JPS59150985A - Radial piston type hydraulic rotary machine - Google Patents

Abstract

PURPOSE:To permit the optimum automatic adjustment of the clearance of a sliding part by a method wherein pushing pistons, abutted against the inner wall of a casing, are provided in respective sub-cylinders provided in the axial direction of the rotor and the pressing forces of the rotor against a distributing shaft are set properly in respective sub-cylinders. CONSTITUTION:An engaging part between the distributing shaft 21 and the rotor 22 is formed into a tapered shape, a plurality of sub-cylinders 24 are provided in the axial direction of the rotor 22 and the pushing pistons 25, generating thrusts into the direction of abutting the pushing pistons against the casing 1A by flowing high pressure operating oil in the cylinder 12 into the sub-cylinders 24 through an oil path 27, are provided in respective sub-cylinders 24. According to this method, the sliding clearance between the distributing shaft 21 and the rotor 22 may be adjusted by setting the pushing force of the rotor against the distributing shaft 21 by the sub-cylinders, therefore, leakage of the operating oil from said clearance may be minimized and the volumetric efficiency may be improved. When said sliding part is worn, the rotor 22 may be displaced in accordance with the abrasion of the sliding part, therefore, the clearance of the sliding part may be adjusted automatically so as to become constant substantially.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydraulic rotary machine that is used as a radial piston hydraulic pump and a hydraulic motor that supply and discharge hydraulic oil to and from cylinders via a distribution shaft.

Figure 1 shows a hydraulic rotary machine according to the prior art.

In the figure, reference numeral 1 indicates the main casing of the hydraulic rotating machine, which is composed of a casing iVi, a front casing IA, a carrier casing IB, and a cam portion IC held between the casings IA and IB. 2 shows a distribution shaft that is integrally formed with the rear casing IB and protrudes into the casing 1; the distribution shaft 2 has suction and discharge passages 3 and 4 bored in its axial direction; The suction and discharge passages 3 and 4 are formed by suction and discharge boats 5 and 6 formed on the outer peripheral surface of the distribution shaft 2.
It communicates with

7 indicates a rotor installed in the casing 1, and the rotor 7
A fitting recess 7A into which the distribution shaft 2 is fitted is provided at the center of rotation of the
is formed, and by fitting the distribution shaft 2 into the fitting recess 7A', the rotor 7 is configured to be rotatably supported by the distribution shaft 2.

In order to rotatably connect the rotor 7 and the distribution shaft 2, the distribution shaft 2 is formed into a cylindrical shape, and the fitting recess 7A of the rotor is formed into a cylindrical shape corresponding to the outer periphery of the distribution shaft 2. has been done. Therefore, the fitting recess 7 of the rotor 7
A is rotated while sliding on the distribution shaft 2. Furthermore, in order to prevent the rotor 7 from being displaced in the axial direction of the distribution shaft 2, projecting wall portions 8 and 9 are provided on the inner wall of the front casing IA and the inner wall of the rear casing IB, respectively. Both sides of the rotor 7ii are the projecting wall portions 8
．． It is positioned in the axial direction by being held between the projecting walls 8 and 9, and rotates while sliding on the projecting walls 8 and 9. In addition, the rotor 7 has a front casing IA.
A protrusion 7B is formed that protrudes outward from the front casing 7B, and a sealed bearing 1o is interposed between the protrusion 7B and the front casing IA. The protruding portion 7BK is provided with a shaft insertion portion 11 that allows insertion of a rotating shaft (input shaft when used as a hydraulic pump, output shaft when used as a hydraulic motor).

Next, reference numeral 12 indicates a plurality of cylinders (only one is shown in the drawing) bored in the radial direction of the rotor, and each cylinder 12 is intermittently communicated with the suction/exhaust port 5.6 through a communication passage 13. It looks like this. A piston 14 is slidably provided in each cylinder 12, and a shoe 15, which serves as a guide member, is swingably connected to the tip of the canyon piston 14. Further, on the inner peripheral wall of the cam portion IC, a cam surface 1 having a center eccentrically from the distribution shaft 2 is provided.
6 is formed, and the shoe 15 is slidably guided on the cam surface 16-F.

In addition, a shoe guide provided on the 17.17-it power arm IC is shown.

The hydraulic rotary machine according to the prior art has the above-mentioned structure, and its operation will be explained below.

First, by attaching a rotating shaft to the shaft insertion part 11 and rotating the rotating shaft when using it as a hydraulic pump,
In addition, when used as a hydraulic motor, the rotor 7 can be
Rotate. As a result, the shoe 15 slides along the cup surface 16, and the piston 14 connected to the shoe 15 is caused to fully reciprocate within the cylinder 12.

Incidentally, since the distribution shaft 2 is fitted into the fitting recess 7A of the rotor 7, the rotor 7 slides on the distribution shaft 2 when the rotor 7 rotates. First, in order to perform this sliding smoothly, it is necessary to form a predetermined gap between the outer circumferential surface of the distribution shaft 2 and the fitting recess 7A of the rotor 7. (2) During the operation of a hydraulic rotating machine, the distribution shaft 2 may undergo thermal expansion due to an increase in the temperature of the hydraulic oil. In order to ensure smooth sliding between the rotor 7 and to prevent cracking or explosions, a 1r opening 30 is provided between the outer circumferential surface of the distributor @2 and the fitting recess 7A. A relatively large gap of about 50 μm is formed.

However, if the above-mentioned sliding gap is formed between the distribution shaft 2 and the fitting recess 7A, there is a drawback that the following disadvantages occur. First, when the hydraulic rotary machine is operated under high pressure, leakage of hydraulic oil from the gap increases, resulting in a decrease in volumetric efficiency. Second, when used as a hydraulic motor, when an external force acts on the hydraulic motor, the hydraulic oil in the cylinder 12 is discharged through the above-mentioned gap, causing the hydraulic motor to rotate and causing slippage. . Therefore, if the gap is large, the amount of slip increases, and there is also the drawback that controllability as an acticoator is poor. Third, when a hydraulic rotary machine is operated for a long period of time, the sliding part between the distribution shaft 2 and the rotor 7 wears out, and the gap between them becomes extremely large, increasing the amount of hydraulic oil leaking. However, it also has the disadvantage of further reducing volumetric efficiency.

In view of the above points, the present invention provides a radial piston type hydraulic rotating machine that can automatically adjust the sliding part clearance between the distribution shaft and the rotor to an optimum clearance. It was done for a purpose.

The configuration adopted by the present invention to achieve the above object is as follows:
The fitting portion between the distribution shaft and the rotor is formed into a tapered shape, and the rotor has a plurality of cylinders in the axial direction of the rotor that open toward the side surface opposite to the fitting portion with the distribution shaft. A pushing piston that makes sliding contact with the inner wall of the casing is inserted into each side cylinder, and an oil passage is bored in the rotor to communicate between each of the sub-cylinders and the cylinder provided in the rotor. Its characteristics are:

Embodiments of the present invention will be described below with reference to FIGS. 2 and 3. In this figure, elements having the same structure as those in FIG. 1 are given the same reference numerals and their explanations will be omitted. 2
11 shows a distribution shaft provided integrally with the casing IB, and the distribution shaft 21 is not formed in a cylindrical shape, but in the shape of a truncated cone. On the other hand, the rotor 22 has a distribution shaft 2
A fitting recess 22A into which the core fitting 1 is fitted is formed, and the core fitting recess 22A is formed in a tapered shape having an angle of 4q to match the outer diameter of the distribution shaft 21. The distal end surface of the distribution shaft 21 is spaced apart from the bottom wall of the fitting recess 22A, and 24 is bored in the axial direction of the rotor 22 so that a chamber 23 is formed therebetween. distribution axis 2
It shows a sub-cylinder that opens on the side of I11 opposite to the fitting part 11 with 1, and has a skeleton cylinder (1 cylinder IJ cylinder 24 is installed in the same number as cylinders 12 bored in the radial direction of rotor 22). ;'l only shows one item). A pushing piston 25 is slidably inserted into the six sub-cylinders 24, and the tip end surface of each pushing piston 25 has an irises.
1 cylinder 24 force \ protrude front casing IA
It is configured so that it can slide into sliding contact with a sliding surface portion 26 formed on the inner wall. Moreover, the rotor 22 has
,) An oil passage 27 is bored to communicate between the cylinder 12 and the sub-cylinder 24, and the oil passage 27 allows high-pressure hydraulic oil in the cylinder 12 to flow into the sub-cylinder 24. ing. By flowing high-pressure hydraulic oil into the Mllll cylinder 24 in this way, a thrust force is applied to the pushing piston 25 in the right direction in the figure, νI'', that is, in the direction of contacting the front casing IA that constitutes the casing 1 as a fixed member. The rotor 22 is generated as a reaction force.
can be pressed to the left in the figure. Furthermore, a spring 28 is installed in the sub-cylinder 24 between the bottom wall of the sub-cylinder 24 and the end face of the pushing piston 25, and the spring 28 applies a pushing force of the rotor 22 to the right in the figure. It is about to be strengthened. Furthermore, a communication hole 29 is bored in the push piston 25 between the push piston 25 and the sliding surface portion 26 of the front casing IA, and a communication hole 29 is formed to supply high pressure hydraulic oil in the cylinder 24. Lubricating oil is supplied between the pushing piston 25 and the sliding surface portion 26 through the communication hole 29, so that sliding therebetween is performed smoothly. In addition, 30 in the figure is an oil passage provided at the connection part with the protruding part 22B of the rotor 22, and the kernel oil passage 30 drains the hydraulic oil in the chamber 23 to the drain formed in the space between the casing 1 and the rotor 22. It is designed so that it can flow out into the oil storage section.

The radial piston hydraulic rotating machine according to the present invention has the above-described configuration, and its operation as a hydraulic rotating machine itself is not particularly different from that of the prior art described above.

Then, when the hydraulic rotary machine is operated, the suction port 5,
6) 75f becomes high pressure, and this pressure acts on the fitting portion 0322A of the rotor 22. Since the fitting recess 22A is formed in the shape of a tenon, the rotor 22 is pressed to the right in the figure due to this tenon shape, and the separating device 1i11121 force/removal force is exerted by a separation force. acts on the rotor 22.On the other hand, each cylinder 24 bored in the rotor 22 has a cylinder 12
High-pressure hydraulic oil is supplied through the oil passage 27 within the push piston 25, and a spring 28 is installed between the end face of the push piston 25 and the bottom wall of the sub-cylinder 24.
5 is pushed to the right in the figure by the action of the hydraulic pressure inside the bolt 11 and the non-da 24 and the force of the spring 28. Since this is a fixed member of the front casing IAUte that slides with the pusher 1b screw y25, the hydraulic pressure in the sub-cylinder 24 and the biasing force of the spring 28 act on the counter-rotating rotor 22, and the cough rotor 22 A pressing force is applied to the left side in the figure, which causes the distribution shaft 21 to fit into the fitting recess 22A of the bottle 11. Here, since both the outer peripheral surface of the distribution shaft 21 and the fitting recess 22A of the rotor 22 are formed in a tapered shape, when the rotor 22 is displaced to the right in the figure, the distance between the rotor 22 and the distribution shaft 21 is When the sliding part gap increases and the rotor 22 is displaced to the left in the figure, the sliding part gap decreases. Therefore, if the diameter of the pushing piston 25 or the biasing force of the spring 28 is set so that the pushing force acting on the rotor 22 is balanced with the repelling force acting on the rotor 22, The sliding clearance of the rotor 22 is maintained at an appropriate level without impairing the smooth sliding rotation of the rotor 22.
Furthermore, leakage of hydraulic oil from the gap can be minimized. The pushing piston 25 is rotated together with the rotor 22 while being pressed against the sliding surface 26 formed on the inner wall of the front casing IA. Hydraulic oil in the sub-cylinder 24 is supplied to the part through the communication hole 29, and this hydraulic oil acts as lubricating oil, allowing the pushing piston 25 to smoothly slide into sliding contact with the sliding surface part 26. It will be done.

By the way, the boat on the high-pressure side of the suction/discharge ports 3 and 4 becomes abnormally high temperature, and the distribution shaft 21 is heated, while the rotor 22 is heated due to the drain oil stored between the rotor 22 and the casing 1. Assume that the distribution shaft 21 and the rotor 22 do not reach a high temperature because they are in contact with each other, and a temperature difference occurs between the distribution shaft 21 and the rotor 22, causing the distribution shaft 21 to thermally expand. 17 However, since the fitting portion between the distribution shaft 21 and the rotor 22 is tapered, the sliding gap between the cough distribution shaft 21 and the rotor 22 is reduced even if the distribution l111I21 expands thermally. There's nothing to do,
The rotor 22 is displaced to the right in the figure, and the gap between the sliding parts is maintained appropriately, and during this period, rapid wear and tearing do not occur.

On the other hand, when the hydraulic rotary machine is operated for a long period of time, the sliding portion between the distribution shaft 21 and the rotor 22 accelerates wear. However, since the rotor 22 is pushed to the left in the figure by the action of the hydraulic pressure in the sub-cylinder 24 and the urging force of the spring 28, the rotor 22 is displaced 1 to the left in the figure in response to the increase in wear. ~,
The sliding gap between the distribution shaft 21 and the rotor 22 is maintained appropriately.

In the above embodiment, the casing 1 is divided into separate front casing IA and rear casing IB.
The cam part IC is composed of three members: the front casing IA, the rear casing IB, and the cam part IC. It is also possible to have a configuration in which the two are provided integrally. Further, although the cam surface 16 is formed directly on the inner circumferential wall of the cam portion 1C, a cam member may be provided separately from the casing 1 and the cam portion may be installed inside the casing. Furthermore, the distribution shaft 21 may be provided separately from the rear casing IB. Furthermore, although the spring 28 is stretched between the bottom wall of the sub-cylinder 24 and the pushing histone 25, this means that the hydraulic pressure within the sub-cylinder 24 cannot accurately match the separation force acting on the rotor 22. This is because it may be difficult to generate a balanced pressing force, and if it is possible to accurately balance the pressing force and repulsion force by appropriately selecting the diameter of the pushing piston 25, it is not always necessary to generate a balanced pressing force. There is no decoration provided.

As explained above, according to the radial piston type hydraulic rotating machine according to the present invention, the fitting portion between the distribution shaft and the rotor is formed into a tapered shape, and a plurality of sub cylinders are provided in the axial direction of the rotor. Since a pushing piston that contacts the inner wall of the casing is provided in each side cylinder, the pressing force against the distribution shaft of the rotor can be appropriately set by the sub-cylinder. ! The IIIJ section gap can be adjusted, leakage of hydraulic oil from the gap can be minimized, and the response volume efficiency of the hydraulic rotating machine can be improved. Furthermore, even if the distribution shaft expands thermally or the sliding part between the distribution shaft and the rotor wears out, the rotor is displaced in the axial direction accordingly, so the clearance between the sliding parts remains almost constant. It will be automatically adjusted as follows.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing a conventional hydraulic rotating machine, FIGS. 2 and 3 show an embodiment of the present invention, FIG. 2 is a longitudinal sectional view of the hydraulic rotating machine, and FIG. It is an enlarged view of the main part of FIG. 2. 1...Casing, 12...Cylinder, 14...
Piston, 15... Shoe, 16... Cam surface, 21
... Distribution shaft, 22 ... Rotor, 22A ... Fitting recess, 24 ... Sub cylinder, 25 ... Pushing piston,
26...Sliding surface portion, 27...Oil passage. Patent applicant: Hitachi Construction Machinery Co., Ltd. Figure 1 Figure 2

Claims (1)

[Claims] A distribution shaft provided to protrude into the casing, a rotor rotatably fitted to the distribution shaft, a plurality of cylinders bored in the radial direction of the rotor, and a cylinder provided slidably in each cylinder. A radial piston type hydraulic rotating machine having a piston, a guide member swingably connected to a tip of each piston, and a cam surface provided eccentrically with respect to the distribution shaft and guiding each guide member. , the fitting portion between the distribution shaft and the rotor is formed into a tapered shape, and the rotor has a plurality of sub-cylinders in the axial direction of the rotor that open toward the side surface opposite to the 1ρ fitting portion with the distribution shaft. A pushing piston that makes sliding contact with the inner wall of the casing is inserted into each sub-cylinder, and an oil passage is bored in the rotor to communicate between each sub-cylinder and each cylinder. A piston-type hydraulic rotary machine with a radial feature.