AIR-BLOWER IN WHICH THE FAN IS FIXED ON A MOTOR SHAFT HAVING ROTATION SPEED CONTROL MEANS

• Main Author: KENJI UMETSU
• Format: Patent
• Language: English
• Published: 29.09.1993
• Subjects: BLASTING; HEATING; LIGHTING; MECHANICAL ENGINEERING; NON-POSITIVE DISPLACEMENT PUMPS; POSITIVE DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS; WEAPONS

An air blower having a speed control circuit has a fan (3) incorporating a vibration damping arrangement (4, 5A, 5B, 6) between the blades (7) and the motor shaft (1). The circuit (10) controls the rotation speed of the motor by controlling the wave-number or phase of AG power voltage. The fan (3) comprises a boss portion (4) attached to the shaft (2), a surrounding hub portion (6) and two groups of interconnecting bridge ribs (5A, 5B). The air-blowing blades (7) are integrally formed on the outer periphery of the hub portion (6). The two groups of bridge ribs (5A, 5B) are spaced in the axial direction of the rotation shaft (2). Each bridge rib of one of the groups is positioned to face a pitch gap between two adjacent ribs of the other group such that the bridge ribs of one of the groups are displaced circumferentially from the bridge ribs of the other group by 45 DEG . In a second embodiment bridging ribs extend between an intermediate hub portion and both the boss and hub portions.