To connect a motor shaft to a fan, a connection rod is used that is symmetrical in shape with respect to a longitudinal axis of the connection rod. The connection rod includes a first part formed with a hole in coaxial with the longitudinal axis, and a second part formed at least partially with a threaded portion. The motor shaft is attached to the connection rod by inserting the motor shaft into the hole of the first part of the connection rod. The fan is attached to the connection rod by inserting the second part of the connection rod into the center hole of the hub portion and supports the fan with a pair of nuts, one at one side of the hub portion and another at another side of the hub portion wherein the nuts are moved toward each other with the hub portion interposed therebetween.