Patent ID: 7870674

Claim:
A production method for an oil-impregnated sintered bearing, comprising: abutting one end surface of the sintered bearing on a die so as to mount the sintered bearing thereon and abutting a tool on the other end surface of the sintered bearing, the one end surface and the other end of the sintered bearing having pores; supplying high frequency vibration to the tool so as to give repeated impacts to the one end surface and the other end surface of the sintered bearing while pressing the sintered bearing by the tool in the above condition of the sintered bearing, so that the pores of the one end surface and the other end surface are sealed, wherein the die and the tool have surfaces abutting the sintered bearing, and the surfaces have roughness of not more than 0.4 s and hardness of not less than HRA 60, and the tool presses the sintered bearing at a pressure of 70 to 700 kPa, and the high frequency vibration supplied to the tool has a power of 50 to 3000 W/cm 2 , a frequency of 10 to 50 kHz and satisfies the relationship Y=A*X −1 , with Y being the vibration time (sec), X being the power (W/cm 2 ), and constant A being in the range of 50≦A≦1000.