PURPOSE: To dispense with work for eliminating distortion due to a thermal treatment so as to enhance productivity by making a seal ring base body having a cylindrical portion and a flange portion by sheeting, followed by induction hardening the flange portion of the base body with the cylindrical portion thereof supported.
CONSTITUTION: A pair of seal sings 3, 3 are air-tightly fitted to the inner circumferential surface 1a of a housing 1 on a stationary side and the inner circumferential surface 2a of a housing 2 on a rotating side, respectively, via load rings 4 made of rubber, so as to prevent leakage of lubricant which is sealed by their sliding motion 5. In manufacturing the seal rings 3 in the thus constituted seal device, a ring-like base plate made of an SK-7 material or the like is bent in a predetermined thickness by a press machine, thus providing a seal ring base body 13 having a cylindrical portion 11 and a flange portion 12. Subsequently, the base body 13 is subjected to an induction hardening thermal treatment where it is heated by a high frequency induction heating coil 16 while a turntable 14 is rotated with the base body 13 supported by a support jig 15, followed by cooling.
OTAKE KATSUYUKI
HASEGAWA HIROSHI
ANDO HARUHIKO
OKAWA KAZUHIDE
KOMATSU MFG CO LTD