Single-Axis Actuator

摘要

As compared to a single-axis actuator in which a ball returning passage of a ball screw mechanism is made of a circulating tube, the cross-sectional shape perpendicular to the longitudinal direction of a threaded shaft of a slider can be made small, when the diameter of the outer circumferential circle of the threaded shaft of the present invention is same as that of the circulating tube type, and the load capacity can be made large, when the size in the longitudinal direction of the threaded shaft of the slider of the present invention is same as that of the circulating tube type. The ball returning passage for returning the balls (4) of a ball screw mechanism from an end point to a start point of a raceway encompasses: a through hole (24) penetrating through a slider (2) in a longitudinal direction of a threaded shaft (3); and end deflectors (6). Each of the end deflector (6) has a direction changing passage to be connected with the through hole (24). A main body (61) of the end deflector (6) is fit into a notch part (26) arranged on each of both ends in the longitudinal direction of the threaded shaft (3) of a slider body (2A).

主权项

1. A single-axis actuator comprising:
a guide rail having a letter U shaped cross section perpendicular to a longitudinal direction of the single-axis actuator; a slider arranged in a depression of the guide rail having the letter U shaped cross section; a plurality of rolling elements allocated between the guide rail and the slider; a nut formed in the slider to be parallel to the guide rail; a threaded shaft penetrating through the nut; and a plurality of balls allocated in a raceway between a spiral groove of the nut and a spiral groove of the threaded shaft, wherein the guide rail has a rolling face implementing a rolling passage for the plurality of rolling elements, on each of inner side faces opposing each of side faces of the slider, a rolling face for opposing the rolling face of the guide rail and implementing the rolling passage, a returning passage for the plurality of rolling elements, and a direction changing passage for communicating the returning passage and the rolling passage, the plurality of rolling elements are allocated in a circulating passage implemented by the rolling passage, the returning passage, and the direction changing passage, a ball returning passage for returning the plurality of balls from an end point of the raceway to a start point of the raceway is implemented by a through hole penetrating through the slider in a longitudinal direction of the threaded shaft, and circulating parts having direction changing passages connected with the through hole and allocated at both ends in the longitudinal direction of the threaded shaft of the slider, a rotational force of the threaded shaft is transmitted via the plurality of balls to the nut by rotation of the threaded shaft, the rolling elements circulate in the circulating passage while rolling in a loaded state, and the slider is movable along the guide rail; the slider includes a slider body and an end cap secured on an outer side of the slider body in the longitudinal direction of the threaded shaft, the spiral groove of the nut is formed in the slider body, the slider body has a depression into which the circulating part is fit, and a direction of the circulating part scooping the plurality of balls is parallel or perpendicular to a top face of the slider body.