Feature:

1. The helical construction uses the stator helical method that the screen lines of casing at the suction and discharge sides are cut to a helical shape,and the triangle suction and discharge port formed by a straight line of the rotor top is to be opened and closed gradually.

2. The rotors are three lobes.

3. By adoption of an unique profile of rotor, the clearance between the rotors can be held to be constant, which makes the efficiency even higher.

4. The precision of rotors is fully controlled and variation of precision between blowers is almost nil because the rotors are produced under the mass production control by utilizing a prenision NC maching.

5. The advanced driving gears are adopted but only to extend the use life but also to make noise lower.