| 摘要 |
A device for reciprocating a plunger according to the present invention comprises: an electric motor; a drive shaft rotated by the electric motor; an inner race fixedly mounted on the drive shaft, the inner race having an inner race track which is formed on the outer cylindrical surface of the inner race in such a manner that the inner trace track is not coaxial with the inner cylindrical surface of the inner race and the drive shaft; an outer race provided around the inner race, the outer race having an outer race track which is coaxial with the inner race track; a plurality of rolling members provided between the outer race track and the inner race track; and a plunger member movably supported in an axial direction thereof, one end of the plunger member being elastically abutted against the outer cylindrical surface of the outer race. According to the present invention, it is possible to make a manufacturing cost lower, to make the whole of the device smaller in weight, and to make a quality higher. |
