Driving device, valve apparatus including the same, and link driving mechanism for turbocharger

A driving device comprising:

• a shaft;
• and
• a cylindrical bush having an insertion hole into which the shaft can be inserted,
• the insertion hole including an opening portion having an inner diameter decreasing from a first end surface toward a second end surface of the bush, and a small-diameter hole portion extending from an end of the opening portion to the second end surface,
• the shaft including a shaft portion having an outer diameter smaller than an inner diameter of the small-diameter hole portion, and an abutment portion having an outer diameter greater than the inner diameter of the small-diameter hole portion,
• the bush having a sealing surface of truncated cone shape configured as a flat surface extending obliquely inward from an inner peripheral edge of the first end surface to the end of the opening portion,
• wherein the driving device is configured such that the abutment portion of the shaft abuts on the sealing surface of the bush in an axial direction of the insertion hole so as to seal a gap formed between the shaft and the bush inside the insertion hole.