Multi-functional wet axle of 5-10 T fork-lift truck

The invention relates to a multi-functional wet axle of a 5-10 T fork-lift truck. Service brakes of the drive axle are wet brakes; inner shells of the left brake and the right brake are provided with a first lubricating oil passage respectively; the first lubricating oil passages on the two sides are communicated with one ends of a right cooling oil pipe and a left cooling oil pipe respectively; the other ends of the right cooling oil pipe and the left cooling oil pipe are connected with a first port and a second port of a three-way pipe respectively; a cooling oil outlet pipe is arranged at the bottom of a drive axle shell corresponding to a main speed reducer assembly; a wheel hub body is provided with an oil drainage hole, a second lubricating oil passage and a third lubricating oil passage respectively; a third port of the three-way pipe and the cooling oil outlet pipe are communicated with an outlet and an inlet of a lubricating pump respectively; and thus, a forced circulatory lubrication system is formed. The service life of the wet axle is 3-5 times the service life of normal drum brakes, and the brake performance does not decline after the wet axle is used for more than three years; and the problem of insufficient engine power supply caused by large size of a hydraulic oil tank and additional arrangement of a cooling fan due to sharing of a cooling mechanism with a hoisting system is solved.