JPS60216079A - Inclined shaft type hydraulic rotary machine - Google Patents

Abstract

PURPOSE:To make a balance between pressing force and dissociating force, by increasing each dissociating force receiving area of suction and discharge ports at a time when the number of pistons situated at the high pressure side is much more. CONSTITUTION:An annular recessed groove 23 is formed at the inner circumferential side of a tip part of a yoke 22. Two hydraulic chambers 26 and 27 are partitively made up in this recessed groove part with an annular projecting part 25 of a valve plate 24. The hydraulic chamber 26 is interconnected to a discharge port 9 through an interconnecting passage 28. On the other hand, the hydraulic chamber 27 is interconnected to an oil guide hole 30 being opened to a top dead center position of a selector surface 24A of the valve plate 24 through an interconnecting passage 29. Therefore, only when the number of pistons at the high pressure side is (N+1)/2 to the piston number N, high pressure oil is led into the hydraulic chamber 27. And, at this hydraulic chamber 27, dissociating force is intermittently produced in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a hydraulic rotary machine as a variable capacity oblique axis type axle or motor used in construction machinery and general machinery.

[Prior art]

1 to 3 show a hydraulic pump as a conventional oblique shaft type hydraulic rotating machine.

In the figure, 1 is a casing, 2 is a rotating shaft rotatably supported by the casing 1, and 3 is a cylinder block that rotates together with the rotating shaft 2. The cylinder block 3 has a plurality of cylinders in the axial direction. 4°4, . . . are drilled. A piston 5 is slidably provided in each cylinder 4, and a connecting rod 6 is provided in each piston 5.
is installed. A spherical portion 6A is formed at the tip of each connecting rod 6, and the spherical portion 6A is connected to the rotating shaft 2.
It is swingably supported by two drive disks formed at the tip of the drive disk.

Reference numeral 7 denotes a valve plate; one end surface of the valve plate 7 rotatably slides on the end surface 3A of the cylinder block 3; Side I
A sliding surface 7B is slidably brought into contact with A. Further, a pair of supply/discharge ports 8, 9 are formed in the valve plate 7, and one side of each supply/discharge port 8.9 has layered port portions 8A, 9.
A and open to the switching surface 7A, and the other sides become long groove port portions 8B and 9B and open to the sliding surface 7B.

Then, by rotating the cylinder block 3, the cylinder 4 is intermittently communicated with the suction/discharge ports 8, 9, so that oil can be supplied and discharged between the cylinder 4 and the suction/discharge ports 8, 9. For this purpose, the cylinder block 3 is provided with a suction/discharge passage 10 that opens to the cylinder 4 at one end and opens to the end surface 3A at the other end. On the other hand, a pair of suction and exhaust passages 11 and 12 are bored in the casing 1,
Each of the suction/exhaust passages 11, 12 opens to the tilting sliding surface IA, and the suction/exhaust passages 11, 12 are always open to the tilting sliding surface IA, regardless of the tilting position of the valve plate 7.
5 to communicate with the long groove port portions 8B and 9B of 9. In order to make the capacity of the hydraulic pump variable, the cylinder block 3 and the valve plate 7 are tilted along the tilting sliding surface IA using a tilting drive mechanism (not shown). It is done.

Further, reference numeral 13 indicates a center shaft, and the center shaft 13 has a spherical portion 13A formed at one end thereof, and the spherical portion 13A is swingably supported by two drive disks. The center shaft 13 extends through the center of the cylinder block 3, and its tip is fitted into the valve plate 7. In addition to this, cylinder block 3
Centering between the valve plate 7 and the valve plate 7 takes place. In the figure, 1
4 is a spring that applies an initial load to the cylinder block 3 in order to maintain close contact between the cylinder block 3 and the valve plate 7; 15 is a bearing interposed between the center shaft 13 and the cylinder block 3; shows.

The hydraulic pump according to the prior art has the above-mentioned configuration, and its operation will be described with port 8't as the suction port and port 9 as the discharge port. Figure 1 shows the cylinder tag opening.
The cylinder block 3 is shown in the zero tilt rotation position, and from this position, the cylinder dog opening, the cylinder block 3, and the valve plate 7 are tilted and driven in the direction of the arrow in the figure by the tilt drive mechanism, and the central axis of the cylinder block 3 is moved to the zero tilt rotation position. As shown by the dashed line in FIG. 1, the rotary shaft 2 is inclined by a tilting angle α with respect to the central axis of the rotating shaft 2. In this state, the rotating shaft 2 is rotated by a driving means (not shown) such as an electric motor or an engine. Since the two drive disks of the rotating shaft 2 and the piston 5 provided in the cylinder 4 of the cylinder block 3 are connected by a connecting rod 6, the cylinder block 3 follows the rotation of the rotating shaft 20. The rotation center axis of the four cylinder tabs 230 is inclined with respect to the rotation center axis of the rotating shaft 2, so the piston 5 reciprocates within the cylinder 4 while the cylinder block 3 is rotating. Then, while the suction and exhaust passage 10 of the cylinder 4 communicates with the suction port 8, the piston 5 extends and oil is supplied into the cylinder 4 during the suction stroke.
While the suction/discharge path 10 communicates with the discharge port 9, the piston 5 enters the cylinder 4, pressurizes the oil in the cylinder 4, and causes the oil to be discharged from the discharge port 9, resulting in a discharge stroke. A sitting action is performed by repeating this suction stroke and discharge stroke.

Incidentally, since the cylinder 4 and the suction/discharge passages 11 and 12 provided in the casing IK are intermittently communicated via the supply/discharge ports 8 and 9 formed on the valve plate 7, the end face is closed during pump operation. In order to prevent oil from leaking from the sliding contact area between the switching surface 3A and the switching surface 7m and the tilting sliding area between the tilting sliding surface IA and the sliding surface 7B, the cylinder block 3 is adjusted by balancing the hydraulic pressure. is brought into close contact with the casing 1 together with the valve plate 7.

By the way, this type of hydraulic rotating machine has a supply/discharge port 8 of the valve plate 7.
, 9 on the sliding surface 7B side should be formed as a long groove port portion 81.9B as shown in FIG. There is. Furthermore, it is desirable that the supply/discharge ports 8 and 9 have a port passage area as large as possible to reduce pressure loss.

On the other hand, regarding the balance of hydraulic pressure, a pressing force A acts on the cylinder block 3 due to the hydraulic reaction force of the piston 5 in the direction of pressing the cylinder block 3 together with the valve plate 7 toward the casing 1 side. Furthermore, a separation force B is generated in the valve plate 7 that tends to separate the valve plate 7 from the casing 1 due to the hydraulic pressure acting on the discharge port 9 on the high pressure side. This opening force B is the hydraulic pressure that acts on the long groove port part 9B of the discharge port 9 and the pressure receiving area in the vicinity of it.The opening force B is always smaller than the pressing force A in order to prevent leakage of discharged oil. There are restrictions that must be met.

Therefore, the conventional technology has the following drawbacks.

First, it is not possible to arbitrarily select the passage area and shape of the supply/discharge port 8゜9 in relation to the opening force B, resulting in a decrease in pump performance or motor performance, especially mechanical efficiency or self-priming power due to pressure loss. It has the disadvantage of inviting

Second, the separation force B is determined by the shape of the long groove port portion 9B of the discharge port 9, and is a constant value as shown in FIG.

On the other hand, the pressing force A is the number of pistons in the discharge stroke or μ out of the total number of pistons N (N is an odd number).
The total pressure-receiving area of .±. is the pressing force acting area, and the υ cylinder block 3 is pressed against the casing together with the valve plate 7 by the hydraulic reaction force acting on the pressing force acting area. As a result, the pressing force A fluctuates in a curved or uneven manner as shown in Fig. 3, and in order to satisfy pressing force A > opening force B under any conditions, the opening force B must be applied to the piston. It must not be set to less than the pressing force A when the number ratio is 1. For this reason, when the number of pistons on the discharge stroke side is warped, there is a drawback that the pressing force A is more than necessary.

Thirdly, due to the second drawback mentioned above, the sliding surface 7B.

There is a disadvantage that the surface pressure on the tilting sliding surface IA increases and the operating force of the actuator of the tilting drive mechanism must be increased, and the amount of wear on the sliding surface 7B and the tilting sliding surface IA increases. This has the disadvantage that it increases the amount of heat generated and, in some cases, causes galling and seizure phenomena.

[Purpose of the invention]

The present invention was developed in view of the drawbacks of the prior art described above, and when the number of pistons located on the high pressure side is alternately changing between 12' and 1, the number of pistons located on the high pressure side is 12' and 1'. Only in this case, by applying pressure oil to the valve plate in the direction of pressing the valve plate against the casing, the pressure balance between the pressing force and the opening force can be maintained even if the opening area of the suction/exhaust port is increased. It is a tree that provides an oblique axis hydraulic rotary machine that can hold well.

[Structure of the invention]

In order to achieve the above object, the feature of the configuration adopted by the present invention is that the valve plate has two hydraulic chambers that press the valve plate in opposite directions when hydraulic pressure is introduced; The hydraulic chamber is communicated with a high-pressure side supply and discharge port of the pair of supply and discharge ports, and the other hydraulic chamber is communicated with an oil guide hole formed at a top dead center or a bottom dead center position on the switching surface of the valve plate. That's true.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 4 to 9. Note that the same components as those in the prior art described above are given the same reference numerals, and their explanations will be omitted.

First, FIGS. 4 to 7 show a first embodiment of the present invention.

In the same figure, 21.21 is a support pin attached to the casing 1, and the support pin 21.21 passes through the axis of the rotating shaft 2, and the spherical part 13 of the center shaft 13 (see FIG. 1) has a spherical center. is disposed on a tilting center line perpendicular to the axis of the rotating shaft 2. 22 is the support pin 21.21
The yoke 22 is a yoke serving as a tilting member that is rotatably supported by the cylinder. A groove 23 is formed, and the inner peripheral side of the tip is fitted into the outer peripheral surface of the valve plate 24. ◎ 45 is formed on the outer peripheral surface of the valve plate 24 so as to fit into the annular groove 23. The inside of the annular groove 23 is defined by the annular protrusion 25 into two hydraulic chambers 26 and 27.

28 is a communication passage formed in the valve plate 24. One end of the communication passage 28 communicates with the long groove port portion 9B of the discharge port 9 which is the high pressure side of the pair of supply/discharge ports 8.9, and the other end communicates with the long groove port portion 9B of the discharge port 9 which is the high pressure side of the pair of supply/discharge ports 8.9. It communicates with room 26. On the other hand, 29 is a communication passage similarly formed in the valve plate 24, one end of the communication passage 29 is connected to an oil guide hole 30 that opens at the top dead center position on the switching surface 24A of the valve plate 24, and the other end is It communicates with the hydraulic chamber 27.

Note that the yoke 22 is provided with a point of action of an actuator (not shown) for tilting drive, and by rotating the jaw 22 around the support bin 21 by the actuator, the valve plate 24 and the cylinder are rotated. The structure is such that the block 3 can be tilted. Also,
In the embodiment, the hydraulic rotary machine is used as a hydraulic pump, and the oil guide hole 30 moves from the discharge stroke, which is the high pressure side, to the low pressure side, when the cylinder block 3 rotates in the direction of the arrow in FIG. It is formed at the top dead center position when switching to a certain suction stroke, but when a hydraulic rotary machine is used as a hydraulic motor,
@6 As shown in the drawing, the oil guide hole 30' is formed at the bottom dead center position where the suction stroke, which is the high pressure side, is switched to the discharge stroke, which is the low pressure side.

Although the present embodiment is configured as described above, the operation itself as a hydraulic pump is not particularly different from that described in the prior art described above. However, looking at the balance effect of the hydraulic pressure between the pressing force and the separating force, the pressing debris in this embodiment is due to the pressing force A due to the hydraulic reaction force of the piston 5, and the communication path 2.
The annular projection 251 of the valve plate 24 in the hydraulic chamber 26 via 8
This is the sum of the pressing force C acting on the force C and the pressing force C acting on the force C. On the other hand, the opening force B is the opening force B acting on the high pressure side discharge port 9 and the annular protrusion 2 of the valve plate 24 within the hydraulic chamber 27 via the communication passage 29.
5 plus the separation force acting on it.

Here, regarding the pressing force C, the high pressure oil in the long groove port portion 9B of the discharge port 9, which is the high pressure side, is guided to the hydraulic chamber 26 via the communication path 28, and the high pressure oil in the long groove port portion 9B of the discharge port I- The discharge pressure is 11! #'! Since it is constant, the pressing force C generated in the hydraulic chamber 'z6 has a constant value.

Next, regarding the separation force, the hydraulic chamber 27 is connected to the communication path 2.
The oil guide hole 30 communicates with the oil guide hole 30 via the oil guide hole 9, and the oil guide hole 30 is configured to open at the top dead center position.

For this reason, the oil guide hole 30 communicates with the supply/discharge path 1o of the cylinder 4 only when the number of pistons on the high pressure side is A1, and guides high pressure oil from the supply/discharge path 1o to the hydraulic chamber 27. The hydraulic chamber 2
In step 7, the separating force D is generated intermittently.

Now, these hydraulic pressures C and D are set in the relationship C=D, and the hydraulic pressure is adjusted so that each of these hydraulic pressures C and D corresponds to the hydraulic reaction force acting on one piston 5. room 26
．． It is assumed that 270 pressure receiving areas are set. In this case, since the pressing force C is in the opposite direction to the releasing force D, the hydraulic pressure C-D is as shown in Fig. 7, and only when the number of pistons on the high pressure side is a snake, the hydraulic pressure Obtained as pressure.

Thus, the pressing force ^ in this example is A-A+(C-D)
The pressing force X is a constant value. As a result, the separation force i in this embodiment is compared with the separation force B (C) of the conventional technology, and the pressing force A
Since it is possible to increase the value to approximately equal to , it is possible to increase the shape of the suction and discharge ports 8 and 9. Therefore, the tilting angle of the hydraulic rotary machine can be increased, and the suction and discharge passages 11 and 12 formed in the casing 1 can also be made large, so that the pressure loss of the hydraulic rotary machine can be reduced.

Next, FIG. 88 shows a second embodiment of the present invention.

However, the feature of this embodiment is that a center shaft hole 32 is bored in the valve plate 31 in the axial direction along the axis, and an annular recess of a larger diameter is formed in the axially intermediate position of the center shaft hole 32. A groove portion 33 is formed. On the other hand, center shaft 3
4 into the center shaft hole 32, and
An annular protrusion 35 is formed on the cough center shaft 34 so as to fit into the annular groove 33, and the annular protrusion 35 defines the annular groove 33 into two hydraulic chambers 36 and 37. One hydraulic chamber 36 communicates with the long groove port portion 9B of the discharge port 9 via a communication passage 38, and the other hydraulic chamber 37 communicates with the long groove port portion 9B of the discharge port 9 via a communication passage 39 at the top dead center position of the switching surface 31A of the valve plate 31. The structure is such that it is connected to the oil guide hole 40 which opens wide.

The present embodiment is constructed as described above, but as in the first embodiment, the pressing force Ci acting on the right inner wall of the valve plate 31 within the hydraulic chamber 36 is a constant value, whereas the pressing force Ci within the hydraulic chamber 37 is a constant value. Valve plate 3
An opening is created that acts on the left inner wall of 1.

Furthermore, FIG. 9 shows a third embodiment of the present invention, and the feature of this embodiment is that the pressure receiving area on the hydraulic chamber 26 side is larger than the pressure receiving area corresponding to one piston in the first embodiment. As for the area, the pressing force C' is set to a larger value than the pressing force C according to the first embodiment, and on the other hand, the pressure receiving area on the hydraulic chamber 27 side is set to a pressure receiving area corresponding to one piston as in the first embodiment. The structure is such that the separation force D is generated as an area.

With this configuration, the pressing force λ' is A'
=A+ (C'-D), the pressing force is larger than A,
And a constant value can be obtained.

Therefore, if the pressure receiving area on the hydraulic chamber 26 side is arbitrarily set as in this embodiment, the pressing force A is larger than the pressing force A.
You can also get

In addition, although each Example demonstrated the case where the hydraulic rotary machine based on this invention is used as a hydraulic ponzo, it goes without saying that it can be used as a hydraulic motor. Further, in the embodiment, the valve plate is illustrated as being made of one plate material, but it may be formed as a separate body consisting of a switching valve plate portion and a valve groove portion. The switching surface of the valve plate may be formed into a concave curved surface or a convex curved surface. Further, although the supply/discharge ports 8 and 9 are described as a pair, the present invention may be applied to a hydraulic rotating machine having two or more pairs.

〔Effect of the invention〕

The oblique shaft type hydraulic rotating machine according to the present invention is as described in detail above, and has the following effects.

■ The pressing force that presses the valve plate against the casing side can be kept constant, so even if the opening force is increased by enlarging the shape of the suction/exhaust port, the hydraulic balance between the valve plate and the casing can be maintained stably. to prevent oil leakage.

■ As a result of the above item 0, the opening area of the supply/discharge port can be increased, so the supply/discharge port can be designed with less pressure loss, and performance such as mechanical efficiency and self-priming performance can be improved. Moreover, the tilt angle of the cylinder can be increased.

■ Since the pressing force can be kept constant and can be set arbitrarily, there is no need to press the valve plate with more than necessary pressing force, reducing wear on the sliding surface and causing curling and seizure phenomena. can be prevented. On the other hand, since the frictional resistance of the sliding surface is reduced, the entire device can be made smaller and lighter as the tilting actuator is made smaller.

[Brief explanation of the drawing]

Figures 1 to 3 show the prior art; Figure 1 is a vertical cross-sectional view of a hydraulic rotating machine, Figure 2 is a right side view of Figure 1 showing the valve plate, and Figure 3 is a diagram showing the pressing force and pressure. Explanatory diagram showing the relationship of separation force, 4th
7 to 7 show a first embodiment of the present invention, FIG. 4 is a longitudinal sectional view of a hydraulic rotating machine, FIG. 5 is an enlarged view of part a in FIG. 4, and FIG. 6 is a valve plate. 4 is a left side view, FIG. 7 is an explanatory diagram showing the relationship between pressing force and separating force, and FIG. 8 is a longitudinal section similar to FIG. 4 showing the second embodiment of the present invention. 9 are explanatory diagrams showing the relationship between pressing force and separating force in a third embodiment of the present invention. DESCRIPTION OF SYMBOLS 1...Casing, 2...Rotating shaft, 3...Cylinder block, 4...Cylinder, 5...Piston, 6
... Connecting rod, 7t24, 3i... Valve plate, 7A. 24A, 31A... Switching surface, 7B, 24B... Sliding surface, 8, 9... Supply/discharge port, 10... Supply/discharge path, 11
．． 12... Supply/discharge passage, 13.34... Center shaft 7
), 21... Support pin, 22... Tilting member (yoke), 23° 33... Annular groove, 25.35...
Annular protrusion, 26.27, 36.37... Hydraulic chamber, 2
8,29°38.39...Communication path, 30.40...
Oil guide hole. Patent Applicant Hitachi Construction Machinery Co., Ltd. Agent Patent Attorney Kazuhiko Hirose Nao Nakamura Horizontal tube 1 Figure 2 Figure 3 Figure 6 Figure 7 Rotation angle Figure 8

Claims (3)

[Claims] (1) A rotating shaft protruding into the casing, a cylinder block that rotates together with the rotating shaft, and a plurality of cylinders drilled in the axial direction of the cylinder block, each of which can slide into each cylinder. a connecting rod whose one end is swingably supported by the rotating shaft and whose other end is connected to each piston, a switching surface and a surface whose one end side slides into contact with the cylinder block, and the other end side of the connecting rod. and a valve plate serving as a sliding contact surface that slidably contacts the casing,
A diagonal shaft hydraulic rotating machine, wherein the valve plate is formed with a pair of supply and discharge ports that communicate intermittently with the cylinder, and the casing is formed with a suction and discharge passage that is constantly communicated with each supply and discharge port. The valve plate has two hydraulic chambers that suppress the valve plate in opposite directions when hydraulic pressure is introduced, and one hydraulic chamber is connected to the high pressure side of the pair of supply and discharge ports. 4
- a diagonal shaft type hydraulic rotating machine, characterized in that the other hydraulic chamber is in communication with an oil guide hole opened at a top dead center or a bottom dead center position on the switching surface of the valve plate; . (2) The tilting system according to claim (1), wherein each of the hydraulic chambers is located on the outer peripheral surface side of the valve plate and is formed between a tilting member for tilting the valve plate. Shaft type% type% (3) Each of the hydraulic chambers is located on the axial center side of the valve plate and is formed between a center shaft for swingably supporting the valve plate (claim 0). Diagonal axis hydraulic rotating machine.