JP5421335B2 - Gear pump - Google Patents

Description

  The present invention relates to a gear pump.

  Conventionally, the technique of patent document 1 is well-known as a gear pump. According to the present invention, when the pump discharge pressure is low, the frictional force between the side plate and the gear is reduced by reducing the reaction force of the seal and reducing the pressing force of the side plate against the gear. On the other hand, when the discharge pressure of the pump is high, the pressure reaction along the side surface of the gear is prevented by increasing the reaction force of the seal and increasing the pressing force of the side plate against the gear.

Japanese Patent Laid-Open No. 11-303767

  However, in the conventional invention, the pressure receiving area with respect to the bottom portion of the seal receiving groove changes due to the deformation of the seal due to the pressure fluctuation, resulting in variations in the pressing force of the side plate against the gear, resulting in the pump performance. There was a problem that variation occurred.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a gear pump that can stably exhibit desired pump performance.

  In the present invention, the seal member is configured to be separated from the bottom of the housing portion by the pressure introduced by the pressure introducing means.

  By reducing and optimizing the variation in the pressing force of the side plate against the gear by the seal, the desired pump performance can be stably exhibited.

It is a back perspective view of the gear pump of Example 1. FIG. It is a front view of the gear pump of Example 1. 1 is an enlarged view of a main part of Example 1. FIG. 1 is an enlarged view of a main part of Example 1. FIG. 2 is a front perspective view of a seal member of Example 1. FIG. 2 is a rear perspective view of a seal member of Example 1. FIG. FIG. 3 is a front perspective view of a first side plate according to the first embodiment. FIG. 3 is a front perspective view of a first side plate according to the first embodiment. 3 is a front view of a first side plate according to Embodiment 1. FIG. FIG. 6 is a rear view of the first side plate according to the first embodiment. 4 is a top view of a first side plate of Example 1. FIG. It is a figure explaining (a) before the connection of the gear pump and motor of Example 1, and (b) after connection. It is a figure explaining arrangement | positioning of the 1st side plate of Example 1, and a 1st gear. It is a figure explaining arrangement | positioning of the sealing member of Example 1, a 1st side plate, and a 1st gear. It is sectional drawing in the A15-A15 line | wire of FIG. It is a back perspective view of the 1st side plate and seal of Example 1. FIG. 17 is a perspective sectional view (only a part) taken along line A17-A17 of FIG. It is a figure explaining the time of attachment (a) of the seal | sticker of Example 1, the time of low pressure action (b) of a seal, and the time of high pressure action (c) of a seal. It is a figure explaining the effect | action of a general seal | sticker. It is a figure explaining the brake device of Example 1. FIG. It is a figure explaining the time of attachment (a) of the seal | sticker of Example 2, the time of a low pressure action (b) of a seal, and the time of a high pressure action (c) of a seal. It is a figure explaining the time (a) of attachment of the seal | sticker in the case where the high voltage | pressure side and low voltage | pressure side of Example 2 reverse, (b) at the time of low pressure action of a seal, and (c) at the time of high pressure action of a seal. It is sectional drawing explaining the gear pump of Example 3. FIG. It is a figure explaining the seal | sticker of Example 4, and its effect | action. It is sectional drawing explaining the gear pump of Example 5. FIG. It is sectional drawing explaining the 1st gear and 2nd gear of Example 5. FIG. 10 is an enlarged cross-sectional view of the vicinity of a seal of a first side plate of Example 5. FIG. 10 is an enlarged cross-sectional view of the vicinity of a seal of a second side plate of Example 5. FIG. It is an expanded sectional view near the seal of other examples.

  Embodiments of the present invention will be described below with reference to the drawings.

Example 1 will be described below.
As shown in FIGS. 1 and 2, the gear pump 1 of the first embodiment is used for an actuator for controlling the brake fluid pressure of an automobile, and includes a housing 2 and a pump assembly 3 accommodated in the housing 2. Is provided.

[About housing]
Next, the housing 2 will be described. The housing 2 is formed in a substantially rectangular shape, and a plurality of mounting holes 2a to which a switching valve and a sensor (not shown) are attached are formed on the outer surface. A pump chamber 4 that is recessed in a substantially cylindrical shape with steps having different diameters is formed in the approximate center of the front surface of the housing 2, and the pump assembly 3 is accommodated therein.

[About pump assembly]
Next, the pump assembly 3 will be described. In addition, the opening end side (the 2nd pump 9 side mentioned later) of the pump chamber 4 is set as the front, and the bottom part side (the 1st pump 8 side mentioned later) of the pump chamber 4 is described as the back. As shown in FIGS. 3 and 4, the pump assembly 3 includes a plug member 5, a cover member 6, a seal member 7, a first pump 8 and a second pump 9. The plug member 5 is formed in a substantially disk shape, and a through hole 5a formed in a hexagonal column shape is formed at the center thereof. The rear end of the plug member 5 is formed with a rear surface 5d that comes into contact with the cover member 6 and an annular protrusion 5b that surrounds the outer periphery of the rear surface 5d and protrudes annularly rearward. Further, a male screw groove 5 c is formed on the outer periphery of the plug member 5. The male screw groove 5 c is screwed into a female screw groove 4 a formed in the inner peripheral portion of the pump chamber 4. The cover member 6 is formed in a substantially disk shape, and has a front surface 6e that comes into contact with the plug member 5 and a step portion 6f cut out over the entire outer periphery of the front surface 6e. Then, the front surface 6e is pressed backward by the axial force generated by the screwing of the plug member 5, so that the front surface 6e comes into contact with the rear surface 5d of the plug member 5, and further, the annular protrusion 5b and the step portion 6f of the plug member 5 are contacted. Are arranged at predetermined positions in a state of being fitted. On the outer periphery of the cover member 6, a convex portion 6 g having a height substantially the same as that of the inner periphery of the pump chamber 4 and substantially the same radial height as the annular protrusion 5 b is formed. Further, a seal groove 6h is formed on the outer periphery of the cover member 6 and behind the convex portion 6g. An annular seal S1 is provided between the convex portion 6g and the annular protrusion 5b to ensure sealing performance with the inner periphery of the pump chamber 4, and the seal groove 6h is provided with the inner periphery of the pump chamber 4. An annular seal S2 is provided to ensure sealing performance. That is, the seals S1 and S2 are mounted at positions separated from each other in the front-rear direction. At the eccentric position of the cover member 6, a stepped through hole 6 b having a different inner diameter is formed. The drive shaft 10 is inserted into the through hole 6b with a gap 6a. On the other hand, annular seals S3 for securing the sealing performance with the drive shaft 10 are respectively mounted on the large diameter side and the small diameter side of the through hole 6b. Further, a recess 6d that is annularly formed forward and an annular protrusion 6c that protrudes annularly rearward from the recess 6d is formed at the rear end of the cover member 6. On the inner periphery of the annular protrusion 6c, a step portion 6i is formed that is cut out over the entire inner periphery.

  As shown in FIGS. 5 and 6, the seal member 7 is formed in a substantially disk shape, and in the drawing, the two through holes 7 a and 7 b have a circular opening cross section in the front-rear direction. It is formed through. Further, side seal portions 7d protruding in the axial direction along the peripheries of the through holes 7a and 7b are formed on the front and rear surfaces of the seal member 7, respectively, and a pair of engagement convex portions 7e are formed on one side surface thereof. It protrudes to the side. Each side seal portion 7d is formed with a ring accommodating portion 7f that is coaxially formed with the through-hole 7a and is annularly recessed inward in the thickness direction. Further, on the inner side in the thickness direction of the ring housing portion 7f on the rear surface of the seal member 7, a small-diameter seal housing portion 7g that is continuously annularly recessed with the ring housing portion 7f is formed. In addition, the outer periphery of the seal member 7 is formed with an accommodating portion 7h that is annularly recessed radially inward, and an annular protrusion 7i that is annularly protruded forward is formed at the front end thereof.

  As shown in FIGS. 3 and 4, the seal member 7 is pressed rearward through the cover member 6 by the axial force generated by the screwing of the plug member 5. As a result, the annular protrusion 7i of the seal member 7 is fitted into the step 6i of the cover member 6, and further, a part of the rear surface thereof is disposed at a predetermined position in contact with the step 4b of the pump chamber 4. (Positioning). The drive shaft 10 is inserted into the through hole 7a of the seal member 7, while the driven shaft 11 is inserted into the through hole 7b. An annular rotary seal member 12 (X ring or the like) is interposed in the seal housing portion 7g of the seal member 7, and a sealing property between the drive shaft 10 and a first pump chamber P1 described later is ensured. Further, a first seal ring 13 a is interposed in the ring housing portion 7 f on the rear surface of the seal member 7 in a state where the seal housing portion 7 g of the rotary seal member 12 is closed. An annular second seal ring 13b is interposed in the front ring accommodating portion 7f. Each of the seal rings 13a and 13b is formed of a material that is harder and more durable than at least the seal member 7. In addition, an annular seal S4 that is in close contact with the inner periphery of the pump chamber 4 and secures the sealing performance between the first pump chamber P1 and the second pump chamber P2 is attached to the housing portion 7h of the seal member 7. ing. A first pump chamber P1 serving as a closed space is formed between the seal member 7 and the recess 4c that is annularly recessed rearward from the step 4b of the pump chamber 4, and the first pump 8 is provided here. It is arranged. On the other hand, between the recessed part 6d of the cover member 6 and the sealing member 7, the 2nd pump chamber P2 used as a closed space is formed, and the 2nd pump 9 is arrange | positioned here. The first pump 8 is provided with a first gear 15 whose front and rear surfaces and tooth tips are sealed by a seal member 7 and a first side plate 14 described later. First, the first side plate 14 will be described. As shown in FIGS. 7 to 11, the first side plate 14 is made of resin and has a substantially triangular shape in front view. Also, three through holes 14a, 14b, 14c are formed in the vicinity of the apex of the substantially triangular shape. On the front surface of the first side plate 14, a side seal portion 14d protruding forward is formed around the through holes 14a and 14b. In addition, a seal block 14e protruding forward in a substantially triangular shape is formed on the front surface of the first side plate 14. The seal block 14e has a passage portion 14f that forms an opening toward the center continuously from the through-hole 14c, and a pair that is formed on both sides of the passage portion 14f and continues to a part of the side seal portion 14d. Are formed with a curved surface tooth tip seal portion 14g and an engagement portion 14h located on the front side of each tooth tip seal portion 14g. Further, the seal block 14e is formed with a groove 14i that is recessed inward from the outer periphery of the tooth tip seal portion 14g so as to surround the through hole 14c. On the other hand, as shown in FIG. 10, the rear surface of the first side plate 14 is provided with a concave annular housing portion 14j bent in a substantially triangular shape so as to surround the through holes 14a to 14c.

  As shown in FIG. 4, the drive shaft 10 is rotatably inserted into the through hole 14 a of the first side plate 14 with a predetermined gap in the radial direction. On the other hand, the driven shaft 11 is inserted into the through hole 14b with a predetermined gap in the radial direction. Further, a seal S5, which will be described later, is interposed in the accommodating portion 14j, and the sealing performance between the later-described high pressure side and the low pressure side of the first pump chamber P1 is ensured.

  Next, the first gear 15 will be described. As shown in FIG. 14, the first gear 15 includes a drive gear 16 through which the drive shaft 10 is inserted, and a driven gear 17 through which the driven shaft 11 is inserted, and the tooth tips 16a, The teeth 17a are meshed with each other at the meshing portion 18. A concave portion 10a that is recessed inward is formed at a position corresponding to the drive gear 16 in the drive shaft 10, and the distal end side of a cylindrical drive pin 10b extending in the radial direction from the axis of the drive shaft 10 is inserted here. Has been. The base end side of the drive pin 10 b is engaged with a recess 16 b formed in the inner periphery of the drive gear 16. On the other hand, a recessed portion 11a that is recessed inward is formed at a position corresponding to the driven gear 17 on the driven shaft 11, and the tip of a cylindrical driven pin 11b that extends radially from the axis of the driven shaft 11 is formed here. The side is inserted. The base end side of the driven pin 11 b is engaged with a recess 17 b formed in the inner periphery of the driven gear 17.

  Further, as shown in FIGS. 12A and 12B, a front surface portion of the drive shaft 10 is formed with a fitting convex portion 19 having a two-sided width, while the rotation shaft 20a of the motor M1 (electric motor). A fitting recess 20b that can be engaged with the fitting protrusion 19 and connected to the rotary shaft 20a is formed at the tip. Thus, the drive shaft 10 is configured to be rotationally driven in the direction around the shaft by driving the motor M1. Further, since the drive gear 16 is prevented from rotating around the drive shaft 10 by engagement with the drive pin 10b, the drive gear 16 rotates in the same rotational direction as the drive shaft 10 as the drive shaft 10 rotates. On the other hand, the driven gear 17 meshed with the drive gear 16 is prevented from rotating around the driven shaft 11 by the engagement with the driven pin 11b, and thus rotates together with the driven shaft 11 in the direction opposite to the drive shaft 10.

  As shown in FIG. 13, the tooth tips 16a and 17a of the gears 16 and 17 are slidable while being in liquid-tight contact with the corresponding tooth tip seal portions 14g of the seal block 14e of the first side plate 14. Yes. Further, as shown in FIGS. 14 and 15, the pair of engaging convex portions 7e on the rear surface of the seal member 7 are engaged in close contact with the curved surfaces of the corresponding engaging portions 14h of the seal block 14e. The tooth tips 16a and 17a of the gears 16 and 17 are sealed with the side seal portion 14d of the first side plate 14. Further, a holding member 21 is mounted in a substantially triangular shape so as to hang over a corresponding groove 14i formed on the outer periphery of the seal block 14e and a corresponding side seal portion 7d of the seal member 7 (see FIG. 7). Although not shown, the pump chamber 4 is provided with a suction port that communicates with the through hole 14c of the first side plate 14 and a discharge port that communicates with the first pump chamber P1. On the other hand, the second pump 9 has a symmetrical configuration with the first pump 8 around the seal member 7. That is, the second gear 23 whose front and rear surfaces are sealed by the seal member 7 and the second side plate 22 is disposed. The second side plate 22 and the second gear 23 have the same shape as the first side plate 14 and the first gear 15 in the left-right symmetry, and thus the description thereof is omitted.

  As shown in FIG. 4, the drive shaft 10 is rotatably inserted into the through hole 22a of the second side plate 22 with a predetermined gap in the radial direction, while the driven shaft is inserted into the through hole 22b. 11 is inserted in a state having a predetermined gap in the radial direction. In addition, a seal S6 having the same shape as the seal S5 is interposed in the storage portion 22j having the same shape as the storage portion 14j, and a sealing property between a high pressure side and a low pressure side, which will be described later, of the second pump chamber P2 is secured. .

  In addition, in the second pump 9, the pump chamber 4 has a suction port (not shown) communicated through the through hole 21 c of the second side plate 22 and the oil passage of the cover member 6, and oil formed in the cover member 6. The configuration is substantially the same as that of the first pump 8 except that a discharge port (not shown) communicated with the second pump chamber P2 via the passage is provided. The diameters of the through holes 14a and 22a of the side plates 14 and 22 are set larger than the diameter of the drive shaft 10, and the diameters of the through holes 14b and 22b are set larger than the diameter of the driven shaft 11. . That is, the drive shaft 10 and the driven shaft 11 are inserted through the through holes 14a and 22a and the through holes 14b and 22b of the corresponding side plates 14 and 22, respectively, through a slight gap.

[Container]
Next, the accommodating portions 14j and 22j of the side plates 14 and 22 will be described in detail. Since both the housing grooves 14j and 22j have the same configuration, only the housing portion 14j is illustrated and described. As shown in FIGS. 16 and 17, the receiving portion 14 j recessed in the rear surface of the first side plate 14 is continuous with the bottom portion 30 extending in the direction perpendicular to the axis of the first side plate 14 and the bottom portion 30. And a high-pressure side wall portion 31 extending in an inclined manner and a low-pressure side wall portion 32 extending in a direction perpendicular to the bottom portion 30, and is recessed in a substantially V-shaped cross section. At a plurality of locations (five locations in the first embodiment) on the circumference of the high-pressure side wall 31, communication grooves 33 are formed in which the bottom portion 30 is widened toward the high-pressure side wall 31. The communication groove 33 is provided with a deformed annular seal S5 having a circular cross section made of an elastic material such as rubber and bent entirely in a substantially triangular shape. Specifically, as shown in FIG. 18A, the seal S5 has a predetermined gap 34 between the bottom portion 30 and the high-pressure side wall portion 31, the low-pressure side wall portion 32, and the housing portion 14j. It is provided in contact with the recess 4c.

Next, the operation of the first embodiment will be described.
[Assembly of gear pump]
Next, assembly of the gear pump 1 will be described. When assembling the gear pump 1 configured as described above, first, the rotary seal member 12 is inserted and temporarily fixed in the seal accommodating portion 7g of the seal member 7 to which the seal S4 is previously attached. Next, the drive shaft 10 is inserted into the through hole 7a of the seal member 7, while the driven shaft 11 is inserted into the through hole 7b. Next, the seal rings 13a and 13b respectively corresponding to the ring accommodating portions 7f of the seal member 7 are inserted. At this time, when the rotary seal member 12 is pressed by the first seal ring 13 a, the rotary seal member 12 is in good contact with the drive shaft 10. Next, the drive pins 10b and 10e and the driven pins 11b and 11d are inserted into the corresponding recesses 10a and 10d of the drive shaft 10 and the recesses 11a and 11c of the driven shaft 11, respectively. Next, the drive gears 16, 26 and the driven gears 17, 27 are assembled to the corresponding drive shaft 10 and the driven shaft 11, respectively. Next, the drive shaft 10 and the driven shaft 11 are inserted into the side plates 14 and 22 to which the seals S5 and S6 and the holding members 21 and 23 are mounted in advance, and are assembled to the seal member 7. At this time, on the first side plate 14 side of the seal member 7, the pair of engaging convex portions 7 e are engaged with the corresponding engaging portions 14 h of the first side plate 14, so that both of them are positioned. Can be assembled easily. In addition, the holding member 21 can fix the seal member 7 and the first side plate 14 in a temporarily held state. In addition, the holding member 21 can be attached to the seal member 7 in advance, and then the diameter can be expanded and hung on the first side plate 14. Similarly, by engaging the pair of engaging projections 7e of the seal member 7 with the corresponding engaging portions of the second side plate 22 on the second side plate 22 side, both of them can be easily positioned. Can be assembled. In addition, the holding member 24 can fix the seal member 7 and the first side plate 14 in a temporarily held state. Furthermore, the holding member 24 can be hung on the second side plate 22 after being expanded in diameter in a state in which the holding member 24 is mounted on the seal member 7 in advance, and the mounting property is good. Next, the drive shaft 10 is inserted into the through-hole 6a of the cover member 6 on which the seals S1 and S2 are mounted in advance, and the annular protrusion 6c of the cover member 6 is fitted to the seal member 7 so that the cover member 6 is inserted. Assembling the seal member 7, the pump assembly 3 is assembled.

  Next, after inserting the pump assembly 3 assembled in this way into the pump chamber 4 of the housing 2, the plug member 5 is screwed into the pump chamber 4 and fixed. At this time, the sealing member 7 can be brought into close contact with the step portion 4b of the pump chamber 4 by the axial force generated by the screwing of the plug member 5 and can be fixed in a stable state, and the positions of the respective members in the front-rear direction can be accurately arranged. It is possible to prevent rattling caused by fluctuations in the pressure of the operating oil. In addition, when the seal S <b> 1 is pressed against the annular protrusion 5 b of the plug member 5, the sealing performance between the pump chamber 4 and the cover member 6 is improved. Thus, in the gear pump 1 of Example 1, the pump assembly 3 can be accommodated in the housing 2 in a temporarily assembled state, and the assembling work can be simplified.

[About operation of gear pump]
Next, the operation of the gear pump 1 will be described. As shown in FIGS. 12 (a) and 12 (b), the gear pump 1 configured as described above is provided at the tip of a cylindrical drive shaft 10 and is a fitting convex portion that is notched open in the shape of a long hole in cross section. 19 is connected to the fitting recess 20b of the rotating shaft 20a of the motor M1.

  As shown in FIG. 13, when the drive shaft 10 is driven to rotate in the direction of the arrow in the drawing by driving the motor M <b> 1, the driven gear 17 is driven via the drive gear 16 in the first pump 8. By this action, low-pressure hydraulic oil is introduced from the through hole 14c of the seal block 14e of the first side plate 14 communicating with the suction port, and high-pressure hydraulic oil is output to the pump chamber P1. This high pressure hydraulic oil is output from the corresponding discharge port. In the second pump 9, as in the first pump 8, the driven gear 18 b is driven via the drive gear 18 a, so that a low pressure (negative pressure) is generated from the through hole 17 c of the seal block 17 e of the second side plate 22. Is introduced, and high-pressure hydraulic oil is output to the pump chamber P2. This high pressure hydraulic oil is output to the corresponding discharge port. In this way, the gear pump 1 performs suction and discharge of hydraulic oil in different piping systems in both pump chambers P1 and P2, and functions as a so-called tandem external gear pump.

[About the pressing force to the gear by the side plate]
Next, the pressing force of the side plates 14 and 22 against the gears 15 and 23 will be described. In addition, since the pressing force to the gears 15 and 23 by each side plate 14 and 22 is the same, only the pressing force to the 1st gear 15 by the 1st side plate 14 is illustrated and demonstrated. As described with reference to FIG. 18A, when the seal S5 is mounted, the seal S5 has a predetermined gap 34 between the seal S5 and the seal S5, which contacts the high-pressure side wall portion 31, the low-pressure side wall portion 32, and the recess 4c. It is provided in contact. Thereby, the seal S5 is arranged in a state facing the high pressure chamber H1 side and the low pressure chamber L1 side in the gap between the first side plate 14 and the recess 4c. As shown in FIG. 18B, the seal S5 receives the pressure of the hydraulic oil from the high-pressure chamber H1 side and deforms at the low-pressure chamber L1 side during the low-pressure action of the hydraulic oil accompanying the operation of the first pump 8. The high pressure chamber H1 side and the low pressure chamber L1 side are sealed and partitioned while being deformed (reduced diameter). Along with this deformation, hydraulic oil on the high pressure chamber H1 side is introduced into the gap 34 through the communication groove 33. That is, at this time, if the portion where the seal S5 is held at a predetermined position is the holding portion 35 of the high-pressure side wall portion 31, the width W1 of the communication groove 33 is larger than the width W2 of the holding portion 35 with respect to the bottom portion 30. The width is set so that the hydraulic oil can flow into the gap 34 from the communication groove 33. Next, as shown in FIG. 18 (c), when the hydraulic oil is actuated by the operation of the first pump 8, the seal S 5 moves away from the bottom 30 due to the pressure from the hydraulic oil flowing into the gap 34. Thus, the high pressure chamber H1 side and the low pressure chamber L1 side are securely sealed. At this time, the seal S5 can be separated from the bottom 30 and completely lifted. Here, the pressing force to the gear is obtained by the following equation (1).

  Pushing force on gear = (side plate receiving area side pressure receiving area−side plate gear side pressure receiving area) × pump chamber pressure + seal reaction force (1)

  Accordingly, as shown in FIGS. 19A to 19C, when a general recess-type storage portion including Patent Document 1 is adopted, the side plate storage portion side pressure receiving area range α (see FIG. 19). ) Changes due to the deformation of the seal due to the pressure fluctuation, and the reaction force of the seal also changes according to the pressure fluctuation and is not stable. In FIG. 19, components corresponding to the respective parts of the first embodiment are denoted by the same reference numerals. In addition, since rubber is usually used as the seal material, it is hardened or sag due to long-term use, and the reaction force changes greatly. Furthermore, since the rubber cannot make the manufacturing dimensional tolerance and assembly dimension crossing small, variations in reaction force due to dimensional variations cannot be ignored. Therefore, it is practically difficult to eliminate variation in the pressing force of the side plate against the gear, and this variation has a problem that it adversely affects pump performance. On the other hand, in the first embodiment, during the low pressure to high pressure action in which the hydraulic oil is pressurized, all of the accommodation portion 14j up to the low pressure side wall portion 32 is the accommodation portion side pressure receiving area range α of the side plate 14 (see FIG. 19). ) Furthermore, when the hydraulic oil is at a high pressure, the seal S5 is separated from the bottom 30 and completely floats, so that the reaction force of the seal S5 is eliminated. Thereby, the pressing force to the gear 15 of Example 1 is calculated | required by following formula (2).

  Pressing force to the gear 15 = (receiving area 14j side pressure receiving area (constant) of the first side plate 14−constant pressure receiving area 15 side of the first side plate 14) × pressure in the first pump chamber P1... (2)

  Accordingly, the first gear 15 is hardly affected by the deformation / reaction force of the seal S5 due to the pressure fluctuation in the first pump P1, so that even if the pressure in the first pump P1 rises, The pressing force can be reduced. Further, by reducing the pressing force, the friction between the first side plate 14 and the gear 15 can be reduced, and the pump performance can be improved. Further, even when the seal S5 is deformed, the pressure receiving area on the side of the accommodating portion 14j of the first side plate 14 is always kept constant, so that the dimensional variation of the seal S5 can be eliminated, and the optimal balance shape of the first side plate 14 is easy. Can be set. Furthermore, since the fluctuation factor of the pressing force is only the internal pressure in the first pump chamber P1, there is little variation and stable pump performance can be ensured. In the first embodiment, the seal S5 is completely lifted from the bottom 30 when the hydraulic oil is operated at a high pressure. However, the seal S5 may be completely lifted from the bottom 30 even when the hydraulic oil is at a low pressure. good.

[Moldability of housing part]
In the first embodiment, since the side plates 14 and 22 are integrally formed of resin, the respective portions of the housing portions 14j and 22j can be easily formed. Further, the communication groove 33 can be easily formed only by partially changing the design of the width of the bottom portion 30.

[Friction stability]
In the first embodiment, a gap 34 is formed in advance between each of the seals S5, S6 and the bottom 30 and pressure is introduced therein, so that the reactivity to the introduction of hydraulic oil is good, and the pumps 8, 9 Immediately after the operation, the friction can be stabilized quickly.

[Application to brake equipment]
Next, an application example of the gear pump 1 to a vehicle brake device will be described. In addition, the structure of the brake device demonstrated below is an example, Comprising: You may apply to other well-known brake devices, and the gear pump 1 can also be applied to things other than a brake device.

  As shown in FIG. 20, the brake device 101 according to the first embodiment has a piping structure called X piping that includes two systems of a P system and an S system. Since the configuration of the booster BS and the like is the same as that of a known device, different points will be described. The P system is connected to the wheel cylinder W / C (FL) for the left front wheel and the wheel cylinder W / C (RR) for the right rear wheel. The wheel cylinder W / C (FR) for the right front wheel is connected to the S system. The wheel cylinder W / C (RL) on the left rear wheel is connected. The P system and the S system are connected to the pump 8 and the pump 9 of the gear pump 1. The master cylinder M / C and the suction sides of the pumps 8 and 9 are connected by pipes 11P and 11S. Respective reservoirs 160P and 160S having a check valve function are provided on the pipes 11P and 11S. Since both the reservoirs 160P and 160S have the same function, only the reservoir 160P will be described. The reservoir 160P includes a ball valve 161, a piston 162, a spring 163 that biases the piston 162 upward, and a wheel cylinder. It has a port 164 for introducing the brake fluid that has flowed out due to pressure reduction into the reservoir 160P, and a port 165 for guiding the brake fluid in the reservoir 160P or the brake fluid in the master cylinder to the pump suction side. When the master cylinder pressure is generated, the ball valve 161 is closed. When the pump 8 is operated in this state, the ball valve 161 is opened by the difference in pressure receiving area between the ball valve 161 and the piston 162 and the spring elastic force, and the brake fluid is sucked in appropriately. Is done.

  A master cylinder pressure sensor PMC that detects the pressure of the master cylinder M / C is provided between the master cylinder M / C and the reservoir 160P. Also, check valves 6P and 6S are provided on the pipelines 11P and 11S and between the reservoirs 160P and 160S and the pumps 8 and 9, and the check valves 6P and 6S are pumped from the reservoirs 160P and 160S. Allow the flow of brake fluid in the direction toward 8, 9, and prohibit the flow in the opposite direction. The discharge sides of the pumps 8 and 9 and the wheel cylinders W / C are connected by pipelines 12P and 12S. Solenoid in valves 4FL, 4RR, 4FR, 4RL, which are normally open solenoid valves corresponding to the respective wheel cylinders W / C, are provided on the pipe lines 12P, 12S. In addition, check valves 7P, 7S are provided on the pipelines 12P, 12S and between the solenoid-in valves 4FL, 4RR, 4FR, 4RL and the pumps 8, 9, respectively. 7S allows the flow of the brake fluid in the direction from the pump 8 toward the solenoid in valves 4FL, 4RR, 4FR, 4RL, and prohibits the flow in the opposite direction. Furthermore, each pipeline 12P, 12S is provided with a pipeline 17FL, 17RR, 17FR, 17RL that bypasses each solenoid-in valve 4FL, 4RR, 4FR, 4RL, and this pipeline 17FL, 17RR, 17FR, 17RL Check valves 10FL, 10RR, 10FR, and 10RL are provided. Each check valve 10FL, 10RR, 10FR, 10RL allows the flow of brake fluid in the direction from the wheel cylinder W / C toward the pumps 8, 9, and prohibits the flow in the opposite direction. Master cylinder M / C and pipes 12P, 12S are connected by pipes 13P, 13S, and pipes 12P, 12S and pipes 13P, 13S are pumps 8, 9 and solenoid valves 4FL, 4RR, 4FR, 4RL. To join. Gate-out valves 3P and 3S, which are normally open solenoid valves, are provided on the pipe lines 13P and 13S. Here, of the pipelines 13P and 13S, the pipeline on the master cylinder side with respect to the gate-out valves 3P and 3S is referred to as a master side pipeline 13a, and the pipeline on the wheel cylinder side is referred to as a foil side pipeline 13b. The pipes 13P and 13S are provided with pipes 18P and 18S that bypass the gate-out valves 3P and 3S, respectively, and check valves 9P and 9S are provided in the pipes 18P and 18S. Each of these check valves 9P, 9S allows the flow of brake fluid in the direction from the master cylinder M / C side toward the wheel cylinder W / C and prohibits the flow in the opposite direction.

  Reservoirs 160P and 160S are provided on the suction side of the pumps 8 and 9, and the reservoirs 160P and 160S are connected to the pumps 8 and 9 by pipe lines 15P and 15S. Check valves 6P and 6S are provided between the reservoirs 160P and 160S and the pumps 8 and 9, and each check valve 6P and 6S has a flow of brake fluid in a direction from the reservoirs 160P and 160S to the pumps 8 and 9. Is allowed and flow in the opposite direction is prohibited. The wheel cylinder W / C and the pipeline reservoirs 160P and 160S are connected by pipelines 14P and 14S. Solenoid out valves 5FL, 5RR, 5FR, and 5RL, which are normally closed solenoid valves, are provided in the pipe lines 14P and 14S, respectively.

[Brake device operation]
In such a brake device 101, anti-skid brake control (hereinafter referred to as ABS control) for setting the slip ratio of the wheels to a predetermined range, vehicle behavior control for imparting yaw rate to the vehicle to stabilize the vehicle behavior, In addition to the brake pedal operation, brake assist control for pressurizing, and automatic brake control for generating a braking force based on the driving situation regardless of the driver's intention are performed. When the gear pump 1 is operated at the time of pressure reduction control in the ABS control or when the wheel cylinder is pressurized, the brake fluid (hydraulic fluid) flows from the target wheel cylinder or master cylinder into the reservoirs 160P and 160S and the low pressure chamber L1 on the pump suction side Flow into. As described above, the seal S5 (seal S6) is deformed by the pressure on the pump discharge side, and the pressure of the wheel cylinder acts on the high pressure chamber H1 through the communication groove 33 along with the deformation.

Finally, the effect of Example 1 is listed with (1)-(14) corresponding to Claims 1-5, 9-12, 15-19.
(1) Pump chambers P1 and P2 provided in the housing 2, gears 15 and 18 which are arranged in the pump chambers P1 and P2 and rotated by an electric motor (motor M1) to perform a pump action, and pump chambers P1, P1 Side plates 14 and 22 arranged between the wall of P2 (recesses 4c and 6d) and the gears 15 and 18 and sealing the sides of the gears 15 and 18, and walls of the pump chambers P1 and P2 (recesses 4c and 6d) And the side plates 14 and 22 are disposed in annular housing portions 14j and 22j formed in the side plates 14 and 22, and the low pressure chamber L1 and the high pressure chamber H1 in the pump chambers P1 and P2 are liquid-tightly partitioned. Sealing members (seal S5, S6), and the accommodating portions 14j, 22j are constituted by the bottom portion 30 and the side wall portions (the high pressure side wall portion 31 and the low pressure side wall portion 32), and the bottom portion 30 and the sealing member ( Pressure introducing means (communication groove 33) for introducing the pressure generated by the pump action is provided between the seals S5 and S6), and the pressure is introduced by the introduced pressure. It was decided to separate seal member (the seal S5, S6) from the bottom 30. As a result, variation in the pressing force of the side plates 14, 22 against the gears 15, 23 due to the deformation of the seals S5, S6 can be reduced and optimized, and desired pump performance can be stably exhibited.

  (2) The seal member (seal S5, S6) is disposed with a gap 34 between the bottom portions 30 of the accommodating portions 14j, 22j, and the pressure introducing means (communication groove 33) is a pressure from the high pressure chamber H1 against the gap 34. It was decided to introduce. Thereby, the air gap 34 is formed in advance, and the pressure is introduced here, so that the responsiveness to the introduction of the pressure is good.

  (3) The side wall portion (high-pressure side wall portion 31) of the accommodating portions 14j and 22j is in contact with the seal member (seal S5, S6) and holds the seal member (seal S5, S6) in a predetermined position. And pressure introducing means (communication groove 33) provided alternately and continuously on the holding portion 35 and formed wider than the holding portion 35 with respect to the bottom portion 30. Thereby, the pressure introducing means (communication groove 33) can be easily formed only by changing the design of the width of the accommodating portions 14j and 22.

  (4) The side plates 14 and 22 are made of resin, and the holding portion 35 and the pressure introducing means (communication groove 33) are integrally formed. Thereby, each part of the holding | maintenance part 35 and a pressure introduction means (communication groove | channel 33) can be shape | molded easily.

  (5) A center plate (seal member 7) is fixed in the housing 2, pump chambers P1 and P2 are provided on both sides of the center plate (seal member 7), and gears 15 and 23 are center plate ( Drive gears 16 and 26 disposed between the seal member 7) and the side plates 14 and 22 and driven to rotate by an electric motor (motor M1), and driven gears 17 and 26 which mesh with the drive gears 16 and 26 and rotate. It was decided to be a tandem external gear type consisting of 27. This can be applied to a circumscribed tandem gear pump.

  (6) Pump chambers P1 and P2 provided in the housing 2, gears 15 and 23 disposed in the pump chambers P1 and P2 and driven to rotate at least by the drive shaft 10, and adjacent to the gears 15 and 23, Faces the side plates 14, 22 disposed between the walls (recesses 4b, 6d) of the pump chambers P1, P2 and the side surfaces of the gears 15, 23, and the walls (recesses 4b, 6d) of the side plates 14, 22 It is disposed in an annular concave groove (accommodating portion 14j, 22j) formed on the surface, and the pump chambers P1, P2 are partitioned into a high pressure chamber H1 and a low pressure chamber L1, and when the gears 15, 23 are driven, the pressure is increased. And a seal member (seal S5, S6) that is pressed in a direction away from the bottom 30 of the groove (accommodating portion 14j, 22j) by the pressure introduced from the chamber H1. Thereby, the same operation and effect as (1) can be obtained.

  (7) The seal member (seal S5, S6) is disposed with a gap 34 between the bottom (bottom 30) in the groove (accommodating portion 14j, 22j), and the pressure from the high pressure chamber H1 is introduced into the gap 45. It was decided to. Thereby, the same operation and effect as (2) can be obtained.

  (8) The high pressure chamber side wall (high pressure chamber side wall portion 31) of the concave groove (accommodating portion 14j, 22j) abuts on the seal member (seal S5, S6) so that the seal member (seal S5, S6) is predetermined. The holding portions 35 that are held in position and the holding portions 35 are alternately provided continuously, and are formed wider than the holding portion 35 with respect to the bottom portion 30, so that the pressure of the high-pressure chamber H <b> 1 is guided to the gap 34. Pressure introducing means (communication groove 33). Thereby, the same operation and effect as (3) can be obtained.

  (9) The side plates 14 and 22 are made of resin, and the concave grooves (accommodating portions 14j and 22j), the holding portions 35, and the pressure introducing means (communication grooves 33) are integrally formed. Thereby, the same operation and effect as (4) can be obtained.

  (10) A center plate (seal member 7) is fixed in the housing 2, pump chambers P1 and P2 are provided on both sides of the center plate (seal member 7), and gears 15 and 23 are center plate ( Drive gears 16 and 26 disposed between the seal member 7) and the side plates 14 and 22 and driven to rotate by the drive shaft 10, and driven gears 17 and 27 rotating in mesh with the drive gears 16 and 26; The tandem circumscribed gear type consisting of Thereby, the same operation and effect as (5) can be obtained.

  (11) At least a pair of meshing drive gear 16 and driven gear 17 (drive gear 26 and driven gear 27), and side plate disposed adjacent to drive gear 16 and driven gear 17 (drive gear 26 and driven gear 27). 14 (side plate 22) and a concave portion 4c (concave portion 6d) disposed at a position facing the driving gear 16 and the driven gear 17 (driving gear 26 and driven gear 27) across the side plate 14 (side plate 22). The tip of the shoulder portion formed between the concave portion 4c (concave portion 6d) and the side plate 14 (side plate 22) and the side plate 14 (side plate 22) and the concave portion 4c (concave portion 6d) It is arranged so as to seal the gap formed therebetween, and is formed in the radial direction of the drive gear 16 and the driven gear 17 (drive gear 26 and driven gear 27). The seal member (seal S5, S6) that partitions the low-pressure part (low-pressure chamber L1) and the high-pressure part (high-pressure chamber H1) and the seal member (seal S5, S6) by the pressure of the high-pressure part (high-pressure chamber H1) And a pressure introducing portion (communication groove 33) that is deformed in the direction of the tip of the shoulder portion. Thereby, the same operation and effect as (1) can be obtained.

  (12) The seal member (seal S5, S6) is disposed with a gap 34 between the bottom portion 30 of the concave groove (accommodating portion 14j, 22j), and the pressure introducing portion (communication groove 33) has a higher pressure than the gap 34. The pressure from the part (high pressure chamber H1) was introduced. Thereby, the same operation and effect as (2) can be obtained.

  (13) The high pressure part side wall (high pressure chamber side wall part 31) of the concave groove (accommodating part 14j, 22j) is in contact with the seal member (seal S5, S6) and the seal member (seal S5, S6) is predetermined. The holding portions 35 held in position and the pressure introducing portions that are provided alternately and continuously with the holding portions 35 and are wider than the holding portions 35 with respect to the bottom 30 of the concave grooves (accommodating portions 14j, 22j) ( The side plates 14 and 22 are made of resin, and the concave grooves (accommodating portions 14j and 22j), the holding portion 35, and the pressure introducing portion (communication groove 33) are integrally formed. Thereby, the same operation and effect as (3) and (4) can be obtained.

  (14) A center plate (seal member 7) is fixed in the housing 2, pump chambers P1 and P2 are provided on both sides of the center plate (seal member 7), and gears 15 and 23 are center plate ( Drive gears 16 and 26 disposed between the seal member 7) and the side plates 14 and 22 and driven to rotate by an electric motor (motor M1), and driven gears 17 and 26 which mesh with the drive gears 16 and 26 and rotate. It was decided to be a tandem external gear type consisting of 27. Thereby, the same operation and effect as (5) can be obtained.

Example 2 will be described below.
In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, the description thereof will be omitted, and only the differences will be described in detail.

  As shown in FIG. 21A, in the invention of the second embodiment, instead of the communication groove 33 described in the first embodiment, the first side plate 14 (second side plate 22) extends in the direction perpendicular to the axis. The first embodiment is different from the first embodiment in that the communication groove 36 is provided so that one end side thereof communicates with the high pressure chamber H1 and the other end side communicates with the vicinity of the bottom 30 side of the gap 34. Therefore, in the invention of the second embodiment, the contact (contact area) of the seal S5 (seal S6) with respect to the high-pressure side wall 31 is uniform over the entire circumference, so that stress concentration on the seal S5 (seal S6) is avoided. Can improve durability. In addition, as shown in FIGS. 21A to 21C, hydraulic oil can be introduced into the gap 34 through the communication groove 36 in the same manner as the communication groove 33 of the first embodiment, and the same functions and effects as those of the first embodiment are achieved. Can be obtained. In addition, as shown in FIGS. 22 (a) to 22 (c), even if the relationship between the high pressure chamber H1 and the low pressure chamber L1 is reversed during the ABS pressure reduction control, the pressure is easily released, so that an increase in friction can be suppressed.

Next, the effect of the second embodiment will be described together with (15) corresponding to claims 6, 13, and 20 and (16) corresponding to claim 7.
(15) A communication groove 36 is formed in the first side plate 14 and the second side plate 22 to communicate the gap 34 and the high pressure chamber H1. Thereby, stress concentration of the seals S5 and S6 can be avoided.

  (16) The gear pump 1 is used in a vehicle brake device, and the brake device includes reservoirs 160P and 160S into which brake fluid (hydraulic fluid) flows from a target wheel cylinder during ABS pressure reduction control. During control, the wheel cylinder W / C communicates with the wheel cylinder W / C via the reservoirs 160P and 160S, and the pressure of the wheel cylinder W / C acts on the low pressure chamber L1, and the seal member (seal S5, S6 is generated by the pressure of the wheel cylinder W / C. ) Is deformed, and the pressure of the wheel cylinder W / C acts on the high pressure chamber H1 through the communication groove 36 in accordance with the deformation. Thereby, even if the relationship between the high pressure chamber H1 and the low pressure chamber L1 is reversed during the ABS pressure reduction control, the pressure is easily released, so that an increase in friction can be suppressed.

Example 3 will be described below.
In the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, the description thereof will be omitted, and only differences will be described in detail.

  As shown in FIG. 23, the third embodiment is different from the first embodiment in that the gear pump of the first embodiment is a tandem external gear pump, whereas a single external gear pump is employed. That is, the components of the second pump 9 described in the first embodiment are omitted, and only the first pump 8 is provided. Further, the seal member 7 in which the cover member 6 and the seal member 7 described in the first embodiment are integrally formed by shortening in the front-rear direction is employed. Therefore, in the invention of the third embodiment, the same actions and effects as those of the first embodiment can be obtained.

Example 4 will be described below.
In the fourth embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, the description thereof will be omitted, and only differences will be described in detail.

  As shown in FIG. 24, in the invention of the fourth embodiment, the seal S5 (both of the seals S6) is formed of an elastic material such as rubber, and is capable of elastic deformation, and at least the elastic deformation portion 37. The second embodiment is different from the first embodiment in that it is formed of a harder material and includes a backup portion 38 that reinforces the elastic deformation portion 37. Note that the fixation between the elastic deformation portion 37 and the backup portion 38 can be set as appropriate. Further, the backup unit 38 has a substantially L-shaped cross section and is disposed facing the boundary between the high pressure chamber H1 and the low pressure chamber L1. Further, a locking portion 37 a protruding outward is formed at a position corresponding to the end of the L-shaped cross section of the backup portion 38 of the elastic deformation portion 37, and each locking portion 37 a is locked to the backup portion 38. Thus, the displacement of the elastic deformation portion 37 is prevented. Therefore, in the invention of Example 4, a part of the seal S5 is deformed and bites into the gap between the first side plate 14 (second side plate 22) and the concave portion 4c (concave portion 5d) when the hydraulic oil acts at a high pressure. Can be prevented.

Next, the effect of the fourth embodiment will be described together with (17) corresponding to claims 8 and 14.
(17) The seal member (seal S5, S6) includes an elastically deformable portion 37 that can be elastically deformed and a backup portion 38 that reinforces the elastically deformable portion 37, and the backup portion 38 includes the low pressure chamber L1 and the high pressure chamber H1. It was placed facing the boundary. As a result, it is possible to prevent the seal member (seal S5, S6) from being caught when the hydraulic oil is under pressure.

Example 5 will be described below.
In the fifth embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, the description thereof will be omitted, and only differences will be described in detail.

  The invention of the fifth embodiment is different from the first embodiment in that the gear pump 1 of the first embodiment is a tandem external gear pump, whereas a tandem internal gear pump is employed. Specifically, as shown in FIG. 25, both side plates 14 and 22 are composed of substantially identical parts, and the outer periphery of each side plate 14 and 22 is replaced with seal blocks 14e and 17e. Outer-diameter seal portions 40 and 41 projecting annularly toward the seal member 7 are formed. The outer diameter seal portions 40 and 41 and the corresponding side seal portions 7d of the seal member 7 are fitted. A first gear 15 constituting the first pump 8 is disposed between the outer diameter portion seal portion 40 of the first side plate 14 and the corresponding side seal portion 7 d of the seal member 7. On the other hand, a second gear 18 constituting the second pump 9 is disposed between the outer side seal portion 41 of the second side plate 22 and the corresponding side seal portion 7d of the seal member 7. . Further, the sealing performance with the first pump chambers P1 and P2 is ensured by the annular seals S8 and S9 hung on the outer circumferences of the outer diameter seal portions 40 and 41, respectively. Although not shown, the seals S8 and S9 are also partially hung on the corresponding side plates 14 and 22 to hold the seal member 7 and the side plates 14 and 22 in the same manner as the holding members 21 and 24. It is like that.

  As shown in FIG. 26, the first gear 15 in the first pump 8 includes an outer rotor 42 having an inner tooth portion 42a formed on the inner periphery and an inner rotor 43 having an outer tooth portion 43a formed on the outer periphery. . Both the rotors 42 and 43 are arranged in an eccentric state, and the inner teeth portion 42 a and the outer teeth portion 43 a are engaged with each other by the meshing portion 44, whereby the pump chamber 45 surrounded by the outer rotor 42 and the inner rotor 43. Is formed. In addition, a rectangular columnar driving convex portion 46 extending in the radial direction from the axis of the driving shaft 10 is integrally formed at a position corresponding to the inner rotor 43 of each pump 8, 9 on the driving shaft 10. The portions 46 are engaged with the recesses 43b formed in the corresponding inner rotor 43 by notches. The axial dimension of the drive projection 46 is set smaller than the thickness of the inner rotor 43. As a result, the inner rotor 43 is prevented from rotating around the drive shaft 10 by the drive convex portion 46, so that the outer rotor 42 can be rotated in the same rotational direction as the inner rotor 43 by the rotational drive of the inner rotor 43. Further, the outer rotor 42 rotates while sliding on the inner periphery of the outer diameter portion seal portion 40. Further, through holes 47 and 48 are formed in the first side plate 14 in the vicinity of the position facing the pump chamber 45 shown in FIG. The through holes 47 and 48 may have a substantially crescent-shaped groove shape. The through hole 47 communicates with the suction port 50 of the pump chamber 4 through a space 49 formed between the pump chamber 4 and the first side plate 14, while the through hole 48 is a discharge port of the pump chamber 4. 51 is communicated. On the other hand, the second gear 23 and the second side plate 22 of the second pump 9 are formed in the same manner as the first gear 15 and the first side plate 14 of the first pump 8, and the second side plate 22 has 2 Two through holes 52 and 53 are formed. The through hole 52 communicates with the suction port 55 of the pump chamber 4 through an oil passage 54 formed in the cover member 6, while the through hole 53 is formed between the cover member 6 and the second side plate 22. The space 56 is communicated with a discharge port 58 of the pump chamber 4 through an oil passage 57 formed in the cover member 6.

  As shown in FIG. 27, the rear surface of the first side plate 14 is provided with an annular accommodating portion 14j similar to that of the first embodiment, and a seal S5 interposed therein. Since the discharge port 51 side is the high-pressure side, the shape of the accommodating portion 14j and the seal S5 is reversed in the inner and outer directions from the first embodiment. On the other hand, as shown in FIG. 26, the front surface of the second side plate 22 is provided with an annular housing portion 22j similar to that of the first embodiment and a seal S6 interposed therein.

[About operation of gear pump]
Next, the operation of the gear pump 1 according to the fifth embodiment will be described. In the gear pump 1 configured as described above, as shown in FIG. 26, when the drive shaft 10 is rotationally driven in the direction of the arrow in the drawing by driving the motor, the outer rotor 42 is interposed between the pumps 8 and 9 via the inner rotor 43. Is driven. At this time, the pump action is generated by the volume change of the pump chamber 45 in each gear 15, 18, and in the first pump 8, low-pressure hydraulic oil is introduced from the suction port 50 side through the through hole 47 of the first side plate 14. After being pressurized, it is output to the discharge port 51 side through the through hole 48 of the first side plate 14. On the other hand, in the second pump 9, after low-pressure hydraulic oil is introduced and pressurized from the suction port 55 side through the through hole 52 of the second side plate 22, the low pressure hydraulic oil is passed through the through hole 53 of the second side plate 22. Output to the discharge port 58 side. Thus, the gear pump 1 of the fifth embodiment performs suction and discharge of hydraulic oil in different piping systems in both pumps 8 and 9, and functions as a so-called tandem internal gear pump.

  As in the first embodiment, when the first pump 8 operates at a low pressure to a high pressure, the hydraulic oil on the high pressure chamber H1 side is introduced into the gap 34 from the communication groove 33 on the rear surface of the first side plate 14. The same action and effect as Example 1 can be obtained. On the other hand, when the second pump 9 operates at a low pressure to a high pressure, by introducing the hydraulic oil on the high pressure chamber H1 side into the gap 34 from the communication groove 33 on the front surface of the second side plate 22, the same action as in the first embodiment. The effect can be obtained.

Although the embodiments have been described above, the present invention is not limited to the above-described embodiments, and design changes and the like within the scope not departing from the gist of the present invention are included in the present invention.
For example, when the rotation direction of the drive shaft described in the first embodiment is reversed, it goes without saying that the hydraulic oil flows from the discharge port side toward the suction port side. In the fifth embodiment, the gear pump may be a single-type internal gear pump.

  Furthermore, as shown in FIG. 29, the gap between the first side plate and the recess 4c is not necessarily constant, and there may be a step, and at this time, the communication groove 33 is formed in an annular shape so that the hydraulic oil The hydraulic oil may be introduced into the gap 34 regardless of the pressure action. In FIG. 42, reference numerals corresponding to those of the first embodiment are given.

S5, S6 Seals 14j, 22j Housing part 30 Bottom part 33 Communication groove

Claims (2)

A brake device equipped with a pump to send the brake fluid to the plurality of wheel cylinders mounted on the vehicle,
The pump is
A pump chamber provided in the housing;
Disposed in said pump chamber, and a gear for performing a pumping action is driven more rotating the motor,
A side plate disposed between a wall of the pump chamber and the gear, and sealing a side surface of the gear ;
A seal member that is disposed in an annular housing portion formed in the side plate, and partitions the low pressure chamber and the high pressure chamber of the pump chamber in a liquid-tight manner between the wall of the pump chamber and the side plate ;
Have,
Together constituting the front Symbol accommodating portion with a bottom portion and a side wall portion, said sealing member, with an annular gap along the housing portion between the seal member and the bottom portion, arranged in the housing portion,
Brake system, characterized in that the gap to introduce the pressure that occur by the pumping action, provided the pressure introducing means for deforming in a direction away said sealing member from said bottom by the introduced pressure. The brake device according to claim 1, wherein
The seal member is disposed so as to seal a gap formed between a front end of a shoulder portion formed on the side plate and the housing, and a low pressure chamber and a high pressure chamber formed in a radial direction of the gear. partitions the said pressure introducing means by the pressure of the high-pressure chamber the sealing member, a brake and wherein the deforming in the direction of the tip of the shoulder portion.

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