US20090047147A1 - Variable displacement vane pump - Google Patents
Variable displacement vane pump Download PDFInfo
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- US20090047147A1 US20090047147A1 US12/191,695 US19169508A US2009047147A1 US 20090047147 A1 US20090047147 A1 US 20090047147A1 US 19169508 A US19169508 A US 19169508A US 2009047147 A1 US2009047147 A1 US 2009047147A1
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- United States
- Prior art keywords
- cam ring
- pressure chamber
- metering orifice
- pressure
- fluid
- 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
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C2/00—Rotary-piston machines or pumps
- F04C2/30—Rotary-piston machines or pumps having the characteristics covered by two or more groups F04C2/02, F04C2/08, F04C2/22, F04C2/24 or having the characteristics covered by one of these groups together with some other type of movement between co-operating members
- F04C2/34—Rotary-piston machines or pumps having the characteristics covered by two or more groups F04C2/02, F04C2/08, F04C2/22, F04C2/24 or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in groups F04C2/08 or F04C2/22 and relative reciprocation between the co-operating members
- F04C2/344—Rotary-piston machines or pumps having the characteristics covered by two or more groups F04C2/02, F04C2/08, F04C2/22, F04C2/24 or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in groups F04C2/08 or F04C2/22 and relative reciprocation between the co-operating members with vanes reciprocating with respect to the inner member
- F04C2/3441—Rotary-piston machines or pumps having the characteristics covered by two or more groups F04C2/02, F04C2/08, F04C2/22, F04C2/24 or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in groups F04C2/08 or F04C2/22 and relative reciprocation between the co-operating members with vanes reciprocating with respect to the inner member the inner and outer member being in contact along one line or continuous surface substantially parallel to the axis of rotation
- F04C2/3442—Rotary-piston machines or pumps having the characteristics covered by two or more groups F04C2/02, F04C2/08, F04C2/22, F04C2/24 or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in groups F04C2/08 or F04C2/22 and relative reciprocation between the co-operating members with vanes reciprocating with respect to the inner member the inner and outer member being in contact along one line or continuous surface substantially parallel to the axis of rotation the surfaces of the inner and outer member, forming the working space, being surfaces of revolution
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C14/00—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations
- F04C14/18—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations characterised by varying the volume of the working chamber
- F04C14/22—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations characterised by varying the volume of the working chamber by changing the eccentricity between cooperating members
- F04C14/223—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations characterised by varying the volume of the working chamber by changing the eccentricity between cooperating members using a movable cam
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Details And Applications Of Rotary Liquid Pumps (AREA)
- Rotary Pumps (AREA)
Abstract
A variable displacement vane pump includes a drive shaft; a rotor formed with slots; vanes received by the slots; a cam ring which can become eccentric and cooperates with the rotor and vanes to define pump chambers; suction and discharge ports opened to the pump chambers; a sealing member dividing a space on an outer circumferential surface of the cam ring into first and second fluid pressure chambers; a metering orifice formed on a discharge passage connected with the discharge port; and a pressure control section adapted to control a pressure which is introduced into the first or second fluid pressure chamber. The pressure control section includes a high pressure chamber into which an upstream pressure of metering orifice is introduced, a medium pressure chamber into which a downstream pressure of metering orifice is introduced, and a low pressure chamber connected with a reservoir tank. The vane pump further includes a relief valve adapted to drain the downstream pressure of metering orifice to the reservoir tank; and a variable metering mechanism configured to narrow an area of the metering orifice at least when the relief valve is opened.
Description
- The present invention relates to a variable displacement vane pump, more particularly to a variable displacement vane pump for a power steering apparatus.
- Japanese Patent Application Publication No. 2003-21076 discloses a previously-proposed variable displacement vane pump. In this technique, the variable displacement vane pump includes a relief valve installed inside a control valve. This relief valve serves to release a discharge-side pressure into a reservoir tank when the discharge-side pressure becomes higher than or equal to a predetermined pressure.
- However, in the above technique, in the case of trying to enhance a fuel economy by reducing a relief amount of working fluid from the relief valve by means of a narrowing of a pilot orifice, the relief valve itself is vibrated due to a vibration of working fluid caused when the working fluid passes through the pilot orifice. If the relief amount is reduced by use of a damper orifice instead of the pilot orifice in order to avoid this vibration, the working fluid leaks from an annular portion of the control valve.
- Accordingly, a pressure difference of valve is reduced so that a control flow rate under a high pressure state is increased. Thereby, a pump workload is increased so as to cancel out an effect of reducing the fuel consumption which is obtained by the reduction of relief amount of working fluid. There has been such a problem.
- It is therefore an object of the present invention to provide a variable displacement vane pump devised to reduce the relief amount and to suppress the increase in pump workload so as to enhance the fuel economy.
- According to one aspect of the present invention, there is provided a variable displacement vane pump comprising: a pump body; a drive shaft supported rotatably by the pump body; a rotor disposed inside the pump body and adapted to be rotatably driven by the drive shaft, the rotor being formed with a plurality of slots spaced from each other in a circumferential direction of the rotor; a plurality of vanes received by the slots so as to be movable out from the slots and into the slots; a cam ring formed in an annular shape and disposed inside the pump body to permit the cam ring to become eccentric relative to the drive shaft, the cam ring cooperating with the rotor and the vanes to define a plurality of pump chambers on an inner circumferential side of the cam ring; a first plate member and a second plate member disposed on axially both sides of the cam ring; a suction port provided on a side of at least one of the first plate member and the second plate member and opened to at least one of the plurality of pump chambers; a discharge port provided on a side of at least one of the first plate member and the second plate member and opened to at least one of the plurality of pump chambers; a sealing member provided on an outer circumferential side of the cam ring, the sealing member dividing a space on an outer circumferential surface of the cam ring into a first fluid pressure chamber and a second fluid pressure chamber, wherein a flow rate of working fluid discharged from the discharge port is increased when the cam ring moves to the first fluid pressure chamber, wherein the flow rate of working fluid discharged from the discharge port is decreased when the cam ring moves to the second fluid pressure chamber; a metering orifice formed on a discharge passage connected with the discharge port; a pressure control section adapted to control a pressure which is introduced into the first fluid pressure chamber or the second fluid pressure chamber, the pressure control section comprising a high pressure chamber into which an upstream pressure of the metering orifice is introduced, a medium pressure chamber into which a downstream pressure of the metering orifice is introduced, and a low pressure chamber connected with a reservoir tank for storing working fluid; a relief valve provided between a downstream side of the metering orifice and the reservoir tank, the relief valve being adapted to be opened by receiving a pressure greater than or equal to a predetermined level and thereby to drain the downstream pressure of the metering orifice to the reservoir tank; and a variable metering mechanism configured to narrow a cross-sectional area of opening portion of the metering orifice at least when the relief valve is opened.
- According to another aspect of the present invention, there is provided a variable displacement vane pump comprising: a pump body; a drive shaft supported rotatably by the pump body; a rotor disposed inside the pump body and adapted to be rotatably driven by the drive shaft, the rotor being formed with a plurality of slots spaced from each other in a circumferential direction of the rotor; a plurality of vanes received by the slots so as to be movable out from the slots and into the slots; a cam ring formed in an annular shape and disposed inside the pump body to permit the cam ring to become eccentric relative to the drive shaft, the cam ring cooperating with the rotor and the vanes to define a plurality of pump chambers on an inner circumferential side of the cam ring; a first plate member and a second plate member disposed on axially both sides of the cam ring; a suction port provided on a side of at least one of the first plate member and the second plate member and opened to at least one of the plurality of pump chambers; a discharge port provided on a side of at least one of the first plate member and the second plate member and opened to at least one of the plurality of pump chambers; a sealing member provided on an outer circumferential side of the cam ring, the sealing member dividing a space on an outer circumferential surface of the cam ring into a first fluid pressure chamber and a second fluid pressure chamber, wherein a flow rate of working fluid discharged from the discharge port is increased when the cam ring moves to the first fluid pressure chamber, wherein the flow rate of working fluid discharged from the discharge port is decreased when the cam ring moves to the second fluid pressure chamber; a metering orifice formed on a discharge passage connected with the discharge port; a pressure control section adapted to control a pressure which is introduced into the first fluid pressure chamber or the second fluid pressure chamber, the pressure control section comprising a high pressure chamber into which an upstream pressure of the metering orifice is introduced, a medium pressure chamber into which a downstream pressure of the metering orifice is introduced, and a low pressure chamber connected with a reservoir tank for storing working fluid; a relief valve provided between a downstream side of the metering orifice and the reservoir tank, the relief valve being adapted to be opened by receiving a pressure greater than or equal to a predetermined level and thereby to drain the downstream pressure of the metering orifice into the reservoir tank; and a variable metering mechanism configured to narrow a cross-sectional area of opening portion of the metering orifice when a discharge pressure on a downstream side of the discharge port is higher than or equal to a predetermined pressure.
- According to still another aspect of the present invention, there is provided a variable displacement vane pump comprising: a pump body; a drive shaft supported rotatably by the pump body; a rotor disposed inside the pump body and adapted to be rotatably driven by the drive shaft, the rotor being formed with a plurality of slots spaced from each other in a circumferential direction of the rotor; a plurality of vanes received by the slots so as to be movable out from the slots and into the slots; a cam ring formed in an annular shape and disposed inside the pump body to permit the cam ring to become eccentric relative to the drive shaft, the cam ring cooperating with the rotor and the vanes to define a plurality of pump chambers on an inner circumferential side of the cam ring; a first plate member and a second plate member disposed on axially both sides of the cam ring; a suction port provided on a side of at least one of the first plate member and the second plate member and opened to at least one of the plurality of pump chambers; a discharge port provided on a side of at least one of the first plate member and the second plate member and opened to at least one of the plurality of pump chambers; a sealing member provided on an outer circumferential side of the cam ring, the sealing member dividing a space on an outer circumferential surface of the cam ring into a first fluid pressure chamber and a second fluid pressure chamber, wherein a flow rate of working fluid discharged from the discharge port is increased when the cam ring moves to the first fluid pressure chamber, wherein the flow rate of working fluid discharged from the discharge port is decreased when the cam ring moves to the second fluid pressure chamber; a metering orifice formed on a discharge passage connected with the discharge port; a pressure control section adapted to control a pressure which is introduced into the first fluid pressure chamber or the second fluid pressure chamber, the pressure control section comprising a high pressure chamber into which an upstream pressure of the metering orifice is introduced, a medium pressure chamber into which a downstream pressure of the metering orifice is introduced, and a low pressure chamber connected with a reservoir tank for storing working fluid; a relief valve provided between a downstream side of the metering orifice and the reservoir tank, the relief valve being adapted to be opened by receiving a pressure greater than or equal to a predetermined level and thereby to drain the downstream pressure of the metering orifice into the reservoir tank; and a variable metering mechanism configured to narrow a cross-sectional area of opening portion of the metering orifice to a larger extent as the eccentricity of the cam ring becomes smaller when the relief valve is open.
- According to still another aspect of the present invention, there is provided a variable displacement vane pump comprising: a pump body; a drive shaft supported rotatably by the pump body; a rotor disposed inside the pump body and adapted to be rotatably driven by the drive shaft, the rotor being formed with a plurality of slots spaced from each other in a circumferential direction of the rotor; a plurality of vanes received by the slots so as to be movable out from the slots and into the slots; a cam ring formed in an annular shape and disposed inside the pump body to permit the cam ring to become eccentric relative to the drive shaft, the cam ring cooperating with the rotor and the vanes to define a plurality of pump chambers on an inner circumferential side of the cam ring; a first plate member and a second plate member disposed on axially both sides of the cam ring; a suction port provided on a side of at least one of the first plate member and the second plate member and opened to at least one of the plurality of pump chambers; a discharge port provided on a side of at least one of the first plate member and the second plate member and opened to at least one of the plurality of pump chambers; a sealing member provided on an outer circumferential side of the cam ring, the sealing member dividing a space on an outer circumferential surface of the cam ring into a first fluid pressure chamber and a second fluid pressure chamber, wherein a flow rate of working fluid discharged from the discharge port is increased when the cam ring moves to the first fluid pressure chamber, wherein the flow rate of working fluid discharged from the discharge port is decreased when the cam ring moves to the second fluid pressure chamber; a metering orifice formed on a discharge passage connected with the discharge port; a pressure control section adapted to control a pressure which is introduced into the first fluid pressure chamber or the second fluid pressure chamber, the pressure control section comprising a high pressure chamber into which an upstream pressure of the metering orifice is introduced, a medium pressure chamber into which a downstream pressure of the metering orifice is introduced, and a low pressure chamber connected with a reservoir tank for storing working fluid; a fluid-pressure sensor adapted to sense a pressure discharged from the discharge port; a relief valve adapted to drain the downstream pressure of the metering orifice to the reservoir tank, and a pressure-using device adapted to use a pressure supplied from the discharge port; and a variable metering mechanism configured to narrow a cross-sectional area of flow passage of the metering orifice on the basis of an output signal of the fluid-pressure sensor.
- The other objects and features of this invention will become understood from the following description with reference to the accompanying drawings.
-
FIG. 1 is a cross-sectional view of a vane pump in a first embodiment according to the present invention, taken in an axial direction of the vane pump. -
FIG. 2 is a cross-sectional view of the vane pump in the first embodiment, taken in a radial direction of the vane pump (at maximum swing position). -
FIG. 3 is an enlarged cross-sectional view near a variable metering mechanism. -
FIG. 4 is a view showing the relation between an opening area of metering orifice and a swing amount of cam ring. -
FIG. 5 is a view showing an example in which a minimum secured area of the metering orifice is provided as a separate hole. -
FIG. 6 is an enlarged view ofFIG. 5 . -
FIG. 7 is a view showing an example in which the metering orifice is provided as a plurality of round holes. -
FIG. 8 is a view showing an example in which a damper orifice is provided outside a first housing. -
FIG. 9 is a view showing an example in which a piston adapted to move in and out in response to the swing of cam ring is formed with the metering orifice. -
FIG. 10 is a cross-sectional view of a vane pump in a second embodiment according to the present invention, taken in an axial direction of the vane pump. -
FIG. 11 is a cross-sectional view of the vane pump in the second embodiment, taken in a radial direction of the vane pump. -
FIG. 12 is a view showing an example in which a spool is provided as an electromagnetic valve in the second embodiment. -
FIG. 13 is a view showing an example in which a relief valve is provided outside a housing in the second embodiment. -
FIG. 14 is a view showing an example in which a shape of the spool is changed in a manner that the spool is operated by use of a drain pressure produced at a downstream side of the relief valve in the second embodiment. -
FIG. 15 is an enlarged view ofFIG. 14 . - Reference will hereinafter be made to the drawings in order to facilitate a better understanding of the present invention. Variable displacement vane pumps according to the present invention will be explained below based on embodiments of the present invention, referring to the drawings.
- [Overview Structure of Vane Pump]
- A first embodiment according to the present invention will now be explained.
FIG. 1 is a cross-sectional view of avane pump 1 in the first embodiment, taken in an axial direction of thevane pump 1.FIG. 2 is a cross-sectional view of thevane pump 1, taken in a radial direction of thevane pump 1.FIG. 2 shows the state where acam ring 4 has moved to its most negative position relative to y-axis (maximum eccentricity amount). InFIG. 2 , Oc denotes a center of thecam ring 4, and OR denotes a center of adrive shaft 2. - X-axis is defined as the axial direction of the
drive shaft 2, and a positive direction of x-axis is defined as a direction in which thedrive shaft 2 is inserted into first andsecond housings FIG. 2 ) for regulating a swing (oscillation) of thecam ring 4. A negative direction of y-axis is defined as a direction in which thespring 91 biases or urges thecam ring 4. Z-axis is defined as an axis orthogonal to x-axis and y-axis, and a positive direction of z-axis is defined as a direction toward an inlet port IN. - The
vane pump 1 includes thedrive shaft 2, arotor 3, thecam ring 4, anadapter ring 5 and apump body 10. Thedrive shaft 2 is connected through a pulley with an engine. Thedrive shaft 2 is supported rotatably by thepump body 10, and rotates integrally with therotor 3. - An outer circumferential portion of the
rotor 3 is formed with a plurality ofslots 31 as axial grooves. The plurality ofslots 31 are given radially in therotor 3, and are spaced from each other in the circumferential direction ofrotor 3. Avane 32 is inserted into or received by eachslot 31 to allow thevane 32 to rise and fall in the radial direction ofrotor 3. That is, eachvane 32 can move in the outward and inward directions of theslot 31. Eachslot 31 is continuously connected with aback pressure chamber 33 which is provided at a radially-inner end of theslot 31 and which is supplied with a fluid pressure. This fluid pressure biases or urges thevane 32 outwardly in the radial direction. - The
pump body 10 includes afirst housing 11 and a second housing 12 (corresponding to a first plate member according to the present invention). Thefirst housing 11 is shaped like a cup having its bottom (11 a) and is opening in the positive direction of x-axis. A pressure plate 6 (corresponding to a second plate member according to the present invention) in the form of a circular disc is disposed on thebottom portion 11 a offirst housing 11. That is, thefirst housing 11 accommodates thepressure plate 6 on thebottom portion 11 a. Thefirst housing 11 includes a pump element receiving portion 11 b at an inner circumferential portion offirst housing 11. The pump element receiving portion 11 b accommodates or receives theadapter ring 5,cam ring 4 androtor 3 which are located adjacent to thepressure plate 6 in the positive direction of x-axis. - The second housing 12 fluid-tightly abuts on the
adapter ring 5,cam ring 4 androtor 3 from the positive side of x-axis. Theadapter ring 5,cam ring 4 androtor 3 are supported by thepressure plate 6 and thesecond housing 12 so as to be sandwiched between thepressure plate 6 and thesecond housing 12. - A
suction port 62 and adischarge port 63 are provided in an x-axispositive side surface 61 of thepressure plate 6. Similarly, asuction port 121 and adischarge port 122 are provided in an x-axisnegative side surface 120 of thesecond housing 12. Thesuction ports discharge ports discharge ports rotor 3 and thecam ring 4. The inlet port IN is connected through afluid passage 7 a with acontrol valve 7. - The
adapter ring 5 is a substantially elliptical annular member having a major axis along the y-axis and a miner axis along the z-axis. The outer circumferential side (i.e., radially outer side) of theadapter ring 5 is surrounded by the inner circumferential surface of thefirst housing 11, and the inner circumferential side (i.e., radially inner side) of theadapter ring 5 surrounds or accommodates thecam ring 4. Theadapter ring 5 is restrained by apin 40 from rotating relative to thefirst housing 11, namely so as not to rotate within thefirst housing 11 at the time of driving operation of thevane pump 1. - The
cam ring 4 is an annular member having a substantially complete roundness (i.e., almost perfect circle). An outer diameter ofcam ring 4 is substantially equal to the miner axis of elliptic bore of theadapter ring 5. Since thecam ring 4 is received inside the substantiallyelliptical adapter ring 5, a fluid pressure chamber “A” is formed between an innercircumferential surface 53 of theadapter ring 5 and an outer circumferential surface of thecam ring 4. Thecam ring 4 can be swung in the direction of y-axis within theadapter ring 5. - As shown in
FIG. 2 , a sealingmember 50 is provided in a z-axis-positive-directional end portion of the innercircumferential surface 53 ofadapter ring 5. On the other hand, theadapter ring 5 is formed with a supporting surface N at a z-axis-negative-directional end portion. Specifically, the sealingmember 50 is located in the most advanced position of the innercircumferential surface 53 ofadapter ring 5 in the positive direction of z-axis, and the supporting surface N is located in the most advanced position of the innercircumferential surface 53 ofadapter ring 5 in the negative direction of z-axis. Thecam ring 4 is swingable about a swing fulcrum given on the supporting surface N. Thecam ring 4 is in contact with the supporting surface N and is swingably supported on the supporting surface N of theadapter ring 5 in the negative direction of z-axis. - A pin (a second sealing member) 40 is provided in the supporting surface N. The
pin 40 and the sealingmember 50 cooperate with each other to divide the fluid pressure chamber “A” defined by thecam ring 4 and theadapter ring 5 into a first fluid pressure chamber A1 and a second fluid pressure chamber A2. That is, since the first fluid pressure chamber A1 is separated from the second fluid pressure chamber A2 by means of thepin 40 and sealingmember 50; the first fluid pressure chamber A1 is formed on the y-axis negative side, and the second fluid pressure chamber A2 is formed on the y-axis positive side. - Since the
cam ring 4 swings by rolling on the supporting surface N, volumetric capacities of the respective fluid pressure chambers A1 and A2 are varied. As shown inFIG. 2 , the supporting surface N is in parallel with ξ-axis which is defined by rotating y-axis about an origin point of the coordinate system in a counterclockwise direction ofFIG. 2 . That is, the supporting surface N is inclined in the z-axis positive direction, and thereby a y-axis positive side of the supporting surface N is located at a more positive position of z-axis than a y-axis negative side of the supporting surface N. Accordingly, thecam ring 4 has a tendency to swing in the y-axis negative direction because of the inclined supporting surface N. - An outer diameter of the
rotor 3 is smaller than a diameter of an inner circumference (surface) 41 ofcam ring 4. Therotor 3 is disposed within a central bore of thecam ring 4. Therotor 3 is arranged so as to prevent the outer circumference ofrotor 3 from abutting on theinner circumference 41 ofcam ring 4 even when the swing movement ofcam ring 4 varies a relative position between therotor 3 andcam ring 4. - When the
cam ring 4 has moved to its swing position farthest in the y-axis negative direction, a distance (radial interval of a pump chamber By−) L between theinner circumference 41 ofcam ring 4 and the outer circumference ofrotor 3 becomes maximum on the y-axis negative side. On the other hand, when theam ring 4 has moved to its swing position farthest in the y-axis positive direction, the distance L becomes maximum on the y-axis positive side. - Each
vane 32 is designed to have a radial length larger than a maximum value of the distance (radial interval) L. Hence, eachvane 32 remains in the state where a radially inner portion ofvane 32 has been inserted or received in thecorresponding slot 31 and a radially outer portion ofvane 32 is in contact with theinner circumference 41 ofcam ring 4, regardless of the relative position between therotor 3 andcam ring 4. Accordingly, the back pressure is always applied from eachback pressure chamber 33 to the correspondingvane 32 so that thevane 32 is fluid-tightly in contact with theinner circumference 41 ofcam ring 4. - Therefore, a space between the
rotor 3 andcam ring 4 is divided into pump chambers B by thevanes 32 which are disposed adjacent to each other in the circumferential direction of thecam ring 4 androtor 3. Each pump chamber B formed by theadjacent vanes 32 is always kept fluid-tight. That is, thecam ring 4 cooperates with therotor 3 andvanes 32 to define the pump chambers B on the inner circumferential side ofcam ring 4. A volume of each pump chamber B varies in accordance with the rotation of therotor 3 in the case where thecam ring 4 and therotor 3 are positioned in the eccentric relation to each other as a result of the swing ofcam ring 4. - The
suction ports discharge ports pressure plate 6 and thesecond housing 12 as mentioned above are formed along the outer circumference ofrotor 3. Thesuction ports rotor 3, as shown inFIG. 2 . Moreover, thedischarge ports rotor 3. The supply and discharge of the working fluid are performed through theseports - The
adapter ring 5 has a radial through-hole 51 at an end portion thereof in the y-axis positive direction. Moreover, thefirst housing 11 has a plug-member insertion hole 114 at an end portion thereof in the y-axis positive direction. Aplug member 90 shaped like a cup having its bottom is inserted in the plug-member insertion hole 114, and serves to keep the first andsecond housings - A
spring 91 is installed radially inside an inner circumference of the plug member 90 (i.e., is installed in an inside bore of plug member 90) and is expandable and compressible in the y-axis direction. Thespring 91 extends through the radial through-hole 51 ofadapter ring 5, and abuts on thecam ring 4. Thereby, thespring 91 biases or urges thecam ring 4 in the y-axis negative direction. - The
spring 91 biases thecam ring 4 in the y-axis negative direction, namely, in the direction causing an amount of swing movement ofcam ring 4 to become maximum (maximum eccentricity). This biasing force ofspring 91 serves to stabilize the swing position ofcam ring 4 at the time of start-up ofvane pump 1 during which the fluid pressure is unstable. That is, thespring 91 serves to stabilize the flow rate of working fluid to be discharged at the time of start-up ofvane pump 1. - [Control Valve]
- The control valve 7 (corresponding to a pressure control section according to the present invention) is a mechanical valve adapted to be driven based on discharge and suction pressures. The
first housing 11 is formed with avalve installation hole 115 located in a z-axis positive portion offirst housing 11. Thecontrol valve 7 is received or installed in thevalve installation hole 115. Thiscontrol valve 7 includes aspool 71 and aspring 72. Radially inside thespool 71 formed in a tubular shape having its bottom, arelief valve 80 is installed. - (Spool)
- The
spool 71 is a hollow cylindrical (tubular) member having one closed end, namely itsbottom portion 71 a. Thebottom portion 71 a is located at an end portion of thespool 71 in the y-axis negative direction. At another end portion of thespool 71 in the y-axis positive direction, namely at anopening portion 71 b of thespool 71; thespring 72 biases thespool 71 in the y-axis negative direction. Moreover, an outer circumference of thespool 71 includes a sealingportion 71 c which is fluid-tightly in contact with an inner circumferential surface of thevalve installation hole 115. - The opening
portion 71 b is also fluid-tightly in contact with the inner circumferential surface of thevalve installation hole 115. Hence, thespool 71 divides thevalve installation hole 115 into three compartments, namely, a high pressure chamber CH, a medium pressure chamber CM and a low pressure chamber CL which are sealed against one another. The high pressure chamber CH is formed on the y-axis negative side of thespool 71. The medium pressure chamber CM is formed on the y-axis positive side of thespool 71. The low pressure chamber CL is formed on the outer circumferential surface of thespool 71 and between the sealingportion 71 c and the openingportion 71 b (i.e.,spool 71's outer peripheral area surrounded by the sealingportion 71 c, the openingportion 71 b and the first housing 11). - The
valve installation hole 115 is connected through afluid passage 113 and a through-hole 52 with the first fluid pressure chamber A1. Thefirst housing 11 is formed with thisfluid passage 113. The through-hole 52 is a radial through-hole provided in theadapter ring 5. The sealingportion 71 c ofspool 71 is located at its position closing thefluid passage 113 when thespring 72 is not compressed. - Therefore, when the
spool 71 moves in the y-axis positive direction, thefluid passage 113 is communicated (or linked) with the high pressure chamber CH so that a high pressure is introduced into the first fluid pressure chamber A1. On the other hand, when thespool 71 moves in the y-axis negative direction, thefluid passage 113 is communicated with the low pressure chamber CL so that a low pressure is introduced into the first fluid pressure chamber A1. - A y-axis negative portion of the high pressure chamber CH is connected through a
pilot orifice 300 and afluid passage 21 with thedischarge ports fluid passage 7 a with the inlet port IN. Thisfluid passage 7 a is provided at a more positive position than the sealingportion 71 c relative to y-axis, and hence is not connected with the high pressure chamber CH. - The medium pressure chamber CM is connected through a
fluid passage 116 and adamper orifice 200 with the second fluid pressure chamber A2. Moreover, the second fluid pressure chamber A2 is connected through ametering orifice 110 with adischarge passage 22 and thedischarge ports metering orifice 110 is provided in thepressure plate 6. Accordingly, the fluid pressures of the high pressure chamber CH and medium pressure chamber CM correspond respectively to an upstream (fluid) pressure and a downstream pressure of themetering orifice 110. A pressure difference between the upstream pressure and the downstream pressure is proportional to a flow rate (flow quantity) of themetering orifice 110. - [Swing of Cam Ring]
- A control fluid pressure of the
control valve 7 is introduced through thefluid passage 113 and through-hole 52 into the first fluid pressure chamber A1. Moreover, the downstream pressure of themetering orifice 110 is introduced in the second fluid pressure chamber A2. - In accordance with an increase of the discharge pressure; the fluid pressure difference of the
metering orifice 110 becomes greater, so that the pressure difference between the high pressure chamber CH connected to the upstream side of themetering orifice 110 and the medium pressure chamber CM connected to the downstream side of themetering orifice 110 also becomes greater. This pressure difference moves thespool 71 ofcontrol valve 7 in the y-axis positive direction against the biasing force of thespring 72. Thereby, the first fluid pressure chamber A1 is communicated with the high pressure chamber CH so that a high pressure Ph is introduced into the first fluid pressure chamber A1. - Meanwhile, the downstream pressure of the
metering orifice 110 is introduced in the second fluid pressure chamber A2 communicating with the medium pressure chamber CM. Thereby, the pressure difference between the first and second fluid pressure chambers A1 and A2 is caused (becomes greater). This pressure difference swings thecam ring 4 in the y-axis positive direction against the biasing force of thespring 91. - As a result, the pump chamber By− located on the y-axis negative side is reduced, so that a quantity of working fluid which is pushed (squeezed) into the
discharge ports suction ports metering orifice 110 is reduced so as to reduce the pressure difference between the high pressure chamber CH and the medium pressure chamber CM. - Accordingly, the
spool 71 becomes incapable of resisting the biasing force of thespring 72, and thereby moves in the y-axis negative direction. Then, the communication between the first fluid pressure chamber A1 and the high pressure chamber CH is blocked so that the fluid pressure of the first fluid pressure chamber A1 is lowered. Accordingly, the pressure difference between the first fluid pressure chamber A1 and the second fluid pressure chamber A2 is reduced, and the y-axis positive directional force caused by this pressure difference becomes balanced (or matched) with the biasing force ofspring 91. Thereby, the swing of thecam ring 4 is stopped. - As explained above, the pressure difference of the
metering orifice 110 and the biasing forces ofsprings cam ring 4 so as to always maintain a constant discharge rate (discharge quantity). In the case that an opening area of themetering orifice 110 is small, the pressure difference becomes large. In the case that the opening area of themetering orifice 110 is large, the pressure difference becomes small. - (Relief Valve)
- The
relief valve 80 includes avalve body 81, avalve seat 82, avalve ball 83 and aspring 84. One end of thespring 84 is fixedly connected with thebottom portion 71 a of thespool 71. Thespring 84 biases or urges thevalve body 81 in the y-axis positive direction. Thereby, thevalve body 81 is in contact with thevalve ball 83, and biases thevalve seat 82 in the y-axis positive direction through thisvalve ball 83. - An outer circumferential surface of a y-axis positive-
directional end portion 81 a of thevalve body 81 is fluid-tightly in contact with an inner circumferential surface of thespool 71. Hence, thevalve body 81 cooperates with the inner circumference of thespool 71 to define a first fluid chamber D1. Thespool 71 is formed with a firstradial hole 71 d provided from the outer circumference of thespool 71. The firstradial hole 71 d connects the inner circumferential surface ofspool 71 with the outer circumferential surface ofspool 71 to communicate an inside space ofspool 71 to an outside space ofspool 71. - When the
spring 84 ofrelief valve 80 is under its most expanded state (i.e., when thespring 84 has expanded to a greatest extent), the firstradial hole 71 d is located at a more negative position relative to y-axis than theend portion 81 a of thevalve body 81. At this time, the firstradial hole 71 d communicates the low pressure chamber CL with the first fluid chamber D1. When thevalve body 81 moves in the y-axis negative direction, the firstradial hole 71 d is closed. - The
valve seat 82 includes a through-hole 82 a formed in the y-axis direction. At a y-axis negative side of this through-hole 82 a, the through-hole 82 a is closed or blocked by thevalve ball 83 provided between the through-hole 82 a and thevalve body 81. A y-axis positive portion of thevalve seat 82 faces the medium pressure chamber CM. The outer circumference of thevalve seat 82 is fixed to the inner circumference of thespool 71 by means of press fitting, and thereby a second fluid chamber D2 is formed between thevalve body 81 and thevalve seat 82. - Since the through-
hole 82 a is provided in thevalve seat 82 in the y-axis direction, a medium pressure Pm is applied through the through-hole 82 a to thevalve ball 83 in the y-axis negative direction. When the medium pressure Pm within the medium pressure chamber CM increases, thevalve ball 83 is pressed in the y-axis negative direction against the biasing force ofspring 84. Thereby, thevalve ball 83 is detached (moves apart) from the through-hole 82 a, so that the medium pressure chamber CM is communicated with the low pressure chamber CL. Thus, a relief state is achieved, in which the medium pressure Pm is drained through thefluid passage 7 a to the inlet port IN. - (Swing of Cam Ring at the Time of Relief)
- Since the
fluid passage 116 anddamper orifice 200 are provided upstream of the medium pressure chamber CM, the fluid pressure of medium pressure chamber CM is reduced at the time of the relief state. Thereby, the pressure difference between the medium pressure chamber CM and the high pressure chamber CH becomes larger so that thespool 71 moves in the y-axis positive direction by resisting against the biasing force ofspring 72. - Then, the first fluid pressure chamber A1 is made to communicate with the high pressure chamber CH. Because of this high pressure, the
cam ring 4 is swung in the y-axis positive direction, so that the discharge flow rate is reduced. Because of the reduction of discharge flow rate, the pressure difference of themetering orifice 110 is reduced so that the pressure difference between the medium pressure chamber CM and the high pressure chamber CH is reduced. Thereby, the pressure Ph of high pressure chamber CH becomes unable to resist the biasing force ofspring 72, so that thespool 71 moves in the y-axis negative direction. - Thereby, the communication between the high pressure chamber CH and the first fluid pressure chamber A1 is blocked, and the pressure of the first fluid pressure chamber A1 is lowered. At this time, the y-axis positive-directional force which is applied from the first fluid pressure chamber A1 to the
cam ring 4 is reduced so that the swing ofcam ring 4 stops. Thus, the discharge flow rate is reduced. - Thereby, the pressure difference between upstream and downstream sides of the
metering orifice 110 is also reduced. That is, the enlargement of this pressure difference between the upstream and downstream sides is corrected, so that the pump discharge flow rate is maintained to a predetermined flow rate. Therefore, under the relief state, a surplus flow rate (quantity) is reduced by means of the swing ofcam ring 4 so as to improve an efficiency. - (Metering Orifice)
-
FIG. 3 is an enlarged cross-sectional view near a variable metering (throttling)mechanism 100. Themetering orifice 110 is a long (and narrow) hole formed long in the circumferential direction ofvane pump 1. An opening area of themetering orifice 110 is varied by the y-axis-directional swing of thecam ring 4. - The long hole defining the
metering orifice 110 is designed to cause a major (longer) axis of themetering orifice 110 to deviate slightly from the z-axis direction. That is, the major axis of themetering orifice 110 is inclined from acam ring 4's tangent which is perpendicular to an imaginary line passing through a center point of the major axis ofmetering orifice 110 and the center Oc ofcam ring 4. Aportion 111 of a z-axis negative-directional end portion of themetering orifice 110 is not closed by thecam ring 4 even when thecam ring 4 swings in the y-axis positive direction to its greatest extent, as shown inFIG. 3 . Hence, themetering orifice 110 is always open to the second fluid pressure chamber A2 at least by the minimum securedarea 111. That is, the minimum securedarea 111 which is not blocked by thecam ring 4 always communicates with the second fluid pressure chamber A2. - When the
cam ring 4 swings in the y-axis positive direction, the opening portion of themetering orifice 110 is partly closed by thecam ring 4 to reduce the opening area ofmetering orifice 110. When thecam ring 4 reaches its position farthest in the y-axis positive direction, themetering orifice 110 is closed except only one portion (minimum secured area 111). Thisvariable metering mechanism 100 adapted to vary the area of flow passage is achieved by themetering orifice 110 and thecam ring 4. - Since the opening portion of the
metering orifice 110 is provided in the shape of a long narrow hole (elliptical slot) elongated in the circumferential direction ofcam ring 4, themetering orifice 110 is gradually closed after thecam ring 4 has swung by a predetermined angle. Therefore, themetering orifice 110 is not closed or narrowed down at the time of a non-relief state where the discharge flow rate is constant. Thereby, it is suppressed that the discharge-rate control is influenced by the variation of the pressure difference between upstream and downstream sides of themetering orifice 110. Thereby, a tuning of the discharge-rate control is made easy to conduct. - Moreover, since the opening portion of the
metering orifice 110 is shaped like a long hole having the greater circumferential width than the radial width thereof as mentioned above, the opening area of themetering orifice 110 can be reduced rapidly relative to an amount (displacement) of swing of thecam ring 4. - [Fluid Pressure Supply to First and Second Fluid Pressure Chambers]
- The discharge pressure is restricted by the
pilot orifice 300 provided on thefluid passage 21, and then is supplied to the high pressure chamber CH so as to urge thespool 71 in the y-axis positive direction. Thereby, thespool 71 moves in the y-axis positive direction so that the high pressure chamber CH is communicated with thefluid passage 113. Accordingly, the pressure Ph of high pressure chamber CH is introduced into the first fluid pressure chamber A1. The discharge pressure is also introduced to thedischarge passage 22, and then is introduced into the second fluid pressure chamber A2 by being restricted by themetering orifice 110, as shown inFIG. 2 . - Since the fluid pressure of second fluid pressure chamber A2 is supplied to a fluid-pressure available pathway (connected to a pressure-using device) provided outside the
vane pump 1, the orifice pressure-difference occurs in proportion to the flow rate of themetering orifice 110. Thereby, the medium pressure Pm of medium pressure chamber CM located downstream of themetering orifice 110 becomes lower than the pressure Ph of high pressure chamber CH located upstream of themetering orifice 110. Accordingly, the second fluid pressure chamber A2 is made to have a lower pressure than that of the first fluid pressure chamber A1 so that thecam ring 4 swings in the y-axis positive direction. - When the
cam ring 4 swings; the pump discharge flow rate decreases, and the flow-rate pressure difference of themetering orifice 110 is lowered. Thereby, the pressure difference between the high pressure chamber CH and the medium pressure chamber CM is reduced so that the biasing force ofspring 72 moves thespool 71 in the y-axis direction. Thereby, the pressure to be supplied to the first fluid pressure chamber A1 is reduced, so that the swing ofcam ring 4 is stopped. Thus, the predetermined discharge flow rate is attained. - The outer circumferential side of
cam ring 4 receives the pressures of first and second fluid pressure chambers A1 and A2, and the inner circumferential side ofcam ring 4 receives the discharge pressure in the y-axis negative direction and also in the z-axis negative direction. The swing ofcam ring 4 is stopped at a position striking a balance among these pressures. - In the case that the discharge rate decreases, because of the reduction of pressure difference of the
metering orifice 110, the pressure Ph within high pressure chamber CH is also reduced. Thereby, thespool 71 is moved in the y-axis negative direction by the biasing force ofspring 72 so that the low pressure chamber CL is communicated with thefluid passage 113. Thereby, a low pressure Pl is introduced into the first fluid pressure chamber A1, so that the first fluid pressure chamber A1 becomes lower in fluid pressure than the second fluid pressure chamber A2. Accordingly, thecam ring 4 returns in the y-axis negative direction. Thus, the pressure difference of themetering orifice 110 becomes constant to attain or maintain the predetermined flow rate. - [Reduction of Discharge Flow Rate During Relief State]
-
FIG. 4 is a view showing a relation between the opening area ofmetering orifice 110 and the swing amount of cam ring 4 (the position ofcam ring 4 by its swing motion). In the case where the swing amount ofcam ring 4 is within a normal use range; themetering orifice 110 is not closed by thecam ring 4, namely, the opening area ofmetering orifice 110 remains constant in its fully open condition. Accordingly, the discharge flow rate is maintained at a constant flow rate, by means of the movement ofspool 71, the swing ofcam ring 4 and the pressure difference ofmetering orifice 110. - In the case of relief state where the pressure of medium pressure chamber CM is drained through the
relief valve 80 and thefluid passage 7 a to the inlet port IN, the pressure of medium pressure chamber CM is reduced because of the existence of thefluid passage 7 a and thepilot orifice 300. - Thereby, the pressure Ph of high pressure chamber CH becomes higher than the pressure Pm of medium pressure chamber CM, so that the pressure P1 of first fluid pressure chamber A1 communicating with the high pressure chamber CH becomes higher than the pressure P2 of the second fluid pressure chamber A2 communicating with the medium pressure chamber CM. Accordingly, the
cam ring 4 swings in the y-axis positive direction, so that the discharge rate is reduced. Here, under the relief state, the swing amount (i.e., displacement in the y-axis positive direction) ofcam ring 4 is further enlarged as mentioned above. - Since the
cam ring 4 moves in the y-axis positive direction, the opening area ofmetering orifice 110 is reduced. Since the opening area ofmetering orifice 110 is reduced, the pressure difference between the both sides ofmetering orifice 110 is increased. Accordingly, the pressure difference between the high pressure chamber CH and the medium pressure chamber CM is also increased. Hence, thespool 71 moves in the y-axis positive direction so that the high pressure chamber CH is communicated with the first fluid pressure chamber A1. Since the pressure P1 of first fluid pressure chamber A1 rises, thecam ring 4 further swings in the y-axis positive direction so that the discharge flow rate is further reduced. - As explained above, at the time of relief state, the surplus quantity of working fluid which is drained from the medium pressure chamber CM to the inlet port IN is reduced by restricting the flow rate to the medium pressure chamber CM. Thus, the drain quantity of working fluid is reduced during the relief state so as to enhance fuel economy.
- In this embodiment, the swing of
cam ring 4 varies the cross sectional area of flow passage (the opening area of metering orifice 110), and thereby the drain quantity of working fluid is reduced. Therefore, the drain quantity of working fluid is linked to the variation of cross sectional area of flow passage with the use of simple structure. - Moreover, by providing the
pilot orifice 300, thecam ring 4 is made easy to move in the y-axis positive direction so that the opening area ofmetering orifice 110 is made easy to be narrowed or reduced. Thereby, the drain quantity of working fluid is further reduced at the time of relief. At that time, the relief state can be accurately judged or recognized by detecting the y-axis positive-directional movement (position) ofcam ring 4. - In case that the
pilot orifice 300 is more narrowed down, it is conceivable that the pressure Pm of medium pressure chamber CM becomes further easy to be reduced at the time of relief state, and thereby the swing amount ofcam ring 4 is made greater to further reduce the surplus flow rate. However in such a case, there is a fear that a vibration ofvalve ball 83 under the relief state fluctuates the pressure Pm of medium pressure chamber CM so as to also vibrate thespool 71 andcam ring 4. Thereby, there is a fear that a vibration of the discharge pressure is caused. - Therefore, in this embodiment according to the present invention, the structure is employed which lessens the
metering orifice 110 at the time of relief state. According to this structure, the lessening (narrowing-down) of thepilot orifice 300 can be set relatively moderately. In this embodiment, the surplus flow rate is reduced without causing the vibration of fluid pressure. - Moreover, by providing the
damper orifice 200; a vibration ofspool 71 which is caused due to the discharge pressure is suppressed, and also the fluid-pressure vibration at the time of relief state is suppressed so that thecontrol valve 7 operates stably resulting in a stable swing ofcam ring 4. - [Structures and Effects According to First Embodiment]
- (1) The variable displacement vane pump in the first embodiment includes the
metering orifice 110 formed on thedischarge passage 22 connected with thedischarge ports control valve 7 adapted to control the pressure which is introduced into the first fluid pressure chamber A1 or the second fluid pressure chamber A2, wherein thecontrol valve 7 includes the high pressure chamber CH into which the upstream pressure of themetering orifice 110 is introduced, the medium pressure chamber CM into which the downstream pressure of themetering orifice 110 is introduced, and the low pressure chamber CL connected with the reservoir tank RSV for storing working fluid; therelief valve 80 provided between the downstream side ofmetering orifice 110 and the reservoir tank RSV, wherein therelief valve 80 is adapted to be opened by receiving a pressure greater than or equal to a predetermined level and thereby to drain the downstream pressure of themetering orifice 110 to the reservoir tank RSV; and thevariable metering mechanism 100 configured to narrow the cross-sectional area of opening portion (flow passage) of themetering orifice 110 at least when therelief valve 80 is opened. - Accordingly, it becomes possible that the flow rate is reduced by the
metering orifice 110 at the time of relief so that thecam ring 4 is swung. Thereby, the surplus fluid quantity to be drained from the medium pressure chamber CM to the inlet port IN is reduced. Thus, the surplus flow rate can be stably reduced without generating the fluid-pressure vibration. Therefore, the increase in pump workload can be suppressed while reducing the relief amount, and thereby the fuel economy is enhanced. - (2) The
cam ring 4 is adapted to swing so as to gradually block the opening portion of themetering orifice 110, and hence thevariable metering mechanism 100 is achieved by themetering orifice 110 and thecam ring 4. Further, the opening portion ofmetering orifice 110 is formed in the axial end surface of thefirst plate member 12 or thesecond plate member 6. Accordingly, the reduction of drain flow rate of working fluid can be linked to the variation of cross sectional area of the flow passage under the relief state, with the use of simple structure. - (3) The
variable metering mechanism 100 is configured to gradually narrow the opening portion of themetering orifice 110 after thecam ring 4 has swung to its position having a predetermined angle. Accordingly, themetering orifice 110 is not blocked or narrowed at the time of non-relief state where the discharge flow rate is constant. Thereby, it is suppressed that the discharge-rate control is influenced by the variation of the pressure difference between upstream and downstream sides of themetering orifice 110. Thereby, the tuning of the discharge-rate control can be made easy to perform. - (4) The circumferential width of opening portion of the
metering orifice 110 is greater than the radial width thereof. Accordingly, the area of themetering orifice 110 can be narrowed sharply for the swing amount of thecam ring 4 so as to greatly reduce the surplus flow rate. - (5) The opening portion of the
metering orifice 110 is formed in an elliptical shape or a slot shape. Accordingly, the area of themetering orifice 110 can be narrowed sharply for the swing amount of thecam ring 4 so as to greatly reduce the surplus flow rate. - (6) The variable displacement vane pump further includes a
pilot orifice 300 provided on the passage connecting thedischarge ports cam ring 4. - (7) The variable displacement vane pump further includes the
damper orifice 200 provided on the passage connecting themetering orifice 110 with the medium pressure chamber CM. Accordingly, the stability ofcontrol valve 7 can be improved at the time of relief. - Other modified examples according to the first embodiment will be explained below.
- [First Modified Example According to First Embodiment]
-
FIGS. 5 and 6 show an example in which the minimum securedarea 111 ofmetering orifice 110 is provided as a separate hole (another hole). Although the major axis of the metering orifice 110 (i.e., the longer axis of cross-section of metering orifice 110) is inclined from the z-axis in the above-mentioned example of the first embodiment, themetering orifice 110 in the first modified example of the first embodiment is formed as a long hole (slot) having its major axis parallel to the z-axis. In the first modified example, the hole (another hole) formed separately on the y-axis positive side of themetering orifice 110 serves as the minimum securedarea 111. - The
metering orifice 110 is completely closed when thecam ring 4 reaches its most positive swing position relative to y-axis, namely is completely closed at the position of an alternate long and two short dashes line ofFIG. 6 . On the other hand, the minimum securedarea 111 is located at a position which is not closed irrespective of the swing position ofcam ring 4. Therefore, the major (longer) axis ofmetering orifice 110 is provided in parallel with the z-axis so that a manufacturing processing of themetering orifice 110 can be simplified. - [Second Modified Example According to First Embodiment]
-
FIG. 7 shows an example in which themetering orifice 110 is provided as a plurality of holes each having a substantially complete roundness. Accordingly, a sufficient opening area can be ensured as well as ensuring a stiffness near the opening portion ofmetering orifice 110. - [Third Modified Example According to First Embodiment]
-
FIG. 8 shows an example further modifying the above-explained first modified example in such a manner that thedamper orifice 200 is provided outside theadapter ring 5. In the third modified example, afluid passage 23 connecting the second fluid pressure chamber A2 with the medium pressure chamber CM is provided outside thefirst housing 11, and thisfluid passage 23 is formed with thedamper orifice 200. - [Fourth Modified Example According to First Embodiment]
-
FIG. 9 shows an example in which apiston 92 adapted to move in and out in response to the swing ofcam ring 4 is provided, and thispiston 92 is formed with themetering orifice 110. Thepiston 92 is located on the y-axis negative side of theplug member 90 and on the y-axis positive side of thecam ring 4. Thepiston 92 is a circular tubular (hollow cylindrical) member having its bottom. The bottom portion ofpiston 92 abuts on thecam ring 4 in the y-axis negative direction. - An outer circumferential surface of
piston 92 is inserted into the plug-member insertion hole 114 slidably and fluid-tightly. Thereby, thepiston 92 cooperates with theplug member 90 to define a third fluid chamber D3. An inner circumference of theplug member 90 is formed with an openingportion 22 a of thedischarge passage 22 communicating with thedischarge ports spring 91 to bias thepiston 92 in the y-axis negative direction. Accordingly, thecam ring 4 is biased in the y-axis negative direction through thepiston 92 by means of the biasing force ofspring 91 and the pressure of the third fluid chamber D3. - A tubular portion of the
piston 92 is formed with small (through-)holes each of which communicates an inner circumferential surface ofpiston 92 with an outer circumferential surface ofpiston 92. These small holes are used as themetering orifice 110. Thepiston 92 is pressed by thecam ring 4 in the y-axis positive direction in accordance with the y-axis positive-directional swing ofcam ring 4, and thereby moves in the y-axis positive direction against the pressures ofspring 91 and third fluid chamber D3. - When the
piston 92 moves in the y-axis positive direction, thepiston 92 is deeply inserted (buried) into the plug-member insertion hole 114. Thereby, themetering orifice 110 is closed by (the inner surface of) the plug-member insertion hole 114. In such a way, thevariable metering mechanism 100 is constructed in the fourth modified example. Accordingly, the drain quantity of working fluid is reduced at the time of relief state in the similar manner as the not-modified example of the first embodiment. In this fourth modified example, since themetering orifice 110 is closed by the plug-member insertion hole 114, a leakage in themetering orifice 110 becomes relatively low so that an accuracy in the quantity metering (reduction) control is enhanced. - (8) The variable displacement vane pump according to the first embodiment further includes the
piston 92 adapted to move in response to the swing ofcam ring 4; and themetering orifice 110 is formed in thepiston 92. Accordingly, the leakage of themetering orifice 110 becomes relatively small so that the accuracy in quantity metering (reduction) control can be enhanced. - A second embodiment according to the present invention will now be explained. A basic structure of the second embodiment is similar as the first embodiment. Although the opening portion provided on the
discharge passage 22 is used as themetering orifice 110 in the first embodiment, aspool 400 adapted to vary an area of flow passage corresponds to themetering orifice 110, in the second embodiment, as a different point from the first embodiment. -
FIG. 10 is a cross-sectional view ofvane pump 1 according to the second embodiment, taken in the axial direction ofvane pump 1.FIG. 11 is a cross-sectional view of thevane pump 1, taken in the radial direction ofvane pump 1. Since the cross section ofFIG. 11 is different from the cross section (FIG. 2 ) taken in the axial direction in the first embodiment, only a part of thecontrol valve 7 is shown inFIG. 11 . Thefirst housing 11 is formed with aspool installation hole 117 located in parallel with thevalve installation hole 115 for thecontrol valve 7. Thespool 400 is installed or received in thisspool installation hole 117. - The
spool 400 includesstep portions spool 400 in the y-axis direction. Thespool 400 further includes arecess portion 424 in a substantially center portion ofspool 400. Thisrecess portion 424 is formed in the entire outer circumference (i.e., all-around) ofspool 400. Moreover, sealingportions spool 400 on y-axis directional both sides of therecess portion 424. Accordingly, thespool installation hole 117 is divided into three compartments, namely, a firstspool fluid chamber 411, a secondspool fluid chamber 412 and a thirdspool fluid chamber 413 which are sealed fluid-tightly against one another. - A
spring 401 is provided in the firstspool fluid chamber 411. One end ofspring 401 is engaged with thestep portion 423 located at the y-axis negative portion of thespool 400, and another end ofspring 401 is fixed to a y-axis negative end portion of thespool installation hole 117. Thereby, thespool 400 is biased in the y-axis positive direction. The firstspool fluid chamber 411 is connected with the inlet port IN, and thereby the suction pressure is introduced into the firstspool fluid chamber 411. The firstspool fluid chamber 411 is also connected through thefluid passage 7 a with the low pressure chamber CL of thecontrol valve 7. - The second
spool fluid chamber 412 and thirdspool fluid chamber 413 are connected with the outlet port OUT. Thereby, the discharge pressure is introduced into the secondspool fluid chamber 412 and thirdspool fluid chamber 413 so that thespool 400 is biased in the y-axis negative direction. The outlet port OUT is connected with thedischarge ports - The second fluid pressure chamber A2 is connected through a
fluid passage 24 with thespool installation hole 117. An openingportion 24 a of thefluid passage 24 which is open to thespool installation hole 117 is provided to overlap with therecess portion 424 in the z-axis direction under a normal state where a sufficient pressure difference is not applied to thespool 400. Specifically, y-axis directional positions of both ends of openingportion 24 a are same as y-axis directional positions of both ends ofrecess portion 424 under the normal state. Accordingly, thefluid passage 24 is connected through therecess portion 424 with the outlet port OUT, under the normal state. - When the discharge pressure becomes higher and reaches the relief pressure, the
spool 400 moves in the y-axis negative direction against the biasing force ofspring 401. Thereby, the openingportion 24 a is gradually closed or narrowed by the sealingportion 422 ofspool 400 which is located on the y-axis positive side of therecess portion 424. Accordingly, the area of flow passage between the second fluid pressure chamber A2 and the outlet port OUT is reduce (corresponding to the narrowing ofmetering orifice 110 in the first embodiment), so that the (some) pressure difference between the second fluid pressure chamber A2 and the outlet port OUT is caused. This pressure difference moves thecontrol valve 7, so that the pressure Ph of high pressure chamber CH is introduced into the first fluid pressure chamber A1. - Thereby, the cam ring is swung in the y-axis positive direction, so that the discharge rate (discharge quantity) and the discharge pressure are reduced. Accordingly, the surplus discharge pressure at the time of relief is reduced in the similar manner as the first embodiment. The biasing force of
spring 401 is adjusted to allow the narrowing of the openingportion 24 a to start when the discharge pressure becomes greater than or equal to a predetermined value. Hence, in this second embodiment, thevariable metering mechanism 100 is constructed by use of a convenient structure. Moreover, the surplus flow rate is cut reliably at the time of relief pressure. - [Structures and Effects According to Second Embodiment]
- (1) The variable displacement vane pump in the second embodiment includes the
variable metering mechanism 100 configured to narrow the cross-sectional area of opening portion (flow passage) of themetering orifice 24 a when the discharge pressure on the downstream side of thedischarge ports - (2) The
variable metering mechanism 100 is achieved by thespool 400 adapted to controllably vary the opening area of themetering orifice 24 a by moving relative to themetering orifice 24 a. Accordingly, thevariable metering mechanism 100 can be simply constructed. - Other modified examples according to the second embodiment will be explained below.
- [First Modified Example According to Second Embodiment]
-
FIG. 12 show an example in which thespool 400 is provided as an electromagnetic (solenoid) valve. In the above-explained non-modified example of the second embodiment, thespool 400 is a mechanical valve adapted to move based on the discharge pressure. On the other hand, in a first modified example of the second embodiment, thespool 400 is constructed by the electromagnetic valve and is connected with anelectromagnetic actuator 500. Moreover, there is provided apressure sensor 510 for sensing the pressure of the outlet port OUT. Theelectromagnetic actuator 500 is driven based on the sensed values ofpressure sensor 510, and thereby narrows or blocks the openingportion 24 a (corresponding to themetering orifice 110 in the first embodiment, i.e., corresponding to the metering orifice according to the present invention). Thus, thevariable metering mechanism 100 is achieved. - (Structures and Effects According to First Modified Example of Second Embodiment)
- (3) The
variable metering mechanism 100 is achieved by the fluid-pressure sensor 510 adapted to sense the discharge pressure, and the electromagnetic valve adapted to be opened based on the sensed signal of the fluid-pressure sensor 510. Accordingly, a freedom degree in design and tuning accuracy can be enhanced since the area of flow passage is varied by moving thespool 400 electromagnetically. - [Second Modified Example According to Second Embodiment]
-
FIG. 13 shows an example further modifying the above-explained first modified example of second embodiment in such a manner that therelief valve 80 is provided outside thehousing 11. In a second modified example of the second embodiment, therelief valve 80 is connected through afluid passage 27 with the secondspool fluid chamber 412 ofspool 400 and the medium pressure chamber CM. Therelief valve 80 is also connected with a reservoir tank RSV. Thisrelief valve 80 only permits a flow from thefluid passage 27 toward the reservoir tank RSV, namely, permits the flow in only one direction. - The second
spool fluid chamber 412 ofspool 400 is connected through afluid passage 26 with thedischarge ports spool fluid chamber 411 is connected through afluid passage 28 with the inlet port IN. - Since the
relief valve 80 is located outside thecontrol valve 7 and there is no orifice between the medium pressure chamber CM and thefluid passage 27; the reduction of pressure of medium pressure chamber CM due to a narrow shape of orifice is not caused at the time of relief state. Thereby, the swing ofcam ring 4 is suppressed. - In the second modified example of the second embodiment, when the sensed value of
pressure sensor 510 reaches the relief pressure, theelectromagnetic actuator 500 is driven to move thespool 400 and thereby narrow the fluid passage 27 (corresponding to the narrowing ofmetering orifice 110 in the first embodiment). Thereby, thecam ring 4 is swung so that the surplus flow quantity is reduced. Therefore, it is not necessary to operate thecontrol valve 7 by using the discharge pressure under the relief state. Thus, the problem regarding the vibration ofcontrol valve 7 is also avoided. - [Third Modified Example According to Second Embodiment]
-
FIGS. 14 and 15 show an example in which the shape of thespool 400 is changed in a manner that thespool 400 is operated by use of a drain pressure produced at a downstream side of therelief valve 80. In a third modified example of the second embodiment, afluid passage 30 is provided at the y-axis negative side (end) of thespool 400, as shown inFIG. 15 . Through thisfluid passage 30, thespool 400 is connected with the downstream side of therelief valve 80. Thespring 401 is provided within the thirdspool fluid chamber 413, and biases thespool 400 in the y-axis negative direction. - In this third modified example, the
spool 400 forms a fourthspool fluid chamber 414 within thespool installation hole 117, in addition to the first to thirdspool fluid chambers 411 to 413. Hence, a volume of the firstspool fluid chamber 411 is smaller than that of the non-modified example of the second embodiment. - The fourth
spool fluid chamber 414 is located between the first and secondspool fluid chambers spool fluid chamber 414 is connected with the thirdspool fluid chamber 413 through a shaft-center hole 430 formed in a shaft center portion of thespool 400, so that the suction pressure is introduced into the thirdspool fluid chamber 413. - Accordingly, when the downstream pressure of the
relief valve 80 becomes high, thespool 400 moves in the y-axis positive direction against the biasing force so that the opening area of the openingportion 24 a offluid passage 24 is reduced. Thus, in the similar manner as the non-modified example of the second embodiment, the surplus discharge pressure is reduced at the time of relief, and thevariable metering mechanism 100 is constructed by use of a convenient structure. Furthermore, since thespool 400 is driven by using the downstream-side pressure ofrelief valve 80, the relief state is more accurately judged or recognized. - (Structures and Effects According to Third Modified Example of Second Embodiment)
- (4) The
variable metering mechanism 100 is configured to vary the area of the opening portion (fluid passage) on the basis of the downstream pressure ofrelief valve 80. Accordingly, the relief state can be more accurately caught. - (5) The
variable metering mechanism 100 is achieved by thespool 400 adapted to controllably vary the opening area by moving in and out. Accordingly, thevariable metering mechanism 100 can be simply constructed. - Although the invention has been described above with reference to certain embodiments of the invention, the invention is not limited to the embodiments described above. Modifications and variations of the embodiments described above will occur to those skilled in the art in light of the above teachings.
- This application is based on prior Japanese Patent Application No. 2007-212854 filed on Aug. 17, 2007. The entire contents of this Japanese Patent Application are hereby incorporated by reference.
- The scope of the invention is defined with reference to the following claims.
Claims (20)
1. A variable displacement vane pump comprising:
a pump body;
a drive shaft supported rotatably by the pump body;
a rotor disposed inside the pump body and adapted to be rotatably driven by the drive shaft, the rotor being formed with a plurality of slots spaced from each other in a circumferential direction of the rotor;
a plurality of vanes received by the slots so as to be movable out from the slots and into the slots;
a cam ring formed in an annular shape and disposed inside the pump body to permit the cam ring to become eccentric relative to the drive shaft, the cam ring cooperating with the rotor and the vanes to define a plurality of pump chambers on an inner circumferential side of the cam ring;
a first plate member and a second plate member disposed on axially both sides of the cam ring;
a suction port provided on a side of at least one of the first plate member and the second plate member and opened to at least one of the plurality of pump chambers;
a discharge port provided on a side of at least one of the first plate member and the second plate member and opened to at least one of the plurality of pump chambers;
a sealing member provided on an outer circumferential side of the cam ring, the sealing member dividing a space on an outer circumferential surface of the cam ring into a first fluid pressure chamber and a second fluid pressure chamber, wherein a flow rate of working fluid discharged from the discharge port is increased when the cam ring moves to the first fluid pressure chamber, wherein the flow rate of working fluid discharged from the discharge port is decreased when the cam ring moves to the second fluid pressure chamber;
a metering orifice formed on a discharge passage connected with the discharge port;
a pressure control section adapted to control a pressure which is introduced into the first fluid pressure chamber or the second fluid pressure chamber, the pressure control section comprising
a high pressure chamber into which an upstream pressure of the metering orifice is introduced,
a medium pressure chamber into which a downstream pressure of the metering orifice is introduced, and
a low pressure chamber connected with a reservoir tank for storing working fluid;
a relief valve provided between a downstream side of the metering orifice and the reservoir tank, the relief valve being adapted to be opened by receiving a pressure greater than or equal to a predetermined level and thereby to drain the downstream pressure of the metering orifice to the reservoir tank; and
a variable metering mechanism configured to narrow a cross-sectional area of opening portion of the metering orifice at least when the relief valve is opened.
2. The variable displacement vane pump as claimed in claim 1 , wherein
the cam ring is adapted to swing so as to gradually block the opening portion of the metering orifice, the variable metering mechanism being achieved by the metering orifice and the cam ring; and
the metering orifice comprises the opening portion formed in an axial end surface of the first plate member or the second plate member.
3. The variable displacement vane pump as claimed in claim 2 , wherein
the variable metering mechanism is configured to gradually narrow the opening portion of the metering orifice after the cam ring has swung to its position having a predetermined angle.
4. The variable displacement vane pump as claimed in claim 2 , wherein
a circumferential width of the opening portion of the metering orifice is greater than a radial width thereof.
5. The variable displacement vane pump as claimed in claim 4 , wherein
the opening portion of the metering orifice is formed in an elliptical shape or a slot shape.
6. The variable displacement vane pump as claimed in claim 4 , wherein
the metering orifice comprises a plurality of holes.
7. The variable displacement vane pump as claimed in claim 2 , further comprising
a pilot orifice provided on a passage connecting the discharge port with the high pressure chamber.
8. The variable displacement vane pump as claimed in claim 2 , further comprising
a damper orifice provided on a passage connecting the metering orifice with the medium pressure chamber.
9. The variable displacement vane pump as claimed in claim 1 , wherein
the variable displacement vane pump further comprises a piston adapted to move in response to a swing of the cam ring; and
the metering orifice is formed in the piston.
10. The variable displacement vane pump as claimed in claim 1 , wherein
the variable metering mechanism is configured to vary the area of opening portion of the metering orifice on the basis of a downstream pressure of the relief valve.
11. The variable displacement vane pump as claimed in claim 10 , wherein
the variable metering mechanism is achieved by a spool adapted to controllably vary the area of opening portion of the metering orifice by moving relative to the metering orifice.
12. A variable displacement vane pump comprising:
a pump body;
a drive shaft supported rotatably by the pump body;
a rotor disposed inside the pump body and adapted to be rotatably driven by the drive shaft, the rotor being formed with a plurality of slots spaced from each other in a circumferential direction of the rotor;
a plurality of vanes received by the slots so as to be movable out from the slots and into the slots;
a cam ring formed in an annular shape and disposed inside the pump body to permit the cam ring to become eccentric relative to the drive shaft, the cam ring cooperating with the rotor and the vanes to define a plurality of pump chambers on an inner circumferential side of the cam ring;
a first plate member and a second plate member disposed on axially both sides of the cam ring;
a suction port provided on a side of at least one of the first plate member and the second plate member and opened to at least one of the plurality of pump chambers;
a discharge port provided on a side of at least one of the first plate member and the second plate member and opened to at least one of the plurality of pump chambers;
a sealing member provided on an outer circumferential side of the cam ring, the sealing member dividing a space on an outer circumferential surface of the cam ring into a first fluid pressure chamber and a second fluid pressure chamber, wherein a flow rate of working fluid discharged from the discharge port is increased when the cam ring moves to the first fluid pressure chamber, wherein the flow rate of working fluid discharged from the discharge port is decreased when the cam ring moves to the second fluid pressure chamber;
a metering orifice formed on a discharge passage connected with the discharge port;
a pressure control section adapted to control a pressure which is introduced into the first fluid pressure chamber or the second fluid pressure chamber, the pressure control section comprising
a high pressure chamber into which an upstream pressure of the metering orifice is introduced,
a medium pressure chamber into which a downstream pressure of the metering orifice is introduced, and
a low pressure chamber connected with a reservoir tank for storing working fluid;
a relief valve provided between a downstream side of the metering orifice and the reservoir tank, the relief valve being adapted to be opened by receiving a pressure greater than or equal to a predetermined level and thereby to drain the downstream pressure of the metering orifice into the reservoir tank; and
a variable metering mechanism configured to narrow a cross-sectional area of opening portion of the metering orifice when a discharge pressure on a downstream side of the discharge port is higher than or equal to a predetermined pressure.
13. The variable displacement vane pump as claimed in claim 12 , wherein
the variable metering mechanism is achieved by a fluid-pressure sensor adapted to sense the pressure discharged from the discharge port and an electromagnetic valve adapted to be opened based on a sensed signal of the fluid-pressure sensor.
14. The variable displacement vane pump as claimed in claim 12 , wherein
the variable metering mechanism is achieved by a spool adapted to controllably vary the area of opening portion of the metering orifice by moving relative to the metering orifice.
15. A variable displacement vane pump comprising:
a pump body;
a drive shaft supported rotatably by the pump body;
a rotor disposed inside the pump body and adapted to be rotatably driven by the drive shaft, the rotor being formed with a plurality of slots spaced from each other in a circumferential direction of the rotor;
a plurality of vanes received by the slots so as to be movable out from the slots and into the slots;
a cam ring formed in an annular shape and disposed inside the pump body to permit the cam ring to become eccentric relative to the drive shaft, the cam ring cooperating with the rotor and the vanes to define a plurality of pump chambers on an inner circumferential side of the cam ring;
a first plate member and a second plate member disposed on axially both sides of the cam ring;
a suction port provided on a side of at least one of the first plate member and the second plate member and opened to at least one of the plurality of pump chambers;
a discharge port provided on a side of at least one of the first plate member and the second plate member and opened to at least one of the plurality of pump chambers;
a sealing member provided on an outer circumferential side of the cam ring, the sealing member dividing a space on an outer circumferential surface of the cam ring into a first fluid pressure chamber and a second fluid pressure chamber, wherein a flow rate of working fluid discharged from the discharge port is increased when the cam ring moves to the first fluid pressure chamber, wherein the flow rate of working fluid discharged from the discharge port is decreased when the cam ring moves to the second fluid pressure chamber;
a metering orifice formed on a discharge passage connected with the discharge port;
a pressure control section adapted to control a pressure which is introduced into the first fluid pressure chamber or the second fluid pressure chamber, the pressure control section comprising
a high pressure chamber into which an upstream pressure of the metering orifice is introduced,
a medium pressure chamber into which a downstream pressure of the metering orifice is introduced, and
a low pressure chamber connected with a reservoir tank for storing working fluid;
a relief valve provided between a downstream side of the metering orifice and the reservoir tank, the relief valve being adapted to be opened by receiving a pressure greater than or equal to a predetermined level and thereby to drain the downstream pressure of the metering orifice into the reservoir tank; and
a variable metering mechanism configured to narrow a cross-sectional area of opening portion of the metering orifice to a larger extent as the eccentricity of the cam ring becomes smaller when the relief valve is open.
16. The variable displacement vane pump as claimed in claim 15 , wherein
the cam ring is adapted to swing so as to gradually block the opening portion of the metering orifice, the variable metering mechanism being achieved by the metering orifice and the cam ring; and
the metering orifice comprises the opening portion formed in an axial end surface of the first plate member or the second plate member.
17. The variable displacement vane pump as claimed in claim 15 , wherein
the variable metering mechanism is configured to gradually narrow the opening portion of the metering orifice after the cam ring has swung to its position having a predetermined angle.
18. The variable displacement vane pump as claimed in claim 15 , further comprising
a pilot orifice provided on a passage connecting the discharge port with the high pressure chamber.
19. A variable displacement vane pump comprising:
a pump body;
a drive shaft supported rotatably by the pump body;
a rotor disposed inside the pump body and adapted to be rotatably driven by the drive shaft, the rotor being formed with a plurality of slots spaced from each other in a circumferential direction of the rotor;
a plurality of vanes received by the slots so as to be movable out from the slots and into the slots;
a cam ring formed in an annular shape and disposed inside the pump body to permit the cam ring to become eccentric relative to the drive shaft, the cam ring cooperating with the rotor and the vanes to define a plurality of pump chambers on an inner circumferential side of the cam ring;
a first plate member and a second plate member disposed on axially both sides of the cam ring;
a suction port provided on a side of at least one of the first plate member and the second plate member and opened to at least one of the plurality of pump chambers;
a discharge port provided on a side of at least one of the first plate member and the second plate member and opened to at least one of the plurality of pump chambers;
a sealing member provided on an outer circumferential side of the cam ring, the sealing member dividing a space on an outer circumferential surface of the cam ring into a first fluid pressure chamber and a second fluid pressure chamber, wherein a flow rate of working fluid discharged from the discharge port is increased when the cam ring moves to the first fluid pressure chamber, wherein the flow rate of working fluid discharged from the discharge port is decreased when the cam ring moves to the second fluid pressure chamber;
a metering orifice formed on a discharge passage connected with the discharge port;
a pressure control section adapted to control a pressure which is introduced into the first fluid pressure chamber or the second fluid pressure chamber, the pressure control section comprising
a high pressure chamber into which an upstream pressure of the metering orifice is introduced,
a medium pressure chamber into which a downstream pressure of the metering orifice is introduced, and
a low pressure chamber connected with a reservoir tank for storing working fluid;
a fluid-pressure sensor adapted to sense a pressure discharged from the discharge port;
a relief valve adapted to drain the downstream pressure of the metering orifice to the reservoir tank, and a pressure-using device adapted to use a pressure supplied from the discharge port; and
a variable metering mechanism configured to narrow a cross-sectional area of flow passage of the metering orifice on the basis of an output signal of the fluid-pressure sensor.
20. The variable displacement vane pump as claimed in claim 19 , wherein
the variable metering mechanism is achieved by an electromagnetic valve adapted to be opened based on the output signal of the fluid-pressure sensor.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2007-212854 | 2007-08-17 | ||
JP2007212854A JP2009047041A (en) | 2007-08-17 | 2007-08-17 | Variable displacement vane pump |
Publications (1)
Publication Number | Publication Date |
---|---|
US20090047147A1 true US20090047147A1 (en) | 2009-02-19 |
Family
ID=40279671
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/191,695 Abandoned US20090047147A1 (en) | 2007-08-17 | 2008-08-14 | Variable displacement vane pump |
Country Status (4)
Country | Link |
---|---|
US (1) | US20090047147A1 (en) |
JP (1) | JP2009047041A (en) |
CN (1) | CN101387292A (en) |
DE (1) | DE102008037665A1 (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20090269233A1 (en) * | 2008-04-23 | 2009-10-29 | Kayaba Industry Co., Ltd. | Variable displacement vane pump |
JP2015059523A (en) * | 2013-09-19 | 2015-03-30 | 日立オートモティブシステムズステアリング株式会社 | Variable displacement vane pump |
US8992184B2 (en) | 2009-06-12 | 2015-03-31 | Mahle International Gmbh | Lubricant pump system |
WO2015159201A1 (en) * | 2014-04-14 | 2015-10-22 | Magna Powertrain Inc. | Variable pressure pump with hydraulic passage |
US20160047280A1 (en) * | 2013-03-18 | 2016-02-18 | Pierburg Pump Technology Gmbh | Lubricant vane pump |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102009024698A1 (en) * | 2009-06-12 | 2010-12-23 | Mahle International Gmbh | Characteristic-map-controlled lubricant pump system, has pressure chambers arranged in lubricant pump and used for moving actuating unit toward spring, where one of pressure chambers has smaller dimension than that of other pressure chamber |
JP5282681B2 (en) * | 2009-06-30 | 2013-09-04 | 株式会社ジェイテクト | Vane pump |
US20130089456A1 (en) * | 2011-10-07 | 2013-04-11 | Steering Solutions Ip Holding Corporation | Cartridge Style Binary Vane Pump |
JP6289943B2 (en) * | 2014-03-10 | 2018-03-07 | 日立オートモティブシステムズ株式会社 | Variable displacement pump |
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US6120256A (en) * | 1998-04-23 | 2000-09-19 | Jidosha Kiki Co., Ltd. | Variable displacement pump |
US6155797A (en) * | 1998-09-10 | 2000-12-05 | Jidosha Kiki Co., Ltd. | Variable displacement pump |
US6352415B1 (en) * | 1999-08-27 | 2002-03-05 | Bosch Braking Systems Co., Ltd. | variable capacity hydraulic pump |
US6524076B2 (en) * | 2000-04-27 | 2003-02-25 | Bosch Braking Systems Co., Ltd. | Variable displacement pump including a control valve |
US7128542B2 (en) * | 2000-12-04 | 2006-10-31 | Toyoda Koki Kabushiki Kaisha | Variable displacement pump |
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JP3851999B2 (en) | 2001-07-03 | 2006-11-29 | ユニシア ジェーケーシー ステアリングシステム株式会社 | Variable displacement pump |
JP4894285B2 (en) | 2006-02-10 | 2012-03-14 | 富士ゼロックス株式会社 | Image display medium and image display apparatus including the same |
-
2007
- 2007-08-17 JP JP2007212854A patent/JP2009047041A/en active Pending
-
2008
- 2008-08-14 US US12/191,695 patent/US20090047147A1/en not_active Abandoned
- 2008-08-14 DE DE102008037665A patent/DE102008037665A1/en not_active Ceased
- 2008-08-15 CN CNA2008101456603A patent/CN101387292A/en active Pending
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
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US6120256A (en) * | 1998-04-23 | 2000-09-19 | Jidosha Kiki Co., Ltd. | Variable displacement pump |
US6155797A (en) * | 1998-09-10 | 2000-12-05 | Jidosha Kiki Co., Ltd. | Variable displacement pump |
US6352415B1 (en) * | 1999-08-27 | 2002-03-05 | Bosch Braking Systems Co., Ltd. | variable capacity hydraulic pump |
US6524076B2 (en) * | 2000-04-27 | 2003-02-25 | Bosch Braking Systems Co., Ltd. | Variable displacement pump including a control valve |
US7128542B2 (en) * | 2000-12-04 | 2006-10-31 | Toyoda Koki Kabushiki Kaisha | Variable displacement pump |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20090269233A1 (en) * | 2008-04-23 | 2009-10-29 | Kayaba Industry Co., Ltd. | Variable displacement vane pump |
US8342817B2 (en) * | 2008-04-23 | 2013-01-01 | Kayaba Industry Co., Ltd. | Variable displacement vane pump |
US8992184B2 (en) | 2009-06-12 | 2015-03-31 | Mahle International Gmbh | Lubricant pump system |
US20160047280A1 (en) * | 2013-03-18 | 2016-02-18 | Pierburg Pump Technology Gmbh | Lubricant vane pump |
US9759103B2 (en) * | 2013-03-18 | 2017-09-12 | Pierburg Pump Technology Gmbh | Lubricant vane pump |
JP2015059523A (en) * | 2013-09-19 | 2015-03-30 | 日立オートモティブシステムズステアリング株式会社 | Variable displacement vane pump |
WO2015159201A1 (en) * | 2014-04-14 | 2015-10-22 | Magna Powertrain Inc. | Variable pressure pump with hydraulic passage |
US10267310B2 (en) | 2014-04-14 | 2019-04-23 | Magna Powertrain Inc. | Variable pressure pump with hydraulic passage |
Also Published As
Publication number | Publication date |
---|---|
CN101387292A (en) | 2009-03-18 |
JP2009047041A (en) | 2009-03-05 |
DE102008037665A1 (en) | 2009-02-19 |
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