Abstract: An oil pump includes a shaft bearing bore, a drive shaft supported by the shaft bearing bore, an annular space between an inner peripheral surface of the shaft bearing bore and an outer peripheral surface of the drive shaft, a communication passage portion formed on the side of a pumping chamber inside the shaft bearing bore, and a communication groove formed opposite to the communication passage portion inside the shaft bearing bore. The communication passage portion is communicated between a discharge port and the annular space, and the communication groove is communicated with the annular space. Oil is stored in the annular space from the discharge port via the communication passage portion, and the oil flows into sliding clearance spaces of first and second journal portions via the annular space and the communication passage portion and the communication groove.

Abstract: An oil pump includes a shaft bearing bore, a drive shaft supported by the shaft bearing bore, an annular space between an inner peripheral surface of the shaft bearing bore and an outer peripheral surface of the drive shaft, a communication passage portion formed on the side of a pumping chamber inside the shaft bearing bore, and a communication groove formed opposite to the communication passage portion inside the shaft bearing bore. The communication passage portion is communicated between a discharge port and the annular space, and the communication groove is communicated with the annular space. Oil is stored in the annular space from the discharge port via the communication passage portion, and the oil flows into sliding clearance spaces of first and second journal portions via the annular space and the communication passage portion and the communication groove.

Abstract: A sand mold-producing apparatus having a sand blower for vertically supplying sand with the help of a first flow of a pressurized air into a molding cavity in which a match plate carrying thereon a pattern is positioned, and an air injecting means for laterally injecting a second flow of a pressurized air having a pressure equal to or smaller than that of the first flow toward the pattern, so that the second flow of the pressurized air carries the sand toward every lateral pocketed pattern portion of the pattern and corners adjacent to the pattern during the supply of the sand into the molding cavity.