Single-plunger high-pressure oil pump

The invention discloses a single-plunger high-pressure oil pump which is compact in structure and long in service life. According to the technical scheme, a front end cap is axially attached to a thrust plate; an oil pump drive shaft sequentially passes through the front end cap, a front bearing bush, the thrust plate, a roller driven by a unilateral cam in a matched mode, a rear bearing bush and an oil delivery pump connected with the oil pump drive shaft in a matched mode; and when the oil pump drive shaft operates, lubricating oil of the front bearing bush and the rear bearing bush passes through the front end cap or a pump tank and forced oil groove lubricating channels formed in the front bearing bush and the rear bearing bush in the circumferential direction, and enters a drive shaft sliding face interval of the oil pump drive shaft to form an oil film. By means of the single-plunger high-pressure oil pump, the problems that in the prior art, an adopted conical roller bearing is large in radial structur