The term air pump or air blower is used interchangeably within the product line. The designation of a pump or blower largely refers to the industry in which it is being used. There is no physical difference between an Ogura air pump or air blower. It is only the industry reference that changes its designation.
The Ogura blower is a roots style positive displacement blower that works by pulling air through a pair of smoothly meshing rotors. These rotors have a unique design and connect to each other internally by a gear set that sets the rotors 90 degrees apart from each other. As the rotors turn (in opposing directions) air is trapped in the pockets formed between the rotors and the housing. For every revolution of the rotor a volume of air (depending upon the supercharger's size) gets pumped from the intake to the discharge. Because of Ogura's special coated rotors and the use of similar materials, expansion rates can be held close between components maintaining a very close tolerance. This gives the Ogura units very high efficiency compared to traditional roots type blowers.
In some applications the input to the Ogura air pump is via an integral electric clutch. This allows remote engagement and disengagement of the air pump. So, the air pump only operates when required. Also, when the air pump is not rotating, air can not flow backwards due to the unique sealing design. This helps to make the rest of whatever system the unit goes into more efficient.