JP2008101581A - Inclined shaft type hydraulic rotating machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inclined shaft type hydraulic rotating machine enlarging a change range of an inclination angle of a piston. <P>SOLUTION: The inclined shaft type hydraulic rotating machine includes: a relief part 20 disposed to a recessed spherical surface joint 3 part of a drive disc 4 to allow engagement/disengagement with/from the recessed spherical surface joint 3 of a spherical part 7a of the piston 7, with the piston 7 inclined; and a lubricating oil supply means disposed at a contact part of the recessed spherical surface joint 3 and the spherical part 7a of the piston 7 through an oil passage 30 formed in the piston 7, and having a first annular groove 33 supplying the lubricating oil. A second annular groove 34 communicating with the inside of the casing 1 is formed on the spherical part 7a of the piston 7, and a communication passage, for example, a recess groove 35 is formed on the spherical part 7a of the piston 7 to constantly connect a second annular groove 34 with the inside of the second annular groove 34. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a slant-shaft hydraulic rotary machine that is a constant-capacity or variable-capacity slant-shaft axial pump motor provided in construction machines such as hydraulic excavators and general machines.

  There exists a thing shown by patent document 1 as this type of prior art. The prior art disclosed in Patent Document 1 has two problems. One of the problems, which is one of the problems, is the complexity of the coupling work associated with the presser plate that holds the spherical portion of the piston in the concave spherical joint of the drive disk. With respect to this, another conventional technique is proposed in Patent Document 2 in order to solve this problem.

  Another problem, namely, means for suppressing the floating of the spherical portion by the high-pressure lubricant supplied to the contact portion between the concave spherical joint of the drive disk and the spherical portion of the piston, tends to have a complicated structure. In order to solve this problem, Patent Document 3 proposes another conventional technique.

  In Patent Document 3, a casing, a rotating shaft that is rotatably supported by the casing, a cylinder block that rotates in synchronization with the rotating shaft, and a plurality of concaves are provided on the outer periphery of the end surface. A drive disk having a spherical joint, and a piston that is slidably connected to the concave spherical joint and has a spherical portion that forms a notch end surface on the cylinder block side, and is slidably inserted into the cylinder of the cylinder block; The concave spherical joint portion has an escape portion that allows engagement and disengagement of the spherical portion of the piston with respect to the concave spherical joint when the piston is tilted, and this escape portion allows a part of the piston rod portion of the piston to enter. Lubricating oil having a shaft groove and supplying lubricating oil to the contact portion between the concave spherical joint of the drive disk and the spherical portion of the piston via an oil passage formed in the piston Configuration with a paper means is shown. The lubricating oil supply means includes a first annular groove formed in the spherical portion of the piston.

  Further, the prior art disclosed in Patent Document 3 is formed in a spherical portion between the first annular groove of the spherical portion of the piston and the neck of the piston, and the spherical portion of the piston and the concave spherical joint of the drive disk are connected to each other. A second annular groove is provided which communicates with the first annular groove via a gap therebetween and is capable of communicating with the inside of the casing and has a larger diameter than the first annular groove.

When the piston is tilted at a certain inclination angle in a state in which the spherical portion of the piston is connected to the concave spherical bearing of the drive disk, the conventional technology shown in Patent Document 3 configured as described above is the second one of the piston. The annular groove communicates with the relief portion of the concave spherical joint, that is, communicates with the inside of the casing, and the high-pressure lubricating oil guided to the first annular groove formed in the spherical portion of the piston is connected to the casing via the second annular groove. Leaks into the inside. Therefore, the pressure receiving area of the tip portion of the spherical portion including the first annular groove that receives a high pressure in the spherical portion of the piston is a relatively small area formed inside the second annular groove of the spherical portion. Thereby, the force given to the spherical part of the piston by the high-pressure lubricant can be reduced, and the floating of the spherical part from the concave spherical joint can be suppressed.
Japanese Utility Model Publication No. 63-39427 Japanese Utility Model Publication No. 5-31271 JP 2005-201221 A

  Although the prior art shown in Patent Document 3 described above has a simple structure in which the second annular groove is simply formed in the spherical portion of the piston, it can suppress the lifting of the spherical portion of the piston from the concave spherical joint of the drive disk. The positional relationship between the formation position of the second annular groove of the spherical part of the piston and the formation position of the relief part of the concave spherical joint provided in the drive disk, or the manufacturing error of the relief part of these second annular groove and concave spherical joint Depending on the case, there is a concern that the change area of the tilt angle of the piston becomes small.

  That is, when the inclination angle of the piston is a relatively small angle and can have a small capacity, the second annular groove of the spherical portion of the piston does not communicate with the relief portion of the concave spherical joint of the drive disk. There is a risk that the spherical part of the drive disk will be lifted from the concave spherical joint. Conversely, when the piston tilt angle is a relatively large angle and can have a large capacity, the first annular groove communicates with the relief portion of the concave spherical joint in addition to the second annular groove of the spherical portion of the piston. As a result, there is a possibility that the spherical portion of the piston is strongly pressed against the concave spherical joint by a large pressing force exceeding a predetermined pressing force with respect to the concave spherical joint of the spherical portion of the piston. In order to eliminate these fears, the prior art disclosed in Patent Document 3 tends to reduce the change region of the tilt angle of the piston, making it difficult to secure a smaller minimum capacity and a larger maximum capacity. There is a concern that it will be difficult to make large changes.

  The present invention has been made from the above-described prior art, and an object of the present invention is to provide a slanted-axis hydraulic rotating machine capable of increasing the change range of the tilt angle of the piston.

  In order to achieve the above object, the present invention provides a casing, a rotating shaft that is rotatably supported by the casing, a cylinder block that rotates in synchronization with the rotating shaft, and an end surface of the rotating shaft. A drive disk having a plurality of concave spherical joints on the outer periphery thereof, and a spherical portion that is slidably coupled to the concave spherical joint and forms a notch end surface on the cylinder block side, and slides into the cylinder of the cylinder block A piston that can be inserted, and the concave spherical joint portion has a relief portion that allows engagement and disengagement of the spherical portion of the piston with the concave spherical joint when the piston is tilted. The shaft has a shaft groove part into which a part of the piston rod part of the piston enters, and the drive disk is connected to the drive disk via an oil passage formed inside the piston. Lubricating oil supplying means for supplying lubricating oil is provided at a contact portion between the spherical joint and the spherical portion of the piston, and the lubricating oil supplying means includes a first annular groove formed in the spherical portion of the piston. A gap between the spherical portion of the piston and the concave spherical joint of the drive disk formed in the spherical portion between the first annular groove of the spherical portion of the piston and the neck of the piston. A slanted axis type hydraulic rotation having a second annular groove that is communicated with the first annular groove through the inside of the casing and has a larger diameter than the first annular groove. The machine is characterized in that a communication passage is formed in the spherical portion of the piston so that the second annular groove communicates with the inside of the casing at all times.

  In the present invention configured as described above, even when the inclination angle of the piston is set to 0 °, for example, the second annular groove and the inside of the casing can be communicated with each other through the communication passage formed in the spherical portion of the piston. The pressure receiving area of the tip portion of the spherical portion including the first annular groove that receives high pressure in the spherical portion of the piston can be a relatively small area. Thereby, the force given to the spherical part of the piston by the high-pressure lubricant can be reduced, and the lifting of the spherical part of the piston from the concave spherical joint of the drive disk can be suppressed.

  Also, if the position of the first annular groove is set in advance so that the first annular groove does not communicate with the inside of the casing when the piston inclination angle is the maximum inclination angle that can be realized structurally, When the piston is held at such a maximum inclination angle, the second annular groove communicates with the inside of the casing, but the first annular groove can be kept from communicating with the inside of the casing. As a result, the tip end portion of the piston is not pressed against the concave spherical joint of the drive disk by a pressing force that is excessively larger than necessary, and a desired set pressing force can be secured.

  Therefore, the inclination angle of the piston can be kept at 0 ° which is the minimum angle, and can be kept at the maximum inclination angle that can be realized structurally. It is possible to change the tilt angle to a maximum possible tilt angle or less, and it is possible to secure a large change region of the tilt angle of the piston.

  Further, the present invention is characterized in that, in the above-mentioned invention, the concave groove is a concave groove opened to the surface side of the spherical portion of the piston.

  In the present invention, the present invention is characterized in that the communication path is formed in a spiral shape.

  In the present invention, since the communication passage that always communicates the second annular groove and the inside of the casing is formed in the spherical portion of the piston, the change region of the inclination angle of the piston can be made larger than before, Thus, even if the change area of the tilt angle of the piston is increased, it is possible to suppress the lifting of the spherical portion of the piston from the concave spherical joint of the drive disk and to secure a desired set pressing force. Therefore, the minimum capacity corresponding to the piston tilt angle of 0 ° and the maximum capacity corresponding to the maximum tilt angle that can be realized in the structure can be secured, and the capacity can be freely set between the minimum capacity and the maximum capacity. It can be changed more than before, and high reliability can be secured.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The best mode for carrying out an oblique axis hydraulic rotating machine according to the present invention will be described below with reference to the drawings.

  FIG. 1 is a cross-sectional view showing a basic configuration of an embodiment of an oblique-axis hydraulic rotating machine according to the present invention. 2 is a plan view showing a drive disk provided in the embodiment shown in FIG. 1, FIG. 3 is a cross-sectional view corresponding to the line AA of FIG. 2, and FIG. 4 is a plan view of the main part of FIG. FIG. 5 is a view showing a piston provided in the present embodiment, where FIG. 5A is a side view and FIG. 5B is a front view. FIG. 6 is a main part explanatory view showing a state in which the piston inclination angle is 0 ° in the present embodiment, and FIG. 7 is a state in which the piston inclination angle is the maximum inclination angle that can be realized structurally in this embodiment. It is principal part explanatory drawing which shows a state.

  This embodiment is provided in, for example, a hydraulic excavator, and its basic configuration includes a casing 1 that forms an outer shell and a rotating shaft 2 that is rotatably supported by the casing 1 as shown in FIG. Yes. For example, a drive disk 4 provided integrally with the end of the rotating shaft 2 and having a plurality of concave spherical joints 3 formed in the circumferential direction of the end surface, and a cylinder block 5 that rotates synchronously with the rotating shaft 2 are provided. The cylinder block 5 is formed with a plurality of cylinders 6 along the circumferential direction, and a piston 7 is slidably inserted into the cylinder 6. The above-described cylinder block 5 rotates with the center shaft 10 connected to the drive disk 4 as the rotation axis. The center shaft 10 is pressed against the drive disk 4 by a spring 11.

  As shown in FIGS. 5A and 5B, the piston 7 described above has a spherical portion 7a that is slidably connected to the concave spherical joint 3 of the drive disk 4 at its end. . Also, a piston rod portion 7b formed in a tapered shape and a cylinder inner surface contact portion 7c that is located on the inner side of the cylinder block 5 and contacts the inner surface of the cylinder 6 from the piston rod portion 7b are integrally formed. Yes. For example, two piston rings 8 and 9 are fitted in the vicinity of the cylinder inner surface contact portion 7c.

  Further, as shown in FIGS. 5A and 5B, the piston 7 is formed along the axial direction inside the piston 7 and leads to the oil passage 30 for guiding the lubricating oil and the tip of the spherical portion 7a. A discharge portion 31 that is formed and includes a fine hole that discharges high-pressure lubricating oil guided by the oil passage 30; an oil groove 32 that guides the lubricating oil flowing out from the discharge portion 31; and the oil groove 32. And a first annular groove 33 in which lubricating oil is accommodated. The oil passage 30, the discharge part 31, the oil groove 32, and the first annular groove 33 supply lubricating oil to the contact part between the concave spherical joint 3 of the drive disk 4 and the spherical part 7a of the piston 7 shown in FIG. The lubricating oil supply means is configured.

  As shown in FIGS. 2 to 4, the concave spherical joint 3 portion of the drive disk 4 described above is a clearance allowing the engagement and disengagement of the spherical portion 7 a of the piston 7 with respect to the concave spherical joint 3 when the piston 7 is tilted. Part 20. The escape portion 20 has a concave groove portions 20a and 20b positioned on both sides along the extending direction of the axial groove portion 20c together with the axial groove portion 20c having a gap portion into which a part of the piston rod portion 7b of the piston 7 enters. ing. The interval B between the concave groove 20a arranged on one side and the concave groove 20b arranged on the other side shown in FIG. 2 is set slightly larger than the diameter of the spherical portion 7a of the piston 7.

  Further, as shown in FIG. 2, for example, a substantially circular concave portion 21 communicating with the shaft groove portion 20 b of the escape portion 20 is formed in the center portion of the drive disk 4. As shown in FIG. 3, the bottom part of the shaft groove part 20b and the bottom part of the recessed part 21 are set, for example in the same depth position.

  Further, as shown in FIGS. 5A and 5B and FIG. 3, the spherical portion 7 a of the piston 7 is formed at the spherical portion 7 a portion between the spherical portion 7 a of the piston 7 and the neck portion of the piston 7. And the concave spherical joint 3 of the drive disk 4 communicate with the first annular groove 33 and can communicate with the inside of the casing 1 and have a larger diameter than the first annular groove 33. A second annular groove 34 is provided.

  In this embodiment, particularly, as shown in FIGS. 5A and 5B and FIG. 3, the second annular groove 34 and the inside of the casing 1 are always in communication with the spherical portion 7 a of the piston 7. For example, a groove 35 opened on the surface side of the spherical portion 7a of the piston 7 is provided.

  In this embodiment configured as described above, when the spherical portion 7a of the piston 7 is engaged with the concave spherical joint 3 of the drive disk 4, the piston 7 is inclined by a predetermined angle as shown in FIG. The concave groove portions 20a and 20b of the escape portion 20 are caused to enter the concave spherical joint 3, and at the same time, the neck portion of the piston rod portion 7b is caused to enter the shaft groove portion 20c, and the trunk portion of the piston rod portion 7b is caused to enter the concave portion 21. By slightly moving the piston 7 in the direction in which the inclination angle becomes smaller, that is, in the counterclockwise direction that is the upward direction in FIG. 3, the notch end surface 7 d of the spherical portion 7 a of the piston 7 becomes the concave spherical joint 3. Engage. As a result, the piston 7 is swingably connected to the drive disk 4 without slipping out during the sliding operation.

  Also, the spherical portion 7a of the piston 7 and the high-pressure lubricating oil supplied to the first annular groove 33 through the oil groove 30 formed in the piston 7, the discharge portion 31 formed in the spherical portion 7a, and the oil groove 32 The contact portion of the drive disk 4 with the concave spherical joint 3 is lubricated, so that the spherical portion 7a can be smoothly swung.

  In particular, in the present embodiment, even when the inclination angle of the piston 7 is, for example, 0 ° as shown in FIG. 6, the second annular groove 34 and the casing are interposed via the concave groove 35 formed in the spherical portion 7 a of the piston 7. Therefore, the first annular groove 33 that receives high pressure in the spherical portion 7a of the piston 7 is located at a position relatively close to the tip of the piston 7, that is, as shown in FIG. The first annular groove 33 can be set in advance at a position where the first annular groove 33 does not communicate with the inside of the casing 1 even when 7 is tilted to the maximum tilt angle that can be realized structurally. Therefore, the pressure receiving area of the tip portion of the spherical portion 7a of the piston 7 including the first annular groove 33 can be made a relatively small area. Thereby, the force given to the spherical portion 7a of the piston 7 by the high-pressure lubricant can be reduced, and the floating of the spherical portion 7a of the piston 7 from the concave spherical joint 3 of the drive disk 4 can be suppressed.

  Further, as shown in FIG. 7, the first annular groove 33 does not communicate with the inside of the casing 1 as described above when the inclination angle of the piston 7 is the maximum inclination angle that can be realized structurally. Since the annular groove 33 is set, when the piston 7 is held at the maximum inclination angle in this way, the second annular groove 34 communicates with the inside of the casing 1, but the first annular groove 33 is connected to the casing 1. It can be kept in a state not communicating with the inside. Thereby, the tip portion of the piston 7 is not pressed against the concave spherical joint 3 of the drive disk 4 with a pressing force larger than necessary, and a desired set pressing force can be secured.

  When the piston 7 is tilted by a predetermined angle greater than 0 °, the second annular groove 34 communicates with the inside of the casing 1, and further, as shown in FIG. 7, while the piston 7 is tilted to the maximum tilt angle, The state where the annular groove 34 communicates with the inside of the casing 1 is maintained. Therefore, while the piston 7 is tilted from the above-mentioned predetermined angle to the maximum inclination angle, the second annular groove 34 communicates directly with the inside of the casing 1 together with the concave groove 35, and as described above, the pressure receiving pressure at the tip portion of the spherical portion 7a. The area can be a relatively small area. Thus, as described above, the force applied to the spherical portion 7a of the piston 7 by the high-pressure lubricant can be reduced, and the floating of the spherical portion 7a of the piston 7 from the concave spherical joint 3 of the drive disk 4 can be suppressed. .

  According to the present embodiment configured as described above, since the concave groove 35 that always communicates the second annular groove 34 and the inside of the casing 1 is formed in the spherical portion 7a of the piston 7, the inclination angle of the piston 7 is increased. The change region can be a large change region having an inclination angle of 0 ° or more shown in FIG. 6 and a maximum inclination angle or less realizable in the structure shown in FIG. Further, even if the change region of the tilt angle of the piston 7 is increased in this way, it is possible to prevent the spherical portion 7a of the piston 7 from lifting from the concave spherical joint 3 of the drive disk 4 and to secure a desired set pressing force. realizable. Therefore, the minimum capacity corresponding to the inclination angle of the piston 7 of 0 ° and the maximum capacity corresponding to the maximum inclination angle that can be realized in the structure can be secured, and the capacity can be freely set between the minimum flow rate and the maximum flow rate. Can be greatly changed, and high reliability can be secured.

  Moreover, since this embodiment is a simple structure which only forms the concave groove 35 in the spherical part 7a of the piston 7, the manufacturing cost can be reduced.

  FIG. 8 is a side view showing a piston constituting the main part of another embodiment of the present invention. In this other embodiment, the concave groove 5 formed in the spherical portion 7a of the piston 7 and constantly communicating the second annular groove 34 and the inside of the casing 1 is formed in a spiral shape. For example, it is formed in a spiral shape formed on the surface of the spherical portion 7a of the piston 7 over one turn. Other configurations are the same as those of the above-described embodiment.

  Another embodiment configured as described above can obtain the same effect as that of the above-described embodiment, and between the entire surface of the spherical portion 7a of the piston 7 and the concave spherical joint 3 via the spiral concave groove 35. Sufficient lubricating oil can be supplied, and smoother swinging motion of the piston 7 can be realized.

  In the above-described embodiment, the communication path that constantly communicates the second annular groove 34 of the spherical portion 7 a of the piston 7 and the inside of the casing 1 is formed from the concave groove 35 that opens to the surface side of the spherical portion 7 a of the piston 7. However, the present invention is not limited to such a configuration, and this communication path is formed in, for example, the spherical portion 7a of the piston 7 so that the second annular groove 34 and the inside of the casing 1 are always in communication. You may comprise by the drill hole to be made.

It is sectional drawing which shows the basic composition of one Embodiment of the slant axis type hydraulic rotating machine which concerns on this invention. It is a top view which shows the drive disk with which one Embodiment shown in FIG. 1 is equipped. It is sectional drawing corresponding to the AA line of FIG. It is a principal part top view of FIG. It is a figure which shows the piston with which this embodiment is equipped, (a) A figure is a side view, (b) A figure is a front view. It is principal part explanatory drawing which shows a state when the inclination-angle of a piston is 0 degree in this embodiment. In this embodiment, it is principal part explanatory drawing which shows a state in case the inclination angle of a piston is the maximum inclination angle which can be implement | achieved structurally. It is a side view which shows the piston which comprises the principal part of another embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Casing 2 Rotating shaft 3 Concave spherical joint 4 Drive disk 5 Cylinder block 6 Cylinder 7 Piston 7a Spherical part 7b Piston rod part 11 Spring 20 Escape part 21 Concave part 30 Oil path (lubricating oil supply means)
31 Discharge unit (lubricating oil supply means)
32 Oil groove (lubricating oil supply means)
33 1st annular groove (lubricating oil supply means)
34 Second annular groove 35 Concave groove (communication path)

Claims (3)

A casing, a rotating shaft that is rotatably supported by the casing, a cylinder block that rotates in synchronization with the rotating shaft, and a drive disk that is provided at an end of the rotating shaft and has a plurality of concave spherical joints on the outer periphery of the end surface When,
A slidably connected to the concave spherical joint, the cylinder block side has a spherical portion forming a notch end surface, and includes a piston that is slidably inserted into the cylinder of the cylinder block;
The concave spherical joint portion has a relief portion that allows engagement and disengagement of the spherical portion of the piston with the concave spherical joint in a state where the piston is inclined, and this relief portion is a piston rod portion of the piston. And a shaft groove part into which a part of
Lubricating oil supply means for supplying lubricating oil to a contact portion between the concave spherical joint of the drive disk and the spherical portion of the piston via an oil passage formed inside the piston,
The lubricating oil supply means includes a first annular groove formed in the spherical portion of the piston,
A gap is formed in the spherical portion between the first annular groove of the spherical portion of the piston and the neck of the piston, and a gap between the spherical portion of the piston and the concave spherical joint of the drive disk is formed. A slant-shaft type hydraulic rotating machine including a second annular groove that is communicated with the first annular groove through the casing and capable of communicating with the inside of the casing and having a larger diameter than the first annular groove. In
A slanted-axis hydraulic rotary machine characterized in that a communication passage is formed in the spherical portion of the piston so that the second annular groove communicates with the inside of the casing at all times. In the invention of claim 1,
The oblique-axis hydraulic rotary machine characterized in that the second annular groove is a concave groove that opens on the surface side of the spherical portion of the piston. In the invention of claim 2,
An oblique axis type hydraulic rotating machine, wherein the concave groove is formed in a spiral shape.

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