JPH05180158A - Variable displacement type slant shaft type hydraulic rotary machine - Google Patents

Abstract

PURPOSE:To surely control a slanting angle highly responsive to a film of high pressure oil by forming a first oil path, in a valve plate, to guide high pressure oil to the lower pressure slidable side of left and right slidable sides and a second oil path, in the same valve plate, to guide high pressure oil from the first oil path to the lower pressure side of a projecting arcuate slidable surface. CONSTITUTION:A first oil path 38 provided in a valve plate 31 has its one side communicating to the discharge side out of supply and ejection ports 36, 37, for example supply and ejection port 37 and the other side opened to the lower side of a slidable surface 34 at the supply and ejection port 36 side on the suction side. A second oil path 39 in the valve plate 31 has one side communicating to the first oil path 38 and the other side opened to a projecting arcuate slidable surface 33 at the left lower side of the lower pressure side as viewed from the rear surface side. Thus, a portion of high pressure oil in the supply and ejection port 37 is adapted to act on the slidable side 34 by the first oil path 38 and on the left lower side of the projecting arcuate slidable surface 33 by the second oil path 39.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable displacement oblique shaft type hydraulic rotary machine which is preferably used as a hydraulic pump or hydraulic motor in, for example, civil engineering / construction machinery, general machinery, etc., and more particularly to a sector type tilting mechanism. And a variable-capacity oblique-shaft hydraulic rotary machine.

[0002]

2. Description of the Related Art Here, a conventional variable displacement type oblique shaft type hydraulic rotating machine will be described with reference to FIGS.

In the figure, reference numeral 1 denotes a casing, and the casing 1
Is a cylindrical casing body 1A, and the casing body 1A
And a head casing 1B fixed to the end surface of the head. Reference numeral 2 denotes a rotary shaft having a rotary axis AA rotatably supported on one side of the casing body 1A via bearings 3 and 3. A drive disk 2A is provided at the tip of the rotary shaft 2 inside the casing body 1A. It is provided integrally.

Reference numeral 4 denotes a cylinder block which rotates together with the rotary shaft 2. The cylinder block 4 is provided with a center shaft insertion hole 5 along a tilt axis BB serving as a central axis and an axis BB. A plurality of cylinders (usually an odd number such as 5, 7, etc.) arranged on the circumference centered on the axis and extending in the axial direction are bored, and a valve plate 11 side described later is provided. The end surface is a concave spherical sliding surface 7.

Reference numeral 8 denotes a center shaft which is inserted through a center shaft insertion hole 5 for centering the cylinder block 4. One end of the center shaft 8 has a rotation axis line with respect to the drive disk 2A via a spherical joint portion 8A. A
-A is swingably connected on A, and the other end is a valve plate 1 described later.
1 is inserted in the central hole 11A. A spring 9 is located inside the cylinder block 4 and stretched between the cylinder block 4 and the center shaft 8. The spring 9 applies an initial load to the valve plate 11 side of the cylinder block 4. ..

The pistons 10, 10 ... Are reciprocally inserted in the respective cylinders 6 of the cylinder block 4, and one end side of each piston 10 is provided with a spherical joint portion 10A. Is swingably connected to the drive disk 2A.

Reference numeral 11 denotes a valve plate made of a rectangular plate material, and the front side of the valve plate 11 is a convex spherical switching surface 1 rotatably slidably contacting a concave spherical sliding surface 7 of the cylinder block 4.
2, the rear side becomes a convex arcuate sliding surface 13 that slides on a concave arcuate tilting sliding surface 20 described later, and the left and right side surfaces are in sliding contact with tilting guide walls 21 and 22 described later. Sliding side 1
It is 4, 15.

Reference numerals 16 and 17 denote a pair of supply / discharge ports formed on the valve plate 11. One side of each of the supply / discharge ports 16 and 17 is connected to each cylinder 6 intermittently by the rotation of the cylinder block 4. The arc-shaped openings 16A and 17A are formed, and the other side is the oil supply / discharge passage 1 formed in the head casing 1B.
The rectangular openings 16B and 17B are in continuous communication with 8 and 19 regardless of the tilted position (see FIGS. 9 and 10).

On the other hand, 20 is a concave arcuate tilt sliding surface formed on the inner surface of the head casing 1B.
On both sides of 0, tilt guide walls 21 and 22 with which the sliding side surfaces 14 and 15 of the valve plate 11 are in sliding contact are formed. Then, the convex arcuate sliding surface 13 of the valve plate 11 slides on the tilt sliding surface 20, and the cylinder block 4 tilts together with the valve plate 11 to make the capacity of the hydraulic rotary machine variable. There is.

Further, 23 is a tilting mechanism provided in the head casing 1B for varying the capacity of the hydraulic rotary machine. The tilting mechanism 23 includes a servo cylinder 24 formed in the head casing 1B, A servo piston 25 slidably provided in the servo cylinder 24, and a swing pin 26 having a spherical portion fixed to the servo piston 25 and slidably fitted in the central hole 11A of the valve plate 11. The servo piston 25 is slidably displaced by the pressure oil supplied to the servo cylinder 24 through the oil passages 27A and 27B, and the valve plate 11 and the cylinder block 4 are tilted through the swing pin 26. It has become.

The hydraulic rotary machine according to the prior art has the above-mentioned structure, and the operation when it is used as a hydraulic pump will be described.

First, the tilting mechanism 23 tilts the valve plate 11 together with the cylinder block 4. Therefore, the oil passage 2
7A supplies pressure oil for control to the servo cylinder 24,
The servo piston 25 is displaced. As a result, the swing pin 26 is displaced together with the servo piston 25, and the valve plate 11 also slides on the concave arcuate tilt sliding surface 20. As a result, the cylinder block 4 also centers on the spherical joint portion 8A of the center shaft 8. As a result, the state becomes as shown in FIG.

Next, a drive source (not shown) such as an engine is rotated to rotationally drive the rotary shaft 2 in the direction shown by the arrow in the figure. At this time, since the drive disk 2A of the rotary shaft 2 and the piston 10 are connected via the spherical joint 10A, the cylinder block 4 is rotated following the rotation of the rotary shaft 2. The tilt axis BB of the cylinder block 4 is inclined by an angle α with respect to the rotation axis AA, and the rotation of the cylinder block 4 causes the piston 10 to reciprocate in the cylinder 6.

At this time, assuming that the supply / discharge port 16 is a supply / discharge port on the suction side (low pressure side) and the supply / discharge port 17 is a supply / discharge port on the discharge side (high pressure side), the cylinder 6 is the supply / discharge port 1.
While communicating with one of the ports 6 and 17 and the port 16 on the low pressure side, the suction stroke in which the piston 10 extends extends,
On the other hand, while the cylinder 6 is in communication with the high-pressure side port 17, the piston 10 has a discharge stroke that contracts, and the pumping action is performed by repeating the suction stroke and the discharge stroke.

[0015]

By the way, in the above-mentioned prior art, during the operation of the pump, the hydraulic reaction force of the piston 10 is applied to the high pressure side of the cylinder block 4 by the pressing force R.
The pressing force R acts in a direction orthogonal to the convex spherical switching surface 12 of the valve plate 11. On the other hand, the pressing reaction force Z of the concave arcuate tilting sliding surface 20 is generated facing the convex arcuate sliding surface 13 of the valve plate 11. At this time, since the switching surface 12 is formed in a convex spherical shape, a combined lateral thrust S due to the composition of the pressing force R and the pressing reaction force Z is generated as a lateral component force on the high pressure side of the valve plate 11. The combined lateral thrust S acts in the direction of the arrow in FIG. 8 so as to be displaced toward the low pressure side with respect to the valve plate 11. Thus, the sliding side surface 14 located on the low pressure side of the valve plate 11 is pressed against the tilt guide wall 21 on the low pressure side.

On the other hand, when the cylinder block 4 rotates, the cylinder block 4 rotates while its concave spherical sliding surface 7 is in sliding contact with the convex arcuate sliding surface 13 of the valve plate 11, A rotational moment M is generated in the valve plate 11 in the direction of the arrow in FIG. 9 due to the rotational frictional force between them.

As described above, in the hydraulic rotary machine according to the above-mentioned prior art, the combined lateral thrust S presses the sliding side surface 14 on the low pressure side of the valve plate 11 against the tilt guide wall 21, and the cylinder block. Due to the rotational moment M generated from the rotational friction sliding of No. 4, the lower side of the sliding side surface 14 is strongly pressed against the tilt guide wall 21 on the low pressure side.

Therefore, the tilt guide wall 21 is attached to the sliding side surface 1.
The surface pressure received from No. 4 becomes high, and an oil film breaks between the tilt guide wall 21 and the sliding side surface 14 to make metal contact. As a result, a galling phenomenon occurs between the tilt guide wall 21 and the sliding side wall 14, and the slidability of the sliding side surface 14 of the valve plate 11 with respect to the tilt guide wall 21 deteriorates.

The theoretical resultant force of the pressing force R of the average hydraulic reaction force by each piston 10 is at the point C as shown in FIG. 9, but the valve plate 11 and the cylinder block 4 rotate. Due to the relationship between the rotational moment M generated by frictional sliding and the pressure distribution, the theoretical force resultant point C is shifted downward to the point C ′. Since the pressing force R of the valve plate 11 is received centering on the resultant force application point C ′, the portion of the convex arcuate sliding surface 13 located below the sliding side surface 15 side is the arcuate sliding surface 20. Will be strongly pressed against.

Here, an oil film of high pressure oil is formed between the convex arcuate sliding surface 13 and the concave arcuate tilting sliding surface 20 near the rectangular opening 17B on the discharge side (high pressure side). It is formed in a wide range, and the high pressure oil exerts a breaking force to balance the pressing force R.

On the other hand, the rectangular opening 16B on the suction side
Although an oil film of suction oil is formed between the convex arcuate sliding surface 13 and the concave arcuate tilting sliding surface 20 in the vicinity, since no pressure acts on this suction oil, the oil film The range is narrow and no opening force is generated.

Therefore, the rectangular opening 1 on the suction side is formed.
Between the portion of the convex arcuate sliding surface 13 near 6B and the concave arcuate tilting sliding surface 20, the portion in which the oil film is cut off becomes large, and that portion makes metal contact. As a result, a galling phenomenon occurs between the concave arcuate tilting sliding surface 20 and the convex arcuate sliding surface 13, the surface roughness increases, and the convex arcuate sliding surface with respect to the concave arcuate tilting sliding surface 20 increases. There is a problem that the slidability of the moving surface 13 deteriorates.

Therefore, for the reason described above, the sliding resistance of the valve plate 11 with respect to the concave arcuate tilt sliding surface 20 becomes high,
A high load is applied to the movement of the servo piston 25 of the tilting mechanism 23, and a smooth tilting operation of the valve plate 11 is prevented. For this reason,
Even if pressure oil is supplied to the servo piston 25, the responsiveness of the tilting operation deteriorates, and it becomes impossible to perform an appropriate control of the angle α (tilt angle control). Further, in the worst case, between the sliding side surface 14 of the valve plate 11 and the tilt guide wall 21, and between the convex arc-shaped sliding surface 13 and the concave arc-shaped tilt sliding surface 2.
There is a problem in that the zero and the zero adhere to each other, and the tilting operation of the valve plate 11 cannot be performed.

The present invention has been made in view of the problems of the prior art as described above, and it is possible to smoothly tilt the valve plate by using the high pressure oil supplied to and discharged from the valve plate. An object is to provide a shaft type hydraulic rotating machine.

[0025]

In order to solve the above-mentioned problems, the feature of the structure adopted by the present invention is that the valve plate has a high pressure from a supply / discharge port on the high pressure side of the pair of supply / discharge ports. A first oil passage that guides oil to the sliding side surface on the low pressure side of the left and right sliding side surfaces is formed, and the valve plate communicates with the first passage and slides in a convex arc shape. The second oil passage for guiding the high-pressure oil from the first oil passage is formed in the low-pressure side portion of the surface.

Further, the opening of the convex arcuate sliding surface of the second oil passage has the valve X when the horizontal direction from the valve plate center is the XX axis and the vertical direction is the YY axis. It is preferable that the plate is formed so as to be located in the quadrant on the lowest pressure side when viewed from the back side of the plate.

[0027]

With the above structure, when pressure oil is supplied and discharged through the pair of supply and discharge ports of the valve plate, a part of the high pressure oil flowing through the supply and discharge port on the high pressure side is passed through the first oil passage. It is possible to prevent the oil film from being broken between the sliding side surface and the tilt guide wall by guiding it to the sliding side surface located on the low pressure side.

Further, the second oil passage communicating with the first oil passage guides high-pressure oil between the convex arcuate sliding surface and the concave arcuate tilting sliding surface to cause the convex arcuate sliding surface. It is possible to prevent oil film breakage between the surface and the concave arcuate sliding surface.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below with reference to FIGS. 1 to 6, taking a case where a hydraulic rotary machine is used as a hydraulic pump as an example. It should be noted that the same components as those of the above-described conventional technique are designated by the same reference numerals, and the description thereof will be omitted.

In the figure, reference numeral 31 denotes a valve plate of this embodiment in which a central hole 31A penetrating through the central portion is formed by a rectangular plate material, and the valve plate 31 has a concave spherical surface of the cylinder block 4 on the front side. A convex spherical switching surface 3 rotatably in sliding contact with the sliding surface 7.
2, the rear surface is a convex arcuate sliding surface 33 that slides on the concave arcuate tilting sliding surface 20, and the left and right side surfaces are sliding side surfaces 34 and 35.

Reference numerals 36 and 37 denote a pair of supply / discharge ports formed in the valve plate 11. One side of each of the supply / discharge ports 36, 37 is connected to each cylinder 6 intermittently by the rotation of the cylinder block 4. The arc-shaped openings 36A and 37A are provided, and the other side is provided with the oil supply / drain passage 1 formed in the head casing 1B.
The rectangular openings 36B and 37B are in continuous communication with 8 and 19 regardless of the tilted position.

Here, for the sake of explanation, as shown in FIG. 3, the axis extending horizontally from the center with respect to the valve plate 31 is XX, and the axis extending vertically is YY.

Reference numeral 38 denotes a first oil passage provided in the valve plate 31, and one side of the first oil passage 38 has a supply / discharge port 3 on one side.
6, 37 communicates with, for example, the supply / discharge port 37 on the discharge side (high pressure side), and the other side is opened below the sliding side surface 34 on the side of the supply / discharge port 36 that is the suction side (low pressure side). Has been formed.

Reference numeral 39 denotes a second oil passage provided in the valve plate 31, one side of the second oil passage 39 communicates with the first oil passage 38, and the other side has a rear surface shown in FIG. When viewed from the side, it is formed so as to open to the convex arcuate sliding surface 33 in the third quadrant (lower left side in FIG. 3), which is the low-pressure side.

Therefore, the first oil passage 38 according to the present embodiment.
Part of the high-pressure oil of the supply / discharge port 37 acts on the sliding side surface 34, and the second oil passage 39 causes the convex arc-shaped sliding surface 33 to move.
Act on the third quadrant of.

The variable displacement oblique shaft type hydraulic rotating machine according to this embodiment is constructed as described above, but the operation itself when it is used as a hydraulic pump is no different from that of the prior art.

However, in the variable displacement oblique shaft type hydraulic rotating machine according to this embodiment, the lower side of the sliding side surface 34 of the valve plate 31 is generated by the rotational friction sliding of the valve plate 31 and the cylinder block 4. Although it is strongly pressed against the tilt guide wall 21 by the rotation moment M, high pressure oil is supplied from the high pressure side supply / discharge port 37 by the first oil passage 38 to this portion, and this high pressure oil is caused to act on the tilt guide wall 21. An oil film can be formed between 21 and the sliding side surface 34. Then, it is possible to reliably prevent metal contact between the tilt guide wall 21 and the sliding side surface 34, and effectively prevent deterioration of slidability of the sliding side surface 34 with respect to the tilt guide wall 21. be able to.

The rectangular opening 36B on the suction side is also provided.
Since high-pressure oil is supplied between the portion of the convex arcuate sliding surface 33 in the vicinity and the concave arcuate tilting sliding surface 20 by the second oil passage 39, the oil film formed by this high-pressure oil is projected. It is formed between the arcuate sliding surface 33 and the concave arcuate tilting sliding surface 20. Then, between the portion of the convex arcuate sliding surface 33 near the rectangular opening 36B on the suction side and the concave arcuate tilting sliding surface 20, a weak opening force is generated by the high pressure oil, and the concave opening is generated. This surely prevents the slidability of the convex arcuate sliding surface 33 from the arcuate tilting sliding surface 20 from decreasing.

Therefore, the high pressure oil supplied from the oil passages 38 and 39 causes the convex arcuate sliding between the sliding side surface 34 and the tilt guide wall 21 and near the rectangular opening 36B on the suction side. An oil film having pressure is formed between the surface 33 and the concave arcuate tilting sliding surface 20 to prevent an increase in sliding resistance of the valve plate 11 with respect to the concave arcuate tilting sliding surface 20. The valve plate 11 can always perform a smooth tilting operation with respect to the concave arc-shaped tilting sliding surface 20, and the tilting mechanism 23 can reliably perform tilting angle control with good responsiveness. it can.

Then, between the sliding side surface 14 of the valve plate 11 and the tilt guide wall 21, which has occurred in the worst state in the prior art, and the convex arcuate sliding surface 13 and the concave arcuate tilting slide. Surface 2
It is possible to surely prevent adhesion between the valve plate 11 and 0 and effectively prevent tilting of the valve plate 11.

In the above embodiment, each oil passage 38, 3
Although the opening portion of 9 is formed as a small diameter hole, the present invention is not limited to this, and as shown in FIG. 4, for example, an oval static pressure pocket 41 at the opening portion of the second oil passage 39, and FIG. You may make it form the static pressure pocket 42 of a perfect circle shape as shown, and the static pressure pocket 43 of a rectangular shape as shown in FIG. 6, and select arbitrary shape by the number of each cylinder 6 of the cylinder block 4. This makes it possible to adjust the force generated from the oil film formed between the sliding surfaces.

Further, in the above-mentioned embodiment, the case where the variable displacement oblique shaft type hydraulic rotating machine is operated as a hydraulic pump has been described as an example, but the present invention is not limited to this, and it is operated as a hydraulic motor. Can also be used. In this case,
One side of the first oil passage 38 formed in the valve plate 31 is the discharge side (high pressure side) when the rotating shafts 2 are rotated in the same direction.
Of the second oil passage 39 is formed so as to communicate with the supply / discharge port 36 of the other side and open at the other side to the sliding side surface 35 of the suction side (low pressure side) of the supply / discharge port 37, and the second oil passage 39 has one side of the first oil. The first that communicates with the passage 38 and becomes the low-pressure side when the other side is viewed from the back side
It may be formed so as to open to the convex arcuate sliding surface 33 in the quadrant (on the upper right side in FIG. 3).

[0043]

As described in detail above, in the variable displacement oblique shaft type hydraulic rotating machine according to the present invention, in order to utilize the pressure oil on the high pressure side flowing through the supply / discharge port of the valve plate, A first oil passage for guiding high-pressure oil from the supply / discharge port on the high-pressure side of the pair of supply / discharge ports to the sliding side surface on the low-pressure side of the left and right sliding side faces is formed, and the first oil passage is formed. Since the second oil passage communicating with the oil passage of No. 1 and guiding the high pressure oil from the first oil passage is formed in the low pressure side portion of the convex arcuate sliding surface, the supply / discharge port on the high pressure side is formed. A part of the flowing high-pressure oil is guided between the sliding side surface on the low-pressure side and the tilt guide wall via the first oil passage, and the convex arcuate sliding surface and the concave surface are recessed via the second oil passage. An oil film is formed between the sliding side surface and the tilting guide wall, and between the convex arcuate sliding surface and the concave arcuate tilting sliding surface by guiding it between the arcuate tilting sliding surface. By the action of the oil film of this high-pressure oil, the galling phenomenon due to the metal contact between the sliding surfaces is prevented, and the valve plate is always tilted smoothly with respect to the concave arc-shaped tilting sliding surface. it can. Therefore, the tilting mechanism can surely perform tilting angle control with good responsiveness.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a variable displacement oblique shaft type hydraulic rotating machine according to an embodiment of the present invention.

FIG. 2 is a plan view of the valve plate according to the present embodiment as viewed from the front side.

FIG. 3 is a plan view of the valve plate according to the present embodiment viewed from the back side.

FIG. 4 is a plan view showing a modified example of the opening portion of the second oil passage according to the present embodiment.

FIG. 5 is a plan view similar to FIG. 4, showing a modified example of the opening portion of the second oil passage according to the present embodiment.

FIG. 6 is a plan view similar to FIG. 4, showing a modified example of the opening portion of the second oil passage according to the present embodiment.

FIG. 7 is a vertical sectional view showing a variable capacity oblique shaft type hydraulic rotating machine according to the prior art.

8 is a cross-sectional view as seen from the direction of arrows VIII-VIII in FIG. 7.

FIG. 9 is a plan view of a valve plate according to a conventional technique as viewed from the front side.

FIG. 10 is a plan view of a valve plate according to the related art as viewed from the back side.

[Explanation of symbols]

 1 Casing 1B Head Casing 2 Rotating Shaft 4 Cylinder Block 6 Cylinder 7 Concave Spherical Sliding Surface 8 Center Shaft 10 Piston 18, 19 Oil Supply / Discharge Passage 20 Concave Circular Tilting Sliding Surface 21, 22 Tilt Guide Wall 23 Tilt Rolling mechanism 31 Valve plate 32 Convex spherical switching surface 33 Convex arcuate sliding surface 34, 35 Sliding side surface 36, 37 Supply / discharge port 38 First oil passage 39 Second oil passage

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yukihiro Motozawa 650 Jinrachi-cho, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery Co., Ltd. Tsuchiura factory (72) Inventor Tetsuya Sakairi 650 Kintate-cho, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery Co., Ltd. Ceremony Company Tsuchiura Factory

Claims (2)

[Claims] 1. A casing, a rotary shaft rotatably supported by the casing, a rotary shaft provided in the casing so as to rotate together with the rotary shaft, and a plurality of cylinders bored in the axial direction. A cylinder block in which a concave spherical sliding surface is formed on one end surface in the axial direction of each cylinder, and one end side is swingably connected to an axis center of the rotation shaft, and an axis extends along the rotation center axis of the cylinder block. Direction, a center shaft inserted in each direction, a piston that is reciprocally inserted into each cylinder of the cylinder block, one end of which is swingably connected to a rotating shaft, and a front surface of which is a concave spherical slide of the cylinder block. A valve plate that is a convex spherical switching surface that is in sliding contact with the surface and a convex arcuate sliding surface on the back side, and left and right side surfaces are sliding side surfaces, and a convex spherical surface on one side formed on the valve plate Open the switching surface and Guides the convex arcuate sliding surface of the valve plate and a pair of supply / exhaust ports that communicate with each cylinder intermittently and open on the convex arcuate sliding surface on the other side to communicate with the supply / discharge passage of the casing. Therefore, a concave arcuate tilt sliding surface having tilt guide walls slidably contacting the respective sliding side surfaces of the valve plate is formed on the head side of the casing, and is provided on the head side of the casing. In a variable displacement oblique shaft type hydraulic rotating machine comprising a cylinder block and a tilting mechanism for tilting the valve plate along the tilt sliding surface, the valve plate has a high pressure of a pair of supply and discharge ports. Forming a first oil passage for guiding the high pressure oil from the supply / discharge port on the side to the sliding side surface on the low pressure side of the left and right sliding side surfaces, and forming the first passage on the valve plate. The first low pressure side of the convex arcuate sliding surface communicating with the first
A variable capacity oblique shaft type hydraulic rotating machine, characterized in that a second oil passage for guiding high-pressure oil from the oil passage is formed. 2. The opening to the convex arcuate sliding surface of the second oil passage is defined when the horizontal direction from the valve plate center is the XX axis and the vertical direction is the YY axis. The variable displacement oblique shaft type hydraulic rotating machine according to claim 1, wherein the variable capacity oblique type hydraulic rotating machine is formed so as to be located in a quadrant that is the lowest pressure side when viewed from the back side of the valve plate.