A driving mechanism used in a railway welding machine that operates along a railway track, comprising: a motor producing a force, and an upper transmission mechanism connected to the motor , characterized in that upper transmission mechanism includes: an upper shaft driven by the motor and including: a shaft key seat , and a shaft key disposed in the shaft key seat , and a coupling mechanism , wherein the upper shaft passes through the coupling mechanism including: a female coupling device , and a male coupling device detachably coupled to the female coupling device through teeth , the male coupling device including a shaft keyway configured to receive and be engaged with the shaft key of the upper shaft so that the upper shaft rotates the male coupling device , wherein when the male coupling device is coupled to the female coupling device , the male coupling device transmits the force to the female coupling device , and when the male coupling device is decoupled from the female coupling device , the male coupling device does not transmit the force to the female coupling device . a motor producing a force, and an upper transmission mechanism connected to the motor , characterized in that upper transmission mechanism includes: an upper shaft driven by the motor and including: a shaft key seat , and a shaft key disposed in the shaft key seat , and a coupling mechanism , wherein the upper shaft passes through the coupling mechanism including: a female coupling device , and a male coupling device detachably coupled to the female coupling device through teeth , the male coupling device including a shaft keyway configured to receive and be engaged with the shaft key of the upper shaft so that the upper shaft rotates the male coupling device , wherein when the male coupling device is coupled to the female coupling device , the male coupling device transmits the force to the female coupling device , and when the male coupling device is decoupled from the female coupling device , the male coupling device does not transmit the force to the female coupling device . an upper shaft driven by the motor and including: a shaft key seat , and a shaft key disposed in the shaft key seat , and a shaft key seat , and a shaft key disposed in the shaft key seat , and a coupling mechanism , wherein the upper shaft passes through the coupling mechanism including: a female coupling device , and a male coupling device detachably coupled to the female coupling device through teeth , the male coupling device including a shaft keyway configured to receive and be engaged with the shaft key of the upper shaft so that the upper shaft rotates the male coupling device , a female coupling device , and a male coupling device detachably coupled to the female coupling device through teeth , the male coupling device including a shaft keyway configured to receive and be engaged with the shaft key of the upper shaft so that the upper shaft rotates the male coupling device , wherein when the male coupling device is coupled to the female coupling device , the male coupling device transmits the force to the female coupling device , and when the male coupling device is decoupled from the female coupling device , the male coupling device does not transmit the force to the female coupling device . <EOS>