG. 3B). In particular, the added refrigerant volume can increase the amount of time refrigerant can be used in heat exchanger135without re-pressurization before it drops to a minimum pressure (e.g., “Z”300), and thus needs re-compression (with whatever mode/source is available).

FIG. 4also shows that air conditioning system400can include secondary pressure switch425(see alsoFIG. 5A), which can provide additional information to magnetic clutch controller140, such as may not otherwise be provided by pressure switch150. In particular, one will appreciate that using multiple pressure switches can, in at least some implementations, refine the accuracy by which magnetic clutch controller identifies whether certain pressure thresholds have been met. Accordingly,FIG. 4shows at least one implementation in which pressure switch425is connected to Schrader valve420, which, in turn, is connected to secondary reservoir405a; while pressure switch150is connected to reservoir410.

Of course, these pressure switch assignments can be varied, such that secondary pressure switch425(or pressure switch150) is alternatively connected to secondary reservoir405b, and so forth. In one implementation, for example, secondary pressure switch425is configured to identify when the high pressure side (i.e.,415,435,127) has dropped to or below a minimum pressurization value, while pressure switch150is configured to determine when the low pressure side (i.e.,143,147) is too high. In another implementation, the pressure switch (150,425, etc.) ensures that occurrences of vehicle waste energy will operate compressor110at all times, unless the refrigerant pressure is at it highest allowable pressurization state (i.e., the “maximum pressurization value).

In addition,FIG. 4shows that air conditioning system400can include compression driving means107c, which comprises at least magnetic clutch controller140configured to engage magnetic clutch145. In contrast withFIGS. 1A-B, however, magnetic clutch145in this example is coupled to axle153, rather than to axle157. Furthermore, in addition to being connected to accelerator switch160,FIG. 4shows that compression driving means107cincludes pedal sensor430connected to magnetic clutch controller140. In one implementation, pedal sensor430provides a direct indication regarding gas pedal depression (or lack thereof), and thus whether engine155is accelerating or decelerating. Pedal sensor430can be configured to operate in conjunction with (or in lieu of) accelerator switch160. For example, it may be easier to install pedal sensor430in some vehicles than to install or access accelerator switch160. In either case, pedal sensor430can be included as an after-market retrofit component.

Accordingly, implementations of the present invention include after-market kits for upgrading conventional vehicle existing air conditioning systems to create waste energy-operated air conditioning system400. In one implementation, for example, such an after-market kit can comprise compression driving means components and refrigeration means components sufficiently configured for any make or model of vehicle to utilize waste energy as the principle mode of refrigerant compression. In at least one implementation, for example, this after-market kit can include one or more secondary reservoirs405aand/or405b(e.g.,FIG. 5B) to increase the available volume of refrigerant, as well as secondary pressure switch425(e.g.,FIG. 5A).

This after-market kit can also include pedal sensor430, as well as a circuit board having electronic control circuitry, such as illustrated inFIG. 2Aor2B. For example, the after-market kit can include a secondary magnetic clutch controller (e.g.,140), which has circuitry as illustrated inFIG. 2A. Alternatively, the after-market kit can include circuitry that simply appends and adds to existing circuitry in an existing magnetic clutch controller, such as the electronic circuitry illustrated inFIG. 2B.

Similarly, this after-market kit can include replacement or appending microprocessors and sufficient memory for storing computer-executable instructions that cause compression to be coupled with the detection of waste energy (or battery power) signals. The after-market kit can still further include any pulleys, belts, and clutches that may be needed to couple existing compressor110to any of the engine fan axle, and/or to the vehicle's drive shaft or transmission shaft. Yet still further, this after-market kit can include self-charging motor175for dual-source configurations, as well as an additional battery in some cases. One will appreciate, therefore, that the number, type, or configuration of these and other necessary components can vary from vehicle to vehicle, as well as in accordance with the types of features a manufacturer may desire to provide.

With respect to these or other types of the after-market kits described herein,FIG. 5Aillustrates a schematic diagram of one implementation of a pressure switch (e.g.,425) that can be added to an air conditioning system (e.g.,400). In particular,FIG. 5Ashows that pressure switch425can comprise a Schrader valve stem505a, as well as a Schrader valve receptacle510a. One will appreciate, however, that pressure switch425can include other types of connectors or interfaces, as appropriate for a particular vehicle. In any event, stem510acan be configured to screw onto an existing refrigerant Schrader valve stem in an existing air conditioning system.

This allows the pressure switch to tap directly into, for example, an existing refrigerant reservoir, tubing, or the like on the low or high pressure sides of refrigeration means105a-c. Pressure switch425can then pass electronic information (e.g., on/off, or specific pressure data) via electrical contacts510, which can be electrically coupled ultimately to magnetic clutch controller140. In one implementation, pressure switch505acan further be coupled to one or more secondary refrigerant reservoirs (e.g.,405a/b), as appropriate.

For example,FIG. 5Billustrates a configuration of a generic coupling component500(i.e., “fitting500”), which is configured to couple a component, such as refrigerant reservoir405a/bdirectly into an existing air conditioning system (e.g.,400). Fitting500can be configured as pressure switch425in some cases, but can also simply be a retrofit coupling component without any additional functionality (e.g., pressure detection). In any event,FIG. 5Ashows that coupling component500comprises a refrigerant Schrader valve receptacle510b, as well as a Schrader valve stem505b. Of course, any other type of interface may be appropriate for other types of vehicles and air conditioning system configurations. In addition,FIG. 5Bfurther shows that fitting500can also be coupled via one or more links (e.g., refrigerant hoses, coils, etc.) to a secondary reservoir, such as reservoir405a/b.

In one implementation, therefore, an after-market kit manufacturer can include at least pressure switch425, any number of fittings515, fluid connectors/links520, reservoirs405a/b, and additional refrigerant. A user can then couple at least pressure switch425directly to one or more Schrader fittings in an existing system, such as on the high or low pressure side of air conditioning system400. The user can then electrically couple contacts510to a clutch controller (or other appropriate controller), such as magnetic clutch controller140. The user can also attach additional reservoirs by attaching fitting500to one or more other Schrader fittings on the high or low pressure side of air conditioning system400. The user can then attach one or more secondary reservoirs405a/bto fitting500via any number of fluid connectors/links520.

Accordingly,FIGS. 1A-5B, and the corresponding text, illustrate or describe a number of components and configurations that can be used to drive refrigerant compression primarily with passive, or waste, energy sources in both single and dual operation modes. In particular, these components and configurations can also be used to drive refrigerant compression independently from braking actions, since they can be activated with any detection of vehicle waste kinetic energy, rather than just waste kinetic energy during braking cycles.

In addition,FIGS. 1A-5Billustrate components, configurations, and functions that can be applied not only to a wide range of new vehicle designs, but also to relatively low cost (and relatively simple) after-market kits for retrofitting existing vehicle designs so that these vehicles can operate much more efficiently when using the air conditioning system. In particular, such kits can be made with components that a lay user with only a basic understanding of vehicle engines could readily install on the vehicle with minimal effort, and with minimal installation or maintenance expenditure(s). Furthermore, and due in part to the relative low cost of the components (as well as relatively low maintenance costs thereof), such kits can allow a user to thus significantly minimize fuel efficiency losses otherwise due to running an air conditioning system without significant cost or resource expenditure.

One will also appreciate, therefore, that a user or manufacturer can modify the components and functions described herein any number of ways within the spirit and scope of the present invention. For example, pressure switch150can be positioned to detect the high pressure side of refrigeration means105, rather than primarily or only the low pressure side. In addition, air conditioning system100a(or100b,400) can be configured to identify pressure on either the low or high pressure sides with a combination of sensors, detectors and microprocessors rather than a specific “pressure switch.” Similarly, magnetic clutch controller140can be configured to determine deceleration with a combination of sensors, detectors and microprocessors rather than a specific “accelerator switch.”

In addition, air conditioning system100a(or100b,400) can be configured to draw power from engine155using mechanisms and components other than a magnetic clutch and pulley system (e.g., pulleys113a-b, notched belt117). In addition, or in alternative thereto, air conditioning system100a(or100b,400) can be configured to draw power from engine155without necessarily be coupled directly to engine155(e.g., via an engine fan). Furthermore, the air conditioning system can include a single sensor in place of pressure switch150, where the single sensor primarily controls magnetic clutch145.

With respect to the electronic circuitry illustrated inFIGS. 2A-2B, thermal shut-off switch230can be positioned so that it opens only when engine155is accelerating. In another or alternative implementation, non-switch sensors other than switches150,160,215,230, or240can be used to indicate refrigerant pressurization and/or acceleration/deceleration modes. Similarly, switches150,160,215,230, or240can comprise any type of dynamic sensor, such as digital or analog sensors, or other types of detection components.

As also mentioned throughout this description, the functions of any of the above-describe switches can be accomplished in some cases with one or more microprocessors and computer-executable software instructions configured to send engagement and/or disengagement signals in response to detected pressure or temperature values. For example, and with particular respect to computer-executable instructions, implementations of the present invention can also comprise a special purpose or general-purpose computerized components. Such computerized components can be configured to store, send, and/or execute instructions or data structures stored in the form of computer-readable media. Such computer-readable media can be any available media that can be accessed by a general purpose or special purpose computer.

By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to carry or store desired program code means in the form of computer-executable instructions or data structures and which can be accessed by a general purpose or special purpose computer. When information is transferred or provided over a network or another communications connection (either hardwired, wireless, or a combination of hardwired or wireless) to a computer, the computer properly views the connection as a computer-readable medium. Thus, any such connection is properly termed a computer-readable medium. Combinations of the above should also be included within the scope of computer-readable media.