A deflection limiting member (110, 310) or a deflection limiting mechanism (512, 514) is used to limit deflection of a motor shaft (102) of a vibrator (105, 305, 505) in a portable electronic device (104,304, 504). The deflection limiting member (110, 310) extends in a radial direction from the motor shaft (102) on a side of the motor shaft (102) that is opposite to the center of gravity (108, 308) of an eccentric weight (108, 308). The deflection limiting member (110, 310) contacts a fixed surface such as a printed circuit board (112) to limit deflection of the motor shaft (102). The deflection limiting mechanism (512, 514) prevents an inertial force of an eccentric weight 510 from being applied directly to the motor shaft (102) under conditions in which there is a high risk of permanent deformation of the motor shaft (102).