US20150240636A1 - Opposed swash plate type fluid pressure rotating machine - Google Patents
Opposed swash plate type fluid pressure rotating machine Download PDFInfo
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- US20150240636A1 US20150240636A1 US14/431,350 US201414431350A US2015240636A1 US 20150240636 A1 US20150240636 A1 US 20150240636A1 US 201414431350 A US201414431350 A US 201414431350A US 2015240636 A1 US2015240636 A1 US 2015240636A1
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- United States
- Prior art keywords
- swash plate
- tilt
- piston
- pressure chamber
- tilt driving
- 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.)
- Abandoned
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Classifications
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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
- F04B3/00—Machines or pumps with pistons coacting within one cylinder, e.g. multi-stage
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01B—MACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES
- F01B3/00—Reciprocating-piston machines or engines with cylinder axes coaxial with, or parallel or inclined to, main shaft axis
- F01B3/0032—Reciprocating-piston machines or engines with cylinder axes coaxial with, or parallel or inclined to, main shaft axis having rotary cylinder block
- F01B3/0035—Reciprocating-piston machines or engines with cylinder axes coaxial with, or parallel or inclined to, main shaft axis having rotary cylinder block having two or more sets of cylinders or pistons
- F01B3/0038—Reciprocating-piston machines or engines with cylinder axes coaxial with, or parallel or inclined to, main shaft axis having rotary cylinder block having two or more sets of cylinders or pistons inclined to main shaft axis
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01B—MACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES
- F01B3/00—Reciprocating-piston machines or engines with cylinder axes coaxial with, or parallel or inclined to, main shaft axis
- F01B3/0032—Reciprocating-piston machines or engines with cylinder axes coaxial with, or parallel or inclined to, main shaft axis having rotary cylinder block
- F01B3/0044—Component parts, details, e.g. valves, sealings, lubrication
- F01B3/0052—Cylinder barrel
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01B—MACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES
- F01B3/00—Reciprocating-piston machines or engines with cylinder axes coaxial with, or parallel or inclined to, main shaft axis
- F01B3/0032—Reciprocating-piston machines or engines with cylinder axes coaxial with, or parallel or inclined to, main shaft axis having rotary cylinder block
- F01B3/0044—Component parts, details, e.g. valves, sealings, lubrication
- F01B3/007—Swash plate
- F01B3/0073—Swash plate swash plate bearing means or driving or driven axis bearing means
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
- F03C—POSITIVE-DISPLACEMENT ENGINES DRIVEN BY LIQUIDS
- F03C1/00—Reciprocating-piston liquid engines
- F03C1/02—Reciprocating-piston liquid engines with multiple-cylinders, characterised by the number or arrangement of cylinders
- F03C1/06—Reciprocating-piston liquid engines with multiple-cylinders, characterised by the number or arrangement of cylinders with cylinder axes generally coaxial with, or parallel or inclined to, main shaft axis
- F03C1/0636—Reciprocating-piston liquid engines with multiple-cylinders, characterised by the number or arrangement of cylinders with cylinder axes generally coaxial with, or parallel or inclined to, main shaft axis having rotary cylinder block
- F03C1/0639—Reciprocating-piston liquid engines with multiple-cylinders, characterised by the number or arrangement of cylinders with cylinder axes generally coaxial with, or parallel or inclined to, main shaft axis having rotary cylinder block having two or more sets of cylinders or pistons
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
- F03C—POSITIVE-DISPLACEMENT ENGINES DRIVEN BY LIQUIDS
- F03C1/00—Reciprocating-piston liquid engines
- F03C1/02—Reciprocating-piston liquid engines with multiple-cylinders, characterised by the number or arrangement of cylinders
- F03C1/06—Reciprocating-piston liquid engines with multiple-cylinders, characterised by the number or arrangement of cylinders with cylinder axes generally coaxial with, or parallel or inclined to, main shaft axis
- F03C1/0678—Control
- F03C1/0686—Control by changing the inclination of the swash plate
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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
- F04B1/00—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders
- F04B1/12—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinder axes coaxial with, or parallel or inclined to, main shaft axis
- F04B1/20—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinder axes coaxial with, or parallel or inclined to, main shaft axis having rotary cylinder block
- F04B1/22—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinder axes coaxial with, or parallel or inclined to, main shaft axis having rotary cylinder block having two or more sets of cylinders or pistons
-
- 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
- F04B1/00—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders
- F04B1/12—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinder axes coaxial with, or parallel or inclined to, main shaft axis
- F04B1/26—Control
-
- 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
- F04B1/00—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders
- F04B1/12—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinder axes coaxial with, or parallel or inclined to, main shaft axis
- F04B1/26—Control
- F04B1/30—Control of machines or pumps with rotary cylinder blocks
- F04B1/32—Control of machines or pumps with rotary cylinder blocks by varying the relative positions of a swash plate and a cylinder block
- F04B1/324—Control of machines or pumps with rotary cylinder blocks by varying the relative positions of a swash plate and a cylinder block by changing the inclination of the swash plate
Definitions
- the prevent invention relates to an opposed swash plate type fluid pressure rotating machine in which a first swash plate and a second swash plate are tilted while facing opposite ends of a cylinder block.
- JP2008-231924A discloses an opposed swash plate type fluid pressure rotating machine provided with a cylinder block including a plurality of cylinders, first pistons and second pistons projecting from opposite ends of the cylinders and a first swash plate and a second swash plate with which projecting ends of the first and second pistons respectively slide in contact.
- the first pistons reciprocate in the cylinders, following the first swash plate, and the second pistons reciprocate in the cylinders, following the second swash plate, whereby working fluid is supplied to and discharged from volume chambers in the cylinders.
- a tilt driving piston for tilting the first swash plate is coupled to one side of the first swash plate and a tilt interlocking mechanism for transmitting the inclination of the first swash plate to the second swash plate is coupled to the other side of the first swash plate.
- the tilt driving piston When the first swash plate is tilted by the tilt driving piston, the second swash plate is also tilted via the tilt interlocking mechanism.
- the floating phenomenon is a phenomenon in which the first swash plate rotates about a rotary shaft of the cylinder block and the tilt shaft part of the first swash plate is separated from the tilt bearing by the action of a force of the tilt driving piston received by the one side of the first swash plate and a reaction force of the tilt interlocking mechanism received by the other side of the first swash plate when the first swash plate is tilted as a torque in the same rotating direction.
- the present invention aims to prevent a floating phenomenon in an opposed swash plate type fluid pressure rotating machine.
- an opposed swash plate type fluid pressure rotating machine in which a first piston and a second piston projecting from opposite ends of a rotary cylinder block reciprocate in a cylinder, respectively following a first swash plate and a second swash plate.
- the opposed swash plate type fluid pressure rotating machine includes a first tilt bearing for tiltably supporting the first swash plate, a first tilt driving piston for tilting the first swash plate in a direction intersecting with an axis of rotation of the cylinder block, a second tilt bearing for tiltably supporting the second swash plate, and a second tilt driving piston for tilting the second swash plate in a direction intersecting with the axis of rotation of the cylinder block.
- FIG. 1 is a sectional view of an opposed swash plate type piston motor according to an embodiment of the present invention
- FIG. 2 is a diagram showing a configuration for tilting a first swash plate and a second swash plate
- FIG. 3 is a diagram showing the configuration for tilting the first and second swash plates
- FIG. 4 is a hydraulic circuit diagram for tilting the first and second swash plates.
- the opposed swash plate type piston motor 1 shown in FIG. 1 is applied to a hydrostatic transmission 90 (see FIG. 4 ; hereinafter, merely referred to as an “HST 90 ”) mounted as a continuously variable transmission in a working vehicle or the like.
- a hydrostatic transmission 90 see FIG. 4 ; hereinafter, merely referred to as an “HST 90 ” mounted as a continuously variable transmission in a working vehicle or the like.
- the opposed swash plate type piston motor 1 includes a shaft 2 which rotates about an axis of rotation O 4 , a cylinder block 4 which is supported on the shaft 2 and a first swash plate 30 and a second swash plate 40 which are tilted while facing opposite ends of the cylinder block 4 .
- the cylinder block 4 is formed into a cylindrical tube including a hollow part, and the shaft 2 is inserted thereinto.
- the cylinder block 4 is formed by arranging a plurality of cylinders 3 side by side in a circumferential direction.
- the cylinders 3 are formed to extend in an axial direction and open on opposite end surfaces 4 C, 4 D of the cylinder block 4 .
- a first piston 8 and a second piston 9 are respectively inserted into the cylinder 3 from opposite opening ends.
- the first and second pistons 8 , 9 include tip parts projecting from the opening ends of the cylinder 3 and a first shoe 21 and a second shoe 22 are slidably coupled to the respective tip parts.
- the first piston 8 reciprocates following an end surface 30 A of the first swash plate 30 via the first shoe 21 and a port plate 16
- the second piston 9 reciprocates following an end surface 40 A of the second swash plate 40 via the second shoe 22 .
- a volume chamber 7 is defined between the first and second pistons 8 , 9 .
- the volume chamber 7 expands and contracts by the reciprocation of the first and second pistons 8 , 9 in the cylinder 3 , whereby hydraulic oil is supplied to and discharged from the volume chamber 7 through a pair of supply/discharge passages 5 , 6 (see FIG. 4 ).
- piston motor 1 uses the hydraulic oil (oil) as the working fluid
- water-soluble alternative liquid or the like may be, for example, used instead of the hydraulic oil.
- Opposite end parts of the cylindrical shaft 2 are rotatably supported on a casing (not shown) via bearings (not shown).
- the casing includes a tubular case (not shown) and a first cover and a second cover (not shown) in the form of lids for closing opposite opening ends of the case.
- the cylinder block 4 is housed in the case, the first swash plate 30 is housed in the first cover and the second swash plate 40 is housed in the second cover.
- a spline 2 A is formed on the outer periphery of the shaft 2 .
- a spline 4 H is formed on the inner periphery of the cylinder block 4 .
- a first retainer plate 23 and a first retainer holder 25 are interposed side by side in the axial direction between the first swash plate 30 and the cylinder block 4 .
- the disk-shaped port plate 16 which rotates together with the cylinder block 4 is provided between the first shoe 21 and the first swash plate 30 .
- the port plate 16 is coupled to the first retainer plate 23 via a plurality of pins 18 .
- a plurality of center springs 19 are interposed side by side in the circumferential direction between the first retainer holder 25 and the cylinder block 4 .
- the cylinder block 4 is biased rightward in FIG. 1 by the center springs 19 and pressed against the end surface 40 A of the second swash plate 40 via a second retainer holder 26 , a second retainer plate 24 and the second shoe 22 .
- the axial position of the cylinder block 4 relative to the second swash plate 40 is determined.
- the first swash plate 30 includes a pair of tilt shaft parts (half log parts) 30 B projecting on a rear surface side.
- the tilt shaft parts 30 B are tiltably supported by a first tilt bearing 33 formed on the casing (not shown).
- the first swash plate 30 rotates about a first tilt axis O 1 .
- the second swash plate 40 includes a pair of tilt shaft parts (half log parts) 40 B projecting on a rear surface side.
- the tilt shaft parts 40 B are tiltably supported by a second tilt bearing 43 formed on the casing.
- the second swash plate 40 rotates about a second tilt axis O 2 .
- the first and second tilt axes O 1 , O 2 are orthogonal to the axis of rotation O 4 of the cylinder block 4 .
- the piston motor 1 includes a first tilt driving mechanism 50 for tilting the first swash plate 30 and a second tilt driving mechanism 60 for tilting the second swash plate 40 .
- a first tilt driving mechanism 50 for tilting the first swash plate 30
- a second tilt driving mechanism 60 for tilting the second swash plate 40 .
- the first tilt driving mechanism 50 includes a first tilt driving piston 31 which is moved by a working hydraulic pressure and a translating mechanism 38 for translating a movement of the first tilt driving piston 31 into a rotational movement of the first swash plate 30 about the first tilt axis O 1 .
- a line G 1 is orthogonal to the axis of rotation O 4 and the first tilt axis O 1 .
- the first tilt driving piston 31 is arranged to move in a direction parallel to the line G 1 .
- the first tilt driving piston 31 may be arranged to move in a direction intersecting at a small angle with the line G 1 .
- the translating mechanism 38 is configured by a slide metal 36 which is slidably engaged with a guide groove 35 of the first tilt driving piston 31 and a pin 37 which projects from an end part of the first swash plate 30 in a direction of the first tilt axis O 1 and is slidably inserted into a hole of the slide metal 36 .
- the first tilt driving piston 31 moves in the axial direction (direction parallel to the line G 1 )
- the slide metal 36 and the pin 37 move along an arc centered on the first tilt axis O 1 while sliding along the guide groove 35 .
- the first swash plate 30 rotates about the first tilt axis O 1 .
- a first push-side piston pressure chamber 53 and a first pull-side piston pressure chamber 54 are respectively defined on opposite ends of the first tilt driving piston 31 .
- a first tilt control valve 70 is provided which switches working hydraulic pressures introduced to these piston pressure chambers 53 , 54 .
- the first tilt driving piston 31 is moved by a working hydraulic pressure difference between the piston pressure chambers 53 , 54 .
- the second tilt driving mechanism 60 includes a second tilt driving piston 41 which is moved by the working hydraulic pressure and a translating mechanism 48 for translating a movement of the second tilt driving piston 41 into a rotational movement of the second swash plate 40 about the second tilt axis O 2 .
- a line G 2 is orthogonal to the axis of rotation O 4 and the second tilt axis O 2 .
- the second tilt driving piston 41 is arranged to move in a direction parallel to the line G 2 .
- the second tilt driving piston 41 may be arranged to move in a direction intersecting at a small angle with the line G 2 .
- the translating mechanism 48 is configured by a slide metal 46 which is slidably engaged with a guide groove 45 of the second tilt driving piston 41 and a pin 47 which projects from an end part of the second swash plate 40 in a direction of the second tilt axis O 2 and is slidably inserted into a hole of the slide metal 46 .
- the slide metal 46 and the pin 47 move along an arc centered on the second tilt axis O 2 while sliding along the guide groove 45 .
- the second swash plate 40 rotates about the second tilt axis O 2 .
- a second push-side piston pressure chamber 63 and a second pull-side piston pressure chamber 64 are respectively defined on opposite ends of the second tilt driving piston 41 .
- a second tilt control valve 80 is provided which switches working hydraulic pressures introduced to these piston pressure chambers 63 , 64 .
- the second tilt driving piston 41 is moved by a working hydraulic pressure difference between the piston pressure chambers 63 , 64 .
- FIG. 4 is a diagram showing the configurations of a hydraulic circuit and a control system provided in the HST 90 .
- the HST 90 includes the piston motor 1 , a piston pump 99 and a closed circuit 100 for circulating the hydraulic oil between these.
- the piston pump 99 is driven to rotate by an engine (not shown).
- the piston pump 99 includes two supply/discharge passages 105 , 106 for supplying and discharging the hydraulic oil to and from a volume chamber, and a discharging direction of the hydraulic oil from the supply/ discharge passages 105 , 106 is changed by switching a tilting direction of a swash plate 107 .
- a travel direction forward or backward
- a fluid pressure source 110 includes a fixed displacement charge pump 111 which is driven to rotate by the engine and a charge passage 113 which introduces the hydraulic oil discharged from the charge pump 111 .
- An oil filter 114 , an oil filter 116 and a relief valve 119 are disposed in the charge passage 113 .
- the hydraulic oil having passed through the relief valve 119 is returned to a tank 109 .
- the charge passage 113 is connected to the first and second circulation passages 101 , 102 via check valves 117 , 118 . If a pressure of the first circulation passage 101 falls below that of the charge passage 113 , the check valve 117 is opened and the hydraulic oil is filled into the first circulation passage 101 from the charge passage 113 . On the other hand, if a pressure of the second circulation passage 102 falls below that of the charge passage 113 , the check valve 118 is opened and the hydraulic oil is filled into the second circulation passage 102 from the charge passage 113 . Thus, the pressures of the first and second circulation passages 101 , 102 are kept not lower than a predetermined value.
- Relief valves 121 , 122 are interposed side by side with the check valves 117 , 118 in the charge passage 113 . If the pressure of the first circulation passage 101 increases beyond the predetermined value relative to that of the charge passage 113 , the relief valve 121 is opened and the working hydraulic pressure of the first circulation passage 101 is allowed to escape into the charge passage 113 . On the other hand, if the pressure of the second circulation passage 102 increases beyond the predetermined value relative to that of the charge passage 113 , the relief valve 122 is opened and the working hydraulic pressure of the second circulation passage 102 is allowed to escape into the charge passage 113 . Thus, increases of the pressures of the first and second circulation passages 101 , 102 beyond the predetermined value are suppressed.
- a high-pressure selector valve 149 is provided between the first and second circulation passages 101 , 102 .
- the working hydraulic pressure taken out via the high-pressure selector valve 149 is introduced to the first and second tilt control valves 70 , 80 .
- the first tilt control valve 70 includes an inlet port 71 communicating with the high-pressure selector valve 149 , an outlet port 72 communicating with the tank 109 , a first push-side port 73 communicating with the first push-side piston pressure chamber 53 and a first pull-side port 74 communicating with the first pull-side piston pressure chamber 54 .
- the first tilt control valve 70 includes a valve housing 76 disposed in the casing, a spool valve 79 slidably housed in the valve housing 76 , a spring 78 for biasing the spool valve 79 toward one side in an axial direction of the spool valve 79 and a solenoid 77 for moving the spool valve 79 in the axial direction of the spool valve 79 against the spring 78 .
- the first tilt control valve 70 is switched to three positions 70 A, 70 B and 70 C.
- the spool valve 79 moves upward in FIG. 2 against the biasing force of the spring 78 due to the thrust force and the first tilt control valve 70 is switched to the push-side position 70 A.
- the hydraulic oil from the high-pressure selector valve 149 is supplied to the first push-side piston pressure chamber 53 through the ports 71 , 73 and the hydraulic oil in the first pull-side piston pressure chamber 54 is returned to the tank 109 though the working hydraulic pressure ports 74 , 72 .
- the first tilt driving piston 31 moves in a direction indicated by an arrow A in FIG. 2 (downward direction) and the first swash plate 30 rotates in a direction to increase a tilt angle as indicated by an arrow B.
- a displacement volume of the piston motor 1 increases and the travel speed of the vehicle decreases.
- the hydraulic oil from the high-pressure selector valve 149 is supplied to the first pull-side piston pressure chamber 54 through the ports 71 , 74 and the hydraulic oil in the first push-side piston pressure chamber 53 is returned to the tank 109 though the ports 73 , 72 .
- the first tilt driving piston 31 moves in a direction indicated by an arrow C in FIG. 3 (upward direction) and the first swash plate 30 rotates in a direction to reduce the tilt angle as indicated by an arrow D.
- the displacement volume of the piston motor 1 decreases and the travel speed of the vehicle increases.
- each port 71 to 74 is closed and the movement of the first tilt driving piston 31 is stopped.
- the first swash plate 30 is kept at the tilt angle at that point of time.
- the controller 170 adjusts a flow rate of the hydraulic oil supplied to and discharged from the first tilt driving mechanism 50 and continuously controls a speed ratio of the HST 90 by switching the positions 70 A, 70 B, 70 C of the first tilt control valve 70 from one to another.
- the second tilt control valve 80 includes an inlet port 81 communicating with the high-pressure selector valve 149 , an outlet port 82 communicating with the tank 109 , a second push-side port 83 communicating with the second push-side piston pressure chamber 63 and a second pull-side port 84 communicating with the second pull-side piston pressure chamber 64 .
- the second tilt control valve 80 includes a valve housing 86 disposed in the casing, a spool valve 89 slidably housed in the valve housing 86 , a spring 88 for biasing the spool valve 89 toward one side in an axial direction of the spool valve 89 and a solenoid 87 for moving the spool valve 89 in the axial direction of the spool valve 89 against the spring 88 .
- the second tilt control valve 80 is switched to three positions 80 A, 80 B and 80 C.
- the hydraulic oil from the high-pressure selector valve 149 is supplied to the second pull-side piston pressure chamber 64 through the ports 81 , 84 and the hydraulic oil in the second push-side piston pressure chamber 63 is returned to the tank 109 though the working hydraulic pressure ports 83 , 82 .
- the second tilt driving piston 41 moves in a direction indicated by an arrow E in FIG. 2 (upward direction) and the second swash plate 40 rotates in a direction to reduce a tilt angle as indicated by an arrow F.
- the displacement volume of the piston motor 1 decreases and the travel speed of the vehicle increases.
- the hydraulic oil from the high-pressure selector valve 149 is supplied to the second push-side piston pressure chamber 63 through the ports 81 , 83 and the hydraulic oil in the second pull-side piston pressure chamber 64 is returned to the tank 109 though the ports 84 , 82 .
- the second tilt driving piston 41 moves in a direction indicated by an arrow H in FIG. 3 (downward direction) and the second swash plate 40 rotates in a direction to increase the tilt angle as indicated by an arrow I.
- the displacement volume of the piston motor 1 increases and the travel speed of the vehicle decreases.
- each port 81 to 84 is closed and the movement of the second tilt driving piston 41 is stopped.
- the second swash plate 40 is kept at the tilt angle at that point of time.
- the controller 170 adjusts a flow rate of the hydraulic oil supplied to and discharged from the second tilt driving mechanism 60 and continuously controls the speed ratio of the HST 90 by switching the positions 80 A, 80 B, 80 C of the second tilt control valve 80 from one to another.
- Denoted by 171 and 172 are potentiometers for respectively reading the tilt angles of the first and second swash plates 30 , 40 .
- the controller 170 feedback-controls opening and closing timings of the first and second tilt control valves 70 , 80 according to detection values of the potentiometers 171 , 172 .
- the tilt angle of the first swash plate 30 is minimized and that of the second swash plate 40 is maximized when power application to the solenoid 77 of the first tilt control valve 70 is stopped and that to the solenoid 87 of the second tilt control valve 80 is stopped as shown in FIG. 3 .
- the speed ratio of the piston motor 1 is set at an intermediate value.
- the tilt angles of the first and second swash plates 30 , 40 are both maximized when power is applied to the solenoid 77 of the first tilt control valve 70 as shown in FIG. 2 and power application to the solenoid 87 of the second tilt control valve 80 is stopped as shown in FIG. 3 . At this time, the displacement volume of the piston motor 1 is maximized and the speed ratio of the piston motor 1 is minimized.
- the tilt angles of the first and second swash plates 30 , 40 are both minimized when power application to the solenoid 77 of the first tilt control valve 70 is stopped as shown in FIG. 3 and power is applied to the solenoid 87 of the second tilt control valve 80 as shown in FIG. 2 . At this time, the displacement volume of the piston motor 1 is minimized and the speed ratio of the piston motor 1 is maximized.
- a tilting movement of the first swash plate 30 caused by the first tilt driving piston 31 pushing the end part of the first swash plate 30 in the direction orthogonal to the tilt axis O 1 and a tilting movement of the second swash plate 40 caused by the second tilt driving piston 41 pushing the end part of the second swash plate 40 in the direction orthogonal to the tilt axis O 2 are respectively independently made.
- the flow rate of the working fluid supplied to and discharged from the first tilt driving mechanism 50 is adjusted by the first tilt control valve 70 and that of the working fluid supplied to and discharged from the second tilt driving mechanism 60 is adjusted by the second tilt control valve 80 different from the first tilt control valve 70 .
- the first and second swash plates 30 , 40 are respectively tilted by being pushed in the directions intersecting with the tilt axes O 1 , O 2 by the first and second tilt driving pistons 31 , 41 .
- no torque acts to rotate the first and second swash plates 30 , 40 about the axis of rotation O 4 . Therefore, a floating phenomenon in which the tilt shaft parts 30 B, 40 B are separated from the first and second tilt bearings 33 , 43 can be prevented.
- actuating strokes of the first and second tilt driving mechanisms 50 , 60 are respectively continuously adjusted by actuating the first and second tilt control valves 70 , 80 , the tilt angles of the first and second swash plates 30 , 40 can be continuously controlled.
- the first tilt driving mechanism 50 can adjust the tilt angle of the first swash plate 30 with good responsiveness and the second tilt driving mechanism 60 can adjust the tilt angle of the second swash plate 40 with good responsiveness.
- the present embodiment relates to the piston motor 1 in which the hydraulic oil is supplied and discharged to rotate the cylinder block
- the present invention may be also applied to the piston pump 111 in which the cylinder block is driven to rotate to supply and discharge the hydraulic oil.
Abstract
An opposed swash plate type fluid pressure rotating machine in which a first piston and a second piston projecting from opposite ends of a rotary cylinder block reciprocate in a cylinder, respectively following a first swash plate and a second swash plate includes a first tilt bearing for tiltably supporting the first swash plate, a first tilt driving piston for tilting the first swash plate in a direction intersecting with an axis of rotation of the cylinder block, a second tilt bearing for tiltably supporting the second swash plate, and a second tilt driving piston for tilting the second swash plate in a direction intersecting with the axis of rotation of the cylinder block.
Description
- The prevent invention relates to an opposed swash plate type fluid pressure rotating machine in which a first swash plate and a second swash plate are tilted while facing opposite ends of a cylinder block.
- JP2008-231924A discloses an opposed swash plate type fluid pressure rotating machine provided with a cylinder block including a plurality of cylinders, first pistons and second pistons projecting from opposite ends of the cylinders and a first swash plate and a second swash plate with which projecting ends of the first and second pistons respectively slide in contact.
- In the fluid pressure rotating machine, according to the rotation of the cylinder, the first pistons reciprocate in the cylinders, following the first swash plate, and the second pistons reciprocate in the cylinders, following the second swash plate, whereby working fluid is supplied to and discharged from volume chambers in the cylinders.
- A tilt driving piston for tilting the first swash plate is coupled to one side of the first swash plate and a tilt interlocking mechanism for transmitting the inclination of the first swash plate to the second swash plate is coupled to the other side of the first swash plate. When the first swash plate is tilted by the tilt driving piston, the second swash plate is also tilted via the tilt interlocking mechanism.
- In the opposed swash plate type fluid pressure rotating machine disclosed in JP2008-231924A, a floating phenomenon in which a tilt shaft part of the first swash plate is separated from a tilt bearing provided on a casing when the first swash plate is driven to tilt may occur.
- The floating phenomenon is a phenomenon in which the first swash plate rotates about a rotary shaft of the cylinder block and the tilt shaft part of the first swash plate is separated from the tilt bearing by the action of a force of the tilt driving piston received by the one side of the first swash plate and a reaction force of the tilt interlocking mechanism received by the other side of the first swash plate when the first swash plate is tilted as a torque in the same rotating direction.
- The present invention aims to prevent a floating phenomenon in an opposed swash plate type fluid pressure rotating machine.
- According to one aspect of the present invention, an opposed swash plate type fluid pressure rotating machine in which a first piston and a second piston projecting from opposite ends of a rotary cylinder block reciprocate in a cylinder, respectively following a first swash plate and a second swash plate is provided. The opposed swash plate type fluid pressure rotating machine includes a first tilt bearing for tiltably supporting the first swash plate, a first tilt driving piston for tilting the first swash plate in a direction intersecting with an axis of rotation of the cylinder block, a second tilt bearing for tiltably supporting the second swash plate, and a second tilt driving piston for tilting the second swash plate in a direction intersecting with the axis of rotation of the cylinder block.
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FIG. 1 is a sectional view of an opposed swash plate type piston motor according to an embodiment of the present invention, -
FIG. 2 is a diagram showing a configuration for tilting a first swash plate and a second swash plate, -
FIG. 3 is a diagram showing the configuration for tilting the first and second swash plates, and -
FIG. 4 is a hydraulic circuit diagram for tilting the first and second swash plates. - An opposed swash plate
type piston motor 1 according to an embodiment of the present invention is described with reference to the drawings. - The opposed swash plate
type piston motor 1 shown inFIG. 1 is applied to a hydrostatic transmission 90 (seeFIG. 4 ; hereinafter, merely referred to as an “HST 90”) mounted as a continuously variable transmission in a working vehicle or the like. - As shown in
FIG. 1 , the opposed swash platetype piston motor 1 includes a shaft 2 which rotates about an axis of rotation O4, acylinder block 4 which is supported on the shaft 2 and afirst swash plate 30 and asecond swash plate 40 which are tilted while facing opposite ends of thecylinder block 4. - The
cylinder block 4 is formed into a cylindrical tube including a hollow part, and the shaft 2 is inserted thereinto. Thecylinder block 4 is formed by arranging a plurality ofcylinders 3 side by side in a circumferential direction. Thecylinders 3 are formed to extend in an axial direction and open onopposite end surfaces cylinder block 4. - A
first piston 8 and asecond piston 9 are respectively inserted into thecylinder 3 from opposite opening ends. The first andsecond pistons cylinder 3 and afirst shoe 21 and asecond shoe 22 are slidably coupled to the respective tip parts. - When the
cylinder block 4 rotates, thefirst piston 8 reciprocates following anend surface 30A of thefirst swash plate 30 via thefirst shoe 21 and aport plate 16, and thesecond piston 9 reciprocates following anend surface 40A of thesecond swash plate 40 via thesecond shoe 22. - In the
cylinder 3, avolume chamber 7 is defined between the first andsecond pistons volume chamber 7 expands and contracts by the reciprocation of the first andsecond pistons cylinder 3, whereby hydraulic oil is supplied to and discharged from thevolume chamber 7 through a pair of supply/discharge passages 5, 6 (seeFIG. 4 ). - Although the
piston motor 1 uses the hydraulic oil (oil) as the working fluid, water-soluble alternative liquid or the like may be, for example, used instead of the hydraulic oil. - Opposite end parts of the cylindrical shaft 2 are rotatably supported on a casing (not shown) via bearings (not shown).
- The casing includes a tubular case (not shown) and a first cover and a second cover (not shown) in the form of lids for closing opposite opening ends of the case. The
cylinder block 4 is housed in the case, thefirst swash plate 30 is housed in the first cover and thesecond swash plate 40 is housed in the second cover. - A
spline 2A is formed on the outer periphery of the shaft 2. Aspline 4H is formed on the inner periphery of thecylinder block 4. By slidably fitting thespline 4H of thecylinder block 4 to thespline 2A of the shaft 2, the rotation of thecylinder block 4 relative to the shaft 2 is regulated and thecylinder block 4 can move in the axial direction relative to the shaft 2. - A
first retainer plate 23 and afirst retainer holder 25 are interposed side by side in the axial direction between thefirst swash plate 30 and thecylinder block 4. - The disk-
shaped port plate 16 which rotates together with thecylinder block 4 is provided between thefirst shoe 21 and thefirst swash plate 30. Theport plate 16 is coupled to thefirst retainer plate 23 via a plurality ofpins 18. - A plurality of
center springs 19 are interposed side by side in the circumferential direction between thefirst retainer holder 25 and thecylinder block 4. Thecylinder block 4 is biased rightward inFIG. 1 by thecenter springs 19 and pressed against theend surface 40A of thesecond swash plate 40 via asecond retainer holder 26, asecond retainer plate 24 and thesecond shoe 22. As a result, the axial position of thecylinder block 4 relative to thesecond swash plate 40 is determined. - Next, a configuration for respectively tilting the first and
second swash plates FIGS. 2 and 3 . - The
first swash plate 30 includes a pair of tilt shaft parts (half log parts) 30B projecting on a rear surface side. Thetilt shaft parts 30B are tiltably supported by a first tilt bearing 33 formed on the casing (not shown). Thefirst swash plate 30 rotates about a first tilt axis O1. Thesecond swash plate 40 includes a pair of tilt shaft parts (half log parts) 40B projecting on a rear surface side. Thetilt shaft parts 40B are tiltably supported by a second tilt bearing 43 formed on the casing. Thesecond swash plate 40 rotates about a second tilt axis O2. The first and second tilt axes O1, O2 are orthogonal to the axis of rotation O4 of thecylinder block 4. - The
piston motor 1 includes a firsttilt driving mechanism 50 for tilting thefirst swash plate 30 and a secondtilt driving mechanism 60 for tilting thesecond swash plate 40. By tilting thefirst swash plate 30, a reciprocating stroke length of thefirst piston 8 in thecylinder 3 changes. By tilting thesecond swash plate 40, a reciprocating stroke length of thesecond piston 9 in thecylinder 3 changes. By changing the stroke lengths, a displacement volume per rotation of thecylinder block 4 changes and an output rotation speed of thepiston motor 1 changes. - The first
tilt driving mechanism 50 includes a firsttilt driving piston 31 which is moved by a working hydraulic pressure and atranslating mechanism 38 for translating a movement of the firsttilt driving piston 31 into a rotational movement of thefirst swash plate 30 about the first tilt axis O1. - In
FIGS. 2 and 3 , a line G1 is orthogonal to the axis of rotation O4 and the first tilt axis O1. The firsttilt driving piston 31 is arranged to move in a direction parallel to the line G1. Without limitation to this, the firsttilt driving piston 31 may be arranged to move in a direction intersecting at a small angle with the line G1. - The
translating mechanism 38 is configured by aslide metal 36 which is slidably engaged with aguide groove 35 of the firsttilt driving piston 31 and apin 37 which projects from an end part of thefirst swash plate 30 in a direction of the first tilt axis O1 and is slidably inserted into a hole of theslide metal 36. When the firsttilt driving piston 31 moves in the axial direction (direction parallel to the line G1), theslide metal 36 and thepin 37 move along an arc centered on the first tilt axis O1 while sliding along theguide groove 35. As a result, thefirst swash plate 30 rotates about the first tilt axis O1. - A first push-side
piston pressure chamber 53 and a first pull-sidepiston pressure chamber 54 are respectively defined on opposite ends of the firsttilt driving piston 31. A firsttilt control valve 70 is provided which switches working hydraulic pressures introduced to thesepiston pressure chambers tilt driving piston 31 is moved by a working hydraulic pressure difference between thepiston pressure chambers - The second
tilt driving mechanism 60 includes a secondtilt driving piston 41 which is moved by the working hydraulic pressure and a translatingmechanism 48 for translating a movement of the secondtilt driving piston 41 into a rotational movement of thesecond swash plate 40 about the second tilt axis O2. - In
FIGS. 2 and 3 , a line G2 is orthogonal to the axis of rotation O4 and the second tilt axis O2. The secondtilt driving piston 41 is arranged to move in a direction parallel to the line G2. Without limitation to this, the secondtilt driving piston 41 may be arranged to move in a direction intersecting at a small angle with the line G2. - The translating
mechanism 48 is configured by aslide metal 46 which is slidably engaged with aguide groove 45 of the secondtilt driving piston 41 and apin 47 which projects from an end part of thesecond swash plate 40 in a direction of the second tilt axis O2 and is slidably inserted into a hole of theslide metal 46. When the secondtilt driving piston 41 moves in the axial direction (direction parallel to the line G2), theslide metal 46 and thepin 47 move along an arc centered on the second tilt axis O2 while sliding along theguide groove 45. As a result, thesecond swash plate 40 rotates about the second tilt axis O2. - A second push-side
piston pressure chamber 63 and a second pull-sidepiston pressure chamber 64 are respectively defined on opposite ends of the secondtilt driving piston 41. A secondtilt control valve 80 is provided which switches working hydraulic pressures introduced to thesepiston pressure chambers tilt driving piston 41 is moved by a working hydraulic pressure difference between thepiston pressure chambers -
FIG. 4 is a diagram showing the configurations of a hydraulic circuit and a control system provided in theHST 90. - The
HST 90 includes thepiston motor 1, apiston pump 99 and aclosed circuit 100 for circulating the hydraulic oil between these. - The
closed circuit 100 includes afirst circulation passage 101 and asecond circulation passage 102 connecting thepiston motor 1 and thepiston pump 99. One end of thefirst circulation passage 101 is connected to the supply/discharge passage 5 of thepiston motor 1 and the other end is connected to a supply/discharge passage 105 of thepiston pump 99. One end of thesecond circulation passage 102 is connected to the supply/discharge passage 6 of thepiston motor 1 and the other end is connected to a supply/discharge passage 106 of thepiston pump 99. - By feeding the hydraulic oil discharged from the
piston pump 99 to thepiston motor 1 through theclosed circuit 100, thepiston motor 1 rotates. Output rotation of thepiston motor 1 is transmitted to left and right wheels via unillustrated transmission (gear type transmission), differential gear and the like. - The
piston pump 99 is driven to rotate by an engine (not shown). Thepiston pump 99 includes two supply/discharge passages discharge passages swash plate 107. By changing the discharging direction of thepiston pump 99, a travel direction (forward or backward) of the vehicle is switched. - A
fluid pressure source 110 includes a fixeddisplacement charge pump 111 which is driven to rotate by the engine and acharge passage 113 which introduces the hydraulic oil discharged from thecharge pump 111. Anoil filter 114, anoil filter 116 and arelief valve 119 are disposed in thecharge passage 113. The hydraulic oil having passed through therelief valve 119 is returned to atank 109. - The
charge passage 113 is connected to the first andsecond circulation passages check valves first circulation passage 101 falls below that of thecharge passage 113, thecheck valve 117 is opened and the hydraulic oil is filled into thefirst circulation passage 101 from thecharge passage 113. On the other hand, if a pressure of thesecond circulation passage 102 falls below that of thecharge passage 113, thecheck valve 118 is opened and the hydraulic oil is filled into thesecond circulation passage 102 from thecharge passage 113. Thus, the pressures of the first andsecond circulation passages -
Relief valves check valves charge passage 113. If the pressure of thefirst circulation passage 101 increases beyond the predetermined value relative to that of thecharge passage 113, therelief valve 121 is opened and the working hydraulic pressure of thefirst circulation passage 101 is allowed to escape into thecharge passage 113. On the other hand, if the pressure of thesecond circulation passage 102 increases beyond the predetermined value relative to that of thecharge passage 113, therelief valve 122 is opened and the working hydraulic pressure of thesecond circulation passage 102 is allowed to escape into thecharge passage 113. Thus, increases of the pressures of the first andsecond circulation passages - A high-
pressure selector valve 149 is provided between the first andsecond circulation passages pressure selector valve 149 is introduced to the first and secondtilt control valves - The first
tilt control valve 70 includes aninlet port 71 communicating with the high-pressure selector valve 149, anoutlet port 72 communicating with thetank 109, a first push-side port 73 communicating with the first push-sidepiston pressure chamber 53 and a first pull-side port 74 communicating with the first pull-sidepiston pressure chamber 54. - As shown in
FIGS. 2 and 3 , the firsttilt control valve 70 includes avalve housing 76 disposed in the casing, aspool valve 79 slidably housed in thevalve housing 76, aspring 78 for biasing thespool valve 79 toward one side in an axial direction of thespool valve 79 and asolenoid 77 for moving thespool valve 79 in the axial direction of thespool valve 79 against thespring 78. - By a movement of the
spool valve 79 to a position where a thrust force of thesolenoid 77 and a biasing force of thespring 78 are balanced, the firsttilt control valve 70 is switched to threepositions - If a predetermined thrust force is generated in the
solenoid 77 by an excitation current fed from acontroller 170, thespool valve 79 moves upward inFIG. 2 against the biasing force of thespring 78 due to the thrust force and the firsttilt control valve 70 is switched to the push-side position 70A. - At the push-
side position 70A, the hydraulic oil from the high-pressure selector valve 149 is supplied to the first push-sidepiston pressure chamber 53 through theports piston pressure chamber 54 is returned to thetank 109 though the workinghydraulic pressure ports piston pressure chamber 53, the firsttilt driving piston 31 moves in a direction indicated by an arrow A inFIG. 2 (downward direction) and the firstswash plate 30 rotates in a direction to increase a tilt angle as indicated by an arrow B. As a result, a displacement volume of thepiston motor 1 increases and the travel speed of the vehicle decreases. - When the excitation current fed from the
controller 170 is stopped, no more thrust force is generated in thesolenoid 77 and thespool valve 79 is moved in a direction shown inFIG. 3 (downward direction) by the biasing force of thespring 78 and the firsttilt control valve 70 is switched to the pull-side position 70B. - At the pull-
side position 70B, the hydraulic oil from the high-pressure selector valve 149 is supplied to the first pull-sidepiston pressure chamber 54 through theports piston pressure chamber 53 is returned to thetank 109 though theports piston pressure chamber 54, the firsttilt driving piston 31 moves in a direction indicated by an arrow C inFIG. 3 (upward direction) and the firstswash plate 30 rotates in a direction to reduce the tilt angle as indicated by an arrow D. As a result, the displacement volume of thepiston motor 1 decreases and the travel speed of the vehicle increases. - At the
neutral position 70C, eachport 71 to 74 is closed and the movement of the firsttilt driving piston 31 is stopped. Thus, the firstswash plate 30 is kept at the tilt angle at that point of time. - The
controller 170 adjusts a flow rate of the hydraulic oil supplied to and discharged from the firsttilt driving mechanism 50 and continuously controls a speed ratio of theHST 90 by switching thepositions tilt control valve 70 from one to another. - The second
tilt control valve 80 includes aninlet port 81 communicating with the high-pressure selector valve 149, anoutlet port 82 communicating with thetank 109, a second push-side port 83 communicating with the second push-sidepiston pressure chamber 63 and a second pull-side port 84 communicating with the second pull-sidepiston pressure chamber 64. - As shown in
FIGS. 2 and 3 , the secondtilt control valve 80 includes avalve housing 86 disposed in the casing, aspool valve 89 slidably housed in thevalve housing 86, aspring 88 for biasing thespool valve 89 toward one side in an axial direction of thespool valve 89 and asolenoid 87 for moving thespool valve 89 in the axial direction of thespool valve 89 against thespring 88. - By a movement of the
spool valve 89 to a position where a thrust force of thesolenoid 87 and a biasing force of thespring 88 are balanced, the secondtilt control valve 80 is switched to threepositions - If a predetermined thrust force is generated in the
solenoid 87 by an excitation current fed from thecontroller 170, thespool valve 89 moves upward inFIG. 2 against the biasing force of thespring 88 due to the thrust force and the secondtilt control valve 80 is switched to the pull-side position 80B. - At the pull-
side position 80B, the hydraulic oil from the high-pressure selector valve 149 is supplied to the second pull-sidepiston pressure chamber 64 through theports piston pressure chamber 63 is returned to thetank 109 though the workinghydraulic pressure ports piston pressure chamber 64, the secondtilt driving piston 41 moves in a direction indicated by an arrow E inFIG. 2 (upward direction) and thesecond swash plate 40 rotates in a direction to reduce a tilt angle as indicated by an arrow F. As a result, the displacement volume of thepiston motor 1 decreases and the travel speed of the vehicle increases. - When the excitation current fed from the
controller 170 is stopped, no more thrust force is generated in thesolenoid 87 and thespool valve 89 is moved in a direction shown inFIG. 3 (downward direction) by the biasing force of thespring 88 and the secondtilt control valve 80 is switched to the push-side position 80A. - At the push-
side position 80A, the hydraulic oil from the high-pressure selector valve 149 is supplied to the second push-sidepiston pressure chamber 63 through theports piston pressure chamber 64 is returned to thetank 109 though theports piston pressure chamber 63, the secondtilt driving piston 41 moves in a direction indicated by an arrow H inFIG. 3 (downward direction) and thesecond swash plate 40 rotates in a direction to increase the tilt angle as indicated by an arrow I. As a result, the displacement volume of thepiston motor 1 increases and the travel speed of the vehicle decreases. - At the
neutral position 80C, eachport 81 to 84 is closed and the movement of the secondtilt driving piston 41 is stopped. Thus, thesecond swash plate 40 is kept at the tilt angle at that point of time. - The
controller 170 adjusts a flow rate of the hydraulic oil supplied to and discharged from the secondtilt driving mechanism 60 and continuously controls the speed ratio of theHST 90 by switching thepositions tilt control valve 80 from one to another. - Denoted by 171 and 172 are potentiometers for respectively reading the tilt angles of the first and
second swash plates controller 170 feedback-controls opening and closing timings of the first and secondtilt control valves potentiometers - The tilt angle of the first
swash plate 30 is minimized and that of thesecond swash plate 40 is maximized when power application to thesolenoid 77 of the firsttilt control valve 70 is stopped and that to thesolenoid 87 of the secondtilt control valve 80 is stopped as shown inFIG. 3 . At this time, the speed ratio of thepiston motor 1 is set at an intermediate value. - The tilt angles of the first and
second swash plates solenoid 77 of the firsttilt control valve 70 as shown inFIG. 2 and power application to thesolenoid 87 of the secondtilt control valve 80 is stopped as shown inFIG. 3 . At this time, the displacement volume of thepiston motor 1 is maximized and the speed ratio of thepiston motor 1 is minimized. - The tilt angles of the first and
second swash plates solenoid 77 of the firsttilt control valve 70 is stopped as shown inFIG. 3 and power is applied to thesolenoid 87 of the secondtilt control valve 80 as shown inFIG. 2 . At this time, the displacement volume of thepiston motor 1 is minimized and the speed ratio of thepiston motor 1 is maximized. - As described above, a tilting movement of the first
swash plate 30 caused by the firsttilt driving piston 31 pushing the end part of the firstswash plate 30 in the direction orthogonal to the tilt axis O1 and a tilting movement of thesecond swash plate 40 caused by the secondtilt driving piston 41 pushing the end part of thesecond swash plate 40 in the direction orthogonal to the tilt axis O2 are respectively independently made. - Further, the flow rate of the working fluid supplied to and discharged from the first
tilt driving mechanism 50 is adjusted by the firsttilt control valve 70 and that of the working fluid supplied to and discharged from the secondtilt driving mechanism 60 is adjusted by the secondtilt control valve 80 different from the firsttilt control valve 70. - According to the above embodiment, the following functions and effects are achieved.
- The first and
second swash plates tilt driving pistons second swash plates tilt shaft parts second tilt bearings - Further, since actuating strokes of the first and second
tilt driving mechanisms tilt control valves second swash plates - Further, since the flow rate of the working fluid supplied to and discharged from the first
tilt driving mechanism 50 and that of the working fluid supplied to and discharged from the secondtilt driving mechanism 60 are respectively adjusted by the first and secondtilt control valves tilt driving mechanism 50 can adjust the tilt angle of the firstswash plate 30 with good responsiveness and the secondtilt driving mechanism 60 can adjust the tilt angle of thesecond swash plate 40 with good responsiveness. - Embodiments of the present invention were described above, but the above embodiments are merely examples of applications of the present invention, and the technical scope of the present invention is not limited to the specific constitutions of the above embodiments.
- For example, although the present embodiment relates to the
piston motor 1 in which the hydraulic oil is supplied and discharged to rotate the cylinder block, the present invention may be also applied to thepiston pump 111 in which the cylinder block is driven to rotate to supply and discharge the hydraulic oil. - Furthermore, although the piston motor constitutes the hydrostatic transmission (HST) in the present embodiment, it may constitute another machine or facility.
- This application claims priority based on Japanese Patent Application No. 2013-73454 filed with the Japan Patent Office on Mar. 29, 2013, the entire contents of which are incorporated into this specification.
Claims (4)
1. An opposed swash plate type fluid pressure rotating machine in which a first piston and a second piston projecting from opposite ends of a rotary cylinder block reciprocate in a cylinder, respectively following a first swash plate and a second swash plate, comprising:
a first tilt bearing for tiltably supporting the first swash plate;
a first tilt driving piston for tilting the first swash plate in a direction intersecting with an axis of rotation of the cylinder block;
a second tilt bearing for tiltably supporting the second swash plate; and
a second tilt driving piston for tilting the second swash plate in a direction intersecting with the axis of rotation of the cylinder block.
2. The opposed swash plate type fluid pressure rotating machine according to claim 1 , comprising:
a first push-side piston pressure chamber and a first pull-side piston pressure chamber defined on opposite ends of the first tilt driving piston;
a first tilt control valve for switching the flow of working fluid supplied to and discharged from the first push-side piston pressure chamber and the first pull-side piston pressure chamber from and to a high-pressure selector valve;
a second push-side piston pressure chamber and a second pull-side piston pressure chamber defined on opposite ends of the second tilt driving piston; and
a second tilt control valve for switching the flow of working fluid supplied to and discharged from the second push-side piston pressure chamber and the first pull-side piston pressure chamber from and to the high-pressure selector valve.
3. The opposed swash plate type fluid pressure rotating machine according to claim 1 , comprising:
a first translating mechanism for translating a linear movement of the first tilt driving piston into a rotational movement of the first swash plate; and
a second translating mechanism for translating a linear movement of the second tilt driving piston into a rotational movement of the second swash plate.
4. The opposed swash plate type fluid pressure rotating machine according to claim 3 , wherein:
the first translating mechanism includes a first guide groove formed on the first tilt driving piston and a first pin member provided on the first swash plate and movable in the first guide groove; and
the second translating mechanism includes a second guide groove formed on the second tilt driving piston and a second pin member provided on the second swash plate and movable in the second guide groove.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2013-073454 | 2013-03-29 | ||
JP2013073454A JP6114089B2 (en) | 2013-03-29 | 2013-03-29 | Opposite swash plate type piston pump / motor |
PCT/JP2014/055782 WO2014156539A1 (en) | 2013-03-29 | 2014-03-06 | Opposed swashplate-type hydraulic rotary machine |
Publications (1)
Publication Number | Publication Date |
---|---|
US20150240636A1 true US20150240636A1 (en) | 2015-08-27 |
Family
ID=51623527
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US14/431,350 Abandoned US20150240636A1 (en) | 2013-03-29 | 2014-03-06 | Opposed swash plate type fluid pressure rotating machine |
Country Status (6)
Country | Link |
---|---|
US (1) | US20150240636A1 (en) |
JP (1) | JP6114089B2 (en) |
KR (1) | KR101743848B1 (en) |
CN (1) | CN104685208A (en) |
DE (1) | DE112014000201T5 (en) |
WO (1) | WO2014156539A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP3693603A1 (en) * | 2019-02-08 | 2020-08-12 | Volvo Car Corporation | Variable pre and de-compression control mechanism and method for hydraulic displacement pump |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN106593535B (en) * | 2015-10-14 | 2021-06-22 | 熵零控股股份有限公司 | Actively driven fluid mechanism |
ITUB20155999A1 (en) * | 2015-11-30 | 2017-05-30 | Merlo Group Innovation Lab S R L | HYDRAULIC FLOATING CYLINDER MACHINE |
CN108869223A (en) * | 2018-08-06 | 2018-11-23 | 华中科技大学 | A kind of two inclined plate plunger pump |
JP7408836B2 (en) | 2020-04-10 | 2024-01-05 | ムーグ インコーポレーテッド | Auxiliary torque electrohydraulic piston pump system |
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US7954316B2 (en) * | 2006-12-28 | 2011-06-07 | Yanmar Co., Ltd. | Hydrostatic stepless transmission |
US8727743B2 (en) * | 2007-03-16 | 2014-05-20 | Kayaba Industry Co., Ltd. | Opposing swash plate piston pump/motor |
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US3898917A (en) * | 1974-01-31 | 1975-08-12 | Abex Corp | Variable displacement fluid translating device |
JPS5318803A (en) * | 1976-08-06 | 1978-02-21 | Daikin Ind Ltd | Duplex pump |
JPH0745870B2 (en) * | 1986-07-30 | 1995-05-17 | 本田技研工業株式会社 | Swash plate type hydraulic system |
CN87207320U (en) * | 1987-07-21 | 1988-03-09 | 启东高压油泵厂 | Axial plunger fuel pump with a sloping cam plate |
JPH09324749A (en) * | 1996-06-04 | 1997-12-16 | Mitsubishi Heavy Ind Ltd | Axial piston type hydraulic machine |
JP3976471B2 (en) * | 2000-04-26 | 2007-09-19 | Ntn株式会社 | Swash plate guide device |
DE602004001946T2 (en) * | 2003-09-29 | 2006-12-14 | Kayaba Industry Co., Ltd. | Swash plate pump or motor |
JP4124716B2 (en) * | 2003-09-29 | 2008-07-23 | カヤバ工業株式会社 | Swash plate type hydraulic pump / motor |
JP2005320912A (en) * | 2004-05-10 | 2005-11-17 | Shin Caterpillar Mitsubishi Ltd | Variable displacement hydraulic pump |
JP4528238B2 (en) * | 2005-09-30 | 2010-08-18 | 株式会社クボタ | Speed control structure of work vehicle |
CN202833000U (en) * | 2012-08-20 | 2013-03-27 | 东莞市神煜机械有限公司 | Variable plunger pump |
-
2013
- 2013-03-29 JP JP2013073454A patent/JP6114089B2/en not_active Expired - Fee Related
-
2014
- 2014-03-06 KR KR1020157006825A patent/KR101743848B1/en active IP Right Grant
- 2014-03-06 WO PCT/JP2014/055782 patent/WO2014156539A1/en active Application Filing
- 2014-03-06 DE DE112014000201.1T patent/DE112014000201T5/en not_active Withdrawn
- 2014-03-06 CN CN201480002590.XA patent/CN104685208A/en active Pending
- 2014-03-06 US US14/431,350 patent/US20150240636A1/en not_active Abandoned
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7954316B2 (en) * | 2006-12-28 | 2011-06-07 | Yanmar Co., Ltd. | Hydrostatic stepless transmission |
US8727743B2 (en) * | 2007-03-16 | 2014-05-20 | Kayaba Industry Co., Ltd. | Opposing swash plate piston pump/motor |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP3693603A1 (en) * | 2019-02-08 | 2020-08-12 | Volvo Car Corporation | Variable pre and de-compression control mechanism and method for hydraulic displacement pump |
US10968741B2 (en) | 2019-02-08 | 2021-04-06 | Volvo Car Corporation | Variable pre and de-compression control mechanism and method for hydraulic displacement pump |
US11306589B2 (en) | 2019-02-08 | 2022-04-19 | Volvo Construction Equipment Ab | Mechanism and method for a high efficiency low noise hydraulic pump/motor |
Also Published As
Publication number | Publication date |
---|---|
KR101743848B1 (en) | 2017-06-05 |
JP2014196726A (en) | 2014-10-16 |
KR20150044940A (en) | 2015-04-27 |
DE112014000201T5 (en) | 2015-06-25 |
WO2014156539A1 (en) | 2014-10-02 |
CN104685208A (en) | 2015-06-03 |
JP6114089B2 (en) | 2017-04-12 |
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Owner name: KYB CORPORATION, JAPAN Free format text: CHANGE OF NAME;ASSIGNOR:KAYABA INDUSTRY CO., LTD.;REEL/FRAME:037355/0142 Effective date: 20151001 |
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