EP1600642B1 - Hydraulic device - Google Patents
Hydraulic device Download PDFInfo
- Publication number
- EP1600642B1 EP1600642B1 EP04716722A EP04716722A EP1600642B1 EP 1600642 B1 EP1600642 B1 EP 1600642B1 EP 04716722 A EP04716722 A EP 04716722A EP 04716722 A EP04716722 A EP 04716722A EP 1600642 B1 EP1600642 B1 EP 1600642B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- fluid pressure
- cylinder
- inner cylinder
- tank chamber
- chamber
- 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.)
- Expired - Fee Related
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Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
- F15B11/08—Servomotor systems without provision for follow-up action; Circuits therefor with only one servomotor
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B23/00—Pumping installations or systems
- F04B23/02—Pumping installations or systems having reservoirs
- F04B23/021—Pumping installations or systems having reservoirs the pump being immersed in the reservoir
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B23/00—Pumping installations or systems
- F04B23/02—Pumping installations or systems having reservoirs
- F04B23/025—Pumping installations or systems having reservoirs the pump being located directly adjacent the reservoir
- F04B23/026—Pumping installations or systems having reservoirs the pump being located directly adjacent the reservoir a pump-side forming a wall of the reservoir
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
- F15B15/18—Combined units comprising both motor and pump
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B7/00—Systems in which the movement produced is definitely related to the output of a volumetric pump; Telemotors
- F15B7/06—Details
- F15B7/10—Compensation of the liquid content in a system
Definitions
- the present invention relates to a fluid pressure apparatus in which both ports of a fluid pressure pump, driven by an electric motor and rotatable in both directions, are respectively connected to both ports of a fluid pressure actuator through a pair of pipe lines.
- An object of the present invention is to provide a fluid pressure apparatus whose installation position is not restricted.
- a fluid pressure apparatus provided with a fluid pressure pump driven by an electric motor and rotatable in both directions, both ports of a fluid pressure actuator and both ports of the fluid pressure pump being respectively connected through a pair of pipe lines, wherein a sliding cavity is formed between an outer cylinder and an inner cylinder.
- the sliding cavity is divided into a preload chamber and a tank chamber by a piston slidably inserted in the sliding cavity.
- the tank chamber and the pair of pipe lines are connected through check valves respectively provided in directions so as to allow discharge from the tank chamber to the fluid pressure actuator.
- the tank chamber is preloaded with the air pressure introduced into the preload chamber, and the fluid pressure pump is disposed in the inner cylinder.
- the fluid pressure pump may be a swash plate pump. Also, it may be possible to arrange the outer cylinder and the inner cylinder coaxially with a rotating shaft of the electric motor, and mount the outer cylinder and the inner cylinder on the electric motor. Furthermore, the tank chamber may communicate with the inside of the inner cylinder. Alternatively, a top end of the rotating shaft of the electric motor may be rotatably supported by a lid member closing one end of the outer cylinder and one end of the inner cylinder.
- Fig. 1 is a cross-sectional view of a fluid pressure apparatus as an embodiment of the present invention.
- Fig. 2 is a hydraulic circuit diagram of the fluid pressure apparatus according to the present embodiment.
- a fluid pressure pump 1 is a swash plate piston pump that can be rotated in both directions. During a rotation in a forward direction, an operating fluid is drawn in from the side of a first port 2 and discharged from the side of a second port 4. During a rotation in a reverse direction, the operating fluid is drawn in from the side of the second port 4 and discharged from the side of the first port 2.
- the fluid pressure pump 1 is connected so as to be rotationally driven by an electric motor 6, such as a servomotor.
- a head side pipe line 8 and a rod side pipe line 10 are respectively connected to the first port 2 and the second port 4.
- the head side pipe line 8 is connected to a head side port 14 of a fluid pressure cylinder 12 of a single-rod type, while the rod side pipe line 10 is connected to a rod side port 16 of the fluid pressure cylinder 12.
- any fluid actuator may be employed, such as a fluid pressure cylinder of a double-rod type and a fluid pressure motor.
- An after-mentioned tank chamber 18 is connected to the head side pipe line 8 through a pilot check valve 20.
- the pilot check valve 20 is oriented in a direction to allow the flow from the tank chamber 18 toward the head side pipe line 8.
- the pilot check valve 20 is connected so as to introduce the fluid pressure in the rod side pipe line 10 as a pilot pressure, and be opened to make the head side pipe line 8 communicate with the tank chamber 18 when the fluid pressure in the rod side pipe line 10 is increased.
- the rod side pipe line 10 is connected to the tank chamber 18 through a pilot check valve 22.
- the pilot valve 22 is oriented in a direction to allow the flow from the tank chamber 18 toward the rod side pipe line 10.
- the pilot check valve 22 is connected so as to introduce the fluid pressure in the head side pipe line 8 as a pilot pressure, and be opened to make the rod side pipe line 10 communicate with the tank chamber 18 when the fluid pressure in the head side pipe line 8 is increased.
- the head side pipe line 8 and the rod side pipe line 10 are connected to the tank chamber 18 through relief valves 24, 26, respectively.
- the relief valves 24, 26 may be provided when necessary.
- a tank body 36 including a tubular outer cylinder 32 and a tubular inner cylinder 34 having a smaller diameter than the outer cylinder 32 and being formed within the outer cylinder 32.
- the outer diameter of the outer cylinder 32 is designed to be approximately the same as the outer diameter of the electric motor 6.
- the outer cylinder 32 and the inner cylinder 34 are arranged coaxially with each other.
- a ring-shaped sliding cavity 38 is formed between the outer cylinder 32 and the inner cylinder 34, one end of the ring-shaped sliding cavity 38 being closed by a wall 40.
- the wall 40 is mounted on one end of the electric motor 6, and thereby the tank body 36 is fixed to the electric motor 6.
- a rotating shaft 42 of the electric motor 6 is provided so as to be positioned coaxially with the outer cylinder 32 and the inner cylinder 34.
- a ring-shaped piston 44 sealed by O-rings 46, 48 is slidably inserted in the sliding cavity 38.
- the sliding cavity 38 is divided into a preload chamber 50, on the side of the wall 40, and the tank chamber 18 by the piston 44.
- a lid member 52 is mounted to the other end of the sliding cavity 38 defined by the outer cylinder 32 and the inner cylinder 34, thereby closing the tank chamber 18.
- the lid member 52 is also inserted inside the inner circumference of the inner cylinder 34 so as to rotatably support a top end of the rotating shaft 42, through a bearing 54.
- a pump chamber 56 is formed by being enclosed by the inner cylinder 34, the wall 40, and the lid member 52.
- the rotating shaft 42 sealed by a seal 57, penetrates the pump chamber 56.
- a cylinder block 58 engagingly attached to and integrally rotatable with the rotating shaft 42, is disposed within the pump chamber 56.
- the cylinder block 58 is provided with a plurality of cylinder holes 60 bored in the axial direction. Through holes 62 are respectively bored adjacent to the cylinder holes 60, and pistons 64 are slidably inserted into the respective cylinder holes 60, so that cylinder chambers 66 are formed by the cylinder holes 60 and the pistons 64.
- a valve plate 68 is provided between the cylinder block 58 and the lid member 52, such that the through holes 62 may communicate with the first port 2 and the second port 4 through a not-shown pair of port holes formed in the valve plate 68 in accordance with the rotation of the cylinder block 58
- a shoe 70 provided to be spherically connected to one end of each of the pistons 64, is designed to slide on an anti-friction member 74 attached to a swash plate 72.
- the swash plate 72 is firmly attached to the wall 40 of the tank body 36 so as to be restricted from rotation.
- a coil spring 76 housed in the preload chamber 50, biases the piston 44 toward the tank chamber 18.
- the preload chamber 50 which is connected to a connection port 78, is connected to an air pressure source 80 through the connection port 78.
- the operating fluid is drawn from the head side port 14 of the fluid pressure cylinder 12 through the head side pipe line 8 into the first port 2 of the fluid pressure pump 1. Also, the pressure fluid is supplied from the second port 4, through the rod side pipe line 10, and the rod side port 16 to the fluid pressure cylinder 12.
- a cylinder rod 86 is driven in a pulling direction.
- the amount of the operating fluid discharged from the head side port 14 is different from the amount of the pressure fluid flowing in from the rod side port 16 by the volume of the cylinder rod 86.
- the excess amount of the operating fluid is discharged through the head side pipe line 8 to the tank chamber 18, since the pilot check valve 20 is opened by the operation of the pilot pressure from the rod side pipe line 10.
- the operation speed and the moving amount of the fluid pressure cylinder 12 can be controlled by controlling the electric motor 6.
- the operating fluid is drawn from the second port 4 of the fluid pressure pump 1 through the rod side port 16 of the fluid pressure cylinder 12, and the rod side pipe line 10, while the pressure fluid is supplied to the fluid pressure cylinder 12 through the first port 2, the head side pipe line 8, and the head side port 14. Accordingly, the cylinder rod 86 is driven in a pushing direction.
- the amount of the operating fluid discharged from the rod side port 16 is different from the amount of the pressure fluid flowing in from the head side port 14 by the volume of the cylinder rod 86 in the same manner as described above.
- the deficient amount of the operating fluid is supplied from the tank chamber 18 to the rod side pipe line 10 through the pilot check valve 22, since the pressure in the rod side pipe line 10 is decreased, and thereby the pilot check valve 22 is opened.
- the operating fluid is supplied to the rod side pipe line 10 through the pilot check valve 22 due to the preload applied to the tank chamber 18, which prevents the occurrence of cavitation on the drawing side of the fluid pressure pump 1.
- both pilot check valves 20 and 20 are opened by the operating fluid pressure in the tank chamber 18 due to the preload of the compressed air from the air pressure source 80. Thereby, the pressure in the tank chamber 18 is introduced into the head side pipe line 8 and the rod side pipe line 10.
- the fluid pressure is introduced through both ports 14 and 16 of the fluid pressure cylinder 12, and the cylinder rod 86 is made difficult to move by a small external force even if the external force is applied to the cylinder rod 86 and, therefore, is prevented from deflecting.
- the tank chamber 18 is preloaded by the piston 44 regardless of the installation position of the tank body 36, there is no restriction on the installation position of the fluid pressure apparatus.
- the circular tank chamber 18 is provided outside the fluid pressure pump 1, a sufficient volume of the tank chamber 18 can be secured and downsizing of the fluid pressure apparatus can be achieved.
- the present invention is not limited to the above described embodiment.
- the fluid pressure apparatus of the present invention presents an advantage that an appropriate preload pressure can be applied regardless of its installation position as well as an advantage that downsizing can be achieved.
- a fluid pressure apparatus capable of applying an appropriate preload pressure regardless of its installation position and capable of being downsized.
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Fluid-Pressure Circuits (AREA)
- Reciprocating Pumps (AREA)
Description
- Technical Field
- The present invention relates to a fluid pressure apparatus in which both ports of a fluid pressure pump, driven by an electric motor and rotatable in both directions, are respectively connected to both ports of a fluid pressure actuator through a pair of pipe lines.
- Background Art
- There are known conventional fluid pressure apparatus, such as one shown in Publication of Unexamined
Japanese Patent Application No. 10-26101 page 2,FIG. 2 ), in which both ports of a fluid pressure pump driven, by an electric motor and rotatable in both directions, are respectively connected to both ports of a fluid pressure actuator through a pair of pipe lines. In this fluid pressure apparatus, a fluid pressure tank and a pair of pipe lines are connected through check valves oriented in respective directions to allow the flow from the fluid pressure tank. The sealed fluid pressure tank is preloaded by introducing air pressure. - According to such a conventional fluid pressure apparatus, however, a supply pipe connected to an air pressure source is connected to the sealed fluid pressure tank, and air pressure is introduced directly to the sealed fluid pressure tank. This leads to a problem that in the installation of the fluid pressure tank, it is necessary for an air layer formed in the fluid pressure tank to be located in an upper position. In other words, the installation position of the fluid pressure tank is restricted. From
JP 61-294 201 - An object of the present invention is to provide a fluid pressure apparatus whose installation position is not restricted.
- Disclosure of Invention
- To achieve the above mentioned object, the present invention has taken the following measures: there is provided a fluid pressure apparatus provided with a fluid pressure pump driven by an electric motor and rotatable in both directions, both ports of a fluid pressure actuator and both ports of the fluid pressure pump being respectively connected through a pair of pipe lines, wherein a sliding cavity is formed between an outer cylinder and an inner cylinder. The sliding cavity is divided into a preload chamber and a tank chamber by a piston slidably inserted in the sliding cavity. The tank chamber and the pair of pipe lines are connected through check valves respectively provided in directions so as to allow discharge from the tank chamber to the fluid pressure actuator. The tank chamber is preloaded with the air pressure introduced into the preload chamber, and the fluid pressure pump is disposed in the inner cylinder.
- The fluid pressure pump may be a swash plate pump. Also, it may be possible to arrange the outer cylinder and the inner cylinder coaxially with a rotating shaft of the electric motor, and mount the outer cylinder and the inner cylinder on the electric motor. Furthermore, the tank chamber may communicate with the inside of the inner cylinder. Alternatively, a top end of the rotating shaft of the electric motor may be rotatably supported by a lid member closing one end of the outer cylinder and one end of the inner cylinder.
- Brief Description of Drawings
-
Fig. 1 is a cross-sectional view of a fluid pressure apparatus as an embodiment of the present invention; and -
Fig. 2 is a hydraulic circuit diagram of the fluid pressure apparatus according to the present embodiment. - Best Mode for Carrying Out the Invention
- An embodiment of the present invention will be described below in detail based on the drawings.
- As shown in
FIG. 2 , afluid pressure pump 1 is a swash plate piston pump that can be rotated in both directions. During a rotation in a forward direction, an operating fluid is drawn in from the side of afirst port 2 and discharged from the side of asecond port 4. During a rotation in a reverse direction, the operating fluid is drawn in from the side of thesecond port 4 and discharged from the side of thefirst port 2. Thefluid pressure pump 1 is connected so as to be rotationally driven by anelectric motor 6, such as a servomotor. - A head
side pipe line 8 and a rodside pipe line 10 are respectively connected to thefirst port 2 and thesecond port 4. The headside pipe line 8 is connected to a head side port 14 of a fluid pressure cylinder 12 of a single-rod type, while the rodside pipe line 10 is connected to a rod side port 16 of the fluid pressure cylinder 12. Other than the fluid pressure cylinder 12 of a single-rod type, any fluid actuator may be employed, such as a fluid pressure cylinder of a double-rod type and a fluid pressure motor. - An after-mentioned
tank chamber 18 is connected to the headside pipe line 8 through apilot check valve 20. Thepilot check valve 20 is oriented in a direction to allow the flow from thetank chamber 18 toward the headside pipe line 8. Thepilot check valve 20 is connected so as to introduce the fluid pressure in the rodside pipe line 10 as a pilot pressure, and be opened to make the headside pipe line 8 communicate with thetank chamber 18 when the fluid pressure in the rodside pipe line 10 is increased. - Also, the rod
side pipe line 10 is connected to thetank chamber 18 through a pilot check valve 22. The pilot valve 22 is oriented in a direction to allow the flow from thetank chamber 18 toward the rodside pipe line 10. The pilot check valve 22 is connected so as to introduce the fluid pressure in the headside pipe line 8 as a pilot pressure, and be opened to make the rodside pipe line 10 communicate with thetank chamber 18 when the fluid pressure in the headside pipe line 8 is increased. In the present embodiment, the headside pipe line 8 and the rodside pipe line 10 are connected to thetank chamber 18 throughrelief valves 24, 26, respectively. Therelief valves 24, 26 may be provided when necessary. - As shown in
FIG. 1 , there is provided atank body 36 including a tubularouter cylinder 32 and a tubular inner cylinder 34 having a smaller diameter than theouter cylinder 32 and being formed within theouter cylinder 32. The outer diameter of theouter cylinder 32 is designed to be approximately the same as the outer diameter of theelectric motor 6. Theouter cylinder 32 and the inner cylinder 34 are arranged coaxially with each other. - A ring-shaped
sliding cavity 38 is formed between theouter cylinder 32 and the inner cylinder 34, one end of the ring-shapedsliding cavity 38 being closed by awall 40. - The
wall 40 is mounted on one end of theelectric motor 6, and thereby thetank body 36 is fixed to theelectric motor 6. A rotating shaft 42 of theelectric motor 6 is provided so as to be positioned coaxially with theouter cylinder 32 and the inner cylinder 34. - A ring-
shaped piston 44 sealed by O-rings 46, 48 is slidably inserted in thesliding cavity 38. Thesliding cavity 38 is divided into apreload chamber 50, on the side of thewall 40, and thetank chamber 18 by thepiston 44. Alid member 52 is mounted to the other end of thesliding cavity 38 defined by theouter cylinder 32 and the inner cylinder 34, thereby closing thetank chamber 18. Thelid member 52 is also inserted inside the inner circumference of the inner cylinder 34 so as to rotatably support a top end of the rotating shaft 42, through abearing 54. - A pump chamber 56 is formed by being enclosed by the inner cylinder 34, the
wall 40, and thelid member 52. The rotating shaft 42, sealed by a seal 57, penetrates the pump chamber 56. A cylinder block 58, engagingly attached to and integrally rotatable with the rotating shaft 42, is disposed within the pump chamber 56. The cylinder block 58 is provided with a plurality ofcylinder holes 60 bored in the axial direction. Through holes 62 are respectively bored adjacent to thecylinder holes 60, and pistons 64 are slidably inserted into therespective cylinder holes 60, so that cylinder chambers 66 are formed by thecylinder holes 60 and the pistons 64. - A valve plate 68 is provided between the cylinder block 58 and the
lid member 52, such that the through holes 62 may communicate with thefirst port 2 and thesecond port 4 through a not-shown pair of port holes formed in the valve plate 68 in accordance with the rotation of the cylinder block 58 - On the other hand, a
shoe 70, provided to be spherically connected to one end of each of the pistons 64, is designed to slide on an anti-friction member 74 attached to aswash plate 72. Theswash plate 72 is firmly attached to thewall 40 of thetank body 36 so as to be restricted from rotation. - A coil spring 76, housed in the
preload chamber 50, biases thepiston 44 toward thetank chamber 18. Thepreload chamber 50, which is connected to aconnection port 78, is connected to anair pressure source 80 through theconnection port 78. Thetank chamber 18, communicating with the pump chamber 56 through a communication path 82, is connected to the above-mentionedpilot check valves 20 and 22, andrelief valves 24 and 26, through a connecting duct 84. - Next, the operation of the above described fluid apparatus in the present embodiment will be described.
- When the
electric motor 6 is rotated in a forward direction, the rotating shaft 42 rotates together with the cylinder block 58. This causes eachshoe 70 to slide on the anti-friction member 74 and each piston 64 to slide within thesliding hole 60 in accordance with the inclination of theswash plate 72, thereby changing the volume of the cylinder chamber 66. So that, an operating fluid is drawn through thefirst port 2 and a pressure fluid is discharged through thesecond port 4. - Accordingly, the operating fluid is drawn from the head side port 14 of the fluid pressure cylinder 12 through the head
side pipe line 8 into thefirst port 2 of thefluid pressure pump 1. Also, the pressure fluid is supplied from thesecond port 4, through the rodside pipe line 10, and the rod side port 16 to the fluid pressure cylinder 12. - Then, a
cylinder rod 86 is driven in a pulling direction. In this case, the amount of the operating fluid discharged from the head side port 14 is different from the amount of the pressure fluid flowing in from the rod side port 16 by the volume of thecylinder rod 86. The excess amount of the operating fluid is discharged through the headside pipe line 8 to thetank chamber 18, since thepilot check valve 20 is opened by the operation of the pilot pressure from the rodside pipe line 10. In this regard, the operation speed and the moving amount of the fluid pressure cylinder 12 can be controlled by controlling theelectric motor 6. - When the
electric motor 6 is rotated in a reverse direction, the operating fluid is drawn from thesecond port 4 of thefluid pressure pump 1 through the rod side port 16 of the fluid pressure cylinder 12, and the rodside pipe line 10, while the pressure fluid is supplied to the fluid pressure cylinder 12 through thefirst port 2, the headside pipe line 8, and the head side port 14. Accordingly, thecylinder rod 86 is driven in a pushing direction. - In this case, the amount of the operating fluid discharged from the rod side port 16 is different from the amount of the pressure fluid flowing in from the head side port 14 by the volume of the
cylinder rod 86 in the same manner as described above. The deficient amount of the operating fluid is supplied from thetank chamber 18 to the rodside pipe line 10 through the pilot check valve 22, since the pressure in the rodside pipe line 10 is decreased, and thereby the pilot check valve 22 is opened. Specifically, the operating fluid is supplied to the rodside pipe line 10 through the pilot check valve 22 due to the preload applied to thetank chamber 18, which prevents the occurrence of cavitation on the drawing side of thefluid pressure pump 1. - In contrast, when the rotation of the
electric motor 6 is stopped, the pressure fluid is not discharged from thefluid pressure pump 1. Accordingly, bothpilot check valves tank chamber 18 due to the preload of the compressed air from theair pressure source 80. Thereby, the pressure in thetank chamber 18 is introduced into the headside pipe line 8 and the rodside pipe line 10. - As a result, the fluid pressure is introduced through both ports 14 and 16 of the fluid pressure cylinder 12, and the
cylinder rod 86 is made difficult to move by a small external force even if the external force is applied to thecylinder rod 86 and, therefore, is prevented from deflecting. Also, since thetank chamber 18 is preloaded by thepiston 44 regardless of the installation position of thetank body 36, there is no restriction on the installation position of the fluid pressure apparatus. In addition, since thecircular tank chamber 18 is provided outside thefluid pressure pump 1, a sufficient volume of thetank chamber 18 can be secured and downsizing of the fluid pressure apparatus can be achieved. - The present invention is not limited to the above described embodiment.
- As described in detail above, the fluid pressure apparatus of the present invention presents an advantage that an appropriate preload pressure can be applied regardless of its installation position as well as an advantage that downsizing can be achieved.
- Industrial Applicability
- According to the present invention, there is provided a fluid pressure apparatus capable of applying an appropriate preload pressure regardless of its installation position and capable of being downsized.
Claims (5)
- A fluid pressure apparatus provided with a fluid pressure pump (1) driven by an electric motor (6) and rotatable in both directions, both ports of a fluid pressure actuator (12) and both ports of the fluid pressure pump (1) being respectively connected through a pair of pipe lines (8, 10),
wherein a sliding cavity(38) is formed between an outer cylinder (32) and an inner cylinder (34), the sliding cavity (38) being divided into a preload chamber (50) and a tank chamber (18) by a piston (44) slidably inserted in the sliding cavity (38);
wherein the tank chamber (18) and the pair of pipe lines are connected through check valves (20, 22) respectively provided in directions so as to allow allow discharging of fluid from the tank chamber (18) to the fluid pressure actuator (12), the tank chamber (18) being preloaded via the piston (44) with air pressure introduced into the preload chamber (50),
and wherein the fluid pressure pump (1) is disposed in the inner cylinder (34). - The fluid pressure apparatus as set forth in claim 1, wherein the fluid pressure pump (1) is a swash plate piston pump.
- The fluid pressure apparatus as set forth in claim 1 or 2, wherein the outer cylinder (32) and the inner cylinder (34) are arranged coaxially with a rotating shaft (42) of the electric motor (6), and the outer cylinder (32) and the inner cylinder (34) are mounted on the electric motor.
- The fluid pressure apparatus as set forth in any of claims 1 to 3, wherein the tank chamber (18) communicates with the inside (82) of the inner cylinder (34).
- The fluid pressure apparatus as set forth in any of claims 1 to 4, wherein a top end of the rotating shaft (42) of the electric motor (6) is rotatably supported by a lid member (52) closing one end of the outer cylinder (32) and one end of the inner cylinder (34).
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2003056258A JP2004263806A (en) | 2003-03-03 | 2003-03-03 | Hydraulic apparatus |
JP2003056258 | 2003-03-03 | ||
PCT/JP2004/002660 WO2004079205A1 (en) | 2003-03-03 | 2004-03-03 | Hydraulic device |
Publications (3)
Publication Number | Publication Date |
---|---|
EP1600642A1 EP1600642A1 (en) | 2005-11-30 |
EP1600642A4 EP1600642A4 (en) | 2007-07-04 |
EP1600642B1 true EP1600642B1 (en) | 2008-10-15 |
Family
ID=32958691
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP04716722A Expired - Fee Related EP1600642B1 (en) | 2003-03-03 | 2004-03-03 | Hydraulic device |
Country Status (6)
Country | Link |
---|---|
US (1) | US20050175467A1 (en) |
EP (1) | EP1600642B1 (en) |
JP (1) | JP2004263806A (en) |
KR (1) | KR20050105971A (en) |
DE (1) | DE602004017135D1 (en) |
WO (1) | WO2004079205A1 (en) |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4317862B2 (en) | 2006-09-15 | 2009-08-19 | 三菱重工業株式会社 | Track system |
CN102454647A (en) * | 2010-10-20 | 2012-05-16 | 住友重机械工业株式会社 | Injection molding machine and hydraulic actuator |
US10871174B2 (en) | 2015-10-23 | 2020-12-22 | Aol | Prime mover system and methods utilizing balanced flow within bi-directional power units |
EP3884170A4 (en) * | 2018-11-21 | 2022-06-08 | AOI (Advanced Oilfield Innovations, Dba A.O. International II, Inc.) | Prime mover system and methods utilizing balanced fluid flow |
DE102019215975A1 (en) * | 2019-10-17 | 2021-04-22 | Deere & Company | Hydraulic arrangement |
Family Cites Families (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2457467A (en) * | 1945-03-08 | 1948-12-28 | Cons Vultee Aircraft Corp | Electrically and hydraulically operated extensible strut |
JPS61294201A (en) * | 1985-06-24 | 1986-12-25 | Matsushita Electric Ind Co Ltd | Hydraulic unit |
JPS63150102U (en) * | 1987-03-23 | 1988-10-03 | ||
JPS63176880A (en) * | 1988-01-12 | 1988-07-21 | Ogura:Kk | Hydraulic actuator |
US5144801A (en) * | 1989-04-28 | 1992-09-08 | Parker Hannifin Corporation | Electro-hydraulic actuator system |
JPH0960607A (en) * | 1995-08-23 | 1997-03-04 | Opton Co Ltd | Hydraulic driving device |
JPH1026101A (en) * | 1996-07-10 | 1998-01-27 | Opton Co Ltd | Hydraulic pressure device |
US20010023928A1 (en) * | 2000-01-06 | 2001-09-27 | Green David Kentfiled | Electrohydraulic valve actuator |
US6979185B2 (en) * | 2000-08-01 | 2005-12-27 | Kaempe Staffan I | Bi-rotational pump/hydraulic actuator |
FR2831226B1 (en) * | 2001-10-24 | 2005-09-23 | Snecma Moteurs | AUTONOMOUS ELECTROHYDRAULIC ACTUATOR |
-
2003
- 2003-03-03 JP JP2003056258A patent/JP2004263806A/en active Pending
-
2004
- 2004-03-03 KR KR1020057001346A patent/KR20050105971A/en not_active Application Discontinuation
- 2004-03-03 US US10/520,971 patent/US20050175467A1/en not_active Abandoned
- 2004-03-03 EP EP04716722A patent/EP1600642B1/en not_active Expired - Fee Related
- 2004-03-03 WO PCT/JP2004/002660 patent/WO2004079205A1/en active Application Filing
- 2004-03-03 DE DE602004017135T patent/DE602004017135D1/en not_active Expired - Lifetime
Also Published As
Publication number | Publication date |
---|---|
WO2004079205A1 (en) | 2004-09-16 |
JP2004263806A (en) | 2004-09-24 |
US20050175467A1 (en) | 2005-08-11 |
DE602004017135D1 (en) | 2008-11-27 |
EP1600642A4 (en) | 2007-07-04 |
EP1600642A1 (en) | 2005-11-30 |
KR20050105971A (en) | 2005-11-08 |
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