KR930007767B1 - Rotary actuator - Google Patents

Abstract

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Description

Rotary actuator

1 is a front view of a partial cross section of an embodiment of the invention.

2 is a cross-sectional view taken along the line A-A in FIG.

Figure 3 is a front view of the rotor showing the manufacturing method of the rotor in the present invention.

Figure 4 is a side view of the vane showing a method of manufacturing the vane in the present invention.

* Explanation of symbols for main parts of the drawings

1: Cylinder 2, 3: End cover

4, 5: bolt 6: insertion hole

7: fixing member 8, 9: stopper

10, 11: oil port 12: rotor shaft

13, 14: flange 15, 16: small diameter

17, 18: vane 19, 20: pressure chamber

20: oil chamber 21, 22: passage

23: notch 24, 25: radial bearing

26, 27: clearance 28, 29: movable space

TECHNICAL FIELD The present invention relates to a rotary actuator that performs rotational reciprocating motion, in other words, oscillating rotational motion within a limited angle.

A general rotary actuator is composed of a cylinder, a stator, and a vane (VRRe) having a stopper fixed to an inner wall, and performs oscillating rotational motion (pendulum motion) by sending pressure oil alternately to both ports of the discharge port and the press-fit port.

In this case, if the pressure oil leaks from the gap between the vane and the cylinder inner wall in the cylinder, proper driving force is not obtained, so that the vane is provided with a sealing material such as rubber or synthetic resin.

However, this sealing material has a drawback which is severe in abrasion loss, and also generates friction between the inner surface of the cylinder and impairs the generation efficiency of the rotating torque.

Thus, a pair of flanges for forming a pressure chamber in which vanes are fixed to a rotary actuator of a type that prevents leakage of oil without using such a sealing material is formed, and the flange and the rotor are formed. A so-called seal-height rotary actuator has been studied that maintains a clearance enough to prevent oil leakage between the inner wall of the receiving cylinder.

In order to realize the sealless rotary actuator, first, it is necessary to maintain a clearance in microns so that oil leakage does not occur between the flange of the rotor and the inner wall of the cylinder.

In addition, in order to ensure smooth rotation of the rotor, the rotor must be configured to sufficiently cope with a thrust load applied to the rotor. That is, if the rotor does not receive a sufficient thrust load, the inner surface of the flange and the stopper fixed to the inner wall of the cylinder are pressed against each other, and smooth rotation of the rotor is inhibited.

Conventionally, a limited sealless rotary actuator has supported the rotor by a thrust bearing, but in this case, the thrust load can be received, but the above gap cannot be maintained.

In addition, the support of the rotor by the radial bearing retained by the bearing retainer was considered, but even in this case, sufficient spacing could not be maintained, and the countermeasure of the thrust load was insufficient, and there were many problems in practical use of the frictional resistance. .

Accordingly, an object of the present invention is to provide a sealless rotary actuator that satisfies the above-mentioned request.

In order to achieve the above object, according to the present invention, in a rotary actuator composed of a pair of oil ports, a rotor shaft, vanes, and a stopper, a flange having a diameter slightly smaller than the inner diameter of the cylinder, The vane is provided between the flanges to form a rotor, a pair of radial bearings supporting the rotor two points in the cylinder, and the outer ring of the radial bearing is press-fitted by screwing directly into the cylinder, On the inner ring side, a movable space is formed, and the stopper is arranged to have a gap between the fixed site on the outside thereof, and at the same time, protrudes into the inner surface of the cylinder and is constrained by the fixing member and is located between the two flanges. It is characterized by including being.

At this time, the vane is preferably formed by cutting a portion of the cylinder having the inner diameter of the same diameter as the rotor shaft.

In addition, it is preferable that the vanes form a suitable number for oil distribution, for example, a compression part of the vane or a cutout part on either side.

Therefore, in the rotary actuator of the present invention according to the above configuration, the rotor first rotates forward or reverse by flow of oil from a pair of oil ports.

The oil in the oil chamber is firmly supported in two places by the radial bearings, in which the rotor is directly pressed into the cylinder, so that a small gap is maintained between the inner wall of the cylinder and the flange so that no leakage of oil can occur. none.

The thrust load on the rotor is received by the inner circumference of the radial bearing being integrated with the rotor and moving in the axial direction.

At this time, the stopper also moves with the rotor and does not contact the inner surface of the flange.

EXAMPLE

An embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a front view of a partial cross section of an embodiment of the present invention, in which a case where vanes and stoppers are provided with two arms is shown (in a basic form, vanes and stoppers are one arm).

There, a rotor is fitted to the cylinder 1, and both ends of the cylinder 1 are blocked by the end covers 2 and 3, respectively.

The end covers 2 and 3 are fixed to the side end faces of the cylinder 1 by bolts 4 and 5, respectively.

The insertion hole 6 is drilled in the upper side and the lower side of the cylinder 1, and the fixing member 7 is inserted therein.

This fixing member 7 is fixed to the cylinder 1 by tightening with a bolt.

This fixing member functions to restrict the operations of the stoppers 8 and 9 as described later.

In addition, oil ports 10 and 11 through which operating oil flows in and out are inserted into the cylinder 1 so as to sandwich the fixing member 7 therebetween.

The rotor fitted in the cylinder 1 has a rotor shaft 12 and a flange 13 attached thereto. This flange (13), (14) between (14) and the small diameter portions (15) and (16) located outside the flanges (13) and (14), and the two flanges (13) and (14). ) And vanes (17), (18) fixed to the.

Then, as shown in FIG. 2, the rotor side 12 has a stopper gradually formed by the passage 21 and the rotor communicating the pressure chambers 19 and 20 formed therein. A passage 22 is formed between the 8 and the vanes 17 and between the stopper 9 and the vanes 18 to communicate with the oil chamber.

The passages 21 and 22 are not necessary when the vane and the stopper are one set.

Moreover, it becomes unnecessary also when the oil port similar to the oil pot 10,11 is formed also in the lower side.

It is preferable to manufacture this rotor by the following method.

That is, as shown in FIG. 3, one cylinder having a diameter equal to or slightly larger than the diameters of the flanges 13 and 14 is prepared, and gradually ground to form a corner portion.

Initially, the parts to be the flanges 13 and 14 are left to the left and right first, and the other parts are ground until the diameters of the small diameter portions 15 and 16 are reached, and then the small diameter portions 15 ), (16) and other parts are ground until the diameter of the rotor shaft 12 is reached, the flanges (13), (14) and small diameters (15), (16), and The rotor shaft 12 is integrally formed in this order.

According to such a method, there is an advantage that it does not take time to join each part, and it is unnecessary to pay attention to errors such as misalignment of the joining position, right angle of each part, etc. at the time of joining.

The present invention is intended to prevent the leakage of oil using the viscosity of the oil without installing a sealing material for preventing the leakage of oil on the vanes (17), (18). It is necessary to maintain the clearance of the micron unit (for example, the sum of the upper and lower clearances of 8 microns) between the inner wall and the peripheral surfaces of the flanges 13 and 14, in which oil leakage does not occur.

Therefore, the precision of the size of each part and the precision of an assembly require the precision of a micron unit, and it is preferable to manufacture a rotor as mentioned above.

On the other hand, the vanes 17 and 18 have the same inner diameter as the diameter of the rotor shaft 12 and the outer diameter equal to the outer diameter of the full flanges 13 and 14 as shown in FIG. Or prepare a donut-shaped cylinder that is slightly larger than that, cut a portion of it into a narrow fan shape and fix it with a bolt between the flanges (13) and (14).

At that time, if the outside diameters of the vanes 17 and 18 are made slightly larger than the set outside diameter of the flange, the vanes 17 are fixed after the vanes 17 and 18 are fixed between the flanges 13 and 14. ), It is possible to grind portions protruding from the flanges 13 and 14 of the (18) to match the outer diameters of the vanes (17) and (18) to the outer diameters of the flanges (13) and (14). Will be

And. The vanes 17 and 18 are secured to the flanges 13 and 14 with bolts.

Further, when the cutouts 23 are formed in the vanes 17 and 18, oil leaks smoothly between the vanes and stoppers in contact with each other.

Next, a method of fitting the rotor into the cylinder 1 will be described. The rotor is inserted into the cylinder 1 while the stoppers 8 and 9 are inserted above and below the flanges 13 and 14. Although they are pushed in, the stokes 8 and 9 are to be accommodated in the space formed by the rotor shaft 12, the flanges 13, 14 and the inner wall of the cylinder 1. Do not fix on anything.

By doing so, as will be described later, the thrust load applied to the rotor shaft 12 can be absorbed, and the dimensional error and assembly error of each part can be corrected.

After the rotor is pushed into the cylinder 1, the radial bearings 24 and 25 whose outer periphery have a diameter slightly smaller than the inside diameter of the cylinder are not pressed using a presser or a chamber, without using a bearing presser. Hit hard on both sides of the cylinder directly.

In this case, the strong hitting means that the bearing is fitted in such a way that the outer diameter is tightened and fitted slightly beyond the allowable range specified by the bearing maker.

Then, the inner bearings of the radial bearings 24 and 25 are tightened to fit the small diameter portions 15 and 16 to support the rotor.

In this way, the rotor is firmly supported by bringing the outer circumference into the cylinder so as to maintain the clearance between the peripheral surfaces of the flanges 13 and 14 and the inner wall of the cylinder.

Then, the fixing member 7 is inserted from the insertion hole 6, and the front end portion thereof is stored in the gaps 26, 27 of the stoppers 8, 9, and the cylinder 1 Secure in.

On both sides of the inner ring of the radial bearings 24 and 25, the movable spaces 28 and 29 of the inner ring are formed.

In the above configuration, when oil is supplied from the oil port 10, oil enters between the upper stopper 8 and the vane 17, that is, from the cutout 23 of the vane, and thus the stopper 8 Rotate in the counterclockwise direction in FIG. 2 until the vanes 17 which are in contact with each other are separated from the stopper 8 one by one, and come into contact with the lower stopper 9.

At that time, a part of the oil passes through the passage 22 and is guided between the vanes 18 and the stopper 9 to act to push away the sun.

On the other hand, the oil filled in the pressure chamber 19 is pushed by the vanes 17 in accordance with the rotation of the rotor, is passed through the passage 21 to the oil chamber 20 side, and the pressure chamber 20 In addition to the oil filled in the inside, it is pushed out to the oil port 11 by the vanes 18.

The rotation of the rotor is stopped by the vanes 17 contacting the stopper 9 and the vanes 18 contacting the stopper 8.

Subsequently, when the entry and exit relationship of the oil in each oil port 10, 11 is changed, the operation opposite to the above is performed, and the vanes 17, 18 rotate in the opposite directions to the Return to the state shown in FIG.

Thereafter, the above positive or reverse rotation is repeated, and the rotor shaft rotates reciprocatingly.

Here, a method of receiving a thrust load of the rotor actuator according to the present invention will be described.

When the rotor is vibrating, the thrust load, which is its component force, in addition to the radial load is necessarily applied to the rotor.

If it is mild, it can be received sufficiently simply by supporting the rotor as a radial bearing.

However, if a slight thrust load is applied, such as when a thrust load is applied to the rotor shaft from the outside, only the radial bearings 24 and 25 cannot accept it.

In order to receive the thrust load, if the thrust bearing is used, the thrust bearing cannot be closed, but since the thrust bearing cannot receive the radial load, the clearance between the inner wall of the cylinder and the flanges (13) and (14) of the rotor can be achieved. none.

However, the radial bearings 24 and 25 in the present invention are press-fitted by directly tightening in the cylinder 1, so that their outer circumference is in close contact with the inner surface of the cylinder 1, even though a thrust load is applied. It does not move, but its inner circumference is integrated with the rotor as opposed to the magnitude of the thrust load to avoid the movable spaces 28 and 29 to move away from the thrust direction.

Here, as in the prior art, when the stoppers 8 and 9 are fixed to the inner wall of the cylinder 1, the inner surface of one flange is strongly pushed against the side surfaces of the stoppers 8 and 9 by the thrust load. As a result of this problem, not only does the output torque be lowered, but also a problem that the rotation of the rotor is inhibited due to the phenomenon of being pressed by friction occurs.

In the rotary actuator of the present invention, since the stoppers 8 and 9 are not fixed to the inner wall of the cylinder 1, the stoppers 8 and 9 become intimate with the surrounding members as the rotor moves. It can move as it goes, thereby preventing the occurrence of the problem.

Of course, even if it can be operated, it can perform the function of the stopper 8, 9, i.e., partition the oil chamber and regulate the rotational angle of the rotor shaft 12 under the pressure of the working fluid. It goes without saying that it is within the limited range that can be made (in the drawings, the sizes of the gaps 26 and 27 with respect to the fixing member 7 are exaggerated, and in fact, they become much narrower gaps.

Also, by holding the stoppers 8 and 9 in an unfixed state, the stoppers 8 and 9 operate freely to become familiar with the surrounding members although they are within a very limited range. And it becomes possible to adjust at the time of assembling an assembly error.

That is, the straightness angle to the rotor shaft 12 of the flanges 13 and 14, the parallel angle between the side surfaces of the flanges 13 and 14 and the side surfaces of the stoppers 8 and 9 during assembly, and the like. If it is the same as the design, there is no problem, but if it exceeds the tolerance, a contact part or an oil leakage part occurs.

In that case, if the stoppers 8 and 9 are fixed to the inner wall of the cylinder 1, the correction is very difficult, but in the case of the present invention, the stoppers 8 and 9 freely move within the movable range. Moving around. Familiarity with the surrounding members makes it possible to compensate for errors in the assembly dimensions of each part and cumulative intersections of right angles.

As described above, the present invention can achieve clearance maintenance between the flange and the inner wall of the cylinder, and can also be subjected to a thrust load, so that the rotor can be smoothly rotated by preventing oil leakage without using a sealing material. In addition, there is an effect that can obtain a rotary actuator that can correct the error of the accuracy of the dimensions and the accuracy of assembly.

Claims (3)

Comprising a cylinder (1) having a pair of oil ports (10), (11), rotor shaft (12), vanes (17), (18), stoppers (8), (9) In the rotary actuator, the flanges (13) and (14) having a diameter slightly smaller than the inner diameter of the cylinder (1) and the vanes (17) and (18) are provided between the flanges (13) and (14). The outer ring of the pair of radial bearings 24 and 25 and the outer bearings of the radial bearings 24 and 25 which form the rotor and which support the rotor two points in the cylinder 1 are provided in the cylinder 1. The presser is pressed by direct tightening in the inner side), and movable spaces 28 and 29 are formed on the inner ring side thereof, and the stoppers 8 and 9 have a gap between the outer fixing member 7. 26), 27, and at the same time, protruding to the inner surface of the cylinder 1 and being constrained by the fixing member 7 and located between the two flanges 13, 14Rotary actuator characterized in that. 2. The rotary actuator according to claim 1, wherein the vanes (17) and (18) are formed by cutting a portion of a cylinder having an inner diameter having the same diameter as the rotor shaft (12). 2. The rotary actuator according to claim 1, wherein the vanes (17) (18) form cutouts (23) for circulating oil.

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