JPH024242Y2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Field of Industrial Application The present invention relates to a rotary actuator that converts the linear motion of a piston into an oscillating motion via a rack and a pinion.

(b) Prior Art Conventionally, in rotary actuators, a rack and a pinion (rotary gear) are meshed together in order to convert linear reciprocating motion into reciprocating rotational motion, as shown in Japanese Patent Application Laid-open No. 12286/1986. However, due to the gap between the rack and pinion, a backlash appears between the rack and pinion at the end of the rack's linear reciprocating motion, that is, at both ends of the pinion's reciprocating rotational motion, resulting in smooth movement. There was a problem that it wasn't.

(c) Problems to be Solved by the Invention The present invention solves the problems of the prior art as described above, namely, the problem that the operation of the rotary actuator is not smooth especially at the operating end due to backlash between the rack and pinion. This is an attempt to resolve the issue.

(d) Means for Solving the Problems The oscillating actuator according to the present invention has a pair of linearly extending cylinder chambers formed in parallel to each other in the housing, and a piston is movably provided in each of the cylinder chambers. , a pinion is rotatably provided in the housing between the pair of cylinder chambers, and a part of the pinion projects into the cylinder chamber;
In a rotary actuator, the piston is provided with a rack that engages with the pinion, and fluid pressure is alternately introduced into both ends of the two cylinder chambers to drive the piston and reciprocate the pinion. The distance from the axis to one end of one cylinder chamber is the distance from the rotation axis of the pinion to the end of the other piston chamber that is point symmetrical with respect to the one end and the rotation axis. , are configured differently.

(e) Effect In the above rotary actuator, if fluid pressure is introduced from two ends that are symmetrical about the rotation axis of the pinion in the two cylinder chambers, and fluid pressure is discharged from the other two ends, each The piston in the cylinder chamber moves to the ejected side and the pinion rotates. Even if one piston comes into contact with the end of the cylinder chamber and stops, the other piston cannot come into contact with the end of the cylinder chamber, so the piston is pressed by the pinion to the point where it is prevented from moving, thus preventing backlash. .

(F) Embodiments Examples of the present invention will be described below with reference to the drawings.

1 to 3, a rotary actuator (hereinafter referred to as actuator) 1 according to this embodiment is shown. This actuator 1
is constructed with the main body portion 2 as a main component.

The main body part 2 includes a housing 20 in which a pair of cylinder chambers 21 and 21a are formed parallel to each other and in a straight line, pistons 30 and 30a that are movably disposed in each cylinder 21 and 21a, and two cylinder chambers 21 and 21a. A pinion 4 rotatably disposed within the housing 20 between the cylinder chambers 21 and 21a.
0. The pinion 40 partially projects into the cylinder chambers 21, 21a and engages with racks 31, 31a formed on the pistons 30, 30a.

Both ends of the cylinder chamber 21 are closed by a pair of covers 25 and 26, and both ends of the cylinder chamber 21a are closed by a pair of covers 25a and 26a. Length of cylinder chamber 21a (2 x la)
The covers 25a and 26a are formed so that they are slightly longer than the length of the cylinder chamber 21 (2×l).

The cylinder chamber 21 is connected through ports 27 and 28 formed in the covers 25 and 26, respectively, and the cylinder chamber 21a is connected to the covers 25a and 26a.
ports 27a and 28a respectively formed in
It is adapted to be connected to a fluid pressure circuit (not shown) via.

In the above configuration, fluid pressure is simultaneously introduced from ports 28 and 27a, and
When a is released to atmospheric pressure, the piston 30 moves to the right and the piston 30a moves to the left at the same time, and the pinion 4
Rotate 0. And the piston 30 is the cover 2
The piston stops at the point where it comes into contact with the inner end surface 29 of the piston. Also, if the fluid pressure supply is reversed, the piston 3
0 and 30a move in the opposite direction to that described above.

If we look at the reciprocating motion of the pistons 30 and 30a in more detail with reference to FIG. 32 comes into contact with the end surface 29 of the cover 25, the length of the cylinder chamber 21a is longer than that of the cylinder chamber 2.
1, so the piston 30a
The left end surface 33a of the cover 26a does not come into contact with the end surface 34a of the cover 26a, and a gap is maintained. For this reason, the fluid pressure continues to push the piston 30a to the left, so the pinion 40
Since the piston 30 receives a clockwise rotational force and a force that moves the piston 30 rightward, no backlash occurs between the racks 31a and 31 and the pinion 40.

When fluid pressure is introduced into the port 28a, even if the left end surface of the piston 30 contacts the end surface of the cover 26, the right end surface of the piston 30a does not contact the end surface of the cover 25a, and the rack 31a and No backlash appears between 31 and pinion 40.

In FIG. 4, a modification of the main body of the embodiment of FIG. 1 is shown. The main body 2' of this usage example uses covers 61 and 62 as covers to close both ends of the cylinder chamber 21, and
Covers 61a and 62a are used to close both ends of 1a. The cover 61 has a passage 63 that communicates the inside of the cylinder chamber 21 with the passage 24.
and two annular grooves 64, 65 and a cover 62.
A passage 67 and an annular groove 68 are formed in the housing to communicate the port 66 with the passage 22 of the housing. The passage 63 communicates with the passage 24 via an annular groove 64 and the passage 22 communicates with the passage 23 via an annular groove 65. The passage 67 also communicates with the passage 22 via an annular groove 68.

An annular groove 64a that communicates the passage 24 and the passage 22a is formed in the cover 61a.
There is a passage 6 that communicates the port 66a with the passage 22a.
7a and an annular groove 68a are formed.

The covers 61a and 62a are formed so that the length of the cylinder chamber 21a is slightly longer than the length of the cylinder chamber 21.

In this main body part 2', when fluid pressure is supplied to the port 66 and the port 66a is opened to the atmosphere, the fluid pressure is applied to the cylinder chamber on the left side of the piston 30.
1 and pushes the piston 30 to the right, and also enters the cylinder chamber 21a on the right side of the piston 30a through the passages 22 and 23 and pushes the piston 30a.
Push to the left.

Fourth regarding movement of pistons 30 and 31a
If you look in detail with reference to the figure, the right end surface 32 of the piston 30 comes into contact with the end surface 69 of the cover 61, but since the length of the cylinder chamber 21a is slightly longer than the length of the cylinder chamber 21, the left end surface of the piston 30a 33a does not come into contact with the end surface 70a of the cover 62a, and a gap is maintained. Therefore, as described above, the racks 3 provided on the pistons 30a and 30
No backlash appears between 1 and 31a and the pinion 40.

When port 66 is opened to the atmosphere and fluid pressure is supplied to port 66a, both pistons 31 and 30a operate in the opposite manner to that described above.

(G) Effect In the swing type actuator according to the present invention, even if one piston contacts the end face of the cylinder chamber at the end of the stroke, the other piston on the drive side does not contact the end face of the cylinder chamber and eliminates the gap. Because it is equipped with a piston, there is no backlash between the rack and pinion provided on the piston.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the rotary actuator according to the present invention, FIG. 2 is a plan view of FIG. 1, FIG. 3 is an end view of the rotary actuator of FIG. The figure is a sectional view showing another example of use of the main body. 1: Actuator, 2: Main body, 20: Housing, 21, 21a: Cylinder chamber, 30, 30
a: Piston, 40: Pinion.

Claims (1)

[Scope of utility model registration request] A pair of linearly extending cylinder chambers are formed in the housing in parallel with each other, a piston is movably provided in each cylinder chamber, and a pinion is rotatably provided in the housing between the pair of cylinder chambers. A portion of the pinion protrudes into the cylinder chamber, a rack is provided on the piston that engages with the pinion, and fluid pressure is alternately introduced into both ends of the two cylinder chambers to drive the piston and reciprocate the pinion. In a rotating rotary actuator, the distance from the rotation axis of the pinion to one end of one cylinder chamber is symmetrical with respect to the one end and the rotation axis. A rotary actuator characterized in that the distance to the end of the other piston chamber is different.