Center bearing device for grinding of crankshaft main journal

The invention provides a center bearing device for grinding of a crankshaft main journal. The center bearing device comprises an L-shaped bearing base, wherein a first support arm and a second support arm are arranged in the L-shaped bearing base; one end of the first support arm is movably connected to the L-shaped bearing base by a lower hinge pin, and a transverse bearing block is arranged at the other end of the first support arm; one end of the second support arm is movably connected to the L-shaped bearing base by an upper hinge pin, and a longitudinal bearing block is arranged at the other end of the second support arm; a first servo motor and a second servo motor are further arranged on the L-shaped bearing base; the first servo motor is connected with a transverse torque adjusting bolt which presses and touches the first support arm; the second servo motor is connected with a longitudinal torque adjusting bolt which presses and touches the second support arm; and the longitudinal bearing block and th