Patent Publication Number: US-11396867-B2

Title: DC voltage air conditioning compressor drive unit

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a U.S. national stage application under 35 U.S.C. § 371 of PCT/AU2018/051273, filed on Nov. 29, 2018, and published as WO2019/104386 A1 on Jun. 6, 2019, which claims priority to Australian application no. 2017904862, filed on Dec. 1, 2017. 
     FIELD OF INVENTION 
     The invention relates to a Direct Current (DC) air conditioning compressor drive unit for use in both buildings and in vehicle installations. Energy savings can be demonstrated in the automotive industry when compared to the current status of known DC air conditioning drive units and in particular those relying on direct or pulley drive. More particularly, when coupled to DC battery and inverter technology for air conditioning purposes within domestic housing, commercial and industrial buildings, it can provide extreme energy savings. Preferably, the purpose of this innovation is to enhance the viability and energy savings opportunities of using DC power in air conditioning if used in conjunction with smart compressor technology. 
     BACKGROUND TO THE INVENTION 
     Air conditioner technology has been recognised for over 100 years. During this time the principle of evaporative cooling using wind chill over a wet surface or over ice has progressed into refrigerated cooling that involves a power source to drive internal electronic parts. This has come about through the advent of a suitable refrigerant gas that when compressed could cool a surface and replace wind over a wet surface as a medium for air conditioning. The progress made in this field dictated the need for internal machinery parts for air conditioners, amongst which was the need for a compressor if the air conditioner was to be effective. This need also applied to the Refrigeration Industry where compressor technology was developed for cool room, refrigeration and deep freezer units. The common power source worldwide had been the acceptance of Alternating Current (AC) and parts for the new industry surrounding compressors was developed on this principle. AC power involves electricity generated from thermal or nuclear stations. Its popularity in recent years has waned due in some cases to blame for global warming and the dangers of radiation in the event of accidents. In the last two decades much work has been done to revisit an alternative power source known as Direct Current (DC). This is a well-known and reliable form of renewable energy that can be generated naturally through harvesting both the wind and the sun with smart technology, thereby eliminating the power source objections. DC powered compressors have been in use for some time in all types motor vehicles to provide air conditioning but they have traditionally required a motor to drive them, and in most cases, this would be a pulley driven unit that could only operate the air conditioning if the motor was running. The electrical circuit and power source is likely to come from either a 12 or 24 volt on board battery. The use of DC air conditioning in domestic housing, commercial buildings and Industrial complexes has been limited because there is no motor to drive the compressor to circulate the refrigerant gas or drive the blowers. Recent developments in battery technology have allowed for harvested DC power to be stored in smart batteries. It follows that an innovative compressor would be required to take advantage of this power source, but it must be able to operate reliably without pulley drive. The compressor generally uses more power than any other part of an air conditioning unit and is integral to an efficient system. 
     The invention addresses that opportunity by developing a unique and novel method of constructing a DC compressor that limits power input whilst providing an output equal to AC compressor technology, and in some instances surpassing it in some features of its construction and performance as we know it to be at this time. 
     Air conditioners rely on a drive unit to operate the refrigeration cycle. Drive units comprise a compressor and a motor. The motor drives the compressor. In both light automotive and heavy duty machinery and other equipment it has been usual for the compressor to be pulley or direct drive units powered by the motor. Direct Current (DC) has always been the power source and provided by on board batteries in various voltages. This arrangement allows for air conditioners to be installed in a variety of locations, such as: light and heavy mobile equipment or machinery, telecommunication shelters, cars, trucks, motor homes, military equipment. Homes, commercial structures, industrial type buildings and other environments have been limited in the past from DC energy by preference for Alternating Current (AC) provided from a central power grid. The relatively recent availability of solar and wind power devices capable of generating DC power has not been exploited to any extent in the domestic, commercial and industrial air conditioning field. Furthermore, the availability of a suitable compressor in DC form that limits energy input whilst providing adequate performance has not been freely available for domestic or commercial premises. DC air conditioner compressor drive units are generally connected to battery, alternator, solar or wind power via a controller in automotive, domestic, commercial and industrial applications. In the case of automotive installations, the compressor drive units are required to be compact. The advent of DC powered air conditioning for homes, commercial and industrial does not necessarily place such a limitation on space. 
     SUMMARY OF THE INVENTION 
     The present Rencool invention provides for a Primary and an Anti Idle and No Pulley drive compressor designed for both small and large equipment use in the air conditioning of vehicles, domestic housing, commercial and industrial buildings. 
     Anti Idle function can best be described as being able to maintain the cool effects of air conditioning within an operators vehicle interior space without having to keep the main engine operating. This is a huge energy savings benefit to large organisations running machinery and which converts into many litres of fuel in savings. 
     Primary function relates to machinery that does not have a Pulley Drive compressor as an option and deemed impossible for installation of air conditioning. With the Rencool DC compressor innovation this is still an option to install air conditioning. Testing is done with alternator capacity, allowable current consumption and the size of the DC compressor. This changes per machine and application configuration setup. 
     The Rencool concept is to use the DC voltage compressor technology instead of the conventional pulley belt drive compressor running from the engine pulley drive. The concept is able to be extended into all areas of air conditioning by applying the different variations and displacements of the compressor volume and speed and also the air conditioner system either rooftop or split type configuration but not limited to either. The compressor testing is done with piston and scroll type configurations and current consumption is married with the HVAC systems performance and allowable current consumption. All units have different cooling capacities and these must match the compressor displacement/output. The compressor capacity range is from 18 cc upwards without limitations and any model can be suited for different ranges of units with matching performance. 
     Current consumption, efficiency and performance are important criteria for testing the full range of DC voltage compressors for allowable current usage. All systems demand more or less power to cool. This must be tuned for the application of the unit for the best cooling capacity with the necessary power requirement. All testing extends to cabling and different brushless direct current (BLDC) controllers, encoders and programming of the software for the BLDC. The testing for the innovation extends to many types of controllers with different controller ampere (amp) capacities. This tends to provide a more efficient air conditioning system running from DC voltage input. 
     DISCLOSURE OF THE INVENTION 
     In one form, although it need not be the only or indeed the broadest form, the invention resides in a DC air conditioning compressor drive unit including: 
     a DC electric motor having a drive shaft— 
     a compressor having a driven shaft— 
     an adaptor which mounts the compressor relative to the electric motor to align the drive shaft of the electric motor and the driven shaft of the compressor- and 
     a coupling connecting the drive shaft of the motor to the drive shaft of the compressor. 
     The Heat Sink Connection Housing (Adaptor) preferably aligns the drive shaft and the driven shaft substantially co-axially. 
     The DC air conditioning compressor drive unit preferably includes a programmable controller for controlling the supply voltage, current, speed, torque and other variations to the electric motor. 
     The DC air conditioning compressor drive unit preferably includes two retaining brackets for mounting the compressor to the Heat Sink Connection Housing (Adaptor) 
     The DC electric motor is preferably a brushless DC electric motor. 
     The compressor is preferably a piston type configuration but not restricted to piston only. 
     The DC air conditioning compressor drive unit is preferably configured so that the electric motor drives the compressor at a speed from and between 1 rpm to 3000 rpm. 
     The DC air conditioning compressor drive unit preferably includes and encoder so the efficiency of the DC electric motor can be tuned increasing the set point efficiency. 
     The DC air conditioning compressor drive unit preferably includes a (3) point terminal head enclosure located on top of the DC electric motor. 
     The DC air conditioning compressor drive unit preferably is sealed from water and dust and carries an IP rating of (56). 
     The compressor preferably has a capacity of and between 45 cc to 120 cc but not restricted to certain displacement. 
     The coupling preferably includes two aligned passages which are each open to a different opposite end of the coupling and which are dimensioned to receive the drive shaft of the electric motor and the driven shaft of the compressor, respectively. 
     The coupling preferably includes an elastomeric component between the passages. 
     The Heat Sink Connection Housing (Adaptor) preferably includes a cylindrical body having a cavity into which the drive shaft of the electric motor and the driven shaft of the compressor project and in which the coupling is located. 
     The Heat Sink Connection Housing (Adaptor) preferably includes a flange having bolt holes for bolting the (Adaptor) to the electric motor. 
     The Heat Sink Connection Housing (HSCH) preferably includes a heat-sink attached to the outer diameter of the alloy main assembly. 
     The Heat Sink Connection Housing (Adaptor) preferably has the heat-sink attached via use of bolts and a heat-sink pad cloth between the heat-sink and alloy main assembly. 
     The invention extends to the Heat Sink Connection Housing (Adaptor) as defined and described hereinabove. 
     The invention extends also to a mounting system comprising the (HSCH) and the retaining brackets. 
     The mounting system preferably includes fasteners for: fixing the retaining brackets to the compressor, fixing the retaining brackets to the (Adaptor) and for fixing the (Adaptor) to the electric motor. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       To assist in understanding the invention and to enable a person skilled in the art to put the invention into practical effect, preferred embodiments of the invention will be described by way of example only with reference to the accompanying drawings, wherein: 
         FIG. 1  shows a first perspective view of the DC air conditioning compressor drive unit in accordance with one embodiment of the invention. 
         FIG. 2  shows a first side view of the DC air conditioning compressor drive unit in accordance with one embodiment of the invention. 
         FIG. 3  shows a top view of the DC air conditioning compressor drive unit in accordance with one embodiment of the invention. 
         FIG. 4  shows an end view of the DC air conditioning compressor drive unit in accordance with one embodiment of the invention. 
         FIG. 5  shows a second perspective view of the DC air conditioning compressor drive unit in accordance with one embodiment of the invention. 
         FIG. 6  shows a second side view of the DC air conditioning compressor drive unit in accordance with one embodiment of the invention. 
         FIG. 7  shows a diagrammatic exploded side view of the DC air conditioning compressor drive unit in accordance with one embodiment of the invention. 
         FIG. 8  shows a diagrammatic assembled view of the DC air conditioning compressor drive unit of  FIG. 1 . 
         FIG. 9  is a diagrammatic perspective view of an electric motor (Encoder) cap of the DC air conditioning compressor drive unit of  FIGS. 1-7 . 
         FIG. 10  is a diagrammatic perspective view of an electric motor of the DC air conditioning compressor drive unit of  FIGS. 1-7 . 
         FIG. 11  is a diagrammatic side view of a compressor of the DC air conditioning compressor drive unit of  FIGS. 1-7 . 
         FIG. 12  is a perspective view of a compressor of the DC air conditioning compressor drive unit of  FIGS. 1-7 . 
         FIG. 13  is a diagrammatic end view of a compressor of the DC air conditioning compressor drive unit of  FIGS. 1-7 . 
         FIG. 14  is a perspective view of a heat sink connection housing (Adaptor) of the DC air conditioning compressor drive unit of  FIGS. 1-7 . 
         FIG. 15  is a diagrammatic side view of a heat sink connection housing (Adaptor) of the DC air conditioning compressor drive unit of  FIGS. 1-7 . 
         FIG. 16  is perspective view of a heat sink connection housing (Adaptor) of the DC air conditioning compressor drive unit of  FIGS. 1-7 . 
         FIG. 17  is a diagrammatic end view of a heat sink connection housing (Adaptor) of the DC air conditioning compressor drive unit of  FIGS. 1-7 . 
         FIGS. 18-20  are diagrammatic views of a (upper and lower) two-part heat-sink attached to the heat sink connection housing (Adaptor) of the DC air conditioning compressor drive unit of  FIGS. 1-7 . 
         FIGS. 21-22  are a diagrammatic isometric views of the (upper and lower) two-part retaining bracket of the DC air conditioning compressor drive unit of  FIGS. 1-7 . 
         FIG. 23  is a perspective view of the coupling of the DC air conditioning compressor drive unit of  FIGS. 1-7 . 
         FIG. 24  is a diagrammatic side view of the coupling of the DC air conditioning compressor drive unit of  FIGS. 1-7 . 
         FIG. 25  is a perspective view of the base plate of the DC air conditioning compressor drive unit of  FIGS. 1-7 . 
         FIG. 26  is a diagrammatic top view of the base plate of the DC air conditioning compressor drive unit of  FIGS. 1-7 . 
         FIG. 27  is a diagrammatic perspective view of the DC air conditioning compressor drive unit of  FIGS. 1-7 . 
         FIGS. 28-29  are is diagrammatic perspective views of the DC air conditioning compressor drive unit with the controller of  FIGS. 1-7 . 
         FIG. 30  is a perspective view of the controller for the DC air conditioning compressor drive unit of  FIGS. 1-7 . 
         FIG. 31  is a diagrammatic top view of the controller for the DC air conditioning compressor drive unit of  FIGS. 1-7 . 
         FIG. 32  is a diagrammatic front view of the front panel of the controller of  FIGS. 30-31 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In this patent specification, adjectives such as first and second, left and right, top and bottom, etc, are used solely to define one element or method step from another element or method step without necessarily required a specific relative position or sequence that is described by the adjectives. Words such as “comprises” or “includes” are not used to define an exclusive set of elements or method steps included in a particular embodiment of the present invention. In the drawings, like reference numbers refer to example parts. 
     The invention relates to a Direct Current (DC) air conditioning compressor drive unit for use in both buildings and in vehicle installations but without limitation to other applications. Preferably the unit according to the present invention is one configuration comprising a motor and a compressor. The unit&#39;s design allows for more versatility and enables the manipulation of power. Energy savings can be demonstrated in the automotive industry when compared to the current status of known DC air conditioning drive units and in particular those relying on indirect or pulley drive. More particularly, when coupled to DC battery and inverter technology for air conditioning purposes within domestic housing, commercial and industrial buildings, it can provide extreme energy savings. This is achieved by understanding that DC HVAC heat and load=energy used. By lowering the heat from the condenser as much as possible without compromising the cooling performance to lower torque we achieve lower power consumption. Should the head pressure be too low or too high then the systems cooling performance will drop so it is necessary to find a balance between the two. This is done by determining the systems configuration, air flow and resistance with the type of refrigerant used. All care is taken to marry up the electric motor and compressor with minimal heat loss in the entire assembly through good design. Preferably, the purpose of this innovation is to enhance the viability and energy savings opportunities of using DC power in air conditioning if used in conjunction with smart compressor technology. 
       FIGS. 1-8  show a DC air conditioning compressor drive unit  10  in accordance with one embodiment of the invention. The unit  10  comprises a brushless DC electric motor  100 , a piston compressor  200 , a heat sink connection housing (Adaptor)  300 , a two-part retaining brackets  400 A &amp;  400 B, a coupling  500 , a base plate  600 . 
       FIGS. 1-7  show the unit  10  in an exploded condition and  FIG. 8  shows the unit  10 A (of  FIGS. 28-29 ) in an assembled condition. The unit  10  is adapted to drive an air conditioning system of about 8 kilowatt cooling power. By suitable selection of the electric motor  100  and compressor  200  the unit  10  may be adapted to drive an air conditioner system of between 1 and 12 kilowatt cooling power. 
       FIGS. 9-10  show the electric motor  100  in more detail. The electric motor  100  has a vaned housing  104 . The housing  104  includes vanes to promote heat dissipation from the electric motor  100 . The electric motor  100  includes a face plate  106  and a back plate  108 . The face plate  106  has three threaded holes  110  therein. The heat sink connection housing (Adaptor) 300 bolts to the front face plate  106  with bolts which are screw-thread received in the threaded holes  110 . The electric motor  100  has a drive shaft  102 . The drive shaft  102  extends through the face plate  106 . 
       FIG. 10  shows the electric motor  100  includes a terminal block  118 . The terminal block  118  has three (3) 8 mm studs enclosed in the terminal block  118 . The three (3) 8 mm studs have three (3) 6 mm wires attached leading to the internal of electric motor  100 . The terminal block  118  has four (4) mounting studs attached to the electric motor  100 . The mounting studs are thread into the electric motor  100  housing on the base  104  of the electric motor  100 . 
     The drive shaft  102  is generally cylindrical and includes a key  112 . The electric motor  100  has an Encoder with cap cover  116  with (4) bolts mounted to the back plate  108 . 
     The electric motor  100  is bolted to the base plate  600  by way of threaded holes  114  (shown in  FIG. 7 ) in the underside of the housing  104 . 
     The unit  10  uses a brushless DC electric (BLDC) motor as brushless DC motors typically suffer less friction losses than other types of DC motors such as brushed DC motors. The less the friction losses, the more energy efficient the electric motor  100  is. The electric motor  100  has permanent magnets bonded to its rotor and thus does not use electric energy to establish a magnetic field in the motor  100 . The electric motor  100  is selected to operate on an input voltage of nominally either 12V, 24V, 48V, 74V. The electric motor  100  is specifically selected for the voltage of the electric system the unit  10  is to be connected to. A 12 volt electric motor  100  is selected for a 12 volt electric system such as used in a car, a 24V electric system is selected for a 24V electric system such as used in a mining machine. Similarly, 48V and 72 v electric motors  100  are selected for the electric systems of different environments. The electric motor  100  is a 1500 watt &amp; 2000 watt rated motor at set speeds from 1700 to 3000 rpm, but not limited to 3000 rpm. 
     Referring to  FIGS. 11-13 , the compressor  200  has a driven shaft  202  through which the compressor is driven. The compressor  200  also has a suction port  204  and a discharge line port  206 . The compressor  200  raises the pressure of the refrigerant which flows from the suction line port  204  to the discharge line port  206  when driven. When installed in an air conditioning system, the compressor  200  is connected between the evaporator and condenser of an air conditioning system to drive the air conditioning system. A suction line of the air conditioning system connects the compressor  200  to the evaporator via the suction line port  204 . A discharge line of the air conditioning system connects the compressor  200  to the condenser via the discharge line port  206 . The cylindrical housing  208  has an oil access thread sealed port  226 . The sealed port access  226  is also used for oil return separation connection. The compressor  200  has a generally cylindrical housing  208  with two and four front mounting lugs  210 ,  212 ,  214  and  216 . The compressor  200  has a generally cylindrical housing  208  with two and four rear mounting lugs  218 ,  220 ,  222  and  224 . The mounting lugs  210 ,  212 ,  214  and  216  have threaded holes formed therein for bolting the retaining brackets  400 A &amp;  400 B to the compressor  200 . 
     The compressor  200  has volume displacement in 45 cc, 92 cc, 120 cc and 150 cc, but not restricted to 150 cc. The compressor has five (5) pistons for 45 cc and ten (10) pistons for 92 cc, 120 cc and 150 cc. The unit  10  is configured so that the electric motor  100  drives the compressor  200  at a speed of between 1000 rpm and 3000 rpm and more preferably at about 2000 rpm during normal operation. The application has found that the use of a piston compressor instead of the more often used scroll-type compressor is more efficient at these speeds. 
       FIGS. 14-17  depict the adaptor  300 . The adaptor  300  includes a cylindrical body  302  having an open end  304  and a closed end  306 . The closed end  304  of the body  302  is closed off by an end plate  312 . A central hole  314  is formed in the end plate  312 , through which the driven shaft  202  of the compressor  200  extends as shown in  FIG. 8 . 
     The adaptor  300  further includes a flange  308  about the open end  304  of the body  302 . The flange  308  has three equi-spaced holes  316  therein, in which bolts are received for bolting the adaptor  300  to the electric motor  100 . The holes  316  are complementary to the threaded holes  110  in the face plate  106  of the electric motor  100 . 
     Two mount formations  310  project from the end plate  312  at the closed end  306  of the body  302 . The mount formations  310  are semi-circular walls each having two threaded holes  318  at their distal ends. The retaining brackets  400 A &amp;  400 B bolts to the mount formations  310  to mount the compressor  200  to the adaptor  300 . 
     The body  302  of the adaptor  300  has a cavity  324 . In the assembled condition of the unit  10 , the drive shaft  102  of the electric motor  100  and the driven shaft  202  of the compressor  200  project into the cavity  324  and the coupling  500  is located in the cavity  324 . The body  302  has two windows  320 ,  322  opposite each other in a cylindrical wall of the body  302 . The window  320  is larger than the window  322 . The cavity  324  is accessible by tools via the window  320  to connect and disconnect the coupling  500 . The windows  320 ,  322  also inhibit resonance of the body  302 . 
       FIGS. 18-20  show the heat-sink sleeves  360  and  362 . The heat-sink sleeves  360  and  362  are attached on and to the adaptor  300 . Heat-sink  360  is bolted to left side of the adaptor  300  to surface of  302 . Heat-sink  362  is bolted to left side of the adaptor  300  to surface of  302 . Heat-sink sleeves  360  and  362  have two holes in each 6 mm of  366 ,  364   368  and  370 . The adaptor  300  has in complementary four threaded holes  372 ,  374 ,  376  and  378  which receives the heat-sink sleeves  360  and  362  at 5 mm thread diameter in the adaptor  300  on surface of  302 . The heat-sink sleeves  360  and  362  are bolted to the adaptor  300  in the assembled condition of the unit  10 . 
       FIGS. 21-22  show end views of the retaining brackets  400 A &amp;  400 B. The retaining brackets  400 A &amp;  400 B is dimensioned to be slid over the compressor  200 . The retaining brackets  400 A &amp;  400 B has three (3) holes on each bracket. Holes  402  which are complementary to the threaded holes in the two mounting lugs  210  and  212  of the compressor  200 . The retaining brackets  400 A &amp;  400 B is thus bolted to the compressor  200  in the assembled condition of the unit  10 . The retaining brackets  400 A &amp;  400 B has four (4) holes  406  which are complementary to the threaded holes  318  in the two mount formations  310  of the adaptor  300 . The retaining brackets  400 A &amp;  400 B is thus also bolted to the adaptor  300  in the assembled condition of the unit  10 . 
       FIG. 24  shows a side view of the coupling  500 . The coupling  500  has an electric motor end  502  and a compressor end  504 . The coupling includes a drive shaft passage  506  which is open to the electric motor end  502  and a driven shaft passage  508  which is open to the compressor end  504 . The passage  506 ,  508  are generally cylindrical. The drive shaft passage  506  is dimensioned to receive the drive shaft  102  of the electric motor  100 . The drive shaft passage  506  has a keyway  510  in which the key  112  of the drive shaft  102  is received in the assembled condition of the unit  10 . The driven shaft passage  508  is dimensioned to receive the driven shaft  202  of the compressor  200 . The passage  506 ,  508  are aligned and co-axial about a rotational axis  520 . The coupling  500  has threaded grub screws holes  516  and  518  that extend into the passage  506  and  508 , respectively. The grub screws holes  516  are transverse to the rotational axis  520 . Grub screw  516  are arranged about the drive shaft passage  506 . Three (3) grub screw holes  518  are arranged about the driven passage  508 . Grub screws (not shown) are screwed into the grub screw holes  516 ,  518  to about the drive shaft  102  and the driven shaft  202  in the assembled condition of the unit  10  to friction lock the shafts  102 ,  202  in the passages  506 ,  508 . 
     Between the passages  506 ,  508  is an elastomeric disc  512 . The elastomeric disc  512  dampens vibration between the drive shaft  102  of the electric motor  100  and the electric motor  100  and the driven shaft  202  of the compressor, respectively. The coupling  500  connects the electric motor  100  to the compressor  200  so that the electric motor  100  can drive the compressor  200 . 
       FIG. 26  shows a top view of the base plate  600 . The base plate  600  has a raised platform  602  on which the electric motor  100  is supported. Counter-sunk holes  604  are drilled in the platform  602  for receiving bolts. The holes  604  are complementary to the threaded holes  114  (shown in  FIG. 7 ) in the underside of the electric motor  100 . In the assembled condition of the unit  10  the electric motor is bolted to the platform  602  by bolts which are received in the counter-sunk holes  604 . The base plate  600  also has holes  606  in the corners thereof for bolting the base plate  600  to a substrate. 
       FIG. 27  shows the unit  10  assembled, including bolts which bolt components of the unit  10  together. The compressor  200  is mounted relative to the electric motor  100  by the adaptor  300 . The coupling  500  connects the drive shaft of the electric motor  100  with the driven shaft of the compressor  200  so that the electric motor  100  drives the compressor  200  directly. 
     The adaptor  300  is designed and configured so that the drive shaft  102  of the electric motor  100  and the driven shaft  202  of the main compressor  200  and substantially co-axially aligned along a rotational axis  12  (shown in  FIG. 7 ) of the unit  10 . 
     A mounting system  1000  of the unit  10  comprises the adaptor  300 , retaining brackets  400 A and  400 B, base plate  600 . The mounting system also includes fasteners such as bolts  14 ,  16  and  18 . The adaptor  300  is bolted to the face plate  106  of the electric motor  100  by bolts  14 . The retaining brackets  400 A and  400 B are bolted to the adaptor  300  by bolts  16 . The compressor  300  is in turn bolted to the retaining brackets  400 A and  400 B by bolts  18 . The electric motor  100  is bolted to the base plate  600 . 
       FIGS. 28-29  show the unit  10 A with the controller  700  (BLDC) cabled to the electric motor  100 . The controller  700  is shown with three phase wires from the electric motor  100  to the controller  700  to enter the terminal block  118 . Each phase cable  118 A,  118 B and  118 C is of different input and colour to the terminal block  118  from the controller  700 . 
       FIGS. 30-32  show a programmable controller  700  for the unit  10 . The controller  700  receives current with an operating voltage from a battery or other DC electricity source of the electric system the  10  is to be connected to. The controller  700  is specifically selected for 12V, 24V, 48V, 72V DC electric systems but not restricted to these voltages. For a 12 volt system, a controller  700  is selected which is adapted to receive an operating voltage of between 10.5 and 15V. Similarly, for a 24V electric system a controller  700  is selected which is adapted to receive a current with an operating voltage of between 21V and 29.5V. For a 48V electric system a controller  700  is selected which is adapted to receive between 42V and 54V, and for a 72V electric system the controller  700  is selected to operate off 72V to 76V, but nor restricted to 76 volt. The controller  700  has two lugs B+ and B− for connecting to the battery or other DC electricity source of the electric system. The controller  700  has three lugs A, B, C which connect to the electric motor  100  via electric cables (as shown in  FIGS. 28-29 ). The lugs A, B, C are each for a different phase of the electric motor  100 . The controller  700  controls the voltage and the current to the electric motor  100 . The voltage to the electric motor  100  is generally about the same as the operating voltage to the controller  700 . 
     Socket  702  of the controller  700  has pins for receiving switching power to power the controller  700 . The socket  702  also includes pins for receiving thermostat inputs. The controller  700  selectively powers the electric motor  100  depending on the thermostat inputs. The controller  700  includes configurable software having logic to start or stop the electric motor  100  depending on the thermostat inputs. The controller also has a pin connected via a wire to an encoder of the electric motor  100 . The encoder determines the position of the rotor of the electric motor  100  and provides the rotor position as an input to the controller via the socket  702 . 
     Connector  704  of the controller  700  is a RS232 connector via to which the controller can interface with a computer to configure the software of the controller  700 . 
     The unit  10 /A of present invention is particular efficient due to its selection of components and direct drive coupling between the electric motor  100  and the compressor  200 . The brushless electric motor  100  is particularly efficient as discussed, and so is the piston type compressor  300 . There is very little energy lost between the electric motor  100  and the compressor  200  due to the direct drive between these components. Direct drive is facilitated by the mounting system of the unit  10 / 10 A, which mounts the electric motor  100  relative to the compressor  200 . The mounting system also provides for the compact design of the unit  10 / 10 A. 
     Particularly, the unit according to the present invention utilizes one motor, one compressor, one configuration. The unit is more versatile and enables manipulation of power. 
     The brushless motor ( 100 ) has a 92% efficiency from power entering the motor and only a loss of 8% from the input energy. The magnet quality is critical to the efficiency of the motor ( 100 ) as well as the calculated copper windings in the main rotor. The calculated segments are also critical to the electric motors efficiency. 
     The electric motor ( 100 ) has an Encoder ( 116 ) which is a solid state electronic plate with a ring magnet on the main shaft of the electric motor. The encoder reads the motor shaft position and speed and sends it to the BLDC controller ( 700 ). The BLDC controller ( 700 ) can then sense the speed, torque and current voltage/amps used to determine the correct amount of output power to be provided to the electric motor. The encoder is able to be manually adjusted under NO LOAD to get the settings correct. This will minimise energy loss, and the encoder will act as an adjustment tuner when being dialled manually (advanced or re-tarted). The encoder works from 3 points (Hall effect) and this allows the system to be fine-tuned to avoid unnecessary energy losses. 
     The BLDC controller ( 700 ) is chosen to suit the application of use with the current controller able to be programmed to suit the application. This programming can enable the system to fine tune its required energy in order to keep the electric motor stable with set speeds, torques, start-up in-current rush current, throttle/torque sensitive, voltage cut-outs, over-voltage, over-heat. The controller will sense more power needed to maintain the current set programmed speed and torque and will adjust accordingly. 
     The electric motor ( 100 ) and controller can enable the system to be interchanged with variable displacements compressors connecting to the same adaptor housing. With this configuration the best combination of compressor, speed and torque is able to be assessed to suit the application. This way the compressors electric drive is matched to the systems configuration, it enables us to change the parameters of the unit so we achieve minimal loss for the compression of the gas through the compressor. 
     The alloy adaptor housing ( 300 ) and heat-sink collars ( 360 - 362 ) with the BLDC controller ( 700 ) heat-sink play an important role in lowering the energy consumption of the full assembly. Option of brushless cooling fan is used in extreme conditions to keep the electric motor ( 100 ) and BLDC controller ( 700 ) stable with good efficiency. 
     The alloy adaptor housing ( 300 ) is secured by 3 bolts in the the front face plate ( 106 ) thread hole numbers ( 110 ). These are insert threads (double side thread nut-re-coil tapper M 8 ). This helps stop heat transfer from the electric motor ( 100 ) spreading through to the alloy housing ( 300 ) and other areas. The use of alloy and the 3 bolt system are unique and integral to the invention and its efficiency in operation. 
     The drive coupling ( 500 ) is constructed from alloy, this is to also help with heat displacement 
     The compressor ( 200 ) is constructed from alloy for better heat displacement than cast iron. This is standard from the compressor manufacture. Lugs are removed and front housing is modified to suit the alloy housing ( 300 ) and the coupling ( 500 ) alignment. 
     Throughout thus specification the aim has been to describe the invention without limiting the invention to any one embodiment of specific collection of features. Persons skilled in the relevant art may realise variations from the specific embodiments that will nonetheless falls within the scope of the invention.