FORM 2
THE PATENT ACT, 1970,
(39 OF 1970)
&
THE PATENTS RULE, 2003
COMPLETE SPECIFICATION
(SEE SECTION 10; RULE 13)
"INTELLIGENT HVAC COMPRESSOR AND A SYSTEM FOR THE RECOVERY OF KINETIC ENERGY DURING BRAKING/RECUPERATION IN AUTOMOBILES"
MAHINDRA & MAHINDRA LIMITED
AN INDIAN COMPANY,
R&D CENTER, AUTOMOTIVE SECTOR,
89, M.I.D.C, SATPUR,
NASHIK-422 007,
MAHARASHTRA, INDIA.
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE NATURE OF THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED

FIELD OF INVENTION:-
The present invention relates to a system to recover kinetic energy wasted during deceleration of the vehicle and effectively utilize it for the functioning of the HVAC compressor in automobiles.
BACKGROUND OF THE PRESENT INVENTION:-
The main problem of fuel energy transformation is only part of the energy supplied by the fuel in an automobile is converted into BHP output. Generally Part of engine energy will be used to drive FEAD (Front End Accessory Drive) system like a water pump, an A/C compressor, a power steering pump, a brake vacuum pump and an alternator. In order to improve the fuel efficiency of any vehicle, optimization of engine FEAD system plays a vital role.
In the conventional vehicles, the A/C compressor used is of ON/OFF type. It will be engaged or disengaged with the engine FEAD system based on the customer request. Effective controlling of the A/C compressor is not possible based on various vehicle system inputs. Thus the effective utilization of the HVAC system is not possible from the energy consumption point of view.
In the existing prior art patent references US 7308799 B1 and US 7458224 B1, the HVAC compressor is coupled to the engine crankshaft pulley through a magnetic clutch. In the prior art technologies, effective control of A/C compressor is not possible based on vehicle driving requirements & thermal comfort, because of magnetic clutch usage in traditional A/C compressor (ON/OFF technique) and also because of the absence of intelligent (Semi automatic/automatic) HVAC controller.
All the attempts which were made to recover the kinetic energy from vehicle braking or recuperation is not economical as it is complicated in design and involves many components.

To address these drawbacks of the conventional kinetic energy recovery systems in automobiles, there is a need in the art to provide a system which reduces the whoosh noise generated in the inlet side of the turbocharger.
OBJECTS OF THE PRESENT INVENT10N:-
An object of the present invention is to recover kinetic energy during recuperation or braking from the automobiles for controlling the HVAC compressor without affecting the performance of the engine.
It is also object of invention to provide an intelligent compressor of vehicle air-conditioner to sense the acceleration and deceleration of vehicle and utilize kinetic energy wasted during breaking of vehicle.
STATEMENT OF INVENTION:-
Accordingly invention provides an intelligent HVAC compressor for the recovery of kinetic energy during braking/recuperation in automobiles comprises a compressor having a rotating swash plate (301), adjustable at variable angle by using springs and linkage that move lengthwise along the driveshaft, to reciprocate pistons (302) for compressing the refrigerant; an electromagnetic clutch in the form of electromagnetic control valve, with port and passages that connect to the suction (low-side) and discharge (high-side) chambers of the compressor head for adjusting compressor housing pressure for refrigerant pressure in the compressor housing to vary the displacement of piston; a pressure and temperature sensor provided to communicate to the compressor housing and an electric control unit to give electrical signal to the said electromagnetic control valve to change the swash plate angle after sensing acceleration or deceleration vehicle and the refrigerant differential pressure before and after a throttle at the discharge side; a pulley to the said drive shaft to take power from engine shaft.

Accordingly the invention also provides a system for the recovery of kinetic energy during braking/recuperation in automobiles comprises a compressor of air-conditioner unit with condenser and evaporator having a rotating swash plate (301), adjustable at variable angle by using springs and linkage that move lengthwise along the driveshaft, to reciprocate pistons (302) for compressing the refrigerant; an electromagnetic clutch in the form of electromagnetic control valve, with port and passages that connect to the suction (low-side) and discharge (high-side) chambers of the compressor head for adjusting compressor housing pressure for refrigerant pressure in the compressor housing to vary the displacement of piston; a pulley provided to the said drive shaft to take power from vehicle engine shaft; an EMS of the said engine connected through CAN to the said the HVAC controller system; a pressure and temperature sensor provided to communicate to said HVAC controller, EMS and compressor housing to give electrical signal to the said electromagnetic control valve to change the swash plate angle after sensing acceleration or deceleration of vehicle and the refrigerant differential pressure before and after a throttle at the discharge side.
BRIEF DESCRIPTION OF THE FIGURES:-
The objects and other advantages of the present invention will become apparent when the disclosure is read in conjunction with the following figures, wherein
Figure 1 shows a schematic diagram of the kinetic energy recovery circuit by the intelligent HVAC compressor;
Figure 2 shows a flow chart of the HVAC compressor performance at vehicle acceleration and deceleration;
Figure 3 shows the sectional view of the intelligent HVAC compressor with the electromagnetic clutch;

Figure 4 shows the graph of the compressor performance with respect to the vehicle speed;
DETAILED DESCRIPTION OF THE PRESENT INVENTION:-
The foregoing objects of the invention are accomplished and the problems and shortcomings associated with the prior art techniques and approaches are overcome by the present invention as described below in the preferred embodiment.
The present invention is illustrated with reference to the accompanying drawings, throughout which reference numbers indicate corresponding parts in the various figures. These reference numbers are shown in bracket in the following description.
Referring to figure 1 of the present invention, the system comprises of an electromagnetic clutch (107) which is placed inside the externally controlled A/C compressor (105) which is used to control the loading of the A/C compressor on the engine (102) based on the vehicle system inputs like vehicle HVAC system boundaries (Refrigerant Low/high Pressure limits, Passenger Thermal comfort etc.,). Generally the A/C compressor (105) uses some of the engine power to compress the refrigerant coming from the evaporator (109) (Low pressure side). The low pressure gas is compressed to high pressure gas by the A/C compressor and is sent to the condenser (106) (heat rejected into ambient air) to convert it into high pressure/temperature liquid. Using an expansion valve (108), the high pressure/temperature liquid is expanded and converted to a low pressure/temperature liquid which is used in the evaporator (109) to cool down the air drawn from the outside ambient or passenger cabin to cool the passenger cabin.
During deceleration, high amount of refrigerant is compressed and sent to the evaporator (109) , which decrease the core temperature of the evaporator (based on lower limits of evaporator core temperature it is possible to disable the deceleration functionality -> HVAC controller). In order to achieve the thermal comfort during

deceleration mode, the air discharge temperature is controlled by the flaps/blending door to mix hot and cold air to meet the required customer cabin air temperature. Besides that it is also possible to store additional refrigerant compressed during deceleration mode and the same can be used during the acceleration mode where the amount of refrigerant available to the evaporator is very less.
During hard acceleration, low amount refrigerant will be compressed & sent to evaporator, it will increase core temperature of evaporator (based on higher limits of evaporator core temperature we can disable acceleration functionality --> HVAC controller). In order to achieve thermal comfort during acceleration mode, In order to achieve exact air discharge temperature, Additional Accumulator (storage device) will be used to store excess refrigerant available from deceleration phase to support refrigeration cycle in acceleration phase where amount of refrigerant available to evaporator will be less.
The HVAC controller gets necessary inputs like acceleration status, deceleration status, high pressure/low pressure refrigerant status/limits, cabin/evaporator core temperature etc., to decide PWM duty cycle to control intelligent A/C compressor. The HVAC controller internally controls flaps/blending door to control the thermal comfort during the vehicle deceleration and acceleration conditions.
ACCELERATION:-
During vehicle hard acceleration, A/C compressor load on engine will be reduced drastically to improve drivability/performance (0 to 100 kmph in xx sec) without affecting the thermal comfort of the customer. The same is achieved by controlling the electromagnetic clutch effectively using the HVAC controller (less duty cycle (10%) -PWM control), so that compressor load on engine will be reduced during acceleration.

DECELERATION:-
During vehicle deceleration, the A/C compressor load on the engine is increased drastically to utilize the kinetic energy available from braking/recuperation without affecting the thermal comfort of the customer. The same is achieved by controlling Electromagnetic clutch effectively using HVAC controller (High duty cycle (90%) - PWM control), so that compressor load on engine will be increased during deceleration.
According to figure 2 of the present invention, it shows the flow of how the acceleration or deceleration of the vehicle affects the performance of the A/C compressor. During vehicle acceleration, the accelerator pedal position is sensed and accordingly the A/C compressor duty is decreased which gives better acceleration and hence there is a reduction in fuel consumption. During Vehicle deceleration, the brake pedal input is sensed and accordingly the A/C compressor duty is increased which gives additional cold air which can either be accumulated or directed to the passenger cabin.
Figure 3 shows the schematic layout of the intelligent HVAC compressor along with the electromagnetic clutch. The compressor (300) has a swash plate (301) that rotates to reciprocate pistons (302), which compresses the refrigerant.
In a swash plate compressor, the plate itself rotates with the drive shaft. A bearing in the bottom of each piston "clamps" around the edge and rides on either face of the swash plate. The plate is set at an angle to the shaft, so as it rotates, the pistons are forced back and forth in their bores.
The angle of the swash plate determines the length of the piston stroke. In a variable displacement compressor, that angle can be changed, which changes the length of the pistons' stroke and, therefore, the amount of refrigerant displaced on each stroke. The angle is adjusted using springs and linkage that move lengthwise along the driveshaft, and it's controlled with refrigerant pressure in the compressor housing.

When housing pressure is increased, the pressure exerted on the back side of the pistons keeps them "higher" in their bores and closer to the cylinder head. This shortens the stroke, reducing displacement.
When housing pressure is reduced, a spring pushes the adjusting linkage away from the cylinder head, increasing plate angle and lengthening the piston stroke to increase displacement.
Housing pressure is adjusted using a control valve with ports and passages that connect it to the suction (low-side) and discharge (high-side) chambers of the compressor head.
Electromagnetic valve:
The electromagnetic control which replaces the diaphragm valve with a solenoid valve and add temperature and pressure sensors in the refrigerant system. This allows an XCU's to control the valve and adjust compressor displacement to control evaporator temperature, rather than using evaporator temperature to control displacement.
The electronic displacement control valve makes it easier to run the compressor continuously because displacement can be reduced closer to zero than with a mechanical valve.
Continuous operation keeps seals lubricated, minimizes oil pooling and prevents other kinds of damage that result from long periods of inactivity.
Ultimately the electronically controlled variable displacement compressor puts less load on the engine, improving fuel economy. And of course, the driver will never feel the A/C clutch cycling or the idle speed surge that sometimes accompanies it. The mechanical control valve is in expensive and reliable, but it doesn't provide the same control as the electronic valve.

The variable displacement compressor changes the swash plate angle to change the refrigerant displacement. The externally controlled type variable displacement compressor (300) changes the swash plate (301) angle in accordance with an electrical signal from an electric control unit. The externally controlled variable displacement compressor manages displacement by controlling the refrigerant differential pressure before and after a throttle at the discharge side; achieving precise cooling capability control in accordance with the cabin environment and the driving conditions. The externally controlled variable displacement compressor with an electromagnetic control valve (303) controls the refrigerant differential pressure before and after a throttle at the discharge side, in accordance with an electric signal from the engine ECU or air conditioner ECU (not shown). By controlling the refrigerant discharge pressure rather than the refrigerant suction pressure, the engine torque used for the compressor can be estimated. This allows the compressor to be controlled in connection with engine management to reduce fuel consumption.
WORKING OF INVENTION:-
The A/C compressor is coupled to Engine Crankshaft pully through A/C compressor pulley. There is no magnetic clutch in between A/C compressor & Engine.
A/C compressor will have electromagnetic clutch which sit inside (Externally controlled) A/C compressor which will be used to control load of A/C compressor on engine based on vehicle system inputs like Vehicle HVAC system boundaries (Refrigerant Low/high Pressure limits, Passenger Thermal comfort etc.,), Vehicle system inputs like acceleration & deceleration.
Generally A/C compressor will use some of the engine power to compress the refrigerant coming from evaporator (Low pressure side). Low pressure liquid will be compressed to high pressure gas by A/C compressor & sent to condenser to convert it into high pressure/temperature liquid. Using expansion valve, high

pressure/temperature liquid will be expanded & changed to low temperature liquid which will be used in evaporator to cool down air drawn from outside ambient or Passenger cabin to cool passenger cabin.
During vehicle hard acceleration, A/C compressor load on engine will be reduced drastically to improve drivability/performance (0 to 100 kmph in xx sec) without affecting thermal comfort of customer. Same will be achieved by controlling Electromagnetic clutch effectively using HVAC controller (less duty cycle (10%) - PWM control), so that compressor load on engine will be reduced during acceleration.
During vehicle deceleration, A/C compressor load on engine will be increased drastically to utilize kinetic energy available from braking/recuperation without affecting thermal comfort of customer. Same will be achieved by controlling Electromagnetic clutch effectively using HVAC controller (High duty cycle (90%) - PWM control), so that compressor load on engine will be increased during deceleration.
HVAC controller will get necessary inputs like acceleration status, deceleration status, high Pressure/low pressure refrigerant status/limits, cabin/evaporator core temperature etc., to decide PWM duty cycle to control intelligent A/C compressor.
HVAC controller internally control flaps/blending door to control thermal comfortless during vehicle deceleration & acceleration conditions.
Referring to the figure 4 of the present invention, it shows the graph of compressor performance during vehicle acceleration and deceleration. The graph clearly shows that the operation of the A/C compressor is decreased during vehicle acceleration and increased during vehicle deceleration.

The technical advantages achieved by the present invention are:
- The externally controlled variable displacement compressor with an electromagnetic control valve that controls refrigerant differential pressure before and after a throttle at the discharge side, in accordance with an electric signal from the HVAC conditioner.
- The externally controlled variable displacement compressor with resin-made DL pulley achieves the lightest weight for equivalent displacement compressors. The housing to have a thinner wall while maintaining its strength, contributing to a smaller and lighter compressor.
- The rotary valve reduces pressure drop of the refrigerant gas drawn into the compression chambers, and prevents heating of the refrigerant gas. This enables the compressor to draw a larger amount of refrigerant into the compressing chambers, increasing the compressor efficiency by approximately 10 percent when compared to a conventional compressor.
- Using electromagnetic control valve, the refrigerant displacement is controlled in accordance with the amplitude of engine torque used for the compressor. This maximizes engine efficiency.
- The rotary valve and the housing's muffler structure significantly reduce the pulsation of refrigerant gas pulled into the compression chambers.
- The pistons are hollow, enabling the compressor to control refrigerant displacement at a maximum of 11,000 revolutions per minute, at high engine speed. This prevents the pistons from disturbing the swash plate inclination control even at the high engine speed.

- By controlling refrigerant discharge pressure rather than refrigerant suction pressure, the engine torque used for the compressor can be estimated. This allows the compressor to be controlled in connection with the engine management to reduce the fuel consumption/Co2 reduction.
It should be understood that the present invention is not to be limited by the exact details of the illustrated embodiment. However, it is to be taken as the preferred example of the invention and that various changes may be resorted to by a person skilled in the art without departing from the spirit of the invention. Also, the terminologies used herein are for the purpose of description and should not be regarded as limiting.

WE CLAIM:-
1. An intelligent HVAC compressor for the recovery of kinetic energy during braking/recuperation in automobiles comprises a compressor having a rotating swash plate (301), adjustable at variable angle by using springs and linkage that move lengthwise along the driveshaft, to reciprocate pistons (302) for compressing the refrigerant; an electromagnetic clutch in the form of electromagnetic control valve, with port and passages that connect to the suction (low-side) and discharge (high-side) chambers of the compressor head for adjusting compressor housing pressure for refrigerant pressure in the compressor housing to vary the displacement of piston; a pressure and temperature sensor provided to communicate to the compressor housing and an electric control unit to give electrical signal to the said electromagnetic control valve to change the swash plate angle after sensing acceleration or deceleration vehicle and the refrigerant differential pressure before and after a throttle at the discharge side; a pulley to the said drive shaft to take power from engine shaft.
2. The intelligent HVAC compressor as claimed in claim 1 wherein the said valve is solenoid valve.
3. The intelligent HVAC compressor as claimed in claims 1 and 2 wherein the said electrical control unit with engine system.
4. The intelligent HVAC compressor as a claimed claims 1 and 2 wherein the said electrical control unit with air conditioner system.
5. A system for the recovery of kinetic energy during braking/recuperation in automobiles comprises a compressor of air-conditioner unit with condenser and evaporator having a rotating swash plate (301), adjustable at variable angle by using springs and linkage that move lengthwise along the driveshaft, to reciprocate pistons (302) for compressing the refrigerant; an electromagnetic clutch in the form of electromagnetic control valve, with port and passages that connect to the suction (low-side) and discharge (high-side) chambers of the compressor head for adjusting compressor housing pressure for refrigerant pressure in the compressor housing to vary the displacement of piston; a pulley provided to the said drive shaft

to take power from vehicle engine shaft; an EMS of the said engine connected through CAN to the said the HVAC controller system; a pressure and temperature sensor provided to communicate to said HVAC controller, EMS and compressor housing to give electrical signal to the said electromagnetic control valve to change the swash plate angle after sensing acceleration or deceleration of vehicle and the refrigerant differential pressure before and after a throttle at the discharge side.