JPH0458070A - hydraulic rotating machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a hydraulic rotating machine, and particularly to a hydraulic rotating machine suitably used as a swash plate type, oblique shaft type, or radial type hydraulic pump or motor. It concerns the improvement of the machine.

[Prior Art 1] Figures 6 to 10 show a swash plate type hydraulic rotary machine according to the prior art.

As shown in the figure, the hydraulic rotating machine includes a casing 1, a rotating shaft 2 rotatably supported within the casing 1 via a bearing, and a rotary shaft 2 rotatable integrally with the rotating shaft 2. a cylinder block 3 provided in the casing 1 and a distribution valve plate 4 provided between the casing 1 and the cylinder block 3;
and a swash plate (not shown) provided on the other side of the distribution valve plate 4 with the cylinder block 3 in between.

Here, the cylinder block 3 rotates while slidingly contacting the distribution valve plate 4. For this purpose, the end face of the cylinder block 3 is provided with a sliding surface 5, and the distribution valve plate 4 is provided with a sliding surface 5. A switching sliding surface 6 with which the moving surface 5 slides is provided. The sliding surface 5 and the switching sliding surface 6 are connected to the rotating shaft 2.
It is formed by a flat or spherical surface perpendicular to .

Further, the cylinder block 3 includes a plurality of pistons 7 that reciprocate as the cylinder block 30 rotates.
An odd number of cylinders 8 (usually an odd number) are bored at equal intervals around the rotating shaft 2, and each cylinder 8 opens into the sliding surface 5 through a cylinder port 9. On the other hand, on the switching sliding contact surface 6 side of the distribution valve plate 4, there are a pair of layer-shaped intake and exhaust ports 10 and 11.
A plurality of stepped cylindrical cylinder holes 12 are provided on the opposite side of the switching sliding contact surface 6 corresponding to the cylinders 8, and each of these cylinder holes 12 is connected to an intake/discharge port 10.11.
are communicated individually.

On the other hand, a plurality of cylinder holes 13 are provided in the casing 1 so as to coaxially oppose each cylinder hole 12, and each cylinder hole 13 communicates with a pair of suction and exhaust passages 14 and 15.

Furthermore, reference numeral 16 denotes a distribution valve plate pressing member provided between the casing 1 and the distribution valve plate 4 in correspondence with the number of cylinders 8 of the cylinder block 3;
6 constantly presses the distribution valve plate 4 toward the cylinder block 3 and prevents the distribution valve plate 4 from rotating. Here, the distribution valve plate pressing member 16 is a cylindrical pressing piston slidably provided between a cylinder hole 12 formed in the distribution valve plate 4 and a cylinder hole 13 formed in the casing 1. 17, and a spring member 1 provided in the cylinder hole 13 to urge the pressing piston 17 toward the distribution valve plate 4.
8, and an oil passage 19 is formed in the pressing piston 17, communicating the suction/discharge port 10.11 with the suction/discharge passage 14-15.

The hydraulic rotating machine according to the prior art has the above-mentioned configuration, in which the suction and discharge passage 14 is used as a suction passage for the working fluid, and the suction and discharge passage 1 is used as a suction passage for the working fluid.
The operation will be explained when the pump is used as a swash plate type pump by using 5 as a discharge passage.

When the cylinder block 3 is rotationally driven in the direction of the arrow in FIG. do.

During a half-turn when the cylinder port 9 bored in the cylinder block 3 opens to the suction-side suction/discharge port 10, the piston 7 in the cylinder 8 extends in the direction away from the sliding surface 5 side. This results in a suction stroke in which the working fluid is sucked into the cylinder 8 via the suction passage 14, cylinder hole 13, oil passage 19, suction/discharge port 10, and cylinder port 9.

On the other hand, the cylinder port 9 is the suction/discharge port 11 on the discharge side.
During the half-rotation opening, the piston 7 moves forward inside the cylinder 8 toward the sliding surface 5, pressurizing the working fluid inside the cylinder 8 and moving it from the cylinder 8 to the cylinder port 9.
This is a discharge stroke in which the oil is discharged through the suction/discharge port 11, the oil passage 19, the cylinder hole 13, and the discharge passage 15. In this way, the pump action is performed by repeating the suction stroke and the discharge stroke.

While the pump action is performed as described above, high pressure acts between the sliding surface 5 of the cylinder block 3 and the switching sliding surface 6 of the distribution valve plate 4 during the discharge stroke, and this high pressure causes the pressure shown in FIG. As shown, a separating force F is generated in a direction that causes the cylinder block 3 and the distribution valve plate 4 to move away from each other.

On the other hand, the biasing force H by the spring member 18 acts on the distribution valve plate 4 via each pressing piston 17, and the pressure in the cylinder hole 13 into which the high-pressure working fluid flows causes the pressure to rise as shown in FIG. A pressing force R is applied to the distribution valve plate 4 against the cylinder block 3 against the above-mentioned opening force F.

Although the opening force F has the effect of reducing the sliding resistance between the cylinder block 3 and the distribution valve plate 4 and improving mechanical efficiency, if it is too large than the pressing force R, There was a phenomenon in which a gap was generated between the cylinder block 3 and the distribution valve plate 4, and fluid leaked.

Here, the relationship between the above-mentioned separating force F and pressing force R will be explained in detail based on FIGS. 8 to 10.

First, to explain the opening force F, assuming that five cylinders 8 are bored in the cylinder block 3,
When the cylinder block 3 rotates in the direction of the arrow in FIGS. 8 and 9, three of the cylinders 8 are in communication with the high pressure side suction and exhaust ports 11 as shown in FIG. 8. , as shown in FIG. 9, there is a state in which the two cylinders 8 are in communication with the suction/exhaust port 11 on the high pressure side. As a result, the pressure acting area (
The shaded areas in Figures 8 and 9) indicate the state in Figure 8 and the state in Figure 9.
The situation is different from the one shown in the figure. Therefore, as shown by the solid line in FIG. 10, the opening force F during one rotation of the cylinder block 3 is
The magnitude of is changed, and a high separation force generation section A and a low separation force generation section B are generated.

On the other hand, the pressing force R is constituted as the sum of the urging force H of the spring member 18 acting on each pressing piston 17 and the fluid pressure acting on each pressing piston 17 within the cylinder hole 13, and this pressing force R is As shown by the dashed line in the figure, it is constant regardless of the rotation of the cylinder block 3.

Therefore, if the spring constant of the spring member 18, the number of pressing pistons 17, the pressure receiving area, etc. are appropriately designed and the pressing force R is set to be larger than the separating force F, the cylinder block 3
The adhesion between the valve plate 4 and the distribution valve plate 4 can be maintained.

[Problem to be solved by the invention]

However, the hydraulic rotating machine according to the prior art has the following problems.

Since the cylinder block 3 slides on the distribution valve plate 4, in order to make the sliding smooth, the pressing force R should be several percent to ten-odd percent larger than the opening force F. It is necessary to keep it in the same state. Therefore,
If the pressing force R is set based on the high separation force generation section A where a high separation force F is generated, a large difference E will occur between the separation force F and the pressing force R in the low separation force generation section B. Therefore, during high pressure operation, large surface pressure is generated and the cylinder block 3
On the other hand, if the pressing force R is set based on the low separation force generation area B in which the low separation force F is generated, the pressurized oil will not be able to slide smoothly in the high separation force generation area A. This causes an inconvenience in that the volumetric efficiency decreases due to leakage.

Further, as described above, when the pressure acting area changes according to the rotation of the cylinder block 3, the application point on which the separation force F acts also changes accordingly. That is, as shown in Fig. 9, the center of action of the separation force F changes from W-X during the high separation force generation section A, and changes from X to Y when entering the low separation force generation section B. It will shift and fluctuate from Y to Z. On the other hand, since the pressing force R is constant, its center of action is constant. Therefore, the center of action of the pressing force R is W−X
If the center of action of the opening force F is Y-Z, the positions of the center of action will be thicker (shifted), and the moment of the distribution valve plate 4 will not be balanced. is not maintained and an unbalanced force is generated.For this reason, a gap is generated between the sliding surface 5 and the switching sliding contact surface 6, causing excessive leakage, reducing volumetric efficiency, and causing unbalanced force. There was a drawback that contact occurred and sliding resistance increased.

The present invention was developed in view of the problems of the prior art described above, and by keeping the difference between the pressing force and the separating force constant, it prevents leakage of working fluid, improves volumetric efficiency, and improves sliding performance. It is an object of the present invention to provide a hydraulic rotary machine capable of reducing resistance and improving mechanical efficiency.

[Means to solve the problem]

In order to solve the above problems, the configuration adopted by the present invention is as follows:
a casing; a cylinder block provided in the casing to be rotatable about a rotation axis and having a plurality of cylinders in which pistons reciprocate; and a pair of cylinder blocks provided between the casing and the cylinder block; a distribution valve plate having suction/exhaust ports drilled therein; and a plurality of distribution valves provided between a casing and the distribution valve plate in correspondence with the number of cylinders in the cylinder block to press the distribution valve plate toward the cylinder block. In a hydraulic rotating machine comprising a plate pressing member, the casing is provided with a small number of other distribution valve plate pressing members (one in total) for pressing the distribution valve plate toward the cylinder block by supplying pressure oil, and the casing A detection device is provided for detecting the number of cylinders that communicate with the high-pressure side of the pair of suction and discharge ports while the valve rotates, and based on a detection signal from the detection device, the other distribution valve plate pressing member The invention is characterized in that a pressure oil supply device is provided for supplying pressure oil to.

Here, the detection device may include detection members provided on the cylinder block at equal intervals corresponding to the number of cylinders, and a detection member for detecting the presence or absence of the multi-branched detection member.

Further, if the cylinder port angle of each cylinder is α, the port angle of the pair of suction/exhaust ports is β, the expansion angle of the detected member is γ, and the number of pistons is 2, then the detected member has the following formula: γ= They can be provided at equal intervals on the cylinder block with the following relationship: α+β−180”X[1−?].

[Operation] With this configuration, even if the magnitude of the opening force fluctuates, the detection device detects the number of cylinders communicating with the suction/exhaust port on the high pressure side, operates the pressure oil supply device, and maintains the pressure. By guiding the oil to another distribution valve plate pressing device, it becomes possible to change the pressing force in accordance with the opening force. Therefore, there is no large difference between the pressing force and the separating force, and it is possible to smoothly slide between the cylinder block and the distribution valve plate. In addition, as the point of application of the pressing force changes as the point of application of the opening force changes, the moment acting on the distribution valve plate can be maintained in equilibrium, and there is no gap between the distribution valve plate and the cylinder block. It is possible to prevent this from occurring, and also to prevent uneven contact from occurring and increasing sliding resistance.

[Example] Hereinafter, examples of the present invention will be described in detail with reference to FIGS. 1 to 5. Note that the same components as those of the prior art shown in FIG. 6 are given the same reference numerals and their explanations will be omitted.

Reference numeral 21 denotes a casing applied to this embodiment, and the casing 21 has a distribution valve plate pressing member 1 similar to that of the prior art.
Although a plurality of cylinder holes 13 are provided corresponding to the cylinders 8 for accommodating the pressing pistons 17 and spring members 18 constituting the cylinders 6, the casing 21 of this embodiment has cylinder holes 13 located radially outward from the cylinders 13. and a plurality of bottomed cylinder holes 2 on the side facing the distribution valve plate 23, which will be described later.
2.22. The difference is that ... are drilled at equal intervals.

Further, 23 is a distribution valve plate of this embodiment, and the distribution valve plate 23 is also provided with a pair of intake/exhaust ports 10.11 and a number of cylinder holes 12 corresponding to the number of cylinders 8, as in the prior art. However, the distribution valve plate 23 of this embodiment has a casing 2.
The difference is that a flange-shaped pressing piston receiving portion 23A extending in the radial direction is integrally formed on the surface opposite to 1.

24.24. . . . are other distribution valve plate pressing members, and the multi-distribution valve plate pressing member 24 cooperates with each distribution valve plate pressing member 16 according to the prior art to push the distribution valve plate 23 against the cylinder block 3.
It is pressed to the side. Here, the distribution valve plate pressing members 24 at each location are slidably provided in each bottomed cylinder hole 22, and are rod-shaped pressing pistons whose tips abut against the pressing piston receiving portions 23A of the distribution valve plate 23. 25 and
It is composed of a spring member 26 that biases the pressing piston 25 toward the pressing piston receiving portion 23A, and a pressure chamber 27 defined in the bottomed cylinder hole 22 by the pressing piston 25.

Reference numeral 28 denotes a detection device that detects the state in which the three cylinder ports 9 are communicated with the suction/exhaust port 11 on the high pressure side (the state shown in FIGS. 2 and 8). Five members to be detected 29 are arranged in protrusions at equal intervals in a relationship to be described later, corresponding to the number of cylinders 8,
29. In order to detect the presence or absence of the multiplexing detection member 29, the upper switching part between the pair of suction/exhaust ports 10.
The detection member 30 is provided on the y-y line in FIG. As the detection member 30, for example, a photosensor including a light emitting element and a light receiving element is used.

Here, as shown in FIG. 4, α Port angle β of the cylinder port 9: Port angle γ of the suction/exhaust port 10.11: Angle ε of the detected member 29 Three of the cylinder ports 9 are high pressure side suction/exhaust ports. Operating angle φ of the opening force at the moment when it communicates with 11 and becomes the state shown in FIG. 4: If the angle at which the lower cylinder port 9 protrudes from the lower switching part in the state shown in FIG. The cylinder block 3 slowly rotates in the direction of the arrow from the state in which it communicates with the suction and exhaust port 11 on the high pressure side (the state shown in Fig. 3), and the cylinder block 3 reaches the state shown in Fig. 4, with the three cylinder ports 9 communicates with the intake/exhaust port 11, and the cylinder block 3
Considering the process in which the cylinder rotates in the direction of the arrow and the two cylinder ports 9 communicate with the intake and exhaust ports 11 again, γ=α−
φ (1) ε=α+β+φ (2) (where 2 is the number of pistons) Therefore, it can be given as follows based on equations (1) to (3). Note that in the embodiment, γ is set to approximately 34° from equation (4).

As a result, the members 29 to be detected may be arranged at equal intervals at angles that satisfy equation (4) so that their leading edges are on the y-y line at the moment shown in FIG.

Furthermore, 31, 31. ... is another distribution valve pressing member 24
Each electromagnetic switching valve 31 supplies pressure oil to the pressing member 24 based on a detection signal from the detection device 28.
It is supplied to the pressure chamber 27 of. On the other hand, 32 indicates a shuttle valve that selects the high-pressure side pressure oil of the pair of suction/discharge ports 1415, one end port of the electromagnetic switching valve 31 is connected to the shuttle valve 32 and the tank 33, and the other end port is connected to the shuttle valve 32 and the tank 33. is connected to the pressure chamber 27. When the electromagnetic switching valve 31 is not energized, it is moved to the switching position (
(a), the pressure chamber 27 is communicated with the tank 33, and the detection signal from the detection device 28 is input to the solenoid, so that the switching position (b) is established, and the high pressure oil selected by the shuttle valve 32 is switched to the pressure The gas is supplied to the chamber 27, and the distribution valve plate 23 is pressed toward the cylinder block 3 by another distribution valve plate pressing member 24.

The present embodiment is configured as described above, and its operation will be explained next.

Note that when the above-mentioned hydraulic rotary machine is used as a swash plate type pump, the basic operation of the pump itself is the same as that of a conventional hydraulic rotary machine, so a description thereof will be omitted.

However, due to the same reasons as in the prior art, the opening force F is
As shown in the figure, even if the cylinder block 3 fluctuates during one rotation and a high separation force generation area A and a low separation force generation area B occur, in this embodiment, this high separation force generation area A is Detection device 2
8, and based on this detection signal, each electromagnetic switching valve 31
is set to the switching position (b), high-pressure side pressure oil is supplied to the pressure chamber 27 of the other distribution valve plate pressing member 24 via the shuttle valve 32, the pressing piston 25 is displaced to the distribution valve plate 23, and the valve is opened. The pressing force R can be changed following the fluctuation of the force F.

That is, by arranging the same number of detected members 29 of the detecting device 28 at equal intervals as the number of cylinders 8 at the angle of formula (4), and arranging the detecting member 30 on the y-y axis in FIG.
A high opening force generation section A in which three cylinder ports communicate with the suction/exhaust port 11 on the high pressure side is detected, and only in this high opening force generation section A, the other distribution valve plate pressing member 24 is operated. The pressing force R is made large.

As a result, as shown in FIG. 5, even if the pressing force R is set based on the high opening force generating section A in cooperation with the distributing valve plate pressing member 16 according to the prior art, the opening force is low. Even if the pressing force R is set based on the generation section B, the difference E between the separating force F and the pressing force R can always be kept constant. Therefore, large surface pressure does not occur between the cylinder block 3 and the distribution valve plate 26, and the cylinder block 3 and the distribution valve plate 26 can always slide smoothly, and the opening force is lower than the pressing force R. It is possible to prevent a situation in which the force F becomes large and the pressure fluid leaks, resulting in a decrease in volumetric efficiency.

Further, as shown in FIG. 9, the point of application of the separation force F is at W-X in the high separation force generation area A.

In the low separation force generation section B, even if the transition from X to Y changes from Y to Z, the point of application of the pressing force R also changes accordingly, so the action of the separating force F and the pressing force R changes. There is no possibility that the positions of the center points are greatly shifted from each other and the moment balance of the distribution valve plate 26 cannot be maintained and an unbalanced force is generated. Therefore, in this embodiment, a gap is generated between the sliding surface 5 and the switching sliding contact surface 6.
Excessive leakage can be prevented, volumetric efficiency can be improved, and mechanical efficiency can also be improved since it is possible to prevent uneven contact from occurring and increase in sliding resistance.

Although the detection device 28 according to the embodiment has been described as one that detects the number of cylinder ports 9 communicating with the suction/exhaust ports 11 on the high pressure side, the number of cylinder ports 9 communicating with the suction/exhaust ports 10 on the low pressure side The opening force generation section A may be detected, and it is sufficient if the state shown in FIG. 3 (high opening force generation section A) can be detected while the cylinder block 3 is rotating.

In addition, although it has been described that a plurality of other distribution valve plate pressing members 24 are provided on the outer circumferential side of the conventional distribution valve plate pressing member 16 (even number or odd number does not matter), the other distribution valve plate pressing members 24 It is sufficient that the pressing force R can be increased in the high-release force generation section A, and the number thereof may be at least one. In this case, it is arranged in the middle part of the suction/discharge port 11 on the high pressure side. It is preferable to do so.

On the other hand, although it has been described that the pressure chamber 27 of the other distribution valve plate pressing member 24 is supplied with its own pressure during pump operation via the shuttle valve 32, it is also possible to supply pressure oil from another pilot hydraulic pressure source. Good too.

Further, in the embodiment, a photosensor is illustrated as the detection member 30 of the detection device 28, but other rotation detection means such as an electromagnetic pickup coil or a magnetoresistive element may also be used.

Furthermore, although the hydraulic rotating machine according to the present invention is an example of a swash plate type hydraulic pump, it goes without saying that it may be applied to a slanted shaft type hydraulic rotating machine, and the side end surface of the rotor (cylinder block) The present invention may be applied to a radial piston type hydraulic rotary machine having a distribution valve plate on the side, and can be widely applied to pumps and motors having a cylinder block and a distribution valve plate.

〔Effect of the invention〕

The hydraulic rotary machine according to the present invention is as described in detail above, and while the cylinder block rotates while sliding in contact with the distribution valve plate, the opening force is applied depending on the number of cylinders communicating with the suction/exhaust port on the high pressure side. Even if the pressure fluctuates, the pressing force follows the opening force and the difference between them is always kept constant, so the cylinder block and distribution valve plate can always slide smoothly. At the same time, it is possible to prevent pressure oil from leaking in the high-separation-force generating section and improve volumetric efficiency. Furthermore, since the point of application of the pressing force can be moved in accordance with the movement of the point of application of the opening force, the moment balance of the distribution valve plate can be maintained, preventing a gap from forming between the cylinder block and the distribution valve plate, and preventing excessive Since leakage of the material can be prevented, volumetric efficiency can be improved, and since uneven contact is prevented from increasing sliding resistance, mechanical efficiency can be improved.

[Brief explanation of the drawing]

1 to 5 show an embodiment of the present invention, FIG. 1 is a cross-sectional view of a main part of a hydraulic rotating machine according to this embodiment, and FIGS. 2 and 3 show the arrangement of the detection device. FIG. 4 is an explanatory diagram showing the mutual angular relationship between the suction/exhaust port and cylinder port, and FIG. 5 is an explanatory diagram showing the mutual angular relationship between the suction/exhaust port and the cylinder port. FIG. Diagrams showing the relationship with pressing force, FIGS. 6 to 10 show the prior art, FIG. 6 is a cross-sectional view of the main part of a hydraulic rotating machine according to the prior art, and FIG. -■ Line sectional view, Figures 8 and 9 are operation explanatory diagrams showing the relationship between the suction and discharge ports and oil passages of the hydraulic pump in different states, and Figure 10 shows the relationship between the opening force and the pressing force. FIG. 1.21...Casing, 2...Rotating shaft, 3...
Cylinder block, 4, 23...Distribution valve plate, 5...
Sliding surface, 6... Switching sliding surface, 7... Piston, 8...
...Cylinder, 9...Cylinder port, 10.11.
...Suction and exhaust port, 12.13...Cylinder hole, 14.
15... Suction and exhaust passage, 16... Distribution valve plate pressing member, 1
7.25... Pressing piston, 18.26... Spring member, 22... Bottomed cylinder hole, 24... Other distribution valve plate pressing member, 27... Pressure chamber, 28... detection device,
29... Member to be detected, 30... Detection member, 31...
・Solenoid switching valve, 32...Shuttle valve. Patent applicant: Hitachi Construction Machinery Co., Ltd. Representative Patent Attorney Kazuhiko Hirose Figures 1 to 10 ri lφ unai

Claims (3)

[Claims] (1) A casing, a cylinder block provided in the casing to be rotatable about a rotating shaft and having a plurality of cylinders in which pistons reciprocate, and a cylinder block provided between the casing and the cylinder block. , a distribution valve plate in which a pair of suction/exhaust ports are bored, and a plurality of valve plates are provided between the casing and the distribution valve plate corresponding to the number of cylinders in the cylinder block, and the distribution valve plate is pressed toward the cylinder block side. In the hydraulic rotating machine, the casing is provided with at least one other distribution valve plate pressing member that presses the distribution valve plate toward the cylinder block by supplying pressure oil, and the A detection device is provided to detect the number of cylinders that communicate with the high pressure side of the pair of suction and discharge ports while the casing rotates, and the other distribution valve plate is pressed based on a detection signal from the detection device. A hydraulic rotating machine characterized by being provided with a pressure oil supply device that supplies pressure oil to members. (2) Claim (2) wherein the detection device comprises detection members provided at equal intervals in correspondence with the number of cylinders in the cylinder block, and a detection member for detecting the presence or absence of each detection member. The hydraulic rotating machine according to item 1). (3) Assuming that the cylinder port angle of each cylinder is α, the port angle of the pair of suction and exhaust ports is β, the expansion angle of the detected member is γ, and the number of pistons is Z, then the detected member is as follows: γ= The hydraulic rotating machine according to claim 2, wherein the cylinder blocks are provided at equal intervals with a relationship of α+β-180°×[1-1/Z].