Wheel Loader is a four wheeled equipment ment for loading of material to dumpers or railway wagons. This is a diesel hydraulic equipment with a diesel engine as prime mover and hydraulic units for all operations and steering. There is a bucket in the front which serves the purpose of loading the material. The engine, transmission, differential and brake system are almost similar as dumpers.
Power Train – The power comes from the engine to torque convertor, transmission, transfer case, differential to wheels. There is also a PTO drive for powering the hydraulic pumps. There are two differential one for front wheels and one for rear wheels. All the wheels get drive from the transmission through the power transfer case.
Steering System – For steering there is an articulated joint between front chassis and rear chassis and steering is done with help of two hydraulic cylinders. The articulated joint helps in easy and shorter turning radius.
Transfer case – In wheel loader the engine and transmission are mounted on rear chassis and are at a higher level above the rear differential. Hence to bring down the power to the level of differential a transfer case is provided. Thus here power flows in a ‘U’ shape rather than in a straight line as in dumper. The transfer case has input from transmission and output in two directions. One for the front differential and one for the rear differential.
Hydraulic system – The hydraulic system for implement operation has a separate pump driven from the PTO. There are double acting hydraulic cylinders for lifting and tilting of the bucket.
Brake system – There are two brake systems one is parking brake and the other is service brake. The parking brake is mounted of the transfer case output shaft and is spring actuated and air release type i.e. in absence of air the brakes will be applied. The parking brake is applied when the machine is not in motion to prevent it from rolling. The service brake is air over hydraulic, shoe type and the brakes are applied on all the four wheels. This brake is applied for stopping the machine when in motion.