Novel electric main shaft cooling device

The invention relates to a novel electric main shaft cooling device. The novel electric main shaft cooling device comprises a main shaft body (1), a main shaft rotor (2), a main shaft stator (3), a spiral cooling water jacket (4), a spiral cooling water jacket inlet (5), a spiral cooling water jacket outlet (6), a support bearing (7), a main shaft front end (8), a lower side venthole (9), a central venthole (10) and an upper side venthole (11). A main shaft system is provided with the spiral water jacket at the outer side of the stator; the upper side of the spiral water jacket is a cooling water inlet; the lower side of the spiral water jacket is a cooling water outlet; and cooling liquid is supplied by an industrial water-cooling machine to circularly flow in the cooling water jacket soas to carry off heat. Meanwhile, the central venthole, the upper side venthole and the lower side venthole are formed in the tail of a main shaft; the three ventholes internally communicate; cooling air is fed into the centra