TOYOTA A/C design

You have an incredible knack for reinventing the wheel!

There is no value in the design effort you put forth or they would have already done it.

The big problem is that the compressor has two speeds, on or off. It is driven by the belts that go around the crank, either directly or indirectly. It is not driven by a variable drive force. There is no way to make the drive variable, so they would need a different compressor with variable valving that would be costly to implement, and prohibitively expensive to retrofit.

Set the AC to the coldest setting and leave the rest to the car to figure out. If you have fog on the inside of the glass, turn the AC on and set the temp to the highest setting until you can't stand it anymore, then set it down to where you think you will be happy.

The short answer to your question is, no.

Look up variable displacement compressor. Basically a swash plate design with an added spring and hinge so that the plate can flatten out. It has a control valve that routes discharge gas to the crankcase as the suction pressure falls below a certain point, usually around 30-40° Fahrenheit. The discharge pressure behind the pistons along with the force of the spring flattens out the wobbling plate so that all the pistons stay closer to TDC with each revolution, hence the compressor pumps less per turn. See the GM V7 compressor which has a maximum displacement of 179cc per revolution and can taper all the way down to 10cc per rev. These compressors never cycle because the suction pressure can't fall far enough to frost the evaporator. The downside is that the control valve must be adjusted when switching refrigerants IE from R12 to R134a.

The Prius compressor is a PM rotor electric scroll compressor that is driven by the same section (circuit board) of the car's inverter that also has the DC-DC converter for the 12v system. Supposedly the compressor on the Highlander hybrid has a built in inverter.

Nissan used variable displacement A/C compressors on the 240SX and probably others. When A/C was on, the compressor was always engaged but varied displacement as needed. None of the herky-Jerky stuff you get with nearly all 4 cylinder powered cars. This obnoxious behavior alone makes 6 cylinder powder a no-brainer.

The compressor is not variable, but variable displacement AC compressors are already in use. Due to their higher complexity and expense, they are mostly used in hybrid vehicles. Automatic temperature control is common and has been around for a long time but they control temperature by controlling blend doors because it was easier to implement than variable displacement compressors were.

If you want the most modern technology, you have to get a more modern higher end car. The lowest priced cars generally will use tried and true to save cost.

How do you keep a belt-driven compressor spinning at a constant RPM as the engine speed changes? One of the American car makers had a special clutch drive that let the compressor spin at half or full pulley speed, but I don't know if it's still used.

Cadillacs had them a long time ago, and they took almost a minute longer than conventional compressors to start cooling -- not fun in

Not sure what you are looking for.

GM has variable displacement compressors that vary the displacement in roder to maintain a constant refrigerant flow based on demand 9as determined by the low side pressure). But systems with cycling clutches work just as well (in my opinion). The compressor is only engaged as needed. When the low side pressure is very low (i.e., when the evaporator temperature is around 38 degrees F) the compressor clutch disengages, so there is no power drain on the engine. The clutch re-engages as necessary to maintain the low side pressure (at a low level).

Ed

I had a York AC compressor in my Jeep CJ5 that was used to fill tires. It created its maximum pressure at a speed just above idle. There was benefit of jamming a block under the gas pedal to rais the engine speed from idle to about 1000 RPM (instead of letting the engine idle at 700-ish RPM), but there was very little additional benefit, and lots more noise, if I jammed the block in to hold the engine at 1250 or 1500 RPM. The airflow was essentially the same once the motor was running at 1000 RPM.

In my configuration, the system was Open. The Low Pressure side sucked in outside air, and the High Pressure side had my air hose connected to it so I could fill my tires up when I was finished with a day of trail riding with 5 PSI in my tires. In an AC system, the lines are all closed, and the flow through the system is regulated by a valve, so the speed of the compressor doesn't matter. In my Open System, I could get more flow up to a point, but after that the flow rate flattened out significantly.

I don't know how you would keep such a system at a constant speed, and I don't know why you would care to.