Abstract: An air conditioning apparatus includes a refrigerant circulation circuit that has a compressor. A driving status of the compressor is detected by first detector. A first calculator calculates a theoretical torque and a driving efficiency of the compressor based on information from the first detector. A second calculator calculates a necessary torque required for driving the compressor. The second calculator calculates the necessary torque based on the theoretical torque.

Abstract: A capacity control device controls a discharge capacity of a variable displacement compressor for use in an automotive air conditioning system. The air conditioning system has the compressor and an evaporator fan. The device includes a control, a first detector, and a second detector. The control changes the discharge capacity of the compressor between a minimum discharge capacity for that compressor and a maximum discharge capacity. The first detector detects an elapsed time of a minimum discharge capacity operation of the compressor. The second detector detects an impressed voltage of the evaporator fan of the air conditioning system. The discharge capacity increases from the minimum discharge capacity to a predetermined discharge capacity when the elapsed time of the minimum discharge capacity operation is greater than a predetermined time and when the impressed voltage of the evaporator fan is greater than a predetermined voltage.

Abstract: In a refrigerant cycle for a vehicle air conditioner, a compressor is operated by a power from a vehicle engine, a load detecting unit is disposed to detect load of the engine, an electromagnetic clutch is turned off so that a consumed power consumed in the compressor is reduced to zero when the load detected by the load detecting unit is equal to or larger than a first threshold value. In the refrigerant cycle, the first threshold value is set to be changed along a power-cutting curved line in such a manner that an increase rate of the first threshold value relative to the vehicle speed becomes larger as the vehicle speed becomes larger.

Abstract: In a control unit of a vehicle air conditioner, a necessary time period T1, between the present time and a time at which the vehicle is stopped next, and a vehicle stopping time period T2, between the time at which the vehicle is stopped next and a time at which the vehicle is re-started, are estimated based on vehicle-travel state information and traffic signal information in a vehicle traveling. Further, a necessary cold release amount Q required for cooling in the vehicle stopping time period T2 is calculated based on the vehicle stopping time period T2, and a cold storage operation is controlled so that the necessary cold release amount Q is stored for the necessary time period T1.

Abstract: A vehicle air conditioner includes a variable displacement compressor forming a part of a coolant circuit, detectors for detecting external information necessary for air conditioning, and a controller. The compressor has pistons and mechanism for actuating the pistons to draw, compress and discharge refrigerant. The piston actuating mechanism is located in a crank chamber. The pressure in the crank chamber is changed to vary the compressor displacement. The controller controls the compressor based on the information from the detectors. When disengaging an electromagnetic clutch, which is located between a vehicle engine and the compressor, the controller quickly decreases the compressor displacement and prevents the pressure difference between the crank chamber and compression chambers excessively increased. Therefore, immediately after being stopped, the compressor is started at the minimum displacement, which minimizes the shock due to load torque change on the engine.

Abstract: An air-conditioning system for a vehicle, including a refrigerant circuit and an engine, has a battery, a compressor, an electric motor and a load torque control mechanism. The battery supplies electric power. The compressor is operative to compress refrigerant gas for the air-conditioning system. The electric motor is electrically connected to the battery. The motor is driven due to the electric power, and is operatively coupled to drive the compressor when the motor is energized. The load torque control mechanism responsive to the operating condition of the engine to control the load torque of the compressor below a predetermined value during times when the motor is driving the compressor.

Abstract: A method for controlling cycling of an air conditioning compressor coupled to an internal combustion engine interrupts normal cycling based on operation conditions. In addition, normal engaged and disengaged cycling durations are adaptively estimated in real-time. The method of the present invention achieves improved fuel economy and improved drive feel. As an example, improved fuel economy is achieved by engaging the compressor during braking or when the engine is being driven by the vehicle. As another example, improved drive feel is achieved by engaging the compressor during transient conditions when drive feel is unaffected.

Abstract: Vehicle air conditioning systems (2) may include an electrically driven compressor (4, 6) that is electrically connected to an alternator (16) driven by a vehicle engine (18). The compressor may be driven in a first drive mode, in which a normal drive control is performed. The compressor also may be driven in a second drive mode, in which the rotational speed of the compressor is increased, as compared to the normal drive control. The compressor may be driven in the second drive mode at least when vehicle running speed is being reduced.

Abstract: An air-conditioning system has a refrigerant circuit. The circuit includes a condenser, a expansion valve, an evaporator and a variable displacement compressor. The system has a pressure difference detector. The pressure difference detector detects the pressure difference between two pressure monitoring points located on the refrigerant circuit. A control valve and a controller control the displacement of the compressor in accordance with the pressure difference detected by the pressure difference detector. This permits the displacement of the compressor to be quickly changed.

Abstract: The performance of mobile air conditioning systems is improved with the use of a pressure sensing valve to control refrigerant flow in the system. The pressure sensing valve is connected between the condenser and the evaporator. The control valve senses the refrigerant pressure adjacent the evaporator, ie. the input, or output, or the combination of both, to control the refrigerant flow through the evaporator in a manner to improve the performance of the system. The reference pressure for the valve can be the atmosphere or a fixed or variable source. Various other operating variables can be sensed to control the variable source in a manner to interact with the sensed pressure to provide added control of system performance.

Abstract: An air-conditioning system for a vehicle including a refrigerant circuit and an engine, has a compressor in the refrigerant circuit, a battery, an electric motor and a mechanism operative to controllably connect and disconnect a power transmitting path between the engine and the motor. The motor is connected to drive the compressor when energized by the battery. A first controller is operative to control the electric power supplied to the motor from the battery. A capacity control mechanism is responsive to the controller to maintain the discharge capacity of the compressor below a predetermined value upon starting the engine by the motor.

Abstract: The invention relates to a method and system for controlling a compressor in a refrigerant circuit of an air-conditioning system of a motor vehicle. The instantaneous load torque is determined and compared with a maximum limiting torque prescribed by an engine controller, and the compressor is controlled depending on the comparison value resulting therefrom. In order to avoid complete shutdown of the compressor, the instantaneous load torque is represented as a function of variables, such as compressor speed and high pressure of the refrigerant, and, using an inverted function belonging to this function, a control signal for the compressor, for example, a set-point value for the high pressure of the refrigerant, is determined as a function of the maximum limiting torque and employed to control the compressor.

Abstract: A controller for a compressor selects a control procedure from a normal displacement control procedure and a temporary control procedure based on information detected by a detector. When the normal displacement control procedure is selected, the controller sends a current, the value of which is based on the detected information, to an electromagnetic actuator. When the temporary displacement control procedure is selected, the controller sends a current having a specific value to the actuator to maximize a target compressor suction pressure. When switching from the temporary displacement control procedure to the normal displacement control procedure, the controller changes the value of the current supplied to the electromagnetic actuator according to a pattern, which is determined based on the detected information, over a predetermined period.

Abstract: The present invention provides a gas heat pump-type air conditioner that can reliably notify a user that the time for changing the engine oil of the gas engine that drives the compressor has arrived without stopping the operation of the gas engine. In a gas heat pump-type air conditioner that forms a cooling cycle by circulating refrigerant using a compressor having a gas engine as a drive source, when the cumulative hours of operation t of the gas engine reaches a second predetermined time T2 (S3), a warning display A is displayed while the operation of the gas engine continues, and thereby the user is notified that the time for changing the engine oil has arrived (S4), and at the same time, after the initial stop procedure is carried out subsequent to reaching the predetermined time T2 (S5), a warning display B is displayed (S6), and the warning restoration operation procedure (S7) is carried out.

Abstract: A controller for improving the durability of a compressor employed in a vehicle air conditioner without decreasing engine fuel efficiency. The controller detects the driving conditions of the vehicle and determines whether the engine is in a reversely driven state, in which the vehicle wheels drive the engine instead of the engine driving the wheels. The controller increases the amount of refrigerant discharged from the compressor when the engine is in the reversely driven state.

Abstract: An air conditioning system for vehicles including a damper door which is normally maintained in a position to permit outside air to circulate through the system to militate against the retention moisture and thereby discourage microbial growth.

Abstract: A method for controlling a clutch 24 for an engine-powered system 26 in an automotive vehicle 10 is provided. In one embodiment, the engine-powered system 26 is an air conditioner system. The method includes the step 58 of generating an engine roll signal responsive to an oscillating roll movement of an engine 22 of the vehicle 10 about a torque roll axis 32. The engine roll signal is indicative of an oscillating engine roll acceleration about the torque roll axis 32. The method further includes the step 66 of determining a direction of the oscillating roll movement utilizing the engine roll signal. Finally, the method includes the step 74 of actuating the clutch 24 responsive to an operational parameter of the engine-powered system 26 and the direction of the oscillating roll movement.

Abstract: An air-conditioning apparatus having a refrigerant circuit including a condenser, a pressure reducing device, an evaporator, and a variable displacement compressor. The air-conditioning apparatus has a torque detecting device and an external information detecting device. The torque detecting device directly or indirectly detects the reaction torque acting on the compressor, and the external information detecting device detects various external information other than the torque. The air-conditioning apparatus further has a control device for determining a target torque in accordance with the external information provided by the external information detecting device. The control device executes a feedback control program for controlling the displacement of the compressor such that the torque detected by the torque detecting device approaches the target torque.

Abstract: A control valve is located in a variable displacement compressor used in a refrigerant circuit. The control valve operates such that the pressure difference between two pressure monitoring points in the refrigerant circuit seeks a predetermined target value. A controller determines the target value of the pressure difference in accordance with external information that represents the required cooling performance. The target value of the pressure difference is represented by a duty ratio applied to the control valve. When the acceleration pedal is pressed beyond a predetermined level, the controller limits the duty ratio. Therefore, the compressor torque does not hinder quick vehicle acceleration. Also, the cooling performance is not lowered unless it is necessary.

Abstract: In a refrigerant cycle for a vehicle air conditioner, a compressor is operated by a power from a vehicle engine, a load detecting unit is disposed to detect load of the engine, an electromagnetic clutch is turned off so that a consumed power consumed in the compressor is reduced to zero when the load detected by the load detecting unit is equal to or larger than a first threshold value. In the refrigerant cycle, the first threshold value is set to be changed along a power-cutting curved line in such a manner that an increase rate of the first threshold value relative to the vehicle speed becomes larger as the vehicle speed becomes larger.

Abstract: A clutch of the compressor is selectively engaged and disengaged by a coaction of an engine ECU and an air-conditioning ECU. If an air-conditioning system operating switch is detected as being turned on after a startup of an engine is detected, the clutch is changed from an off-state to an on-state to actuate the compressor to discharge a liquid refrigerant therefrom on the condition that an engine coolant temperature is higher than a reference engine coolant temperature. When the engine coolant temperature is higher than the reference engine coolant temperature, e.g., 40° C., the liquid refrigerant stored in the compressor is discharged of its own accord, and hence the amount of the liquid refrigerant stored in the compressor becomes small.

Abstract: An apparatus and system for manipulating the air temperature within an interior compartment of a vehicle, the apparatus and system includes a HVAC system and an operating system. A compressor receives and circulates a gas through a heat exchanger in order to regulate the air within the vehicle. The compressor has a capacity control valve that is manipulated by the control system in response to a user setting.

Abstract: The present invention balances power consumption reduction and a cooling in a vehicle air-conditioning system having a compressor selectively driven by a vehicle engine or a motor while the compressor is driven by the motor. At least one of a capacity of a blower and a capacity of a compressor arranged in a refrigeration cycle R while the compressor being driven by a motor is reduced in comparison to the capacity of the blower and the capacity of the compressor while the compressor being driven by a vehicle engine. Furthermore, while a cooling heat load of an evaporator is greater than a predetermined value, the capacity of the compressor is first reduced prior to reducing the capacity of the blower.

Abstract: An improved system and method for suppressing high side pressure transients in a motor vehicle air conditioning system due to engine speed transients during vehicle acceleration through the use of a throttling valve. The throttling valve may be mechanically or electrically activated, and is connected in the low pressure side of the air conditioning system to controllably restrict refrigerant flow in response to one or more parameters that detect or anticipate a high side transient pressure condition. The parameters may include the high side pressure itself, or engine parameters such as engine speed and vehicle speed. In a preferred embodiment, the throttling valve may be controlled to prevent evaporator icing in addition to suppressing high side pressure transients.

Abstract: An automobile moves at a traveling speed in accordance with the position of an acceleration pedal. A compressor is driven by the engine of the automobile. The discharge displacement of the compressor is adjusted by an external control procedure. When the position of the acceleration pedal reaches a determining value, or above at which it is determined that engine power is needed for accelerating the vehicle, the compressor is controlled such that the discharge displacement decreases. The determining value is selected by a controller in relation to the traveling speed detected by a speed sensor. The determining value increases as the speed increases.

Abstract: A compressor control system and method are provided for a vehicle air conditioner. The control device controls engagement of a compressor clutch member at engine start-up to discharge liquid refrigerant from the compressor. The control system provides for disengagement of the clutch member if the detected operating conditions are indicative of compressor lock-up without the use of a dedicated compressor lock-up sensor.

Abstract: An air conditioning system for use in a motor vehicle powered by an internal combustion engine is described. The system comprises an electric motor powered by a battery; a compressor arranged to be powered by at least one of the internal combustion engine and the electric motor; and a control unit that controls the driving of the compressor. The control unit is configured to execute driving the compressor by only the electric motor when the combustion engine is under an idling stop; restarting the combustion engine upon expiration of a first given time from the time when the idling stop has occurred, so that thereafter the compressor is driven by both the combustion engine and the electric motor; and stopping the driving of the compressor by the electric motor upon expiration of a second given time from the restarting of the combustion engine, so that thereafter the compressor is driven by only the combustion engine.

Abstract: A vehicle air conditioning apparatus includes a refrigerant circuit. The air conditioning apparatus is driven by an engine. The air conditioning apparatus includes a variable displacement compressor. An external information detector detects external information used for the air conditioning. An E/G-ECU controls the output of the power source. An A/C-ECU is connected to the E/G-ECU via a communication line. The A/C-ECU computes a target value of the displacement of the compressor based on the external information. The A/C-ECU sends the computed target value to the E/G-ECU. The E/G-ECU controls the displacement of the compressor based on the computed target value. This is capable of rapidly changing the discharge displacement in accordance with the driving condition of the engine.

Abstract: In a device for air conditioning a motor-vehicle passenger compartment, a control module adjusts electrical power supplied to a motor-driven fan unit delivering airflow to a condenser of the device. Means are furthermore provided for recording an air throughput passing over the condenser and produced, at least in part, by the motor-driven fan unit. A regulation module estimates a maximum value of the electrical power supply to the motor-driven fan unit, for a given air throughput, with a view to limiting the electrical power supply to this maximum value, as a function of the air throughput.

Abstract: The system comprises a pressure sensor for providing a signal indicative of the pressure of the refrigerant fluid of the air-conditioning system at the output or delivery of the compressor of the system, a sensor for detecting the temperature of the liquid flowing through the engine-cooling system (R), an activation sensor for providing a signal when the air-conditioning system is activated, a sensor for detecting the speed of forward movement of the motor vehicle, and a control and operating unit connected to the sensors and to the electric motor and arranged for: determining a first speed for the electric motor in accordance with a function of the pressure of the refrigerant fluid of the air-conditioning system and of the speed of the vehicle, determining a second speed for the electric motor in accordance with a function of the temperature of the engine-coolant liquid and of the speed of forward movement of the vehicle, and sending to the electric motor control signals to bring its speed of rotation to

Abstract: An engine control apparatus of a vehicle having an air conditioner that has a variable displacement compressor is disclosed. The pressure difference between two points in a refrigeration circuit is monitored. The pressure difference represents the compressor displacement. The compressor is controlled by a control valve. The control valve operates based on the pressure difference. A controller compares the temperature of the passenger compartment with a temperature setting. If they differ, the controller determines a target pressure difference for the control valve. The controller computes the compressor torque based on the target pressure difference signal. The controller determines a target engine torque based on the compressor torque and controls the engine based on the target engine torque.

Abstract: In a vehicle air-conditioning system, an evaporator is disposed in an air-conditioning case to form a bypass passage through which air bypasses the evaporator, and an opening degree of the bypass passage is adjusted by a bypass door. When a vehicle engine operates, the system performs a cold-storing mode where cold quantity stored in condensed water on the evaporator is increased. On the other hand, when operation of the vehicle engine is stopped, the system performs a cold-releasing mode where air passing through the evaporator is cooled by cold released from frozen condensed water. During the cold-storing mode and the cold-releasing mode, temperature of air blown into a passenger compartment can be adjusted by adjusting the opening degree of the bypass passage. Thus, in the vehicle air-conditioning system, cold-storing quantity in the evaporator can be improved while power-saving effect of the vehicle engine is improved.

Abstract: An improved control apparatus for a vehicle air conditioning system controls a variable displacement compressor. The discharge capacity of the compressor is changed by changing the difference between the pressure in the crank chamber and the suction pressure. The difference between the pressure in the crank chamber and the pressure of the suction chamber is maintained at a set value. A target value is determined based on the temperature of the passenger compartment. The target value is corrected based on the rotational speed of the engine driving the compressor, which is detected. The set value is determined by the corrected target value.

Abstract: A capacity control device controls a discharge capacity of a variable displacement compressor for use in an automotive air conditioning system. The air conditioning system has the compressor and an evaporator fan. The device includes a control, a first detector, and a second detector. The control changes the discharge capacity of the compressor between a minimum discharge capacity for that compressor and a maximum discharge capacity. The first detector detects an elapsed time of a minimum discharge capacity operation of the compressor. The second detector detects an impressed voltage of the evaporator fan of the air conditioning system. The discharge capacity increases from the minimum discharge capacity to a predetermined discharge capacity when the elapsed time of the minimum discharge capacity operation is greater than a predetermined time and when the impressed voltage of the evaporator fan is greater than a predetermined voltage.

Abstract: Measurements are taken and associated with chosen models giving access to an average temperature (on the surface) of the window, for instance the windscreen, and to a dew temperature of the air in the passenger compartment of the vehicle. A comparison between the two temperatures represents a risk of misting of the window.

Abstract: A method for controlling cycling of an air conditioning compressor coupled to an internal combustion engine interrupts normal cycling based on operation conditions. In addition, normal engaged and disengaged cycling durations are adaptively estimated in real-time. The method of the present invention achieves improved fuel economy and improved drive feel. As an example, improved fuel economy is achieved by engaging the compressor during braking or when the engine is being driven by the vehicle. As another example, improved drive feel is achieved by engaging the compressor during transient conditions when drive feel is unaffected.

Abstract: In order to achieve a smooth shift between two drive sources, an electromagnetic clutch is engaged, when the rotation rate of the compression unit and the engine rotation rate match, to switch from motor drive to engine drive during engine startup or engine acceleration. The motor is driven before the electromagnetic clutch is cut off to switch from engine rive to motor drive during engine stop or engine deceleration.

Abstract: A displacement control apparatus controls the displacement of a variable displacement controller. A drive shaft of the compressor is driven by an engine. Torque acting on the drive shaft represents the displacement. The apparatus includes a control valve, an air conditioner controller and a compressor controller. The control valve changes the compressor displacement. The air conditioner controller produces a torque setting signal, which represents a target torque, to the compressor controller. The compressor controller changes the valve opening based on the torque setting signal such that the actual load torque matches the target torque value. Accordingly, the compressor is controlled according to the torque. The air conditioner controller may send the torque setting signal to an engine controller, which eliminates the need for load torque maps.

Abstract: A hybrid vehicle includes: a metal V-belt type infinitely variable gear-change mechanism 20 whereby the rotation of an engine E is subjected to change in gear ratio, a forwards clutch 14 and a reverse brake 15 that perform engagement/disengagement control of the engine and the infinitely variable gear-change mechanism, and a second motor generator 50 capable of driving the drive wheels arranged parallel with the engine. The control device is provided with a first hydraulic pump 3 for engine drive, a second hydraulic pump 56 that is driven by an electric motor 55 for pump drive, and a forwards/reverse clutch control valve 73 that performs changeover control of supply of working hydraulic pressure to the forwards clutch 14 etc.

Abstract: An air conditioning system for use in a motor vehicle powered by an internal combustion engine is described. The system comprises an electric motor powered by a battery; a compressor arranged to be powered by at least one of the internal combustion engine and the electric motor; and a control unit that controls the driving of the compressor. The control unit is configured to execute driving the compressor by only the electric motor when the combustion engine is under an idling stop; restarting the combustion engine upon expiration of a first given time from the time when the idling stop has occurred, so that thereafter the compressor is driven by both the combustion engine and the electric motor; and stopping the driving of the compressor by the electric motor upon expiration of a second given time from the restarting of the combustion engine, so that thereafter the compressor is driven by only the combustion engine.

Abstract: The invention relates to a method for reliably determining the temperature of the passenger compartment of a motor vehicle, in particular for controlling an air-conditioning system in the motor vehicle in which a sensor which detects the temperature of the passenger compartment of a motor vehicle is ventilated by a fan motor. In a method for determining the temperature of the passenger compartment, in which the noise nuisance from the fan motor is eliminated, another motor vehicle device which generates a noise is operated simultaneously with the fan motor.

Abstract: An engine control apparatus of a vehicle having an air conditioner that has a variable displacement compressor is disclosed. The pressure difference between two points in a refrigeration circuit is monitored. The pressure difference represents the compressor displacement. The compressor is controlled by a control valve. The control valve operates based on the pressure difference. A controller compares the temperature of the passenger compartment with a temperature setting. If they differ, the controller determines a target pressure difference for the control valve. The controller computes the compressor torque based on the target pressure difference signal. The controller determines a target engine torque based on the compressor torque and controls the engine based on the target engine torque.

Abstract: The present invention balances power consumption reduction and a cooling in a vehicle air-conditioning system having a compressor selectively driven by a vehicle engine or a motor while the compressor is driven by the motor. At least one of a capacity of a blower and a capacity of a compressor arranged in a refrigeration cycle R while the compressor being driven by a motor is reduced in comparison to the capacity of the blower and the capacity of the compressor while the compressor being driven by a vehicle engine. Furthermore, while a cooling heat load of an evaporator is greater than a predetermined value, the capacity of the compressor is first reduced prior to reducing the capacity of the blower.

Abstract: In a device for air conditioning a motor-vehicle passenger compartment, a control module adjusts electrical power supplied to a motor-driven fan unit delivering airflow to a condenser of the device. Means are furthermore provided for recording an air throughput passing over the condenser and produced, at least in part, by the motor-driven fan unit. A regulation module estimates a maximum value of the electrical power supply to the motor-driven fan unit, for a given air throughput, with a view to limiting the electrical power supply to this maximum value, as a function of the air throughput.

Abstract: An improved performance and cost-effective control for an automatic motor vehicle HVAC system in which the system variables are controlled without regard to a measured in-car temperature during steady-state conditions, and in which the steady-state control is modified during transient conditions by a time-dependent open-loop compensation term, INCAR. The initial value of INCAR, a target value and a time rate of change are initialized as a function of environmental and system conditions at the onset of the transient condition. At ignition key-on, INCAR is initialized in accordance with an estimate of the in-car temperature, and exponentially adjusted toward a predetermined reference temperature (target), such as 75°, at a rate determined by the initial temperature, preferably with adjustments being made for door opening and closing.

Abstract: The invention relates to the control of an automatic clutch in the drive train of a motor vehicle having a gearbox which can be changed arbitrarily by the driver between drive positions and idle (isolation of gearbox input and gearbox output). During idling, the clutch is essentially kept disengaged in order to reduce noise (gearbox rattling), but is temporarily closed at intervals for very short periods of time, in order to reset a temperature drift of an actuator unit which operates the clutch and which assumes a self-adjusting position when the clutch is engaged. The air conditioning system is switched off temporarily when, during idling, the clutch is engaged temporarily in order to eliminate the risk of rattling noise of the gearbox due to the air conditioning system being on.

Abstract: A vehicle cooling apparatus having a simple construction that enables the size of a cooling fan electric motor to be reduced without the need to increase the number of batteries provided for driving the motor. The cooling fan provides necessary cooling for an engine radiator and an air-conditioning system condenser by driving the motor at an input power lower than its rated power by a predetermined amount until the temperature of the engine cooling water reaches a predetermined temperature. If the water temperature rises above the predetermined temperature, the electric motor input power is increased to a level greater than its rated input power for a predetermined time period. As a result, cooling capacity can be increased and the water temperature can be lowered with a smaller motor when the water temperature has become abnormally high. Because the electric motor is normally driven at an input power lower than its rated input power, the life of the electric motor is increased.

Abstract: A drive for the compressor of a vehicle air conditioner has a magnetic clutch for mechanically driving the compressor shaft within a predetermined range of torque and a rotatable input element on the magnetic clutch to be rotated by the vehicle motor at varying speeds with changes in the vehicle motor's speed. The drive includes a first electromagnetic element on the rotatable input element and a compressor shaft on the output side of the magnetic clutch for supplying torque to drive the compressor. Also, there is a second electromagnetic element on the compressor shaft with a magnetic field between the first and second electromagnetic elements to rotate the compressor. An electric control is provided for varying the electrical power to the electromagnetic clutch as the vehicle motor changes speed to vary the magnetic field and torque being applied to rotate the compressor shaft.

Abstract: An air conditioning system (10) for a passenger compartment of a motor vehicle having a windscreen comprises a first heat exchanger (14) positionable outside the passenger compartment; a second heat exchanger (18) positionable inside the passenger compartment; an expansion device (16) positioned in a first fluid passage (22) between the heat exchangers; an electronically controlled variable stroke compressor (12) for pumping fluid into the second fluid passage and either in a first direction (X) or in a second direction (Y); reverse flow means (32) in the second fluid passage for controlling the direction of the flow of fluid; first sensing means (36, 40) providing a first output signal indicative of the dewpoint temperature of the air leaving the second heat exchanger; second sensing means (53; 44,46,48) providing a second output signal indicative of the temperature of the windscreen; and control means (26,30) electrically connected to the first and second sensing means and to the compressor for receiving th

Abstract: A method is provided of determining windshield fog secondary for automatically controlling a heating, ventilation and air conditioning (HVAC) system of a vehicle. The method includes the steps of determining whether rain is occurring on a windshield of a vehicle, determining a windshield parameter as a function of the rain occurring and determining a temperature difference based on temperature within a cabin of the vehicle and ambient temperature. The method also includes the steps of determining a fog boundary based on the windshield parameter and temperature difference, determining a relative humidity based on the windshield parameter and the temperature difference and fog boundary and determining a fog probability based on the fog boundary relative humidity and a nominal base relative humidity for rain conditions. The method further includes the steps of determining anti-fog actions to be taken based on the fog probability and taking the anti-fog actions determined to control the HVAC system.