Ram boring machine, boring machine and method of cooling a ram bearings in a boring

摘要

The ram comprises a body ram (14), a liner (16) rotatably mounted in the body of the ram (14) by a plurality of bearings (17, 18) each comprise a radially inner portion (17a , 18a) coupled to the liner (16) so that it rotates with the liner (16) and a radially outer portion (17b, 18b) fixed, and a shaft (15) mounted on the liner (16) so as to rotate with the liner (16). Furthermore, the ram comprises a circuit for a cooling fluid. This circuit has at least one section configured so that the cooling fluid into direct contact with the radially inner portion (17a, 18a) of at least one of the bearings (17, 18). Thus, this radially inner part can be cooled efficiently.