Example shown is for a Whirlpool dryer. All dryer motors operate similarly. Some centrifugal switches are separately replaceable (like this one); some are not.
For an electric dryer no-heat complaint where you've checked everything else and still not getting heat, that only leaves a bad centrifugal switch in the dryer motor. On most models, that means a new motor.
Buy parts for your dryer with a 365-day return policy here ==> http://www.repairclinic.com/Dryer-Parts