CN214887511U - Piston assembly and hydraulic rotary device provided with same - Google Patents
Piston assembly and hydraulic rotary device provided with same Download PDFInfo
- Publication number
- CN214887511U CN214887511U CN202120844522.5U CN202120844522U CN214887511U CN 214887511 U CN214887511 U CN 214887511U CN 202120844522 U CN202120844522 U CN 202120844522U CN 214887511 U CN214887511 U CN 214887511U
- Authority
- CN
- China
- Prior art keywords
- hole
- shoe
- piston
- piston assembly
- swash plate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Reciprocating Pumps (AREA)
- Hydraulic Motors (AREA)
Abstract
The utility model provides a piston assembly that can restrain the pollutant and get into the piston assembly of piston shoe perforating hole and possess the hydraulic pressure rotary device of this piston assembly. The piston assembly is a piston assembly of a hydraulic rotary device having a swash plate, and includes: a piston having a piston through hole penetrating in an axial direction and a spherical convex portion formed at one end in the axial direction; and a shoe having a concave spherical portion in which the convex spherical portion is slidably fitted, a sliding surface on which the swash plate slides, a shoe through-hole which penetrates between the concave spherical portion and the sliding surface, a through-hole forming portion which is formed around the shoe through-hole and has a protruding portion protruding toward the concave spherical portion, and a catching groove formed around the protruding portion of the through-hole forming portion; the through hole forming portion forms a throttle portion between the through hole forming portion and the convex ball portion.
Description
Technical Field
The present invention relates to a piston assembly including a piston and a shoe (shoe), and a hydraulic rotating device including the piston assembly.
Background
As a shoe of a hydraulic rotary device such as a swash plate pump and a swash plate motor, for example, a shoe of patent document 1 is known. The shoe of patent document 1 has a weir formed around the opening of the shoe through hole (communication hole). This prevents contaminants moving along the inner wall of the concave-spherical portion (spherical sliding portion) from entering the through hole.
Prior art documents:
patent documents:
patent document 1: japanese patent laid-open No. 9-184477.
SUMMERY OF THE UTILITY MODEL
Problem that utility model will solve:
as described above, the shoe of patent document 1 can suppress entry of contaminants (contamination) into the through hole. However, in a hydraulic rotary device having a high pressure and a high rotation speed, it is desired to further suppress entry of contaminants into the through hole.
Therefore, an object of the present invention is to provide a piston assembly capable of suppressing entry of contaminants into a shoe through hole, and a hydraulic rotary device including the piston assembly.
Means for solving the problems:
a piston assembly according to a first aspect of the present invention is a piston assembly of a hydraulic rotary device having a swash plate, comprising: a piston having a piston through hole penetrating in an axial direction and a spherical convex portion formed at one end in the axial direction; and a shoe having a concave spherical portion into which the convex spherical portion is slidably fitted, a sliding surface that slides with respect to the swash plate, a shoe through-hole that penetrates between the concave spherical portion and the sliding surface, a through-hole forming portion that is formed around the shoe through-hole and has a protruding portion that protrudes toward the concave spherical portion, and a catching groove that is formed around the protruding portion of the through-hole forming portion; the through hole forming portion forms a throttle portion between the through hole forming portion and the convex portion.
According to the invention of the first aspect, the working fluid is guided to the catching groove via the piston through-hole. The working fluid introduced into the catch tank is guided between the sliding surface and the swash plate via the throttle portion and the shoe through hole. The working fluid introduced into the trap groove flows to the shoe through-hole through the throttle portion, and therefore the flow of the working fluid from the trap groove to the shoe through-hole can be suppressed. In this way, a swirling flow of the working fluid is generated in the catch tank. Thus, the contaminants contained in the working fluid in the catch tank are pushed out radially outward, and therefore, the contaminants can be prevented from entering the shoe through-hole located inside the catch tank.
A piston assembly according to a second aspect of the present invention is a piston assembly of a hydraulic rotary device having a swash plate, comprising: a piston having a piston through hole penetrating in an axial direction and a spherical convex portion formed at one end in the axial direction; and a shoe having a concave spherical portion into which the convex spherical portion is slidably fitted, a sliding surface that slides with respect to the swash plate, a shoe through-hole that penetrates between the concave spherical portion and the sliding surface, a through-hole forming portion that is formed around the shoe through-hole and has a protruding portion that protrudes toward the concave spherical portion, and a catching groove that is formed around the protruding portion of the through-hole forming portion; the catching groove has a concavely curved bottom surface facing the sliding surface side; the shoe through hole has a first passage portion formed on the concave ball portion side and a second passage portion formed closer to the sliding surface side than the first passage portion and having a smaller diameter than the first passage portion.
According to the utility model of the second aspect, the working fluid is guided to the catching groove via the piston through-hole. The working fluid introduced into the catching groove is guided between the sliding surface and the swash plate through the through-hole forming portion and the clearance between the convex ball portion and the shoe through-hole. At this time, the working fluid introduced into the capturing groove flows through between the through-hole forming portion and the convex ball portion to the slipper through-hole, and thus the flow of the working fluid from the capturing groove to the slipper through-hole is suppressed. Further, the aperture of the second passage portion is smaller than the aperture of the first passage portion, and therefore the flow of the working fluid in the shoe through hole can be restricted. Therefore, the working fluid flowing from the catch tank to the shoe through hole can be restricted, and a swirling flow can be generated in the catch tank. Thus, the contaminants contained in the working fluid in the catch tank are pushed out radially outward, and therefore, the contaminants can be prevented from entering the shoe through-hole located inside the catch tank. On the other hand, since the bottom surface of the catch groove is curved in a concave shape toward the sliding surface side, the working fluid can smoothly flow in the catch groove. This promotes the generation of swirling flow, and thus entry of contaminants into the shoe through-hole located inside the catch groove can be further suppressed.
The utility model of the third aspect has: the piston assembly described above; a shell; a cylinder rotatably housed in the housing and having a plurality of piston chambers for housing the piston in a manner capable of advancing and retreating; and the inclined plate is used for sliding the sliding shoe.
According to the invention of the third aspect, a hydraulic rotary device that achieves the aforementioned functions can be provided.
The utility model has the advantages that:
according to the utility model discloses, can restrain the pollutant and get into the perforating hole.
Drawings
Fig. 1 is a cross-sectional view showing a swash plate type hydraulic apparatus according to an embodiment of the present invention;
fig. 2 is an enlarged sectional view of a region X of the swash plate type hydraulic apparatus of fig. 1;
fig. 3 is an enlarged sectional view showing an enlarged area Y of the piston assembly of fig. 2;
FIG. 4 is an enlarged cross-sectional view illustrating the flow of the working fluid within the slipper of FIG. 3;
description of the symbols:
1 piston assembly
2 swash plate type hydraulic device (Hydraulic rotating device)
11 case
13 Cylinder body
13a piston chamber
15 inclined plate
16 piston
17 sliding shoe
18 throttling part
22 convex ball part
23 piston through hole
31 concave ball part
32 sliding surface
33 through hole forming part
34 catching groove
35 through hole of slipper
35a first path portion
35b second path portion
35c inflow port
Aperture of D1 first pass section
D2 Aperture of second Path portion
Width of H1 throttle
H2 catches the depth of the groove.
Detailed Description
Hereinafter, a piston assembly 1 according to an embodiment of the present invention and a swash plate type hydraulic device 2 including the piston assembly 1 will be described with reference to the drawings. Note that the concept of the direction used in the following description is used for convenience of description, and the direction of the structure of the present invention and the like are not limited to this direction. The piston assembly 1 and the swash plate type hydraulic device 2 including the piston assembly 1 described below are only one embodiment of the present invention. Therefore, the present invention is not limited to the embodiments, and can be added, deleted, and changed without departing from the spirit of the present invention.
< swash plate type hydraulic device >
The swash plate type hydraulic device 2 as a hydraulic rotating device can discharge the working fluid by receiving a rotational driving force or output a rotational force by receiving a force of the working fluid. The swash plate type hydraulic device 2 is a swash plate pump that receives a rotational driving force and discharges the hydraulic fluid in the present embodiment. The swash plate type hydraulic device 2 may be a swash plate motor that receives the force of the hydraulic fluid and outputs a rotational force. To describe the swash plate type hydraulic device 2 in more detail, the swash plate type hydraulic device 2 includes a housing 11, a rotary shaft 12, a cylinder block 13, a valve plate 14, a swash plate 15, a plurality of piston assemblies 1, and a pressure plate 19.
The housing 11 accommodates a rotary shaft 12, a cylinder block 13, a valve plate 14, a swash plate 15, a plurality of piston assemblies 1, and a pressure plate 19. The casing 11 is formed with a suction passage 11a and a discharge passage 11 b. The suction passage 11a is a passage for sucking the working fluid. The discharge passage 11b is a passage for discharging the working fluid.
The rotary shaft 12 is rotatably supported by the housing 11. The rotary shaft 12 has one axial end portion, which is an end portion on one axial side, protruding from the housing 11. One end in the axial direction of the rotary shaft 12 is connected to a drive source (for example, an engine or a motor) via a speed reducer (not shown) or the like. Therefore, a rotational driving force can be applied from the driving source to the rotary shaft 12 to rotate the rotary shaft 12.
The cylinder 13 is externally fitted to the other side of the rotary shaft 12 in the axial direction, and rotates integrally with the rotary shaft 12 about the axis L1 of the rotary shaft 12. The cylinder 13 is formed with a plurality of piston chambers 13a and cylinder ports 13 b. The plurality of piston chambers 13a are formed at equal intervals around the rotary shaft 12. The plurality of piston chambers 13a are open at one axial end face, which is one axial end face, of the cylinder 13. The cylinder port 13b is formed corresponding to each piston chamber 13 a. The cylinder port 13b is open at the other end surface on the other side in the axial direction, that is, the other end surface in the axial direction, and is connected to the corresponding piston chamber 13 a.
The swash plate 15 is disposed so as to be inclined to the axis L1. Then, a shoe 17 of a piston assembly 1 described later slides on the swash plate 15. More specifically, the swash plate 15 is inserted through the rotary shaft 12. The swash plate 15 faces one end in the axial direction of the cylinder block 13 and is disposed obliquely to the one end in the axial direction. Therefore, the shoe 17 slides on the inclined plate 15 arranged obliquely. The swash plate 15 is inclined so that the piston chamber 13a is closest to the top dead center (see the upper piston chamber 13a in fig. 1) and is farthest from the bottom dead center. In the present embodiment, the swash plate 15 includes a swash plate main body 15a and a shoe plate 15 b. The swash plate body 15a faces one end in the axial direction of the cylinder block 13 and is disposed obliquely to the one end in the axial direction. Further, a shoe plate 15b is provided on a surface of the swash plate body 15a on one end side in the axial direction of the cylinder block 13. The shoe 17 slides on the shoe plate 15 b.
The piston assembly 1 is provided in the cylinder block 13 corresponding to each piston chamber 13a, and is disposed on the swash plate 15. Then, the piston assembly 1 rotates about the axis L1 together with the cylinder 13. In this way, the piston assembly 1 slides on the swash plate 15 about the axis L1. Thereby, the piston assembly 1 advances and retreats in the piston chamber 13 a. The working fluid is sucked into the piston chamber 13a by the extension of the piston assembly 1, and the working oil is discharged from the piston chamber 13a by the retraction of the piston assembly 1. More specifically, the piston assembly 1 includes a piston 16 and a shoe 17 as shown in fig. 2.
The piston 16 is inserted into each piston chamber 13a to be able to advance and retreat. That is, the piston 16 moves in the extension direction by the working fluid guided to the piston chamber 13a via the cylinder port 13 b. The piston 16 moves in the retracting direction to discharge the working fluid in the piston chamber 13a to the cylinder port 13 b. More specifically, the piston 16 includes a piston main body 21, a convex ball portion 22, and a piston through hole 23. The piston main body 21 is inserted into the piston chamber 13a to be able to advance and retreat. In the present embodiment, the piston main body 21 is formed in a cylindrical shape. The convex portion 22 is integrally provided on the other side in the axial direction of the piston main body 21. The convex portion 22 is formed in a spherical shape in the present embodiment. The piston through hole 23 is a hole penetrating the piston 16 along the axis L2 of the piston 16. More specifically, the piston through hole 23 passes through the piston main body 21 and the convex ball portion 22 along the axis L2 of the piston main body 21. The piston through hole 23 is open at the other end in the axial direction in the piston main body 21, and is open at one end in the axial direction in the convex spherical portion 22. This allows the working fluid in the piston chamber 13a to be guided to the spherical convex portion 22 through the piston through hole 23.
The piston 16 is rotatably held by the shoe 17. The shoe 17 slides on the swash plate 15 about the axis L1 to advance and retract the piston 16. More specifically, the slipper 17 has a slipper body 25 and a flange 26. The slipper main body 25 rotatably holds the piston 16. More specifically, the shoe main body 25 is formed in a bottomed cylindrical shape having one end opening in the axial direction. A flange 26 is formed on the outer peripheral surface of the shoe main body 25 over the entire circumference in the circumferential direction at the other end in the axial direction. To describe the shoe main body 25 in more detail, the shoe main body 25 includes the spherical concave portion 31, the sliding surface 32, the shoe through hole 35, the through hole forming portion 33, and the catching groove 34.
The concave spherical portion 31 can fit the convex spherical portion 22 of the piston 16. The concave ball portion 31 rotatably holds the inserted convex ball portion 22. More specifically, the concave ball portion 31 is an inner hole portion of the slipper main body 25. In the present embodiment, the concave spherical portion 31 is spherical and formed in the same shape as the convex spherical portion 22. Concave ball portion 31 is swaged at the opening portion to hold convex ball portion 22 so as not to be detached. The working fluid guided to the convex spherical portion 22 through the piston through-hole 23 is supplied to the concave spherical portion 31. This enables the convex spherical portion 22 to smoothly rotate in the concave spherical portion 31. The concave spherical portion 31 having such a shape is formed on one end side in the axial direction of the shoe main body 25 in the present embodiment.
The sliding surface 32 abuts against the swash plate 15. The sliding surface 32 slides on the swash plate 15. More specifically, the shoe 17 rotates integrally with the cylinder 13 by caulking the convex ball portion 22 of the piston 16 to the concave ball portion 31. Therefore, when the cylinder block 13 rotates, the shoe 17 slides and rotates on the swash plate 15 about the axis L1. In this way, the shoe 17 approaches and separates from the cylinder 13. The piston 16, which is caulked to the shoe 17, advances and retreats in the piston chamber 13 a. The sliding surface 32 is formed at the other end in the axial direction of the shoe main body 25 in the present embodiment.
The shoe through hole 35 is formed in the shoe main body 25. The shoe through hole 35 penetrates between the concave ball portion 31 and the sliding surface 32. In the present embodiment, the shoe through hole 35 is formed along the axis L3 of the shoe 17. The shoe through hole 35 may be formed obliquely to the axis L3. The shoe through hole 35 can guide the working fluid guided to the recessed ball portion 31 to the sliding surface 32. As shown in fig. 3, the shoe through hole 35 has a first passage portion 35a and a second passage portion 35 b. The shoe through hole 35 may be formed of three or more passage portions. Also, the second passage portion 35b may be in the form of a throttle as a short passage.
The first passage portion 35a is formed on the inlet 35c side, which is an opening of the shoe through hole 35 on the concave ball portion 31 side. That is, the first passage portion 35a is connected to an inlet port 35c of the shoe through hole 35, which is an opening on the side of the spherical concave portion 31. The second passage portion 35b is formed closer to the sliding surface 32 than the first passage portion 35a in the shoe through hole 35. In the present embodiment, the second passage portion 35b is continuous with the first passage portion 35a and is also continuous with the outflow port 35d, which is an opening on the sliding surface 32 side of the shoe through hole 35. Also, the aperture D2 (diameter) of the second passage portion 35b is smaller than the aperture D1 (diameter) of the first passage portion 35 a. That is, the shoe through hole 35 is closed on the sliding surface 32 side. This suppresses the flow of the working fluid in the shoe through hole 35.
The through-hole forming portion 33 is a portion formed around the shoe through-hole 35. In the through-hole forming portion 33, a protruding portion 33a, which is a portion on the inflow port 35c side, protrudes toward the spherical concave portion 31. Further, the protruding portion 33a of the through-hole forming portion 33 is close to the spherical concave portion 31. That is, the protruding portion 33a protrudes toward the convex ball portion 22 of the piston 16 and is close to the convex ball portion 22. Therefore, the inlet 35c is close to and faces the spherical surface of the convex spherical portion 22 of the piston 16. Thereby, the throttle portion 18 is formed between the through-hole forming portion 33 and the convex ball portion 22. More specifically, when the angle of the swash plate 15 with respect to the cylinder block 13 (the angle of the swash plate 15) is equal to or greater than a predetermined angle, the inlet port 35c faces the spherical surface of the spherical portion 22 (i.e., the surface portion other than the piston through-hole 23). Therefore, in the present embodiment, the throttle portion 18 is formed in a ring shape so as to surround the periphery of the inlet port 35c over the entire circumference.
The trap tank 34 is a chamber for trapping contaminants contained in the working fluid. The catching groove 34 is formed around the protruding portion 33a of the through-hole forming portion 33. More specifically, the periphery of the protruding portion 33a of the through-hole forming portion 33 is recessed toward the sliding surface 32 side with respect to the inflow port 35c to form the catching groove 34. In the present embodiment, the catching groove 34 is formed in an annular shape so as to surround the protruding portion 33a of the through-hole forming portion 33. Then, by forming the catching groove 34 concavely, the protruding portion 33a of the through-hole forming portion 33 is formed to protrude toward the spherical concave portion 31. The bottom surface 34a of the catching groove 34 is concavely curved so as to protrude toward the sliding surface 32. Further, the circumferential surface 34b of the catching groove 34 is formed in a steep manner. More specifically, the circumferential surface 34b of the catching groove 34 is formed to stand sharply with respect to the end surface of the protruding portion 33a of the through-hole forming portion 33. In the present embodiment, the circumferential surface 34b of the catching groove 34 is formed parallel to the axis L3 of the shoe through hole 35. When the angle of the swash plate 15 is equal to or greater than a predetermined angle, the opening on the one axial end side of the piston through hole 23 faces the catch groove 34 thus formed, and the opening on the one axial end side of the piston through hole 23 does not face the inlet 35 c. In other words, inlet port 35c faces the spherical surface of spherical portion 22. As described above, the throttle portion 18 is formed annularly so as to surround the periphery of the inflow port 35c over the entire periphery.
The throttle portion 18 connects the catch groove 34 and the shoe through hole 35. The throttle portion 18 also suppresses the flow from the trap groove 34 to the shoe through hole 35. More specifically, the throttle portion 18 is a narrow portion formed by projecting the projecting portion 33a of the through-hole forming portion 33 toward the spherical concave portion 31. In the present embodiment, the throttle portion 18 is formed between the protruding portion 33a of the through-hole forming portion 33 and the concave ball portion 31 when the angle of the swash plate 15 is equal to or greater than a predetermined angle. That is, the throttle portion 18 is formed between the one end portion of the through-hole forming portion 33 and the concave ball portion 31 in a state where the axis L2 of the piston 16 and the axis L3 of the shoe 17 are inclined to each other. The throttle portion 18 may be formed when the angle of the swash plate 15 is smaller than a predetermined angle. The width H1 of the throttle part 18 thus formed is smaller than the depth H2 of the catching groove 34. Here, the width H1 of the throttle portion 18 is the width of the portion where the throttle portion 18 becomes narrowest in the axial direction of the shoe 17. The depth H2 of the catching groove 34 is the depth of the catching groove 34 at the position farthest from the convex ball portion 22 in the axial direction of the shoe 17. Describing the throttle section 18 in more detail, the ratio of the width H1 of the throttle section 18 to the depth H2 of the catch groove 34 is 1.2 ≦ H2/H1. Further, the ratio of the width H1 of the throttle section 18 to the depth H2 of the catching groove 34 is preferably 1.5 ≦ H2/H1 ≦ 10. This suppresses the flow of the working fluid from the catch groove 34 to the shoe through hole 35.
The flow passage area a1 of the throttle portion 18 is larger than the flow passage area a2 of a part of the shoe through hole 35. In the present embodiment, a part of the shoe through hole 35 is a first passage portion 35 a. More specifically, the flow passage area a1 of the throttle section 18 is a1 ═ pi × R1 × H1. Here, R1 is the effective bore diameter (diameter) of the throttle portion 18. On the other hand, the flow passage area a2 of the first passage portion 35a is a2 ═ pi × D12)/4. The ratio of the flow path area A1 of the throttle section 18 to the flow path area A2 of the shoe through hole 35 is 1 < A1/A2. Preferably, the ratio of the flow path area a1 of the throttle section 18 to the flow path area a2 of the shoe through hole 35 is 5 < a1/a2 ≦ 100. This suppresses the flow of the working fluid from the catch groove 34 to the shoe through hole 35.
The pressure plate 19 is inserted through the rotary shaft 12. The pressure plate 19 presses the plurality of shoes 17 against the swash plate 15. Thereby, the shoe 17 is supported by the swash plate 15 and is rotatable on the swash plate 15 about the axis L1. More specifically, the pressure plate 19 has a plurality of holes 19a formed therein corresponding to the respective shoes 17. The shoe main body 25 of the shoe 17 corresponding to each hole 19a is inserted into the pressing plate 19. The pressure plate 19 is disposed on the sloping plate 15 in the form of a holding flange 26. The pressure plate 19 is pressed toward the swash plate 15 by a spherical bush (boss) 12a attached to the rotary shaft 12. Thereby, the flange 26 of the shoe 17 is pressed against the swash plate 15.
In the swash plate type hydraulic device 2 configured as described above, when the drive source rotates the rotary shaft 12, the cylinder block 13 rotates. Thereby, the piston assembly 1 rotates on the swash plate 15 about the axis L1 and advances and retreats relative to the piston chamber 13 a. When the piston assembly 1 expands, the working fluid is sucked into the piston chamber 13a from the suction port 14 a. Then, if the piston assembly 1 starts retracting beyond the top dead center, the working fluid is discharged from the piston chamber 13a to the discharge port 14 b.
In the piston assembly 1 of the swash plate type hydraulic device 2, the opening of the piston through hole 23 on the side of the convex ball portion 22 faces the catch groove 34. Therefore, the working fluid in the piston chamber 13a is guided to the catch groove 34 through the piston through hole 23 as shown in fig. 4. The hydraulic fluid guided to the catch groove 34 is guided between the sliding surface 32 and the swash plate 15 through the orifice 18 and the shoe through hole 35. More specifically, a gap is left between the sliding surface 32 and the swash plate 15. The working fluid guided to the sliding surface 32 is supplied to the gap between the sliding surface 32 and the swash plate 15. Thereby, the shoe 17 can slide smoothly on the swash plate 15.
In the piston assembly 1 of the swash plate type hydraulic device 2 according to the present embodiment, the working fluid guided to the catch groove 34 flows to the shoe through hole 35 through the throttle portion 18, and therefore the flow of the working fluid from the catch groove 34 to the shoe through hole 35 is suppressed. In this way, a swirling flow (spiral flow) F of the working fluid is generated in the trap tank 34. Thereby, the contaminants contained in the working fluid in the trap tank 34 are pushed radially outward, and the contaminants can be prevented from entering the inlet 35c inside the trap tank 34. That is, entry of contaminants into the shoe through hole 35 can be further suppressed. This can prevent the shoe through hole 35 from being clogged with contaminants.
In the piston assembly 1 of the present embodiment, the ratio of the flow passage area a1 of the throttle portion 18 to the flow passage area a2 of the shoe through hole 35 is 1 < a1/a 2. That is, the flow passage area a2 of the shoe through hole 35 is smaller than the flow passage area a1 of the throttle portion 18. Therefore, the flow of the working fluid from the throttle portion 18 to the shoe through hole 35 can be restricted. This can restrict the working fluid flowing from the catch tank 34 to the shoe through-hole 35 via the throttle portion 18, and can promote the generation of the swirling flow F in the catch tank 34. Further, the contaminant trapping performance of the trap tank 34 can be improved. This can further suppress entry of contaminants into the shoe through hole 35.
More preferably, the ratio of the flow path area a1 of the throttle section 18 to the flow path area a2 of the shoe through hole 35 is 5 < a1/a2 ≦ 100. That is, the flow passage area a1 of the throttle portion 18 is 5 times larger than the flow passage area a2 of the shoe through hole 35. This can more appropriately restrict the flow of the working fluid from the throttle portion 18 to the shoe through hole 35. Therefore, the contaminant trapping performance of the trap tank 34 can be further improved. This can further suppress entry of contaminants into the inflow port 35 c.
In the piston assembly 1 of the swash plate type hydraulic device 2, the bore diameter D2 of the second passage portion 35b is smaller than the bore diameter D1 of the first passage portion 35 a. Therefore, the flow of the working fluid in the shoe through hole 35 can be restricted. This can restrict the working fluid flowing from the catch tank 34 to the shoe through-hole 35 via the throttle portion 18, and can promote the generation of the swirling flow F in the catch tank 34. Further, the contaminant trapping performance of the trap tank 34 can be improved. This can further suppress entry of contaminants into the shoe through hole 35.
In the piston assembly 1 of the swash plate type hydraulic device 2, in a more preferred embodiment, the ratio of the width H1 of the throttle portion 18 to the depth H2 of the catch groove 34 is 1.5 ≦ H2/H1 ≦ 10. That is, the depth H2 of the catching groove 34 is 1.5 times or more the width H1 of the throttle 18. Therefore, the flow of the working fluid from the catch tank 34 to the throttle portion 18 can be restricted. This promotes the generation of the swirling flow F in the trap tank 34. Further, the contaminant trapping performance of the trap tank 34 can be improved. This can further suppress entry of contaminants into the shoe through hole 35. Further, although the depth H2 of the trap groove 34 is 1.2 times or more the width H1 of the throttle 18, and the entry of the contaminants into the inlet 35c can be further suppressed, the depth H2 of the trap groove 34 is more preferably 1.5 times or more the width H1 of the throttle 18.
In the piston assembly 1 of the present embodiment, the working fluid guided to the catch groove 34 passes between the through-hole forming portion 33 and the convex ball portion 22 and flows to the slipper through-hole 35, and the flow of the working fluid from the catch groove 34 to the slipper through-hole 35 is suppressed. Further, the bore diameter D2 of the second passage portion 35b is smaller than the bore diameter D1 of the first passage portion 35a, and the flow of the hydraulic fluid in the shoe penetration hole 35 can be restricted. This can restrict the working fluid flowing from the catch groove 34 to the shoe through hole 35, and can generate the swirling flow F in the catch groove 34. Thereby, the contaminants contained in the working fluid in the trap tank 34 are pushed radially outward, and the contaminants can be prevented from entering the inlet 35c located inside the trap tank 34. That is, entry of contaminants into the shoe through hole 35 can be further suppressed. On the other hand, the bottom surface 34a of the catch groove 34 is curved in a concave shape toward the sliding surface 32 side, so that the working fluid can smoothly flow in the catch groove 34. This promotes the generation of the swirling flow F, and thereby entry of contaminants into the shoe through hole 35 located inside the catch groove 34 can be further suppressed.
In the piston assembly 1 of the present embodiment, the circumferential surface 34b of the catching groove 34 is formed to stand sharply. Therefore, the working fluid can be smoothly flowed in the catch tank 34. This promotes the generation of the swirling flow F, and thereby entry of contaminants into the shoe through hole 35 located inside the catch groove 34 can be further suppressed.
< As to other embodiments >
In the piston assembly 1 of the present embodiment, the convex spherical portion 22 of the piston 16 is formed in a spherical shape, but the convex spherical portion 22 may be formed in a partial spherical shape in which one end side in the axial direction of the piston 16 is partially notched. That is, the convex portion 22 may be formed to be fitted into the concave portion 31 and rotatable in the concave portion 31. The shape of the catching groove 34 is not limited to the circular shape, and may be a square shape, a rectangular shape, an oval shape, or a combination thereof when viewed from the axial direction. The swash plate type hydraulic device 2 according to the present embodiment may be either a fixed displacement type hydraulic device in which the swash plate 15 is fixed or a variable displacement type hydraulic device in which the swash plate 15 is tiltable. The swash plate 15 does not necessarily have to have the shoe plate 15b, and may have only the swash plate body 15 a. In this case, the shoe 17 slides on the swash plate body 15 a.
Claims (8)
1. A piston assembly of a hydraulic rotary device having a swash plate, characterized in that,
the disclosed device is provided with:
a piston having a piston through hole penetrating in an axial direction and a spherical convex portion formed at one end in the axial direction; and
a shoe having a concave spherical portion into which the convex spherical portion is slidably fitted, a sliding surface that slides with respect to the swash plate, a shoe through-hole that penetrates between the concave spherical portion and the sliding surface, a through-hole forming portion that is formed around the shoe through-hole and that has a protruding portion protruding toward the concave spherical portion, and a catching groove that is formed around the protruding portion of the through-hole forming portion;
the through hole forming portion forms a throttle portion between the through hole forming portion and the convex portion.
2. The piston assembly according to claim 1, wherein a flow passage area of the throttle portion is larger than a flow passage area of at least a part of the shoe through hole.
3. The piston assembly according to claim 1, wherein the slipper through-hole has a first passage portion formed on the concave ball portion side and a second passage portion formed closer to the sliding surface side than the first passage portion and having a smaller hole diameter than the first passage portion.
4. The piston assembly according to claim 3, wherein a flow passage area of the throttle portion is 5 times or more as large as a flow passage area of the first passage portion.
5. The piston assembly according to any one of claims 1 to 4, wherein a depth of the catching groove is 1.5 times or more a width of the throttle portion.
6. A piston assembly of a hydraulic rotary device having a swash plate, characterized in that,
the disclosed device is provided with:
a piston having a piston through hole penetrating in an axial direction and a spherical convex portion formed at one end in the axial direction; and
a shoe having a concave spherical portion into which the convex spherical portion is slidably fitted, a sliding surface on which the swash plate slides, a shoe through-hole that penetrates between the concave spherical portion and the sliding surface, a through-hole forming portion formed around the shoe through-hole and having a protruding portion protruding toward the concave spherical portion, and a catching groove formed around the protruding portion of the through-hole forming portion;
the catching groove has a concavely curved bottom surface facing the sliding surface side;
the shoe through hole has a first passage portion formed on the concave ball portion side and a second passage portion formed closer to the sliding surface side than the first passage portion and having a smaller diameter than the first passage portion.
7. The piston assembly of claim 6, wherein a circumferential surface of said catching groove is formed in a steep form.
8. A hydraulic rotating device is characterized by comprising: a piston assembly of any one of claims 1 to 7;
a shell;
a cylinder rotatably housed in the housing and having a plurality of piston chambers in which the pistons are housed so as to be able to advance and retreat; and
the inclined plate is used for sliding the sliding shoes.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2020-077382 | 2020-04-24 | ||
| JP2020077382A JP2021173216A (en) | 2020-04-24 | 2020-04-24 | Piston assembly, and hydraulic rotary device with the same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN214887511U true CN214887511U (en) | 2021-11-26 |
Family
ID=78281391
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202120844522.5U Active CN214887511U (en) | 2020-04-24 | 2021-04-23 | Piston assembly and hydraulic rotary device provided with same |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP2021173216A (en) |
| CN (1) | CN214887511U (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2023062994A (en) | 2021-10-22 | 2023-05-09 | 株式会社日本製鋼所 | Shut-off nozzle, injection apparatus, and injection molding machine |
-
2020
- 2020-04-24 JP JP2020077382A patent/JP2021173216A/en active Pending
-
2021
- 2021-04-23 CN CN202120844522.5U patent/CN214887511U/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| JP2021173216A (en) | 2021-11-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP0829643B1 (en) | Vane type rotary pump | |
| US10451063B2 (en) | Vane pump including back pressure grooves | |
| CN214887511U (en) | Piston assembly and hydraulic rotary device provided with same | |
| US6877969B2 (en) | Vane pump | |
| JP3547900B2 (en) | Axial piston type hydraulic pump | |
| CN100447410C (en) | Axial piston hydraulic pump motor | |
| JP6401509B2 (en) | Piston pump and piston pump valve plate | |
| JP2010174690A (en) | Valve plate, and piston pump or motor equipped with the same | |
| KR100289782B1 (en) | Hydraulic pump | |
| US20160003241A1 (en) | Vane pump | |
| US20060104828A1 (en) | Radial plunger pump and method for manufacturing pump housing | |
| JP6770370B2 (en) | Vane pump | |
| JP6670119B2 (en) | Vane pump | |
| EP1209360A1 (en) | Rotary pump apparatus | |
| JP5307514B2 (en) | Hydraulic piston pump / motor | |
| US7314359B2 (en) | Vane pump for continuously variable transmission | |
| JP2002048252A (en) | Switching valve | |
| JPH07189887A (en) | Axial piston type pump | |
| JP3909988B2 (en) | Rotary swash plate type piston pump | |
| JP2000073939A (en) | Piston pump | |
| JP6006646B2 (en) | Hydraulic system using piston pump | |
| JPH09280159A (en) | Axial piston type hydraulic pump | |
| US20240352932A1 (en) | Variable-Capacity Oil Pump | |
| US20240369060A1 (en) | Variable Displacement Oil Pump | |
| JP2018168780A (en) | Vane type compressor |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |