JP2008231954A - Vane pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vane pump which prevents the increase in resistance and wear due to friction between a rotor and casing caused by slide contact between the rotor and the casing when the rotor rotates. <P>SOLUTION: The vane pump consists of a casing 10 with a pump chamber 2 formed thereinside; a rotor 3 accommodated in the pump chamber 2; a rotational driving means for rotating the rotor 3 with respect to the casing 10; a plurality of vanes 4 which are provided to the rotor 3 and whose tips are brought into slide contact with an inner peripheral surface of the pump chamber 2; an operation chamber 5 which is surrounded by the inner peripheral surface 2a of the pump chamber 2, an outer peripheral surface of the rotor 3 and vanes 4, and which changes its volume in large and small by the rotational driving of the rotor 3; a suction port 6 forcing a working fluid to flow in the operation chamber 5 in a volume expanding process; and a discharge port 7 for discharging the working fluid from the operation chamber 5 in a volume reducing process, wherein a biasing part 32 for producing biasing force in a direction separating from the casing 10, to a thrust slide surface 31 of the rotor 3 thrust sliding with the casing 10. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vane pump.

  Conventionally, a vane pump is known (see, for example, Patent Document 1). For example, as shown in FIG. 8, the vane pump 1 houses the rotor 3 at an eccentric position of the pump chamber 2 formed in the casing 10, and the tip of the rotor 3 is in sliding contact with the inner peripheral surface 2 a of the pump chamber 2. A plurality of vanes 4 are provided. When the rotor 3 is driven to rotate, the front end surface 4 a of each vane 4 receives the action of centrifugal force due to the rotation of the rotor 3 and is brought into sliding contact with the inner peripheral surface 2 a of the pump chamber 2, whereby the inner surface of the pump chamber 2 and the rotor 3 The volume of the working chamber 5 surrounded by the outer peripheral surface and the vane 4 changes in size, and the working fluid is drawn from the suction port 6 through the working chamber 5 and discharged from the discharge port 7. Reference numeral 21 in the figure is a pressing spring.

Such a vane pump has a problem that when the rotor 3 rotates, the rotor 3 and the casing 10 are brought into sliding contact with each other, resulting in an increase in resistance and an increase in wear due to friction.
Japanese Patent Laid-Open No. 53-2704

  The present invention has been invented in view of the above-described conventional problems. The object of the present invention is to provide resistance by friction between the rotor and the casing when the rotor rotates and the rotor and the casing are in sliding contact. It is an object of the present invention to provide a vane pump that does not cause increase in wear and wear.

  In order to solve the above problem, a vane pump according to a first aspect of the present invention includes a casing 10 in which a pump chamber 2 is formed, a rotor 3 housed in the pump chamber 2, and a rotation for rotating the rotor 3 relative to the casing 10. A driving means and a plurality of vanes 4 provided on the rotor 3 and having their tips slidably contacted with the inner peripheral surface of the pump chamber 2 are provided. The inner peripheral surface 2a of the pump chamber 2, the outer peripheral surface of the rotor 3, and the vanes 4 A working chamber 5 that is surrounded and changes its volume by rotating the rotor 3, a suction port 6 that allows the working fluid to flow into the working chamber 5 during the volume expansion process, and a working fluid that is discharged from the working chamber 5 during the volume reduction process. The vane pump having the discharge port 7 is provided with a biasing portion 32 that generates a biasing force in a direction away from the casing 10 with respect to the thrust sliding surface 31 with the casing 10 of the rotor 3. It is an butterfly.

  With such a configuration, it is possible to avoid direct contact between the thrust sliding surface 31 of the rotor 3 and the casing 10, and the sliding resistance between the thrust sliding surface 31 of the rotor 3 and the casing 10. (Friction resistance) can be reduced and these wears can be eliminated.

  The invention according to claim 2 is the invention according to claim 1, wherein a part of the working fluid discharged from the discharge port 7 is disposed between the thrust sliding surface 31 of the rotor 3 and the casing 10 as the urging portion 32. The branch path 94 is made to flow into the flow path. The flow path section (case flow path section 94a) formed in the casing 10 is connected to the branch path 94 from the upstream side, and the rotor 3 is pivotally supported by being fixed to the casing 10. The rotor includes a shaft passage portion 94b formed in the fixed shaft 20 that communicates with the passage portion, and a rotor passage portion 94d that is formed in the rotor 3 and communicates with the shaft passage portion 94b. The outlet of the flow path portion 94d is formed on the thrust sliding surface 31.

  By adopting such a configuration, the vane pump 1 itself is used as a conveying means for flowing a working fluid between the thrust sliding surface 31 of the rotor 3 and the casing 10, and therefore it is necessary to provide a conveying means such as a pump separately. There is no.

  The invention according to claim 3 is the invention according to claim 1, wherein a part of the working fluid discharged from the discharge port 7 is disposed between the thrust sliding surface 31 of the rotor 3 and the casing 10 as the biasing portion 32. The branch path 95 is provided to flow into the casing 10, and the branch path 95 is constituted by a flow path portion (upper case flow path portion 95a, lower case flow path portion 95ab) formed in the casing 10 from the upstream side, The outlet of the branch path 95 is formed on a surface facing the thrust sliding surface 31 of the rotor 3 of the casing 10.

  By adopting such a configuration, the vane pump 1 itself is used as a conveying means for flowing a working fluid between the lower surface of the rotor 3 and the bottom surface of the lower recess 16, and therefore it is necessary to provide a conveying means such as a pump separately. In addition, since it is only necessary to form the branch path 95 only on the casing 10 side that is the fixed side, it is not necessary to provide a path for the working fluid in the rotor 3 that is the rotation side, and the configuration becomes easy.

  In the present invention, the thrust sliding surface of the rotor and the casing are in direct contact with each other by providing a biasing portion that generates a biasing force in a direction away from the casing with respect to the thrust sliding surface with the rotor casing. Therefore, it is possible to reduce the sliding resistance (friction resistance) between the thrust sliding surface of the rotor and the casing and to eliminate these wears.

  Hereinafter, the present invention will be described based on embodiments shown in the accompanying drawings. First, based on FIG.2 and FIG.3, the general structure (part except the characteristic of this invention) of the vane pump 1 is demonstrated.

  As shown in FIGS. 2 and 3, the vane pump 1 houses a rotor 3 in an eccentric manner in a pump chamber 2 provided in a casing 10, and has a plurality of sliding ends that are in sliding contact with the inner peripheral surface 2 a of the pump chamber 2. The vane 4 is provided in the rotor 3, the suction port 6 and the discharge port 7 are provided in the casing 10 so as to reach the pump chamber 2, and the rotor 3 is rotationally driven to rotate the inner surface of the pump chamber 2 and the outer peripheral surface 3 a of the rotor 3. The volume of the working chamber 5, which is a space surrounded by the vanes 4, is increased and decreased, and the working fluid from the suction port 6 is discharged from the discharge port 7 through the working chamber 5. This will be described in detail below.

  The casing 10 is formed by combining the upper case 11 and the lower case 12. A lower recess 16 that is recessed downward from the mating surface of the upper case 11 is formed in the lower case 12, and the pump chamber 2 is formed by closing the upper opening of the lower recess 16 with the mating surface of the upper case 11. Is done. The pump chamber 2 is formed in a circular or elliptical shape in plan view. Although not shown, a stator is disposed below the lower case 12 so as to be adjacent to the bottom surface of the lower recess 16.

  The rotor 3 is provided with a bearing portion 18 at the center and is formed in a circular shape in plan view, and a plurality of (four in this example) vane grooves 19 are formed radially on the top of the rotor 3. Although not shown, a magnetic body is integrally attached to the lower portion of the rotor 3. The rotor 3 is configured such that the bearing portion 18 is rotatably inserted through a fixed shaft 20 penetrating the pump chamber 2 so that the outer peripheral surface 3a faces the inner peripheral surface 2a of the pump chamber 2 and a thrust surface (upper surface). 3b) is rotatably arranged in the pump chamber 2 so as to face the upper surface constituting part of the pump chamber 2 of the upper case 11. Further, the vanes 4 are slidably accommodated in the vane grooves 19 so as to protrude and retract from the outer peripheral surface 3 a of the rotor 3. When the rotor 3 is arranged in the pump chamber 2, a permanent magnet or magnetic body (not shown) and a stator (not shown) are arranged adjacent to each other. The stator constitutes a rotational drive means for rotationally driving the rotor 3. In other words, this rotational drive means generates a rotational torque in the permanent magnet or the magnetic body by a magnetic action between the stator and the permanent magnet or the magnetic body by inputting a current from the power supply unit (not shown) to the stator. By this rotational torque, the permanent magnet or the magnetic body, and thus the rotor 3 is rotationally driven.

  When the rotor 3 housed in the pump chamber 2 is rotationally driven by the rotational drive means (arrow f), each vane 4 receives a centrifugal force due to the rotation of the rotor 3 and is removed from the outer peripheral surface 3a of the rotor 3. The tip end surface 4a is slidably contacted with the inner peripheral surface 2a of the pump chamber 2, and the inner surface (the inner peripheral surface 2a, the upper surface, etc.) of the pump chamber 2, the outer peripheral surface 3a of the rotor 3, and the vane 4 The pump chamber 2 is formed with a plurality of working chambers 5 surrounded by. Since the rotor 3 is in the eccentric position of the pump chamber 2, the distance between the inner peripheral surface 2 a of the pump chamber 2 and the outer peripheral surface 3 a of the rotor 3 varies depending on the rotational position of the rotor 3 and the vanes 4 protrude from the rotor 3. The amount also varies depending on the rotational position of the rotor 3, that is, by rotating the rotor 3, each working chamber 5 changes its volume while moving in the rotational direction of the rotor 3. Here, the upper case 11 is formed with a suction port 6 for drawing the working fluid into the working chamber 5 and a discharge port 7 for discharging the working fluid from the working chamber 5. The suction port 6 and the discharge port 7 are opened on the upper surface of the pump chamber 2 so as to communicate with the working chamber 5. In the figure, reference numeral 14 denotes a suction path to the suction port 6, and reference numeral 8 denotes a discharge path to the discharge port 7.

  That is, the volume of each working chamber 5 increases as the rotor 3 rotates when it is in a position communicating with the suction port 6, and the volume decreases as the rotor 3 rotates when it is in a position communicating with the discharge port 7. Accordingly, when the rotor 3 is driven to rotate, the working fluid flows from the suction port 6 into the working chamber 5 communicating therewith (arrow a), and is compressed from the working chamber 5 and then discharged from the discharge port 7. (Arrow b), thereby functioning as a pump.

  The vane 4 protrudes outward by centrifugal force when the rotor 3 is driven to rotate, but via a pressing spring 21 (see FIG. 8) that biases the vane 4 outward in the vane groove 19. The tip of the vane 4 may be brought into sliding contact with the inner peripheral surface 2a of the pump chamber 2 without depending on the rotational speed of the rotor 3. In the above embodiment, the rotor 3 is pivotally supported with respect to the fixed shaft 20, but the rotary shaft fixed to the rotor 3 is rotatable with respect to the pump chamber 2 instead of the fixed shaft 20. You may employ | adopt the structure pivotally supported by. In the above embodiment, the rotation driving means for rotating the rotor 3 is composed of a stator that generates a magnetic action and a permanent magnet or a magnetic material. However, as the rotation driving means, a rotating shaft fixed to the rotor 3 is a motor. You may employ | adopt the structure driven by rotation.

  In the present invention, an urging portion 32 that generates an urging force in a direction away from the casing 10 is provided on the thrust sliding surface 31 that is in the thrust direction of the rotor 3 and slides on the casing 10. is there.

  In the present embodiment, the thrust sliding surface 31 of the rotor 3 (that is, the lower surface of the rotor 3 in a state where the direction of the vane pump 1 is set so that the rotation axis of the rotor 3 faces the vertical direction) is The lower case 12 of the lower casing 12 located on the lower side of the casing 10 is separated from the bottom surface of the lower recess 16 by levitation so that the sliding resistance (friction resistance) between the lower surface of the rotor 3 and the bottom surface of the lower recess 16 is increased. It eliminates these wears as well as eliminating them.

  The urging portion 32 shown in FIG. 1A has a conveyance path 9 formed in the lower case 12 so as to communicate with the inside of the lower depression 16 from the bottom surface of the lower depression 16, and operates via the conveyance path 9. The fluid is allowed to flow from the bottom surface of the lower recess 16 into the lower recess 16, and the lower surface of the rotor 3 is lifted from the bottom surface of the lower recess 16 and separated. In this case, it is provided with a conveying means such as a pump (not shown) for conveying the working fluid to the bottom surface of the lower recess 16 via the conveying path 9, or a part of the working fluid by the vane pump 1 as will be described later. The working fluid is conveyed to the bottom surface of the lower recess 16 via the conveying path 9.

  Further, the urging portion 32 shown in FIG. 1B is provided with a spring material 92 that urges the lower surface of the rotor 3 through the sliding member 91 from the bottom surface side of the lower recess 16. The spring material 92 is a coil spring, and an accommodation recess 93 is formed in the bottom surface of the lower recess 16, and the spring material 92 is accommodated in the accommodation recess 93. The material of the sliding member 91 is, for example, a resin material such as PTFE (polytetrafluoroethylene), PPS (polyphenylene sulfide), POM (polyoxymethylene), PE (polyethylene), PEEK (polyetheretherketone), ceramic, Examples thereof include inorganic materials such as carbon and graphite, and molybdenum disulfide, but are not particularly limited.

  By configuring as shown in FIGS. 1A and 1B, the urging portion 32 can be formed with a simple configuration.

  Next, another embodiment will be described with reference to FIGS. In the present embodiment, as the urging portion 32, a part of the working fluid discharged from the discharge port 7 and transported through the discharge path 8 is transported in order through the casing 10, the fixed shaft 20, the bearing 18, and the rotor 3. The thrust sliding surface 31 (the lower surface in this embodiment) of the rotor 3 and the bottom surface of the lower recess 16 are poured.

  A branch path 94 is branched from the middle of the discharge path 8. The branch path 94 includes a flow path portion formed in the casing 10 (in this embodiment, a case flow path portion 94 a formed in the upper case 11), and a fixed shaft. 20, the shaft passage portion 94 b formed on the bearing 20, the bearing passage portion 94 c formed on the bearing 18 rotating with respect to the fixed shaft 20, and the rotor passage portion 94 d formed on the rotor 3.

  The case flow path portion 94a branches off from the discharge path 8, and the outlet thereof is provided on the inner bottom surface of the pump chamber 2 (the upper surface constituting portion of the pump chamber 2 of the upper case 11). The axial flow path portion 94b is a flow path that extends from the upper end of the fixed shaft 20 to the inside of the fixed shaft 20 and branches into a plurality of parts, and then reaches the outer peripheral surface of the fixed shaft 20. An inlet provided on the upper end surface of the fixed shaft 20 is It communicates with the outlet of the case channel portion 94a. The bearing flow path portion 94c includes a circumferential groove 18a formed on the inner peripheral surface of the tubular bearing 18 and branch holes 18b formed at a plurality of locations in the circumferential direction of the circumferential groove 18a. The circumferential groove 18 a is formed over the entire inner circumferential surface of the bearing 18, and always communicates with a plurality of outlets of the axial flow path portion 94 b regardless of the rotation angle of the rotor 3. A plurality of rotor flow path portions 94 d are provided in the circumferential direction of the rotor 3, and are formed inside the rotor 3. The inlet of each rotor flow path portion 94d communicates with the branch hole of the bearing flow path portion 94c. Further, the outlet of each rotor flow path portion 94 d is provided on the thrust sliding surface 31 (lower surface) of the rotor 3.

  When the vane pump 1 of this example is driven, a part of the working fluid discharged from the pump chamber 2 through the discharge port 7 to the discharge path 8 constitutes the branch path 94. The case flow path portion 94a and the axial flow path section 94b, the bearing flow passage portion 94c, and the rotor flow passage portions 94d in this order, flow into the space between the lower surface of the rotor 3 and the bottom surface of the lower recess 16, and the lower surface of the rotor 3 floats from the bottom surface of the lower recess 16. They are separated.

  Thereby, it becomes possible to eliminate the sliding resistance (friction resistance) between the rotor 3 and the casing 10 and to eliminate such wear. Further, in this case, since the vane pump 1 itself is used as a conveying means for flowing the working fluid between the lower surface of the rotor 3 and the bottom surface of the lower recess 16, it is not necessary to separately provide a conveying means such as a pump. is there.

  Next, still another embodiment will be described with reference to FIGS. In the present embodiment, as the urging portion 32, a part of the working fluid that is discharged from the discharge port 7 and is transported through the discharge path 8 is transported to the casing 10, and the thrust sliding surface 31 (main book) of the rotor 3 is transported. It flows between the lower surface in the embodiment) and the bottom surface of the lower recess 16.

  A branch path 95 is branched from the middle of the discharge path 8, and the branch path 95 is connected to a flow path portion formed in the casing 10, that is, an upper case flow path portion 95 a formed in the upper case 11 and a lower case 12. The lower case channel portion 95b is formed.

  The upper case flow path portion 95a is branched from the discharge path 8 and is formed inside the upper case 11. The outlet is formed on the lower surface of the upper case 11, and the lower case flow path portion 95b is formed on the upper surface of the lower case 12. In the state where the upper case 11 and the lower case 12 are combined, the outlet of the upper case flow path portion 95a and the inlet of the lower case flow path portion 95b are communicated with each other. The lower case flow path portion 95b is formed inside the lower case 12, and its outlet is formed on the bottom surface of the lower recess 16 of the lower case 12.

  At the time of driving the vane pump 1 of this example, a part of the working fluid discharged from the pump chamber 2 through the discharge port 7 to the discharge path 8 constitutes the branch path 95. The upper case flow path portion 95a, the lower case flow It flows between the thrust sliding surface 31 (lower surface) of the rotor 3 and the bottom surface of the lower recess 16 through the path portion 95b in order, and the lower surface of the rotor 3 is lifted from the bottom surface of the lower recess 16 and separated. is there.

  Thereby, it becomes possible to eliminate the sliding resistance (friction resistance) between the rotor 3 and the casing 10 and to eliminate such wear. In this case, since the vane pump 1 itself is used as a conveying means for flowing the working fluid between the lower surface of the rotor 3 and the bottom surface of the lower recess 16, it is not necessary to separately provide a conveying means such as a pump. Since the branch path 95 only needs to be formed on the casing 10 side that is the fixed side, it is not necessary to provide a path for the working fluid in the rotor 3 that is the rotation side, and the configuration becomes easy.

(A) is sectional drawing of the vane pump of one Embodiment of this invention, (b) is sectional drawing of the vane pump of other embodiment of this invention. It is a disassembled perspective view of a vane pump. It is a horizontal sectional view of a vane pump. It is a disassembled perspective view of the vane pump of other embodiment. (A) is the assembly sectional view seen from the A direction of FIG. 4, (b) is the assembly sectional view seen from the B direction of FIG. 4, (c) is the horizontal sectional view of the principal part. It is a disassembled perspective view of the vane pump of other embodiment. (A) is the assembly sectional view seen from the A direction of FIG. 5, (b) is the assembly sectional view seen from the B direction of FIG. It is a horizontal sectional view of the conventional vane pump.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vane pump 10 Casing 2 Pump chamber 2a Inner peripheral surface 3 Rotor 3a Outer peripheral surface 31 Thrust sliding surface 32 Energizing part 4 Vane 4a Tip surface 41 Concave groove 5 Actuation chamber 6 Suction port 7 Discharge port 8 Discharge route

Claims (3)

  A casing in which a pump chamber is formed, a rotor housed in the pump chamber, a rotation driving means for rotating the rotor with respect to the casing, and a tip provided on the rotor are slidably contacted with the inner peripheral surface of the pump chamber. A working chamber that is surrounded by the inner peripheral surface of the pump chamber, the outer peripheral surface of the rotor, and the vane, and whose volume is changed by the rotational drive of the rotor, and the working fluid in the working chamber of the volume expansion process. In a vane pump having a suction port for inflow and a discharge port for discharging a working fluid from a working chamber in a volume reduction process, a biasing force that generates a biasing force in a direction away from the casing is generated with respect to a thrust sliding surface of the rotor casing. A vane pump characterized by comprising a force member.   As the urging unit, a branch path is provided for allowing a part of the working fluid discharged from the discharge port to flow between the thrust sliding surface of the rotor and the casing. The branch path is formed in the casing from the upstream side. A flow path section, a shaft flow path section fixed to the casing and pivotally supported by the rotor and communicating with the flow path section, and a rotor flow formed within the rotor and communicating with the shaft flow path section. The vane pump according to claim 1, wherein the vane pump is formed by forming the outlet of the rotor flow path portion on a thrust sliding surface.   As the urging unit, a branch path is provided for allowing a part of the working fluid discharged from the discharge port to flow between the thrust sliding surface of the rotor and the casing. The branch path is formed in the casing from the upstream side. 2. The vane pump according to claim 1, wherein the vane pump is formed by the flow path portion and the outlet of the branch path is formed on a surface facing the thrust sliding surface of the rotor of the casing.

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