Fan wheel for electric motor, particularly series motor, of electric tool, has multiple fan blades, where two types of fan blades are provided, which are different in their shape or size, and two types of fan blade have different masses

摘要

The fan wheel (12) has multiple fan blades (18), where two types of fan blades are provided, which are different in their shape or size. The number of identical fan blades of a fan blade type arranged on the fan wheel in each case is a prime number, where the prime number is three or five. Two different types of fan blade have different masses. The different types of fan blade are uniformly distributed on the fan wheel in a circumferential direction.