US20100247362A1 - Gear Pump - Google Patents
Gear Pump Download PDFInfo
- Publication number
- US20100247362A1 US20100247362A1 US12/651,790 US65179010A US2010247362A1 US 20100247362 A1 US20100247362 A1 US 20100247362A1 US 65179010 A US65179010 A US 65179010A US 2010247362 A1 US2010247362 A1 US 2010247362A1
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- US
- United States
- Prior art keywords
- gear
- pump
- side plate
- seal member
- chamber
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- 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
- F04C2/08—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
- F04C2/12—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type
- F04C2/14—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with toothed rotary pistons
- F04C2/18—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with toothed rotary pistons with similar tooth forms
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
- B60T8/32—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration
- B60T8/34—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition
- B60T8/36—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition including a pilot valve responding to an electromagnetic force
- B60T8/3615—Electromagnetic valves specially adapted for anti-lock brake and traction control systems
- B60T8/3675—Electromagnetic valves specially adapted for anti-lock brake and traction control systems integrated in modulator units
- B60T8/368—Electromagnetic valves specially adapted for anti-lock brake and traction control systems integrated in modulator units combined with other mechanical components, e.g. pump units, master cylinders
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
- B60T8/32—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration
- B60T8/34—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition
- B60T8/40—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition comprising an additional fluid circuit including fluid pressurising means for modifying the pressure of the braking fluid, e.g. including wheel driven pumps for detecting a speed condition, or pumps which are controlled by means independent of the braking system
- B60T8/4031—Pump units characterised by their construction or mounting
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01C—ROTARY-PISTON OR OSCILLATING-PISTON MACHINES OR ENGINES
- F01C19/00—Sealing arrangements in rotary-piston machines or engines
- F01C19/005—Structure and composition of sealing elements such as sealing strips, sealing rings and the like; Coating of these elements
-
- 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
- F04C11/00—Combinations of two or more machines or pumps, each being of rotary-piston or oscillating-piston type; Pumping installations
- F04C11/001—Combinations of two or more machines or pumps, each being of rotary-piston or oscillating-piston type; Pumping installations of similar working principle
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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
- F04C14/02—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations specially adapted for several machines or pumps connected in series or in parallel
-
- 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
- F04C15/00—Component parts, details or accessories of machines, pumps or pumping installations, not provided for in groups F04C2/00 - F04C14/00
- F04C15/0003—Sealing arrangements in rotary-piston machines or pumps
- F04C15/0007—Radial sealings for working fluid
- F04C15/0015—Radial sealings for working fluid of resilient material
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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
- F04C15/00—Component parts, details or accessories of machines, pumps or pumping installations, not provided for in groups F04C2/00 - F04C14/00
- F04C15/0003—Sealing arrangements in rotary-piston machines or pumps
- F04C15/0023—Axial sealings for working fluid
- F04C15/0026—Elements specially adapted for sealing of the lateral faces of intermeshing-engagement type machines or pumps, e.g. gear machines or pumps
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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
- F04C15/00—Component parts, details or accessories of machines, pumps or pumping installations, not provided for in groups F04C2/00 - F04C14/00
- F04C15/0042—Systems for the equilibration of forces acting on the machines or pump
- F04C15/0049—Equalization of pressure pulses
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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
- F04C15/00—Component parts, details or accessories of machines, pumps or pumping installations, not provided for in groups F04C2/00 - F04C14/00
- F04C15/06—Arrangements for admission or discharge of the working fluid, e.g. constructional features of the inlet or outlet
-
- 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
- F04C2/08—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
- F04C2/082—Details specially related to intermeshing engagement type machines or pumps
- F04C2/086—Carter
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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
- F04C2/08—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
- F04C2/10—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of internal-axis type with the outer member having more teeth or tooth-equivalents, e.g. rollers, than the inner member
- F04C2/102—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of internal-axis type with the outer member having more teeth or tooth-equivalents, e.g. rollers, than the inner member the two members rotating simultaneously around their respective axes
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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
- F04C15/00—Component parts, details or accessories of machines, pumps or pumping installations, not provided for in groups F04C2/00 - F04C14/00
- F04C15/0057—Driving elements, brakes, couplings, transmission specially adapted for machines or pumps
- F04C15/0061—Means for transmitting movement from the prime mover to driven parts of the pump, e.g. clutches, couplings, transmissions
- F04C15/0073—Couplings between rotors and input or output shafts acting by interengaging or mating parts, i.e. positive coupling of rotor and shaft
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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
- F04C2240/00—Components
- F04C2240/60—Shafts
Abstract
A gear pump includes: a pump chamber formed in the housing; a gear disposed in the pump chamber; a side plate disposed between a wall of the pump chamber and the gear, and arranged to seal a side surface of the gear, the side plate including an annular receiving portion formed between the wall of the pump chamber and the side plate, the receiving portion having a bottom portion and a side wall portion; a seal member disposed in the receiving portion of the side plate, and arranged to liquid-tightly separate the low pressure chamber and the high pressure chamber of the pump chamber; a pressure introducing section arranged to introduce a pressure generated by the pump operation, to a space between the bottom portion of the receiving portion and the seal member, and thereby to separate the seal member away from the bottom portion of the receiving portion.
Description
- This invention relates to a gear pump.
- A patent document (Japanese Patent Application Publication No. 11-303767) discloses a conventional gear pump including a gear, a seal, and a side plate. In this gear pump, at a low pressure of the discharge pressure of the gear pump, a pressing force of the side plate to a gear decreases by decreasing a reaction force of the seal. With this, a frictional force between the side plate and the gear decreases. On the other hand, at a high pressure of the discharge pressure, the pressing force of the side plate to the gear increases by increasing the reaction force of the seal. With this, it is possible to prevent the pressure from discharging along a side surface of the gear.
- However, in the above-described conventional gear pump, a pressure receiving area with respect to a bottom portion of a receiving groove receiving the seal varies in accordance with the deformation of the seal by the pressure variation. Consequently, the variation of the pressing force of the side plate to the gear is generated. Therefore, the variation of the performance of the pump is generated.
- It is an object of the present invention to provide a gear pump devised to solve the above mentioned problem, and to attain a desired stable pump ability.
- According to one aspect of the present invention, a gear pump comprises: a housing; a pump chamber formed in the housing, the pump chamber having a low pressure chamber and a high pressure chamber; a gear disposed in the pump chamber, and arranged to be driven by a motor to perform a pump operation; a side plate disposed between a wall of the pump chamber and the gear, and arranged to seal a side surface of the gear, the side plate including an annular receiving portion formed between the wall of the pump chamber and the side plate, the receiving portion having a bottom portion and a side wall portion; a seal member disposed in the receiving portion of the side plate, and arranged to liquid-tightly separate the low pressure chamber and the high pressure chamber of the pump chamber; a pressure introducing section arranged to introduce a pressure generated by the pump operation, to a space between the bottom portion of the receiving portion and the seal member, and thereby to separate the seal member away from the bottom portion of the receiving portion.
- According to another aspect of the invention, a gear pump comprises: a housing; a pump chamber formed in the housing, the pump chamber having a high pressure chamber and a low pressure chamber; a gear disposed within the pump chamber, and arranged to rotate at least by a drive shaft; a side plate disposed adjacent to the gear, between a side surface of the gear and a wall of the pump chamber, the side plate having an annular recessed groove formed in a surface confronting the wall of the pump chamber, and the annular recessed groove having a bottom portion; and a seal member disposed in the annular recessed groove of the side plate, and arranged to separate the high pressure chamber and the low pressure chamber of the pump chamber, and to be pushed in a direction away from the bottom portion of the recessed groove by a pressure introduced from the high pressure chamber when the gear is driven.
- According to still another aspect of the invention, a gear pump comprises: at least a pair of gears engaged with each other; a side plate disposed adjacent to the gears, the side plate including an annular recessed groove, and a shoulder portion; a housing disposed at a position to sandwich the side plate with the gear, and to confront the gear; a seal member disposed in the annular recessed groove of the side plate, and arranged to seal a gap between the housing and an end of the shoulder portion of the side plate, and to separate a low pressure chamber and a high pressure chamber formed in a radial direction of the gear; and a pressure introducing section arranged to transform the seal member by a pressure of the high pressure chamber in a direction toward the end of the shoulder portion.
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FIG. 1 is a rear perspective view showing a gear pump according to a first embodiment of the present invention. -
FIG. 2 is a front view showing the gear pump ofFIG. 1 . -
FIG. 3 is an enlarged view showing a main part of the gear pump ofFIG. 1 . -
FIG. 4 is an enlarged view showing a main part of the gear pump ofFIG. 1 . -
FIG. 5 is a front perspective view showing a seal member of the gear pump ofFIG. 1 . -
FIG. 6 is a rear perspective view showing the seal member of the gear pump ofFIG. 1 . -
FIG. 7 is a front perspective view showing a first side plate of the gear pump ofFIG. 1 . -
FIG. 8 is a front perspective view showing the first side plate of the gear pump ofFIG. 1 . -
FIG. 9 is a front view showing the first side plate of the gear pump ofFIG. 1 . -
FIG. 10 is a rear view showing the first side plate of the gear pump ofFIG. 1 . -
FIG. 11 is a top view showing the first side plate of the gear pump ofFIG. 1 . -
FIG. 12A is a view illustrating a state before the gear pump ofFIG. 1 is connected with a motor.FIG. 12B is a view illustrating a state after the gear pump ofFIG. 1 is connected with the motor. -
FIG. 13 is a view illustrating an arrangement of the first side plate and the first gear of the gear pump ofFIG. 1 . -
FIG. 14 is a view illustrating an arrangement of the seal member, the first side plate and the first gear of the gear pump ofFIG. 1 . -
FIG. 15 is a sectional view taken along a section line A15-A15 ofFIG. 14 . -
FIG. 16 is a rear perspective view showing the first side plate and the seal of the gear pump ofFIG. 1 . -
FIG. 17 is a partially sectional perspective view taken along a section line of A17-A17 ofFIG. 16 . -
FIG. 18A is a view illustrating a state in which the gear pump is mounted.FIG. 18B is a view illustrating a state in which a low pressure is acted to the seal.FIG. 18C is a view illustrating a state in which a high pressure is acted to the seal. -
FIGS. 19A to 19C are views illustrating a general seal of a conventional gear pump apparatus.FIG. 19A is a view illustrating a state in which seal S5 is mounted.FIG. 19B is a view illustrating a state in which a low pressure is acted to the seal.FIG. 19C is a view illustrating a state in which a high pressure is acted to the seal. -
FIG. 20 is a view illustrating a brake apparatus to which the gear pump ofFIG. 1 is attached. -
FIG. 21A is a view illustrating a state in which the seal is mounted in a gear pump according to a second embodiment of the present invention.FIG. 21B is a view illustrating a state in which a low pressure is acted to the seal.FIG. 21C is a view illustrating a state in which a high pressure is acted to the seal. -
FIGS. 22A , 22B and 22C are views showing the gear pump according to the second embodiment when the high pressure side and the low pressure side are reversed.FIG. 22A is a view illustrating a state in which the seal is mounted.FIG. 22B is a view illustrating a state in which a low pressure is acted to the seal.FIG. 22C is a view illustrating a state in which a high pressure is acted to the seal. -
FIG. 23 is a sectional view illustrating a gear pump according to a third embodiment of the present invention. -
FIG. 24 is a view showing a seal of a gear pump according to a fourth embodiment of the present invention. -
FIG. 25 is a sectional view illustrating a gear pump according to a fifth embodiment of the present invention. -
FIG. 26 is a sectional view illustrating a first gear and a second gear of the gear pump ofFIG. 25 . -
FIG. 27 is an enlarged sectional view showing a portion of a first side plate near a seal in the gear pump ofFIG. 25 . -
FIG. 28 is an enlarged sectional view showing a portion of a second side plate near a seal in the gear pump ofFIG. 25 . -
FIGS. 29A , 29B and 29C are enlarged sectional views showing a portion near a seal of a gear pump according to another embodiment of the present invention. - Hereinafter, gear pumps according to embodiments of the present invention are illustrated.
- Hereinafter, a gear pump according to a first embodiment of the present invention is illustrated.
FIG. 1 is a rear perspective view showing the gear pump according to a first embodiment of the present invention.FIG. 2 is a front view showing thegear pump 1 ofFIG. 1 . As shown inFIGS. 1 and 2 ,gear pump 1 is used as an actuator for controlling a brake fluid pressure of a vehicle.Gear pump 1 includes ahousing 2, and apump assembly 3 received inhousing 2. - [Housing] Next,
housing 2 is illustrated.Housing 2 is formed into a substantially rectangular shape.Housing 2 includes a plurality of mountingholes 2 a which are formed on an outer surface ofhousing 2, and to which selector valves (not shown) and sensors (not shown) are mounted.Gear pump 1 includes apump chamber 4 which is formed on a front surface ofhousing 2 at a substantially central position ofhousing 2, which is recessed into a substantially cylindrical shape, which has a stepped cylindrical shape having different diameters, and which receivespump assembly 3. - [Pump Assembly] Next,
pump assembly 3 is illustrated. A side of an open end of pump chamber 4 (side of asecond pump 9 described later) represents a front side (lower side ofFIG. 3 ). A side of a bottom of pump chamber 4 (side of afirst pump 8 described later) is a rear side (upper side ofFIG. 3 ). As shown inFIGS. 3 and 4 , pumpassembly 3 includes aplug member 5, acover member 6, aseal member 7, afirst pump 8, asecond pump 9 and so on.Plug member 5 is shaped like a circular disc.Plug member 5 includes a throughhole 5 a which is located at a substantially central position ofplug member 5, and which is a hexagonal through hole penetrating throughplug member 5. Moreover, plugmember 5 includes arear surface 5 d which is located at a rear end portion ofplug member 5, and which is abutted oncover member 6; and anannular protrusion 5 b which surrounds an outer circumference ofrear surface 5 d, and which protrudes in the rearward direction. Moreover, plugmember 5 includes an externally threadedportion 5 c formed on an outer circumference surface ofplug member 5. Externally threadedportion 5 c ofplug member 5 is screwed into an internally threadedportion 4 a formed on an inner circumference surface ofpump chamber 4.Cover member 6 is shaped like a circular disc.Cover member 6 includes afront surface 6 e abutted onplug member 5, and a steppedportion 6 f cut around an outer circumference surface offront surface 6 e.Front surface 6 e is pushed rearwards by an axial force produced byplug member 5 whenplug member 5 is screwed intopump chamber 4, and consequentlyfront surface 6 e is abutted onrear surface 5 d ofplug member 5.Plug member 5 is disposed at a predetermined position in a state in whichannular protrusion 5 b ofplug member 5 is fit on steppedportion 6 f ofcover member 6.Cover member 6 includes a raisedportion 6 g which is formed on the outer circumference surface ofcover member 6, which has an outside diameter substantially identical to an inside diameter ofpump chamber 4, and an outside diameter ofannular protrusion 5 b ofplug member 5. Moreover,cover member 6 includes aseal groove 6 h formed on the outer circumference surface ofcover member 6, and located on a rear side of raisedportion 6 g. An annular seal S1 is disposed between raisedportion 6 g ofcover member 6 andannular protrusion 5 b ofplug member 5 to seal a clearance radially between the outside surface ofcover member 6 and the inside surface ofpump chamber 4. An annular seal S2 is provided inseal groove 6 h to seal a clearance betweencover member 6 and the inner circumference ofpump chamber 4. That is, seals S1 and S2 are mounted, respectively, at positions away from each other in the forward and rearward directions (in the upward and downward directions).Cover member 6 includes a stepped throughhole 6 b which is located in an eccentric position ofcover member 6. Stepped throughhole 6 b includes a larger diameter (front) portion and a smaller diameter (rear) portion having an inside diameter smaller than the inside diameter of the larger diameter portion. Adrive shaft 10 is inserted in this stepped throughhole 6 b with aclearance 6 a in the smaller diameter portion. Annular seals S3 are disposed, respectively, in the larger diameter portion and the smaller diameter portion of stepped throughhole 6 b to seal a clearance arounddrive shaft 10. Moreover,cover member 6 includes an annular recessedportion 6 d located at a rear end portion ofcover member 6, and recessed in the forward direction; and anannular protrusion 6 c protruding from recessedportion 6 d in the rearward direction. On an inner circumference surface ofannular protrusion 6 c, there is formed a steppedportion 6 i which is cut around the inner circumference surface ofannular protrusion 6 c. - As shown in
FIGS. 5 and 6 ,seal member 7 is formed into a substantially circular disc shape.Seal member 7 includes a pair of throughholes seal member 7 includesside seal portions 7 d which are formed, respectively, on the front and rear surfaces ofseal member 7, each of which surround throughholes side seal portions 7 d includes a pair of engagement raisedportions 7 e each protruding from theside seal portion 7 d in the lateral direction. Each ofside seal portions 7 d includes an annularring receiving portion 7 f which has a center identical to the center of throughhole 7 a, and which is recessed in the inward direction of the thickness (axially inwards).Seal member 7 includes an annularseal receiving groove 7 g which is recessed in the inside direction of the thickness inring receiving portion 7 f on the rear surface ofseal member 7, which has a smaller diameter, and which is continuous withring receiving portion 7 f. Moreover,seal member 7 includes anannular receiving portion 7 h formed on the outer circumference surface ofseal member 7, and recessed radially inwards; and anannular protrusion 7 i which is located in a front end portion ofseal member 7, and which protrudes in the forward direction. - As shown in
FIGS. 3 and 4 ,seal member 7 is pushed in the rearward direction throughcover member 6 by the axial force produced byplug member 5 when screwed intopump chamber 4. Consequently,annular protrusion 7 i ofseal member 7 is mounted in (fit in) steppedportion 6 i ofcover member 6. An outer region of the rear side surface ofseal member 7 abuts on steppedportion 4 b ofpump chamber 4, so thatseal member 7 is reliably positioned at a predetermined position. Driveshaft 10 is inserted into throughhole 7 a ofseal member 7. A drivenshaft 11 is inserted into throughhole 7 b ofseal member 7. An annular rotation seal member (X-ring and so on) 12 is mounted inseal receiving portion 7 g ofseal member 7 to seal between thedrive shaft 10 and a first pump chamber P1 described later. Moreover, a firstannular seal ring 13 a is mounted inring receiving portion 7 f on the rear side surface ofseal member 7 to closeseal receiving portion 7 g ofrotation seal member 12. A secondannular seal ring 13 b is mounted inring receiving portion 7 f on the front side surface ofseal member 7. Each of seal rings 13 a and 13 b is made of a material which is more rigid and more durable than a material ofseal member 7. Moreover, an annular seal S4 is mounted in receivingportion 7 h ofseal member 7. Annular seal S4 contacts the inner circumference surface of pump chamber to seal between first pump chamber P1 and second pump chamber P2. First pump chamber P1 is formed betweenseal member 7 and an annular recessedportion 4 c recessed in the rearward direction from steppedportion 4 b ofpump chamber 4. First pump chamber P1 is a closed space.First pump 8 is disposed in first pump chamber P1. On the other hand, a second pump chamber P2 is formed betweenseal member 7 and a recessedportion 6 d ofcover member 6. Second pump chamber P2 is a closed space.Second pump 9 is disposed in second pump chamber P2.First pump 8 is provided with (includes) afirst gear 15 having a front surface, a rear surface, and tooth top portions which are sealed byseal member 7 andfirst side plate 14 described later. - Next,
first side plate 14 is illustrated. As shown inFIGS. 7-11 ,first side plate 14 is formed into a substantially triangular shape, as viewed from the forward direction.First side plate 14 is made of a resin.First side plate 14 includes three throughholes first side plate 14, and which penetrate throughfirst side plate 14.First side plate 14 includes aside seal portion 14 d which is located around throughholes first side plate 14, and which protrudes in the forward direction.First side plate 14 includes aseal block 14 e which is shaped like a triangular shape, which is formed on the front surface offirst side plate 14, and which protrudes in the forward direction.Seal block 14 e offirst side plate 14 includes apassage portion 14 f forming an open portion extending continuously from the throughhole 14 c toward the center offirst side plate 14; a pair of toothtop seal portions 14 g which are formed on both sides of thepassage section 14 f, which are continuous with a part of theside seal portion 14 d, and which are in the form of a curved surface; andengagement portions 14 h located on the front side of the respective toothtop seal portions 14 g. Moreover,seal block 14 e includes agroove 14 i which is recessed in the inward direction of the thickness, and which surrounds throughhole 14 c from the outer circumference of toothtop seal portions 14 g. On the other hand,first side plate 14 includes a receivingportion 14 j which is formed on the rear surface offirst side plate 14, which has three circular portions having different diameters, and which surround throughholes FIG. 10 . - As shown in
FIG. 4 , driveshaft 10 is rotatably inserted into throughhole 14 a offirst side plate 14 with a radial clearance. On the other hand, drivenshaft 11 is inserted into throughhole 14 b offirst side plate 14 with a radial clearance. Moreover, a seal S5 described later is fit in receivingportion 14 j to seal between the high pressure side and the low pressure side of first pump chamber P1, as described later. - Next,
first gear 15 is illustrated. As shown inFIGS. 13 and 14 ,first gear 15 includes adrive gear 16 into whichdriver shaft 10 is inserted; and a drivengear 17 into which drivenshaft 11 is inserted. Atooth top 16 a ofdrive gear 16 and a tooth top 17 a of drivengear 17 are engaged with each other at a tooth engagement portion (region) 18. Driveshaft 10 includes a recessedportion 10 a located in a position corresponding to drivegear 16, and recessed radially inwards. Acylindrical drive pin 10 b is received in this recessedportion 10 a. Drivepin 10 a extends from a center ofdrive shaft 10 in the radial direction. Drivepin 10 b includes a first end received in recessedportion 10 a ofdrive shaft 10, and a second end engaged with a recessedportion 16 b which is recessed radially inward from the inner circumference surface ofdrive gear 16. On the other hand, driveshaft 11 includes a recessedportion 11 a located in a position corresponding to drivengear 17, and recessed radially inwards. A cylindrical drivenpin 11 b is received in this recessedportion 11 a. Drivenpin 11 b extends from a center of drivenshaft 11 in the radial direction. Drivenpin 11 b includes a first end received in recessedportion 11 a of drivenshaft 11, and a second end engaged with a recessedportion 17 b which is recessed radially outwards from the inner circumference surface of drivengear 17. - Moreover, drive
shaft 10 includes a mounting raisedportion 19 which has a substantially rectangular column, and which is located at a front end portion ofdrive shaft 10, as shown inFIGS. 12A and 12B . Arotational shaft 20 a of motor M1 includes a mounting recessedportion 20 b which is located at an end portion ofrotational shaft 20 a, and which is arranged to be engaged and connected with mounting raisedportion 19 ofdrive shaft 10. Accordingly, motor M1 drives and rotates driveshaft 10 aroundrotational shaft 20 a. Moreover, drivepin 10 b is engaged withdrive gear 16, and arranged to prevent the rotation ofdrive gear 16 relative to driveshaft 10, and to cause thedrive gear 16 to rotate as a unit withdrive shaft 10. Whendrive shaft 10 is driven,drive gear 16 rotates in accordance with the rotation ofdrive gear 16 in the same direction asdrive shaft 10. On the other hand,drive gear 17 is engaged withdrive gear 16. Drivenpin 11 b is engaged with drivengear 17, and to prevent the rotation ofdrive gear 17 relative to drivenshaft 11. Accordingly, drivengear 17 rotates together with drivenshaft 11 in a direction opposite to the rotational direction ofdrive shaft 10. - As shown in
FIG. 13 , tooth tops 16 a and 17 a ofgears top seal portions 14 g ofseal block 14 e offirst side plate 14. As shown inFIGS. 14 and 15 , the pair of engagement raisedportions 7 e on the rear surface ofseal member 7 are engaged with and contacted on, respectively, the curved surfaces of theengagement portions 14 h ofseal block 14 e, so as to seal tooth tops 16 a and 17 a ofgears side seal portion 14 d offirst side plate 14. A substantially triangular holdingmember 21 is mounted around the correspondingside seal portion 7 d ofseal member 7 and groove 14 i formed in the outer circumference ofseal block 14 e (cf.FIG. 14 ). Inpump chamber 4, there are provided a suction port (not shown) connected with throughhole 14 c offirst side plate 14 and a discharge port (not shown) connected with first pump chamber P1. On the other hand,second pump 9 is symmetrical tofirst pump 8 with respect to sealmember 7. That is, there is provided asecond gear 23 having front and rear surfaces sealed byseal member 7 andsecond side plate 22.Second side plate 22 andsecond gear 23 are bilaterally symmetrical tofirst side plate 14 andfirst gear 15. Therefore, the illustration is omitted. - As shown in
FIG. 4 , driveshaft 10 is rotatably inserted into throughhole 22 a ofsecond side plate 22 with a radial clearance. On the other hand, drivenshaft 11 is inserted into throughhole 22 b ofsecond side plate 22 with a radial clearance.Second side plate 22 includes a receivingportion 22 j which is identical in shape to receivingportion 14 j offirst side plate 14. A seal S6 identical in shape to seal S5 is fit in receivingportion 22 j ofsecond side plate 22 to seal between the high pressure side and the low pressure side of second pump chamber P2 as described later. - In
second pump 9, pumpchamber 4 includes a suction port (not shown) connected through a through hole 22 c ofsecond side plate 22 and a hydraulic passage ofcover member 6; and a discharge port (not shown) connected with second pump chamber P2 through a hydraulic passage formed incover member 6, unlikefirst pump 8. The other structures ofsecond pump 9 is substantially identical to the structure offirst pump 8. Each of throughholes side plates drive shaft 10. Each of throughholes shaft 11. That is,drive shaft 10 is inserted into throughholes second side plates shaft 11 is inserted into throughholes second side plates - [Receiving Portion] Next, receiving
portions second side plates portion 22 j is identical in shape to receivingportion 14 j. Therefore, only receivingportion 14 j is illustrated. Receivingportion 14 j is recessed on the rear surface offirst side plate 14, as shown inFIGS. 16 and 17 . Receivingportion 14 j includes abottom portion 30 extending in a direction perpendicular to the axial direction offirst side plate 14; a high pressureside wall portion 31 which extends continuously withbottom portion 30, and which is inclined; and a low pressureside wall portion 32 extending in a direction perpendicular tobottom portion 30. Receivingportion 14 j has a substantially V-shaped cross section. Receivingportion 14 j includes a plurality of communicating grooves 33 (five communicating groove in the first embodiment) each formed on high pressureside wall portion 31, by cutting high pressureside wall portion 31 to increase the width ofbottom portion 30 toward high pressureside wall portion 31. Communicatinggrooves 33 receive seal S5 which is a transformed annular shape bent in a substantially triangular shape, which has a circular cross section, and which is made of an elastic material such as rubber. In particular, as shown inFIG. 18A , seal S5 is disposed with a clearance or void 34 between seal S5 andbottom portion 30. Seal S5 abuts on high pressureside wall portion 31 and low pressureside wall portion 32 of receivingportion 14 j, and recessedportion 4 c. - Next, operation of the first embodiment is illustrated. [Assembly Operation of Gear Pump] Next, assembly operation of
gear pump 1 is illustrated. In the assembly operation of thisgear pump 1,rotation seal member 12 is inserted into and temporally fixed to seal receivingportion 7 g ofseal member 7 preliminary equipped with seal S4. Then, driveshaft 10 is inserted into throughhole 7 a ofseal member 7, and drivenshaft 11 is inserted into throughhole 7 b ofseal member 7. Next, seal rings 13 a and 13 b are inserted, respectively, intoring receiving portions 7 f. In this case,rotation seal member 12 is pushed byfirst ring 13 a, so thatrotation seal member 12 appropriately contacts driveshaft 10. Then, drive pins 10 b and 10 e and drivenpins 11 b and 11 d are inserted, respectively, into recessedportions drive shaft 10 and recessedportions 11 a and 11 c of drivenshaft 11. Next, drive gears 16 and 26 and drivengears drive shaft 10 and drivenshaft 11. Then, driveshaft 10 and drivenshaft 11 are inserted, respectively, into first andsecond side plates members second side plates member 7. In this case, onfirst side plate 14's side ofseal member 7, the pair ofengagement portions 7 e ofseal member 7 are engaged, respectively, with theengagement portions 14 h offirst side plate 14 to positionseal member 7 andfirst side plate 14. Therefore, it is facilitate the assembly operation by positioningseal member 7 andfirst side plate 14. Holdingmember 19 can temporarily hold and fixseal member 7 andfirst side plate 14. Holdingmember 16 can be readily mounted onseal member 7 andfirst side plate 14 by first mounting the holdingmember 16 onseal member 7, and then expanding holdingmember 16 ontofirst side plate 14. Similarly, on thesecond side plate 22's side, the pair of engagement raisedportions 7 e ofseal member 7 are engaged, respectively, with the engagement portions ofsecond side plate 22 to positionseal member 7 andsecond side plate 22. Therefore, it is facilitate the assembly operation by positioningseal member 7 andsecond side plate 22. Holdingmember 24 can be readily mounted onseal member 7 andfirst side plate 14 by first mounting the holdingmember 24 onseal member 7, and then expanding holdingmember 24 ontosecond side plate 22. Next, driveshaft 10 is inserted into throughhole 6 a ofcover member 6 provisionally equipped with seals S1 and S2.Annular protrusion 6 c ofcover member 6 is mounted onseal member 7 to assemblecover member 6 and sealmember 7, so thatpump assembly 3 is assembled. - Next, the thus-assembled
pump assembly 3 is inserted intopump chamber 4 ofhousing 2. Then, plugmember 5 is screwed into and fixed to pumpchamber 4. In this case,seal member 7 can be stably contacted with and fixed to steppedportion 4 b ofpump chamber 4 by the axial force produced byplug member 5 whenplug member 5 is screwed intopump chamber 4. Accordingly, it is possible to dispose each member in an accurate position in the forward and rearward directions, and to prevent the unsteadiness or shakiness by the pressure variation of the hydraulic fluid described later. In addition, seal S1 is pushed byannular protrusion 5 b ofplug member 5, and accordingly it is possible to improve the seal ability betweenpump chamber 4 and covermember 6. In this way, ingear pump 1 according to the first embodiment, pumpassembly 3 can be received inhousing 2 in the temporally assembled state ofpump assembly 3. Accordingly, it is possible to simplify the assembly operation. - [Operation of Gear Pump] Next, the operation of
gear pump 1 is illustrated. The thus-constructedgear pump 1 is provided at the end portion of thecylindrical drive shaft 10, as shown inFIGS. 12A and 12B . Mounting raisedportion 19 ofgear pump 1 is connected with mounting recessedportion 20 b ofrotational shaft 20 a of motor M1. - When
drive shaft 10 is rotated by motor M1 in a direction shown by an arrow ofFIG. 13 , drivengear 17 offirst pump 8 is driven throughdrive gear 16. By this operation, the hydraulic fluid of the low pressure is introduced from throughhole 14 c ofseal block 14 e offirst side plate 14 which is connected with the suction port, and the hydraulic fluid of the high pressure is outputted to pump chamber P1. This hydraulic fluid of the high pressure is outputted to the corresponding discharge port. Similarly, insecond pump 9, drivengear 27 is driven throughdrive gear 26, likefirst gear pump 8. By this operation, the hydraulic fluid of the low (negative) pressure is introduced from through hole 22 c of seal block 22 e ofsecond side plate 22, and the high pressure hydraulic fluid is outputted to pump chamber P2. This hydraulic fluid of the high pressure is outputted to the corresponding discharge port. In this way,gear pump 1 can perform the suction operations and the discharge operations of the hydraulic fluid in the pump chambers P1 and P2 in the two separate piping systems. That is,gear pump 1 serves as a tandem external gear pump. - [Pressing Force of Side Plate to Gear] Next, the pressing forces of first and
second side plates gears first side plate 14 to gear 15 is identical to the pressing force bysecond side plate 22 togear 23. Therefore, the only pressing force byfirst side plate 14 to gear 15 is illustrated.FIG. 18A is a view illustrating a state in which seal S5 is mounted.FIG. 18B is a view illustrating a state in which a low pressure is acted to seal S5.FIG. 18C is a view illustrating a state in which a high pressure is acted to seal S5. As described above with reference toFIG. 18A , seal S5 is disposed with the clearance betweenbottom portion 30 of receivingportion 14 j and seal S5, and seal S5 abuts on high pressureside wall portion 31, low pressureside wall portion 32, and recessedportion 4 c. Accordingly, seal S5 is disposed in the clearance betweenfirst side plate 14 and recessedportion 4 c to separate the high pressure chamber H1 and the low pressure chamber L1. At the low pressure operation of the hydraulic fluid by the actuation offirst pump 8, seal S5 is transformed (varies its shape) by receiving the pressure of the hydraulic fluid from the high pressure chamber H1, and transformed (varies its shape) toward low pressure chamber L1 (the diameter of seal S5 decreases), as shown inFIG. 18B . Seal S5 seals and divides between the high pressure chamber H1 and the low pressure chamber L1. The hydraulic fluid of the high pressure chamber H1 is introduced through communicatinggroove 33 toclearance 34 in response to the transformation of seal S5. High pressureside wall portion 31 includes a holdingportion 35 to dispose and hold seal S5 in a predetermined position. Communicatinggroove 33 has a width W1 larger than a width W2 of holdingportion 35 with respect tobottom portion 30. Therefore, the hydraulic fluid can be introduced from communicatinggroove 33 toclearance 34. Next, at the high pressure operation of the hydraulic fluid by the actuation offirst pump 8, seal S5 is moved away frombottom portion 30 by the pressure of the hydraulic fluid flowing intoclearance 34, as shown inFIG. 18C . Seal S5 surely seals between the high pressure side H1 and the low pressure side L1. In this case, seal S5 can be away frombottom portion 30, and completely floated frombottom portion 30. -
FIGS. 19A to 19C are views illustrating a general seal of a conventional gear pump apparatus.FIG. 19A is a view illustrating a state in which seal S5 is mounted.FIG. 19B is a view illustrating a state in which a low pressure is acted to the seal.FIG. 19C is a view illustrating a state in which a high pressure is acted to the seal. In the general gear pump as shown inFIGS. 19A-19C , the pressing force to the gear is calculated by a following mathematical expression (1). -
The pressing force to the gear=(the pressure receiving area of the side plate on the receiving portion's side−the pressure receiving area of the side plate on the gear's side)×the pressure in the pump chamber+the seal reaction force (1) - In case of the gear pump described in
Patent Document 1 employing a general receiving portion of a recessed shape as shown inFIGS. 19A-19C , the pressure receiving area α (FIGS. 19-19C ) of the side plate on the receiving portion's side is varied in accordance with the transformation of the seal by the pressure variation. Moreover, the reaction force of the seal varies in accordance with the pressure variation. Accordingly, the seal reaction force is not stable. InFIGS. 19A-19C , the same reference numerals are given to similar component parts. Moreover, in general, the seal is made of a rubber. Accordingly, the curing and the wear-out are generated due to the long time use, so that the variation of the reaction force is large. Moreover, it is not possible to neglect the variation of the reaction force by the dimension variation since it is not possible to decrease the manufacturing dimension tolerance, and the assembly dimension tolerance of the rubber. Accordingly, in fact, it is difficult eliminate the variation of the pressing force of the side plate to the gear. This variation of the pressing force adversely affects the pumping performance. On the other hand, in the first embodiment, at the low to high pressure operation in which the pressure is applied to the hydraulic fluid, the entire of the receivingportion 14 j to low pressureside wall portion 32 is the pressure receiving area a ofside plate 14 on the receiving portion's side (cf.FIGS. 18B and 18C ). Moreover, at the operation of the high pressure of the hydraulic fluid, seal S5 is away frombottom portion 30, and completely floated away frombottom portion 30, so that the reaction force of seal S5 is eliminated. Accordingly, the pressing force to gear 15 ingear pump 1 of the first embodiment is calculated by a following mathematical expression (2). -
The pressing force to gear 15=(the pressure receiving area offirst side plate 14 on the receivingportion 14j's side (constant)−the pressure receiving area offirst side plate 14 on thegear 15's side (constant))×the pressure in the first pump chamber P1 (2) - Accordingly,
first gear 15 receives little influence from the transformation of seal S5 and the reaction force of seal S5 by the pressure variation in first pump P1. Therefore, even when the pressure increases in first pump P1, it is possible to decrease the pressing force by the elimination of the reaction force of seal S5. Moreover, it is possible to decrease the friction betweenfirst side plate 14 andgear 15 by decreasing the pressing force, and to improve the pump ability (performance). Moreover, even when seal S5 is transformed (varies its shape), the pressure receiving area offirst side plate 14 on the receivingportion 14 j's side is held constant. Accordingly, it is possible to exclude the dimension variation of seal S5, and to readily set an appropriate valance shape offirst side plate 14. Moreover, the factor of the variation of the pressing force becomes only the inner pressure inside first pump chamber P1. Accordingly, it is possible to decrease the variation, and to ensure the stable pump performance. Ingear pump 1 according to the first embodiment, seal S5 is completely floated frombottom portion 30 at the high pressure operation of the hydraulic fluid. Moreover, seal S5 may be arranged to be floated frombottom portion 30 at the low pressure operation of the hydraulic fluid. - [Molding of Receiving Portion] In the first embodiment, each of
side plates portions groove 33 by varying a part of the width ofbottom portion 30. - [Stability of Friction] In the first embodiment,
clearance 34 is formed in advance between each of seals S5 and S6 and thecorresponding bottom portion 30. The pressure is supplied toclearance 34. Accordingly, it is possible to improve the responsiveness to the supply of the hydraulic fluid. Therefore, it is possible to rapidly stabilize the friction suddenly after the start of the operation of each ofpumps - [Application to Brake Apparatus] Next, application of
gear pump 1 to a brake apparatus for a vehicle is illustrated. A structure of the brake apparatus described below is one example.Gear pump 1 can be applicable to other known brake apparatuses, and applicable to other apparatuses other than the brake apparatus. - As shown in
FIG. 20 , abrake apparatus 101 according to the first embodiment has an X-piping system having a P-system and an S-system. A booster Bs and so on are identical in a structure to a booster and so on of the conventional apparatus. Therefore, the different parts are illustrated below. The P-system is connected with a wheel cylinder W/C (FL) of a front left wheel and a wheel cylinder W/C (RR) of a rear right wheel. The S-system is connected with a wheel cylinder W/C (FR) of a front right wheel and a wheel cylinder W/C (RL) of a rear left wheel. The P-system and the S-system are connected, respectively, withpump 8 and pump 9 ofgear pump 1. Master cylinder M/C is connected with the suction sides ofpumps passages Reservoirs passages reservoirs Reservoirs reservoir 160P is illustrated.Reservoir 160P includes aball valve 161; apiston 162; aspring 163 arranged to urgepiston 162 in the upward direction; aport 164 arranged to introduce, toreservoir 160P, a brake fluid flowing from the wheel cylinder by the pressure reduction; aport 165 arranged to introduce, to the pump suction side, a brake fluid withinreservoir 160P or the brake fluid in the master cylinder. When the master cylinder pressure is generated,ball valve 161 is closed. Whenpump 8 is actuated in this state,ball valve 161 is opened by the difference between the pressure receiving areas ofball valve 161 andpiston 162, and the spring elastic force. The brake fluid is appropriately sucked. - A master cylinder pressure sensor PMC is provided between master cylinder M/C and
reservoir 160P, and arranged to sense a pressure of master cylinder M/C.A check valve 6P is provided inpassage 11P betweenreservoir 160P and pump 8, and arranged to allow a flow of the brake fluid fromreservoir 160P to pump 8, and to restrict a flow of the brake fluid frompump 8 toreservoir 160P. Acheck valve 6S is provided inpassage 11S betweenreservoir 160S and pump 9, and arranged to allow a flow of the brake fluid fromreservoir 160S to pump 9, and to restrict a flow of the brake fluid frompump 8 toreservoir 160S. The discharge sides ofpumps passages passages check valve 7P is provided inpassage 12P betweenpump 8 and solenoid-in-valves 4FL and 4RR, and arranged to allow flows of the brake fluid frompump 8 to solenoid-in-valves 4FL and 4RR, and to restrict flows of the brake fluid from solenoid-in-valves 4FL and 4RR to pump 8. Acheck valve 7S is provided inpassage 12S betweenpump 9 and solenoid-in-valves 4FR and 4RL, and arranged to allow flows of the brake fluid frompump 9 to solenoid-in-valves 4FR and 4RL, and to restrict flows of the brake fluid from solenoid-in-valves 4FR and 4RL to pump 9. Moreover, inpassages pumps pumps passages passages Passage 12P andpassage 13P are connected (joined) betweenpump 8 and solenoid-in-valve 4FL and 4RR.Passage 12S andpassage 13S are connected (joined) betweenpump 9 and solenoid-in-valve 4FR and 4RL. Inpassages valves passages master side passage 13 a which is located between master cylinder M/C and the corresponding gate outvalve wheel side passage 13 b which is located between the wheel cylinders and the corresponding gate outvalve passages passages valves check valve 9P is provided inpassage 18P, and arranged to allow a flow of the brake fluid from master cylinder M/C to wheel cylinders W/C, and to restrict a flow of the brake fluid from wheel cylinders W/C to master cylinder M/C.A check valve 9S is provided inpassage 18S, and arranged to allow a flow of the brake fluid from master cylinder M/C to wheel cylinders W/C, and to restrict a flow of the brake fluid from wheel cylinders W/C to master cylinder M/C. - On the suction sides of
pumps reservoirs Reservoirs pumps passages check valve 6P is provided betweenreservoir 160P and pump 8, and arranged to allow a flow of the brake fluid fromreservoir 160P to pump 8, and to restrict a flow of the brake fluid frompump 8 toreservoir 160P. Acheck valve 6S is provided betweenreservoir 160S and pump 9, and arranged to allow a flow of the brake fluid fromreservoir 160S to pump 9, and to restrict a flow of the brake fluid frompump 9 toreservoir 160S. Wheel cylinders W/C are connected, respectively, withpassage reservoirs passages passages - [Operation of Brake Apparatus] This
brake apparatus 101 performs an anti-skid control (ABS control) to keep a slip rate of the wheel to a predetermined range, a vehicle behavior (movement) control to provide a yaw rate to the vehicle to stabilize the behavior (movement) of the vehicle, a brake assist control to boost in addition to the brake pedal operation of the driver, and an automatic brake control to produce a brake force based on the running condition irrespective of the intension of the driver. When the gear pump is actuated at the pressure decreasing control in the ABS control or at the pressure increase of the wheel cylinder, the brake fluid (the hydraulic fluid) flows from the wheel cylinder or the master cylinder toreservoirs groove 33 to high pressure chamber H1 in accordance with the transformation (deformation). - (1) The gear pump according to the embodiments of the present invention includes: a housing (2); a pump chamber (P1, P2) formed in the housing (2), the pump chamber (P1, P2) having a low pressure chamber (L1) and a high pressure chamber (H1); a gear (15, 18) disposed in the pump chamber (P1,P2), and arranged to be driven by a motor (M1) to perform a pump operation; a side plate (14, 22) disposed between a wall of the pump chamber (P1, P2) and the gear (15, 18), and arranged to seal a side surface of the gear (15, 18), the side plate (14, 22) including an annular receiving portion (14 j, 22 j) formed between the wall of the pump chamber (P1, P2) and the side plate (14, 22), the receiving portion having a bottom portion (30) and a side wall portion (31, 32); a seal member (S5, S6) disposed in the receiving portion (14 j, 22 j) of the side plate (14, 22), and arranged to liquid-tightly separate the low pressure chamber (L1) and the high pressure chamber (H1) of the pump chamber (P1, P2); a pressure introducing section (33) arranged to introduce a pressure generated by the pump operation, to a space between the bottom portion (30) of the receiving portion (14 j, 22 j) and the seal member (S5,S6), and thereby to separate the seal member (S5, S6) away from the bottom portion (30) of the receiving portion (14 j, 22 j. Accordingly, it is possible to decrease and optimize the variation (fluctuation) of the pressing forces of
side plates gears - (2) In the gear pump according to the embodiments of the present invention, the seal member (S5, S6) is disposed with a clearance (34) between the seal member (S5, S6) the bottom portion (30) of the receiving portion (14 j, 22 j); and the pressure guide section (33) is arranged to introduce the pressure from the high pressure chamber (H1) to the clearance (34). There is formed, in advance,
clearance 34. The pressure is introduced intoclearance 34, and accordingly it is possible to improve the responsiveness to the introduction of the pressure. - (3) In the gear pump according to the embodiments of the present invention, the side wall portion (31) of the receiving portion (14 j, 22 j) includes a holding portion (35) arranged to abut on the seal member (S5, S6), and thereby to hold the seal member (S5, S6) in a predetermined position, and a plurality of the pressure introducing sections (33) provided alternatively in the holding portion (35) of the side wall portion (31) of the receiving portion (14 j, 22 j); and the pressure introducing section (33) has a width larger than a width of the holding portion (35) with respect to the bottom portion (30). Accordingly, it is possible to readily form the pressure guiding section (communicating groove 33) only by varying widths of receiving
portions - (4) In the gear pump according to the embodiments of the present invention, the side plate (14, 22) is made from a resin; and the holding portion (35) and the pressure introducing section (33) are integrally formed. Accordingly, it is possible to readily mold holding
portion 35 and the pressure guiding section (communicating groove 33). - (5) In the gear pump according to the embodiments of the present invention, the gear pump further comprises a center plate (7) fixed within the housing (2), and a pair of pump chambers (P1, P2) including the pump chamber; the pump chambers (P1, P2) are disposed on both sides of the center plate (7) to sandwich the center plate (7); the gear (16, 26) is disposed between the center plate (7) and the side plate (14, 22); the gear includes a drive gear (16, 26) arranged to rotate by the motor, and a driven gear (17, 27) arranged to be engaged with the drive gear (16, 26), and to be driven by the drive gear (16, 26); and the gear is a tandem external gear. Accordingly, the present invention can be applied to an external pump of the tandem type.
- (6) A gear pump according to the embodiments of the present invention includes: a housing (2); a pump chamber (P1, P2) formed in the housing (2), the pump chamber (P1, P2) having a high pressure chamber (H1) and a low pressure chamber (L1); a gear (15, 23) disposed within the pump chamber (P1, P2), and arranged to rotate at least by a drive shaft (10); a side plate (14, 22) disposed adjacent to the gear (15, 23), between a side surface of the gear (15, 23) and a wall of the pump chamber (P1, P2), the side plate (14, 22) having an annular recessed groove (14 j, 22 j) formed in a surface confronting the wall (4 b, 6 d) of the pump chamber (P1, P2), and the annular recessed groove (14 j, 22 j) having a bottom portion (30); and a seal member (S5, S6) disposed in the annular recessed groove (14 j, 22 j) of the side plate (14, 22), and arranged to separate (partition) the high pressure chamber (H1) and the low pressure chamber (L1) of the pump chamber (P1, P2), and to be pushed in a direction away from the bottom portion (30) of the recessed groove (14 j, 22 j) by a pressure introduced from the high pressure chamber (H1) when the gear (15, 23) is driven. The thus-constructed gear pump can provide the same advantageous effects and operations as in (1).
- (7) In the gear pump according to the embodiments of the present invention, the seal member (S5, S6) is disposed with a clearance (34) between the seal member (S5, S6) and the bottom portion (30) of the recessed groove (14 j, 22 j); and the high pressure chamber (H1) is arranged to introduce the pressure to the clearance (34). The thus-constructed gear pump can provide the same advantageous effects and operations as in (2).
- (8) In the gear pump according to the embodiments of the present invention, the recessed groove (14 j, 22 j) of the side plate (14, 22) includes a side wall portion (31) disposed on the high pressure chamber's side; and the side wall portion (31) of the recessed groove (14 j, 22 j) includes a holding portion (35) arranged to abut on the seal member (S5, S6), and to hold the seal member (S5, S6) in a predetermined position, and a plurality of pressure introducing sections (33) provided alternatively in the holding portion (35); and each of the pressure guide sections (33) of the side wall portion (31) has a width larger than a width of the holding portion (35) with respect to the bottom portion (30) to introduce the pressure of the high pressure chamber (H1) to the clearance (34). The thus-constructed gear pump can provide the same advantageous effects and operations as in (3).
- (9) In the gear pump according to the embodiments of the present invention, the side plate (14, 22) is made of a resin; and the recessed groove (14 j, 22 j), the holding portion (35), and the pressure introducing section (33) are integrally formed. The thus-constructed gear pump can provide the same advantageous effects and operations as in (4).
- (10) In the gear pump according to the embodiments of the present invention, the gear pump further comprises a center plate (7) fixed within the housing (2), and a pair of pump chambers (P1, P2) including the pump chamber; the pump chambers (P1, P2) are disposed both sides of the center plate (7) to sandwich the center plate (7); the gear (15, 23) is disposed between the center plate (7) and the side plate (14, 22); and the gear (15, 23) includes a drive gear (16, 26) driven by the drive shaft (10), and a driven gear (17, 27) arranged to be engaged with the drive gear (16, 26), and to be driven by the drive gear (16, 26); and the gear pump is a tandem external gear. The thus-constructed gear pump can provide the same advantageous effects and operations as in (5).
- (11) A gear pump according to the embodiments of the present invention includes: at least a pair of gears (16, 17) engaged with each other; a side plate (14, 22) disposed adjacent to the gears (16, 17), the side plate (14, 22) including an annular recessed groove (4 c, 6 d), and a shoulder portion; a housing (2) disposed at a position to sandwich the side plate (14, 22) with the gear (16, 17), and to confront the gear (16, 17); a seal member (S5, S6) disposed in the annular recessed groove (4 c, 6 d) of the side plate (14, 22), and arranged to seal a gap between the housing (2) and an end of the shoulder portion of the side plate (14, 22), and to separate a low pressure chamber (L1) and a high pressure chamber (H1) formed in a radial direction of the gear (16, 17); and a pressure introducing section (33) arranged to transform the seal member (S5, S6) by a pressure of the high pressure chamber in a direction toward the end of the shoulder portion. The thus-constructed gear pump can provide the same advantageous effects and operations as in (1).
- (12) In the gear pump according to the embodiments of the present invention, the seal member (S5, S6) is disposed with a clearance (34) between the seal member (S5, S6) and the bottom portion (30) of the recessed portion (14 j, 22 j) of the side plate (14, 22); and the pressure introducing section (33) is arranged to introduce the pressure of the high pressure portion (H1) to the clearance (34). The thus-constructed gear pump can provide the same advantageous effects and operations as in (2).
- (13) In the gear pump according to the embodiments of the present invention, the recessed portion (14 j, 22 j) of the side plate (14, 22) includes a side wall portion (31) on the high pressure chamber's side; the side wall portion (14, 22) of the recessed portion (14 j, 22 j) includes a holding portion (35) arranged to abut on the seal member (S5, S6), and to hold the seal member (S5, S6) in a predetermined position, and a plurality of the pressure guide sections (33) provided alternatively in the holding portion (35), and which has a width larger than the bottom portion (30) of the recessed portion (14 j, 22 j); the side plate (14, 22) is made of a resin; and the recessed groove (14 j, 22 j), the holding portion (35), the pressure introducing sections (33) are integrally formed. The thus-constructed gear pump can provide the same advantageous effects and operations as in (3) and (4).
- (14) In the gear pump according to the embodiments of the present invention, the gear pump further comprises a center plate (7) fixed within the housing (2), and a pair of pump chambers (P1, P2); the pump chambers (P1, P2) are disposed on both sides of the center plate (7) to sandwich the center plate (7); the gear (15, 23) is disposed between the center plate (7) and the side plate (14, 22); the gear includes a drive gear (16,26) driven by the motor (M1), and a driven gear (17, 27) arranged to be engaged with the drive gear (16, 26), and to be driven by the drive gear (16, 26); and the gear is a tandem external gear. The thus-constructed gear pump can provide the same advantageous effects and operations as in (5).
- Hereinafter, a gear pump according to a second embodiment of the present invention is illustrated. The following explanation is directed only to points different from the first embodiment, and repetitive explanation is omitted as to similar component parts to which the same reference numerals are given.
-
FIG. 21A is a view illustrating a state in which seal S5 is mounted.FIG. 21B is a view illustrating a state in which a low pressure is acted to seal S5.FIG. 21C is a view illustrating a state in which a high pressure is acted to seal S5. As shown inFIG. 21A , the gear pump according to the second embodiment includes a communicatinggroove 36 extending in a direction perpendicular to the axial direction of first side plate 14 (second side plate 22), in place of communicatinggroove 33, unlike the first embodiment. Communicatinggroove 36 includes a first end connected with high pressure chamber H1, and a second end connected with a part ofclearance 34 nearbottom portion 30. Accordingly, in the second embodiment, a contact area between seal S5 (seal S6) and high pressureside wall portion 31 is uniform around (over) the entire circumference. Accordingly, it is possible to prevent the concentration of the stress of seal S5 (seal S6), and to improve the durability. As shown inFIGS. 21A to 21C , the hydraulic fluid can be introduced through communicatinggroove 36 tocavity 34, like communicatinggroove 33 of the first embodiment. Therefore, it is possible to attain the same effect as the first embodiment.FIGS. 22A to 22C are views showing the gear pump according to the second embodiment when the high pressure side and the low pressure side are reversed.FIG. 22A is a view illustrating a state in which seal S5 is mounted.FIG. 22B is a view illustrating a state in which a low pressure is acted to seal S5.FIG. 22C is a view illustrating a state in which a high pressure is acted to seal S5. In addition, as shown inFIGS. 22A to 22C , even when the high pressure chamber H1 and low pressure chamber L1 is reversed at the ABS pressure decreasing control, the pressure is readily discharged, and it is possible to suppress the increase of the friction. - (15) In the gear pump according to the embodiments of the present invention, the gear pump further comprises a communicating groove (36) formed in the side plate (14, 22), and arranged to communicate the clearance (34) and the high pressure chamber (H1). Accordingly, it is possible to prevent the concentration of the stress to seals S5 and S6.
- (16) In the gear pump according to the embodiments of the present invention, the gear pump is used for a brake apparatus for a vehicle; the brake apparatus includes a reservoir (160P, 160S) arranged to receive a brake fluid from a wheel cylinder (W/C) at an ABS pressure decreasing control; the gear pump is connected through the reservoir (160P, 1605) to the wheel cylinder (W/C) at the ABS pressure decreasing control, so that the pump chamber receives the pressure of the wheel cylinder; the pressure of the wheel cylinder (W/C) is acted to the low pressure chamber (L1); the seal member (S5, S6) is transformed by the pressure of the wheel cylinder (W/C) so that the pressure of the wheel cylinder (W/C) is acted through the communicating groove (36) to the high pressure chamber (H1) in accordance with the deformation. Accordingly, the pressure is readily discharged even when high pressure chamber H1 and low pressure chamber L1 is reversed at the ABS pressure decreasing control, the pressure is readily discharged, and it is possible to suppress the increase of the friction.
- Hereinafter, a gear pump according to a third embodiment of the present invention is illustrated. The following explanation is directed only to points different from the first embodiment, and repetitive explanation is omitted as to similar component parts to which the same reference numerals are given.
- The gear pump according to the first embodiment is the external gear pump of the tandem type. As shown in
FIG. 23 , the gear pump according to the third embodiment is the external gear pump of a single type, unlike the first embodiment. That is, component parts ofsecond pump 9 of the first embodiment are omitted, and there is provided only thefirst gear pump 8. Moreover, in the third embodiment,seal member 7 and covermember 6 of the first embodiment are shortened in the forward and rearward directions, and integrally formed to formsingle seal member 7. Accordingly, it is possible to attain the same effects as the first embodiment. - Hereinafter, a gear pump according to a fourth embodiment is illustrated. The following explanation is directed only to points different from the first embodiment, and repetitive explanation is omitted as to similar component parts to which the same reference numerals are given.
-
FIG. 24 is a view illustrating a state in which seal S5 is mounted in the gear pump according to the fourth embodiment. As shown inFIG. 24 , seal S5 (seal S6) includes a circularelastic transformation portion 37 made of an elastic material such as a rubber, and arranged to elastically transform (vary its shape), and abackup portion 38 made of a material having a rigidness larger than a rigidness ofelastic transformation portion 37, and arranged to enforce (reinforce)elastic transformation portion 37.Elastic transformation portion 37 andbackup portion 38 may be arbitrary fixed.Backup portion 38 has a substantially L-shaped cross section.Backup portion 38 is disposed to confront a boundary between high pressure chamber H1 and low pressure chamber L1.Elastic transformation portion 37 includes retainingportions 37 a which protrudes outwards, and each of which is located at a position corresponding to the end portion of L-shapedbackup portion 38. Retainingportions 37 a are retained tobackup portion 38, and accordingly it is possible to prevent the misalignment or deviation ofelastic transformation portion 37. Accordingly, when the high pressure of the hydraulic fluid is acted, it is possible to prevent a transformed part of seal S5 from engaging in the interspace between first side plate 14 (second side plate 22) and recessedportion 4 c (recessedportion 5 d). - (17) In the gear pump according to the embodiments of the present invention, the seal member (S5, S6) includes an elastic transformation portion (37) arranged to elastically transform, and a backup portion (38) arranged to reinforce the elastic transformation portion (37); and the backup portion (38) of the seal member (S5,S6) confronts a boundary between the low pressure chamber (L1) and the high pressure chamber (H1). Accordingly, it is possible to prevent the engagement of the seal member (seals S5 and S6) when the pressure of the hydraulic fluid is acted.
- Hereinafter, a gear pump according to a fifth embodiment of the present invention is illustrated. The following explanation is directed only to points different from the first embodiment, and repetitive explanation is omitted as to similar component parts to which the same reference numerals are given.
- The
gear pump 1 according to the first embodiment is the external gear pump of the tandem type. A gear pump according to the fifth embodiment is an internal gear pump of the tandem type, unlike the first embodiment. In particular, each ofside plates FIG. 25 . On the outer circumferences ofside plates outer seal portions seal member 7, in place of seal blocks 14 e and 22 e.Outer seal portions side seal portions 7 d ofseal member 7.First gear 15 formingfirst pump 8 is disposed in a space surrounded byouter seal portion 40 offirst side plate 14 and the correspondingside seal portion 7 d ofseal member 7.Second gear 23 formingsecond pump 9 is disposed in a space surrounded byouter seal portion 41 ofsecond side plate 22 and the correspondingside seal portion 7 d ofseal member 7. Annular seals S8 and S9 are provided, respectively, on the outer circumference surfaces ofouter seal portions members side plates seal member 7 andside plates - As shown in
FIG. 26 ,first gear 15 offirst pump 8 includes anouter rotor 42 having an internallytoothed portion 42 a formed on an inner circumference surface ofouter rotor 42, and aninner rotor 43 having an externallytoothed portion 43 a formed on an outer circumference surface ofinner rotor 43.Outer rotor 42 andinner rotor 43 are disposed in an eccentric state. Internallytoothed portion 42 a ofouter rotor 42 and externallytoothed portion 43 a ofinner rotor 43 are engaged with each other at anengagement portion 44 to form apump chamber 45 surrounded byouter rotor 42 andinner rotor 43. Driveshaft 10 includes a drive raisedportion 46 which is formed integrally withdrive shaft 10, which is located at a position corresponding to the position ofinner rotor 43 of each pumps 8 and 9, and which extends radially in a rectangular column fromdrive shaft 10. This drive raisedportion 46 is engaged with recessedportion 43 b cut in the correspondinginner rotor 43. Drive raisedportion 46 has an axial length smaller than an axial length (thickness) ofinner rotor 43. Consequently, drive raisedportion 46 is arranged to prevent the rotation ofinner rotor 42 relative to driveshaft 10.Outer rotor 42 is arranged to rotate in the same direction asinner rotor 43 by the rotation ofinner rotor 43.Outer rotor 42 rotates whileouter rotor 42 slides on the inner circumference surface ofouter seal portion 40.First side plate 14 includes throughholes pump chamber 45. Each of throughholes hole 47 is connected through a space 29 formed betweenpump chamber 4 andfirst side plate 1, to asuction portion 50 ofpump chamber 4. Throughhole 48 is connected withdischarge port 51 ofpump chamber 4. On the other hand,second gear 23 ofsecond pump 9 andsecond side plate 22 are formed likefirst gear 15 offirst pump 8 andfirst side plate 14.Second side plate 22 includes two throughholes hole 52 is connected through ahydraulic passage 54 formed incover member 6, to asuction port 55 ofpump chamber 4. On the other hand, throughhole 53 is connected through aspace 56 formed betweencover member 6 andsecond side plate 22, and through ahydraulic passage 57 formed incover member 6, to adischarge port 58 ofpump chamber 4. - As shown in
FIG. 27 ,first side plate 14 includes anannular receiving portion 14 j formed on a rear surface offirst side plate 14, like the first embodiment. Seal S5 is provided in receivingportion 14 j offirst side plate 14. Thedischarge port 51 is the high pressure side. Receivingportion 14 j and seal S5 have the shapes which are opposite to the shapes in the inward and outward directions in the first embodiment. On the other hand,second side plate 22 includes anannular receiving portion 22 j formed on a front surface ofsecond side plate 22, like the first embodiment. Seal S6 is provided in receivingportion 22 j ofsecond side plate 22, as shown inFIG. 28 . - [Operation of Gear Pump] Next, an operation of
gear pump 1 according to the fifth embodiment is illustrated. In the thus-constructedgear pump 1, whendrive shaft 10 is rotated by the motor in a clockwise direction ofFIG. 26 shown by an arrow,outer rotors 42 ofpumps inner rotors 43. In this case, the pump operation (function) is acted by the variation of the volume ofpump chambers 45 ofgears first pump 8, the hydraulic fluid of the low pressure is introduced fromsuction port 50 through throughhole 47 offirs side plate 14, and pressurized. Then, the hydraulic fluid is outputted through throughhole 48 offirst side plate 14 to dischargeport 51. On the other hand, insecond pump 9, the hydraulic fluid of the low pressure is introduced fromsuction port 55 through throughhole 52 ofside plate 22, and pressurized. Then, the hydraulic fluid is discharged through throughhole 53 ofsecond side plate 22 to dischargeport 58. In this way, ingear pump 1 according to the fifth embodiment, both ofpumps Gear pump 1 serves as the internal gear pump of the tandem type. - The hydraulic fluid of high pressure chamber H1 is introduced in the rear surface of
first side plate 14 from communicatinggroove 33 toclearance 34 at the low to high pressure operation offirst pump 8, like the first embodiment. Accordingly, it is possible to attain the same effects as the first embodiment. On the other hand, the hydraulic pressure of high pressure chamber H1 is introduced in the front surface ofsecond side plate 22 from communicatinggroove 33 toclearance 34 at the low to high pressure operation ofsecond pump 9. Accordingly, it is possible to attain the same effects as the first embodiment. - Although the embodiments of the present invention has been described above, the invention is not limited to the embodiments described above. Various forms and modifications are included as long as they are not deviated from the gist of the invention. For example, when the drive shaft rotates in the direction opposite to the rotational direction of the drive shaft in the first embodiment, the hydraulic fluid flows from the discharge port to the suction port. Moreover, in the fifth embodiment, the gear pump may be an internal gear pump of a single type.
-
FIGS. 29A , 29B and 29C are enlarged sectional views showing a portion near a seal of a gear pump according to another embodiment of the present invention.FIG. 29A is a view illustrating a state in which seal S5 is mounted.FIG. 29B is a view illustrating a state in which a low pressure is acted to the seal.FIG. 29C is a view illustrating a state in which a high pressure is acted to the seal. InFIGS. 29A-29C , the same reference numerals are given to similar component parts. Moreover, the interspace between the first side plate and recessedportion 4 c may be not even. Thefirst side plate 14 may have a stepped portion. In this case, communicatinggroove 33 may be formed into an annular shape so as to introduce the hydraulic fluid toclearance 34, irrespective of the pressure function of the hydraulic fluid. - The entire contents of Japanese Patent Application No. 2009-072938 filed Mar. 24, 2009 are incorporated herein by reference.
- Although the invention has been described above by 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. The scope of the invention is defined with reference to the following claims.
Claims (20)
1. A gear pump comprising:
a housing;
a pump chamber formed in the housing, the pump chamber having a low pressure chamber and a high pressure chamber;
a gear disposed in the pump chamber, and arranged to be driven by a motor to perform a pump operation;
a side plate disposed between a wall of the pump chamber and the gear, and arranged to seal a side surface of the gear, the side plate including an annular receiving portion formed between the wall of the pump chamber and the side plate, the receiving portion having a bottom portion and a side wall portion;
a seal member disposed in the receiving portion of the side plate, and arranged to liquid-tightly separate the low pressure chamber and the high pressure chamber of the pump chamber;
a pressure introducing section arranged to introduce a pressure generated by the pump operation, to a space between the bottom portion of the receiving portion and the seal member, and thereby to separate the seal member away from the bottom portion of the receiving portion.
2. The gear pump as claimed in claim 1 , wherein the seal member is disposed with a clearance between the seal member the bottom portion of the receiving portion; and the pressure guide section is arranged to introduce the pressure from the high pressure chamber to the clearance.
3. The gear pump as claimed in claim 2 , wherein the side wall portion of the receiving portion includes a holding portion arranged to abut on the seal member, and thereby to hold the seal member in a predetermined position, and a plurality of the pressure introducing sections provided alternatively in the holding portion of the side wall portion of the receiving portion; and the pressure introducing section has a width larger than a width of the holding portion with respect to the bottom portion.
4. The gear pump as claimed in claim 3 , wherein the side plate is made from a resin; and the holding portion and the pressure introducing section are integrally formed.
5. The gear pump as claimed in claim 1 , wherein the gear pump further comprises a center plate fixed within the housing, and a pair of pump chambers including the pump chamber; the pump chambers are disposed on both sides of the center plate to sandwich the center plate; the gear is disposed between the center plate and the side plate; the gear includes a drive gear arranged to rotate by the motor, and a driven gear arranged to be engaged with the drive gear, and to be driven by the drive gear; and the gear is a tandem external gear.
6. The gear pump as claimed in claim 2 , wherein the gear pump further comprises a communicating groove formed in the side plate, and arranged to communicate the clearance and the high pressure chamber.
7. The gear pump as claimed in claim 6 , wherein the gear pump is used for a brake apparatus for a vehicle; the brake apparatus includes a reservoir arranged to receive a brake fluid from a wheel cylinder at an ABS pressure decreasing control; the gear pump is connected through the reservoir to the wheel cylinder at the ABS pressure decreasing control, so that the pump chamber receives the pressure of the wheel cylinder; the pressure of the wheel cylinder is acted to the low pressure chamber; the seal member is transformed by the pressure of the wheel cylinder so that the pressure of the wheel cylinder is acted through the communicating groove to the high pressure chamber in accordance with the transformation.
8. The gear pump as claimed in claim 2 , wherein the seal member includes an elastic transformation portion arranged to elastically transform, and a backup portion arranged to reinforce the elastic transformation portion; and the backup portion of the seal member confronts a boundary between the low pressure chamber and the high pressure chamber.
9. A gear pump comprising:
a housing;
a pump chamber formed in the housing, the pump chamber having a high pressure chamber and a low pressure chamber;
a gear disposed within the pump chamber, and arranged to rotate at least by a drive shaft;
a side plate disposed adjacent to the gear, between a side surface of the gear and a wall of the pump chamber, the side plate having an annular recessed groove formed in a surface confronting the wall of the pump chamber, and the annular recessed groove having a bottom portion; and
a seal member disposed in the annular recessed groove of the side plate, and arranged to separate the high pressure chamber and the low pressure chamber of the pump chamber, and to be pushed in a direction away from the bottom portion of the recessed groove by a pressure introduced from the high pressure chamber when the gear is driven.
10. The gear pump as claimed in claim 9 , wherein the seal member is disposed with a clearance between the seal member and the bottom portion of the recessed groove; and the high pressure chamber is arranged to introduce the pressure to the clearance.
11. The gear pump as claimed in claim 10 , wherein the recessed groove of the side plate includes a side wall portion disposed on the high pressure chamber's side; and the side wall portion of the recessed groove includes a holding portion arranged to abut on the seal member, and to hold the seal member in a predetermined position, and a plurality of pressure introducing sections provided alternatively in the holding portion; and each of the pressure guide sections of the side wall portion has a width larger than a width of the holding portion with respect to the bottom portion to introduce the pressure of the high pressure chamber to the clearance.
12. The gear pump as claimed in claim 11 , wherein the side plate is made of a resin; and the recessed groove, the holding portion, and the pressure introducing section are integrally formed.
13. The gear pump as claimed in claim 10 , wherein the side plate includes a communicating groove connecting the clearance and the high pressure chamber.
14. The gear pump as claimed in claim 10 , wherein the seal member includes an elastic transformation portion arranged to elastically transform, and a backup portion arranged to reinforce the elastic transformation portion; and the backup portion confronts a boundary between the high pressure chamber and the low pressure chamber.
15. The gear pump as claimed in claim 10 , wherein the gear pump further comprises a center plate fixed within the housing, and a pair of pump chambers including the pump chamber; the pump chambers are disposed both sides of the center plate to sandwich the center plate; the gear is disposed between the center plate and the side plate; and the gear includes a drive gear driven by the drive shaft, and a driven gear arranged to be engaged with the drive gear, and to be driven by the drive gear; and the gear pump is a tandem external gear.
16. A gear pump comprising:
at least a pair of gears engaged with each other;
a side plate disposed adjacent to the gears, the side plate including an annular recessed groove, and a shoulder portion;
a housing disposed at a position to sandwich the side plate with the gear, and to confront the gear;
a seal member disposed in the annular recessed groove of the side plate, and arranged to seal a gap between the housing and an end of the shoulder portion of the side plate, and to separate a low pressure chamber and a high pressure chamber formed in a radial direction of the gear; and
a pressure introducing section arranged to transform the seal member by a pressure of the high pressure chamber in a direction toward the end of the shoulder portion.
17. The gear pump as claimed in claim 16 , wherein the seal member is disposed with a clearance between the seal member and the bottom portion of the recessed portion of the side plate; and the pressure introducing section is arranged to introduce the pressure of the high pressure portion to the clearance.
18. The gear pump as claimed in claim 17 , wherein the recessed portion of the side plate includes a side wall portion on the high pressure chamber's side; the side wall portion of the recessed portion includes a holding portion arranged to abut on the seal member, and to hold the seal member in a predetermined position, and a plurality of the pressure guide sections provided alternatively in the holding portion, and which has a width larger than the bottom portion of the recessed portion; the side plate is made of a resin; and the recessed groove, the holding portion, the pressure introducing sections are integrally formed.
19. The gear pump as claimed in claim 16 , wherein the gear pump further comprises a center plate fixed within the housing, and a pair of pump chambers; the pump chambers are disposed on both sides of the center plate to sandwich the center plate; the gear is disposed between the center plate and the side plate; the gear includes a drive gear driven by the motor, and a driven gear arranged to be engaged with the drive gear, and to be driven by the drive gear; and the gear is a tandem external gear.
20. The gear pump as claimed in claim 17 , wherein the side plate includes a communicating groove connecting the clearance and the high pressure chamber.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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JP2009-072938 | 2009-03-24 | ||
JP2009072938A JP4931952B2 (en) | 2009-03-24 | 2009-03-24 | Gear pump |
Publications (1)
Publication Number | Publication Date |
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US20100247362A1 true US20100247362A1 (en) | 2010-09-30 |
Family
ID=42675156
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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US12/651,790 Abandoned US20100247362A1 (en) | 2009-03-24 | 2010-01-04 | Gear Pump |
Country Status (3)
Country | Link |
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US (1) | US20100247362A1 (en) |
JP (1) | JP4931952B2 (en) |
DE (1) | DE102010001599B4 (en) |
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Also Published As
Publication number | Publication date |
---|---|
DE102010001599A1 (en) | 2010-10-07 |
DE102010001599B4 (en) | 2014-10-30 |
JP2010223144A (en) | 2010-10-07 |
JP4931952B2 (en) | 2012-05-16 |
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Legal Events
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AS | Assignment |
Owner name: HITACHI AUTOMOTIVE SYSTEMS, LTD., JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:KOIZUMI, TOSHIHIRO;MISUNOU, MASAKI;NAKAZAWA, CHIHARU;REEL/FRAME:026016/0776 Effective date: 20091106 |
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STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO PAY ISSUE FEE |