JPH0337042B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a screw-type torque actuator that converts fluid pressure supplied into a cylinder into rotational force of a main shaft installed in the cylinder.

Conventional technology Conventionally, in this type of screw-type torque actuator, even if the helical screw carved into the main shaft and the helical nut that fits into it are precisely machined, there is always a clearance in terms of play accuracy. When an arm or the like is attached to the output shaft and rotated, the error increases in proportion to the length at the radius end of the arm, resulting in an unstable range. When performing high-precision positioning, the main shaft will wear out, so it is necessary to design the arm so that it touches the guide stopper.Also, this type of actuator must be designed with a few degrees plus in order to eliminate backlash. I needed to put it down. In this case, the piston inside the cylinder naturally does not hit the cylinder end, but comes to rest slightly before the cylinder end, and the torque is small.

Problems to be Solved by the Invention The present invention eliminates backlash of the main shaft in a screw-type torque actuator by eliminating the clearance between the helical screw of the main shaft and the helical nut of the piston installed in the cylinder. In addition, the amount of rotation of the main shaft is adjusted by changing the engagement position of the helical nut of the piston with respect to the helical screw of the main shaft, thereby eliminating the need for a guide stopper and attempting to alleviate the impact when the piston stops.

Means for Solving the Problems The present invention incorporates a pair of pistons having helical screw nuts having leads in opposite directions in a cylinder tube so as to reciprocate in the axial direction, and A pair of helical screws having leads are provided, one of the pair of helical screws of these main shafts is screwed into the helical screw nut of the one piston, and the other of the helical screws of the main shaft is screwed into the helical screw nut of the other piston. It is screwed into a helical screw nut, and the fluid that is pressurized into the cylinder tube from the inside port of the cylinder tube acts on the pistons on both sides at the same time, widening the gap between both pistons, rotating the main shaft in one direction, and rotating the cylinder tube on both outside sides. The fluid injected into the cylinder from the port narrows the gap between both pistons and rotates the main shaft in the other direction, causing one side or the other side to move against the cylinder tube.
Alternatively, both pistons can be finely rotated to change the engagement position between the piston's helical screw nut and the main shaft's helical screw to have a buffer function and set the desired rotation of the main shaft. be.

Function As described above, the present invention provides a pair of pistons housed in a cylinder tube with helical screw nuts having leads in opposite directions, and a helical screw nut having leads in opposite directions on the main axis of these helical screw nuts. When the piston is actuated by fluid pressure by interlocking the screws, the thrust force exerted on the helical screw crests of the main shaft by the screws of the helical screw nut acts on both sides of the reed crests, resulting in occlusion. Play due to surface clearance is eliminated, torque increases, and the amount of rotation of the main shaft, that is, the output shaft, is adjusted by slightly moving one or both helical screw nuts in the axial direction.

Embodiment 1 is a cylinder tube, 2 and 3 are pistons hermetically fitted inside the cylinder tube 1 and on both sides of the partition ring 4, 5 and 6 are gears provided on the outer periphery of each piston 2 and 3, 7 and 8 9 and 10 are helical screw nuts carved on the inner circumferences of the pistons 2 and 3; , the leads of the helical screw nuts 9 and 10 are carved in opposite directions (clockwise and counterclockwise). Reference numeral 11 denotes an annular metal fitted on the inner periphery of the partition ring 4, and an inner fluid supply/exhaust port 12 provided in the partition ring 4.
The pressure of the fluid such as air or oil that has been injected is guided to the inner surface of each piston 2 and 3. 13 are caps 14 and 15 fitted into the openings at both ends of the cylinder tube 1.
The main shaft is mounted so that it only rotates using bearings 16 and 17. Helical screws 18 and 19 are provided near the center of the main shaft 13 with leads turned in opposite directions (clockwise and counterclockwise) so as to engage the helical screw nuts 9 and 10, respectively. Reference numerals 20 and 21 are outer fluid supply and exhaust ports provided in the caps 14 and 15, through which fluid such as air oil is injected to cover the outer surfaces of the pistons 2 and 3 in the cylinder tube 1. Press each. 22 is a tie rod connecting and fixing the four corners of caps 14 and 15 with nuts 3, 24 and 25 are internal gears 7,
Wrench hole provided at 8, seal at 26.

Next, the operation will be explained.

To adjust any specified angle, use tie rod 2.
After loosening the second group of nuts 23, rotate the internal gears 7 and 8 little by little to move the helical screw nuts 9 and 10 relative to the helical screws 18 and 19 of the main shaft 13, and connect the piston 2 and the By changing the space amount of the gap B between the main shaft 13 and the null gear 8, the angle of the main shaft 13 can be adjusted by a small amount. When fluid is pressurized through the fluid supply/discharge port 12, the pistons 2 and 3 are pressurized in opposite directions, and the pistons 2 and 3 are controlled by the internal gears 7 and 8, respectively, so that the piston 2 moves to the left in FIG. , the piston 3 is simultaneously pushed out and moved to the right in FIG.

Therefore, the thrust acting on the helical screws 18 and 19 of the main shaft that mesh with the helical screw nuts 9 and 10 acts to eliminate the clearance between the leads of each helical screw 18 and 19, and attaches an arm, etc. to the main shaft (output shaft). When rotated, an error proportional to the length or an unstable range corresponding to the error does not occur at the radius tip of the arm.

Effects As described above, the present invention provides one or more sets of helical screws with opposite lead directions on the main shaft, and these helical screws are engaged with the helical screw nut of the piston installed in the cylinder tube so as to reciprocate. As a result, there is no misalignment between the helical screw of the main shaft and the helical screw nut of the piston, and there is no occurrence of backlash on the main shaft, and a highly accurate rotation angle can be obtained for the main shaft. By rotating the spindle, you can obtain twice the torque of the conventional spindle, and the rotation angle of the spindle can be set arbitrarily, and there is no need for a guide stopper for the spindle, which reduces the impact on the spindle, making it quiet and smooth. There are effects such as being able to perform rotation.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional side view of the present invention, FIG. 2 is a front view of the same, and FIG. 3 is a longitudinal sectional side view in which one piston is finely adjusted in the axial direction to provide a gap for backlash. 1... Cylinder tube, 2, 3... Piston, 4... Partition ring, 5, 6... Piston gear,
7, 8... Internal gear, 9, 10... Helical screw nut, 12... Inner fluid supply/discharge port, 13... Main shaft, 18, 19... Helical screw of main shaft, 20, 21... Outside Fluid supply and discharge port.

Claims (1)

[Claims] 1 A set of pistons each having a helical screw nut with leads formed in opposite directions, an internal gear that engages these sets of piston gears so as to reciprocate in the axial direction of the main shaft, and a set of internal gears. a main shaft having helical screws in opposite directions that engage with the helical screw nuts of the pistons, an inner fluid supply/discharge port that presses fluid between the pistons, and an outer surface of the pistons. It consists of a cylinder tube with an external fluid supply/discharge port and a required stroke and adjustment stroke, and the fluid injected from the internal fluid inlet moves each piston in opposite directions to rotate the main shaft in one direction. The fluid injected through the fluid supply and discharge ports retracts each piston in opposite directions, rotates the main shaft in the other direction, then stops, rotates one or both of the pistons, and connects the helical screw nut of the piston and the main shaft. A torque cylinder characterized by a buffer function and the ability to set any rotation angle of the main shaft by changing the occlusion position with the helical screw.