JPH11193772A - Hydraulic swing motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydraulic swing motor capable of preventing leakage of a working fluid, stopping an output shaft at an arbitrary rotation angle, and reducing the size and weight thereof. SOLUTION: An arc shaped space 21f having at least one closed end is formed within a housing 21. An output shaft 25 is rotatively disposed so as to be concentric with the space 21f and is attached thereto fluid tightly. An arc shaped piston 26 that moves in the space 21f with the aid of the pressure of fluid admitted into the space 21f is connected to the output shaft 25 using the respective arc shaped piston shafts 28a, 28b and a torque arm 29 constituting conversion means. As a result, the movement of the piston 26 can be converted into the rotation of the output shaft 25.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic oscillating motor used for a power steering device of an automobile, a direction switching device of a conveyor line, a valve opening / closing device, and the like.

[0002]

[Related Background Art] A hydraulic oscillating motor is a hydraulic actuator that performs oscillating rotational movement with a limited rotation angle.
It is widely used because a large torque can be obtained in a relatively small space without the need for a link mechanism or a speed reduction mechanism. As shown in FIG. 4, a conventional hydraulic oscillating motor 10 has a cylindrical housing 11, a fixed wall 11 a formed on an inner wall of the housing 11, and is rotatable concentric with the housing 11 and with respect to the housing 11. , The output shaft 12 having a part of the outer periphery constantly in contact with the fixed wall 11a, and extending in the radial direction from the output shaft 12, and the extended end constantly slidably in contact with the inner wall of the housing. Vane 1
2a and ports 11b and 11c for introducing and discharging a vane driving fluid to and from two hydraulic chambers defined by the inner wall surface of the housing 11, the output shaft 12 and the vanes 12a.

The hydraulic oscillating motor 10 shown in FIG.
Since a is a single-sheet configuration, it is called a single vane type hydraulic oscillating motor. Other examples include a double vane type hydraulic oscillating motor in which two fixed walls and vanes are arranged at predetermined intervals, or a triple vane type hydraulic oscillating motor in which three fixed walls and vanes are disposed at predetermined intervals. In some cases, these can obtain a larger rotational force than a single vane type motor.

In the single vane type hydraulic oscillating motor 10 shown in FIG. 4, when hydraulic oil flows into the working chamber from one port 11b, the hydraulic pressure acts on one side surface of the vane 12a, and the pressure increases the volume of the hydraulic chamber. Vane 1 in increasing direction
2a moves (see the two-dot chain line in the figure). At the same time, the hydraulic oil in the other hydraulic chamber is discharged from the other port 11c. Since the vane 12a moves in this manner, the output shaft 12 integrated with the vane 12a also rotates accordingly. By the above operation, the output shaft 12 can be rotated by flowing the hydraulic oil into the hydraulic chamber. Subsequently, when hydraulic oil flows into the other port 11c, the vane 12a moves in a direction opposite to the above-described movement direction, and as a result, the output shaft 12 also rotates in a direction opposite to the above-described rotation direction.

[0005]

In the vane type hydraulic oscillating motor 10 described above, the output shaft 12 and the fixed wall 11a are only in line contact with each other, and the vane 12a is plate-shaped, so that the inner wall of the housing is formed. The contact area between the blade and the vane 12a is small. Therefore, it is difficult to interpose a seal packing or a seal ring between the output shaft 12 and the fixed wall and between the vane 12a and the inner wall of the housing, and the liquid tightness between the hydraulic chambers becomes insufficient. Therefore,
When hydraulic oil, which is generally at high pressure, is introduced into one hydraulic chamber, part of the hydraulic oil leaks into the other hydraulic chamber.

Therefore, the conventional vane-type hydraulic oscillating motor 10 is inefficient in converting hydraulic pressure into rotational force due to such leakage of hydraulic oil, and the vane 12a cannot be stopped at an intermediate position in its operating range. Was. For this reason, the conventional rocking motor 10 cannot be used for driving an actuator that requires the output shaft to stop accurately at an arbitrary intermediate position, for example, a power steering of an automobile. .

On the other hand, a hydraulic motor having a structure in which a direct-acting hydraulic cylinder and a link mechanism are combined to rotate an output shaft connected to the link mechanism is also known. Such a hydraulic motor can accurately stop the output shaft at an arbitrary intermediate position in its operation range. However, a large number of components are required to convert the linear movement of the cylinder into the rotation movement of the link, which not only complicates the structure but also increases the size of the hydraulic motor itself. Therefore, such a hydraulic oscillating motor cannot be used for a hydraulic motor requiring a reduction in size and weight, such as a motor for driving a power steering of an automobile.

An object of the present invention is to provide a hydraulic oscillating motor having a simple structure and having no leakage of hydraulic oil between hydraulic chambers.

[0009]

SUMMARY OF THE INVENTION A hydraulic oscillating motor according to the present invention has a housing in which an arc-shaped space portion at least one end of which is closed is formed inside, and a housing which is concentric with the arc of the space portion. A rotatable output shaft, an arc-shaped piston which is fitted to the space part in a liquid-tight and slidable manner, and moves in the space part by the fluid pressure of the fluid introduced into the space part; and a piston. And an output shaft, and a conversion means for converting the movement of the piston into the rotation of the output shaft.

In the above-mentioned hydraulic oscillating motor, the arc-shaped piston is fitted in the arc-shaped space, so that the contact area between the piston and the housing in the space becomes large, and leakage of the fluid can be easily prevented. Then, the piston moves in an arcuate space inside the housing by hydraulic pressure in an arc shape, and the movement of the piston is converted into rotation of the output shaft by the conversion means in the housing, so that it is almost the same as a conventional rocking motor. Hydraulic oil does not leak to the same degree as a direct acting hydraulic cylinder, despite its simple structure.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A hydraulic oscillating motor 20 according to an embodiment of the present invention will be described below with reference to the drawings.
As shown in FIGS. 1 and 2, a hydraulic oscillating motor 20 of the present invention includes a housing 21 having an arc-shaped space 21 f formed therein, and an output shaft 2 provided in the housing 21.
5, an arc-shaped piston 26 which is moved by a fluid introduced into the arc-shaped space 21f, a conversion means for converting the movement of the piston 26 into a rotational movement of the output shaft 25, and the like.

The housing 21 has a casing main body 22 having a circular concave portion 22c opened upward, and a circular concave portion 24c having a downward open opening formed therein. The casing body 22 has a rectangular base 23 formed integrally with the casing body 22 and incorporating a hydraulic circuit described later.

As shown in FIG. 1, on the outer peripheral side wall surface of the casing body 22, bolt mounting portions 22a for fixing the lid are formed at predetermined intervals over the entire circumference.
2a is provided with a bolt insertion hole for fixing the lid.
An arc-shaped ridge 22d is formed in the circular concave portion 22c of the casing body 22 concentrically with the center of the concave portion 22c.
The height of the ridge 22d is substantially equal to the height of the peripheral wall of the casing body 22. A bolt insertion hole 22e for attaching a lid is formed at a predetermined interval in the protruding ridge 22d. An arc-shaped groove 22f is formed by the arc-shaped ridge 22d and the peripheral wall and the bottom surface of the casing body 22. The surface of the groove 22f is subjected to Teflon processing so that an arc-shaped piston 26 described later can slide easily. Further, stoppers 22g and 22s for restricting the movement of the arc-shaped piston 26 to a certain range are attached to the bottom surface of the groove 22f. The mounting positions of the stoppers 22g, 22s are set in consideration of the hydraulic oil communication holes 22p, 22q, which will be described later, are not closed by the movement of the arc-shaped piston 26, and the necessary movement stroke of the arc-shaped piston 26 is considered.

Grooves 22x and 22y for fitting the seal packing are formed along the inner peripheral edge of the upper surface of the peripheral wall of the casing main body 22 and along the outer peripheral edge of the upper surface of the ridge 22d, respectively (see FIG. 3). At substantially the center of the bottom surface of each of the grooves 22x and 22y, a convex ridge for holding the packing having a height slightly lower than the depth of the groove is provided concentrically along the groove. Inside a base 23 integrally formed on the side of the casing body 22, hydraulic control circuits (not shown) such as valves and flow paths for controlling the supply and discharge of hydraulic oil of the hydraulic oscillating motor 20 are respectively provided. Is formed. The flow path is formed at the bottom of the casing body 22 and has communication holes 22p, 2p,
It leads to 2q. The openings of the communication holes 22p and 22q are formed by the arc-shaped piston 26 as described above.
g, 22s, it is formed at a position where it is not closed by the piston 26 even when it comes into contact with the g.

As shown in FIG. 2, a lid 24 is attached to the upper surface of the casing body 22. Lid 24
Except for the base portion 23, is formed in a substantially symmetrical shape with the casing main body 22, and has a recess 24c having the same size as the main body 22. The concave portion 24c has a convex ridge 24 having substantially the same shape as the arc-shaped convex ridge 22d of the casing body.
d is formed. The ridges 24d are formed on the lid 24.
When the ridges 22 are placed on the casing body 22,
d and 24d are formed at positions where the upper end surfaces are in contact with each other. An arc-shaped groove 24f is formed by the arc-shaped ridge 24d, the peripheral wall of the lid 24, and the inner upper surface. The surface of the groove 24f is Teflon-treated like the casing body 22.

The grooves 2 of the casing body 22 are respectively formed along the inner peripheral edge of the lower end surface of the lid 24 and the outer peripheral edge of the lower end surface of the ridge 24d.
Seal packing fitting groove 24 having substantially the same shape as 2x, 22y
x and 24y are formed (see FIG. 3). In addition, lid 2
As shown in FIG. 2, a bolt mounting portion 24a for mounting the lid is formed on the outer peripheral side wall of the casing 4 at a position matching the bolt mounting portion 22a of the casing body 22. A bolt insertion hole for fixing the lid is formed in the bolt mounting portion 24a. Further, a bolt insertion hole 24d for attaching the lid 24 to the casing main body 22 is formed in the ridge 24d.

The groove 22x of the casing body 22 and the lid 24
As shown in FIG. 2, a ring-shaped seal packing 30 having an H-shaped cross section is fitted between the groove 24x and the groove 24x. The seal packing 30 is for maintaining the liquid-tightness of the contact surface between the upper surface of the peripheral wall of the casing body 22 and the lower surface of the peripheral wall of the lid 24. Similarly, an arc-shaped seal packing 31 having an H-shaped cross-section is fitted between a groove 22y of the ridge 22d of the casing main body 22 and a groove 24y of the lid 24. As shown in FIG. 1, the total length of the seal packing 31 is the groove 22y,
24y, the both ends of the seal packing 31 are engaged with both end faces of the ridges 22d and 24d,
A lip 31a for preventing misalignment is formed. still,
The seal packing 31 is for maintaining the liquid tightness of the gap between the ridges.

The casing body 22 and the lid 24 are shown in FIG.
As shown in (1), the bolts and nuts are assembled at the respective bolt mounting portions 22a and 24a. Similarly, the ridges 22d, 24d of the casing body 22 and the lid 24, respectively.
The bolts are also inserted through the bolt insertion holes 22e and 24e of d, and are fixedly fastened by the bolts and nuts. As a result, the casing main body 22 and the lid 24 are brought into close contact with each other at the contact surfaces of the ridges, and the above-mentioned seal packings 30 and 31 are compressed to further improve liquid tightness.

The arc-shaped groove 22f of the casing body 22
And an arc-shaped groove 24f of the lid 24 are opposed to each other to form an arc-shaped space 21f in which an arc-shaped piston 26 described later moves. As shown in FIG. 2, a recess 22m is formed at the center of the bottom surface of the casing body 22, and a bearing 34 is fitted into the recess 22m. An output shaft insertion hole 24h penetrates through the center of the lid 24, and a step is formed at the periphery of the opening of the hole 24h on the upper surface of the lid, and the output shaft 25 is rotatably supported at the step. Bearing 35 is fitted. A circular mounting plate 36 is fixed to the upper surface of the lid 24 via bolts. An output shaft insertion hole 36a having an inner diameter equivalent to that of an output shaft 25 described later is formed in the center of the mounting plate 36, and an annular groove for O-ring fitting is formed along the circumferential direction on the inner surface of the hole 36a. Is formed. An O-ring is fitted in the groove. A groove is formed on the lower surface of the plate concentrically with the insertion hole 36a, and an O-ring for sealing is fitted into the groove.

The output shaft 25 has a small diameter portion 25a at the lower end and a torque arm 2 (described later) at a predetermined portion above the step portion.
9 is formed. Output shaft 2
5 is inserted into the shaft insertion hole 24h of the lid 24, and the shaft 25
The lower end small diameter portion 25 a is fitted to the bearing 34. By supporting the output shaft 25 with the bearing 35 of the lid 24 and the bearing 34 of the casing body 22, the output shaft 25 can freely rotate with respect to the housing 21.

An arc-shaped space 2 formed in the housing
As shown in FIG. 1, a block 40 for closing this space is fitted to one end of 1f. Block 40 is
As shown in FIG. 3, it is an arc-shaped block body having a square cross section that matches the inner wall of the arc-shaped space 21f and having the same curvature in the circumferential direction as the arc-shaped space 21f.
As shown in FIG. 1, an annular groove is formed on the outer peripheral surface near both end surfaces of the block 40, and an O-ring 41,
42 are fitted. Thereby, the arc-shaped space portion 21f
Is kept liquid-tight at the closed end. The block 40 further has a through hole 40c for inserting an arcuate piston shaft, which will be described later, along the center line in the circumferential direction. The curvature of the through-hole 40c matches the curvature of the circular-arc piston shaft 28a.
c is formed in such a shape that the piston shaft 28a having a square cross section can slide in the through hole in a liquid-tight manner. Also, as shown in FIG. 3, grooves 40d, 4d,
0e is formed over the inner circumference thereof, and an O-ring 43 is fitted into each groove as shown in FIG.
0c and the circular piston shaft 28a are kept liquid-tight.
A knock pin 45 is implanted on the upper surface of the block 40 as shown in FIG.
The block 40 is fixed to the end of the arc-shaped space 21f by engaging with a hole (not shown) formed in the hole.

Inside the housing, as shown in FIG.
An arcuate piston 26 movable along the arcuate space 21f is provided. The arc-shaped piston 26 is a block having a square cross section that matches the inner wall of the arc-shaped space 21f and having the same curvature in the circumferential direction as the arc-shaped space 21f. Like the block 40, the arc-shaped piston 26 has a groove formed on the outer peripheral surface near both end surfaces thereof, and O-rings 46 and 47 are fitted in the groove. Thus, the liquid-tightness of the sliding surface between the arc-shaped space 21f and the arc-shaped piston 26 is maintained. Holes 26c and 26d for attaching an arc piston shaft, which will be described later, are formed in both end surfaces of the arc piston 26. Piston shafts 28a and 28b having a square cross section are press-fitted and fixed to the holes 26c and 26d, and the pistons and the shafts are connected.

The circular-arc piston shafts 28a and 28b fixed to both end surfaces of the circular-arc piston 26 are
4 is an arc axis having a rectangular cross section and the same curvature as f. One circular piston shaft (left piston shaft in FIG. 1) 28
As for a, one end is connected to the arc-shaped piston 26 as described above, and the other end passes through the hole 40c of the block 40, and is fixed to a peripheral portion (a left end portion in FIG. 1) of the torque arm 29 described later with a screw. Have been. Also, the other circular piston shaft (FIG. 1)
One end of the middle and right piston shafts 28b is connected to the arc-shaped piston 26 as described above, and the other end is fixed to a peripheral portion (right end in FIG. 1) of a torque arm 29 described later with screws. I have. Further, the arc-shaped piston shafts 28a and 28b are in contact with guide rollers 51a and 51b provided rotatably at the bottom of the casing body 22, respectively.

A torque arm 29 to which the other ends of the arcuate piston shafts 28a and 28b are fixed has a boss 29a for connecting the output shaft 25, and a fan-shaped plate 29b formed integrally with the boss. Consists of The boss portion 29a is formed with a serration hole that fits with the output shaft 25. Thus, when the arc piston 26 moves, the arc piston shafts 28 a and 28 b and the torque arm 29 are arranged to rotate around the center axis of the output shaft 25. The conversion means is constituted by the arc piston shafts 28a and 28b and the torque arm 29 fixed thereto.

Next, the operation based on the above configuration will be described. First hydraulic chamber 21a defined by arc-shaped space 21f, arc-shaped piston 26 and block 40
Is filled with the hydraulic oil supplied via the communication hole 22p. On the other hand, the internal space of the housing other than the first hydraulic chamber 21a, that is, the second hydraulic chamber 21b is formed in the communication hole 22q.
Filled with hydraulic oil supplied via

Here, when the hydraulic control circuit of the base 23 is operated to supply hydraulic oil into the first hydraulic chamber 21a, the pressure in the first hydraulic chamber rises, and the hydraulic pressure is increased at one end of the arc-shaped piston 26. (The left end face in FIG. 1). Due to this oil pressure, the arc-shaped piston 26 moves in an arc shape along the arc-shaped space 21f in a direction of increasing the volume of the first hydraulic chamber 21a (clockwise in FIG. 1).

Accordingly, the circular piston shafts 28a, 28a
8b is a moving direction of the arc-shaped piston 26 along the circumferential direction while being guided by the guide rollers 51a and 51b (FIG. 1).
Move clockwise). Along with this, the torque arm 29 rotates similarly (clockwise in FIG. 1) about the boss 29a. As a result, the output shaft 25 fitted to the boss 29a also rotates (clockwise in FIG. 1). Then, it stops at a position that balances the supplied hydraulic oil amount, and is held at that position.

The volume of the second hydraulic chamber 21b decreases with the movement of the arc-shaped piston 26, and the hydraulic oil corresponding to the decrease corresponds to the hydraulic oil flowing through the communication passage 22q and the flow passage in the base. It is returned to the first hydraulic chamber 21b side. Next, when the hydraulic oil is pressure-fed to the second hydraulic chamber 21b, the pressure in the second hydraulic chamber rises, and the hydraulic pressure acts on the other end surface of the arcuate piston 26. This hydraulic pressure causes the arc-shaped piston 26 to move along the arc-shaped space 21f in the direction in which the volume of the first hydraulic chamber 21a decreases (counterclockwise in FIG. 1).

Accordingly, the circular piston shafts 28a, 28
8b similarly moves (counterclockwise in FIG. 1) along the circumferential direction while being guided by the guide rollers 51a and 51b. Accordingly, the torque arm 29 is connected to the boss 2
Similarly, it rotates around 9a (counterclockwise in FIG. 1). As a result, the output shaft 2 fitted to the boss 29a
5 also rotates (counterclockwise in FIG. 1).

As described above, by alternately feeding hydraulic oil into the hydraulic chamber from the communication holes 22p and 22q, the arcuate piston 26 reciprocates between desired positions, and the output shaft 25 is accordingly kept constant. Rotate within a range of angles. The seal between the upper surface of the peripheral wall of the casing body 22 and the lower surface of the peripheral wall of the lid 24 and the O-ring fitted to the plate 36 maintain liquid tightness inside and outside the housing.
The O-rings 41, 42, 46, 47 fitted to the arc-shaped piston 26 and the block 40, and the seal packing 31 fitted between the convex upper surface of the casing main body 22 and the convex lower surface of the lid body. The first hydraulic chamber 21a and the second hydraulic chamber 21
The liquid tightness between b is maintained.

Accordingly, the arc-shaped piston 26 moves exactly in correspondence with the amount of hydraulic oil pumped from the communication holes 22p, 22q, and the amount of hydraulic oil to be pumped is adjusted to move the arc-shaped piston 26 within its operating range. Can be stopped at any intermediate position. As a result, the output shaft 25 can also be rotated corresponding to the amount of hydraulic oil accurately, stopped at an arbitrary intermediate position in the operation range, and maintained at that position.

Unlike the embodiment of the present invention, the block 40 may be press-fitted into the groove 22f of the casing body 22 and fixed, or the block 40 may be formed integrally with the casing body 22. Also, the boss 2 of the torque arm 29
9a and the fan-shaped plate portion 29b may be provided separately and fixed to each other.

Further, the arc-shaped convex ridges 22d and 24d may be formed separately and fixed to the casing body 22 and the lid 24. Furthermore, although the lip seals 30 and 31 do not need to have an H-shaped cross-section in particular, the H-shaped cross-section has an effect that liquid tightness can be more reliably maintained. or,
Not only one end but also the other end of the arcuate space 21f is closed by a block similar to the block 40, and the arcuate piston 26
Thus, two spaces may be defined in the space, and these may be used as a first hydraulic chamber and a second hydraulic chamber. Furthermore, by providing a spring return mechanism on the output shaft without introducing the hydraulic oil into the second hydraulic chamber, when the hydraulic pressure in the first hydraulic chamber is reduced, a spring return force acts to cause the first hydraulic chamber to return. The volume may be reduced.

[0034]

As described above, according to the present invention, at least one end of the housing is provided in the housing so as to be concentric with the arc of the space. A rotatable output shaft, an arc-shaped piston fitted to the space in a liquid-tight and slidable manner, and moved in the space by the fluid pressure of the fluid introduced into the space, and the piston and the output shaft And the conversion means for converting the movement of the piston into the rotation of the output shaft, so that the arc-shaped piston moves liquid-tightly along the arc-shaped space inside the housing by the hydraulic pressure of the hydraulic oil. be able to. Therefore, leakage of hydraulic oil between the hydraulic chambers can be prevented, and as a result, the arc-shaped piston can be stopped at an arbitrary position, and the output shaft can also be stopped at an arbitrary rotation angle.

Further, the movement of the arc-shaped piston can be converted into the rotation of the output shaft by a conversion means having a simple structure. Therefore, the number of parts is reduced, and the entire hydraulic oscillating motor can be reduced in size and weight. As a result, the hydraulic oscillating motor according to the present invention stops the output shaft at an arbitrary intermediate position in the operation range, such as not only a direction switching device and a valve opening / closing device of a conveyor line, but also a power steering device of an automobile, for example. It is also possible to apply to a device that needs to be performed.

[Brief description of the drawings]

FIG. 1 shows a hydraulic oscillating motor according to an embodiment of the present invention.
It is a top view which shows the state which removed the cover.

FIG. 2 shows a hydraulic oscillating motor according to one embodiment of the present invention.
FIG. 2 is a sectional view taken along the line II-II in FIG. 1.

FIG. 3 shows a hydraulic oscillating motor according to an embodiment of the present invention.
FIG. 3 is a sectional view taken along the line III-III in FIG. 1.

FIG. 4 is a schematic sectional view showing the structure of a conventional hydraulic oscillating motor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 21 Housing 22 Casing main body 24 Cover 25 Output shaft 26 Arc-shaped piston 27 Conversion means 28a, 28b Arc-shaped piston shaft 29 Torque arm 41, 42, 43, 46, 47 O-ring 30, 31 Seal packing

Claims (1)

[Claims] 1. A housing in which an arc-shaped space portion at least one end of which is closed is formed therein; a rotatable output shaft provided in the housing so as to be concentric with the arc of the space portion; An arc-shaped piston fitted in the space portion in a liquid-tight and slidable manner and moving in the space portion by a fluid pressure of a fluid introduced into the space portion; and connecting the piston and the output shaft. And a converting means for converting the movement of the piston into the rotation of the output shaft.