Tsubakimoto Chain Company

Toshio Mitsuyama

Kenichiro Nakamura

Takashi Noguchi

Makoto Kishida

Koichi Saeda

Minoru Komada

An anti-rotation mechanism in a linear actuator has outer and inner cylinders, affords high accuracy and rigidity, is simple in structure, not requiring the use of a tie rod, and is inexpensive to manufacture. The outer cylinder 3 has both end portions 3 of circular cross section and an intermediate portion whose inner surface has an axially uniform non-circular cross-sectional shape including a rotation inhibiting surface 3F. The inner cylinder 4 has a collar 7 on the outer peripheral surface which is guided and supported slidably by the intermediate portion of the outer cylinder and has a conforming non-circular cross-sectional shape including a flat surface 7B for sliding engagement with the rotation inhibiting surface 3F to inhibit rotation of the inner cylinder.

Anti-rotation mechanism in a screw type linear actuator

To prevent a ball-threaded shaft from slipping out of a linear actuator, a linear actuator 10 has an output shaft 18 threaded in a nut 16 for moving forward and backward linearly with respect to an outer tube 22 secured to a housing 20. Linear reciprocating movement of the nut 16 is effected by a ball-threaded shaft 14 rotated normally and reversely by a driving motor 12. The shaft is held against axial displacement by a bearing assembly 8 having an axial disk 32 secured to a proximal end 24 of the ball-threaded shaft 14. On the nut side of the disk within the assembly are disposed a first tension receiving rotational body 36, a thrust bearing 45 and a second tension receiving rotational body 58. The assembly 8 is retained by a tension stopper 62 spread and inserted into an annular central groove 60 in the tube 22. The second tension receiving rotational body 58 is formed with a reduced diameter preventing circumferential surface 66 corresponding to an inner peripheral circumferential surface of the C-shaped tension stopper 62. Even if tension and a rotating force are exerted on the tension stopper 62, causing it to be reduced in diameter, the inner peripheral surface thereof comes into contact with the reduced diameter preventing surface 66.

Ball-threaded shaft anti-slipout type linear actuator

A linear actuator in which the number of limit switches to be mounted, as well as the mounting position and direction of limit switches, can be selected with a high degree of freedom, the limit switch mounting spacing can be made short, and a positive operation is ensured while using a small number of components. Flat limit switch mounting flanges are fixed onto an outer cylinder of a linear actuator so that their positions are adjustable in both axial and circumferential directions of the outer cylinder, and a guide rail for slidably guiding a striker is supported by and between the limit switch mounting flanges. The striker is connected with the actuator rod of the actuator by a connecting rod. With projection or retraction of the actuating rod, the striker moves and actuates limit switches attached to the associated limit switch mounting flanges.

Limit switch mounting structure for a linear actuator

A device for detecting a change in the thrust load acting on the actuating rod of a linear actuator. The thrust detecting device includes a pinion which converts and enlarges an axial linear displacement of a rotating drive screw shaft caused by a change in the load on an actuating rod driven by the screw shaft into an angular displacement of a vertical shaft of the pinion. A circular scale plate is attached to the vertical shaft of the pinion and serves to indicate a preset value for the load change to be detected. A pair of striker plates each having a pointer effective to select a preset value on the circular scale plate and a striker effective to activate a corresponding limit switch are attached to the circular scale plate.

Thrust detecting device of a linear actuator

A device providing an accurate adjustment of the length of a reciprocating stroke of an actuating rod of a linear actuator. The stroke control device includes a cam-plate mounting shaft 9 horizontally disposed within a limit switch box so that a plurality of limit-switch actuating cam plates 11A-11C mounted on the mounting shaft 9 for actuation of a corresponding number of limit switches LA-LC to control the stroke length of the actuating rod can be observed in one view as a horizontal array of laterally spaced, vertically disposed cam plates.

Growing community of inventors

Osaka-fu, Japan

Toshio Mitsuyama