The Story of Sakichi Toyoda
Sakichi Toyoda, the founder of Toyota Industries Corporation, possessed a strong ambition to contribute to society from his days as a youth. He had devoted his 63-year-long life to invention.
Since Toyota Motor Corporation first released its Prius in 1997, sales of hybrid vehicles have continued to grow.
The first-generation Prius used engine power to drive the car air-conditioning compressor, and when the engine stopped with the idle stop function or when driving using electric power alone, the compressor also stopped. In this way, by prioritizing fuel efficiency and thus stopping the engine, the air conditioning is less responsive; conversely, giving priority to the air conditioning will make it impossible to stop the engine, leading to a large drop in fuel efficiency.
To resolve such problems, Toyota Industries released the ES18, the world's first mass-produced electric compressor, for the second-generation Prius launched in 2003.
Electric compressors operate regardless of whether the engine is running, and comprise three elements—the scroll-type compressor, the compressor drive motor, and the inverter that controls the motor. By reducing size, reducing noise, and optimizing these three elements, the ES18 achieved air-conditioning responsiveness while the hybrid vehicle engine was stopped, at the same time improving fuel efficiency.
It is now 18 years since the first-generation Prius went on sale, and 2015 has seen the release of the fourth-generation Prius. This incorporates the ESB20 compressor, which inherits the legacy of the ES18. The ESB20 is smaller and lighter than the previous model, with 30% better cooling functionality, and at the same time reducing power consumption by 8%.
The development of a new inverter with a short-shaft, lightweight motor design together with increased output density has enabled a smaller, more-lightweight model than previously, with a 30% increase in cooling performance.
By using a compression mechanism that automatically adjust the scroll pressure, this reduces the frictional resistance of the compression section, and reduces power consumption by 8% over previous models.
By developing small, lightweight, and high-efficiency electric compressors, Toyota Industries shall continue to help to improve the fuel efficiency of hybrid vehicles and plug-in hybrids (PHVs).