DEVICE FOR PREVENTING OIL LEAK IN SEWING MACHINE

摘要

PROBLEM TO BE SOLVED: To provide a device for preventing oil leak in a sewing machine in which lubricating oil in an oil storage chamber does not leak out of an oil seal by suppressing pressure increase in the oil storage chamber surrounded by a bearing, a driving shaft, and the oil seal.

SOLUTION: A bearing 5 is fixed to a frame 2 forming an outer shell of a head 1 of a sewing machine, and a needle bar 4 is inserted through the bearing 5 so as to be vertically movable. An oil seal 6 elastically touching the outer peripheral surface of the needle bar 4 is externally fixed to the bearing 5. The bearing 5 is provided with a communicating hole 5b. The communicating hole 5b is formed so as to open at the upper and lower end faces of the bearing 5 by penetrating a wall part of the bearing 5 vertically. The communicating hole 5b is formed so as to make a needle bar chamber B communicate with the oil storage chamber C to let the pressure in the oil storage chamber C out to the needle bar chamber B.

COPYRIGHT: (C)2012,JPO&INPIT