KR100413948B1 - Variable Displacement Type Axial Piston Unit - Google Patents

Abstract

The present invention relates to a variable displacement swash plate axial piston unit.

The present invention relates to a universal joint having a bearing outer ring 94 coupled to an end of an extension portion 92 branched in a triangular direction so that rotation of the extension portion 92 is freely rotated and diffracted in an axial direction thereof. 90 is fixed on the shaft 40, and the shoe holder assembly 80 including the joint hole 82 for receiving the universal joint is coupled to slide on the swash plate 70 so that the shoe 81 is swash plate ( The bearing outer ring 94 corresponds to the position of the shoe 81 that is variable in the process of sliding and sliding along 70, so that power can be transmitted or connected.

According to the present invention, when the piston 53 slides on the swash plate 70 having an inclined surface, when the piston 53 reciprocates, the diffraction angle of the piston rod 53 slidably coupled to the shoe that slides on the swash plate 70 is bent. By widening, the piston 53 can be moved in parallel with the axial direction of the cylinder 51, and the stroke distance of the piston 53 is increased by increasing the inclination angle of the swash plate 70 by increasing the diffraction angle of the piston rod. It can be extended to enhance the pumping flow rate of the fluid or the rotational force of the shaft 40.

Description

Variable Displacement Type Axial Piston Unit

The present invention relates to a variable displacement swash plate type axial piston unit used in heavy equipment and various industrial fields, and more particularly, has an inclined surface for converting the linear motion of the piston into a linear motion or the linear motion of the piston. When the piston unit reciprocates while sliding on the swash plate, it expands the diffraction angle of the piston rod that is slidably coupled to the swash plate on the swash plate so that the piston unit can be moved in the same axis as the cylinder axis. By not limiting the diffraction angle of the piston rod, the inclination angle of the swash plate can be further increased, thereby increasing the stroke distance of the piston, thereby increasing the pumping flow rate of the fluid or the rotational force of the shaft. It relates to an axial piston unit.

The swash plate type refers to a cylinder barrel that includes a plurality of cylinders that rotate together with the shaft after the rotating plate (called swash plate) mounted on the shaft is rotated about the shaft axis or fixed to the swash plate. By rotating, the piston slides on the inclined surface of the swash plate to rotate so that the piston unit reciprocates.

These variable displacement swash plate axial piston units have different functions depending on passive and active.

That is, in the case of active, when the fluid is injected into the cylinder at a constant pressure, the hydraulic motor outputs the rotational force generated when the piston rotates and slides along the inclined surface of the swash plate while rotating the piston to supply the rotational power to the device requiring the rotational force. It becomes

In the case of manual operation, a hydraulic pump is provided by inputting rotational power to the shaft to pump the fluid in the cylinder to the outside while reciprocating the piston.

Such variable displacement swash plate axial piston units are widely used in heavy equipment or various industrial fields such as excavators, fork cranes, bulldozers, cranes, and the like.

Piston unit as defined herein is a term that includes the meaning of performing two functions as described above. In other words, it means a device that pumps the fluid by the pumping operation or generates a rotational power by the piston unit movement.

In general, the swash plate does not rotate according to the rotation of the cylinder barrel and the piston unit assembly in the swash plate type hydraulic pump (compressor) and the motor. There is a trunnion type in which the shaft is connected, and a cradle type in which both sides of the swash plate and the bottom form a semi-cylindrical shape, and have a complicated structure in terms of processability and miniaturization.

As a conventional oscillating swash plate type variable displacement compressor, those disclosed in Japanese Patent Application Laid-Open No. 62-183082, Korean Patent Publication No. 1996-14656 and Korean Patent Publication No. 1999-6228 have been proposed. In the former Japanese seal compressor, the rotating drive body is inclined in the front-back direction by a connecting pin with respect to the rotating support fixed to the shaft, and the rotating drive body supports the rocking plate and supports each other in the plurality of cylinder bores. The rotary motion of the rotary drive body is converted into reciprocating motion of each piston via a plurality of pistons inserted in parallel at predetermined intervals and a piston rod interposed between the swing swash plates.

In addition, a long hole for slidingly guiding the connecting pin is formed in the rotatable support, and allows the inclined motion of the rotatable drive and the oscillating swash plate, and at the end of the compression stroke, the piston is almost constant at the top dead center. In order to maintain the clearance, the top dead center position of the rocking swash plate is characterized in that it is not displaced in the front-rear direction even if the inclination angle is changed.

In addition, the latter Korean patent hydraulic pump extends the piston to directly contact the inclined surface or to make the sliding and rotational movement at the same time with the swash plate interposed on the inner surface to change the rotational movement to a straight motion The zoom causes the piston to reciprocate.

The operation principle of the variable displacement swash plate axial piston unit that has been recently implemented in more detail with reference to Figures 1 to 4 as follows.

As shown in FIG. 1, the rotational force is transmitted to the cylinder barrel 50 by the side force of the piston 53 while the piston 53 in the cylinder barrel 50 reciprocates in the axial direction of the shaft 40. .

That is, in the order of power transmission, first, when the fluid is injected into the cylinder into the fluid inlet 62 of the fluid flow block 60 in the function of the motor generating the rotational force, the piston 53 reciprocates while the shoe holder assembly 80 When rotating along the inclined surface of the swash plate 72, the cylinder block 50 is rotated together by the side force according to the rotation to rotate the shaft 40.

In the power transmission process when used as a hydraulic pump for pumping fluid, when power is input to the free end of the shaft 40, the cylinder block 50 coupled to the spline 42 of the shaft 40 rotates and the cylinder ( As the shoe holder assembly 80 coupled with the free end of the piston 53 in the 51 rotates along the inclined surface of the swash plate 70, the piston 53 reciprocates to pump the fluid in the cylinder 51.

As described above, the conventional variable displacement swash plate axial piston unit rotates while the shoe holder assembly 80 is slid along the spherical surface 41a coupled to the shaft 40 when the cylinder block rotates. This is achieved by the side force of the cylinder block and the piston.

Severe friction force is generated on the bore surface of the piston 53 and the cylinder barrel 50 of this structure, and the friction force interferes with the reciprocating motion of the piston 53 to reduce the mechanical efficiency, as well as heat generation and early Wear and tear.

In an effort to alleviate this problem somewhat, the entire cylinder barrel 50 is made of copper (Cu) material, or the eastern city is inserted into the bore, but there is a big problem of increased manufacturing labor and economic burden.

In addition, as shown in FIG. 3, the size of the inclination angle of the swash plate 70 in the oscillation motion of the piston 53 and the shoe 81 is limited to a range in which the shoe 81 may oscillate. There is a limit to improvement, the range of which is less than about 14 degrees.

The fact that the inclination angle of the swash plate 70 can be increased means that the stroke of the piston 53, that is, the stroke length of the piston 53 can be extended even if the volume of the piston 53 is the same in the hydraulic pump or the hydraulic motor. It makes sense.

However, when the inclination angle of the swash plate 70 is at least 14 °, the diffraction angle between the spherical shaft 53a of the piston 53 itself and the shoe 81 increases, and the piston 53 is deformed from a linear motion to an oblique motion and thus the piston ( 53) and a serious problem of severe wear or damage occurs on the surface of the cylinder 51 in contact with.

As a result, such a problem is that the lifespan of the cylinder 51 and the piston 53 is drastically shortened, thereby limiting the angular design of the swash plate 70 and the piston 53 along the diffraction angle of the spherical shaft of the shoe and the piston 53. It can be seen that it directly affects the reciprocation of).

Therefore, if the diffraction angle of the spherical shaft 53a of the piston 53 itself coupled with the shoe 81 can be adjusted to a larger range, the piston 53 performs a reciprocating motion in parallel with the axial direction of the cylinder 51. Since the wear of the cylinder 51 and the piston 53 can be prevented as much as possible, the angle of the swash plate 70 can be adjusted to a larger inclination angle than before, so that the stroke of the piston 53 can be extended. In the case of providing a hydraulic pump to improve the pumping flow rate of the piston 53, in the case of a motor will be able to enhance the rotational force.

In order to solve this problem, the inclination angle of the swash plate 70 should not affect the reciprocating motion and stroke length of the piston 53 and the diffraction angle between the spherical shaft 53a and the shoe 81 of the piston unit. It's a challenge.

As a result, in the upward adjustment of the angle of the swash plate 70 or the friction plate 72 attached thereto, the shoe must not affect the reciprocating motion of the piston 53, and the shoe continuously varies in position along the inclined surface of the swash plate 70. There is a need for a power transmission means that can respond variably so that power can be transferred with room in position (81).

The present invention has been devised to solve the above problems, and an object of the present invention is to provide a swash plate with the inclination angle of the swash plate upwardly adjusted so as to extend the stroke length of the piston unit. By adjusting the inclination angle, the reciprocating motion of the piston unit interlocked with the shoe is kept in parallel with the axis of the cylinder to minimize wear due to mechanical friction, and according to the position of the shoe rotating along the power transmission plate between the shaft and the shoe. The present invention provides a variable displacement swash plate axial piston unit of a universal joint type that transmits power while responding variably.

Another object of the present invention is to use a universal joint to change the rotational force in a linear motion or linear motion to a rotational force when the transmission medium that transmits the power is connected to the universal joint so that the variable connection correspondingly freely the transmission of power The present invention provides a variable displacement swash plate axial piston unit which is lowered and thereby enables upward adjustment of the inclination angle of the swash plate.

Another object of the present invention is to increase the pumping flow rate of the piston unit by increasing the stroke length of the piston unit by being able to adjust the tilt angle of the swash plate by transmitting the power variably corresponding to the universal joint, thereby improving the rotational force of the drive shaft To provide a variable capacity swash plate axial piston unit that can greatly improve the.

An implementation means according to the first embodiment for achieving the object of the present invention comprises a housing comprising a bearing block for receiving the shaft, a fluid flow path block having a fluid inlet and a fluid outlet and a body having a cylindrical chamber therein;

A swash plate fixed to an inner surface of the bearing block and having an inclined surface inclined at a predetermined angle;

A cylinder barrel each having a fluid passage selectively passing through the fluid inlet or the fluid outlet and having a plurality of cylinders having parallel axes to each other;

A spring interposed on the shaft inside the cylinder barrel;

A variable displacement swash plate type axial piston unit comprising a shoe that is slidably coupled to the swash plate and is diffrably coupled to a spherical axis of each piston unit itself that is slidably coupled to the cylinder.

The shaft is rotated in the circumferential direction of the shaft, and freely rotated in the circumferential direction of the extension portion at each end of the triangularly extending extension portion to transfer power between the shoe holder assembly and the shaft, and can be diffracted in the axial direction. A universal joint having a bearing outer ring coupled to each other, the inner surface of the shoe holder assembly forming a joint hole for receiving the universal joint so that the surface of the bearing outer ring corresponds to a variable position of the shoe It features one place to be connected while slipping.

In the first embodiment of the present invention, in rotating a shoe holder assembly having a swash plate fixed by a shaft and having a plurality of shoes, the end portion of the extension portion rotated circumferentially and triangularly formed on the shaft on the shaft. After coupling the universal joint having a bearing outer ring freely rotated in the circumferential direction and diffractive in the axial direction thereof, the slide holder is formed to be slidably coupled so as not to be separated from the swash plate surface and to form a joint hole for accommodating the universal joint. Is achieved.

In the first embodiment, the outer ring is joined to the extension by forming a joint freely rotatable in the circumferential direction with respect to the axis of the extension and diffracted with respect to the axis of the extension at the end of the triangularly branched extension. By combining the contact with the shoe holder assembly, the outer ring of the bearing is diffracted according to the position of the shoe which is variable in the course of the shoe sliding along the swash plate to transmit power.

Therefore, even if the position of the shoe is changed, the power between the shoe and the universal joint can be transmitted to each other. And it is thereby possible to rotate the shoe even if the inclination angle of the swash plate is adjusted upward. In addition, the shift distance of the shoe can be adjusted upwardly, that is, upwardly adjusted from 14 ° to about 30 °. As a preferable example of this invention, it set to 20 degrees.

In addition, as the stroke of the shoe becomes longer, the piston unit itself is connected to the piston rod having a separate diffractive joint joint between the shoe and the piston unit so that the linear movement of the piston unit itself does not move in an oblique direction as in the prior art, thereby affecting the reciprocating motion of the piston unit. It will be able to perform the pumping operation and rotation operation without giving.

As a result, the piston can reciprocate linearly with no lateral force to generate rotational power. Even if the piston is shortened by shortening the piston length without using the lateral force, the shoe swings by connecting with the shoe through the piston rod. The angle can be increased to 20 °, so that the stroke of the larger piston can not only improve the hydraulic pump or motor output, but also avoid the friction caused by the lateral force of the piston, thereby increasing the mechanical efficiency.

In a second embodiment of the present invention, in a variable displacement swash plate axial piston unit in which a swash plate is rotated together with a shaft, rotation of the circumferential direction is performed at an end portion of the shaft which is rotated in the circumferential direction and branched in the triangular direction. A universal joint having a bearing outer ring freely diffracted in its axial direction is fixed, and a triangular joint hole is formed on the swash plate to receive the universal joint, and the swash plate is freely rotated in the circumferential direction of the shaft. And a cylinder block comprising a plurality of cylinders is secured in the housing, and the free end of the reciprocating piston in the cylinder is assembled by sliding around the edge of the swash plate.

In the case of the second embodiment, the load generated when the swash plate is rotated by slidably surrounding the rim of the swash plate to allow the universal joint to rotate the swash plate to reciprocate the piston in the rotating cylinder when the shaft rotates. Can be reduced.

Therefore, even if the angle of the swash plate is adjusted upward, the load is made by the universal joint at the time of power transmission between the shaft and the swash plate, and the upward adjustment of the swash plate angle is possible, thereby improving the pumping flow rate of the piston and the rotational force of the shaft.

In other words, the greater the inclination angle of the swash plate when the shaft is first rotated or the piston unit is operated in order to operate the pump or motor, the more the load is added. However, in the present invention, the load is transmitted by the slip between the swash plate and the bearing outer ring. There is a relatively very low advantage.

1 is a longitudinal sectional view showing the internal structure of a conventional axial variable displacement swash plate axial piston unit;

2 is a cross-sectional view of a conventional axial variable displacement swash plate axial piston unit,

3 is a cross-sectional view of the piston unit side action in the conventional axial variable displacement swash plate axial piston unit,

Figure 4 is a sectional view showing the main part of the circulation of the fluid during operation of the conventional axial variable displacement swash plate axial piston unit,

Figure 5 is a longitudinal sectional view showing the internal structure of a variable displacement swash plate axial piston unit according to the present invention,

6 is a cross-sectional view showing an example of power transmission between the shaft and the shoe holder assembly by the universal joint according to the present invention,

7 is a perspective view of a shoe holder assembly according to the present invention;

Figure 8 (a) is a cross-sectional view of a piston unit having a spherical shaft in itself, (b) is a cross-sectional view showing an example of a piston unit having a spherical bearing in the piston unit,

9 is a cross-sectional view of a piston rod diffrably coupled between the shoe and the piston unit according to the present invention.

10 is a cross-sectional view of the universal joint according to the present invention,

11 is a cross-sectional view showing the assembled state of the universal joint and the shoe holder assembly of the present invention,

12 is a cross-sectional view showing main parts showing a stroke of a shoe which is variable in position according to the present invention and a piston rod interlocking with the shoe.

<Description of Symbols for Main Parts of Drawings>

10: body 10a: chamber

20: housing 30: bearing block

31: Bearing 32: Fastening pin

40: shaft 42: spline

50: cylinder barrel 51: cylinder

52: fluid passage 53: piston unit

54: spring 53a: spherical shaft

53b: Spherical bearing 60: Fluid flow block

60a: bearing 62: fluid inlet

70: swash plate 71: slope

72: friction plate 73: round clip

80: Shoo holder assembly 81: Shoo

81a: spherical bearing 82: joint hole

83: piston rod 83a, 83b: spherical shaft

84, 85: Micro euro 90: Universal joint

91: through-hole 92: extension part

93: spherical ball bearing 94: bearing outer ring

Hereinafter, preferred embodiments of the variable displacement swash plate axial piston unit according to the present invention will be described in detail with reference to the accompanying drawings.

Figure 5 is a cross-sectional view showing the internal structure of a variable displacement swash plate axial piston unit according to the present invention, the same elements as the conventional components are denoted by the same reference numerals.

In the drawings, reference numeral 20 denotes a housing of the variable displacement swash plate axial piston unit.

The housing 20 has a bearing block 30 which receives the shaft 40 largely, a cylinder barrel 50 that rotates together with the shaft 40, and a fluid into the cylinder 51 of the cylinder barrel 50. Is composed of a fluid flow block 60 made of a manifold for introducing or discharging the body 10 having a cylindrical chamber (10a) for receiving the cylinder barrel 50 therein.

The shaft 40 is rotatably fixed to the bearing block 30 and the fluid flow block 60 by bearings 31 and 61, and a spline 42 is formed in a predetermined section. In the bearing block 30, a swash plate 70 is fixed to the inner side by a fastening pin 32. The swash plate 70 includes a friction plate 72 made of a cemented carbide having an inclined surface 71 inclined at about 20 degrees on its surface.

In the shaft 40, a plurality of shoes 81 which are slidably positioned on the inclined surface at the central portion thereof, and preferably nine shoes 81 are arranged at regular intervals and assembled. Each shoe holder assembly 80 includes triangular branched joint holes 82 therein, as shown in FIGS. 7 and 11, and as shown in FIG. 5, a friction plate of the swash plate 70. 72 and covered by an annular clip 73 on top thereof. The annular clip 73 is fastened to the swash plate 70 by a bolt.

The annular clip 73 guides and does not separate the shoe holder assembly 80 to have a concentric rotation radius when the shoe holder assembly 80 is rotated along the inclined surface 71.

As shown in FIG. 4, the cylinder barrel 50 is provided with a fluid passage 52 communicating therewith with the fluid inlet 62 and the fluid outlet 63 of the fluid flow block 60 therein. Of the cylinders 51, the piston 53 is inserted into the cylinder 51. The cylinders 51 are arranged such that their axes are parallel. The cylinder barrel 50 is coupled to the spline 42 so as to be slidable in the axial direction of the shaft 40 and does not rotate unless the shaft 40 is rotated in the circumferential direction of the shaft 40. In addition, the compression spring 54 is inserted into the cylinder barrel 50 so that the elastic force acting on the cylinder barrel 50 toward the fluid flow block 60 is inherent.

The piston 53 may have a spherical shaft 53a formed integrally with itself at its free end, as shown in Fig. 8A, and as shown in Fig. 8B, the piston 53 has a spherical shape. It may also include a spherical bearing 53b on a shape. This is because the shape of the piston 53 may employ both of the above-mentioned two types of piston 53 in the power transmission intended by the present invention. The working example thereof will be described more clearly below.

In the spherical bearing 81a, the spherical bearing 53b provided at the free end of the piston 53 and the spherical bearing 53 of the shoe 81 are diffracted by being engaged with the spherical shaft 53a of the piston 53. 81a) may be connected to each other through the piston rod 83. Of course, both ends of the piston rod 83 has spherical shafts 83a and 83b coupled to the respective spherical bearings 53b and 81a and diffracted freely. In addition, the spherical bearing 81a of the shoe 81 is formed with a microchannel 85 penetrating toward the surface in contact with the friction plate 72 of the swash plate 70 so that lubricating oil is introduced.

The piston rod 83 has a predetermined length and includes a fine flow path 84 penetrating in the longitudinal direction. Oil is injected into the micro channel 84 by the internal pressure generated during the reciprocating motion of the piston 53, so that the mechanical friction generated in each shoe 81 and the friction plate 72 is minimized.

The universal joint 90 is used to convert the straight motion into the rotational motion, that is, when the fluid is forced into the cylinder 51, the piston 53 reciprocates so that the shoe 81 is the friction plate 72 of the swash plate 70. The piston 53 is a straight motion for transmitting the rotational force generated when the slide rotates to the shaft 40 or for converting the rotational movement into a linear movement, that is, the rotational force input from the outside to the shaft 40. It is a medium for delivering to the shoe 81 which is interlocked with the piston 53 and the piston rod 83 so as to be.

The universal joint 90 is firmly coupled to the shaft 40 through the central through hole 91 as shown in FIG. 10, and is integrally rotated with the shaft 40. The universal joint 90 is provided with respective extensions 92 extending radially with respect to the through-hole 91 in the triangular direction, and each of the spherical ball bearings 93 is formed at the ends of the extensions 92. ) Is included. The spherical ball bearing 93 is coupled to a bearing outer ring 94 rotatably coupled to surround the single spherical ball bearing 93. The bearing outer ring 94 has a slip surface having at least flat surfaces facing each other.

Accordingly, the universal joint 90 may rotate in the circumferential direction of the shaft 40 to transmit or receive power to rotate the shoe holder assembly 80 in the circumferential direction of the shaft 40, and also to receive a bearing outer ring. 94 is freely rotated in the circumferential direction of the extension 92 and diffracted also in the axial direction, so that the surface of the joint hole 82 in contact with the bearing outer ring 94 is slipped even if it slips.

In other words, the bearing outer ring 94 can be diffracted by the spherical ball bearing 93, so that the bearing outer ring 94 can be inclined at an angle in all directions up to an inclined angle of the swash plate 70. The bearing outer ring 94 has a rectangular outer surface, and one side thereof is inserted into the joint hole 82 of the shoe holder assembly 80.

Accordingly, when the universal joint 90 rotates, the bearing outer ring 94 of the universal joint 90 rotating in the radial direction of the shaft 40 rotates the shoe holder assembly 80 or vice versa. By the reciprocating motion of the shoe holder assembly 80 is rotated along the swash plate 70, the rotational force is transmitted to the bearing outer ring 94 to rotate the shaft 40.

In a second embodiment of the present invention, as in the Republic of Korea Patent Publication No. 1996-14656, the shaft 40 and the swash plate 70 are rotated together, and both edges of the swash plate 70 are slidably connected to the shaft 40. In the case of reciprocating the piston unit by rotating the swash plate during the rotation of the swash plate 70 and the shaft 40 to form a joint hole 82 for receiving the universal joint 90 of the present invention on the swash plate and the By installing the above-mentioned universal joint 90 on the shaft 40, the angle of the swash plate can be adjusted upward.

In the second embodiment, the larger the inclination angle of the swash plate when the shaft is first rotated or the piston unit is operated to operate the pump or the motor, the more the load increases, but in the present invention, power is transmitted by the slip between the swash plate and the bearing outer ring. This has the advantage that the load is relatively very low.

Therefore, in the variable displacement swash plate axial piston unit according to the present invention, the power is directly transmitted by the universal joint 90 coupled to the shoe holder assembly 80 and the shaft 40 when the cylinder block rotates, and thus the cylinder block. By rotating with (50) no side force is generated.

An operation example of the variable displacement swash plate axial piston unit according to the first embodiment of the present invention configured as described above will be described.

First, the case where the present invention is used as a hydraulic pump for fluid pumping will be described first.

5 to 7, when the external power, that is, rotational force is input to the shaft 40, the shaft 40 is rotated. When the shaft 40 rotates, the universal joint 90 and the cylinder barrel 50 rotate at the same time while the bearing outer ring 94 rotates in contact with the inner surface of the joint hole 82.

In this case, the shoe is rotated according to the angle of the inclined surface of the swash plate 70 as shown in FIG. 12. As shown in ⓐ, ⓒ, the shoe 81 rotates along the friction plate 72 of the swash plate 70. The slip surface and the slip angle of the joint hole 82 and the outer ring of the bearing 94 are deformed by being closer to or farther from the 51.

In other words, even if the shoe is rotated in a guided state on the swash plate 70, even if it is rotated, even if it is located at the point ⓐ which is the uppermost part of the swash plate 70 or at the point ⓒ which is the lowest position, the shoe 81 is the swash plate 70 The contact surface with the bearing outer ring 94 does not vary greatly because the angle in close contact with the phase does not deform and only the distance from the cylinder 51 is different.

However, when the position of the shoe 81 is varied, the spherical ball bearing 93 of the bearing outer ring 94 in contact with the shoe holder assembly 80 is diffracted and rotated while being connected to each other.

As a result, the rotating rotational force acts, while being in close contact with the surface of the bearing outer ring 94 is slipped and diffracted to come in contact with the shoe 81 regardless of the position change.

As the position is changed by the distance between ⓐ and ⓒ of FIG. 12 by the rotation of the rotating shoe holder assembly 80, the piston 53 or the piston rod 83 having its own axis rotates and reciprocates. . Accordingly, while the cylinder barrel 50 rotates together with the rotating piston 53 rod, the fluid passage 52 passes through the fluid inlet 62 of the fluid flow block 60, as shown in FIG. It flows into the cylinder 51 quickly.

In this case, the piston 53 starts from the time when it retracts from the cylinder 51. In other words, when the position of the shoe 81 on the swash plate 70 rotates by sliding from position ⓐ to position ⓒ as shown in FIGS. 4 and 12, the fluid flows from the initial ⓐ position to the fluid of the fluid flow block 60. As the fluid passage 52 of the inlet 62 and the cylinder barrel 50 gradually flows, fluid begins to flow into the plurality of cylinders 51, that is, the four cylinders 51, and is completely passed between the ⓑ and ⓒ points. After losing, at ⓒ it will be blocked. At this time, the shoe reaches the lowermost position of the swash plate 70 and the piston 53 becomes a bottom dead center.

After the cylinder barrel 50 is rotated by the continuously rotating shaft 40, the cylinder 51 slides again from the point ⓒ to the point ⓐ, and performs the operation as described above in the reverse direction and blocks the fluid inlet 62. And the fluid is discharged by the pumping operation of the piston 53 while the fluid outlet 63 and the fluid passage 52 are passed through.

In this process, the piston rod connected between the shoe 81 and the piston 53 may reciprocate in an oblique direction with respect to the axis of the cylinder 51. However, the diffraction by the spherical joints on both sides is diffracted according to the reciprocating motion of the piston 53 itself, so that the slip surface of the piston 53 and the cylinder 51 does not wear and reciprocates. This operation is performed while power is input to the shaft 40 from the outside. Thus, it is possible to pump the fluid.

On the contrary, the operation according to the operation in the case of employing the present invention as a function of the hydraulic motor to generate the rotational power will be described.

In this case, when the fluid is forcibly injected into the fluid inlet 62, the fluid flows into the fluid passage 52 of the cylinder 51 communicating with the fluid inlet of the fluid flow block 60, and presses and pushes the piston 53. To me. When the piston 53 is retracted, the spherical shaft 53a of the piston unit 83 or the piston unit having its own shaft and the shoe 81 retreat back together to slide along the slope of the swash plate 70. Will be.

The rotational force generated at this time rotates the cylinder barrel 50 while the shoe 81 rotates simultaneously, and the shoe rotates the shaft 40 while pressing the bearing outer ring 94 of the universal joint 90 oppositely. .

Of course, the rotating cylinder barrel 50 is the fluid passage 52 therein and the fluid inlet 62 or the fluid discharge port (63) through the simultaneous operation of the flow through or blocked while the fluid is continuously introduced and or The discharge takes place simultaneously. Therefore, the fluid is forcibly injected into the cylinder 51 to generate rotational force on the shaft 40.

As described above, the variable displacement swash plate axial piston unit according to the present invention, which can also serve as a hydraulic pump and a motor, can pump a tooth by rotational power or generate a rotational force with hydraulic power. In addition, since friction occurs very frequently at the joints at both ends of the rod of the piston 53, the lubricating oil is introduced through the microchannel to prevent wear of the diffractive portion, thereby minimizing wear.

On the other hand, as shown in FIGS. 5 and 8, the short piston 53 and the piston rod 83 have spherical ball bearings coupled thereto, and the piston 53 forms a capillary flow path having a small diameter so that the piston 53 is formed. By supplying the supporting pressure oil to the pocket portion of the spherical ball bearing, the friction force can be minimized even when the piston 53 and the piston rod 83 are in close contact with a large load and move.

As described above, the motion of the piston 53 is moved to the axis of the cylinder 51 by diffracting the angle range according to the diffraction between the conventional piston 53 and the shoe that restricts the inclination angle of the swash plate 70 to a larger angle. It is possible to reciprocate side by side, and the angle of the swash plate 70 can be adjusted upward from the conventional 14 ° to 20 ° to extend the stroke of the shoe 81 to rotate while sliding on the swash plate conventional hydraulic pump or It can have a larger capacity than the motor.

As a result, in transmitting the rotational power of the variable displacement swash plate axial piston unit, friction with the bore inner surface of the cylinder barrel 50 can be minimized by not using the side force of the piston 53 or the piston rod 83. It can be, and there is no need to install a copper bush for preventing sticking due to side forces on the inner surface of the bore, and by applying spherical ball bearings on both sides of the piston rod 83, mechanical friction on the main moving parts can be minimized to improve mechanical efficiency.

Claims (12)

delete delete The shaft 40 which is supported by the bearings 31 and 61 to be rotatably fixed, the bearing block 30 which receives the shaft 40, and the plurality of cylinders 51 are provided and the shaft 40 is provided. And a cylinder barrel 50 which rotates together with the fluid flow block 60 having the fluid inlet 62 and the fluid discharge port 63 for circulating the fluid to the cylinder 51, and the bearing block 30. A plurality of swash plates 70 are assembled with fastening pins 32 on the inner surface and have an inclined surface inclined at a predetermined angle, and a joint hole 82 is formed in the inner central portion and spherical bearings 81a are formed along the circumferential surface thereof. A shoe 81 is installed to assemble a shoe holder assembly 80 diffracted along the inclined surface of the swash plate 70 and a bearing outer ring 94 to be axially diffracted in the extension portion 92 so that the bearing outer ring ( 94 is assembled to the surface contact with the joint hole 82 corresponding to the variable position of the shoe 81 Universal joint 90 to rotate in the circumferential direction with the shaft 40, and one side is mounted to the piston 53 built in the cylinder 51 and the other side is mounted to the spherical bearing 81a of the shoe 81 In the case comprising a housing having a piston rod (83) coupled at both ends thereof to be diffractive and a body (10) composed of a cylindrical chamber (10a), The shoe 81 is formed with a microchannel 85 penetrating toward an inner surface of the spherical shaft support 81a and a surface in contact with the friction plate 72 of the swash plate 70 so that lubricating oil is introduced into the microchannel 85. A variable displacement swash plate axial piston unit. delete The shaft 40 which is supported by the bearings 31 and 61 to be rotatably fixed, the bearing block 30 which receives the shaft 40, and the plurality of cylinders 51 are provided and the shaft 40 is provided. And a cylinder barrel 50 which rotates together with the fluid flow block 60 having the fluid inlet 62 and the fluid discharge port 63 for circulating the fluid to the cylinder 51, and the bearing block 30. A plurality of swash plates 70 are assembled with fastening pins 32 on the inner surface and have an inclined surface inclined at a predetermined angle, and a joint hole 82 is formed in the inner central portion and spherical bearings 81a are formed along the circumferential surface thereof. A shoe 81 is installed to assemble a shoe holder assembly 80 diffracted along the inclined surface of the swash plate 70 and a bearing outer ring 94 to be axially diffracted in the extension portion 92 so that the bearing outer ring ( 94 is assembled to the surface contact with the joint hole 82 corresponding to the variable position of the shoe 81 Universal joint 90 to rotate in the circumferential direction with the shaft 40, and one side is mounted to the piston 53 built in the cylinder 51 and the other side is mounted to the spherical bearing 81a of the shoe 81 In the case comprising a housing having a piston rod (83) coupled at both ends thereof to be diffractive and a body (10) composed of a cylindrical chamber (10a), Forming a fine flow path 84 in the longitudinal direction in the inner central portion of the piston rod 83 is characterized in that the lubricating oil intervenes in the diffraction portion of the piston 53 and the shoe 81 through the fine flow path 84 Variable displacement swash plate axial piston unit. delete delete delete The variable displacement swash plate axial piston unit according to claim 3 or 5, wherein the inclination angle of the swash plate (70) is 14 ° to 30 °. delete delete The method of claim 3, wherein a fine flow path 84 in the longitudinal direction in the inner central portion of the piston rod 83 is formed in the lubricating oil to the diffraction portion of the piston 53 and the shoe 81 through the micro flow path 84. A variable displacement swash plate axial piston unit, characterized in that the intervention.